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Haruhara K, Okabayashi Y, Sasaki T, Kubo E, D'Agati VD, Bertram JF, Tsuboi N, Yokoo T. Podocyte density as a predictor of long-term kidney outcome in obesity-related glomerulopathy. Kidney Int 2024:S0085-2538(24)00406-X. [PMID: 39046396 DOI: 10.1016/j.kint.2024.05.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 05/15/2024] [Accepted: 05/28/2024] [Indexed: 07/25/2024]
Abstract
Glomerulomegaly and focal segmental glomerulosclerosis are histopathological hallmarks of obesity-related glomerulopathy (ORG). Podocyte injury and subsequent depletion are regarded as key processes in the development of these glomerular lesions in patients with ORG, but their impact on long-term kidney outcome is undetermined. Here, we correlated clinicopathological findings and podocyte depletion retrospectively in patients with ORG. Relative (podocyte density) and absolute (podocyte number per glomerulus) measures of podocyte depletion were estimated using model-based stereology in 46 patients with ORG. The combined endpoint of kidney outcomes was defined as a 30% decline in estimated glomerular filtration rate (eGFR) or kidney failure. Patients with lower podocyte density were predominantly male and had larger body surface area, greater proteinuria, fewer non-sclerotic glomeruli, larger glomeruli and higher single-nephron eGFR. During a median follow-up of 4.1 years, 18 (39%) patients reached endpoint. Kidney survival in patients with lower podocyte density was significantly worse than in patients with higher podocyte density. However, there was no difference in kidney survival between patient groups based on podocyte number per glomerulus. Cox hazard analysis showed that podocyte density, but not podocyte number per glomerulus, was associated with the kidney outcomes after adjustment for clinicopathological confounders. Thus, our study demonstrates that a relative depletion of podocytes better predicts long-term kidney outcomes than does absolute depletion of podocytes. Hence, the findings implicate mismatch between glomerular enlargement and podocyte number as a crucial determinant of disease progression in ORG.
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Affiliation(s)
- Kotaro Haruhara
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan; Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia.
| | - Yusuke Okabayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Takaya Sasaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Eisuke Kubo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Vivette D D'Agati
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York, USA
| | - John F Bertram
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia; Australian Research Council Training Centre for Cell and Tissue Engineering Technologies, Brisbane, Australia
| | - Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan.
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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2
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Sasaki T, Tosaki T, Kuno H, Marumoto H, Okabayashi Y, Haruhara K, Kanzaki G, Koike K, Kobayashi A, Yamamoto I, Tsuboi N, Yokoo T. Estimating baseline creatinine levels based on the kidney parenchymal volume. Clin Exp Nephrol 2024:10.1007/s10157-024-02526-2. [PMID: 38914912 DOI: 10.1007/s10157-024-02526-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 06/05/2024] [Indexed: 06/26/2024]
Abstract
BACKGROUND Acute kidney injury (AKI) diagnosis often lacks a baseline serum creatinine (Cr) value. Our study aimed to create a regression equation linking kidney morphology to function in kidney donors and chronic kidney disease patients. We also sought to estimate baseline Cr in minimal change disease (MCD) patients, a common AKI-predisposing condition. METHODS We analyzed 119 participants (mean age 60 years, 50% male, 40% donors) with CT scans, dividing them into derivation and validation groups. An equation based on kidney parenchymal volume (PV) was developed in the derivation group and validated in the validation group. We estimated baseline Cr in 43 MCD patients (mean age 45 years, 61% male) using the PV-based equation and compared with their 6 month post-MCD onset Cr values. RESULTS In the derivation group, the equation for the estimated glomerular filtration rate (eGFR) was: eGFR (mL/min/1.73m2) = 0.375 × PV (cm3) + (- 0.395) × age (years) + (- 2.93) × male sex + (- 13.3) × hypertension + (- 14.0) × diabetes + (- 0.210) × height (cm) + 82.0 (intercept). In the validation group, the eGFR and estimated Cr values correlated well with the measured values (r = 0.46, p = 0.01; r = 0.51, p = 0.004, respectively). In the MCD group, the baseline Cr values were significantly correlated with the estimated baseline Cr values (r = 0.52, p < 0.001), effectively diagnosing AKI (kappa = 0.76, p < 0.001). CONCLUSIONS The PV-based regression equation established in this study holds promise for estimating baseline Cr values and diagnosing AKI in patients with MCD. Further validation in diverse AKI populations is warranted.
