[1] Sungkyunkwan Univ, Div Gastroenterol, Dept Med, Samsung Med Ctr,Sch Med, Seoul 135710, South Korea
[2] Armed Forces Capital Hosp, Dept Internal Med, Songnam, South Korea
[3] Konkuk Univ, Sch Med, Dept Internal Med, Seoul, South Korea
[4] Inst Biomed Sci & Technol, Med Immunol Ctr, Seoul, South Korea
[5] Samsung Biomed Res Inst, Biostat Team, Seoul, South Korea