Inhibition of Lymphocyte Cytotoxicity by Serum from Patients with Alcoholic Liver Disease: Partial Characterization of Serum Inhibitors

Studies were performed to explore the effect on normal lymphocyte function of serum derived from patients with alcohol-induced liver injury and healthy controls. We examined the effect of such serum on the generation of both spontaneous and Concanavalin A (Con A)-induced lymphocyte cytotoxicity for Chang target cells. Normal lymphocytes, when incubated in the presence of 5% serum from patients with alcoholic liver disease, showed a marked (20.75 ± 5.1% mean ± SEM) reduction in the capacity to generate spontaneously cytotoxic cells compared to 5% control serum (3.2 ± 1.9%) (p < 0.001). Similar results were found in studies of Con A-stimulated cytotoxicity (36 ± 7.2% vs. 5 ± 2.3%; p < 0.001). Fractionation of serum by gel chromatography demonstrated the presence of inhibitory activity of various molecular weights, although a major peak of inhibitory activity (approximately 270,000 daltons) was identified in severe alcoholic hepatitis. Thus, this study demonstrates the presence of serum inhibitors in alcoholic liver disease which influence normal lymphocyte function.