[1] Natl Univ Hlth Syst, Univ Med Cluster, Div Gastroenterol & Hepatol, Singapore, Singapore
[2] Natl Univ Singapore, Yong Loo Lin Sch Med, Singapore 117595, Singapore
[3] Natl Univ Hlth Syst, Univ Med Cluster, Div Rheumatol, Singapore, Singapore
[4] Swiss Trop & Publ Hlth Inst, Basel, Switzerland
[5] Univ Basel, Basel, Switzerland
[6] ASTAR, IMB, Singapore, Singapore