Impact of HLA Evolutionary Divergence and HLA Donor-recipient Molecular Mismatches on Kidney Allograft Rejection

The Human Leucocyte Antigen (HLA) system is pivotal in kidney transplant rejection. In-silico methods such as HLA eplet mismatches and PIRCHE-II scores have emerged to refine HLA immunogenicity assessment and stratify patients for immunological risk. However, large-scale studies in unselected large kidney transplant cohorts are lacking to support their broader clinical applicability. Additionally, recent studies on HLA evolutionary divergence (HED), quantifying HLA polymorphism, highlight its potential impact on rejection. Yet, the association of HED with kidney allograft rejection or de novo DSA occurrence remains unexplored in kidney transplantation. The complexity introduced by diverse in-silico methods for assessing HLA immunogenicity necessitates further research to comprehensively understand their role in relation to kidney allograft rejection. This project thus aims to investigate the association between various aspects of HLA immunogenicity, including HLA molecular mismatches and HLA evolutionary divergence, along with standard immunological and clinical parameters assessed at the time of transplantation, with the occurrence of antibody-mediated rejection and de novo DSA formation post-transplant in a large, comprehensively annotated kidney transplant cohort.