Perspective on the role of haploidentical transplantation in the management of hematologic malignancies: why do it?

Haploidentical hematopoietic stem cell transplantation (HSCT) using mismatched family member donors has historically been complicated by high rates of nonrelapse toxicity and the need for laboratory expertise in depleting grafts of T lymphocytes. Over the past decade, improvements in supportive care, the increased use of peripheral-blood stem cell grafts, and improved T-cell depletion techniques have reduced the incidence of graft failure and lowered the rate of nonrelapse mortality. In addition, clinical studies have demonstrated that the donor-recipient mismatch may be beneficial in this setting, stimulating an immunologic cell-mediated antileukemia effect that results in lower disease recurrence rates. All of these advances have led to improvements in outcomes following haploidentical HSCT, making it an attractive option available to some patients. Because most patients do not have a matched related donor available and time to identify an unrelated donor may be excessive, haploidentical HSCT is a potentially curative option for these patients.