[1] Univ Copenhagen, Dept Med Gastroenterol, Hvidovre Hosp, Fac Hlth Sci, DK-2650 Hvidovre, Denmark
[2] Royal Free Hampstead NHS Trust, Royal Free Hosp, Royal Free Sheila Sherlock Liver Ctr, London, England
[3] UCL, London, England
[4] Univ Copenhagen, Dept Clin Physiol & Nucl Med, Hvidovre Hosp, Fac Hlth Sci, DK-2650 Hvidovre, Denmark