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田中 靖人タナカ ヤスヒト

所属部署医学研究科ウイルス学分野
職名教授
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Last Updated :2019/07/06

研究者基本情報

学歴

  •  - 1991年, 名古屋市立大学, 医学部

学位

  • 博士(医学), 名古屋市立大学

所属学協会

  • 日本内科学会
  • 日本消化器病学会
  • 日本肝臓学会
  • 日本内視鏡学会
  • 日本ウイルス学会
  • 日本臨床検査医学会
  • 日本臨床検査自動化学会

経歴

  •   1999年11月 - 2001年07月, 米国立保健研究所(NIH), Visiting Fellow
  •   2006年06月, 国立感染症研究所ウイルス第二部
  •   2008年07月 - 現在, 名古屋市立大学病院 肝疾患センター, 副センター長
  •   2009年10月 - 現在, 名古屋市立大学 大学院医学研究科 , 病態医科学講座(ウイルス学), 教授
  •   2009年10月 - 現在, 名古屋市立大学病院, 中央臨床検査部, 部長

研究活動情報

研究キーワード

    肝臓病学, 消化器内科学, 肝炎ウイルス, 肝発癌, 薬剤開発

論文

  • Intrahepatic Cross-Presentation and Hepatocellular Antigen Presentation Play Distinct Roles in the Induction of Hepatitis B Virus-Specific CD8+ T Cell Responses., Murata Y, Kawashima K, Sheikh K, Tanaka Y, Isogawa M, Journal of virology, 92, (21) ,   2018年11月, 査読有り
  • Serum M2BPGi level and risk of hepatocellular carcinoma after oral anti-viral therapy in patients with chronic hepatitis B., Hsu YC, Jun T, Huang YT, Yeh ML, Lee CL, Ogawa S, Cho SH, Lin JT, Yu ML, Nguyen MH, Tanaka Y, Alimentary pharmacology & therapeutics, 48, (10) 1128 - 1137,   2018年11月, 査読有り
  • Independent and additive effects of PNPLA3 and TM6SF2 polymorphisms on the development of non-B, non-C hepatocellular carcinoma., Raksayot M, Chuaypen N, Khlaiphuengsin A, Pinjaroen N, Treeprasertsuk S, Poovorawan Y, Tanaka Y, Tangkijvanich P, Journal of gastroenterology,   2018年11月, 査読有り
  • Combining hepatitis B core-related and surface antigens at end of nucleos(t)ide analogue treatment to predict off-therapy relapse risk., Hsu YC, Nguyen MH, Mo LR, Wu MS, Yang TH, Chen CC, Tseng CH, Tai CM, Wu CY, Lin JT, Tanaka Y, Chang CY, Alimentary pharmacology & therapeutics,   2018年11月, 査読有り
  • Circulating let-7 Levels in Serum Correlate With the Severity of Hepatic Fibrosis in Chronic Hepatitis C., Matsuura K, Aizawa N, Enomoto H, Nishiguchi S, Toyoda H, Kumada T, Iio E, Ito K, Ogawa S, Isogawa M, Alter HJ, Tanaka Y, Open forum infectious diseases, 5, (11) ,   2018年11月, 査読有り
  • Efficacy of direct-acting antiviral treatment in patients with compensated liver cirrhosis: a multicenter study., Itokawa N, Atsukawa M, Tsubota A, Ikegami T, Shimada N, Kato K, Abe H, Okubo T, Arai T, Iwashita AN, Kondo C, Mikami S, Asano T, Matsuzaki Y, Toyoda H, Kumada T, Iio E, Tanaka Y, Iwakiri K, Hepatology research : the official journal of the Japan Society of Hepatology,   2018年10月, 査読有り
  • Risk of HBV reactivation in patients with B-cell lymphomas receiving obinutuzumab or rituximab immunochemotherapy., Kusumoto S, Arcaini L, Hong X, Jin J, Kim WS, Kwong YL, Peters MG, Tanaka Y, Zelenetz AD, Kuriki H, Fingerle-Rowson G, Nielsen T, Ueda E, Piper-Lepoutre H, Sellam G, Tobinai K, Blood,   2018年10月, 査読有り
  • TLL1 variant associated with development of hepatocellular carcinoma after eradication of hepatitis C virus by interferon-free therapy., Iio E, Matsuura K, Shimada N, Atsukawa M, Itokawa N, Abe H, Kato K, Takaguchi K, Senoh T, Eguchi Y, Nomura H, Yoshizawa K, Kang JH, Matsui T, Hirashima N, Kusakabe A, Miyaki T, Fujiwara K, Matsunami K, Tsutsumi S, Iwakiri K, Tanaka Y, Journal of gastroenterology,   2018年10月, 査読有り
  • Dysregulation of miRNA in chronic hepatitis B is associated with hepatocellular carcinoma risk after nucleos(t)ide analogue treatment., Wakasugi H, Takahashi H, Niinuma T, Kitajima H, Oikawa R, Matsumoto N, Takeba Y, Otsubo T, Takagi M, Ariizumi Y, Suzuki M, Okuse C, Iwabuchi S, Nakano M, Akutsu N, Kang JH, Matsui T, Yamada N, Sasaki H, Yamamoto E, Kai M, Sasaki Y, Sasaki S, Tanaka Y, Yotsuyanagi H, Tsutsumi T, Yamamoto H, Tokino T, Nakase H, Suzuki H, Itoh F, Cancer letters, 434, 91 - 100,   2018年10月, 査読有り
  • Serum Wisteria floribunda agglutinin-positive Mac-2 binding protein level as a diagnostic marker of hepatitis B virus-related hepatocellular carcinoma., Chuaypen N, Chittmittraprap S, Pinjaroen N, Sirichindakul B, Poovorawan Y, Tanaka Y, Tangkijvanich P, Hepatology research : the official journal of the Japan Society of Hepatology, 48, (11) 872 - 881,   2018年10月, 査読有り
  • Type I interferon signaling prevents hepatitis B virus-specific T cell responses by reducing antigen expression., Kawashima K, Isogawa M, Hamada-Tsutsumi S, Baudi I, Saito S, Nakajima A, Tanaka Y, Journal of virology, 92, (23) ,   2018年09月, 査読有り
  • Is metatarsus primus elevatus truly observed in hallux rigidus? Radiographic study using mapping methods., Ohara K, Tanaka Y, Taniguchi A, Kurokawa H, Kumai T, Yamada H, Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association,   2018年09月, 査読有り
  • Gut Dysbiosis Associated With Hepatitis C Virus Infection., Inoue T, Nakayama J, Moriya K, Kawaratani H, Momoda R, Ito K, Iio E, Nojiri S, Fujiwara K, Yoneda M, Yoshiji H, Tanaka Y, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 67, (6) 869 - 877,   2018年08月, 査読有り
  • Screening of microRNAs for a repressor of hepatitis B virus replication., Naito Y, Hamada-Tsutsumi S, Yamamoto Y, Kogure A, Yoshioka Y, Watashi K, Ochiya T, Tanaka Y, Oncotarget, 9, (52) 29857 - 29868,   2018年07月, 査読有り
  • Sofosbuvir-velpatasvir plus ribavirin in Japanese patients with genotype 1 or 2 hepatitis C who failed direct-acting antivirals., Izumi N, Takehara T, Chayama K, Yatsuhashi H, Takaguchi K, Ide T, Kurosaki M, Ueno Y, Toyoda H, Kakizaki S, Tanaka Y, Kawakami Y, Enomoto H, Ikeda F, Jiang D, De-Oertel S, McNabb BL, Camus G, Stamm LM, Brainard DM, McHutchison JG, Mochida S, Mizokami M, Hepatology international, 12, (4) 356 - 367,   2018年07月, 査読有り
  • De Novo Macrocyclic Peptide Inhibitors of Hepatitis B Virus Cellular Entry., Passioura T, Watashi K, Fukano K, Shimura S, Saso W, Morishita R, Ogasawara Y, Tanaka Y, Mizokami M, Sureau C, Suga H, Wakita T, Cell chemical biology, 25, (7) 906 - 915.e5,   2018年07月, 査読有り
  • Differentiation Therapy by Epigenetic Reconditioning Exerts Antitumor Effects on Liver Cancer Cells., Gailhouste L, Liew LC, Yasukawa K, Hatada I, Tanaka Y, Nakagama H, Ochiya T, Molecular therapy : the journal of the American Society of Gene Therapy, 26, (7) 1840 - 1854,   2018年07月, 査読有り
  • High levels of serum Mac-2-binding protein glycosylation isomer (M2BPGi) predict the development of hepatocellular carcinoma in hepatitis B patients treated with nucleot(s)ide analogues., Shinkai N, Nojima M, Iio E, Matsunami K, Toyoda H, Murakami S, Inoue T, Ogawa S, Kumada T, Tanaka Y, Journal of gastroenterology, 53, (7) 883 - 889,   2018年07月, 査読有り
  • 日本肝臓学会評議員を対象としたB型肝炎ワクチンに関するアンケート調査, 田中 靖人, 乾 あやの, 森屋 恭爾, 江口 有一郎, 四柳 宏, 肝臓, 59, (6) 259 - 263,   2018年06月, B型肝炎(HB)ワクチンの在り方を検討するために、日本肝臓学会HBワクチンワーキンググループとして日本肝臓学会評議員などを対象にHBワクチンに関するアンケート調査を実施した。その結果、1)「HBワクチンの適切な接種時期(キャッチアップ)」に関しては、小学生高学年64%と最多であった。2)「ワクチン無効例に対する対策」としては、筋肉内注射や4回以上投与などが挙げられた。3)「HBs抗体価が低下した医療従事者に対するHBワクチンのブースターの必要性」について、「必要」が63%で最も多く、その施設の多くは職員に対するHBs抗体の定期検査を12ヵ月ごとに行い、HBs抗体価10mIU/mL未満の時点でHBワクチンを追加接種していた。これらの結果を踏まえると、「追加のワクチン接種は必要ではない」とする日本環境感染学会ガイドラインについて再度議論する必要があるように思われた。(著者抄録)
  • A novel association between core mutations in hepatitis B virus genotype F1b and hepatocellular carcinoma in Alaskan Native People., Hayashi S, Khan A, Simons BC, Homan C, Matsui T, Ogawa K, Kawashima K, Murakami S, Takahashi S, Isogawa M, Ikeo K, Mizokami M, McMahon BJ, Tanaka Y, Hepatology (Baltimore, Md.),   2018年06月, 査読有り
  • Efficacy and safety of ombitasvir/paritaprevir/ritonavir combination therapy for genotype 1b chronic hepatitis C patients complicated with chronic kidney disease., Arai T, Atsukawa M, Tsubota A, Ikegami T, Shimada N, Kato K, Abe H, Okubo T, Itokawa N, Kondo C, Mikami S, Asano T, Chuganji Y, Matsuzaki Y, Toyoda H, Kumada T, Iio E, Tanaka Y, Iwakiri K, Hepatology research : the official journal of the Japan Society of Hepatology, 48, (7) 549 - 555,   2018年06月, 査読有り
  • 肝線維化をcatch 肝線維化のバイオマーカー, 飯尾悦子, 田中靖人, 臨床検査, 62, (5) ,   2018年05月15日
  • Real-world virological efficacy and safety of elbasvir and grazoprevir in patients with chronic hepatitis C virus genotype 1 infection in Japan., Toyoda H, Atsukawa M, Takaguchi K, Senoh T, Michitaka K, Hiraoka A, Fujioka S, Kondo C, Okubo T, Uojima H, Tada T, Yoneyama H, Watanabe T, Asano T, Ishikawa T, Tamai H, Abe H, Kato K, Tsuji K, Ogawa C, Shimada N, Iio E, Deguchi A, Itobayashi E, Mikami S, Moriya A, Okubo H, Tani J, Tsubota A, Tanaka Y, Masaki T, Iwakiri K, Kumada T, Journal of gastroenterology,   2018年05月, 査読有り
  • Late Relapse after a Sustained Virologic Response at 24 Weeks after Treatment with Daclatasvir and Asunaprevir Combination Therapy for Chronic Hepatitis C Virus Genotype 1b Infection with Liver Cirrhosis., Uojima H, Murakami S, Nakatani S, Hidaka H, Takeuchi A, Tanaka Y, Inoue T, Yamane K, Kubota K, Nakazawa T, Shibuya A, Tanaka Y, Koizumi W, Internal medicine (Tokyo, Japan), 57, (7) 951 - 956,   2018年04月, 査読有り
  • Combination of PNPLA3 and TLL1 polymorphism can predict advanced fibrosis in Japanese patients with nonalcoholic fatty liver disease, Yuya Seko, Kanji Yamaguchi, Naoki Mizuno, Keiichiro Okuda, Masashi Takemura, Hiroyoshi Taketani, Tasuku Hara, Atsushi Umemura, Taichiro Nishikawa, Michihisa Moriguchi, Kohichiroh Yasui, Mai Kamaguchi, Kenichi Nishioji, Naomi Mochizuki, Masao Kobayashi, Kojiroh Mori, Saiyu Tanaka, Kentaro Matsuura, Yasuhito Tanaka, Yoshito Itoh, Journal of Gastroenterology, 53, (3) 438 - 448,   2018年03月01日, 査読有り, © 2017, Japanese Society of Gastroenterology. Background: Hepatic fibrosis is an independent risk factor for mortality and liver-related events in patients with nonalcoholic fatty liver disease (NAFLD). PNPLA3 rs738409 has been associated with fibrosis in viral and non-viral hepatitis. TLL1 rs17047200 also has been associated with developing hepatocellular carcinoma probably via hepatic fibrogenesis. We estimated the impact of these genetic polymorphisms on hepatic fibrosis in Japanese patients with NAFLD. Methods: We analyzed the association between these genetic variants and the backgrounds of 817 individuals who received health checkups (health check cohort) from 2012 to 2014. Then, we investigated the relationship between genetic variants and liver histology in 258 consecutive patients with biopsy-proven NAFLD in Japan (NAFLD cohort) from 2012 to 2017 (UMIN000027399). Results: The prevalence of PNPLA3 CG/GG in the NAFLD cohort was higher than that in the health check cohort (p < 0.001). The prevalence of patients with advanced fibrosis (stages 3–4) was higher for PNPLA3 genotype CG/GG than CC (p = 0.048) and for TLL1 genotype AT/TT than AA (p = 0.044). The high-risk group which had at least two risk alleles of these variants was more likely to have advanced fibrosis (p = 0.004). Multivariate analysis identified body mass index [odds ratio (OR) 1.123, serum AST (OR 1.037, p = 0.004], serum albumin (OR 0.247, p = 0.032), and genetic high risk (OR 2.632, p = 0.026) as predictors of advanced fibrosis. Conclusions: In Japanese patients with NAFLD, individuals with risk alleles of PNPLA3 and TLL1 may have a risk of advanced fibrosis.
  • Efficacy and safety of ledipasvir/sofosbuvir for genotype 1b chronic hepatitis C patients with moderate renal impairment., Okubo T, Atsukawa M, Tsubota A, Toyoda H, Shimada N, Abe H, Kato K, Hayama K, Arai T, Nakagawa-Iwashita A, Itokawa N, Kondo C, Kawamoto C, Iio E, Tanaka Y, Kumada T, Iwakiri K, Hepatology international, 12, (2) 133 - 142,   2018年03月, 査読有り
  • Antiviral therapy for hepatitis B virus during second pregnancies., Wakano Y, Sugiura T, Endo T, Ito K, Suzuki M, Tajiri H, Tanaka Y, Saitoh S, The journal of obstetrics and gynaecology research, 44, (3) 566 - 569,   2018年03月, 査読有り
  • 肝癌リスク遺伝子, 松浦健太郎, 田中靖人, 日本臨床, 76, (2) ,   2018年02月01日
  • 母子感染予防実施例におけるOccult HBV感染の頻度, 伊藤彰悟, 伊藤孝一, 遠藤剛, 戸川貴夫, 杉浦時雄, 村上周子, 田中靖人, 齋藤伸治, 日本小児科学会雑誌, 122, (2) ,   2018年02月01日
  • Host genetic variations associated with disease progression in chronic hepatitis C virus infection, Kentaro Matsuura, Yasuhito Tanaka, Hepatology Research, 48, (2) 127 - 133,   2018年02月, 査読有り, © 2017 The Japan Society of Hepatology Treatment with recently developed interferon-free oral regimens combining direct-acting antiviral agents (DAAs) results in the elimination of hepatitis C virus (HCV) in almost all chronic hepatitis C (CHC) patients. In the era of DAAs, surveillance of hepatocellular carcinoma (HCC) after eradication of HCV by anti-HCV therapy is particularly important. As is well known, an advanced state of hepatic fibrosis is the major risk factor for developing HCC. Therefore, an increased understanding of various factors associated with disease progression and development of HCC in CHC patients is essential for implementing personalized treatment and surveillance of disease progression and HCC. Recent genome-wide association studies (GWAS) have identified several host genetic variants influencing treatment efficacy or clinical course in HCV infection. This review focuses on these host genetic variations recently identified, mainly by GWAS, which are associated with the clinical course of chronic HCV infection, especially disease progression and hepatocarcinogenesis.
  • Combinational use of hepatitis B viral antigens predicts responses to nucleos(t)ide analogue/peg-interferon sequential therapy., Matsumoto A, Nishiguchi S, Enomoto H, Kang JH, Tanaka Y, Shinkai N, Kurosaki M, Enomoto M, Kanda T, Yokosuka O, Yatsuhashi H, Nagaoka S, Okuse C, Kagawa T, Mine T, Takaguchi K, Saito S, Hino K, Ikeda F, Sakisaka S, Morihara D, Miyase S, Tsuge M, Chayama K, Hiramatsu N, Suzuki Y, Murata K, Tanaka E, Journal of gastroenterology, 53, (2) 247 - 257,   2018年02月, 査読有り
  • Changes in serum lipid profiles caused by three regimens of interferon-free direct-acting antivirals for patients infected with hepatitis C virus, Takako Inoue, Takaaki Goto, Etsuko Iio, Kayoko Matsunami, Kei Fujiwara, Noboru Shinkai, Kentaro Matsuura, Takeshi Matsui, Shunsuke Nojiri, Yasuhito Tanaka, Hepatology Research, 48, (3) E203 - E212,   2018年02月, 査読有り, © 2017 The Japan Society of Hepatology Aim: Serum low-density lipoprotein cholesterol (LDL-C) increases during treatment of chronic hepatitis C (CHC) with interferon-free direct-acting antivirals (DAAs). We sought to compare the changes of serum lipid profiles caused by three regimens. Methods: A total of 216 CHC patients were enrolled. Among 170 patients infected with hepatitis C virus (HCV) genotype 1b, 85 received daclatasvir plus asunaprevir (DCV/ASV) and 85 received sofosbuvir plus ledipasvir (SOF/LDV). Forty-six infected with HCV genotype 2 received sofosbuvir plus ribavirin (SOF/RBV). Serum total cholesterol (TC), LDL-C, high-density lipoprotein cholesterol, and triglyceride were measured at baseline and 4, 8, 12 (for all regimens), and 24 weeks (for DCV/ASV) during treatment (4w, 8w, 12w, and 24w, respectively) and 12 and 24 weeks after treatment (p12w and p24w, respectively). Results: In 69 (81.2%) patients who received DCV/ASV and achieved a sustained virologic response at 24 weeks after the end of treatment (SVR24), TC and LDL-C increased significantly from baseline to p24w. In 84 (98.8%) treated with SOF/LDV who achieved SVR24, TC and LDL-C increased significantly from baseline to 8w, and TC decreased significantly from 8w to p12w. The 45 (97.8%) who received SOF/RBV and achieved SVR24 showed no significant changes. At 12w, TC and LDL-C increased to a greater degree in patients receiving SOF/LDV than in those receiving DCV/ASV or SOF/RBV. Conclusion: During treatment with DAAs, the serum lipid profile may reflect not only recovery from the disruption of lipid metabolism induced by HCV, but also the pharmacological effects of DAAs. Further investigations are needed to elucidate the effect of DAAs on serum lipid profiles.
  • Effect of hepatitis B virus subgenotype on antiviral response in nucleoside-treated hepatitis B envelope antigen-positive patients., Shen S, Liang X, Hamed K, Tanaka Y, Omagari K, Fan R, Xie Q, Tan D, Zhou B, Jia JD, Hou J, Sun J, Hepatology research : the official journal of the Japan Society of Hepatology, 48, (2) 134 - 143,   2018年02月, 査読有り
  • ゲノムサイエンスの肝疾患診療への応用 C型肝炎の将来を予測するゲノム診断―これまでの功績と将来展望―, 松浦健太郎, 田中靖人, 月刊消化器・肝臓内科, 3, (1) ,   2018年01月28日
  • 肝炎ウイルス克服時代の肝臓病学 IV.B型肝炎ウイルス治療:“臨床的治癒”から“機能的治癒”を目指して, 田中靖人, 日本内科学会雑誌, 107, (1) ,   2018年01月10日
  • Efficacy and safety of sofosbuvir–velpatasvir with or without ribavirin in HCV-infected Japanese patients with decompensated cirrhosis: an open-label phase 3 trial, Tetsuo Takehara, Naoya Sakamoto, Shuhei Nishiguchi, Fusao Ikeda, Tomohide Tatsumi, Yoshiyuki Ueno, Hiroshi Yatsuhashi, Yasuhiro Takikawa, Tatsuo Kanda, Minoru Sakamoto, Akihiro Tamori, Eiji Mita, Kazuaki Chayama, Gulan Zhang, Shampa De-Oertel, Hadas Dvory-Sobol, Takuma Matsuda, Luisa M. Stamm, Diana M. Brainard, Yasuhito Tanaka, Masayuki Kurosaki, Journal of Gastroenterology,   2018年01月01日, 査読有り, © 2018, The Author(s). Background: In Japan, hepatitis C virus (HCV)-infected patients with decompensated cirrhosis currently have no treatment options. In this Phase 3 study, we evaluated sofosbuvir–velpatasvir with or without ribavirin for 12 weeks in patients with any HCV genotype and decompensated cirrhosis [Child–Pugh–Turcotte (CPT) class B or C] in Japan. Methods: Patients were randomized 1:1 to receive sofosbuvir–velpatasvir with or without ribavirin for 12 weeks. Randomization was stratified by CPT class and genotype. Sustained virologic response 12 weeks following completion of treatment (SVR12) was the primary efficacy endpoint. Results: Of the 102 patients enrolled, 57% were treatment naive, 78% and 20% had genotype 1 and 2 HCV infection, respectively, and 77% and 20% had CPT class B and C cirrhosis, respectively, at baseline. Overall, 61% of patients were female and the mean age was 66 years (range 41–83). SVR12 rates were 92% (47/51) in each group. Among patients who achieved SVR12, 26% had improved CPT class from baseline to posttreatment week 12. Most adverse events (AEs) were consistent with clinical sequelae of advanced liver disease or known toxicities of ribavirin. Four patients (8%) who received sofosbuvir–velpatasvir and seven (14%) who received sofosbuvir–velpatasvir plus ribavirin experienced a serious AE. The 3 deaths (bacterial sepsis, gastric varices hemorrhage, hepatocellular carcinoma) were attributed to liver disease progression. Conclusion: Sofosbuvir–velpatasvir for 12 weeks provides a highly effective and well-tolerated therapy for Japanese patients with HCV and decompensated cirrhosis. Ribavirin did not improve efficacy but increased toxicity.
  • Efficacy and safety of elbasvir/grazoprevir for Japanese patients with genotype 1b chronic hepatitis C complicated by chronic kidney disease, including those undergoing hemodialysis: A post hoc analysis of a multicenter study, Masanori Atsukawa, Akihito Tsubota, Hidenori Toyoda, Koichi Takaguchi, Chisa Kondo, Tomomi Okubo, Atsushi Hiraoka, Kojiro Michitaka, Shinichi Fujioka, Haruki Uojima, Tsunamasa Watanabe, Hiroki Ikeda, Toru Asano, Toru Ishikawa, Yoshihiro Matsumoto, Hiroshi Abe, Keizo Kato, Kunihiko Tsuji, Chikara Ogawa, Noritomo Shimada, Etsuko Iio, Shigeru Mikami, Yasuhito Tanaka, Takashi Kumada, Katsuhiko Iwakiri, Journal of Gastroenterology and Hepatology (Australia),   2018年01月01日, 査読有り, © 2018 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd Background and Aim: This study aimed to evaluate the efficacy and safety of elbasvir/grazoprevir in genotype 1b chronic hepatitis C Japanese patients with chronic kidney disease (CKD), including those undergoing hemodialysis. Methods: This post hoc analysis of a multicenter, retrospective study included patients who had received elbasvir/grazoprevir. CKD was defined by an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2. The sustained virologic response (SVR) rate and frequency of treatment-emergent adverse events were assessed in patients with CKD. Results: The study population comprised 155 men and 182 women. The median eGFR level at baseline was 69.6 mL/min/1.73 m2(range, 3.0–128.5 mL/min/1.73 m2). Among the 337 patients, 109 (32.3%) had CKD: 72, 14, and 23 (including 20 hemodialysis) had CKD stages 3, 4, and 5, respectively. The SVR rates according to the baseline CKD stages were 98.1% (51/52) in stage 1, 98.3% (173/176) in stage 2, 93.9% (46/49) in stage 3a, 100% (23/23) in stage 3b, 100% (14/14) in stage 4, and 100% (23/23) in stage 5. All 20 patients undergoing hemodialysis achieved SVR. There was no significant decrease from baseline in the median eGFR level throughout the treatment period among the patients with CKD. The incidence of treatment-emergent adverse events was 6.4% (7/109) among the patients with CKD and 9.7% (22/228) among the patients without CKD (not significant, P = 0.323). Conclusions: The present study demonstrated that elbasvir and grazoprevir are highly effective and safe for genotype 1b chronic hepatitis C Japanese patients with CKD, including those undergoing hemodialysis.
  • Serial changes of NS5A P32deletion mutant in HCV genotype 1b patients after Daclatasvir/Asunaprevir failure, Etsuko Iio, Shintaro Ogawa, Noritomo Shimada, Yuichiro Eguchi, Noboru Hirashima, Kentaro Matsuura, Yasuhito Tanaka, Acta Hepatologica Japonica, 59, 230 - 233,   2018年01月01日, © 2018 The Japan Society of Hepatology. After direct-acting antiviral agents (DAAs) failure, multiple RAVs emerged in NS5A, especially, P32 deletion ( del ) in some patients. Total 74 patients with Daclatasvir/Asunaprevir (DCV/ASV) failure were examined NS5A resistant associated variant (RAV), and 32 or 29 del emerged in 9% after DCV/ASV failure. Four of seven patients with del had history of Peginterferon/ribavirin/simeprevir treatment. Changes of NS5A quasispieces were examined by population sequencing in 4 patients with NS5A P32del. Three of 4 patients have detected P32del since the treatment failure (up to 28 months after DCV/ASV failure). Note that P32del firstly emerged in one patient 6 months after the failure. Hence, NS5A RAVs should be examined before re-treatment of DAA treatment, because P32 del could be resistant to Glecaprevir/Pibrentasvir.
  • Suppression of hepatitis B surface antigen production by combination therapy with nucleotide analogues and interferon in children with genotype C hepatitis B virus infection, Hitoshi Tajiri, Tomoko Takano, Yasuhito Tanaka, Jun Murakami, Stephen Brooks, Hepatology Research,   2018年01月01日, 査読有り, © 2018 The Japan Society of Hepatology Aim: Sustained suppression of hepatitis B surface antigen (HBsAg) production after interferon (IFN) treatment has not been reported for children with genotype C chronic hepatitis B virus (HBV) infection, which is prevalent in Asia. Among children with hepatitis B envelope antigen-positive genotype C chronic HBV infection, we compared the efficacy of combination therapy with nucleotide analogues and IFN-α in 11 children with 12 historical cases treated with IFN monotherapy. Methods: The combination of lamivudine and conventional IFN-α was introduced for the first three patients; the other eight patients were treated with entecavir and pegylated IFN. Results: Demographic factors as well as baseline HBsAg titers and HBV-DNA levels were similar between the two groups. In the combination therapy group, viral loads were suppressed in 9/11 to below 4.0 log copies/mL both at the end of the therapy (EOT) and at 6 months after EOT. In contrast, in the IFN monotherapy group, suppression of viral loads was observed in 2/12 and 3/12 at EOT and at 6 months after EOT, respectively. In the combination therapy group, HBsAg titers dropped from 4.03 at pretreatment to 2.91 log IU/mL at 6 months after EOT with 4/11 showing a drop to below 1000 IU/mL (one patient achieved HBsAg clearance). In contrast, the amount of HBsAg did not change during the corresponding periods in the IFN monotherapy group. Conclusions: Our preliminary results suggest that combination therapy might be effective in the suppression of HBsAg production as well as HBV-DNA production for children with genotype C chronic HBV infection.
  • Clinical evaluation of a novel and highly sensitive immunoassay for anti-hepatitis B core antigen using a fully automated immunochemical analyzer, Kyo Izumida, Atsushi Kaneko, Kazuya Takahashi, Shigeru Kusumoto, Tomoko Narita, Akiyoshi Takami, Shinsuke Iida, Katsumi Aoyagi, Yasuhito Tanaka, Hepatology Research,   2018年01月01日, 査読有り, © 2018 The Authors. Hepatology Research published by John Wiley & Sons Australia, Ltd on behalf of Japan Society of Hepatology Aim: Recently, the measurement of hepatitis B surface antigen and anti-hepatitis B core antigen (HBcAb) and/or anti-hepatitis B surface antigen has been recommended before various therapies to identify patients at risk of hepatitis B virus (HBV) reactivation. However, a recent study reported that HBV reactivation occurred in HBcAb-negative patients, indicating that it is challenging to identify patients with a history of HBV infection using conventional HBcAb reagent. We developed a highly sensitive HBcAb (HBcAb-HS) assay for reducing the risk of HBV reactivation. Methods: The HBcAb-HS assay is an automated chemiluminescent enzyme immunoassay system, which is suitable for clinical use. The cut-off was set at 0.020 IU/mL from the distribution patterns of HBcAb-negative specimens, and we evaluated the performance of this assay compared with conventional reagents. Results: This new assay showed a 27–81-fold greater sensitivity than conventional HBcAb reagents; the quantified measurement range was from 0.005 IU/mL to 1.500 IU/mL, and it showed excellent quantitative performance and correlated well with two conventional assays, using the HBcAb-positive specimens. Moreover, it showed 100% specificity for the 469 purchased HBcAb-negative specimens. Notably, this newly developed HBcAb-HS assay showed positivity in the preserved specimens before HBV reactivation, for which conventional HBcAb reagents gave negative results, and the HBcAb-HS assay could detect the lower HBcAb levels even after intensive immunosuppressive therapies, including autologous hematopoietic stem cell transplantation. Conclusions: The clinical efficacy of the newly developed, highly sensitive HBcAb assay would enable the identification of patients at risk of HBV reactivation more accurately.
  • Daclatasvir and asunaprevir in hemodialysis patients with hepatitis C virus infection: a nationwide retrospective study in Japan, Goki Suda, Norihiro Furusyo, Hidenori Toyoda, Yoshiiku Kawakami, Hiroki Ikeda, Michihiro Suzuki, Keiko Arataki, Nami Mori, Keiji Tsuji, Yoshio Katamura, Koichi Takaguchi, Toru Ishikawa, Kunihiko Tsuji, Noritomo Shimada, Atsushi Hiraoka, Sho Yamsaki, Masato Nakai, Takuya Sho, Kenichi Morikawa, Koji Ogawa, Mineo Kudo, Atsushi Nagasaka, Ken Furuya, Yoshiya Yamamoto, Kanji Kato, Yoshiyuki Ueno, Etsuko Iio, Yasuhito Tanaka, Masayuki Kurosaki, Takashi Kumada, Kazuaki Chayama, Naoya Sakamoto, Journal of Gastroenterology, 53, (1) 119 - 128,   2018年01月01日, 査読有り, © 2017, Japanese Society of Gastroenterology. Background: Hepatitis C virus (HCV) infection is common in hemodialysis patients and worsens their prognosis, while antiviral therapy options are limited. Recently, clinical trial and real-world, small-scale studies have reported excellent responses to direct-acting antivirals in patients with advanced chronic kidney diseases. However, real-world, large-scale data were lacking. This large multicenter analysis included HCV-infected hemodialysis patients receiving combination therapy with a nonstructural protein 5A (NS5A) inhibitor, daclatasvir (DCV), and a protease inhibitor, asunaprevir (ASV). Methods: Twenty-three centers in Japan participated in this study of 123 hemodialysis patients with genotype 1 HCV infection, who received DCV/ASV combination therapy between November 2014 and March 2016. We collected and analyzed data relating to treatment outcome, baseline clinical information, laboratory measurements (during and after the treatment), and adverse events. Results: Thirty-nine patients (31.7%) had advanced liver fibrosis, 12 (9.8%) had histories of hepatocellular carcinoma (HCC), and 18 (14.6%) had baseline resistance-associated variants (RAVs) of NS5A. The overall sustained virological response (SVR)12 rate was 95.9% (118/123). Notably, all patients with HCC and 94.4% (17/18) of those with NS5A RAVs achieved SVR12. Significant factors associated with non-SVR were advanced fibrosis and the interleukin-28B non-TT genotype at rs8099917. Four patients (3.3%) discontinued therapy because of adverse events including elevated serum alanine transaminase levels (n = 2), rash (n = 1), and HCC (n = 1); all of these achieved SVR12. Conclusions: This real-world, nationwide study revealed that DCV/ASV combination therapy was safe and highly effective for hemodialysis patients with genotype 1 HCV infections. This study was registered at the UMIN Clinical Trials Registry (UMIN000024227).
  • Clinical evaluation of hepatocarcinogenesis and outcome using a novel glycobiomarker wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA+-M2BP) in chronic hepatitis C with advanced fibrosis, Inoue T, Tsuzuki Y, Iio E, Shinkai N, Matsunami K, Fujiwara K, Matsuura K, Nojiri S, Tanaka Y, Japanese Journal of Infectious Diseases, 71, (3) 177 - 183,   2018年01月, 査読有り, © 2018, National Institute of Health. All rights reserved. This study aimed to assess the association between the serum glycobiomarker Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA+-M2BP) for liver fibrosis and outcomes and carcinogenesis of hepatocellular carcinoma (HCC) in chronic hepatitis C (CHC) patients with advanced fibrosis. Serum WFA+-M2BP levels were measured in 128 consecutive CHC patients including 49 with HCC histopathologically diagnosed with advanced fibrosis (44 with fibrosis stage F3 and 84 with fibrosis stage F4) in our hospital. The median WFA+-M2BP level was significantly higher in F4 than in F3 patients (6.9 vs. 2.3 cutoff index [COI], respectively; p < 0.001). The difference in WFA+-M2BP levels between patients with and without HCC was not significant. The respective 5-/8-yr survival rates of patients without HCC at enrollment with high (≥ 4 COI, n = 39), intermediate (1–4 COI, n = 33), and low WFA+-M2BP (< 1 COI, n = 7) levels were 78%/48%, 100%/82%, and 100%/100%, respectively. The differences in survival rates between groups were significant (p = 0.0041). Patients with high WFA+-M2BP levels had a significantly higher incidence of HCC than those with low WFA+-M2BP levels (p = 0.0019). Cumulative 5-yr carcinogenesis rates in patients with high, intermediate, and low WFA+-M2BP levels were 48.7%, 16.9%, and 0%, respectively; the differences between groups were significant (p = 0.002). Serum WFA+-M2BP levels might allow the prediction of carcinogenesis and outcome in CHC patients with advanced fibrosis.
  • Efficacy of regimens combining direct acting antiviral agents for hepatitis C virus recombinant form RF1_2k/1b., Matsuura K, Tanaka Y, Hepatology research : the official journal of the Japan Society of Hepatology, 48, (1) 3 - 4,   2018年01月, 査読有り
  • 高ウイルス量妊婦への核酸アナログ投与によるB型肝炎ウイルス母子感染予防, 杉浦時雄, 遠藤剛, 伊藤孝一, 田中靖人, 高野智子, 田尻仁, 三善陽子, 鈴木光幸, 日本小児栄養消化器肝臓学会雑誌, 31, (2) ,   2017年12月31日
  • B型肝炎ウイルス再活性化~現状と当院での取り組み~, 井上貴子, 新海登, 田中靖人, 臨床病理, 65, (12) ,   2017年12月
  • Clinical evaluation of sofosbuvir/ledipasvir in patients with chronic hepatitis C genotype 1 with and without prior daclatasvir/asunaprevir therapy, Etsuko Iio, Noritomo Shimada, Koichi Takaguchi, Tomonori Senoh, Yuichiro Eguchi, Masanori Atsukawa, Akihito Tsubota, Hiroshi Abe, Keizo Kato, Keizo Kato, Atsunori Kusakabe, Tomokatsu Miyaki, Kentaro Matsuura, Kayoko Matsunami, Noboru Shinkai, Kei Fujiwara, Shunsuke Nojiri, Yasuhito Tanaka, Hepatology Research, 47, (12) 1308 - 1316,   2017年11月01日, 査読有り, © 2017 The Japan Society of Hepatology Aim: This study explored treatment outcomes of sofosbuvir (SOF)/ledipasvir (LDV) therapy for chronic hepatitis C patients with and without prior daclatasvir (DCV)/asunaprevir (ASV) therapy. Methods: Overall, 530 Japanese patients who were infected with hepatitis C virus genotype 1 received SOF/LDV therapy for 12 weeks, and resistance-associated variants (RAVs) in the hepatitis C virus non-structural protein (NS)5A and NS5B regions were assessed at baseline and virological relapse by direct sequencing. Results: Sustained virological response (SVR) rates did not significantly differ between patients with and without NS5A Y93H/N (94.2% [113/120] vs. 97.7% [345/353]), but the SVR rate was significantly lower in patients with prior DCV/ASV therapy compared to those without (69.2% [18/26] vs. 98.4% [496/504], P < 0.001). Among 26 patients with prior DCV/ASV therapy, the prevalence of NS5A multi-RAVs (≥2) was similar between responders and non-responders (61% [11/18] vs. 75% [5/8]), but all patients without RAVs achieved SVR. Multivariate analysis showed that prior DCV/ASV therapy and history of hepatocellular carcinoma were independently associated with treatment failure (odds ratio, 37.55; 95% confidence interval, 10.78–130.76; P < 0.001 for prior DCV/ASV therapy; odds ratio, 4.42; 95% confidence interval, 1.09–18.04; P = 0.03 for the history of HCC). All SOF/LDV failure patients (n = 8) with prior DCV/ASV treatment had two or more factors of cirrhosis, IL28B unfavorable genotype, and baseline NS5A multi-RAVs. The multiple NS5A RAVs had increased but NS5B substitutions, C316N/A207T/A218S or L159F, had not changed at the time of relapse. Conclusions: Prior DCV/ASV therapy is associated with failure of SOF/LDV therapy due to multiple RAVs.
  • 薬剤師による保険薬局でのC型肝炎患者への受診・受療勧奨の試み, 井上 貴子, 浦野 滋行, 井上 巖, 是永 匡紹, 田中 靖人, 肝臓, 58, (11) 639 - 642,   2017年11月, C型肝炎患者の多くは直接作用型抗ウイルス薬(DAAs)治療を受けているが、過去の治療で受けたマイナスの印象(副作用、治療期間、ウイルス排除不成功など)からDAAs治療をためらう症例や、「高い医療費」等の先入観から治療に消極的な場合もある。そこで、地域の薬剤師会と連携し、保険薬局を訪れるC型肝炎患者やその周囲の人々に対して受診・受療勧奨を行った。具体的には、豊田加茂薬剤師会に所属する保険薬局156軒で勤務する薬剤師に依頼し、C型肝炎受診勧奨リーフレット『今こそたたけ!肝炎ウイルス』愛知県版を掲示・配布してもらうようにした。その効果を調べるため、4ヵ月後に各薬局に対してFAXによるアンケートを行った。結果、有効回答は71軒から得られ、このうちリーフレットを掲示しているのは43軒(61%)、配布したのは13軒(18%)であった。受診・受療勧奨が実施されたのは12軒(17%)で、合計32名の患者にリーフレットが使用され、このうち受診・受療に至ったのは16名(50%)であった。
  • Reply., Matsuura K, Kurosaki M, Tanaka Y, Gastroenterology, 153, (5) 1449 - 1450,   2017年11月, 査読有り
  • Retreatment with sofosbuvir, ledipasvir, and add-on ribavirin for patients who failed daclatasvir and asunaprevir combination therapy, Goki Suda, Koji Ogawa, Yoshiya Yamamoto, Masaki Katagiri, Ken Furuya, Kenichi Kumagai, Jun Konno, Megumi Kimura, Naoki Kawagishi, Masatsugu Ohara, Machiko Umemura, Jun Ito, Takaaki Izumi, Masato Nakai, Takuya Sho, Mitsuteru Natsuizaka, Kenichi Morikawa, Akihito Tsubota, Noritomo Shimada, Etsuko Iio, Yasuhito Tanaka, Naoya Sakamoto, Journal of Gastroenterology, 52, (10) 1122 - 1129,   2017年10月01日, 査読有り, © 2017, Japanese Society of Gastroenterology. Background: The optimal retreatment regimen for patients with hepatitis C virus (HCV) infection who failed interferon-free, direct-acting antiviral (DAA) therapy is undetermined. In this study, we aimed to evaluate the efficacy and safety of 12-week retreatment with ledipasvir (LDV) and sofosbuvir (SOF) with add-on ribavirin (RBV) for patients who previously failed to respond to HCV-NS5A inhibitor, daclatasvir (DCV), and HCV-NS3 inhibitor, asunaprevir (ASV), therapy. Methods: This multicenter, prospective study enrolled 15 patients with genotype-1 HCV infection who failed DCV/ASV combination therapy. They were retreated with SOF, LDV, and RBV for 12 weeks and underwent physical examinations and blood tests at baseline, during treatment, and after therapy. At baseline and relapse, NS3/NS5A and NS5B resistance-associated variants (RAVs) were evaluated. Results: Of the 15 enrolled patients, 73.3% (11/15), 86.7% (13/15), and 0% (0/15) had RAVs in NS3 D168A/V/T/E, NS5A L31I/M/F/V plus Y93H, and NS5B S282T, respectively. Overall, 86.7% (13/15) of patients achieved a sustained viral response, and all patients completed therapy. No patients experienced severe adverse events. Two patients who failed to respond to SOF, LDV, and RBV combination therapy were elderly women, had the IL28B non-TT genotype, and NS5A RAVs in L31I/Y93H or NS5A A92 K at baseline. Conclusions: This study revealed that SOF, LDV, and RBV combination therapy was effective and well-tolerated for patients with genotype-1 HCV infection who failed DCV and ASV combination therapy. Thus, RBV added to DAA therapy for difficult-to-treat patients might improve treatment outcomes.
  • Daclatasvir and asunaprevir for genotype 1b chronic hepatitis C patients with chronic kidney disease., Kondo C, Atsukawa M, Tsubota A, Shimada N, Abe H, Asano T, Yoshizawa K, Okubo T, Chuganji Y, Aizawa Y, Iio E, Tanaka Y, Iwakiri K, Hepatology research : the official journal of the Japan Society of Hepatology, 47, (11) 1165 - 1173,   2017年10月, 査読有り
  • Successful Treatment of Oral Lichen Planus with Direct-Acting Antiviral Agents after Liver Transplantation for Hepatitis C Virus-Associated Hepatocellular Carcinoma., Nagao Y, Nakasone K, Maeshiro T, Nishida N, Kimura K, Kawahigashi Y, Tanaka Y, Sata M, Case reports in gastroenterology, 11, (3) 701 - 710,   2017年09月, 査読有り
  • Functional association of cellular microtubules with viral capsid assembly supports efficient hepatitis B virus replication., Iwamoto M, Cai D, Sugiyama M, Suzuki R, Aizaki H, Ryo A, Ohtani N, Tanaka Y, Mizokami M, Wakita T, Guo H, Watashi K, Scientific reports, 7, (1) ,   2017年09月, 査読有り
  • Effectiveness and safety of community-based treatment with sofosbuvir plus ribavirin for elderly patients with genotype 2 chronic hepatitis C., Atsukawa M, Tsubota A, Kondo C, Shimada N, Abe H, Kato K, Okubo T, Arai T, Itokawa N, Iio E, Tanaka Y, Iwakiri K, Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver, 49, (9) 1029 - 1035,   2017年09月, 査読有り
  • Effects of vaccine-acquired polyclonal anti-HBs antibodies on the prevention of HBV infection of non-vaccine genotypes., Kato M, Hamada-Tsutsumi S, Okuse C, Sakai A, Matsumoto N, Sato M, Sato T, Arito M, Omoteyama K, Suematsu N, Okamoto K, Kato T, Itoh F, Sumazaki R, Tanaka Y, Yotsuyanagi H, Kato T, Kurokawa MS, Journal of gastroenterology, 52, (9) 1051 - 1063,   2017年09月, 査読有り
  • Novel monitoring of hepatitis B reactivation based on ultra-high sensitive hepatitis B surface antigen assay, Noboru Shinkai, Shigeru Kusumoto, Shuko Murakami, Shintaro Ogawa, Masaki Ri, Tekeshi Matsui, Tekeshi Matsui, Akihiro Tamori, Hidenori Toyoda, Takashi Ishida, Shinsuke Iida, Yasuhito Tanaka, Liver International, 37, (8) 1138 - 1147,   2017年08月01日, 査読有り, © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Background & Aims: Occult hepatitis B virus (HBV) infection should be evaluated before systemic chemotherapy to prevent HBV reactivation-related hepatitis. We investigated HBV reactivation using high sensitivity HB surface antigen (HBsAg) chemiluminescent enzyme immunoassay (HBsAg-HQ) and ultra-high sensitive HBsAg assay employing a semi-automated immune complex transfer chemiluminescence enzyme technique (ICT-CLEIA). Methods: Of 120 HBV-resolved patients with haematological malignancy receiving systemic chemotherapy from 2012 to 2015 in our hospital, 13 patients had HBV DNA reactivation (in 12/13 patients HBV DNA became quantifiable) according to HBV DNA monitoring. These patients were applied for Architect HBsAg-QT (detection limit:50 mIU/mL), HBsAg-HQ (5 mIU/mL) and ICT-CLEIA (0.5 mIU/mL) using stored samples. Results: When HBV DNA was firstly quantifiable by regular HBV DNA monitoring, HBsAg-QT was detected in 1/12 patients (8%), HBsAg-HQ was detected in 4/12 patients (33%) and ICT-CLEIA was detected in all 12 patients (100%), suggesting that the sensitivity of ICT-CLEIA was comparable to that of HBV DNA quantification. Interestingly, two patients were HBsAg positive by ICT-CLEIA before HBV DNA became detectable. Median difference of detectable point between HBV DNA and ICT-CLEIA was zero (range from −28 to 56 days), while median delay by HBsAg-QT or HBsAg-HQ was 52.5 days after HBV DNA became detectable. Although anti-HBs titres were high (131.9 mIU, 80.4 mIU) in two patients with escape mutations (Saa126V, Saa145R), HBsAg by ICT-CLEIA and HBV DNA were detectable concurrently. Conclusions: ICT-CLEIA is a novel assay for HBV monitoring to prevent hepatitis caused by HBV reactivation.
  • Identification of the novel 3' UTR sequences of human IL-21 mRNA as potential targets of miRNAs., Enomoto Y, Takagi R, Naito Y, Kiniwa T, Tanaka Y, Hamada-Tsutsumi S, Kawano M, Matsushita S, Ochiya T, Miyajima A, Scientific reports, 7, (1) ,   2017年08月, 査読有り
  • Hepatic IFNL4 expression is associated with non-response to interferon-based therapy through the regulation of basal interferon-stimulated gene expression in chronic hepatitis C patients, Miyako Murakawa, Yasuhiro Asahina, Fukiko Kawai-Kitahata, Mina Nakagawa, Sayuri Nitta, Satoshi Otani, Hiroko Nagata, Shun Kaneko, Yu Asano, Tomoyuki Tsunoda, Masato Miyoshi, Yasuhiro Itsui, Seishin Azuma, Sei Kakinuma, Sei Kakinuma, Yasuhito Tanaka, Sayuki Iijima, Kaoru Tsuchiya, Namiki Izumi, Shuji Tohda, Mamoru Watanabe, Journal of Medical Virology, 89, (7) 1241 - 1247,   2017年07月, 査読有り, © 2017 Wiley Periodicals, Inc. Single nucleotide polymorphisms (SNPs) within or near interferon lambda 4 (IFNL4) gene located upstream of IFNL3 are associated with response to anti-HCV therapy both in interferon (IFN)-based and IFN-free regimens. IFNL4 encodes IFNλ4, a newly discovered type III IFN, and its expression is controlled by rs368234815-TT/ΔG, which is in strong linkage disequilibrium (LD) with other tag SNPs within or near IFNL4 such as rs12979860 and rs8099917. Intrahepatic expression levels of IFN-stimulated genes (ISGs) affect the responsiveness to IFNα and are also associated with IFNL4 genotype. However, IFNL4 expressions and its role in intrinsic antiviral innate immunity remain unclear. This study evaluated the effect of IFNL4 on intrahepatic ISG expression and investigated its relationship with treatment outcomes in liver samples obtained from 49 chronic hepatitis C patients treated with pegylated (PEG)-IFN/ribavirin therapy. IFNL4 mRNA was detected in 11 of 22 patients with IFNL4-unfavorable SNPs but not in patients with favorable genotypes. IFNL4 expression was associated with non-response to PEG-IFN/ribavirin therapy. Intrahepatic expression of antiviral ISGs (ISG15 and MX1) was significantly higher in IFNL4-unfavorable patients with detectable IFNL4 mRNA than in patients with undetectable IFNL4 mRNA, whereas the expression of suppressive ISGs (RNF125, SOCS1, SOCS3, and RNF11) was lower in patients with detectable IFNL4 mRNA. In summary, intrahepatic expression of IFNL4 was associated with increased antiviral ISG expression and decreased suppressive ISG expression at baseline, resulting in poor responsiveness to IFNα-based therapy in HCV infection.
  • Interferon-β response is impaired by hepatitis B virus infection in Tupaia belangeri., Kayesh MEH, Ezzikouri S, Chi H, Sanada T, Yamamoto N, Kitab B, Haraguchi T, Matsuyama R, Nkogue CN, Hatai H, Miyoshi N, Murakami S, Tanaka Y, Takano JI, Shiogama Y, Yasutomi Y, Kohara M, Tsukiyama-Kohara K, Virus research, 237, 47 - 57,   2017年06月, 査読有り
  • Genome-Wide Association Study Identifies Risk Variants for Lichen Planus in Patients With Hepatitis C Virus Infection., Nagao Y, Nishida N, Toyo-Oka L, Kawaguchi A, Amoroso A, Carrozzo M, Sata M, Mizokami M, Tokunaga K, Tanaka Y, Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association, 15, (6) 937 - 944.e5,   2017年06月, 査読有り
  • Genome-Wide Association Study Identifies TLL1 Variant Associated With Development of Hepatocellular Carcinoma After Eradication of Hepatitis C Virus Infection, Kentaro Matsuura, Hiromi Sawai, Kazuho Ikeo, Shintaro Ogawa, Etsuko Iio, Masanori Isogawa, Noritomo Shimada, Atsumasa Komori, Hidenori Toyoda, Takashi Kumada, Tadashi Namisaki, Hitoshi Yoshiji, Naoya Sakamoto, Mina Nakagawa, Yasuhiro Asahina, Masayuki Kurosaki, Namiki Izumi, Nobuyuki Enomoto, Atsunori Kusakabe, Eiji Kajiwara, Yoshito Itoh, Tatsuya Ide, Akihiro Tamori, Misako Matsubara, Norifumi Kawada, Ken Shirabe, Eiichi Tomita, Masao Honda, Shuichi Kaneko, Sohji Nishina, Atsushi Suetsugu, Yoichi Hiasa, Hisayoshi Watanabe, Takuya Genda, Isao Sakaida, Shuhei Nishiguchi, Koichi Takaguchi, Eiji Tanaka, Junichi Sugihara, Mitsuo Shimada, Yasuteru Kondo, Yosuke Kawai, Kaname Kojima, Masao Nagasaki, Katsushi Tokunaga, Yasuhito Tanaka, Gastroenterology, 152, (6) 1383 - 1394,   2017年05月, 査読有り, © 2017 AGA Institute Background & Aims There is still a risk for hepatocellular carcinoma (HCC) development after eradication of hepatitis C virus (HCV) infection with antiviral agents. We investigated genetic factors associated with the development of HCC in patients with a sustained virologic response (SVR) to treatment for chronic HCV infection. Methods We obtained genomic DNA from 457 patients in Japan with a SVR to interferon-based treatment for chronic HCV infection from 2007 through 2015. We conducted a genome-wide association study (GWAS), followed by a replication analysis of 79 candidate single nucleotide polymorphisms (SNPs) in an independent set of 486 patients in Japan. The study end point was HCC diagnosis or confirmation of lack of HCC (at follow-up examinations until December 2014 in the GWAS cohort, and until January 2016 in the replication cohort). We collected clinical and laboratory data from all patients. We analyzed expression levels of candidate gene variants in human hepatic stellate cells, rats with steatohepatitis caused by a choline-deficient L-amino acid-defined diet, and a mouse model of liver injury caused by administration of carbon tetrachloride. We also analyzed expression levels in liver tissues of patients with chronic HCV infection with different stages of fibrosis or tumors vs patients without HCV infection (controls). Results We found a strong association between the SNP rs17047200, located within the intron of the tolloid like 1 gene (TLL1) on chromosome 4, and development of HCC; there was a genome-wide level of significance when the results of the GWAS and replication study were combined (odds ratio, 2.37; P = 2.66 × 10−8). Multivariate analysis showed rs17047200 AT/TT to be an independent risk factor for HCC (hazard ratio, 1.78; P =.008), along with male sex, older age, lower level of albumin, advanced stage of hepatic fibrosis, presence of diabetes, and higher post-treatment level of α-fetoprotein. Combining the rs17047200 genotype with other factors, we developed prediction models for HCC development in patients with mild or advanced hepatic fibrosis. Levels of TLL1 messenger RNA (mRNA) in human hepatic stellate cells increased with activation. Levels of Tll1 mRNA increased in liver tissues of rodents with hepatic fibrogenesis compared with controls. Levels of TLL1 mRNA increased in liver tissues of patients with progression of fibrosis. Gene expression levels of TLL1 short variants, including isoform 2, were higher in patients with rs17047200 AT/TT. Conclusions In a GWAS, we identified the association between the SNP rs17047200, within the intron of TLL1, and development of HCC in patients who achieved an SVR to treatment for chronic HCV infection. We found levels of Tll1/TLL1 mRNA to be increased in rodent models of liver injury and liver tissues of patients with fibrosis, compared with controls. We propose that this SNP might affect splicing of TLL1 mRNA, yielding short variants with high catalytic activity that accelerates hepatic fibrogenesis and carcinogenesis. Further studies are needed to determine how rs17047200 affects TLL1 mRNA levels, splicing, and translation, as well as the prevalence of this variant among other patients with HCC. Tests for the TLL1 SNP might be used to identify patients at risk for HCC after an SVR to treatment of HCV infection.
  • B型肝炎創薬研究の最前線, 堤 進, 新海 登, 田中 靖人, 肝臓, 58, (4) 217 - 227,   2017年04月, 2012年にB型肝炎ウイルス(HBV)感染を成立させるための受容体が発見され、その受容体を人為的に発現させた培養細胞を用いて、HBVの増殖サイクルを簡便に解析できる技術が開発された。この技術によりHBVの感染成立過程、複製メカニズムの研究が進展するとともに、大量の抗ウイルス薬候補を簡便に評価することが可能になった。HBV複製サイクルを再現する持続感染培養系の確立により抗HBV創薬研究が加速したこと、HBVの複製機構および宿主因子を標的とした新しい作用機序の新規治療薬の開発が精力的に進められていることを紹介した。
  • Human induced-pluripotent stem cell-derived hepatocyte-like cells as an in vitro model of human hepatitis B virus infection., Sakurai F, Mitani S, Yamamoto T, Takayama K, Tachibana M, Watashi K, Wakita T, Iijima S, Tanaka Y, Mizuguchi H, Scientific reports, 7,   2017年04月, 査読有り
  • Cyclosporin derivatives inhibit hepatitis B virus entry without interfering with NTCP transporter activity, Satomi Shimura, Koichi Watashi, Kento Fukano, Michael Peel, Ann Sluder, Fumihiro Kawai, Masashi Iwamoto, Senko Tsukuda, Junko S. Takeuchi, Takeshi Miyake, Masaya Sugiyama, Yuki Ogasawara, Sam Yong Park, Yasuhito Tanaka, Hiroyuki Kusuhara, Masashi Mizokami, Camille Sureau, Takaji Wakita, Journal of Hepatology, 66, (4) 685 - 692,   2017年04月, 査読有り, © 2016 European Association for the Study of the Liver Background & Aims The sodium taurocholate co-transporting polypeptide (NTCP) is the main target of most hepatitis B virus (HBV) specific entry inhibitors. Unfortunately, these agents also block NTCP transport of bile acids into hepatocytes, and thus have the potential to cause adverse effects. We aimed to identify small molecules that inhibit HBV entry while maintaining NTCP transporter function. Methods We characterized a series of cyclosporine (CsA) derivatives for their anti-HBV activity and NTCP binding specificity using HepG2 cells overexpressing NTCP and primary human hepatocytes. The four most potent derivatives were tested for their capacity to prevent HBV entry, but maintain NTCP transporter function. Their antiviral activity against different HBV genotypes was analysed. Results We identified several CsA derivatives that inhibited HBV infection with a sub-micromolar IC50. Among them, SCY446 and SCY450 showed low activity against calcineurin (CN) and cyclophilins (CyPs), two major CsA cellular targets. This suggested that instead, these compounds interacted directly with NTCP to inhibit viral attachment to host cells, and have no immunosuppressive function. Importantly, we found that SCY450 and SCY995 did not impair the NTCP-dependent uptake of bile acids, and inhibited multiple HBV genotypes including a clinically relevant nucleoside analog-resistant HBV isolate. Conclusions This is the first example of small molecule selective inhibition of HBV entry with no decrease in NTCP transporter activity. It suggests that the anti-HBV activity can be functionally separated from bile acid transport. These broadly active anti-HBV molecules are potential candidates for developing new drugs with fewer adverse effects. Lay summary In this study, we identified new compounds that selectively inhibited hepatitis B virus (HBV) entry, and did not impair bile acid uptake. Our evidence offers a new strategy for developing anti-HBV drugs with fewer side effects.
  • A new class of hepatitis B and D virus entry inhibitors, proanthocyanidin and its analogs, that directly act on the viral large surface proteins., Tsukuda S, Watashi K, Hojima T, Isogawa M, Iwamoto M, Omagari K, Suzuki R, Aizaki H, Kojima S, Sugiyama M, Saito A, Tanaka Y, Mizokami M, Sureau C, Wakita T, Hepatology (Baltimore, Md.), 65, (4) 1104 - 1116,   2017年04月, 査読有り
  • Novel and highly sensitive immunoassay for total hepatitis B surface antigen, including that complexed with hepatitis B surface antibody, Akihiro Matsumoto, Masayasu Imaizumi, Yasuhito Tanaka, Shuhei Nishiguchi, Hiroshi Yatsuhashi, Takehiko Ishida, Kazushige Moriyama, Katsumi Aoyagi, Katsumi Aoyagi, Eiji Tanaka, Journal of Gastroenterology, 52, (3) 376 - 384,   2017年03月01日, 査読有り, © 2016, Japanese Society of Gastroenterology. Background: Hepatitis B surface antigen (HBsAg) is used as a clinical marker of hepatitis B virus (HBV) infection. However, conventional HBsAg assays have so far failed to accurately detect HBsAg in blood because of interference by patient-derived antibodies against HBsAg (HBsAb). Methods: We developed a novel, fully automated assay system that can detect total HBsAg in blood, including antigens complexed with HBsAb. The immunoassay inactivates HBsAb via a simple pretreatment step to dissociate the HBsAg molecule from HBsAg–HBsAb complexes and thereby estimate total HBsAg. Accordingly, the test has been termed the “immunoassay for total antigen including complex via pretreatment (iTACT)-HBsAg.” Results: The recovery rate of HBsAg in the presence of HBsAb was greater than 87 % at a cutoff value set at 5.0 mIU/mL on the basis of data from 545 healthy controls. Analyses using serial serum samples from 25 HBV carriers who became negative for HBsAg during follow-up showed that the iTACT-HBsAg could detect HBsAg over a period of years despite a loss in detection by conventional assays and was able to detect HBsAg in 39 (53 %) of 73 samples with HBsAb. Conclusions: The new iTACT-HBsAg assay appears to detect total HBsAg with high sensitivity, even in the presence of HBsAb, and may useful in identifying subclinical or occult HBV carriers.
  • Characteristics of escape mutations from occult hepatitis B virus infected patients with hematological malignancies in South Egypt, Abeer Elkady, Sayuki Iijima, Sahar Aboulfotuh, Elsayed Mostafa Ali, Douaa Sayed, Nashwa M. Abdel-Aziz, Amany M. Ali, Shuko Murakami, Masanori Isogawa, Yasuhito Tanaka, World Journal of Hepatology, 9, 477 - 486,   2017年03月, 査読有り, © 2017 Baishideng Publishing Group Inc. All rights reserved. AIM To investigate the prevalence and virological characteristics of occult hepatitis B virus (HBV) infections in patients with hematological malignancies in South Egypt. METHODS Serum samples were collected from 165 patients with hematological malignancies to monitor titers of HBV DNA, hepatitis B surface antigen (HBsAg), and antibodies to HBV core (anti-HBc) and surface antigens. Serum samples negative for HBsAg and positive for anti-HBc were subjected to nucleic acid extraction and HBV DNA detection by real-time polymerase chain reaction. DNA sequences spanning the S region were analyzed in cases with occult HBV infection. In vitro comparative study of constructed 1.24-fold wild type and S protein mutant HBV genotype D clones was further performed. RESULTS HBV DNA was detected in 23 (42.6%) of 54 patients with hematological malignancies who were HBsAg negative, but anti-HBc positive, suggesting the presence of occult HBV infection. The complete HBV genome was retrieved from 6 occult HBV patients, and P120T and S143L were detected in 3 and 2 cases, respectively. Site directed mutagenesis was done to produce 1.24-fold genotype D clones with amino acid mutations T120 and L143. The in vitro analyses revealed that a lower level of extracellular HBsAg was detected by chemiluminescence enzyme immunoassay (CLEIA) with the clone containing T120 mutation, compared with the wild type or the clone with S143L mutation despite the similar levels of extracellular and intracellular HBsAg detected by Western blot. Southern blot experiments showed that the levels of intracellular HBV DNA were not different between these clones. CONCLUSION Occult HBV infection is common in patients with hematological malignancies and associated with P120T and S143L mutations. 120T mutation impairs the detection of HBsAg by CLEIA.
  • Molecular epidemiology of co-infection with hepatitis B virus and human immunodeficiency virus (HIV) among adult patients in Harare, Zimbabwe, Ian Baudi, Sayuki Iijima, Nyasha Chin'ombe, Sekesai Mtapuri-Zinyowera, Shuko Murakami, Masanori Isogawa, Atsuko Hachiya, Yasumasa Iwatani, Yasuhito Tanaka, Journal of Medical Virology, 89, (2) 257 - 266,   2017年02月01日, 査読有り, © 2016 Wiley Periodicals, Inc. The objective of this study was to determine the prevalence of co-infection with hepatitis B virus (HBV) and human immunodeficiency virus (HIV) and the genetic characteristics of both viruses among pre-HIV-treatment patients in Harare, Zimbabwe. This cross-sectional survey involved 176 remnant plasma samples collected from consenting HIV patients (median age 35 [18–74]) between June and September 2014. HBV seromarkers were determined by high-sensitivity chemiluminescence assays. Molecular evolutionary analyses were conducted on the basal core promoter/precore (BCP/PC) and S regions of HBV, as well as part of the HIV pol region. Of the 176 participants (65.7% female), 19 (10.8%) were positive for HBsAg (median 0.033 IU/ml (IQR 0.01–415). The HBsAg incidence was higher in men than women (P = 0.009). HBsAg-positive subjects had lower median CD4 counts (P = 0.016). HBV DNA was detectable in 12 HBsAg-positive samples (median 3.36 log cp/ml (2.86–4.51), seven being amplified and sequenced. All isolates were subgenotype A1 without HBV drug resistance mutations but each had at least one BCP/PC mutation. PreS deletion mutants and small S antigen variants M133I/T and D144G were identified. Of the 164 HIV isolates successfully genotyped, 163 (99.4%) were HIV-1 subtype C and only one was HIV-1 subtype F1. Sixteen (9.8%) had at least one drug resistance mutation, predominantly non-nucleoside reverse transcriptase inhibitor-related mutations, observed mostly among female participants. This study shows that co-infection with HBV is present among HIV patients enrolling into HIV care in Zimbabwe, suggesting that HBV screening and monitoring programmes be strengthened in this context. J. Med. Virol. 89:257–266, 2017. © 2016 Wiley Periodicals, Inc.
  • Hepatitis B virus X protein impairs α-interferon signaling via up-regulation of suppressor of cytokine signaling 3 and protein phosphatase 2A, Seiji Tsunematsu, Goki Suda, Kazushi Yamasaki, Megumi Kimura, Takaaki Izumi, Machiko Umemura, Jun Ito, Fumiyuki Sato, Masato Nakai, Takuya Sho, Kenichi Morikawa, Koji Ogawa, Yasuhito Tanaka, Koichi Watashi, Takaji Wakita, Naoya Sakamoto, Journal of Medical Virology, 89, (2) 267 - 275,   2017年02月01日, 査読有り, © 2016 Wiley Periodicals, Inc. Hepatitis B Virus (HBV) causes liver cirrhosis and hepatocellular carcinoma. Standard therapy includes treatment with interferon (IFN); however, its efficacy is limited. HBV has been reported to impair IFN signaling; however, the mechanism is unclear. Here, the relationship between HBV X protein (HBx) and IFN signaling was investigated by establishing HepG2 cells, stably expressing HBx (HepG2/HBx) via retrovirus-mediated gene transfer. Subsequently, IFN negative-regulator expression and its mechanism were studied. HepG2/HBx cells showed reduced expression of IFN-stimulated genes and expressed higher levels of suppressor of cytokine signaling 3 (SOCS3) and protein phosphatase 2A (PP2A) suppressor compared with control cells. Knockdown of SOCS3 and PP2A restored IFN sensitivity. Moreover, HepG2/HBx cells showed higher phosphorylation levels of signal transducers and activators of transcription 3 and endoplasmic reticulum stress, which are inducers of SOCS3 and PP2A, respectively. Additionally, HBx-knockdown restored IFN sensitivity in HepG2.2.15.7 cells. It was also confirmed that SOCS3 and PP2A expression levels were up-regulated in the liver of patients with HBV infection. The results of this study demonstrated that HBx impairs IFN signaling via increased expression of SOCS3 and PP2A, a novel mechanistic insight, providing a potential therapeutic target to enhance the efficiency of IFN therapy. J. Med. Virol. 89:267–275, 2017. © 2016 Wiley Periodicals, Inc.
  • Quantifying antiviral activity optimizes drug combinations against hepatitis C virus infection., Koizumi Y, Ohashi H, Nakajima S, Tanaka Y, Wakita T, Perelson AS, Iwami S, Watashi K, Proceedings of the National Academy of Sciences of the United States of America, 114, (8) 1922 - 1927,   2017年02月, 査読有り
  • Successful treatment of three patients with human immunodeficiency virus and hepatitis C virus genotype 1b co-infection by daclatasvir plus asunaprevir, Noboru Hirashima, Hiroaki Iwase, Masaaki Shimada, Nobumitsu Ryuge, Junji Imamura, Hiroki Ikeda, Yasuhito Tanaka, Nobuyuki Matsumoto, Chiaki Okuse, Fumio Itoh, Yoshiyuki Yokomaku, Tsunamasa Watanabe, Clinical Journal of Gastroenterology, 10, (1) 41 - 46,   2017年02月, 査読有り, © 2016, Japanese Society of Gastroenterology. Co-infection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) often accelerates the course of HCV-associated liver disease. Daclatasvir (DCV) plus asunaprevir (ASV) have been shown to be highly effective for HCV-infected patients with genotype 1b. Three patients co-infected with HIV/HCV genotype 1b were enrolled in this study. Prior to initiation of HCV treatment, the variants associated with L31 and Y93 in the non-structural protein 5A (NS5A) region of the HCV genome were confirmed to be absent using a direct sequencing method. Taking into consideration the lower risk of drug–drug interaction and the need for immediate treatment, the patients received 60 mg DCV once daily plus 100 mg ASV twice daily for 24 weeks. In one patient, the alanine aminotransferase level was elevated to 228 IU/L at 24 weeks after the start of treatment, but he completed the 24-week treatment course. All three patients achieved sustained viral response, without severe complications (including HIV virological rebound). Thus, in cases where NS5A variants are confirmed to be absent and patients are antiretroviral therapy-naïve, with CD4+ over 500/μL or HIV well controlled by RAL-based cART, DCV plus ASV may represent a good treatment option for HIV and HCV genotype 1b co-infected patients.
  • Efficacy of daclatasvir/asunaprevir according to resistance-associated variants in chronic hepatitis C with genotype 1, Etsuko Iio, Noritomo Shimada, Hiroshi Abe, Masanori Atsukawa, Kai Yoshizawa, Koichi Takaguchi, Yuichiro Eguchi, Hideyuki Nomura, Tomoyuki Kuramitsu, Jong Hon Kang, Takeshi Matsui, Noboru Hirashima, Akihito Tsubota, Atsunori Kusakabe, Izumi Hasegawa, Tomokatsu Miyaki, Noboru Shinkai, Kei Fujiwara, Shunsuke Nojiri, Yasuhito Tanaka, Journal of Gastroenterology, 52, (1) 94 - 103,   2017年01月01日, 査読有り, © 2016, Japanese Society of Gastroenterology. Background: The present study explored the treatment outcome of daclatasvir (DCV) and asunaprevir (ASV) therapy combining oral direct-acting antiviral agents (DAAs) for chronic hepatitis C (HCV) including liver cirrhosis according to resistance-associated variants (RAVs) in NS3/NS5A region. Methods: Overall, 641 patients enrolled in Japan with HCV-1b received DCV and ASV for 24 weeks. Baseline drug-resistant mutations L31F/I/M/V, Q54H, P58S, A92K, and Y93H in the HCV NS5A region and V36A, T54A/S, Q80K/L/R, R155K/T/Q, A156S/V/T, and D168A/E/H/T/V in the HCV NS3/4A region were assessed by direct sequencing. Results: Overall, 86.9 % (543/625) of patients had SVR12, which was significantly higher in NS5A 93Y (wild) (88.3 %) compared with NS5A 93H at baseline (48.0 %), indicating the SVR12 rate was significantly lower in patients with 93H mutations. Additionally, 66.7 % (18/27) of patients with prior triple therapy including simeprevir (SMV) failure had virological failure. The virological failure rate of DCV/ASV therapy after SMV failure was significantly higher in those with preexisting NS3/4A 168 substitutions compared with without substitutions at baseline [84.2 % (16/19) vs. 28.6 % (2/7), p = 0.014]. The number of patients with multiple RAVs or deletions in NS5A increased from 0 to 85 % in failed patients. Alanine aminotransferase elevation was a frequent adverse event causing discontinuation of DCV/ASV therapy, although 87.5 % (14/16) patients achieved SVR12, subsequently. Conclusions: History of SMV therapy and pre-existing NS5A Y93H were associated with virological failure of DCV/ASV therapy, resulting in the emergence of multiple RAVs. Patients with RAVs at baseline should be assessed to optimize future DAA therapies.
  • Recommendation of medical consultation and/ or treatment by pharmacists to patients with chronic hepatitis C who visited health insurance pharmacies, Takako Inoue, Shigeyuki Urano, Iwao Inoue, Masaaki Korenaga, Yasuhito Tanaka, Acta Hepatologica Japonica, 58, 639 - 642,   2017年01月, 査読有り, © 2017 The Japan Society of Hepatology. Pharmacists belonging to the local pharmaceutical society advised patients with chronic hepatitis C (CHC) who visited their health insurance pharmacies. From March to June 2017 a leaflet was used to recommend medical consultation and/or treatment to the patients. After this period a questionnaire was sent to each pharmacy and replies were received from 73 of 156 pharmacies (46.8%) with 71 informative responses. A total of 32 copies of the leaflet was used for advice at 12 pharmacies and 16 patients (50%) received medical consultation and/or treatment in specialized institutions. These results indicate that pharmacists are respected as experts by patients and local inhabitants and advice from the pharmacists regarding CHC is effective.
  • Recent advances in hepatitis B research and drug development, Susumu Tsutsumi, Noboru Shinkai, Yasuhito Tanaka, Acta Hepatologica Japonica, 58, 217 - 227,   2017年01月, 査読有り
  • Clinical significance of two real-time PCR assays for chronic hepatitis C patients receiving protease inhibitor-based therapy, Takako Inoue, Su Su Hmwe, Noritomo Shimada, Noritomo Shimada, Keizo Kato, Tatsuya Ide, Takuji Torimura, Takashi Kumada, Hidenori Toyoda, Akihito Tsubota, Koichi Takaguchi, Takaji Wakita, Yasuhito Tanaka, PLoS ONE, 12, (1) ,   2017年01月, 査読有り, © 2017 Inoue et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The aim of this study was to determine the efficacy of two hepatitis C virus (HCV) real-time PCR assays, the COBAS AmpliPrep/COBAS TaqMan HCV test (CAP/CTM) and the Abbott RealTime HCV test (ART), for predicting the clinical outcomes of patients infected with HCV who received telaprevir (TVR)-based triple therapy or daclatasvir/asunaprevir (DCV/ASV) dual therapy. The rapid virological response rates in patients receiving TVR-based triple therapy were 92% (23/25) and 40% (10/25) for CAP/CTM and ART, respectively. The false omission rate (FOR) of ART was 93.3% (14/15), indicating that CAP/CTM could accurately predict clinical outcome in the early phase. In an independent examination of 20 patients receiving TVR-based triple therapy who developed viral breakthrough or relapse, the times to HCV disappearance by ART were longer than by CAP/CTM, whereas the times to HCV reappearance were similar. In an independent experiment of WHO standard HCV RNA serially diluted in serum containing TVR, the analytical sensitivities of CAP/CTM and ART were similar. However, cell cultures transfected with HCV and grown in medium containing TVR demonstrated that ART detected HCV RNA for a longer time than CAP/CTM. Similar results were found for 42 patients receiving DCV/ASV dual therapy. The FOR of ART was 73.3% (11/15) at week 8 after initiation of therapy, indicating that ART at week 8 could not accurately predict the clinical outcome. In conclusion, although CAP/CTM and ART detected HCV RNA with comparable analytical sensitivity, CAP/CTM might be preferable for predicting the clinical outcomes of patients receiving protease inhibitor-based therapy.
  • Physician perspectives on the management of viral hepatitis and hepatocellular carcinoma in Myanmar., Kim YA, Trinh S, Thura S, Kyi KP, Lee T, Sze S, Richards A, Aronsohn A, Wong GLH, Tanaka Y, Dusheiko G, Nguyen MH, PloS one, 12, (8) ,   2017年, 査読有り
  • Hepatocellular carcinoma in children and young patients with chronic HBV infection and the usefulness of alpha-fetoprotein assessment, Hitoshi Tajiri, Tomoko Takano, Hideo Tanaka, Kosuke Ushijima, Ayano Inui, Yoko Miyoshi, Keiichi Ozono, Daiki Abukawa, Takeshi Endo, Stephen Brooks, Yasuhito Tanaka, Cancer Medicine, 5, (11) 3102 - 3110,   2016年11月01日, 査読有り, © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd. The aims of the study were to elucidate the clinical characteristics of patients who developed hepatocellular carcinoma (HCC) related to persistent HBV infection since childhood and to investigate usefulness of assessing alpha-fetoprotein (AFP) in this population. A nationwide multicenter survey of children with chronic HBV infection was performed. Among 548 patients, 15 patients developed HCC at the median age of 15 years (range 9–36), including 13 males and 2 females. A case–control comparison showed that HBeAg seroconversion and liver cirrhosis were associated with the occurrence of HCC. Of the 15 HCC patients, 5 were treated with interferon and none of them responded to interferon therapy as compared with 12 of the 17 responders in the control group. Of the 15 patients, 10 died and 9 of the 10 who died never visited any medical facilities until diagnosis of HCC, while the remaining 5 surviving patients never stopped their clinic visits. The usefulness of AFP assessment was shown by the findings that AFP levels were elevated in all HCC cases, that elevations in AFP levels were detected prior to the diagnosis in the surviving patients, and that sensitivity of AFP as a diagnostic test for HCC was very high among 40 patients including our 14 and an additional 26 collected from the literature. HBeAg seroconversion and liver cirrhosis are associated with the occurrence of HCC. Regular measurement of AFP might be helpful to watch for the occurrence of HCC when following children and young patients with chronic HBV infection since childhood.
  • Efficacy and safety of sofosbuvir plus ribavirin treatment for patients with chronic Hepatitis C genotype 2, Kayo Sugimoto, Soo Ki Kim, Soo Ryang Kim, Mana Kobayashi, Airi Kato, Eri Morimoto, Susumu Imoto, Chi Wan Kim, Yasuhito Tanaka, Masatoshi Kudo, Yoshihiko Yano, Yoshitake Hayashi, Digestive Diseases, 34, 627 - 631,   2016年10月, © 2016 S. Karger AG, Basel. Objectives: The efficacy of sofosbuvir plus ribavirin (RBV) treatment for hepatitis C virus (HCV) genotype 2 focusing on virological response was compared with that of pegylated interferon (peg-IFN) plus RBV treatment. Safety of the former focusing on the decline in hemoglobin levels was compared with that of the latter and assessed in terms of age and inosine triphosphatase (ITPA). Methods: Patients (n = 17) receiving sofosbuvir plus RBV and those (n = 24) receiving peg-IFN plus RBV diagnosed with chronic HCV genotype 2 were enrolled in this study, and the efficacy and safety of both treatments were assessed. Results: Rapid virological response was attained with sofosbuvir plus RBV treatment compared with peg-IFN plus RBV treatment. All patients under sofosbuvir plus RBV treatment achieved end-of-treatment response compared with 70% who sustained viral response under the peg-IFN plus RBV treatment, with the former demonstrating greater virological response. The decline in hemoglobin levels under the former treatment was greater than that under the latter and in patients over 65 years of age with ITPA gene major. Conclusion: Efficacy and safety of sofosbuvir plus RBV treatment were clearly demonstrated compared with those of peg-IFN plus RBV treatment. The decline in hemoglobin levels was not related to the discontinuation of the former treatment, irrespective of age or the effect of the ITPA gene.
  • Genome-wide association study identifies ZNF354C variants associated with depression from interferon-based therapy for chronic hepatitis C, Kayoko Matsunami, Nao Nishida, Naoko Kaneko, Kazuho Ikeo, Licht Toyo-Oka, Hiroshi Takeuchi, Kentaro Matsuura, Akihiro Tamori, Hideyuki Nomura, Hitoshi Yoshiji, Masatoshi Imamura, Naohiko Masaki, Tatsuro Hayakawa, Tatsuya Ide, Noritomo Shimada, Fusao Ikeda, Keisuke Hino, Shuhei Nishiguchi, Chiaki Okuse, Shunsuke Nojiri, Kazunobu Sawamoto, Katsushi Tokunaga, Takashi Joh, Yasuhito Tanaka, PLoS ONE, 11, (10) ,   2016年10月, 査読有り, © 2016 Matsunami et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The therapeutic use of interferon (IFN) is known to cause depression that frequently interrupts treatment. To identify genetic variants associated with IFN-induced depression, we conducted a genome-wide association study (GWAS) of 224 Japanese chronic hepatitis C patients receiving IFN-based therapy in a multicenter prospective study and stratified them into two groups according to the Beck Depression Inventory, Second Edition (BDI-II) score. In the GWAS stage, we selected 42 candidate single nucleotide polymorphisms (SNPs) to perform replication analysis in an independent set of 160 subjects. The SNP rs1863918 in strong linkage disequilibrium with SNPs located around the Zinc finger 354C (ZNF354C) gene on chromosome 5 showed a significant association when the results of GWAS and replication were combined (odds ratio = 2.55, P = 7.89×10-8in the allele frequency model), suggesting that the rs1863918 T allele was associated with IFN-induced depression. Furthermore, logistic regression analysis showed that rs1863918 T allele, a history of depression, and younger age were independent predictive factors for IFN-induced depression. Interestingly, western blotting and immunofluorescence showed that ZNF354C was highly expressed in the hippocampus in mice, a region implicated in the pathology of psychiatric symptoms. In conclusion, we identified rs1863918 as significantly associated with IFN-induced depression, and revealed that the candidate gene ZNF354C is highly expressed in the hippocampus of mice. Our data might be useful for elucidating the pathogenic mechanisms of depression induced by drugs including IFN.
  • Smoking is a risk factor for development of adult T-cell leukemia/lymphoma in Japanese human T-cell leukemia virus type-1 carriers, Hisayoshi Kondo, Midori Soda, Norie Sawada, Manami Inoue, Manami Inoue, Yoshitaka Imaizumi, Yasushi Miyazaki, Masako Iwanaga, Yasuhito Tanaka, Masashi Mizokami, Shoichiro Tsugane, Cancer Causes and Control, 27, (9) 1059 - 1066,   2016年09月01日, 査読有り, © 2016, Springer International Publishing Switzerland. Background and purpose: Adult T-cell leukemia/lymphoma (ATLL) is an aggressive hematological malignancy caused by human T-cell leukemia virus type-1 (HTLV-1); no effective methods have yet been identified to prevent development of ATLL in carriers of HTLV-1. This study investigated the association between cigarette smoking and the risk of ATLL development among Japanese carriers of HTLV-1. Methods: This study examined the association between smoking and development of ATLL in a cohort of 1,332 Japanese HTLV-1 carriers aged 40–69 years free of ATLL at baseline from two different HTLV-1-endemic areas of Japan. Cox proportional hazards models adjusted for sex, geographic area, age at baseline, and alcohol drinking were used to estimate the effect of cigarette smoking on ATLL development. Results: Between 1993 and 2012, 25 new ATLL cases were identified among these subjects. The overall crude incidence rate for ATLL was 1.08 per 1,000 person-years among HTLV-1 carriers and was higher among male carriers than among female carriers (2.21 vs. 0.74). The risk of ATLL development increased significantly with increasing numbers of cigarettes smoked per day (hazard ratio for every increment of 20 cigarettes, 2.03; 95 % confidence interval (CI) 1.13–3.66 overall, 2.07 (95 % CI 1.13–3.73) in male carriers). Conclusions: Cigarette smoking may influence ATLL development among HTLV-1 carriers in Japan.
  • Inhibitory effect of CDK9 inhibitor FIT-039 on hepatitis B virus propagation, Tomohisa Tanaka, Kaori Okuyama-Dobashi, Shuko Murakami, Wenjia Chen, Toru Okamoto, Keiji Ueda, Takamitsu Hosoya, Yoshiharu Matsuura, Akihide Ryo, Yasuhito Tanaka, Masatoshi Hagiwara, Kohji Moriishi, Antiviral Research, 133, 156 - 164,   2016年09月01日, 査読有り, © 2016 Elsevier B.V. Current therapies for hepatitis B virus (HBV) cannot completely eliminate the HBV genome because of the stable population of covalently closed circular DNA (cccDNA) and so on. FIT-039, which is a cyclin-dependent kinase (CDK) 9 inhibitor, is known to suppress the replication of several DNA viruses including HSV, HPV and human adenovirus. In this study, we investigated the antiviral effect of FIT-039 on HBV infection. HepG2 cells expressing human sodium taurocholate cotransporting polypeptide (HepG2/NTCP cells) were infected with HBV in the presence of FIT-039. FIT-039 dose-dependently reduced intracellular viral RNA, nucleocapsid-associated viral DNA, and supernatant viral antigens without cytotoxicity in the infected cells (IC50= 0.33 μM, CC50> 50 μM). The antiviral activity of FIT-039 was prominent at an early phase of viral infection, although the compound did not inhibit preS1-binding to HepG2/NTCP cells. FIT-039 reduced cccDNA in HBV-replicating or HBV-infected cells. Furthermore, the antiviral activity of entecavir was significantly enhanced by the combination with FIT-039 in the chimeric mice having human hepatocytes infected with HBV. None of the mice had significant drug-related body weight or serum human-albumin concentration changes. These data suggest that CDK9 inhibitor FIT-039 is a promising antiviral candidate for HBV infection.
  • The value of serum Wisteria floribunda agglutinin-positive human Mac-2-binding protein as a predictive marker for hepatitis C virus-related complications after systemic chemotherapy, Haruhito Totani, Shigeru Kusumoto, Yasuhito Tanaka, Nana Suzuki, Shinya Hagiwara, Shiori Kinoshita, Etsuko Iio, Asahi Ito, Masaki Ri, Takashi Ishida, Hirokazu Komatsu, Shinsuke Iida, International Journal of Hematology, 104, (3) 384 - 391,   2016年09月01日, 査読有り, © 2016, The Japanese Society of Hematology. Wisteria floribunda agglutinin-positive human Mac-2-binding protein (WFA+-M2BP) was developed recently as a predictive marker of progression to liver fibrosis and hepatocellular carcinoma (HCC) in patients seropositive for hepatitis C virus (HCV). We retrospectively analyzed 16 HCV-seropositive patients who received systemic chemotherapy for hematologic malignancies to evaluate the usefulness of WFA+-M2BP for predicting HCV-related complications. These were defined as the onset of significant liver damage (LD) with increased HCV RNA levels, leading to interrupted or discontinued chemotherapy or the occurrence of HCC after chemotherapy. Baseline WFA+-M2BP levels were determined using preserved serum samples. The median level of WFA+-M2BP was 1.59 [cutoff index (C.O.I.) value range 0.38–6.66]. With a median follow-up of 623 days (range 120–2404), LD and HCC were observed in three and two patients, respectively. Detectable HCV RNA and WFA+-M2BP ≥2.0 C.O.I. at baseline were identified as risk factors for these HCV-related complications (P = 0.034 and P = 0.005, respectively). The sensitivity, specificity, and positive and negative predictive values of the WFA+-M2BP level (cutoff point: 2.0 C.O.I.) for the occurrence of HCV-related complications were 100.0, 81.8, 71.4, and 100.0 %, respectively. WFA+-M2BP may be a useful marker for the prediction of HCV-related complications in HCV-seropositive patients following systemic chemotherapy.
  • Hepatitis B virus and its sexually transmitted infection - an update., Inoue T, Tanaka Y, Microbial cell (Graz, Austria), 3, (9) 420 - 437,   2016年09月, 査読有り
  • Serum levels of Mac-2 binding protein increase with cardiovascular risk and reflect silent atherosclerosis, Tomonori Sugiura, Yasuaki Dohi, Hiroyuki Takase, Sumiyo Yamashita, Shunsuke Murai, Yuji Tsuzuki, Shintaro Ogawa, Yasuhito Tanaka, Nobuyuki Ohte, Atherosclerosis, 251, 192 - 196,   2016年08月01日, 査読有り, © 2016 Elsevier Ireland Ltd Background and aims Mac-2 binding protein (M2BP) was reported to be a useful biomarker for liver fibrosis and malignant tumors. We hypothesized that expression of M2BP might also change in the process of atherosclerosis. Methods This study included subjects who visited our hospital for a physical checkup. Results The M2BP levels in subjects with hypertension, dyslipidemia, or abnormal glucose metabolism were higher than those in subjects without such risk factors. Moreover, the M2BP levels were associated with severity of cardiovascular risk. Subdivision of M2BP levels into quartiles revealed that M2BP was significantly associated with reactive oxygen metabolites, central systolic blood pressure, and radial augmentation index (AI). Logistic regression analysis with the endpoint of high radial AI (above mean value) showed that high radial AI was independently associated with high M2BP. Conclusions Although the spectrum was narrow as compared to that in cases of hepatic fibrosis, serum M2BP may reflect silent atherosclerosis in apparently healthy subjects.
  • Safety and efficacy of dual direct-acting antiviral therapy (daclatasvir and asunaprevir) for chronic hepatitis C virus genotype 1 infection in patients on hemodialysis, Hidenori Toyoda, Takashi Kumada, Toshifumi Tada, Koichi Takaguchi, Toru Ishikawa, Kunihiko Tsuji, Mikio Zeniya, Etsuko Iio, Etsuko Iio, Yasuhito Tanaka, Journal of Gastroenterology, 51, (7) 741 - 747,   2016年07月01日, 査読有り, © 2016, Japanese Society of Gastroenterology. Background: Hepatitis C virus (HCV) infection is a major comorbidity in patients receiving hemodialysis. Interferon-based antiviral therapy to eradicate HCV is less effective in patients receiving hemodialysis than patients without renal dysfunction. Recently reported combination therapy with two oral direct-acting antiviral drugs, daclatasvir and asunaprevir, both of which are metabolized in the liver and excreted into the bile ducts, reportedly showed a high rate of HCV eradication. We evaluated the safety and efficacy of this therapy in patients receiving hemodialysis. Methods: The safety and viral responses were compared among patients infected with HCV genotype 1, between 28 patients receiving hemodialysis, and propensity score-matched 56 patients without renal dysfunction. Results: The reduction in serum HCV RNA levels 1 day after the start of therapy was significantly larger (p = 0.0329) and the disappearance of serum HCV RNA occurred significantly earlier (p = 0.0017) in patients receiving hemodialysis than those without renal dysfunction. The rates of sustained virologic response, i.e., the eradication of HCV, were comparable between two groups; the rate of SVR12 was 100 % in patients receiving hemodialysis and 94.6 % in patients without renal dysfunction. No adverse constitutional events were observed in either of the groups. The elevation of serum alanine aminotransferase levels, a known adverse effect of these drugs, was observed in comparable rate of patients between the two groups. Conclusions: The therapy with daclatasvir and asunaprevir has high antiviral efficacy in patients receiving hemodialysis with a comparable safety profile to patients without renal dysfunction.
  • Peginterferon therapy in children with chronic Hepatitis C: A nationwide, multicenter study in Japan, 2004-2013, Mitsuyoshi Suzuki, Hitoshi Tajiri, Yasuhito Tanaka, Tomoko Takano, Yoko Miyoshi, Jun Murakami, Toshiaki Shimizu, Stephen Brooks, Journal of Pediatric Gastroenterology and Nutrition, 63, (1) 88 - 93,   2016年07月01日, 査読有り, © 2016 by ESPGHAN and NASPGHAN. Objectives: The aim of the present study was to review the medical treatment of Japanese children and adolescents with chronic hepatitis C in the past 10 years. Methods: This nationwide, multicenter study evaluated patients who were younger than 18 years of age when diagnosed with chronic hepatitis C virus (HCV) infection and were treated with pegylated interferon (PEG-IFN) monotherapy or PEG-IFN/ribavirin (RBV) combination therapy between 2004 and 2013. The subjects' median age was 10 (3-18) years, with a male to female ratio of 52:50 and a genotype-1 to genotype-2 ratio of 45:57. Among the 102 patients, 18 received PEG-IFN monotherapy and 84 received PEG-IFN/RBV combination therapy. The IL28B genotype polymorphism was analyzed in patients infected with genotype-1. Results: In patients with HCV genotype-1 infections, sustained virological response (SVR) rates obtained by PEG-IFN monotherapy and by PEG-IFN/RBV combination therapy were 100% (2/2) and 72% (31/43), respectively. In patients with HCV genotype-2 infections, SVRs were 75% (12/16) and 100% (41/41), respectively. In 32 genotype-1 patients available for the IL28B genotype (rs8099917), SVR was achieved in more patients in the IL28B major allele group than in the minor allele group (15/17 vs 7/15, P=0.021) after PEG-IFN/RBV combination therapy. The frequencies of adverse events were similar between the treatment regimens. Conclusions: Overall, both therapies showed encouraging results, and were reasonably safe in children and adolescents with chronic hepatitis C. The IL28B genotype was useful for predicting the treatment response to PEG-IFN/RBV combination therapy in this cohort.
  • Novel 4'-modified nucleoside analogs exert antiviral replication against hepatitis B virus with drug resistance mutations, Sanae Hayashi, Shuko Murakami, Katsumi Omagari, Takeshi Matsui, Masanori Isogawa, Tsunamasa Watanabe, Yasuhito Tanaka, Yuki Takamatsu, Kenji Maeda, Hiroaki Mitsuya, Kenji Maeda, Satoru Kohgo, Hiroaki Mitsuya, Takeshi Matsui, Yoshiyasu Karino, Satoru Kohgo, Hiroaki Mitsuya, Acta Hepatologica Japonica, 57, 299 - 301,   2016年07月, 査読有り, © 2016 The Japan Society of Hepatology. Novel nucleoside analogues (NAs), 4'-C-cyano-2-amino-2'-deoxyadenosine (CAdA) and 4'-C-cyano-2'-deoxyguanosine (CdG) in lesser concentration strongly suppressed HIV-1 as well as viral replication of HBV clones with Adefovir resistance mutation (rtA181T/N236T) (ADVr) or Entecavir resistance mutations (ETVr1: rtL180M/M204V/S202G, ETVr2: rtL180M/M204V/I163V/A186T) in vitro. Moreover, we inoculated HBV wild or mutant strain (ETVr1) to chimeric mice with human hepatocytes, and administered CAdA and CdG. The in vivo experiments showed that CAdA/CdG significantly had greater levels of HBV reduction during 3 and 14 days in the wild group, compared with ETV. CAdA/CdG also elicited significantly greater levels of HBV reduction by day 7 in ETVr1 group. In conclusion, CAdA and CdG exert potent anti-HBV activity against both ETVr and ADVr, indicating new therapeutic option.
  • Erratum to: Safety and efficacy of dual direct-acting antiviral therapy (daclatasvir and asunaprevir) for chronic hepatitis C virus genotype 1 infection in patients on hemodialysis., Toyoda H, Kumada T, Tada T, Takaguchi K, Ishikawa T, Tsuji K, Zeniya M, Iio E, Tanaka Y, Journal of gastroenterology, 51, (7) ,   2016年07月, 査読有り
  • Virological characteristics of hepatitis B genotype G/A2 recombination virus in Japan, Yuji Tsuzuki, sunamasa Watanabe, Etsuko Iio, Seiichiro Fujisaki, Shiro Ibe, Satomi Kani, Susumu Hamada-Tsutsumi, Yoshiyuki Yokomaku, Yasumasa Iwatani, Wataru Sugiura, Chiaki Okuse, Akihiko Okumura, Yoshihisa Sato, Yasuhito Tanaka, Hepatology Research, 46, (8) 775 - 783,   2016年07月, 査読有り, © 2015 The Japan Society of Hepatology Aim: We identified four cases of infection with hepatitis B virus genotype G and A2 recombinant (HBV/G/A2) strains, which were initially overlooked by enzyme immunoassay-based genotyping. The patients were all men who have sex with men (MSM) and inhabited several metropolitan areas of Japan, suggesting that the recombinant strains may be circulating among high-risk groups such as MSM. Here, we investigated the genomic structure and virological properties of the HBV/G/A2 strains. Methods: Complete genome sequences of the isolates were determined and phylogenetically analyzed. Replication efficiency of HBV/G/A2 was investigated by transfecting plasmids containing 1.24-fold viral genome. The in vivo viral kinetics of HBV/G/A2 were investigated using chimeric mice with humanized livers. Results: Phylogenetic analysis revealed that the four strains were almost identical (>99.7% homologous). The preS2/S region of these strains was highly homologous to that of genotype A2 and the remaining region was almost identical to that of genotype G, reflecting inter-genotypic recombination. Interestingly, in all four cases, genotype A was co-infected as a minor population. In vitro analysis revealed that HBV/G/A2 had a low replication rate. Although detectable viremia was not measurable following the inoculation of HBV/G/A2 into chimeric mice, subsequent superinfection of HBV genotype A greatly enhanced HBV/G/A2 replication and viral spread. Conclusion: We found that four cases of HBV/G/A2 recombinant among MSM patients in the metropolitan areas of Japan, and HBV/A co-infections are required for its efficient replication. High-risk groups such as MSM should be carefully tested for infection of genotype G-derived variants.
  • Serum hepatitis B core-related antigen as a treatment predictor of pegylated interferon in patients with HBeAg-positive chronic hepatitis B, Natthaya Chuaypen, Nawarat Posuwan, Sunchai Payungporn, Yasuhito Tanaka, Noboru Shinkai, Yong Poovorawan, Pisit Tangkijvanich, Liver International, 36, (6) 827 - 836,   2016年06月01日, 査読有り, © 2016 John Wiley & Sons A/S. Background & Aims: The role of quantitative serum hepatitis B core-related antigen (HBcrAg) in patients with chronic hepatitis B (CHB) receiving pegylated interferon (PEG-IFN) is unclear. This study was aimed at comparing its usefulness with quantitative HBsAg in patients with HBeAg-positive CHB receiving PEG-IFN therapy. Methods: A total 46 patients treated with PEG-IFN for 48 weeks were retrospectively analysed. Intrahepatic covalently closed circular DNA (cccDNA) from paired liver biopsies and serial serum HBsAg and HBcrAg during therapy were assessed. Results: Virological response (VR), defined as HBeAg clearance and HBV DNA <2000 IU/ml at 24 weeks post treatment, was achieved in 15 (32.6%) patients. Responders had significantly higher cccDNA decline from baseline compared with non-responders. Baseline HBsAg and HBcrAg were correlated with cccDNA (r = 0.424, P = 0.020 and r = 0.564, P = 0.001, respectively), and changes in the corresponding markers during therapy were correlated with cccDNA reduction (r = 0.579, P = 0.001 and r = 0.503, P = 0.005, respectively). Responders showed more rapid decline of both markers during therapy compared with non-responders. In multivariate analysis, serum HBcrAg at week 12 was identified as a predictor of VR. The optimal cut-off value for HBcrAg (log108.0 U/ml) provided negative predictive value (NPV) of achieving VR at weeks 12 and 24 of 94.4 and 100%, respectively, while using HBsAg > 20 000 IU/ml provided NPV of 80 and 100% respectively. Conclusions: The convenient quantitative HBcrAg represented a reliable marker of intrahepatic cccDNA. Monitoring HBcrAg levels during PEG-IFN therapy may help identify patients with a very low probability of response comparable to, if not better than, quantitative HBsAg.
  • Longitudinal profiles of highly sensitive hepatitis B surface antigen levels: Re-evaluation of HBsAg seroclearance, Wai Kay Seto, Yasuhito Tanaka, Danny K.H. Wong, Noboru Shinkai, Ka Shing Cheung, Kevin S.H. Liu, James Fung, Ching Lung Lai, Man Fung Yuen, Liver International, 36, (5) 642 - 650,   2016年05月, 査読有り, © 2016 John Wiley & Sons A/S. Background & Aims: Serologic profiles after hepatitis B surface antigen (HBsAg) seroclearance in chronic hepatitis B (CHB) have not been well-studied. Methods: We employed a highly sensitive HBsAg (hs-HBsAg) assay (lower detection limit 0.5 mIU/ml), 100 times more sensitive than conventional HBsAg measurements. CHB patients achieving HBsAg seroclearance defined by conventional assays were followed up for serum hs-HBsAg, HBV DNA and antibody to HBsAg (anti-HBs) levels at 0 months, 6-12 months and 3-5 years after HBsAg seroclearance. Factors associated with hs-HBsAg detectability were determined. Results: One hundred and nine patients were recruited; 94 (86.2%) were followed up to years 3-5; and 25 patients (22.9%) were on nucleoside analogue therapy for a median duration of 6.0 (range 1.5-12.7) years before HBsAg seroclearance. Detectable hs-HBsAg was noted in 88 (80.7%), 60 (55.0%) and 20 (21.3%) patients at 0 months, 6-12 months and 3-5 years respectively. At years 3-5, genotype B patients, when compared to genotype C patients, had a higher anti-HBs positive rate (63.2% and 41.1% respectively, P = 0.036). Serum anti-HBs positivity, when compared to persistent anti-HBs negativity, was associated with a lower rate of hs-HBsAg detection (7.4% and 40% respectively, P < 0.001). Multivariate analysis showed anti-HBs negativity at years 3-5 to be independently associated with persistently positive hs-HBsAg (P = 0.007, odds ratio 7.1, 95% confidence interval 1.7-29.3). Conclusion: Serum hs-HBsAg could detect HBsAg presence in a substantial proportion of CHB after HBsAg seroclearance defined by conventional assays, especially among anti-HBs negative individuals. Serum hs-HBsAg could potentially assist differentiating HBsAg-negative CHB from individuals with only past HBV exposure without carrier state.
  • Novel pH-sensitive multifunctional envelope-type nanodevice for siRNA-based treatments for chronic HBV infection, Naoki Yamamoto, Yusuke Sato, Tsubasa Munakata, Masakazu Kakuni, Chise Tateno, Takahiro Sanada, Yuichi Hirata, Shuko Murakami, Yasuhito Tanaka, Kazuaki Chayama, Hiroto Hatakeyama, Mamoru Hyodo, Hideyoshi Harashima, Michinori Kohara, Journal of Hepatology, 64, (3) 547 - 555,   2016年03月01日, 査読有り, © 2015 European Association for the Study of the Liver. Background & Aims Antiviral agents including entecavir (ETV) suppress the replication of the hepatitis B virus (HBV) genome in human hepatocytes, but they do not reduce the abundance of viral proteins. The present study focused on effectively reducing viral protein levels. Methods We designed siRNAs (HBV-siRNA) that target consensus sequences in HBV genomes. To prevent the emergence of escaped mutant virus, we mixed three HBV-siRNAs (HBV-siRNAmix); the mixture was encapsulated in a novel pH-sensitive multifunctional envelope-type nanodevice (MEND), a hepatocyte-specific drug delivery system. Coagulation factor 7 siRNA was used to assess delivery and knockdown efficiencies of MEND/siRNA treatments in mice. The potency of MEND/HBV-siRNAmix was evaluated in primary human hepatocytes and in chimeric mice with humanized liver persistently infected with HBV. Results Effective knockdown of targets, efficient delivery of siRNA, and liver-specific delivery were each observed with MEND. MEND/HBV-siRNA caused efficient reduction of HBsAg and HBeAg in vitro and in vivo. However, ETV treatment did not efficiently reduce HBsAg or HBeAg when compared with a single MEND/HBV-siRNAmix treatment. Furthermore, the suppressive effects of a single dose of MEND/HBV-siRNAmix persisted for 14 days in vitro and in vivo. Conclusion We demonstrated that MEND/HBV-siRNA controlled HBV more efficiently than did ETV. Furthermore, the effect of a single dose of MEND/HBV-siRNA persisted for a long time. These results indicated that MEND/HBV-siRNA may be a promising novel HBV treatment that is more effective than reverse transcriptase inhibitors.
