Long-term Effects of Regular Whole Blood Donation on Peripheral Blood CD34+ Cells Population with using Leukoreduction Filters

Background Objective: Trapped cell population in leukoreduction filters (LRFs) contains such a significant number of CD34+ hematopoietic stem cells that can be recovered to be used in research studies. Methods: Samples (n=20) were obtained from 10 first-time donors and 10 regular blood donors with more than 30 times blood donation. After separating leukocytes from LRFs by backflushing, total leukocyte number and differential count were determined in both groups using an automated haemocytometer. Then cell viability and CD34+ cell quantification were assessed using 7- amino-actinomycin D and fluorescent-labeled monoclonal antibodies using flow cytometry, respectively. Results: Total leukocyte count was 665±164.92×10^6 in the first-time blood donors and 883±233.89×10^6 in the regular donors, which were not significantly different (P=0.08). While the number of CD34+ cells was significantly reduced in the regular donors compared to the first-time donors (0.58±0.20×10^6/μL vs. 0.36±0.22×10^6/μL; P=0.034). There was no significant difference in terms of absolute neutrophil count (10.58±3.66×06 vs. 13.17±6.45×106/μL; P=0.349), lymphocytes (7.75±3.11×106 vs. 10.38±3.77×106 /μL; P=0.917), and monocytes (2.31±0.88×10^6 vs. 2.59±1.09×10^6/μL; P=0.591) between the first-time and regular donor groups, respectively. Based on the correlation coefficients, the participants’ age had no significant effect on these variables. Conclusion: The results of this study depicted that regular blood donation reduces the number of CD34+ cells in the peripheral blood (PB) of regular donors while it has no significant effect on the ratio of myeloid to lymphoid cells of the two groups.