The great debate: haploidentical or cord blood transplant

One of the truly revolutionary advances in hematopoietic cell transplantation (HCT) is the increasingly successful use of alternative donors, thereby allowing the delivery of a potentially curative transplant to ∼75% of patients who do not have an HLA-matched sibling donor. A substantial proportion of the need has been met by HLA-matched volunteer unrelated donors, but an unmet need still exists, particularly among minority populations and for people who need a more immediate source of hematopoietic cells. Two such sources, umbilical cord blood (UCB) and haploidentical related donors, have filled most of this need, and outcomes following transplants from these donor sources are very promising. UCB has the advantages of ready availability and is less capable of causing GVHD but hematological recovery and immune reconstitution are slow. Haploidentical HCT is characterized by the nearly uniform and immediate availability of a donor and the availability of the donor for post transplant cellular immunotherapy, but is complicated by a high risk of GVHD and poor immune reconstitution when GVHD is prevented by vigorous ex vivo or in vivo T-cell depletion. This review will discuss the pertinent issues that affect the choice of one donor source over another and offer recommendations regarding the optimal utilization of these donor sources.