DEPRESSED STIMULATION IN THE MLR BY LYMPHOCYTES-B IN CHRONIC LYMPHOCYTIC-LEUKEMIA - FAILURE TO DEMONSTRATE A SUPPRESSOR CELL

Unfractionated peripheral blood lymphocytes and B-cell enriched fractions from patients with chronic lymphocytic leukemia (CLL) were compared with similar populations from normal donors for their ability to stimulate allogeneic cells in the mixed lymphocyte reaction (MLR). Both unfractionated lymphocytes and enriched B cells from patients with CLL stimulated allogenetic lymphocytes poorly. This poor stimulation did not appear to be the result of low numbers of peripheral blood monocytes in the CLL lymphocyte populations, nor was it due to a shift in the kinetics of the MLR. To determine if a suppressor cell in patients with CLL was affecting the response of allogeneic cells, T- and B-enriched lymphocyte populations from these patients were added as third-party cells to a normal MLR. In five experiments, no suppression of a normal MLR was observed. In addition, plastic adherent and plastic nonadherent lymphocyte populations from patients with CLL were assayed for their ability to stimulate normal lymphocytes in a MLR and to function as suppressor cells in a normal MLR. Both of these subpopulations failed to function as good stimulating cells and to demonstrate suppressive activity in a MLR. Thus, the poor proliferative response observed in a MLR composed of normal responding lymphocytes and CLL-stimulating lymphocytes is probably due to an intrinsic defect in the CLL B lymphocyte. © 1979.