Overlap of primary biliary cirrhosis and autoimmune hepatitis: Characteristics, therapy, and long term outcomes.

Background: Coexistence of primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) is referred to as PBC-AIH overlap. Pathogenesis of PBC-AIH is not well understood and its diagnosis is challenging. We previously reported the clinical characteristics of 10 patients diagnosed with PBC-AIH overlap.
Aims: The aim of the study was extend the earlier series and evaluate the diagnostic criteria, biological characteristics, potential therapy, and long-term outcomes of patients with PBC-AIH overlap.
Methods and Results: We retrospectively analyzed clinical, biochemical, and histological characteristics of 144 patients diagnosed with PBC and 73 diagnosed with AIH. We identified 16 cases of PBC-AIH overlap, according to criteria established by Chazouillères et al. and other studies. PBC preceded AIH in 6 patients and both diseases occurred simultaneously in the remaining 10 patients. PBC-AIH overlap has clinical, biochemical, and histological characteristics of both PBC and AIH. Thirteen patients treated with both ursodeoxycholic acid (UDCA) and immunosuppressive therapy responded well, with normal alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels. The remaining three patients treated with either prednisolone (PSL) or UDCA alone developed cirrhosis, varices, ascites, encephalopathy, or died of liver-related causes at the 5, 12, and 14-year follow up.
Conclusions: PBC-AIH overlap is not a rare entity; it was observed in 11% of PBC patients in this study. Further studies will be required to investigate whether PBC-AIH overlap is distinct from the two individual diseases in terms of long-term outcomes and therapeutic implications.