Effect of bone marrow CD34+cells and T-cell subsets on clinical outcomes after myeloablative allogeneic hematopoietic cell transplantation

Donor-derived T-cells mediate graft-versus-leukemia effect, immune reconstitution, and graft-versus-host-disease (GvHD) after allogeneic hematopoietic cell transplantation (HCT). We examined the association of donor cell subsets with outcomes in recipients of myeloablative allogeneic HCT using bone marrow (BM, N = 359) grafts from 2002 to 2014 with related or unrelated donors. Analysis considered pre-infusion graft total nucleated cell (TNC), CD34+ CD3+, CD4+, CD8+ doses. Most patients received busulfan-cyclophosphamide or etoposide-total body irradiation conditioning for acute leukemia or myelodysplastic syndrome. Calcineurin inhibitor-mycophenolate mofetil (CNI-MMF) (49%) or calcineurin inhibitor-methotrexate (CNI-MTX) (47%) were used for GvHD prophylaxis. In multivariable analysis, higher CD34+ dose was associated with platelet engraftment (P