Association of primary biliary cirrhosis and rheumatoid arthritis.

Primary biliary cirrhosis (PBC) and rheumatoid arthritis (RA) are chronic medical conditions in which, although the etiology is uncertain, autoimmune features predominate. These two conditions are, in fact, multisystemic diseases, with a multitude of manifestations that are not limited to their target end organ. It has been well established that patients with PBC may have musculoskeletal complaints and patients with RA may have evidence of hepatic dysfunction. Both of these conditions are fairly rare, with RA being found in approximately 1% of the population and PBC being found in approximately 20/100,000 women and 2/100,000 men.The likelihood of these uncommon conditions occurring in the same patient is very rare and unusual. We have identified a unique group of 25 patients who have met disease-defining criteria for both RA and PBC. Awareness of this combination should prompt rheumatologists to assess for PBC with antimitochondrial antibody testing in patients with abnormal liver tests and also to raise awareness that abnormal liver tests in RA patients are not always due to drugs.