OBJECTIVETo study the influence of CD34(+) and T cells doses in grafts on prognosis after HLA-identical sibling allogeneic peripheral blood stem cell transplantation (allo-PBSCT).

METHODSSixty-five patients received HLA-identical sibling allo-PBSCT were studied. The numbers of CD34(+), CD3(+), CD3(+)CD4(+) and CD3(+)CD8(+) T cells in the grafts were measured by fluorescence-activated cell sorting (FACS). The doses of MNC, and the above cells in grafts were calculated as per kilogram of recipient's body weight. The patients were divided into high-dose (HD) or low-dose (LD) groups according to median dose of those cells, respectively. Hematopoiesis reconstitution, incidence of graft versus host disease (GVHD), transplant-related mortality (TRM), overall survival (OS), and disease-free survival (DFS) were analyzed.

RESULTSHD CD34(+) cells significantly accelerated neutrophil and platelet reconstitution (P < 0.05). There seems a trend toward increasing incidence of grade II approximately IV acute GVHD (aGVHD) in HD CD3(+)CD4(+) and CD3(+)CD8(+) T cells groups compared with those LD groups (P = 0.089 and 0.098, respectively). The TRM rates were significantly higher and OS rates were significantly in HD CD3(+)CD4(+) and CD3(+)CD8(+) T cells groups than in LD groups, respectively (both P < 0.05). Multivariate analyses showed that CD3(+)CD4(+) and CD3(+)CD8(+) T cells doses in grafts were significant risk factors for TRM \[relative risk (RR) were 13.12 and 25.90, respectively, both P < 0.05\] and for OS (RR were 3.71 and 3.01, respectively, both P < 0.05). The DFS rate was significantly lower in HD CD3(+)CD4(+) T cells groups than in LD groups (P < 0.05). Multivariate analyses showed that CD3(+)CD4(+) cells dose in grafts was a significant risk factor for DFS (RR = 6.91, P = 0.011).

CONCLUSIONSHigh dose CD34(+) cells in grafts significantly accelerate hematopoietic reconstitution. Transfusion of high doses CD3(+)CD4(+) and CD3(+)CD8(+) cells increases TRM, but decrease OS or DFS.