Long Term Outcomes in Living Kidney Donors Over 30 Years

INTRODUCTION: Living kidney donor transplantation provides major benefits for recipients, but long-term donor safety remains a critical concern. METHODS: We conducted a prospective, multicenter cohort study using data from the Swiss Organ Living-Donor Health Registry. A total of 1863 living kidney donors (1993-2018) with ≥ 5 years of follow-up were followed until death, kidney failure (KF), or last visit (censoring March 31, 2024). Kidney function trajectories from 12 months postdonation onward were analyzed using linear mixed-effects models. A composite secondary end point included early death, dialysis-dependent KF, estimated glomerular filtration rate (eGFR) < 30 ml/min per 1.73 m², or persistent proteinuria. Risk factors were assessed. RESULTS: A total of 1863 living kidney donors (median age 53 years, 66.2% female) were included; 15.5% had treated arterial hypertension before donation. Median predonation eGFR was 96 ml/min per 1.73 m², 1% had an eGFR < 60 ml/min per 1.73 m². Median follow-up was 12 years (interquartile range [IQR]: 7-18 years). Kidney function remained stable, with an average annual eGFR change of +0.14 ml/min per 1.73 m². Slopes differed by donor characteristics, as follows: women, nonobese, and those without predonation hypertension presented with more stable slopes, whereas obese and hypertensive donors showed attenuated slopes. No differences were observed by age or predonation eGFR. Three donors (0.2%) progressed to dialysis-dependent KF. Overall, 17 donors (0.9%) developed an eGFR < 30 ml/min per 1.73 m², 28 (1.5%) developed persistent severe proteinuria, and 40 (2.1%) reached the combined end point. Male sex, age, and predonation obesity independently predicted the combined endpoint. CONCLUSION: These findings support safety while underscoring the need for standardized long-term surveillance to optimize donor care and counseling.