1. Division of Rheumatology, Department of Internal Medicine, Chung-Ang University Hospital, Seoul, Korea
2. Division of Rheumatology, Department of Internal Medicine, Eunpyeong St. Mary’s Hospital, The Catholic University of Korea, Seoul, Korea
3. Division of Rheumatology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
4. Division of Rheumatology, Department of Internal Medicine, Gachon University College of Medicine Gil Medical Center, Incheon, Korea