  • A novel drug-resistant HIV-1 circulating recombinant form CRF76-01B identified by near full-length genome analysis, Satoko Ogawa, Atsuko Hachiya, Masumi Hosaka, Masakazu Matsuda, Hirotaka Ode, Urara Shigemi, Reiko Okazaki, Kenji Sadamasu, Mami Nagashima, Takao Toyokawa, Masao Tateyama, Yasuhito Tanaka, Wataru Sugiura, Yoshiyuki Yokomaku, Yasumasa Iwatani, AIDS Research and Human Retroviruses, 32, 284 - 289,   2016年03月, © Mary Ann Liebert, Inc. 2016. HIV-1 CRF01-AE and subtype B (B) have dominated and their different circulating recombinant forms (CRFs) have emerged in East and Southeast Asian countries. Here, we report a novel drug-resistant HIV-1 CRF. Five independent recombinant specimens exhibiting discordant subtype results for the gag, pol, and env sequences were isolated. These recombinants had the CRF01-AE (gag p17)/B (pol PR-RT and IN)/CRF01-AE (env C2-V3) pattern similar to CRF69-01B. Sequence analysis of four near full-length HIV-1 genomes revealed a unique phylogenetic cluster distinct from previously reported CRFs. Of the four recombinants, three shared an identical mosaic structure including seven breakpoints in the gag, pol, vif, and env regions, designated CRF76-01B. The one remaining recombinant had additional recombination breakpoints in the vpu region and exhibited another unique recombinant form composed of CRF76-01B and B. These findings provide important insight into the transmission dynamics of HIV-1 in Asia that may be important for its effective prevention.
  • Host genetic variants influencing the clinical course of Hepatitis B virus infection, Kentaro Matsuura, Masanori Isogawa, Yasuhito Tanaka, Journal of Medical Virology, 88, (3) 371 - 379,   2016年03月, 査読有り, © 2016 Wiley Periodicals, Inc. The clinical course of hepatitis B virus (HBV) infection greatly differs in individuals. Various viral, host, and environmental factors influence the natural history of HBV infection. Recent genome-wide association studies identified several host genetic factors influencing the clinical course of HBV infection. Genetic variations in HLA class II loci were significantly associated with susceptibility to persistent HBV infection. Other polymorphisms in or near the genes EHMT2, TCF19, and HLA-C, located near HLA class II loci, and UBE2L3 were also associated with persistent HBV infection. Meanwhile, polymorphisms in KIF1B, GRIK1, and STAT4 were associated with HBV-related hepatocellular carcinoma (HCC). Interestingly, HLA class II genetic variations were strongly associated with not only persistent HBV infection, but also disease progression and HBV-related HCC in chronic hepatitis B. Understanding the various genetic factors associated with the clinical course of HBV infection is essential for personalized treatment and surveillance of disease progression and HCC.
  • Hepatitis B and C virus infection and risk of pancreatic cancer: A population-based cohort study (JPHC study cohort II), Sarah Krull Abe,Manami Inoue, Norie Sawada, Motoki Iwasaki, Taichi Shimazu, Taiki Yamaji, Shizuka Sasazuki, Eiko Saito, Yasuhito Tanaka, Masashi Mizokami, Shoichiro Tsugane, T. Hanaoka, J. Ogata, S. Baba, T. Mannami, A. Okaya, Y. Kokubo, K. Miyakawa, F. Saito, A. Koizumi, Y. Sano, I. Hashimoto, T. Ikuta, Y. Tanaba, H. Sato, Y. Roppongi, T. Takashi, H. Suzuki, Y. Miyaji, N. Suzuki, S. Nagasawa, Y. Furusugi, N. Nagai, Y. Ito, S. Komatsu, T. Minamizono, H. Sanada, Y. Hataya, F. Kobayashi, H. Uchino, Y. Shirai, T. Kondo, R. Sasaki, Y. Watanabe, Y. Miyagawa, Y. Kobayashi, M. Machida, K. Kobayashi, M. Tsukada, Y. Kishimoto, E. Takara, T. Fukuya, M. Kinjo, M. Irei, H. Sakiya, K. Imoto, H. Yazawa, T. Seo, A. Seiko, F. Ito, F. Shoji, R. Saito, A. Murata, K. Minato, K. Motegi, T. Fujieda, S. Yamato, K. Matsui, T. Abe, M. Katagiri, M. Suzuki, K. Matsui, M. Doi, A. Terao, Y. Ishikawa, T. Tagami, H. Sueta, H. Doi, M. Urata, N. Okamoto, F. Ide, H. Goto, R. Fujita, H. Sakiya, N. Onga, H. Takaesu, M. Uehara, T. Nakasone, M. Yamakawa, F. Horii, I. Asano, H. Yamaguchi, K. Aoki, S. Maruya, M. Ichii, M. Takano, Y. Tsubono, K. Suzuki, Cancer Epidemiology Biomarkers and Prevention, 25, (3) 555 - 557,   2016年03月, 査読有り, © 2015 AACR. Background: The aim of this study was to assess the association between hepatitis B virus (HBV) and hepatitis C virus (HCV) and the risk of pancreatic cancer among Japanese adults. Methods: A total of 20,360 subjects of the Japan Public Health Center (JPHC)-based prospective study cohort II with available data on HBV and HCV infection status from blood samples were followed up until the end of 2010 for an average of 16 years. Cox proportional hazards models were employed to calculate HRs and 95% confidence intervals (CI). Results: During 324,394 person-years, 116 newly diagnosed cases of pancreatic cancer were identified. Compared with individuals without a positive infection marker, the multivariate-adjusted HRs were 1.22 (95% CI, 0.81-1.84) for anti-HBc and 0.69 (95% CI, 0.28-1.69) for anti-HCV. There were no pancreatic cancer cases among HBsAg-positive participants. Conclusion: In the JPHC study, we did not observe a statistically significant association between hepatitis B or C and the risk of pancreatic cancer. Impact: Our results do not support an association between hepatitis B or C and the risk of pancreatic cancer. Cancer Epidemiol Biomarkers Prev; 25(3); 555-7.
  • A Novel Drug-Resistant HIV-1 Circulating Recombinant Form CRF76_01B Identified by Near Full-Length Genome Analysis., Ogawa S, Hachiya A, Hosaka M, Matsuda M, Ode H, Shigemi U, Okazaki R, Sadamasu K, Nagashima M, Toyokawa T, Tateyama M, Tanaka Y, Sugiura W, Yokomaku Y, Iwatani Y, AIDS research and human retroviruses, 32, (3) 284 - 289,   2016年03月, 査読有り
  • Latest Treatment of Viral Hepatitis--Overcoming Hepatitis C and Reactivation of Hepatitis B, Yasuhito Tanaka, Rinsho byori. The Japanese journal of clinical pathology, 64, 211 - 218,   2016年02月01日, Hepatitis B virus (HBV) and hepatitis C virus (HCV), discovered as causative viruses of post-transfusion hepatitis, become persistent infections, leading to chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). For HCV, recent IFN-free direct-acting antiviral (DAA) therapies have increased sustained virological response (SVR) rates and reduced adverse events. IFN-based therapies, still the standard of care in Asian countries, are influenced by IL28B genetic variants and the liver fibrosis stage, but the DAA combinations obscure the influence of these factors. These new therapies can eradicate HCV and prevent HCC development. On the other hand, it is difficult to eradicate HBV completely. Although HBV infection can be prevented by vaccination, reactivation of HBV following anti-cancer chemotherapy and immunosuppressive therapy is a well-known complication. HBV reactivation has been reported to be associated with anti-CD20 monoclonal antibody rituximab-containing chemotherapy and TNF-α inhibitor-containing immunosuppressive therapy in HBV-resolved patients. Our prospective observational study revealed that monthly monitoring of HBV DNA was useful for preventing HBV reactivation-related hepatitis among B-cell non-Hodgkin lymphoma patients with resolved HBV infection following rituximab-steroid-chemo, suggesting that preemptive therapy guided by serial HBV DNA monitoring should be recommended. Recently, highly sensitive HBsAg detection by Lumipulse HBsAg-HQ may be useful for several clinical applications. The sensitivity of this assay (5 mIU/mL) was approximately 10-fold higher than Abbott ARCHITECT, but still lower than HBV-DNA assays. The convenient HBsAg-HQ may be useful for detecting occult HBV infection and HBV reactivation in relatively low-risk groups except for those receiving rituximab-steroid-chemo. [
  • JSH Guidelines for the Management of Hepatitis C Virus Infection: A 2016 update for genotype 1 and 2, Yasuhiro Asahina, Namiki Izumi, Kumada Hiromitsu, Masayuki Kurosaki, Kazuhiko Koike, Fumitaka Suzuki, Hajime Takikawa, Atsushi Tanaka, Eiji Tanaka, Yasuhito Tanaka, Hirohito Tsubouchi, Norio Hayashi, Naoki Hiramatsu, Hiroshi Yotsuyanagi, Hepatology Research, 46, (2) 129 - 165,   2016年02月01日, 査読有り
  • Host genetic variants influencing the clinical course of hepatitis C virus infection, Kentaro Matsuura, Yasuhito Tanaka, Journal of Medical Virology, 88, (2) 185 - 195,   2016年02月, 査読有り, © 2016 Wiley Periodicals, Inc. The clinical course of hepatitis C virus (HCV) infection greatly differs in individuals. Various viral, host, and environmental factors influence the natural history of HCV infection. Recent genome-wide association studies identified several host genetic factors influencing treatment efficacy or clinical course in HCV infection. A landmark discovery was that IFNL3-IFNL4 variants are strongly associated with responses to interferon-based treatment. Genetic variants in IFNL3-IFNL4 as well as those in HLA class II loci influence the spontaneous clearance of acute HCV infection. Interestingly, these genetic variants also affect the activity of hepatitis, or disease progression in chronic hepatitis C. In addition, polymorphisms in apoptosis-related genes such as RNF7, TULP1, and MERTK are associated with fibrosis progression, and DEPDC5 and MICA variants are associated with HCV-related hepatocellular carcinoma. Understanding the genetic factors associated with the clinical course of HCV infection is essential for personalized treatment and surveillance of disease progression and hepatocellular carcinoma.
  • Property of hepatitis B virus replication in Tupaia belangeri hepatocytes, Takahiro Sanada, Kyoko Tsukiyama-Kohara, Kyoko Tsukiyama-Kohara, Naoki Yamamoto, Sayeh Ezzikouri, Soumaya Benjelloun, Shuko Murakami, Yasuhito Tanaka, Chise Tateno, Michinori Kohara, Biochemical and Biophysical Research Communications, 469, (2) 229 - 235,   2016年01月08日, 査読有り, © 2015 The Authors. The northern treeshrew (Tupaia belangeri) has been reported to be an effective candidate for animal infection model with hepatitis B virus (HBV). The objective of our study was to analyze the growth characteristics of HBV in tupaia hepatocytes and the host response to HBV infection. We established primary tupaia hepatocytes (3-6-week old tupaia) and infected them with HBV genotypes A, B and C, and all the genotypes proliferated as well as those in human primary hepatocytes (>105copies/ml in culture supernatant). We next generated a chimeric mouse with tupaia liver by transplantation of tupaia primary hepatocytes to urokinase-type plasminogen activator cDNA (cDNA-uPA)/severe combined immunodeficient (SCID) mice and the replacement ratio with tupaia hepatocytes was found to be more than 95%. Infection of chimeric mice with HBV (genotypes B, C, and D) resulted in HBV-DNA level of 104-106copies/ml after 8 weeks of infection, which were almost similar to that in humanized chimeric mouse. In contrast, serum HBV level in adult tupaia (1-year-old tupaia) was quite low (<103copies/ml). Understanding the differences in the response to HBV infection in primary tupaia hepatocytes, chimeric mouse, and adult tupaia will contribute to elucidating the mechanism of persistent HBV infection and viral eradication. Thus, T. belangeri was found to be efficient for studying the host response to HBV infection, thereby providing novel insight into the pathogenesis of HBV.
  • Circulating let-7 levels in plasma and extracellular vesicles correlate with hepatic fibrosis progression in chronic hepatitis C, Kentaro Matsuura, Kentaro Matsuura, Kentaro Matsuura, Valeria De Giorgi, Cathy Schechterly, Richard Y. Wang, Patrizia Farci, Yasuhito Tanaka, Harvey J. Alter, Hepatology, 64, (3) 732 - 745,   2016年01月01日, 査読有り, © 2016 by the American Association for the Study of Liver Diseases. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. The goal of this study was to determine whether an association exists between circulating microRNA (miRNA) levels and disease progression in chronic hepatitis C (CHC), whether plasma or extracellular vesicles (EVs) were optimal for miRNA measurement and their correlation with hepatic miRNA expression, and the mechanistic plausibility of this association. We studied 130 CHC patients prospectively followed over several decades. A comprehensive miRNA profile in plasma using microarray with 2578 probe sets showed 323 miRNAs differentially expressed between healthy individuals and CHC patients, but only six that distinguished patients with mild versus severe chronic hepatitis. Eventually, let-7a/7c/7d-5p and miR-122-5p were identified as candidate predictors of disease progression. Cross-sectional analyses at the time of initial liver biopsy showed that reduced levels of let-7a/7c/7d-5p (let-7s) in plasma were correlated with advanced histological hepatic fibrosis stage and other fibrotic markers, whereas miR-122-5p levels in plasma were positively correlated with inflammatory activity, but not fibrosis. Measuring let-7s levels in EVs was not superior to intact plasma for discriminating significant hepatic fibrosis. Longitudinal analyses in 60 patients with paired liver biopsies showed that let-7s levels in plasma markedly declined over time in parallel with fibrosis progression. However, circulating let-7s levels did not parallel those in the liver. Conclusion: Of all miRNAs screened, the let-7 family showed the best correlation with hepatic fibrosis in CHC. A single determination of let-7s levels in plasma did not have superior predictive value for significant hepatic fibrosis compared with that of fibrosis-4 index, but the rate of let-7s decline in paired longitudinal samples correlated well with fibrosis progression. Pathway analysis suggested that low levels of let-7 may influence hepatic fibrogenesis through activation of transforming growth factor β signaling in hepatic stellate cells. (Hepatology 2016;64:732-745).
  • Global, cancer-specific microRNA cluster hypomethylation was functionally associated with the development of non-B non-C hepatocellular carcinoma, Masanori Nojima, Takeshi Matsui, Takeshi Matsui, Akihiro Tamori, Shoji Kubo, Ken Shirabe, Koichi Kimura, Mitsuo Shimada, Tohru Utsunomiya, Yasuteru Kondo, Etsuko Iio, Yutaka Naito, Takahiro Ochiya, Yasuhito Tanaka, Molecular Cancer, 15, (1) ,   2016年01月01日, 査読有り, � 2016 Nojima et al. Background: While hepatitis B and C viral infection have been suppressed, non-B non-C hepatocellular carcinoma (NBNC-HCC) is considered to be rising in incidence terms in some developed countries where prevalence of those viral infections among HCC patients had been very high (such as Japan, Korea, and Italy). To elucidate critical molecular changes in NBNC-HCC, we integrated three large datasets relating to comprehensive array-based analysis of genome-wide DNA methylation (N = 43 pairs) and mRNA/miRNA expression (N = 15, and 24 pairs, respectively) via statistical modeling. Results: Hierarchical clustering of DNA methylation in miRNA coding regions clearly distinguished NBNC-HCC tissue samples from relevant background tissues, revealing a remarkable tumor-specific hypomethylation cluster. In addition, miRNA clusters were extremely hypomethylated in tumor samples (median methylation change for non-clustered miRNAs: -2.3%, clustered miRNAs: -24.6%). The proportion of CpGs hypomethylated in more than 90% of the samples was 55.9% of all CpGs within miRNA clusters, and the peak methylation level was drastically shifted from 84% to 39%. Following statistical adjustment, the difference in methylation levels within miRNA coding regions was positively associated with their expression change. Receiver operating characteristic (ROC) analysis revealed a great discriminatory ability in respect to cluster-miRNA methylation. Moreover, miRNA methylation change was negatively correlated with corresponding target gene expression amongst conserved and highly matched miRNA sites. Conclusions: We observed a drastic negative shift of methylation levels in miRNA cluster regions. Changes in methylation status of miRNAs were more indicative of target gene expression and pathological diagnosis than respective miRNA expression changes, suggesting the importance of genome-wide miRNA methylation for tumor development. Our study dynamically summarized global miRNA hypomethylation and its genome-wide scale consequence in NBNC-HCC.
  • A novel glycobiomarker, Wisteria floribunda agglutinin macrophage colony-stimulating factor receptor, for predicting carcinogenesis of liver cirrhosis, Etsuko Iio, Makoto Ocho, Akira Togayachi, Masanori Nojima, Atsushi Kuno, Atsushi Kuno, Yuzuru Ikehara, Izumi Hasegawa, Hiroshi Yatsuhashi, Kazumi Yamasaki, Noritomo Shimada, Tatsuya Ide, Noboru Shinkai, Shunske Nojiri, Kei Fujiwara, Takashi Joh, Masashi Mizokami, Hisashi Narimatsu, Yasuhito Tanaka, International Journal of Cancer, 138, (6) 1462 - 1471,   2016年01月, 査読有り, © 2015 UICC. Recently, we identified a novel liver fibrosis glycobiomarker, Wisteria floribunda agglutinin (WFA)-reactive colony stimulating factor 1 receptor (WFA+-CSF1R), using a glycoproteomics-based strategy. The aim of this study was to assess the value of measuring WFA+-CSF1R levels for the prognosis of carcinogenesis and outcome in liver cirrhosis (LC) patients with hepatitis C virus (HCV). WFA+-CSF1R and Total-CSF1R levels were measured in serum samples from 214 consecutive HCV-infected patients to evaluate their impact on carcinogenesis and the survival of LC patients. Serum WFA+-CSF1R levels were significantly higher in LC patients than chronic hepatitis (CH) patients (p < 0.001). The AUC of WFA+-CSF1R for predicting overall survival, calculated by time-dependent ROC analysis, was 0.691 and the HR (per 1-SD increase) was 1.80 (95% CI, 1.23-2.62, p < 0.001). Furthermore, the survival rate of LC patients with high WFA+-CSF1R levels (≥310 ng/ml) was significantly worse than those with lower levels (p < 0.01). The AUC of WFA+/total-CSF1R percentage (WFA+-CSF1R%) for predicting the cumulative carcinogenesis rate was 0.760, with an HR of 1.66 (95% CI 1.26-2.20, p < 0.001). In fact, the carcinogenesis rate was significantly higher in LC patients with a high WFA+-CSF1R% (≥ 35%, p = 0.006). Assessing serum levels of WFA+-CSF1R has diagnostic value for predicting carcinogenesis and the survival of LC patients. What's new? To find better biomarkers of liver fibrosis the authors developed a novel assay to detect serum levels of Wisteria floribunda agglutinin (WFA)-reactive colony-stimulating factor 1 receptor (WFA+-CSF1R). CSF1R is a membrane glycoprotein associated with cell proliferation and found elevated in a variety of cancers. They report that in hepatitis C virus-infected patients who developed liver cirrhosis, the survival rate of patients with high WFA+-CSF1R levels was significantly worse. Similarly, the carcinogenesis rate was higher in patients with high percentage of WFA+-CSF1R, suggesting that this glycobiomarker may have clinical applications beyond the mere evaluation of liver fibrosis.
  • Geographic distribution and characteristics of genotype A hepatitis B virus infection in acute and chronic hepatitis B patients in Japan, Kiyoaki Ito, Hiroshi Yotsuyanagi, Masaya Sugiyama, Hiroshi Yatsuhashi, Yoshiyasu Karino, Yasuhiro Takikawa, Takafumi Saito, Yasuji Arase, Fumio Imazeki, Masayuki Kurosaki, Takeji Umemura, Takafumi Ichida, Hidenori Toyoda, Masashi Yoneda, Yasuhito Tanaka, Eiji Mita, Kazuhide Yamamoto, Kojiro Michitaka, Tatsuji Maeshiro, Junko Tanuma, Masaaki Korenaga, Kazumoto Murata, Naohiko Masaki, Kazuhiko Koike, Masashi Mizokami, Yasuharu Imai, Norie Yamada, Hideaki Takahashi, Koji Ishii, Hideyuki Nomura, Jiro Nishida, Shigeru Mikami, Tsuneo Kitamura, Akihito Tsubota, Noritomo Shimada, Tetsuya Ishikawa, Yoshiyuki Ueno, Tomoyoshi Ohno, Etsuro Orito, Michihiro Suzuki, Satoshi Kakizaki, Hitoshi Takagi, Eiichi Tomita, Kumada Takashi, Toshihiko Mizuta, Tetsuya Mine, Jong Hon Kang, Katsuji Hirano, Hirohito Tsubouchi, Akito Nozaki, Akito Sakai, Shuhei Nishiguchi, Akihiro Tamori, Satoru Hagiwara, Takahide Nakazawa, Michio Sata, Toshiro Kamoshida, Atsushi Takahashi, Yoshimasa Kobayashi, Shigeru Sasaki, Tadashi Ikegami, Yoichi Hiasa, Kenji Nagata, Tomoyuki Kubota, Hiroshi Mitsui, Norihiko Yamamoto, Masataka Tsuge, Shuichi Sato, Yoshito Ito, Wataru Sato, Shigeharu Uchida, Yuki Tada, Toshiaki Mizuochi, Norihiro Furusho, Shuhei Hige, Yoshiyasu Karino, Minoru Kobayashi, Keiko Hosho, Satoshi Yamagiwa, Isao Sakaida, Kunio Nakane, Journal of Gastroenterology and Hepatology (Australia), 31, (1) 180 - 189,   2016年01月, 査読有り, © 2016 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd. Background and Aims: The prevalence of sexually transmitted acute infections of the genotype A hepatitis B virus (HBV) has been increasing in Japan. Genotype A HBV is associated with an increased risk of HBV progression to chronic infection after acute hepatitis B (AHB) in adults. A nationwide survey was conducted to evaluate the geographic distribution, clinical, and virologic characteristics of genotype A AHB and chronic hepatitis B (CHB) in Japan. Methods: Five hundred seventy AHB patients were recruited between 2005 and 2010, and 3682 CHB patients were recruited between 2010 and 2011. HBV genotypes were determined for 552 and 3619 AHB and CHB patients, respectively. Clinical characteristics were compared among different genotypes in AHB and CHB patients. Genomic characteristics of HBV genotype A were examined by molecular evolutionary analysis. Results: Hepatitis B virus genotype A was the predominant genotype for AHB between 2005 and 2010. Phylogenetic analysis showed that all strains in the AHB patients with genotype A were classified into subtype Ae. Among CHB patients, the occurrence of genotype A was 4.1%, and genotype A was spreading in young adults. In genotype A CHB patients, early stage liver diseases were predominant, although liver diseases progressed to cirrhosis or hepatocellular carcinoma in some patients. Conclusions: The distribution of HBV genotypes is quite different between AHB and CHB in Japanese patients. Genotype A infection is spreading in young adults of Japanese CHB patients. Sequences derived from Japanese AHB patients were identical to or closely resembled the sequences derived from other Japanese AHB patients.
  • Immune responses to HBV infection, Masanori Isogawa, Yasuhito Tanaka, Nihon rinsho. Japanese journal of clinical medicine, 73, 397 - 401,   2015年12月01日
  • Analysis of interferon-stimulated genes expression associated with early elimination of HCV RNA, Kentaro Matsuura, Sayuki Iijima, Yasuhito Tanaka, Nihon rinsho. Japanese journal of clinical medicine, 73, 171 - 177,   2015年12月01日
  • Clinical manifestations of HBV genotypes, Keigo Kawashima, Yasuhito Tanaka, Nihon rinsho. Japanese journal of clinical medicine, 73, 434 - 438,   2015年12月01日
  • Fatal reactivation of hepatitis B virus infection in a patient with adult T-cell leukemia-lymphoma receiving the anti-CC chemokine receptor 4 antibody mogamulizumab, Hideki Ifuku, Shigeru Kusumoto, Yasuhito Tanaka, Haruhito Totani, Takashi Ishida, Masaya Okada, Shuko Murakami, Masashi Mizokami, Ryuzo Ueda, Shinsuke Iida, Hepatology Research, 45, (13) 1363 - 1367,   2015年12月01日, 査読有り, © 2015 John Wiley & Sons, Ltd. We report an adult T-cell leukemia-lymphoma (ATL) patient suffering from fatal reactivation of hepatitis B virus (HBV) infection after treatment with the anti-CC chemokine receptor 4 (CCR4) monoclonal antibody, mogamulizumab. HBV reactivation occurred without liver damage in this hepatitis B surface antigen (HBsAg) negative patient, who was seropositive for antibodies against the viral core and surface antigens at baseline, after two cycles of CHOP regimen (cyclophosphamide, doxorubicin, vincristine and prednisolone) followed by six cycles of THP-COP regimen (cyclophosphamide, pirarubicin, vincristine and prednisolone). Unexpectedly, mogamulizumab monotherapy for relapsed CCR4 positive ATL induced sudden and fatal liver failure due to HBV reactivation, despite antiviral prophylaxis with entecavir. This clinical course may not only offer important suggestions to prevent critical HBV reactivation in HBsAg positive cancer patients who receive immune-enhancing drugs such as anti-CCR4 antibody, but also provide a clue to understanding the pathogenesis of HBV reactivation following systemic chemotherapy.
  • Factors associated with the effect of interferon-α sequential therapy in order to discontinue nucleoside/nucleotide analog treatment in patients with chronic hepatitis B, Akihiro Matsumoto, Hiroshi Yatsuhashi, Shinya Nagaoka, Yoshiyuki Suzuki, Tetsuya Hosaka, Masataka Tsuge, Kazuaki Chayama, Tatsuo Kanda, Osamu Yokosuka, Shuhei Nishiguchi, Masaki Saito, Shiho Miyase, Jong Hon Kang, Noboru Shinkai, Yasuhito Tanaka, Takeji Umemura, Eiji Tanaka, Hepatology Research, 45, (12) 1195 - 1202,   2015年12月01日, 査読有り, © 2015 The Japan Society of Hepatology. Aim: The factors associated with the outcome of sequential therapy with interferon-α (IFN-α) in order to halt nucleoside/nucleotide analog (NUC) maintenance treatment for chronic hepatitis B were analyzed. Methods: A total of 50 patients with chronic hepatitis B who underwent IFN-α sequential therapy for cessation of NUC were enrolled retrospectively. The subjects received NUC plus IFN-α for 4weeks followed by IFN-α alone for 20weeks. Natural IFN-α of 6-MU doses was administrated three times a week. A successful response to NUC/IFN-α sequential therapy was defined as serum hepatitis B virus (HBV) DNA below 4.0log copies/mL, serum alanine aminotransferase (ALT) below 30IU/L, and hepatitis B e-antigen negativity at 24months after completing the treatment. Results: Multivariate analysis revealed that hepatitis B surface antigen (HBsAg) of 3.0logU/mL or more (P<0.002) and hepatitis B core-related antigen (hepatitis B core-related antigen [HBcrAg]) of 4.5logU/mL or more (P<0.003) at the start of IFN-α administration were significant factors associated with a 24-month non-response. Maximal levels of ALT and HBV DNA during the follow-up period after completing IFN-α therapy were significantly related (P<0.001), and receiver operating characteristic analysis showed that both maximal ALT (P<0.001) and HBV DNA (P<0.001) were significantly related to the final 24-month response. Conclusion: The combinational use of HBsAg and HBcrAg levels may be useful to predict the 24-month outcome of NUC/IFN-α sequential therapy. Maximal levels of ALT and HBV DNA during post-treatment follow-up may also help monitor responses to IFN-α sequential therapy.
  • Control of temporal activation of hepatitis C virus-induced interferon response by domain 2 of nonstructural protein 5A, Marie Sophie Hiet, Oliver Bauhofer, Margarita Zayas, Hanna Roth, Yasuhito Tanaka, Peter Schirmacher, Joschka Willemsen, Joschka Willemsen, Oliver Grünvogel, Silke Bender, Marco Binder, Marco Binder, Volker Lohmann, Vincent Lotteau, Alessia Ruggieri, Ralf Bartenschlager, Journal of Hepatology, 63, (4) 829 - 837,   2015年10月01日, 査読有り, © 2015 European Association for the Study of the Liver. Background & Aims Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is a multifunctional protein playing a crucial role in diverse steps of the viral replication cycle and perturbing multiple host cell pathways. We showed previously that removal of a region in domain 2 (D2) of NS5A (mutant NS5AD2Δ) is dispensable for viral replication in hepatoma cell lines. By using a mouse model and immune-competent cell systems, we studied the role of D2 in controlling the innate immune response. Methods In vivo replication competence of NS5AD2Δwas studied in transgenic mice with human liver xenografts. Results were validated using primary human hepatocytes (PHHs) and mechanistic analyses were conducted in engineered Huh7 hepatoma cells with reconstituted innate signaling pathways. Results Although the deletion in NS5A removed most of the interferon (IFN) sensitivity determining-region, mutant NS5AD2Δwas as sensitive as the wild type to IFN-α and IFN-λ in vitro, but severely attenuated in vivo. This attenuation could be recapitulated in PHHs and was linked to higher activation of the IFN response, concomitant with reduced viral replication and virus production. Importantly, immune-reconstituted Huh7-derived cell lines revealed a sequential activation of the IFN-response via RIG-I (retinoic acid-inducible gene I) and MDA5 (Myeloma differentiation associated factor 5), respectively, that was significantly higher in the case of the mutant lacking most of NS5A D2. Conclusions Our study reveals an important role of NS5A D2 for suppression of the IFN response that is activated by HCV via RIG-I and MDA5 in a sequential manner.
  • 4′-modified nucleoside analogs: Potent inhibitors active against entecavir-resistant hepatitis B virus, Yuki Takamatsu, Yasuhito Tanaka, Satoru Kohgo, Shuko Murakami, Kamalendra Singh, Debananda Das, David J. Venzon, Masayuki Amano, Nobuyo Higashi-Kuwata, Manabu Aoki, Nicole S. Delino, Sanae Hayashi, Satoru Takahashi, Yoshikazu Sukenaga, Kazuhiro Haraguchi, Stefan G. Sarafianos, Kenji Maeda, Hiroaki Mitsuya, Hepatology, 62, (4) 1024 - 1036,   2015年10月, 査読有り, © 2015 by the American Association for the Study of Liver Diseases. Certain nucleoside/nucleotide reverse transcriptase (RT) inhibitors (NRTIs) are effective against human immunodeficiency virus type 1 (HIV-1) and hepatitis B virus (HBV). However, both viruses often acquire NRTI resistance, making it crucial to develop more-potent agents that offer profound viral suppression. Here, we report that 4′-C-cyano-2-amino-2′-deoxyadenosine (CAdA) is a novel, highly potent inhibitor of both HBV (half maximal inhibitory concentration [IC50]=0.4 nM) and HIV-1 (IC50=0.4 nM). In contrast, the approved anti-HBV NRTI, entecavir (ETV), potently inhibits HBV (IC50=0.7 nM), but is much less active against HIV-1 (IC50=1,000 nM). Similarly, the highly potent HIV-1 inhibitor, 4′-ethynyl-2-fluoro-2′-deoxyadenosine (EFdA; IC50=0.3 nM) is less active against HBV (IC50=160 nM). Southern analysis using Huh-7 cells transfected with HBV-containing plasmids demonstrated that CAdA was potent against both wild-type (IC50=7.2 nM) and ETV-resistant HBV (IC50=69.6 nM for HBVETV-RL180M/S202G/M204V), whereas ETV failed to reduce HBVETV-RL180M/S202G/M204V DNA even at 1 μM. Once-daily peroral administration of CAdA reduced HBVETV-RL180M/S202G/M204V viremia (P=0.0005) in human-liver-chimeric/ HBVETV-RL180M/S202G/M204V-infected mice, whereas ETV completely failed to reduce HBVETV-RL180M/S202G/M204V viremia. None of the mice had significant drug-related body-weight or serum human-albumin concentration changes. Molecular modeling suggests that a shallower HBV-RT hydrophobic pocket at the polymerase active site can better accommodate the slightly shorter 4′-cyano of CAdA-triphosphate (TP), but not the longer 4′-ethynyl of EFdA-TP. In contrast, the deeper HIV-1-RT pocket can efficiently accommodate the 4′-substitutions of both NRTIs. The ETV-TP's cyclopentyl ring can bind more efficiently at the shallow HBV-RT binding pocket. Conclusion: These data provide insights on the structural and functional associations of HBV- and HIV-1-RTs and show that CAdA may offer new therapeutic options for HBV patients.
  • Hepatitis B surface gene variants isolated from blood donors with overt and occult HBV infection in north eastern Egypt, Rania Kishk, Nader Nemr, Abeer Elkady, Abeer Elkady, Mohamed Mandour, Mohamed Aboelmagd, Nevene Ramsis, Mohamed Hassan, Nashaat Soliman, Sayuki Iijima, Shuko Murakami, Yasuhito Tanaka, Mostafa Ragheb, Virology Journal, 12,   2015年09月30日, 査読有り, © 2015 Kishk et al. Background: Major hydrophilic region in genomic HBV extending from aa99 to aa169, clustered with a highly conformational epitope, is critical to the antigenicity of hepatitis B surface antigen (HBsAg) and may affect the diagnosis of HBV in HBV screening test. So, this study aimed to characterize variants of S gene product of hepatitis B virus (HBV) isolated from patients with overt or occult HBV infection in north-eastern Egypt. Methods: The study included sera of two different groups of volunteer blood donors (VBDs), 82 with overt HBV that were positive for HBsAg and anti-HBc and 343 donors negative for HBsAg eligible for donation. Of the latter group, only 44 were positive for anti-HBc. All anti-HBc positive sera were subjected to HBV DNA detection and partial sequence analysis targeting the HBV S gene. Results: HBV DNA was detected in 22.7 % of HBsAg-/anti-HBc∈+∈(10/44 patients) and in 90 % of HBsAg∈+∈donors (74/82 patients) with significant statistical difference (P∈=∈0.0001). Phylogenetic analysis showed that HBV strains retrieved from both groups were of genotype D. Amino acid escape mutation T125M was detected in only 2 samples of the occult infection group and in none of the overt group (P∈=∈0.01). Different amino acid substitutions were identified in overt infection group: S143L/T (16.2 %, 12/74) and P120T/S (2.7 %, 2/74). Q129R was significantly more frequent in cases with occult HBV infection (40 %, 4/10) than overt group (6.8 %, 5/74) (P∈=∈0.01). Conclusions: HBV genotype D predominated both in patients with overt and occult HBV infection. Different profiles of amino acid substitutions in the major hydrophilic region were seen in these two groups in Egypt.
  • Genetic polymorphisms of IL28B and PNPLA3 are predictive for HCV related rapid fibrosis progression and identify patients who require urgent antiviral treatment with new regimens, Nobuharu Tamaki, Masayuki Kurosaki, Mayu Higuchi, Hitomi Takada, Natsuko Nakakuki, Yutaka Yasui, Shoko Suzuki, Kaoru Tsuchiya, Hiroyuki Nakanishi, Jun Itakura, Yuka Takahashi, Shintaro Ogawa, Yasuhito Tanaka, Yasuhiro Asahina, Namiki Izumi, PLoS ONE, 10, (9) ,   2015年09月09日, 査読有り, © 2015 Tamaki et al. The assessment of individual risk of fibrosis progression in patients with chronic hepatitis C is an unmet clinical need. Recent genome-wide association studies have highlighted several genetic alterations as predictive risk factors of rapid fibrosis progression in chronic hepatitis C. However, most of these results require verification, and whether the combined use of these genetic predictors can assess the risk of fibrosis progression remains unclear. Therefore, genetic risk factors associated with fibrosis progression were analyzed in 176 chronic hepatitis C patients who did not achieve sustained virological response by inter-feron-based therapy and linked to the fibrosis progression rate (FPR). FPR was determined in all patients by paired liver biopsy performed before and after therapy (mean interval: 6.2 years). Mean FPR in patients with IL28B (rs8099917) TG/GG and PNPLA3 (rs738409) CG/GG were significantly higher than in those with IL28B TT (FPR: 0.144 vs. 0.034, P < 0.001) and PNPLA3 CC (FPR: 0.10 vs. 0.018, P = 0.005), respectively. IL28B TG/GG [hazard ratio (HR):3.9, P = 0.001] and PNPLA3 CG/GG (HR: 3.1, P = 0.04) remained independent predictors of rapid fibrosis progression upon multivariate analysis together with average alanine aminotransferase after interferon therapy >40 IU/l (HR: 4.2, P = 0.002). Based on these data, we developed a new clinical score predicting the risk of fibrosis progression (FPR-score). The FPR-score identified subgroups of patients with a low (FPR: 0.005), intermediate (FPR: 0.103, P < 0.001), and high (FPR: 0.197, P < 0.001) risk of fibrosis progression. In conclusion, IL28B and PNPLA3 genotypes are associated with rapid fibrosis progression, and the FPR-score identifies patients who has a high risk of fibrosis progression and require urgent antiviral treatment. Copyright:
  • Risk Management of HBV Reactivation: Construction of Check System, Yasuhito Tanaka, Rinsho byori. The Japanese journal of clinical pathology, 63, 1052 - 1059,   2015年09月01日, In recent years, reactivation of HBV in patients receiving cancer chemotherapy or immunosuppressive therapy has been a problem. Generally, HBV-DNA levels are elevated prior to HBsAg concentration, and then hepatic dysfunction is observed in the process of hepatitis by HBV reactivation. Therefore, the monitoring of HBV-DNA is useful for the prediction of hepatic dysfunction, and nucleoside/nucleoside analogue (NA) administration is able to prevent this HBV reactivation. According to these facts, "Guidelines for the Prevention of HBV Reactivation in Patients Receiving Immunosuppressive Therapy or Chemotherapy", 2009 (revised as "JSH Guidelines for the Management of Hepatitis B Virus Infection", 2013) is established, and the diagnostic algorithm of HBsAg, anti-HBc, anti-HBs, and HBV-DNA has relevant descriptions. Combination therapy with rituximab and steroid for malignant lymphoma has a high risk of leading to fulminant hepatitis and, consequently, the guidelines are widely followed in such cases. We introduced the improvement of electronic medical recording and ordering systems in collaboration with hepatologists, and such a system has been widely used. Although the monitoring of HBV-DNA levels is required every 1-3 months, the guidelines are not followed strictly in cases such as rheumatoid disease and solid tumors only with chemotherapy or steroid treatment. Since a DNA assay is complicated and expensive, cost-effective, time-saving, and highly sensitive/specific measurements are required as well. Therefore, Lumipulse HBsAg-HQ (CLIA method) with high sensitivity is expected to be used for the monitoring of HBV reactivation.
  • Characterization of novel entecavir resistance mutations, Sanae Hayashi, Shuko Murakami, Katsumi Omagari, Takeshi Matsui, Takeshi Matsui, Etsuko Iio, Masanori Isogawa, Tsunamasa Watanabe, Yoshiyasu Karino, Yasuhito Tanaka, Journal of Hepatology, 63, (3) 546 - 553,   2015年09月01日, 査読有り, © 2015 European Association for the Study of the Liver. Background & Aims Entecavir (ETV) is approved for the treatment of chronic hepatitis B virus (HBV) infections, but the virus can acquire resistance to the drug. This requires lamivudine resistance mutations (LAMr) and at least one additional mutation. Here, we characterized two novel mutations, rtI163V and rtA186T, associated with viral breakthrough (VBT) in an ETV-refractory patient. Methods HBV from an ETV-refractory patient was sequenced, and newly identified mutations were inserted into a replication-competent clone by mutagenesis. Clones were analyzed for replication efficacy and susceptibility to ETV in vitro. Chimeric mice with human hepatocytes were inoculated with the patient's serum at VBT, and monitored for viral mutation pattern using a next-generation sequencing approach. Results RtI163V and rtA186T mutations were detected together with LAMr (rtL180M and rtM204V) at VBT. RtA186T plus LAMr reduced susceptibility to ETV more than 111.1-fold compared with the wild-type clone, while rtI163V plus LAMr resulted in a 20.4-fold reduction. RtA186T significantly reduced viral replication efficacy, while the rtI163V mutation rescued it. Interestingly, the viral mutation pattern in the chimeric mice indicated dominant (or selective) proliferation of a clone containing rtI163V and rtA186T mutations plus LAMr under ETV treatment. Three-dimensional docking simulation indicated that rtA186T reduced the binding affinity of the HBV polymerase to ETV. Conclusions VBT in this ETV-refractory patient is attributable to the novel ETV resistance mutations rtI163V and rtA186T. RtA186T was apparently responsible for ETV resistance but the selection of a clone with the double mutation plus LAMr suggests that rtI163V is required to sustain viral fitness.
  • Comparative Study for Anti-Hepatitis B Surface Antigen Titers Based on Two Measurement Methods: Using Monoclonal Antibodies Isolated from Hepatitis B Vaccinated Recipients, Kumiko Oone, Satomi Kani, Minoru Oohashi, Noboru Shinkai, Takako Inoue, Yukio Wakimoto, Yasuhito Tanaka, Rinsho byori. The Japanese journal of clinical pathology, 63, (8) 907 - 912,   2015年08月01日, 査読有り, BACKGROUND: As anti-hepatitis B surface antigen (anti-HBs) titers vary depending on the measurement methods, we compared two different methods to measure anti-HBs titers in sera and HBs monoclonal antibodies.METHODS: The sera from 182 HB virus-resolved patients who were negative for HBsAg but positive for antiHB core protein (HBc) and/or anti-HBs were obtained. The measurement of anti-HBs was compared using either Lumipulse G1200 or Architect i2000SR. Six different monoclonal antibody (mAbs) clones isolated from healthy individuals inoculated with hepatitis B vaccine Bimmugen (genotype C) were used.RESULTS: A statistically significant correlation in anti-HBs titers was found between the two methods tested (Y = 0.951X + 100.7, R = 0.813, p < 0.001), although anti-HBs titers in 72 samples (39.6%) measured by Architect were less than 50% of that by Lumipulse and 12 (6.6%) were opposite results. Measuring 2 mAbs with HBV neutralizing activity, the titers of the 116 antibody (1.0 μg/mL) were comparable (689.3 mIU/mL by Lumipulse and 440.7 mIU/mL by Architect), whereas those of the 478 antibody (1.0 μg/mL) were much lower by Architect than by Lumipulse (42.6 vs. 818.6 mIU/mL, respectively). Of four other mAbs without HBV neutralizing activity, equal titers were observed for one; two mAbs had less anti-HB titers by Architect; and one was below the cut-off index (< 5 mIU/mL).CONCLUSIONS: Anti-HBs titers measured by Architect are likely to be lower than by Lumipulse, and the potential ability to detect the 478 antibody with neutralizing activity is low, indicating that Architect might underestimate anti-HBs titers. Future studies should standardize the anti-HBs titer measurement system.
  • Hepatitis B and C virus infection and risk of lymphoid malignancies: A population-based cohort study (JPHC Study), Sarah Krull Abe, Manami Inoue, Manami Inoue, Norie Sawada, Motoki Iwasaki, Taichi Shimazu, Taiki Yamaji, Shizuka Sasazuki, Yasuhito Tanaka, Masashi Mizokami, Shoichiro Tsugane, Shoichiro Tsugane, S. Tsugane, N. Sawada, M. Iwasaki, S. Sasazuki, T. Yamaji, T. Shimazu, T. Hanaoka, J. Ogata, S. Baba, T. Mannami, A. Okayama, Y. Kokubo, K. Miyakawa, F. Saito, A. Koizumi, Y. Sano, I. Hashimoto, T. Ikuta, Y. Tanaba, H. Sato, Y. Roppongi, T. Takashima, Y. Miyajima, N. Suzuki, S. Nagasawa, Y. Furusugi, N. Nagai, Y. Ito, S. Komatsu, T. Minamizono, H. Sanada, Y. Hatayama, F. Kobayashi, H. Uchino, Y. Shirai, T. Kondo, R. Sasaki, Y. Watanabe, Y. Miyagawa, Y. Kobayashi, M. Machida, K. Kobayashi, M. Tsukada, Y. Kishimoto, E. Takara, T. Fukuyama, M. Kinjo, M. Irei, H. Sakiyama, K. Imoto, H. Yazawa, T. Seo, A. Seiko, F. Ito, F. Shoji, R. Saito, A. Murata, K. Minato, K. Motegi, T. Fujieda, S. Yamato, K. Matsui, T. Abe, M. Katagiri, M. Suzuki, K. Matsui, M. Doi, A. Terao, Y. Ishikawa, T. Tagami, H. Sueta, H. Doi, M. Urata, N. Okamoto, F. Ide, H. Goto, H. Sakiyama, N. Onga, H. Takaesu, M. Uehara, T. Nakasone, M. Yamakawa, F. Horii, I. Asano, H. Yamaguchi, K. Aoki, S. Maruyama, M. Ichii, Cancer Epidemiology, 39, (4) 562 - 566,   2015年08月01日, 査読有り, © 2015 Elsevier Ltd. Several studies have assessed the association between hepatitis B virus (HBV) and hepatitis C virus (HCV) and non-Hodgkin's lymphoma. However, few studies are cohort by design, conducted within the Asian context and even fewer studies consider other lymphoid malignancies. The aim of this study was to assess the association between HBV and HCV and the risk of lymphoid malignancies among Japanese adults. Materials and methods: The Japan Public Health Center prospective-based Study Cohort II was initiated in 1993/1994. 20,360 subjects with available data on HBV and HCV infection status from blood samples were followed up until the end of 2010 for an average of 16 years. During 324,139 person-years, 120 newly diagnosed cases of lymphoid malignancies were identified. Cox proportional hazards models were employed to calculate hazard ratios (HRs) and 95% confidence intervals (95%CIs). Results: Of 20,360 subjects, 508 were HBsAg positive, 11,035 were anti-HBc positive, and 1,129 subjects were anti-HCV positive at baseline. The presence of HBsAg was positively associated with malignant lymphoma, especially with non-Hodgkin's lymphoma (HR. =. 3.56, 95%CI. =. 1.37-9.18) and diffuse large B-cell lymphoma (HR=7.22, 95%CI=2.34-22.29). In contrast, no clear association was observed between the presence of anti-HBc and anti-HCV. Conclusion: In conclusion, HBsAg but not anti-HBc or anti-HCV was positively associated with malignant lymphoma, particularly non-Hodgkin's lymphoma and diffuse large B-cell lymphoma in Japanese adults.
  • Reactivation of hepatitis B virus (HBV) infection in adult T-cell leukemia–lymphoma patients with resolved HBV infection following systemic chemotherapy, Haruhito Totani, Shigeru Kusumoto, Takashi Ishida, Arisa Masuda, Takashi Yoshida, Asahi Ito, Masaki Ri, Hirokazu Komatsu, Shuko Murakami, Masashi Mizokami, Ryuzo Ueda, Akio Niimi, Hiroshi Inagaki, Yasuhito Tanaka, Shinsuke Iida, International Journal of Hematology, 101, (4) 398 - 404,   2015年04月01日, 査読有り, © 2015, The Japanese Society of Hematology. Reactivation of hepatitis B virus (HBV) infection may occur in adult T-cell leukemia–lymphoma (ATL) patients with resolved HBV infection who receive monotherapy with the anti-CC chemokine receptor 4 monoclonal antibody, mogamulizumab. However, there is little evidence regarding the incidence and characteristics of HBV reactivation in ATL patients receiving systemic chemotherapy, including the use of this antibody. We conducted a retrospective study for 24 ATL patients with resolved HBV infection underwent regular HBV DNA monitoring to assess HBV reactivation in Nagoya City University Hospital between January 2005 and June 2013. With median HBV DNA follow-up of 238 days (range 57–1420), HBV reactivation (defined as the detection of HBV DNA) was observed in three (12.5 %) of 24 patients with resolved HBV infection. No hepatitis due to HBV reactivation occurred in those patients who were diagnosed with HBV DNA levels below 2.1 log copies/mL and who received antiviral drugs. Mogamulizumab was administered prior to HBV reactivation in two of three HBV-reactivated patients. In the mogamulizumab era, further well-designed prospective studies are warranted to estimate the incidence of HBV reactivation and to establish regular HBV DNA monitoring-guided preemptive antiviral therapy for such patients.
  • Plasma isoflavones and risk of primary liver cancer in Japanese women and men with hepatitis virus infection: A nested case-control study, Takehiro Michikawa, Takehiro Michikawa, Manami Inoue, Manami Inoue, Norie Sawada, Yasuhito Tanaka, Taiki Yamaji, Motoki Iwasaki, Taichi Shimazu, Shizuka Sasazuki, Masashi Mizokami, Shoichiro Tsugane, Cancer Epidemiology Biomarkers and Prevention, 24, (3) 532 - 537,   2015年03月01日, 査読有り, © 2014 AACR. Background: Evidence suggests that estrogen plays a preventive role in primary liver cancer development, and it might be thought that isoflavones, which are structurally similar to estrogens and bind to estrogen receptors, are associated with the risk of liver cancer. We investigated this suspected association by measuring plasma concentrations of isoflavones in a nested case-control study of a population-based prospective cohort in Japan. Methods: From 18,628 target participants ages 40 to 69 years who returned the baseline questionnaire and provided blood samples, we selected those with either hepatitis B or hepatitis C virus infection at baseline (n = 1,544). Among these, 90 (28 women and 62 men) were newly diagnosed with primary liver cancer from 1993 through 2006; they were matched with 175 controls (54 women and 121 men). Plasma concentrations of isoflavones (genistein, daidzein, glycitein, and equol) were measured using triple quadrupole tandem liquid chromatographymass spectrometry. The ORs of liver cancer development based on plasma concentrations were estimated with a conditional logistic regression model. Results: Basically, distributions of plasma isoflavone concentrations did not differ between the cases and controls. No statistically significant associations of genistein, daidzein, glycitein, and equol with primary liver cancer risk were found in either women or men. Conclusions: In middle-aged Japanese women and men with hepatitis virus infection, plasma isoflavones were unassociated with the occurrence of primary liver cancer. Impact: The role of isoflavones in liver carcinogenesis merits further study using both biomarkers and data on dietary intake of isoflavones.
  • Dysregulation of retinoic acid receptor diminishes hepatocyte permissiveness to hepatitis B virus infection through modulation of sodium taurocholate cotransporting polypeptide (NTCP) expression, Senko Tsukuda, Senko Tsukuda, Koichi Watashi, Koichi Watashi, Masashi Iwamoto, Ryosuke Suzuki, Hideki Aizaki, Maiko Okada, Masaya Sugiyama, Soichi Kojima, Yasuhito Tanaka, Masashi Mizokami, Jisu Li, Shuping Tong, Takaji Wakita, Journal of Biological Chemistry, 290, (9) 5673 - 5684,   2015年02月27日, 査読有り, © 2015 by The American Society for Biochemistry and Molecular Biology Inc. Published. Sodium taurocholate cotransporting polypeptide (NTCP) is an entry receptor for hepatitis B virus (HBV) and is regarded as one of the determinants that conferHBVpermissiveness to host cells. However, how host factors regulate the ability of NTCP to supportHBVinfection is largely unknown.Weaimed to identify the host signaling that regulated NTCP expression and thereby permissiveness to HBV. Here, a cell-based chemical screening method identified that Ro41-5253 decreased host susceptibility to HBV infection. Pretreatment with Ro41-5253 inhibited the viral entry process without affecting HBV replication. Intriguingly, Ro41-5253 reduced expression of both NTCP mRNA and protein. We found that retinoic acid receptor (RAR) regulated the promoter activity of the human NTCP (hNTCP) gene and that Ro41-5253 repressed the hNTCP promoter by antagonizing RAR. RAR recruited to the hNTCP promoter region, and nucleotides α112 to α96 of the hNTCP was suggested to be critical for RAR-mediated transcriptional activation. HBV susceptibility was decreased in pharmacologically RAR-inactivated cells. CD2665 showed a stronger anti-HBV potential and disrupted the spread ofHBVinfection that was achieved by continuous reproduction of the whole HBV life cycle. In addition, this mechanism was significant for drug development, as antagonization of RAR blocked infection of multiple HBV genotypes and also a clinically relevant HBV mutant that was resistant to nucleoside analogs. Thus, RAR is crucial for regulating NTCP expression that determines permissiveness to HBV infection. This is the first demonstration showing host regulation of NTCP to support HBV infection.
  • Influence of genes suppressing interferon effects in peripheral blood mononuclear cells during triple antiviral therapy for chronic hepatitis C, Sayuki Iijima, Kentaro Matsuura, Kentaro Matsuura, Kentaro Matsuura, Tsunamasa Watanabe, Koji Onomoto, Takashi Fujita, Kyoko Ito, Etsuko Iio, Etsuko Iio, Tomokatsu Miyaki, Kei Fujiwara, Noboru Shinkai, Atsunori Kusakabe, Mio Endo, Shunsuke Nojiri, Takashi Joh, Yasuhito Tanaka, PLoS ONE, 10, (2) ,   2015年02月23日, 査読有り, © 2015 Iijima et al. The levels of expression of interferon-stimulated genes (ISGs) in liver are associated with response to treatment with pegylated interferon (PEG-IFN) plus ribavirin (RBV). However, associations between the responses of ISGs to IFN-based therapy and treatment efficacy or interleukin-28B (IL28B) genotype have not yet been determined. Therefore, we investigated the early responses of ISGs and interferon-lambdas (IFN-λs) in peripheral blood mononuclear cells (PBMCs) during PEG-IFN/RBV plus NS3/4 protease inhibitor (PI) therapy. We prospectively enrolled 50 chronic hepatitis C patients with HCV genotype 1, and collected PBMCs at baseline, 8 and 24 h after the initial administration of PEG-IFN/RBV/PI. Levels of mRNAs for selected ISGs and IFN-λs were evaluated by real-time PCR. All 31 patients with a favorable IL28B genotype and 13 of 19 with an unfavorable genotype achieved sustained virological responses (SVR). Levels of mRNA for A20, SOCS1 , and SOCS3, known to suppress antiviral activity by interfering with the IFN signaling pathway, as well as IRF1 were significantly higher at 8 h in patients with an unfavorable IL28B genotype than in those with a favorable one (P = 0.007, 0.026, 0.0004, 0.0006, respectively), especially in the non-SVR group. Particularly, the fold-change of IRF1 at 8 h relative to baseline was significantly higher in non-SVR than in SVR cases with an unfavorable IL28B genotype (P = 0.035). In conclusion, levels of several mRNAs of genes suppressing antiviral activity in PBMCs during PEG-IFN/RBV/PI differed according to IL28B genotypes, paralleling treatment efficacy.
  • Validation of cross-genotype neutralization by hepatitis B virus-specific monoclonal antibodies by in vitro and in vivo infection, Susumu Hamada-Tsutsumi, Etsuko Iio, Etsuko Iio, Tsunamasa Watanabe, Shuko Murakami, Masanori Isogawa, Sayuki Iijima, Takako Inoue, Kayoko Matsunami, Kayoko Matsunami, Kazuto Tajiri, Kazuto Tajiri, Tatsuhiko Ozawa, Hiroyuki Kishi, Atsushi Muraguchi, Takashi Joh, Yasuhito Tanaka, PLoS ONE, 10, (2) ,   2015年02月18日, 査読有り, Copyright: © 2015 Hamada-Tsutsumi et al. Vaccines based on hepatitis B virus (HBV) genotype A have been used worldwide for immunoprophylaxis and are thought to prevent infections by non-A HBV strains effectively, whereas, vaccines generated from genotype C have been used in several Asian countries, including Japan and Korea, where HBV genotype C is prevalent. However, acute hepatitis B caused by HBV genotype A infection has been increasing in Japan and little is known about the efficacy of immunization with genotype C-based vaccines against non-C infection. We have isolated human monoclonal antibodies (mAbs) from individuals who were immunized with the genotype C-based vaccine. In this study, the efficacies of these two mAbs, HB0116 and HB0478, were analyzed using in vivo and in vitro models of HBV infection. Intravenous inoculation of HBV genotype C into chimeric mice with human hepatocytes resulted in the establishment of HBV infection after five weeks, whereas preincubation of the inocula with HB0116 or HB0478 protected chimeric mice from genotype C infection completely. Interestingly, both HB0116 and HB0478 were found to block completely genotype A infection. Moreover, infection by a genotype C strain with an immune escape substitution of amino acid 145 in the hepatitis B surface protein was also completely inhibited by incubation with HB0478. Finally, in vitro analysis of dose dependency revealed that the amounts of HB0478 required for complete protection against genotype C and genotype A infection were 5.5 mIU and 55 mIU, respectively. These results suggested that genotype Cbased vaccines have ability to induce cross-genotype immunity against HBV infection.
  • Genome-wide association study identifies a PSMD3 variant associated with neutropenia in interferon-based therapy for chronic hepatitis C, Etsuko Iio, Etsuko Iio, Kentaro Matsuura, Kentaro Matsuura, Nao Nishida, Nao Nishida, Shinya Maekawa, Nobuyuki Enomoto, Mina Nakagawa, Naoya Sakamoto, Naoya Sakamoto, Hiroshi Yatsuhashi, Masayuki Kurosaki, Namiki Izumi, Yoichi Hiasa, Naohiko Masaki, Tatsuya Ide, Keisuke Hino, Akihiro Tamori, Masao Honda, Shuichi Kaneko, Satoshi Mochida, Hideyuki Nomura, Shuhei Nishiguchi, Chiaki Okuse, Yoshito Itoh, Hitoshi Yoshiji, Isao Sakaida, Kazuhide Yamamoto, Hisayoshi Watanabe, Shuhei Hige, Shuhei Hige, Akihiro Matsumoto, Eiji Tanaka, Katsushi Tokunaga, Yasuhito Tanaka, Human Genetics, 134, (3) 279 - 289,   2015年02月06日, 査読有り, © 2014, Springer-Verlag Berlin Heidelberg. Cytopenia during interferon-based (IFN-based) therapy for chronic hepatitis C (CHC) often necessitates reduction of doses of drugs and premature withdrawal from therapy resulting in poor response to treatment. To identify genetic variants associated with IFN-induced neutropenia, we conducted a genome-wide association study (GWAS) in 416 Japanese CHC patients receiving IFN-based therapy. Based on the results, we selected 192 candidate single nucleotide polymorphisms (SNPs) to carry out a replication analysis in an independent set of 404 subjects. The SNP rs2305482, located in the intron region of the PSMD3 gene on chromosome 17, showed a strong association when the results of GWAS and the replication stage were combined (OR = 2.18, P = 3.05 × 10−7in the allele frequency model). Logistic regression analysis showed that rs2305482 CC and neutrophil count at baseline were independent predictive factors for IFN-induced neutropenia (OR = 2.497, P = 0.0072 and OR = 0.998, P < 0.0001, respectively). Furthermore, rs2305482 genotype was associated with the doses of pegylated interferon (PEG-IFN) that could be tolerated in hepatitis C virus genotype 1-infected patients treated with PEG-IFN plus ribavirin, but not with treatment efficacy. Our results suggest that genetic testing for this variant might be useful for establishing personalized drug dosing in order to minimize drug-induced adverse events.
  • [Natural history of hepatitis C virus infection], Kentaro Matsuura, Yasuhito Tanaka, Nihon rinsho. Japanese journal of clinical medicine, 73, 195 - 200,   2015年02月01日, Over 70% of individuals acutely infected with hepatitis C virus (HCV) develop chronic infection at significant risk of progressive liver fibrosis and subsequent liver cirrhosis and hepatocellular carcinoma. Various viral, host, and environmental factors have been reported to affect the natural history of HCV infection such as chronicity in acute phase and disease progression in chronic phase. Recent genome-wide association studies (GWAS) identified several host factors which are associated with treatment efficacy and clinical course in HCV infection. In this review, we focus on the host factors identified by GWAS, especially on HCV spontaneous clearance and disease progression in chronic HCV infection.
  • Postexposure prophylactic effect of hepatitis B virus (HBV)-Active antiretroviral therapy against HBV infection, Tsunamasa Watanabe, Tsunamasa Watanabe, Susumu Hamada-Tsutsumi, Yoshiyuki Yokomaku, Junji Imamura, Wataru Sugiura, Yasuhito Tanaka, Antimicrobial Agents and Chemotherapy, 59, (2) 1292 - 1298,   2015年02月01日, 査読有り, Copyright © 2015 American Society for Microbiology. All Rights Reserved. Retrospective study indicates that hepatitis B virus (HBV)-active nucleoside (nucleotide) analogues (NAs) used for antiretroviral therapy reduce the incidence of acute HBV infections in human immunodeficiency virus (HIV)-infected patients. Learning from HIV postexposure prophylaxis (PEP), we explored the possibility of using NAs in PEP following HBV exposure, if preexposure prophylaxis is feasible clinically. Using freshly isolated primary human hepatocytes cultured in vitro, we analyzed the effect of HBV-active tenofovir and lamivudine in primary HBV infection and also the effect of treatment with these NAs after HBV infection. HBV-active NAs applied from 24 h before inoculation could not prevent the secretion of hepatitis B surface antigen into the culture medium, and cessation of the NAs after inoculation allowed the cells to establish an apparent HBV infection. In contrast, hepatitis B immune globulin was able to prevent HBV infection completely. NA treatment before infection, however, can control the spread of HBV infection, as detected by immunohistochemistry. Practically, starting NA treatment within 2 days of primary HBV infection inhibited viral spread effectively, as well as preexposure treatment. We demonstrated that preexposure NA treatment was not able to prevent the acquisition of HBV infection but prevented viral spread by suppressing the production of mature progeny HBV virions. The effect of postexposure treatment within 2 days was similar to the effect of preexposure treatment, suggesting the possibility of HBV PEP using HBV-active NAs in HIV- and HBV-susceptible high-risk groups.
  • A case of chronic hepatitis B detectable a entecavir resistance mutation (rtA186T), Keisuke Amano, Yasuhito Tanaka, Sanae Hayashi, Reiichiro Kuwahara, Kei Ogata, Ichiro Miyajima, Teruko Arinaga, Tatsuya Ide, Takuji Torimura, Acta Hepatologica Japonica, 56, 482 - 484,   2015年01月01日, © 2015 The Japan Society of Hepatology. Entecavir was approved as a drug for chronic hepatitis B. However, hepatitis B virus (HBV) may acquire drug resistance. For entecavir (drug) resistance (ETVr), another mutation (rt184, rt202, or rt250) must be acquired in addition to lamivudine (LAM)-resistant mutations (rtL180M and rtM204V). We performed HBV DNA sequencing in a LAM-resistant patient with viral breakthrough after the administration of entecavir for 27 months. In this patient, previously-reported ETVr mutants at the position of rt184, rt202, or rt250 were not found, but a mutation rtA186T was observed with LAM resistance (rtL180M and rtM204V). As it is difficult to evaluate rtA186T mutation using commercially available assays in Japan, it would be important to recognize it as a new resistant mutation.
  • Hepatitis B in children—topics of the vaccination, Masayoshi Kage, Ayano Inui, Yuichiro Eguchi, Takahiko Kubo, Yasuhito Tanaka, Hiroshi Yotsuyanagi, Acta Hepatologica Japonica, 56, 39 - 56,   2015年01月01日
  • A novel tricyclic polyketide, vanitaracin A, specifically inhibits the entry of hepatitis B and D viruses by targeting sodium taurocholate cotransporting polypeptide, Manabu Kaneko, Manabu Kaneko, Koichi Watashi, Koichi Watashi, Shinji Kamisuki, Shinji Kamisuki, Hiroki Matsunaga, Masashi Iwamoto, Masashi Iwamoto, Fumihiro Kawai, Hirofumi Ohashi, Hirofumi Ohashi, Senko Tsukuda, Senko Tsukuda, Satomi Shimura, Satomi Shimura, Satomi Shimura, Ryosuke Suzuki, Hideki Aizaki, Masaya Sugiyama, Sam Yong Park, Takayoshi Ito, Naoko Ohtani, Fumio Sugawara, Yasuhito Tanaka, Masashi Mizokami, Camille Sureau, Takaji Wakita, Journal of Virology, 89, (23) 11945 - 11953,   2015年01月01日, 査読有り, © 2015, American Society for Microbiology. Anti-hepatitis B virus (HBV) drugs are currently limited to nucleos(t)ide analogs (NAs) and interferons. A challenge of drug development is the identification of small molecules that suppress HBV infection from new chemical sources. Here, from a fungusderived secondary metabolite library, we identify a structurally novel tricyclic polyketide, named vanitaracin A, which specifically inhibits HBV infection. Vanitaracin A inhibited the viral entry process with a submicromolar 50% inhibitory concentration (IC50) (IC50= 0.61 ± 0.23 μM), without evident cytotoxicity (50% cytotoxic concentration of >256 μM; selectivity index value of>419) in primary human hepatocytes. Vanitaracin A did not affect the HBV replication process. This compound was found to directly interact with the HBV entry receptor sodium taurocholate cotransporting polypeptide (NTCP) and impaired its bile acid transport activity. Consistent with this NTCP targeting, antiviral activity of vanitaracin A was observed with hepatitis D virus (HDV) but not hepatitis C virus. Importantly, vanitaracin A inhibited infection by all HBV genotypes tested (genotypes A to D) and clinically relevant NA-resistant HBV isolate. Thus, we identified a fungal metabolite, vanitaracin A, which was a potent, well-tolerated, and broadly active inhibitor of HBV and HDV entry. This compound, or its related analogs, could be part of an antiviral strategy for preventing reinfection with HBV, including clinically relevant nucleos(t)ide analog-resistant virus.
  • Differential expression of CX3CL1 in hepatitis B virus-replicating hepatoma cells can affect the migration activity of CX3CR1+immune cells, Yasuteru Kondo, Osamu Kimura, Yasuhito Tanaka, Masashi Ninomiya, Tomoaki Iwata, Takayuki Kogure, Jun Inoue, Masaya Sugiyama, Tatsuki Morosawa, Yasuyuki Fujisaka, Tooru Shimosegawa, Journal of Virology, 89, (14) 7016 - 7027,   2015年01月01日, 査読有り, © 2015, American Society for Microbiology. In addition to stellate cells and immune cells, inflamed hepatocytes and hepatoma cells express various kinds of chemokines that attract various kinds of immune cells. Previously, we reported that hepatitis B virus (HBV) replication can induce physiological stress. The aim of this study was to analyze the effect of chemokines produced by HBV-infected hepatocytes and hepatoma cells. A real-time PCR array targeting genes related to chemokines and enzyme-linked immunosorbent assay (ELISA) were carried out to detect the specific chemokines produced by Huh7 cells and HepG2 cells infected with various HBV genotypes. A migration assay, flow cytometry analysis, and immunohistochemistry were carried out to analyze the candidate immune cells that can affect the immunopathogenesis of HBV infection. The expressions of CX3CL1 mRNA and protein were significantly different among HBV genotypes A, B, and C and control cells (mock) (P<0.05). CD56+NK cells and CD8+T cells migrated to the hepatoma cells with HBV replication. Moreover, the migration activity of both immune cells was partially cancelled after the treatment of CX3CL1 neutralizing antibody. The expression level of NKG2D on CX3CR1+NK cells in HCC with HBV infection was significantly lower than that in hepatocellular carcinoma (HCC) with HCV infection and chronic hepatitis B and C patients (P<0.05). On the other hand, the frequency of PD-1high CX3CR1+CD8+T cells in HCC with HBV infection was significantly higher than that in HCC with HCV infection and chronic hepatitis B and C (P<0.05). The expression of CX3CL1 in HBV-replicating hepatocytes and hepatoma cells could contribute to the immunopathogenesis of HBV infection.
  • The RNA Sensor RIG-I Dually Functions as an Innate Sensor and Direct Antiviral Factor for Hepatitis B Virus, Seiichi Sato, Seiichi Sato, Kai Li, Kai Li, Takeshi Kameyama, Takeshi Kameyama, Takaya Hayashi, Yuji Ishida, Shuko Murakami, Tsunamasa Watanabe, Sayuki Iijima, Yu Sakurai, Koichi Watashi, Susumu Tsutsumi, Yusuke Sato, Hidetaka Akita, Takaji Wakita, Charles M. Rice, Hideyoshi Harashima, Michinori Kohara, Yasuhito Tanaka, Akinori Takaoka, Akinori Takaoka, Immunity, 42, (1) 123 - 132,   2015年01月01日, 査読有り, © 2015 Elsevier Inc. Host innate recognition triggers key immune responses for viral elimination. The sensing mechanism of hepatitis B virus (HBV), a DNA virus, and the subsequent downstream signaling events remain to be fully clarified. Here we found that type III but nottype I interferons are predominantly induced in human primary hepatocytes in response to HBV infection, through retinoic acid-inducible gene-I (RIG-I)-mediated sensing of the 5'-ε region of HBV pregenomic RNA. In addition, RIG-I could also counteract the interaction of HBV polymerase (P protein) with the 5'-ε region in an RNA-binding dependent manner, which consistently suppressed viral replication. Liposome-mediated delivery and vector-based expression of this ε region-derived RNA in liver abolished the HBV replication in human hepatocyte-chimeric mice. These findings identify an innate-recognition mechanism by which RIG-I dually functions as an HBV sensor activating innate signaling and to counteract viral polymerase in human hepatocytes.
  • MicroRNAs and hepatitis B, Yutaka Naito, Yasuhito Tanaka, Takahiro Ochiya, Advances in Experimental Medicine and Biology, 888, 389 - 399,   2015年01月01日, 査読有り, © Springer International Publishing Switzerland 2015. The hepatitis B virus (HBV) infection is the leading cause of persistent liver diseases, cirrhosis, and hepatocellular carcinoma (HCC). However, the precise mechanism underlying the development of HBV-related diseases is not fully understood. In addition, the therapeutic strategies for the diseases are less than optimum. microRNAs (miRNAs) are small noncoding RNAs that have been described as a “fine-tuner” in various cellular events. The dysregulation of miRNAs play a role in the development of the cancer as well as viral interference. Recent articles have demonstrated that several miRNAs are deregulated by HBV infection and contribute to viral replication and pathogenesis. Thus, it suggests that the precise mechanism between miRNA and HBV biology will be leading to the development of the novel diagnosis and therapy. This chapter aims to provide the basic principals of miRNAs in development of the HBV-related diseases. We also discuss about the possibility of miRNAs on the clinical application for diagnosis and therapy of HBVrelated diseases.
  • Monitoring of hepatitis b virus (HBV) DNA and risk of HBV reactivation in B-cell lymphoma: A prospective observational study, Shigeru Kusumoto, Yasuhito Tanaka, Ritsuro Suzuki, Takashi Watanabe, Masanobu Nakata, Hirotaka Takasaki, Noriyasu Fukushima, Takuya Fukushima, Yukiyoshi Moriuchi, Kuniaki Itoh, Kisato Nosaka, Ilseung Choi, Masashi Sawa, Rumiko Okamoto, Hideki Tsujimura, Toshiki Uchida, Sachiko Suzuki, Masataka Okamoto, Tsutomu Takahashi, Isamu Sugiura, Yasushi Onishi, Mika Kohri, Shinichiro Yoshida, Rika Sakai, Minoru Kojima, Hiroyuki Takahashi, Akihiro Tomita, Dai Maruyama, Yoshiko Atsuta, Eiji Tanaka, Takayo Suzuki, Tomohiro Kinoshita, Michinori Ogura, Masashi Mizokami, Ryuzo Ueda, Clinical Infectious Diseases, 61, (5) 719 - 729,   2015年01月01日, 査読有り, Background. There is no standard management of reactivation of hepatitis B virus (HBV) infection in HBVresolved patients without hepatitis B surface antigen (HBsAg), but with antibodies against hepatitis B core antigen and/or antibodies against HBsAg (anti-HBs). Methods. We conducted a prospective observational study to evaluate the occurrence of HBV reactivation by serial monthly monitoring of HBV DNA and to establish preemptive therapy guided by this monitoring in B-cell non-Hodgkin lymphoma (B-NHL) treated with rituximab plus corticosteroid-containing chemotherapy (R-steroidchemo). The primary endpoint was the incidence of HBV reactivation defined as quantifiable HBV DNA levels of ?11 IU/mL. Results. With a median HBV DNA follow-up of 562 days, HBV reactivation was observed in 21 of the 269 analyzed patients. The incidence of HBV reactivation at 1.5 years was 8.3% (95% confidence interval, 5.5-12.4). No hepatitis due to HBV reactivation was observed in patients who received antiviral treatment when HBV DNA levels were between 11 and 432 IU/mL. An anti-HBs titer of <10 mIU/mL and detectable HBV DNA remaining below the level of quantification at baseline were independent risk factors for HBV reactivation (hazard ratio, 20.6 and 56.2, respectively; P < .001). Even in 6 patients with a rapid increase of HBV due to mutations, the monthly HBV DNA monitoring was effective at preventing HBV-related hepatitis. Conclusions. Monthly monitoring of HBV DNA is useful for preventing HBV reactivation-related hepatitis among B-NHL patients with resolved HBV infection following R-steroid-chemo (UMIN000001299).
  • Immunobiology of hepatitis B virus infection, Masanori Isogawa, Yasuhito Tanaka, Hepatology Research, 45, (2) 179 - 189,   2015年01月01日, 査読有り, © 2014 The Japan Society of Hepatology. The adaptive immune response, particularly the virus-specific CD8+T-cell response, is largely responsible for viral clearance and disease pathogenesis during hepatitis B virus (HBV) infection. The HBV-specific CD8+T-cell response is vigorous, polyclonal and multispecific in acutely infected patients who successfully clear the virus and relatively weak and narrowly focused in chronically infected patients. The immunological basis for this dichotomy is unclear. A recent study using HBV transgenic mice and HBV-specific T-cell receptor transgenic mice suggests that intrahepatic antigen presentation by HBV positive hepatocytes suppresses HBV-specific CD8+T-cell responses through a co-inhibitory molecule, programmed cell death 1 (PD-1). In contrast, antigen presentation by activated professional antigen-presenting cells induces functional differentiation of HBV-specific CD8+T cells. These findings suggest that the outcome of T-cell priming is largely dependent on the nature of antigen-presenting cells. Another study suggests that the timing of HBV-specific CD4+T-cell priming regulates the magnitude of the HBV-specific CD8+T-cell response. Other factors that could regulate HBV-specific cellular immune responses are high viral loads, mutational epitope inactivation, T-cell receptor antagonism and infection of immunologically privileged tissues. However, these pathways become apparent only in the setting of an ineffective cellular immune response, which is therefore the fundamental underlying cause. Understanding the cellular and molecular mechanisms by which HBV evades host immune responses will eventually help develop new immunotherapeutic strategies designed to terminate chronic HBV infection.
  • Efficient Engraftment of Human Induced Pluripotent Stem Cell-Derived Hepatocyte-Like Cells in uPA/SCID Mice by Overexpression of FNK, a Bcl-xL Mutant Gene, Yasuhito Nagamoto, Kazuo Takayama, Katsuhisa Tashiro, Chise Tateno, Fuminori Sakurai, Masashi Tachibana, Kenji Kawabata, Kazuo Ikeda, Yasuhito Tanaka, Hiroyuki Mizuguchi, Cell transplantation, 24, 1127 - 1138,   2015年01月, 査読有り, Human liver chimeric mice are expected to be applied for drug toxicity tests and human hepatitis virus research. Human induced pluripotent stem cell-derived hepatocyte-like cells (iPSC-HLCs) are a highly attractive donor source for the generation of human liver chimeric mice because they can be produced on a large scale and established from an individual. Although these cells have been successfully used to generate human liver chimeric mice, there is still room for improvement in the repopulation efficiency. To enhance the repopulation efficacy, the human iPSC-HLCs were transduced with an adenovirus vector (Ad-FNK) expressing FNK, a hyperactive mutant gene from Bcl-xL, which was expected to inhibit apoptosis in the process of integration into liver parenchyma. We then transplanted Ad-FNK-transduced human iPSC-HLCs into urokinase-type plasminogen activator-transgenic severe combined immunodeficiency (uPA/SCID) mice (FNK mice) and evaluated the repopulation efficacy. The antiapoptotic effects of the human iPSC-HLCs were enhanced by FNK overexpression in vitro. Human albumin levels in the transplanted mice were significantly increased by transplantation of Ad-FNK-transduced human iPSC-HLCs (about 24,000 ng/ml). Immunohistochemical analysis with an anti-human αAT antibody revealed greater repopulation efficacy in the livers of FNK mice than control mice. Interestingly, the expression levels of human hepatocyte-related genes in the human iPSC-HLCs of FNK mice were much higher than those in the human iPSC-HLCs before transplantation. We succeeded in improving the repopulation efficacy of human liver chimeric mice generated by transplanting the Ad-FNK-transduced human iPSC-HLCs into uPA/SCID mice. Our method using ectopic expression of FNK was useful for generating human chimeric mice with high chimerism.
  • Natural history of chronic hepatitis B virus infection in childhood and efficacy of interferon therapy, Tomoko Takano, Hitoshi Tajiri, Yuri Etani, Yoko Miyoshi, Yasuhito Tanaka, Stephen Brooks, Scandinavian Journal of Gastroenterology, 50, 892 - 899,   2015年01月, 査読有り, © Informa Healthcare. Objectives. In short-term observations, interferon (IFN) therapy has been shown to be effective in producing both biochemical and virological responses in children with chronic hepatitis B virus (HBV) infection. However, in long-term follow up, no studies have shown a clear advantage of IFN therapy during childhood. We conducted a retrospective study on the sustained effect of IFN therapy among a Japanese pediatric population. Methods and subjects. A retrospective study was performed on 155 children with chronic HBV infection who were followed in two affiliated hospitals during the period from 1986 to 2013. Results. The 155 patients comprised 97 males and 58 female. Infection route was maternal transmission in 96/155 patients. HBV genotype was A in 17, B in 6, and C in 51 patients. IFN therapy was performed in 48 patients. One year after the completion of IFN therapy, normalization of alanine aminotransferase (ALT) and lower viral levels (<104 copies/ml) was observed in 43 and 29 patients, respectively. The sustained effects of IFN therapy were evaluated by comparison between 43 hepatitis B e-antigen (HBeAg)-positive patients treated with IFN and 67 patients with chronic hepatitis B observed without IFN therapy. A Cox's proportional hazard analysis showed a higher seroconversion rate in the IFN group than in the untreated group (p = 0.003). Similarly, there were higher rates of ALT normalization and lower viral levels in the IFN group than in the untreated group (p = 0.001 for both). Conclusion. IFN therapy showed sustained effects for achieving ALT normalization and HBeAg seroconversion and for reducing the viral load in children with chronic hepatitis B.
  • Serum interferon-gamma-inducible protein-10concentrations and IL28B genotype associated with responses to pegylated interferon plus ribavirin with and without telaprevir for chronic hepatitis C, Kentaro Matsuura, Kentaro Matsuura, Kentaro Matsuura, Tsunamasa Watanabe, Sayuki Iijima, Shuko Murakami, Kei Fujiwara, Etsuro Orito, Etsuko Iio, Mio Endo, Atsunori Kusakabe, Noboru Shinkai, Tomokatsu Miyaki, Shunsuke Nojiri, Takashi Joh, Yasuhito Tanaka, Hepatology Research, 44, (12) 1208 - 1216,   2014年11月01日, 査読有り, © 2013 The Japan Society of Hepatology. Aim: Several studies have shown that high pretreatment concentrations of serum interferon-γ-inducible protein-10 (IP-10) are correlated with non-response to pegylated interferon (PEG-IFN) plus ribavirin (RBV) for chronic hepatitis C (CHC). However, there are few reports on their effect on the Asian population. Methods: We enrolled 104 Japanese genotype 1 CHC individuals treated with PEG-IFN/RBV and 45 with PEG-IFN/RBV/telaprevir, and evaluated the impact of pretreatment serum IP-10 concentrations on their virological responses. Results: The pretreatment serum IP-10 concentrations were not correlated with IL28B genotype. The receiver-operator curve analysis determined the cut-off value of IP-10 for predicting a sustained virological response (SVR) as 300 pg/mL. In multivariate analysis, the IL28B favorable genotype and IP-10 concentration of less than 300 pg/mL were independent factors for predicting SVR. In a subgroup of patients with the IL28B favorable genotype, the SVR rate was higher in the patients with IP-10 of less than 300 than in those with 300 pg/mL or more, whereas no patient with the IL28B unfavorable genotype and IP-10 of 300 pg/mL or more achieved SVR. Among the patients treated with PEG-IFN/RBV/telaprevir, low pretreatment concentrations of serum IP-10 were associated with a very rapid virological response, defined as undetectable HCV RNA at week 2 after the start of therapy. Conclusion: Pretreatment serum IP-10 concentrations are associated with treatment efficacy in PEG-IFN/RBV and with early viral kinetics of hepatitis C virus in PEG-IFN/RBV/telaprevir therapy.
  • Association of IL28B polymorphisms with virological response to peginterferon and ribavirin therapy in children and adolescents with chronic hepatitis C, Hitoshi Tajiri, Yasuhito Tanaka, Tomoko Takano, Mitsuyoshi Suzuki, Daiki Abukawa, Yoko Miyoshi, Toshiaki Shimizu, Stephen Brooks, Hepatology Research, 44,   2014年10月01日, © 2013 The Japan Society of Hepatology. Aim: The objective of the current study was to find baseline predictive factors of response to therapy with pegylated interferon and ribavirin (PEG-IFN/RBV therapy) in children and adolescents with chronic hepatitis C. Methods: IL28B genotype and mutations in the core of hepatitis C virus (HCV) were analyzed in 30 patients treated with PEG-IFN/RBV for HCV infection. The initial rate of decrease in the viral load was assessed during the first 2 weeks of treatment. Results: IL28B major allele was seen more frequently in patients with sustained virologic response (SVR) than in non-SVR patients (P<0.001). There was no difference between these two groups in frequency of Core 70 mutation. Among patients with genotype-1, SVR was achieved in more patients (P=0.007) in the IL28B major allele group than in those in the minor allele group. The early decrements in the viral load (log/2 weeks) were 3.80±0.86 in the genotype-2 major allele group, 1.82±0.84 in the genotype-1 major allele group, and 0.41±0.33 in the genotype-1 minor allele group. Conclusions: Among pediatric patients with HCV infection the effectiveness of PEG-IFN/RBV therapy may be lower in the group with genotype-1 IL28B minor alleles than in other groups with IL28B major allele. Treatment strategy should be carefully implemented in patients with IL28B unfavorable type.
  • Effect of hepatitis B virus reverse transcriptase variations on entecavir treatment response, Danny Ka Ho Wong, Malgorzata Kopaniszen, Katsumi Omagari, Yasuhito Tanaka, Daniel Yee Tak Fong, Wai Kay Seto, James Fung, Fung Yu Huang, An Ye Zhang, Ivan Fan Ngai Hung, Ching Lung Lai, Man Fung Yuen, Journal of Infectious Diseases, 210, (5) 701 - 707,   2014年09月, 査読有り, Background. Entecavir therapy often reduces hepatitis B virus (HBV) DNA to an undetectable level, but HBV DNA remain detectable in some patients.We investigated whether baseline HBV reverse transcriptase (rt) polymorphism and quasispecies complexity and diversity were associated with treatment response. Methods. Pretreatment HBV DNA levels, HBV rt sequence, serology, and quasispecies complexity and diversity from 305 entecavir-treated patients were determined. These data were tested for their association with year 1 virological outcome, defined by optimal response (undetectable HBV DNA; lower limit of detection, ≤12 IU/mL) or partial response (detectable HBV DNA). Results. Four rt variants were more frequently detected in the 64 partial responders than in the 241 optimal responders (all P < .05). Multivariate analysis revealed that high baseline HBV DNA level (P < .0001; odds ratio [OR], 2.32), HBV e antigen (HBeAg) positivity (P < .001; OR, 3.70), and rt124N (P = .002; OR, 3.06) were associated with a partial entecavir response. Compared with the optimal responders, the partial responders had a lower quasispecies complexity and diversity. Conclusions. Apart from the known factors (high baseline HBV DNA level and HBeAg positivity), a novel single nucleotide polymorphism (rt124N) and lower quasispecies complexity and diversity were associated with partial entecavir response at year 1. © The Author 2014.
  • Mechanisms for interferon-α-induced depression and neural stem cell dysfunction, Lian Shun Zheng, Lian Shun Zheng, Seiji Hitoshi, Seiji Hitoshi, Naoko Kaneko, Keizo Takao, Keizo Takao, Tsuyoshi Miyakawa, Tsuyoshi Miyakawa, Tsuyoshi Miyakawa, Yasuhito Tanaka, Hongjing Xia, Ulrich Kalinke, Koutaro Kudo, Shigenobu Kanba, Kazuhiro Ikenaka, Kazunobu Sawamoto, Stem Cell Reports, 3, (1) 73 - 84,   2014年07月08日, 査読有り, New neurons generated by the neural stem cells (NSCs) in the adult hippocampus play an important role in emotional regulation and respond to the action of antidepressants. Depression is a common and serious side effect of interferon-α (IFN-α), which limits its use as an antiviral and antitumor drug. However, the mechanism(s) underlying IFN-induced depression are largely unknown. Using a comprehensive battery of behavioral tests, we found that mice subjected to IFN-α treatment exhibited a depression-like phenotype. IFN-α directly suppressed NSC proliferation, resulting in the reduced generation of new neurons. Brain-specific mouse knockout of the IFN-α receptor prevented IFN-α-induced depressive behavioral phenotypes and the inhibition of neurogenesis, suggesting that IFN-α suppresses hippocampal neurogenesis and induces depression via its receptor in the brain. These findings provide insight for understanding the neuropathology underlying IFN-α-induced depression and for developing new strategies for the prevention and treatment of IFN-α-induced depressive effects. © 2014 The Authors.
  • Application of a glycoproteomics-based biomarker development method: Alteration in glycan structure on colony stimulating factor 1 receptor as a possible glycobiomarker candidate for evaluation of liver cirrhosis, Makoto Ocho, Akira Togayachi, Etsuko Iio, Hiroyuki Kaji, Atsushi Kuno, Maki Sogabe, Masaaki Korenaga, Masanori Gotoh, Yasuhito Tanaka, Yuzuru Ikehara, Masashi Mizokami, Hisashi Narimatsu, Journal of Proteome Research, 13, 1428 - 1437,   2014年03月07日, The importance of diagnosis and therapies for liver cirrhosis (LC) is indisputable. Thus, a reliable method for monitoring the progression of liver fibrosis and resultant LC is urgently needed. Previously, using a lectin-assisted glycoproteomic method, we identified 26 serum glycoproteins as promising glycobiomarker candidates for monitoring the progression of liver diseases. In this study, we identified colony stimulating factor 1 receptor (CSF1R) as a promising LC marker candidate and then established Wisteria floribunda agglutinin (WFA)-reactive CSF1R (WFA+-CSF1R) as a novel possible glycobiomarker candidate by utilizing a glycoproteomics-based strategy. The serum level of WFA+-CSF1R in patients with hepatitis C virus (HCV)-infected liver disease was measured by an antibody-lectin sandwich ELISA. In a proof-of-concept experiment of the strategy preceding to future clinical studies, LC patients showed a high serum WFA+-CSF1R level in selected samples (P = 1.3 × 10-17). This result suggests WFA+-CSF1R is a possible biomarker candidate for evaluation of LC. Our results verified feasibility of this strategy for glycobiomarker development. © 2014 American Chemical Society.
  • α-Fetoprotein is a surrogate marker for predicting treatment failure in telaprevir-based triple combination therapy for genotype 1b chronic hepatitis C Japanese patients with the IL28B minor genotype, Noritomo Shimada, Akihito Tsubota, Masanori Atsukawa, Masanori Atsukawa, Hiroshi Abe, Makiko Ika, Keizo Kato, Yoshiyuki Sato, Chisa Kondo, Choitsu Sakamoto, Yasuhito Tanaka, Yoshio Aizawa, Journal of Medical Virology, 86, 461 - 472,   2014年03月01日, Even when treated with telaprevir-based triple therapy, some patients fail to achieve a sustained virological response. This study identified factors related closely to treatment failure. A total of 146 Japanese genotype 1b chronic hepatitis C patients were enrolled in this prospective, multicenter study and received a 24-week regimen of triple therapy. The end-of-treatment response rate was significantly lower in patients with the interleukin 28B (IL28B) (rs8099917) non-TT genotype (85.2%) than in those with the TT genotype (100%, P=0.0002). Multiple logistic regression analysis identified high α-fetoprotein levels as an independent factor related to non-end-of-treatment response in patients with the non-TT genotype. A cut-off value of 20ng/ml was determined for a non-end-of-treatment response; sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 75.0%, 95.7%, 75.0%, 75.0%, and 92.6%, respectively. Multiple logistic regression analysis for a sustained virological response identified the IL28B TT genotype, low α-fetoprotein levels, non-responders, and a rapid virological response. The sustained virological response rate was significantly lower in patients with the non-TT genotype (59.3%) than in those with the TT genotype (96.7%, P<0.0001). In patients with the non-TT genotype, α-fetoprotein was the most significant predictor for non-sustained virological response by univariate analysis. A cut-off value of 7.4ng/ml α-fetoprotein was determined for non-sustained virological response; sensitivity, specificity, PPV, NPV, and accuracy were 63.6%, 87.5%, 77.8%, 77.8%, and 77.8%, respectively. For the non-TT patients, serum α-fetoprotein levels may be a surrogate marker for predicting treatment failure in telaprevir-based therapy for genotype 1b chronic hepatitis C. J. Med. Virol. 86:461-472, 2014. © 2013 Wiley Periodicals, Inc.
  • New susceptibility and resistance HLA-DP alleles to HBV-related diseases identified by a trans-ethnic association study in Asia, Nao Nishida, Hiromi Sawai, Koichi Kashiwase, Mutsuhiko Minami, Masaya Sugiyama, Wai Kay Seto, Man Fung Yuen, Nawarat Posuwan, Yong Poovorawan, Sang Hoon Ahn, Kwang Hyub Han, Kentaro Matsuura, Yasuhito Tanaka, Masayuki Kurosaki, Yasuhiro Asahina, Yasuhiro Asahina, Namiki Izumi, Jong Hon Kang, Shuhei Hige, Tatsuya Ide Kazuhide Yamamoto, Tatsuya Ide Kazuhide Yamamoto, Isao Sakaida, Yoshikazu Murawaki, Yoshito Itoh, Akihiro Tamori, Etsuro Orito, Yoichi Hiasa, Masao Honda, Shuichi Kaneko, Eiji Mita, Kazuyuki Suzuki, Keisuke Hino, Eiji Tanaka, Satoshi Mochida, Masaaki Watanabe, Yuichiro Eguchi, Naohiko Masaki, Kazumoto Murata, Masaaki Korenaga, Yoriko Mawatari, Jun Ohashi, Minae Kawashima, Katsushi Tokunaga, Masashi Mizokami, PLoS ONE, 9, (2) ,   2014年02月, 査読有り, Previous studies have revealed the association between SNPs located on human leukocyte antigen (HLA) class II genes, including HLA-DP and HLA-DQ, and chronic hepatitis B virus (HBV) infection, mainly in Asian populations. HLA-DP alleles or haplotypes associated with chronic HBV infection or disease progression have not been fully identified in Asian populations. We performed trans-ethnic association analyses of HLA-DPA1, HLA-DPB1 alleles and haplotypes with hepatitis B virus infection and disease progression among Asian populations comprising Japanese, Korean, Hong Kong, and Thai subjects. To assess the association between HLA-DP and chronic HBV infection and disease progression, we conducted high-resolution (4-digit) HLA-DPA1 and HLA-DPB1 genotyping in a total of 3,167 samples, including HBV patients, HBV-resolved individuals and healthy controls. Trans-ethnic association analyses among Asian populations identified a new risk allele HLA-DPB1*09:01 (P = 1.36x10-6; OR = 1.97; 95% CI, 1.50-2.59) and a new protective allele DPB1*02:01 (P = 5.22x10-6; OR = 0.68; 95% CI, 0.58-0.81) to chronic HBV infection, in addition to the previously reported alleles. Moreover, DPB1*02:01 was also associated with a decreased risk of disease progression in chronic HBV patients among Asian populations (P = 1.55x10-7; OR = 0.50; 95% CI, 0.39-0.65). Trans-ethnic association analyses identified Asian-specific associations of HLA-DP alleles and haplotypes with HBV infection or disease progression. The present findings will serve as a base for future functional studies of HLA-DP molecules in order to understand the pathogenesis of HBV infection and the development of hepatocellular carcinoma. © 2014 Nishida et al.
  • Genetic association of human leukocyte antigens with chronicity or resolution of hepatitis B infection in Thai population, Nawarat Posuwan, Nawarat Posuwan, Nawarat Posuwan, Sunchai Payungporn, Sunchai Payungporn, Pisit Tangkijvanich, Pisit Tangkijvanich, Shintaro Ogawa, Shuko Murakami, Sayuki Iijima, Kentaro Matsuura, Noboru Shinkai, Tsunamasa Watanabe, Yong Poovorawan, Yasuhito Tanaka, PLoS ONE, 9, (1) ,   2014年01月23日, 査読有り, Background: Previous studies showed that single nucleotide polymorphisms (SNPs) in the HLA-DP, TCF19 and EHMT2 genes may affect the chronic hepatitis B (CHB). To predict the degree of risk for chronicity of HBV, this study determined associations with these SNPs. Methods: The participants for this study were defined into 4 groups; HCC (n = 230), CHB (n = 219), resolved HBV infection (n = 113) and HBV uninfected subjects (n = 123). The HLA-DP SNPs (rs3077, rs9277378 and rs3128917), TCF19 SNP (rs1419881) and EHMT2 SNP (rs652888) were genotyped. Results: Due to similar distribution of genotype frequencies in HCC and CHB, we combined these two groups (HBV carriers). The genotype distribution in HBV carriers relative to those who resolved HBV showed that rs3077 and rs9277378 were significantly associated with protective effects against CHB in minor dominant model (OR = 0.45, p<0.001 and OR = 0.47, p<0.001). The other SNPs rs3128917, rs1419881 and rs652888 were not associated with HBV carriers. Conclusions: Genetic variations of rs3077 and rs9277378, but not rs3128917, rs1419881 and rs652888, were significantly associated with HBV carriers relative to resolved HBV in Thai population. © 2014 Posuwan et al.
  • JSH Guidelines for the Management of Hepatitis C Virus Infection: A 2014 Update for Genotype 1, Yasuhiro Asahina, Norio Hayashi, Naoki Hiramatsu, Namiki Izumi, Kazuhiko Koike, Hiromitsu Kumada, Masayuki Kurosaki, Makoto Oketani, Fumitaka Suzuki, Hajime Takikawa, Atsushi Tanaka, Eiji Tanaka, Yasuhito Tanaka, Hirohito Tsubouchi, Hiroshi Yotsuyanagi, Hepatology Research, 44, 59 - 70,   2014年01月16日
  • JSH Guidelines for the Management of Hepatitis B Virus Infection, Yasuhiro Asahina, Norio Hayashi, Naoki Hiramatsu, Namiki Izumi, Kazuhiko Koike, Hiromitsu Kumada, Masayuki Kurosaki, Makoto Oketani, Fumitaka Suzuki, Hajime Takikawa, Atsushi Tanaka, Eiji Tanaka, Yasuhito Tanaka, Hirohito Tsubouchi, Hiroshi Yotsuyanagi, Hepatology Research, 44, 1 - 58,   2014年01月16日
