label: Bidirectional HLA Mismatch
label_lc: bidirectional hla mismatch
description: "The state when a recipient of a hematopoietic stem cell transplantation is not fully matched with their unrelated adult volunteer donor for HLA-A, HLA-B, HLA-C, and HLA-DRB1 and both are heterozygous for different alleles at one locus."