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Affiliation(s)
- Takaya Sasaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan.
| | - Takeshi Tosaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan
| | - Hideaki Kuno
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan
| | - Hirokazu Marumoto
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan
| | - Yusuke Okabayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan
| | - Kotaro Haruhara
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan
| | - Go Kanzaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan
| | - Kentaro Koike
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan
| | - Akimitsu Kobayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan
| | - Izumi Yamamoto
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan
| | - Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan.
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-Ku, Tokyo, Japan
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3
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Asghar MS, Denic A, Rule AD. Morphometric analysis of chronicity on kidney biopsy: a useful prognostic exercise. Clin Kidney J 2024; 17:sfad226. [PMID: 38327281 PMCID: PMC10849190 DOI: 10.1093/ckj/sfad226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Indexed: 02/09/2024] Open
Abstract
Chronic changes on kidney biopsy specimens include increasing amounts of arteriosclerosis, glomerulosclerosis, interstitial fibrosis and tubular atrophy, enlarged nephron size, and reduced nephron number. These chronic changes are difficult to accurately assess by visual inspection but are reasonably quantified using morphometry. This review describes the various patient populations that have undergone morphometric analysis of kidney biopsies. The common approaches to morphometric analysis are described. The chronic kidney disease outcomes associated with various chronic changes by morphometry are also summarized. Morphometry enriches the characterization of chronicity on a kidney biopsy and this can supplement the pathologist's diagnosis. Artificial intelligence image processing tools are needed to automate the annotations needed for practical morphometric analysis of kidney biopsy specimens in routine clinical care.
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Affiliation(s)
- Muhammad S Asghar
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Aleksandar Denic
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Andrew D Rule
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
- Division of Epidemiology, Mayo Clinic, Rochester, MN, USA
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4
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Okabayashi Y, Tsuboi N, Marumoto H, Sasaki T, Haruhara K, Kanzaki G, Koike K, Ueda H, Shimizu A, Puelles VG, D'Agati V, Yokoo T. Single-Nephron GFR in Different Glomerular Basement Membrane Stages of Membranous Nephropathy. KIDNEY360 2023; 4:e777-e786. [PMID: 37166967 PMCID: PMC10371379 DOI: 10.34067/kid.0000000000000142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 03/22/2023] [Indexed: 05/12/2023]
Abstract
Key Points The first study that estimated single-nephron GFR (SNGFR) in patients with membranous nephropathy (MN). Associations of SNGFR with MN staging by electron microscopy and clinicopathologic findings were cross-sectionally investigated. This study illustrates a role for disease-specific GBM structural lesions as determinants of SNGFR in patients with MN. Background Alterations in single-nephron dynamics have been demonstrated in animal models of membranous nephropathy (MN). This study applied a recently developed technique to estimate single-nephron parameters in human MN. Methods Single-nephron GFR (SNGFR) and single-nephron urinary protein excretion (SNUPE) were calculated by dividing total GFR and UPE by the total estimated number of nonglobally sclerotic glomeruli (NSG). The NSG number per kidney was estimated using cortical volume assessment and biopsy-based stereology. MN staging by electron microscopy was performed using Ehrenreich-Churg (EC) criteria. Single-nephron parameters were analyzed in relation to clinicopathological factors known to associate with disease outcomes. Results The study included 109 patients with MN (mean age 65 years; 73% male; eGFR 62 ml/min, 36% on renin-angiotensin-aldosterone system inhibitors prebiopsy). EC stages were I, 19%; II, 49%; III, 26%; and IV, 6%. There was no difference in glomerular volume among EC stage groups. With advancing EC stage, SNGFR and SNUPE decreased from mean 56–42 nl/min and 5.1–3.8 µ g/d, respectively. In multivariable models, EC stage was associated with SNGFR even after adjustment for key clinicopathological factors, such as reduced GFR, serum albumin, UPE, segmental glomerulosclerosis, chronic tubulointerstitial damage, and prebiopsy use of renin-angiotensin-aldosterone system inhibitors. By contrast, EC stage was not associated with glomerular volume and SNUPE after multivariable adjustment. Conclusions These results provide the first clinical evidence of alterations in single-nephron dynamics with advancing EC stage of human MN and support a role for disease-specific glomerular basement membrane structural lesions as determinants of SNGFR.
