Intra-apheresis CD34+ cell count: A dynamic approach to predicting peripheral blood stem cell collection yield

Area of Science:

• Hematology
• Cellular Therapy
• Biostatistics

Background:

• Optimizing hematopoietic stem cell collection requires accurate peripheral blood stem cell (PBSC) yield prediction.
• Traditional CD34+ cell prediction models often fail to account for cell recruitment during apheresis.
• This study investigated the utility of intra-apheresis CD34+ measurements for enhanced yield prediction.

Purpose of the Study:

• To evaluate the predictive accuracy of a single intra-apheresis CD34+ measurement for PBSC yield.
• To compare the efficacy of intra-apheresis prediction against established pre-apheresis formulas.
• To determine optimal timing for intra-apheresis measurements to improve prediction accuracy.

Main Methods:

• Retrospective analysis of 150 PBSC collections from 123 donors.
• Development of univariable and multivariable linear regression models using intraprocedural CD34+ counts and final yield.
• Validation through bootstrap resampling, cross-validation, and subgroup analyses (age, sex, weight, diagnosis, sampling time).

Main Results:

• Intra-apheresis CD34+ counts strongly correlated with final PBSC yield (R²=0.95).
• High predictive accuracy (R²=0.91-0.99) was maintained across diverse donor subgroups.
• The intra-apheresis model demonstrated superior performance (higher R², lower error) compared to pre-apheresis formulas.

Conclusions:

• A single intra-apheresis CD34+ measurement provides a reliable, real-time prediction of final PBSC yield.
• Measurements taken at or beyond 1.20 processed blood volumes optimize predictive accuracy.
• This intraprocedural approach enhances collection efficiency and minimizes donor inconvenience.