Fcgamma receptor expression on hepatic macrophages and histological activity of chronic hepatitis.

ABSTRACT

AIMS/BACKGROUND: Activated liver macrophages in chronic hepatitis express a high affinity receptor for IgG named FcgammaRI. This study was performed to find the difference in FcgammaRI expression between chronic hepatitis B (CHB) and C (CHC) with reference to histological activity. METHODS: Consecutive patients with CHB (20 cases) and CHC (25 cases) were enrolled in the study. Inflammatory activity was evaluated using the modified histological activity index (HAI). FcgammaRI-positive macrophages were quantitatively measured by computer assisted morphometry. RESULTS: Total HAI score was significantly higher in CHB than in CHC. Confluent necrosis was observed in significantly higher frequency in CHB at Stages 3 5 than in CHC. The percentage area of FcgammaRI-positive macrophages was significantly higher in CHB than in CHC. In CHB, the percentage area of FcgammaRI-positive macrophages correlated with total HAI (<0.01) as well as the degree of confluent necrosis (<0.01), interface hepatitis (<0.05) and portal inflammation (<0.05). FcgammaRI-positive macrophages accumulated mainly at the site of confluent necrosis. In CHC, no correlation was observed between activated macrophages and any histological categories. CONCLUSION: These results suggest that FcgammaRI-positive macrophages are associated with confluent necrosis in CHB, which is more common in CHB patients than in CHC.