Development of autoimmune hepatitis in the setting of long-standing primary biliary cirrhosis.

Primary biliary cirrhosis and autoimmune hepatitis, the most common autoimmune liver diseases in adults, are frequently easily differentiated by a combination of clinical, biochemical, and histological features along with the presence of highly sensitive and characteristic serum autoantibodies. Patients presenting with "overlapping" features of both conditions simultaneously are not uncommon. However, patients who switch over time from one disease to another have remained largely unrecognized. We report here two cases from the spectrum of autoimmune liver disease, patients who had well-defined primary biliary cirrhosis for a number of years and then developed the classic picture of superimposed autoimmune hepatitis. The importance of its recognition and the appropriate management modifications are discussed.