Retrospective analysis of autoimmune hepatitis- primary biliary cirrhosis overlap syndrome in Korea: characteristics, treatments, and outcomes

Background/Aims: Overlap syndrome of autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) (AIH-PBC overlap syndrome) is a rare disease that has not been clearly characterized in Korean patients. This study investigated the clinical features of AIH-PBC overlap syndrome compared with those of AIH and PBC alone. Methods: This retrospective cohort study included 158 consecutive patients who were diagnosed as AIH (n=61), PBC (n=81), or AIH-PBC overlap syndrome (n=9) based on the Paris and the International Autoimmune Hepatitis Group (IAIHG) criteria from 2001 to 2011 in Korea. We compared the clinical features of these three groups retrospectively, including their biochemical characteristics, treatments, responses, and clinical outcomes. Results: The AIH-PBC overlap syndrome patients exhibited biochemical characteristics of both AIH and PBC, and showed a similar response to ursodeoxycholic acid (UDCA) monotherapy as for the PBC patients. However, the response of AIHPBC overlap syndrome patients to UDCA and steroid combination therapy was worse than the response of AIH patients to steroid-based therapy (P=0.024). Liver cirrhosis developed more rapidly in AIH-PBC overlap syndrome patients than in AIH patients group (P=0.013), but there was no difference between AIH-PBC overlap syndrome patients and PBC patients. The rates of developing hepatic decompensation did not differ significantly between the groups. Conclusions: The AIH-PBC overlap syndrome patients exhibited a worse response to UDCA and steroid combination therapy and a faster cirrhotic progression compared with AIH patients.