Donor lymphocyte infusions after HCT are associated with low risk of graft-versus-host disease in pediatric and young adult patients.

Abstract

Donor lymphocyte infusion (DLI) enhances the graft-versus-leukemia effect and can prevent graft rejection after an allogeneic hematopoietic cell transplant (HCT), but its use is limited by the risk of graft-versus-host disease (GVHD). From 2005 to 2021, 179 patients received 191 HCTs, followed by ≥1 DLIs (n = 626), and 561 patients received 608 HCTs without subsequent DLI. Among DLI recipients, 31.4% and 12.6% developed acute GVHD (aGVHD) and chronic GVHD (cGVHD), respectively, compared with 39% and 18.1%, respectively, of HCT recipients who did not receive DLI (P = .06 for aGVHD, P = .08 for cGVHD). A longer interval between HCT and DLI was associated with a decreased risk of aGVHD. The overall response to DLI for mixed chimerism was 45.2% for HCTs using matched sibling donors, 33.3% for HCTs using matched unrelated donors, and 43.1% for haploidentical HCTs. In our study, the incidence of GVHD among pediatric HCT recipients was similar regardless of whether they received DLI after HCT or not. The risk of GVHD decreased as the interval between HCT and DLI increased, and there was an encouraging response rate for patients receiving DLI for mixed chimerism. Hence, DLI offers a potential therapeutic option for patients with impending graft rejection.