Glossary Term

Antigen Mismatch

An antigen mismatch occurs when an identified deceased or living donor antigen is not recognized as equivalent to the recipient’s own antigens. In cases where a donor or candidate only has one antigen identified at a human leukocyte antigen (HLA) locus (A, B, or DR), the antigens are considered to be identical at that locus.
(OPTN Policy Definitions May 2021)