MITOGEN-STIMULATED IMMUNOGLOBULIN PRODUCTION BY CHRONIC LYMPHOCYTIC LEUKEMIC LYMPHOCYTES

  • 1 January 1982
    • journal article
    • research article
    • Vol. 47  (3) , 697-705
Abstract
The capacity of B cells from patients with chronic lymphocytic leukemia (CLL) to produce and secrete Ig following mitogen stimulation was investigated using sensitive radioimmunoassays for .mu., .gamma., .alpha., .kappa. and .lambda. Ig chains. Lymphocytes from 7 of the 11 patients studied secreted Ig in response to pokeweed mitogen (PWM). IgM was always the major Ig in 5 of the 7 responders it was the only class detected. Only 1 type of L chain was observed in most cases. This was in contrast to normal lymphocytes which secreted all classes of Ig (IgM was invariably the lowest) containing both types of L chain. Lipopolysaccharide [from Escherichia coli] induced Ig secretion in only 1 of 4 CLL cases; this was again IgM with only 1 type of L chain. The assays are therefore most probably measuring a response by the leukemic cells. In most CLL cases, Ig secretion by the residual normal cells, which proliferate in response to mitogen, was not observed. This inability of the normal lymphocytes to differentiate fully into Ig secreting cells and the block in switching from IgM production to other classes in the leukemic cells may be attributable to a defect in the regulatory system of the immune response in CLL patients.