Harvesting and Enrichment of Hematopoietic Progenitor Cells Mobilized into the Peripheral Blood of Normal Donors by Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) or G-CSF: Potential Role in Allogeneic Marrow Transplantation

Abstract

To explore the use of stem/progenitor cells from peripheral blood (PB) for allogeneic transplantation, we have studied the mobilization of progenitor cells in normal donors by growth factors. Normal subjects were administered either granulocyte-macrophage colony-stimulating factor (GM-CSF) at 10 μg/kg/d, or G-CSF at 10 μg/kg/d, or a combination of G- and GM-CSF at 5 μg/kg/d each, administered subcutaneously for 4 days, followed by leukapheresis on day 5. Mononuclear cells expressing CD34 (CD34+ cells) were selectively enriched by affinity labeling using Dynal paramagnetic microspheres (Baxter Isolex; Baxter Healthcare Corp, Santa Ana, CA). The baseline CD34+ cells in peripheral blood before mobilization was 0.07% ± 0.05% (1.6 ± 0.7/μL; n = 18). On the fifth day after stimulation (24 hours after the fourth dose), the CD34+ cells were 0.99% ± 0.40% (61 ± 14/ μL) for the 8 subjects treated with G-CSF, 0.25% ± 0.25% (3 ± 3/μL, both P < .5 v GM-CSF). Parallel to this increase in CD34+ cells, clonogenic assays showed a corresponding increase in CFU-GM and BFU-E. The total number of CD34+ cells collected from the G-CSF group during a 3-hour apheresis was 119 ± 65 × 106 and was not significantly different from that collected from the group treated with G- and GM-CSF (101 ± 35 × 106 cells), but both were greater than that from the group treated with GM-CSF (12.6 ± 6.1 × 106; P