Further evidence on HLA-DR matching in determining heart transplantation outcomes.

We read the recent retrospective study of Osorio-Jaramillo et al.1 conducted on 1,167 cardiac transplant recipients between 1984 and 2016 among which typing at serological split antigen level was available in 312 recipients. The authors reported that patients with a higher HLA-DR amino acid mismatch-load (AAMM) had inferior 1-year graft survival (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.01-1.28)1 . No impact on the development of cardiac allograft vasculopathy (CAV) was found and they concluded that molecular-level HLA mismatch analysis could be used as a tool for risk stratification after heart transplantation1 .