Human B cell function in normal individuals of various ages. 1. In vitro enumeration of pokeweed-induced peripheral blood lymphocyte immunoglobulin-synthesizing cells and the comparison of the results with numbers of peripheral B and T cells, mitogen responses, and levels of serum immunoglobulins.

The effect of age on the in vitro generation of immunoglobulin-secreting cells in pokeweed mitogen-stimulated cultures was examined using a staphylococcal protein A plaque assay. Although there was no statistically significant decrease with age in the numbers of plaque-forming cells, subjects whose cells failed to produce immunoglobulin were four times more common amongst individuals over 55 years of age. Simultaneously-measured T and B lymphocyte numbers. 3H-thymidine incorporation by mitogen-stimulated cultures, and serum immunoglobulins were comparable in both the young and the aged.