Tatsuo Kanda1, Osamu Yokosuka2, Mitsuhiko Moriyama3. 1. Division of Gastroenterology and Hepatology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kamicho, Itabashi-ku, Tokyo, 173-8610, Japan. kanda.tatsuo@nihon-u.ac.jp. 2. Department of Gastroenterology and Nephrology, Chiba University Graduate School of Medicine, Chiba, Japan. 3. Division of Gastroenterology and Hepatology, Department of Medicine, Nihon University School of Medicine, 30-1 Oyaguchi-kamicho, Itabashi-ku, Tokyo, 173-8610, Japan.