lymphocyte proliferation test

a functional test of the ability of lymphocytes to respond to mitogens, specific antigens, or allogenic cells. Lymphocytes are cultured both with and without the stimulant for several days and then are cultured for several hours with ³H-labeled thymidine. The ratio of the thymidine uptake in the stimulated and control cultures is reported as the “stimulation index” (SI) or “stimulation ratio” (SR). The test with allogenic cells, called a mixed lymphocyte culture (MLC), is commonly performed for transplantation tissue typing; all three types of stimulants are used in investigation of immunodeficiency. Commonly used mitogens are phytohemagglutinin (PHA), concanavalin A (ConA), and pokeweed mitogen (PWM); commonly used antigens are PPD (tuberculin), Candida antigen, and streptokinase-streptodornase. Called also blastogenesis assay and lymphocyte proliferation assay.