1. Department of Gastroenterology, Research Institute, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan
2. Department of Clinical Pathology, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
3. AIDS Clinical Center (ACC), Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
4. Department of Infectious Disease, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
5. Department of Clinical Research and Informatics, International Clinical Research Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
6. Department of Gastroenterology and Hepatology, Kohnodai Hospital, National Center for Global Health and Medicine, Chiba, Japan