Age and the associations of living donor and expanded criteria donor kidneys with kidney transplant outcomes.
BACKGROUND
Recent studies show a survival advantage with kidney transplant in elderly patients compared with those on dialysis therapy.


METHODS
In our present study, we examined and compared the association of expanded criteria donor (ECD) kidney and living kidney donation with the outcome of kidney transplant across different ages, including elderly recipients.


METHODS
Using the Scientific Registry of Transplant Recipients, we identified 145,470 adult kidney transplant patients. Mortality and death-censored transplant failure risks were estimated by Cox proportional regression analyses during follow-up with a median of 3.9 years.


METHODS
ECD kidney and living kidney donation and age compared with others.


RESULTS
Mortality and death-censored transplant failure risk.


RESULTS
Patients were aged 45 ± 16 years and included 40% women and 19% patients with diabetes. Compared with transplant recipients 55 to younger than 65 years, the fully adjusted death-censored transplant failure risk was higher in patients 75 years and older (HR, 1.30; 95% CI, 1.09-1.56), 35 to younger than 55 years (HR, 1.13; 95% CI, 1.08-1.17), and 18 to younger than 35 years (HR, 1.64; 95% CI, 1.57-1.71). Compared with non-ECD kidneys, ECD kidneys were significant predictors of mortality in nonelderly 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 65 to younger than 70 years (HR, 1.20; 95% CI, 1.05-1.36), but not in other groups of elderly patients (HRs of 1.12 [95% CI, 0.93-1.36] for 70-<75 years and 1.04 [95% CI, 0.74-1.47] for ≥75 years). Similar results were found for risk of transplant loss. Compared with deceased donor kidneys, a living donor kidney was associated with better survival in all age groups and lower transplant loss risk in patients younger than 70 years.


CONCLUSIONS
Unmeasured confounders cannot be adjusted for.


CONCLUSIONS
For deceased donors, ECD kidneys are not associated with increased mortality or transplant failure in recipients older than 70 years. For 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.
Harold Simmons Center for Chronic Disease Research & Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA 90509-2910, USA.
Miklos Z
MZ
Molnar
Elani
E
Streja
Csaba P
CP
Kovesdy
Anuja
A
Shah
Edmund
E
Huang
Suphamai
S
Bunnapradist
Mahesh
M
Krishnan
Joel D
JD
Kopple
Kamyar
K
Kalantar-Zadeh
D000328:Adult; D000367:Age Factors; D000368:Aged; D002140:California; D002423:Cause of Death; D015331:Cohort Studies; D016208:Databases, Factual; D046148:Donor Selection; D005260:Female; D015577:Geriatric Assessment; D006084:Graft Rejection; D006085:Graft Survival; D006801:Humans; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D016030:Kidney Transplantation / Q000379:methods / Q000401:mortality*; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D016896:Treatment Outcome