A 39 year old man with chronic hepatitis.

The diagnosis of primary sclerosing cholangitis in association with autoimmune hepatitis was made in this case after the discovery of inflammatory bowel disease prompted a cholangiogram. Immunosuppressive therapy with cyclosporine prior to ERCP resulted in a significant decrease in serum aminotransferase. Liver histology and autoimmune serologies favored a diagnosis of AIH, while cholangiographic findings suggested PSC. A review of similar cases describing the simultaneous occurrence of AIH and PSC is presented. The shared autoimmune characteristics of the two diseases, such as serum autoantibodies, peripheral lymphocyte subsets and HLA haplotypes, raises the question of whether similar mechanisms of immune dysfunction can result in both processes. The existence of a PSC-AIH overlap syndrome may help provide the linkage between the two diseases.