  • Risk factors for long-term persistence of serum hepatitis B surface antigen following acute hepatitis B virus infection in Japanese adults, Kiyoaki Ito, Kiyoaki Ito, Hiroshi Yotsuyanagi, Hiroshi Yatsuhashi, Yoshiyasu Karino, Yasuhiro Takikawa, Takafumi Saito, Yasuji Arase, Fumio Imazeki, Masayuki Kurosaki, Takeji Umemura, Takafumi Ichida, Hidenori Toyoda, Masashi Yoneda, Eiji Mita, Kazuhide Yamamoto, Kojiro Michitaka, Tatsuji Maeshiro, Junko Tanuma, Yasuhito Tanaka, Masaya Sugiyama, Kazumoto Murata, Naohiko Masaki, Masashi Mizokami, Yasuharu Imai, Norie Yamada, Hideaki Takahashi, Koji Ishii, Hideyuki Nomura, Jiro Nishida, Shigeru Mikami, Tsuneo Kitamura, Akihito Tsubota, Noritomo Shimada, Tetsuya Ishikawa, Yoshiyuki Ueno, Tomoyoshi Ohno, Etsuro Orito, Michihiro Suzuki, Hitoshi Takagi, Eiichi Tomita, Kumada Takashi, Toshihiko Mizuta, Tetsuya Mine, Jong Hon Kang, Katsuji Hirano, Hirohito Tsubouchi, Akito Nozaki, Akito Sakai, Shuhei Nishiguchi, Akihiro Tamori, Satoru Hagiwara, Takahide Nakazawa, Michio Sata, Toshiro Kamoshida, Atsushi Takahashi, Satoshi Kakizaki, Yoshimasa Kobayashi, Shigeru Sasaki, Tadashi Ikegami, Yoichi Hiasa, Kenji Nagata, Tomoyuki Kubota, Hiroshi Mitsui, Norihiko Yamamoto, Masataka Tsuge, Shuichi Sato, Yoshito Ito, Wataru Sato, Shigeharu Uchida, Yuki Tada, Toshiaki Mizuochi, Norihiro Furusho, Shuhei Hige, Hepatology, 59, 89 - 97,   2014年01月01日, © 2013 by the American Association for the Study of Liver Diseases. The proportion of patients who progress to chronicity following acute hepatitis B (AHB) varies widely worldwide. Moreover, the association between viral persistence after AHB and hepatitis B virus (HBV) genotypes in adults remains unclear. A nationwide multicenter study was conducted throughout Japan to evaluate the influence of clinical and virological factors on chronic outcomes in patients with AHB. For comparing factors between AHB patients with viral persistence and those with self-limited infection, 212 AHB patients without human immunodeficiency virus (HIV) coinfection were observed in 38 liver centers until serum hepatitis B surface antigen (HBsAg) disappeared or a minimum of 6 months in cases where HBsAg persisted. The time to disappearance of HBsAg was significantly longer for genotype A patients than that of patients infected with non-A genotypes. When chronicity was defined as the persistence of HBsAg positivity for more than 6 or 12 months, the rate of progression to chronicity was higher in patients with genotype A, although many cases caused by genotype A were prolonged cases of AHB, rather than chronic infection. Multivariate logistic regression analysis revealed only genotype A was independently associated with viral persistence following AHB. A higher peak level of HBV DNA and a lower peak of alanine aminotransferase (ALT) levels were characteristics of AHB caused by genotype A. Treatment with nucleotide analogs (NAs) did not prevent progression to chronic infection following AHB overall. Subanalysis suggested early NA initiation may enhance the viral clearance. Conclusion: Genotype A was an independent risk factor for progression to chronic infection following AHB. Our data will be useful in elucidating the association between viral persistence after AHB, host genetic factors, and treatment with NAs in future studies.
  • Strong prediction of virological response to combination therapy by IL28B gene variants rs12979860 and rs8099917 in chronic hepatitis C genotype 4, Mostafa M. Ragheb, Nader A. Nemr, Rania M. Kishk, Mohamed F. Mandour, Mohamed M. Abdou, Kentaro Matsuura, Tsunamasa Watanabe, Yasuhito Tanaka, Liver International, 34, 890 - 895,   2014年01月01日, Background: A strong association between single nucleotide polymorphisms (SNPs) of IL28B and treatment outcomes of pegylated interferon-α (PEG IFNα) and ribavirin (RBV) has been shown in chronic hepatitis C (CHC) patients with genotype 1. Aim: This study aimed to assess two SNPs of IL28B, rs12979860 and rs8099917, in predicting sustained virological responses (SVR) to treatment of CHC patients with genotype 4 (HCV-4). The value of rs8099917 was investigated in carriers of unfavourable genotypes of rs12979860. Methods: This study included 119 CHC patients with HCV-4 receiving combination therapy. Both SNPs of IL28B were determined by real-time detection polymerase chain reaction. Results: Genotypes CC/CT/TT of rs12979860 were found in 42 (35.3%), 56 (47.1%) and 21 (17.6%) and rs8099917 TT/TG/GG were found in 74 (62.2%), 40 (33.6%) and 5 (4.2%). In carriers of rs12979860 CC and rs8099917 TT, the rate of SVR was 87.5 and 65.7% respectively. In 54 patients heterozygous for the C allele of rs12979860, testing of rs8099917 revealed SVR in 42.3% of carriers of the TT genotype but no such responses in carriers of TG or GG (P < 0.0001, OR = 47.3, 95% CI: 2.33-767.2). By multivariate analysis, predictors of SVR were baseline ALT (P = 0.014, OR = 6.3, 95% CI: 1.45-27.33), rs12979860 CC (P = 0.001, OR = 13.48, 95% CI: 2.95-61.69) and rs8099917 TT (P = 0.027, OR = 7.5, 95% CI: 1.25-44.88). Conclusion: In CHC genotype 4 patients, favourable genotypes of both SNPs of IL28B are valuable for predicting SVR. Additional genotyping of rs8099917 in carriers of the heterozygous C allele of rs12979860 can improve the prediction of SVR. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
  • Reactivation of hepatitis B virus in a patient with adult T-cell leukemia-lymphoma receiving the anti-CC chemokine receptor 4 antibody mogamulizumab, Nobuaki Nakano, Shigeru Kusumoto, Yasuhito Tanaka, Takashi Ishida, Shogo Takeuchi, Yoshifusa Takatsuka, Shiro Akinaga, Masashi Mizokami, Ryuzo Ueda, Atae Utsunomiya, Hepatology Research, 44, 354 - 357,   2014年01月01日, The introduction of molecularly targeted drugs has increased the risk of reactivation of hepatitis B virus (HBV), which is a potentially fatal complication following anticancer chemotherapy even in patients who have previously resolved their HBV infection. CC chemokine receptor 4 (CCR4) has been identified as a novel molecular target in antibody therapy for patients with adult T-cell leukemia-lymphoma (ATL) and peripheral T-cell lymphoma, and the humanized anti-CCR4 monoclonal antibody mogamulizumab has been developed. We reported HBV reactivation of an ATL patient with previously resolved HBV infection after mogamulizumab treatment in a dose-finding study for this antibody. Our retrospective analysis using preserved samples also revealed the detailed kinetics of HBV DNA levels before and just after HBV reactivation. © 2013 The Japan Society of Hepatology.
  • Pretreatment prediction of the outcome of response-guided peginterferon-α and ribavirin therapy for chronic hepatitis C, Naohiko Masaki, Masaya Sugiyama, Noritomo Shimada, Yasuhito Tanaka, Makoto Nakamuta, Namiki Izumi, Sumio Watanabe, Akihito Tsubota, Masafumi Komatsu, Tsutomu Masaki, Nobuyuki Enomoto, Masashi Yoneda, Kazumoto Murata, Kiyoaki Ito, Kiyoaki Ito, Kazuhiko Koike, Masashi Mizokami, Journal of Gastroenterology and Hepatology (Australia), 29, 1996 - 2005,   2014年01月01日, © 2014 Wiley Publishing Asia Pty Ltd and Journal of Gastroenterology and Hepatology Foundation. Background and Aim: The accuracy for predicting virological outcomes of peginterferon-α and ribavirin therapy in patients with chronic hepatitis C is limited to approximately 80%, even with IL28B genotyping. Our in vitro study revealed that the numbers of (TA) dinucleotide repeats [(TA)n] of rs72258881, which is located in the promoter region of IL28B gene, might regulate IL28B transcription. We aimed to evaluate the usefulness of these host factors for predicting virological outcomes of this therapy in response-guided clinical settings. Methods: A nationwide, multi-center prospective study in Japan determined IL28B (rs8099917) genotype, (TA)n of rs72258881, and amino acid substitutions of hepatitis C virus and used these for multivariate analysis together with other parameters at pretreatment. Results: After enrolling 215 patients with genotype 1 and high viral load from 23 hospitals between October 2009 and February 2011, intent-to-treat analysis identified 202 patients in whom the final virological outcomes could be determined. Non-virological response by non-TT genotype was predicted with 79.7% accuracy. When combined with the (TA)n, the incidences of virological response tended to be higher in the longer (TA)n group, regardless of rs8099917 genotype. Multivariate logistic regression analysis revealed that rs8099917 non-TT genotype (P<0.001), shorter (TA)n (P=0.011), mutation of amino acid 70 in the virus core region (P=0.029), and lower levels of serum albumin (P=0.036) were independently associated with non-virological response. Conclusions: IL28B genotype and (TA)n of rs72258881 may independently affect virological outcomes of peginterferon-α and ribavirin as host factors, even in response-guided therapy.
  • ITPA genetic variants influence efficacy of PEG-IFN/RBV therapy in older patients infected with HCV genotype 1 and favourable IL28B type, K. Matsuura, K. Matsuura, Y. Tanaka, T. Watanabe, K. Fujiwara, E. Orito, M. Kurosaki, N. Izumi, N. Sakamoto, N. Sakamoto, N. Enomoto, H. Yatsuhashi, A. Kusakabe, N. Shinkai, S. Nojiri, T. Joh, M. Mizokami, Journal of Viral Hepatitis, 21, 466 - 474,   2014年01月01日, Summary Inosine triphosphatase (ITPA) genetic variants are strongly associated with ribavirin (RBV)-induced anaemia during pegylated interferon (PEG-IFN) plus RBV therapy. However, the treatment efficacy of ITPA genetic variants has not been fully explored. We enrolled 309 individuals infected with hepatitis C virus genotype 1, who were treated with PEG-IFN plus RBV for 48 weeks. The ITPA SNP: rs1127354 and IL28B SNP: rs8099917 were genotyped. We examined the risk factors for severe anaemia up to week 12 after the start of treatment and treatment efficacy. The incidence of severe anaemia, ≥3 g/dL reduction or <10 g/dL of haemoglobin (Hb) up to week 12, was more frequent in patients with CC at rs1127354 [65% (145/224), 33% (73/224)] than in those with CA/AA [25% (21/85), 6% (8/85)] (P < 0.0001). ITPA genotype, pretreatment Hb level and age were independent predictive factors for severe anaemia: Hb < 10 g/dL. In IL28B favourable type, the sustained virologic response rate was higher in ≥60-year-old patients with CA/AA than in those with CC [71% (22/31) vs 40% (26/65), P = 0.005], although there was no significant difference in treatment efficacy according to ITPA genetic variants in the <60-year-old patients. The proportion of patients administered ≥80% of the dosage of RBV was significantly higher in the patients with CA/AA than in those with CC (P = 0.025), resulting in a lower relapse rate. In conclusion, ITPA genetic variants were associated with severe RBV-induced anaemia and could influence the efficacy of PEG-IFN plus RBV treatment among elderly patients with IL28B favourable type. © 2013 John Wiley & Sons Ltd.
  • JSH guidelines for the management of hepatitis C virus infection (ver 3; abstract), Yasuhiro Asahina, Namiki Izumi, Hiromitsu Kumada, Masayuki Kurosaki, Kazuhiko Koike, Fumitaka Suzuki, Hajime Takikawa, Atsushi Tanaka, Eiji Tanaka, Yasuhito Tanaka, Hirohito Tsubouchi, Norio Hayashi, Naoki Hiramatsu, Hiroshi Yotsuyanagi, Acta Hepatologica Japonica, 55, 634 - 644,   2014年01月01日
  • Relationship between inosine triphosphate genotype and outcome of extended therapy in hepatitis C virus patients with a late viral response to pegylated-interferon and ribavirin, Hoang Hai, Akihiro Tamori, Masaru Enomoto, Hiroyasu Morikawa, Sawako Uchida-Kobayashi, Hideki Fujii, Atsushi Hagihara, Etsushi Kawamura, Le Thi Thanh Thuy, Yasuhito Tanaka, Norifumi Kawada, Journal of Gastroenterology and Hepatology (Australia), 29, 201 - 207,   2014年01月01日, Background and Aim: It is not yet clear which factors are associated with the outcome of 72-week treatment with pegylated-interferon and ribavirin (RBV) in patients with chronic hepatitis C virus (HCV) infection. Methods: In 66 patients with HCV genotype 1 who had a late viral response (LVR) to 72-week treatment of pegylated-interferon and RBV, we examined the factors that determined the outcome, including single nucleotide polymorphisms of interleukin-28B and inosine triphosphatase (ITPA) genes. Results: Thirty seven of 66 (56%) patients with LVR achieved a sustained viral response (SVR). The mean age of these 37 SVR patients was 55, compared with 61 in 29 relapsed patients (P=0.009). Twenty six of 54 (48%) patients with the CC genotype and 11 of 12 (92%) with the CA/AA genotype of ITPA rs1127354 achieved SVR (P=0.006). The SVR rates were 79%, 40%, 60%, and 33% in patients with undetectable HCV RNA on weeks 16, 20, 24, and 28 or later, respectively (P=0.014). Finally, serum RBV concentration at week 44 of treatment was significantly higher in the SVR group (2651ng/mL) than in the relapse group (1989ng/mL, P=0.002). In contrast, the rate of the interleukin-28B genotype was not different between the groups. Multiple regression analysis showed that age <60 years, ITPA CA/AA genotype, and serum RBV concentration were significant independent predictive factors for SVR. Conclusions: Our findings elucidated the association of four factors, including ITPA genotype, with the outcome of 72-week treatment in LVR patients. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.
  • Cyclosporin A and its analogs inhibit hepatitis B virus entry into cultured hepatocytes through targeting a membrane transporter, sodium taurocholate cotransporting polypeptide (NTCP), Koichi Watashi, Ann Sluder, Takuji Daito, Takuji Daito, Satoko Matsunaga, Akihide Ryo, Shushi Nagamori, Masashi Iwamoto, Syo Nakajima, Senko Tsukuda, Senko Tsukuda, Katyna Borroto-Esoda, Masaya Sugiyama, Yasuhito Tanaka, Yoshikatsu Kanai, Hiroyuki Kusuhara, Masashi Mizokami, Takaji Wakita, Hepatology, 59, 1726 - 1737,   2014年01月01日, Chronic hepatitis B virus (HBV) infection is a major public health problem worldwide. Although nucleos(t)ide analogs inhibiting viral reverse transcriptase are clinically available as anti-HBV agents, emergence of drug-resistant viruses highlights the need for new anti-HBV agents interfering with other targets. Here we report that cyclosporin A (CsA) can inhibit HBV entry into cultured hepatocytes. The anti-HBV effect of CsA was independent of binding to cyclophilin and calcineurin. Rather, blockade of HBV infection correlated with the ability to inhibit the transporter activity of sodium taurocholate cotransporting polypeptide (NTCP). We also found that HBV infection-susceptible cells, differentiated HepaRG cells and primary human hepatocytes expressed NTCP, while nonsusceptible cell lines did not. A series of compounds targeting NTCP could inhibit HBV infection. CsA inhibited the binding between NTCP and large envelope protein in vitro. Evaluation of CsA analogs identified a compound with higher anti-HBV potency, having a median inhibitory concentration <0.2 μM. Conclusion: This study provides a proof of concept for the novel strategy to identify anti-HBV agents by targeting the candidate HBV receptor, NTCP, using CsA as a structural platform. © 2014 The Authors. Hepatology published by Wiley on behalf of the American Association for the Study of Liver Diseases.
  • A case of a HBV carrier with HDV superinfection treated by PEG-IFN, Atsunori Kusakabe, Yasuhito Tanaka, Etsuko Iio, Shuko Murakami, Kentaro Matsuura, Noboru Shinkai, Tomokatsu Miyaki, Kei Fujiwara, Shunsuke Nojiri, Etsuro Orito, Takashi Joh, Acta Hepatologica Japonica, 55, 653 - 660,   2014年01月01日, © 2014 The Japan Society of Hepatology. A 26-year-old Mongolian woman was admitted to our hospital because of liver dysfunction As she has been a HBV carrier, acute exacerbation of chronic hepatitis B seemed to be the cause of liver dysfunction at first. However, the loads of serum HBV-DNA on admission were low (2.8 log copy/ml). As she was pregnant, she was observed without treatment. Liver function once improved without treatment, but it became worse again after delivery. At this time, it was suspected HDV superinfection could affect the liver dysfunction. For HDV-RNA was positive in stored sera by RT-PCR, she was diagnosed as HBV and HDV superinfection and started treatment with Peg-IFN. Although HDV infection is rare in Japan, in case of acute exacerbation of a HBV carrier with low serum HBV-DNA level, HBV and HDV superinfection should be considered.
  • Strategy for preventing hepatitis B reactivation in patients with resolved hepatitis B virus infection after rituximab-containing chemotherapy, Shigeru Kusumoto, Yasuhito Tanaka, Masashi Mizokami, Ryuzo Ueda, Hepatology, 60, (2) 765 - 766,   2014年01月01日, 査読有り
  • Hepatitis virus infection affects DNA methylation in mice with humanized livers, Yasuyuki Okamoto, Yasuyuki Okamoto, Yasuyuki Okamoto, Keiko Shinjo, Keiko Shinjo, Yasuhiro Shimizu, Tsuyoshi Sano, Kenji Yamao, Wentao Gao, Makiko Fujii, Hirotaka Osada, Yoshitaka Sekido, Shuko Murakami, Yasuhito Tanaka, Takashi Joh, Shinya Sato, Satoru Takahashi, Takaji Wakita, Jingde Zhu, Jean Pierre J. Issa, Yutaka Kondo, Yutaka Kondo, Yutaka Kondo, Gastroenterology, 146, (2) 562 - 572,   2014年01月01日, 査読有り, Background & Aims Cells of tumors associated with chronic inflammation frequently have altered patterns of DNA methylation, including hepatocellular carcinomas. Chronic hepatitis has also been associated with aberrant DNA methylation, but little is known about their relationship. Methods Pyrosequencing was used to determine the methylation status of cultured Huh7.5.1 hepatoma cells after hepatitis C virus (HCV) infection. We also studied mice with severe combined immunodeficiency carrying the urokinase-type plasminogen activator transgene controlled by an albumin promoter (urokinase-type plasminogen activator/severe combined immunodeficient mice), in which up to 85% of hepatocytes were replaced by human hepatocytes (chimeric mice). Mice were given intravenous injections of hepatitis B virus (HBV) or HCV, liver tissues were collected, and DNA methylation profiles were determined at different time points after infection. We also compared methylation patterns between paired samples of hepatocellular carcinomas and adjacent nontumor liver tissues from patients. Results No reproducible changes in DNA methylation were observed after infection of Huh7.5.1 cells with HCV. Livers from HBV- and HCV-infected mice had genome-wide, time-dependent changes in DNA methylation, compared with uninfected urokinase-type plasminogen activator/severe combined immunodeficient mice. There were changes in 160 ± 63 genes in HBV-infected and 237 ± 110 genes in HCV-infected mice. Methylation of 149 common genes increased in HBV- and HCV-infected mice; methylation of some of these genes also increased in hepatocellular carcinoma samples from patients compared with nontumor tissues. Expression of Ifng, which is expressed by natural killer cells, increased significantly in chimeric livers, in concordance with induction of DNA methylation, after infection with HBV or HCV. Induction of Ifng was reduced after administration of an inhibitor of natural killer cell function (anti-asialo GM1). Conclusions In chimeric mice with humanized livers, infection with HBV and HCV appears to activate a natural kill cell-dependent innate immune response. This contributes to the induction and accumulation of aberrant DNA methylation in human hepatocytes. © 2014 by the AGA Institute.
  • Role of IL28B for chronic hepatitis C treatment toward personalized medicine, Kentaro Matsuura, Kentaro Matsuura, Kentaro Matsuura, Tsunamasa Watanabe, Yasuhito Tanaka, Journal of Gastroenterology and Hepatology (Australia), 29, (2) 241 - 249,   2014年01月01日, 査読有り, © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd. Genome-wide association studies recently revealed that certain interleukin-28B (IL28B) polymorphisms are strongly associated with responses to pegylated interferon (PEG-IFN) and ribavirin (RBV) therapy in patients chronically infected with hepatitis C virus (HCV) genotype 1, as well as with spontaneous clearance of HCV. Subsequent reports revealed that IL28B genotypes also affect treatment efficacy in chronic infection with other HCV genotypes. Furthermore, there have been several reports that implicate IL28B genotypes in inflammatory status, progression of fibrosis and adverse clinical outcomes in chronic hepatitis C (CHC). Therapy of CHC recently entered a new era with the deployment of direct-acting antivirals. These include nonstructural 3/4A protease inhibitors which have shown promise in combination with PEG-IFN/RBV in several clinical trials. IFN-free therapy is expected to be useful especially in IFN-resistant patients and may become the standard of care in the future. Several clinical trials have revealed an association between IL28B genotype and treatment efficacy in triple therapy or IFN-free regimens. On the other hand the mechanism of the effect of IL28B on HCV infection has not yet been elucidated. Recently, it was shown that the polymorphism of IFN-lambda 4 (IFNL4) is in high linkage disequilibrium with that of near IL28B, and more strongly associated with spontaneous or treatment-induced HCV clearance than IL28B genotypes, especially in individuals of African ancestry. This finding provides new insights into the genetic regulation of HCV clearance and its clinical management. IL28B genotyping will be also useful for personalized CHC treatment in the forthcoming era of direct-acting antivirals.
  • Novel point mutations and mutational complexes in the enhancer II, core promoter and precore regions of hepatitis B virus genotype D1 associated with hepatocellular carcinoma in Saudi Arabia, Anis Khan, Anis Khan, Mohammed A. Al Balwi, Mohammed A. Al Balwi, Mohammed A. Al Balwi, Yasuhito Tanaka, Ali Hajeer, Ali Hajeer, Faisal M. Sanai, Ibrahim Al Abdulkarim, Latifah Al Ayyar, Motasim Badri, Dib Saudi, Waleed Tamimi, Masashi Mizokami, Masashi Mizokami, Bandar Al Knawy, International Journal of Cancer, 133, (12) 2864 - 2871,   2013年12月15日, 査読有り, In this study, a cohort of 182 patients [55 hepatocellular carcinoma (HCC) and 127 non-HCC] infected with hepatitis B virus (HBV) in Saudi Arabia was investigated to study the relationship between sequence variation in the enhancer II (EnhII), basal core promoter (BCP) and precore regions of HBV genotype D (HBV/D) and the risk of HCC. HBV genotypes were determined by sequencing analysis and/or enzyme-linked immunosorbent assay. Variations in the EnhII, BCP and precore regions were compared between 107 non-HCC and 45 HCC patients infected with HBV/D, followed by age-matched analysis of 40 cases versus equal number of controls. Age and male gender were significantly associated with HCC (p = 0.0001 and p = 0.03, respectively). Serological markers such as aspartate aminotransferase, albumin and anti-HBe were significantly associated with HCC (p = 0.0001 for all), whereas HBeAg positivity was associated with non-HCC (p = 0.0001). The most prevalent HBV genotype was HBV/D (94%), followed by HBV/E (4%), HBV/A (1.6%) and HBV/C (0.5%). For HBV/D1, genomic mutations associated with HCC were T1673/G1679, G1727, C1741, C1761, A1757/T1764/G1766, T1773, T1773/G1775 and C1909. Age- and gender-adjusted stepwise logistic regression analysis indicated that mutations G1727 [odds ratio (OR) = 18.3; 95% confidence interval (CI) = 2.8-118.4; p = 0.002], A1757/T1764/G1766 (OR = 4.7; 95% CI = 1.3-17.2; p = 0.01) and T1773 (OR = 14.06; 95% CI = 2.3-84.8; p = 0.004) are independent predictors of HCC development. These results implicate novel individual and combination patterns of mutations in the X/precore region of HBV/D1 as predictors of HCC. Risk stratification based on these mutation complexes would be useful in determining high-risk patients and improving diagnostic and treatment strategies for HBV/D1. © 2013 UICC.
  • Is antiviral prophylaxis necessary to prevent hepatitis b virus (HBV) reactivation in patients with HBV-resolved infection receiving rituximab-containing chemotherapy?, Shigeru Kusumoto, Yasuhito Tanaka, Masashi Mizokami, Ryuzo Ueda, Journal of Clinical Oncology, 31, (35) ,   2013年12月10日, 査読有り
  • In vitro replication competence of a hepatitis B genotype D/A recombinant virus: Dissimilar biological behaviour regarding its parental genotypes, Julieta Trinks, Julieta Trinks, Masaya Sugiyama, Masaya Sugiyama, Yasuhito Tanaka, Fuat Kurbanov, Jorge Benetucci, Edgardo Giménez, Mercedes C. Weissenbacher, Mercedes C. Weissenbacher, Masashi Mizokami, José R. Oubiña, Journal of General Virology, 94, 2724 - 2728,   2013年12月01日, Hepatitis B virus (HBV) DNA recombinants contribute to ~30% of the overall full-length sequences already deposited in GenBank. However, their biological behaviour has not been analysed so far. In this study, the in vitro replication kinetics of the first D/A recombinant from the American continent differed from its parental genotypes, exhibiting higher extracellular levels of HBV DNA and hepatitis B e antigen. Southern blots of intracellular core-associated HBV DNA were in agreement with such results. Because this recombinant was obtained from an Argentinian injecting drug user belonging to a vulnerable community, these results are of singular relevance for regional public health. Further in vivo studies are urgently needed to determine the pathogenicity of these replicative competent clones. © 2013 SGM.
  • Hepatitis C virus genotype 2 may not be detected by the Cobas Ampliprep/Cobas TaqMan HCV test, version 1.0, Tsunamasa Watanabe, Takako Inoue, Yasushi Tanoue, Hisato Maekawa, Susumu Hamada-Tsutsumi, Shinsho Yoshiba, Yasuhito Tanaka, Yasuhito Tanaka, Journal of Clinical Microbiology, 51, (12) 4275 - 4276,   2013年12月01日, 査読有り
  • Hepatic failure in pregnancy successfully treated by online hemodiafiltration: Chronic hepatitis B virus infection without viral genome mutation, Shinju Arata, Akito Nozaki, Kenichi Takizawa, Masaaki Kondo, Manabu Morimoto, Kazushi Numata, Sanae Hayashi, Tsunamasa Watanabe, Yasuhito Tanaka, Katsuaki Tanaka, Hepatology Research, 43, 1356 - 1360,   2013年12月01日, A 23-year-old nulliparous woman, a hepatitis B virus (HBV) carrier with stable liver functions, presented with exacerbation of viral replication (HBV DNA level >9.0log copies/mL) in gestational week 26. During the subsequent follow up without antiviral therapy, she was hospitalized with progression to hepatic failure in gestational week 35. Following initiation of antiviral therapy with lamivudine, emergent cesarean delivery was conducted for fetal safety. Liver atrophy and persistent hepatic encephalopathy (stage 2) necessitated artificial liver support (ALS) involving online hemodiafiltration (HDF) and plasma exchange. She regained full consciousness after the sixth online HDF session. ALS was terminated after the seventh online HDF session. On day 33 of hospitalization, she was discharged home without sequelae. Genetic analysis of the HBV strain isolated from her serum showed that this strain had genotype C. Direct full-length sequencing identified no known mutations associated with fulminant hepatitis B. HBV-related hepatic failure observed in the present case might have been related to perinatal changes in the host immune response. © 2013 The Japan Society of Hepatology.
  • Plasma levels of adiponectin and primary liver cancer risk in middle-aged Japanese adults with hepatitis virus infection: A nested case-control study, Takehiro Michikawa, Takehiro Michikawa, Manami Inoue, Manami Inoue, Norie Sawada, Shizuka Sasazuki, Yasuhito Tanaka, Motoki Iwasaki, Taichi Shimazu, Taiki Yamaji, Masashi Mizokami, Shoichiro Tsugane, Cancer Epidemiology Biomarkers and Prevention, 22, (12) 2250 - 2257,   2013年12月01日, 査読有り, Background: Excess body weight is an independent risk factor for primary liver cancer, and the role of adiponectin in the pathogenesis of obesity-related malignancies is a focus of research interest. Few prospective studies have examined the association between circulating adiponectin and liver cancer risk, so we investigated this association in a nested case-control study of a population-based prospective cohort in Japan. Methods: From 18,628 target participants of ages 40 to 69 years who returned the baseline questionnaire and provided blood samples, we selected those with either hepatitis B or C virus infection at baseline (n = 1,544). Among these, 90 were newly diagnosed with primary liver cancer from 1993 through 2006, and matched to 177 controls. The ORs of liver cancer development based on plasma levels of adiponectin were estimated with a conditional logistic regression model. Results: Median values of total and high-molecular-weight (HMW) adiponectin tended to be higher in the patients with liver cancer, and plasma levels of adiponectin were positively associated with liver cancer risk. Body mass index- and diabetes-adjusted ORs for the highest tertile of total and HMW adiponectin levels versus the lowest were 3.30 [95% confidence interval (CI), 1.45-7.53; Ptrend< 0.01] and 3.41 (95% CI, 1.50-7.73; Ptrend< 0.01), respectively. There was no effect modification by body mass index and diabetes. Conclusions: Higher plasma adiponectin levels were associated with an increased risk of primary liver cancer in middle-aged Japanese adults with hepatitis virus infection. Impact: Circulating adiponectin levels may be a risk marker for primary liver cancer. © 2013 AACR.
  • Interleukin-1 and tumor necrosis factor-α trigger restriction of hepatitis b virus infection via a cytidine deaminase activation-induced cytidine deaminase (AID), Koichi Watashi, Guoxin Liang, Masashi Iwamoto, Hiroyuki Marusawa, Nanako Uchida, Takuji Daito, Kouichi Kitamura, Masamichi Muramatsu, Hirofumi Ohashi, Tomoko Kiyohara, Ryosuke Suzuki, Jisu Li, Shuping Tong, Yasuhito Tanaka, Kazumoto Murata, Hideki Aizaki, Takaji Wakita, Journal of Biological Chemistry, 288, 31715 - 31727,   2013年11月01日, Virus infection is restricted by intracellular immune responses in host cells, and this is typically modulated by stimulation of cytokines. The cytokines and host factors that determine the host cell restriction against hepatitis B virus (HBV) infection are not well understood. We screened 36 cytokines and chemokines to determine which were able to reduce the susceptibility of HepaRG cells to HBV infection. Here, we found that pretreatment with IL-1β and TNFα remarkably reduced the host cell susceptibility to HBV infection. This effect was mediated by activation of the NF-κB signaling pathway. A cytidine deaminase, activation-induced cytidine deaminase (AID), was up-regulated by both IL-1β and TNFα in a variety of hepatocyte cell lines and primary human hepatocytes. Another deaminase APOBEC3G was not induced by these proinflammatory cytokines. Knockdown of AID expression impaired the anti-HBV effect of IL-1β, and overexpression of AID antagonized HBV infection, suggesting that AID was one of the responsible factors for the anti-HBV activity of IL-1/TNFα. Although AID induced hypermutation of HBV DNA, this activity was dispensable for the anti-HBV activity. The antiviral effect of IL-1/TNFα was also observed on different HBV genotypes but not on hepatitis C virus. These results demonstrate that proinflammatory cytokines IL-1/TNFα trigger a novel antiviral mechanism involving AID to regulate host cell permissiveness to HBV infection. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.
  • Factors of response to pegylated interferon/ribavirin combination therapy and mechanism of viral clearance, Kayo Sugimoto, Soo Ryang Kim, Ahmed El-Shamy, Susumu Imoto, Kenji Ando, Ke Ih Kim, Yasuhito Tanaka, Yoshihiko Yano, Soo Ki Kim, Yutaka Hasegawa, Aya Fujinami, Mitsuhiro Ohta, Hatae Takashi, Hak Hotta, Yoshitake Hayashi, Masatoshi Kudo, Digestive Diseases, 31, 421 - 425,   2013年11月01日, Objectives: This study explores viral factors of the interferon (IFN) and ribavirin (RBV) resistance-determining region (IRRDR), the IFN sensitivity-determining region (ISDR) and the core protein, and host factor interleukin 28B associated with response to pegylated IFN (PEG-IFN) and RBV combination therapy, and the correlation of viral and host factors with IFN-λ1. Methods: A total of 58 patients underwent PEG-IFN/RBV combination therapy for 48 weeks. The pretreatment factors associated with rapid virological response (RVR) and sustained virological response (SVR) were analyzed. Pretreatment IFN-λ1 serum levels were compared with the viral and host factors. Results: Univariate analysis showed that IRRDR ≥6 and ISDR ≥2 were significant pretreatment predictors of RVR, and multivariate analysis identified IRRDR ≥6 and hemoglobin as significant predictors of SVR. Pretreatment IFN-λ1 was significantly higher in the SVR group than in the non-SVR group and also in the IRRDR ≥6 group than in the IRRDR ≤5 group. Conclusions: IRRDR ≥6 was the only significant predictor of SVR and was correlated with IFN-λ1. High serum levels of IFN-λ1 may be conducive to effective PEG-IFN/RBV combination therapy because of the immunomodulatory system. © 2013 S. Karger AG, Basel.
  • Outcome of double-filtration plasmapheresis plus interferon treatment in nonresponders to pegylated interferon plus ribavirin combination therapy, Kayo Sugimoto, Soo Ryang Kim, Ahmed El-Shamy, Susumu Imoto, Haruma Fujioka, Ke Ih Kim, Yasuhito Tanaka, Yoshihiko Yano, Soo Ki Kim, Yutaka Hasegawa, Aya Fujinami, Mitsuhiro Ohta, Takashi Hatae, Hak Hotta, Yoshitake Hayashi, Masatoshi Kudo, Digestive Diseases, 31, 434 - 439,   2013年11月01日, Objectives: We assessed the outcome of double-filtration plasmapheresis (DFPP) combined with pegylated interferon (PEG-IFN) and ribavirin (RBV) therapy in patients infected with hepatitis C virus (HCV)-1b whose HCV had not disappeared during PEG-IFN/RBV combination therapy, or who had relapsed after the end of the therapy. Additionally, we investigated factors predictive of sustained virological response (SVR), including host and viral genetic factors, to DFPP plus IFN/RBV therapy. Methods: A total of 40 patients infected with HCV-1b whose HCV virus had not been eradicated by previous PEG-IFN/RBV therapy were enrolled for treatment by DFPP plus IFN/RBV. Rapid virological response (RVR) and SVR were assessed, and pretreatment factors associated with SVR - the interleukin (IL)28B gene, the IFN/RBV resistance-determining region (IRRDR) and the IFN sensitivity-determining region (ISDR) - were analyzed. Results: Of the 40 patients, 9 (23%) achieved RVR and 10 (25%) achieved SVR. The significant factors associated with SVR were IL28B major and RVR, as assessed by multivariate analysis (p = 0.0182, p = 0.0005). Conclusion: Patients whose HCV is not eradicated by previous PEG-IFN/RBV would be good candidates for combined DFPP and IFN/RBV retreatment provided they demonstrate IL28B major and have achieved RVR. © 2013 S. Karger AG, Basel.
  • Reactivation of hepatitis B virus in patients with undetectable HBsAg undergoing chemotherapy for malignant lymphoma or multiple myeloma, Takeshi Matsui, Takeshi Matsui, Jong Hon Kang, Masanori Nojima, Akiko Tomonari, Hironori Aoki, Hajime Yamazaki, Kei Yane, Kunihiko Tsuji, Seisho Andoh, Sachiko Andoh, Hajime Sakai, Masayo Maemori, Hiroyuki Maguchi, Yasuhito Tanaka, Journal of Medical Virology, 85, (11) 1900 - 1906,   2013年11月01日, 査読有り, Despite increasing reports of hepatitis B virus (HBV) reactivation in hematological malignancies, its incidence, and risk factors are still obscure. The aim of this study was to clarify the frequency and risk factors of HBV reactivation in hepatitis B surface antigen (HBsAg) undetectable patients with malignant lymphoma or multiple myeloma, during or after chemotherapy. A total of 109 patients with undetectable HBsAg undergoing chemotherapy for malignant lymphoma or multiple myeloma were enrolled in this study. Anti-hepatitis B surface (anti-HBs) and anti-hepatitis B core (anti-HBc) were checked before treatment, and HBV DNA in sera was quantified monthly during and after chemotherapy. Out of 109 patients, 42 (38.5%) had anti-HBs and 59 (54.1%) had anti-HBc. Among the 59 anti-HBc positive patients, four patients (4/59, 6.8%) showed HBV reactivation during 20.5 median follow-up months. In all four patients with HBV reactivation, peripheral lymphocyte counts before chemotherapy were lower than those without HBV reactivation (P=0.033). HBV reactivation occurred during and after chemotherapy containing rituximab for non-Hodgkin lymphoma. Four patients, who had HBV reactivation, did not develop de novo hepatitis due to HBV reactivation and were able to undergo chemotherapy against malignant lymphoma as scheduled. Monitoring of HBV DNA in sera is useful for the early diagnosis of HBV reactivation, and preemptive therapy is an useful alternative to prevent hepatitis due to HBV reactivation. Patients must be monitored periodically for HBV-DNA levels during and after chemotherapy. © 2013 Wiley Periodicals, Inc.
  • Application of a newly developed high-sensitivity HBsAg chemiluminescent enzyme immunoassay for hepatitis B patients with HBsAg seroclearance, Noboru Shinkai, Noboru Shinkai, Kentaro Matsuura, Kentaro Matsuura, Fuminaka Sugauchi, Fuminaka Sugauchi, Tsunamasa Watanabe, Shuko Murakami, Etsuko Iio, Etsuko Iio, Shintaro Ogawa, Shunsuke Nojiri, Takashi Joh, Yasuhito Tanaka, Journal of Clinical Microbiology, 51, (11) 3484 - 3491,   2013年11月01日, 査読有り, We modified and automated a highly sensitive chemiluminescent enzyme immunoassay (CLEIA) for surface antigen (HBsAg) detection using a combination of monoclonal antibodies, each for a specific epitope of HBsAg, and by improving an earlier conjugation technique.Of 471 hepatitis B virus (HBV) carriers seen in our hospital between 2009 and 2012, 26 were HBsAg seronegative as determined by the Abbott Architect assay.The Lumipulse HBsAg-HQ assay was used to recheck those 26 patients who demonstrated seroclearance by the Abbott Architect assay.The performance of the Lumipulse HBsAg-HQ assay was compared with that of a quantitative HBsAg detection system (Abbott Architect) and the Roche Cobas TaqMan HBV DNA assay (CTM) (lower limit of detection, 2.1 log copies/ml) using blood serum samples from patients who were determined to be HBsAg seronegative by the Abbott Architect assay.Ten patients had spontaneous HBsAg loss.Of 8 patients treated with nucleotide analogues (NAs), two were HBsAg seronegative after stopping lamivudine therapy and 6 were HBsAg seronegative during entecavir therapy.Eight acute hepatitis B (AH) patients became HBsAg seronegative.Of the 26 patients, 16 were HBsAg positive by the Lumipulse HBsAg-HQ assay but negative by the Abbott Architect assay.The differences between the two assays in terms of detectable HBsAg persisted over the long term in the spontaneous loss group (median, 10 months), the NA-treated group (2.5 months), and the AH group (0.5 months).In 9 patients, the Lumipulse HBsAg-HQ assay detected HBsAg when HBV DNA was negative by the CTM assay.HBsAg was also detected by the Lumipulse HBsAg-HQ assay in 4 patients with an anti-HBs concentration of>10 mIU/ml, 3 of whom had no HBsAg escape mutations.The automatic, highly sensitive HBsAg CLEIA Lumipulse HBsAg-HQ is a convenient and precise assay for HBV monitoring.© 2013, American Society for Microbiology.All Rights Reserved.
  • Incidence and characteristics of HBV reactivation in hematological malignant patients in south Egypt, Abeer Elkady, Abeer Elkady, Sahar Aboulfotuh, Elsayed Mostafa Ali, Douaa Sayed, Nashwa M. Abdel-Aziz, Amany M. Ali, Shuko Murakami, Sayuki Iijima, Yasuhito Tanaka, World Journal of Gastroenterology, 19, (37) 6214 - 6220,   2013年10月07日, 査読有り, Aim: To investigate characteristics of hepatitis B virus (HBV) implicated in HBV reactivation in patients with hematological malignancies receiving immunosuppressive therapy. Methods: Serum samples were collected from 53 patients with hematological malignancies negative for hepatitis B surface antigen (HBsAg) before the start of and throughout the chemotherapy course. HBV reactivation was diagnosed when the HBsAg status changed from negative to positive after the initiation of chemotherapy and/or when HBV DNA was detected by realtime detection polymerase chain reaction (RTD-PCR). For detecting the serological markers of HBV infection, HBsAg as well as antibodies to the core antigen (anti- HBc) and to the surface antigen were measured in the sera by CEIA. Nucleic acids were extracted from sera, and HBV DNA sequences spanning the S gene were amplified by RTD-PCR. The extracted DNA was further subjected to PCR to amplify the complete genome as well as the specific genomic sequences bearing the enhancer II/core promoter/pre-core/core regions (nt 1628-2364). Amplicons were sequenced directly. Results: Thirty-five (66%) of the 53 HBsAg-negative patients were found to be negative serologically for anti- HBc, and the remaining 18 (34%) patients were positive for anti-HBc. Five of the 53 (9.4%) patients with hematologic malignancies experienced HBV reactivation. Genotype D1 was detected in all five patients. Four types of mutant strains were detected in the S gene product of HBV strains and were isolated from 3 patients with HBV reactivation: T/S120, L143, and I126. HBV DNA was detected in the pretreatment HBsAg-negative samples in one of the five patients with HBV reactivation. In this patient, sequences encompassing the HBV full genome obtained from sera before the start of chemotherapy and at the time of de novo HBV hepatitis were detected and it showed 100% homology. Furthermore, in the phylogenetic tree, the sequences were clustered together, thereby indicating that this patient developed reactivation from an occult HBV infection. Conclusion: Past infection with HBV is a risk factor for HBV reactivation in Egypt. Mandatory anti-HBc screening prior to chemotherapy in patients with hematological malignancies is recommended. © 2013 Baishideng. All rights reserved.
  • Evolutionary analysis of hepatitis C virus gene sequences from 1953, Rebecca R. Gray, Yasuhito Tanaka, Yutaka Takebe, Gkikas Magiorkinis, Zelma Buskell, Leonard Seeff, Harvey J. Alter, Oliver G. Pybus, Philosophical Transactions of the Royal Society B: Biological Sciences, 368,   2013年09月19日, Reconstructing the transmission history of infectious diseases in the absence of medical or epidemiological records often relies on the evolutionary analysis of pathogen genetic sequences. The precision of evolutionary estimates of epidemic history can be increased by the inclusion of sequences derived from 'archived' samples that are genetically distinct from contemporary strains. Historical sequences are especially valuable for viral pathogens that circulated for many years before being formally identified, including HIV and the hepatitis C virus (HCV). However, surprisingly few HCV isolates sampled before discovery of the virus in 1989 are currently available. Here,we report and analyse two HCV subgenomic sequences obtained from infected individuals in 1953, which represent the oldest genetic evidence of HCV infection. The pairwise genetic diversity between the two sequences indicates a substantial period of HCV transmission prior to the 1950s, and their inclusion in evolutionary analyses provides new estimates of the common ancestor of HCV in the USA. To explore and validate the evolutionary information provided by these sequences, we used a new phylogenetic molecular clock method to estimate the date of sampling of the archived strains, plus the dates of four more contemporary reference genomes. Despite the short fragments available, we conclude that the archived sequences are consistent with a proposed sampling date of 1953, although statistical uncertainty is large. Our cross-validation analyses suggest that the bias and low statistical power observed here likely arise from a combination of high evolutionary rate heterogeneity and an unstructured, star-like phylogeny.We expect that attempts to date other historical viruses under similar circumstances will meet similar problems. © 2013 The Author(s) Published by the Royal Society. All rights reserved.
  • Molecular epidemiology and genetic history of hepatitis C virus subtype 3a infection in Thailand, Srunthron Akkarathamrongsin, Srunthron Akkarathamrongsin, Pitchaya Hacharoen, Pisit Tangkijvanich, Apiradee Theamboonlers, Yasuhito Tanaka, Masashi Mizokami, Yong Poovorawan, Intervirology, 56, 284 - 294,   2013年09月01日, Objective: Among all hepatitis C virus (HCV) infections, subtype 3a is the most common genotype in Thailand. This study investigates the molecular epidemiology and epidemic history of HCV subtype 3a in Thailand. Methods: Three hundred and fifty-six serum samples were collected from HCV-infected Thai patients. The virus was isolated, after which the core and NS5B regions were sequenced. Subsequently, the HCV genotype was classified by phylogenetic analysis based on the core and NS5B regions. Molecular evolution analysis of HCV subtype 3a was estimated using BEAST (Bayesian Evolutionary Analysis by Sampling Trees) v.1.5.4. Results: Based on our phylogenetic analyses, subtype 3a (38.5%) was the most prevalent, followed by 1a (21%), 1b (13.8%), genotype 6 (19.9%) [comprised of subtypes 6e (0.3%), 6f (11%), 6i (1.9%), 6j (1.9%) and 6n (4.8%)] and 3b (5.6%). Our phylogenetic tree indicates the existence of a specific group of HCV subtype 3a strains in the Thai population. Molecular evolutionary analysis dated the most recent common ancestor of the Thai HCV subtype 3a strains as existing approximately 200 ago, and a Bayesian skyline plot showed that this particular strain spread to Thailand during the mid-1970s and early 1980s. This period overlaps with the Vietnam War (1955-1975) and the widespread use of injection stimulants introduced by the US Army during this time. Conclusion: The estimated history of HCV subtype 3a infection in Thailand may help to predict the future burden of HCV-related diseases and facilitate better public health control and surveillance. © 2013 S. Karger AG, Basel.
  • Hepatitis C virus kinetics by administration of pegylated interferon-α in human and chimeric mice carrying human hepatocytes with variants of the IL28B gene, Tsunamasa Watanabe, Fuminaka Sugauchi, Yasuhito Tanaka, Kentaro Matsuura, Hiroshi Yatsuhashi, Shuko Murakami, Sayuki Iijima, Etsuko Iio, Masaya Sugiyama, Takashi Shimada, Masakazu Kakuni, Michinori Kohara, Masashi Mizokami, Gut, 62, (9) 1340 - 1346,   2013年09月01日, 査読有り, Objective Recent studies have demonstrated that genetic polymorphisms near the IL28B gene are associated with the clinical outcome of pegylated interferon α ( peg-IFN-α) plus ribavirin therapy for patients with chronic hepatitis C virus (HCV). However, it is unclear whether genetic variations near the IL28B gene influence hepatic interferon (IFN)-stimulated gene (ISG) induction or cellular immune responses, lead to the viral reduction during IFN treatment. Design Changes in HCV-RNA levels before therapy, at day 1 and weeks 1, 2, 4, 8 and 12 after administering peg-IFN-α plus ribavirin were measured in 54 patients infected with HCV genotype 1. Furthermore, we prepared four lines of chimeric mice having four different lots of human hepatocytes containing various single nucleotide polymorphisms (SNP) around the IL28B gene. HCV infecting chimeric mice were subcutaneously administered with peg-IFN-α for 2 weeks. Results There were significant differences in the reduction of HCV-RNA levels after peg-IFN-α plus ribavirin therapy based on the IL28B SNP rs8099917 between TT (favourable) and TG/GG (unfavourable) genotypes in patients; the first-phase viral decline slope per day and second-phase slope per week in TT genotype were significantly higher than in TG/GG genotype. On peg-IFN-α administration to chimeric mice, however, no significant difference in the median reduction of HCV-RNA levels and the induction of antiviral ISG was observed between favourable and unfavourable human hepatocyte genotypes. Conclusions As chimeric mice have the characteristic of immunodeficiency, the response to peg-IFN-α associated with the variation in IL28B alleles in chronic HCV patients would be composed of the intact immune system.
  • [Clinical evaluation of a newly developed high-sensitive detection of hepatitis B virus surface antigen by a semi-automated immune complex transfer chemiluminescent enzyme immunoassay]., Kumiko Ohne, Satomi Kani, Minoru Ohashi, Noboru Shinkai, Takako Inoue, Yukio Wakimoto, Yasuhito Tanaka, Rinsho byori. The Japanese journal of clinical pathology, 61, (9) 787 - 794,   2013年09月01日, 査読有り, A highly sensitive semi-automated immune complex transfer chemiluminescence enzyme immunoassay (ICT-CLEIA) for the detection of hepatitis B surface antigen (HBsAg) was recently developed. Our aim is to investigate clinical significance of ICT-CLEIA in patients with HBV. Of 829 HB carriers in our hospital and 167 commercial panels, performance of ICT-CLEIA(detection range 0.0005-2.5 IU/mL) was compared with two quantitative HBsAg detection systems (Architect HBsAg QT assay [0.05-250 IU/mL] and HISCL HBsAg assay [0.03-2500 IU/mL]) and COBAS TaqMan HBV-DNA assay (CTM, 2.1 Log copies/ml) using serum samples from patients or panels. The ICT-CLEIA had good accuracy and reproducibility. The sensitivity of wild type and HBsAg escape mutants (I126S, D144A, G145R) by ICT-CLEIA was 2- -5 to 2- -6 times higher than that of Architect HBsAg QT. For clinical practice, ICT-CLEIA assay could detect HBsAg even in the presence of anti-HBs during window periods in acute hepatitis B panel. HBsAg has been detectable for around 9 years in a patient with HBsAg clearance by Architect. In a patient with HBV reactivation after bone marrow transplantation followed by systematic chemotherapy, HBsAg by ICT-CLEIA was detectable at the same time point when HBV-DNA was detected by PCR. In conclusion, the ICT-CLEIA assay permits not only an earlier detection of acute hepatitis B infection but also may be useful for monitoring hepatitis B patients.
  • Glycoproteomic discovery of serological biomarker candidates for HCV/HBV infection-associated liver fibrosis and hepatocellular carcinoma, Hiroyuki Kaji, Makoto Ocho, Akira Togayachi, Atsushi Kuno, Maki Sogabe, Takashi Ohkura, Hirofumi Nozaki, Takashi Angata, Takashi Angata, Yasunori Chiba, Hidenori Ozaki, Jun Hirabayashi, Yasuhito Tanaka, Masashi Mizokami, Masashi Mizokami, Yuzuru Ikehara, Hisashi Narimatsu, Journal of Proteome Research, 12, 2630 - 2640,   2013年07月01日, We previously proposed a high-throughput strategy to discover serological biomarker candidates of cancer. This strategy focuses on a series of candidate glycoproteins that are specifically expressed in the original tissues (cells) of the target cancer and that carry glycan structures associated with carcinogenesis [Narimatsu, H., et al. FEBS J.2010, 277(1), 95-105]. Here, we examined the effectiveness of our strategy in identifying biomarkers to assess progression of liver fibrosis and for the early detection of hepatocellular carcinoma (HCC). On the basis of the results of lectin array analyses in culture media of hepatoma cell lines, we captured glycopeptides carrying AAL-ligands (fucosylated glycans) or DSA-ligands (branched glycans) from digests of culture media proteins and sera from HCC patients with a background of liver cirrhosis (LC). Glycoproteins were identified by the IGOT-LC-MS method. In all, 21 candidates were selected from 744 AAL-bound glycoproteins for further verification according to (i) their abundance in serum, (ii) their specific expression in liver, and (iii) the availability of antibodies to the glycoproteins. All selected candidates showed enhancement of AAL-reactivity in sera of HCC patients compared with that of healthy volunteers (HV). These results indicate that our glycoproteomic strategy is effective for identifying multiple glyco-biomarker candidates in a high-throughput manner. © 2013 American Chemical Society.
  • Role of HLA-DP Polymorphisms on Chronicity and Disease Activity of Hepatitis B Infection in Southern Chinese, Danny Ka Ho Wong, Danny Ka Ho Wong, Tsunamasa Watanabe, Yasuhito Tanaka, Wai Kay Seto, Cheuk Kwong Lee, James Fung, James Fung, Che Kit Lin, Fung Yu Huang, Ching Lung Lai, Ching Lung Lai, Man Fung Yuen, Man Fung Yuen, PLoS ONE, 8,   2013年06月25日, Background and Aims:The association between HLA-DP single nucleotide polymorphisms (SNPs) and chronic hepatitis B virus (HBV) infection varies between different populations. We aimed to study the association between HLA-DP SNPs and HBV infection and disease activity in the Chinese population of Hong Kong.Methods:We genotyped SNPs rs3077 (near HLA-DPA1) and rs9277378 and rs3128917 (both near HLA-DPB1) in 500 HBV carriers (hepatitis B surface antigen [HBsAg]-positive), 245 non-HBV infected controls (HBsAg- and antibody to hepatitis B core protein [anti-HBc]-negative), and 259 subjects with natural HBV clearance (HBsAg-negative, anti-HBc-positive). Inactive HBV carriers state was defined by HBV DNA levels <2,000 IU/ml and persistently normal alanine aminotransferase level for least 12 months.Results:Compared to the non-HBV infected subjects, the HBV carriers had a significantly lower frequency of the rs3077 T allele (p = 0.0040), rs9277378 A allele (p = 0.0068) and a trend for lower frequency of rs3128917 T allele (p = 0.054). These alleles were associated with an increased chance of HBV clearance (rs3077: OR = 1.41, p = 0.0083; rs9277378: OR = 1.61, p = 0.00011; rs3128917: OR = 1.54, p = 0.00017). Significant associations between HLA-DP genotypes and HBV clearance were also found under different genetic models. Haplotype TAT was associated with an increased chance of HBV clearance (OR = 1.64, p = 0.0013). No association was found between these SNPs and HBV disease activity.Conclusion:HLA-DP SNPs rs3077, rs9277378 and rs3128917 were associated with chronicity of HBV disease in the Chinese. Further studies are required to determine whether these SNPs influence the disease endemicity in different ethnic populations. © 2013 Wong et al.
  • The Cobas AmpliPrep/Cobas TaqMan real-time polymerase chain reaction assay produced false-negative results in two patients with hepatitis C virus genotype 2, Yasushi Tanoue, Hisato Maekawa, Takako Inoue, Tsunamasa Watanabe, Hiroki Shimoda, Takaaki Kuroda, Rika Nakano, Naoki Sasahira, Yasuhito Tanaka, Yasuhito Tanaka, Shinsho Yoshiba, Acta Hepatologica Japonica, 54, 507 - 508,   2013年05月30日, A highly-sensitive, reliable and easy-to-use measurement of hepatitis C virus (HCV) RNA is essential for diagnosis and treatment of patients with HCV infection. The Roche Cobas AmpliPrep/Cobas TaqMan real-time polymerase chain reaction (PCR) assay (CAP/CTM) is the most widely used commercial quantification for HCV RNA in Japan. Here, we report two patients with HCV genotype 2 in whom HCV RNA was undetectable by CAP/CTM, whereas HCV infection was confirmed with the Abbott RealTime HCV test and the chemiluminescence microparticle immunoassay (Abbott-ARCHITECT hepatitis C Core Antigen assay). It would be useful for checking by the other real-time PCR assay for those with high titer of anti-HCV and undetectable HCV RNA by routine assays. © 2013 The Japan Society of Hepatology.
  • Mechanism of the dependence of hepatitis B virus genotype G on co-infection with other genotypes for viral replication, T. Sakamoto, T. Sakamoto, Y. Tanaka, T. Watanabe, S. Iijima, S. Kani, M. Sugiyama, S. Murakami, K. Matsuura, K. Matsuura, A. Kusakabe, A. Kusakabe, N. Shinkai, N. Shinkai, F. Sugauchi, F. Sugauchi, M. Mizokami, M. Mizokami, Journal of Viral Hepatitis, 20,   2013年04月01日, Hepatitis B virus (HBV) is classified into several genotypes. Genotype G (HBV/G) is characterised by worldwide dispersion, low intragenotypic diversity and a peculiar sequence of the precore and core region (stop codon and 36-nucleotide insertion). As a rule, HBV/G is detected in co-infection with another genotype, most frequently HBV/A2. In a previous in vivo study, viral replication of HBV/G was significantly enhanced by co-infection with HBV/A2. However, the mechanism by which co-infection with HBV/A2 enhances HBV/G replication is not fully understood. In this study, we employed 1.24-fold HBV/A2 clones that selectively expressed each viral protein and revealed that the core protein expressing construct significantly enhanced the replication of HBV/G in Huh7 cells. The introduction of the HBV/A2 core promoter or core protein or both genomic regions into the HBV/G genome showed that both the core promoter and core protein are required for efficient HBV/G replication. The effect of genotype on the interaction between foreign core protein and HBV/G showed that HBV/A2 was the strongest enhancer of HBV/G replication. Furthermore, Western blot analysis of Dane particles isolated from cultures of Huh7 cells co-transfected by HBV/G and a cytomegalovirus (CMV) promoter-driven HBV/A2 core protein expression construct indicated that HBV/G employed HBV/A2 core protein during particle assembly. In conclusion, HBV/G could take advantage of core proteins from other genotypes during co-infection to replicate efficiently and to effectively package HBV DNA into virions. © 2013 Blackwell Publishing Ltd.
  • Targeted Induction of Interferon-λ in Humanized Chimeric Mouse Liver Abrogates Hepatotropic Virus Infection, Shin ichiro Nakagawa, Shin ichiro Nakagawa, Yuichi Hirata, Yuichi Hirata, Takeshi Kameyama, Yuko Tokunaga, Yasumasa Nishito, Kazuko Hirabayashi, Junichi Yano, Takahiro Ochiya, Chise Tateno, Yasuhito Tanaka, Masashi Mizokami, Kyoko Tsukiyama-Kohara, Kazuaki Inoue, Makoto Yoshiba, Akinori Takaoka, Michinori Kohara, PLoS ONE, 8,   2013年03月28日, Background & Aims: The interferon (IFN) system plays a critical role in innate antiviral response. We presume that targeted induction of IFN in human liver shows robust antiviral effects on hepatitis C virus (HCV) and hepatitis B virus (HBV). Methods: This study used chimeric mice harboring humanized livers and infected with HCV or HBV. This mouse model permitted simultaneous analysis of immune responses by human and mouse hepatocytes in the same liver and exploration of the mechanism of antiviral effect against these viruses. Targeted expression of IFN was induced by treating the animals with a complex comprising a hepatotropic cationic liposome and a synthetic double-stranded RNA analog, pIC (LIC-pIC). Viral replication, IFN gene expression, IFN protein production, and IFN antiviral activity were analyzed (for type I, II and III IFNs) in the livers and sera of these humanized chimeric mice. Results: Following treatment with LIC-pIC, the humanized livers of chimeric mice exhibited increased expression (at the mRNA and protein level) of human IFN-λs, resulting in strong antiviral effect on HBV and HCV. Similar increases were not seen for human IFN-α or IFN-β in these animals. Strong induction of IFN-λs by LIC-pIC occurred only in human hepatocytes, and not in mouse hepatocytes nor in human cell lines derived from other (non-hepatic) tissues. LIC-pIC-induced IFN-λ production was mediated by the immune sensor adaptor molecules mitochondrial antiviral signaling protein (MAVS) and Toll/IL-1R domain-containing adaptor molecule-1 (TICAM-1), suggesting dual recognition of LIC-pIC by both sensor adaptor pathways. Conclusions: These findings demonstrate that the expression and function of various IFNs differ depending on the animal species and tissues under investigation. Chimeric mice harboring humanized livers demonstrate that IFN-λs play an important role in the defense against human hepatic virus infection. © 2013 Nakagawa et al.
  • Evidence of serologic activity in chronic hepatitis B after surface antigen (HBsAg) seroclearance documented by conventional HBsAg assay, Wai Kay Seto, Yasuhito Tanaka, Danny Ka Ho Wong, Ching Lung Lai, Ching Lung Lai, Noboru Shinkai, John Chi Hang Yuen, Teresa Tong, James Fung, Ivan Fan Ngai Hung, Man Fung Yuen, Man Fung Yuen, Hepatology International, 7, 98 - 105,   2013年03月01日, Background: Possible serologic activity after hepatitis B surface antigen (HBsAg) seroclearance documented by conventional assays in chronic hepatitis B (CHB) has not been thoroughly investigated. Methods: We determined the levels of serum hepatitis B virus (HBV) DNA, hepatitis B core-related antigen (HBcrAg), and linearized HBsAg (CLEIA prototype) in 329 CHB patients (72.0% male) after HBsAg seroclearance was documented by a conventional HBsAg assay. Results: The median interval between presentation and HBsAg seroclearance was 69.4 months. The median age at HBsAg seroclearance was 50 years. Assays for serum HBV DNA, HBcrAg, and linearized HBsAg were performed at a median time interval of 11.2 months after HBsAg loss. Linearized HBsAg and HBcrAg were detectable in 85 (25.8%) and 69 (21%) patients, respectively, and one or both serologic markers were detectable in 133 patients (40.4%). Serum HBV DNA was detectable in only 7 patients (2.1%). There was no correlation between linearized HBsAg and HBcrAg levels (r = 0.095, p = 0.924). The incidences of detectable linearized HBsAg and HBcrAg did not differ between patient samples taken at 6-12 and >12 months after HBsAg seroclearance (p = 0.146 and 0.079, respectively). Among patients with detectable serologic markers, median levels of linearized HBsAg (p = 0.581) and HBcrAg (p = 0.951) did not significantly change with time after HBsAg seroclearance. Conclusion: Using novel HBcrAg and linearized HBsAg assays, viral serologic activity after HBsAg seroclearance was demonstrated in more than 40% of CHB patients. These tests have potential applications in diagnosing and prognosticating CHB patients with HBsAg seroclearance. © 2012 Asian Pacific Association for the Study of the Liver.
  • Model incorporating the ITPA genotype identifies patients at high risk of anemia and treatment failure with pegylated-interferon plus ribavirin therapy for chronic hepatitis C, Masayuki Kurosaki, Yasuhito Tanaka, Nao Nishida, Naoya Sakamoto, Nobuyuki Enomoto, Kentaro Matsuura, Yasuhiro Asahina, Mina Nakagawa, Mamoru Watanabe, Minoru Sakamoto, Shinya Maekawa, Katsushi Tokunaga, Masashi Mizokami, Namiki Izumi, Journal of Medical Virology, 85, 449 - 458,   2013年03月01日, This study aimed to develop a model for predicting anemia using the inosine triphosphatase (ITPA) genotype and to evaluate its relationship with treatment outcome. Patients with genotype 1b chronic hepatitis C (n=446) treated with peg-interferon alpha and ribavirin (RBV) for 48 weeks were genotyped for the ITPA (rs1127354) and IL28B (rs8099917) genes. Data mining analysis generated a predictive model for anemia (hemoglobin (Hb) concentration <10g/dl); the CC genotype of ITPA, baseline Hb <14.0g/dl, and low creatinine clearance (CLcr) were predictors of anemia. The incidence of anemia was highest in patients with Hb <14.0g/dl and CLcr <90ml/min (76%), followed by Hb <14.0g/dl and ITPA CC (57%). Patients with Hb ≥14.0g/dl and ITPA AA/CA had the lowest incidence of anemia (17%). Patients with two predictors (high-risk) had a higher incidence of anemia than the others (64% vs. 28%, P<0.0001). At baseline, the IL28B genotype was a predictor of a sustained virological response [adjusted odds ratio 9.88 (95% confidence interval 5.01-19.48), P<0.0001]. In patients who achieved an early virological response, the IL28B genotype was not associated with a sustained virological response, while a high risk of anemia was a significant negative predictor of a sustained virological response [0.47 (0.24-0.91), P=0.026]. For high-risk patients with an early virological response, giving >80% of the planned RBV dose increased sustained virological responses by 24%. In conclusion, a predictive model incorporating the ITPA genotype could identify patients with a high risk of anemia and reduced probability of sustained virological response. © 2013 Wiley Periodicals, Inc.
  • Add-on therapy of pitavastatin and eicosapentaenoic acid improves outcome of peginterferon plus ribavirin treatment for chronic hepatitis C, Motoyuki Kohjima, Munechika Enjoji, Munechika Enjoji, Munechika Enjoji, Tsuyoshi Yoshimoto, Ryoko Yada, Tatsuya Fujino, Yoko Aoyagi, Nobuyoshi Fukushima, Kunitaka Fukuizumi, Naohiko Harada, Masayoshi Yada, Masaki Kato, Kazuhiro Kotoh, Manabu Nakashima, Naoya Sakamoto, Yasuhito Tanaka, Makoto Nakamuta, Makoto Nakamuta, Journal of Medical Virology, 85, 250 - 260,   2013年02月01日, Despite the use of pegylated-interferon (peg-IFN) plus ribavirin combination therapy, many patients infected with hepatitis C virus (HCV)-1b remain HCV-positive. To determine whether addition of pitavastatin and eicosapentaenoic acid (EPA) is beneficial, the "add-on" therapy option (add-on group) was compared retrospectively with unmodified peg-IFN/ribavirin therapy (standard group). Association of host- or virus-related factors with sustained virological response was assessed. In HCV replicon cells, the effects of pitavastatin and/or EPA on HCV replication and expression of innate-immunity- and lipid-metabolism-associated genes were investigated. In patients infected with HCV-1b, sustained virological response rates were significantly higher in the add-on than standard group. In both groups, sustained virological response rates were significantly higher in patients with genotype TT of IL-28B (rs8099917) than in those with non-TT genotype. Among the patients with non-TT genotype, sustained virological response rates were markedly higher in the add-on than standard group. By multivariate analysis, genome variation of IL28B but not add-on therapy remained as a predictive factor of sustained virological response. In replicon cells, pitavastatin and EPA suppressed HCV replication. Activation of innate immunity was obvious in pitavastatin-treated cells and EPA suppressed the expression of sterol regulatory element binding protein-1c and low-density lipoprotein receptor. Addition of pitavastatin and EPA to peg-IFN/ribavirin treatment improved sustained virological response in patients infected with HCV-1b. Genotype variation of IL-28B is a strong predictive factor in add-on therapy. J. Med. Virol. 85:250-260, 2013. © 2012 Wiley Periodicals, Inc. Copyright © 2012 Wiley Periodicals, Inc.
  • Specific mutations of basal core promoter are associated with chronic liver disease in hepatitis B virus subgenotype D1 prevalent in Turkey, Mustafa Sunbul, Masaya Sugiyama, Fuat Kurbanov, Hakan Leblebicioglu, Anis Khan, Abeer Elkady, Yasuhito Tanaka, Masashi Mizokami, Microbiology and Immunology, 57, 122 - 129,   2013年02月01日, The role of hepatitis B virus (HBV) genetics in the clinical manifestations of infection is being increasingly recognized. Genotype D is one of eight currently recognized major HBV genotypes. The virus is ubiquitous worldwide, but shows different features in different regions. One hundred and ninety-eight patients with chronic HBV infection were enrolled in this study, 38 of whom had been diagnosed with cirrhosis of the liver and/or hepatocellular carcinoma. HBV DNA was isolated from the patients' blood samples and the entire genome and/or the basal core promoter/core promoter region sequenced. Phylogenetic analysis of the complete genomes revealed that subgenotype D1 is the most prevalent subgenotype in Turkey, but there was no definite phylogenetic grouping according to geography for isolates from different regions within Turkey, or for isolates in Turkey relative to other parts of the world. Turkish isolates tended to be genetically similar to European and central Asian isolates. Overall, HBV-infection in Turkey appears to be characterized by early HBeAg seroconversion, a high incidence of the A1896 core promoter mutation and a small viral load. Genotype D characteristic mutations A1757 and T1764/G1766 were found in the BCP region. T1773 was associated with T1764/G1766 and a larger viral load. In conclusion, infection with HBV genotype D in Turkey has a similar clinical outcome to that of Europe and central Asia. Genotypic mutations in genotype D may be linked with disease prognosis in Turkey, but further studies with higher sample numbers and balanced clinical groups are needed to confirm this. © 2012 The Societies and Wiley Publishing Asia Pty Ltd.
  • Reactivation of hepatitis viruses following immunomodulating systemic chemotherapy, Tsunamasa Watanabe, Yasuhito Tanaka, Hepatology Research, 43, (2) 113 - 121,   2013年02月01日, 査読有り, Reactivation of hepatitis B virus (HBV) or hepatitis C virus (HCV) infection following anticancer chemotherapy and immunosuppressive therapy is a well-known complication. HBV reactivation has been reported to be associated with anti-CD20 monoclonal antibody rituximab-containing chemotherapy and tumor necrosis factor-α inhibitor-containing immunosuppressive therapy in HBV resolved patients (hepatitis B surface antigen negative and antibodies against hepatitis B core antigen positive and/or antibodies against surface antigen positive). On the other hand, HCV reactivation has been reported to be associated with liver damage or hepatic dysfunction, but fulminant hepatitis due to HCV reactivation is a rare complication. In this review, we describe the pathophysiology of the reactivation of HBV and HCV infection, as well as the clinical evidence and management of HCV reactivation. © 2012 The Japan Society of Hepatology.
  • A serum sweet-doughnut protein facilitates fibrosis evaluation and therapy assessment in patients with viral hepatitis, Atsushi Kuno, Yuzuru Ikehara, Yasuhito Tanaka, Kiyoaki Ito, Atsushi Matsuda, Satoru Sekiya, Shuhei Hige, Michiie Sakamoto, Masayoshi Kage, Masashi Mizokami, Hisashi Narimatsu, Scientific Reports, 3,   2013年01月28日, Although liver fibrosis reflects disease severity in chronic hepatitis patients, there has been no simple and accurate system to evaluate the therapeutic effect based on fibrosis. We developed a glycan-based immunoassay, FastLec-Hepa, to fill this unmet need. FastLec-Hepa automatically detects unique fibrosis-related glyco-alteration in serum hyperglycosylated Mac-2 binding protein within 20 min. The serum FastLec-Hepa counts increased with advancing fibrosis and illustrated significant differences in medians between all fibrosis stages. FastLec-Hepa is sufficiently sensitive and quantitative to evaluate the effects of PEG-interferon-α/ribavirin therapy in a short post-therapeutic interval. The obtained fibrosis progression is equivalent to-0.30 stages/year in patients with sustained virological response, and 0.01 stages/year in relapse/nonresponders. Furthermore, long-term follow-up of the severely affected patients found hepatocellular carcinoma developed in patients after therapy whose FastLec-Hepa counts remained above a designated cutoff value. FastLec-Hepa is the only assay currently available for clinically beneficial therapy evaluation through quantitation of disease severity.
  • 2′-Fluoro-6′-methylene-carbocyclic adenosine phosphoramidate (FMCAP) prodrug: In vitro anti-HBV activity against the lamivudine-entecavir resistant triple mutant and its mechanism of action, Ravindra K. Rawal, Uma S. Singh, Satish N. Chavre, Jianing Wang, Masaya Sugiyama, Wai Hung, Rajgopal Govindarajan, Brent Korba, Yasuhito Tanaka, Chung K. Chu, Bioorganic and Medicinal Chemistry Letters, 23, 503 - 506,   2013年01月15日, Novel 2′-fluoro-6′-methylene-carbocyclic adenosine (FMCA) monophosphate prodrug (FMCAP) was synthesized and evaluated for its in vitro anti-HBV potency against a lamivudine-entecavir resistant clone (L180M + M204V + S202G). FMCA demonstrated significant antiviral activity against wild-type as well as lamivudine-entecavir resistant triple mutant (L180M + M204V + S202G). The monophosphate prodrug (FMCAP) demonstrated greater than 12-fold (12×) increase in anti-HBV activity without increased cellular toxicity. Mitochondrial and cellular toxicity studies of FMCA indicated that there is no significant toxicity up to 100 μM. Mode of action studies by molecular modeling indicate that the 2′-fluoro moiety by hydrogen bond as well as the Van der Waals interaction of the carbocyclic ring with the phenylalanine moiety of the polymerase promote the positive binding, even in the drug-resistant mutants. © 2012 Elsevier Ltd. All rights reserved.
  • Guidelines for the management of hepatitis B virus infection, Yasuhiro Asahina, Norio Hayashi, Naoki Hiramatsu, Namiki Izumi, Kazuhiko Koike, Hiromitsu Kumada, Masayuki Kurosaki, Makoto Oketani, Fumitaka Suzuki, Hajime Takikawa, Atsushi Tanaka, Eiji Tanaka, Yasuhito Tanaka, Hirohito Tsubouchi, Hiroshi Yotsuyanagi, Acta Hepatologica Japonica, 54, 402 - 472,   2013年01月01日
  • Tracing the spread of Hepatitis C virus in Turkey: A phylogenetic analysis, Mustafa Sunbul, Anis Khan, Fuat Kurbanov, Hakan Leblebicioglu, Masaya Sugiyama, Yasuhito Tanaka, Masashi Mizokami, Masashi Mizokami, Intervirology, 56, 201 - 205,   2013年01月01日, © 2013 S. Karger AG, Basel. Background/Aims: Molecular epidemiology of hepatitis C virus (HCV) shows that HCV genotypes are unique with respect to their nucleotide sequence, geographical distribution and clinical relationship. Methods: In this study we enrolled 67 HCV-infected individuals with various stages of liver disease from four geographical regions of Turkey. A partial NS5B region of the HCV genome was sequenced and subjected to phylogenetic analysis to determine the circulating HCV genotypes and subtypes. Results: The results showed that HCV genotype 1 (subtype1b) is the main genetic variant of HCV in Turkey but did not reveal any Turkish indigenous phylogenetic cluster. Phylogenetic analysis showed that Turkish strains have their closest matches from both Asia (Japan) and Europe/USA. Conclusions: In view of Turkey's geographic position, HCV-1b transmission from Europe is not exceptional. This study could not establish a clear role of other HCV genotypes prevalent in neighboring Asian countries in Turkey's HCV transmission, which would need to be confirmed by further regional epidemiological studies.
  • Prediction of response to pegylated interferon/ribavirin combination therapy for chronic hepatitis C genotypes 2a and 2b and high viral load, Soo Ryang Kim, Ahmed El-Shamy, Ahmed El-Shamy, Susumu Imoto, Ke Ih Kim, Kayo Sugimoto, Soo Ki Kim, Yasuhito Tanaka, Takashi Hatae, Yutaka Hasegawa, Aya Fujinami, Mitsuhiro Ohta, Hak Hotta, Masatoshi Kudo, Digestive Diseases, 31, 426 - 433,   2013年01月01日, © 2013 S. Karger AG, Basel. Objective: We investigated the impact of host genetics represented by the single nucleotide polymorphism (SNP) of the IL28B gene and viral genetic variations within the nonstructural protein 5A (NS5A) [including the interferon (IFN)/ribavirin (RBV) resistance-determining region (IRRDR) and the IFN sensitivity-determining region (ISDR)] on the outcome of pegylated IFN and RBV (PEG-IFN/RBV) treatment. Methods: Sixty-six patients infected with hepatitis C virus (HCV)-2a or HCV-2b who received PEG-IFN/RBV for 24 weeks were examined. Results: In HCV-2a, the major genotype of IL28B SNP showed a tendency toward association with sustained virological response (SVR) and rapid virological response (RVR), and four or more mutations in IRRDR (IRRDR[2a] ≥4) and one or more mutations in ISDR plus its carboxyl-flanking region (ISDR/+C[2a] ≥1) were significantly associated with SVR and RVR. In HCV-2b, one or more mutations in the N-terminal part of IRRDR (IRRDR/N[2b] ≥1) were significantly associated with RVR. Multivariate analysis identified the major genotype of IL28B SNP and IRRDR[2a] ≥4 as independent predictive factors of SVR in HCV-2a, with IRRDR[2a] ≥4 being more powerful than the IL28B SNP. Also, IRRDR[2a] ≥4 in HCV-2a and IRRDR/N[2b] ≥1 in HCV-2b were significant determiners of RVR. Conclusion: The NS5A sequence heterogeneity and IL28B SNP are useful factors to predict the sensitivity to PEG-IFN/RBV therapy in HCV-2a and HCV-2b infections.
  • Association of ITPA gene variation and serum ribavirin concentration with a decline in blood cell concentrations during pegylated interferon-alpha plus ribavirin therapy for chronic hepatitis C, Mina Nakagawa, Mina Nakagawa, Naoya Sakamoto, Naoya Sakamoto, Naoya Sakamoto, Takako Watanabe, Yuki Nishimura-Sakurai, Izumi Onozuka, Seishin Azuma, Sei Kakinuma, Sei Kakinuma, Sayuri Nitta, Kei Kiyohashi, Akiko Kusano-Kitazume, Miyako Murakawa, Kohei Yoshino, Yasuhiro Itsui, Yasuhito Tanaka, Masashi Mizokami, Mamoru Watanabe, Hepatology International, 7, (1) 153 - 161,   2013年01月01日, 査読有り, Background: Genetic variation leading to inosine triphosphatase (ITPA) deficiency protects chronic hepatitis C patients receiving ribavirin against hemolytic anemia. The relationship between ITPA gene variation and serum ribavirin concentration was analyzed in association with a reduction in blood cells and dose reduction of pegylated interferon (PEG-IFN) or ribavirin. Patients and methods: A total of 300 hepatitis C patients treated with PEG-IFN plus ribavirin were analyzed. Genetic polymorphisms were determined in ITPA and the quantitative reduction in blood cells from the baseline was analyzed every 4 weeks for the duration of treatment and after the end of therapy. The decline in hemoglobin (Hb) or platelet (PLT) level at week 4 compared to baseline was also assessed according to ribavirin concentrations. Results: Patients with the ITPA-CA/AA genotypes showed a lower degree of Hb reduction throughout therapy than those with the ITPA-CC genotype and a marked difference in mean Hb reduction was found at week 4 (CA/AA -1.0 vs. CC -2.8, p < 0.001). The ITPA-CC genotype had significantly less reduction in the mean platelet count than the ITPA-CA/AA genotypes early during treatment (p < 0.001 for weeks 4 and 8). Patients with the ITPA-CA/AA genotypes were less likely to develop anemia, regardless of the concentration of ribavirin. Patients with baseline PLT counts below 130 × 103/μl had a significantly lower tendency to achieve sustained virological response (SVR), especially those with the ITPA-CA/AA genotypes. ITPA gene variation was not extracted by multivariable analysis as an important predictor of SVR. Conclusions: Despite the fact that ITPA variants were less likely to develop anemia, patients with low baseline PLT counts were difficult to treat, especially those with the ITPA-CA/AA genotype. These results may give a valuable pharmacogenetic diagnostic tool for the tailoring of dosing to minimize drug-induced adverse events. © 2012 Asian Pacific Association for the Study of the Liver.
  • Sequential immunological analysis of HBV/HCV co-infected patients during Peg-IFN/RBV therapy, Yasuteru Kondo, Yoshiyuki Ueno, Masashi Ninomiya, Keiichi Tamai, Yasuhito Tanaka, Jun Inoue, Eiji Kakazu, Koju Kobayashi, Osamu Kimura, Masahito Miura, Takeshi Yamamoto, Tomoo Kobayashi, Takehiko Igarashi, Tooru Shimosegawa, Journal of Gastroenterology, 47, 1323 - 1335,   2012年12月01日, Background: The immunopathogenesis of dual chronic infection with hepatitis B virus and hepatitis C virus (HBV/HCV) remains unclear. The in vivo suppressive effects of each virus on the other have been reported. In this study we aimed to analyze the virological and immunological parameters of HBV/HCV coinfected patients during pegylated interferon/ribavirin (Peg-IFN/RBV) therapy. Methods: One patient with high HBV-DNA and high HCV-RNA titers (HBV-high/HCV-high) and 5 patients with low HBV-DNA and high HCV-RNA titers (HBV-low/HCV-high) were enrolled. Twenty patients monoinfected with HBV and 10 patients monoinfected with HCV were enrolled as control subjects. In vitro cultures of Huh 7 cells with HBV/HCV dual infection were used to analyze the direct interaction of HBV/HCV. Results: Direct interaction of HBV clones and HCV could not be detected in the Huh-7 cells. In the HBV-high/HCV-high-patient, the HCV-RNA level gradually declined and HBV-DNA gradually increased during Peg-IFN/RBV therapy. Activated CD4- and CD8-positive T cells were increased at 1 month of Peg-IFN/RBV-therapy, but HBV-specific IFN-γ-secreting cells were not increased and HBV-specific interleukin (IL)-10 secreting cells were increased. The level of HBV- and HCV-specific IFN-γ-secreting cells in the HBV-high/HCV-high-patient was low in comparison to that in the HBV- or HCV-monoinfected patients. In the HBV-low/HCV-high-patient, HCV-RNA and HBV-DNA rapidly declined during Peg-IFN/RBV therapy. Activated CD4- and CD8-positive T cells were increased, and HBV- and HCV-specific IFN-γ-secreting cells were also increased during Peg-IFN/RBV-therapy. Conclusion: The immunological responses of the HBV-high/HCV-high patient were low in comparison to the responses in HBV and HCV monoinfected patients. Moreover, the response of immune cells in the HBV-high/HCV-high patient during Peg-IFN/RBV therapy was insufficient to suppress HBV and HCV. © 2012 Springer.
  • Comparison of LecT-Hepa and FibroScan for assessment of liver fibrosis in hepatitis B virus infected patients with different ALT levels, Dongning Du, Dongning Du, Dongning Du, Xuejuan Zhu, Atsushi Kuno, Atsushi Matsuda, Chikayuki Tsuruno, Demin Yu, Yan Zhang, Yan Zhang, Yuzuru Ikehara, Yasuhito Tanaka, Xinxin Zhang, Hisashi Narimatsu, Hisashi Narimatsu, Clinica Chimica Acta, 413, 1796 - 1799,   2012年11月12日, Background: FibroScan is one of the noninvasive techniques based on the transient elastography that can assess the progression of liver fibrosis in chronic hepatitis patients in daily clinical practice. Recently, LecT-Hepa was validated as a serological glycomarker correlating well with the fibrosis stage determined by liver biopsy, and was superior to many other noninvasive biochemical markers and tests. We compared the reliability of LecT-Hepa with that of FibroScan for evaluation of liver fibrosis. Methods: The effects of increased alanine aminotransferase (ALT) activities on LecT-Hepa and FibroScan were investigated. Results: The areas under the receiver-operating characteristic curves, sensitivity and specificity for detecting cirrhosis, which is one of the outcomes of fibrosis estimation, were 0.82, 72.5% and 78.2% of LecT-Hepa, 0.85, 87.0% and 74.1% of FibroScan; these did not differ significantly. The count distribution of LecT-Hepa in non-cirrhosis group or cirrhosis group did not differ between the patients grouped according to their ALT levels, whereas that of FibroScan was substantially affected. Conclusion: LecT-Hepa was confirmed as a reliable noninvasive test for the evaluation of liver fibrosis in hepatitis B virus-infected patients with comparable performance to that of FibroScan and proved to be unaffected by inflammation. © 2012 Elsevier B.V..
  • Prediction of response to pegylated interferon/ribavirin combination therapy for chronic hepatitis C genotype 1b and high viral load, Soo Ryang Kim, Ahmed El-Shamy, Ahmed El-Shamy, Susumu Imoto, Ke Ih Kim, Yoshi Hiro Ide, Lin Deng, Ikuo Shoji, Yasuhito Tanaka, Yutaka Hasegawa, Mitsuhiro Ota, Hak Hotta, Journal of Gastroenterology, 47, 1143 - 1151,   2012年10月01日, Background: This study explores pretreatment predictive factors for ultimate virological responses to pegylated interferon-α (1.5 μg/kg/week) and ribavirin (600-1000 mg/day) (PEG-IFN/RBV) combination therapy for patients infected with hepatitis C virus (HCV)-1b and a high viral load. Methods: A total of 75 patients underwent PEG-IFN/RBV combination therapy for 48 weeks. HCV amino acid (aa) substitutions in non-structural protein 5a, including those in the IFN/RBV resistance-determining region (IRRDR) and the IFN sensitivity-determining region and the core regions, as well as the genetic variation (rs8099917) near the interleukin 28B (IL28B) gene (genotype TT) were analyzed. Results: Of the 75 patients, 49 % (37/75) achieved a sustained virological response (SVR), 27 % (20/75) showed relapse, and 24 % (18/75) showed null virological response (NVR). Multivariate logistic regression analysis identified IRRDR with 6 or more mutations (IRRDR ≥6) [odds ratio (OR) 11.906, p < 0.0001] and age <60 years (OR 0.228, p = 0.015) as significant determiners of SVR and IL28B minor (OR 14.618, p = 0.0019) and platelets <15 × 104/mm3 (OR 0.113, p = 0.0096) as significant determiners of NVR. A combination of IRRDR ≥6 and age <60 years improved SVR predictability (93.3 %), and that of IRRDR ≤5 and age ≥60 years improved non-SVR predictability (84.0 %). Similarly, a combination of IL28B minor and platelets <15 × 104/mm3 improved NVR predictability (85.7 %), and that of IL28B major and platelets ≥15 × 104/mm3 improved non-NVR (response) (97.1 %) predictability. Conclusion: IRRDR ≥6 and age <60 years were significantly associated with SVR. IL28B minor and platelets <15 × 10 4/mm3 were significantly associated with NVR. Certain combinations of these factors improved SVR and NVR predictability and could, therefore, be used to design therapeutic strategies. © 2012 Springer.
  • Novel cell culture-adapted genotype 2a hepatitis C virus infectious clone, Tomoko Date, Takanobu Kato, Junko Kato, Hitoshi Takahashi, Hitoshi Takahashi, Kenichi Morikawa, Kenichi Morikawa, Kenichi Morikawa, Daisuke Akazawa, Daisuke Akazawa, Asako Murayama, Keiko Tanaka-Kaneko, Tetsutaro Sata, Tetsutaro Sata, Yasuhito Tanaka, Masashi Mizokami, Takaji Wakita, Journal of Virology, 86, 10805 - 10820,   2012年10月01日, Although the recently developed infectious hepatitis C virus system that uses the JFH-1 clone enables the study of whole HCV viral life cycles, limited particular HCV strains have been available with the system. In this study, we isolated another genotype 2a HCV cDNA, the JFH-2 strain, from a patient with fulminant hepatitis. JFH-2 subgenomic replicons were constructed. HuH-7 cells transfected with in vitro transcribed replicon RNAs were cultured with G418, and selected colonies were isolated and expanded. From sequencing analysis of the replicon genome, several mutations were found. Some of the mutations enhanced JFH-2 replication; the 2217AS mutation in the NS5A interferon sensitivity-determining region exhibited the strongest adaptive effect. Interestingly, a full-length chimeric or wild-type JFH-2 genome with the adaptive mutation could replicate in Huh-7.5.1 cells and produce infectious virus after extensive passages of the virus genome-replicating cells. Virus infection efficiency was sufficient for autonomous virus propagation in cultured cells. Additional mutations were identified in the infectious virus genome. Interestingly, full-length viral RNA synthesized from the cDNA clone with these adaptive mutations was infectious for cultured cells. This approach may be applicable for the establishment of new infectious HCV clones. © 2012 American Society for Microbiology.
  • LecT-hepa, a glyco-marker derived from multiple lectins, as a predictor of liver fibrosis in chronic hepatitis C patients, Kiyoaki Ito, Atsushi Kuno, Yuzuru Ikehara, Masaya Sugiyama, Hiroaki Saito, Yoshihiko Aoki, Teppei Matsui, Masatoshi Imamura, Masaaki Korenaga, Kazumoto Murata, Naohiko Masaki, Yasuhito Tanaka, Shuhei Hige, Namiki Izumi, Masayuki Kurosaki, Shuhei Nishiguchi, Michiie Sakamoto, Masayoshi Kage, Hisashi Narimatsu, Masashi Mizokami, Hepatology, 56, 1448 - 1456,   2012年10月01日, Assessment of liver fibrosis in patients with chronic hepatitis C (CHC) is critical for predicting disease progression and determining future antiviral therapy. LecT-Hepa, a new glyco-marker derived from fibrosis-related glyco-alteration of serum alpha 1-acid glycoprotein, was used to differentiate cirrhosis from chronic hepatitis in a single-center study. Herein, we aimed to validate this new glyco-marker for estimating liver fibrosis in a multicenter study. Overall, 183 CHC patients were recruited from 5 liver centers. The parameters Aspergillus oryzae lectin (AOL)/Dature stramonium lectin (DSA) and Maackia amurensis lectin (MAL)/DSA were measured using a bedside clinical chemistry analyzer in order to calculate LecT-Hepa levels. The data were compared with those of seven other noninvasive biochemical markers and tests (hyaluronic acid, tissue inhibitor of metalloproteases-1, platelet count, aspartate aminotransferase-to-platelet ratio index [APRI], Forns index, Fib-4 index, and Zeng's score) for assessing liver fibrosis using the receiver-operating characteristic curve. LecT-Hepa correlated well with the fibrosis stage as determined by liver biopsy. The area under the curve (AUC), sensitivity, and specificity of LecT-Hepa were 0.802, 59.6%, and 89.9%, respectively, for significant fibrosis; 0.882, 83.3%, and 80.0%, respectively, for severe fibrosis; and 0.929, 84.6%, and 88.5%, respectively, for cirrhosis. AUC scores of LecT-Hepa at each fibrosis stage were greater than those of the seven aforementioned noninvasive tests and markers. Conclusion: The efficacy of LecT-Hepa, a glyco-marker developed using glycoproteomics, for estimating liver fibrosis was demonstrated in a multicenter study. LecT-Hepa given by a combination of the two glyco-parameters is a reliable method for determining the fibrosis stage and is a potential substitute for liver biopsy. © 2012 American Association for the Study of Liver Diseases.
  • Anti-interferon-α neutralizing antibody is associated with nonresponse to pegylated interferon-α plus ribavirin in chronic hepatitis C, F. Matsuda, Y. Torii, H. Enomoto, C. Kuga, N. Aizawa, Y. Iwata, M. Saito, H. Imanishi, S. Shimomura, H. Nakamura, H. Tanaka, H. Iijima, H. Tsutsui, Y. Tanaka, S. Nishiguchi, Journal of Viral Hepatitis, 19, 694 - 703,   2012年10月01日, Summary. Pegylated interferon-α (PEG-IFN-α) plus ribavirin (RBV) treatment fails to achieve a sustained virological response (SVR) in approximately 20-50% of patients with chronic hepatitis C virus (HCV) infection. We assessed the contribution of an anti-IFN-α neutralizing antibody (NAb) on the nonresponse to treatment. NAbs were detected using an antiviral assay that assessed the neutralizing effects of serum samples against IFN. Serum samples were obtained at the end of the treatment and evaluated for the presence of NAbs using recombinant IFN-α as a standard. We studied 129 PEG-IFN-α/RBV-treated patients. In the 82 end-of-treatment responders, no NAbs were detected. Of the 47 patients who did not respond, seven (15%) were positive for NAbs. We also examined an additional 83 patients who had not responded to PEG-IFN-α treatment, and detected 12 with NAbs. Patients with good IFN-responsive characteristics, including HCV genotype 2/3 and major allele homozygotes for interleukin-28B, were included in the 19 patients with NAbs. No NAbs interfered with the antiviral activity of natural human IFN-β (nIFN-β) and re-treatement of patients with NAbs with nIFN-β/RBV achieved SVR. Our analyses revealed that the emergence of anti-IFN-α NAbs was a candidate causal factor of PEG-IFN-α-treatment failure. Therefore, these antibodies should be assayed in patients who do not respond to PEG-IFN-α therapy, and if detected, other effective treatments, i.e., medications that are not neutralized by anti-IFN-α NAbs, should be considered. © 2012 Blackwell Publishing Ltd.
  • [Management for reactivation of hepatitis B virus following systemic chemotherapy]., Yasuhito Tanaka, [Rinshō ketsueki] The Japanese journal of clinical hematology, 53, 1793 - 1800,   2012年10月01日
  • Soluble MICA and a MICA Variation as Possible Prognostic Biomarkers for HBV-Induced Hepatocellular Carcinoma, Vinod Kumar, Vinod Kumar, Paulisally Hau Yi Lo, Hiromi Sawai, Naoya Kato, Atsushi Takahashi, Zhenzhong Deng, Yuji Urabe, Hamdi Mbarek, Katsushi Tokunaga, Yasuhito Tanaka, Masaya Sugiyama, Masashi Mizokami, Ryosuke Muroyama, Ryosuke Tateishi, Masao Omata, Kazuhiko Koike, Chizu Tanikawa, Naoyuki Kamatani, Michiaki Kubo, Yusuke Nakamura, Koichi Matsuda, PLoS ONE, 7,   2012年09月14日, MHC class I polypeptide-related chain A (MICA) molecule is induced in response to viral infection and various types of stress. We recently reported that a single nucleotide polymorphism (SNP) rs2596542 located in the MICA promoter region was significantly associated with the risk for hepatitis C virus (HCV)-induced hepatocellular carcinoma (HCC) and also with serum levels of soluble MICA (sMICA). In this study, we focused on the possible involvement of MICA in liver carcinogenesis related to hepatitis B virus (HBV) infection and examined correlation between the MICA polymorphism and the serum sMICA levels in HBV-induced HCC patients. The genetic association analysis revealed a nominal association with an SNP rs2596542; a G allele was considered to increase the risk of HBV-induced HCC (P = 0.029 with odds ratio of 1.19). We also found a significant elevation of sMICA in HBV-induced HCC cases. Moreover, a G allele of SNP rs2596542 was significantly associated with increased sMICA levels (P = 0.009). Interestingly, HCC patients with the high serum level of sMICA (>5 pg/ml) exhibited poorer prognosis than those with the low serum level of sMICA (≤5 pg/ml) (P = 0.008). Thus, our results highlight the importance of MICA genetic variations and the significance of sMICA as a predictive biomarker for HBV-induced HCC. © 2012 Kumar et al.
  • Development of a prediction model for 10-year risk of hepatocellular carcinoma in middle-aged Japanese: The Japan Public Health Center-based Prospective Study Cohort II, Takehiro Michikawa, Takehiro Michikawa, Manami Inoue, Norie Sawada, Motoki Iwasaki, Yasuhito Tanaka, Taichi Shimazu, Shizuka Sasazuki, Taiki Yamaji, Masashi Mizokami, Shoichiro Tsugane, S. Tsugane, M. Inoue, T. Sobue, T. Hanaoka, J. Ogata, S. Baba, T. Mannami, A. Okayama, Y. Kokubo, K. Miyakawa, F. Saito, A. Koizumi, Y. Sano, I. Hashimoto, T. Ikuta, Y. Tanaba, Y. Miyajima, N. Suzuki, S. Nagasawa, Y. Furusugi, N. Nagai, Y. Ito, H. Sanada, Y. Hatayama, F. Kobayashi, H. Uchino, Y. Shirai, T. Kondo, R. Sasaki, Y. Watanabe, Y. Miyagawa, Y. Kobayashi, M. Machida, Y. Kishimoto, E. Takara, T. Fukuyama, M. Kinjo, M. Irei, H. Sakiyama, K. Imoto, H. Yazawa, T. Seo, A. Seiko, F. Ito, F. Shoji, R. Saito, A. Murata, K. Minato, K. Motegi, T. Fujieda, S. Yamato, K. Matsui, T. Abe, M. Katagiri, M. Suzuki, M. Doi, A. Terao, Y. Ishikawa, T. Tagami, H. Sueta, H. Doi, M. Urata, N. Okamoto, F. Ide, H. Goto, H. Sakiyama, N. Onga, H. Takaesu, M. Uehara, F. Horii, I. Asano, H. Yamaguchi, K. Aoki, S. Maruyama, M. Ichii, M. Takano, Y. Tsubono, K. Suzuki, Y. Honda, K. Yamagishi, S. Sakurai, N. Tsuchiya, M. Kabuto, M. Yamaguchi, Y. Matsumura, S. Sasaki, S. Watanabe, M. Akabane, T. Kadowaki, Preventive Medicine, 55, 137 - 143,   2012年08月01日, Objective: The purpose of the present study was to develop a risk estimation model for the 10-year risk of hepatocellular carcinoma (HCC) that could be easily used in a general population to aid in the prevention of HCC. Methods: Our prediction model was derived from data obtained on 17,654 Japanese aged 40 to 69. years who participated in health checkups (follow-up: 1993-2006). Cox proportional hazards regression was applied to obtain coefficients for each predictor. Results: During follow-up, a total of 104 cases of HCC were newly diagnosed. After checking the model fit, we incorporated age, sex, alcohol consumption, body mass index, diabetes, coffee consumption, and hepatitis B and C virus infection into the prediction model. The model showed satisfactory discrimination (Harrell's c-index = 0.94) and was well calibrated (the overall observed/expected ratio = 1.03, 95% confidence interval = 0.83-1.29). We also developed a simple risk scoring system. Those subjects with total scores of 17 or more under this system (score range: - 1 to 19) had an estimated 10-year HCC risk of over 90%; those with 4 points or less had an estimated risk of less than 0.1%. Conclusion: We developed a simple 10-year risk prediction model for HCC in the Japanese general population as a public education tool. © 2012 Elsevier Inc.