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Affiliation(s)
- Yusuke Okabayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
- Ill. Department of Medicine, University Medical Center Hamburg-Eppendorf, Germany
| | - Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Hirokazu Marumoto
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Takaya Sasaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kotaro Haruhara
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Go Kanzaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kentaro Koike
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Hiroyuki Ueda
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Akira Shimizu
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo, Japan
| | - Victor G. Puelles
- Ill. Department of Medicine, University Medical Center Hamburg-Eppendorf, Germany
| | - Vivette D'Agati
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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5
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Baldelomar EJ, Emoto KC, Jordan MVC, Charlton JR, Reichert DE, Parvin N, Yokono C, Hann BD, Bennett KM. Synthesis and Expression of a Targeted, Ferritin-Based Tracer for PET Imaging of Kidney Glomeruli. Methods Mol Biol 2023; 2664:201-213. [PMID: 37423992 DOI: 10.1007/978-1-0716-3179-9_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Cationic ferritin (CF) has been developed as a multimodal, targeted imaging tracer to directly detect and map nephrons in the kidney in vivo. Direct detection of functional nephrons provides a unique, sensitive biomarker to predict or monitor kidney disease progression. CF has been developed to map functional nephron number from magnetic resonance imaging (MRI) or positron emission tomography (PET). Previous preclinical imaging studies have used non-human-derived ferritin and commercial formulations that must still be developed for translation to clinical use. Here we describe the reproducible formulation of CF (either derived from horse or from human recombinant ferritin) optimized for intravenous injection and radiolabeling by PET. The human recombinant heteropolymer ferritin is spontaneously assembled in liquid culture (Escherichia coli, E. coli) and modified to form human recombinant cationic ferritin (HrCF) to mitigate potential immunologic reactions for use in humans.
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Affiliation(s)
- Edwin J Baldelomar
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Kasey C Emoto
- Department of Biology, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Maria Veronica Clavijo Jordan
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA, USA
| | - Jennifer R Charlton
- Department of Pediatrics, Division of Nephrology, University of Virginia, Charlottesville, VA, USA
| | - David E Reichert
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Neda Parvin
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Courtnie Yokono
- Department of Biology, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Bradley D Hann
- Department of Biology, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Kevin M Bennett
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA.
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6
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Tran T, Song CJ, Nguyen T, Cheng SY, McMahon JA, Yang R, Guo Q, Der B, Lindström NO, Lin DCH, McMahon AP. A scalable organoid model of human autosomal dominant polycystic kidney disease for disease mechanism and drug discovery. Cell Stem Cell 2022; 29:1083-1101.e7. [PMID: 35803227 PMCID: PMC11088748 DOI: 10.1016/j.stem.2022.06.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/28/2022] [Accepted: 06/08/2022] [Indexed: 12/13/2022]
Abstract
Human pluripotent stem-cell-derived organoids are models for human development and disease. We report a modified human kidney organoid system that generates thousands of similar organoids, each consisting of 1-2 nephron-like structures. Single-cell transcriptomic profiling and immunofluorescence validation highlighted patterned nephron-like structures utilizing similar pathways, with distinct morphogenesis, to human nephrogenesis. To examine this platform for therapeutic screening, the polycystic kidney disease genes PKD1 and PKD2 were inactivated by gene editing. PKD1 and PKD2 mutant models exhibited efficient and reproducible cyst formation. Cystic outgrowths could be propagated for months to centimeter-sized cysts. To shed new light on cystogenesis, 247 protein kinase inhibitors (PKIs) were screened in a live imaging assay identifying compounds blocking cyst formation but not overall organoid growth. Scaling and further development of the organoid platform will enable a broader capability for kidney disease modeling and high-throughput drug screens.
