Higher numbers of blood CD14+ cells before starting conditioning regimen correlate with greater risk of acute graft-versus-host disease in allogeneic stem cell transplantation from related donors

Host antigen-presenting cells (APCs) have been shown to induce acute graft-versus-host disease (aGVHD) in experimental models. In this study, we investigated whether pretransplantation blood levels of host APCs, such as plasmacytoid and myeloid dendritic cells and monocytes, correlate with the development of aGVHD. A total of 89 consecutive patients undergoing allogeneic hernatopoietic stem cell transplantation (HSCT) from HILA-matched related (n = 48) or unrelated (n = 41) donors were enrolled in the study. Blood samples were analyzed by flow cytometry before initiating the conditioning regimen. In related donor transplants, patientdonor sex mismatch and monocyte levels significantly correlated with aGVHD grade H-IV in both univariate and multivariate analyses. Similar results were not observed in recipients of matched unrelated transplants, possibly due to use of antithymocyte globulin (ATG) or differences in graft source in these patients. In conclusion, pretransplantation recipient monocyte levels are relevant to the development of GVHD in HSCT from related donors. (c) 2007 American Society for Blood and Marrow Transplantation.