  • Genome-wide association study confirming association of HLA-DP with protection against chronic hepatitis B and viral clearance in Japanese and Korean, Nao Nishida, Nao Nishida, Hiromi Sawai, Kentaro Matsuura, Masaya Sugiyama, Sang Hoon Ahn, Jun Yong Park, Shuhei Hige, Jong Hon Kang, Kazuyuki Suzuki, Masayuki Kurosaki, Yasuhiro Asahina, Satoshi Mochida, Masaaki Watanabe, Eiji Tanaka, Masao Honda, Shuichi Kaneko, Etsuro Orito, Yoshito Itoh, Eiji Mita, Akihiro Tamori, Yoshikazu Murawaki, Yoichi Hiasa, Isao Sakaida, Masaaki Korenaga, Keisuke Hino, Tatsuya Ide, Minae Kawashima, Yoriko Mawatari, Yoriko Mawatari, Megumi Sageshima, Yuko Ogasawara, Asako Koike, Namiki Izumi, Kwang Hyub Han, Yasuhito Tanaka, Katsushi Tokunaga, Masashi Mizokami, PLoS ONE, 7,   2012年06月21日, Hepatitis B virus (HBV) infection can lead to serious liver diseases, including liver cirrhosis (LC) and hepatocellular carcinoma (HCC); however, about 85-90% of infected individuals become inactive carriers with sustained biochemical remission and very low risk of LC or HCC. To identify host genetic factors contributing to HBV clearance, we conducted genome-wide association studies (GWAS) and replication analysis using samples from HBV carriers and spontaneously HBV-resolved Japanese and Korean individuals. Association analysis in the Japanese and Korean data identified the HLA-DPA1 and HLA-DPB1 genes with Pmeta= 1.89×10-12for rs3077 and Pmeta= 9.69×10-10for rs9277542. We also found that the HLA-DPA1 and HLA-DPB1 genes were significantly associated with protective effects against chronic hepatitis B (CHB) in Japanese, Korean and other Asian populations, including Chinese and Thai individuals (Pmeta= 4.40×10-19for rs3077 and Pmeta= 1.28×10-15for rs9277542). These results suggest that the associations between the HLA-DP locus and the protective effects against persistent HBV infection and with clearance of HBV were replicated widely in East Asian populations; however, there are no reports of GWAS in Caucasian or African populations. Based on the GWAS in this study, there were no significant SNPs associated with HCC development. To clarify the pathogenesis of CHB and the mechanisms of HBV clearance, further studies are necessary, including functional analyses of the HLA-DP molecule. © 2012 Nishida et al.
  • No association for Chinese HBV-related hepatocellular carcinoma susceptibility SNP in other East Asian populations, Hiromi Sawai, Nao Nishida, Nao Nishida, Hamdi Mbarek, Koichi Matsuda, Yoriko Mawatari, Megumi Yamaoka, Shuhei Hige, Jong Hon Kang, Koichi Abe, Satoshi Mochida, Masaaki Watanabe, Masayuki Kurosaki, Yasuhiro Asahina, Namiki Izumi, Masao Honda, Shuichi Kaneko, Eiji Tanaka, Kentaro Matsuura, Yoshito Itoh, Eiji Mita, Masaaki Korenaga, Keisuke Hino, Yoshikazu Murawaki, Yoichi Hiasa, Tatsuya Ide, Kiyoaki Ito, Masaya Sugiyama, Sang H. Ahn, Kwang Hyub Han, Jun Y. Park, Man Fung Yuen, Yusuke Nakamura, Yasuhito Tanaka, Masashi Mizokami, Katsushi Tokunaga, BMC Medical Genetics, 13,   2012年06月19日, Background: A recent genome-wide association study (GWAS) using chronic HBV (hepatitis B virus) carriers with and without hepatocellular carcinoma (HCC) in five independent Chinese populations found that one SNP (rs17401966) in KIF1B was associated with susceptibility to HCC. In the present study, a total of 580 HBV-derived HCC cases and 1351 individuals with chronic hepatitis B (CHB) or asymptomatic carrier (ASC) were used for replication studies in order to evaluate the reported association with HBV-derived HCC in other East Asian populations.Results: We did not detect any associations between rs17401966 and HCC in the Japanese cohorts (replication 1: OR = 1.09, 95 % CI = 0.82-1.43; replication 2: OR = 0.79, 95 % CI = 0.54-1.15), in the Korean cohort (replication 3: OR = 0.95, 95 % CI = 0.66-1.36), or in the Hong Kong Chinese cohort (replication 4: OR = 1.17, 95 % CI = 0.79-1.75). Meta-analysis using these cohorts also did not show any associations with P = 0.97.Conclusions: None of the replication cohorts showed associations between rs17401966 and HBV-derived HCC. This may be due to differences in the genetic diversity among the Japanese, Korean and Chinese populations. Other reasons could be the high complexity of multivariate interactions between the genomic information and the phenotype that is manifesting. A much wider range of investigations is needed in order to elucidate the differences in HCC susceptibility among these Asian populations. © 2012 Sawai et al.; licensee BioMed Central Ltd.
  • Novel evidence of HBV recombination in family cluster infections in Western China, Bin Zhou, Zhanhui Wang, Jie Yang, Jian Sun, Hua Li, Yasuhito Tanaka, Masashi Mizokami, Jinlin Hou, PLoS ONE, 7,   2012年06月04日, Two hepatitis B virus (HBV) C/D recombinants were isolated from western China. No direct evidence indicates that these new viruses arose as a result of recombination between genotype C and D or a result of convergence. In this study, we search for evidence of intra-individual recombination in the family cluster cases with co-circulation of genotype C, D and C/D recombinants. We studied 68 individuals from 15 families with HBV infections in 2006, identified individuals with mixed HBV genotype co-infections by restriction fragment length polymorphism and proceeded with cloning and DNA sequencing. Recombination signals were detected by RDP3 software and confirmed by split phylogenetic trees. Families with mixed HBV genotype co-infections were resampled in 2007. Three of 15 families had individuals with different HBV genotype co-infections in 2006. One individual (Y2) had a triple infection of HBV genotype C, D and C/D recombinant in 2006, but only genotype D in 2007. Further clonal analysis of this patient indicated that the C/D recombinant was not identical to previously isolated CD1 or CD2, but many novel recombinants with C2, D1 and CD1 were simultaneously found. All parental strains could recombine with each other to form new recombinant in this patient. This indicates that the detectable mixed infection and recombination have a limited time window. Also, as the recombinant nature of HBV precludes the possibility of a simple phylogenetic taxonomy, a new standard may be required for classifying HBV sequences. © 2012 Zhou et al.
  • Response-guided therapy for patients with chronic hepatitis who have high viral loads of hepatitis C virus genotype 2, Yasunori Yamaguchi, Akihiro Tamori, Yasuhito Tanaka, Shuji Iwai, Sawako Kobayashi, Hideki Fujii, Hiroyasu Morikawa, Atsushi Hagihara, Masaru Enomoto, Norifumi Kawada, Hepatology Research, 42, (6) 549 - 557,   2012年06月01日, 査読有り, Aim: We evaluated the efficacy of response-guided therapy in patients with hepatitis C virus (HCV) genotype 2. Methods: We studied 105 patients with an HCV genotype 2 load of higher than 5.0Log IU/mL who received more than 75% of the target dose of pegylated interferon plus ribavirin. Among patients with rapid viral response (RVR; no HCV RNA detected at week 4), 14 selected 16weeks of therapy (group A), and 28 selected 24weeks of therapy (group B). Among non-RVR patients, 40 selected 24weeks of therapy (group C), and 19 selected 48weeks of therapy (group D). Results: All patients in group A and B achieved a sustained viral response (SVR). Clinical characteristics did not differ significantly between groups C and D. However, the proportion of patients in whom HCV RNA disappeared at a later week after starting treatment was higher in group D (P=0.0578). SVR rate was 73% in C, and 79% in D. Among patients in whom HCV RNA disappeared between weeks 5 and 8, SVR was achieved in 28 (82%) of 34 patients in C and 10 (91%) of 11 patients in D. Among patients whose HCV RNA disappeared between weeks 9 and 12, SVR was achieved in one (20%) of five patients in C and five (63%) of eight patients in D (not statistically significant). Conclusions: 16weeks of combination therapy could achieve an adequate antiviral effect for RVR patients. Extending therapy could not significantly improve SVR rate in non-RVR patients. © 2012 The Japan Society of Hepatology.
  • Replication and infectivity of a novel genotype 1b hepatitis C virus clone, Tomoko Date, Kenichi Morikawa, Kenichi Morikawa, Kenichi Morikawa, Yasuhito Tanaka, Keiko Tanaka-Kaneko, Tetsutaro Sata, Masashi Mizokami, Takaji Wakita, Microbiology and Immunology, 56, 308 - 317,   2012年05月01日, Hepatitis C virus infection is a major public health problem because of an estimated 170 million carriers worldwide. Genotype 1b is the major subtype of HCV in many countries and is resistant to interferon therapy. Study of the viral life cycle is important for understanding the mechanisms of interferon resistance of genotype 1b HCV strains. For such studies, genotype 1b HCV strains that can replicate and produce infectious virus particles in cultured cells are required. In the present study, we isolated HCV cDNA, which we named the NC1 strain, from a patient with acute severe hepatitis. Subgenomic replicon experiments revealed that several mutations enhanced the colony-formation efficiency of the NC1 replicon. The full-length NC1 genome with these adaptive mutations could replicate in cultured cells and produce infectious virus particles. The density gradient profile and morphology of the secreted virus particles were similar to those reported for the JFH-1 virus. Further introduction of a combination of mutations of the NS3 and NS5a regions into the NC1 mutants further enhanced secreted core protein levels and infectious virus titers in the culture medium of HCV-RNA-transfected cells. However, the virus infection efficiency was not sufficient for autonomous virus propagation in cultured cells. In conclusion, we established a novel cell culture-adapted genotype 1b HCV strain, termed NC1, which can produce infectious virus when the viral RNA is transfected into cells. This system provides an important opportunity for studying the life cycle of the genotype 1b HCV. © 2012 The Societies and Blackwell Publishing Asia Pty Ltd.
  • Development of new IL28B genotyping method using Invader Plus assay, Satomi Kani, Satomi Kani, Yasuhito Tanaka, Yasuhito Tanaka, Kentaro Matsuura, Tsunamasa Watanabe, Hiroshi Yatsuhashi, Etsuro Orito, Ken Inose, Nao Motojuku, Yukio Wakimoto, Masashi Mizokami, Microbiology and Immunology, 56, (5) 318 - 323,   2012年05月01日, 査読有り, IL28B polymorphism is associated with the response to pegylated interferon-α with ribavirin (PEG-IFN-α/RBV) treatment in chronic hepatitis C patients. As a genotyping assay for IL28B single nucleotide polymorphisms (SNPs) in clinical practice, the Invader Plus assay was developed. The accuracy, intra-assay, inter-assay precision, and the limit of detection of the Invader Plus assay were evaluated. Two SNPs (rs8099917 and rs12979860) associated with IL28B were genotyped by the Invader Plus and TaqMan assay in 512 Japanese patients. In comparison with direct sequencing, the Invader Plus assay showed 99% accuracy in rs8099917 and 100% accuracy in rs12979860. Intra-assay and inter-assay precision were sufficient to use in clinical practice and the detection limit was 1ngDNA/assay. Genotyping by rs8099917 showed that 361 (71%), 144 (28%) and seven (1%) of the patients were major homozygous, heterozygous and minor homozygous types, respectively. Five of the 512 cases (1%) had haplotype differences, but none showed differences between the two genotyping methods. For patients with HCV genotype 1, the prevalence of responders in the major homozygous type was 83.3%, and that of non-responders in the minor heterozygous/homozygous type was 72.5%. A convenient IL28B genotyping method using the Invader Plus assay could be useful to predict the treatment outcome in clinical practice. © 2012 The Societies and Blackwell Publishing Asia Pty Ltd.
  • A noncanonical mu-1A-binding motif in the N terminus of HIV-1 Nef determines its ability to downregulate major histocompatibility complex class I in T lymphocytes, Sayuki Iijima, Sayuki Iijima, Young Jung Lee, Hirotaka Ode, Stefan T. Arold, Nobuyuki Kimura, Masaru Yokoyama, Hironori Sato, Yasuhito Tanaka, Klaus Strebel, Hirofumi Akari, Hirofumi Akari, Journal of Virology, 86, 3944 - 3951,   2012年04月01日, Downregulation of major histocompatibility complex class I (MHC-I) by HIV-1 Nef protein is indispensable for evasion of protective immunity by HIV-1. Though it has been suggested that the N-terminal region of Nef contributes to the function by associating with a mu-1A subunit of adaptor protein 1, the structural basis of the interaction between Nef and mu-1A remains elusive. We found that a tripartite hydrophobic motif (Trp13/Val16/Met20) in the N terminus of Nef was required for the MHC-I downregulation. Importantly, the motif functioned as a noncanonical mu-1A-binding motif for the interaction with the tyrosine motif-binding site of the mu-1A subunit. Our findings will help understanding of how HIV-1 evades the antiviral immune response by selectively redirecting the cellular protein trafficking system. © 2012, American Society for Microbiology.
  • Erratum: Antiviral activity of novel 2′-fluoro-6′-methylene- carbocyclic adenosine against wild-type and drug-resistant hepatitis B virus mutants (Bioorganic and Medicinal Chemistry Letters (2011) 21 (6328-6331)), Jianing Wang, Uma S. Singh, Ravindra K. Rawal, Masaya Sugiyama, Jakyung Yoo, Ashok K. Jha, Melissa Scroggin, Zhuhui Huang, Michael G. Murray, Rajgopal Govindarajan, Yasuhito Tanaka, Brent Korba, Chung K. Chu, Bioorganic and Medicinal Chemistry Letters, 22,   2012年04月01日
  • Multiple intra-familial transmission patterns of hepatitis B virus genotype D in north-eastern Egypt, Mostafa Ragheb, Abeer Elkady, Yasuhito Tanaka, Shuko Murakami, Fadia M. Attia, Adel A. Hassan, Mohamed F. Hassan, Mahmoud M. Shedid, Hassan B. Abdel Reheem, Anis Khan, Masashi Mizokami, Journal of Medical Virology, 84, 587 - 595,   2012年04月01日, The transmission rate of intra-familial hepatitis B virus (HBV) and mode of transmission were investigated in north eastern Egypt. HBV infection was investigated serologically and confirmed by molecular evolutionary analysis in family members (N=230) of 55 chronic hepatitis B carriers (index cases). Hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc) prevalence was 12.2% and 23% among family members, respectively. HBsAg carriers were prevalent in the age groups; <10 (16.2%) and 21-30 years (23.3%). The prevalence of HBsAg was significantly higher in the family members of females (19.2%) than males (8.6%) index cases (P=0.031). HBsAg and anti-HBc seropositive rates were higher significantly in the offspring of females (23%, 29.8%) than those of the males index cases (4.3%, 9.8%) (P=0.001, 0.003), as well as higher in the offspring of an infected mother (26.5, 31.8%) than those of an infected father (4.7%, 10.5%) (P=0.0006, 0.009). No significant difference was found in HBsAg seropositive rates between vaccinated (10.6%) and unvaccinated family members (14.8%). Phylogenetic analysis of the preS2 and S regions of HBV genome showed that the HBV isolates were of subgenotype D1 in nine index cases and 14 family members. HBV familial transmission was confirmed in five of six families with three transmission patterns; maternal, paternal, and sexual. It is concluded that multiple intra-familial transmission routes of HBV genotype D were determined; including maternal, paternal and horizontal. Universal HBV vaccination should be modified by including the first dose at birth with (HBIG) administration to the newborn of mothers infected with HBV. © 2012 Wiley Periodicals, Inc.
  • [Tailor-made strategy in HCV treatment]., Tsunamasa Watanabe, Yasuhito Tanaka, Nihon rinsho. Japanese journal of clinical medicine, 70, (4) 681 - 687,   2012年04月01日, 査読有り, Hepatitis C virus (HCV) infection is a global health problem and a leading cause of end-stage liver disease and hepatocellular carcinoma. Treatment of HCV infection with pegylated interferon-alpha and ribavirin can eradicate chronic HCV infection in approximately 50% of patients infected with high viremia of HCV genotype 1, and spontaneous viral clearance was observed in approximately 30% of individuals with acute infection. These findings were strongly expected to reflect variations of the host genome. Significant breakthrough by the genome-wide association study (GWAS) approach led to the discovery of genetic polymorphisms playing a major role in the evolution of infection, as well as on treatment response and adverse effects. Herein, we present current evidence with regard to the relationship between host variations and clinical outcome of hepatitis C, and focus on the potential clinical implications with respect to tailor-made therapy for chronic hepatitis C.
  • Combination of hepatitis B viral antigens and DNA for prediction of relapse after discontinuation of nucleos(t)ide analogs in patients with chronic hepatitis B, Akihiro Matsumoto, Eiji Tanaka, Yoshiyuki Suzuki, Mariko Kobayashi, Yasuhito Tanaka, Noboru Shinkai, Shuhei Hige, Hiroshi Yatsuhashi, Shinya Nagaoka, Kazuaki Chayama, Masataka Tsuge, Osamu Yokosuka, Fumio Imazeki, Shuhei Nishiguchi, Masaki Saito, Kei Fujiwara, Nobuyuki Torii, Naoki Hiramatsu, Yoshiyasu Karino, Hiromitsu Kumada, Hepatology Research, 42, 139 - 149,   2012年02月01日, Aim: The factors associated with hepatitis recurrence after discontinuation of nucleos(t)ide analogs (NAs) in patients with chronic hepatitis B were analyzed to predict the risk of relapse more accurately. Methods: A total of 126 patients who discontinued NA therapy were recruited retrospectively. The clinical conditions of a successful discontinuation were set as alanine aminotransferase (ALT) below 30IU/L and serum hepatitis B virus (HBV) DNA below 4.0 log copies/mL. Results: Relapse of hepatitis B were judged to occur when maximal serum ALT became higher than 79IU/L or when maximal serum HBV DNA surpassed 5.7 log copies/mL following NA discontinuation since these values corresponded with mean values of ALT (30IU/L) and HBV DNA (4.0 log copies/mL), respectively. At least 90% of patients with either detectable hepatitis B e antigen or serum HBV DNA higher than 3.0 log copies/mL at the time of NA discontinuation relapsed within one year. In the remaining patients, higher levels of both hepatitis B surface and core-related antigens at the time of discontinuation, as well as a shorter course of NA treatment, were significantly associated with relapse by multivariate analysis. Conclusions: It appears that negative results for hepatitis B e antigen and serum HBV DNA lower than 3.0 log copies/mL are essential for successful NA discontinuation, which may be attained by a longer treatment period. Levels of hepatitis B surface and core-related antigens are also significant factors independently associated with relapse of hepatitis. © 2011 The Japan Society of Hepatology.
  • Production of infectious chimeric hepatitis C virus genotype 2b harboring minimal regions of JFH-1, Asako Murayama, Takanobu Kato, Daisuke Akazawa, Nao Sugiyama, Tomoko Date, Takahiro Masaki, Shingo Nakamoto, Yasuhito Tanaka, Masashi Mizokami, Osamu Yokosuka, Akio Nomoto, Akio Nomoto, Takaji Wakita, Journal of Virology, 86, 2143 - 2152,   2012年02月01日, To establish a cell culture system for chimeric hepatitisCvirus (HCV) genotype 2b, we prepared a chimeric construct harboring the 5′ untranslated region (UTR) to the E2 region of theMAstrain (genotype 2b) and the region of p7 to the 3′ UTR of the JFH-1 strain (genotype 2a). This chimericRNA(MA/JFH-1.1) replicated and produced infectious virus in Huh7.5.1 cells. Replacement of the 5′ UTR of this chimera with that from JFH-1 (MA/JFH-1.2) enhanced virus production, but infectivity remained low. In a long-term follow-up study, we identified a cell culture-adaptive mutation in the core region (R167G) and found that it enhanced virus assembly.Wepreviously reported that the NS3 helicase (N3H) and the region of NS5B to 3′X(N5BX) of JFH-1 enabled replication of the J6CF strain (genotype 2a), which could not replicate in cells. To reduce JFH-1 content in MA/JFH-1.2, we produced a chimeric viral genome forMA harboring theN3Hand N5BX regions of JFH-1, combined with a JFH-1 5′ UTR replacement and the R167G mutation (MA/N3H+N5BX-JFH1/R167G). This chimericRNAreplicated efficiently, but virus production was low. After the introduction of four additional cell culture-adaptive mutations, MA/N3H+N5BX-JFH1/5am produced infectious virus efficiently. Using this chimeric virus harboring minimal regions of JFH-1, we analyzed interferon sensitivity and found that this chimeric virus was more sensitive to interferon than JFH-1 and another chimeric virus containing more regions from JFH-1 (MA/JFH-1.2/R167G). In conclusion, we established anHCVgenotype 2b cell culture system using a chimeric genome harboring minimal regions of JFH-1. This cell culture system may be useful for characterizing genotype 2b viruses and developing antiviral strategies. © 2012, American Society for Microbiology.
  • Origin and evolution of the unique hepatitis C virus circulating recombinant form 2k/1b, Jayna Raghwani, Xiomara V. Thomas, Sylvie M. Koekkoek, Janke Schinkel, Richard Molenkamp, Thijs J. van de Laar, Yutaka Takebe, Yasuhito Tanaka, Masashi Mizokami, Andrew Rambaut, Andrew Rambaut, Oliver G. Pybus, Journal of Virology, 86, 2212 - 2220,   2012年02月01日, Since its initial identification in St. Petersburg, Russia, the recombinant hepatitis C virus (HCV) 2k/1b has been isolated from several countries throughout Eurasia. The 2k/1b strain is the only recombinant HCV to have spread widely, raising questions about the epidemiological background in which it first appeared. In order to further understand the circumstances by which HCV recombinants might be formed and spread, we estimated the date of the recombination event that generated the 2k/1b strain using a Bayesian phylogenetic approach. Our study incorporates newly isolated 2k/1b strains from Amsterdam, The Netherlands, and has employed a hierarchical Bayesian framework to combine information from different genomic regions. We estimate that 2k/1b originated sometime between 1923 and 1956, substantially before the first detection of the strain in 1999. The timescale and the geographic spread of 2k/1b suggest that it originated in the former Soviet Union at about the time that the world's first centralized national blood transfusion and storage service was being established. We also reconstructed the epidemic history of 2k/1b using coalescent theory-based methods, matching patterns previously reported for other epidemic HCV subtypes. This study demonstrates the practicality of jointly estimating dates of recombination from flanking regions of the breakpoint and further illustrates that rare genetic-exchange events can be particularly informative about the underlying epidemiological processes. © 2012, American Society for Microbiology.
  • Consumption of n-3 fatty acids and fish reduces risk of hepatocellular carcinoma, Norie Sawada, Manami Inoue, Motoki Iwasaki, Shizuka Sasazuki, Taichi Shimazu, Taiki Yamaji, Ribeka Takachi, Yasuhito Tanaka, Masashi Mizokami, Shoichiro Tsugane, Gastroenterology, 142, 1468 - 1475,   2012年01月01日, Background & Aims: Fish is a rich source of n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA). Although consumption of fish and n-3 PUFA has been reported to protect against the development of some types of cancer, little is known about its association with hepatocellular carcinoma (HCC). Methods: We investigated the association between fish and n-3 PUFA consumption and HCC incidence (n = 398) in a population-based prospective cohort study of 90,296 Japanese subjects (aged, 45-74 y). Hazard ratios and 95% confidence intervals (CIs) for the highest vs the lowest quintile were estimated from multivariable adjusted Cox proportional hazards regression models. We also conducted subanalyses of subjects with known hepatitis B virus (HBV) or hepatitis C virus (HCV) status, and of subjects who were anti-HCV and/or hepatitis B surface antigen positive. All tests of statistical significance were 2-sided. Results: Among all subjects, consumption of n-3 PUFA-rich fish and individual n-3 PUFAs was associated inversely with HCC, in a dose-dependent manner. Hazard ratios for the highest vs lowest quintiles were 0.64 (95% CI, 0.42-0.96) for n-3 PUFA-rich fish, 0.56 (95% CI, 0.36-0.85) for EPA, 0.64 (95% CI, 0.41-0.98) for DPA, and 0.56 (95% CI, 0.35-0.87) for DHA. These inverse associations were similar irrespective of HCV or HBV status. Conclusions: Consumption of n-3 PUFA-rich fish or n-3 PUFAs, particularly EPA, DPA, and DHA, appears to protect against the development of HCC, even among subjects with HBV and/or HCV infection. © 2012 AGA Institute.
  • Host genetic factors control hepatitis C Virus Infection, Yasuhito Tanaka, Masashi Mizokami, Chronic Hepatitis B and C: Basic Science to Clinical Applications, 325 - 340,   2012年01月01日
  • Favorable factors for re-treatment with pegylated interferon α2a plus ribavirin in patients with high viral loads of genotype 1 hepatitis C virus, Akihiro Tamori, Kiyohide Kioka, Osamu Kurai, Hiroki Sakaguchi, Masaru Enomoto, Hideki Fujii, Sawako Kobayashi, Shuji Iwai, Hiroyasu Morikawa, Seiko Yamaguchi, Yasuko Kawasaki, Hiroko Oka, Yasuhito Tanaka, Norifumi Kawada, Hepatology Research, 41, 1169 - 1177,   2011年12月01日, Aim: Effect of re-treatment for pegylated interferon (PEG-IFN) plus ribavirin was not fully evaluated. We examined the effects of re-treatment with PEG-IFN plus ribavirin in patients with high viral loads of genotype 1 hepatitis C virus who failed to achieve a sustained virological response (SVR) with combination therapy. Methods: We examined 38 patients who were re-treated with PEG-IFN α2a plus ribavirin for more than 60weeks, among whom 14 were non-responders and 24 were relapsers after previous treatment with PEG-IFN α2b plus ribavirin. IL28B genotyping was done in 21 patients. Results: The overall SVR rate was 34%. Analysis of baseline characteristics showed that the relapsers had a significantly higher SVR rate than the non-responders (50.0%, 12/24 vs. 7.1%, 1/14, respectively, P=0.012) The SVR rates of re-treated patients who had turned hepatitis C virus (HCV) RNA-negative at weeks 8, 12, 24, and 48 of the previous therapy were 67% (4/6), 67% (4/6), 29% (2/7), and 25% (1/4), respectively. Re-treatment achieved an SVR in five of 12 patients with IL28B major alleles and three of nine patients with IL28B minor alleles. During the re-treatment, patients with complete viral suppression at week-12 achieved a significantly higher SVR rate (P=0.001). Conclusions: Re-treatment with PEG-IFN α2a plus ribavirin therapy is effective in patients who relapse after a course of PEG-IFN α2b plus ribavirin therapy. Re-treatment is a particularly useful option for patients who achieve early viral clearance during previous therapy. © 2011 The Japan Society of Hepatology.
  • Suppressor of cytokine signal 3 and IL28 genetic variation predict the viral response to peginterferon and ribavirin, Hisamitsu Miyaaki, Tatsuki Ichikawa, Hiroshi Yatsuhashi, Naota Taura, Satoshi Miuma, Tetsuya Usui, Sayaka Mori, Shimeru Kamihira, Yasuhito Tanaka, Masashi Mizokami, Kazuhiko Nakao, Hepatology Research, 41, 1216 - 1222,   2011年12月01日, Aim: The aim of this study was to investigate the relationship among the expression of suppressor of cytokine signaling 3 (SOCS 3) in the liver, the SNPs in the IL28B locus, and the outcome of interferon therapy. Methods: Prior to interferon treatment, we immunostained 67 liver specimens from chronic hepatitis C (CHC) patients who were receiving peginterferon alpha-2b/ribavirin therapy for suppressor of cytokine signaling 3 (SOCS3), and compared the expression of SOCS3, IL28 polymorphisms and other clinical factors between the patients and compared their eventual outcomes. Results: Significant differences between the low SOCS3 group and high SOCS3 group were found in age, as well as in the platelet, transaminase, gamma-glutamyl transpeptidase levels. The incidence of high SOCS3 was not significantly different between subjects with the TT genotype and the TG genotype (TT:TG=71%:29%, P=0.250). In a multivariate analysis, age (≥65 years old) (odds ratio 0.221 [0.120-0.966], P=0.045), IL28B gene (genotype TT) (odds ratio 5.422 [1.254-23.617], P=0.024) and SOCS3 (high) (odds ratio 0.308 [0.104-0.948], P=0.040) were significant predictors of the interferon response. In patients with the TT genotype, those with low SOCS3 immunostaining showed a high sustained virological response (69%), while the sustained virological rate was low (27%) in the patients with high SOCS3 immunostaining. Conclusions: Using a combination of the SOCS3 immunostained area in the liver and the expression of IL28B single nucleotide polymorphisms might be a useful predictor of hepatitis C virus clearance by interferon therapy. © 2011 The Japan Society of Hepatology.
  • Double-filtration plasmapheresis plus interferon-β for HCV-1b patients with non-sustained virological response to previous combination therapy, Soo Ryang Kim, Jun Saito, Susumu Imoto, Takamitsu Komaki, Yoshiaki Nagata, Ke Ih Kim, Noriko Sasase, Noriyo Kimura, Kanako Sasatani, Erika Konishi, Yutaka Hasegawa, Aya Fujinami, Mitsuhiro Ohta, Ahmed El-Shamy, Yasuhito Tanaka, Masahiko Sugano, Masanori Sakashita, Akira Nakamura, Shinobu Tsuchida, Tetsuya Makino, Tetsumi Kawada, Takatoshi Nakajima, Teruhisa Morikawa, Akira Muramatsu, Hiroshi Kasugai, Hak Hotta, Masatoshi Kudo, Digestion, 84, 10 - 16,   2011年12月01日, Background and Aims: Double-filtration plasmapheresis (DFPP) together with interferon (IFN) administration produces a substantial reduction in the viral load during the early stages of treatment. Methods: Based on their responses to previous pegylated IFN and ribavirin (PEG-IFN/RBV) therapy, 20 patients were divided into null virological response (NVR; n = 12) and relapse (n = 8) groups. DFPP was used in combination with IFN-β/RBV with subsequent administration of PEG-IFN-α2a/RBV therapy (DFPP + IFN-β/RBV then PEG-IFN/RBV). Early viral dynamics was assessed, focusing especially on complete early virological response (cEVR) associated with sustained virological response. Additionally, the interleukin 28B gene, the IFN/RBV resistance-determining region, the IFN sensitivity-determining region and the core regions were analyzed. Results: Rapid virological response was achieved in 0% (0/12) of NVR and in 75% (6/8) of relapse patients, with a significant difference between the two groups (p = 0.001). Similarly, cEVR was achieved in 8% (1/12) of NVR and in 88% (7/8) of relapse patients, with a significant difference between the two groups (p = 0.037). By multivariate logistic regression analysis, interleukin-28B major was a significant determiner of cEVR (odds ratio = 24.19, p = 0.037). Conclusion: DFPP + IFN-β/RBV then PEG-IFN/RBV therapy is indicated more for relapse than for NVR patients. Copyright © 2011 S. Karger AG, Basel.
  • Interleukin28B and inosine triphosphatase help to personalize hepatitis c treatment, Yasuhito Tanaka, Digestion, 84, 50 - 55,   2011年12月01日, 査読有り, In the therapy using a combination of pegylated interferon-α and ribavirin (PEG-IFN/RBV) for chronic hepatitis C (CHC), approximately 50% of CHC patients infected with high viremia of HCV genotype 1 reached sustained viral response. The recent discovery revealed by a genome-wide association study technology provides the unexpected role of IL28B and inosine triphosphatase (ITPA) in HCV infection. The former single nucleotide polymorphisms (SNPs) around the IL28B gene could improve the diagnostics on the prediction of spontaneous clearance and the response to anti-HCV treatment, suggesting that these findings could be strong evidence to enhance the development of a novel therapeutic strategy and the basic study of IFN-λs. Interestingly, the discovered IL28B SNPs revealed the enigma that the viral clearance rate was dependent on ethnicity. The latter functional SNP in ITPA locus was the most significant SNP associated with RBV-induced anemia as well as IFN-induced thrombocytopenia. Note that severe Hb decline, which is mainly found in ITPA-CC patients, was inversely correlated with platelet reduction, contributing to an association between severe anemia and relative reactive increase in platelet count. These data may provide a valuable pharmacogenetic diagnostic tool for tailoring PEG-IFN/RBV dosing to minimize drug-induced adverse events and for further optimization of clinical anti-HCV chemotherapeutics. Copyright © 2011 S. Karger AG, Basel.
  • Antiviral activity of novel 2'-fluoro-6'-methylene-carbocyclic adenosine against wild-type and drug-resistant hepatitis B virus mutants, Jianing Wanga, Uma S. Singh, Ravindra K. Rawal, Massaya Sugiyama, Jakyung Yoo, Ashok K. Jha, Melissa Scroggin, Zhuhui Huang, Michael G. Murray, Rajgopal Govindarajan, Yasuhito Tanaka, Brent Korba, Chung K. Chu, Bioorganic and Medicinal Chemistry Letters, 21, 6328 - 6331,   2011年11月01日, Novel 2'-fluoro-6'-methylene-carbocyclic adenosine (9) was synthesized and evaluated its anti-HBV activity. The titled compound demonstrated significant antiviral activity against wild-type as well as lamivudine, adefovir and double lamivudine/entecavir resistant mutants. Molecular modeling study indicate that the 2'-fluoro moiety by a hydrogen bond, as well as the van der Waals interaction of the carbocyclic ring with the phenylalanine moiety of the polymerase promote the positive binding, even in the drug resistant mutants. © 2011 Elsevier Ltd. All rights reserved.
  • Genetic variation of the IL-28B promoter affecting gene expression, Masaya Sugiyama, Masaya Sugiyama, Masaya Sugiyama, Yasuhito Tanaka, Takaji Wakita, Makoto Nakanishi, Masashi Mizokami, PLoS ONE, 6,   2011年10月25日, The current standard of care for the treatment of chronic hepatitis C is pegylated interferon-α (PEG-IFNα) and ribavirin (RBV). The treatment achieves a sustained viral clearance in only approximately 50% of patients. Recent whole genome association studies revealed that single nucleotide polymorphisms (SNPs) around IL-28B have been associated with response to the standard therapy and could predict treatment responses at approximately 80%. However, it is not clear which SNP is most informative because the genomic region containing significant SNPs shows strong linkage disequilibrium. We focused on SNPs in close proximity to the IL-28B gene to evaluate the function of each and identify the SNP affecting the IL-28B expression level most. The structures of IL-28A/B from 5′ to 3′-UTR were determined by complete cDNA cloning. Both IL-28A and 28B genes consisted of 6 exons, differing from the CCDS data of NCBI. Two intron SNPs and a nonsynonymous SNP did not affect IL-28B gene function and expression levels but a SNP located in the proximal promoter region influenced gene expression. A (TA) dinucleotide repeat, rs72258881, located in the promoter region was discovered by our functional studies of the proximal SNPs upstream of IL-28B; the transcriptional activity of the promoter increased gradually in a (TA)nlength-dependent manner following IFN-α and lipopolysaccharide stimulation. Healthy Japanese donors exhibited a broad range of (TA) dinucleotide repeat numbers from 10 to 18 and the most prevalent genotype was 12/12 (75%), differing from the database (13/13). However, genetic variation of IL-28A corresponding to that of IL-28B was not detected in these Japanese donors. These findings suggest that the dinucleotide repeat could be associated with the transcriptional activity of IL-28B as well as being a marker to improve the prediction of the response to interferon-based hepatitis C virus treatment. © 2011 Sugiyama et al.
  • LecT-Hepa: A triplex lectin-antibody sandwich immunoassay for estimating the progression dynamics of liver fibrosis assisted by a bedside clinical chemistry analyzer and an automated pretreatment machine, Atsushi Kuno, Yuzuru Ikehara, Yasuhito Tanaka, Kozue Saito, Kiyoaki Ito, Chikayuki Tsuruno, Shinya Nagai, Youichi Takahama, Masashi Mizokami, Jun Hirabayashi, Hisashi Narimatsu, Clinica Chimica Acta, 412, 1767 - 1772,   2011年09月18日, Background: A quantitative analysis of glyco-alteration in serum glycoproteins provides glyco-parameters for estimating the progression of liver fibrosis. In the analysis of glycans, a manual pretreatment process for clinical specimens leads to a complicated manipulation and loss-of-clinical implementation of the assay. Method: We evaluated an automated triplex lectin-antibody sandwich immunoassay assisted by an automated protein purification system (ED-01) and a bedside clinical chemistry analyzer (HISCL) for the acquisition of two glyco-parameters (AOL/DSA and MAL/DSA) derived from a fibrosis-related glyco-alteration of serum alpha1-acid glycoprotein (AGP). Results: We adjusted the auto-machines with their accuracy set to CV < 5.0% (ED-01) and < 1.0% (HISCL). AGP samples were enriched from 275 serum specimens. Two glyco-parameters obtained by HISCL showed a linear correlation with that from a reported assay (R > 0.90). The formula for monitoring fibrosis (LecT-Hepa) was given by a combination of the glyco-parameters. This correlated with the fibrosis stage from biopsy (R = 0.68) and diagnosed severe fibrosis and cirrhosis. It was superior to that of FIB-4 index. Conclusions: We automated a multilectin-assisted immunoassay with an order of magnitude reduction of operation time without any loss-of-accuracy. LecT-Hepa is a reliable method to assess fibrosis-dynamics from moderate fibrosis to cirrhosis. © 2011 Elsevier B.V.
  • Relationship between polymorphisms of the inosine triphosphatase gene and anaemia or outcome after treatment with pegylated interferon and ribavirin, Masayuki Kurosaki, Yasuhito Tanaka, Keisuke Tanaka, Yuichiro Suzuki, Yuichiro Suzuki, Yoshihide Hoshioka, Nobuharu Tamaki, Tomoji Kato, Yutaka Yasui, Takanori Hosokawa, Ken Ueda, Kaoru Tsuchiya, Teiji Kuzuya, Hiroyuki Nakanishi, Jun Itakura, Yuka Takahashi, Yasuhiro Asahina, Kentaro Matsuura, Fuminaka Sugauchi, Nobuyuki Enomoto, Nao Nishida, Katsushi Tokunaga, Masashi Mizokami, Namiki Izumi, Antiviral Therapy, 16, 685 - 694,   2011年09月12日, Background: A genome-wide association study revealed an association between variants of the inosine triphosphatase (ITPA) gene and ribavirin (RBV)-induced anaemia. The aim of this study was to replicate this finding in an independent Japanese cohort and to define a method to allow pretreatment prediction of anaemia in combination with other factors. Methods: Genotype 1b chronic hepatitis C patients (n=132) treated with pegylated interferon (PEG-IFN)-α and RBV for 48 weeks were genotyped for ITPA rs1127354 and examined for anaemia and treatment outcome. Results: Variants of the ITPA gene protected against severe anaemia throughout the 48-week treatment period and were associated with lower incidence of anaemia-related RBV dose reduction. A combination of the ITPA genotype with baseline haemoglobin (Hb) and creatinine clearance (CLcr) levels predicted severe anaemia with high accuracy (90% sensitivity and 62% specificity). Among a subset of patients with the IL28B genotype of TT at rs8099917, patients with variants of the ITPA gene were associated with a higher rate of receiving >80% of the expected RBV dose, a higher rate of sustained virological response (SVR), and a lower rate of relapse. Conclusions: The variants of the ITPA gene, which could protect against haemolytic anaemia and RBV dose reduction, were associated with a high rate of SVR by standard PEG-IFN and RBV therapy in a subset of Japanese patients with the favourable TT genotype at rs8099917 of IL28B. A combination of ITPA genetic polymorphisms with baseline Hb and CLcr levels further improves the predictive accuracy of severe anaemia. ©2011 International Medical Press.
  • [Quantitative analysis of hepatitis B surface antigen as a clinical marker]., Erina Nakamura, Hirokazu Kakuda, Kentaro Matsuura, Fuminaka Sugauchi, Noboru Shinkai, Yasuhito Tanaka, Rinsho byori. The Japanese journal of clinical pathology, 59, 838 - 843,   2011年09月01日, There are 1.5 million hepatitis B virus (HBV) infected patients in Japan. Anti-viral therapy is important for chronic hepatitis B patients to prevent hepatocellular carcinoma. Recently, HBs antigen (HBsAg) quantification has been reported to be useful for not only HBV screening but also for monitoring of anti-viral treatment. In this paper, we evaluated the clinical utility of quantitative assay of HBsAg by HISCL HBsAg kit. Although there can be a significant difference in age, HBeAg positive/negative and viral genotype, there is not in the disease stage. Moreover, the weak correlation was confirmed between HBsAg and HBV-DNA levels with or without anti-virus treatment. In the clinical practice, as HBV-DNA becomes undetectable immediately by anti-viral therapy such as entecavir, it may be difficult to evaluate the efficacy. The monitoring of the HBsAg concentration in addition to HBV-DNA would be useful for the evaluation. Hence, the clinical role of HBsAg concentration could spread widely in Japan.
  • Clarification of interspousal hepatitis C virus infection in acute hepatitis C patients by molecular evolutionary analyses: Consideration on sexual and non-sexual transmission between spouses, Ikuo Nakamura, Ikuo Nakamura, Yasuhito Tanaka, Kaori Ochiai, Fuminori Moriyasu, Masashi Mizokami, Michio Imawari, Hepatology Research, 41, 838 - 845,   2011年09月01日, Aim: Previous studies evaluating the possibilities of interspousal sexual transmission of hepatitis C virus (HCV) have yielded many conflicting results. The aim of this study was to clarify the source of HCV infection in acute hepatitis C patients using phylogenetic analyses of nucleotide sequences of HCV E1 region. Methods: Four acute hepatitis C patients were hospitalized in 2002-2007. The diagnosis was based on medical records, laboratory tests including HCV markers, and ultrasonographic examination of the liver. In each spouse of four patients, serum HCV antibody was assayed. In the subjects whose serum HCV antibody was positive, additional tests on HCV viral load and genotype were carried out. Then phylogenetic analyses of nucleotide sequences of partial HCV E1 region (440 nucleotides) of the patients and their spouses were performed. Results: Hepatitis C virus antibody changed from negative to positive in the course of hospitalization and HCV RNA could be detected in every patient. Therefore they were diagnosed as acute hepatitis caused by HCV infection. In every spouse of four patients, HCV antibody and HCV RNA were positive. Three of four couples had the identical genotype and homogeneity of nucleotide sequences of HCV E1 region in three couples ranged from 97.9% to 100%. The results of phylogenic analyses suggested that interspousal HCV infection occurred in the three couples. Conclusion: In conclusion, interspousal infection might be one of the important sources of acute HCV infection in Japan. The usefulness of phylogenetic analysis of nucleotide sequences of HCV E1 region for clarifying interspousal HCV infection was validated. © 2011 The Japan Society of Hepatology.
  • Recommendation of lamivudine-to-entecavir switching treatment in chronic hepatitis B responders: Randomized controlled trial, Kentaro Matsuura, Kentaro Matsuura, Yasuhito Tanaka, Atsunori Kusakabe, Shuhei Hige, Jun Inoue, Masashi Komatsu, Tomoyuki Kuramitsu, Katsuharu Hirano, Tomoyoshi Ohno, Izumi Hasegawa, Haruhiko Kobashi, Keisuke Hino, Yoichi Hiasa, Hideyuki Nomura, Fuminaka Sugauchi, Shunsuke Nojiri, Takashi Joh, Masashi Mizokami, Hepatology Research, 41, 505 - 511,   2011年06月01日, Aim: In the 2007-2008 guidelines of the study group (Ministry of Health, Labor and Welfare of Japan), lamivudine (LAM)-continuous treatment was recommended in patients treated with LAM for more than 3years who maintained hepatitis B virus (HBV) DNA less than 2.6 log copies/mL, because in these patients LAM resistance might exist and switching treatment to entecavir (ETV) might cause ETV resistance. However, there was no evidence on whether switching treatment to ETV- or LAM-continuous treatment was better in those patients. In the present study, we performed a randomized controlled trial of LAM-to-ETV switching treatment. Methods: Twenty-seven patients treated with LAM for more than 3years whose HBV DNA levels were less than 2.6 log copies/mL were enrolled and randomly divided into two groups, LAM-continued group or switching to ETV group. Then, we examined incidence of virological breakthrough (VBT) and breakthrough hepatitis (BTH) in each group. Results: There was no BTH in any of the patients. VBT was observed in six patients of the LAM group (6/15, 40%), and no patient of the ETV group (0/11, 0%) (P=0.02). The differences of the proportion of cumulated VBT using a log-rank test with Kaplan-Meier analysis were significant between the LAM and ETV groups (P=0.025). Conclusion: In patients treated with LAM for more than 3years maintaining HBV DNA less than 2.6 log copies/mL, switching treatment to ETV is recommended at least during the 2years' follow-up period. © 2011 The Japan Society of Hepatology.
  • Cross-species transmission of gibbon and orangutan hepatitis B virus to uPA/SCID mice with human hepatocytes, Pattaratida Sa-nguanmoo, Yasuhito Tanaka, Parntep Ratanakorn, Masaya Sugiyama, Shuko Murakami, Sunchai Payungporn, Angkana Sommanustweechai, Masashi Mizokami, Yong Poovorawan, Virus Research, 158, 209 - 215,   2011年06月01日, To investigate the potential of cross-species transmission of non-human primate HBV to humans, severe combined immunodeficiency mice transgenic for urokinase-type plasminogen activator, in which the mouse liver has been engrafted with human hepatocytes, were inoculated with non-human primate HBV. HBV-DNA positive serum samples from a gibbon or orangutan were inoculated into 6 chimeric mice. HBV-DNA, hepatitis B surface antigen (HBsAg), and HB core-related antigen in sera and HBV cccDNA in liver were detectable in 2 of 3 mice each from the gibbon and orangutan. Likewise, applying immunofluorescence HBV core protein was only found in human hepatocytes expressing human albumin. The HBV sequences from mouse sera were identical to those from orangutan and gibbon sera determined prior to inoculation. In conclusion, human hepatocytes have been infected with gibbon/orangutan HBV. © 2011 Elsevier B.V.
  • The rs8099917 polymorphism, when determined by a suitable genotyping method, is a better predictor for response to pegylated alpha interferon/ribavirin therapy in Japanese patients than other single nucleotide polymorphisms associated with interleukin-28B, Kiyoaki Ito, Katsuya Higami, Naohiko Masaki, Masaya Sugiyama, Motokazu Mukaide, Hiroaki Saito, Yoshihiko Aoki, Yo Sato, Masatoshi Imamura, Kazumoto Murata, Hideyuki Nomura, Shuhei Hige, Hiroshi Adachi, Keisuke Hino, Hiroshi Yatsuhashi, Etsuro Orito, Satomi Kani, Yasuhito Tanaka, Masashi Mizokami, Journal of Clinical Microbiology, 49, 1853 - 1860,   2011年05月01日, We focused on determining the most accurate and convenient genotyping methods and most appropriate single nucleotide polymorphism (SNP) among four such polymorphisms associated with interleukin-28B (IL-28B) in order to design tailor-made therapy for patients with chronic hepatitis C virus (HCV) patients. First, five different methods (direct sequencing, high-resolution melting analysis [HRM], hybridization probe [HP], the InvaderPlus assay [Invader], and the TaqMan SNP genotyping assay [TaqMan]) were developed for genotyping four SNPs (rs11881222, rs8103142, rs8099917, and rs12979860) associated with IL-28B, and their accuracies were compared for 292 Japanese patients. Next, the four SNPs associated with IL-28B were genotyped by Invader for 416 additional Japanese patients, and the response to pegylated interferon/ribavirin (PEG-IFN/RBV) treatment was evaluated when the four SNPs were not in linkage disequilibrium (LD). HRM failed to genotype one of the four SNPs in five patients. In 2 of 287 patients, the results of genotyping rs8099917 by direct sequencing differed from the results of the other three methods. The HP, TaqMan, and Invader methods were accurate for determination of the SNPs associated with IL-28B. In 10 of the 708 (1.4%) patients, the four SNPs were not in LD. Eight of nine (88.9%) patients whose rs8099917 was homozygous for the major allele were virological responders, even though one or more of the other SNPs were heterozygous. The HP, TaqMan, and Invader methods were suitable to determine the SNPs associated with IL-28B. The rs8099917 polymorphism should be the best predictor for the response to the PEG-IFN/RBV treatment among Japanese chronic hepatitis C patients. Copyright © 2011, American Society for Microbiology. All Rights Reserved.
  • The effects of IL-28B and ITPA polymorphisms on treatment of hepatitis C virus genotype 6, Wai Kay Seto, Yasuhito Tanaka, Kevin Liu, Ching Lung Lai, Man Fung Yuen, American Journal of Gastroenterology, 106, 1007 - 1008,   2011年05月01日
  • Association of IL28B variants with response to pegylated-interferon alpha plus ribavirin combination therapy reveals intersubgenotypic differences between genotypes 2a and 2b, Naoya Sakamoto, Naoya Sakamoto, Mina Nakagawa, Yasuhito Tanaka, Yuko Sekine-Osajima, Mayumi Ueyama, Masayuki Kurosaki, Nao Nishida, Akihiro Tamori, Nishimura Sakurai Yuki, Yasuhiro Itsui, Yasuhiro Itsui, Seishin Azuma, Sei Kakinuma, Sei Kakinuma, Shuhei Hige, Yoshito Itoh, Eiji Tanaka, Yoichi Hiasa, Namiki Izumi, Katsushi Tokunaga, Masashi Mizokami, Mamoru Watanabe, Journal of Medical Virology, 83, 871 - 878,   2011年05月01日, Genetic polymorphisms of the interleukin 28B (IL28B) locus are associated closely with outcomes of pegylated-interferon (PEG-IFN) plus ribavirin (RBV) combination therapy. The aim of this study was to investigate the relationship between IL28B polymorphism and responses to therapy in patients infected with genotype 2. One hundred twenty-nine chronic hepatitis C patients infected with genotype 2, 77 patients with genotype 2a and 52 patients with genotype 2b, were analyzed. Clinical and laboratory parameters, including genetic variation near the IL28B gene (rs8099917), were assessed. Drug adherence was monitored in each patient. Univariate and multivariate statistical analyses of these parameters and clinical responses were carried out. Univariate analyses showed that a sustained virological response was correlated significantly with IL28B polymorphism, as well as age, white blood cell and neutrophil counts, adherence to RBV, and rapid virological response. Subgroup analysis revealed that patients infected with genotype 2b achieved significantly lower rapid virological response rates than those with genotype 2a. Patients with the IL28B-major allele showed higher virus clearance rates at each time point than those with the IL28B-minor allele, and the differences were more profound in patients infected with genotype 2b than those with genotype 2a. Furthermore, both rapid and sustained virological responses were associated significantly with IL28B alleles in patients with genotype 2b. IL28B polymorphism was predictive of PEG-IFN plus RBV combination treatment outcomes in patients infected with genotype 2 and, especially, with genotype 2b. In conclusion, IL-28B polymorphism affects responses to PEG-IFN-based treatment in difficult-to-treat HCV patients. © 2011 Wiley-Liss, Inc.
  • [Clinical implication of hepatitis B virus genotype]., Noboru Shinkai, Yasuhito Tanaka, Nihon rinsho. Japanese journal of clinical medicine, 69 Suppl 4, 422 - 427,   2011年05月01日, 査読有り
  • [Relation of IL28B gene polymorphism to chronic hepatitis C]., Kentaro Matsuura, Yasuhito Tanaka, Nihon rinsho. Japanese journal of clinical medicine, 69 Suppl 4, 227 - 233,   2011年05月01日, 査読有り
  • Investigating an outbreak of acute viral hepatitis caused by hepatitis E virus variants in Karachi, South Pakistan, Anis Khan, Yasuhito Tanaka, Fuat Kurbanov, Abeer Elkady, Zaigham Abbas, Zahid Azam, Amna Subhan, Sajjad Razza, Saeed Hamid, Wasim Jafri, James Shih, Ningshao Xia, Kazuaki Takahashi, Shunji Mishiro, Masashi Mizokami, Journal of Medical Virology, 83, 622 - 629,   2011年04月01日, Hepatitis E is a classic water-borne disease in developing countries. Detection of anti-HEV IgM and IgG antibodies, in addition to HEV RNA are useful epidemiological markers in diagnosis of hepatitis E. This study was conducted to investigate an outbreak of acute viral hepatitis in South-Pakistan. Anti-HEV IgM and IgG were assessed comparatively with serological kits manufactured by Abbott, Cosmic, TGH, and Wantai, selecting HEV RNA as reference assay. Molecular evolutionary analysis was performed by phylogeny and HEV spread time analysis by Bayesian Coalescent Theory approach. Of the 89 patients, 24 (26.9%) did not have acute hepatitis viral marker. Of the remaining 65 cases, 4 (6.1%) were positive for anti-HAV IgM, one (1.5%) for anti-HBc IgM, 2 (3%) for HCV, 53 (81.5%) for anti-HEV IgM, and 5 (7.7%) were hepatitis-negative. The Wantai test was 100% sensitive and specific followed by Cosmic (98.1% and 100%), TGH (98.1% and 97.2%) and Abbott (79.2% and 83.3%). Two HEV variant strains were detected by phylogeny responsible for this acute hepatitis outbreak. Estimates on demographic history of HEV showed that HEV in Pakistan has remained at a steady nonexpanding phase from around 1970 to the year 2005, in which it expanded explosively with the emergence of new HEV variants. In conclusion, the limited sensitivity of available assay (Abbott anti-HEV EIA) may be a concern in HEV diagnosis in Pakistan. This study cautions that the dissemination of the variant strains to other areas of Pakistan may lead to explosive HEV outbreaks. © 2011 Wiley-Liss, Inc.
  • Host sphingolipid biosynthesis is a promising therapeutic target for the inhibition of hepatitis B virus replication, Kanako Tatematsu, Yasuhito Tanaka, Masaya Sugiyama, Masayuki Sudoh, Masashi Mizokami, Masashi Mizokami, Journal of Medical Virology, 83, 587 - 593,   2011年04月01日, Serine palmitoyltransferase (SPT) catalyzes the first step in the sphingolipid biosynthetic pathway. Myriocin inhibits SPT and was shown to suppress the replication of hepatitis C virus (HCV) in vitro and in vivo. However, its effect on hepatitis B virus (HBV) replication is unknown. In this study, the HBV DNA levels in HuH7 cell culture supernatants were lowered successfully by using myriocin and it was found that the 50% inhibitory concentration of myriocin is approximately 5μM. Myriocin and/or pegylated interferon (PEG-IFN) were also administered to chimeric mice for 2 weeks and the effects of these compounds on HBV DNA levels were determined. Myriocin alone did not reduce effectively the HBV DNA levels, whereas PEG-IFN alone reduced the DNA levels to 1/10th of the control levels. The combination of myriocin with PEG-IFN reduced the HBV levels to about 1/1,000th of the control levels and induced a 1.0log reduction in the levels of the HBV surface antigen and core protein. This latter effect was not observed in the other treatment groups. In conclusion, the combination of myriocin with PEG-IFN represses synergistically HBV replication in vivo without inducing hepatotoxicity. © 2011 Wiley-Liss, Inc.
  • Novel findings for the development of drug therapy for various liver diseases: Genetic variation in IL-28B is associated with response to the therapy for chronic hepatitis C, Masaya Sugiyama, Masaya Sugiyama, Yasuhito Tanaka, Makoto Nakanishi, Masashi Mizokami, Journal of Pharmacological Sciences, 115, 263 - 269,   2011年03月24日, Hepatitis C infection is a global health problem. Spontaneous viral clearance was observed in approximately 30% of individuals with acute infection. In the therapy using a combination of pegylated interferon-α and ribavirin, approximately 50% of chronic hepatitis C patients infected with high viremia of hepatitis C virus infection (HCV) genotype 1 reached a sustained viral response. These findings were strongly expected to reflect variations of the host genome. To reveal genetic effects against viral clearance or treatment response, four independent groups applied a genome-wide association study (GWAS) to HCV infection. These groups almost simultaneously reported a strong association of interleukin (IL)-28B polymorphisms with viral clearance or final decision of HCV therapy. The discovered single nucleotide polymorphisms (SNPs) also revealed the enigma that the viral clearance rate was dependent on ethnic type. The significant SNPs are useful for prediction prior to treatment because of the strong association with clinical outcome. In addition, the unexpected results revealed by GWAS could promote the development of a novel drug related to IL-28B. Herein, we present current understanding in regard to the relationship between host variations and clinical outcome of hepatitis C. © The Japanese Pharmacological Society.
  • Pre-treatment prediction of response to pegylated-interferon plus ribavirin for chronic hepatitis C using genetic polymorphism in IL28B and viral factors, Masayuki Kurosaki, Yasuhito Tanaka, Nao Nishida, Naoya Sakamoto, Nobuyuki Enomoto, Masao Honda, Masaya Sugiyama, Kentaro Matsuura, Fuminaka Sugauchi, Yasuhiro Asahina, Mina Nakagawa, Mamoru Watanabe, Minoru Sakamoto, Shinya Maekawa, Akito Sakai, Shuichi Kaneko, Kiyoaki Ito, Naohiko Masaki, Katsushi Tokunaga, Namiki Izumi, Masashi Mizokami, Masashi Mizokami, Journal of Hepatology, 54, 439 - 448,   2011年03月01日, Background & Aims: Pegylated interferon and ribavirin (PEG-IFN/RBV) therapy for chronic hepatitis C virus (HCV) genotype 1 infection is effective in 50% of patients. Recent studies revealed an association between the IL28B genotype and treatment response. We aimed to develop a model for the pre-treatment prediction of response using host and viral factors. Methods: Data were collected from 496 patients with HCV genotype 1 treated with PEG-IFN/RBV at five hospitals and universities in Japan. IL28B genotype and mutations in the core and IFN sensitivity determining region (ISDR) of HCV were analyzed to predict response to therapy. The decision model was generated by data mining analysis. Results: The IL28B polymorphism correlated with early virological response and predicted null virological response (NVR) (odds ratio = 20.83, p <0.0001) and sustained virological response (SVR) (odds ratio = 7.41, p <0.0001) independent of other covariates. Mutations in the ISDR predicted relapse and SVR independent of IL28B. The decision model revealed that patients with the minor IL28B allele and low platelet counts had the highest NVR (84%) and lowest SVR (7%), whereas those with the major IL28B allele and mutations in the ISDR or high platelet counts had the lowest NVR (0-17%) and highest SVR (61-90%). The model had high reproducibility and predicted SVR with 78% specificity and 70% sensitivity. Conclusions: The IL28B polymorphism and mutations in the ISDR of HCV were significant pre-treatment predictors of response to PEG-IFN/RBV. The decision model, including these host and viral factors may support selection of optimum treatment strategy for individual patients. © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
  • Virological and clinical characteristics on reactivation of occult hepatitis B in patients with hematological malignancy, Fuminaka Sugauchi, Yasuhito Tanaka, Shigeru Kusumoto, Kentaro Matsuura, Masaya Sugiyama, Fuat Kurbanov, Ryuzo Ueda, Masashi Mizokami, Journal of Medical Virology, 83, 412 - 418,   2011年03月01日, The virological characteristics of hepatitis B virus (HBV) implicated in the reactivation of occult hepatitis B in patients who have received hematopoietic stem-cell transplantation or chemotherapy for the hematological malignancy are not well defined. Twenty-eight HBsAg-negative patients who received hematopoietic stem-cell transplantation and 138 HBsAg-negative patients treated for malignant lymphoma with chemotherapy including rituximab were enrolled. Three of the 28 patients (10.7%) received hematopoietic stem-cell transplantation and one of the 138 (0.72%) patients treated for malignant lymphoma with chemotherapy developed de novo HBV hepatitis. Anti-HBc was detected in four and anti-HBs in two patients. Genotype Bj was detected in two and C in two of they all possessed wild-type sequences in the core promoter region. A precore stop mutation (A1896) was detected in a patient with genotype Bj who developed fulminant hepatic failure. HBV DNA was detected in pretreatment HBsAg-negative samples in two of four patients, and the HBV genome sequence identified from sera before chemotherapy and at the time of de novo HBV hepatitis showed 100% homology. In an in vitro replication model, genotype Bj with the A1896 clone obtained from a fulminant case had a replication level much higher than clones obtained from de novo hepatitis B patients with genotype Bj or C with G1896. In conclusion, this is the first report demonstrating de novo hepatitis B from the reactivation of occult HBV infection confirmed by molecular evolutional analysis. The fulminant outcome of HBV reactivation can be associated with genotype Bj exhibiting high replication due to the A1896 mutation. J. Med. Virol. 83:412-418, 2011. © 2011 Wiley-Liss, Inc.
  • Transmissibility of hepatitis B virus (HBV) infection through blood transfusion from blood donors with occult HBV infection, Man Fung Yuen, Danny Ka Ho Wong, Cheuk Kwong Lee, Yasuhito Tanaka, Jean Pierre Allain, James Fung, Jennifer Leung, Che Kit Lin, Masaya Sugiyama, Fuminaka Sugauchi, Masashi Mizokami, Ching Lung Lai, Clinical Infectious Diseases, 52, 624 - 632,   2011年03月01日, Background: Studies of the transmissibility of hepatitis B virus (HBV) in occult hepatitis B (OHB) through blood transfusion are scarce. We aimed to determine the transmissibility of HBV in blood donors with OHB through transfusion in animal and human studies. Methods: Among 217,595 blood donors, 67 donors with OHB were identified. Four chimeric mice populated with human hepatocytes were inoculated with 2 donor serum samples. Serial serum and liver HBV DNA levels were measured. Forty-nine recipients of blood transfusions traced from 10 donors with OHB (9 of whom were positive for antibody to hepatitis B surface antigen [anti-HBs]) were tested for HBV infection. Homology and phylogenetic analyses between the HBV genomic sequences of donors and recipients were performed. Results: Serum HBV DNA was detectable (104copies/mL) in 1 mouse at weeks 5 and 7 after inoculation. Total HBV DNA and HBV replication template (covalently closed circular DNA) and hepatitis B core antigen were detected in the mouse liver. After transfusion, 45 recipients (91.8%) had no HBV infection (ie, they tested negative for hepatitis B surface antigen and HBV DNA). Four tested positive for HBV DNA. In 3 recipients, 83%-86% homology and distant phylogenetic relatedness with their donor HBV excluded transmission through transfusion. The remaining recipient HBV had 95% sequence homology with her donor HBV, compatible with acquisition of HBV infection from the transfusion. High anti-HBs levels in 7 other recipients suggested recent transfusion-related HBV immune response. Conclusions: OHB donor blood infectivity was shown in our animal and human studies. However, the risk of HBV transmission in humans was low, especially from blood products obtained from donors with OHB who were anti-HBs positive. © The Author 2011.
  • Clinical significance of Hepatitis B Virus (HBV) -DNA monitoring to detect HBV reactivation after systemic chemotherapy, Shigeru Kusumoto, Yasuhito Tanaka, Masashi Mizokami, Ryuzo Ueda, Journal of Clinical Oncology, 29,   2011年02月01日
  • Molecular characterization of hepatitis B virus isolates from Zimbabwean blood donors, Zandiswa Gulube, Michael Chirara, Michael Kew, Yasuhito Tanaka, Masashi Mizokami, Anna Kramvis, Journal of Medical Virology, 83, 235 - 244,   2011年02月01日, Hepatitis B virus (HBV) is endemic in Africa, being hyperendemic in sub-Saharan Africa. Genotypes A, D, and E circulate in Africa, showing a distinct geographical distribution. The aim of the present study was to determine the HBV genotype distribution in blood donors from different geographical locations in Zimbabwe. Using a restriction fragment polymorphism assay, sequencing of the basic core promoter/precore region and of the complete S open reading frame showed that 29 HBV isolates from geographically distinct regions belong to subgenotype A1. The complete genome of two of these Zimbabwean HBV isolates was sequenced. Forty-four percent of the Zimbabwean HBV isolates (11/23) were characterized by a G1862C missense mutation, which causes a Val to Leu amino acid substitution at position 17 of the precore region. The majority of Zimbabwean HBV isolates clustered with a number of South African HBV isolates, with which they shared characteristic amino acids in the preS1, preS2, and polymerase spacer regions. The wide distribution of subgenotype in Africa, as well as the high intragroup divergence and the geographical clustering of the African and Asian subgenotype A1 HBV isolates indicate that this subgenotype has a long period of endemicity in these regions. © 2010 Wiley-Liss, Inc.
  • Impact of viral load of hepatitis C on the incidence of hepatocellular carcinoma: A population-based cohort study (JPHC Study), Seiji Ishiguro, Seiji Ishiguro, Manami Inoue, Yasuhito Tanaka, Masashi Mizokami, Motoki Iwasaki, Shoichiro Tsugane, Cancer Letters, 300, 173 - 179,   2011年01月28日, Impact of viral load of HCV on the incidence of hepatocellular carcinoma was investigated using a population-based cohort consisting of 20,794 Japanese. A total of 114 newly arising cases of hepatocellular carcinoma were diagnosed during follow-up. Compared to the hepatitis virus-negative group, the hazard ratio (HR) of developing hepatocellular carcinoma was 35.8-fold higher in HCV monoinfection (95% confidence interval [CI], 20.7-62.7). A titer-dependent increase in risk was not identified. The risk was 3.86-fold higher (CI; 1.73-8.62) for genotype 1 than genotype 2. Our findings suggest that HCV viremia strongly influences the occurrence of hepatocellular carcinoma without titer-dependence. © 2010 Elsevier Ireland Ltd.
  • Management of hepatitis B: Consensus of the Japan Society of Hepatology 2009, Osamu Yokosuka, Masayuki Kurosaki, Fumio Imazeki, Yasuji Arase, Yasuhito Tanaka, Kazuaki Chayama, Eiji Tanaka, Hiromitsu Kumada, Namiki Izumi, Masashi Mizokami, Masatoshi Kudo, Hepatology Research, 41, 1 - 21,   2011年01月01日, Recently, much progress has been made in the field of hepatitis B, such as natural history of the disease in relation to the amount of hepatitis B virus (HBV) DNA, genotypes of HBV influencing the natural course and treatment effects, mutations of HBV influencing the severity of the disease and development of hepatocellular carcinoma, and antiviral treatment such as nucleos(t)ide analogues and pegylated interferon. To make the consensus for the diagnosis, management and treatment of hepatitis B, a meeting was held during 45th annual meeting of Japan Society of Hepatology (JSH) in June 2009. In the meeting, recommendations and informative statements were discussed on the following subjects: (i) natural history of HBV infection; (ii) clinical implication of HBV genotypes; (iii) HBV mutations and their potential impact on pathogenesis of HBV infection; (iv) indications for antiviral treatment of chronic hepatitis B; (v) nucleos(t)ide analogues for chronic hepatitis B; and (vi) interferon therapy for chronic hepatitis B. The presenters reviewed the data on these subjects and proposed the consensus statements and recommendations. These statements were discussed among the organizers and presenters, and were approved by the participants of the meeting. In the current report, the relevant data were reviewed and the 12 consensus statements and nine recommendations on chronic hepatitis B were described. © 2010 The Japan Society of Hepatology.
  • Multilectin assay for detecting fibrosis-specific glyco-alteration by means of lectin microarray, Atsushi Kuno, Yuzuru Ikehara, Yasuhito Tanaka, Takashi Angata, Sachiko Unno, Maki Sogabe, Hidenori Ozaki, Kiyoaki Ito, Jun Hirabayashi, Masashi Mizokami, Masashi Mizokami, Hisashi Narimatsu, Clinical Chemistry, 57, 48 - 56,   2011年01月01日, BACKGROUND: Despite the progress made in understanding glyco-alterations of specific glycoproteins such as α1-acid glycoprotein (AGP) associated with liver fibrosis, there has been no useful diagnostic assay with a lectin recognizing the fibrosis-specific alteration and an antibody against the core protein. We therefore developed a compatible multiple lectin-antibody sandwich immunoassay on the basis of the results obtained by the lectin microarray analysis for monitoring fibrosis. METHODS: AGP-enriched fractions derived from 0.5-μ L sera of 125 patients with staging-determined fibrosis (26.4% F0-F1, 25.6% F2, 24% F3, and 23.2% F4) were subjected to systematic analysis by antibodyoverlay lectin microarray. Data were analyzed to statistically relate to the degree of fibrosis progression. Additionally, we applied an optimal lectin signal set on the microarray to distinguish 45 patients with cirrhosis from 43 patients with chronic hepatitis. RESULTS: Signal patterns of the 12 selected lectins reflected fibrosis-associated glyco-alteration of AGP. Among the 12 lectins, we found a specific lectin at each stage of fibrosis (i.e., significant fibrosis, severe fibrosis, and cirrhosis) (P<0.0001). The test for the detection of cirrhosis showed that combinational use of 3 lectins (AOL, MAL, and DSA) on the array enhanced the diagnostic value for liver cirrhosis to 95% diagnostic sensitivity and 91% diagnostic specificity. CONCLUSIONS: The multiple lectin-antibody sandwich immunoassay targeting AGP enables monitoring of disease progression in chronic hepatitis patients at risk of developing hepatocellular carcinoma. © 2010 American Association for Clinical Chemistry.
  • Reactivation of hepatitis B virus following rituximab-plus-steroid combination chemotherapy, Shigeru Kusumoto, Yasuhito Tanaka, Ryuzo Ueda, Masashi Mizokami, Journal of Gastroenterology, 46, 9 - 16,   2011年01月01日, Reactivation of hepatitis B virus (HBV) has been reported as a fatal complication following systemic chemotherapy or other immunosuppressive therapy. The risk of HBV reactivation differs according to both the patient's HBV infection status prior to systemic chemotherapy and the degree of immunosuppression due to chemotherapy. For establishing an optimal strategy for hepatitis prevention and treatment, it is necessary to understand the characteristics, the clinical course and the risk factors for HBV reactivation and to recognize the difference between hepatitis B surface antigen (HBsAg)-positive and -negative patients with HBV reactivation. Among the important viral risk factors, HBV-DNA level and HBV-related serum markers have been reported to be associated with HBV reactivation in addition to cccDNA, genotypes and gene mutations. Rituximab-plus-steroid combination chemotherapy has recently been identified as a host risk factor for HBV reactivation in hepatitis B core antibody (anti-HBc)-positive and/or hepatitis B surface antibody (anti-HBs) positive-but nonetheless HBsAg-negative-lymphoma patients. For these patients with resolved hepatitis B, preemptive therapy guided by serial HBV-DNA monitoring is a reasonable strategy to enable early diagnosis of HBV reactivation and initiation of antiviral therapy. In this review, we summarize the characteristics of HBV reactivation following rituximab-plus- steroid combination chemotherapy, mainly in HBsAg-negative lymphoma patients, and propose a strategy for managing HBV reactivation. © 2010 Springer.
  • Evolution of hepatitis B genotype C viral quasi-species during hepatitis B e antigen seroconversion, Shuang Wu, Fumio Imazeki, Fuat Kurbanov, Kenichi Fukai, Makoto Arai, Tatsuo Kanda, Yutaka Yonemitsu, Yasuhito Tanaka, Masashi Mizokami, Osamu Yokosuka, Journal of Hepatology, 54, 19 - 25,   2011年01月01日, Background & Aims: Although the evolution of viral quasi-species may be related to the pathological status of disease, little is known about this phenomenon in hepatitis B, particularly with respect to hepatitis B e antigen (HBeAg) seroconversion. Methods: Nucleotide sequences of the hepatitis B virus (HBV) X/precore/core region was analyzed at five time-points in four groups of chronic hepatitis B patients, interferon-induced seroconverters (IS, N = 9), interferon non-responders (IN, N = 9), spontaneous seroconverters (SS, N = 9), and non-seroconverters (SN, N = 9) followed during 60 months on an average. Only patients with genotype C were studied. Results: Analysis of 1800 nucleotide sequences showed that there was no statistical difference between the nucleotide genetic distances of seroconverters (IS and SS; 6.9 × 10-3substitutions (st)/site and 6.7 × 10-3st/site, respectively) and those of non-seroconverters (IN and SN; 5.3 × 10-3st/site and 3.8 × 10-3st/site, respectively) before seroconversion. Compared to non-seroconverters (IN and SN; 5.1 × 10-3st/site and 5.9 × 10-3st/site, respectively), the sequence diversity of seroconverters (IS and SS; 10.9 × 10-3st/site and 9.9 × 10-3st/site, respectively) was significantly higher after seroconversion (p <0.05), and was higher in seroconverters after seroconversion than before seroconversion (p <0.05), while this changed very little in non-seroconverters during the observation period. Phylogenetic trees showed greater complexity in secoconverters than non-seroconverters. Parsimony-based estimation of the direction of sequence change between descendants and ancestors before HBeAg seroconversion, revealed higher frequencies of transversional A to T substitution in seroconverters (0.06 vs. 0.02, p = 0.0036) that coincided with the dynamics of quasi-species possessing A1762T mutation. Conclusions: The distinctly greater viral diversity in HBeAg seroconverters after seroconversion could be related to escape mutants resulting from stronger selection pressure. © 2010 European Association for the Study of the Liver.
  • Hepatitis C pharmacogenetics: State of the art in 2010, Nezam H. Afdhal, John G. McHutchison, Stefan Zeuzem, Alessandra Mangia, Jean Michel Pawlotsky, Jeffrey S. Murray, Kevin V. Shianna, Yasuhito Tanaka, David L. Thomas, David R. Booth, David B. Goldstein, Hepatology, 53, 336 - 345,   2011年01月01日, In 2009, a correlated set of polymorphisms in the region of the interleukin-28B (IL28B) gene were associated with clearance of genotype 1 hepatitis C virus (HCV) in patients treated with pegylated interferon-alfa and ribavirin. The same polymorphisms were subsequently associated with spontaneous clearance of HCV in untreated patients. The link between IL28B genotype and HCV clearance may impact decisions regarding initiation of current therapy, the design and interpretation of clinical studies, the economics of treatment, and the process of regulatory approval for new anti-HCV therapeutic agents. © 2010 American Association for the Study of Liver Diseases.
  • A population-based cohort study for the risk factors of HCC among hepatitis B virus mono-infected subjects in Japan, Atsunori Kusakabe, Yasuhito Tanaka, Manami Inoue, Fuat Kurbanov, Kanako Tatematsu, Shunsuke Nojiri, Takashi Joh, Shoichiro Tsugane, Masashi Mizokami, Journal of Gastroenterology, 46, 117 - 124,   2011年01月01日, Background: There have only been a few prospective studies investigating risk factors associated with the development of hepatocellular carcinoma (HCC) among chronic hepatitis B patients all over the world, and no study has been conducted in Japanese population. Methods: A population-based cohort consisting of 19393 subjects (middle aged or older) with over 13 years' follow-up was investigated in Japan. Results: Of 19393 subjects, 479 had hepatitis B virus (HBV) mono-infection (2.5%). During the 245923 person-years' follow-up (average follow-up period 12.7 years), 13 cases of newly diagnosed HCC were documented in the HBV mono-infected group. Several factors at baseline (male, smoking, alanine aminotransferase, the positivity of HBe antigen and HB core-related antigen, the proportion of HBV DNA ≥ 5 log copies/mL, T1753V mutation, and A1762T/G1764A double mutation) were significantly associated with HCC among HBV mono-infected subjects. Multivariate-adjusted Cox hazard model showed that A1762T/G1764A (hazard ratio 7.05 [95% confidence interval (CI) 1.03-48.12, P = 0.046]) was the only independent risk factor for the development of HCC. Kaplan-Meier method also showed that the probability of HCC occurrence-free was significantly lower in HBV mono-infected subjects with A1762T/G1764A double mutation than those without these mutations. Conclusion: HBV mono-infected subjects with A1762T/G1764A double mutation could be at high risk of HCC development during the natural course of HBV infection. © 2010 Springer.
  • Genome-wide association study identified ITPA/DDRGK1 variants reflecting thrombocytopenia in pegylated interferon and ribavirin therapy for chronic hepatitis C., Jun 23 Epub ahead of print,   2011年
  • Performance of two Real-Time RT-PCR assays for quantitation of hepatitis C virus RNA: Evaluation on HCV genotypes 1-4, Abeer Elkady, Yasuhito Tanaka, Fuat Kurbanov, Fuminaka Sugauchi, Masaya Sugiyama, Anis Khan, Elsayed Mostafa Ali, Layla Mouhamed, Sahar Abou el-fetouh, Abdel Rahaman Abdel-Hameed, Masashi Mizokami, Journal of Medical Virology, 82, 1878 - 1888,   2010年11月01日, Accuracy for monitoring of the concentration of hepatitis C virus (HCV) RNA represents a major challenge throughout the management of patients with chronic hepatitis C. To investigate the genotype-independent efficiency and the accuracy of two real-time detection reverse transcription-polymerase chain reaction (RT-PCR) assays; the Cobas Ampliprep/Cobas TaqMan (CAP/CTM); and the Abbott RealTime HCV (ART), a total of 184 samples with different HCV subtypes were examined; 1b (n=58), 2a (n=39), 2b (n=26), 3a (n=20), and 4 (n=41). A robust linear correlation was observed between the two assays applied to genotypes 1b, 2a, 2b, and 3a [the correlation coefficient (R) ranged from 0.99 to 0.98], but not to genotype 4 specimens (R=0.78). A significant difference in measurements of HCV RNA using CAP/CTM and ART in serum samples with genotypes 1b and 4 was observed (0.72, -0.53logIU/ml, P<0.0001, 0.01, respectively). A robust correlation was observed between the HCV core antigen and HCV RNA values by either of the HCV RNA quantitation assays applied to all genotypes with exception of genotype 4, for which R was higher with ART (R=0.95) than with CAP/CTM (R=0.80). The lower limit of detection of CAP/CTM and ART were 41.4 and 28.5IU/ml using the WHO standards, respectively. In conclusion, two RT-PCR assays had a high efficiency and accuracy for quantitation of HCV RNA of genotypes 2a, 2b, and 3a, but the mean values of HCV RNA differed for genotype 1b and 4. J. Med. Virol. 82:1878-1888, 2010. © 2010 Wiley-Liss, Inc.
  • ITPA gene variant protects against anemia induced by pegylated interferon-α and ribavirin therapy for Japanese patients with chronic hepatitis C, Naoya Sakamoto, Naoya Sakamoto, Yasuhito Tanaka, Mina Nakagawa, Mina Nakagawa, Hiroshi Yatsuhashi, Shuhei Nishiguchi, Nobuyuki Enomoto, Seishin Azuma, Yuki Nishimura-Sakurai, Sei Kakinuma, Sei Kakinuma, Nao Nishida, Katsushi Tokunaga, Masao Honda, Kiyoaki Ito, Masashi Mizokami, Mamoru Watanabe, Hepatology Research, 40, 1063 - 1071,   2010年11月01日, Aim: Host genetic variants leading to inosine triphosphatase (ITPA) deficiency, a condition not thought to be clinically important, protect against hemolytic anemia in chronic hepatitis C patients receiving ribavirin. In this study, we evaluated the clinical significance of ITPA variants in Japanese hepatitis C patients who were treated with pegylated interferon plus ribavirin.Methods: In this multicenter retrospective cross-sectional study, 474 hepatitis C patients were enrolled who were treated with pegylated interferon plus ribavirin in four geographically different hospitals in Japan. Patients were grouped according to hemoglobin decline of more than 3 g/dL at week 4. Two single nucleotide polymorphisms (SNP) within or adjacent to the ITPA gene (rs6051702, rs1127354) were genotyped.Results: A functional SNP, rs1127354, within the ITPA exon was strongly associated with protection against anemia with only one (0.8%) in 129 patients with the ITPA minor variant A developing severe anemia (P = 5.9 × 10-20). For rs6051702, which had significant association in European-Americans, significant but weak association with severe hemoglobin reduction was found in Japanese (P = 0.009). In patients excluding genotype 1b and high viral load, those with the ITPA minor variant A achieved significantly higher sustained viral response rate than those with the major variant (CC) (96% vs 70%, respectively, P = 0.0066).Conclusion: ITPA SNP, rs1127354, is confirmed to be a useful predictor of ribavirin-induced anemia in Japanese patients. Patients with the ITPA minor variant A (~27%) have an advantage in pegylated interferon plus ribavirin-based therapies, due to expected adherence of ribavirin doses, resulting in a higher viral clearance rate. © 2010 The Japan Society of Hepatology.
  • [Evaluation and application of a newly developed highly sensitive HBsAg chemiluminescent enzyme immunoassay for chronic hepatitis B patients]., Noboru Shinkai, Yasuhito Tanaka, Kentaro Matsuura, Satomi Kani, Hatsue Naganuma, Masashi Mizokami, Rinsho byori. The Japanese journal of clinical pathology, 58, 1078 - 1084,   2010年11月01日, A high sensitive chemiluminescent enzyme immunoassay (CLEIA) was developed for quantitative hepatitis B surface antigen (HBsAg) detection by a combination of monoclonal antibodies, each one for a specific epitope of HBsAg, and by improving the conjugation technique (Matsubara, et al. Transfusion 2009). We modified and automated Matsubara's techniques. Our aim is to evaluate the fundamental performance of our assay (prototype) and to investigate the clinical significance of prototype in patients with hepatitis B virus (HBV) infection. We used 226 HBsAg-negative samples and 59 HBsAg-positive samples for evaluation of prototype's accuracy, reproducibility, specificity and sensitivity. We examine correlation between the prototype assay and commercial quantitative HBsAg detection assay (the Abbott ARCHITECT). Performance of prototype was compared with the Abbott ARCHITECT in one chronic hepatitis B patient and one patient with HBsAg seroconversion sequentially. The prototype assay had good accuracy, reproducibility, specificity and sensitivity. There is positive correlation between the prototype and the Abbott ARCHITECT. The sensitivity of the prototype (5 mIU/mL) was approximately 10 fold higher than the Abbott ARCHITECT (50 mIU/ml). The prototype could detect HBsAg at the HBsAg-negative point by Abbott ARCHITECT in these patients. Automatic highly sensitive HBsAg CLEIA prototype is convenient and precise assay for HBV monitoring.
  • High sensitivity assay using serum sample for IL28B genotyping to predict treatment response in chronic hepatitis C patients, Srunthron Akkarathamrongsin, Srunthron Akkarathamrongsin, Masaya Sugiyama, Kentaro Matsuura, Kentaro Matsuura, Fuat Kurbanov, Yong Poovorawan, Yasuhito Tanaka, Masashi Mizokami, Hepatology Research, 40, 956 - 962,   2010年10月01日, Aim: Recent human genome-wide association studies (GWAS) revealed a strong association between IL28B gene variation and the pegylated interferon-α with ribavirin (PEG-IFN-α/RBV) treatment response in chronic hepatitis C patients. Two single nucleotide polymorphisms (SNP), rs8103142 and rs11881222 located in the IL28B gene, were found in significant association with the viral clearance. The present study employed these SNPs to develop a new accessible screening method allowing identification of potential non-responders before starting the therapy. Methods: Primer sets were designed to amplify rs8103142 and rs11881222 fragments from genomic DNA extracted from serum samples. This method was validated using microarray typing (GWAS) and applied for genotyping of 68 hepatitis C virus-infected patients with PEG-IFN-α/RBV treatment at baseline. Results: In comparison with GWAS, the screening method showed 100% and 95.6% accuracy in typing of rs8103142 and rs11881222, respectively, indicating incomplete specificity but 100% of sensitivity in both. Genotyping by both SNP showed that 53 (77.9%), 14 (20.6%) and one (1.5%) of the patients were of major homozygous, heterozygous and minor homozygous type, respectively. The majority (85%) of homozygous patients exhibited response to therapy in contrast to heterozygous patients (29%). Among all genotyped only one case was found with the minor homozygous genotype which had late virological response to therapy before relapsing. Conclusion: This study described a highly sensitive assay that can be useful in determining SNP genotypes as well as in predicting the response to IFN-based treatment. © 2010 The Japan Society of Hepatology.
  • Preemptive therapy for HBV reactivation by serial HBV-DNA monitoring, Shigeru Kusumoto, Yasuhito Tanaka, Masashi Mizokami, Journal of Japanese Society of Gastroenterology, 107, 1441 - 1449,   2010年09月01日
  • Occult hepatitis B in the genotype H-infected Nahuas and Huichol native Mexican population, Sonia Roman, Yasuhito Tanaka, Anis Khan, Fuat Kurbanov, Hideaki Kato, Masashi Mizokami, Arturo Panduro, Journal of Medical Virology, 82, 1527 - 1536,   2010年09月01日, Mexico is considered to be a low endemic country for HBV infection. However, a high anti-HBc against a low hepatitis B surface antigen (HBsAg) seroprevalence is the reported characteristic of native Mexicans. HBV diagnosis and genotype distribution was examined in native populations (Nahuas and Huichol, n = 306), and compared to a non-native population (Mestizos, n = 17). Overall, 6% of the natives were positive for HBsAg and 33% had detectable anti-HBc. HBsAg prevalence was lower in Nahuas compared to Huichols (1.4% vs. 9.4%, P < 0.002). Occult hepatitis B was detected in 14.2% (41/289) of natives, who either tested positive (5.88%, 17/289 HBsAg-negative) or negative for anti-HBc marker (8%, 24/289 HBsAg-negative). Age-adjusted anti-HBc seroprevalence and HBsAg quantitation revealed a sub-optimal sensitivity of conventional immunoassays. Nahuas had HBV/H and Huichol had HBV/A as the predominant genotypes followed by genotypes D, C, B, A, and D, G and H, respectively. A less variable HBV/H was characteristic in Mestizos, compared to a much variable HBV/H identified among the Nahuas. In conclusion, these findings indicate a high HBV endemicity among native Mexican groups where occult B infection is common. The different distribution of HBV genotypes among natives suggests multiple reservoirs of HBV from which these genotypes spread into the local communities. High anti-HBc seroprevalence against a low HBsAg prevalence ratemay be due to the limited sensitivity of the immunoassays for the detection of HBsAg that are available in Mexico and/or unknown immunogenetic characteristics of native Mexicans. © 2010 Wiley-Liss, Inc.
  • Panel discussion: HCV infection and host factor, IL28B in particular, Yasuhito Tanaka, Katsushi Tokunaga, Masao Honda, Norio Akuta, Yasuhiro Asahina, Masashi Mizokami, Acta Hepatologica Japonica, 51, 327 - 347,   2010年09月01日
  • Molecular epidemiological study of hepatitis B virus among migrant workers from Cambodia, Laos, and Myanmar to Thailand, Pattaratida Sa-nguanmoo, Pattaratida Sa-nguanmoo, Pisit Tangkijvanich, Nutchanart Thawornsuk, Preeyaporn Vichaiwattana, Kesmanee Prianantathavorn, Apiradee Theamboonlers, Yasuhito Tanaka, Yong Poovorawan, Journal of Medical Virology, 82, 1341 - 1349,   2010年08月01日, Although hepatitis B virus (HBV) infection is endemic in Southeast Asia, molecular epidemiological data on HBV circulating in some countries are limited. The aims of this study were to evaluate the seroprevalence of HBV and its genetic variability among migrant workers from Cambodia, Laos, and Myanmar in Thailand. Sera collected from 1,119 Cambodian, 787 Laotian, and 1,103 Myanmarese workers were tested for HBsAg. HBV DNA was amplified and the pre-S/S region was sequenced for genotyping and genetic mutation analysis. HBsAg was detected in 282 (9.4%). The prevalence of HBsAg among migrant workers from Cambodia, Laos, and Myanmar was 10.8%, 6.9%, and 9.7%, respectively. Of 224 subjects positive for HBV DNA, 86% were classified as genotype C (99% were subgenotype C1) and 11.6% were genotype B (30.8%, 34.6%, and 30.8% were sub-genotypes B2, B3, and B4, respectively). Various point mutations in the "a" determinant region were detected in approximately 18% of these samples, of which Ile126Ser/Asn was the most frequent variant. Sequencing analysis showed that 19.1% of samples had pre-S mutations, with pre-S2 deletion as the most common mutant (7.7%) followed by pre-S2 start codon mutation (3.8%) and both pre-S2 deletion and start codon mutation (3.3%). High prevalence of HBV infection (approximately 7-11%) was found among migrant workers from Cambodia, Laos, and Myanmar, which may reflect the current seroprevalence in their respective countries. The data also demonstrated that HBV sub-genotype C1 was the predominant strain and various mutations of HBV occurring naturally were not uncommon among these populations. © 2010 Wiley-Liss, Inc.
  • Characterization of streptococcus pyogenes isolated from balanoposthitis patients presumably transmitted by penile-oral sexual intercourse, Masaaki Minami, Yukio Wakimoto, Masakado Matsumoto, Hideyuki Matsui, Yasue Kubota, Atsushi Okada, Masanori Isaka, Ichiro Tatsuno, Yasuhito Tanaka, Tadao Hasegawa, Current Microbiology, 61, 101 - 105,   2010年08月01日, Streptococcus pyogenes is indigenous to the human pharynx and causes acute pharyngitis. Balanoposthitis is an inflammatory disease of the glans and the foreskin. However, balanoposthitis caused by S. pyogenes is not widely recognized as a sexually transmitted disease. In addition, bacteriological features of the isolates causing balanoposthitis are unclear. The four S. pyogenes strains isolated from adult balanoposthitis were examined. We performed emm typing, T antigen typing, RAPD assay, PCR assay for the streptococcal pyrogenic exotoxin-related genes and antibiotic-resistant genes, and antibiotic susceptibility assay. All four strains were suspected to be transmitted by penile-oral sexual intercourse, were found to be different by genetic analysis, and also harbored some antibiotic-resistant factors. We propose that S. pyogenes should be considered as a causative agent of sexually transmitted disease. The drug resistant S. pyogenes must be taken into account when balanoposthitis patients are treated with antibiotic. © 2010 Springer Science+Business Media, LLC.
  • Hepatitis B virus replication could enhance regulatory T cell activity by producing soluble heat shock protein 60 from hepatocytes, Yasuteru Kondo, Yoshiyuki Ueno, Koju Kobayashi, Eiji Kakazu, Masaaki Shiina, Jun Inoue, Keiichi Tamai, Yuta Wakui, Yasuhito Tanaka, Masashi Ninomiya, Noriyuki Obara, Koji Fukushima, Motoyasu Ishii, Tomoo Kobayashi, Hirofumi Niitsuma, Satonori Kon, Tooru Shimosegawa, Journal of Infectious Diseases, 202, 202 - 213,   2010年07月15日, Background. HBcAg-specific regulatory T (Treg) cells play an important role in the pathogenesis of chronic hepatitis B. Soluble heat shock proteins, especially soluble heat shock protein 60 (sHSP60), could affect the function of Tregcells via Toll-like receptor. Methods. We analyzed the relationship between soluble heat shock protein production and hepatitis B virus (HBV) replication with both clinical samples from HBeAg-positive patients with chronic hepatitis B (n=24) and HBeAb-positive patients with chronic hepatitis B (n=24) and in vitro HBV-replicating hepatocytes. Thereafter, we examined the biological effects of sHSP60 with isolated Tregcells. Results. The serum levels of sHSP60 in patients with chronic hepatitis B were statistically significantly higher than those in patients with chronic hepatitis C (P < .01), and the levels of sHSP60 were correlated with the HBV DNA levels (R=0.532; P < .001) but not with the alanine aminotransferase levels. Moreover, the levels of sHSP60 in HBV-replicating HepG2 cells were statistically significantly higher than those in control HepG2 cells. Preincubation of CD4+CD25+cells with recombinant HSP60 (1 ng/mL) statistically significantly increased the frequency of HBcAg-specific interleukin 10-secreting Tregcells. The frequency of IL7R-CD4+CD25+cells, the expression of Toll-like receptor 2, and the suppressive function of Tregcells had declined during entecavir treatment. Conclusion. The function of HBcAg-specific Tregcells was enhanced by sHSP60 produced from HBV-infected hepatocytes. Entecavir treatment suppressed the frequency and function of Tregcells; this might contribute to the persistence of HBV infection. © 2010 by the Infectious Diseases Society of America.
  • Molecular epidemiology of hepatitis C virus genotypes in West Mexico, Arturo Panduro, Sonia Roman, Anis Khan, Yasuhito Tanaka, Fuat Kurbanov, Erika Martinez-Lopez, Octavio Campollo, Zamira Hernandez-Nazara, Masashi Mizokami, Virus Research, 151, 19 - 25,   2010年07月01日, The identification of hepatitis C virus (HCV) genotypes and subtypes may be helpful to identify the source of an HCV outbreak among a specific group of individuals within a given country or the pattern of spread throughout nations worldwide. Mexico is a transit country for people who migrate north towards the United States from Central and South America, however, to date, no Mexican HCV sequences have been reported. The present study was conducted to identify the HCV genotypes and subtypes prevalent in Mexico by DNA sequencing and phylogenetic analysis in the NS5B region of the HCV genome. Serum samples from a total of 75 anti-HCV positive patients were included in this study. Out of the 75 samples, 48 cases (64%) were amplifiable in the 5' UTR and 46 (61%) in NS5B region. HCV genotype 1a determined in 54.3% (25/46) was predominant in this cohort, followed by 1b 21.8% (10/46), 2b 13% (6/46), 3a 6.5% (3/46), and 2a 4.4% (2/46). Phylogenetic analysis showed that HCV sequences of genotype 1 (1a and 1b) were clustering more closely to the United States isolates published previously. These results may suggest that both Mexico and the United States share an epidemiological network of HCV genotype 1 while other genotypes represent sporadic infections that are specific to Mexico. © 2010 Elsevier B.V.
