Increased prevalence of primary sclerosing cholangitis among first-degree relatives

Background/Aims: The aim of the present study was to investigate the familial occurrence of autoimmune diseases in a large group of patients with primary sclerosing cholangitis (PSC). Methods: All patients with PSC treated at Huddinge University Hospital between 1984 and 1999 were included (n = 145). For every patient with PSC and inflammatory bowel disease (IBD) (n = 126) we randomly selected a control patient with HID (n = 126), matched for age, sex and type of IBD. A questionnaire comprising information about autoimmune diseases among first-degree relatives was answered by all patients and controls. Results: We identified 22 index cases with PSC from 21 families with a first-degree relative with either chronic liver disease and/or IBD. Five patients with PSC had a first-degree relative with PSC (3.4%). The prevalence of PSC among first-degree relatives was 0.7% (5/717). In siblings the prevalence was 1.5% (4/269). The prevalence of first-degree relatives with autoimmune diseases outside the liver was similar in PSC patients and controls. Conclusions: First-degree relatives of patients with PSC have a PSC prevalence of 0.7%. This represents a nearly 100-fold increased risk of developing PSC compared with the general population, supporting the hypothesis that genetic factors are of importance for development of PSC. (C) 2004 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.