Peripheral blood CD34+ cell enumeration as a predictor of apheresis yield: an analysis of more than 1,000 collections.

The role of the peripheral blood (PB) CD34(+) cell count in predicting the CD34(+) cell yield in hematopoietic progenitor cell apheresis collections is well established. However, sometimes unexpectedly poor CD34(+) cell yields are obtained. To determine the effect, if any, of a range of factors on the ability of the PB CD34(+) count to predict collection CD34(+) cell count, we performed a retrospective analysis on consecutive hematopoietic progenitor cell apheresis collections between 2004 and 2008. Factors investigated included mobilization regimen, PB white blood cell count, body weight, and disease. After exclusion of collections involving apheresis complications, a total of 1,225 PB CD34(+) cell results with corresponding collection CD34(+) cell results from 458 patients were analyzed. Although differences in the median PB CD34(+) cell counts and collection CD34(+) cell counts were seen between mobilized collections with chemotherapy plus granulocyte colony-stimulating factor and those with granulocyte colony-stimulating factor alone, the predictive capability of the PB CD34(+) cell count for the collection CD34(+) cell yield remained similar. Although poorer collection efficiencies were observed in the myelodysplastic syndrome/myeloproliferative disorder diagnostic subgroup, our findings confirm that PB CD34(+) cell analysis remains a powerful and irreplaceable tool for predicting hematopoietic progenitor cell apheresis CD34(+) cell yield.