[1] Natl Univ Hosp Iceland, Dept Internal Med, Sect Gastroenterol & Hepatol, IS-101 Reykjavik, Iceland
[2] Akureyri Hosp, Dept Internal Med, Sect Gastroenterol & Hepatol, Akureyri, Iceland
[3] Natl Univ Hosp Reykjavik, Dept Pathol, Reykjavik, Iceland
[4] Univ Iceland, Fac Med, Reykjavik, Iceland