Graves' hyperthyroidism in a patient with primary sclerosing cholangitis. Coincidence or combined pathogenesis?

Several autoimmune disorders have been associated with the diagnosis of primary sclerosing cholangitis (PSC). We report on a 19-year-old male PSC patient with a history of ulcerative colitis who developed hyperthyroidism consistent with Graves' disease. In contrast to primary biliary cirrhosis, hyperthyroidism appears to be very uncommon in PSC patients. Nevertheless, the rarity of Graves' disease in young males, the presence of a human leucocyte antigen (HLA) phenotype often encountered in both Graves' disease and PSC and the presence of several autoantibodies suggest a common immunogenetic predisposition, rather than mere coincidence, of both diseases in this patient. Since many patients with thyroid disease exhibit mild cholestatic liver function abnormalities but few of them undergo cholangiographic examination, PSC may be underdiagnosed. Physicians should therefore be aware of the potential association between thyroid disease and PSC.