HLA-DQB1 mismatch increase risk of severe bleeding independently in recipients of allogeneic stem cell transplant.

Severe bleeding is a major cause of death in acute leukemia (AL) patients with graft-versus-host disease (GVHD) after allogene hematopoietic stem-cell transplantation (allo-HSCT). However, the prognostic value and prediction of HSCT-associated severe bleeding in GVHD patients have not been reported in cohort studies. We did a retrospective analysis of 200 AL patients with GVHD after allo-HSCT from Feb 1, 2014, to Dec 1, 2015. Multivariate analysis showed that the severe bleeding class was associated with the risk of death (HR 2.26, 95% CI 1.31-3.92, p<0.001***). In order to predict severe bleeding and figure out the solution to bleeding events, we established a multiple logistic regression model. HLA-DQB1 unmatching, megakaryocyte reconsititution failure, and III or IV GVHD were the independent risk factors for severe bleeding. Among all the variations above, OR of HLA-DQB1 was the highest (OR: 16.02, 95% CI: 11.54-48.68). Adding HLA-DQB1 to other factors improved the reclassification for predicting severe bleeding (NRI=0.195, z=2.634, p=0.008**; IDI=0.289, z=3.249, p<0.001***). Lasso regression was used to select variants. A nomogram of the logistic model was generated and displayed. Calibration curve demonstrated excellent accuracy in estimating severe bleeding (C index of 0.935). HLA-DQB1 showed excellent efficacy of predicting severe bleeding in HSCT patients.