Platelet transfusion refractoriness after T-cell-replete haploidentical transplantation is associated with inferior clinical outcomes.

Haploidentical stem cell transplantation (haplo-SCT) has been an alternative source of bone marrow for patients without human leukocyte antigen (HLA)-matched donors. The aim of this study was to investigate the relationships between platelet transfusion refractoriness (PTR) and clinical outcomes in the setting of haplo-SCT. Between May 2012 and March 2014, 345 patients who underwent unmanipulated haplo-SCT were retrospectively enrolled. PTR occurred in 20.6% of all patients. Patients in the PTR group experienced higher transplant-related mortality (TRM, 43.7% vs. 13.5%, P<0.001), lower overall survival (OS, 47.9% vs. 76.3%, P<0.001) and lower leukemia-free survival (LFS, 47.9% vs. 72.3%, P<0.001) compared to patients in the non-PTR group. The multivariate analysis showed that PTR was associated with TRM (P=0.002), LFS (P<0.001), and OS (P<0.001). The cumulative incidences of PTR in patients receiving >12 platelet (PLT) transfusions (third quartile of PLT transfusions) were higher than in patients receiving either >6 (second quartile) or >3 (first quartile) PLT transfusions (56.1% vs. 41.6% vs. 28.2%, respectively; P<0.001). The multivariate analysis also showed that PTR was associated with the number of PLT transfusions (P<0.001). PTR could predict poor transplant outcomes in patients who underwent haploidentical SCT.