Ran Song1, Sang Wan Chung2, Sang-Hoon Lee3. 1. School of Medicine, Kyung Hee University, Division of Rheumatology, Department of Internal Medicine, Kyung Hee University Hospital at Gangdong. 2. Division of Rheumatology, Department of Internal Medicine, Kyung Hee University Hospital at Gangdong. 3. School of Medicine, Kyung Hee University, Division of Rheumatology, Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, Seoul, South Korea. boltaguni@yahoo.co.kr.