title: Influence of the different CD34+ and CD34- cell subsets infused on clinical outcome after non-myeloablative allogeneic peripheral blood transplantation from human leucocyte antigen-identical sibling donors.
abstract: Currently, no information is available regarding the influence of the different CD34+ cell subsets infused on the haematopoietic recovery, following non-myeloablative allogeneic peripheral blood stem cell transplantation (allo-PBSCT). We have explored, in a group of 13 patients receiving non-myeloablative allo-PBSCT from human leucocyte antigen-identical sibling donors, the influence of the total dose of CD34+ haematopoietic progenitor cells (HPC) infused, compared with that of the different CD34+ HPC and CD34- leucocyte subsets in the leukapheresis samples, on both engraftment and clinical outcome. The overall numbers of total CD34+ HPC (P = 0.002) and myelomonocytic-committed CD34+ HPC infused (P = 0.0002) were strongly associated with neutrophil recovery (> 1 x 109 neutrophils/l), the latter being the only independent parameter influencing neutrophil recovery. Regarding long-term engraftment, only the number of immature CD34+ HPC infused/kg correlated with the duration of hospitalization in the first 2 years after discharge (r = -0.75, P = 0.005). Both the overall amount of CD34+ HPC and the number of myelomonocytic CD34+ HPC infused showed a significant influence on the risk of graft-versus-host disease (GVHD). Thus, the overall probability of GVHD was 100%vs 25% for patients receiving >/= 5 x 106 CD34+ HPC or >/= 3.5 x 106 of myelomonocytic-committed CD34+ HPC vs lower doses (P = 0.013). None of the other CD34+ and CD34- cell subsets analysed correlated with development of GVHD. In summary, our results suggest that in non-myeloablative allo-PBSCT, high numbers of CD34+ HPC, especially the myelomonocytic-committed CD34+ progenitors, lead to rapid neutrophil engraftment. However, they also strongly impair clinical outcome by increasing the incidence of GVHD.
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000008:administration & dosage / Q000145:classification*; D005260:Female; D005434:Flow Cytometry; D006085:Graft Survival; D006086:Graft vs Host Disease / Q000209:etiology; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000145:classification* / Q000276:immunology; D006801:Humans; D007962:Leukocytes / Q000145:classification; D008223:Lymphoma / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D036102:Peripheral Blood Stem Cell Transplantation / Q000379:methods*; D011446:Prospective Studies; D012307:Risk Factors; D018183:Transplantation Chimera; D014184:Transplantation, Homologous
chemical_list: D018952:Antigens, CD34