CHRONIC HEPATITIS-C - ANALYSIS OF HOST IMMUNE-RESPONSE BY IMMUNOHISTOCHEMISTRY

The pathogenesis and perpetuation of hepatocellular injury in hepatiti s C viral infection remains unclear. It has been proposed that a direc t viropathic effect, the host immune response, or both mediate cell da mage. To address this issue, the immunophenotype of the inflammatory i nfiltrate in the liver of 18 patients with abnormal liver function tes ts and serologically detectable hepatitis C virus antibodies was compa red with seven control patients (three cases with hepatitis B virus in fection, two with alcoholic hepatitis, and one patient each with prima ry biliary cirrhosis and autoimmune hepatitis). The immunohistochemica l markers included UCHL1, L26, Ham-56, Mac-387, CD68, Leu-M1, and cath epsin B. We found that T cells represent the predominant cell type in both histopathologic patterns of hepatitis C, ie, chronic active hepat itis and chronic persistent hepatitis, but the intensity of the T-cell infiltrate displayed marked differences. B-cell infiltrates were only seen in the germinal centers of lymphoid follicles in portal tracts. Furthermore, significant numbers of CD68-positive macrophages/monocyte s were seen in the more aggressive form of hepatitis C viral infection . These data suggest that the T-lymphocyte-mediated host immune respon se is similar in chronic active and chronic persistent hepatitis patte rns of hepatitis C viral infection, but varies in its intensity. In ad dition, macrophages/monocytes may play a role in hepatocyte and bile d uct injury in chronic hepatitis C.