[1] Sungkyunkwan Univ, Samsung Med Ctr, Dept Lab Med & Genet, Sch Med, 81 Irwon Ro, Seoul 06351, South Korea
[2] Sungkyunkwan Univ, Sch Med, Kangbuk Samsung Hosp, Dept Lab Med, 29 Saemunan Ro, Seoul 03181, South Korea
[3] Sungkyunkwan Univ, Samsung Med Ctr, Dept Med, Div Gastroenterol,Sch Med, 81 Irwon Ro, Seoul 06351, South Korea