Bone marrow processing for transplantation

As indications for BMT increase, so do variations in bone marrow processing and manipulation techniques. Many centers have their own unique methods of mononuclear cell purification, concentration and storage. This is particularly evident in the processing of bone marrow for autologous BMT to allow dose intensification as salvage therapy for malignant disease. Unique procedures have been developed to maximize yields, concentrate mononuclear cells necessary for engraftment, and reduce the likelihood of GVH disease. Graft rejection and disease relapse still remain a problem in some of these "manipulated" marrows. Newer procedures may allow titration of the optimum numbers of immune reconstituting cells; however, at this time, these techniques are not precise and the balance between preventing GVH disease at the expense of graft failure or relapse may still jeopardize disease-free survival. Innovative purging techniques that include pharmacologic and immunologic methods, continue to evolve, necessitating standards for bone marrow processing that are flexible yet practical. Quality control and viability assays are essential to verify the biologic proliferative potential of progenitor cells capable of marrow reconstitution. Although no standards are yet established, all centers should have criteria to monitor the quality of the processed marrow. Blood banks and transfusion services are well versed in regulations governing processing, labeling, storage, and quality control of blood components. Bone marrow is the ultimate blood component, and it stands to reason that methods outlined in this article be integrated into transfusion medicine.