The addition of allogeneic peripheral blood-derived progenitor cells to bone marrow for transplantation: results of a randomised clinical trial.

BACKGROUND The use of cytokine-mobilised peripheral-blood-derived progenitor cells (PBPC) has resulted in a significant improvement in the safety of autologous transplantation. Collections of PBPC contain large numbers of haemopoietic progenitors and T-lymphocytes when compared with bone marrow (BM). AIMS To assess the clinical effects and safety of filgrastim-mobilised allogeneic PBPC, in particular whether PBPC would alter the kinetics of engraftment or the incidence and severity of graft-versus-host disease (GVHD). METHODS Twenty-seven patients undergoing allogeneic transplantation were randomised to receive BM or BM supplemented by PBPC. Patients were conditioned with busulphan 16 mg/kg and cyclophosphamide 120 mg/kg. GVHD prophylaxis was with methotrexate and cyclosporin. Ganciclovir prophylaxis was administered to all cytomegalovirus seropositive patients. No haemopoietic growth factor was used after BMT. Donors of PBPC underwent a single, seven litre apheresis after four days of filgrastim, 10 microg/kg/day by subcutaneous injection. RESULTS Donor toxicity was mild, with the most frequently reported being bone pain in the cytokine-treated donors. The patients transplanted with BM+PBPC received an eight-fold increase in CD3+ T-lymphocytes (1.65X 10(8)kg vs 0.22 x 10(8)/kg, p=0.04) and the cytokine product contained a median of 5 x 10(6) CD34+ cells/kg. BM+PBPC patients had more rapid engraftment of neutrophils to 0.5x 10(9)/L (17 days vs 19 days, p=0.02) and platelets to 50X 10(9)/L (22 days vs 35 days, p=0.04). BM megakaryocyte numbers were significantly enhanced at days 14 and 28 after BMT (both p=0.04), however platelet transfusions were not significantly different. The incidence, organ distribution, severity and time to onset of acute and chronic GVHD were not different between the treatment groups and there was no difference in overall survival or event-free survival. CONCLUSIONS Allogeneic PBPC from HLA-identical siblings may speed engraftment of neutrophils and platelets without detrimental effects on GVHD or survival.