Clinicolaboratory characteristics of Japanese patients with primary biliary cirrhosis-autoimmune hepatitis overlap.

To clarify the clinicolaboratory characteristics of patients with primary biliary cirrhosis (PBC)-autoimmune hepatitis (AIH) overlap, we analyzed their clinicolaboratory findings and compared them with those of patients with AIH or PBC retrospectively. We analyzed the laboratory findings of 177 patients that diagnosed 103 PBC and 74 AIH patients at our department during the period from January 1990 to April 2005. Of 103 PBC patients with a diagnosis of PBC, we identified 10 cases (9.7%) of PBC-AIH overlap (2 male, 8 female; mean age 56.5 years). PBC preceded AIH in 2 patients, and both diseases occurred simultaneously in the other 8 patients. There is no patients AIH preceded PBC. Positive frequency of anti-smooth muscle antibody (ASMA), IgG and IgM levels were significantly higher in patients with overlap than in those with AIH or PBC. Ursodeoxychoric acid (UDCA) was administered to all 10 patients initially, and later an immunosuppressant, prednisolone or azathioprine, was added in 6 patients. Two of the 10 patients died of liver failure 5 and 12 years after diagnosis, respectively. Both patients had been treated by either prednisolone or UDCA alone. We conclude that in patients with PBC-AIH overlap, the clinical characteristics of both PBC and AIH exist in an enhanced manner.