1. Division of General Internal Medicine, Department of Medicine, Tokyo Medical University Ibaraki Medical Center, Ibaraki, Japan
2. Fujita Health University, Toyoake, Japan
3. Department of General Medicine, Juntendo University, Faculty of Medicine, Tokyo, Japan
4. Division of General Internal Medicine, Department of Medicine, St Lukes International Hospital, Tokyo, Japan
5. Department of Integrated Medicine, Kagawa Prefectural Central Hospital, Takamatsu, Japan
6. Center for Medical Sciences, St. Luke’s International University, Tokyo, Japan
7. Department of Virology, Tohoku University Graduate School of Medicine, Sendai, Japan