A Study to Identify Correlation of Hematopoietic Progenitor Cell(XN-HPC) By Sysmex Cell Counters with Final Yield of CD34 + Stem Cells

Successful bone marrow transplantation depends on the collection and infusion of enough numbers of peripheral blood stem cells. Several predictors of stem cell yield are used now, including white blood cell (TLC) count and CD34 in peripheral blood. This study evaluated the utility of the new automated hematopoietic progenitor cell count(HPC) available on Sysmex XN hematology analyzers (XN-HPCs) in stem cell harvest. STUDY DESIGN AND METHODS

The characteristics of XN-HPC, CD34+ stem cells, and TLC analysis were compared using 217 matched peripheral blood and apheresis bag samples. RESULTS

Good correlation was observed between HPC and CD34+ stem cell counts in peripheral blood (r = 0.90; slope, 0.82) and apheresis collections (r = 0.93; slope, 0.91). There is a good corelation that peripheral blood HPC and CD34 analysis showed ability to predict successful stem cell harvests (≥ 2 × 106 CD34+ cells/kg). Fixing a cutoff of 25 × 10⁶ HPC/L, peripheral blood XN- HPC and CD34 analysis both showed negative predictive values (NPVs) of 100% and positive predictive values (PPVs) of 66% and 80%, respectively. In contrast, the correlation between peripheral blood TLC and CD34 analysis was poor (r = 0.39), and the peripheral blood WBC count (cutoff, 20 × 10⁹/L) was a poor predictor of PBPC harvest (NPV 55%, PPV 38.7%). CONCLUSION

Hematopoietic Progenitor cell (HPC) compares well with both peripheral blood and bag CD34 analysis and may act as a cheap surrogate marker for CD34 analysis to predict optimal timing of stem cell harvest especially in Autologous bone marrow transplant receipients.This will help us in reducing costs in a resource limited developing country like India.