Comparison of two single-platform ISHAGE-based CD34 enumeration protocols on BD FACSCalibur and FACSCanto flow cytometers

Background aimsEnumeration of viable CD34+ cells provides critical information for the bone marrow (BM) transplant physician. The single-platform ISHAGE protocol is the most reliable method currently available to quantitate accurately this important subset of cells. Previous studies have shown that 5 CD34+ cells/µL blood predicts the collection of at least 0.5 × 106 CD34+ cells/kg patient weight. From the apheresis product, infusion of 2.5 × 106 viable CD34+ cells (measured pre-cryopreservation)/kg patient weight will reliably permit engraftment of the hematopoietic system (as measured by the time to 20000 platelets/µL) by day 12–14 post-infusion.MethodsWe compared the CD34+ cell numbers derived from Flow Count-based Stem-Kit™; (Beckman Coulter) and Trucount™ tube-based stem cell enumeration (SCE) kit (BD Biosciences) ISHAGE templates on BD FACSCalibur™ and BD FACSCanto™ cytometers on 12 granulocyte–colony-stimulating factor (G-CSF)-mobilized peripheral blood (MPB) and 10 peripheral blood stem cell (PBSC) samples.ResultsComparison of results showed that there was no statistical difference between samples run with Stem-Kit on the FACSCalibur versus SCE kit-based assays on either the FACSCalibur or FACSCanto. Mean results for the Stem-Kit/Calibur combination were 137, for SCE kit/Calibur 140 and for SCE kit/Canto 137 cells/µL. Pair-wise comparison of data based on rank order showed no statistically significant difference and all correlation coefficients had an R2>0.98.ConclusionsThe two kits generated very similar data on a range of fresh samples regardless of instrument platform. These results confirm and extend the utility of the single-platform ISHAGE protocols with a variety of reagent kits and instrument platforms.