Background : The use of peripheral blood stem cells(PBSCs), an alternative hematopoietic rescue product to bone marrow, is limited by the low progenitor cell content of peripheral blood. To overcome this limitation, PBSCs mobilization with cytotoxic chemotherapy and/or hematopoietic growth factors is used, but, in general, multiple leukaphereses are still needed to collect an adequate number of PBSCs for transplantation. Thus, to improve the usefullness of PBSCs, a more efficient collection strategy is necessary.
Methods : PBSC collections were evaluated in 12 patients with acute leukemia in complete remission who underwent large-volume leukapheresis(LVL) on a Fenwall CS3000 Plus blood cell separator. Granulocyte colony-stimulating factor(G-CSF) was administered subcutaneously(5㎍/㎏/day) after induction or consolidation chemotherapy. Patients underwent leukaphereses designed to maximize PBSC yield(blood flow rate, 85mL/min).
Results : Thirty LVL procedures were done on twelve patients(mean 2.5, range, 1∼3). Mean(±SD) volume processed was 20.0±0.4L at a single apheresis. The collection volume was 131.7±28.6mL that contained 36.1mL of red blood cells. The mean percentage of mononuclear cells(MNCs) was 97.1±7.4%, and the MNC collection efficiency was 54.9±20.4%. The PBSC product per LVL contained a mean 3.39× 108 MNCs/kg 6.82×106 CD34+ cells/㎏, and 6.08×104 CFU-GMs/kg, respectively. A mean of 2.5 leukaphereses resulted in a mean of 8.21×108 MNCs/kg, 12.2×106 CD34+ cells/kg and 14.0×104 CFU-GMs/㎏, respectively. The phenotype characterization of collected CD34+ cells showed that a mean of 94.2% coexpressed HLA-DR, 97.1% coexpressed CD38. The percentage of CD34+ /CD33+ and CD34+/c-kit+ cells was 85.6% and 14.2%, respectively. Posta-pheresis hematocrit and platelets were reduced from prepheresis value by 12.0%, and 53.5%, respectively. No adverse events were related to the leukapheresis.
Conclusion : We conclude that large-volume leukapheresis, following chemotherapy plus G-CSF, for patients with acute leukemia was tolerable, and allowed the collection of adequate numbers of PBSC in a few procedures.