Interleukin-2 activity in chronic active liver diseases: response by T cells and in the autologous mixed lymphocyte reaction.

The T cell growth factor, interleukin-2 (IL-2), is a lymphokine which supports the immunoregulatory function of T cells. We measured the production of and response to IL-2 of peripheral blood T cell subsets from patients with chronic active liver diseases (CALD) and other liver diseases (Others) by the proliferative response of the cells activated with phytohaemogglutin P. Both production of and response to IL-2 of T cells from 24 patients with CALD were markedly decreased (P less than 0.001) in comparison with 13 controls. T cells from 10 patients with Others yielded low IL-2 titre (P less than 0.05) and responded to IL-2 in a depressed manner (P less than 0.05). OKT4+ and OKT8+ cells from five CALD patients as well as five controls equally produced IL-2 and responded to it. However, IL-2 production (P less than 0.05) and response to IL-2 (P less than 0.01) of OKT4+ cells from CALD patients were decreased in contrast to those of OKT8+ cells. We also examined the effect of IL-2 on the autologous mixed lymphocyte reaction. A highly significant increase (P less than 0.001) in the proliferative response of OKT8+ cells and unseparated T cells from 15 patients with CALD occurred with the addition of IL-2 although the values were still lower (P less than 0.01) than those of OKT8+ and unseparated T cells from 12 controls. Addition of IL-2 did not result in a significant increase of the reactivity of OKT4+ cells from patients with CALD. These results further delineate the nature of the immunoregulatory aberration in CALD.