Introduction
The number of infused CD34+ cells is crucial to the success of peripheral blood stem cell transplantation (PBSCT). Here, we present, for the first time, a new method of enumerating hematopoietic progenitor cells (HPCs) for PBSCT.
Method
This novel method is based on hemolysis and chemical staining, followed by flow cytometry‐based optical detection, conducted using an automated hematology analyzer (XN series, Sysmex). CD34+ cells and HPCs were compared in 76 granulocyte colony‐stimulating factor (G‐CSF)‐mobilized blood or apheresis samples taken from healthy donors (n = 18) or patients undergoing autologous PBSCT (n = 6).
Results
There was a strong correlation between the numbers of HPCs and CD34+ cells (R2 = 0.958). The expected total number of HPCs in the final products, which was estimated from HPCs in pre‐apheresis PB or mid‐apheresis products, also correlated well with the total number of CD34+ cells in the final products. The change in HPCs in PB closely resembled that of CD34+ cells during mobilization. Experiments using immunomagnetic beads suggested that the majority of CD34+ cells existed in HPCs, and vice versa.
Conclusion
Hematopoietic progenitor cells may serve as surrogates for CD34+ cells in PBSCT. However, further investigations are required to verify this.