Abstract:

BACKGROUND: Approximately 1/3 allogeneic peripheral blood stem cells (PBSCs) transplantation treatments are performed between ABO mismatched donors-recipients pairs.
OBJECTIVE: To evaluate the feasibility of PBSCs collection in major ABO mismatched donors with COM. TEC blood cell separator and infusion to the recipients without removal of erythrocytes from the PBSCs graft.
METHODS: Twenty-seven HLA-identical sibling donors received priming with granulocyte colony stimulating factor (G-CSF)    5 μg/kg/d via subcutaneous injection for 5 days. PBSCs collection started on day 5 using COM.TEC blood cell separator. The procedure processed 3.0-3.5 times of the total blood volume (TBV). For major ABO mismatched donors, specialized harvesting strategies of adjusting the volume of buffy coat and maintaining adequate and stable flow rate during apheresis were to diminish red blood cells (RBCs) contents of PBSCs.
RESULTS AND CONCLUSION: Of the 27 donors, there were 11 major ABO-incompatible and 16 ABO-identical. The volumes of PBSCs graft and RBCs harvested in major ABO-incompatible group were significantly lower than those of ABO-identical group (P　< 0.05). The number of mononuclear cells and CD34⁺ cells per recipient body weight did not statistically differ between the two groups (P > 0.05). All recipients reconstituted hematopoiesis following allo-PBSCT. Mean time to neutrophil and platelet engraftment was no significant difference between ABO-identical and major incompatible transplantaions (P > 0.05). PBSC harvesting from major ABO mismatched donors can be successfully performed with COM.TEC blood cell separator. Adjustment the volume of buffy coat and maintenance of adequate and stable flow rate during procedure can reduce RBC contamination for prevention of immune hemolysis; meanwhile collecting a sufficient number of CD34⁺ cells to ensure prompt engraftment post-transplantation.