  • JSH Consensus Kobe 2009: Diagnosis and treatment of hepatitis B, Masashi Mizokami, Eiji Tanaka, Kazuaki Chayama, Yasuhito Tanaka, Masayuki Kurosak, Namiki Izumi, Yasuji Arase, Hiromitsu Kumada, Fumio Imazeki, Osamu Yokosuka, Masatoshi Kudo, Acta Hepatologica Japonica, 51, 243 - 260,   2010年06月21日
  • Reactivation of hepatitis B virus in HBsAg-negative patients with multiple myeloma: Two case reports, Tatsuya Yoshida, Shigeru Kusumoto, Atsushi Inagaki, Fumiko Mori, Asahi Ito, Masaki Ri, Takashi Ishida, Hirokazu Komatsu, Shinsuke Iida, Fuminaka Sugauchi, Yasuhito Tanaka, Masashi Mizokami, Ryuzo Ueda, International Journal of Hematology, 91, 844 - 849,   2010年06月01日, It was recently reported that hepatitis B virus (HBV) reactivation had occurred in HBsAg-negative lymphoma patients who received rituximab plus steroid combination chemotherapy. HBV reactivation in myeloma patients have not been reported extensively. We describe here two cases of HBV reactivation in HBsAg-negative myeloma patients receiving systemic chemotherapy: one from the medical records of 40 patients and another from 61 patients with prospective HBV-DNA monitoring. In the first case positive for anti-HBs, HBV reactivation was diagnosed when hepatitis developed during conventional chemotherapy such as MP and MCP regimen in a relapsed patient after autologous stem cell transplantation (APBSCT); in the second case positive for anti-HBc and anti-HBs, elevation of HBV-DNA was recognized by serial HBV-DNA monitoring performed prospectively following APBSCT. Interestingly, these two cases had the reduction of the titer of anti-HBs during the treatment, followed by HBV reactivation. These clinical data suggest that the HBV-DNA monitoring is necessary for not only HBsAg-positive but also HBsAg-negative myeloma patients with anti-HBc-positive and/or anti-HBs-positive following transplantation and after conventional chemotherapy in the salvage setting. Establishment of a standard strategy to prevent HBV reactivation is important for myeloma patients receiving systemic chemotherapy. © 2010 The Japanese Society of Hematology.
  • Positive selection of core 70Q variant genotype 1b hepatitis C virus strains induced by pegylated interferon and ribavirin, Fuat Kurbanov, Yasuhito Tanaka, Kentaro Matsuura, Kentaro Matsuura, Fuminaka Sugauchi, Abeer Elkady, Anis Khan, Izumi Hasegawa, Tomoyoshi Ohno, Hiroshi Tokuda, Masashi Mizokami, Masashi Mizokami, Journal of Infectious Diseases, 201, 1663 - 1671,   2010年06月01日, Background. Approximately 20% of patients with hepatitis C virus (HCV) genotype lb infection have nonresponse to the most current treatment, pegylated interferon with ribavirin. Mutations in the HCV core region were recently proposed to be associated with nonresponse. Our aim was to evaluate the viral factors associated with treatment failure. Methods. HCV variants were determined directly and after cloning in 66 HCV-lb-infected Japanese patients and in 5 urokinase-type plasminogen activator transgenic severe combined immunodeficiency mice with human hepatocytes (chimeric mice), at baseline, during treatment, and after treatment. Results. At baseline, glutamine at position 70 of the HCV core protein (70Q) was detected by direct sequencing in 20% of patients with virologic response and in 43.8% of patients with nonresponse. Among patients with nonresponse, who were examined during and after treatment, the prevalence of the 70Q substitution increased to 56.3%, which indicates that treatment-induced selection occurred in all patients with nonresponse who had 70Q quasispecies detectable by cloning. This observation was reinforced by the results from experimentally infected chimeric mice. Logistic regression analysis indicated that detection of 70Q quasispecies was associated with a statistically significantly increased risk of nonresponse (odds ratio, 15.1; P = .004) in the studied cohort. Conclusion. Presence of the 70Q quasispecies at baseline was associated with an increased risk of treatment failure, as indicated by the positive selection of the 70Q clones induced by treatment with pegylated interferon with ribavirin. These results urge further investigation of the mechanisms of this association. © 2010 by the Infectious Diseases Society of America. All rights reserved.
  • Biological properties of purified recombinant HCV particles with an epitope-tagged envelope, Hitoshi Takahashi, Hitoshi Takahashi, Daisuke Akazawa, Daisuke Akazawa, Takanobu Kato, Tomoko Date, Masayuki Shirakura, Masayuki Shirakura, Noriko Nakamura, Hidenori Mochizuki, Keiko Tanaka-Kaneko, Tetsutaro Sata, Yasuhito Tanaka, Masashi Mizokami, Tetsuro Suzuki, Takaji Wakita, Biochemical and Biophysical Research Communications, 395, 565 - 571,   2010年05月14日, To establish a simple system for purification of recombinant infectious hepatitis C virus (HCV) particles, we designed a chimeric J6/JFH-1 virus with a FLAG (FL)-epitope-tagged sequence at the N-terminal region of the E2 hypervariable region-1 (HVR1) gene (J6/JFH-1/1FL). We found that introduction of an adaptive mutation at the potential N-glycosylation site (E2N151K) leads to efficient production of the chimeric virus. This finding suggests the involvement of glycosylation at Asn within the envelope protein(s) in HCV morphogenesis. To further analyze the biological properties of the purified recombinant HCV particles, we developed a strategy for large-scale production and purification of recombinant J6/JFH-1/1FL/E2N151K. Infectious particles were purified from the culture medium of J6/JFH-1/1FL/E2N151K-infected Huh-7 cells using anti-FLAG affinity chromatography in combination with ultrafiltration. Electron microscopy of the purified particles using negative staining showed spherical particle structures with a diameter of 40-60 nm and spike-like projections. Purified HCV particle-immunization induced both an anti-E2 and an anti-FLAG antibody response in immunized mice. This strategy may contribute to future detailed analysis of HCV particle structure and to HCV vaccine development. © 2010 Elsevier Inc. All rights reserved.
  • λ-Interferons and the single nucleotide polymorphisms: A milestone to tailor-made therapy for chronic hepatitis C, Yasuhito Tanaka, Nao Nishida, Masaya Sugiyama, Katsushi Tokunaga, Masashi Mizokami, Masashi Mizokami, Hepatology Research, 40, 449 - 460,   2010年05月01日, Type III interferons (IFN) (IFN-λ1, -λ2, -λ3/interleukin [IL]-29, -28A, -28B) are cytokines with type I IFN-like antiviral activities. Most cells have expressed both type I and III IFN following Toll-like receptor (TLR) stimulation or viral infection, whereas the ability of cells to respond to IFN-λ was restricted to a specific subset of cells. It was reported that signal transduction pathway of IFN-λ was similar to that of IFN-α/β although a receptor adapted by IFN-λ were distinct from that of IFN-α/β. However, the clinical significance and the role of each IFN-λ were unclear. Recent genome-wide association studies (GWAS) of the human whole genome revealed several single nucleotide polymorphism sites (SNP) strongly associated with the response to pegylated IFN-α (PEG-IFN) plus ribavirin (RBV) treatment in chronic hepatitis C patients. The SNP, which are located near the IL-28B gene of chromosome 19, were discovered simultaneously by three independent studies opening a new prospective in hepatitis C research. The present review highlights significant insights that can be derived from the GWAS approach, and summarizes current knowledge of in vitro and in vivo study on the role of IFN-λ in antiviral effect. © 2010 The Japan Society of Hepatology.
  • Reply to the letter by Bedognetti et al. "relevance of HBV/HBcAb screening in lymphoma patients treated in the Rituximab era", Shigeru Kusumoto, Yasuhito Tanaka, International Journal of Hematology, 91, 345 - 346,   2010年03月01日
  • Geographic distribution of hepatitis C virus genotype 6 subtypes in Thailand, Srunthron Akkarathamrongsin, Kesmanee Praianantathavorn, Nisachol Hacharoen, Apiradee Theamboonlers, Pisit Tangkijvanich, Yasuhito Tanaka, Masashi Mizokami, Masashi Mizokami, Yong Poovorawan, Journal of Medical Virology, 82, 257 - 262,   2010年02月01日, The nucleotide sequence of hepatitis C virus (HCV) genotype 6 found mostly in south China and south-east Asia, displays profound genetic diversity. The aim of this study to determine the genetic variability of HCV genotype 6 (HCV-6) in Thailand and locate the subtype distribution of genotype 6 in various geographic areas. Four hundred nineteen anti-HCV positive serum samples were collected from patients residing in - the central part of the country. HCV RNA positive samples based on reverse transcriptasepolymerase chain reaction (RT-PCR) of the 50UTR were amplified with primers specific for the core and NS5B regions. Nucleotide sequences of both regions were analyzed for the genotype by phylogenetic analysis. To determine geographic distribution of HCV-6 subtypes, a search of the international database on subtype distribution in the respective countries was conducted. Among 375 HCV RNA positive samples, 71 had HCV-6 based on phylogenetic analysis of partial core and NS5B regions. The subtype distribution in order of predominance was 6f (56%), 6n (22%), 6i (11%), 6j (10%), and 6e (1%). Among the 13 countries with different subtypes of HCV-6, most sequences have been reported from Vietnam. Subtype 6f was found exclusively in Thailand where five distinct HCV-6 subtypes are circulating. HCV-6, which is endemic in south China and south-east Asia, displays profound genetic diversity and may have evolved over a considerable period of time. © 2009 Wiley-Liss, Inc.
  • Mechanism of entecavir resistance of hepatitis B virus with viral breakthrough as determined by long-term clinical assessment and molecular docking simulation, Motokazu Mukaide, Motokazu Mukaide, Yasuhito Tanaka, Tadasu Shin-I, Man Fung Yuen, Fuat Kurbanov, Osamu Yokosuka, Michio Sata, Yoshiyasu Karino, Gotaro Yamada, Kohsaku Sakaguchi, Etsuro Orito, Manami Inoue, Sumbella Baqai, Ching Lung Lai, Masashi Mizokami, Antimicrobial Agents and Chemotherapy, 54, 882 - 889,   2010年02月01日, The mechanism by which entecavir resistance (ETVr) substitutions of hepatitis B virus (HBV) can induce breakthrough (BT) during ETV therapy is largely unknown. We conducted a cross-sectional study of 49 lamivudine (LVD)-refractory patients and 59 naïve patients with chronic hepatitis B. BT was observed in 26.8% of the LVD-refractory group during weeks 60 to 144 of ETV therapy. A line probe assay revealed ETVr substitutions only in the LVD-refractory group, i.e., in 4.9% of patients at baseline, increasing to 14.6%, 24.4%, and 44.8% at weeks 48, 96, and 144, respectively. Multivariate logistic regression analysis adjusted for age, gender, HBV DNA levels, and LVD resistance (LVDr) (L180M and M204V, but not M204I) indicated that T184 substitutions and S202G (not S202C) were a significant factor for BT (adjusted odds ratio [OR], 141.12, and 95% confidence interval [CI], 6.94 to 2,870.20; OR, 201.25, and 95% CI, 11.22 to 3608.65, respectively). Modeling of HBV reverse transcriptase (RT) by docking simulation indicated that a combination of LVDr and ETVr (T184L or S202G) was characterized by a change in the direction of the D205 residue and steric conflict in the binding pocket of ETV triphosphate (ETV-TP), by significantly longer minimal distances (2.2 Å and 2.1 Å), and by higher potential energy (-117 and -99.8 Kcal/mol) for ETV-TP compared with the wild type (1.3 Å; -178 Kcal/mol) and LVDr substitutions (1.5 Å; -141 Kcal/mol). Our data suggest that the low binding affinity of ETV-TP for the HBV RT, involving conformational change of the binding pocket of HBV RT by L180M, M204V plus T184L, and S202G, could induce BT. Copyright © 2010, American Society for Microbiology. All Rights Reserved.
  • RNA polymerase activity and specific RNA structure are required for efficient HCV replication in cultured cells, Asako Murayama, Leiyun Weng, Tomoko Date, Daisuke Akazawa, Daisuke Akazawa, Xiao Tian, Tetsuro Suzuki, Takanobu Kato, Yasuhito Tanaka, Masashi Mizokami, Takaji Wakita, Tetsuya Toyoda, PLoS Pathogens, 6, 1 - 11,   2010年01月01日, We have previously reported that the NS3 helicase (N3H) and NS5B-to-3'X (N5BX) regions are important for the efficient replication of hepatitis C virus (HCV) strain JFH-1 and viral production in HuH-7 cells. In the current study, we investigated the relationships between HCV genome replication, virus production, and the structure of N5BX. We found that the Q377R, A450S, S455N, R517K, and Y561F mutations in the NS5B region resulted in up-regulation of J6CF NS5B polymerase activity in vitro. However, the activation effects of these mutations on viral RNA replication and virus production with JFH-1 N3H appeared to differ. In the presence of the N3H region and 3' untranslated region (UTR) of JFH-1, A450S, R517K, and Y561F together were sufficient to confer HCV genome replication activity and virus production ability to J6CF in cultured cells. Y561F was also involved in the kissing-loop interaction between SL3.2 in the NS5B region and SL2 in the 3'X region. We next analyzed the 3' structure of HCV genome RNA. The shorter polyU/UC tracts of JFH-1 resulted in more efficient RNA replication than J6CF. Furthermore, 9458G in the JFH-1 variable region (VR) was responsible for RNA replication activity because of its RNA structures. In conclusion, N3H, high polymerase activity, enhanced kissing-loop interactions, and optimal viral RNA structure in the 3'UTR were required for J6CF replication in cultured cells. © 2010 Murayama et al.
  • Hepatic ISG expression is associated with genetic variation in interleukin 28B and the outcome of IFN therapy for chronic hepatitis C, Masao Honda, Masao Honda, Akito Sakai, Tatsuya Yamashita, Yasunari Nakamoto, Eishiro Mizukoshi, Yoshio Sakai, Taro Yamashita, Mikiko Nakamura, Takayoshi Shirasaki, Katsuhisa Horimoto, Yasuhito Tanaka, Katsushi Tokunaga, Masashi Mizokami, Shuichi Kaneko, Takashi Kagaya, Kuniaki Arai, Kaheita Kakinoki, Kazunori Kawaguchi, Hajime Takatori, Hajime Sunakosaka, Touru Nakahama, Shinji Kamiyamamoto, Yasuhiro Takemori, Hikaru Oguri, Yatsugi Noda, Hidero Ogino, Yoshinobu Hinoue, Keiji Minouchi, Nobuyuki Hirai, Tatsuho Sugimoto, Koji Adachi, Yuichi Nakamura, Masashi Unoura, Ryuhei Nishino, Hideo Morimoto, Hajime Ohta, Hirokazu Tsuji, Akira Iwata, Shuichi Terasaki, Tokio Wakabayashi, Yukihiro Shirota, Takeshi Urabe, Hiroshi Kawai, Yasutsugu Mizuno, Shoni Kameda, Hirotoshi Miyamori, Uichiro Fuchizaki, Haruhiko Shyugo, Hideki Osaka, Eiki Matsushita, Yasuhiro Katou, Nobuyoshi Tanaka, Kazuo Notsumata, Mikio Kumagai, Manabu Yoneshima, Gastroenterology, 139, 499 - 509,   2010年01月01日, Background & Aims: Multiple viral and host factors are related to the treatment response to pegylated-interferon and ribavirin combination therapy; however, the clinical relevance and relationship of these factors have not yet been fully evaluated. Methods: We studied 168 patients with chronic hepatitis C who received pegylated-interferon and ribavirin combination therapy. Gene expression profiles in the livers of 91 patients were analyzed using an Affymetrix genechip (Affymetrix, Santa Clara, CA). The expression of interferon-stimulated genes (ISGs) was evaluated in all samples by real-time polymerase chain reaction. Genetic variation in interleukin 28B (IL28B; rs8099917) was determined in 91 patients. Results: Gene expression profiling of the liver differentiated patients into 2 groups: patients with up-regulated ISGs and patients with down-regulated ISGs. A high proportion of patients with no response to treatment was found in the up-regulated ISGs group (P = .002). Multivariate logistic regression analysis showed that ISGs (<3.5) (odds ratio [OR], 16.2; P < .001), fibrosis stage (F1-F2) (OR, 4.18; P = .003), and ISDR mutation (<2) (OR, 5.09; P = .003) were strongly associated with the viral response. The IL28B polymorphism of 91 patients showed that 66% were major homozygotes (TT), 30% were heterozygotes (TG), and 4% were minor homozygotes (GG). Interestingly, hepatic ISGs were associated with the IL28B polymorphism (OR, 18.1; P < .001), and its expression was significantly higher in patients with the minor genotype (TG or GG) than in those with the major genotype (TT). Conclusions: The expression of hepatic ISGs is strongly associated with treatment response and genetic variation of IL28B. The differential role of host and viral factors as predicting factors may also be present. © 2010 AGA Institute.
  • Geographical and genetic diversity of the human hepatitis B virus, Fuat Kurbanov, Yasuhito Tanaka, Masashi Mizokami, Masashi Mizokami, Hepatology Research, 40, 14 - 30,   2010年01月01日, Hepatitis B virus (HBV) is one of the most widely distributed viruses that infect humankind. Distinct clinical and virological characteristics of the HBV-infection have been reported in different geographical parts of the world and are increasingly associated with genetic diversity of the infecting virus. HBV is classified into genotypes and subgenotypes that are associated with ethnicity and geography. The genetic diversity of HBV in its various aspects has been the subject of extensive investigations during the last few decades. Since molecular epidemiology research tools have become widely available, the number of new publications in this field has grown exponentially. This review summarises the recent publications on the geographical distribution of genetic variants of HBV, and proposes updated criteria for the identification of new genotypes and subgenotypes of the virus. © 2010 The Japan Society of Hepatology.
  • [Direct cytopathic effects of particular hepatitis B virus genotypes in immunosuppressive condition]., Yasuhito Tanaka, Masaya Sugiyama, Masashi Mizokami, Uirusu. Journal of virology, 60, 79 - 86,   2010年01月01日, Little is known about the direct cytopathic effect of hepatitis B virus (HBV) and its association with particular viral genotype or genetic mutation. In some immunosuppressed chronic HBV patients who had liver transplantation or HIV-coinfection, high viremia and liver fibrosis may occur. These findings suggest that hepatic injuries could arise in the absence of a mature immune system and the difference of genotype and/or specific mutation would affect cytopathic potential of the virus. We investigate HBV genotype-related differences in viral replication, antigens expression and histopathology using in vitro replication model or uPA/SCID mice harboring human hepatocytes, demonstrating that different HBV genotypes and even particular mutation are associated with different virological and histopathological characteristics. Infection with HBV/C2 as well as PC mutant of the HBV/B1 in immunosuppressive conditions can induce direct cytopathic effect in "humanized" part of the murine liver.
  • lambda-Interferons and the single nucleotide polymorphisms: A milestone to tailor-made therapy for chronic hepatitis C, 40(5),   2010年
  • Universal hepatitis B vaccination: Pros and cons, Yasuhito Tanaka, Hiroshi Yotsuyanagi, Koji Yano, Akahito Sakou, Eiji Mita, Kentaro Matsuura, Kazuhiko Hayashi, Masaki Tsuge, Kazuto Tajiri, Naoko Yoshioka, Tomoo Fujisawa, Shigeharu Uchida, Kazuhiko Koike, Acta Hepatologica Japonica, 50, 598 - 604,   2009年12月01日
  • A genetic variant of hepatitis B virus divergent from known human and ape genotypes isolated from a Japanese patient and provisionally assigned to new genotype J, Kanako Tatematsu, Yasuhito Tanaka, Fuat Kurbanov, Fuminaka Sugauchi, Shuhei Mano, Tatsuji Maeshiro, Tomokuni Nakayoshi, Moriaki Wakuta, Yuzo Miyakawa, Masashi Mizokami, Masashi Mizokami, Journal of Virology, 83, 10538 - 10547,   2009年10月01日, Hepatitis B virus (HBV) of a novel genotype (J) was recovered from an 88-year-old Japanese patient with hepatocellular carcinoma who had a history of residing in Borneo during the World War II. It was divergent from eight human (A to H) and four ape (chimpanzee, gorilla, gibbon, and orangutan) HBV genotypes, as well as from a recently proposed ninth human genotype I, by 9.9 to 16.5% of the entire genomic sequence and did not have evidence of recombination with any of the nine human genotypes and four nonhuman genotypes. Based on a comparison of the entire nucleotide sequence against 1,440 HBV isolates reported, HBV/J was nearest to the gibbon and orangutan genotypes (mean divergences of 10.9 and 10.7%, respectively). Based on a comparison of four open reading frames, HBV/J was closer to gibbon/orangutan genotypes than to human genotypes in the P and large S genes and closest to Australian aboriginal strains (HBV/C4) and orangutan-derived strains in the S gene, whereas it was closer to human than ape genotypes in the C gene. HBV/J shared a deletion of 33 nucleotides at the start of preS1 region with C4 and gibbon genotypes, had an S-gene sequence similar to that of C4, and expressed the ayw subtype. Efficient infection, replication, and antigen expression by HBV/J were experimentally established in two chimeric mice with the liver repopulated for human hepatocytes. The HBV DNA sequence recovered from infected mice was identical to that in the inoculum. Since HBV/J is positioned phylogenetically in between human and ape genotypes, it may help to trace the origin of HBV and merits further epidemiological surveys. Copyright © 2009, American Society for Microbiology. All Rights Reserved.
  • Genome-wide association of IL28B with response to pegylated interferon-α and ribavirin therapy for chronic hepatitis C, Yasuhito Tanaka, Yasuhito Tanaka, Nao Nishida, Nao Nishida, Masaya Sugiyama, Masayuki Kurosaki, Kentaro Matsuura, Naoya Sakamoto, Mina Nakagawa, Masaaki Korenaga, Keisuke Hino, Shuhei Hige, Yoshito Ito, Eiji Mita, Eiji Tanaka, Satoshi Mochida, Yoshikazu Murawaki, Masao Honda, Akito Sakai, Yoichi Hiasa, Shuhei Nishiguchi, Asako Koike, Isao Sakaida, Masatoshi Imamura, Kiyoaki Ito, Koji Yano, Naohiko Masaki, Fuminaka Sugauchi, Namiki Izumi, Katsushi Tokunaga, Masashi Mizokami, Masashi Mizokami, Nature Genetics, 41, 1105 - 1109,   2009年10月01日, The recommended treatment for patients with chronic hepatitis C, pegylated interferon-α (PEG-IFN-α) plus ribavirin (RBV), does not provide sustained virologic response (SVR) in all patients. We report a genome-wide association study (GWAS) to null virological response (NVR) in the treatment of patients with hepatitis C virus (HCV) genotype 1 within a Japanese population. We found two SNPs near the gene IL28B on chromosome 19 to be strongly associated with NVR (rs12980275, P = 1.93 × 10 13, and rs8099917, 3.11 × 10 15). We replicated these associations in an independent cohort (combined P values, 2.84 × 10 27 (OR = 17.7; 95% CI = 10.0-31.3) and 2.68 × 10 32 (OR = 27.1; 95% CI = 14.6-50.3), respectively). Compared to NVR, these SNPs were also associated with SVR (rs12980275, P = 3.99 × 10 24, and rs8099917, P = 1.11 × 10 27). In further fine mapping of the region, seven SNPs (rs8105790, rs11881222, rs8103142, rs28416813, rs4803219, rs8099917 and rs7248668) located in the IL28B region showed the most significant associations (P = 5.52 × 10 28 -2.68 × 10 32; OR = 22.3-27.1). Real-time quantitative PCR assays in peripheral blood mononuclear cells showed lower IL28B expression levels in individuals carrying the minor alleles (P = 0.015). © 2009 Nature America, Inc. All rights reserved.
  • The duration of lamivudine therapy for chronic hepatitis b: Cessation vs. continuation of treatment after HBeAg seroconversion, James Fung, Ching Lung Lai, Yasuhito Tanaka, Masashi Mizokami, John Yuen, Danny Ka Ho Wong, Man Fung Yuen, American Journal of Gastroenterology, 104, 1940 - 1946,   2009年08月01日, OBJECTIVES: The aim of this study was to compare the virological and biochemical relapse rates in Asian chronic hepatitis B patients with lamivudine-induced hepatitis B e antigen (HBeAg) seroconversion, between those who stopped therapy after HBeAg seroconversion and those who continued to receive lamivudine.METHODS:All patients with lamivudine-induced HBeAg seroconversion were included. Patients who stopped lamivudine after HBeAg seroconversion (n22) were compared with 79 patients who continued to receive lamivudine (n79). Demographic, virological, and biochemical parameters were recorded at baseline, and throughout the duration of follow-up.RESULTS:In patients who stopped lamivudine, the median follow-up after stopping lamivudine was 20 months. Of these patients, 14 (64%) had virological rebound, with a cumulative incidence of 82% at 4 years. There was no significant difference in number of flares between patients with normal alanine aminotransferase (ALT) and undetectable hepatitis B virus (HBV) DNA at the time of stopping lamivudine compared with that in patients with either abnormal ALT, detectable HBV DNA, or both (P0.73). The cumulative incidence of HBeAg seroreversion and ALT flares at 5 years after stopping lamivudine was 9 and 44%, respectively. Of the 79 patients who continued with lamivudine, 62 (78%) had undetectable HBV DNA at the time of last follow-up, whereas no patients had undetectable HBV DNA after stopping lamivudine (P<0.001). The cumulative incidence of ALT flares at 5 years was 16% (P<0.001 compared with those who stopped taking lamivudine). After a median treatment duration of 79 months, lamivudine-resistant mutations occurred in eight patients (10%).CONCLUSIONS:In Asian HBeAg-positive patients, continuing with lamivudine after achieving HBeAg seroconversion was associated with a higher proportion of undetectable HBV DNA and a lower number of ALT flares, when compared with those with cessation of lamivudine. In patients who achieved HBeAg seroconversion with lamivudine, the resistance rate was not high when treatment was continued after HBeAg seroconversion. © 2009 by the American College of Gastroenterology.
  • Case-control study for the identification of virological factors associated with fulminant hepatitis B, Atsunori Kusakabe, Atsunori Kusakabe, Yasuhito Tanaka, Satoshi Mochida, Nobuaki Nakayama, Kazuaki Inoue, Michio Sata, Norio Isoda, Jong Hon Kang, Yasukiyo Sumino, Hiroshi Yatsuhashi, Yasuhiro Takikawa, Shuichi Kaneko, Gotaro Yamada, Yoshiyasu Karino, Eiji Tanaka, Junji Kato, Isao Sakaida, Namiki Izumi, Fuminaka Sugauchi, Shunsuke Nojiri, Takashi Joh, Yuzo Miyakawa, Masashi Mizokami, Masashi Mizokami, Hepatology Research, 39, 648 - 656,   2009年07月07日, Background: Host and viral factors can promote the development of fulminant hepatitis B (FHB), but there have been no case-control studies for figuring out virological parameters that can distinguish FHB. Methods: In a case-control study, virological factors associated with the development of FHB were sought in 50 patients with FH developed by transient hepatitis B virus (HBV) infection (FH-T) and 50 with acute self-limited hepatitis B (AHB) who were matched for sex and age. In addition, 12 patients with FH developed by acute exacerbation (AE) of asymptomatic HBV carrier (ASC) (FH-C) were also compared with 12 patients without FH by AE of chronic hepatitis B (AE-C). Results: Higher HBV DNA levels, subgenotype B1/Bj, A1762T/G1764A, G1896A, G1899A and A2339G mutation were significantly more frequent (P < 0.05), while hepatitis B e-antigen was less frequent in the FH-T patients than AHB. In multivariate analysis, G1896A mutation (odds ratio [OR], 13.53; 95% confidence interval [CI], 2.75-66.64), serum HBV DNA more than 5.23log copies/mL (OR, 5.14; 95% CI, 1.10-24.15) and total bilirubin more than 10.35mg/mL (OR, 7.81; 95% CI, 1.77-34.51) were independently associated with a fulminant outcome by transient HBV infection. On the other hand, in comparison with the patients between FH-C and AE-C groups, there was no significant difference of virological factors associated with the development of FHB. Conclusion: A number of virological factors have been defined that may distinguish FH-T from AHB in a case-control study. The pathogenic mechanism of FHB between transient HBV infection and AE of ASC would be different. © 2009 The Japan Society of Hepatology.
  • Evaluation of the reference range of retinol-binding protein (RBP) levels by the latex turbidimetric immunoassay, Kazumi Takagi, Yasuhito Tanaka, Kumiko Hiramatu, Satomi Kani, Kanako Tatematsu, Hatsue Naganuma, Tetsuo Ueno, Takaaki Gotou, Yukio Wakimoto, Masashi Mizokami, Rinsho byori. The Japanese journal of clinical pathology, 57, 638 - 643,   2009年07月01日, The clinical implication of the hepatitis B surface antigen (HBsAg) concentrations has been reported in HBV-infected patients during anti-viral treatment. HBV genotypes A and D are ubiquitous and scattered worldwide, especially northern America as well as Europe, whereas genotypes B and C are common in Asia. The aim of this study was to evaluate a new version of the Sysmex HBsAg quantitative kit based on Chemiluminescence Enzyme Immunoassay. Sera collected from 172 patients infected with any of the four major genotypes A to D (HBV/A, n = 18; B, n = 25; C, n = 84; D, n = 45), including the genotype D cases with weak reaction in the previous version of the kit. The new version of the kit having additional monoclonal antibody, showed improved sensitivity compared to the previous version as well as robust correlation with another quantitative HBsAg assay: the Abbot Architect. Observed during lamivudine therapy, increase in HBsAg and HBV DNA concentrations preceded the aminotransferase (ALT) elevation associated with drug-resistant HBV variant emergence (breakthrough hepatitis). In conclusion, reliability of the Sysmex HBsAg quantitative assay was confirmed for the four HBV genotypes common worldwide. Monitoring of serum HBsAg concentrations in addition to HBV DNA quantification, is helpful in evaluation of the response or resistance to anti-viral therapy.
  • Epidemic spread of hepatitis C virus genotype 3a and relation to high incidence of hepatocellular carcinoma in Pakistan, Anis Khan, Yasuhito Tanaka, Zahid Azam, Zaigham Abbas, Fuat Kurbanov, Uzma Saleem, Saeed Hamid, Wasim Jafri, Masashi Mizokami, Journal of Medical Virology, 81, 1189 - 1197,   2009年07月01日, Studies conducted in different populations worldwide revealed an association between HCV genotype 1 and the development of hepatocellular carcinoma (HCC) than in infection with other HCV genotypes. There are reports which reveal the association of HCV genotype 3a (HCV-3a) with hepatic steatosis and fibrosis but its relation with the development of HCC has not been investigated. In Pakistan, where the incidence of HCC is increasing, 189 patients with chronic liver disease including 82 with HCC were enrolled. HCV genotypes were determined by phylogeny in the NS5B region and the epidemic history of HCV-3a was examined using coalescent theory based methods. HCV-3a was the predominant genotype (81.4%) in the cohort studied, followed by 3b (9.3%), 3k (2.3%), 1a (1.5%), 1c (1.5%), 1b (0.8%), and 2a (0.8%) where 76% of HCC and 86% of non-HCC were infected with HCV-3a. The significant factors associated with HCC were older age (mean ± SD) 55.8 (± 9.9) (P < 0.0001), and male gender (P < 0.001). HCV RNA was significantly higher in patients with HCC and chronic hepatitis than in liver cirrhosis (P < 0.0001). Molecular evolutionary analysis revealed a distinct phylogenetic cluster of HCV-3a in Pakistan and an estimation of the effective number of HCV infections indicated the appearance of HCV-3a in this region around 1920s and a rapid exponential growth in the 1950s. This indicates that the epidemic spread of HCV-3a occurred earlier in Pakistan than in other countries in which this genotype has been reported. HCV-3a which spread earlier in Pakistan may be associated with an increasing incidence of HCC. © 2009 Wiley-Liss, Inc.
  • Metabolic factors and subsequent risk of hepatocellular carcinoma by hepatitis virus infection status: A large-scale population-based cohort study of Japanese men and women (JPHC Study Cohort II), Manami Inoue, Norie Kurahashi, Motoki Iwasaki, Yasuhito Tanaka, Masashi Mizokami, Mitsuhiko Noda, Shoichiro Tsugane, Cancer Causes and Control, 20, 741 - 750,   2009年07月01日, Objective: The association between metabolic factors and hepatocellular carcinoma (HCC) has not been well clarified. We prospectively examined whether metabolic factors predicts the subsequent risk of HCC in the Japan Public Health Center-based Prospective Study Cohort II, in consideration of hepatitis virus infection status. Methods: A total of 17,590 subjects aged 40-69 participating in a questionnaire and health checkup survey during 1993-1994 were followed for incidence of HCC through 2006. A total of 102 cases of HCC were newly documented. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for metabolic factors controlling for potential confounding factors. Results: The presence of metabolic factors in the aggregate was associated with a significantly increased risk of HCC, especially with hepatitis virus infection. HCC was positively associated particularly with high glucose (HR = 1.75, CI = 1.11-2.74) and overweight (HR = 2.22, CI = 1.42-3.48). Results were similar when analyses were limited to subjects with HCV infection. Conclusions: Although metabolic factors in the aggregate may be associated with an increased risk of HCC, the main contributors to this association under HCV infection appear to be overweight and high glucose. Improvement of these factors may be a crucial target in preventing progression to HCC in those with HCV infection. © 2008 Springer Science+Business Media B.V.
  • Reactivation of hepatitis B virus following systemic chemotherapy for malignant lymphoma, Shigeru Kusumoto, Yasuhito Tanaka, Masashi Mizokami, Masashi Mizokami, Ryuzo Ueda, International Journal of Hematology, 90, 13 - 23,   2009年07月01日, Reactivation of hepatitis B virus (HBV) has been reported not only in HBsAg-positive patients undergoing systemic chemotherapy, but also in a proportion of HBsAg-negative patients with HBc antibody and/or HBs antibody. Recently, rituximab-plus-steroid combination chemotherapy (R-CHOP, etc.) has been identified as a risk factor for HBV reactivation in HBsAg-negative patients with malignant lymphoma. Prophylaxis with antiviral drugs is essential for preventing HBV reactivation in HBsAg-positive patients, but there is little evidence on which to base the choice of drug or appropriate duration of prophylaxis. There are also few clinical data on HBsAg-negative patients and no established standard of care for such patients with HBV reactivation. Based on the limited number of previous reports, preemptive therapy, guided by serial HBV-DNA monitoring, is a reasonable strategy to prevent HBV reactivation in HBsAg-negative patients. However, clinical evidence alone is insufficient for determining optimal frequency of HBV-DNA monitoring during and after chemotherapy, or for determining when to stop preemptive therapy for HBV reactivation. Thus, well-designed clinical trials should be carried out to investigate the efficacy and safety of such preemptive therapy. Additionally, assessment of viral factors such as HBV genotypes and gene mutations may assist in the development of strategies to prevent the occurrence of severe hepatitis. In this review, we summarize the characteristics of HBV reactivation after systemic chemotherapy including rituximab, and propose a management strategy for malignant lymphoma patients suffering from HBV reactivation. © 2009 The Japanese Society of Hematology.
  • Effect of coffee and green tea consumption on the risk of liver cancer: Cohort analysis by hepatitis virus infection status, Manami Inoue, Norie Kurahashi, Motoki Iwasaki, Taichi Shimazu, Yasuhito Tanaka, Masashi Mizokami, Shoichiro Tsugane, Cancer Epidemiology Biomarkers and Prevention, 18, 1746 - 1753,   2009年06月01日, In spite of their anticarcinogenic potential, the effect of coffee and green tea consumption on the risk of liver cancer has not been clarified prospectively in consideration of hepatitis C (HCV) and B virus (HBV) infection. We examined whether coffee and green tea consumption was associated with a reduced risk of liver cancer by hepatitis virus infection status in the Japan Public Health Center-Based Prospective Study Cohort II. A total of 18,815 subjects ages 40 to 69 years participating in a questionnaire and health checkup survey in 1993 to 1994 were followed for the incidence of liver cancer through 2006. A total of 110 cases of liver cancer were newly documented. Hazard ratios for coffee and green tea consumption categories were calculated with a Cox proportional hazards model. Compared with almost never drinkers, increased coffee consumption was associated with a reduced risk of liver cancer in all subjects (hazard ratio for <1, 1-2, and ≥3 cups/d; Ptrend= 0.67, 0.49, 0.54, and 0.025). A similar risk tendency was observed in those with either or both HCV and HBV infection. In contrast, no association was observed between green tea consumption and the risk of liver cancer in all subjects. Our results suggest that coffee consumption may reduce the risk of liver cancer regardless of HCV and HBV infection status, whereas green tea may not reduce this risk. Copyright © 2009 American Association for Cancer Research.
  • Genetic variability of hepatitis C virus in south Egypt and its possible clinical implication, Abeer Elkady, Yasuhito Tanaka, Fuat Kurbanov, Fuminaka Sugauchi, Masaya Sugiyama, Anis Khan, Douaa Sayed, Ghada Moustafa, Abdel Rahman Abdel-Hameed, Masashi Mizokami, Journal of Medical Virology, 81, 1015 - 1023,   2009年06月, Egypt is one of the countries with very high rates of hepatitis C virus (HCV) related morbidity and mortality. However, little is known about geographical and clinical differences in genetic variability of HCV in Egypt. Using direct sequencing and phylogenetic analysis of partial core/E1 and NS5B regions of the HCV genome, HCV genotype/subtype was determined in 129 HCV-infected patients residing in three governates in south Egypt: Assuit, Sohag, and Qena. According to clinical stage of infection, patients were categorized into four groups: asymptomatic carriers, n = 16; chronic hepatitis C patients, n = 36; liver cirrhosis, n = 54; and hepatocellular carcinoma (HCC), n = 23. Genotype 4a was detected in 80.6%, whereas 1g, 4l, 4n, 4o, 4f, and 4m were identified in 7.7%, 4.7%, 3.9%, 1.6%, 0.8%, and 0.8% of cases, respectively. The prevalence of 4a differed regionally; from 88.5% (in Sohag) to 64% (in Assuit, P = 0.002). Genotypes 4l and 4n had a higher prevalence in Assuit (12.8%, 10.3%) than Sohag (0%, 0%; P≤0.011). Difference in clinical features of determined genotypes/subtypes was observed; more carriers of non-4a variants (4l and 4n, 4f, or 4m) had chronic hepatitis compared to carriers of 4a (53.3% vs. 23.1%, P = 0.025), while more patients with 4a had liver cirrhosis (45.2% vs. 13.3%, P = 0.023). Two HCV-4o strains were isolated in this study, both from patients with HCC. In conclusion, geographical diversity of HCV was revealed in this study in southern Egypt.Afurther case-control study is required to confirm the trends of differential pathogenicity of HCV subtypes, indicated by this study. © 2009 Wiley-Liss, Inc.
  • Distribution of hepatitis B virus genotypes among patients with chronic infection in Japan shifting toward an increase of genotype A, Kentaro Matsuura, Yasuhito Tanaka, Shuhei Hige, Gotaro Yamada, Yoshikazu Murawaki, Masafumi Komatsu, Tomoyuki Kuramitsu, Sumio Kawata, Eiji Tanaka, Namiki Izumi, Chiaki Okuse, Shinichi Kakumu, Takeshi Okanoue, Keisuke Hino, Yoichi Hiasa, Michio Sata, Tatsuji Maeshiro, Fuminaka Sugauchi, Shunsuke Nojiri, Takashi Joh, Yuzo Miyakawa, Masashi Mizokami, Journal of Clinical Microbiology, 47, 1476 - 1483,   2009年05月, Acute hepatitis B virus (HBV) infection has been increasing through promiscuous sexual contacts, and HBV genotype A (HBV/A) is frequent in patients with acute hepatitis B (AHB) in Japan. To compare the geographic distribution of HBV genotypes in patients with chronic hepatitis B (CHB) in Japan between 2005 and 2006 and between 2000 and 2001, with special attention to changes in the proportion of HBV/A, a cohort study was performed to survey changes in genotypes of CHB patients at 16 hospitals throughout Japan. Furthermore, we investigated the clinical characteristics of each genotype and examined the genomic characteristics of HBV/A isolates by molecular evolutionary analyses. Of the 1,271 patients, 3.5%, 14.1%, and 82.3% were infected with HBV/A, -B, and -C, respectively. In comparison with our previous survey during 2000 and 2001, HBV/A was twice as frequent (3.5% versus 1.7%; P = 0.02). The mean age was lower in the patients with HBV/A than in those with HBV/B or -C. Based on phylogenetic analyses of 11 full-length genomes and 29 pre-S2/S region sequences from patients, HBV/A isolates were imported from Europe and the United States, as well as the Philippines and India. They clustered with HBV/A from AHB patients and have spread throughout Japan. HBV/A has been increasing in CHB patients in Japan as a consequence of AHB spreading in the younger generation through promiscuous sexual contacts, aided by a tendency of HBV/A to induce chronic hepatitis. The spread of HBV/A infection in Japan should be prevented by universal vaccination programs. Copyright © 2009, American Society for Microbiology. All Rights Reserved.
  • Isoflavone consumption and subsequent risk of hepatocellular carcinoma in a population-based prospective cohort of Japanese men and women, Norie Kurahashi, Manami Inoue, Motoki Iwasaki, Yasuhito Tanaka, Masashi Mizokami, Shoichiro Tsugane, International Journal of Cancer, 124, 1644 - 1649,   2009年04月, The incidence of hepatocellular carcinoma (HCC) is much higher in men than in women. Several experiment and epidemiological studies have suggested that estrogen might play an inhibitory role in the development of HCC. Because isoflavones have a similar structure as 17p-estradiol and appear to have an anti-estrogenic effect in women and estrogenic effect in men, we hypothesized that the effect of isoflavones on HCC differs by sex. We investigated the association between isoflavones (genistein and daidzein) and soy products and HCC in Japan in a population-based prospective study in 19,998 Japanese (7,215 men and 12,783 women) aged 40-69 years. During 11.8 years of follow-up, 101 subjects (69 men and 32 women) were newly diagnosed with HCC. Case patients were grouped according to consumption of isoflavones and soy products and stratified by hepatitis virus infection. Hazard ratios (HRs) and 95% confidence intervals (CIs) for HCC were calculated by Cox proportional-hazards modeling. In women, genistein and daidzein were dose-dependently associated with an increased risk of HCC, with multivariable HRs for the highest versus lowest tertile of 3.19 (95%CI = 1.13-9.00,ptrend = 0.03) and 3.90 (95% CI = 1.30-11.69,ptrend= 0.01), respectively. No association between isoflavones and HCC was observed in men. These results persisted when analysis was restricted to subjects positive for either or both hepatitis C and B virus. In conclusion, isoflavone consumption may be associated with an increased risk of HCC in women. Women with hepatitis virus infection may be advised to abstain from isoflavone consumption. Further studies are warranted to confirm these findings. © 2008 Wiley-Liss, Inc.
  • Impact of determination of hepatitis B virus subgenotype and pre-core/ core-promoter mutation for the prediction of acute exacerbation of asymptomatic carriers, Tadashi Ikegami, Yasuhiko Matsuki, Yasuhito Tanaka, Masashi Mizokami, Akira Honda, Takeshi Hirayama, Yoshifumi Saito, Yasushi Matsuzaki, Hepatology Research, 39, 341 - 345,   2009年04月, Aim: A large cohort study in Japan revealed that the specific viral profile may influence the fulminant outcome in acute hepatitis B virus (HBV) infections, while the genetic influence on outcome has not been clarified in patients with acute exacerbation of chronic liver disease caused by HBV. We experienced a case of fatal liver failure that developed as the result of chronic HBV infection. To determine possible genetic factor involving acute exacerbation, genetic analysis of serum from the patient and his siblings was performed. Methods: HBV subgenotype as well as pre-core/core-promoter mutations of samples mentioned above were determined. Results: Patient had HBV-Bj with pre-core (1896/1899) and core-promoter (1762/1764) mutations, the genomic profile frequently seen in fulminant hepatitis caused by acute HBV infection. Conclusion: This result suggests that determination of the HBV subgenotype and pre-core/core promoter mutations could provide a rationale for development of a treatment strategy in asymptomatic HBV carriers. © 2009 The Japan Society of Hepatology.
  • Strategy for glycoproteomics: Identification of glyco-alteration using multiple glycan profiling tools, Hiromi Ito, Atsushi Kuno, Hiromichi Sawaki, Maki Sogabe, Hidenori Ozaki, Yasuhito Tanaka, Masashi Mizokami, Jun Ichi Shoda, Takashi Angata, Takashi Sato, Jun Hirabayashi, Yuzuru Ikehara, Hisashi Narimatsu, Journal of Proteome Research, 8, 1358 - 1367,   2009年03月06日, Glycan alterations of proteins, a common feature of cancer cells, are associated with carcinogenesis, invasion and metastasis. Glycomics, the study of glycans and glycan-binding proteins in various biological systems, is an emerging field in the postgenome and postproteomics era. However, systematic and robust strategies for glycomics are still not fully established because the structural analysis of glycans, which comprise different patterns of branching, various possible linkage positions as well as monomer anomericity, is technically difficult. Here, we introduce a new strategy for glyco-alteration analysis of glycoproteins by using multiple glycan profiling tools. To understand glycan alterations of proteins by correlating the glycosyltransferase expression profile with the actual glycan structure, we systematically used three glycan profiling tools: (1) multiplex quantitative PCR (qPCR) array format for profiling the expression pattern of glycogenes, (2) lectin microarray as a multiplex glycan-lectin interaction analysis system for profiling either a pool of cell glycoproteins or a target glycoprotein, and (3) tandem mass spectrometry for identifying the glycan structure connected to a target glycoprotein. Using our system, we successfully identified glycan alterations on alpha-fetoprotein (AFP), including a novel LacdiNAc structure in addition to previously reported alterations such as a.1,6 fucosylation. © 2009 American Chemical Society.
  • Evaluation of serum PIVKA-II by Lumipulse PrestoII assay, Kumiko Hiramatsu, Yasuhito Tanaka, Kazumi Takagi, Satomi Kani, Takaaki Goto, Yoshimitsu Takasaka, Kentaro Matsuura, Fuminaka Sugauchi, Kazushige Moriyama, Hiroshi Murakami, Sachiko Kitajima, Masashi Mizokami, Rinsho byori. The Japanese journal of clinical pathology, 57, 200 - 205,   2009年03月01日, Measurements of serum concentrations of Des-gamma-carboxy Prothrombin (PIVKA-II) are widely used for diagnosing hepatocellular carcinoma (HCC). Recently, in Lumipulsef assay, it was reported that antibodies against alkaline phosphatase (ALP) derived from anti bleeding sheets led false high values of PIVKA-II in the patients with HCC resection. To improve the previous issue, newly developed Lumipulse PrestoII assay was examined. (1) The assay was reliable and positively correlated with the previous assays (Lumipulse f and Picolumi, R = 0.997 and 0.994 (n=115), respectively). (2) Eleven cases, which had false high values of PIVKA-II by the Lumipulsef assay, were examined by the PrestoII assay with excess of inactive ALP. The false high values of 10 cases were improved, but only one was still high. False reactivity of this case was stronger than other cases, more effective adsorption was required. (3) Comparing the absorbent activity of inactive ALP among 6 different kinds, we found inactive ALP with much higher adsorbent activity. When this inactive ALP was applied to assay, false high values of PIVKA-II were improved in all 11 cases. In conclusion, the PrestoII assay, which applies the inactive ALP with high activity, is reliable and useful for clinical screening.
  • HBV genotypes in India: Do they influence disease severity?, Kaushal Madan, Yogesh Batra, Vishnubhatla Sreenivas, Masashi Mizokami, Yasuhito Tanaka, Sreenivasa Baba Chalamalasetty, Subrat K. Panda, Subrat K. Acharya, Hepatology Research, 39, 157 - 163,   2009年02月05日, Aims: Association of HBV genotypes (especially A and D) with severity of liver disease is controversial. We studied the influence of HBV genotypes on liver disease severity among Indian patients. Methods: We selected 247 HBV infected patients (42 acute hepatitis, 87 carriers, 44 chronic hepatitis B [CHB], 35 liver cirrhosis [LC]and 40 hepatocellular carcinoma [HCC]). Genotyping of stored sera was performed using genotype-specific enzyme-linked immunosorbent assay (ELISA) and restriction fragment length polymorphism (RFLP). The distribution of genotypes in disease states of differing clinical, histological and biochemical severity were compared. Results: The most common genotype was D (162/237, 68.3%), followed by A (61, 25.7%) and C (14, 5.9%). The distribution of HBV genotypes between patients with acute hepatitis and CHB (carriers + CHB + LC + HCC), or between carriers and disease states (CHB + LC + HCC), or between mild chronic infection (carriers + CHB) and complications of chronic HBV infection (LC + HCC) was similar. Eighty-seven patients had liver biopsy; the median histological activity index (HAI) and fibrosis stage at baseline were similar between genotype groups (four [1 - 9]genotype A[n = 28]), three (2 - 4) genotype C (n = 4) and four (1 - 10) genotype D (n = 55); P = 0.33 for HAI score; (0.5 [0 - 6]genotype A, 0.5 [0 - 4]genotype C and 1 [0 - 6]genotype D; P = 0.92 for fibrosis stage). The response to therapy was similar between the genotypes. Conclusion: Clinical, histological severity and therapeutic responses are similar among patients with HBV genotypes A and D. © 2009 The Japan Society of Hepatology.
  • Prevention of immunosuppressive therapy or chemotherapy-induced reactivation of hepatitis B virus infection - Joint report of the Intractable Liver Diseases Study Group of Japan and the Japanese Study Group of the Standard Antiviral Therapy for Viral Hepa, Hirohito Tsubouchi, Hiromitsu Kumada, Kendo Kiyosawa, Satoshi Mochida, Isao Sakaida, Eiji Tanaka, Takafumi Ichida, Masashi Mizokami, Kazuyuki Suzuki, Shinsyo Yoshiba, Hisataka Moriwaki, Toshifumi Hibi, Norio Hayashi, Norihiro Kokudo, Tomoo Fujisawa, Hiromi Ishibashi, Yasuhiko Sugawara, Hiroshi Yatsuhashi, Akio Ido, Yasuhiro Takikawa, Kazuaki Inoue, Makoto Oketani, Hirofumi Uto, Nobuaki Nakayama, Takafumi Naiki, Shinichiro Tada, Shinichi Kiso, Koji Yano, Ryujin Endo, Yasuhito Tanaka, Takeji Umemura, Kotaro Kumagai, Acta Hepatologica Japonica, 50, 38 - 42,   2009年02月03日
  • Abbott realtime hepatitis C virus (HCV) and Roche Cobas AmpliPrep/Cobas TaqMan HCV assays for prediction of sustained virological response to pegylated interferon and ribavirin in chronic hepatitis C patients, Kentaro Matsuura, Yasuhito Tanaka, Izumi Hasegawa, Tomoyoshi Ohno, Hiroshi Tokuda, Fuat Kurbanov, Fuminaka Sugauchi, Shunsuke Nojiri, Takashi Joh, Masashi Mizokami, Journal of Clinical Microbiology, 47, 385 - 389,   2009年02月, Two commercial real-time PCR assays are currently available for sensitive hepatitis C virus (HCV) RNA quantification: the Abbott RealTime HCV assay (ART) and Roche Cobas AmpliPrep/Cobas TaqMan HCV assay (CAP/CTM). We assessed whether the two real-time PCR assays were more effective than Roche Cobas Amplicor HCV Monitor test, v.2.0 (CAM) for prediction of the sustained virological response (SVR) to pegylated interferon (PEG-IFN) plus ribavirin (RBV) in chronic hepatitis C. Sixty patients chronically infected with HCV genotype 1b (37 males and 23 females, 53 ± 12 years of age) were treated with PEG-IFNα2b plus RBV for 48 weeks. Stored specimens at nine time points for each patient (at baseline, on treatment, and 24 weeks after treatment) were tested by the two real-time PCR assays and CAM. Twenty-six (43.3%) patients reached SVR. The positive predictive values (PPVs) for SVR of undetectable HCV RNA at week 12 by CAM, ART, and CAP/CTM were 74.3%, 88.0%, and 95.2%, respectively. An undetectable HCV RNA level by CAM, ART, and CAP/CTM correctly predicted SVR at week 4 in 100%, 100%, and 100% of patients, at weeks 5 to 8 in 91.7%, 100%, and 100% of patients, at weeks 9 to 12 in 55.6%, 75%, and 87.5% of patients, and at weeks 13 to 24 in 0%, 26.7%, and 40% of patients, respectively. Of 16 patients who relapsed after treatment, HCV RNA was detectable in 2 patients at the end of treatment by CAP/CTM but undetectable by ART and CAM. HCV RNA tests using ART and CAP/CTM are considered to be more effective at predicting SVR than CAM, and the PPV for SVR was slightly higher in CAP/CTM than in ART. Copyright © 2009, American Society for Microbiology. All Rights Reserved.
  • Serum aminotransferase level and the risk of hepatocellular carcinoma: A population-based cohort study in Japan, Seiji Ishiguro, Yasuhito Tanaka, Masashi Mizokami, Motoki Iwasaki, Shoichiro Tsugane, European Journal of Cancer Prevention, 18, 26 - 32,   2009年02月, Aminotransferase level is presumed to be a marker of hepatic inflammation, but uncertainty remains whether elevated aminotransferase levels are associated with an increased risk of hepatocellular carcinoma (HCC). We evaluated the incidence of HCC by aminotransferase level in 19812 middle-aged and older individuals with and without hepatitis virus infection from a large-scale population-based cohort study (JPHC Study cohort II) in Japan. Hepatitis virus infection was identified at baseline in 1236 participants, namely 737 (3.7%) with hepatitis C virus, 479 (2.4%) with hepatitis B virus, and 20 (0.1%) with both. By the end of follow-up, a total of 109 newly arising HCC cases were diagnosed (71 men, 38 women), of which 87 (79.8%) had evidence of viral etiology. Alanine aminotransferase (ALT) was concentration-dependently associated with an increased risk of HCC in both virus-positive and virus-negative participants. Compared with virus-negative participants with ALT levels of less than 30IU/I, a significant increase in the risk of HCC was observed in virus-negative participants with an ALT level greater than 30IU/I, and in virus-positive participants with an ALT less than 30IU/I, 30-69IU/I, and ≥ 70IU/I [Hazard ratio (95% confidence interval): 9.4 (3.9-22.3), 15.2 (6.1-37.6), 180.5 (89.4-364.2), 454.2 (221.5-931.2), respectively; P for trend <0.001]. In conclusion, our findings suggest that elevated ALT levels are strongly associated with the incidence of HCC regardless of hepatitis virus positivity. This finding indicates that ALT level is a good independent determinant of the need for intervention. Clinical application of these findings may help decrease HCC-associated mortality in hepatitis virusendemic regions. European Journal of Cancer Prevention 18:26-32 © 2009 Wolters Kluwer Health.
  • Vegetable, fruit and antioxidant nutrient consumption and subsequent risk of hepatocellular carcinoma: A prospective cohort study in Japan, N. Kurahashi, M. Inoue, M. Iwasaki, Y. Tanaka, M. Mizokami, S. Tsugane, British Journal of Cancer, 100, 181 - 184,   2009年01月13日, In a population-based prospective study of 19 998 Japanese individuals, consumption of vegetables, green-yellow and green leafy vegetables was inversely associated with the risk of hepatocellular carcinoma (101 cases), with multivariable hazard ratios for the highest vs lowest tertile of 0.61 (95% confidence interval (CI)=0.36-1.03, Ptrend=0.07), 0.65 (95% CI=0.39-1.08, Ptrend=0.06) and 0.59 (95% CI=0.35-1.01, Ptrend=0.04), respectively. © 2009 Cancer Research UK.
  • Independent risk factors and predictive score for the development of hepatocellular carcinoma in chronic hepatitis B, Man Fung Yuen, Yasuhito Tanaka, Daniel Yee Tak Fong, James Fung, Danny Ka Ho Wong, John Chi Hang Yuen, David Yiu Kuen But, Annie On On Chan, Benjamin Chun Yu Wong, Masashi Mizokami, Ching Lung Lai, Journal of Hepatology, 50, 80 - 88,   2009年01月01日, Background/Aims: To determine whether gender, age, hepatitis B virus genotype, core promoter and precore mutations, HBeAg/ anti-HBe status, HBV DNA, ALT levels and cirrhosis on presentation were independent risk factors and derive a novel risk score for the development of HCC. Methods: CHB patients (820) were followed up (mean duration 76.8 months) for the occurrence of HCC. Results: The 5- and 10-year prevalence of HCC were 4.4% and 6.3%, respectively. Cox regression analysis showed that male gender (p = 0.025, RR 2.98), increasing age (p < 0.001, RR 1.07), higher HBV DNA levels (p = 0.02, RR 1.28), core promoter mutations (p = 0.007, RR 3.66), and presence of cirrhosis (p < 0.001, RR 7.31) were independent risks for the development of HCC. A risk score was derived and validated with sensitivity > 84% and specificity > 76% to predict the 5- and 10- year risks for the development of HCC. The AUC for the 5- and 10-year prediction were 0.88 and 0.89, respectively. Conclusions: The risk score, based on age, gender, HBV DNA levels, core promoter mutations and cirrhosis, can estimate the chance of development of HCC in 5 and 10 years after presentation. It can be used to identify high-risk CHB patients for treatment and screening of HCC. © 2008 European Association for the Study of the Liver.
  • Evaluation of hepatitis B virus genotyping EIA kit, Yasuhito Tanaka, Fuminaka Sugauchi, Kentaro Matsuuraa, Hatsue Naganuma, Kanako Tatematsu, Kazumi Takagi, Kumiko Hiramatsu, Satomi Kani, Takaaki Gotoh, Yukio Wakimoto, Masashi Mizokami, Rinsho byori. The Japanese journal of clinical pathology, 57, 42 - 47,   2009年01月01日, Clinical significance of Hepatitis B virus(HBV) genotyping is increasingly recognized. The aim of this study was to evaluate reproducibility, accuracy, and sensitivity of an enzyme immunoassay (EIA) based HBV genotyping kit, which designed to discriminate between genotypes to A, B, C, or D by detecting genotype-specific epitopes in PreS2 region. Using the four genotypes panels, the EIA demonstrated complete inter and intra-assay genotyping reproducibility. Serum specimens had stable results after 8 days at 4 degrees C, or 10 cycles of freezing-thawing. In 91 samples that have been genotyped by DNA sequencing, 87(95.6%) were in complete accordance with EIA genotyping. Of examined 344 HBsAg-positive serum specimens, genotypes A, B, C and D were determined in 26 (7.6%), 62 (18.0%), 228 (66.3%), and 9 (2.6%) cases, respectively. Of 19 (5.5%) specimens unclassified by the EIA, 13 were found to have low titer of HBsAg concentration (< 3 IU/ml), and the other 5 had amino acid mutations or deletions within targeted PreS2 epitopes. The EIA allowed genotyping even in HBV DNA negative samples (96.2%). In conclusion, HBV genotype EIA is reliable, sensitive and easy assay for HBV genotyping. The assay would be useful for clinical use.
  • Direct Cytopathic Effects of Particular Hepatitis B Virus Genotypes in Severe Combined Immunodeficiency Transgenic With Urokinase-Type Plasminogen Activator Mouse With Human Hepatocytes, Masaya Sugiyama, Yasuhito Tanaka, Fuat Kurbanov, Isao Maruyama, Takashi Shimada, Satoru Takahashi, Tomoyuki Shirai, Keisuke Hino, Isao Sakaida, Masashi Mizokami, Gastroenterology, 136,   2009年01月, Background & Aims: Little is known about the direct cytopathic effect of hepatitis B virus (HBV) and its association with particular viral genotypes or genetic mutations. We investigate HBV genotype-related differences in viral replication, antigen expression, and histopathology in severe combined immunodeficiency transgenic with urokinase-type plasminogen activator mice harboring human hepatocytes. Methods: Mice were inoculated with wild-type of different genotype strains (3 for each HBV/A2, B1, and C2) recovered from preinfected-mice sera or patient sera. Results: Histologic analysis of mice infected with HBV/C2 for 22-25 weeks showed abundant ground-glass appearance of the hepatocytes and fibrosis in the humanized part of the murine liver owing to the activation of hepatic stellate cells mediated by oxidative stress through transforming growth factor-β1 signaling, whereas neither was observed with HBV/A2 and B1. The HBV-DNA level in sera was the highest in mice infected with HBV/C2 compared with those with HBV/A2 and HBV/B1 (109, 107, and 104log copies/mL, respectively, P < .05) during 6-8 weeks postinoculation. HB core-related antigen excretion had a similar trend among the genotypes, whereas secretion of HB surface antigen was more pronounced for HBV/A2 followed by HBV/C2 and much less for HBV/B1. Introduction of precore stop-codon mutation in the HBV/B1 caused a significant increase in viral replication, antigen expression, and a histopathologic picture similar to HBV/C2. Conclusions: By using a humanized in vivo model, we show that different HBV genotypes and even particular mutations resulted in different virologic and histopathologic outcomes of infection, indicating that particular genetic variants of HBV may be directly cytopathic in immunosuppressive conditions. © 2009 AGA Institute.
  • Genome-wide association of IL28B with response to pegylated interferon-alpha and ribavirin therapy for chronic hepatitis C., 41(10),   2009年
  • Transition and problems of hepatitis B virus genotypes among patients with acute and chronic infection in Japan, Kentaro Matsuura, Yasuhito Tanaka, Masashi Mizokami, Acta Hepatologica Japonica, 49, 549 - 552,   2008年12月
  • Two simultaneous hepatitis B virus epidemics among injecting drug users and men who have sex with men in Buenos Aires, Argentina: Characterization of the first D/A recombinant from the American continent, J. Trinks, M. L. Cuestas, Y. Tanaka, V. L. Mathet, M. L. Minassian, C. W. Rivero, J. A. Benetucci, E. D. Gímenez, M. Segura, M. C. Bobillo, D. Corach, P. D. Ghiringhelli, D. O. Sánchez, M. M. Ávila, L. A.M. Peralta, F. Kurbanov, M. C. Weissenbacher, P. Simmonds, M. Mizokami, J. R. Oubiña, Journal of Viral Hepatitis, 15, 827 - 838,   2008年11月, Previous studies have revealed that hepatitis B virus (HBV)/D and HBV/F predominate among blood donors from Buenos Aires, Argentina. In the present study, blood samples from two high-risk groups were analysed: 160 corresponding to street- and hospital-recruited injecting drug users [81.2% showing the 'anti-hepatitis B core antigen (anti-HBc) only' serological pattern] and 20 to hepatitis B surface antigen (HBsAg)+/anti-HBc+men who have sex with men. HBV genotypes were assigned by polymerase chain reaction amplification followed by restriction fragment length polymorphism and confirmed by nucleotide sequencing of two different coding regions. HBV DNA was detected in 27 injecting drug users (16.9%, occult infection prevalence: 7.7%), and 14 men who have sex with men (70%). HBV/A prevailed among injecting drug users (81.8%) while HBV/F was predominant among men who have sex with men (57.1%). The high predominance of HBV/A among injecting drug users is in sharp contrast to its low prevalence among blood donors (P = 0.0006) and men who have sex with men (P = 0.0137). Interestingly, all HBV/A S gene sequences obtained from street-recruited injecting drug users encoded the rare serotype ayw1 and failed to cluster within any of the known A subgenotypes. Moreover, one of the HBV strains from a hospital-recruited injecting drug user was fully sequenced and found to be the first completely characterized D/A recombinant genome from the American continent. Data suggest that two simultaneous and independent HBV epidemics took place in Buenos Aires: one spreading among injecting drug users and another one sexually transmitted among the homosexual and heterosexual population. © 2008 The Authors.
  • Molecular epidemiology and interferon susceptibility of the natural recombinant hepatitis C virus strain RF1_2k/1b, Fuat Kurbanov, Yasuhito Tanaka, Elena Chub, Isao Maruyama, Aziza Azlarova, Hiroshi Kamitsukasa, Tomoyoshi Ohno, Stefania Bonetto, Isabelle Moreau, Liam J. Fanning, Florence Legrand-Abravane, Jaques Izopet, Nikolai Naoumov, Takashi Shimada, Sergei Netesov, Masashi Mizokami, Journal of Infectious Diseases, 198, 1448 - 1456,   2008年11月, Background. Hepatitis C virus (HCV) genotype is an important determinant of virological response to antiviral therapies. Currently, there are no data available on the molecular epidemiology and interferon susceptibility of the natural intergenotypic recombinant RF1_2k/1b (RF1) strain. Methods. Genotyping and RF1-PCR screening were performed on samples from 604 HCVRNA-positive individuals from 7 countries. uPA/SCID mice carrying human hepatocytes (chimeric mice) were infected with the RF1_2k/1b strain, and the susceptibility of the strain to interferon and ribavirin was compared with the susceptibilities of 2 different strains of genotype B, used as references. Results. Six new RF1 cases were identified in this study; 5 (2%) of 281 in Russia and 1 (1%) of 90 in Uzbekistan. Phylogenetic analyses based on Core/E1 and NS5b indicated that all RF1 representatives share a common evolutionary ancestor. Infection with RF1 was established in chimeric mice. Reduction of RF1 viral load was observed in response to 3 injections of 3 μg/kg pegylated-interferon alpha-2a alone or in combination with 50 mg/kg of ribavirin (0.5 or 1.4 log-copies/mL). Conclusions. All identified RF1-type strains appear to be introduced from a single source, suggesting that intergenotypic recombination in HCV is sporadic and not associated with cocirculation of different genotypes in a population. The RF1 strain in this study was responsive to interferon in vivo. © 2008 by the Infectious Diseases Society of America. All rights reserved.
  • When should "I" consider a new hepatitis B virus genotype?, Fuat Kurbanov, Yasuhito Tanaka, Anna Kramvis, Peter Simmonds, Masashi Mizokami, Journal of Virology, 82, 8241 - 8242,   2008年08月01日
  • Characteristics of hepatitis B virus genotype G coinfected with genotype H in chimeric mice carrying human hepatocytes, Yasuhito Tanaka, Laura V. Sanchez, Masaya Sugiyama, Tomoyuki Sakamoto, Fuat Kurbanov, Kanako Tatematsu, Sonia Roman, Satoru Takahashi, Tomoyuki Shirai, Arturo Panduro, Masashi Mizokami, Virology, 376, 408 - 415,   2008年07月05日, Accumulated evidence indicated that hepatitis B virus genotype G (HBV/G) is present exclusively in coinfection with other HBV genotypes. In Mexico, HBV/G from 6 men who had sex with men were coinfected with HBV/H. Phylogenetically complete genomes of the 6 Mexican HBV/G strains were closely related to previous ones from the US/Europe. Using uPA/SCID mice with human hepatocytes, monoinfection with HBV/G did not result in detectable HBV DNA in serum, whereas superinfection with HBV/G at week 10 inoculated HBV/H when HBV/H DNA was elevated to > 107copies/mL has enhanced the replication of HBV/G. The HBV/G was enhanced in another 3 inoculated with a serum passage containing HBV/G with a trace of HBV/H. Coinfection of mice with HBV/G and H induced fibrosis in the liver. In conclusion, the replication of HBV/G can be enhanced remarkably when it is coinfected with HBV/H. Coinfection with HBV/G may be directly cytopathic in immunosuppressive conditions. © 2008 Elsevier Inc. All rights reserved.
  • What can be revealed by extending the sensitivity of HBsAg detection to below the present limit?, Hitoshi Togashi, Chika Hashimoto, Junji Yokozawa, Akihiko Suzuki, Kazuhiko Sugahara, Takafumi Saito, Ichiro Yamaguchi, Hala Badawi, Norikazu Kainuma, Masaaki Aoyama, Hiroaki Ohya, Takao Akatsuka, Yasuhito Tanaka, Masashi Mizokami, Sumio Kawata, Journal of Hepatology, 49, 17 - 24,   2008年07月01日, Background/Aims: We investigated what can be revealed by extending the sensitivity of HBsAg detection to below the present limit. Methods: We examined the sensitivity of this immunoassay in comparison with real-time PCR detection of HBV DNA using serially diluted sera from HBV carriers. Low HBsAg was measured in 210 healthy volunteers and 368 patients with non-B chronic liver diseases who were negative for HBsAg by a standard EIA method. Results: The radical immunoassay was able to detect HBsAg at a concentration of 0.025 ng/ml. Low HBsAg was positive in 6 of 210 normal volunteers (2.86%), 5 of 65 non-B, non-C cirrhosis patients (7.69%), 6 of 62 non-B, non-C hepatocellular carcinoma patients (9.68%: p = 0.04 vs. volunteers), 12 of 134 chronic hepatitis C patients (8.96%: p < 0.02 vs. volunteers), and 11 of 107 hepatocellular carcinoma patients complicated by chronic hepatitis C (10.28%: p < 0.008 vs. volunteers). Although no HBV DNA was positive in healthy volunteers, 9 patients with non-B chronic liver diseases were positive for HBV DNA by real-time PCR analysis. Conclusions: Increasing the sensitivity of HBsAg detection to below the present limit has revealed that infection with HBV, including occult HBV, is far more endemic than suspected previously. © 2008 European Association for the Study of the Liver.
  • Suppressive effect of oral administration of branched-chain amino acid granules on oxidative stress and inflammation in HCV-positive patients with liver cirrhosis, Tomoyoshi Ohno, Yasuhito Tanaka, Fuminaka Sugauchi, Etsuro Orito, Izumi Hasegawa, Haruhiko Nukaya, Atsunaga Kato, Seijiro Matunaga, Masayuki Endo, Yoshito Tanaka, Kenji Sakakibara, Masashi Mizokami, Hepatology Research, 38, 683 - 688,   2008年07月, Aim: In chronic hepatitis C virus (HCV) infection, it is thought that both chronic persistent inflammation and oxidative stress contribute to the development of hepatocellular carcinoma (HCC), and it has been reported that long-term oral supplementation with branched-chain amino acid (BCAA) granules could inhibit liver carcinogenesis. However, the extent of the involvement of these factors remains obscure. Methods: To clarify the involvement of inflammation and oxidative stress in the inhibition of liver carcinogenesis, we evaluated the effect of oral administration of BCAA granules on oxidative stress and inflammation in HCV-positive patients with liver cirrhosis. Results: Twenty-seven patients were enrolled in the study: 18 of the patients were treated with BCAA granules (administered group) and nine were observed without BCAA granules (non-administered group). In the non-administered group, the production of oxidative stress, as indicated by urine 8-hydroxydeoxyguanosine (8-OHdG) and 15-F2t-Isoprostane (8-IsoPs), significantly increased with time, while in the administered group the levels of ferritin and 8-OHdG decreased significantly. Comparison of the two groups demonstrated that highly sensitive CRP, ferritin, 8-OHdG and 8-IsoPs were significantly reduced by taking BCAA granules. The time-course analysis showed that ferritin and highly sensitive CRP seemed to decrease first, followed by a decrease of 8-OHdG and 8-IsoPs. Conclusion: These findings indicated that the administration of BCAA granules influenced microinflammation and the metabolism of iron in HCV-positive patients with liver cirrhosis, and subsequently seemed to reduce the production of oxidative stress, possibly leading to a decrease in the occurrence of HCC. © 2008 The Japan Society of Hepatology.
  • Detection of hepatitis C virus natural recombinant RF1_2k/1b strain among intravenous drug users in Uzbekistan, Fuat Kurbanov, Yasuhito Tanaka, Dildora Avazova, Anis Khan, Fuminaka Sugauchi, Nataliya Kan, Dinara Kurbanova-khudayberganova, Aziza Khikmatullaeva, Erkin Musabaev, Masashi Mizokami, Hepatology Research, 38, 457 - 464,   2008年05月, Aim: A series of recent studies have indicated the presence of natural intergenotypic recombinant hepatitis C virus (HCV) strains in distinct parts of the world. The majority of the current genotyping methods are based on analysis of either 5′UTR, structural (Core/E1/E2) or non-structural (NS5B) genomic regions of the virus. Methods: In the present study, based on both structural and non-structural regions, we determined the genotype of 55 anti-HCV-positive intravenous drug users (IDUs) in Uzbekistan. Results: HCV-3a (67.3%) was the most prevalent genotype in this cohort, followed by HCV-1b (27.3%). A discrepancy in results was observed between structural and non-structural regions in one case (1.8%). Phylogenetically this strain was related to the previously reported RF1_2k/1b variant. Based on accumulated sequences, specific primers were designed for polymerase chain reaction (PCR) spanning the tentative intergenotypic crossover point of RF1_2k/1b. The sensitivity and specificity of the method were assessed using generated template clones of HCV-1b, 2a, 2 k and RF1_2k/1b. The method was applied to 55 cases in the present study and only one case showed a positive result, indicating that in these individuals, the variant is not present as a minor quasispecies clone. Conclusion: In conclusion, the finding of RF1_2k/1bin Central Asia indicates that the variant has wide geographic distribution. The PCR-based screening method developed in this study should be useful in further epidemiological and clinical studies on the recombination phenomenon in HCV. © 2007 The Japan Society of Hepatology.
  • Development and public release of a comprehensive hepatitis virus database, Tadasu Shin-I., Yasuhito Tanaka, Yoshio Tateno, Masashi Mizokami, Hepatology Research, 38, 234 - 243,   2008年03月01日, Aim: Currently, approximately 44000 hepatitis C virus (HCV), 11000 hepatitis B virus (HBV), and 1600 hepatitis E virus (HEV) sequences are available at the International Nucleotide Sequence Database Collaboration (INSDC, previously known as DDBJ/EMBL/GenBank), and the number of these virus sequences is growing rapidly. However, since INDSC is not specialized to hepatitis viruses, it is difficult to retrieve information of virological or clinical interests from it. Thus, it is quite worthwhile to construct a specialized database for the hepatitis virus sequences and to make it accessible to researchers worldwide. Methods: We developed a WWW-based database hepatitis virus database (HVDB), which contains all the HCV, HBV, and HEV sequences available at INSDC. In the HVDB, all piece sequences obtained from INSDC are arranged to the genomesequence of each virus. Also given in the database are the phylogenetic relationships of each locus on the genome among variants for each virus. Results: Users of the database can easily retrieve entries (sequences with annotations) of the specific genotype by referring to the phylogenetic relationships or those of specific loci by referring to the genome map information. HVDB provides users with a tool for phylogenetic analysis that can be used in combination with the data retrieval tools. Conclusion: The latest release is publicly accessible at the HVDB website: http://s2as02.genes.nig.ac.jp. © 2007 The Japan Society of Hepatology.
  • Hepatitis B caused by a hepatitis B surface antigen escape mutant, Eiji Kajiwara, Yasuhito Tanaka, Tomoko Ohashi, Kotarou Uchimura, Seizo Sadoshima, Mitsuru Kinjo, Masashi Mizokami, Journal of Gastroenterology, 43, 243 - 247,   2008年03月01日, Amino acid substitutions within the S gene involving the major antigenic a determinant of the hepatitis B virus (HBV) surface antigen (HBsAg) have been detected in cases of failure of immunization against the virus. Our report showed development of clinical hepatitis in presence of antibody to HBsAg in a healthy individual. A single amino acid substitution (G145R) within the a determinant of the HBsAg was determined by sequencing of the isolated HBV strain. Lamivudine treatment efficiently cleared the peripheral HBV DNA, HBsAg, and hepatitis B e antigen. In conclusion, the immune escape mutant in the S gene can cause hepatitis despite pre-existing naturally acquired immunity. © Springer Japan 2008.
  • Transmission of hepatitis B virus (HBV) genotypes among Japanese immigrants and natives in Bolivia, Anis Khan, Yasuhito Tanaka, Hidetsugu Saito, Hirotoshi Ebinuma, Hitoshi Sekiguchi, Hideaki Iwama, Go Wakabayashi, Toshio Kamiya, Fuat Kurbanov, Abeer Elkady, Masashi Mizokami, Virus Research, 132, 174 - 180,   2008年03月01日, Hepatitis B virus genotypes are associated with transmission pattern, virological and clinical features and outcome of the chronic infection course. HBV genotypes other than Genotype F (HBV/F) are considered a reflection of human migration into South America. A total of 487 individuals in Bolivia, including Japanese immigrants (n = 287) and natives (n = 200), were screened for HBV serological markers. Overall 22/487 (4.5%) of the subjects were positive for HBsAg, 217/487 (44.5%) for anti-HBc and 162/487 (33.3%) for anti-HBs. Genotypes were determinable in 22 cases by EIA, followed by sequencing and phylogenetic analysis in 17 cases. HBV genotype distribution in Japanese and Bolivians was HBV/F (4 and 8); HBV/C (5 and 3); and HBV/B (1 and 1), respectively. Phylogenetic analyses of nine complete and eight partial (HBsAg/pre-core/core region) genomes, revealed that HBV/F strains cluster with previously reported regional strains, whereas HBV/B and HBV/C strains belonged to Asian subgenotype B2 (Ba) and C2 (Ce), respectively. Japanese immigrants might have introduced HBV/B and HBV/C to natives in Bolivia, conversely, exposed to the indigenous HBV/F. This report provides evidence of an inter-communities transmission of HBV revealed by its genotypes. Further study is required to investigate peculiarities of the genotypes in different ethnic groups in Bolivia. © 2007 Elsevier B.V. All rights reserved.
  • Epidemiological and clinical evaluation of hepatitis B, hepatitis C, and delta hepatitis viruses in Tajikistan, Anis Khan, Fuat Kurbanov, Yasuhito Tanaka, Abeer Elkady, Masaya Sugiyama, Abdusamad Dustov, Masashi Mizokami, Journal of Medical Virology, 80, 268 - 276,   2008年02月, The implication of genotypes is recognized increasingly in the clinical course of hepatitis B virus (HBV) and in response to anti-viral drugs of hepatitis C virus (HCV). Genotypic prevalence of both etiological agents varies geographically and no data are available for Tajikistan. To investigate the epidemiology and clinical significance of HBV and HCV genotypes in chronic hepatitis (group 1) and liver cirrhosis/hepatocellular carcinoma (HCC) (group 2) patients in Tajikistan, 124 patients with chronic liver disease (group 1 = 84 and group 2 = 40) were enrolled. Genotypes of HBV, HCV, and delta hepatitis virus (HDV) were determined by sequencing. The overall prevalence of anti-HCV, HCV core antigen (HCVcAg) and HBsAg was 46% (57/124) and 41.1% (51/124), respectively. Coinfection of HCV/HBV, HBV/HDV, and HCV/HBV/HDV was found in 4.8% (6/124), 11.2% (12/124), and 0.8% (1/124) of cases, respectively. HDV genotype 1 was found in 19.6% (10/51) of HBsAg-positive patients. The HBV/HDV coinfection was relatively high in group 2 compared to group 1 (15% vs. 7.1%). HCV/1b detected in 84.6% (44/52) of HCV RNA-positive patients, followed by 3a (7.6%), 2a (5.7%), and 2c (1.9%). HBV/D was detected in 94.1% (48/51) of HBsAg-positive patients, followed by HBV/A [5.8% (3/51)]. T1762/A1764 double mutation was associated with liver cirrhosis/HCC in HBV-infected patients (P = 0.0004). This is the first study on the molecular epidemiology of hepatitis viruses among chronic liver diseases patients in Tajikistan. Among HBV-infected patients, the T1762/A1764 mutation was associated with liver cirrhosis/HCC. © 2007 Wiley-Liss, Inc.
  • Hepatitis B virus transmission pattern and vaccination efficiency in Uzbekistan, Dildora Avazova, Fuat Kurbanov, Yasuhito Tanaka, Masaya Sugiyama, Ivan Radchenko, Dilmurod Ruziev, Erkin Musabaev, Masashi Mizokami, Journal of Medical Virology, 80, 217 - 224,   2008年02月, A national program of universal vaccination for the prevention of chronic hepatitis B virus (HBV) infection was launched in Uzbekistan since 1998. To evaluate the 6 years' outcome of the program, 567 children were enrolled in the study. Among those enrolled, 333 had immunized with adw2 type based Engerix-B (Glaxo Smith Kline Beechem, Rixensart, Belgium) and 48 with adr type based Hepavax-Gene (Green Cross Vaccine Corporation, Korea). A cohort of 186 children born before the immunization program, was also included in the study. When 45 vaccinated children were compared to age/sex-matched 45 unvaccinated children, the sero-prevalence of HBsAg was 0 versus 11% (P = 0.56), and of anti-HBc was 0% versus 44% (P < 0.0001), respectively. Loss of anti-HBs was observed in 18.4% after 5 years. Among 13 HBsAg carriers found in this study, genotype HBV/D was found in 69%, HBV/A in 23% (all in unvaccinated group) and HBV/C in 8% (in vaccinated group). No significant differences were observed in this study between groups which received different vaccine formulation. Phylogenetic analysis of the HBV isolates obtained from family members of the HBsAg-positive children, revealed evidence suggesting that transmission in the vaccinated group was exclusively perinatal, whereas in the unvaccinated group horizontal transmission pattern predominated. In conclusion, HBV universal vaccination is efficient in Uzbekistan irrespective of the vaccine formulation used, because the horizontal transmission pattern predominates currently in this endemic region. © 2007 Wiley-Liss, Inc.
  • Risk for hepatocellular carcinoma with respect to hepatitis B virus genotypes B/C, specific mutations of enhancer II/core promoter/precore regions and HBV DNA levels, M. F. Yuen, Y. Tanaka, N. Shinkai, R. T. Poon, D. Yiu Kuen But, D. Y.T. Fong, J. Fung, D. Ka Ho Wong, J. Chi Hang Yuen, M. Mizokami, C. L. Lai, Gut, 57, 98 - 102,   2008年01月, Background/aim: To examine the risks for hepatocellular carcinoma (HCC) with respect to hepatitis B virus (HBV) genotypes, specific viral mutations (MT), serum HBV DNA levels, and cirrhosis. Methods: HBV genotypes, 1653/1753/core promoter (CP)/precore MT and HBV DNA levels were determined in 248 HBV patients with HCC and 248 HBV controls. Results: Genotype C, CP-MT, T1653, HBV DNA levels ≥4 log10copies/ml and cirrhosis had a higher risk for HCC compared to patients with genotype B (p = 0.001, OR 1.9), CP wild-type (WT) (p<0.001, OR 4.1), C1653 (p = 0.028, OR 2.4), HBV DNA <4 log10copies/ml (p = 0.003, OR 2.1) and without cirrhosis (p<0.001, OR 4.0) respectively. Multivariate analysis showed that CP-MT, T1653, HBV DNA ≥4 log10copies/ml and cirrhosis were independent factors for HCC (all p<0.05). A receiver operating characteristics curve showed no cut-off HBV DNA level associated with minimal chance of HCC. Patients with CP-MT and cirrhosis had a 22.2-fold increased risk of HCC compared to patients with CP-WT and without cirrhosis. Patients with CP-MT and HBV DNA levels ≥4 log10copies/ml had a 7.2-fold increased risk of HCC compared to patients with CP-WT and HBV DNA levels <4 log10copies/ml. Patients with CP-MT and T1653 had a 9.9-fold increased risk of HCC compared to patients with wild-type for both regions. Conclusions: CP-MT, T1653, HBV DNA levels ≥4 log10copies/ml and cirrhosis are independent factors for development of HCC. The risks increased substantially in patients having these factors in combination.
  • Virological and clinical implication of core promoter C1752/V1753 and T1764/G1766 mutations in hepatitis B virus genotype D infection in Mongolia, Abeer Elkady, Yasuhito Tanaka, Fuat Kurbanov, Tsendsuren Oynsuren, Masashi Mizokami, Journal of Gastroenterology and Hepatology (Australia), 23, 474 - 481,   2008年01月, Background and Aim: The aim of the present study was to reveal virological and clinical features of hepatitis B virus (HBV) genotype D infection. Methods: One hundred and twenty-two Mongolian chronic liver disease (CLD) patients infected with HBV were subjected for serological HBV-markers screening and HBV-enzyme immunoassay (EIA) genotyping. Nucleotide sequences were analyzed for 48 HBV/D strains (23 isolated from hepatocellular carcinoma (HCC) and 25 from CLD patients). Results: Prevalence of hepatitis B e antigen (HBeAg) positivity was low (25.9%) in young patients (≤30 years old) indicating early HBeAg seroclearance in HBV/D carriers. The T1764/G1766 double mutation was the most common basal core promoter (BCP) mutation (29.2%) and was frequent in HBeAg-negative patients (39.3%). Patients harboring T1764/G1766 mutants exhibited lower HBV-DNA and HBV core antigen (HBcAg) levels than those with wild-type BCP strains (P = 0.024, 0.049, respectively). C1752 and/or V (not T) 1753 mutation was significantly prevalent in HCC patients (HCC vs CLD; 52.2% vs 20%, P = 0.033). T1762/A1764 mutation was detected in 75.0% of HCC patients with high viral load (≥5 log copies/mL). Precore stop codon mutation A1896 was detected in (70.8%) of HBV/D-infected patients. Conclusions: In Mongolians infected with HBV/D, C1752 and/or V1753 mutation was associated with HCC. © 2008 The Authors.
  • Japanese case of hepatitis B virus genotypes C/D hybrid, Yoshihiko Yano, Bui X. Truong, Yasushi Seo, Hirotaka Kato, Akira Miki, Yasuhito Tanaka, Masashi Mizokami, Ayako Kagawa, Hiroyuki Miyazaki, Masato Kasuga, Takeshi Azuma, Yoshitake Hayashi, Hepatology Research, 37, 1095 - 1099,   2007年12月01日, Hepatitis B virus (HBV) is classified into eight genotypes based on complete genome sequence. Each genotype is related to geographic distribution and race. In Japan, most of the genotypes are B and C. In the present study, we report the first Japanese strain of HBV having a recombination between genotypes C and D. A 30-year-old woman was admitted to Kobe Medical Center because of liver dysfunction. She was diagnosed with spontaneous reactivation of chronic hepatitis B. She had no history of blood transfusion and her parents were negative for HBV. The phylogenetic analysis based on the complete genome sequences revealed that this strain was classified into genotype C, whereas the analysis based on S gene sequence showed that this strain was genotype D. By using a SimPlot program, this strain was confirmed as a recombinant strain between genotypes C and D. Compared with previous recombinant strains in China, the breakpoint was the same and the difference was only 0.8% of the complete genome sequence. It was unclear whether or not this strain was transmitted from China, but the recombinant strains and intergenotypes of HBV have already existed in Japan. © 2007 The Japan Society of Hepatology.
  • Hepatitis B virus core-related antigens as markers for monitoring chronic hepatitis B infection, Danny Ka Ho Wong, Yasuhito Tanaka, Ching Lung Lai, Masashi Mizokami, James Fung, Man Fung Yuen, Journal of Clinical Microbiology, 45, 3942 - 3947,   2007年12月, A sensitive chemiluminescence enzyme immunoassay has been developed for hepatitis B virus (HBV) core-related antigen (HBcrAg) detection. We aimed to investigate the usefulness of HBcrAg measurement for monitoring chronic hepatitis B disease. HBcrAg levels were measured by a chemiluminescence enzyme immunoassay in 54 untreated patients and 39 patients treated with either entecavir or lamivudine. The HBcrAg concentration correlated positively with the levels of serum HBV DNA (r = 0.820), intrahepatic total HBV DNA (r = 0.700), and covalently closed circular DNA (cccDNA) (r = 0.664; for all, P values were <0.001). A higher HBcrAg concentration was associated with a greater proportion of hepatitis B core antigen immunostaining. Although the differences were not statistically significant, patients with higher Knodell necroinflammation and fibrosis scores tended to have higher serum HBcrAg concentration levels. In the treated patients, the logarithmic reduction in HBcrAg at week 48 correlated positively with the logarithmic reduction of serum HBV DNA, intrahepatic total HBV DNA, and cccDNA. Of the 31 patients with undetectable serum HBV DNA (<300 copies/ml) at the end of treatment, 20 (65%) still had detectable HBcrAg. A greater reduction in posttreatment HBcrAg concentration was associated with histological improvement and a decrease in hepatitis B core antigen immunostaining. HBcrAg concentrations of <40,000 kU/ml at baseline and <200 kU/ml at week 24 were associated with a higher chance of having undetectable HBV DNA at week 48. In conclusion, serum HBcrAg levels correlated with HBV virological markers and reflected the chronic hepatitis B disease activity in the liver. Copyright © 2007, American Society for Microbiology. All Rights Reserved.
  • Alterations of DNA methylation and histone modifications contribute to gene silencing in hepatocellular carcinomas, Yutaka Kondo, Lanlan Shen, Seiji Suzuki, Tsuyoshi Kurokawa, Kazuo Masuko, Yasuhito Tanaka, Hideaki Kato, Yoshiki Mizuno, Masamichi Yokoe, Fuminaka Sugauchi, Noboru Hirashima, Etsuro Orito, Hirotaka Osada, Ryuzo Ueda, Yi Guo, Xinli Chen, Jean Pierre J. Issa, Yoshitaka Sekido, Hepatology Research, 37, 974 - 983,   2007年11月01日, Aim: The aim of the present study was to examine DNA methylation and histone modification changes in hepatocellular carcinomas (HCC). Methods: DNA methylation in the P16, RASSF1a, progesterone receptor (PGR) and estrogen receptor α (ER α) promoters was determined by quantitative bisulfite-pyrosequencing technique in HCC patients. Histone H3-lysine (K) 4, H3-K9 and H3-K27 modifications in all these four genes were examined by chromatin immunoprecipitation (ChIP) assay in HCC cell lines. Expression of two DNA methyltransferases (DNMT1 and DNMT3b) and three histone methyltransferases (SUV39H1, G9a and EZH2) in HCC patients was measured by real-time polymerase chain reaction. Results: Aberrant DNA methylation was detected in all the HCC. Patients with DNA methylation in the RASSF1a, PGR and ER α promoters in cancers also had substantial DNA methylation in their non-cancerous liver tissues, whereas DNA methylation in the P16 promoter was cancer specific. Epigenetic states in HCC cell lines showed that silencing of P16 and RASSF1a depended on DNA methylation and histone H3-K9 methylation. However, silencing of the PGR and ER α genes was more closely related to H3-K27 methylation rather than DNA methylation. Consistent with the alteration of histone status, higher expression of G9a and EZH2 was found in HCC than in non-cancerous liver tissues (P < 0.01). Conclusion: These data suggest that multiple epigenetic silencing mechanisms are inappropriately active in HCC cells. © 2007 The Japan Society of Hepatology.
  • Evaluation of anti-hepatitis E virus (HEV) immunoglobulin A in a serological screening for HEV infection, Abeer Elkady, Yasuhito Tanaka, Fuat Kurbanov, Noboru Hirashima, Masaya Sugiyama, Anis Khan, Hideaki Kato, Akihiko Okumura, Masashi Mizokami, Journal of Gastroenterology, 42, 911 - 917,   2007年11月01日, Background: Several formulations of serological diagnostic kits were developed recently in Japan for detecting hepatitis E virus (HEV) infection. The present study was conducted to evaluate a novel anti-HEV serological kit based on detection of class A immunoglobulin antibody (anti-HEV IgA). Methods: Serum samples from 81 acute hepatitis (AH) and 112 chronic hepatitis (CH) patients were tested for anti-HEV IgG, anti-HEV IgM, and anti-HEV IgA by enzyme immunoassay, and HEV RNA was detected by reverse transcription-polymerase chain reaction. Results: Eight of 81 (9.9%) AH patients were positive for anti-HEV IgG; 6/81 (7.4%) were positive for anti-HEV IgM; and 3/81 (3.7%) were positive for anti-HEV IgA. HEV RNA was detected only in two patients, and both were positive for anti-HEV IgA and negative for hepatitis A, B, and C virus markers. Of 112 CH patients, reactivity to anti-HEV IgM and anti-HEV IgG was found in two and four patients, respectively. None of these six patients was positive for anti-HEV IgA or HEV RNA. For these six CH patients, serial serum samples stored during the clinical follow-up (1994-2003) were further subjected to anti-HEV IgG, IgM, IgA, and HEV RNA examinations. None of the examined stored samples was reactive for anti-HEV IgA or HEV RNA despite reactivity to anti-HEV IgM and IgG. Conclusions: Serological examination for anti-HEV IgA together with IgM and IgG allows sensitive and specific determination of acute or past infection with HEV. Although its prevalence is low, HEV infection must be investigated in acute hepatitis patients even in nonendemic HEV countries. © Springer-Verlag Tokyo 2007.
  • Predicting sustained virological response in chronic hepatitis C patients treated with pegylated interferon and ribavirin using a novel highly sensitive Real-time detection PCR assay, Kentaro Matsuura, Yasuhito Tanaka, Kazumi Takagi, Kumiko Hiramatsu, Satomi Kani, Takaaki Gotoh, Yukio Wakimoto, Takashi Joh, Masashi Mizokami, Rinsho byori. The Japanese journal of clinical pathology, 55, 983 - 988,   2007年11月01日, The Abbott Real Time HCV assay (lower limit of detection 12 IU/ml) was developed as a highly sensitive HCV RNA quantitative assay using real-time detection PCR(RTD-PCR). We assessed whether the new assay more effectively predicts sustained virological response (SVR) than conventional PCR (PCR) in 38 chronic hepatitis patients infected with HCV genotype 1b and treated with pegylated interferon alpha2b plus ribavirin. Sixteen patients reached SVR, 10 patients relapsed, 9 patients did not respond, 3 patients discontinued treatment. Positive predictive value (PPV) for SVR of undetectable HCV RNA at W4, 8, 12 by RTD-PCR and PCR was (100% vs. 100% at W4), (100% vs. 100% at W8), (83.3% vs. 72.7% at W12). HCV RNA undetectable at W12 had a higher PPV for SVR when measured by RTD-PCR than by conventional PCR.
