Immunological characterization of lymphocytes in lymphoproliferative diseases. Restriction of classes, subclasses, and Gm allotypes of membrane-bound Ig.

Abstract

Lymphocytes from nineteen patients with chronic lymphocytic leukemia and two with lymphosarcoma with transformation to leukemia had membrane‐bound Ig, showing restriction for Ig class, IgG subclass, Gm allotype, and light chain class. IgM was found on cells from all patients except one, who had IgG. These data, together with results from lymphocyte stimulation in vitro with mitogens, and studies of rosette formation with sheep erythrocytes, suggested that tumor cells were products of monoclonal proliferation of B cells. Lymphocytes in chronic lymphocytic leukemia stained with concanavalin A and with antilymphocyte antiserum as strongly as normal lymphocytes. Lymphocytes from patiems with lymphosarcoma of the bone marrow or aleukemic chronic lymphocytic leukemia usually had a normal percentage of B lymphocytes in blood, but a tendency to restriction to one Ig class on B lymphocytes was seen, Blast cells from patients with acute lymphoblastic leukemia did not have membrane‐bound Ig. Lymphocytes from patients with lymphosarcoma of the bone marrow or aleukemic chronic lymphocytic leukemia and from those with acute lymphoblastic leukemia, reacted normally on stimulation in vitro with T lymphocyte mitogens.