Abstract
INTRODUCTION: Highly sensitized kidney transplant candidates have reduced access to deceased-donor kidney transplantation (DDKT) and worse waitlist outcomes. In France, allocation relies on sensitization-based prioritization through the acceptable-antigen pathway driven by the Taux de Greffons Incompatibles (TGI)' however, the sensitization threshold at which this system fails to preserve equity remains unclear. METHODS: We conducted a retrospective multicenter cohort study including 14,485 adult kidney transplant candidates listed between 2011 and 2021. Sensitization was measured using TGI (0-100) and reported using calculated panel reactive antibody (cPRA)-labeled strata for international readability. Access to DDKT was the primary outcome, with living-donor transplantation, death, and delisting treated as competing events. The secondary outcome was waitlist attrition (death or delisting). Fine-Gray models adjusted for key demographic, clinical, and immunologic variables were truncated at 10 years. RESULTS: Access to DDKT declined progressively with increasing sensitization and fell sharply from cPRA ≥ 96%. Compared with cPRA 0%, the adjusted subdistribution hazard ratio (SHR) for DDKT was 0.781 at 96%, 0.658 at 97%, 0.701 at 98%, 0.353 at 99%, and 0.082 at 100%. Conversely, the risk of waitlist attrition increased from cPRA ≥ 97% (sHR: 1.793), reaching 2.713 at 100%. Candidates with cPRA of 85% to 95% retained preserved access, consistent with the intended effect of the acceptable-antigen pathway. CONCLUSION: In the French TGI-based allocation system, cPRA ≥ 96% marks a threshold of impaired access to DDKT, whereas cPRA ≥ 97% identifies excess waitlist attrition. These findings define an ultrasensitized subgroup insufficiently served by current prioritization and support refined allocation strategies within the 96% to 100% range.