Peripheral blood progenitor cell mobilization in healthy donors receiving recombinant human granulocyte colony-stimulating factor

Objective. We analyzed the incidence of primitive (LTC-IC) and committed (CFU-mix, BFU-E, CFU-GM) hematopoietic progenitors detected under steady- state conditions and upon progenitor cell mobilization in a cohort of healthy donors receiving recombinant human granulocyte colony-stimulating factor (rhG-CSF). Materials and methods. Healthy donors (n = 30) of HLA-mismatched or -matched stem cell transplants were mobilized with rhG-CSF (8 μg/Kg body weight subcutaneously twice daily until completion of leukapheresis). PBPC collections were started after 4 days of rhG-CSF therapy. Results. Steady- state incidence of bone marrow LTC-IC, but not committed progenitors, significantly correlated with the numbers of mobilized CD34+ cells (r = 0.6, p = 0.004), CFU-GM (r = 0.79, p = 0.0005) and CFC (r = 0.76, p = 0.001) detected after 4 days of rhG-CSF therapy. Statistically significant correlations were also found between steady-state blood CFU-GM and peak numbers of CD341 cells (r = 0.68, p = 0.001), numbers of day 4 CD341 cells (r = 0.52, p = 0.005), CFU-GM (r = 0.63, p = 0.002), and CFC (r = 0.61, p = 0.003). Conclusion. Our data show that in normal volunteers baseline marrow LTC-IC and blood CFU-GM correlate with rhG-CSF-mobilized PBPC. The potential clinical relevance of these findings in the identification of poor mobilizers will be tested in a prospective study.