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Affiliation(s)
- Tracy Tran
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Cheng Jack Song
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA; Amgen Research, Cardiometabolic Disorders, 1120 Veterans Blvd, South San Francisco, CA 94080, USA
| | - Trang Nguyen
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Shun-Yang Cheng
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Jill A McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Rui Yang
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Qiuyu Guo
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Balint Der
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Nils O Lindström
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Daniel C-H Lin
- Amgen Research, Cardiometabolic Disorders, 1120 Veterans Blvd, South San Francisco, CA 94080, USA
| | - Andrew P McMahon
- Department of Stem Cell Biology and Regenerative Medicine, Broad-CIRM Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA.
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7
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Denic A, Rule AD, Glassock RJ. Healthy and unhealthy aging on kidney structure and function: human studies. Curr Opin Nephrol Hypertens 2022; 31:228-234. [PMID: 35067600 PMCID: PMC9035051 DOI: 10.1097/mnh.0000000000000780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW This review is intended to provide an up-to-date analysis of the structural and functional alterations of the kidneys that accompany healthy and unhealthy aging in humans. Macro- and micro- structural changes and glomerular filtration rate (whole kidney and single nephron) accompanying aging will be stressed. RECENT FINDINGS Comparative findings concerning distribution of anatomic changes of the kidney healthy and unhealthy aging are reviewed. Challenges concerning definition of chronic kidney disease (CKD) in otherwise healthy aging patients are discussed. The complex interactions of CKD and aging are discussed. The role of podocyte dysbiosis in kidney aging is reviewed. SUMMARY Kidney aging is a complex phenomenon often difficult to distinguish from CKD. Nonetheless, phenotypes of healthy and unhealthy aging are evident. Much more information concerning the molecular characteristics of normal kidney aging and its relevance to chronic kidney disease is needed.
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Affiliation(s)
- Aleksandar Denic
- Department of Medicine, Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Andrew D. Rule
- Department of Medicine, Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Richard J. Glassock
- Department of Medicine, Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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8
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Bennett KM, Baldelomar EJ, Charlton JR. Delivering on the potential of measuring nephron number in the clinic. Nat Rev Nephrol 2022; 18:271-272. [PMID: 35264770 DOI: 10.1038/s41581-022-00560-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kevin M Bennett
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA.
| | - Edwin J Baldelomar
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Jennifer R Charlton
- Division of Nephrology, Department of Pediatrics, University of Virginia, Charlottesville, VA, USA
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9
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Blijdorp CJ, Hartjes TA, Wei K, van Heugten MH, Bovée DM, Budde RP, van de Wetering J, Hoenderop JG, van Royen ME, Zietse R, Severs D, Hoorn EJ. Nephron mass determines the excretion rate of urinary extracellular vesicles. J Extracell Vesicles 2022; 11:e12181. [PMID: 35064766 PMCID: PMC8783354 DOI: 10.1002/jev2.12181] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 11/15/2021] [Accepted: 12/08/2021] [Indexed: 12/20/2022] Open
Abstract
Urinary extracellular vesicles (uEVs) are emerging as non-invasive biomarkers for various kidney diseases, but it is unknown how differences in nephron mass impact uEV excretion. To address this, uEV excretion was measured before and after human kidney donor nephrectomy and rat nephrectomy. In male and female donors, uEVs were quantified in cell-free spot and 24-h urine samples using nanoparticle tracking analysis (NTA), EVQuant, and CD9-time-resolved fluorescence immunoassay. Female donors had significantly lower total kidney volume (TKV) and excreted 49% fewer uEVs than male donors. uEV excretion correlated positively with estimated glomerular filtration rate (eGFR), creatinine clearance, and TKV (R's between 0.6 and 0.7). uEV excretion rate could also be predicted from spot urines after multiplying spot uEV/creatinine by 24-h urine creatinine. Donor nephrectomy reduced eGFR by 36% ± 10%, but the excretion of uEVs by only 16% (CD9+ uEVs -37%, CD9- uEVs no decrease). Donor nephrectomy increased the podocyte marker WT-1 and the proximal tubule markers NHE3, NaPi-IIa, and cubilin in uEVs two- to four-fold when correcting for the nephrectomy. In rats, the changes in GFR and kidney weight correlated with the changes in uEV excretion rate (R = 0.46 and 0.60, P < 0.01). Furthermore, the estimated degree of hypertrophy matched the change in uEV excretion rate (1.4- to 1.5-fold after uninephrectomy and four-fold after 5/6th nephrectomy). Taken together, our data show that uEV excretion depends on nephron mass, and that nephrectomy reduces uEV excretion less than expected based on nephron loss due to compensatory hypertrophy. The major implication of our findings is that a measure for nephron mass or uEV excretion rate should be included when comparing uEV biomarkers between individuals.
