Hematopoietic stem cell transplantation in sickle cell disease: patient selection and special considerations

Since the first report of a young girl affected by sickle cell anemia, treated successfully by bone marrow transplantation (BMT) for acute myeloid leukemia, more than 200 patients have been transplanted worldwide for sickle cell anemia. The disease-free survival (DFS) is good (80-85% in several series), even though many children who received allografts had already significant sickle-related complications. The best results are obtained in young children who have HLA-identical sibling donors and are transplanted early in the course of the disease (DFS: 93%). Future directions in the field of stem cell transplantation of sickle cell anemia include (1) the establishment of new protocols with less toxicity, but still effective, (2) adapted conditioning regimen for adult patients, and (3) new sources of stem cells for broader application: umbilical cord blood and volunteer unrelated donors.