  • Classification of hepatitis B virus genotype B into 2 major types based on characterization of a novel subgenotype in arctic indigenous populations, Tomoyuki Sakamoto, Yasuhito Tanaka, Josephine Simonetti, Carla Osiowy, Malene L. Børresen, Anders Koch, Fuat Kurbanov, Masaya Sugiyama, Gerald Y. Minuk, Brian J. McMahon, Takashi Joh, Masashi Mizokami, Journal of Infectious Diseases, 196, 1487 - 1492,   2007年11月, Hepatitis B virus genotype B (HBV/B) has been classified into 5 subgenotypes. Except for Bj/B1 in Japan, the subgenotypes (Ba/B2-B5) have undergone recombination with HBV/C in the core promoter/precore/core genomic region. Phylogenetic analyses of complete sequences show that the Arctic strains belong to a novel subgenotype (HBV/B6) without the recombination, analogous to what is seen with Bj/B1. Comparison of 50 HBV/B6 carriers from the Arctic versus 50 Bj and 50 Ba age- and sex-matched carriers from Asia revealed that clinical characteristics of HBV/B6 carriers were similar to those of Bj/B1 carriers in Japan. The results suggest that HBV/B may be classified into nonrecombinant (Bj/B1 and B6) and recombinant (Ba/B2-B5) types. © 2007 by the Infectious Diseases Society of America. All rights reserved.
  • Comparison of complete sequences of hepatitis B virus genotype C between inactive carriers and hepatocellular carcinoma patients before and after seroconversion, Kiyoaki Ito, Yasuhito Tanaka, Michio Kato, Kei Fujiwara, Kei Fujiwara, Fuminaka Sugauchi, Tomoyuki Sakamoto, Tomoyuki Sakamoto, Noboru Shinkai, Noboru Shinkai, Etsuro Orito, Masashi Mizokami, Journal of Gastroenterology, 42, 837 - 844,   2007年10月, Background: Most patients who acquire chronic hepatitis B virus (HBV) infection by perinatal transmission become inactive carriers (IC) after hepatitis B e (HBe) antigen seroconversion, whereas some patients have persistent abnormal serum transaminase levels and develop hepatocellular carcinoma (HCC) in the anti-HBe-positive phase. The aim of this study was to investigate the HCC-related mutations of HBV. Methods: Complete sequences of HBV were examined among eight IC and eight HCC patients infected with HBV genotype C before and after seroconversion. Results: The frequency of the T1653 mutation tended to be higher among HCC patients after seroconversion (16.7% vs. 62.5%; P = 0.086). The prevalence of a basal core promoter double mutation (T1762/A1764) was high among both IC and HCC patients after seroconversion (83.3% vs. 87.5%; P = 0.825). Among the HCC patients, a pre-S deletion mutant was detected in 62.5% patients before seroconversion, and in 37.5% patients after seroconversion. The core deletion mutant was also detected in 50% of HCC patients only before seroconversion. Deletion mutants of the pre-S or core region before seroconversion were significantly associated with HCC patients (0% vs. 62.5%; P = 0.007, 0% vs. 50%; P = 0.021, respectively). Conclusions: Our data showed a significant association of pre-S and core deletion mutants before seroconversion with HCC development. The T1653 mutation after seroconversion was frequently found in HCC patients infected with HBV genotype C. These results suggest that mutations may be predictive factor for development of HCC. © Springer-Verlag Tokyo 2007.
  • Influence of hepatitis B virus X and core promoter mutations on hepatocellular carcinoma among patients infected with subgenotype C2, Noboru Shinkai, Yasuhito Tanaka, Kiyoaki Ito, Motokazu Mukaide, Izumi Hasegawa, Yasuhiro Asahina, Namiki Izumi, Hiroshi Yatsuhashi, Etsuro Orito, Takashi Joh, Masashi Mizokami, Journal of Clinical Microbiology, 45, 3191 - 3197,   2007年10月, Hepatitis B virus (HBV) genotypes/subgenotypes and their related mutations in the HBV genome have been reported to be associated with hepatocellular carcinoma (HCC). To determine the HCC-associated mutations of the HBV genome in the entire X, core promoter, and precore/core regions, a cross-sectional control study was conducted comparing 80 Japanese patients infected with HBV C2 and suffering from HCC with 80 age-, sex-, and hepatitis B e antigen (HBeAg) status-matched patients without HCC (non-HCC group). Each HBeAg-positive group (31 with HCC; 29 without HCC) and HBeAg-negative group (49 with HCC; 51 without HCC) was also matched with respect to age and sex. The C1479, T1485, H1499, A1613, T1653, V1753, T1762/A1764, and A1896 mutations were frequent in this population. The prevalences of the T1653 mutation in the box α region and the V1753 and T1762/A1764 mutations in the basal core promoter region were significantly higher in the HCC group than in the non-HCC group (56% versus 30%, 50% versus 24%, and 91% versus 73% [P = 0.0013, P = 0.0010, and P = 0.0035, respectively]). The platelet count was significantly lower for the HCC group than for the non-HCC group (10.7 × 104± 5.1 × 104versus 17.3 x 104± 5.1 × 104platelets/mm3[P < 0.0001]). Regardless of HBeAg status, the prevalence of the T1653 mutation was higher in the HCC group (52% versus 24% [P = 0.036] for HBeAg-positive patients and 59% versus 33% [P = 0.029] for HBeAg-negative patients). In the multivariate analysis, the presence of T1653, the presence of V1753, and a platelet count of ≤10 × 104/mm3were independent predictive factors for HCC (odds ratios [95% confidence intervals], 4.37 [1.53 to 12.48], 7.98 [2.54 to 25.10], and 24.39 [8.11 to 73.33], respectively). Regardless of HBeAg status, the T1653 mutation increases the risk of HCC in Japanese patients with HBV/C2. Copyright © 2007, American Society for Microbiology. All Rights Reserved.
  • Influences on hepatitis B virus replication by a naturally occurring mutation in the core gene, Masaya Sugiyama, Yasuhito Tanaka, Fuat Kurbanov, Nobuaki Nakayama, Satoshi Mochida, Masashi Mizokami, Virology, 365, 285 - 291,   2007年09月01日, Little is known about specific naturally occurring mutations of hepatitis B virus (HBV) and underlying mechanisms of their association with fulminant hepatitis. A HBV clone isolated from a patient with fulminant hepatitis was analyzed, and the features of the particular mutations observed around furin cleavage site in core region (A2339G/G2345A) were assessed using an in vitro replication model. The clone belonged to genotype B with precore stop codon mutation (G1896A). Replication efficiency of 1.24-fold HBV genome in Huh-7 cells was increased in the presence of A2339G. Further in vitro studies using furin inhibitor indicated that the effect of the mutation was probably associated with accumulation of the full-length core protein without cleavage by furin-like protease, suggesting that a processing of the core protein might play an important role in regulation of viral replication. In conclusion, the A2339G mutation was considered as one of the viral factors involved in high replication efficiency. © 2007 Elsevier Inc. All rights reserved.
  • Increasing genetic diversity of hepatitis C virus in haemophiliacs with human immunodeficiency virus coinfection, Yasuhito Tanaka, Kousuke Hanada, Hideji Hanabusa, Fuat Kurbanov, Takashi Gojobori, Masashi Mizokami, Journal of General Virology, 88, 2513 - 2519,   2007年09月01日, Patients with inherited bleeding disorders who received clotting factor concentrates before 1987 have high rates of hepatitis C virus (HCV) or HCV/human immunodeficiency virus (HIV) infection. To determine whether the persistent nature of HIV affects the genetic diversity of HCV by less selective pressure through the immunosuppression of HIV/ HCV-coinfected patients, both the change of genetic diversity and selective pressure were examined in the HCV envelope genes (E1 and E2) of 325 genotype 1a subclones from eight HIV-positive and five HIV-negative patients with two time points (more than 6 years apart). To infer the genetic diversity of HCV in each patient, we used two approaches. One method was to estimate the difference of total evolutionary distances in the phylogenetic tree between the two time points, and another was to estimate the changes of genetic diversity along the time based on the coalescence theory. The two results indicate that the HIV-positive group has significantly more diverse population structure than the HIV-negative group. A comparative analysis of the synonymous and non-synonymous substitutions found that the HIV-positive group was subject to less selective pressure than the HIV-negative group. In conclusion, HIV-positive patients would have a more diversified HCV population than HIV-negative patients due to less selective pressure from the immune system. © 2007 SGM.
  • Virological features of hepatitis B virus-associated nephropathy in Japan, Atsunori Kusakabe, Yasuhito Tanaka, Fuat Kurbanov, Kenji Goto, Hitoshi Tajiri, Jun Murakami, Chiaki Okuse, Hiroshi Yotsuyanagi, Takashi Joh, Masashi Mizokami, Journal of Medical Virology, 79, 1305 - 1311,   2007年09月, Hepatitis B virus (HBV)-associated nephropathy is considered as an immune-mediated disorder which is dependent on interactions between viral, host, and environmental factors. But there are few reports that investigated the relationship between the development of HBV-associated nephropathy and HBV genotypes and the mutations. To clarify the relationship between nephropathy and HBV genotype in Japan, six male patients with HBV-associated nephropathy were examined. The complete genome sequences of HBV were determined directly and the specific mutations associated with the development of HBV-associated nephropathy were examined by comparison of the alignments along with consensus sequences [HBV/A1 (Aa), A2 (Ae), B1 (Bj), B2 (Ba), C1 (Cs) and C2 (Ce)] retrieved from international database. The mean age of the six patients was 33.5 years. HBeAg was found in all patients and serum HBV-DNA levels were relatively high. Histological findings of renal tissues indicated five cases of membranous nephropathy and one membranoproliferative glomerulonephritis. HBV genotypes from the six patients were two HBV/A1, two A2 and two C2, suggesting HBV/A was predominant. G1862T mutation was observed in the two HBV/A1 patients, resulting in the pre-core amino acid substitution with a switch from valine (Val) to phenylalanine (Phe). Only one patient had core deletions. It is concluded that HBV/A may be associated with membranous nephropathy, but little relationship between HBV gene mutations and the development of HBV-associated nephropathy was observed. © 2007 Wiley-Liss, Inc.
  • Variations in the core promoter/pre-core region in HBV genotype C in Japanese and Northern Vietnamese patients, Xuan Truong Bui, Yoshihiko Yano, Yasushi Seo, Minh Phuong Tran, Yasuhito Tanaka, Hirotaka Kato, Akira Miki, Takako Utsumi, Takeshi Azuma, Khanh Trach Nguyen, Masashi Mizokami, Yoshitake Hayashi, Masato Kasuga, Journal of Medical Virology, 79, 1293 - 1304,   2007年09月, Hepatitis B virus (HBV) subgenotypes Cs (C1) and Ce (C2) are common in East Asia. To investigate the genomic difference of HBV genotype C between two separated regions, 50 subgenotype Cs-infected Vietnamese and 70 subgenotype Ce-infected Japanese patients were enrolled for analysis. The patients were categorized to either a hepatocellular carcinoma group (HCC) or a non-HCC group including liver cirrhosis, chronic hepatitis, and asymptomatic carriers. HBV serology, HBV-DNA level, and variations in core promoter/pre-core region were examined. Phylogenetic analysis based on the full genome sequences and nucleotide sequences partly in the S gene and in the P gene revealed that all Japanese strains (70/70) were subgenotype Ce, and nearly all of the Vietnamese strains (50/51) were subgenotype Cs, excluding one subgenotype C5. C1858 and G1775 were common in the Vietnamese (64% and 40%) but not in the Japanese (0%). The prevalence of C/A1753 in Vietnamese was higher than that in the Japanese (32% vs. 17.1%), however the frequency of A1896 in the Japanese was significantly higher (32.9% vs. 12%, P < 0.05). Most of the Vietnamese patients with HCC had a high level of HBV-DNA, the Japanese HCC had a relatively low level. In the Vietnamese, C/A1753 and C1858 were associated closely with T1762A1764, higher HBV-DNA levels and higher HCC incidence. The multivariate analysis revealed that male, T1653 and C/A1753 were independent risk factors for HCC. The subgenotypes and unique mutations of HBV genotype C in the Vietnamese and Japanese differed, and C/A1753 and C1858 variants might play a role in the pathogenesis of liver disease in Vietnamese patients. © 2007 Wiley-Liss, Inc.
  • Tracing hepatitis C and Delta viruses to estimate their contribution in HCC rates in Mongolia, F. Kurbanov, Y. Tanaka, A. Elkady, T. Oyunsuren, M. Mizokami, Journal of Viral Hepatitis, 14, 667 - 674,   2007年09月, An estimated incidence of hepatocellular carcinoma (HCC) in Mongolia is currently one of the highest in the world. According to previous reports, the sero-prevalence of hepatitis B (HBV) and hepatitis C (HCV) viruses in general population of the country is very high (HBV, 10% and HCV, 15%, respectively). Moreover, the majority (75-100%) of the HBV-infected individuals have co-infection with hepatitis Delta virus (HDV). Despite reported observations that HBV + HDV/HCV co-infection have significantly stronger association with HCC when compared with HCV-monoinfection, the later is still frequently observed among Mongolian HCC patients (39%). In this study, an approach based on principles of population genetics and mathematical epidemiology was used to trace an epidemic history of HCV and HDV. In agreement with the sero-epidemiological and social-historical background of the country, the results have demonstrated that the viruses had different epidemic dynamics in Mongolia; HCV was characterized by earlier epidemic expansion, whereas HDV spread with approximately 50 years lag. This may explain the comparable contribution of the HCV-monoinfection and HBV + HDV co-infection in current HCC rate despite different levels of risk of carcinogenesis. Used approach is useful in evaluation of current and prospective disease burden. © 2007 Blackwell Publishing Ltd.
  • Clinical evaluation of a novel HBsAg quantitative assay, Kazumi Takagi, Yasuhito Tanaka, Hatsue Naganuma, Kumiko Hiramatsu, Takayasu Iida, Yoshimitsu Takasaka, Masashi Mizokami, Rinsho byori. The Japanese journal of clinical pathology, 55, 619 - 625,   2007年07月01日, The clinical implication of the hepatitis B surface antigen (HBsAg) concentrations in HBV-infected individuals remains unclear. The aim of this study was to evaluate a novel fully automated Chemiluminescence Enzyme Immunoassay (Sysmex HBsAg quantitative assay) by comparative measurements of the reference serum samples versus two independent commercial assays (Lumipulse f or Architect HBsAg QT). Furthermore, clinical usefulness was assessed for monitoring of the serum HBsAg levels during antiviral therapy. A dilution test using 5 reference-serum samples showed linear correlation curve in range from 0.03 to 2,360 IU/ml. The HBsAg was measured in total of 400 serum samples and 99.8% had consistent results between Sysmex and Lumipulse f. Additionally, a positive linear correlation was observed between Sysmex and Architect. To compare the Architect and Sysmex, both methods were applied to quantify the HBsAg in serum samples with different HBV genotypes/subgenotypes, as well as in serum contained HBV vaccine escape mutants (126S, 145R). Correlation between the methods was observed in results for escape mutants and common genotypes (A, B, C) in Japan. Observed during lamivudine therapy, an increase in HBsAg and HBV DNA concentrations preceded the aminotransferase (ALT) elevation associated with drug-resistant HBV variant emergence (breakthrough hepatitis). In conclusion, reliability of the Sysmex HBsAg quantitative assay was confirmed for all HBV genetic variants common in Japan. Monitoring of serum HBsAg concentrations in addition to HBV DNA quantification, is helpful in evaluation of the response to lamivudine treatment and diagnosis of the breakthrough hepatitis.
  • Molecular evidence of father-to-child transmission of hepatitis B virus, Hitoshi Tajiri, Yasuhito Tanaka, Seiiti Kagimoto, Jun Murakami, Daisuke Tokuhara, Masashi Mizokami, Journal of Medical Virology, 79, 922 - 926,   2007年07月, At present in Japan, only high-risk infants born to chronic hepatitis B virus (HBV)-infected mothers are given HBV vaccine. However, children can contract the virus from other HBV-infected family members, including fathers. The aim of this study is to present substantial and unequivocal evidence of father-to-child transmission of HBV infection using techniques including homology analysis and phylogenetic analysis. Thirteen chronic HBV-infected members of five families that included eight children and their respective fathers were enrolled in this study. Homology analysis and phylogenetic analyses of 2 coding region, the S gene and X gene, from the HBV genome were performed comparing the 13 nucleotide sequences from the 13 subjects. The nucleotide homology among the five sets of fathers and children was quite high (99.3-100%). A phylogenetic tree constructed on the 13 nucleotide sequences showed that all 5 sets of fathers and children were grouped into the same cluster with high bootstrap values. These results strongly indicate that father-to-child transmission is an important route of HBV infection in Japan and it is recommend that universal vaccination against HBV infection be instituted immediately in Japan for all children, in accordance with the WHO recommendation of 1997. © 2007 Wiley-Liss, Inc.
  • Distribution and characteristics of hepatitis B virus genotype C subgenotypes in China, Z. Wang, J. Hou, G. Zeng, S. Wen, Y. Tanaka, J. Cheng, F. Kurbanov, L. Wang, J. Jiang, N. V. Naoumov, M. Mizokami, Y. Qi, Journal of Viral Hepatitis, 14, 426 - 434,   2007年06月, Genetic diversity within the same hepatitis B virus (HBV) genotype indicates the presence of several subgenotypes. We have found that genotype C is the most common in China, and this study aimed to determine the geographical distribution and characteristics of HBV-C subgenotypes in the country. A cohort of 534 patients with chronic HBV genotype C infection, collected across China, was analysed by nucleotide sequencing or polymerase chain reaction-restriction fragment length polymorphism. HBV-C1/Cs (n = 112, 21%) and HBV-C2/Ce (n = 397, 74%) were the most common HBV-C subgenotypes and showed different geographical distribution in China. No significant differences were found between patients infected with HBV-C1 and HBV-C2 when comparing liver function tests, hepatitis B e antigen positive rate and clinical manifestations. We identified two other types of HBV-C provisionally designated as HBV-CD1 and HBV-CD2, which have particular virological features and clustered in one geographic area. These two types of C/D hybrids have emerged through recombination with genotype D and encode serotype ayw2 hepatitis B surface antigen. In conclusion, there are at least four subtypes of HBV genotype C: subgenotypes C1, C2 and two types of C/D recombinants CD1 and CD2 in China, which have a distinct geographic distribution. Whether HBV-C subgenotypes differ in their impact on liver disease progression requires prospective studies. © 2007 The Authors.
  • Hepatitis B virus (HBV) genotypes/subgenotypes in China: Mutations in core promoter and precore/core and their clinical implications, Jing Yuan, Boping Zhou, Yasuhito Tanaka, Fuat Kurbanov, Etsuro Orito, Zuojiong Gong, Liumei Xu, Jian Lu, Xiaoling Jiang, Weizhen Lai, Masashi Mizokami, Journal of Clinical Virology, 39, 87 - 93,   2007年06月, Background: The association of hepatitis B virus (HBV) genotypes with clinical course of infection is increasingly recognized. Objectives: In order to investigate the genetic diversity of HBV and its clinical implications, 241 HBV-infected patients including 34 with hepatocellular carcinoma (HCC) were enrolled in this study. Methods: HBV genotyping was performed with an ELISA assay. HBV subgenotypes were determined by PCR-RFLP. HBV core promoter/precore/core mutations were analyzed by direct sequencing. Results: The overall prevalence of HBV/B and C was 65% and 33%, respectively. Among HBV/C, 42% were Cs/C1 and 58% were Ce/C2. The HBV/C1 was only found in the patients originating from Southern China (p = 0.0001). Among HCC patients, HBV/C2 was only found in the elder age group (≥51 years; p < 0.05) and HBV/Ba was associated with young HCC patients (<35 years). Mutations associated with HCC were V1753 and T1762/A1764 (p < 0.01). The prevalence of the V1753 was higher in HBV/C1 strains (p < 0.04), A1898 was only found among HBV/C1 (p = 0.056). T1762/A1764 was frequently demonstrated in both subgenotypes. The T1858 (90%) and A1896 (40%) mutations were most frequent in HBV/C2 (p < 0.008). Conclusions: HBV/C1 and HBV/C2 have distinct geographic distributions in China. V1753 in addition to T1762/A1764 double mutation in the basal core promoter region seems to be associated with HCC development, especially in the patients with HBV/C1. © 2007 Elsevier B.V. All rights reserved.
  • Clinical and virological characteristics of hepatitis B virus subgenotypes Ba, C1, and C2 in China, Zhanhui Wang, Yasuhito Tanaka, Yuehua Huang, Fuat Kurbanov, Jinjun Chen, Guobing Zeng, Bin Zhou, Masashi Mizokami, Jinlin Hou, Journal of Clinical Microbiology, 45, 1491 - 1496,   2007年05月, Hepatitis B virus (HBV) subgenotypes Ba, C1 (Cs), and C2 (Ce) are the most prevalent HBV variants in China. To investigate the virological characteristics of these subgenotypes and their clinical implications, we enrolled a cohort of 211 patients in the Guangdong Province of China, including 132 with chronic hepatitis B virus infection (CH), 32 with liver cirrhosis (LC), and 47 with hepatocellular carcinoma (HCC) according to clinical examination, liver function test, and ultrasonograph results. Overall, HBV Ba was found in 51.2% (108/211), HBV C1 in 33.6% (71/211), and HBV C2 in 15.2% (32/211) of the cases. The distribution of HBV genotype C was greater among patients in the LC and HCC groups than among patients in the CH group, while the distribution of HBV genotype B was greater among the CH patients than among the LC and HCC patients. No significant differences in clinical features were found among patients with HBV Ba, C1, and C2. Virologically, HBV C1 had the strongest association with the A1762T G1764A double mutation, while the mutation at position 1896 resulting in A (1896A) was uncommon. In contrast, HBV Ba had the highest frequency of 1896A but the lowest of A1762T G1764A, and HBV C2 had intermediate frequencies of these mutations. Mutations of 1653T and 1753V were specifically associated with HBV C2 and C1, respectively. Multivariate analyses showed that the 1653T, 1753V, and A1762T G1764A mutations and patient age significantly increased the risk of HCC development. In conclusion, HBV Ba, Cl, and C2 have different mutation patterns in the enhancer II/core promoter/precore region. Therefore, genotyping and detecting the 1653T and 1753V mutations, in addition to the A1762T G1764A double mutation, might have important clinical implications as predictive risk factors for hepatocarcinogenesis. Copyright © 2007, American Society for Microbiology. All Rights Reserved.
  • A reduction in selective immune pressure during the course of chronic hepatitis C correlates with diminished biochemical evidence of hepatic inflammation, Kousuke Hanada, Yasuhito Tanaka, Masashi Mizokami, Takashi Gojobori, Harvey J. Alter, Virology, 361, 27 - 33,   2007年04月25日, It is considered that selection pressure exerted by the host immune response during early HCV infection might influence the outcome of that infection particularly as it relates to persistence or clearance of the agent. However, it is unclear whether positive selection pressure plays a role in determining the severity of hepatitis C during the course of persistent HCV infection. To address the evolutionary mechanism by which HCV escapes from the host immune response and to assess the relationship between viral evolution and hepatic inflammation, we determined 57 sequences (3-5 serial samples per patient) from 5 individuals with persistent HCV infection of genotype 1a who were under long-term follow-up ranging from 15.6 to 21.6 years. We applied a novel method to estimate serial alternations of selective pressure against the HCV enveloped region and compared this to fluctuation in transaminase level over time. Positive selection pressure was reduced over time postinfection, as evidenced by a reduction in nonsynonymous substitutions in the later phase of infection. Furthermore, serum transaminase, as a measure of inflammatory necrosis of hepatocytes, was reduced in parallel with decreased positive selection pressure. These results suggest that during persistent HCV infection, the virus faces diminished immune pressure over time, either from mutation to an immune resistant sequence or from immunologic exhaustion, and that this diminished immune attack is reflected in diminished inflammatory activity. This observation may be applicable to other viruses characterized by a slow rate of disease progression. © 2006 Elsevier Inc. All rights reserved.
  • Impaired cytotoxic T lymphocyte inductivity by dendritic cells derived from patients with hepatitis C virus-positive hepatocellular carcinoma, Tomoyoshi Ohno, Noboru Hirashima, Etsuro Orito, Izumi Hasegawa, Kei Fujiwara, Kiyoaki Itoh, Atsushi Ozasa, Noboru Shinkai, Yasuhito Tanaka, Takanobu Kato, Ryuzo Ueda, Kenji Sakakibara, Hepatology Research, 37, 276 - 285,   2007年04月01日, Aim: Peptide-based therapeutic vaccines are being developed. The aim of this study was to determine the feasibility of immunotherapy to hepatitis C virus (HCV)-positive hepatocellular carcinoma (HCC) by assessing the inductivity of peptide-specific cytotoxic T lymphocyte (CTL) by dendritic cells. Methods: The inductivity of CTL was characterized in six patients with HCV-positive HCC, and compared to seven healthy volunteers and six patients with chronic HCV hepatitis (control). Results: Peptide-specific CTL was comparably induced in controls, but not induced in any patients with HCC. To characterize this, the cytokine profile and the expression of surface molecules interacting between dendritic and T cells were evaluated. Among the cytokines, production of interferon (IFN)-γ was found to be impaired and closely related to the results of CTL assays, while the expression of surface molecules showed no significant changes. Conclusions: In HCV-positive HCC patients, CTL inductivity by dendritic cells is impaired. This may be related to the impaired production of IFN-γ. © 2007 The Japan Society of Hepatology.
  • False positive serum des-gamma-carboxy prothrombin after resection of hepatocellular carcinoma, Kumiko Hiramatsu, Yasuhito Tanaka, Kazumi Takagi, Takayasu Iida, Yoshimitsu Takasaka, Masashi Mizokami, Rinsho byori. The Japanese journal of clinical pathology, 55, 330 - 337,   2007年04月01日, Measurements of serum concentrations of des-gamma-carboxy-prothrombin (PIVKA-II) are widely used for diagnosing hepatocellular carcinoma (HCC). Recently, when we evaluated the correlation of PIVKA-II between two commercially available PIVKA-II immunoassay kits (Lumipulse f vs. Picolumi) to introduce it in our hospital, false high values of PIVKA-II were observed in Lumipulse assay. Four(4%) of 100 serum samples showed false high values, and all of them were obtained from patients less than 2 month after curative resection of HCC. Examining additional 7 patients with HCC resection, serum samples from the 5 patients had the same trend. To elucidate the non-specific reaction by Lumipulse assay which utilized alkaline phosphatase (ALP) enzymatic reaction, inhibition assays by various absorbents such as inactive ALP and IgM antibodies were performed. Excess of inactive ALP reduced the high values of PIVKA-II. Note that anti-bleeding sheets (fibrinogen combined drug), which included bovine thrombin, were directly attached on liver of all patients with HCC resection in this study. As the sheets also contaminate ALP and probably produce IgM antibodies to ALP, the IgM may cross-react with anti-PIVKA-II antibodies directly. Taken together, it was suggested that produced antibodies against ALP derived from anti-bleeding sheets led false high values of PIVKA-II in the patients with HCC resection.
  • A weak association between occult HBV infection and non-B non-C hepatocellular carcinoma in Japan, Atsunori Kusakabe, Yasuhito Tanaka, Etsuro Orito, Fuminaka Sugauchi, Fuat Kurbanov, Tomoyuki Sakamoto, Noboru Shinkai, Noboru Hirashima, Izumi Hasegawa, Tomoyoshi Ohno, Ryuzo Ueda, Masashi Mizokami, Journal of Gastroenterology, 42, 298 - 305,   2007年04月, Background: In Japan, approximately 10% of hepatocellular carcinoma (HCC) patients are negative for both hepatitis B surface antigen (HBsAg) and antibodies to hepatitis C virus (anti-HCV), i.e., they constitute the so-called category of non-B non-C (NBNC) HCC. Little is known about the characteristics of NBNC-HCC. Methods: Potential risk factors for carcinogenesis (including occult HBV infection [HBsAg is negative but HBV DNA is positive by polymerase chain reaction (PCR)], obesity, and diabetes) were assessed in 233 HCC patients grouped according to hepatitis virus serological status (152 with HCV-HCC, 36 with HBV-HCC, and 45 with NBNC-HCC). Results: The prevalence of patients with obesity or diabetes was significantly higher in the NBNC-HCC group than in the HBV-HCC group. The same trend was observed even when patients with massive alcohol intake were excluded from the analysis. Only 8 patients (18%) in the NBNC-HCC group had detectable serum HBV DNA, and this was at very low levels (HBV/Ce/C2 and HBV/D were determined in 7 and 1 patients, respectively). In the NBNC-HCC group, the determined nucleotide sequences of the enhancer II/core promoter/precore/core region did not contain any HCC-associated mutations, whereas 25 of 30 patients in the HBV-HCC group carried strains with C1653T, T1753V, and/or A1762T/G1764A mutations. Conclusions: A weak association between occult HBV infection and HCC development was observed in the NBNC patients. This study indicates that nonalcoholic steato-hepatitis should be further investigated to assess its contribution to HCC development in this category of patients. © Springer-Verlag Tokyo 2007.
  • Early dynamics of hepatitis B virus in chimeric mice carrying human hepatocytes monoinfected or coinfected with genotype G, Masaya Sugiyama, Yasuhito Tanaka, Tomoyuki Sakamoto, Isao Maruyama, Takashi Shimada, Satoru Takahashi, Tomoyuki Shirai, Hideaki Kato, Masataka Nagao, Yuzo Miyakawa, Masashi Mizokami, Hepatology, 45, 929 - 937,   2007年04月, Of the 8 genotypes of HBV (genotypes A-H), genotype G is unique in that it has an insertion in the core gene and two stop codons in the precore region preventing the synthesis of hepatitis B e antigen. Most individuals with genotype G are coinfected with other genotypes, typically genotype A. Mice with severe combined immunodeficiency disease carrying human hepatocytes were infected with HBV particles propagated in Huh7 cells in culture. Mice monoinfected with genotype G did not raise detectable HBV DNA in serum, although products of the core gene emerged 4 to 8 weeks after inoculation. When they were superinfected with genotype A at week 10, however, HBV DNA of genotype A developed, which was replaced almost completely by that of genotype G within 10 weeks. Such a rapid takeover was also observed in mice initially infected with genotype A or C and superinfected with genotype G. Similar viral dynamics occurred in mice simultaneously coinfected with genotypes G and A. Takeover was markedly enhanced in mice inoculated with a serum passage containing genotype G with a trace of genotype A. Coinfection of mice with genotypes G and A induced abundant cellular steatosis along with increased fibrosis in the liver, which was not detected in mice monoinfected with genotype A or G. Conclusion: Genotype G can monoinfect chimeric mice at very low levels, and its replication increases maredly when coinfected with other genotypes. Coinfection with genotype G could enhance fibrosis under immunocompromised states. Copyright © 2007 by the American Association for the Study of Liver Diseases.
  • Adefovir dipivoxil monotherapy and combination therapy with lamivudine for the treatment of chronic hepatitis B in an Asian population, James Fung, Ching Lung Lai, John Chi Hang Yuen, Danny Ka Ho Wong, Yasuhito Tanaka, Masashi Mizokami, Man Fung Yuen, Antiviral Therapy, 12, 41 - 46,   2007年03月07日, Aim: To determine differences in Chinese patients treated with adefovir (ADV) monotherapy or ADV in combination with lamivudine (3TC) after development of resistance to 3TC, with respect to biochemical improvement, HBV DNA suppression and development of subsequent ADV resistance. Methods: All hepatitis B patients with 3TC resistance treated with ADV for 3 months or more at our centre were included, and monitored 3-6 monthly for biochemical and virological response, and development of ADV resistance. Results: A total of 56 patients were included, 50% switched to ADV monotherapy and 50% received combination 3TC/ADV therapy. Median follow-up was 15.5 months. Normalization of alanine aminotransferase (ALT) occurred in 25 (89%) patients in the ADV group compared with 24 (86%) in the 3TC/ADV group (P=0.686). Virological response (VR) was achieved in seven (35%) patients in the ADV group at 12 months compared with five (28%) in the 3TC/ADV group (P=0.637). By 24 months, seven (64%) patients in the ADV group achieved VR compared with two (40%) in the 3TC/ADV group (P=0.377). Cumulative probability of developing genotypic ADV resistance in the ADV group at 24 months was 18% compared with 7% in the 3TC/ADV group (P=0.94). Conclusion: There was no obvious improvement in ALT normalization and virological suppression or reduction in the development of ADV-resistant mutations with 3TC/ADV therapy compared with ADV monotherapy. Further studies with longer follow-ups are required to determine whether combination 3TC/ADV therapy will reduce the emergence of ADV resistance compared with ADV monotherapy. © 2007 International Medical Press.
  • Accidental exposure to HCV antibody-positive blood in hospital and pre-emptive one-shot interferon alpha-2b treatment, Haruhiko Nukaya, Tomoyoshi Ohno, Kenji Sakakibara, Atunaga Kato, Izumi Hasegawa, Seijiro Matunaga, Masayuki Endo, Yoshito Tanaka, Noboru Hirashima, Yasuhito Tanaka, Etsuro Orito, Takashi Joh, Masashi Mizokami, Hepatology Research, 37, 179 - 185,   2007年03月01日, Aims: Infection with hepatitis viruses following blood exposure accidents, such as needle stick injuries, is a serious issue for medical staff. In particular, although accidental exposure to hepatitis C virus (HCV) occurs frequently, postexposure prophylactic measures have not been established yet. In this study we investigate the efficacy of recombinant α-2b interferon (IFN) as a single, 10 MU intramuscular injection for preventing transmission. Methods: 264 incidents of accidental blood to HCV antibody-positive blood, occurring between 1993 and 2003 in the Social Insurance Chukyo Hospital, were surveyed. Accident reports, which described in detail the circumstances and the presence or absence of infectious disease in the blood, and accidental exposure to HCV antibody-positive blood was investigated. Results: Pre-emptive IFN treatment was given in 115 out of 157 cases occurring between 1993 and 1998. One case developed acute HCV. Phylogenetic analysis provided evidence that the accident caused the infection and the patient was cured by immediate IFN therapy. Between 1999 and 2003, the exposed were in principle followed-up without IFN treatment; IFN treatment was only given when requested. As a result, IFN was given in 14 of 107 cases. During this period, no transmission was observed. Conclusion: Taken together, the benefits of pre-emptive IFN treatment were considered unremarkable and a follow-up without treatment, or immediate IFN therapy after confirmation of the onset, was recommended. © 2007 The Japan Society of Hepatology.
  • Molecular epidemiological study of hepatitis B virus infection in two different ethnic populations from the Solomon Islands, Takako Utsumi, Yoshihiko Yano, Xuan Truong Bui, Yasuhito Tanaka, Masashi Mizokami, Yasushi Seo, Masato Kasuga, Masato Kawabata, Yoshitake Hayashi, Journal of Medical Virology, 79, 229 - 235,   2007年03月, The Solomon Islands is a multi-ethnic nation with a high rate of hepatitis B virus (HBV) infection. The prevalence relative to ethnicity was examined in relation to HBV infection, genotypes, and mutations. Asymptomatic populations (n = 564, 308 Melanesian and 118 Micronesian) from the Western Province were enrolled. Positive samples for Hepatitis B surface antigen (HBsAg) were examined for serological status, genotyping, viral load, and mutations of the basic core promoter (BCP) and pre-core (Pre-C) regions. The positive rate for HBsAg was 21.5%. The major Melanesian genotype was C (HBV/C), whereas the major Micronesian genotype was D (HBV/D). The prevalence of Hepatitis B e antigen (HBeAg) in serum was lower in carriers of HBV/D than of HBV/C. While the prevalence of the BCP mutation (T1762A1764) tended to be higher in HBV/C, that of the Pre-C mutation (T1846) was significantly higher in HBV/D (P < 0.0001). Genetic distance and phylogenetic analyses based on complete genome sequences were also carried out for two strains of HBV/C and two strains of HBV/D, and the findings were compared with those in the DDBJ/EMBL/GenBank database. The full-length sequence revealed that strains from the Solomon Islands were classified into subgenotype C3 (HBV/C3) and D4 (HBV/D4), and that the HBV/D strains were related closely to those from Papua New Guinea. HBV infection in the Solomon Islands is hyperendemic, and the genotype is ethnicity-specific. HBeAg appears to clear from the serum in young adulthood in HBV/D infection, which may be influenced by genotype-dependent features in relation to viral mutations. © 2007 Wiley-Liss, Inc.
  • Genotype B and younger patient age associated with better response to low-dose therapy: A trial with pegylated/nonpegylated interferon-α-2b for hepatitis B e antigen-positive patients with chronic hepatitis B in China, Hong Zhao, Fuat Kurbanov, Mo Bin Wan, You Kuan Yin, Jun Qi Niu, Jin Lin Hou, Lai Wei, Gui Qiang Wang, Yasuhito Tanaka, Masashi Mizokami, Chong Wen Si, Chong Wen Si, Clinical Infectious Diseases, 44, 541 - 548,   2007年02月15日, Background. Cost and clinically significant adverse effects are the major limiting factors of interferon (IFN) use in therapy for chronic hepatitis B virus (HBV) infection. A clinical trial was conducted in China to study the efficiency and clinical relevance of low-dose regimen of IFN treatment for chronic HBV infection and to reveal factors predicting sustained combined response. Methods. During a randomized, open-label control study, hepatitis B e antigen (HBeAg)-positive patients with chronic HBV infection (n = 230) were assigned to receive pegylated IFN-α-2b (1.0 μg/kg) (n = 115) or IFN-α-2b (3 MIU; n = 115) for a 24-week period. Sustained combined response was assessed 24 weeks after the completion of treatment. Results. The greater rate of HBeAg loss in the pegylated IFN-group (23%) was the only statistically significant difference between the 2 treatment arms observed at the end of follow-up. The results of the multivariate statistical analysis revealed that HBV genotype B and patient age (≤25 years) were 2 independent factors associated with sustained combined response. A total of 40% of patients with HBV genotype B aged ≤25-years achieved sustained combined response. Only 4 (1.7%) of 230 patients discontinued therapy because of clinically significant adverse effects. Conclusions. The choice of low-dose IFN regimen might be a relevant clinical option to reduce the cost and adverse effects of therapy for younger patients with chronic HBV infection and genotype B infection in countries where it is prevalent. © 2007 by the Infectious Diseases Society of America. All rights reserved.
  • Genetic diversity of hepatitis B virus as an important factor associated with differences in clinical outcomes, Yasuhito Tanaka, Masashi Mizokami, Journal of Infectious Diseases, 195, 1 - 4,   2007年01月
  • Difference of hepatitis B virus genotype distribution in two groups of Mexican patients with different risk factors: High prevalence of genotype H and G, L. V. Sánchez, Y. Tanaka, M. Maldonado, M. Mizokami, A. Panduro, A. Panduro, Intervirology, 50, 9 - 15,   2006年12月01日, Background: Hepatitis B virus (HBV) has been classified in eight genotypes, from A to H (HBV/A to HBV/H). HBV genotypes were determined in two groups with different risk factors. Methods: Group I consisted of 42 patients with chronic and acute hepatitis and group II with 25 men who have sex with men (MSM). HBV genotypes were determined by DNA sequencing of the S-gene. Results: Both groups differed with respect to genotype distribution (p < 0.001). In group I, there were 31 (74%), 9 (21%) and 2 patients (5%) with HBV/H, HBV/D and HBV/A; respectively. In group II, HBV/H, HBV/A, and HBV/G were found in 13 (52%), 8 (32%) and 4 (16%) cases, respectively. By using an HBV/G-specific PCR, 3 more cases of HBV/G were identified in group II, rising to a total 28%. All HBV/G strains were present in coinfection with other HBV genotypes, 86% with HBV/H, and 14% with HBV/A. Conclusions: HBV/H predominated in both groups. A high frequency of HBV/G was found in MSM, which was always coinfected with HBV/H or HBV/A. Significant differences in HBV genotype distribution were also found, since HBV/D was present only in patients with liver disease, whereas HBV/G was present only in MSM. Copyright © 2007 S. Karger AG.
  • High frequency of hepatocellular carcinoma in Mongolia; association with mono-, or co-infection with hepatitis C, B, and delta viruses, Tsendsuren Oyunsuren, Fuat Kurbanov, Yasuhito Tanaka, Abeer Elkady, Ruvjir Sanduijav, Onkhoon Khajidsuren, Byambin Dagvadorj, Masashi Mizokami, Journal of Medical Virology, 78, 1688 - 1695,   2006年12月, To investigate the association between viral infection pattern and hepatocellular carcinoma (HCC), 292 chronic hepatitis patients, including 108 with developed HCC were screened using serological and molecular genetics methods. Viral etiology was established in 267 (91.4%), anti-HCV detected in 198 (67.8%), and HBsAg in 124 (42.5%) including 93 (74.4%) cases with HDV co-infection. HCV mono-infection predominated in both, "non-HCC" and "HCC" groups (54% and 39%, respectively) with higher frequency in the first group (P = 0.011), whereas HBV in co-infection with HDV was more frequent in HCC group (14% vs 25%, P = 0.017). Patients with HCV mono-infection were older than those with co-infection (P < 0.02), had higher frequency of HCV-viraemia (82% vs 7%, P < 0.0001), and yet had significantly lower prevalence of HCC (29.6% vs. 49.1%, P = 0.003). Alpha-fetoprotein (AFP) and protein induced by vitamin K antagonist-II (PIVKA-II) were specifically elevated in 71% of HCC patients. In conclusion, although HCV monoinfection pattern predominates in Mongolia, co-infection with HBV and HDV had stronger association with HCC development at younger age. Liver tumor markers; AFP and PIVKA-II are useful tools for complex HCC-screening and clinical follow-up for chronic hepatitis patients in Mongolia. © 2006 Wiley-Liss, Inc.
  • Clinical examinations based on nucleic acids of hepatitis viruses, Yasuhito Tanaka, Masashi Mizokami, Rinsho byori. The Japanese journal of clinical pathology, 54, 1164 - 1171,   2006年11月01日, Viral hepatitis is the most common cause of acute and chronic hepatitis. The term, viral hepatitis, generally refers to infections resulting from one of the hepatotrophic viruses: hepatitis A, B, C, D and E. As hepatitis B virus (HBV) and hepatitis C virus (HCV) mainly cause chronic hepatitis and hepatocellular carcinoma, early diagnosis, prevention and viral elimination are necessary. Eight genotypes of HBV have been detected by sequence divergence of >8% in the entire HBV genome, and designated by capital letters from A to H in the order of documentation. They have distinct geographical distribution and influence the severity of liver disease as well as the response to antiviral therapies. Similarly, HCV has at least six genotypes, of which HCV-1 and -2 are the major genotypes worldwide. Only interferon therapy can eradicate HCV at present, and the sustained virological response depends on HCV genotypes and viral loads. Here, we summarize examinations based on viral nucleic acids and the clinical manifestations of HBV and HCV genotypes.
  • Specific mutations in enhancer II/core promoter of hepatitis B virus subgenotypes C1/C2 increase the risk of hepatocellular carcinoma, Yasuhito Tanaka, Motokazu Mukaide, Etsuro Orito, Man Fung Yuen, Kiyoaki Ito, Fuat Kurbanov, Fuminaka Sugauchi, Yasuhiro Asahina, Namiki Izumi, Michio Kato, Ching Lung Lai, Ryuzo Ueda, Masashi Mizokami, Journal of Hepatology, 45, 646 - 653,   2006年11月, Background/Aims: Hepatitis B virus genotype C (HBV/C) has been classified into two geographically distinct subgenotypes; HBV/C1/Cs (Southeast Asia) and HBV/C2/Ce (East Asia). Methods: Viral differences in enhancer II/core promoter and precore regions between the subgenotypes and their association with hepatocellular carcinoma (HCC) were assessed in a matched cross-sectional control study of 118 carriers (from Hong Kong) with HBV/C1/Cs (48.0 years, 81% male, 40% HBeAg+, 44% HCC) and 210 HBV/C2/Ce (172 from Japan, 38 from Hong Kong) (50.2 years, 78% male, 30% HBeAg+, 46% HCC). Results: Univariate analyses showed that mutation V1753 was predictive for HCC among HBeAg-positive-C1/Cs-carriers (P = 0.0055), and T1653 among HBeAg-positive-C2/Ce-carriers (P = 0.018), and T1653 or V1753 or T1762/A1764 among HBeAg-negative-C2/Ce-carriers (P < 0.05). In the multivariate analysis on all HBV/C subjects, independent predictive factors for HCC were subgenotype C2/Ce (odds ratio, 4.21; 95% confidence interval, 1.07-16.23), T1653 (3.64; 1.93-6.86), V1753 (3.07; 1.66-5.65) and T1762/A1764 (2.58; 1.21-5.49) mutations, age (≥50 years), gender (male) and HBeAg (positive). Conclusions: Our data indicate that T1653 and/or V1753 mutations in addition to T1762/A1764 are differently associated with HCC in context of HBeAg status among HBV/C1/Cs and C2/Ce-carriers. HBV/C subgenotypes have specific mutation patterns, which is probably responsible for increased carcinogenesis of HBV/C2/Ce. © 2006 European Association for the Study of the Liver.
  • Molecular evolution of hepatitis B virus over 25 years, Carla Osiowy, Elizabeth Giles, Yasuhito Tanaka, Masashi Mizokami, Gerald Y. Minuk, Journal of Virology, 80, 10307 - 10314,   2006年11月, Determining the longitudinal molecular evolution of hepatitis B virus (HBV) is difficult due to HBVs genomic complexity and the need to study paired samples collected over long periods of time. In this study, serial samples were collected from eight hepatitis B virus e antigen-negative asymptomatic carriers of HBV genotype B in 1979 and 2004, thus providing a 25-year period to document the long-term molecular evolution of HBV. The rate, nature, and distribution of mutations that emerged over 25 years were determined by phylogenetic and linear regression analysis of full-length HBV genome sequences. Nucleotide hypervariability was observed within the polymerase and pre-S/S overlap region and within the core gene. The calculated mean number of nucleotide substitutions/site/year (7.9 × 10-5) was slightly higher than published estimates (1.5 × 10-5to 5 × 10-5). Nucleotide changes in the quasispecies population did not significantly alter the molecular evolutionary rate, based on linear regression analysis of evolutionary distances among serial clone pre-S region sequences. Therefore, the directly amplified or dominant sequence was sufficient to estimate the putative molecular evolutionary rate for these long-term serial samples. On average, the ratio of synonymous (dS) to nonsynonymous (dN) substitutions was highest for the polymerase-coding region and lowest for the core-coding region. The low dS/dNratios observed within the core suggest that selection occurs within this gene region, possibly as an immune evasion strategy. The results of this study suggest that HBV sequence divergence may occur more rapidly than previously estimated, in a host immune phase-dependent manner. Copyright © 2006, American Society for Microbiology. All Rights Reserved.
  • Variations in the viral NS5B region in Japanese patients with chronic hepatitis C virus genotype 1b infection: No specific amino acid substitution was identified as determinants of treatment response to interferon/ribavirin combination therapy, Kanji Sugihara, Etsuro Orito, Yasuhito Tanaka, Takanobu Kato, Johnson Y.N. Lau, Tomoyoshi Ohno, Katsuo Hayashi, Masataka Ogino, Noboru Hirashima, Kenji Sakakibara, Yoshiki Mizuno, Hideaki Kato, Seiji Suzuki, Ryuzo Ueda, Masashi Mizokami, Intervirology, 49, 319 - 326,   2006年10月, Objective: A recent study suggested that the substitution of amino acid 415 of HCV NS5B from phenylalanine to tyrosine in patients with HCV genotype 1a infection is induced by ribavirin and responsible for resistance to ribavirin therapy. The aim of this study was to evaluate whether specific variations in the HCV NS5B sequence in Japanese patients with HCV genotype 1b (HCV/1b) infection are associated with treatment response or selected by treatment with interferon-α/ribavirin combination therapy. Methods: Eighteen Japanese patients with HCV/1b infection receiving interferon-α/ribavirin combination therapy for 24 weeks were studied. Five patients treated with interferon-α monotherapy for 24 weeks were also studied as controls. The entire HCV NS5B sequence before and after therapy was determined. Results: All HCV isolates had tyrosine at position 415 of NS5B before and after therapy. Further analysis showed that no specific amino acid substitutions were identified to associate with clinical response and no specific amino acid substitutions were induced/selected by the clinical treatment. Conclusion: No specific HCV NS5B nucleotide/amino acid sequence variations, including amino acid 415 of NS5B, were identified as being associated with clinical treatment response or selected by the combination therapy in Japanese patients with HCV/1b infection. Copyright © 2006 S. Karger AG.
  • Influence of hepatitis B virus genotypes on the intra- and extracellular expression of viral DNA and antigens, Masaya Sugiyama, Yasuhito Tanaka, Takanobu Kato, Etsuro Orito, Kiyoaki Ito, Subrat K. Acharya, Robert G. Gish, Anna Kramvis, Takashi Shimada, Namiki Izumi, Masahiko Kaito, Yuzo Miyakawa, Masashi Mizokami, Hepatology, 44, 915 - 924,   2006年10月, Various genotypes of the hepatitis B virus (HBV) induce liver disease of distinct severity, but the underlying virological differences are not well defined. Huh7 cells were transfected with plasmids carrying 1.24-fold the HBV genome of different genotypes/subgenotypes (2 strains each for Aa/A1, Ae/A2, Ba/B2 and D; 3 each for Bj/B1 and C). HBV DNA levels in cell lysates, determined by Southern hybridization, were the highest for C followed by Bj/Ba and D/Ae (P < .01), and the lowest for Aa (P < .01), whereas in culture media, they were the highest for Bj, distantly followed by Ba/C/D and further by Ae/Aa (P < .01). The intracellular expression of core protein was more than 3-fold lower for Ae/Aa than the others. Hepatitis B e antigen (HBeAg) was excreted in a trend similar to that of HBV DNA with smaller differences. Secretion of hepatitis B surface antigen (HBsAg) was most abundant for Ae followed by Aa, Ba, Bj/C and remotely by D, which was consistent with mRNA levels. Cellular stress determined by the reporter assay for Grp78 promoter was higher for C and Ba than the other genotypes/subgenotypes (P < .01). Severe combined immunodeficiency mice transgenic for urokinase-type plasminogen activator (uPA/SCID), with the liver replaced for human hepatocytes, were inoculated with virions passed in mouse and recovered from culture supernatants. HBV DNA levels in their sera were higher for C than Ae by 2 logs during 4-7 weeks after inoculation. In conclusion, virological differences among HBV genotypes were demonstrated both in vitro and in vivo. These differences may influence HBV infections with distinct genotypes in clinical and epidemiological settings. Copyright © 2006 by the American Association for the Study of Liver Diseases.
  • Spatial and chronological differences in hepatitis B virus genotypes from patients with acute hepatitis B in Japan, Fuminaka Sugauchi, Etsuro Orito, Tomoyoshi Ohno, Yasuhito Tanaka, Atsushi Ozasa, Jong Hon Kang, Joji Toyoda, Tomoyuki Kuramitsu, Kazuyuki Suzuki, Eiji Tanaka, Yoshihiro Akahane, Takafumi Ichida, Namiki Izumi, Kazuaki Inoue, Hiromi Hoshino, Shiro Iino, Hiroshi Yotsuyanagi, Shinichi Kakumu, Eiichi Tomita, Takeshi Okanoue, Shuhei Nishiguchi, Yoshikazu Murawaki, Keisuke Hino, Morikazu Onji, Hiroshi Yatsuhashi, Michio Sata, Yuzo Miyakawa, Ryuzo Ueda, Masashi Mizokami, Hepatology Research, 36, 107 - 114,   2006年10月, Genotypes of hepatitis B virus (HBV) were determined in 485 patients with acute hepatitis B from all over Japan. They were A in 92 (19%), Ba in 26 (5%), Bj in 32 (7%), C in 330 (68%) and D in 5 (1%). Sexual contacts were the main route of transmission in them. Overall, HBV persisted in only 5 of the 464 (1%) followed patients. Genotypes C accounted for more than 68% in northern as well as southern areas, contrasting with genotype A accounting for 34% in and around the Metropolitan areas. During 24 years from 1982 to 2005, genotype A increased from 5% to 33%, while genotype B gradually decreased from 26% to 8%. Fulminant hepatitis was significantly more frequent in infection with genotype Bj (41%) than those with the other genotypes (p < 0.01). The core-promoter double mutation (T1762/A1764) and precore stop-codon mutation (A1896) were more frequent in patients with fulminant than acute self-limited hepatitis (57% versus 15% and 58% versus 10%, respectively, p < 0.01 for both). In conclusion, genotype A distributes unevenly over Japan, prevails in younger patients through sexual transmission and has increased with years. Furthermore, fulminant outcome was more frequent in patients with genotype Bj than those with the other genotypes. © 2006 Elsevier Ireland Ltd. All rights reserved.
  • Phylogenetic relatedness and genetic diversity of hepatitis B virus isolates in Eastern India, Arup Banerjee, Fuat Kurbanov, Sibnarayan Datta, Partha Kumar Chandra, Yasuhito Tanaka, Masashi Mizokami, Runu Chakravarty, Journal of Medical Virology, 78, 1164 - 1174,   2006年09月, Hepatitis B virus (HBV) has been classified into eight genotypes, and several subgenotypes, distinctly distributed geographically. The genotypes A and D were previously reported to be predominant in India. Recent studies indicated evidence of circulation of genotype C in Eastern part of India. With the aim to confirm the phylogenetic relation and molecular genetic characteristics of the HBV circulating in Kolkata, the most populous city in Eastern India, 11 strains were isolated and the complete genome sequences were analyzed. Phylogenetic analysis determined; three genotype C (adr-serotype) isolates closely related with C1 (Cs) subgenotype references from South East Asia, and three genotype A (adw2-serotype) isolates, related to Asia-variant references of subgenotype A1 (Aa). Whereas, five genotype D (ayw2, ayw3 serotype) isolates were highly divergent; one was related to subgenotype D1, two to subgenotype D3, and the remaining two clustered with a single genotype D isolate from Japan belonging to an unclassified subgenotype. Together, these two isolates differed from HBV D1-D4 subgenotypes by nucleotide differences ranging from 5.0 to 5.49%, probably indicating a new subgenotype, which we designate as D5. All serotype ayw3 of genotype D isolates had specific amino acid substitution Threonine at codon 118 and Methionine at codon 125 in antigenic determinant of surface gene that has not been reported previously in isolates from other parts of India. In conclusion; using the complete genome analyses this study has confirmed circulation of the genotype C in Eastern part of India and demonstrated considerable genotypic heterogeneity of the Indian genotype D. © 2006 Wiley-Liss, Inc.
  • Molecular epidemiology of hepatitis B virus in the United Republic of Tanzania, Izumi Hasegawa, Yasuhito Tanaka, Fuat Kurbanov, Namiko Yoshihara, Ahmed El-Gohary, Eligius Lyamuya, Mecky Matee, Pius Magessa, Kei Fujiwara, Atsushi Ozasa, Fuminaka Sugauchi, Etsuro Orito, Ryuzo Ueda, Masashi Mizokami, Journal of Medical Virology, 78, 1035 - 1042,   2006年08月, In the United Republic of Tanzania, 457 voluntary blood donors were enrolled in hepatitis B virus (HBV) serological screening; 4.8% (22/457) carried HBsAg, 13.6% (3/22) of whom were HBeAg-positive. The mean age among HBeAg-negative carriers was 31 years, HBV DNA was detectable in 81.8% (18/22), the mean level was 3.67 (±1.77) log copies/ml. Genotype A was determined in 90.9% (20/22) and 18/20 were classified into subgenotype Aa (Asia/Africa), The basal core promoter, precore and partial core nucleotide sequences were analyzed in the 18 strains; T1809/T1812 ("Kozak" sequence) and A/T1888 (encapsidation signal) variants were identified in 100% and 78%, respectively. The complete genome sequencing for one of the Tanzanian strains revealed no recombination. In conclusion, HBV seroprevalence is high among general population in Tanzania, and the HBV/Aa-infection is predominant. The indicated tendency to early HBeAg seroconversion and declining of the viral load should be confirmed further in case-control studies. © 2006 Wiley-Liss, Inc.
  • Influence of genotypes and precore mutations on fulminant or chronic outcome of acute hepatitis B virus infection, Atsushi Ozasa, Yasuhito Tanaka, Etsuro Onto, Masaya Sugiyama, Jong Hon Kang, Shuhei Hige, Tomoyuki Kuramitsu, Kazuyuki Suzuki, Eiji Tanaka, Shunichi Okada, Hajime Tokita, Yasuhiro Asahina, Kazuaki Inoue, Shinichi Kakumu, Takeshi Okanoue, Yoshikazu Murawaki, Keisuke Hino, Morikazu Onji, Hiroshi Yatsuhashi, Hiroshi Sakugawa, Yuzo Miyakawa, Ryuzo Ueda, Masashi Mizokami, Hepatology, 44, 326 - 334,   2006年08月, The outcome of acute hepatitis B virus (HBV) infection is variable, influenced by host and viral factors. From 1982 through 2004, 301 patients with acute HBV infection entered a multi-center cross-sectional study in Japan. Patients with fulminant hepatitis (n = 40) were older (44.7 ± 16.3 vs. 36.0 ± 14.3 years, P < .0017), less predominantly male (43% vs. 71%, P = .0005), less positive for hepatitis B e antigen (HBeAg) (23% vs. 60%, P < .0001), less infected with subgenotype Ae (0% vs. 13%, P < .05), and more frequently with Bj (30% vs. 4%, P < .0001) than those with acute self-limited hepatitis (n = 261). Precore (G1896A) and core-promoter (A1762T/G1764A) mutations were more frequent in patients with fulminant than acute self-limited hepatitis (53% vs. 9% and 50% vs. 17%, P < .0001 for both). HBV infection persisted in only three (1%) patients, and they represented 2 of the 23 infected with Ae and 1 of the 187 with the other subgenotypes (9% vs. 0.5%, P = .032); none of them received antiviral therapy. In multivariate analysis, age 34 years or older, Bj, HBeAg-negative, total bilirubin 10.0 mg/dL or greater, and G1896A mutation were independently associated with the fulminant outcome. In in vitro transfection experiments, the replication of Bj clone was markedly enhanced by introducing either G1896A or A1762T/G1764A mutation. In conclusion, persistence of HBV was rare (1%) and associated with Ae, whereas fulminant hepatitis was frequent (13%) and associated with Bj and lack of HBeAg as well as high replication due to precore mutation in patients with acute HBV infection. Copyright © 2006 by the American Association for the Study of Liver Diseases.
  • Fundamental and clinical evaluation of hepatitis B virus core-related antigen assay by LUMIPULSE f, Yasuhito Tanaka, Kazumi Takagi, Kumiko Hiramatsu, Hatsue Naganuma, Takayasu Iida, Yoshimitsu Takasaka, Masashi Mizokami, Rinsho byori. The Japanese journal of clinical pathology., 54, 692 - 698,   2006年07月01日, A sensitive chemiluminescence enzyme immunoassay (CLEIA) has been developed for hepatitis B virus (HBV) core-related antigens (HBcrAg) detection. The HBcrAg is designated as the precore/core gene products including HBeAg. The aim of this study is to evaluate reproducibility of HBcrAg and correlation with HBV-DNA in serum using the automatic LUMIPULSE f to estimate an assay suitable for general laboratory use. In this study, we demonstrated that HBcrAg assay had highly intra-assay reproducible [coefficients of variation(CVs); 2.8-5.2%] and inter-assay reproducible [CVs; 3.9-9.1%]. When the cutoff value was tentatively set at 1 kU/ml, all healthy controls (HBsAg/HBV-DNA negative; n=100) and anti-HCV antibody-positive (n=50) sera were identified as negative. The assay showed a detection limit of 0.5 kU/ml using four serially diluted HBV high-titer sera, indicating higher sensitivity than HBV-DNA (transcription-mediated amplification). The HBcrAg concentration correlated positively with serum HBV-DNA (n=125, r = 0.860, p < 0.0001) regardless of HBeAg, although the HBcrAg levels were higher in HBeAg-positive group than in HBeAg-negative group. In the natural course of HBV infection, the HBcrAg concentration usually changed in accordance with HBV-DNA levels, however during lamivudine therapy the change of HBcrAg was more gradual than that of HBV-DNA. In conclusion, HBcrAg concentration provides a reflection of HBV virus load equivalent to HBV-DNA level, and the assay therefore offers a simple method for monitoring hepatitis B patients.
  • Novel subtypes (subgenotypes) of hepatitis B virus genotypes B and C among chronic liver disease patients in the Philippines, Tomoyuki Sakamoto, Yasuhito Tanaka, Etsuro Orito, Jonard Co, Joseph Clavio, Fuminaka Sugauchi, Kiyoaki Ito, Atsushi Ozasa, Alvin Quino, Ryuzo Ueda, Jose Sollano, Masashi Mizokami, Journal of General Virology, 87, 1873 - 1882,   2006年07月, Several hepatitis B virus (HBV) subtypes (subgenotypes), HBV/Aa (A1:Asia/ Africa), Ae (A2:Europe), Bj (B1:Japan) and Ba (B2:Asia), have been reported with respect to clinical differences between patients infected with these subtypes (subgenotypes). HBV genotype distribution among patients with chronic liver diseases was investigated in the Philippines, where such studies have not been carried out previously. One hundred sera were obtained from such patients, consisting of 32 chronic hepatitis (CH), 37 cirrhosis and 31 hepatocellular carcinoma (HCC) patients. Nine complete genomes and 100 core promoter/precore genes of HBV were sequenced directly. Phylogenetic analyses revealed 51 HBV/A (Aa/A1), 22 HBV/B and 27 HBV/C strains. Interestingly, most HBV/C strains in the Philippines formed a specific cluster distinct from previous HBV/C strains (C1-4), indicating a novel subtype (subgenotype), HBV/C5. Moreover, most HBV/B strains fell within the specific cluster of the HBV/B subtype (subgenotype) B5, with viral characteristics of HBV/Ba (B2) carrying a recombination with HBV/C over the precore and core genes. Of the three genotypes, HBV/B and HBV/C were significantly more prevalent than HBV/A in cirrhosis and HCC patients (P<0.02). The prevalence of the core promoter mutations T1762/A1764 was higher in HCC patients with HBV/B and HBV/C. Multivariate analysis indicated that age [odds ratio (OR) 3.43; 95% confidence interval (CI) 1.04-11.36; P=0.044] and the core promoter mutation (OR 14.08; 95% CI 3.62-4.74; P<0.001) were significant factors for HCC development. In conclusion, novel HBV subtypes (subgenotypes) C5 and B5 are prevalent in the Philippines, as well as HBV/Aa (A1). © 2006 SGM.
  • A case-control study of response to lamivudine therapy for 2 years in Japanese and Chinese patients chronically infected with hepatitis B virus of genotypes Bj, Ba and C, Etsuro Orito, Kei Fujiwara, Yasuhito Tanaka, Man Fung Yuen, Ching Lung Lai, Takanobu Kato, Fuminaka Sugauchi, Atsunori Kusakabe, Michio Sata, Takeshi Okanoue, Hirofumi Niitsuma, Hiroshi Sakugawa, Izumi Hasegawa, Masashi Mizokami, Hepatology Research, 35, 127 - 134,   2006年06月01日, Background/aims: In eastern Asian countries, hepatitis B virus (HBV) genotype Ba (HBV/Ba), HBV/Bj and HBV/C are prevalent. The aim was to investigate the response or resistance to lamivudine therapy among patients with different HBV genotypes. Methods: Of 67 Japanese and Chinese patients with chronic hepatitis B, 18 patients with HBV/Bj, 15 with HBV/Ba and 34 with HBV/C were selected for a case-control study matched according to gender and age. All the patients were treated with lamivudine for 2 years and evaluated the response or emergence of the YMDD mutation at year 2 during the treatment. HBV genotypes were detected by the restriction fragment length polymorphism. The YMDD mutation was detected by the direct sequencing after amplification by PCR. Results: At year 2 during therapy, 44.8% of the patients showed normalization of ALT and undetectable HBV DNA (favorable response), 35.8% developed the YMDD mutation. There was no significant difference of response to the therapy among the three genotype groups. The emergence of the YMDD mutation was associated with HBV/C. By the multiple logistic regression analysis, however, the significant factor of a favorable response was a higher pretreatment ALT level and negative HBeAg status and the significant factor of the emergence of the YMDD mutation was HBV/C. Conclusions: Higher pretreatment ALT level, HBeAg status or HBV genotype may affect the response or resistance to lamivudine therapy. © 2006 Elsevier Ireland Ltd. All rights reserved.
  • A case of acute hepatitis C in which transmission of HCV strain from a patient with chronic hepatitis C was demonstrated, Hideaki Kato, Etsuro Orito, Yuji Nishi, Makoto Ohyama, Makoto Nakamura, Yutaka Kondo, Fuminaka Sugauchi, Yasuhito Tanaka, Masashi Mizokami, Acta Hepatologica Japonica, 47, 105 - 112,   2006年04月18日, A 32-year-old male was admitted to Toyokawa City Hospital because of jaundice and dark brown urine. Laboratory findings showed that abnormality of liver function test, and positive for anti-HCV as well as HCV RNA but negative for other virus markers. Thus he was diagnosed as acute hepatitis C. After admission, his clinical course was uneventful and he was discharged 18 days later. He (patient 1) confessed that he shared unsterilized syringe with his friend (patient 2) who had been to our hospital for chronic hepatitis C. Molecular biological analysis was carried out within E1 as well as NS5B region of HCV isolated from the two patients. The nucleotide sequences of E1 and NS5B region of patient 1 were identical to those of patient 2. Phylogenetic analysis was also carried out and revealed that these 2 strains were classified into genotype 2a. These findings indicated that acute hepatitis C was caused by HCV strain transmitted from patient 2 to patient 1 via sharing of unsterilized syringe. Further investigations of HCV infection among intravenous drug users (IDUs) in Japan as well as education to IDUs are required.
  • Molecular tracing of Japan-indigenous hepatitis E viruses, Yasuhito Tanaka, Kazuaki Takahashi, Etsuro Orito, Yoshiyasu Karino, Jong Hon Kang, Kazuyuki Suzuki, Atsushi Matsui, Akiko Hori, Hiroyuki Matsuda, Hiroshi Sakugawa, Yasuhiro Asahina, Tsuneo Kitamura, Masashi Mizokami, Shunji Mishiro, Journal of General Virology, 87, 949 - 954,   2006年04月01日, The ancestor(s) of apparently Japan-indigenous strains of Hepatitis E virus (HEV) was probably of foreign origin, but it remains unclear when and from where it made inroads. In this study, 24 genotype 3 and 24 genotype 4 HEV strains recovered in Japan each showed a significant cluster, clearly distinct from those of foreign strains, in the phylogenetic tree constructed from an 821 nt RNA polymerase gene fragment. The evolutionary rate, approximately 0.8 × 10-3nucleotide substitutions per site per year, enabled tracing of the demographic history of HEV and suggested that the ancestors of Japan-indigenous HEV had made inroads around 1900, when several kinds of Yorkshire pig were imported from the UK to Japan. Interestingly, the evolutionary growth of genotype 3 in Japan has been slow since the 1920s, whereas genotype 4 has spread rapidly since the 1980s. In conclusion, these data suggest that the indigenization and spread of HEV in Japan were associated with the popularization of eating pork. © 2006 SGM.
  • Clinical manifestations of hepatitis B virus genotype, Yasuhito Tanaka, Masashi Mizokami, Rinsho byori. The Japanese journal of clinical pathology., 54, 400 - 407,   2006年04月01日, Eight genotypes of hepatitis B virus (HBV) have been detected by sequence divergence > 8% in the entire HBV genome of about 3,200 nucleotides (nt), and designated by capital letters from A to H in the order of documentation. They have distinct geographical distribution and influence the severity of liver disease as well as the response to antiviral therapies. Furthermore, subgenotypes have been reported for genotypes A (HBV/A), B and C, and named Aa/A1 (Asian/African type) and Ae/A2 (European type), Bj/B (Japanese type) and Ba/B2 (Asian type), and Cs/C1 (Southeast Asian type) and Ce/C2 (East Asian type). There have been increasing lines of evidence that subgenotypes of A and B influence the replication of HBV and are clinically relevant. In Japan, mass vaccination has not been performed because of the extremely high efficacy of immunoprophylaxis on babies born to carrier mothers; it has decreased the persistent HBV carrier state from 1.4% to 0.03%. However, HBV/Ae of the European type has increased in young male adults by sexual transmission because the foreign genotypes have been imported from sexual workers where the genotypes are prevalent. Here, we summarize the clinical manifestations of HBV genotypes.
  • Molecular Tracing of Global Hepatitis C Virus Epidemic Predicts Regional Patterns of Hepatocellular Carcinoma Mortality. (共著), Tanaka Y, Kurbanov F, Mano S, Orito E, Vargas V, Esteban JI, Yuen MF, Lai CL, Kramvis A, Kew MC, Smuts HE, Netesov SV, Alter HJ, Mizokami M, Gastroenterology, 130, (3) 703 - 714,   2006年03月, 査読有り
  • Measurement of hepatitis B virus core-related antigen is valuable for identifying patients who are at low risk of lamivudine resistance, Eiji Tanaka, Akihiro Matsumoto, Fumitaka Suzuki, Mariko Kobayashi, Masashi Mizokami, Yasuhito Tanaka, Takeshi Okanoue, Masahito Minami, Kazuaki Chayama, Michio Imamura, Hiroshi Yatsuhashi, Shinya Nagaoka, Hiroshi Yotsuyanagi, Sumio Kawata, Tatsuji Kimura, Noboru Maki, Shiro Iino, Kendo Kiyosawa, Kiyomi Yasuda, Hitoshi Togashi, Takatumi Saito, Masataka Tsuge, Rumiko Nakao, Chiaki Okuse, Hideaki Takahashi, Liver International, 26, 90 - 96,   2006年02月01日, Objective: The clinical usefulness of hepatitis B virus core-related antigen (HBVcrAg) assay was compared with that of HBV DNA assay in predicting the occurrence of lamivudine resistance in patients with chronic hepatitis B. Patients: Of a total of 81 patients who were treated with lamivudine, 25 (31%) developed lamivudine resistance during a median follow-up period of 19.3 months. Results: The pretreatment positive rate of HBe antigen, or pretreatment levels of HBVcrAg or HBV DNA did not differ between patients with and without lamivudine resistance. Levels of both HBVcrAg and HBV DNA decreased after the initiation of lamivudine administration; however, the level of HBVcrAg decreased significantly more slowly than that of HBV DNA. The occurrence of lamivudine resistance was significantly less frequent in the 56 patients whose HBV DNA level was less than 2.6log copy/ml at 6 months of treatment than in the remaining 25 patients. The cumulative rate of lamivudine resistance was as high as 70% within 2 years in the latter group, while it was only 28% in the former group. Lamivudine resistance did not occur during the follow-up period in the 19 patients whose HBVcrAg level was less than 4.6 log U/ml at 6 months of treatment, while it did occur in 50% of the remaining patients within 2 years. Conclusion: These results suggest that measurement of HBV DNA is valuable for identifying patients who are at high risk of developing lamivudine resistance, and that, conversely, measurement of HBVcrAg is valuable for identifying those who are at low risk of lamivudine resistance. Copyright © Blackwell Munksgaard 2005.
  • Prevalence of low positive anti-HCV antibodies in blood donors: Schistosoma mansoni co-infection and possible role of autoantibodies, Salah Agha, Noha El-Mashad, Mohamed El-Malky, Mohamed El-Malky, Huda El-Shony, Mohamed Zaki El-Sherif, Mohamed Abo El-Hasan, Yasuhito Tanaka, Masashi Mizokami, Microbiology and Immunology, 50, 447 - 452,   2006年01月01日, Patients infected with schistosoma frequently show a high seroprevalence of anti-hepatitis C virus (anti-HCV) antibodies. The aim of this study was to find the underlying reason for this phenomenon, and to examine a possible involvement of autoantibodies. Out of 2,400 Egyptian blood donors, 192 (8%) were anti-HCV positive by ELISA. They were 133 males and 59 females with age ranging from 27 to 48 years. According to optical density ratio (ODR) of anti-HCV antibodies, 96 cases were low positive (LP) with ODR (1-2) designated as group I, and 96 were high positive (HP) with ODR (≥2) (group II). Both groups were examined for quantitative HCV core antigen (HCVcAg), liver function (Albumin, ALT, AST) and anti-Schistosoma mansoni (anti-Sm) IgG. Group I cases were HCVcAg negative with normal liver function tests, and 44 of them were anti-Sm positive. Ninety cases (93.75%) of group II were HCVcAg positive with markedly affected liver function tests and 72 cases were anti-Sm positive. All group I cases were examined for autoimmune markers (ANA, AMA, SMA and LKM). In group I, 33 (75%) of anti-Sm positive cases were positive for one or more of the autoimmune markers examined, while none of anti-Sm negative was positive for any marker with significant difference between the two groups (P>0.0001). Our results primarily on blood donors indicate that LP anti-HCV frequently represents false-positive reactivity with a possible role of Sm-induced autoantibodies in this phenomenon.
  • Spread times of hepatitis C virus estimated by the molecular clock differ among Japan, the United States and Egypt in reflection of their distinct socioeconomic backgrounds, Masashi Mizokami, Masashi Mizokami, Yasuhito Tanaka, Yuzo Miyakawa, Intervirology, 49, 28 - 36,   2006年01月01日, Infection with hepatitis C virus (HCV) is taking an ever increasing role in the development of hepatocellular carcinoma (HCC) over the world. Dynamics of HCV infection were determined by the molecular clock, estimating the dissemination time when HCV entered the country and the 'spread time' when it started to grow exponentially on a national scale. A comparison of HCV dynamics in Japan, the United States and Egypt has disclosed different dissemination and spread times among the three countries. Furthermore, they faithfully mirror socioeconomic as well as medical and paramedical events inherent to each country responsible for the wide spread of HCV infection during the past. Epidemic histories of HCV would enable us to predict what is going to happen in the future for HCV infection, in special reference to HCC associated with it. Population dynamics of HCV need to be determined in other countries where HCV prevails and compared with those in the three countries described. These studies should help foresee what will happen in the near future for HCV infection in a given country, time the future development of HCC and take measures for preventing it. Copyright © 2006 S. Karger AG.
  • Tracing the history of hepatitis B virus genotype D in Western Japan, Kojiro Michitaka, Yasuhito Tanaka, Norio Horiike, Tran Nhu Duong, Yan Chen, Kana Matsuura, Yoichi Hiasa, Masashi Mizokami, Morikazu Onji, Morikazu Onji, Journal of Medical Virology, 78, 44 - 52,   2006年01月, The major hepatitis B virus (HBV) genotypes in Japan are B and C. HBV genotype D (HBV/D), however, is widespread in a small area of Western Japan, where the Gianotti-Crosti syndrome caused by HBV subtype ayw, which is suspected to be HBV/D, was endemic in the 1970s. The aim of the study was to elucidate its origin, time of transmission, and spread in this area. Genotyping of HBV-DNA was done in 363 patients with HBV infection. The year of birth was checked in patients with HBV/D. The full genome sequences of 20 HBV/D strains, 2 of which were obtained from a single carrier with a 19-year-interval, were analyzed. An evolutionary rate, the date of the most recent common ancestor, and the effective number of HBV/D infections were calculated. Fifty-two of 363 patients were infected with HBV/D, and 39 were born in 1970s. In a phylogenetic tree, the 20 HBV/D strains produced a definite cluster, and the evolutionary rate was calculated to be 5.4 × 10-5nucleotide substitutions/site/year. The root of the tree was estimated to be in approximately 1,900 and began to spread from the 1940s, leading to a rapid increase of infected patients in the 1970s. From these results, it is suspected that HBV/D was likely transmitted to the area investigated approximately 100 years ago and then spread widely in the 1970s. From the history of the area and the genetic analysis, HBV/D in this area was speculated to be of Russian origin. © 2005 Wiley-Liss, Inc.
  • T1653 mutation in the box α increases the risk of hepatocellular carcinoma in patients with chronic hepatitis B virus genotype C Infection, Kiyoaki Ito, Yasuhito Tanaka, Etsuro Orito, Masaya Sugiyama, Kei Fujiwara, Fominaka Sugauchi, Takanobu Kato, Hajime Tokita, Namiki Izumi, Michio Kato, Man Fung Yuen, Ching Lung Lai, Robert G. Gish, Ryuzo Ueda, Masashi Mizokemi, Clinical Infectious Diseases, 42, 1 - 7,   2006年01月, Background. Most patients with chronic hepatitis B virus infection become carriers of inactive virus after hepatitis B e antigen seroconversion; however, a subgroup of patients have persistent abnormal transaminase levels and develop hepatocellular carcinoma after seroconversion. Methods. In an age-matched case-control study, 40 carriers of inactive virus (mean age ± standard deviation [SD], 50.9 ± 11.1 years), 40 parents with chronic hepatitis (mean age ± SD, 50.2 ± 8.9 years), and 40 patients with hepatocellular carcinoma (mean age ± SD, 50.7 ± 9.4 years) who were infected with hepatitis B virus genotype C and had test results positive for antibody to hepatitis B e antigen were analyzed. Results. The prevalence of T1653 in the box α was significantly higher among patients with hepatocellular carcinoma than among carriers|of inactive virus who did not have hepatocellular carcinoma (70% vs. 25%; P < .0001) or chronic hepatitis (70% vs. 35%; P = .003). Mutations in the basic core promoter region (T1762/A1764) were frequently found in all groups, regardless of clinical status (in 77.5% of carriers of inactive virus, 77.5% of patients with chronic hepatitis, and 90% of patients with hepatocellular carcinoma). In the multivariate analysis, the presence of T1653, an alanine aminotransferase level of ≥ 37 U/L, and a platelet count of < 18 × 104platelets/ mm3were independent predictive values for hepatocellular carcinoma (odds ratio [95% confidence interval], 5.05 [1.56-16.35], 12.56 [3.05-51.77], and 11.5 [3.47-38.21], respectively). High α-fetoprotein level was the only independent predictive value for T1653 in patients with hepatocellular carcinoma (odds ratio, 12.67; 95% confidence interval, 1.19-134.17]). Among patients with test results positive for antibody to hepatitis B e antigen who had hepatocellular carcinoma and were infected with different genotypes of hepatitis B virus, the prevalence of T1653 was 40%, 15%, 25%, 25%, 67%, and 23% in patients infected with hepatitis B virus genotypes Aa, Ae, Ba, Bj, C, and D, respectively (P < .05 for genotype C vs. genotypes Ae, Ba, Bj, or D). Conclusions. Our data indicate that the addition of T1653 mutation in the box a to the basic core promoter mutation increases the risk of hepatocellular carcinoma in patients with hepatitis B virus genotype C. © 2005 by the Infectious Diseases Society of America. All rights reserved.
  • Distribution of HBV genotypes among HBV carriers in Benin: Phyologenetic analysis and virological characteristics of HBV genotype E, Kei Fujiwara, Yasuhito Tanaka, Etsuro Orito, Tomoyoshi Ohno, Takanobu Kato, Kanji Sugihara, Izumi Hasegawa, Mayumi Sakurai, Kiyoaki Ito, Atsushi Ozasa, Yuko Sakamoto, Isao Arita, Ahmed El-Gohary, Agossou Benoit, Sophie I. Ogoundele-Akplogan, Namiko Yoshihara, Ryuzo Ueda, Masashi Mizokami, World Journal of Gastroenterology, 11, 6410 - 6415,   2005年11月07日, Aim: To determine the distribution of Hepatitis B virus (HBV) genotypes in Benin, and to clarify the virological characteristics of the dominant genotype. Methods: Among 500 blood donors in Benin, 21 HBsAg-positive donors were enrolled in the study. HBV genotypes were determined by enzyme immunoassay and restriction fragment length polymorphism. Complete genome sequences were determined by PCR and direct sequencing. Results: HBV genotype E (HBV/E) was detected in 20/21 (95.2%), and HBV/A in 1/21 (4.8%). From the age-specific prevalence of HBeAg to anti-HBe seroconversion (SC) in 19 HBV/E subjects, SC was estimated to occur frequently in late teens in HBV/E. The comparison of four complete HBV/E genomes from HBeAg-positive subjects in this study and five HBV/E sequences recruited from the database revealed that HBV/E was distributed throughout West Africa with very low genetic diversity (nucleotide homology 96.7-99.2%). Based on the sequences in the basic core promoter (BCP) to precore region of the nine HBV/E isolates compared to those of the other genotypes, a nucleotide substitution in the BCP, G1757A, was observed in HBV/E. Conclusion: HBV/E is predominant in the Republic of Benin, and SC is estimated to occur in late teens in HBV/E. The specific nucleotide substitution G1757A in BCP, which might influence the virological characteristics, is observed in HBV/E. © 2005 The WJG Press and Elsevier Inc. All rights reserved.
  • Detection of anti-hepatitis C virus effects of interferon and ribavirin by a sensitive replicon system, Takanobu Kato, Takanobu Kato, Tomoko Date, Michiko Miyamoto, Masaya Sugiyama, Yasuhito Tanaka, Etsuro Orito, Tomoyoshi Ohno, Kanji Sugihara, Izumi Hasegawa, Kei Fujiwara, Kiyoaki Ito, Atsushi Ozasa, Masashi Mizokami, Takaji Wakita, Takaji Wakita, Journal of Clinical Microbiology, 43, 5679 - 5684,   2005年11月01日, Although combination therapy with interferon and ribavirin has improved the treatment for chronic hepatitis C virus (HCV) infection, the detailed anti-HCV effect of ribavirin in clinical concentrations remains uncertain. To detect the anti-HCV effect of ribavirin in lower concentrations, a sensitive and accurate assay system was developed using the reporter replicon system with an HCV genotype 2a subgenomic replicon (clone JFH-1) that exhibits robust replication in various cell lines. This reporter replicon was generated by introducing the luciferase reporter gene (instead of the neomycin resistance gene) into the subgenomic JFH-1 replicon. To assess the replication of this reporter replicon, luciferase activity was measured serially up to day 3 after transient transfection of Huh7 cells. The luciferase activity increased exponentially over the time course of the experiment. After adjustment for transfection efficiency and transfected cell viability, the impacts of interferon and ribavirin were determined. The administration of interferon and ribavirin resulted in dose-dependent suppression of replicon RNA replications. The 50% inhibitory concentration of interferon and ribavirin was 1.80 IU/ml and 3.70 μg/ml, respectively. In clinical concentrations, replications were reduced to 0.09% and 53.74% by interferon (100 IU/ml) and ribavirin (3 μg/ml), respectively. Combination use of ribavirin and interferon enhanced the anti-HCV effect of interferon by 1.46- to 1.62-fold. In conclusion, we developed an accurate and sensitive replicon system, and the antivirus effect of interferon and ribavirin was easily detected within their clinical concentrations by this replicon system. This system will provide a powerful tool for screening new antiviral compounds against HCV. Copyright © 2005, American Society for Microbiology. All Rights Reserved.
  • Two subtypes (subgenotypes) of hepatitis B virus genotype C: A novel subtyping assay based on restriction fragment length polymorphism, Yasuhito Tanaka, Etsuro Orito, Man Fung Yuen, Motokazu Mukaide, Fuminaka Sugauchi, Kiyoaki Ito, Atsushi Ozasa, Tomoyuki Sakamoto, Fuat Kurbanov, Ching Lung Lai, Masashi Mizokami, Hepatology Research, 33, 216 - 224,   2005年11月01日, Recently hepatitis B virus genotype C (HBV/C) has been classified into geographically typical two subtypes (subgenotypes); HBV/C1 in Southeast Asia (Cs) and HBV/C2 in East Asia (Ce). Our aim is to develop a rapid subtyping assay and to examine the virological features of these two subtypes. Based on 171 HBV/C strains retrieved from the database, 17 single nucleotides polymorphisms (SNPs) were found between two subtypes. Taking advantage of five SNPs in non-overlapping polymerase region, a restriction fragment length polymporphism method with three endonucleases was newly developed for distinguishing between HBV/Cs and HBV/Ce. The method was applied to 49 HBV/C carriers from Japan and Hong Kong. The 24 in Hong Kong were classified into HBV/Cs, and the 25 in Japan were HBV/Ce, confirmed by sequencing. Some specific mutations were detected in the encapsidation signal; precore stop mutation (A1896), accompanied by a C-to-T substitution at nt 1858, was found in HBV/Ce strains, and another precore mutation (A1898), accompanied by a C-to-T mutation at nt 1856, was found in HBV/Cs. Especially, two closely linked mutations (A1896 and A1899) in HBV/Ce could stabilize the epsilon loop structure more efficiently and influece viral replication. Hence, these virological differences between the two subtypes might influence clinical features. © 2005 Elsevier Ireland Ltd. All rights reserved.
  • Novel type of hepatitis B virus mutation: Replacement mutation involving a hepatocyte nuclear factor 1 binding site tandem repeat in chronic hepatitis B virus genotype E, Kei Fujiwara, Kei Fujiwara, Yasuhito Tanaka, Emma Paulon, Etsuro Orito, Masaya Sugiyama, Kiyoaki Ito, Ryuzo Ueda, Masashi Mizokami, Masashi Mizokami, Nikolai V. Naoumov, Journal of Virology, 79, 14404 - 14410,   2005年11月01日, The genetic diversity of hepatitis B virus (HBV) strains has evolved through mutations such as point mutations, deletions or insertions, and recombination. We identified and characterized a novel type of mutation which is a complex of external insertion, deletion, and internal duplication in sequences from one of six patients with chronic hepatitis B virus genotype E (HBV/E). We provisionally named this mutation a "replacement mutation"; the core promoter upstream regulatory sequence/basic core promoter was replaced with a part of the S1 promoter covering the hepatocyte nuclear factor 1 (HNF1) binding site, followed by a tandem repeat of the HNF1 site. A longitudinal analysis of the HBV population over 6 years showed the clonal change from wild-type HBV/E to replacement-mutant type, resulting in a lower hepatitis B (HB) e antigen titer, a high HBV DNA level in serum, and progression of liver fibrosis. In an in vitro study using a replication model, the replacement-mutant HBV showed higher replication levels than the wild-type HBV/E replicon, probably mediated by altered transcription factor binding. Additionally, this HNF1 site replacement mutation was associated with excessive HB nucleocapsid protein expression in hepatocytes, in both in vivo and in vitro studies. This novel mutation may be specific to HBV genotype E, and its prevalence requires further investigation. Copyright © 2005, American Society for Microbiology. All Rights Reserved.
  • Classifying genotype F of hepatitis B virus into F1 and F2 subtypes, Hideaki Kato, Kei Fujiwara, Robert G. Gish, Hiroshi Sakugawa, Hiroshi Yoshizawa, Fuminaka Sugauchi, Etsuro Orito, Ryuzo Ueda, Yasuhito Tanaka, Takanobu Kato, Yuzo Miyakawa, Masashi Mizokami, World Journal of Gastroenterology, 11, 6295 - 6304,   2005年10月28日, Aim: To explore the propriety of providing hepatitis B Virus (HBV) genotypes F and H with two distinct genotypes. Methods: Eleven HBV isolates of genotype F (HBV/F) were recovered from patients living in San Francisco, Japan, Panama, and Venezuela, and their full-length sequences were determined. Phylogenetic analysis was carried out among them along with HBV isolates previously reported. Results: Seven of them clustered with reported HBV/F isolates in the phylogenetic tree constructed on the entire genomic sequence. The remaining four flocked on another branch along with three HBV isolates formerly reported as genotype H. These seven HBV isolates, including the four in this study and the three reported, had a sequence divergence of 7.3-9.5% from the other HBV/F isolates, and differed by >13.7% from HBV isolates of the other six genotypes (A-E and G). Based on a marked genomic divergence, falling just short of >8% separating the seven genotypes, these seven HBV/F isolates were classified into F2 subtype and the former seven into F1 subtype provisionally. In a pairwise comparison of the S-gene sequences among the 7 HBV/F2 isolates and against 47 HBV/F1 isolates as well as 136 representing the other six genotypes (A-E and G), two clusters separated byrdistinct genetic distances emerged. Conclusion: Based on these analyses, classifying HBV/F isolates into two subtypes (F1 and F2) would be more appropriate than providing them with two distinct genotypes (F and H). © 2005 The WJG Press and Elsevier Inc. All rights reserved.
  • Tracing the evolution of hepatitis C virus in the United States, Japan, and Egypt by using the molecular clock, Masashi Mizokami, Masashi Mizokami, Yasuhito Tanaka, Clinical Gastroenterology and Hepatology, 3,   2005年10月01日, The molecular clock has been a very powerful tool in looking back at the epidemic spread of HCV infection in the United States (US) and Japan, as well as in Egypt. This analysis estimates that the growth of the US HCV genotype 1a (HCV-1a)-infected population occurred around 1960, at least 30 years later than the widespread introduction of HCV-1b into the Japanese population. In Japan, the estimated effective number of HCV infections indicated a rapid exponential growth in the 1920s among patients with schistosomiasis, which coincides with injection treatment for schistosomiasis since 1921 in previously schistosomiasis-endemic areas. In Egypt, the spread of HCV-4a would have increased exponentially during the 1940s through 1980, which was also consistent with the duration of intravenous antimony campaigns for the treatment of shistosomiasis in that country. The implications are that Japan has set the model for HCV-related HCC, and that the high HCC incidence in Japan might be replicated by the rest of the world as their HCV-infected population ages and the duration of HCV infection approaches that currently observed in Japan. © 2005 by the American Gastroenterological Association.
  • Hepatic necroinflammation and fibrosis in patients with genotypes Ba and C, core-promoter and precore mutations, Mang Fung Yuen, Mang Fung Yuen, Y. Tanaka, I. O.L. Ng, M. Mizokami, J. C.H. Yuen, D. K.H. Wong, H. J. Yuan, S. M. Sum, A. O.O. Chan, C. L. Lai, Journal of Viral Hepatitis, 12, 513 - 518,   2005年09月01日, The role of infection with hepatitis B virus (HBV) genotypes on liver histology is largely unknown. The aim of study was to investigate the relationships between HBV genotypes (B, C), core-promoter (CP) and precore mutants and liver histology in 66 patients. Liver biopsies were scored by histologic activity index (HAI). HBV genotypes were determined by enzyme-linked immunosorbent assay (ELISA). Eighteen (27.3%) and 48 patients (72.7%) had genotype B (all were subtype Ba) and C, respectively. Forty-seven (71.2%) and 27 (40.9%) had CP and precore mutations, respectively. Patients with genotype C compared with sub-type Ba had higher median scores of HAI-necroinflammation (HAI-NI) (7 vs 3), HAI-fibrosis (HAI-F) (1 vs 0) and total HAI (8.5 vs 3) (all P < 0.03). Patients with CP mutations compared with wild-type had higher median scores of HAI-NI (7 vs 3), HAI-F (3 vs 0) and total HAI (9 vs 3) (all P < 0.03). Forty patients (83.5%) with genotype C had CP mutations. Age and alanine aminotransferase levels were positively correlated with HAI scores while albumin levels were negatively correlated (P < 0.01 for all, except albumin levels and HAI-F, P = 0.08). There was no association between precore mutations and HAI scores. Multivariate analysis indicated that higher alanine aminotransferase (ALT) levels were associated with higher HAI scores (P < 0.04) and CP mutations were associated with higher HAI-NI (P = 0.034), but not with HAI-F score (P = 0.3). CP mutations were associated with more severe necroinflammation. The association between genotype C and poor histology was probably because of the association between genotype C and CP mutations. © 2005 Blackwell Publishing Ltd.
