Inhibition of Phytohemagglutinin-Induced In Vitro Lymphocyte Transformation by Serum From Patients With Carcinoma

Abstract

The in vitro reactivity in autologous serum of lymphocytes from 100 normal persons and 120 cancer patients was determined by quantitation of phytohemagglutinin-induced tritiated thymidine incorporation. With the data from the study of normal lymphocytes, an age-correlated range of normal lymphocyte reactivity in autologous serum was derived. With this used as the criterion, the sera of 9 patients with carcinoma, whose lymphocytes in autologous serum had markedly low reactivity, were isolated and assayed for a suppressive effect on normal lymphocyte reactivity. A pool of AB sera, in which the reactivity of normal lymphocytes did not differ from their reactivity in autologous serum, was used as a constant homologous reference serum. The reactivity of normal lymphocytes in serum from each of the 9 cancer patients was lower than their reactivity in the homologous pooled AB serum. The data demonstrate an inhibitor of normal lymphocyte reactivity in the sera of patients with carcinoma.