The Human Leukocyte Antigen-DPB1 Degree of Compatibility Is Determined by Its Expression Level and Mismatch Permissiveness: A German Multicenter Analysis

T-cell epitope matching according to the TCE3 algorithm classifies HLA-DPB1 mismatches in permissive and non-permissive. This classification has been shown be predictive for mortality acute GvHD (aGvHD) events large international cohorts. We retrospectively genotyped 3523 patients transplanted Germany between 2000 2014 their unrelated donors using an Illumina amplicon-NGS based assay. Aim of study was evaluate DP-compatibility beyond established by assessing combined effect several DP-mismatch parameters on post-transplant outcome. implemented extended assessment model where TCE3, DP allotype expression with respect rs9277534, mismatch vector number were conjointly taken into consideration. In this model, non-permissive showed significantly increased aGvHD risk if they accompanied two GvH direction (HR: 1.46) or one mismatched highly expressed patient 1.53). As previously reported, associated a higher non-relapse (HR 1.36 1.21, respectively), which turn translated worse relapse free survival 1.13). Effects GvL appeared strongest GvH-directed mismatches. Our results support consideration additional along refinement future donor selection. particular, our findings suggest that non-permissiveness at least should avoided.