Factors Associated with Successful Mobilization and Collection of Peripheral Blood Hematopoietic Stem Cells in Autologous and Allogeneic Donors

Abstract

BACKGROUND: Peripheral blood hematopoietic stem cells (PBSC) have largely replaced bone marrow derived stem cells in autologous transplantations, and have become the preferred source of stem cells in the majority of allogeneic transplantations. Sufficient number of mobilized and collected hematopoietic stem cells (HSC) is needed for successful hematopoietic stem cell transplantation.MATERIAL AND METHOD: This study was performed in the Institute for Transfusion Medicine of RM and the University Clinic of Hematology from 2008 till 2016. There were 30 allogeneic and 90 autologous donors that underwent mobilization and collection of PBSC. The association between possible predictive factors such as demographic characteristics, laboratory parameters and collection parameters in both groups, and mobilization strategy and clinical characteristics in autologous donors and number of collected PBSC was analyzed.RESULTS: There were 226 apheresis, 182 in autologous donors (mean 2, range 1-3) and 44 apheresis in 30 allogeneic donors (mean 1.5, range 1-2). The mean number of collected MNC in autologous donors was 3.09 x 108/kg and 2.85 x 106/kg CD34+ cells, and 3.23 x 108/kg MNC and 3.20 x 106/kg CD34+ cells in allogeneic donors. Significantly larger number of MNC and CD34+ cells was collected with the WBC set. There was a statistically significant correlation between the total number of collected MNC in autologous donors and platelet count before mobilization, the number of cycles in one apheresis procedure, quantity of collected graft and the number of collected MNC and CD34+ cells on the first day of harvestration. There was a statistically significant correlation between the total number of collected MNC in allogeneic donors and platelet count before mobilization, the number of cycles in one apheresis procedure, quantity of collected graft and number of MNC on first day of harvestration. There was a strong correlation between the number of collected MNC and CD34+ cells on the first harvest and the total number of collected MNC and CD34+ cells in poor mobilizers, and inverse correlation with the number of apheresis procedures. Donors who donated MNC ≤ 0.7 x 108/kg and/or ≤ 0.7 x 106/kg CD34+ cells on the first harvest (84.6%) were strong predictors of poor mobilizers.CONCLUSION: Determining the proper level of baseline and preaheresis laboratory parameters for initiating mobilization and apheresis procedure which is safe for donors and greatly efficient in collection of PBSC is needed for optimization of these procedures, as well as for early intervention in poor mobilizers.