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Affiliation(s)
- Charles J. Blijdorp
- Department of Internal Medicine, Division of Nephrology and TransplantationErasmus MC, University Medical Center RotterdamRotterdamThe Netherlands
| | - Thomas A. Hartjes
- Department of PathologyErasmus Medical Center, University Medical Center RotterdamRotterdamThe Netherlands
| | - Kuang‐Yu Wei
- Department of Internal Medicine, Division of Nephrology and TransplantationErasmus MC, University Medical Center RotterdamRotterdamThe Netherlands
| | - Martijn H. van Heugten
- Department of Internal Medicine, Division of Nephrology and TransplantationErasmus MC, University Medical Center RotterdamRotterdamThe Netherlands
| | - Dominique M. Bovée
- Department of Internal Medicine, Division of Nephrology and TransplantationErasmus MC, University Medical Center RotterdamRotterdamThe Netherlands
| | - Ricardo P.J. Budde
- Department of Radiology and Nuclear MedicineErasmus Medical Center, University Medical Center RotterdamRotterdamThe Netherlands
| | - Jacqueline van de Wetering
- Department of Internal Medicine, Division of Nephrology and TransplantationErasmus MC, University Medical Center RotterdamRotterdamThe Netherlands
| | - Joost G.J. Hoenderop
- Department of PhysiologyRadboud University Medical CenterNijmegenThe Netherlands
| | - Martin E. van Royen
- Department of PathologyErasmus Medical Center, University Medical Center RotterdamRotterdamThe Netherlands
| | - Robert Zietse
- Department of Internal Medicine, Division of Nephrology and TransplantationErasmus MC, University Medical Center RotterdamRotterdamThe Netherlands
| | - David Severs
- Department of Internal Medicine, Division of Nephrology and TransplantationErasmus MC, University Medical Center RotterdamRotterdamThe Netherlands
| | - Ewout J. Hoorn
- Department of Internal Medicine, Division of Nephrology and TransplantationErasmus MC, University Medical Center RotterdamRotterdamThe Netherlands
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10
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Abstract
The kidney is one of the target organs that may show health disorders as a result of obesity. Obesity-related glomerulopathy (ORG) is a kidney disease category based on a biopsy diagnosis that may occur secondary to obesity. Detailed clinicopathologic observations of ORG have provided significant knowledge regarding obesity-associated renal complications. Glomerulomegaly with focal segmental glomerulosclerosis of perihilar locations is a typical renal histopathologic finding in ORG, which has long been considered to represent a state of single-nephron glomerular hyperfiltration. This hypothesis was recently confirmed in ORG patients by estimating single-nephron glomerular filtration rate using a combined image analysis and biopsy-based stereology. Overshooting in glomerulotubular and tubuloglomerular interactions may lead to glomerular hyperfiltration/hypertension, podocyte failure, tubular protein-traffic overload, and tubulointerstitial scarring, constituting a vicious cycle of a common pathway to the further loss of functioning nephrons and the progression of kidney functional impairment.
