The influence of diagnostic and remission leukemic sera on normal lymphocyte transformation.

The influence of acute lymphoblastic leukemic serum on normal lymphocyte transformation was studied using four different blastogenic stimulants, pokeweed mitogen (PWM), phytohemagglutinin (PHA), Concanavalin-A (Con-A), and mytomycin-treated allogeneic lymphocytes. Marked inhibition of lymphocyte transformation was observed in all leukemic sera tested (15/15) when PHA was used to induce transformation. Inhibition of lymphocyte transformation induced by Con-A, PWM and allogeneic cells was observed in 6 of 15, 4 of 15 and 5 of 15 sera respectively. A series of studies with PHA-induced transformation demonstrated that the observed inhibitory activity of sera collected at the time of diagnosis was not present in sera collected during complete remission states. However, serial studies in four patients from the time of diagnosis throughout complete remission to relapse of acute leukemia were inconclusive with regard to the significance of inhibitors as prognostic indicators. Preliminary evidence is presented which indicates that the observed inhibition is not completely accounted for by alpha-globulin concentrations.