Loss of suppressor T cell function and circulating immune complexes in chronic active liver diseases

Suppressor T cell function is decreased in patients with chronic active liver diseases (CALD). To account for the alterations, we examined the effect of sera of patients with various liver diseases on concanavalin A (Con A) induced suppressor T cell activity of normal individuals. The suppressor T cell activity was inhibited by heat-inactivated serum pretreatment in 13 of 27 cases of patients with CALD and in five of 11 cases of patients with acute viral hepatitis, whereas only two sera of 18 patients with other liver diseases affected suppressor cell activity. Using a 125I-C1q-binding test, a significant correlation (P less than 0.01) was detected between the degree of inhibition in the development of suppressor T cells and the level of circulating immune complexes in the sera of CALD patients. The blocking effect of patients' sera disappeared when the immune complexes were removed with polyethylene glycol. These data suggest that circulating immune complexes modulate cellular immunity in patients with CALD by influencing the suppressor T cell function.