HLA-DP mismatch and CMV reactivation increase risk of aGVHD independently in recipients of allogeneic stem cell transplant

HLA-DP mismatched allogeneic hematopoietic stem cell transplantation (allo-HCT) is associated with increased risk of aGVHD and decreased risk of relapse with no effects on overall survival (OS). It has been proposed that CMV-reactivation induces expression of HLA-DP molecules on GVHD target tissues by releasing inflammatory cytokines. We hypothesized that the increased GVHD incidence in HLA-DP mismatched allo-SCTs correlates with recipient CMV serostatus or CMV reactivation. In addition, CMV reactivation is associated with increased risk of GVHD with an unknown mechanism. Here, we analyzed the association between HLA-DPB1 and CMV reactivation on cumulative incidence of aGVHD and relapse as well as OS in 613 patients with AML and MDS who underwent matched related or unrelated allo-HCT at MD Anderson Cancer Center from 2005 to 2011. In multivariable analysis, HLA-DPB1 mismatching was associated with increased risk of aGVHD (hazard ratio (HR): 1.53, P