Surface markers, 5'-nucleotidase activity, and in vitro functions of lymphocytes from patients with primary humoral immunodeficiency.

Immunologic surface markers, 5'-nucleotidase activity, and in vitro cell functions were determined on peripheral blood mononuclear cells from 20 patients with primary humoral immunodeficiencies. Imbalances of T-cell subsets were a frequent finding and often associated with a deficiency of helper T lymphocytes, predominantly in common variable immunodeficiency. The magnitude of the blastogenic response to mitogens was subnormal in the majority of the samples and showed no correlations to the proportions of helper, suppressor T cells or monocytes in the cultures. Moderate to marked suppression of the pokeweed mitogen-driven allogenic B-cell maturation was mostly mediated by T lymphocytes but modified by monocytes in some patients. In identical twins, T lymphocytes selectively suppressed IgA production. Both in sex-linked agammaglobulinemia and common variable immunodeficiency the activity of 5'-nucleotidase was significantly lower than in controls. This deficiency was mediated by T lymphocytes and showed no correlations to imbalances of T-cell subpopulations or to alterations of lymphocyte functions.