Donor Lymphocyte Infusions After Allogeneic Transplantation: A Single-Center Experience

Allogeneic hematopoietic cell transplantation (AHCT) represents the only curative therapy for many hematological malignancies. The graft versus leukemia effect, driven by donor T cells, plays a major role in its curative potential. This effect is sometimes very evident when patients with acute myeloid leukemia and myelodysplasia relapse after AHCT and are treated with donor lymphocyte infusions (DLIs). We retrospectively reviewed the charts of 64 patients who received DLI between 2012 and 2017 in our center. The mean age of the patients was 59 years (range, 34-79). Fifty percent were male (n = 32). The mean follow-up time after AHCT was 50.17 months (range, 8-174). The indication for DLI were disease progression, mixed chimerism, minimal residual disease, and other etiologies in 43.8%, 40.7%, 14%, and 1.5% of patients, respectively. The most common diagnosis was acute leukemia, followed by multiple myeloma. Of all patients, 59.4% received a transplant from a related donor, 39% received a transplant from an unrelated donor, and 1.6% received a transplant from a haploidentical donor. Reduced-intensity conditioning AHCT was the most frequent regimen used (53%). DLI was given alone in 79.7% of patients. Prophylactic DLI was given at 30 days after transplantation in patients who received human leukocyte antigen (HLA)-matched related human stem cell transplantation (HSCT) or 45 to 60 days post-transplant in patients receiving haploidentical HSCT or HLA-matched unrelated HSCT. Patients were treated without graft versus host disease (GVHD) prophylaxis. The use of DLI after transplantation remains a feasible procedure with rates of response >60%. Moreover, DLIs are well tolerated with a GVHD rate <10% in our series. We can hypothesize that in our experience the efficacy of this strategy does not rely on the induction of GVHD.