[1] Seoul Natl Univ Hosp, Dept Internal Med, Seoul 110744, South Korea
[2] Gachon Univ, Sch Med, Dept Internal Med, Inchon, South Korea
[3] Hanyang Univ, Coll Med, Hosp Rheumat Dis, Dept Internal Med, Seoul 133791, South Korea
[4] Catholic Univ Korea, Coll Med, Dept Internal Med, Seoul, South Korea
[5] Korea Univ, Coll Med, Dept Internal Med, Seoul 136705, South Korea
[6] Inha Univ, Coll Med, Dept Internal Med, Inchon, South Korea