만성 B형 간염환자의 간조직에서의 Fas 항원의 발현

Backgroud/Aims: Liver damage in chronic B viral hepatitis depends on host immune response, not direct toxicity. Fas-Fas ligand interaction induced apoptosis plays an important role in liver damage from viral hepatitis. In the present study, we examined the incidence of Fas antigen expression, concordancy between Fas antigen (Ag) and hepatitis B surface antigen (HBsAg) expression, and finally correlation of Fas Ag expression with histological activity index in liver tissue of patients with chronic B viral hepatitis. Methods: We studied liver biopsy samples from 59 patients (chronic active B viral hepatitis 40 cases, chronic persistent R viral hepatitis 10 cases, normal control 9 cases). We evaluated immunohistochemically the expression of Fas Ag and HBsAg with anti-Fas Ag monoclonal IgM antibody and anti-HBsAg polyclonal IgG antibody respectively in liver tissue. Results: Fas Ag was expressed in 9 among 10 cases (90%) of chronic persistent B viral hepatitis and 34 among 40 cases (85%) of chronic active B viral hepatitis, but none in the normal control group. Fas Ag was diffusely expressed in 67.6% of chronic active B viral hepatitis and 33.3% of chronic persistent B viral hepatitis. The cases which showed diffuse expression of Fas Ag tend to have higher transaminase levels, and higher histological activity indexes. The concordancy between Fas Ag and HBsAg expression was 62.8% and it tended to be higher in diffusely or multifocally expressed group of Fas Ag. Conclusions: The Fas Ag expression in hepatocytes may be induced by hepatitis B virus infection and it was correlated with histological activity index. Liver damage in chronic B viral hepatitis may be related to Fas Ag mediated host immune response. (Korean J Gastroenterol 1998;31:204-211)