Risk Factors for Acute Graft-Versus-Host Disease After Allogeneic Haematopoietic Stem Cell Transplantation: A Single-Center Experience. 
BACKGROUND Acute graft-versus-host disease (aGVHD) remains the most common and challenging complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT).  An important obstacle to the therapeutic effect of aGVHD is the inability to identify risk factors for an individual patient at the onset of symptoms.  We performed a retrospective study with the aim of defining clinically meaningful pre-transplantation risk factors for grades II-IV aGVHD patients.  MATERIAL AND METHODS To identify pre-transplantation risk factors for grades II-IV aGVHD after allo-HSCT, we performed a retrospective study in 292 patients who underwent allo-HSCT at our center from January 2010 to July 2015.  RESULTS The cumulative incidence of grades II-IV aGVHD was 36.6±2.8%.  The most common target organ of aGVHD was the skin (46.7%), followed by the gastrointestinal tract (29.9%).  The risk factors we identified included HLA-mismatched related donors (odds ratio [OR], 3.21; 95% confidence interval [CI], 1.82-5.67) and conditioning regimens containing TBI but no ATG (OR, 2.66; 95% CI, 1.40-5.06).  Simultaneously, transplantation with an identical sibling donor (OR, 0.31; 95% CI, 0.18-0.55) and the use of ATG in the conditioning regimen containing TBI (OR 0.37; 95% CI, 0.15-0.93) were two factors found to be associated with a decreased risk of grades II-IV aGVHD.  CONCLUSIONS Our study suggests that pre-transplantation characteristics of donor and recipient play an important role in identifying patients at high risk for grades II-IV aGVHD, which provide a direction for the prevention and treatment of aGVHD in the future.