Myeloid-derived suppressor cells mobilized by G-CSF in allografts correlate with low risk of acute graft-versus host disease in patients undergoing unmanipulated allogeneic blood and marrow transplantation (126.18)

Abstract

Abstract Introduction:The aim of this study was to investigate the association of donor myeloid-derived suppressor cells (MDSCs) in allografts with acute graft-versus host disease(aGVHD) in patients who had undergone granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood progenitor cell (G-PBPC) and G-CSF-primed bone marrow (G-BM) transplantation. Methods: Unmanipulated allografts from 71 patients were prospectively analyzed for MDSCs with respect to aGVHD, in which 23 patients got HLA-matched donors and 48 patients had haploidentical donors. Results: Median numbers (range) of monocytic/ granulocytic/ promyelocytic MDSCs were:3.43(0.31-10.65)×106/kg, 8.23(0.85-16.2 )×106/kg , 1.11(0.51-3.53)×107/kg ,respectively in G-BM and these of monocytic/ granulocytic MDSCs were:1.64(0.28-4.3)×107/kg , 1.96(0.62-6.2)×107/kg , respectively in G-PBPC. The incidence of grades II-IV aGVHD was 29.6%, and there was no difference between the HLA-matched and haploidentical transplantation group. Patients who received a higher dose of promyelocytic MDSCs(>0.82×107/kg, p<0.001) in G-BM or a higher total dose of monocytic MDSCs in G-BM and G-PBPC (>1.23×107/kg, p<0.001) exhibited a lower incidence of grades II-IV aGVHD. Conclusion: Our results suggest that a high number of MDSCs infused were associated with decreased risk of aGVHD in allogeneic blood and marrow transplantation, which may reflect the immune suppressive function of MDSCs in allogeneic transplantation.