Among patients with 10/10 HLA matching, nonpermissive HLA-DPB1 mismatches were associated with a significantly increased risk of acute GVHD (III-IV) (P < .001), and had a trend of slight increasing risk of acute GVHD (II-IV) (P = .101). Here, HLA-DPB1 is linked to acute graft versus host disease.