Living donor postnephrectomy kidney function and recipient graft loss: A dose-response relationship.

Development of end-stage renal disease (ESRD) in living kidney donors is associated with increased graft loss in the recipients of their kidneys. Our goal was to investigate if this relationship was reflected at an earlier stage postdonation, possibly early enough for recipient risk prediction based on donor response to nephrectomy. Using national registry data, we studied 29 464 recipients and their donors from 2008-2016 to determine the association between donor 6-month postnephrectomy estimated GFR (eGFR) and recipient death-censored graft failure (DCGF). We explored donor BMI as an effect modifier, given the association between obesity and hyperfiltration. On average, risk of DCGF increased with each 10 mL/min decrement in postdonation eGFR (adjusted hazard ratio [aHR] 1.06, 95% confidence interval [CI] 1.02-1.10, P = .007). The association was attenuated with higher donor BMI (interaction P = .049): recipients from donors with BMI = 20 (aHR 1.12, 95% CI 1.04-1.19, P = .002) and BMI = 25 (aHR 1.07, 95% CI 1.03-1.12, P = .001) had a higher risk of DCGF with each 10 mL/min decrement in postdonation eGFR, whereas recipients from donors with BMI = 30 and BMI = 35 did not have a higher risk. The relationship between postdonation eGFR, donor BMI, and recipient graft loss can inform counseling and management of living donor kidney transplant recipients.