Background: Reduced harvest volumes in pediatric donors appear to have the potential to reduce donor-associated risks while maintaining engraftment in recipients; however, the allowable harvest volume reduction remains undefined.
Methods: We retrospectively analyzed the data pairs of 553 bone marrow (BM) harvests from pediatric (age at harvest <18 yr) sibling donors and clinical outcomes of 553 pediatric (age at infusion <14 yr) transplant-naïve recipients to assess the optimal BM harvest volume needed from pediatric donors to obtain the desired CD34+ cell count (≥3.0×106 cells per kg of recipient weight), and to study its impact on the clinical outcomes of transplantation in pediatric recipients.
Results: The minimum desired CD34+ cell count of ≥3.0×106 per kg of recipient weight was achieved for 506 (95.3%) of donor-recipient pairs. The median CD34+ cell yield was 6.4×106 per kg of recipient weight (range, 1.2‒33.8×106) in donors younger than 5 years old at harvest, 4.7×106 (range, 0.3‒28.5×106) in donors aged 5‒10 years and 2.1×106 (range, 0.3‒11.3×106) in donors older than 10 years (P<0.001).
Conclusion: The infused CD34+ cell dose (×106 cells/kg of recipient weight) had no impact on GRFS; however, a CD34+ cell dose of ＞7×106 cells/kg of recipient weight did not improve hematopoietic recovery.
Keywords: Harvest volume; Marrow transplant; Pediatric donors.