OBJECTIVETo analyze the impact of the time to hematopoietic reconstitution on the prognosis of hematological malignancies after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS173 patients with hematological malignancies treated with allo-HSCT (excluding umbilical cord blood transplantation) at Peking University first Hospital between 2003 and 2011 were analyzed retrospectively. According to the median time to neutrophil and platelet engraftment, the patients were divided into tow groups. The 5-year overall survival (OS), transplant-related mortality (TRM), relapse rate (RR) and prognostic factors were analyzed.

RESULTSThe quicker neutrophil engraftment group with an estimated 5-year OS rate of 66.63%, 5-year TRM of 21.58% and 5-year RR of 18.65%. The slower neutrophil engraftment group with OS of 61.84%, TRM of 24.14% and RR of 23.57%. Univariate analysis demonstrated that no relationship was found between time to neutrophil engraftment and OS, TRM and RR (P = 0.462, P = 0.893, P = 0.545, respectively). There seems to be a trend toward increasing incidence of OS in quicker platelet engraftment group(OS were 69.44% and 54.31%, respectively), but no significant difference (P = 0.065). TRM were 19.13% and 25.45%, respectively (P = 0.424), RR were 17.36% and 24.71%, respectively (P = 0.251). Multivariate analyses showed that the time to neutrophil engraftment was not a significant risk factor for prognosis, the time to platelet engraftment was an independent risk factor for OS and TRM, but not a significant risk factor for RR. Pre-transplantation disease status was the only independent prognostic factor for RR.

CONCLUSIONSThe time to platelet engraftment was a significant predictor after allo-HSCT. Early platelet engraftment increased OS, which this may be due to decreasing TRM.