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 granulocyte 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.

Analysis of hematopoietic progenitor cells in patients with myelodysplastic syndromes according to their cytogenetic abnormalities.

The present work analyzes the hematopoietic progenitor cells (HPC) in myelodysplastic syndrome (MDS) patients using both an immunophenotypical and a functional approaches in order to know whether they are similar in patients with or without cytogenetic abnormalities. Among CD34+ HPC, the proportion of myeloid committed progenitors was higher in patients with an abnormal karyotype. Ninety MDS patients were studied. Patients with abnormal karyotype showed a similar platting efficiency than patients with normal cytogenetics. Trisomy 8 and 5q- showed a significant higher P.E. than patients with normal karyotype or monosomy 7. We observed that when the most immature HPC were studied, the total number of granulo-monocytic colonies produced by LTBMC was higher in the normal karyotype group. In summary, the present study shows that in MDS the HPC are impaired; this impairment is deeper in patients with abnormal karyotype.