MO954: Older Living Donors—is it A Feasible Alternative For Kidney Transplantation?
Authors: Figueiredo Cátia , Sousa Círia , Ventura Sofia , Cruz Gonçalo , Silvano José , Malheiro Jorge , Pedroso Sofia , Almeida Manuela , Salete Martins La , Cabrita António 
Published: May 2022

Abstract

BACKGROUND AND AIMS
Kidney transplantation (KT) improves survival and quality of life of patients with end-stage renal disease. However, there is still an unbalance between supply and demand for kidneys. To increase the number of available grafts and reduce the waiting list for transplantation, recruitment of older living donors has expanded. This approach remains controversial for several reasons, including the impact of kidney function decline on long-term graft and recipient survival. We aimed to evaluate the impact of living donor (LD) age on recipient graft survival and on graft function decline over time.

METHOD
This is a Unicenter retrospective observational study that included kidney transplants of LD between 2008 and 2017. Several clinical data were analyzed, including donors’ comorbidities, immunological features of the transplant, induction immunosuppression, number of acute rejections (AR) at the first year, and the graft glomerular filtration rate (eGFR) during the follow-up period. The eGFR was calculated using the CKD-EPI equation. The LDs were classified as young (&lt;60 years) and old (≥60 years) for analysis purposes.
The Kaplan–Meier curves and Cox proportional hazards multivariable regression were used for survival analysis and linear mixed regression was used to evaluate the annual slope of recipient eGFR, comparing both groups.

RESULTS
We observed 210 LD kidney transplants: 86% (n = 181) from young (D &lt; 60) and 14% (n = 29) from old donors (D ≥60). The average age was 41.3 ± 13.3 years for recipients and 48.0 ± 10.6 years for donors. The pre-donation eGFR was significantly higher in D &lt; 60 than D ≥60 (101.7 ± 14.0 versus 90.2 ± 11.0 mL/min/1.73 m2; P &lt; 0.001). There was no significant difference in AR in the first year between both groups. (Table 1)
The censored recipient graft survival was similar for D &lt; 60 and D ≥60 (86% versus 84%, P = 0.144) (Figure 1) and the older donors’ age was not a predictor of censored graft failure [hazard ratio (HR): 2.689 (95% CI: 0.832–8.690; P = 0.098)]. Although not statistically significant, the overall recipient graft survival was lower in D ≥60 (67% versus 86%, P = 0.071) (Figure 1) and donors’ age ≥60 years was an independent predictor of global recipient graft failure (HR: 3.303, 95% CI: 1.102–9.899; P = 0.033).
Linear mixed regression showed that recipient eGFR from D ≥60 was lower than D &lt; 60 at 12 months [46.5 mL/min/1.73 m2 (95% CI: 41.4–51.5) versus 58.6 mL/min/1.73 m2 (95% CI: 56.4–60.8); P = 0.026] and, beyond 1-year, eGFR slope annual decline was steeper in older donor recipients by −1.4 mL/min/1.73 m2 each year [95% CI: (−2.4) to (−0.4); P = 0.005] than in those from younger donors.

CONCLUSION
Although the greater eGFR graft decline in the first 12 months and beyond, we demonstrated that kidneys from older living donors did not significantly compromise the censored recipient graft survival. We did not evaluate the age match between donor and recipient, as has been done in other studies, but even so, these results support the importance of increasingly encouraging KT from older living donors. It can improve the quality of life, compared to the time on dialysis and, especially for old candidates, can be the only chance to get transplanted.