Non-Myeloablative Conditioning and Bone Marrow Transplantation

Allogeneic blood or marrow transplantation (alloBMT) is a curative therapy for a variety of hematologic disorders, including sickle cell disease and thalassemia. Even when it is clear that alloBMT can give to these patients an improvement in their disease, myeloablative transplants have important toxicities and mortalities associated. The lack of suitable donors continues to be a limit to access to transplantation. Substantial progress has been made recently in the development of pre-treatment regimens that facilitate the sustained engraftment of donor marrow with reduced toxicity. Most of these regimens incorporate highly immunosuppressive drugs, which allow the reduction or elimination of myeloablative agents or total body irradiation without endangering the sustained engraftment of HLA-identical allogeneic stem cells. Preliminary results of non-myeloablative allogeneic stem cell transplantation suggest that the procedure can be performed in patients who are ineligible for myeloablative alloBMT, and that sustained remissions of several hematologic malignancies can be obtained.