Primary sclerosing cholangitis--an immunologically mediated disease?

Primary sclerosing cholangitis (PSC) is an uncommon, chronic disorder characterized by inflammatory fibrosis usually involving the entire biliary tree. The etiology has been unknown, but PSC is closely associated with ulcerative colitis, which coexists in more than two thirds of patients with PSC. In recent studies 3% to 5% of all patients with ulcerative colitis had PSC. We propose that PSC is, at least in part, an immunologically mediated disease; it is closely associated with human leckocyte antigens B8 and DR3, and circulating autoantibodies to colon and portal tract are frequently present. The anticolon antibody cross-reacts with enteric Escherichia coli. The disease may possibly be triggered in susceptible patients with ulcerative colitis by immunization with antigens shared between enteric microorganisms and the biliary system.