Expression of perforin and Fas ligand mRNA in the liver of viral hepatitis

Cytotoxic T lymphocytes (CTLs) play an important role in the pathogenesis o f viral hepatitis. We studied the expression of mRNAs of perforin and Fas l igand (Fas-L) in biopsy specimens from chronic hepatitis B (CHB) (15 cases) and hepatitis C (CHC) patients (13 cases). Both perforin and Fas-L mRNAs w ere detected in all cases of both CHB and CHC. No messages were detected in the control livers from two cases of fatty liver, a case of Gilbert's synd rome, and a case of Dubin-Johnson syndrome. Semiquantitative analysis revea led a positive correlation between the intensity of perforin and Fas-L mRNA s in both CHB and CHC. In CHB, the intensity of both perforin and Fas-L mRN As showed a positive correlation with the histological activity and serum a lanine aminotransferase level, while the correlation was not apparent in CH C. These results suggest that both perforin and Fas/Fas-L systems are invol ved in the pathogenesis of liver cell injury of CHB and CHC.