Comparison between single- and dual-platform flow cytometry for CD34+ stem cell enumeration in a pediatric population

Area of Science:

• Hematology
• Pediatric Oncology
• Cell Therapy

Background:

• Accurate enumeration of CD34+ hematopoietic progenitor cells (HPCs) is crucial for successful stem cell collection.
• Current single and dual-platform methods for CD34+ HPC enumeration have unclear comparative accuracy in pediatric patients.

Purpose of the Study:

• To compare the accuracy and implications of single versus dual-platform CD34+ HPC enumeration in pediatric patients undergoing autologous apheresis.
• To assess the impact of enumeration method discrepancies on clinical decisions regarding collection adequacy and the need for additional collection procedures.

Main Methods:

• Retrospective review of 131 autologous apheresis collections from 120 pediatric patients.
• Analysis of absolute and percent differences, systematic bias, and agreement between single and dual-platform methods.
• Evaluation of the impact on meeting CD34+ dose thresholds and potential need for additional collection days.

Main Results:

• High correlation between platforms but significant systematic bias observed.
• Single-platform counts were significantly higher, particularly in HPC(A) (15.9% difference vs. 6.3% in peripheral blood).
• Enumeration discrepancies varied by hematology analyzer and patient characteristics (age, weight, disease type), potentially impacting collection decisions in 30% of cases.

Conclusions:

• CD34+ enumeration methodology significantly impacts cell counts and can alter clinical decisions regarding collection adequacy and the number of collection days required.
• Understanding platform-specific variability is essential for accurate interpretation and clinical outcomes in pediatric stem cell transplantation.
• Standardization or method-specific adjustments may be necessary to ensure reliable CD34+ enumeration in pediatric care.