Reduced mobilization of CD34⁺ stem cells in advanced human immunodeficiency virus type 1 disease

Granulocyte colony-stimulating factor (r-met Hu G-CSF; filgrastim; 10 μg/kg/day for 7 days) was used to mobilize CD34⁺stem cells into the peripheral blood of human immunodeficiency virus type 1 (HIV-1)-infected individuals and a group of HIV-1-uninfected donors as a measure of immunologic reserve in HIV-1-infected people. G-CSF mobilized CD34⁺ cells of HIV-1-infected individuals with cell counts >500 CD4⁺ cells/mm³, as well as in HIV-1-uninfected donors. In contrast, CD34⁺ cell mobilization was significantly blunted in HIV-1-infected individuals with cell counts <500 CD4⁺ cells/mm³ (<200 cell days vs. >650 cell days, P < .0005, compared with the >500 CD4⁺ cell cohort). At least 1.75 x 10⁷ CD34⁺ cells were harvested by leukapheresis from patients in each study cohort. CD34⁺ cell viability and the ability to differentiate precursor cells into myeloid and erythroid progenitor cells were not affected by HIV-1 infection.