Rationale for large scale bone marrow hemopoietic stem cell manipulation.

Many years have passed since the first attempt in marrow grafting was performed (1939). During this period several techniques have been developed in marrow processing and manipulation to overcome bone marrow transplant complications: the ABO barrier in case of major incompatibility between donor and recipient, the graft-versus-host disease due to the presence of allogeneic mature T-lymphocytes in cellular suspension and the neoplastic cell residue in autografts. At the end, the final volume of autologous mononuclear cell suspension must be frozen and an optimized cryopreservation allows a cell viability and subsequently an adequate medullar repopulating capacity.