Method comparison between hematopoietic progenitor cell and CD34+ cell counts in hematopoietic stem cell collection

Area of Science:

• Hematology
• Stem Cell Transplantation
• Clinical Laboratory Science

Background:

• Flow cytometry for CD34+ cell analysis is the standard for hematopoietic stem cell enumeration.
• Evaluating alternative methods can optimize clinical workflows and reduce turnaround times.

Purpose of the Study:

• To assess the utility of hematopoietic progenitor cell (HPC) counts from a Sysmex hematology analyzer as a surrogate for flow cytometry in guiding apheresis.
• To determine if HPC counts can safely replace some CD34+ cell analyses for apheresis timing.

Main Methods:

• Comparison of HPC counts and CD34+ cell counts in peripheral blood samples and apheresis products.
• Analysis of pre-apheresis HPC counts to predict adequate stem cell mobilization in different patient groups.

Main Results:

• Pre-apheresis HPC counts ≥24 × 10^6/L (healthy donors) and ≥36 × 10^6/L (lymphoma patients) predicted adequate mobilization with 100% specificity, significantly reducing flow cytometry use.
• A higher threshold (HPC < 132 × 10^6/L) was needed for multiple myeloma patients due to positive bias, yielding a 24% reduction in flow cytometry analyses.
• Initiating apheresis based on HPC counts above thresholds can expedite decision-making.

Conclusions:

• Hematopoietic progenitor cell counts can be utilized to safely initiate apheresis without immediate flow cytometry confirmation when above established thresholds.
• This approach can significantly reduce the time to decision for initiating apheresis.
• Lower HPC values necessitate confirmatory flow cytometry analysis to ensure adequate stem cell mobilization.