Lymphocyte phenotype does not predict immune function in pediatric patients infected with human immunodeficiency virus type 1.

To determine whether assays of lymphocyte phenotype were predictive of antigen-specific immunologic function in children infected with human immunodeficiency virus type 1 (HIV-1), we compared the antigen-specific cellular and humoral functions (tetanus toxoid-induced T lymphocyte blastogenesis and anti-tetanus toxoid antibody) with the patients' T lymphocyte phenotype, determined at the same time. Although both HIV-1-infected patient populations studied (pediatric hemophilia patients and other pediatric patients) had decreases in the values determined by their functional and phenotypic assays, no association between the functional and phenotypic assays was demonstrated. Thus some HIV-1-infected patients with a normal phenotype had no antigen-specific function, whereas other patients with a markedly abnormal T lymphocyte phenotype had normal antigen specific T lymphocyte function. These results indicate that the assessment of HIV-1-infected patients should include assays of antigen-specific immune function in addition to assays of T lymphocyte phenotype.