We retrospectively compared the antileukemic effects of
chemotherapy alone and
chemotherapy followed by modified donor lymphocyte infusion (DLI) in 82 patients with relapsed acute
leukemia after haploidentical
hematopoietic stem cell transplantation (HSCT) without in vitro T-cell depletion. We also investigated prognostic factors in patients receiving
chemotherapy followed by modified DLI. Thirty-two patients received
chemotherapy alone, and the remaining 50 patients received
chemotherapy followed by modified DLI. In patients receiving
chemotherapy followed by modified DLI, complete remission rate was significantly higher (64.0% vs. 12.5%, P = 0.000), the incidence of relapse was significantly lower (50.0% vs. 100.0%, P = 0.000), and disease-free survival was significantly improved (36.0% vs. 0.0%, P = 0.000) compared with patients receiving
chemotherapy alone. Multivariate analysis demonstrated that patients with
chronic graft-versus-host disease (GVHD) after intervention (P = 0.000) and patients receiving
chemotherapy followed by modified DLI (P = 0.037) were associated with a lower relapse rate. Furthermore, in patients receiving
chemotherapy followed by modified DLI, multivariate analysis demonstrated that chronic GVHD after modified DLI (P = 0.039) and duration of
minimal residual disease (MRD) (-) ≥4 months after modified DLI (P = 0.001) were associated with a lower relapse rate. Our study is the first to suggest that
chemotherapy followed by modified DLI is associated with stronger antileukemic effects and better survival in relapsed acute
leukemia after haploidentical HSCT without in vitro T-cell depletion. Furthermore, our study suggests that lack of chronic GVHD and duration of MRD (-) <4 months after modified DLI are associated with higher relapse rates in patients receiving
chemotherapy followed by modified DLI.