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Affiliation(s)
- Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan.
| | - Yusuke Okabayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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11
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Assessment of nephron number and single-nephron glomerular filtration rate in a clinical setting. Hypertens Res 2021; 44:605-617. [PMID: 33526913 DOI: 10.1038/s41440-020-00612-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 12/02/2020] [Accepted: 12/08/2020] [Indexed: 01/31/2023]
Abstract
Total nephron counts vary widely between individuals and may affect susceptibility to certain diseases, including hypertension and chronic kidney disease. Detailed analyses of whole kidneys collected from autopsy patients remain the only method for accurately counting nephrons in humans, with no equivalent option in living subjects. Current technological advances have enabled estimations of nephron numbers in vivo, particularly the use of total nephron number and whole-kidney glomerular filtration rate to estimate the mean single-nephron glomerular filtration rate. The use of this method would allow physicians to detect dynamic changes in filtration function at the single-nephron level rather than to simply count the number of nephrons that appear to be functioning. Currently available methods for estimating total nephron number in clinical practice have the potential to overcome limitations associated with autopsy analyses and may therefore pave the way for new therapeutic interventions and improved clinical outcomes.
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Bennett KM, Baldelomar EJ, Morozov D, Chevalier RL, Charlton JR. New imaging tools to measure nephron number in vivo: opportunities for developmental nephrology. J Dev Orig Health Dis 2021; 12:179-183. [PMID: 31983353 PMCID: PMC8765346 DOI: 10.1017/s204017442000001x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The mammalian kidney is a complex organ, requiring the concerted function of up to millions of nephrons. The number of nephrons is constant after nephrogenesis during development, and nephron loss over a life span can lead to susceptibility to acute or chronic kidney disease. New technologies are under development to count individual nephrons in the kidney in vivo. This review outlines these technologies and highlights their relevance to studies of human renal development and disease.
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Affiliation(s)
- K M Bennett
- Department of Radiology, Washington University, Saint Louis, MO, USA
| | - E J Baldelomar
- Department of Radiology, Washington University, Saint Louis, MO, USA
| | - D Morozov
- Department of Radiology, Washington University, Saint Louis, MO, USA
| | - R L Chevalier
- Department of Pediatrics, University of Virginia, Charlottesville, VA, USA
| | - J R Charlton
- Department of Pediatrics, University of Virginia, Charlottesville, VA, USA
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13
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Marumoto H, Tsuboi N, D’Agati VD, Sasaki T, Okabayashi Y, Haruhara K, Kanzaki G, Koike K, Shimizu A, Kawamura T, Rule AD, Bertram JF, Yokoo T. Total Nephron Number and Single-Nephron Parameters in Patients with IgA Nephropathy. KIDNEY360 2021; 2:828-841. [PMID: 35373063 PMCID: PMC8791345 DOI: 10.34067/kid.0006972020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/09/2021] [Indexed: 02/04/2023]
Abstract
Background Single-nephron dynamics in progressive IgA nephropathy (IgAN) have not been studied. We applied novel methodology to explore single-nephron parameters in IgAN. Methods Nonglobally sclerotic glomeruli (NSG) and globally sclerotic glomeruli (GSG) per kidney were estimated using cortical volume assessment via unenhanced computed tomography and biopsy-based stereology. Estimated single-nephron GFR (eSNGFR) and single-nephron urine protein excretion (SNUPE) were calculated by dividing eGFR and UPE by the number of NSG. Associations with CKD stage and clinicopathologic findings were cross-sectionally investigated. Results This study included 245 patients with IgAN (mean age 43 years, 62% male, 45% on renin-angiotensin aldosterone system [RAAS] inhibitors prebiopsy) evaluated at kidney biopsy. CKD stages were 10% CKD1, 43% CKD2, 19% CKD3a, 14% CKD3b, and 14% CKD4-5. With advancing CKD stage, NSG decreased from mean 992,000 to 300,000 per kidney, whereas GSG increased from median 64,000 to 202,000 per kidney. In multivariable models, advancing CKD stage associated with lower numbers of NSG, higher numbers of GSG, and lower numbers of GSG + NSG, indicating potential resorption of sclerosed glomeruli. In contrast to the higher mean glomerular volume and markedly elevated SNUPE in advanced CKD, the eSNGFR was largely unaffected by CKD stage. Lower SNGFR associated with Oxford scores for endocapillary hypercellularity and crescents, whereas higher SNUPE associated with segmental glomerulosclerosis and tubulointerstitial scarring. Conclusions SNUPE emerged as a sensitive biomarker of advancing IgAN. The failure of eSNGFR to increase in response to reduced number of functioning nephrons suggests limited capacity for compensatory hyperfiltration by diseased glomeruli with intrinsic lesions.
