[Clinical and pathological characterization of the overlap syndrome of primary biliary cirrhosis and autoimmune hepatitis].

OBJECTIVE: To analyze the clinical and pathological characteristics of primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) overlap syndrome. METHODS: Of our 68 patients with the diagnosis of PBC, we identified 9 overlap syndrome cases strictly using the revised descriptive criteria and scoring system for diagnosis of AIH proposed by the International Autoimmune Hepatitis Group Report. The clinical manifestations and pathological changes shown in liver biopsies from the overlap syndrome and pure PBC were analyzed and compared. RESULTS: The mean aggregate scores of the 9 cases (13.2%) of the overlap syndrome group and 59 cases of pure PBC (86.8%) were 10.2+/-0.2 and 4.7+/-0.7 respectively among the 68 total. The serum levels of ALT and AST, immunoglobulin G, gammaglobulin, in the overlap syndrome group were significantly higher than those in the pure PBC group, and also there was a frequent presence of antinuclear antibody and/or smooth muscle antibody positivity in the overlap syndrome group. Histopathologically the livers in the overlap syndrome group showed combined features of interface hepatitis and piecemeal necrosis, characterizing the two diseases. CONCLUSION: The overlap syndrome group showed combined features of both PBC and AIH. There were differences in clinical aspects, serology and histology between the overlap syndrome and pure PBC groups.