Pre-transplant sensitization and its effect on heart transplant rejection and survival outcomes

Sensitization of heart transplant (HT) recipients increases the risk of rejection. Assessment of sensitization using a calculated panel reactive antibody (cPRA) is crucial for evaluating transplant compatibility and predicting outcomes. This study investigated the impact of cPRA and pre-existing and de novo Human Leukocyte Antigen (HLA)-donor-specific antibodies (DSAs) on HT outcomes and aimed to identify recipients at a high risk of rejection.

This retrospective study included 121 adult recipients of HT from a single institution (2014-2023). cPRA values, flow cytometric crossmatches (FCXM), and DSAs were analyzed for their associations with antibody-mediated rejection (AMR) and T cell-mediated rejection (TCMR).

Among the 121 HT recipients, 51.2 % experienced TCMR and 7.4 % experienced AMR. cPRA (I) ≥ 50 % was significantly associated with AMR, pre-existing DSA (pDSA), and positive FCXM. pDSA was present in 16.5 % of HT recipients and correlated with AMR but not mortality. De novo DSAs frequently emerged in 38 % of the recipients following TCMR episodes. Higher cPRA (I) levels correlated with increased rejection risk and shorter AMR-free survival.

High cPRA (≥50 %) significantly predicted the risk of AMR and correlated with pDSA and positive FCXM results. Pre-transplant cPRA assessment is crucial for identifying high-risk recipients and optimizing management strategies to improve HT outcomes.