Outcome and risk factors of kidney transplantation in the European Senior Program

BACKGROUND The organ shortage and long waiting times have dramatically increased the age of potential kidney transplant recipients. The Eurotransplant Senior Program (ESP) was initiated to allocate kidneys from deceased donors aged =65 years to recipients with a comparable age independent of pre-transplant human leucocyte antigen (HLA) matching; however, parameters affecting the long-term benefits of this strategy remain poorly defined. MATERIAL AND METHODS We retrospectively evaluated outcome and risk factors for mortality in kidney recipients aged =65 years that were transplanted according to the ESP protocol relative to patients aged >50 years transplanted according to the Eurotransplant kidney allocation system (ETKAS) criteria at the University Freiburg Medical Center, Germany, between 2008 and 2018. RESULTS Graft survival, graft function, the maintenance immunosuppressive therapy, and the incidence of rejections and infections did not differ between groups. Infectious diseases were the main cause of death in both groups; however, infection-associated mortality was more than double in the ESP group, and 5-year patient survival was 61.4% in the ESP group compared to 83.2% in the ETKAS group. Multivariate analysis identified age, the number of HLA mismatches, and the CMV serostatus with a seropositive donor and negative recipient as the main risk factors for mortality. CONCLUSIONS A comparable immunosuppressive regimen used in ESP and ETKAS patients was associated with similar rejection rates and infectious disease complications, and infections were the most common cause of death in both groups. CMV-negative patients receiving an organ from a CMV-positive donor and patients with a high number of HLA mismatches require close follow-up to reduce mortality.