Chemotherapy plus DLI for relapse after haploidentical HSCT: the biological characteristics of relapse influences clinical outcomes of acute leukemia patients.

This study investigated the prognostic factors in patients (n = 89) who experienced relapse and received chemotherapy plus donor leukocyte infusion (Chemo-DLI) after haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Patients with early relapse (< 6 vs. > 6 months after haplo-HSCT), higher bone marrow blast count before chemo-DLI (> 20% vs. 5-19%), and without chronic graft-versus-host disease (cGVHD) after chemo-DLI had a higher rate of progressive disease (PD) and worse progression-free survival (PFS) and overall survival (OS). In multivariate analysis, non-cGVHD after Chemo-DLI and high blast count predicted a higher risk of PD and poorer PFS, and non-cGVHD after Chemo-DLI and early relapse predicted poorer OS. The patients were stratified into three groups according to these three risk factors. Patients with all three risk factors (n = 14) had the highest PD rate and poorest survival compared with those with one or two risk factors (n = 63) or no risk factors (n = 12). Thus, early relapse, high leukemia burden before Chemo-DLI, and non-cGVHD after Chemo-DLI can predict outcomes in patients who have experienced relapse and received Chemo-DLI after haplo-HSCT. New therapeutic strategies should be identified for these patients.