Factors predicting peripheral blood progenitor cell collection from pediatric donors for allogeneic transplantation.

BACKGROUND AND OBJECTIVES: Although several studies have reported on the use of children as donors for peripheral blood progenitor cells (PBPC), no specific characteristics have been identified as predictors of PBPC collection in this population. In this study we analyzed predictive factors for PBPC collection in pediatric donors.

DESIGN AND METHODS: We retrospectively analyzed factors predicting the yield for a target CD34+ cell dose of > or =4x10(6)/Kg donor or recipient body weight, in 105 aphereses from 76 healthy pediatric donors (36 boys and 40 girls) included in the Spanish National Donor Registry. Mobilization consisted of granulocyte colony-stimulating factor (G-CSF) in single doses of 10 microg/kg per day subcutaneously for 4 or 5 days. Apheresis started after the fourth dose of G-CSF.

RESULTS: Median age and body weight were 10 years (range 1-18) and 42 kg (range 9-89), respectively. The median number of CD34+ cells/kg recipient body weight was 4.22 (range 0.1-32). On multivariate analysis variables that had a significant negative impact on the CD34+ cell yield, considering the recipient's body weight were the total blood volume processed (regression coefficient (RC): 0.41, 95% CI: 0.21-0.81; p=0.01) and day of apheresis other than first (RC: 0.16, 95% CI: 0.07-0.34; p<0.0001). When considering donor's body weight the variables that positively influenced collection were younger age (RC: 6.79, 95% CI: 1.57-29.25; p<0.01) and large volume leukapheresis (RC: 3.33, 95% CI: 1.13-9.77; p<0.02).

INTERPRETATION AND CONCLUSIONS: Our data suggest that pediatric donors mobilized by G-CSF may donate sufficient numbers of CD34+ cells for allogeneic transplantation. The variables that influenced the yield were the donor's age, blood volume processed and the first day of the apheresis.