Cyclooxygenase-2 expression in chronic hepatitis C and the effect of interferon α treatment

Background and Aim: Cyclooxygenase-2 (COX-2), a target of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs), is upregulated in chronic hepatitis B and may have a role in hepatocellular carcinoma. Little is known about the expression of COX-2 in chronic hepatitis C (HCV) infection. The aim the present study was to evaluate the extent of COX-2 expression in liver biopsies in patients with HCV infection and to determine the effect of treatment with interferon alpha (IFN). Methods: Percutaneous liver biopsy specimens were retrieved. Following formalin fixation and paraffin embedding, the biopsies were histologically evaluated for inflammation and fibrosis. The extent of COX-2 expression was measured by the avidin biotin immunohistochemical technique using a monoclonal COX-2 antibody. The extent of COX-2 expression was graded according to the number of hepatocytes expressing COX-2. Data were analyzed using Student's t-test. Results: Liver biopsies from 10 patients before and after treatment with IFN were obtained and compared with nine normal liver biopsies. All of the liver biopsies showed some COX-2 expression. COX-2 expression was confined to hepatocytes and bile duct epithelium and was not detected in vascular endothelium or inflammatory cells. The extent of COX-2 expression was greater in hepatitis C infected liver biopsies than in normal biopsies. Following treatment with IFN, there was a greater than threefold reduction in COX-2 expression (P < 0.01). This result was independent of the sustained virological response. Conclusion: In this small pilot study we have shown that COX-2 is overexpressed in liver biopsies infected with HCV and COX-2 expression is reduced following treatment with IFN.