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Affiliation(s)
- Hirokazu Marumoto
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Vivette D. D’Agati
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York
| | - Takaya Sasaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Yusuke Okabayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kotaro Haruhara
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Go Kanzaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kentaro Koike
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Akira Shimizu
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo, Japan
| | - Tetsuya Kawamura
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Andrew D. Rule
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - John F. Bertram
- Department of Anatomy and Developmental Biology and Biomedical Discovery Institute, Monash University, Melbourne, Australia
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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DeFreitas MJ, Katsoufis CP, Infante JC, Granda ML, Abitbol CL, Fornoni A. The old becomes new: advances in imaging techniques to assess nephron mass in children. Pediatr Nephrol 2021; 36:517-525. [PMID: 31953750 DOI: 10.1007/s00467-020-04477-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/09/2019] [Accepted: 01/08/2020] [Indexed: 12/19/2022]
Abstract
Renal imaging is widely used in the assessment of surrogate markers of nephron mass correlated to renal function. Autopsy studies have tested the validity of various imaging modalities in accurately estimating "true" nephron mass. However, in vivo assessment of nephron mass has been largely limited to kidney volume determination by ultrasonography (US) in pediatric populations. Practical limitations and risks create challenges in incorporating more precise 3D volumetric imaging, like magnetic resonance imaging (MRI), and computed tomography (CT) technologies, compared to US for routine kidney volume assessment in children. Additionally, accounting for structural anomalies such as hydronephrosis when estimating renal parenchymal area in congenital anomalies of the kidney and urinary tract (CAKUT) is important, as it correlates with chronic kidney disease (CKD) progression. 3D imaging using CT and MRI has been shown to be superior to US, which has traditionally relied on 2D measurements to estimate kidney volume using the ellipsoid calculation. Recent innovations using 3D and contrast-enhanced US (CEUS) provide improved accuracy with low risk. Indexing kidney volume to body surface area in children is an important standard that may allow early detection of CKD progression in high-risk populations. This review highlights current understanding of various imaging modalities in assessing nephron mass, discusses applications and limitations, and describes recent advances in the field of imaging and kidney disease. Although renal imaging has been a long-standing, essential tool in assessing kidney disease, innovation and new applications of established technologies provide important tools in the study and management of kidney disease in children.
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Affiliation(s)
- Marissa J DeFreitas
- Division of Pediatric Nephrology, University of Miami Miller School of Medicine, P.O. Box 016960 (M714), Miami, FL, 33130, USA.