  • A new subtype (subgenotype) Ac (A3) of hepatitis B virus and recombination between genotypes A and E in Cameroon, Fuat Kurbanov, Yasuhito Tanaka, Kei Fujiwara, Fuminaka Sugauchi, Dora Mbanya, Leopold Zekeng, Nicaise Ndembi, Charlotte Ngansop, Lazare Kaptue, Tomoyuki Miura, Eiji Ido, Masanori Hayami, Hiroshi Ichimura, Masashi Mizokami, Journal of General Virology, 86, 2047 - 2056,   2005年07月01日, Blood samples (n=544) from two different populations (Pygmies and Bantus) in Cameroon, West Africa, were analysed. Serological tests indicated that the anti-hepatitis C virus (HCV) prevalence in Bantus (20.3 %) was higher than that in Pygmies (2.3 %, P<0.0001), whereas the distribution of hepatitis B virus (HBV) serological markers was equally high in both populations: in total, 9.4, 17.3 and 86.8 % for HBsAg, anti-HBs and anti-HBc, respectively. HBV genotype A (HBV/A) and HBV/E were predominant (43.5 % each) in both populations, and HBV/D was found in a minority (13 %). The preS/S region was sequenced in nine cases (five HBV/A and four HBV/E) and the complete genome in six cases (four HBV/A and two HBV/E). Subsequent phylogenetic analysis revealed that the HBV/A strains were distinct from the subtypes (subgenotypes) described previously, Ae (A2) and Aa (A1), and in the preS/S region they clustered with previously reported sequences from Cameroon. Based on the nucleotide difference from Aa (A1) and Ae (A2), more than 4 % in the complete genome, the Cameroonian strains were suggested to represent a new subtype (subgenotype), designated HBV/Ac (A3). A high (3.9 %) nucleotide divergence in HBV/Ac (A3) strains suggested that the subtype (subgenotype) has a long natural history in the population of Cameroon. One of the HBV/Ac (A3) strains was found to be a recombinant with an HBV/E-specific sequence in the polymerase reverse transcriptase domain. Further cohort studies will be required to assess detailed epidemiological, virological and clinical characteristics of HBV/Ac (A3), as well as its recombinant form. © 2005 SGM.
  • Differences of hepatocellular carcinoma patients with hepatitis B virus genotypes of Ba, Bj or C in Japan, Etsuro Orito, Fuminaka Sugauchi, Yasuhito Tanaka, Takafumi Ichida, Michio Sata, Eiji Tanaka, Takeshi Okanoue, Hiroshi Sakugawa, Hisatsuyo Watanabe, Hiroshi Miyakawa, Shuhei Nishiguchi, Hiromitsu Kumada, Ryuzo Ueda, Masashi Mizokami, Masashi Mizokami, Intervirology, 48, 239 - 245,   2005年07月01日, Hepatitis B virus (HBV) genotypes B (HBV/B) and C (HBV/C) are prevalent in Asia. Recently HBV/B has been classified into two subtypes, HBV/Ba which is ubiquitously found in Asia, and HBV/Bj which is specific in Japan. In addition, the frequency of positive HBeAg has been reported to be higher in patients with HBV/Ba than those with HBV/Bj. However, little is known about the differences between patients with various genotypes who developed hepatocellular carcinoma (HCC). In 296 serum samples of HCC patients collected from all over Japan, HBV genotypes were determined with the restriction fragment length polymorphism. HBV/A was detected in 1.0%, HBV/Ba in 4.4%, HBV/Bj in 7.4%, and HBV/C in 86.5%. In the Tohoku district and Okinawa, HBV/Ba, HBV/ Bj and HBV/C were found in 6.7, 40.0 and 48.9%, compared to 4.0, 1.6 and 93.2% in the other districts in Japan. HBV/Bj patients were more frequently found in the group older than 65 years while HBV/Ba patients were found in all age groups. The frequency of positive HBeAg in HBV/ Bj patients was significantly low compared to that in the other patients. More than 60% of the patients with HCC had cirrhosis as the underlying liver diseases. However, in HBV/Ba patients aged 50 years or younger, 80% of them had chronic hepatitis, while 87.5% of those aged older than 50 years had cirrhosis. These data suggest that great differences exist among patients with HCC infected with different genotypes. Copyright © 2005 S. Karger AG, Basel.
  • New combination test for hepatitis C virus genotype and viral load determination using Amplicor GT HCV MONITOR test v2.0, Motokazu Mukaide, Yasuhito Tanaka, Hirokazu Kakuda, Kei Fujiwara, Fuat Kurbanov, Eturo Orito, Kentaro Yoshioka, Kiyotaka Fujise, Shoji Harada, Takazumi Kozaki, Kazuo Takemura, Kazumasa Hikiji, Masashi Mizokami, World Journal of Gastroenterology, 11, 469 - 475,   2005年01月28日, Aim: To develop a new sensitive and inexpensive hepatitis C virus (HCV) combination test (HCV Guideline test) that enables the determination of HCV genotypes 1, 2 and 3, and simultaneous determination of HCV viral load using commercial Amplicor GT HCV MONITOR test v2.0 (microwell version). Methods: The HCV Guideline test used the PCR product generated in commercial Amplicor GT HCV Monitor test v2.0 for viral load measurement using microwell plate version of Amplicor HCV Monitor and also captured on separate plates containing capture probes and competitive oligonucleotide probes specific for HCV genotypes 1, 2 and 3, The HCV genotype was subsequently determined using the biotin-labeled PCR product and five biotin-labeled HCV-specific probes. Results: The sensitivity of the HCV Guideline test was 0.5 KIU/mL. Specificity of the HCV Guideline test was confirmed by direct sequencing of HCV core region and molecular evolutionary analyses based on a panel of 31 samples. The comparison of the HCV Guideline test and an in-house HCV core genotyping assay using 252 samples from chronic hepatitis C patients indicated concordant results for 97.2% of samples (59.5% genotype 1, 33.7% genotype 2, 6.0% genotype 3, and 0.8% mixed genotypes). Similarly, the HCV Guideline test showed concordance with a serological test, and the serological test failed to assign any serotype in 12.7% of the samples, indicating a better sensitivity of the HCV Guideline test. Conclusion: Clinically, both viral load and genotypes (1, 2 and 3) have been found to be major predictors of antiviral therapy outcome regarding chronic hepatitis C based on guidelines and they are, in normal circumstances, performed as separate stand-alone assays. The HCV Guideline test is a useful method for screening large cohorts in a routine clinical setting for determining the treatment regimen and for predicting the outcome of antiviral therapy of chronic hepatitis C. © 2005 The WJG Press and Elsevier Inc. All rights reserved.
  • Nucleic acid-based testing for hepatitis B viruss infectious disease, Yasuhito Tanaka, Masashi Mizokami, Nippon rinsho. Japanese journal of clinical medicine, 63 Suppl 12, 331 - 337,   2005年01月01日
  • Molecular evolutionary analyses implicate injection treatment for schistosomiasis in the initial hepatitis C epidemics in Japan, Yasuhito Tanaka, Kousuke Hanada, Etsuro Orito, Yoshihiro Akahane, Kazuaki Chayama, Hiroshi Yoshizawa, Michio Sata, Nobuo Ohta, Yuzo Miyakawa, Takashi Gojobori, Masashi Mizokami, Journal of Hepatology, 42, 47 - 53,   2005年01月01日, The mortality due to hepatocellular carcinoma (HCC) has ranged widely in various areas of Japan since 30 years ago and the incidence was particularly high in once Schistosoma japonicum (Sj)-endemic areas. Our aim was to estimate the spread time of hepatitis C virus (HCV) infection in the past with possible relevance to a higher incidence of HCC in once Sj-endemic than Sj-nonendemic areas. During 2001, 131 strains of HCV-1b were obtained from patients in three previously Sj-endemic areas, as well as Sj-nonendemic areas in Japan and a cross-sectional study was conducted on them with molecular evolutionary analyses. A phylogenetic tree reconstructed on HCV-1b sequences in the NS5B region disclosed 2 independent clusters for Sj-positive and -negative groups with a high bootstrap value. The estimated effective number of HCV-infections indicated a transition from quiescence to rapid exponential growth in the 1920s among patients with schistosomiasis, which is 20 years earlier than that among patients without schistosomiasis. The estimated spread time in previously Sj-endemic areas in Japan coincides with injection treatment for Sj since 1921. A high incidence of HCC there would be attributed to a long duration of HCV infection since 1920s. © 2004 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
  • Impact of occult hepatitis B virus infection on efficacy and prognosis of interferon-α therapy for patients with chronic hepatitis C, Izumi Hasegawa, Izumi Hasegawa, Etsuro Orito, Yasuhito Tanaka, Noboru Hirashima, Kenji Sakakibara, Mayumi Sakurai, Seiji Suzuki, Fuminaka Sugauchi, Tomoyoshi Ohno, Ryuzo Ueda, Masashi Mizokami, Liver International, 25, 247 - 253,   2005年01月01日, Background/Aims: It is reported that some patients with undetectable hepatitis B surface antigen (HBsAg) have serum hepatitis B virus (HBV) DNA in patients with chronic hepatitis C (HCV). The aim of this study was to elucidate the impact of occult HBV infection on the efficacy and prognosis of interferon-α (IFN) therapy in HCV patients. Methods: One hundred and forty HCV patients without HBsAg who received IFN therapy were studied. Serum HBV DNA was quantified by real-time detection polymerase chain reaction. Results: Of 140 patients, 11 (7.9%) were HBV DNA-positive before IFN therapy. The serum HBV DNA levels ranged from 106 to 884 copies/ml. Four of these 11 patients showed a sustained virologic response by IFN, compared with 39 of 129 without HBV DNA (P = NS). Interestingly, two of the 11 patients developed hepatocellular carcinoma (HCC) after therapy, compared with 16 of 129 without HBV DNA (P = NS). In the serial study, serum HBV DNA was transiently undetectable during and after IFN; however, most became positive during follow-up. Conclusions: Occult HBV infection may not have a significant impact on response to IFN therapy for chronic HCV and development of HCC after therapy. Occult HBV may be sensitive to IFN although HBV is not completely eradicated. © Blackwell Munksgaard 2005.
  • Hepatitis B virus genotype G is an extremely rare genotype in Japan, Hideaki Kato, Hideaki Kato, Fuminaka Sugauchi, Atsushi Ozasa, Takanobu Kato, Yasuhito Tanaka, Hiroshi Sakugawa, Michio Sata, Keisuke Hino, Morikazu Onji, Takeshi Okanoue, Eiji Tanaka, Sumio Kawata, Kazuyuki Suzuki, Shuhei Hige, Tomoyoshi Ohno, Etsuro Orito, Ryuzo Ueda, Masashi Mizokami, Hepatology Research, 30, 199 - 203,   2004年12月01日, Background: Hepatitis B virus (HBV) has been classified into seven genotypes (A-G). HBV genotypes have a geographically characteristic distribution. Since HBV genotype G (HBV/G) was identified recently, little is known about the distribution of HBV/G in Japan. The aim of this study was to clarify this issue. Patients and methods: Seven hundred and twenty-one serum samples obtained from patients with HBV in Japan were investigated. The patients included 149 asymptomatic carriers, 325 with chronic hepatitis, 129 with liver cirrhosis, and 118 with hepatocellular carcinoma. Six HBV genotypes (A-F) were determined by restriction fragment length polymorphim targeting to the S region of the HBV genome. Furthermore, HBV/G was investigated by polymerase chain reaction with hemi-nested primers derived from an HBV/G-specific nucleotide sequence. Results: Of the 721 serum samples investigated, 12 subjects were classified as having HBV/A, 88 HBV/B, 610 HBV/C, 3 HBV/D, and 1 HBV/F. Seven subjects had a mixed infection with distinct genotypes, two with HBV/A and HBV/D, and five with HBV/B and HBV/C. HBV/G was not identified among the 721 samples. Conclusion: HBV/G was not identified in a large cohort of patients with HBV, either single or dual infection. HBV/G seems to be an extremely rare genotype in Japan. © 2004 Elsevier B.V. All rights reserved.
  • Longitudinal study of hepatitis activity and viral replication before and after HBeAg seroconversion in chronic hepatitis B patients infected with genotypes B and C, Man Fung Yuen, Scott K. Fung, Yasuhito Tanaka, Takanobu Kato, Masashi Mizokami, John Chi Hang Yuen, Danny Ka Ho Wong, He Jun Yuan, Siu Man Sum, Annie On On Chan, Benjamin Chun Yu Wong, Ching Lung Lai, Ching Lung Lai, Journal of Clinical Microbiology, 42, 5036 - 5040,   2004年11月01日, The aims of this study were to compare chronic hepatitis B (CHB) patients with genotypes B and C for the probability of HBeAg seroconversion, hepatitis activity, and viral replication before and after HBeAg seroconversion and to compare the prevalence of core promoter and precore mutations. A total of 180 asymptomatic Chinese patients with CHB were monitored for a median of 53.8 months, and 38 patients with cirrhosis-related complications were studied. Hepatitis B virus (HBV) DNA levels were measured in 16 patients with HBeAg seroconversion at 3 months before, during, and 3 months after HBeAg seroconversion and in all patients at the last follow-up. Hepatitis B genotypes and core promoter and precore mutations were determined. Compared to patients with genotype C (n = 109), patients with subtype Ba (n = 69) had a higher rate of anti-HBe positivity on presentation (P = 0.05). HBeAg-positive patients with subtype Ba had a higher cumulative rate of HBeAg seroconversion than patients with genotype C (P = 0.02). However, there were no differences between the two groups with regard to the median HBV DNA levels before, during, and after HBeAg seroconversion; the probability of having persistently normal or elevated aminotransferase levels; and the median HBV DNA levels and liver biochemistry at the last follow-up. There was no difference in the prevalence of genotypes and core promoter and precore mutations between patients with and without cirrhosis-related complications. Though patients with subtype Ba had earlier HBeAg seroconversion, the liver biochemistry, HBV DNA levels in different phases of the disease, and the probability of development of cirrhosis-related complications were the same with genotypes Ba and C.
  • Molecular evolutionary analysis predicts the incidence of hepatocellular carcinoma in the United States and Japan, Masashi Mizokami, Yasuhito Tanaka, Cancer Chemotherapy and Pharmacology, 54,   2004年09月01日, Long-term serial serum samples containing hepatitis C virus (HCV) from the US and Japan were molecularly clocked to determine the time-origin of the HCV epidemic. Based on the molecular clock that held significantly, it is estimated that HCV genotype 1 first appeared in the US around 1910 whereas in Japan HCV surfaced before 1882. By regression analyses and coalescent theory, widespread dissemination of HCV in the US population occurred during the 1960s, approximately 30 years later than in Japan. Currently, the prevalence of hepatocellular carcinoma (HCC) is strikingly higher in Japan than in the US. If HCC is a function of increased HCV exposure time, the molecular clock predicts that the burden of HCC in the US will accelerate in the next two to three decades. © Springer-Verlag 2004.
  • Eight genotypes (A-H) of hepatitis B virus infecting patients from San Francisco and their demographic, clinical, and virological characteristics, Hideaki Kato, Hideaki Kato, Robert G. Gish, Natalie Bzowej, Margaret Newsom, Fuminaka Sugauchi, Fuminaka Sugauchi, Yasuhito Tanaka, Takanobu Kato, Etsuro Orito, Sadakazu Usuda, Ryuzo Ueda, Yuzo Miyakawa, Masashi Mizokami, Masashi Mizokami, Journal of Medical Virology, 73, 516 - 521,   2004年08月01日, Clinical lines of evidence have been accumulated that hepatitis B virus (HBV) genotypes have characteristic geographical distributions and distinct clinical impact on liver diseases. The distribution of HBV genotypes was determined with reference to hepatitis B e antigen (HBeAg) and alanine aminotransferase (ALT) levels in 165 patients with hepatitis B in San Francisco. HBV genotypes were determined by enzyme-linked immunosorbent assay (ELISA) and the unclassified samples were sequenced within the S region for phylogenetic analysis. Genotype A occurred in 60 (36%) patients, B in 16 (10%), C in 56 (34%), D in 19 (12%), E in 1 (1%), F in 1 (1%), G in 8 (5%), and H in 4 (2%). Caucasians were infected predominantly with HBV genotype A (HBV/A) (38 of 57 [67%]), Asians with HBV/C (45 of 63 [71%]), and Hispanics with HBV/F and HBV/H (4 of 9 [44%]). Serum ALT levels were higher in the patients infected with HBV/A (P = 0.03) or HBV/G (P = 0.02) than HBV/C. HBeAg was more frequent in patients infected with HBV/G than HBV/C or HBV/D (7 of 8 [88%] vs. 25 of 56 [45%] or 6 of 19 [32%], P=0.03 or 0.01). In conclusion, eight genotypes (A-H) were identified in San Francisco in association with various ethnicities and then influenced ALT levels as well as the prevalence of serum HBeAg. HBV genotype H might be identified by combination of preS2 serotpe bksf and HBsAg serotype adw. © 2004 Wiley-Liss, Inc.
  • Gianotti-crosti syndrome caused by acute hepatitis B virus genotype D infection, Kojiro Michitaka, Norio Horiike, Yan Chen, Tran Nhu Duong, Ichiro Konishi, Toshie Mashiba, Yoshio Tokumoto, Yoichi Hiasa, Yasuhito Tanaka, Masashi Mizokami, Morikazu Onji, Internal Medicine, 43, 696 - 699,   2004年08月01日, A 12-year-old girl with Gianotti-Crosti syndrome caused by hepatitis B virus (HBV) infection was admitted due to eruption on her extremities. Laboratory findings revealed elevation of transaminase, positivity for HB surface antigen (HBsAg), and an IgM type anti-HB core. The eruption and level of transaminase improved, and HBsAg became negative within 2 months of onset. Analysis of the virus revealed it to be genotype D with a genomic length of 3,182 bases and the HBsAg serotype was ayw3, which is very rare in Japan. The possible relationship between Gianotti-Crosti syndrome and HBV genotype D infection is discussed.
  • Prognostic indicators of breakthrough hepatitis during lamivudine monotherapy for chronic hepatitis B virus infection, Yasuhito Tanaka, Anthony E.T. Yeo, Etsuro Orito, Kiyoaki Ito, Noboru Hirashima, Tatsuya Ide, Michio Sata, Masashi Mizokami, Journal of Gastroenterology, 39, 769 - 775,   2004年08月01日, Background. Breakthrough hepatitis (BTH), defined as a flare of transaminases alanine aminotransferase [ALT]) can occur during lamivudine monotherapy for hepatitis B virus (HBV) infection. There have been many reports of lamivudine-resistant mutations within the C domain of the viral reverse transcriptase; however, the appearance of these mutants is not necessarily correlated with BTH during lamivudine therapy. Methods and Results. Entire serial HBV genomic sequences before and during lamivudine therapy for 4 patients with BTH and 1 patient without BTH were analyzed and showed changes in the pre-S region. These changes may be associated with ALT flares. Further investigation in a cohort of 36 patients with a median treatment period of 25 months showed that 21 patients had a rise in HBV-DNA titer, of whom 18 had BTH. Univariate statistical analyses showed that possible prognostic indicators for the occurrence of BTH were pre-S deletions (P = 0.03) and L180M/M204L mutations (P = 0.04). By multivariate Cox regression analyses, significant variables were pre-S deletions (hazard ratio, 0.17; 95% confidence internal (CI), 0.044-0.66) and precore mutations (hazard ratio, 5.70; 95% CI 1.74-18.71) prior to the commencement of lamivudine monotherapy. Interestingly, BTH occurred after the selection of the wild-type species in the pre-S region during lamivudine monotherapy. Conclusions. These results suggest that patients with HBV pre-S deletion mutants should be monitored carefully during lamivudine therapy. © Springer-Verlag 2004.
  • Epidemiological study of hepatitis B virus genotypes, core promoter and precore mutations of chronic hepatitis B infection in Hong Kong, Man Fung Yuen, Erwin Sablon, Yasuhito Tanaka, Takanobu Kato, Masashi Mizokami, Joke Doutreloigne, He Jun Yuan, Danny Ka Ho Wong, Siu Man Sum, Ching Lung Lai, Journal of Hepatology, 41, 119 - 125,   2004年07月01日, Background/Aims We conducted a population study to document the prevalence of hepatitis B virus (HBV) genotypes in Hong Kong. Methods HBV genotypes, core promoter (CP) and precore mutations were determined in 776 asymptomatic patients. Results 92.6% patients had single genotype [B (32.5%), C (62.5%)]. 99.1% of genotype B was subtype Ba. Patients with age <50 years had a lower prevalence of genotype B than patients with age >51 years (32.5% vs. 41%, respectively, P=0.028). Compared to patients with genotype C, patients with genotype B had a higher cumulative rate (P=0.018) and younger age (40.1 vs. 34.2 years, respectively, P=0.018) of HBeAg seroconversion. There were no differences in the HBV DNA levels between patients with genotypes B and C, and with wild-type and mutants of CP and precore regions. By multivariate analysis, patients with genotype C and with CP mutations had higher alanine aminotransferase (ALT) levels. Conclusions B and C were the two most common HBV genotypes in Hong Kong. The former had a higher chance of earlier HBeAg seroconversion and lower ALT levels. The prevalence of genotype B was lower in patients with age <50, probably related to influx of immigrants from China since 1949. © 2004 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
  • Reliability of Hepatitis C Virus Core Antigen Assay for Detection of Viremia in HCV Genotypes 1, 2, 3, and 4 Infected Blood Donors: A Collaborative Study between Japan, Egypt, and Uzbekistan, Salah Agha, Yasuhito Tanaka, Niveen Saudy, Fuat Kurbanov, Mostafa Abo-Zeid, Mohamed El-Malky, Mohamed Khalaf, Nobuo Ohta, Hiroshi Yoshizawa, Masashi Mizokami, Masashi Mizokami, Journal of Medical Virology, 73, 216 - 222,   2004年06月01日, Nucleic acid amplification-based methods are used for confirmation of viremia in antibody to hepatitis C virus (anti-HCV)-positive patients. However, this technology is labor intensive, time consuming, requires complex laboratory conditions, and expensive. The aim of this study was to evaluate the sensitivity and specificity of the HCV core antigen (HCVcAg) assay as an alternative approach for confirmation of viremia in HCV-infected subjects with HCV genotype 1-4. Two hundred forty-six asymptomatic HCV RNA-positive donors were enrolled in this study, consisting of 122 blood donors from Egypt (116 with genotype 4, 4 with genotype 1, and 2 with 1 + 4 genotypes), 109 from Japan (85 with genotype 1, and 24 with genotype 2), and 15 from Uzbekistan (all with genotype 3). A total of 234 (95.1%) of 246 RNA-positive specimens were detected by the HCVcAg assay; the sensitivity of HCVcAg assay consisted 93.4, 100, 100, and 94.8% for genotypes 1, 2, 3, and 4, respectively in comparison with RT-PCR assay. The specificity of the assay was confirmed in the absence of the false-positive results among 53 anti-HCV-negative, but anti-Schistosoma mansoni (anti-Sm) positive donors from Egypt. A positive correlation between HCVcAg and HCV RNA concentration levels (r = 0.671, P < 0.05) was observed among specimens with HCV genotype 4. The mean HCVcAg level was significantly lower in specimens with genotype 4 (2,935 fmol/L) comparing to genotypes 1, 2, and 3 (5,034, 4,962, and 4,740 fmol/L, respectively). No specific mutation was found in the core-encoding region of the studied specimens. In conclusion, HCVcAg is shown to be specific, sensitive, and informative qualitative index for HCV viremia in asymptomatic carriers. © 2004 Wiley-Liss, Inc.
  • Analysis of HCV genotypes from blood donors shows three new HCV type 6 subgroups exist in Myanmar, Toshiyuki Shinji, Yi Kyaw Yi, Katsunori Gokan, Yasuhito Tanaka, Koji Ochi, Nobuchika Kusano, Takaaki Mizushima, Shin Ichi Fujioka, Hidenori Shiraha, Hidenori Shiraha, Aye Lwin Aye, Yasushi Shiratori, Masashi Mizokami, Myo Khin, Masayuki Miyahara, Shigeru Okada, Norio Koide, Acta Medica Okayama, 58, 135 - 142,   2004年06月01日, The prevalence of hepatitis C virus (HCV) genotypes in Myanmar in comparison with the rest of Southeast Asia is not well known. Serum samples were obtained from 201 HCV antibody-positive volunteer blood donors in and around the Myanmar city of Yangon. Of these, the antibody titers of 101 samples were checked by serial dilution using HCV antibody PA test II and Terasaki microplate as a low-cost method. To compare antibody titers by this method and RNA identification, we also checked HCV-RNA using the Amplicor 2.0 test. Most high-titer groups were positive for HCV-RNA. Of the 201 samples, 110 were successfully polymerase chain reaction (PCR) amplified. Among them, 35 (31.8%) were of genotype 1, 52 (47.3%) were of genotype 3, and 23 (20.9%) were of type 6 variants, and phylogenetic analysis of these type 6 variants revealed that 3 new type 6 subgroups exist in Myanmar. We named the subgroups M6-1, M6-2, and M6-3, M6-1 and M6-2 were relatively close to types 8 and 9, respectively. M6-3, though only found in one sample, was a brand-new subgroup. These subtypes were not seen in Vietnam, where type 6 group variants are widely spread. These findings may be useful for analyzing how and when these subgroups were formed.
  • A randomized controlled trial of consensus interferon with or without lactoferrin for chronic hepatitis C patients with genotype 1b and high viral load, Noboru Hirashima, Etsuro Orito, Kenichi Ohba, Hajime Kondo, Tomoyuki Sakamoto, Seijiro Matsunaga, Atsunaga Kato, Haruhiko Nukaya, Kenji Sakakibara, Tomoyoshi Ohno, Hideaki Kato, Fuminaka Sugauchi, Takanobu Kato, Yasuhito Tanaka, Ryuzo Ueda, Masashi Mizokami, Hepatology Research, 29, 9 - 12,   2004年05月01日, Recently, lactoferrin has been reported to have anti-HCV effects. The aim of this study was to investigate the effect of combination therapy using consensus interferon (CIFN) and lactoferrin in patients with chronic hepatitis C. Twenty-one patients with chronic HCV infection, who were positive for HCV-RNA genotype 1b with serum viral loads from 100 to 700 KIU/ml, were randomly assigned to two groups; the CIFN + Lac group received CIFN with lactoferrin and the CIFN group received CIFN alone. Nine patients in each group completed this trial; the other patients dropped out because of side effects. Three, two and four patients were categorized as complete responders, relapsers and non-responders, respectively, in the CIFN + Lac group, and four, one and four in the CIFN group, respectively. There was no statistically significant difference in virologic response between the two groups. During the follow up after CIFN therapy with continued lactoferrin, there were two relapsers in the CIFN + Lac group and their HCV-RNA titers before treatment were over 400 KIU/ml. In conclusion, the combination therapy of CIFN and lactoferrin did not increase the response rate or prevent relapse after discontinuation of IFN. © 2004 Elsevier B.V. All rights reserved.
  • PCR-Probe Capture Hybridization Assay and Statistical Model for SEN Virus Prevalence Estimation, Yasuhito Tanaka, Yasuhito Tanaka, Ruth Pfeiffer, Ruth Pfeiffer, Anthony E.T. Yeo, Anthony E.T. Yeo, Masashi Mizokami, Brian R. Edlin, Brian R. Edlin, Philip Castle, Thomas R. O'Brien, Harvey J. Alter, J. Wai Kuo Shih, Journal of Medical Virology, 73, 123 - 130,   2004年05月01日, SEN viruses (SENV) are newly discovered blood-borne single-stranded circular DNA viruses that may play a role in liver disease. To date, no serologic assays are available for the detection of SENV antigens or antibodies. We report on a rapid and sensitive molecular assay for the detection of four SENV strains (SENV-A, -C, -D, -H). This method uses PCR with universal primers and microwell capture hybridization with type-specific probes. Cut-off points to define "infected" based on chemiluminescence readings were determined from a statistical mixture model applied to samples from 300 injection drug users (IDUs) in San Francisco. Based on the estimated cut-off points, we examined the prevalence of SENV infection among 232 healthy US blood donors and assessed sensitivity and specificity of the assay in a small validation sample of infected individuals with partial sequence information. © 2004 Wiley-Liss, Inc.
  • Two subtypes of genotype B (Ba and Bj) of hepatitis B virus in Japan, Fuminaka Sugauchi, Fuminaka Sugauchi, Hiromitsu Kumada, Hiroshi Sakugawa, Masafumi Komatsu, Hirofumi Niitsuma, Hisayoshi Watanabe, Yoshihiro Akahane, Hajime Tokita, Takanobu Kato, Yasuhito Tanaka, Etsuro Orito, Ryuzo Ueda, Yuzo Miyakawa, Masashi Mizokami, Masashi Mizokami, Clinical Infectious Diseases, 38, 1222 - 1228,   2004年05月01日, We have previously reported 2 subtypes of hepatitis B virus (HBV) genotype B, one of which has the recombination with genotype C over the precore region plus core gene (Ba) and the other of which does not (Bj). A restriction fragment-length polymorphism method with 2 endonucleases was newly developed for distinguishing between subtypes Ba and Bj and was applied to 313 carriers of HBV genotype B in Japan. Subtype Ba was detected in 38 (12%) and subtype Bj in 275 (88%) of the carriers of HBV genotype B. Hepatitis B e antigen in serum was found more frequently in patients with chronic infection with subtype Ba than in those with chronic infection with subtype Bj (8 [32%] of 25 vs. 25 [9%] of 273; P < .01). The new method for distinguishing between Ba and Bj by restriction fragment-length polymorphism would be useful in examining the distribution of these 2 subtypes in situations in which HBV genotype B is prevalent.
  • Comparison of Genotypes C and D of the Hepatitis B Virus in Japan: A Clinical and Molecular Biological Study, Tran Nhu Duong, Norio Horiike, Kojiro Michitaka, Chen Yan, Masashi Mizokami, Yasuhito Tanaka, Kouji Jyoko, Kazutoshi Yamamoto, Hiroaki Miyaoka, Yoshimasa Yamashita, Naofumi Ohno, Morikazu Onji, Journal of Medical Virology, 72, 551 - 557,   2004年04月01日, The genotype-related differences between genotype C and genotype D of the hepatitis B virus (HBV) remain unknown. The relationship was studied between the HBV genotypes and their clinical features, paying special attention to genotypes C and D. Serum samples from 413 HBV carriers were genotyped using an enzyme immunoassay (EIA) and by restriction fragment length polymorphism. The nucleotide sequences at the basic core promoter (BCP) and precore (PreC) regions were analysed by direct sequencing. The full genome sequences of three HBV genotype D cases were also examined. Almost all carriers with HBV genotype D were asymptomatic carriers (84.2%). Genotype D was not found in patients with liver cirrhosis and hepatocellular carcinoma. In contrast, carriers with genotype C had mainly chronic liver disease (63.2%; P < 0.001). The ratio of hepatitis B e antigen (HBeAg)/anti-HBe was significantly higher in genotype C than in genotype D in the young age-matched group (P < 0.01). The mutation at BCP (T1762, A1764) was significantly lower in genotype D than in genotype C among HBeAg-negative patients (P < 0.05). The HBV full-genome sequences are very similar to certain HBV genotype D sequences from Europe. In conclusion, genotype C was associated with chronic liver disease, whereas genotype D was related to asymptomatic carriers with earlier HBeAg seroconversion. Thus, the outcome of chronic HBV infection may be different in persons infected with HBV genotypes C and D. © 2004 Wiley-Liss, Inc.
  • Epidemiological and sequence differences between two subtypes (Ae and Aa) of hepatitis B virus genotype A, Fuminaka Sugauchi, Fuminaka Sugauchi, Hiromitsu Kumada, Subrat A. Acharya, Santosh Man Shrestha, Maria Teresita A. Gamutan, Mobin Khan, Robert G. Gish, Yasuhito Tanaka, Takanobu Kato, Etsuro Orito, Ryuzo Ueda, Yuzo Miyakawa, Masashi Mizokami, Journal of General Virology, 85, 811 - 820,   2004年04月01日, Complete nucleotide sequences of 19 hepatitis B virus (HBV) isolates of genotype A (HBV/A) were determined and analysed along with those of 20 previously reported HBV/A isolates. Of the 19 HBV/A isolates, six including three from Japan and three from the USA clustered with the 14 HBV/A isolates from Western countries. The remaining 13 isolates including four from The Philippines, two from India, three from Nepal and four from Bangladesh clustered with the six HBV/A isolates reported from The Philippines, South Africa and Malawi. Due to distinct epidemiological distributions, genotype A in the 20 HBV isolates was classified into subtype Ae (e for Europe), and that in the other 19 into subtype Aa (a for Asia and Africa) provisionally. The 19 HBV/Aa isolates had a sequence variation significantly greater than that of the 20 HBV/Ae isolates (2.5 ± 0.3% vs 1.1 ± 0.6%, P<0.0001); they differed by 5.0 ± 0.40% (4.1-6.4%). The double mutation (T1762/A1764) in the core promoter was significantly more frequent in HBV/Aa isolates than in HBV/Ae isolates (11/19 or 58% vs 5/20 or 25%, P<0.01). In the pregenome encapsidation (E) signal, a point mutation from G to A or T at nt 1862 was detected in 16 of the 19 (84%) HBV/Aa isolates but not in any of the 20 HBV/Ae isolates, which may affect virus replication and translation of hepatitis B e antigen. Subtypes Aa and Ae of genotype A deserve evaluation for any clinical differences between them, with a special reference to hepatocellular carcinoma prevalent in Africa. © 2004 SGM.
  • Predicting Relapse after Cessation of Lamivudine Monotherapy for Chronic Hepatitis B Virus Infection, Kiyoaki Ito, Kiyoaki Ito, Yasuhito Tanaka, Etsuro Orito, Noboru Hirashima, Tatsuya Ide, Teruko Hino, Ryukichi Kumashiro, Atunaga Kato, Haruhiko Nukaya, Kenji Sakakibara, Motokazu Mukaide, Hidemi Ito, Michio Sata, Ryuzo Ueda, Masashi Mizokami, Masashi Mizokami, Clinical Infectious Diseases, 38, 490 - 495,   2004年02月15日, There have been reports of relapse after cessation of lamivudine monotherapy for hepatitis B virus (HBV) infection. The aim of this study was to examine factors that predict posttreatment relapse. Comparison 22 patients who experienced relapse with 11 who did not after cessation of therapy showed that predictive factors for nonrelapse were hepatitis B e antigen seroconversion and duration of undetectable HBV DNA load (<0.7 log IU/mL), as determined by HBV real-time detection direct testing. However, 7 of 12 patients with seroconversion experienced relapse after cessation of therapy. Multivariate analysis revealed that the duration of an undetectable HBV DNA load was the only independent predictive factor for nonrelapse (odds ratio, 0.50; 95% confidence interval, 0.27-0.9). More-prolonged lamivudine therapy is required after seroconversion, and persistent duration of an HBV DNA level of <0.7 log IU/mL for >6 months can more accurately aid in the decision of when to stop lamivudine therapy.
  • Lack of association between occult hepatitis B virus DNA viral load and aminotransferase levels in patients with hepatitis C virus-related chronic liver disease, Kei Fujiwara, Kei Fujiwara, Yasuhito Tanaka, Etsuro Orito, Tomoyoshi Ohno, Takanobu Kato, Fuminaka Sugauchi, Seiji Suzuki, Yuko Hattori, Mayumi Sakurai, Izumi Hasegawa, Takashi Ozasa, Futoshi Kanie, Hideyuki Kano, Ryuzo Ueda, Masashi Mizokami, Masashi Mizokami, Journal of Gastroenterology and Hepatology (Australia), 19, 1343 - 1347,   2004年01月01日, Background and Aim: Occult hepatitis B virus (HBV) infection in hepatitis C virus (HCV)-infected patients might enhance the severity of chronic liver disease (CLD). To elucidate the correlation between occult HBV infection and the clinical course of HCV-related CLD, we evaluated whether the fluctuation of occult HBV-DNA directly affects the serum alanine aminotransferase (ALT) level. Methods: Forty-one patients with HCV-related CLD who received regular outpatient treatment and 42 age-, sex-, and antibody to hepatitis B core antigen positivity-matched healthy volunteers were enrolled. Serum HBV-DNA was quantitatively detected using real-time detection polymerase chain reaction (RTD-PCR). Serial serum samples in three patients were measured for HBV-DNA, ALT and HCV core antigen. Results: Hepatitis B virus DNA was amplified in eight of the HCV-related CLD patients (19.5%), which was significantly higher than that of healthy volunteers (2.4%). No significant difference between the genotype 1 HCV-related CLD group and the genotype 2 group was found. Based on the analyses using serial serum samples, the elevation of HBV-DNA did not occur before the ALT flares, but occurred at the same time or after the ALT flares. Conclusions: The prevalence of occult HBV infection of HCV-related CLD is significantly higher than that of control. Occult HBV infection has no influence on ALT flares among patients with HCV-related CLD. © 2004 Blackwell Publishing Asia Pty Ltd.
  • Clinical characteristics and prevalence of GB virus C, SEN virus, and HFE gene mutation in Japanese patients with nonalcoholic steatohepatitis, Norihito Yamauchi, Yoshito Itoh, Yasuhito Tanaka, Masashi Mizokami, Masahito Minami, Atsuhiro Morita, Tetsuya Toyama, Kanji Yamaguchi, Hideki Fujii, Takeshi Okanoue, Journal of Gastroenterology, 39, 654 - 660,   2004年01月01日, Background. This study was carried out to clarify differences in clinical characteristics between fatty liver and nonalcoholic steatohepatitis in a Japanese population, and to assess the significance of GB virus C (GBV-C) infection, SEN virus (SENV) infection, and HFE gene mutation in the pathophysiology of these conditions. Methods. Twenty patients with nonalcoholic steatohepatitis and 18 patients with simple steatosis were enrolled, and their clinical characteristics and histological findings were compared. Detection of GBV-C RNA and SENV DNA was performed by polymerase chain reaction (PCR). Mutational analysis of the HFE gene was performed by PCR-restriction fragment length polymorphism (RFLP). Results. Serum aspartate aminotransferase (AST) and ferritin were significantly higher (P < 0.05, for both) in NASH than in simple steatosis, and serum total cholesterol (T-Chol) was significantly lower (P < 0.05) in NASH than in simple steatosis. While GBV-C was detectable in the serum of only one patient with NASH, SENV was detected in 50% (15/30) of the patients whose sera were tested for this virus, but the prevalence was not significantly different between the two groups (42% [8/19] in simple steatosis and 64% [7/11] in NASH). The sex ratio, body mass index (BMI), and age were not significantly different between the two groups, and mutation in the HFE gene was not detected in any patient. Conclusions. Higher serum AST and ferritin, and lower serum T-Chol are distinctive features in NASH when compared with simple steatosis. GBV-C infection, SENV infection, and HFE gene mutation were not considered to influence the development of NASH from simple fatty liver. © Springer-Verlag 2004.
  • Epidemiology of intrafamilial transmission of hepatitis C virus by molecular evolutionary analysis, Izumi Hasegawa, Yasuhito Tanaka, Nippon rinsho. Japanese journal of clinical medicine, 62 Suppl 7, 291 - 295,   2004年01月01日
  • Clinical manifestations of hepatitis B virus genotypes, Yasuhito Tanaka, Masashi Mizokami, Nippon rinsho. Japanese journal of clinical medicine, 62 Suppl 8, 293 - 298,   2004年01月01日
  • Exponential spread of hepatitis C virus genotype 4a in Egypt., 58/,191-195,   2004年
  • Roleof hepatitis B virus genotypes Ba and C, core promoter and precore mutations on hepatocellular carcinoma: a case controlstudy., 25/9,1593-1598,   2004年
  • A novel hepatitis B virus genotype A subtyping assay that distinguishes subtypes Aa from Ae and its application in epidemiological studies., 78/14,7575-7578,   2004年
  • A case-control study for differences among hepatitis B virus infections of genotypes A (subtypes Aa and Ae) and D., 40/,747-755,   2004年
  • Hepatitis B genotypes in chronic hepatitis B and lamivudine therapy, Man Fung Yuen, Man Fung Yuen, Yasuhito Tanaka, Ching Lung Lai, Intervirology, 46, 373 - 376,   2003年12月01日, The influence of hepatitis B virus (HBV) genotypes on the natural history and the response to treatment of patients with chronic hepatitis B are of potential interest. Compared to the patients with HBV genotype C, those with genotype B were of a younger age and had a higher cumulative rate of hepatitis B e antigen (HBeAg) seroconversion during the initial 6 years of follow-up. The earlier HBeAg seroconversion in the patients with genotype B, however, did not provide them with a benefit in terms of a reduced risk of developing long-term complications. The response to lamivudine therapy was evaluated in 21 patients infected with HBV genotype B (all of subtype Ba) and 61 with genotype C. There were no differences in the virological response to lamivudine therapy, based on the reduction in median logarithmic HBV DNA titer as well as alanine aminotransferase (ALT) levels, normalization of ALT and the rate of HBeAg seroconversion between the patients with genotypes B and C. No differences were noted either, in the frequency of YMDD mutants at week 52 or the cumulative risk of HBV DNA breakthroughs with YMDD mutations during long-term lamivudine therapy (median 37.5 months). In conclusion, there is no influence of HBV genotypes on the development of long-term complications and lamivudine therapy in Hong Kong. Copyright © 2003 S. Karger AG, Basel.
  • The technology to produce thermoplastic elastomer based on waste rubber, Y. Tanaka, T. Watanabe, T. Okita, M. Matsushita, H. Okamoto, K. Fukumori, N. Suzuki, Y. Suzuki, SAE Technical Papers,   2003年12月01日, A new rubber recycling technology to produce a thermoplastic elastomer (TPE) based on ethylene-propylene-diene rubber (EPDM) waste was developed. In this technology, the developed process consists of devulcanization of EPDM waste, blending of the devulcanized EPDM and polypropylene (PP), and dynamic vulcanization of the rubber component. All three are set up in as a continuous process in which the Recycled Rubber based Thermoplastic Elastomer (which is indicated as "RR-TPE" henceforth) is finally obtained. The RR-TPE exhibits elasticity and mechanical properties similar to those of commercial Thermoplastic olefins (TPO). These properties may be due to a suitably formed phase structure. Automotive parts are being developed and are going to be produced with the RR-TPE manufactured by this new technology. This technology will contribute to both protecting the environment and saving resources. Copyright © 2003 SAE International.
  • Human immunodeficiency virus in Uzbekistan: Epidemiological and genetic analyses, Fuat Kurbanov, Fuat Kurbanov, Masashi Mizokami, Mitsunobu Imai, Makiko Kondo, Yasuhito Tanaka, Mariam Zalalieva, Mariam Zalalieva, Guzal Giasova, Takako Shima, Nao Jounai, Nadira Yuldasheva, Ruslan Ruzibakiev, AIDS Research and Human Retroviruses, 19, 731 - 738,   2003年09月01日, This study investigates the molecular epidemiology of HIV in Uzbekistan - a former Soviet Union (FSU) country located in central Asia. A total of 18,910,370 subjects were involved in an HIV serological examination through a population survey conducted in 1987-2002. Rapid changes in epidemiological dynamics and transmission modes have been observed since 1999: incidence rose from 25 newly HIV-infected subjects per year to more than 100 new cases per month within the first half of 2002, and the rate of intravenous drug use (IVDU)-associated HIV infection increased to 75% per year during the same period. Thirty HIV-1 strains, isolated from specimens obtained in 1999-2000, were directly sequenced in the env region. Phylogenetic analysis revealed a relationship to genotype A in 56.7%, and to 03_CRFAB in 13.3%; both variants have been previously reported in the FSU. The majority (85.7%) of these strains were isolated from IVDUs. The demographic history of the most prevalent HIV strain in Uzbekistan was inferred from reconstructed molecular phylogenies; exponential growth of the viral population size was thus observed to occur after the mid-1990s. In summary, detectable HIV seroprevalence remains low in the general population of Uzbekistan. However, the current study demonstrates a substantially increasing number of new infections, in association with IVDU, and an exponentially growing effective population size of the IVDU-associated HIV strain.
  • High stability of enzyme immunoassay for hepatitis C virus core antigen - Evaluation before and after incubation at room temperature, Yasuhito Tanaka, Yasuhito Tanaka, Kazumi Takagi, Toshiya Fujihara, Katsuhiko Kitsugi, Kei Fujiwara, Kumiko Hiramatsu, Yoshinori Ito, Yoshimitsu Takasaka, Masaji Sakai, Masashi Mizokami, Masashi Mizokami, Hepatology Research, 26, 261 - 267,   2003年08月01日, Hepatitis C virus (HCV) RNA is thought to be less stable than HCV core antigen (HCV-Ag), however there have been few studies on comparing the stability of HCV-Ag with that of HCV-RNA in vitro. The aim of this study is to evaluate serial levels of HCV-Ag and HCV-RNA in serum before and after incubation at 4 or 25 °C for 7 days to estimate an assay suitable for general laboratory use. In this study, we demonstrate that HCV-Ag levels are highly reproducible (coefficients of variation (CVs); 0.89-6.92%) and stable (84.8% of the initial level) with incubation of even 25 °C for 7 days, whereas HCV-RNA levels are much less reproducible (CVs; 9.13-29.66%) and decrease dramatically (15.1% of the initial level) after incubation, particularly at 25 °C. The measurement of the HCV-Ag level was found to be suitable for HCV quantification with serum samples stored either at 4 °C or under unknown conditions. Additionally, it successfully eliminated inhibitors such as heparin from plasma and could be applied to a variety of clinical specimens. Our data suggest the significance of measuring the HCV-Ag level during clinical management independently of the HCV-RNA level, particularly because of its high stability. © 2003 Elsevier Science B.V. All rights reserved.
  • Genotypes and phylogenetic characterization of hepatitis B and delta viruses in Egypt, Niveen Saudy, Niveen Saudy, Fuminaka Sugauchi, Yasuhito Tanaka, Seiji Suzuki, Amina Abdel Aal, Mostafa Abo Zaid, Salah Agha, Masashi Mizokami, Masashi Mizokami, Journal of Medical Virology, 70, 529 - 536,   2003年08月01日, Hepatitis B virus (HBV) and hepatitis D virus (HDV) sequences among HBV carriers from Egypt have not been evaluated sufficiently. The genotypes of HBV isolated from 105 serum samples from Egyptian carriers were determined. Four complete genomes and 11 entire preS1/S2/S genes were sequenced and evaluated. All serum samples were classified into HBV genotype D using serologic and genetic methods. The length of four complete nucleotide sequences was 3,182 bp. In all 15 samples, the common 33 nucleotides (11 amino acids) deletions in the preS1 region specific for HBV genotype D were observed. In the phylogenetic analysis based on the complete nucleotide sequences, all samples were clustered with the HBV isolates reported from previously Western and Mediterranean countries with nucleotide homology ranging from 96.0-98.0%. Of 75 HBsAg positive samples, anti-HDV was found in 15 (20%), and HDV RNA was detected in 9 of 15 (60%). The proportion of the patients with liver disease was higher in HBV carriers of anti-HDV positive with HDV RNA than in HBV carriers of anti-HDV positive without HDV RNA (P < 0.05). In the phylogenetic analysis based on the sequences in nucleotide position 853-1267 of HDV, nine samples were classified into HDV genotype I with the nucleotide homology ranging from 88.3-92.1% (mean; 90.5%) and clustered with HDV strains reported previously from Ethiopia, Somalia, Egypt, and Lebanon. These results indicate that HBV genotype D and HDV genotype I are most prevalent in Egypt, and HDV co-infection in HBV carriers is related to severity of liver disease. © 2003 Wiley-Liss, Inc.
  • Interleukin 1β gene polymorphism and hepatitis C virus-related hepatocellular carcinoma [2] (multiple letters), Anthony E.T. Yeo, Yasuhito Tanaka, Takahisa Furuta, Naoya Kato, Yue Wang, Yujin Hoshida, Masao Omata, Hepatology, 38, 267 - 269,   2003年07月01日
  • Hepatitis C virus molecular epidemiology in Uzbekistan, Fuat Kurbanov, Fuat Kurbanov, Yasuhito Tanaka, Fuminaka Sugauchi, Hideaki Kato, Ruslan Ruzibakiev, Mariam Zalyalieva, Zulhumor Yunusova, Masashi Mizokami, Journal of Medical Virology, 69, 367 - 375,   2003年03月01日, The aim of this study was to identify hepatitis C virus (HCV) genotypes and to estimate their prevalence in various risk groups and the regional distribution in Uzbekistan. Preliminary serological screening of 1,269 subjects revealed 6.5% anti-HCV-positive in a general population, 27.1% in patient groups, and 51.7% among intravenous drug users. HCV genotypes of 104 anti-HCV-positive subjects were determined using a PCR-genotyping system in core region, and the results were supported by nucleotide sequencing of the NS5B region. Genotype 1b identified in total 64.2%, was the most prevalent. The genotype 3a identified in 25.0% was the second one distributed. HCV genotypes 2a, 1a, 2b, and 3b were identified in 3.8%, 2.9%, 2.9%, and 1.0% of cases, respectively. The intravenous drug users were distinguished from other groups by having the highest prevalence of genotype 3a, i.e., 50.0%, higher than the 33.3% for genotype 1b in this group. Geographically, genotype 1b was common; genotype 3a was also found frequently in all three regions. Uncommon HCV genotypes (la, 2a, 2b, and 3b) were found in comparatively greater variability in the western region. Molecular evolutionary analysis based on the NS5B region did not reveal specific clustering or indigenous strains among Uzbekistan HCV isolates. In summary, two main mechanisms of HCV infection distribution were observed in Uzbekistan: HCV 1b genotype infection is widespread through blood products, and HCV 3a genotype infection is spreading through the growing number of intravenous drug users. © 2003 Wiley-Liss, Inc.
  • Evaluation of loss of heterozygosity before and after interferon therapy in patients with hepatitis C virus infection who developed hepatocellular carcinoma during follow up, Seiji Suzuki, Seiji Suzuki, Yutaka Kondo, Noboru Hirashima, Hideaki Kato, Fuminaka Sugauchi, Fuminaka Sugauchi, Yasuhito Tanaka, Etsuro Orito, Ying Yang, Yu Shen, Kenji Sakakibara, Ryuzo Ueda, Masashi Mizokami, Masashi Mizokami, Journal of Gastroenterology and Hepatology (Australia), 18, 1364 - 1372,   2003年01月01日, Background and Aim: The aim of the present study was to determine whether evaluating the status of loss of heterozygosity (LOH) before interferon (IFN) therapy is predictive for development of hepatocellular carcinoma (HCC) in chronic hepatitis and liver cirrhosis patients. Methods: Eighteen patients with hepatitis C virus were studied, nine of whom developed HCC (HCC group) after IFN therapy and nine whom did not (non-HCC group). Samples before IFN therapy from both groups (pre-IFN-N and pre-IFN-H samples from the non-HCC and HCC groups, respectively) were analyzed for LOH using 12 microsatellite markers. To evaluate the LOH incidence in different steps in HCC patients, paired samples of cancerous tissue (CT) and adjacent non-CT (ANCT) obtained from the HCC group were also analyzed. Results: Frequency of LOH in the pre-IFN-H samples was significantly higher than that in the pre-IFN-N samples regardless of the response to IFN therapy. Interestingly, in the HCC group, there is no significant difference in the frequency of LOH among the pre-IFN-H, ANCT and CT samples. Conclusions: The present results suggest the theory that genetic instability, such as LOH, had already accumulated at stages before the development of HCC. The authors propose that the status of LOH in chronic hepatitis and liver cirrhosis patients before IFN therapy could be a potential predictor for the development of HCC. © 2003 Blackwell Publishing Asia Pty Ltd.
  • Development of real-time detection direct test for hepatitis B virus and comparison with two commercial tests using the WHO international standard, Motokazu Mukaide, Yasuhito Tanaka, Satoshi Katayose, Hiroyuki Tano, Mitsuhiro Murata, Mikio Hikata, Kiyotaka Fujise, Hiroshi Sakugawa, Kazuo Suzuki, John Zaunders, Yoko Nagasawa, Gotaro Toda, Masashi Mizokami, Masashi Mizokami, Journal of Gastroenterology and Hepatology (Australia), 18, 1264 - 1271,   2003年01月01日, Aims: A highly reproducible and sensitive hepatitis B virus real-time detection direct (HBV RTD-direct) test using DNA extraction by magnetic beads coated with polyclonal anti-HBsAg, followed by the real-time detection polymerase chain reaction (PCR) method, was developed for the detection of HBV DNA. Methods: The HBV DNA could be extracted from the HBsAg positive viral particles without resulting in viral DNA fragmentation. The HBV RTD-direct test was validated using a serial dilution panel of the WHO standard HBV DNA 97/746 I. Results: The test had a dynamic range of 0.7-8.0 log10international units (IU) per mL and the results were shown to be comparable to those obtained with two commercially available tests: the HBV DNA transcription-mediated amplification-hybridization protection assay and the Amplicor HBV Monitor test. In addition, the HBV RTD-direct test, based on magnetic extraction, successfully eliminated PCR inhibitors in clinical specimens. Conclusion: We conclude that the HBV RTD-direct test is an excellent alternative for monitoring patients undergoing antiviral treatment or for screening various clinical specimens. © 2003 Blackwell Publishing Asia Pty Ltd.
  • Transforming growth factor-beta-1 genetic polymorphism in Japanese patients with chronic hepatitis C virus infection, Seiji Suzuki, Seiji Suzuki, Yasuhito Tanaka, Etsuro Orito, Fuminaka Sugauchi, Fuminaka Sugauchi, Izumi Hasegawa, Izumi Hasegawa, Mayumi Sakurai, Mayumi Sakurai, Kei Fujiwara, Kei Fujiwara, Tomoyoshi Ohno, Ryuzo Ueda, Masashi Mizokami, Masashi Mizokami, Journal of Gastroenterology and Hepatology (Australia), 18, 1139 - 1143,   2003年01月01日, Background and Aim: Transforming growth factor beta-1 (TGF-β1) is one of the most dominant fibrogenic cytokines in hepatic fibrosis. The aim of the present study was to examine the effects of TGF-β1 polymorphisms in Japanese patients with chronic hepatitis C virus (HCV) infection and in healthy control subjects. Methods: The TGF-β1 genotypes at codon 10 and codon 25 were determined in 206 Japanese patients with chronic HCV infection and in 101 Japanese healthy control subjects. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used for the detection of these polymorphisms. The degree of hepatic fibrosis was assessed by liver biopsy and graded according to the New Inuyama Classification for chronic hepatitis graded F0-4. Results: The authors found no significant differences in genotype distributions and allele frequency between the HCV patients and the healthy control subjects. The frequencies of the TT, TC, and CC genotypes of codon 10 were 24%, 42% and 35%, respectively, among the patients of the F0-2 group, and 31%, 40% and 29%, respectively, among those of the F3-4 group. No significant differences were shown between the TGF-β1 polymorphism at codon 10 and the stage of hepatic fibrosis. In contrast, no genetic alteration of codon 25 was found in healthy controls and patients with chronic HCV infection. Conclusion: These results suggest that there may not be a significant relationship between polymorphism at codon 10 and the development of progressive hepatic fibrosis in the Japanese population. © 2003 Blackwell Publishing Asia Pty Ltd.
  • HBV--clinical impact of HBV genotypes, Yasuhito Tanaka, Masashi Mizokami, Nippon rinsho. Japanese journal of clinical medicine, 61 Suppl 3, 621 - 626,   2003年01月01日
  • Impact of interleukin-1 beta genetic polymorphism on development of hepatitis C virus-related hepatocellular carcinoma in Japan., 187/11,1822-1825,   2003年
  • Prevalence of SEN viruses among injection drug users in the San Francisco Bay area., 188/1,13-18,   2003年
  • Observation of positive selection within hypervariable regions of a newly identified DNA virus (SEN virus), Umemura T, Tanaka Y, Kiyosawa K, Alter HJ, Shih JW, FEBS Letters, 510, (3) 171 - 174,   2002年01月, 査読有り, To elucidate the evolution of SEN virus (SEN-V), serial sequences of chronically SEN-V-infected patients were analyzed. In the hypervariable regions, non-synonymous substitutions significantly predominated. This could be attributed to positive selection in evading immune surveillance of the hosts and to establish a persistent infection. On the basis of the sequences in the two open reading frames of SEN-V DNA, the rate of synonymous substitutions was 7.32×10-4per site per year. Since this rate is close to RNA viruses and higher than other DNA viruses, the SEN-V might be replicated by machinery with poor or no proofreading function. © 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.
  • A comparison of molecular clock of hepatitis C virus in the United States and Japan predicts that hepatocellular carcinoma incidence..., Proc Natl Acad Sci US A, 99/24,15584-15589,   2002年
  • A potential new hepatitis agent: Making SEN-se of the data, T. Umemura, A. E.T. Yeo, A. Sottini, D. Moratto, Y. Tanaka, R. Y.H. Wang, J. W.K. Shih, P. Donahue, D. Primi, H. J. Alter, Gastroenterology, 121, 734 - 735,   2001年01月01日
  • SEN virus infection and its relationship to transfusion-associated hepatitis, Takeji Umemura, Anthony E.T. Yeo, Alessandra Sottini, Daniele Moratto, Yasuhito Tanaka, Richard Y.H. Wang, J. Wai Kuo Shih, Peter Donahue, Daniele Primi, Harvey J. Alter, Hepatology, 33, 1303 - 1311,   2001年01月01日, SEN virus (SEN-V) is a recently identified single-stranded, circular DNA virus. Two SEN-V variants (SENV-D and SENV-H) were assayed by polymerase chain reaction (PCR) to investigate their role in the causation of transfusion-associated non-A to E hepatitis. The incidence of SEN-V infection after transfusion was 30% (86 of 286) compared with 3% (3 of 97) among nontransfused controls (P < .001). Transfusion risk increased with the number of units transfused (P < .0001) and donor-recipient linkage for SEN-V was shown by sequence homology. The prevalence of SEN-V in 436 volunteer donors was 1.8%. Among patients with transfusion-associated non-A to E hepatitis, 11 of 12 (92%) were infected with SEN-V at the time of transfusion compared with 55 of 225 (24%) identically followed recipients who did not develop hepatitis (P < .001). No effect of SEN-V on the severity or persistence of coexistent hepatitis C virus (HCV) infection was observed. In 31 infected recipients, SEN-V persisted for greater than 1 year in 45% and for up to 12 years in 13%. SEN-V-specific RNA (a possible replicative intermediate) was recovered from liver tissue. In summary, SENV-D and -H were present in nearly 2% of US donors, and were unequivocally transmitted by transfusion and frequently persisted. The strong association of SEN-V with transfusion-associated non-A to E hepatitis compared with controls raises the possibility, but does not establish that SEN-V might be a causative agent of posttransfusion hepatitis. The vast majority of SEN-V-infected recipients did not develop hepatitis.
  • Genomic and molecular evolutionary analysis of a newly identified infectious agent (SEN virus) and its relationship to the TT virus family., 183/3,359-367,   2001年
  • Molecular evolutionary analysis of the complete nucleotide sequence of hepatitis B virus (HBV) in a case of HBV infection acquired through a needlestick accident, F. Sugauchi, M. Mizokami, E. Orito, T. Ohno, K. Hayashi, T. Kato, Y. Tanaka, H. Kato, R. Ueda, Clinical Infectious Diseases, 31, 1195 - 1201,   2000年12月01日, To elucidate needlestick transmission of hepatitis B virus (HBV), strains isolated from 1 physician who acquired HBV infection through a needlestick accident and 3 patients with chronic hepatitis B (donor patients A, B, and C) were tested using molecular evolutionary analysis based on full-length HBV genomic sequences. Nucleotide sequences of these isolates were aligned with 55 previously reported full-length genomic sequences. Genetic distances were estimated using the 6-parameter method, and phylogenetic trees were constructed using the neighbor-joining method. Strains isolated from patient A and the recipient pair were clustered within a closer range of evolutionary distances than were strains recovered from the recipient pair and patients B and C. Furthermore, strains from patient A and the recipient were also clustered on the S gene sequences of HBV. These results demonstrated that patient A alone was the source of direct transmission to the recipient. This approach can be used to investigate the transmission route of HBV.
  • Genomic and molecular evolutionary analysis of a novel dna virus (sen virus) and relationship to variants of TT virus, Yasuhito Tanaka, Daniele Primi, Richard Y. Wang, Takeji Umemura, Anthony E.T. Yeo, Masashi Mizokami, James W.K. Shih, Harvey J. Alter, Blood, 96,   2000年12月01日, A novel single-stranded DNA virus distantly related to TT virus (TTV), designated as SEN virus (SENV), was isolated from a blood sample obtained from a HIV-infected intravenous drug user. Eight different isolates of SENV have been described but currently only isolates SENV-D and SENV-H, have been shown to be transmitted by blood transfusion and suggested as a cause of transfusion-associated non-A to E hepatitis. The SENV-D and SENV-H were circular single-stranded (ss) DNA viruses with a nucleotide length of 3788 and 3815 nucleotides, respectively, slightly shorter than the prototype TTV. SENV had at least three putative ORFs: overlapping ORF1 and ORF2, and a novel ORF3 at the 3' end of ORF1. The amino acid residues encoded by ORF1 (pORFl) had a N-terminal arginine/lysine-rich domain and the sequence motifs of putative replication associated proteins, and pORF3 had a serine-rich tract preceded by a cluster of basic amino acids (R and K). Phylogenetic analyses of the entire coding region (ORF1 to 3) known to have few recombinant regions, using 8 SENV isolates, 6 prototype TTV isolates, and 6 TTV variants (including SANBAN, TUS01, and YONBAN) indicated great diversity with three distinct clusters separated by a bootstrap value of 100%. To determine a root of the phylogenetic tree, using TTV-like mini virus as an outgroup indicated that YONBAN isolates formed a distinct outer group indicating the first divergent species (group 1). SENV, SANBAN and TUS01 isolates formed the second group (group II). Prototype TTV formed the last and most recent divergent species (group III). These circular ssDNA viruses probably evolved from a common ancestor virus. Any association of these novel TTV-related species with human diseases of unknown etiology should be investigated.
  • Cosmic-ray tests for quality control of the CDF plug upgrade EM calorimeter and the CDF plug preshower detector, T. Asakawa, K. Hara, K. Hata, T. Kadotani, H. Kawamoto, T. Kikuchi, S. H. Kim, K. Kondo, T. Kuwabara, M. Okura, H. Okutomi, M. Sano, Y. Seiya, Y. Seiya, T. Shibayama, T. Suzuki, S. Takashima, K. Takikawa, M. Tanaka, Y. Tanaka, T. Uchida, T. Watanabe, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 452, 67 - 80,   2000年09月21日, The CDF Plug Upgrade electromagnetic (EM) calorimeter and the preshower detector consist of tile-fiber elements forming a projective tower geometry. Each of the 23 longitudinal layers is separated into 24 units in the azimuthal direction. Cosmic-ray tests as a quality control of these mechanically basic units, called the 15° units, were carried out since January 1995 and completed in June 1996. All the units amounting to a total 1200 units were processed. By using HAMAMASU R4125 for the photon readout, the average light yields were measured to be 5.8 and 21 photoelectrons for the EM and the preshower units, respectively. The light yield variation along the longitudinal layers of EM tower was measured to be 10%. A GEANT-simulation study using the results of the cosmic-ray tests was performed for a realistic calorimeter configuration. It was found that the simulated energy resolution was consistent with the requirement of ΔE/E = √(16%)2/E+(1%)2(E in GeV). Adding preshower response to EM response improved in particular the linearity of the calorimeter. It was possible to achieve the non-linearity of 1% level for energies in the range of 10-200 GeV.
  • Lack of association between TTV viral load and aminotransferase levels in patients with hepatitis C or non-B-C, H. Kato, M. Mizokami, E. Orito, T. Ohno, K. Hayashi, T. Nakano, T. Kato, Y. Tanaka, F. Sugauchi, M. Mukaide, R. Ueda, Scandinavian Journal of Infectious Diseases, 32, 259 - 262,   2000年08月14日, TT virus (TTV) is a newly identified un-enveloped single-stranded DNA virus. Although TTV was initially thought to be a new hepatitis virus, it is still unclear whether it causes hepatitis. To clarify the natural history and pathogenesis of TTV infection, serial serum samples from patients with chronic hepatitis were analysed. TTV DNA was quantified by real-time detection polymerase chain reaction assay (RTD-PCR), which was adapted for TTV. Five patients with chronic hepatitis, 4 with hepatitis C and 1 with non-B-C, were studied. The study period ranged from 9 to 50 months. In 3 patients there were frequent increases in TTV DNA titres, but no concomitant elevation of the aminotransferase (ALT) levels. In 2 patients who were treated with interferon, the changes in TTV titres were not synchronized with those of the ALT levels. Thus, in cases of chronic hepatitis, no correlation was observed between the serum TTV DNA titres and the ALT levels.
  • Development of a TT virus DNA quantification system using real-time detection PCR, Takanobu Kato, Masashi Mizokami, Masashi Mizokami, Motokazu Mukaide, Etsuro Orito, Tomoyoshi Ohno, Tatsunori Nakano, Yasuhito Tanaka, Hideaki Kato, Fuminaka Sugauchi, Ryuzo Ueda, Noboru Hirashima, Kazuhide Shimamatsu, Masayoshi Kage, Masamichi Kojiro, Journal of Clinical Microbiology, 38, 94 - 98,   2000年01月24日, Although TT virus (TTV) was isolated from a cryptogenic posttransfusion hepatitis patient, its pathogenic role remains unclear. It has been reported that the majority of the healthy population is infected with TTV. To elucidate the differences between TTV infection in patients with liver diseases and TTV infection in the healthy population, a quantification system was developed. TTV DNA was quantified by a real-time detection PCR (RTD-PCR) assay on an ABI Prism 7700 sequence detector. With this system, TTV DNA was quantified in 78 hepatitis C virus (HCV)-infected patients (63 with elevated serum alanine aminotransferase [ALT] levels and 15 with normal ALT levels) and in 70 voluntary blood donors (BDs). The quantification range was 2.08 to 7.35 log copies/ml. The intra-assay and interassay coefficients of variation were 0.37 to 6.33% and 0.60 to 7.07%, respectively. The mean serum TTV DNA levels in the HCV-infected patients with both elevated and normal ALT levels and BDs were 3.69 ± 0.89, 3.45 ± 0.76, and 3.45 ± 0.67 log copies/ml, respectively. Comparison of the serum TTV DNA levels among the HCV-infected patients revealed that they were not related to the serum ALT and HCV core protein levels or to the histopathological score on liver biopsy. This study showed that (i) the RTD-PCR assay for the detection of TTV was accurate and had a high degree of sensitivity, (ii) the mean serum TTV DNA level was similar among HCV-infected patients, irrespective of their ALT level, and also among BDs, and (iii) a high serum TTV DNA level does not affect the serum ALT and HCV levels or liver damage in HCV-infected patients.
  • Lack of integrated TT virus (TTV) genomes into cellular DNA in infected human hematopoietic cells, Yasuhito Tanaka, Masashi Mizokami, Masashi Mizokami, Etsuro Orito, Tomoyoshi Ohno, Tatsunori Nakano, Takanobu Kato, Shinsuke Iida, Ryuzo Ueda, Leukemia and Lymphoma, 38, 411 - 417,   2000年01月01日, TT virus (TTV) isolated from the serum of a patient with posttransfusion hepatitis has been characterized as a member of the Circoviridae, a family of small DNA viruses with single-stranded circular genomes. TTV appeared to infect not only the serum and liver, but also the peripheral blood mononuclear cells (PBMC). We investigated the prevalence of TTV DNA in human hematopoietic cells, based on 84 mononuclear cell samples obtained from the bone marrow or lymph nodes of patients with hematopoietic malignancies including leukemia, malignant lymphoma and aplastic anemia. Forty-nine (58.3%) out of the 84 samples were positive for TTV DNA with polymerase chain reaction analysis, which was almost similar to the frequency found in the patients' serum. Southern blot analyses using a 3.2-kb fragment derived from the TTV DNA, however, showed no evidence supporting the fact that the TTV genomes are integrated into the human hematopoietic cell genomes, thus suggesting their existence as episomal forms.
  • Identification of a 23kDa protein encoded by putative open reading frame 2 of TT virus (TTV) genotype 1 different from the other genotypes., 145/,1385-1398,   2000年
  • Prevalence of TT virus and GBV-C infections among patients with liver diseases and the general population in Shanghai, China, Xin Ding, Masashi Mizokami, Masashi Mizokami, Lai Yi Kang, Kun Cao, Etsuro Orito, Yasuhito Tanaka, Ryuzo Ueda, Makoto Sasaki, Virus Genes, 19, 51 - 58,   1999年09月09日, To determine the prevalence of TT virus (TTV) and GB virus C/hepatitis G virus (GBV-C) infections among patients with liver disease and the general population in Shanghai, China, we studied 90 patients with liver diseases (acute hepatitis, 28; chronic hepatitis, 27; liver cirrhosis, 20; hepatocellular carcinoma, 15) and 90 age, sex matched healthy blood donors as controls. There were no significant differences in the clinical and demographic characteristics between the two groups, except for liver function test values. There was a statistical difference between the patient group and the control group with regard to the prevalence of TTV DNA (23.5% in patient group, 11.1% in control group, P < 0.05), although no clinical differences can be found between TTV DNA-positive and negative subjects. Also, no differences in TTV DNA prevalence among various categories of liver diseases were noted (P = NS). The prevalence of HBsAg was significantly different between the patient group (36.7%) and the control group (3.3%) (P 0.01), whereas the prevalence of anti-HCV and GBV-C RNA were not significantly different between the two groups. The nucleotide sequences were determined in the TTV DNA-positive samples and evaluated using phylogenetic analysis which suggested that they could be divided into two main genotypes designated as genotype 1 and 2. There were five samples clustered into 3 hitherto unknown subtypes of genotype 2. We concluded that (1) although TTV infection is widespread among both groups and there is a statistical difference of TTV infection between them, no hepatic damaging evidence and correlation with certain liver disease could be found in this study, suggest that TTV may not be major cause of liver disease, (2) GBV-C infection is frequent, but the virus is not the cause of liver diseases, and (3) new subtypes of TTV may exist in Shanghai, China.
  • Hepatitis B virus genotype assignment using restriction fragment length polymorphism patterns, Masashi Mizokami, Masashi Mizokami, Tatsunori Nakano, Etsuro Orito, Yasuhito Tanaka, Hiroshi Sakugawa, Motokazu Mukaide, Betty H. Robertson, FEBS Letters, 450, 66 - 71,   1999年04月30日, Hepatitis B virus (HBV) is classified into genotypes A-F, which is important for clinical and etiological investigations. To establish a simple genotyping method, 68 full-genomic sequences and 106 S gene sequences were analyzed by the molecular evolutionary method. HBV genotyping with the S gene sequence is consistent with genetic analysis using the full-genomic sequence. After alignment of the S sequences, genotype specific regions are identified and digested by the restriction enzymes, HphI, NciI, AlwI, EarI, and NlaIV. This HBV genotyping system using restriction fragment length polymorphism (RFLP) was confirmed to be correct when the PCR products of the S gene in 23 isolates collected from various countries were digested with this method. A restriction site for EarI in genotype B was absent in spite of its presence in all the other genotypes and genotype C has no restriction site for AlwI. Only genotype E is digested with NciI, while only genotype F has a restriction site for HphI. Genotype A can be distinguished by a single restriction enzyme site for NlaIV, while genotype D digestion with this enzyme results in two products that migrates at 265 and 186 bp. This simple and accurate HBV genotyping system using RFLP is considered to be useful for research on HBV. Copyright (C) 1999 Federation of European Biochemical Societies.
  • Amino acid substitutions in NS5A region of GB virus C and response to interferon therapy, Takanobu Kato, Masashi Mizokami, Masashi Mizokami, Etsuro Orito, Ken Ichi Ohba, Tatsunori Nakano, Yutaka Kondo, Yasuhito Tanaka, Ryuzo Ueda, Motokazu Mukaide, Kiyomi Yasuda, Shiro Iino, Journal of Medical Virology, 57, 376 - 382,   1999年03月22日, GB virus C (GBV-C) is related to hepatitis C virus (HCV) and has a similar genomic structure. Some predictors for the efficacy of interferon (IFN) therapy on HCV have been reported: geno-type, viral load, IFN dose, and the amino acid substitutions in the NS5A region, designated as the interferon sensitivity determining region (ISDR). To evaluate the correlation between the amino acid substitutions in the GBV-C NS5A region and the response to IFN therapy, single-strand conformation polymorphism (SSCP) analysis was performed in the 12 concomitantly GBV-C-and HCV-infected patients who received IFN therapy at three time points: before, end-point, and after the IFN therapy. The region in the GBV-C NS5A studied includes the amino acids that exhibit some homology to the ISDR and the various substitutions. By SSCP analysis, amplicons were separated into 1-4 bands, which indicated the existence of heterogeneity in each host. However, the deduced amino acid sequences in these bands exhibited no characteristic differences among these strains irrespective of response to IFN therapy. Of the 32 strains separated by SSCP, 7 strains were responders, and 25 were nonresponders. The mean amino acid substitution, compared with the consensus sequence of nonresponders, was 1.00 ± 0.93 among responders, and 1.40 ± 0.85 among nonresponders (P = NS). No correlation between the amino acid sequence in the GBV-C NS5A region and response to IFN therapy was found, indicating that the GBV-C NS5A region dose not act as the ISDR.
  • A new genotype of TT virus (TTV) infection among Colombian native Indians, Yasuhito Tanaka, Masashi Mizokami, Masashi Mizokami, Etsuro Orito, Tatsunori Nakano, Takanobu Kato, Xin Ding, Tomoyoshi Ohno, Ryuzo Ueda, Shunro Sonoda, Kazuo Tajima, Tomoyuki Miura, Masanori Hayami, Journal of Medical Virology, 57, 264 - 268,   1999年02月15日, Serum TTV DNA was assayed in 140 native Indians and 40 members of the general population in Colombia to determine the prevalence of TT virus (TTV) infection among Colombian native Indians. Of the 140 native Indians, 23 (16.4%) were positive for TTV DNA, compared to 4 (10.0%) of 40 from the general population (P = not significant). The prevalence of TTV DNA among native Indians was much higher than that of HBsAg and anti-HCV. Comparison of subjects with and without TTV DNA revealed no significant differences in all characteristics between the two groups. A phylogenetic tree, using the open reading frame 1 sequence (222 bp), indicated that the virus could be classified into four different genotypes, including three previously reported ones. The results show that TTV infection is common in Colombian native Indians without liver disease and also indicate the existence of a novel genotype of TTV.
  • Molecular evolution and genotype classification of TT virus, M. Mizokami, Y. Tanaka, Nippon rinsho. Japanese journal of clinical medicine, 57, 1250 - 1255,   1999年01月01日, Based on sequences data, TTV have a partial Rep protein motifs found among Circoviridae and the conserved region of parvoviral nonstructural polypeptides (NS)-1 genes, however we could not perform phylogenetic analyses among TTV and other viruses because of few similar sequences. Putative ORF2 among G2 and G4 encoded 49 aa because of in-frame stop codon, although that of G1 encoded 202 aa. Just down-stream of the stop codon, another putative new ORF(ORF3) were found around 150 aa. A phylogenetic analysis, using the ORF1 sequences of 93 TTV obtained from various geographical areas, indicated that the virus could be classified into six different genotypes. Further studies using more than 350 isolates obtained from DDBJ showed at least nine genotypes.
  • Slow evolutionary rate of GB virus C/hepatitis G virus, Yoshiyuki Suzuki, Kazuhiko Katayama, Shuetsu Fukushi, Tsutomu Kageyama, Akira Oya, Hirofumi Okamura, Yasuhito Tanaka, Masashi Mizokami, Takashi Gojobori, Journal of Molecular Evolution, 48, 383 - 389,   1999年01月01日, With the aim of elucidating evolutionary features of GB virus C/hepatitis G virus (GBV-C/HGV), molecular evolutionary analyses were conducted using the entire coding region of this virus. In particular, the rate of nucleotide substitution for this virus was estimated to be less than 9.0 x 10-6per site per year, which was much slower than those for other RNA viruses. The phylogenetic tree reconstructed for GBV-C/HGV, by using GB virus A (GBV-A) as outgroup, indicated that there were three major clusters (the HG, GB, and Asian types) in GBV-C/HGV, and the divergence between the ancestor of GB- and Asian-type strains and that of HG-type strains first took place more than 7000-10,000 years ago. The slow evolutionary rate for GBV- C/HGV suggested that this virus cannot escape from the immune response of the host by means of producing escape mutants, implying that it may have evolved other systems for persistent infection.
  • TT virus infection among blood donors and patients with non-B, non-C liver diseases in Korea, Tatsunori Nakano, Young Min Park, Masashi Mizokami, Jong Young Choi, Etsuro Orito, Tomoyoshi Ohno, Takanobu Kato, Yutaka Kondo, Yasuhito Tanaka, Hideaki Kato, Tetsuo Kato, Boo Sung Kim, Journal of Hepatology, 30, 389 - 393,   1999年01月01日, Background/Aims: A novel virus, designated the TT virus (TTV), was isolated from the serum of a patient with posttransfusion hepatitis of unknown etiology, in Japan. Subsequently, TTV was suggested to be a causative agent in a proportion of cases with cryptogenic hepatitis in Japan. This study aimed to elucidate the significance of TTV infection in cases with cryptogenic liver disease in Korea, a neighbor of Japan. Methods: The prevalence of TTV infection was studied in 120 patients with liver diseases, including 85 patients diagnosed as having non-B, non-C liver diseases. As controls, 220 blood donors were also examined. TTV DNA was detected by polymerase chain reaction, and the sequence was analyzed by phylogenetic analysis. Results: Fourteen (14.0%) of 100 accepted blood donors, 23 (19.2%) of 120 rejected blood donors, and 15 (17.6%) of 85 patients with non-B, non- C liver diseases were positive for TTV DNA. The prevalences of TTV infection among these groups were not significantly different. Phylogenetic analysis suggested the existence of four major genotypes of TTV. The proportions of each genotype among patients with non-B, non-C liver diseases were not different from those among accepted blood donors. Conclusions: TTV exists in Korea, but the prevalence among patients with non-B, non-C liver diseases was almost the same as that among blood donors. TTV may not be the main causative agent of cryptogenic liver disease in Korea. The relationship between non-B, non-C liver diseases and TTV genotype remains unclear, although TTV can be classified into four genotypes.
  • High prevalance of TT virus infection in Japanese patients with liver diseases and in blood donors, Takanobu Kato, Masashi Mizokami, Etsuro Orito, Tatsunori Nakano, Yasuhito Tanaka, Ryuzo Ueda, Noboru Hirashima, Yoshihiko Iijima, Tetsuo Kato, Fuminaka Sugauchi, Motokazu Mukaide, Kazuhide Shimamatsu, Masayoshi Kage, Masamichi Kojiro, Journal of Hepatology, 31, 221 - 227,   1999年01月01日, Background/Aims: Although a novel DNA virus, TT virus (TTV), has been isolated from a patient with cryptogenic post-transfusion hepatitis, its pathogenic role remains unclear. To elucidate its prevalence and clinical impact in patients with liver diseases, the presence of TTV DNA was assessed in patients with liver diseases and blood donors (BDs) in Japan using two primer sets, one conventional and the other new and highly sensitive. Methods: We studied 261 samples, 72 with chronic hepatitis associated hepatitis C virus (HCV-CH), 57 with hepatocellular carcinoma associated HCV (HCV-HCC), 12 with HCC without either HCV or hepatitis B virus (NBNC-HCC), and 120 of BDs. Results: Using two primer sets, TTV DNA was detected in 68 (94.4%), 53 (93.0%), 12 (100%), and 98 (81.7%) HCV-CH, HCV-HCC, NBNC-HCC, and BDs, respectively. The prevalence was not significantly different between HCV-CH and HCV-HCC, or between HCV-HCC and NBNC-HCC. Comparison between patients with and without TTV revealed no significant differences in backgrounds or biochemical findings. Histopathological findings in patients with HCV-CH, and number, maximum diameter, and histological differentiation of HCC also did not demonstrate any relation to TTV infection. TTV strains can be divided into five groups using phylogenetic analysis, but no disease- specific group appears to exist. Conclusions: Our data suggest that: 1) TTV is very prevalent among patients with liver diseases and even among BDs in Japan, 2) TTV infection does not impact on liver damage with HCV infection, and 3) TTV infection also does not affect the development or progression of HCC.
  • New genotypes of TT virus (TTV) and a genotyping assay based on restriction fragment length polymorphism, Yasuhito Tanaka, Masashi Mizokami, Etsuro Orito, Tomoyoshi Ohno, Tatsunori Nakano, Takanobu Kato, Hideaki Kato, Motokazu Mukaide, Young Min Park, Boo Sung Kim, Ryuzo Ueda, FEBS Letters, 437, 201 - 206,   1998年10月23日, A phylogenetic analysis, using the open reading frame 1 sequence of 93 TT viruses (TTV) obtained from various geographical areas, indicated that the virus could be classified into six different genotypes including three hitherto unreported genotypes. The high reliability of the six clusters was confirmed by bootstrap analysis. On the basis of these sequence data, a new simple genotyping assay based on a restriction fragment length polymorphism of TTV was developed. Using the enzymes NdeI and PstI, followed by cleavage with NlaIII or MseI, it was possible to distinguish between the six TTV genotypes. This system will provide the framework for future detailed epidemiological and clinical investigations. Copyright (C) 1998 Federation of European Biochemical Societies.
  • Heterogeneity in E2 region of GBV-C/hepatitis G virus and hepatitis C virus, Takanobu Kato, Masashi Mizokami, Masashi Mizokami, Tatsunori Nakano, Etsuro Orito, Ken Ichi Ohba, Yutaka Kondo, Yasuhito Tanaka, Ryuzo Ueda, Motokazu Mukaide, Kaoru Fujita, Kiyomi Yasuda, Shiro Iino, Journal of Medical Virology, 55, 109 - 117,   1998年06月01日, GB virus C/hepatitis G virus (GBV-C/HGV) is related distantly to hepatitis C virus (HCV). HCV has a hypervariable region (HVR), and exists as quasispecies in vivo. Although GBV-C/HGV also has replaceable amino acids in the presumed antigenic region, the existence and fluctuation of population of heterogeneous virus have not been evaluated. In this study, the heterogeneity of GBV-C/HGV and HCV was investigated by the single-strand conformation polymorphism (SSCP) analysis in six concomitantly infected patients, Two patients were observed for 4 years without any treatment, and four were treated with interferon-α (IFN). By SSCP analysis, amplicons of GBV-C/HGV RNA were separated into 1-5 bands on gels for each patient. The amplicons had different nucleotide but the same amino acid sequences in the presumed antigenic region. The amplicons of HCV RNA, separated into 1-4 bands, had different nucleotide and amino acid sequences in the HVR. In the two patients without treatment, the predominant strain of GBV-C/HGV was unchanged for the 4 years. In the four patients administered IFN, some strains of GBV-C/HGV disappeared after IFN therapy, whereas other strains persisted. The mean genetic distance among GBV-C/HGV strains represented by SSCP analysis was significantly lower than that of HCV (P < 0.05). The data indicate that: 1) GBV-C/HGV can be devoid of antigenic drift unlike HCV; 2) GBV-C/HGV has no HVR as seen in HCV in the presumed antigenic region; and 3) the sensitivity to IFN differs among GBV-C/HGV strains in the same hosts, as with HCV.
  • Analysis of conserved ambisense sequences within GB virus C, Yutaka Kondo, Masashi Mizokami, Tatsunori Nakano, Takanobu Kato, Yasuhito Tanaka, Noboru Hirashima, Ryuzo Ueda, Mitoshi Kunimatsu, Makoto Sasaki, Kiyomi Yasuda, Shiro Iino, Journal of Infectious Diseases, 178, 1185 - 1188,   1998年01月01日, No analysis has been done of the ambisense of GB virus C (GBV-C). When the anti-genomes of 16 reported sequences of GBV-C were analyzed, nucleotide codons 1758 and 1402 within the antigenome were conserved initiation and stop codons, respectively. Nucleotide sequences were also determined within the same region of 22 GBV-C strains. The anti-genomes of 38 sequences were translated and a consensus sequence was determined. In accordance with the consensus sequence, overlapping peptides were synthesized and used for the detection of anti-synthetic peptide antibodies by ELISA. The positivity of antibodies among sera with GBV-C RNA was Significantly higher than among sera without GBV-C RNA (66.7% vs. 15.6%), regardless of the simultaneous presence of hepatitis B surface antigen or antibodies to hepatitis C virus (P < .05). These results indicated that a novel protein associated with GBV-C might be expressed from the ambisense of this virus.
  • GB virus C/hepatitis G virus infection among Colombian native Indians, Yasuhito Tanaka, Masashi Mizokami, Etsuro Orito, Ken Ichi Ohba, Tatsunori Nakano, Takanobu Kato, Yutaka Kondo, Xin Ding, Ryuzo Ueda, Shunro Sonoda, Kazuo Tajima, Tomoyuki Miura, Masanori Hayami, American Journal of Tropical Medicine and Hygiene, 59, 462 - 467,   1998年01月01日, To elucidate the prevalence of GB virus C/hepatitis G virus (GBV-C/HGV) infection in Colombian native Indians, serum GBV-C/HGV RNA was assayed in 163 native Indians and 67 members of the general population in Colombia. The native Indians (males:females = 40:123) and the members of the general population (males: females = 20:47) were tested by reverse transcription- semi-nested polymerase chain reaction. Of the 163 native Indians, 10 (6.1%) were positive for GBV-C/HGV RNA, compared with one (1.5%) of 67 from the general population. All Indians were negative for hepatitis B surface antigen and antibody to hepatitis C virus. Of 10 Indians with GBV-C/HGV RNA, the genotype of nine subjects was the Asian type. These data indicated that 1) the prevalence of GBV-C/HGV RNA in Colombian native Indians is high, and 2) GBV-C/HGV was probably brought from Asia and inherited for generations in some native Indian groups.
  • African origin of GB virus C/hepatitis G virus., 423/,143-148,   1998年
  • Familial clustering of GB virus C/hepatitis G virus infection among the Jewish population in Uzbekistan, Takanobu Kato, Masashi Mizokami, Tatsunori Nakano, Yutaka Kondo, Yasuhito Tanaka, Ken Ichi Ohba, Etsuro Orito, Ryuzo Ueda, Kouji Shibata, Toshiyasu Yamauchi, Vladimir Gurtsevitch, Alexander Syrtsev, Alexander Syrtsev, Ruslan Ruzibakiev, Masahiro Yamashita, Masanori Hayami, Hepatology Research, 9, 135 - 143,   1997年12月01日, GB virus C/hepatitis G virus (GBV-C/HGV) was recently cloned from patients with hepatitis and is regarded as transmissible through blood and blood products. However, other modes of transmission, such as intrafamilial transmission, are still unknown. In this study, the prevalence in serum of GBV-C/HGV RNA and antibody to HGV E2 (anti-E2), a newly developed marker to indicate past infection and familial clustering are investigated among the Jewish general population in Uzbekistan, previously reported as a GBV-C/HGV epidemic group. Of 66 subjects, belonging to 28 families, GBV-C/HGV RNA was detected in seven (10.6%) and anti-E2 was detected in six (9.1%). Subjects doubly positive for both GBV-C/HGV RNA and anti-E2 were not observed. The mean age of subjects positive for GBV-C/HGV RNA was 29.1 years. In contrast, the mean age of subjects positive for anti-E2 was 53.2 years and these ages are significantly different (P < 0.05). Familial clustering of persistent and past GBV-C/HGV infection was observed in three families, one married couple and two mother and infant pairs. Our data indicate that: (1) subjects positive for GBV-C/HGV RNA are distributed among the younger generation and subjects positive for anti-E2 among the older generation; and (2) GBV-C/HGV is possibly spread by intrafamilial transmission, both mother to infant and spouse to spouse, in this studied group.
  • GB virus C/hepatitis G virus infection among patients with hepatocellular carcinoma, Yasuhito Tanaka, Yasuhito Tanaka, Masashi Mizokami, Takanobu Kato, Yuko Matsumoto, Tetsuyoshi Ishihama, Fuminaka Sugauchi, Seiji Suzuki, Norikazu Miyata, Hepatology Research, 8, 44 - 51,   1997年08月01日, To elucidate the prevalence and association of GB virus Clhepatitis G virus (GBV-C/HGV) infection among patients with hepatocellular carcinoma (HCC), GBV-C/HGV RNA was screened by the reverse transcription polymerase chain reaction using the specific primers derived from 5'-untranslated region and NS3 in sera from 60 HCC patients admitted in our hospital between 1993 and 1996. Of 60 patients, 12 (20%) showed positivity for one of HBV related viral markers such as HBsAg, anti-HBs, anti-HBc and HBV DNA, 24(40%) for one of HCV markers such as anti-HCV and HCV RNA, 18 (30%) for both HBV and HCV markers, and six (10%) showed negativity for both HBV and HCV markers. GBV- C/HGV RNA was detected in five (8.3%). One patient (8.3%) was included in 12 HCC patients with. HBV markers, one (4.2%) was in 24 with HCV markers alone, and two (11.1%) was in 18 with HBV and HCV markers, and one (16.7%) was in six without HBV and HCV markers. Only the history of blood transfusion was significantly different between the patients with and without GBV-C/HGV RNA. These results indicated that: (1) GBV-C/HGV infection is associated with only a small proportion of HCC; (2) blood transfusion is a major important route for GBV- C/HGV transmission; (3) laboratory findings and characteristics of HCC are not significantly different between HCC patients with and without GBV-C/HGV.
  • A case of liver and intraperitoneal abscess after percutaneous ethanol injection therapy (PEIT) for hepatocellular carcinoma, Tetsuyoshi Ishihama, Seiji Suzuki, Fuminaka Sugauchi, Akira Tanaka, Yasuhito Tanaka, Yukou Matsumoto, Norikazu Miyata, Acta Hepatologica Japonica, 38, 101 - 106,   1997年01月01日, The patient (40-year-old female) had a history of right hepatic posterior segmentectomy for ruptured hepatocellular carcinoma (HCC) with hepatitis B virus positive liver cirrhosis in 1988. Because of recurrence of HCC in the right anterior-superior segment (S8), she was re-admitted for the percutaneous ethanol injection therapy (PEIT) in September 1995. One month later, she had fever and right hypochondralgia. Abdominal contrast enhanced- CT showed a belt-like low density lesion from the lesion treated with PEIT in the S8 to the right intraperitoneal space through the inferior surface of the liver. She was diagnosed as liver and intraperitoneal abscess after PEIT. Although dome-like protruded lesions were appeared with oozing pus on the skin in the right hypochondrium, she recovered without surgical therapy. However it may be rare that patients have liver and intraperitoneal abscess after PEIT like this case, careful observations after PEIT for the therapy of HCC are needed.
  • GB virus C/hepatitis G virus infection among Japanese patients with hematological diseases, Tatsunori Nakano, Masashi Mizokami, Etsuro Orito, Ken Ichi Ohba, Yutaka Kondo, Takanobu Kato, Yasuhito Tanaka, Atsushi Wakita, Hirokazu Komatsu, Masakazu Nitta, Ryuzo Ueda, Hepatology Research, 9, 180 - 191,   1997年01月01日, To evaluate the association between GB virus C and hepatitis G virus (GBV-C/HGV) infection and hematological diseases for which frequent transfusion is required, 60 patients with such diseases were examined. GBV- C/HGV RNA and antibody to HGV envelope protein E2 (anti-E2) in serum were detected by a reverse transcription polymerase chain reaction (RT-PCR) and ELISA, respectively. These patients had been transfused with 189.2 ± 396.5 (0-2206) units of blood from 54.0 ± 109.4 (0-494) blood donors. Eight (13.3%) and seven (11.7%) of them were positive for GBV-C/HGV RNA and anti- E2, respectively. Only one patient was positive for both. Thus, 14 (23.3%) were positive for GBV-C/HGV RNA and/or anti-E2. There was no significant correlation between the positivities for GBV-C/HGV RNA and/or anti-E2 and any particular disease. The number of transfused units (P < 0.05) and the number of donors (P < 0.05) in the patients positive for GBV-C/HGV RNA and/or anti- E2 were significantly higher than those negative for both. There was no significant difference in received units of blood or the number of blood donor between the patients with and without anti-E2 in the patients infected by GBV-C/HGV. These data indicate that (1) GBV-C/HGV infection was not associated directly with the hematological diseases and (2) GBV-C/HGV infection in the patients with hematological diseases was likely to have been acquired through blood transfusion.
  • Examination of percutaneous minocycline hydrochloride injection therapy for hepatic cyst by one puncture method, Tanaka Y., Ogino M., Tokuda H., Mizuno M., Yamauchi M., Iijima Y., Hattori K., Kato T., Komatsubara Y., Kato H., Hayashi K., Japanese Journal of Gastroenterology, 93, (11) 828 - 836,   1996年12月07日, Minocycline hydrochloride (M1NO) at a dose of 500 mg (in principle) was injected into each of 11 hepatic cysts/10 cases (mean maximum diameter : 12.6 cm) that exhibited symptoms or a tendency toward growth by percutaneous transhepatic one puncture method, and the relation between therapeutic efficacy and pH of cystic fluid was examined. The efficacy was evaluated by abdominal CT after 3 months, and when a shrink of 50% or more in the maximum diameter was observed, it was judged as marked response. Marked effect was observed in 9 lesions of 11 (82%). This MINO injection therapy by one puncture method is very safe, simple and useful. Reduction in intra-cystic pH was not always related to the therapeutic efficacy, so involvement of cytotoxicity of MINO was suggested in degenerating the cystic epithelial cells.

