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

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.

We retrospectively analyzed factors predicting the yield for a target CD34 cell dose of >3×10⁶/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.

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 3.9×10⁶/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 3×10⁶kg RBW were donor to recipient weight ratio and periperal CD34+ cell count.

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.