Early engraftment of G-CSF-primed allogeneic bone marrow transplantation in pediatric patients regardless of donor-recipient weight differences

Harvesting sufficient progenitor cells from bone marrow (BM) for pediatric patients is a challenging process, especially from smaller donors. Growth factor administration to donors prior to harvest results in an enrichment of the graft and leads to early engraftment. A total of 41 patients received a human leukocyte antigenidentical sibling transplantation using granulocyte colonystimulating factor (G-CSF)-primed BM. All donors received G-CSF 10 μg/kg/day for 2 days prior to harvest. The median weight difference between donor and recipient was 3.9 kg (range, -29.8 to 32 kg), and the median number of CD34 ⁺ cells harvested was 4.16×10 ⁶/kg (range, 1.17- 31.9×10 ⁶/kg). The median time to neutrophil engraftment was 12 days (range, 10-27 days), and the time for platelet engraftment was 20 days (range, 12-64 days). The cumulative incidence of acute grade 2 to 3 graft-versushost disease (GVHD) and chronic GVHD was 4.9% and 5.1%, respectively. An analysis according to the weight difference between donor and recipient showed there was no significant difference in harvested CD34 ⁺ cell dose and in time required for engraftment between smaller and heavier donor recipients. G-CSF-primed BM allows successful engraftment and provides a valuable alternative to unstimulated BM and peripheral blood stem cells with good engraftment and tolerable GVHD even in patients with smaller donors.