MISC

  • B型肝炎に対する免疫治療の展望, 五十川正記, 田中靖人, 月刊メディカル・サイエンス・ダイジェスト, 44,   2018年07月30日
  • ウイルス性から脂肪性肝炎診療の最前線~バイオマーカーの有用性, 田中靖人, 臨床化学, 47,   2018年07月24日
  • HISCL試薬での甲状腺検査項目(FT4,FT3)乖離例の解析, 佐野まゆ美, 五藤孝秋, 大根久美子, 大池知行, 佐藤茂, 井上貴子, 田中靖人, 臨床化学, 47,   2018年07月
  • 小児B型・C型慢性肝炎の治療指針(平成29年度版), 田尻仁, 高野智子, 藤井洋輔, 伊藤嘉規, 田中英夫, 細野覚代, 田中靖人, 羽鳥麗子, 中山佳子, 杉山真也, 乾あやの, 小松陽樹, 村上潤, 工藤豊一郎, 鈴木光幸, 虻川大樹, 惠谷ゆり, 三善陽子, 要藤裕孝, 四柳宏, 日本小児栄養消化器肝臓学会雑誌, 32,   2018年04月27日
  • ウイルス性肝炎診療の最前線, 田中靖人, 臨床とウイルス, 46,   2018年04月21日
  • B型肝炎診療の最前線 1 B型肝炎の診療ガイドライン―HBV再活性化も含めて, 松波加代子, 松波加代子, 田中靖人, 週刊日本医事新報,   2018年04月07日
  • 【B型肝炎診療の最前線】 B型肝炎の診療ガイドライン HBV再活性化も含めて, 松波 加代子, 田中 靖人, 日本医事新報, (4902) 28 - 36,   2018年04月, <POINT>▼B型慢性肝炎における抗ウイルス療法の目標は、肝炎の活動性と肝線維化進展の抑制による慢性肝不全の回避ならびに肝発癌の抑制である▼抗ウイルス療法の短期目標は、(1)ALT持続正常化(30U/L以下)、(2)HBe抗原陰性かつHBe抗体陽性、(3)HBV-DNA増殖抑制の3項目であり、長期目標はHBs抗原消失である▼2017年にテノホビルジソプロキシル(TDF)のプロドラッグであるテノホビルアラフェナミド(TAF)が承認され、TDFからTAFに切り替えることで腎機能障害や骨密度低下の改善が見込まれる▼B型肝炎ウイルス(HBV)の再活性化は、癌化学療法・免疫抑制療法後の合併症として、一部の症例においては劇症肝炎に至り、致死的な経過をたどることが報告されている。ステロイド単独投与に際しても、HBs抗原の有無は必ず確認すべきである▼治療前スクリーニング検査によるHBs抗原陰性例のうち、HBc抗体陽性あるいはHBs抗体陽性例(両方陽性を含む)においては、定期的(1〜3ヵ月に1回)なHBV-DNA定量検査を行い、「20IU/mL(1.3Log IU/mL)以上」になった時点で核酸アナログの投与を開始する(preemptive antiviral therapy)(著者抄録)
  • 【肝癌-診断・治療の最新知見-】 肝癌リスク遺伝子, 松浦 健太郎, 田中 靖人, 日本臨床, 76, (2) 164 - 168,   2018年02月
  • B型肝炎治療 2018 B型肝炎ウイルス感染・複製機構:なぜHBV排除は困難なのか, 五十川正記, 田中靖人, Mebio, 35,   2018年01月
  • 日本肝臓学会評議員を対象としたB型肝炎ワクチンに関するアンケート調査, 田中靖人, 乾あやの, 森屋恭爾, 江口有一郎, 四柳宏, 肝臓, 59,   2018年
  • 肝疾患の新展開 B型肝炎ウイルス再活性化 現状と当院での取り組み, 井上 貴子, 新海 登, 田中 靖人, 臨床病理, 65, (12) 1291 - 1298,   2017年12月
  • 電子カルテを応用したB型肝炎ウイルス再活性化予防システムの改良, 井上 貴子, 五藤 孝秋, 大池 知行, 可児 里美, 佐藤 茂, 菊池 祥平, 田中 靖人, 臨床病理, 65, (補冊) 207 - 207,   2017年10月
  • 【甲状腺ホルモンと関連疾患】 甲状腺ホルモンと肝機能障害, 井上 貴子, 田中 靖人, 日本甲状腺学会雑誌, 8, (2) 193 - 206,   2017年09月, 肝臓は代謝・合成の中心的な臓器で甲状腺ホルモンの影響を受けやすく、甲状腺ホルモンが正常に機能するためには肝機能も正常である必要があり、肝臓と甲状腺は密接に関連している。甲状腺中毒症では肝細胞の代謝が亢進し、甲状腺機能低下症では代謝の低下から胆汁うっ滞が生じ、ともに肝機能障害の原因となる。自己免疫性肝炎・原発性胆汁性胆管炎・非アルコール性脂肪性肝疾患・C型慢性肝炎では甲状腺機能異常の合併が多く、肝硬変に至ればさらに増加する。C型慢性肝炎をインターフェロン(IFN)-αで治療する際は、IFN誘発性甲状腺炎(IIT)に留意する。自己免疫性IITは慢性甲状腺炎・甲状腺機能亢進症・非疾患性甲状腺抗体陽性に、非自己免疫性IITは破壊性甲状腺炎・非自己免疫性甲状腺機能低下症に分類される。本章では甲状腺疾患診療時に遭遇する肝機能障害、慢性肝疾患に関連する甲状腺機能障害の両者について、最新の知見を交えて概説する。(著者抄録)
  • 【ここまで変わったC型肝炎の治療】 治療効果を規定する要因 DAA治療における宿主要因の意義, 松浦 健太郎, 田中 靖人, 最新医学, 72, (9) 1280 - 1284,   2017年09月, C型慢性肝疾患に対するIFNを基本とした治療の効果には,さまざまなウイルス因子,IL28B遺伝子多型をはじめとした宿主因子が関連することが報告されてきた.現在,主流であるDAAs併用療法により,これまで難治例とされていた高齢,肝線維化進展,IL28B遺伝子型が治療抵抗型の患者においても極めて高いHCV排除率が得られるようになった.(著者抄録)
  • 【ウイルス肝炎のすべて】 ウイルス肝炎総論 ウイルス肝炎研究におけるGWASの意義, 松浦 健太郎, 田中 靖人, 医学のあゆみ, 262, (14) 1233 - 1238,   2017年09月, 近年、網羅的な一塩基多型(SNP)のタイピング技術が飛躍的に進歩し、ゲノムワイド関連分析法(GWAS)を用いることにより、肝疾患領域においても治療・病態に関連する遺伝要因が明らかにされている。著者らは、C型慢性肝疾患に対するインターフェロン(IFN)治療効果にきわめて強く関連するIL28B遺伝子多型を同定し、後の実臨床、新規薬剤の開発に大きく貢献した。そのほかにも、GWASにより、IFN治療の副作用、B型・C型肝炎の臨床経過に影響を及ぼす遺伝子多型が同定されている。本稿ではこれらの概要と、とくに著者らが最近同定したIFN治療によるC型肝炎ウイルス(HCV)排除後の肝発がんに関連するTLL1遺伝子多型を中心に解説する(表1)。(著者抄録)
  • HCV排除後のHBV再活性化はどのようにして起こるか? IFNフリー治療での発生が目立つ。抗ウイルス活性の減弱などが原因として考えられる, 田中 靖人, 日本医事新報, (4869) 62 - 62,   2017年08月
  • 最近のC型肝炎治療 C型肝炎撲滅を目指して, 田中 靖人, 明日の臨床, 29, (1) 13 - 18,   2017年06月, 最近のC型肝炎治療について概説した。C型慢性肝疾患の治療は2004年に承認されたペグインターフェロン(PEG-IFN)/リバビリン(RBV)併用療法によって格段に進歩した。2010年にはIL28Bの遺伝子診断によるインターフェロン効果の予測評価が新規先制医療に認可され、治療前に遺伝子型を測定することで高確率に治療効果を予測し、治療適応を判断できるようになった。そして近年、Direct Acting Antivirals(DAAs)の登場によりC型肝炎ウイルス(HCV)に対する治療効果は飛躍的に向上している。インターフェロンフリーの内服治療により、これまで治療することのできなかった多くの患者が治療可能となり、HCVを完全に排除することができる時代となった。C型肝炎は治療の進歩により制御できる時代となったが、今後はHCV排除よりも背景肝の改善および肝癌の制御が課題となる。特に、高齢、線維化進展例においては持続性ウイルス学的著効(SVR)後も一定の頻度で発癌例が見られる可能性があり、SVR後の肝発癌予測因子の検討を含めて、効率的なフォローアップ体制の構築が望まれる。
  • 【激変する肝疾患診療の現状】 ウイルス性肝炎の診療 B型肝炎の再活性化とその対策, 楠本 茂, 田中 靖人, 臨牀と研究, 94, (5) 545 - 551,   2017年05月

講演・口頭発表等

  • 肝線維化評価における肝硬度測定と糖鎖マーカーM2BPGi有用性, 松波加代子, 飯尾悦子, 飯尾悦子, 松浦健太郎, 松浦健太郎, 藤原圭, 野尻俊輔, 田中靖人, 肝臓,   2018年09月20日
  • B型慢性肝炎患者に対するインターフェロン治療のインパクト, 新海登, 熊田卓, 田中靖人, 肝臓,   2018年09月20日
  • 非アルコール性脂肪肝疾患に伴うB型慢性肝炎の増悪と肝発癌メカニズムの解明, 大西雅也, 大西雅也, 五十川正記, 田中靖人, 肝臓,   2018年09月20日
  • C型慢性肝疾患におけるDAA治療後肝発癌及び線維化改善とTLL1遺伝子多型の関連性, 飯尾悦子, 松浦健太郎, 田中靖人, 肝臓,   2018年09月20日
  • CKD合併C型慢性肝炎患者に対するエルバスビル・グラゾプレビルの有効性と安全性, 葉山惟信, 厚川正則, 近藤千紗, 豊田秀徳, 高口浩一, 魚嶋晴紀, 渡邊網正, 島田紀朋, 三上繁, 加藤慶三, 安部宏, 小川力, 飯尾悦子, 田中靖人, 熊田卓, 肝臓,   2018年09月20日
  • C型肝炎ウイルス排除後の肝癌発症に関連するTLL1遺伝子多型の同定および機能解析, 松浦健太郎, 堤進, 田中靖人, 肝臓,   2018年09月20日
  • C型肝炎ウイルス感染による腸内細菌叢異常(Dysbiosis)とC型肝炎病態進展へのインパクト, 井上貴子, 吉治仁志, 田中靖人, 田中靖人, 日本消化器がん検診学会雑誌,   2018年09月15日
  • 当院でのヒト免疫不全ウイルス(HIV)スクリーニング検査実施状況とHIV抗原抗体同時検出法の有用性について, 井上 貴子, 大池 知行, 五藤 孝秋, 可児 里美, 佐藤 茂, 菊池 祥平, 田中 靖人, 日本臨床検査自動化学会会誌,   2018年09月01日
  • 高ウイルス量妊婦への核酸アナログ投与によるB型肝炎ウイルス母子感染予防, 杉浦 時雄, 遠藤 剛, 伊藤 孝一, 齋藤 伸治, 田中 靖人, 三善 陽子, 鈴木 光幸, 高野 智子, 田尻 仁, 日本小児科学会雑誌,   2018年08月01日
  • 当院での梅毒スクリーニング検査実施状況と確定診断症例の特徴, 井上 貴子, 五藤 孝秋, 大池 知行, 可児 里美, 佐藤 茂, 菊池 祥平, 田中 靖人, 臨床化学,   2018年07月24日
  • HISCL試薬での甲状腺検査項目(FT4、FT3)乖離例の解析, 佐野 まゆ美, 五藤 孝秋, 大根 久美子, 大池 知行, 佐藤 茂, 井上 貴子, 田中 靖人, 臨床化学,   2018年07月
  • ウイルス性から脂肪性肝炎診療の最前線 バイオマーカーの有用性, 田中 靖人, 臨床化学,   2018年07月
  • 効率的な肝炎用診療情報提供書(簡易版)導入までの経緯とその成果, 井上 貴子, 飯尾 悦子, 松波 加代子, 松浦 健太郎, 藤原 圭, 野尻 俊輔, 是永 匡紹, 田中 靖人, 肝臓,   2018年04月20日
  • Genotype2型C型肝炎に対するソホスブビル+リバビリン治療の有効性と安全性に関する検討 ペグインターフェロン+リバビリン療法との比較, 大谷 綾, 金 秀基, 金 守良, 井本 勉, 音野 由美, 藤井 友実, 金 啓二, 林 祥剛, 矢野 嘉彦, 田中 靖人, 肝臓,   2018年04月20日
  • C型慢性肝疾患でのDAAs治療例におけるSVR例からの実臨床での初回肝発癌予測因子, 島田紀朋, 田中靖人, 高口浩一, 肝臓,   2018年04月20日
  • HBV複製を制御するヒトmicroRNAの網羅的スクリーニングと機能解析, 堤進, 松浦健太郎, 田中靖人, 肝臓,   2018年04月20日
  • C型慢性肝疾患におけるDAA再治療,治療後発癌および肝線維化の検討, 飯尾悦子, 松浦健太郎, 島田紀朋, 高口浩一, 江口有一郎, 厚川正則, 平嶋昇, 日下部篤宣, 宮木知克, 野尻俊輔, 藤原圭, 松波加代子, 田中靖人, 肝臓,   2018年04月20日
  • 日本肝臓学会評議員を対象としたB型肝炎ワクチンに関するアンケート調査, 田中靖人, 乾あやの, 四柳宏, 肝臓,   2018年04月20日
  • C型肝炎の将来を予測するゲノム診断~GWASで得られた成果と臨床応用, 田中靖人, 肝臓,   2018年04月20日
  • HBV排除における肝臓内インターフェロンシグナル誘導の重要性, 河島圭吾, 河島圭吾, 五十川正記, 田中靖人, 肝臓,   2018年04月20日
  • C型慢性肝炎患者の血清におけるlet‐7発現解析, 松浦健太郎, 飯尾悦子, 会澤信弘, 榎本平之, 西口修平, 豊田秀徳, 熊田卓, 松波加代子, 藤原圭, 野尻俊輔, 田中靖人, 肝臓,   2018年04月20日
  • 症候性急性C型肝炎の経過中におけるHCV RNA量の再上昇に伴った血清IFN‐γの出現は,引き続いてのHCVの消失を示唆する有用な指標である, 井本勉, 金秀基, 天野恵介, 尹聖哲, 廣畑成也, 飯尾悦子, 石川達, 矢野嘉彦, 勝島慎二, 福永豊和, 堀江裕, 鄭浩柄, 国立裕之, 田中靖人, 金守良, 肝臓,   2018年04月20日
  • B型慢性肝疾患に対する抗ウイルス療法別のHBs抗原量の推移, 松波加代子, 松波加代子, 新海登, 飯尾悦子, 松浦健太郎, 藤原圭, 野尻俊輔, 田中靖人, 肝臓,   2018年04月20日
  • 核酸アナログ投与中のB型慢性肝炎患者における肝発癌予測モデルの構築, 新海登, 熊田卓, 田中靖人, 肝臓,   2018年04月20日
  • 持続的かつ強力な抗HBV活性を有する新規核酸アナログCFCPの同定, 林佐奈衣, 田中靖人, 満屋裕明, 満屋裕明, 肝臓,   2018年04月20日
  • 高脂肪食によるB型慢性肝炎の増悪と肝細胞癌の誘導, 大西雅也, 大西雅也, 五十川正記, 田中靖人, 肝臓,   2018年04月20日
  • 実臨床におけるエルバスビル+グラゾプレビル併用療法のC型慢性肝炎症例に対する有効性と安全性, 近藤千紗, 厚川正則, 豊田秀徳, 高口浩一, 淺野徹, 安部宏, 加藤慶三, 島田紀朋, 三上繁, 渡邊網正, 魚嶋晴紀, 小川力, 出口章広, 守屋昭男, 尾立磨琴, 谷丈二, 藤岡真一, 飯尾悦子, 田中靖人, 正木勉, 熊田卓, 肝臓,   2018年04月20日
  • 免疫細胞におけるmiRNA発現変化はNF‐κBシグナルを介して抗ウイルス免疫病態に不利に影響する, 近藤泰輝, 近藤泰輝, 近藤泰輝, 福田遼, 福田遼, 田中靖人, 肝臓,   2018年04月20日
  • HCV感染非代償性肝硬変の日本人患者における12週間のribavirin併用の有無によるsofosbuvir/velpatasvir療法(Sofosbuvir/Velpatasvir with or without Ribavirin for 12 Weeks in HCV-Infected Japanese Patients with Decompensated Cirrhosis), 竹原 徹郎, 西口 修平, 黒崎 雅之, 田中 靖人, 坂本 直哉, 肝臓,   2018年04月
  • C型慢性肝疾患をインターフェロンフリー直接作用型抗ウイルス薬(DAAs)で治療した際に見られる血中脂質代謝の特徴, 井上 貴子, 五藤 孝秋, 飯尾 悦子, 松波 加代子, 藤原 圭, 新海 登, 松浦 健太郎, 野尻 俊輔, 田中 靖人, 糖尿病,   2018年04月
  • pgRNAを内包したB型肝炎ウイルスの全原子分子動力学シミュレーション, 山口陽平, 今井甫, 藤本和士, 浦野諒, 篠田渉, 尾曲克己, 田中靖人, 石川哲也, 中川敦史, 岡崎進, 分子シミュレーション討論会講演要旨集,   2017年11月29日
  • C型慢性肝疾患に対するIFNフリー治療成績及び治療後発癌に寄与する宿主因子の同定, 飯尾悦子, 松浦健太郎, 田中靖人, 肝臓,   2017年11月05日
  • N市での肝炎検査陽性者フォローアップ事業の導入と陽性者受診率向上への試み, 井上貴子, 是永匡紹, 田中靖人, 肝臓,   2017年11月05日
  • 当院のB型慢性肝疾患に対するテノホビルの治療効果と副作用の検討, 松波 加代子, 飯尾 悦子, 松浦 健太郎, 藤原 圭, 野尻 俊輔, 城 卓志, 田中 靖人, 肝臓,   2017年11月
  • B型、C型肝炎患者拾い上げの取り組み N市での肝炎検査陽性者フォローアップ事業の導入と陽性者受診率向上への試み, 井上 貴子, 是永 匡紹, 田中 靖人, 肝臓,   2017年11月
  • C型肝炎におけるDAA治療の成果と今後の課題 C型慢性肝疾患に対するIFNフリー治療成績及び治療後発癌に寄与する宿主因子の同定, 飯尾 悦子, 松浦 健太郎, 田中 靖人, 肝臓,   2017年11月
  • 生活習慣病関連肝疾患の基礎と臨床 NAFLDにおけるPNPLA3、TLL1遺伝子多型を用いた線維化リスク分類, 瀬古 裕也, 田中 靖人, 伊藤 義人, 肝臓,   2017年11月
  • B型肝炎に対する治療の成果と今後の課題 肝臓内RIG-I Like Receptors(RLR)刺激によるB型肝炎ウイルス(HBV)特異的CD8+T細胞応答の誘導, 五十川 正記, 河島 圭吾, 田中 靖人, 肝臓,   2017年11月
  • HBV再活性化対策のUp-to-date HBV DNAモニタリング研究(C-SHOT0802)の保存検体を用いた高感度HBs抗原検査の有用性の検討, 楠本 茂, 田中 靖人, 溝上 雅史, 日本消化器病学会雑誌,   2017年09月
  • SVR100%を目指すDAAs治療 C型慢性肝疾患に対するIFN-free治療非著効例の宿主因子、薬剤耐性変異の検討, 飯尾 悦子, 田中 靖人, 島田 紀朋, 日本消化器病学会雑誌,   2017年09月
  • B型肝炎治療の進歩 B型慢性肝炎に対するペグインターフェロン単独療法の有用性 多施設共同研究, 新海 登, 松居 剛志, 田中 靖人, 日本消化器病学会雑誌,   2017年09月
  • 電子カルテのアラート・オーダリング機能を用いた肝炎ウイルス検査支援 HBV再活性化予防と早期発見, 井上 貴子, 五藤 孝秋, 是永 匡紹, 田中 靖人, 日本臨床検査自動化学会会誌,   2017年08月
  • ソホスブビル・リバビリン併用療法で再燃後オムビタスビル・パリタプレビル・リトナビル・リバビリンによる再治療でSVRが得られたC型慢性肝炎genotype 2aの1例, 近藤 千紗, 厚川 正則, 坪田 昭人, 飯尾 悦子, 田中 靖人, 大久保 知美, 新井 泰央, 糸川 典夫, 岩切 勝彦, 肝臓,   2017年08月, 73歳女。HCV抗体陽性を指摘されて紹介受診した。腹部US、CTにて肝硬変の所見は認めず、治療開始前検査所見ではHCV genotype 2a、FIB-4 index 2.19、IL28B(rs8099917) TTであり、NS5B領域の薬剤耐性変異は認めなかった。初回のソホスブビル・リバビリン(SOF+RBV)併用療法で治療不成功となったが、オムビタスビル・パリタプレビル・リトナビル・リバビリン(OBV/PTV/r+RBV)併用療法による再治療を行い、sustained viral responseを獲得できた。SOF+RBV併用療法で治療不成功となったgenotype 2のC型慢性肝炎症例であっても、genotype 2a症例ではOBV/PTV/r+RBV併用療法による再治療が有効である可能性が示唆された。
  • B型肝炎研究の新展開 肝臓内HBV特異的CD8+T細胞応答はI型インターフェロンシグナルにより制御される, 河島 圭吾, 五十川 正記, 田中 靖人, 肝臓,   2017年04月
  • C型肝炎治療の今後の課題 HCV排除後の肝癌発症に関連する遺伝要因の探索 ゲノムワイド関連解析, 松浦 健太郎, 飯尾 悦子, 田中 靖人, 肝臓,   2017年04月
  • ゲノタイプ1型C型慢性肝疾患(GT1-CHC)に対する直接作用型抗ウイルス薬(DAAs)治療が脂質代謝に及ぼす影響, 井上 貴子, 飯尾 悦子, 新海 登, 松波 加代子, 藤原 圭, 野尻 俊輔, 田中 靖人, 糖尿病,   2017年04月
  • ウイルス性肝炎の病態解析と新規治療 I型インターフェロンはHBV Large S抗原を蓄積した肝細胞の細胞死を誘導する, 五十川 正記, 河島 圭吾, 田中 靖人, 肝臓,   2017年04月
  • HBe抗原陽性B型慢性肝炎に対するペグインターフェロン単独療法の有用性-タイと本邦の症例の比較, 新海 登, Chuaypen Natthaya, 松居 剛志, 榎本 大, 柘植 雅貴, 厚川 正則, 日下部 篤宣, 田中 靖人, 肝臓,   2017年04月
  • B型肝炎ウイルスの感染性粒子形成に影響を与える細胞内小胞輸送経路の解析, 井上 淳, 二宮 匡史, 梅津 輝行, 中村 琢也, 小暮 高之, 嘉数 英二, 諸沢 樹, 高井 智, 田中 靖人, 下瀬川 徹, 肝臓,   2017年04月
  • GT2に対するSOF/RBV治療の再燃に関する検討, 島田 紀朋, 飯尾 悦子, 松倉 聡, 厚川 正則, 安部 宏, 加藤 慶三, 安達 哲史, 糸川 典夫, 相澤 良夫, 田中 靖人, 坪田 昭人, 肝臓,   2017年04月
  • 高度肝線維化を伴うゲノタイプ1型C型慢性肝疾患に対する直接作用型抗ウイルス薬治療による脂質代謝の変化, 井上 貴子, 飯尾 悦子, 新海 登, 松波 加代子, 藤原 圭, 野尻 俊輔, 田中 靖人, 肝臓,   2017年04月
  • 散発性急性C型肝炎例に於ける血清type-1 IFNs及びtype-3 IFNs値の動態とその臨床的意義, 井本 勉, 天野 恵介, 飯尾 悦子, 尹 聖哲, 廣畑 成也, 石川 達, 矢野 嘉彦, 勝島 慎二, 米田 俊貴, 福永 豊和, 堀江 裕, 鄭 浩柄, 國立 裕之, 金 秀基, 金 守良, 工藤 正俊, 田中 靖人, 肝臓,   2017年04月
  • C型肝炎SVR後の問題点 IFN-free治療でのSVR例のreal worldでの肝発癌及び肝癌再発抑制効果関連因子, 島田 紀朋, 厚川 正則, 田中 靖人, 肝臓,   2017年04月
  • 肝疾患における新規バイオマーカーの探索 非B非C型肝癌におけるmiRNA216ファミリーの発現, 松居 剛志, 田中 靖人, 肝臓,   2017年04月
  • ウイルス性肝炎の疫学・自然史 B型肝炎母子感染予防不成功例の原因と経過に関する検討, 高野 智子, 田尻 仁, 田中 靖人, 虻川 大樹, 乾 あやの, 牛島 高介, 惠谷 ゆり, 鈴木 光幸, 三善 陽子, 村上 潤, 四柳 宏, 肝臓,   2017年04月
  • ウイルス性肝炎の疫学・自然史 高ウイルス量妊婦への核酸アナログ投与によるB型肝炎ウイルス母子感染予防, 杉浦 時雄, 遠藤 剛, 伊藤 孝一, 鈴木 光幸, 三善 陽子, 高野 智子, 田尻 仁, 田中 靖人, 肝臓,   2017年04月
  • CKD合併C型慢性肝炎患者に対するIFN-free治療の成績, 厚川 正則, 三上 繁, 島田 紀朋, 池上 正, 浅野 徹, 安部 宏, 加藤 慶三, 佐藤 愼一, 甲嶋 洋平, 近藤 千紗, 糸川 典夫, 新井 泰央, 大久保 知美, 仁平 武, 田中 靖人, 忠願寺 義通, 松崎 靖司, 岩切 勝彦, 肝臓,   2017年04月
  • C型慢性肝疾患に対するSofosbuvir/Ledipasvir併用療法における非著効例の検討, 飯尾 悦子, 島田 紀朋, 高口 浩一, 妹尾 知典, 江口 有一郎, 厚川 正則, 坪田 昭人, 安部 宏, 加藤 慶三, 日下部 篤宣, 宮木 知克, 松浦 健太郎, 野尻 俊輔, 松波 加代子, 藤原 圭, 田中 靖人, 肝臓,   2017年04月
  • C型慢性肝炎へのダクラタスビル・アスナプレビル併用療法が肝合成能に与える影響, 井上 貴子, 飯尾 悦子, 松波 加代子, 藤原 圭, 新海 登, 野尻 俊輔, 田中 靖人, 日本内分泌学会雑誌,   2017年04月
  • B型肝炎治療のup to date I型インターフェロンシグナルは肝臓内HBV特異的CD8+T細胞応答を阻害する, 河島 圭吾, 五十川 正記, 田中 靖人, 日本消化器病学会雑誌,   2017年03月
  • C型肝炎の治療到達点と新たな課題 TLL1遺伝子多型はC型肝炎ウイルス排除後の肝細胞癌発症予測に関連する, 松浦 健太郎, 吉治 仁志, 田中 靖人, 日本消化器病学会雑誌,   2017年03月

特許

  • 抗B型肝炎ウイルス剤, 嶋根 和毅, 田中 靖人, JP2016079614, WO2017-061466
  • 肝硬変患者における肝細胞がん発生リスク及び予後を予測するための方法, 成松 久, 栂谷内 晶, 雄長 誠, 梶 裕之, 久野 敦, 佐藤 隆, 曽我部 万紀, 千葉 靖典, 池原 譲, 田中 靖人, 飯尾 悦子, JP2016077683, WO2017-047813
  • 骨髄線維症の状態の診断を補助する方法、予後の予測を補助する方法、及び治療効果のモニター方法、並びにそれらの方法に用いるマーカー及び装置, 田中 靖人, 楠本 茂, 高浜 洋一, 香川 孝司, JP2016071746, WO2017-018385
  • 糖タンパク質の測定方法、肝疾患の検査方法および糖タンパク質定量用試薬, 成松 久, 池原 譲, 久野 敦, 曽我部 万紀, 田中 靖人, 溝上 雅史, 伊藤 清顕, 松原 俊介, 鶴野 親是, 高浜 洋一, 香川 孝司, 永井 慎也, 特願2012-110964, 特開2012-185172
  • 糖タンパク質の測定方法、肝疾患の検査方法および糖タンパク質定量用試薬, 成松 久, 池原 譲, 久野 敦, 曽我部 万紀, 田中 靖人, 溝上 雅史, 伊藤 清顕, 松原 俊介, 鶴野 親是, 高浜 洋一, 香川 孝司, 永井 慎也, 特願2012-110964, 特開2012-185172, 特許第5441280号
  • 遺伝子型1bのC型肝炎ウイルスゲノム由来の核酸を含む核酸構築物、及び該核酸構築物が導入されたC型肝炎ウイルスゲノム複製細胞、並びに感染性C型肝炎ウイルス粒子の製造方法, 脇田 隆字, 伊達 朋子, 田中 靖人, 溝上 雅史, JP2012058516, WO2012-133735
  • 糖タンパク質の測定方法、肝疾患の検査方法、糖タンパク質定量用試薬および肝疾患病態指標糖鎖マーカー糖タンパク質, 成松 久, 池原 譲, 久野 敦, 曽我部 万紀, 田中 靖人, 溝上 雅史, 伊藤 清顕, 松原 俊介, 鶴野 親是, 高浜 洋一, 香川 孝司, 永井 慎也, JP2010061891, WO2011-007797
  • 糖タンパク質の測定方法、肝疾患の検査方法、糖タンパク質定量用試薬および肝疾患病態指標糖鎖マーカー糖タンパク質, 成松 久, 池原 譲, 久野 敦, 曽我部 万紀, 田中 靖人, 溝上 雅史, 伊藤 清顕, 松原 俊介, 鶴野 親是, 高浜 洋一, 香川 孝司, 永井 慎也, 特願2011-522830, 特許第5031928号
  • 肝疾患病態指標糖鎖マーカー, 成松 久, 平林 淳, 池原 譲, 安形 高志, 梶 裕之, 久野 敦, 大倉 隆司, 鹿内 俊秀, 曽我部 万紀, 栂谷内 晶, 雄長 誠, 田中 靖人, 溝上 雅史, JP2010061791, WO2011-007764
  • 肝疾患病態指標糖鎖マーカー, 成松 久, 平林 淳, 池原 譲, 安形 高志, 梶 裕之, 久野 敦, 大倉 隆司, 鹿内 俊秀, 曽我部 万紀, 栂谷内 晶, 雄長 誠, 田中 靖人, 溝上 雅史, 特願2011-522807, 特許第6028960号
  • C型肝炎の治療効果を予測するためのマーカー群、検査方法及び検査用キット, 田中 靖人, 溝上 雅史, 徳永 勝士, 特願2010-063622, 特開2011-193786, 特許第5787337号
  • C型肝炎の治療効果を予測するためのマーカー群、検査方法及び検査用キット, 田中 靖人, 溝上 雅史, 徳永 勝士, 特願2010-063622, 特開2011-193786
  • C型肝炎の治療効果を予測するためのマーカー及びC型肝炎の治療効果の予測を行う方法並びにC型肝炎の予防又は治療剤, 田中 靖人, 溝上 雅史, 徳永 勝士, 特願2009-192615, 特開2011-041526, 特許第5727694号
  • C型肝炎の治療効果を予測するためのマーカー及びC型肝炎の治療効果の予測を行う方法並びにC型肝炎の予防又は治療剤, 田中 靖人, 溝上 雅史, 徳永 勝士, 特願2009-192615, 特開2011-041526
  • HBV感染症を治療または予防するための医薬組成物, 溝上 雅史, 田中 靖人, 杉山 真也, 須藤 正幸, JP2009061087, WO2009-154248
  • 肝炎ウイルスの増殖方法、及び肝炎ウイルス感染細胞を培養するための中空糸並びにその利用, 山口 達哉, 瀬川 昌也, 溝上 雅史, 田中 靖人, 下遠野 邦忠, 土方 誠, JP2007068611, WO2008-038641
  • 肝炎ウイルスの増殖方法、及びその利用, 山口 達哉, 瀬川 昌也, 溝上 雅史, 田中 靖人, 下遠野 邦忠, 土方 誠, 特願2008-536382, 特許第5327793号
  • B型肝炎ウイルスのジェノタイプCのサブタイプの識別方法及びそのためのキット, 溝上 雅史, 田中 靖人, 向出 雅一, 特願2005-189266, 特開2007-006734
  • B型肝炎ウイルスのジェノタイプCのサブタイプの識別方法及びそのためのキット, 溝上 雅史, 田中 靖人, 向出 雅一, 特願2005-189266, 特開2007-006734, 特許第5572276号
  • B型肝炎ウイルスのジェノタイプAのサブタイプの判別方法, 溝上 雅史, 田中 靖人, 特願2004-090314, 特開2005-270031
  • B型肝炎ウイルスのジェノタイプBのサブタイプの判別方法, 溝上 雅史, 田中 靖人, 特願2004-088512, 特開2005-269994
  • B型肝炎ウイルスのジェノタイプBのサブタイプの判別方法, 溝上 雅史, 田中 靖人, 特願2004-088512, 特開2005-269994, 特許第4108057号
  • B型肝炎ウイルスのジェノタイプAのサブタイプの判別方法, 溝上 雅史, 田中 靖人, 特願2004-090314, 特開2005-270031, 特許第4689968号

受賞

  •   2010年, 上原記念生命科学財団 研究推進特別奨励賞
  •   2007年, 日本臨床検査医学会学会賞 学術賞
  •   2007年, アジア太平洋肝臓学会議会長賞
  •   2006年, 日本肝臓学会 Hepatology Research賞
  •   2005年, 第18回日本消化器病学会奨励賞
  •   2004年, 上原記念生命科学財団 研究奨励賞
  •   2003年, 財団法人桜仁会医学研究助成ヒポクラテス賞
  •   2003年, Liver Forum in Kyoto 奨励研究賞
  •   2003年, 東海学術奨励賞

競争的資金

  • 実用化に向けたB型肝炎新規治療薬の探索及び最適化, 日本医療研究開発機構研究費(AMED), B型肝炎創薬実用化等研究事業,   2017年 - 2021年, 田中靖人
  • 日本と台湾の大規模コホートにおけるC型肝癌及び排除後肝癌に寄与する遺伝要因の解明, 日本学術振興会 , 二国間交流事業,   2017年 - 2018年, 田中靖人
  • B型肝炎根絶を目指した安全な新規免疫療法の開発, 日本学術振興会, 科学研究費補助金 基盤研究(B),   2016年 - 2018年, 田中靖人
  • C型肝炎の新たな治療関連因子及び治癒後の病態進展・改善に関連する宿主因子等の同定を目指したゲノムワイド研究, 日本医療研究開発機構研究費(AMED), 肝炎等克服緊急対策研究事業,   2016年 - 2018年, 田中靖人
  • B型肝炎ウイルスの持続感染を再現する効率的な培養細胞評価系の開発に関する研究, 厚生労働省, B型肝炎創薬実用化等研究事業,   2012年 - 2016年, 田中靖人
  • iPS細胞を活用したヒトキメラマウス肝炎発症モデルの開発とその臨床応用, 日本学術振興会, 科学研究費補助金 基盤研究(B),   2013年 - 2015年, 田中靖人
  • C型肝炎の新規診断法や新規治療法を開発するためのゲノムワイド関連解析の手法を用いた宿主因子の解析に関する研究, 厚生労働省, 肝炎等克服緊急対策研究事業,   2013年 - 2015年, 田中靖人
  • 日本とタイ国の慢性ウイルス性肝炎の病態進展及び治療効果に寄与する遺伝要因の検討, 日本学術振興会, 二国間交流事業,   2011年 - 2012年, 田中靖人
  • C型慢性肝炎に対するテーラーメイド治療を目指したIL28B遺伝要因の包括的解, 日本学術振興会, 科学研究費補助金 基盤研究(B),   2010年 - 2012年, 田中靖人
  • ウイルス性肝炎に対する応答性を規定する宿主因子も含めた情報のデータベース構築・治療応用に関する研究, 厚生労働省, 肝炎等克服緊急対策研究事業,   2010年 - 2012年, 田中靖人
  • C型慢性肝炎に対するテーラーメイド治療を目指したIL28B遺伝要因の包括的解析, 日本学術振興会, 科学研究費補助金 基盤研究 (B),   2010年 - 2012年, 田中靖人
  • アフリカ由来のB型肝炎ウイルス株の分子疫学及び機能解析, 日本学術振興会, 二国間交流事業,   2009年 - 2010年, 田中靖人
  • B型肝炎ウイルス複製モデルを用いた肝病態進展メカニズムの解明, 日本学術振興会, 基盤研究 (C),   2008年 - 2009年, 田中靖人
  • テーラーメイド治療を目指した肝炎ウイルスデータベース構築に関する研究, 厚生労働省, 肝炎等克服緊急対策研究事業,   2007年 - 2009年, 田中靖人
  • B型肝炎ウイルスコアプロモーター領域の変異と発癌メカニズムの解明, 日本学術振興会, 基盤研究 (C),   2006年 - 2007年, 田中靖人

社会貢献活動情報

社会貢献活動

  • 愛知県肝炎患者医療給付事業認定審査会構成員, 行政,   2011年04月01日 - 現在, 愛知県肝炎患者医療給付事業認定審査会において、受給者の認定を行う。
  • 愛知県肝疾患診療連携拠点病院等連絡協議会 構成員, 行政,   2012年04月01日 - 2013年03月31日, 愛知県肝疾患診療連携拠点病院等連絡協議会開催時に構成員として参加する。
  • 平成24年度第1回都道府県肝疾患診療連携拠点病院間連絡協議会 構成員, 行政,   2012年07月13日 - 2012年07月13日, 平成24年度第1回都道府県肝疾患診療連携拠点病院間連絡協議に構成員として参加する。
  • 平成24年度第2回都道府県肝疾患診療連携拠点病院間連絡協議会 構成員, 行政,   2013年01月18日 - 2013年01月18日, 平成24年度第2回都道府県肝疾患診療連携拠点病院間連絡協議に構成員として参加する。
  • 福祉施設嘱託医師, 行政,   2012年04月01日 - 2013年03月31日, 自立支援医療(更生医療)判定及び障害程度審査委員会委員
  • 愛知県准看護師試験委員, 行政,   2012年06月01日 - 2013年05月31日, 愛知県准看護師試験委員として、准看護師の試験問題作成及び准看護師試験合否判定、准看護師の行政処分に関わる審議
  • 平成24年度愛知県肝疾患診療連携拠点病院・専門医療機関連絡協議会 講師, 行政,   2013年03月17日 - 2013年03月17日, 平成24年度愛知県肝疾患診療連携拠点病院・専門医療機関連絡協議会において、講演を行った。
  • 講演会講師, その他,   2012年07月14日 - 2012年07月14日, 京都消化器医会定例学術講演会
  • 愛知県医師会精度管理委員会委員, その他,   2012年04月01日 - 2013年03月31日, 愛知県医師会精度管理委員会委員を務めた。
  • 愛知県臨床検査標準化協議会 推進委員会 委員, その他,   2012年04月01日 - 2013年03月31日, 愛知県臨床検査標準化協議会の委員とし、年一回の会議に参加する。
  • 愛知県臨床検査標準化協議会 理事会 理事, その他,   2012年04月01日 - 2013年03月31日, 愛知県臨床検査標準化協議会の理事とし、年一回の会議に参加する。
  • 肝炎診療に関する助言, その他,   2013年03月15日 - 2013年03月15日, 福井済生会に対する肝炎診療に関する助言
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