Frequency Distribution Analysis of the Normal Lymphocyte Response to Phytohemaggluitnin

Abstract

Phytohemagglutinin (PHA)-induced lymphocyte blastogenesls was used as an in vitro test for the immunocompetence of circulating thymus-dependent (T) lymphocytes. The data accumulated from a pool of normal individuals showed a wide range of responses and are presented here. The response variability is a function of time-dependent variations within individuals at high PHA concentrations. At low PHA concentrations, there is large variability of response within individuals as a function of time as well as large variability in mean responses between individuals. A non-Gaussian frequency distribution of responses is also obtained at low PHA concentration. The frequency distribution of responses observed does not appear to be strongly dependent upon the age distribution of the normals.