Should HLA Mismatch Acceptability for Sensitized Transplant Candidates Be Determined at the High‐Resolution Rather Than the Antigen Level?

Division of Transplant Pathology, Thomas E. StarzlTransplantation Institute, University of Pittsburgh MedicalCenter, Pittsburgh, PACorresponding author: Rene J. Duquesnoy,Duquesnoyr@upmc.eduDefining HLA mismatch acceptability of organ trans-plant donors for sensitized recipients has traditionallybeenbasedonserologicallydefinedHLAantigens.Now,however, it is well accepted that HLA antibodiesspecifically recognize a wide range of epitopes presenton HLA antigens and that molecularly defined highresolution alleles corresponding to the same lowresolution antigen can possess different epitope reper-toires.Hence,determinationofHLAcompatibilityattheallele level represents a more accurate approach toidentify suitable donors for sensitized patients. Thisapproach would offer opportunities for increasedtransplantratesandimprovedlongtermgraftsurvivals.Abbreviations: cPRA, calculated panel reactive anti-body; NMDP, National Marrow Donor Program; SAB,single allele bead; UNOS, United Network for OrganSharingReceived 28 July 2014, revised 19 October 2014 andaccepted for publication 11 November 2014