Long-term bone marrow culture data are the most powerful predictor of peripheral blood progenitor cell mobilization in healthy donors

Background and Objectives. There is wide interindividual variation in progenitor cell mobilization. The present study was aimed to analyze steady state hematopoiesis in healthy donors and its influence on hematopoietic progenitor cell (HPC) mobilization. Design and Methods. Bone marrow (BM) was aspirated from 72 healthy donors prior to administration of recombinant human granuloyte colony-stimulating factor (G-CSF). Analyses of CD34(+) cells and semisolid cultures as well as long-term cultures were performed from BM or leukapheresis products. Results. Male donors showed a higher number of BFU-E (p=0.007) and committed progenitors (p=0.05), a better stromal layer (p=0.02), and higher long-term bone marrow culture (LT-BMC) counts (p < 0.05) when compared to those in female donors. When correlating the culture pattern of the BM with the data from the leukapheresis products, we observed that the number of the immature progenitors in BM correlated significantly with both the number of CD34(+) cells and CFU-GM in the first leukapheresis. Univariate analysis revealed that the following variables had a beneficial impact on the number of CD34(+) cells: male sex, body weight > 73 Kg, G-CSF schedule and results of LT-BMC, although in the multivariate analysis only the number of CFU-GM obtained after LT-BMC showed a significant influence (p < 0.001). Interpretation and Conclusions. These results confirm the interindividual variation in HPC mobilization among healthy subjects, with LT-BMC counts being the most reliable predictor, expressing the behavior of the immature progenitors and their relationship with the microenvironment.