Efficacy and safety of prophylactic modified donor lymphocyte infusion following allogeneic hematopoietic stem cell transplantation for high-risk acute leukemia

Objective To evaluate the efficacy and safety of prophylactic modified donor lymphocyte infusion (DLI) early after allogeneic hematopoietic stem cell transplantation (allo-HSCT) to prevent the relapse of patients with high-risk acute leukemia. Methods We retrospectively analyzed the clinical data of 62 patients with high-risk acute leukemia, who underwent allo-HSCT and received prophylactic modified DLI in our center between January 1, 2013 and June 30, 2017. All the patients received infusion of recombinant human colony-stimulating factor-primed peripheral blood progenitor cells and short-term immunosuppressant therapy with low-dose closporine A in complete remission (CR) to prevent graft versus host disease (GVHD). Results At a median time of 105.5 (59~355) days after the transplantation, the 62 patients received prophylactic modified DLI of a median of 3.95 (0.4~7.6)×107/kg CD3+ cells. The patients were followed up for 3.4~64.7 months (median 33.2 months), during which 41 patients were alive with CR, 17 had relapses, and 21 died. The 3-year probability of overall survival (OS) and leukemia-free survival (LFS) was 69.6% and 63.6% and the 3-year cumulative incidences of relapse and non-relapse mortality (NRM) were 29.7% and 6.7% in these patients, respectively. The incidences of grades Ⅱ~Ⅳ and Ⅲ~Ⅳ acute GVHD at 100 d after DLI were 22.6% and 11.3%, respectively, and the 3-year cumulative incidence of moderate and severe chronic GVHD was 32.9%; the 3-year cumulative GVHD-free and relapse-free survival (GRFS) was 31.7% in these patients. Conclusion In patients with high-risk acute leukemia, prophylactic modified DLI early after allo-HSCT is effective for preventing relapse without increasing the incidences of GVHD morbidity or NRM.