Cell Source and Apheresis

Peripheral blood stem cells have largely replaced harvested bone marrow stem cells both in the autologous and allogeneic settings. Advantages of peripherally harvested cells include higher stem cell dose, more rapid engraftment, reduced donor/patient discomfort, and better graft-versus-leukemia effect in the allogeneic setting. Within the apheresis machine, whole blood is separated into its components by centrifugation, and the red cell-depleted, stem cell-rich buffy coat is extracted for use as a stem cell product, simultaneously returning the other blood components back to the donor. Prediction of procedure length is based on the required cell dose target but still remains challenging. Moreover, the number of apheresis procedures needed should be as few as possible in order to reduce costs and patient/donor discomfort and to increase safety. The volume of blood which needs to be processed in order to collect an adequate number of stem cells depends on several factors such as method of stem cell mobilization, vascular access, and collection efficiency.