1. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Japan
2. Center for Diagnostic and Therapeutic Endoscopy, Keio University School of Medicine, Japan
3. Division of Rheumatology, Department of Internal Medicine, Keio University School of Medicine, Japan
4. Division of Rheumatology, Toho University Ohashi Medical Center, Japan