The effect of bone marrow graft composition on pediatric bone marrow transplantation outcomes

: Hematopoietic stem cell graft cellular composition has been generally accepted to impact outcomes. Recent studies question this hypothesis. We conducted a single-center retrospective study of sixty-one pediatric BMT recipients for malignant (68%) and nonmalignant diseases (32%) examining effects of graft composition on engraftment, acute GVHD, chronic GVHD, and survival at day 100 and 1 year. Grafts contained a median of 3.63 x  08 TNC/kg (range: 0.031-10.31 x 108 TNC/kg) and 4.09 x 106 CD34+ /kg (range: 0.76-24.15 x 106 CD34+ /kg) with median neutrophil and platelet engraftment times of 17 and 29 days, respectively. A univariate analysis showed a trend for increasing TNC and increasing time to neutrophil engraftment HR: 0.875; CI: 0.075-1.001). Increasing CD34+ counts shortened time to platelet engraftment (HR: 1.085; CI: 1.015-1.161). No significant relationship was found between TNC, CD34+ , or CD3+ and acute or chronic GVHD. TNC or CD34+ did not affect day 100, 1-year survival, or 2-year survival. Increasing CD3+ counts demonstrated a negative trend on day 100 survival (HR: 1.108; CI: 1.001-1.036) but not 1-year survival or 2-year survival. These results add additional data questioning the effect of graft composition on outcomes in pediatric BMT patients with important ramifications for the management of donors.