[1] Univ Hosp Lausanne CHUV, Dept Gastroenterol & Hepatol, Lausanne, Switzerland
[2] Triemlispital Zurich, Dept Gastroenterol & Hepatol, Zurich, Switzerland
[3] Abbott AG, Div Immunol, Baar, Switzerland
[4] Univ Basel Hosp, Dept Gastroenterol & Hepatol, CH-4031 Basel, Switzerland