Tissue Is the Issue: Kidney Biopsy Findings and Long-term Outcomes in Living Kidney Donors

Potential living kidney donors are extensively evaluated to minimize postdonation risks for adverse and cardiovascular outcomes. Although in the United States face a 3.5 5.3 times higher 15-year observed risk of end-stage disease (ESKD) compared with healthy nondonors, absolute is less than 3% almost all donors.1Grams M. Sang Y. Levey A. et al.Kidney-failure projection kidney-donor candidate.N Engl J Med. 2016; 374: 411-421Crossref PubMed Scopus (199) Google Scholar Yet, optimal predonation assessment renal essential improve efficacy donor screening, on one hand maintain safety other facilitate an adequate pool. At same time, presence or factors at donation can determine intensity follow-up. Donors subclinical damage development progressive function loss eventually ESKD after donation.2Massie A.B. Holscher C.M. Henderson M.L. al.Association early subsequent donors.JAMA Surg. 2020; 155: e195472Crossref (11) Clinical parameters including measured glomerular filtration rate (GFR) estimated GFR (eGFR), age, body mass index, blood pressure, proteinuria widely used identify individuals established those high future damage. substantial part variance not captured by these clinical parameters.3Rook Hofker H.S. Van Son W.J. Homan van der Heide J.J. Ploeg R.J. Navis G. Predictive capacity pre-donation reserve donation.Am Transplant. 2006; 6: 1653-1659Crossref (69) Early may remain undetected because compensatory increase individual remaining nephrons: single-nephron GFR.4Deen W. Robertson C. Brenner B. A model ultrafiltration rat.Am Physiol. 1972; 223: 1178-1183Crossref (201) In study donors, both acquired (obesity) inherent (family history ESKD) chronic (CKD) were associated GFR.5Denic Mathew J. Lerman L.O. al.Single-nephron adults.N 2017; 376: 2349-2357Crossref (123) addition, was larger nephrons nephrosclerosis biopsy. highly elegant, calculation requires sophisticated measurements stereologically assessed biopsy specimen. preimplantation itself already provide important prognostic information another from group revealed that nephron hypertrophy systolic (possibly reflecting malignant hyperfiltration), urine albumin excretion.6Denic Alexander M.P. Kaushik V. al.Detection patterns among apparently adults.Am Kidney Dis. 68: 58-67Abstract Full Text PDF (37) So far, implications microstructural features long-term outcomes had been assessed. this issue Mayo Clinic Proceedings, Merzkani al7Merzkani Denic Narasimhan R. al.Kidney time predict donors.Mayo Clin Proc. 2021; 96: 40-51Abstract (2) studied wide range number, size, specimens 807 as potential predictors hypertension CKD. After mean follow-up 10.5 years, 6.4% reached eGFR below 45 mL/min/1.73 m2, 5.1% reported proteinuria. volume Interestingly, previous group, GFR.6Denic These findings be reconciled concept relatively GFR, driven increased (which current study), reflect hyperfiltration response demand (eg, obesity) premature nephrons. Glomerular hyperfiltration, turn, predisposes accelerated function.8Brenner B.M. Nephron adaptation injury ablation.Am 1985; 249: F324-F337PubMed keeping concept, al, lower number (below age-specific 5th percentile) also m2 self-reported context pathogenic condition such diabetes obesity, considered detrimental. setting donation, adaptive (ie, beyond half GFR) lead adversely affect donors.9Lenihan C.R. Busque S. Derby Blouch K. Myers B.D. Tan J.C. Longitudinal dynamics nephrectomy.J Invest. 2015; 125: 1311-1318Crossref (92) underlying mechanisms well understood, it discriminate preexisting changes GFR. caused hamper which could explain association between residual eGFR, defined ratio eGFR. Yet during follow-up, disentangling challenging if impossible. Here value consider specimen who susceptible Merkanzi colleagues based unique dataset, results should interpreted caution. The outcome prone recall bias, probably selection bias. Furthermore, use fixed post-donation thresholds measures impaired questioned. First, there ongoing debate whether CKD adapted given gradual age absence disease.10Denic Lieske Chakkera H.A. al.The human kidneys aging.J Am Soc Nephrol. 28: 313-320Crossref (127) Second, always since impact <45 mL/min/1.73m2 45-year old remarkably different 75-year donor. Third, patient function. Defining will due low incidence post-donation. Analyzing continuous repeated additional insight into predictive features. Finally, some prior short-term study11Issa N. Vaughan L.E. al.Larger donating kidney.Am 2019; 19: 1989-1998PubMed reproduced Specifically, arteriosclerosis four months years Since seems unlikely solitary declines over unfortunately data re-analyzed cohort, further studies warranted validate observations. What study? limitations addressed here do justify structural biopsies evaluation. Nevertheless, readily available influence selected cases. Intensified screening clinically manifest albuminuria function) trigger renoprotective interventions Surrogate markers preclinical might theoretically feasible application practice, but so far no validated available. For example, computed tomography scans reveal surface roughness, cysts, cortical volume, medullary have nephrosclerosis.6Denic studies. holds true has previously linked cross-sectional analyses6Denic known influenced birth weight.12Manalich Reyes L. Herrera Melendi Fundora I. Relationship weight size glomeruli humans: histomorphometric study.Kidney Int. 2000; 58: 770-773Abstract (442) To best our knowledge, linking weight, simple, costless, noninvasive measure, Taken together, al takes approach large donors. Their observation contribute understanding how health disease. Moreover, need closer Future circulating, urinary, imaging abnormalities selection. Microstructural Features Time Donation Predict Long-term Risk Chronic Disease Living DonorsMayo ProceedingsVol. 96Issue 1PreviewTo obtained transplant surgery Full-Text