Stem cell transplantation for treatment of sickle cell disease: Bone marrow versus cord blood transplants

The transplantation of stem cells harvested from bone marrow and cord blood for the treatment of sickle cell disease (SCD) is reviewed. Current treatment options have lengthened the lifespan of patients with SCD. Hydroxyurea is the standard of care for the management of SCD, but it does not prevent serious complications in all patients. For those patients with severe disease, stem cell transplantation may be an appropriate curative option. However, less than one third of these patients find an appropriate matched related bone marrow donor. Cord blood offers a more readily available source of stem cells for transplantation. Donor morbidity is eliminated, since the cells come from banked cords, and the harvesting process is noninvasive for the donor. Another advantage of cord blood transplantation is the lower occurrence of graft-versus-host disease (GVHD). One disadvantage of transplantation with cord blood includes delayed time to engraftment. Due to the mortality associated with stem cell transplantation, it may be most appropriate to reserve the procedure for patients who have a more severe course of SCD. Although bone marrow, peripheral blood, and cord blood transplantation has been successfully performed in patients with SCD, data remain limited regarding the optimal preparative regimens, the most appropriate stem cell source, and the type of GVHD prophylaxis to be used after transplantation. More data are warranted before this treatment approach can be recommended as a standard of care for SCD.