Immunologic reaction and genetic factors in biliary atresia.

The characteristic histopathological features seen in the livers of patients with biliary atresia (BA) are very similar to those of primary biliary cirrhosis, which is an autoimmune disease. To clarify whether BA liver possess an immunological response similar to that in primary biliary cirrhosis, we studied HLA-DR expression in liver tissue of BA patients, using a HLA-DR staining method, and determined the frequency of HLA types in BA patients and their families. HLA-DR was expressed by the bile duct epithelium in 11 of 16 liver specimens obtained from 13 BA patients. By contrast, HLA-DR was not expressed in liver specimens from 6 patients with congenital biliary dilatation. Among the HLA types seen in BA patients and their families, HLA-A33, -B44 and -DR6 were frequently expressed in blood. These results suggest that certain immunological factors and disease-susceptible genes might be involved in the etiology of BA.