The expression of Fas on the epithelial cells of bile ducts was examined in liver specimens from 10 patients with primary biliary cirrhosis (PBC), and 14 patients with chronic hepatitis by both light and electron microscopy using the indirect peroxidase-labeled antibody method. In all patients with PBC, Fas was observed on the surface of epithelial cells of interlobular bile ducts. By electron microscopy, electron-dense reaction products of Fas were detected on the basolateral plasma membrane of the bile duct epithelial cells, as well as on some membranes of the endoplasmic reticulum. Fas was expressed more strongly on the surface of the epitherial cells of interlobular bile ducts in PBC than of those in chronic hepatitis. These findings suggest that increased expression of Fas on such bila ducts may play some role in the pathogenesis of PBC.
primary biliary cirrhosis