Living kidney donor estimated glomerular filtration rate and recipient graft survival

Background — Kidney transplants from living donors with an estimated glomerular filtration rate (eGFR) < 80 mL/min per 1.73 m² may be at risk for increased graft loss compared with a recipient who receives a kidney from a living donor with a higher eGFR.

Methods — This retrospective cohort study considered 2057 living kidney donors and their recipients from July 1993 to March 2010 at five centres in Ontario, Canada, and linked them to population-based, universal healthcare databases. Recipients were divided into five groups based on their donor's baseline eGFR. The median (interquartile range) for the lowest eGFR group was 73 (68-77) mL/min per 1.73 m². Subjects were followed for a median of 6 years (IQR: 3-10 years).

Results — There was no significant difference in the adjusted hazard ratio (HR) for graft loss when comparing recipients in each eGFR category to the referent group (≥110 mL/min per 1.73 m²). The adjusted HRs (95% CI) from the lowest (<80 mL/min per 1.73 m²) to highest (100-109.9 mL/min per 1.73 m²) eGFR categories were 1.27 (0.84-1.92), 1.43 (0.96-2.14), 1.23 (0.86-1.77) and 1.23 (0.85-1.77), respectively. Similar results were observed when dichotomizing the baseline donor eGFR using a cut-point of 80 mL/min per 1.73 m²–adjusted HR 1.01 [95% confidence interval (95% CI) (0.76-1.44)].

Conclusions — Further research in this setting should clarify whether additional tests (i.e., measured GFR) should be performed in potential donors whose eGFR is considered borderline, whether eGFR values should be standardized to body surface area, and the outcomes for donors after nephrectomy.