Principles of Bone Marrow Processing and Progenitor Cell/Mononuclear Cell Concentrate Collection in a Continuous Flow Blood Cell Separation System

The application of continuous flow apheresis technology to processing bone marrow for collection of the mononuclear progenitor cell population appears to follow the same principles as collection of mononuclear cells from peripheral blood. Unlike peripheral blood, however, where mobilization of cells from extravascular sites during the procedures contributes significantly to the final cell yield, the entire quantity of progenitor cells available for recovery from marrow is present in the original marrow when it is pooled. The process then becomes one of attempting optimal recovery of the cells of interest while excluding contaminating erythrocytes and cells of the myeloid series. This study reports the development of a protocol for recovery of MNC, CD33+, CD34+, and CD34+/ DR- cells from harvested marrow for autologous and allogeneic transplants using a continuous flow blood cell separator, the variables influencing the recovery of the cells of interest and the clinical response to infusion of the processed cells.