Abstract:
Introduction: The growing shortage of donor kidneys has led to the increased utilization of older
deceased donors. Age-related structural changes in the renal parenchyma may reduce graft longevity,
raising clinical concerns regarding long-term outcomes. This study evaluated the association between
donor age and graft survival using large-scale registry data to refine organ allocation strategies.
Material and Methods: Data were obtained from the United Network for Organ Sharing (UNOS) and
Eurotransplant registries for adult deceased-donor kidney transplants performed between 2011 and
2016. This range ensured a minimum 10-year follow-up for all subjects by late 2025. Recipients were
stratified by donor age: <40, 40–59, and ≥60 years. The primary outcome was ten-year death-censored
graft survival (DCGS). Multivariable Cox proportional hazards models, adjusted for Kidney Donor
Profile Index (KDPI), cold ischemia time (CIT), and recipient comorbidities, were used to calculate
adjusted hazard ratios (aHR).
Results: Increased donor age was significantly associated with progressively lower graft survival. Tenyear DCGS rates were 72% for donors <40, 61% for 40–59, and 42% for those ≥60 years. Donors in
the ≥60 age group exhibited a significantly higher risk of graft loss (aHR 2.04; 95% CI, 1.81–2.29; p
< 0.01). While older grafts were associated with higher rates of delayed graft function (DGF), modern
“old-for-old” allocation and the increased use of machine perfusion during the 2011–2025 period
partially mitigated early failure rates in the elderly cohort.
Conclusions: Donor age is a critical determinant of long-term kidney graft survival. While older
donors remain essential for expanding the donor pool, the significant decline in ten-year survival
highlights the need for optimized preservation techniques, such as machine perfusion. These findings
support the continued refinement of age-matching strategies to maximize the utility of available
organs. Future research should focus on the molecular markers of renal aging to better predict the
longevity of “expanded criteria” organs.
