1. Division of Rheumatology, Department of Internal Medicine, Ewha Womans University College of Medicine, Seoul, Korea
2. Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases, Seoul, Korea
3. Division of Rheumatology, Department of Internal Medicine, Wonkwang University Hospital, Iksan, Korea
4. Division of Rheumatology, Department of Internal Medicine, Gil Medical Center, Gachon University College of Medicine, Incheon, Korea