In 2022, which is preferred: haploidentical or cord transplant?

Abstract

Allogeneic hematopoietic stem cell transplantation is the treatment of choice for high-risk hematological malignancies such as acute myeloid and lymphocytic leukemia, myelodysplastic syndrome, and myeloproliferative disorders. Alternative donor transplantation from either haploidentical (haplo-SCT) or cord blood donor (CBT) is an established therapeutic alternative for patients who need transplants but lack a human leukocyte antigen–matched donor. Although haplo-SCT (mainly non–T-cell-depleted haplo-SCT with posttransplant cyclophosphamide) is increasing while CBT is decreasing worldwide (Figure 1), recent developments in CBT, especially cord blood expansion and other strategies to improve engraftment and immune reconstitution post-CBT, make CBT still a valuable option. This article discusses the 2 options based on the currently available data, focusing on adults, and tries to give some clues to help the transplant physician choose a haploidentical vs a cord blood donor. Given the limited numbers of published or ongoing well-designed randomized controlled trials comparing haplo-SCT to CBT and the overall similar clinical results in the available, mostly registry-based, and single-center studies, with substantial heterogeneity and variability, the decision to perform haplo-SCT or CBT in a given patient depends not only on the patient, disease, and donor characteristics and donor availability (although most if not all patients should have in principle an alternative donor) but also on the transplant physician's discretion and, most importantly, the center's experience and preference and ongoing protocols and strategies.

Single‐unit unrelated cord blood transplantation versus HLA‐matched sibling transplantation in adults with advanced myelodysplastic syndrome: A registry‐based study from the adult MDS working group of the Japanese society for transplantation and cellular therapy

“…Moreover, GVHD has a varied effect on outcomes following adult single‐unit CBT in European and Japanese populations 48 . In the United States and Europe, the number of transplants from haploidentical‐related donors is growing while CBT is dropping 49 . Based on these situations, our findings may be less directly relevant to cohorts of different races.…”

“…48 In the United States and Europe, the number of transplants from haploidentical-related donors is growing while CBT is dropping. 49 Based on these situations, our findings may be less directly relevant to cohorts of different races. Despite such limitations, the strength of our study was the relatively larger patient population and the focus on advanced MDS in comparing the efficacy and safety of MSD HCT and single CBT.…”

Conditioning

“…Historically, these types of allo-HCT were the most challenging ones with a relatively high incidence of non-engraftment and high TRM, on one hand, and increased GVHD rate, on the other. Recent development in the field of transplantation, including novel conditioning regimens and better supportive care, has resulted in major improvement in the results of HCT from alternative donors and marked increase, in particular with the haplo-HCT (Nagler and Mohty 2022).…”

Fifty years of BMT: risk stratification, donor matching, and stem cell collection for transplantation

“…In terms of transplant, a higher infectious risk is due to slow immune reconstitution, count recovery, and graft failure. The number of UCB transplants has recently declined owing to the increased use of HHD ( 61 ). Our approach to donor selection is illustrated in Figure 4 .…”