Changes in kidney function follow living donor nephrectomy

Abstract

Better understanding of kidney function after living donor nephrectomy and how it differs by donor characteristics can inform patient selection, counselling, and follow-up care. To evaluate this, we conducted a retrospective matched cohort study of living kidney donors in Alberta, Canada between 2002-2016, using linked healthcare administrative databases. We matched 604 donors to 2,414 healthy non-donors from the general population based on age, sex, year of cohort entry, urban residence and the estimated glomerular filtration rate (eGFR) before cohort entry (nephrectomy date for donors and randomly assigned date for non-donors). The primary outcome was the rate of eGFR change over time (median follow-up seven years; maximum 15 years). The median age of the cohort was 43 years, 64% women, and the baseline (pre-donation) eGFR was 100 mL/min/1.73 m 2. Overall, from six weeks onwards, the eGFR increased by D0.35 mL/min/1.73 m 2 per year (95% confidence interval D0.21 to D0.48) in donors and significantly decreased by-0.85 mL/min/1.73 m 2 per year (-0.94 to-0.75) in the matched healthy non-donors. The change in eGFR between six weeks to two years, two to five years, and over five years among donors was D1.06, D0.64, and-0.06 mL/min/1.73 m 2 per year, respectively. In contrast to the steady age-related decline in kidney function in non-donors, post-donation kidney function on average initially increased by 1 mL/min/1.73 m 2 per year attributable to glomerular hyperfiltration, which began to plateau by five years post-donation. Thus, the average change in eGFR over time is significantly different between donors and non-donors.

GFR after kidney donation: early recovery and subsequent decline

“…The GFR decline in controls in the studies by Kasiske et al 4 and Lam et al 5 is similar to findings in previous reports in healthy populations. The GFR decline in donors is also consistent with previous reports.…”

“…The studies of Kasiske et al 4 and Lam et al 5 improve our understanding of GFR trends during the first 10 years following living kidney donation. The major strength of both studies is the comparison to an appropriate control group.…”

“…The study by Lam et al is a large retrospective matched cohort study using administrative databases in Alberta, Canada between 2002 and 2016. 5 Donors were ascertained by hospital diagnosis codes using a validated algorithm. Controls were selected from the general population, first by random assignment of the index data (simulated nephrectomy date) during the 2002-2016 interval, then by restriction and matching on numerous administrative, demographic, and clinical conditions and laboratory measures.…”

“…The study by Kasiske et al 4 is prospective, including data on important baseline characteristics that are associated with adverse outcomes, and uses robust measurement methods, but it had a large number of participants with missing data and is too small to detect many subgroup differences. The study by Lam et al 5 is large, uses robust methods to select the matched controls, and excludes only a small number of patients because of missing data, but it is retrospective, subject to selection bias and residual confounding, and lacks information on baseline characteristics and other metabolic and physiologic measures. The main limitation common to both studies is that the study population contains few nonwhites (which comprise 30% of donors in the US) and few with high BMI (a rapidly growing proportion of the US population, which is likely to raise the transplant program threshold for donor acceptance).…”

The Alteration of Pro-inflammatory Cytokines and Oxidative Stress Markers at Six-Month Post-living Kidney Donation

“…In our study, we found a significant decrease in GFR at 6 months of follow-up, which suggests that renal donors are approximately in stage 2 of CKD (50). Although it has been previously reported that living kidney donors experience an early reduction in GFR of 25-40% after nephrectomy, this decrease could improve in the long term (51). The fundamental principle is close to medical surveillance and the commitment of the donor and his family to maintain a healthy lifestyle, at 6 months of follow-up.…”