A spectrum of histopathologic findings in autoimmune liver disease

We retrospectively studied 42 liver biopsy specimens from 39 patients who m et serologic and histologic criteria of autoimmune liver diseases. We found 10 cases of overlap syndrome (OLS), 10 autoimmune cholangitis (AIC), 10 pr imary biliary cirrhosis (PBC), and 9 autoimmune hepatitis (AIH) type 1. The following results were obtained (1) Granulomas and biliary duct lesions we re more prominent in PBC and AIC than in OLS and AIH. (2) Bile duct loss wa s not observed in AIH cases. (3) Features of hepatocellular damage such as piecemeal necrosis, spotty lobular necrosis, and confluent necrosis, were m uch more prevalent in OLS and AIH than in PBC and AIC. (4) HLA-DR antigen e xpression by hepatocytes was more frequent in AIH and OLS, whereas the expr ession of the same antigen by the bile duct epithelium was more frequent in PBC and AIC. We conclude there is a morphologic spectrum in autoimmune liv er diseases, in which PBC forms one end of the spectrum, AIH the other; OLS the middle but closer clinically and histologically to AIH than to PBC, an d AIC, which seems to be an antimitochondrial antibody-negative subtype of PBC.