Defective in vitro growth of the hemopoietic progenitor cells in the acquired immunodeficiency syndrome.

In addition to immunologic derangement, hematological abnormalities have been reported in the majority of patients with acquired immunodeficiency syndrome (AIDS). In this study 15 patients with AIDS or AIDS-related complex (ARC) were evaluated for the in vitro growth of hemopoietic progenitor cells. In all patients a significant reduction of growth (mean +/- SEM) of colony-forming unit-granulocyte, erythrocyte, macrophage, (megakaryocyte) (CFU-GEM) (1.2 +/- 0.3), burst-forming unit-erythroid (BFU-E) (17 +/- 10), CFU-megakaryocyte (CFU-Mk) (1.7 +/- 0.6), and CFU-granulocyte-macrophage (CFU-GM) (35 +/- 10) was observed in comparison with normal controls. Depletion of T cells from the bone marrow before culture led to a significant increase in colony growth, which indicated an imbalance of the normally modulating T cell subsets. This increase was reversed by readdition of autologous T cells causing a decrease in colony growth to a degree, dependent on the T4 to T8 ratio. A decreased number of hemopoietic progenitor cells and/or a defective modulation of progenitor cell growth, normally carried out by T lymphocyte subsets, might be the cause of the hematological abnormalities in AIDS patients.