A Study to Determine If Donor Kidney Volume Influences Kidney Function After Renal Transplantation

Kidney transplantation is the preferred treatment for end-stage renal disease. Donor kidney volume (DKV) and its adjustment to recipient body surface area (BSA), termed nephron dose (DKV/BSA), may influence graft function based on the nephron dosing hypothesis. This study evaluated the impact of nephron dose on recipient estimated glomerular filtration rate (eGFR) at 1 year.

A prospective observational study was conducted on 130 living donor kidney transplants at a tertiary care center (August 2022 to July 2023). Donor kidney volume was measured via computed tomography angiography and 3-dimensional volumetric analysis. Nephron dose (mL/m²) was calculated and correlated with recipient eGFR (Chronic Kidney Disease Epidemiology Collaboration 2021) at baseline, 3, 6, and 12 months. A ≥30% eGFR decline from peak was defined as significant deterioration.

The mean DKV was 103.2 ± 20.9 mL, with a mean nephron dose of 64.5 ± 14.7 mL/m². A significant positive correlation was observed between nephron dose and eGFR, strongest at baseline (r = 0.436) and persisting at 1 year (r = 0.184). Receiver operating characteristic curve analysis identified a nephron dose cutoff of 61.88 mL/m², predicting >30% eGFR decline with 79.3% sensitivity and 54.1% specificity (area under the curve = 0.634, P = .028).

Donor kidney volume relative to recipient size significantly predicts graft function at 1 year. Incorporating nephron dose into preoperative planning may optimize donor-recipient matching and improve long-term outcomes.