Barriers to bone marrow transplantation for sickle cell anemia.
While allogeneic marrow transplantation is curative therapy for patients with sickle cell anemia, only a small fraction of patients in the United States receive this treatment. We surveyed participants in our multicenter study of marrow transplantation for sickle cell anemia to determine reasons for not proceeding to transplantation. Among the 4848 patients less than 16 years of age with sickle cell anemia that were followed in 22 collaborating centers, 315 (6.5%) patients were reported to meet protocol entry criteria for transplantation, although there was wide variation among the institutions (0.9-36%). Among the 315 patients eligible for transplantation, 128 (41%) had human leukocyte antigen (HLA) typing performed, and of these 44 (14% of those meeting entry criteria) had an HLA-identical sibling. Common reasons for not proceeding with HLA typing in the remaining 187 patients included lack of a candidate sibling donor (76 patients, 24% of those meeting criteria) and lack of financial or psychosocial support (33, 10.5%). Parental refusal (30, 9.5%), physician refusal (13, 4%), history of medical noncompliance (2, < 1%), and other reasons (33, 10.5%) were less frequently cited. To date, 25 patients have been transplanted. Of the remaining 19 patients with HLA-matched donors, seven did not proceed to transplantation because of parental refusal, while the others anticipate a future transplantation (6), have experienced symptomatic improvement (4), or have relocated abroad (2). We conclude that the major barrier to marrow transplantation for sickle cell anemia is lack of an HLA-identical donor. But since only 6.5% of all children with sickle cell disease were considered eligible for transplantation, it is possible that other significant obstacles remain to be identified. For patients reported to meet eligibility criteria, parental refusal and limited financial or psychosocial support were infrequent barriers to transplantation.