HEPATITIC BILE-DUCT INJURIES IN CHRONIC HEPATITIS-C - HISTOPATHOLOGICAND IMMUNOHISTOCHEMICAL STUDIES

Interlobular bile ducts are reported to be damaged in viral hepatitis. Such damages are called hepatitic duct injuries and mimic chronic non suppurative destructive cholangitis of primary biliary cirrhosis. In t his study, hepatitic bile duct injuries were evaluated histopathologic ally and immunohistochemically in 149 needle liver biopsy specimens fr om patients with chronic hepatitis C and compared immunohistochemicall y with primary biliary cirrhosis. Fifty-one of the needle biopsies fro m patients with chronic hepatitis C (34.2%) showed hepatitic bile duct injuries which were distributed focally in the liver and showed varia ble epithelial damages such as cytoplasmic swelling, vacuolation and a cidophilia, nuclear pleomorphism, and loss of nuclear polarity. Some o f the injured bile ducts were embedded within lymphoid aggregates, whe reas others were surrounded by lymphocytes as well as other inflammato ry cells to varied degrees. The majority of lymphoid cells around hepa titic bile duct injury were B- and T-cells mixed in various proportion s, and activated T-cells were occasionally found within the biliary ep ithelial layer. Histopathologic and serial section studies disclosed t hat bile duct loss was rare in chronic hepatitis C. Statistical analys is revealed that advancement of chronic hepatitis and the degree of ne croinflammatory processes of the liver, particularly in the portal tra cts, were positively correlated with the occurrence of hepatitic bile duct injuries. Immunohistochemical studies demonstrated that, whereas strong ectopic expression of HLA-DR and enhanced expression of HLA-A,B ,C and pyruvate dehydrogenase E(2)-complex in biliary epithelial cells were frequently observed in chronic nonsuppurative destructive cholan gitis of primary biliary cirrhosis, such unusual expressions were gene rally absent or mild, even if present, in bile duct injuries in chroni c hepatitis C. These findings suggest that hepatitic bile duct injurie s are found in a third of chronic hepatitis C patients, that they are not usually followed by loss of the bile duct, and that their immunopa thogenesis is different from that of primary biliary cirrhosis.