1. Division of Hepatobiliary and Pancreatic Disease, Department of Internal Medicine; Hyogo College of Medicine; Hyogo Japan
2. Department of Gastroenterology and Internal Medicine; Gifu University Graduate School of Medicine; Gifu Japan
3. Department of Gastroenterology and Metabolism, Applied Life Science, Institute of Biomedical and Health Science; Hiroshima University; Hiroshima Japan
4. Department of Infection Control and Prevention, Graduate School of Medicine; The University of Tokyo; Tokyo Japan
5. Department of Hepatology and Pancreatology; Kawasaki Medical School; Okayama Japan