When there is no match, the game is not over: Alternative donor options for hematopoietic stem cell transplantation in sickle cell disease

Many patients with sickle cell disease experience severe morbidity and early mortality. The only curative option remains hematopoietic stem cell transplantation. Although HLA-matched sibling transplantation has been very successful for adults and children, the vast majority of patients with sickle cell disease do not have an HLA-matched sibling. Alternative donor options include haploidentical, unrelated umbilical cord blood, and matched unrelated donor transplantation. This report summarizes major alternative donor transplantation studies reported to date and ongoing and upcoming clinical trials. We conclude that when there is no HLA-match, all these approaches should be systematically considered before ruling out the option of hematopoietic stem cell transplantation.