Increased frequency of autoimmune diseases in patients with primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown origin that mostly affects male patients with inflammatory bowel disease (IBD). The immune system is believed to be involved in the etiology/pathogenesis as these patients present with several immunological disturbances. Susceptibility to develop primary sclerosing cholangitis is partly determined by genes in the HLA complex. The aim of this study was to compare the prevalence of autoimmune disorders in IBD patients with and without PSC and to correlate the presence of autoimmune disorders in PSC to outcome and HLA association.

One hundred nineteen PSC patients were included in the study. Each PSC patient with IBD was matched to a IBD patient without PSC. The presence of autoimmune disorders was carefully evaluated in each group. Moreover, comparisons between PSC patients with and without autoimmune disorders were performed.

Twenty-five percent of the PSC patients had at least one autoimmune disorder outside the liver and colon compared to 9% in the IBD group without PSC (p < 0.005). Nine of the PSC patients had two or more autoimmune diseases compared to only one patient in the IBD group (p < 0.02). The PSC patients with and without associated autoimmune disease did not differ in clinical presentation, outcome of PSC or HLA alleles. A significant overrepresentation of DRB1*03 was still present after excluding PSC patients with concomitant autoimmune diseases outside the liver and colon compared to a healthy Swedish control group.

Autoimmune disorders are more frequent among PSC patients compared to IBD patients without liver disease. Associated autoimmune diseases in PSC patients does not influence the outcome or clinical presentation of PSC.