Prevention of relapse using granulocyte CSF-primed PBPCs following HLA-mismatched/haploidentical, T-cell-replete hematopoietic SCT in patients with advanced-stage acute leukemia: a retrospective risk-factor analysis

The role of donor lymphocyte infusion (DLI) in the prophylaxis of relapse has not been defined. We retrospectively analyzed the data from 88 patients with advanced-stage acute leukemia after HLA-mismatched/haploidentical hematopoietic SCT (HSCT) whose treatment did (n=61) or did not (n=27) include granulocyte CSF (GCSF)-primed PBPCs infusion (GPBPCI). The two groups were compared with respect to relapse and OS. Further, a detailed analysis of risk factors was performed. The 2-year cumulative incidence of relapse in patients receiving prophylactic GPBPCI and not receiving prophylactic GPBPCI were 36% and 55% (P=0.017), respectively. Estimated survival at 3 years was 31% for patients receiving prophylactic GPBPCI and 11% for patients not receiving prophylactic GPBPCI (P=0.001). The three-year probability of leukemia-free survival was also higher in patients who received prophylactic GPBPCI (22%) compared with patients who did not (11%) (P=0.003). Multivariate analysis for relapse showed that use of prophylactic GPBPCI after transplantation was an independent prognostic factor (P=0.025). Higher OS was associated with use of prophylactic GPBPCI (P=0.002), AML (P=0.027) and female sex (P=0.023). Our results suggest that use of prophylactic GPBPCI may increase survival of patients with advanced-stage acute leukemia who receive HLA-mismatched/haploidentical HSCT.