1. Department of Internal Medicine, Kyushu University Beppu Hospital , Oita, Japan
2. Department of Rheumatology and Infectious Diseases, Kitasato University School of Medicine , Kanagawa, Japan
3. Department of Rheumatology and Nephrology, Chubu Rosai Hospital , Aichi, Japan
4. Department of Clinical Research, Rheumatology and Allergology, Osaka Minami Medical Center , Osaka, Japan
5. Department of Rheumatology, Niigata Rheumatic Center , Niigata, Japan
6. Division of Rheumatology, Department of Internal Medicine, Keio University , Tokyo, Japan