Impact of donor age on allo-HSCT outcomes: A CIBMTR registry study

Results from a retrospective Center for International Blood and Marrow Transplant Research (CIBMTR) registry study of 7,116 patients, evaluating the impact of donor age on allogeneic hematopoietic stem cell transplantation (allo-HSCT) outcomes in patients receiving haploidentical or human leukocyte antigen (HLA)-mismatched unrelated donor (MMUD) allo-HSCT with post-transplantation cyclophosphamide (PTCy)-based graft-versus-host disease (GvHD) prophylaxis, were published in Transplantation and Cellular Therapy by Mehta et al.

Key data: Older MMUDs (≥30 years) exhibited inferior GvHD-free relapse-free survival (GRFS) compared with younger haploidentical donors (<30 years; hazard ratio [HR], 1.20; 95% confidence interval [CI], 1.06–1.36; p = 0.003), with higher risk of treatment-related mortality and Grade 3–4 acute GvHD. Younger MMUDs showed modest GRFS improvement over older haploidentical donors (HR, 0.87; 95% CI, 0.78–0.98; p = 0.02), with reduced acute and chronic GvHD risks.

Key learning: Younger donors, regardless of donor type, are associated with superior allo-HSCT outcomes compared with older donors. Therefore, where feasible, the use of younger donors aged <30 years should be prioritized when choosing between haploidentical donors and MMUDs.