[1] Chiba Univ, Grad Sch Med, Dept Gastroenterol, Chuo Ku, 1-8-1 Inohana, Chiba 2608670, Japan
[2] Chiba Univ, Grad Sch Med, Dept Mol Virol, Chuo Ku, 1-8-1 Inohana, Chiba 2608670, Japan
[3] Nihon Univ, Dept Gastroenterol & Hepatol, Sch Med, Itabashi Ku, 30-1 Oyaguchi Kamicho, Tokyo 1738610, Japan
[4] Juntendo Univ, Grad Sch Med, Dept Gastroenterol, Bunkyo Ku, 2-1-1 Hongo, Tokyo 1138421, Japan
[5] Kings Coll Hosp London, Inst Liver Studies, London SE5 9RS, England
[6] Tokai Univ, Inst Med Sci, Div Hematol Malignancy, 143 Shimokasuya, Isehara, Kanagawa 2591193, Japan
[7] Univ Tokyo, Grad Sch Med, Dept Gastroenterol, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1138655, Japan
[8] Chiba Univ, Grad Sch Med, Dept Gen Surg, Chuo Ku, 1-8-1 Inohana, Chiba 2608670, Japan