Abstract
Background aims. Stem cells are commonly enumerated with bead-based methods in blood and marrow progenitor cell transplantation centers. We compared the International Society of Hematotherapy and Graft Engineering (ISHAGE) bead-based method with a true volumetric one that obviates the use of fluorescent beads for enumeration. Methods. From 31 samples, including 15 peripheral blood samples and 16 leukapheresis products, CD34 + cells were enumerated with the single-platform bead-based ISHAGE method and a true volumetric method. After exclusion of two outliers, one from the peripheral blood group and the other from the leukapheresis group, the results were compared. Results. In the peripheral blood category, no significant difference was observed. However, a proportional systematic error was seen in the leukapheresis group. The systematic error was corrected in the leukapheresis group using a regression line equation. The 95% confidence interval of differences was [–5.83, 2.18] for the peripheral blood and [–38.40, 38.77] for the leukapheresis group after correction of the systematic error. Conclusions. The true volumetric method is a simple and reliable approach that can be used instead of the more popular bead-based procedures.
Acknowledgments
The authors wish to thank Dr Reza Shahsiah for proofreading of the manuscript, the anonymous reviewers for their valuable comments and Ms Leila Kojouri for her co-operation in sample collection and providing the clinical information for our cases. This study was granted by Tehran University of Medical Sciences Research Committee (grant number 10762).
Disclosure of interest: The authors declare no conflict of interest.