Comparable post-relapse outcomes between haploidentical and matched related donor allogeneic stem cell transplantation

We investigated the impact of donor type on post-relapse survival (PRS) in 85 patients with hematological relapse after their first allogeneic hematological stem cell transplantation (allo-HSCT) for hematological malignancy. The median follow-up was 64 months among survivors. Both 3-year overall survival and 3-year PRS were similar in haploidentical donor (HID) and matched sibling donor (MRD) transplantation (13.0%±4.7% vs 19.4%±7.1%, P =0.913 and 7.7±3.9% vs 9.7±5.3%, P = 0.667). Higher rates of post-relapse grade II–IV and III–IV acute GvHD (aGvHD) were observed in HID transplantation patients. A higher cumulative incidence of post-relapse extensive chronic GvHD was also observed for HID transplantation patients. Multivariate analyses confirmed that treatment including donor lymphocyte infusion (DLI), late relapse >1 year, and in first CR at transplantation were associated with superior PRS ( P =0.012, hazard ratio (HR)=0.527 (0.320−0.866)); P =0.033, HR=0.534 (0.300−0.952) and P =0.046, HR=0.630 (0.400−0.992). The data suggest that post-relapse outcomes are comparable in HID and MRD transplantation, and that DLI is safe for relapsed patients after haploidentical transplantation.