Donor lymphocyte infusions in AML and MDS: Enhancing the graft-versus-leukemia effect

•Donor lymphocyte infusion (DLI) provides a way to enhance the graft-versus-leukemia effect.•GvHD represents the main toxicity after DLI.•Pre-DLI low disease burden and late DLI are associated with favorable outcomes.•Preemptive DLI and overcoming T-cell exhaustion are promising strategies.•DLI for extramedullary relapse needs further study.

Allogeneic hematopoietic cell transplantation (allo-HCT) represents the only curative therapy for many haematological malignancies. Its curative potential is mostly attributed to the graft-versus-leukemia effect (GvL), which is mainly driven by donor T-cells. Donor lymphocyte infusions (DLI), likewise a second allo-HCT, have become a standard approach to treat AML and MDS relapses post allo-HCT. Although DLI have been used in this setting for decades, its effectivity and toxicity are still unpredictable in many patients. Over these recent years, new DLI strategies and therapies have been developed for AML and MDS. In this review, we will overview the recent use of DLI for AML and MDS, with up to date information from novel studies and research lines.