Differentiation of human lymphocytes by pokeweed mitogen in vitro: studies in normal and in immunodeficient subjects.

Immunoglobulin (Ig) synthesis and secretion by peripheral blood lymphocytes activated by pokeweed mitogen (PWM), and by phytohemagglutinin (PHA) was measured in normal individuals and in subjects with primary immunodeficiency. Unstimulated cultures demonstrated stable, low Ig synthesis of all major Ig classes; PWM showed a peak of Ig synthesis at day 5; PHA cultures demonstrated a late peak of ig production at day 9. Three cases of common variable immunodeficiency showed different patterns of data when the percentage of B cells in blood and Ig production in vitro were used as parameters. Two persons with immunodeficiency and thymoma showed decreased Ig production in vitro, and had suppressor cells capable of blocking Ig production by normal lymphocytes in co-cultivation experments.