Pre‐ and post‐donation kidney function in donors of a kidney paired donation with unique criteria for donor glomerular filtration rate ‐ a longitudinal cohort analysis

: Baseline predonation estimated GFR (eGFR) appears to predict the risk of postdonation chronic kidney disease in live donors. New KIDGO guidelines recommend an eGFR ≥90 ml/min/1.73 m2 as an acceptable level of glomerular filtration rate (GFR) for kidney donation. In the Australian Paired Kidney Exchange (AKX) program, all donors with a raw measured GFR (mGFR) ≥80 ml/min are deemed suitable for donation, but the significance of this selection indicator is unclear. We analysed the first 129 live donors in the AKX program with at least 1-year follow-up linking records in the AKX database and ANZDATA. There were 73 male and 56 female donors; mean (±SD) age was 53 ± 11 years. Predonation eGFR was 94 ± 13 ml/min/1.73 m2 , mGFR 99 ± 17 ml/min/1.73 m2 and raw mGFR 108 ± 18 ml/min. Baseline eGFR was <80 ml/min/1.73 m2 in 19 donors, and <90 ml/min/1.73 m2 in 42 donors. At 1 year postdonation eGFR was 68 ± 15 ml/min/1.73 m2 and the predicted eGFR at 30 years postdonation was on average 50 (29-83) ml/min/1.73 m2 . The hypothetical mean age at end-stage kidney disease was estimated to be 145 (95% CI 120-263) years. Over 30% of AKX live donors would have been excluded from donation using KDIGO guidelines. Using AKX donor guidelines, the majority of donors with predicted eGFR <30 ml/min/1.73 m2 30-year postdonation were aged ≥50 years. Long-term outcome data on AKX donors with low eGFR will need careful monitoring.