Evaluation of kidney function in living kidney donor candidates.

PURPOSE OF REVIEW: Living kidney donation remains the most effective and cost-efficient therapy for end-stage kidney disease (ESKD), yet the donor population is aging and pre-donation glomerular filtration rate (GFR) thresholds are increasingly encountered in the intermediate range (60-89 ml/min/1.73 m 2 ). Concurrently, evolving evidence has refined our understanding of long-term donor risk and the accuracy of GFR measurement. This review summarizes contemporary approaches to kidney function assessment in living donor candidates.

RECENT FINDINGS: Recent studies reaffirm a graded association between lower pre-donation GFR and long-term ESKD risk, while emphasizing that absolute risk remains low in carefully selected donors. Advances in plasma clearance methodologies (e.g., Iohexol) have improved the feasibility of measured GFR. Adoption of the 2021 chronic kidney disease epidemiology collaboration (CKD-EPI) race-free equation has enhanced equity in transplantation without major loss of accuracy. Emerging data also support combined creatinine-cystatin C equations and individualized end-stage renal disease (ESRD) risk projection models for donor counseling.

SUMMARY: Accurate kidney function assessment in donor candidates requires integration of race-free eGFR equations, confirmatory measured GFR when indicated, age-calibrated interpretation, and individualized risk prediction. Contemporary literature supports a structured, risk-based framework that prioritizes donor safety while preserving access to living donation.