The overlap syndrome: combination of the autoimmune hepatitis with the primary biliary cholangitis

Abstract

The overlap syndrome in hepatology traditionally defined as the simultaneous presence in a patient of clinical or laboratory signs of two different autoimmune liver diseases. The most common combination is autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC). In this case, a differential diagnosis based on clinical signs is often difficult. Routine laboratory tests indicate the presence of both parenchymal and cholestatic variants of liver damage. There are no international criteria that clearly define the case of overlap syndrome. There is a set of descriptive criteria presented by the International Group for the Study of Autoimmune Hepatitis (IAIHG), which includes not only biochemical and serological indicators, but also the histological examination of the liver. Usually, in the case of overlap syndrome, the course of the liver disease is more aggressive. For example, in case of combination of PBC and AIH, severe fibrosis is more frequent at the time of diagnosis, hepatocellular insufficiency develops faster and indications for liver transplantation appear earlier. The management of patients with overlap syndrome in each case is individual and focused on the prevailing component: autoimmune hepatitis or primary biliary cholangitis. The feasibility of combined immunosuppressive therapy and ursodeoxycholic acid (UDCA) has not been completely clarified. Moreover, this applies both to individual publications and to the consensus documents of the International Group for the Study of Autoimmune Hepatitis. In the absence of a sustained response in the case of a combination therapy, tactics may be revised in favor of monotherapy with UDCA, given the high percentage of complications with continued treatment with immunosuppressants.