Early loss of circulating hemopoietic progenitors in HIV-1-infected subjects.

We investigated the in vitro growth of circulating progenitors from mononuclear nonadherent cells (MNAC) and T-depleted MNAC (non-T-MNAC) in the peripheral blood (PB) of 20 human immunodeficiency virus type 1 (HIV-1) seropositive subjects, compared with 12 normal adult volunteers, in order to clarify whether the loss of hemopoietic progenitors described in the bone marrow (BM) of AIDS-related complex (ARC)/AIDS patients could occur in PB before the AIDS stage, only those patients at the early stages of the disease who had never undergone cytotoxic therapy were considered in the study. We found a significant reduction in the number of granulocyte-macrophage progenitors (granulocyte-macrophage colony-forming units, CFU-GM; p less than 0.001), megakaryocytic progenitors (megakaryocyte colony-forming units, CFU-MK; p less than 0.001) and erythroid progenitors (erythroid burst-forming units, BFU-E; p less than 0.05) in non-T-MNAC cultures of PB from HIV-1 seropositive subjects compared with normal PB control cultures. Although most of our patients had an inverted CD4/CD8 ratio and a marked reduction in the absolute number of CD4+ cells, there was no correlation with the absolute number of CD4+ cells or with the CD4/CD8 ratio. The loss of hemopoietic progenitors in PB seemed to occur earlier than in BM, because the hemograms of the patients considered in the study were normal in most cases.