Background
Recent studies show a survival advantage with kidney transplant amongst elderly patients compared to those on dialysis.
Study Design
In our present study we examined and compared the association of expanded donor criteria (ECD) kidney and living kidney donation with outcome of kidney transplant across different ages including elderly recipients.
Setting and Participants
Using the Scientific Registry of Transplant Recipients, we identified 145,470 adult kidney transplanted patients. Mortality and death-censored graft failure risks were estimated by Cox proportional regression analyses over a follow-up period with a median of 3.9 years.
Predictors
ECD kidney and living kidney donation and age compared to others.
Outcomes
Mortality and death-censored graft failure risk.
Results
Patients were 45±16 years old and included 40% women and 19% diabetics. Compared to transplanted patients 55-<65 years old, the fully adjusted death-censored graft failure risk was somewhat higher in patients ≥75 years old (HR, 1.30; 95% CI, 1.09–1.56), 35-<55 years (HR, 1.13; 95% CI, 1.08–1.17) and 18-<35 years (HR, 1.64; 95% CI, 1.57–1.71). Compared to non-ECD kidneys, ECD kidneys were significant predictors of mortality in non-elderly patients (18–<35 years: HR, 1.46 [95% CI, 1.19–1.77]; 35-<55 years: HR, 1.23 [95% CI, 1.14–1.32]; and 55-<65 years: HR, 1.26 [95% CI, 1.15–1.38]) and patients aged 65-<70 years (HR, 1.20; 9% CI, 1.05–1.36); but not in other groups of elderly patients (HRs of 1.12 [95% CI, 0.93–1.36] 70-<75 years and 1.04 [95% CI, 0.74–1.47] for ≥75 years). Similar results were found in risk of graft loss. Compared to deceased donor, living kidney was associated with better survival in all age groups and lower graft loss risk in patients aged <70 years.
Limitations
Unmeasured confounders cannot be adjusted for.
Conclusions
Among deceased donors, the ECD kidneys are not associated with either increased mortality or graft failure in recipients over 70 years. Among all types of donors, the persistent association between living donor kidneys and lower all-cause mortality across all ages suggests that, if possible, elderly patients gain longevity from living donor kidney transplant.