Single Apheresis Session on the 4th Day of Granulocyte Colony-Stimulating Factor Administration Seems Convenient to Collect Enough Peripheral Blood Stem Cells from Healthy Donors

Background: To minimize adverse events of peripheral blood stem cell (PBSC) collection in healthy donors, it is reasonable to limit the total dose of granulocyte colony-stimulating factor (G-CSF) and/or the number of apheresis days without decreasing of PBSCs yield. Therefore, we have started to collect G-CSF induced PBSCs on day 4 instead of on day 5. So, we retrospectively aimed to investigate the results of this 4-day G-CSF administration. Study Design and Methods: Seventy-six healthy donors who performed on G-CSF induced PBSCs donation consecutively between January 2020 and July 2022 were included in this study. G-CSF (filgrastim) at 2 × 5 µg/kg/day subcutaneously was applied. Apheresis started on day 4. Results: Sixty-nine (90.8%) of 76 donors provided enough PBSCs on day 4 apheresis session. Younger age (p = 0.004), higher PB CD34+ cell count on the 4th day of G-CSF (p < 0.001), and male donor (p = 0.010) were correlated with increased amounts of PBSCs yield. Univariate and multivariate logistic regression analyses to predict very good mobilizers (collected PBSCs ≥8 × 106/kg after the first apheresis) were performed. In multivariate logistic regression analyses, male sex (p = 0.004), PB CD34+ cell count ≥100/µL on the 4th day of G-CSF (p < 0.001), and glomerular filtration rate ≥115 mL/min (p = 0.031) were found to be independent predicting factors to demonstrate very good mobilizer. Conclusion: It seems that starting the apheresis on the 4th day of G-CSF administration is effective and to provide minimal G-CSF exposure in healthy donors.