Factors associated with peripheral blood stem cell yield in healthy pediatric donors.

Background And Objectives: Although several studies have reported on the use of children as donors for peripheral blood stem cells (PBSC), data on the predictive factors of CD34+ stem cell yield in healthy pediatric donors are very limited.

Design And Method: We retrospectively analyzed factors predicting the yield for a target CD34 cell dose of >3×10/kg recipient body weight in 140 apheresis in 100 healthy pediatric donors. The donors were evaluated in four groups assigned according to their ages of being 0-4 years, 5-9 years, 10-14 years and 15-18 years. 38 donors underwent second apheresis, two of which required third apheresis.

Results: Median age and body weight were 9.8 years (range: 2-18 years) and 35.8kg (range 11-84kg), respectively. The median number of CD34+ cells in first apheresis was 3.9×10/kg of recipient body weight (RBW) (range: 0.03-33×106/kg RBW). Sixty-two out of 100 donors (62%) needed only one apheresis. The CD34+ cell count in stem cell product and the amount of CD34+ cell yield considering donors' body weight obtained from the first apheresis was not statistically different among defined age groups. On multivariate analysis, variables that had a significant impact on CD34+ cell collection being more than 3×10kg RBW were donor to recipient weight ratio and periperal CD34+ cell count.

Conclusion: Our data suggest that CD34+ stem cell yield can be predicted from circulating CD34+ cell concentration on apheresis day and donor to recipient weight ratio in healthy pediatric donors.