HLA-B and acute graft versus host disease: HLA-A*29, HLA-B*07, HLA-B*18, HLA-B*57, HLA-DRB1*07 and HLA-DRB1*13 were associated with the increase in incidence of grades II-IV acute GVHD; among which, A*29 and B*57 alleles caused a greater increase in the odds of acute GVHD incidence compared to other alleles (OR: 2.76; 75% CI: 1.35-5.66; P = 0.098).