| | - Chryso P Katsoufis
- Division of Pediatric Nephrology, University of Miami Miller School of Medicine, P.O. Box 016960 (M714), Miami, FL, 33130, USA
| | - Juan C Infante
- Section of Pediatric Radiology, Department of Diagnostic Radiology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Michael L Granda
- Division of General Internal Medicine, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Carolyn L Abitbol
- Division of Pediatric Nephrology, University of Miami Miller School of Medicine, P.O. Box 016960 (M714), Miami, FL, 33130, USA
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
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15
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Baldelomar EJ, Reichert DE, Shoghi KI, Beeman SC, Charlton JR, Strong L, Fettig N, Klaas A, Bennett KM. Mapping nephron mass in vivo using positron emission tomography. Am J Physiol Renal Physiol 2021; 320:F183-F192. [PMID: 33283644 PMCID: PMC8091936 DOI: 10.1152/ajprenal.00418.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 01/19/2023] Open
Abstract
Nephron number varies widely in humans. A low nephron endowment at birth or a loss of functioning nephrons is strongly linked to increased susceptibility to chronic kidney disease. In this work, we developed a contrast agent, radiolabeled cationic ferritin (RadioCF), to map functioning glomeruli in vivo in the kidney using positron emission tomography (PET). PET radiotracers can be detected in trace doses (<30 nmol), making them useful for rapid clinical translation. RadioCF is formed from cationic ferritin (CF) and with a radioisotope, Cu-64, incorporated into the ferritin core. We showed that RadioCF binds specifically to kidney glomeruli after intravenous injection in mice, whereas radiolabeled noncationic ferritin (RadioNF) and free Cu-64 do not. We then showed that RadioCF-PET can distinguish kidneys in healthy wild-type (WT) mice from kidneys in mice with oligosyndactylism (Os/+), a model of congenital hypoplasia and low nephron mass. The average standardized uptake value (SUV) measured by PET 90 min after injection was 21% higher in WT mice than in Os/+ mice, consistent with the higher glomerular density in WT mice. The difference in peak SUV from SUV at 90 min correlated with glomerular density in male mice from both WT and Os/+ cohorts (R2 = 0.98). Finally, we used RadioCF-PET to map functioning glomeruli in a donated human kidney. SUV within the kidney correlated with glomerular number (R2= 0.78) measured by CF-enhanced magnetic resonance imaging in the same locations. This work suggests that RadioCF-PET appears to accurately detect nephron mass and has the potential for clinical translation.
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Affiliation(s)
- Edwin J Baldelomar
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - David E Reichert
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Kooresh I Shoghi
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Scott C Beeman
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona
| | | | - Lori Strong
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Nikki Fettig
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Amanda Klaas
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
| | - Kevin M Bennett
- Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, Missouri
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16
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Charlton JR, Xu Y, Wu T, deRonde KA, Hughes JL, Dutta S, Oxley GT, Cwiek A, Cathro HP, Charlton NP, Conaway MR, Baldelomar EJ, Parvin N, Bennett KM. Magnetic resonance imaging accurately tracks kidney pathology and heterogeneity in the transition from acute kidney injury to chronic kidney disease. Kidney Int 2020; 99:173-185. [PMID: 32916180 DOI: 10.1016/j.kint.2020.08.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 08/07/2020] [Accepted: 08/20/2020] [Indexed: 01/09/2023]
Abstract
Acute kidney injury (AKI) increases the risk for chronic kidney disease (CKD). However, there are few tools to detect microstructural changes after AKI. Here, cationic ferritin-enhanced magnetic resonance imaging (CFE-MRI) was applied to examine the heterogeneity of kidney pathology in the transition from AKI to CKD. Adult male mice received folic acid followed by cationic ferritin and were euthanized at four days (AKI), four weeks (CKD-4) or 12 weeks (CKD-12). Kidneys were examined by histologic methods and CFE-MRI. In the CKD-4 and CKD-12 groups, glomerular number was reduced and atubular cortical lesions were observed. Apparent glomerular volume was larger in the AKI, CKD-4 and CKD-12 groups compared to controls. Glomerular hypertrophy occurred with ageing. Interglomerular distance and glomerular density were combined with other MRI metrics to distinguish the AKI and CKD groups from controls. Despite significant heterogeneity, the noninvasive (MRI-based) metrics were as accurate as invasive (histological) metrics at distinguishing AKI and CKD from controls. To assess the toxicity of cationic ferritin in a CKD model, CKD-4 mice received cationic ferritin and were examined one week later. The CKD-4 groups with and without cationic ferritin were similar, except the iron content of the kidney, liver, and spleen was greater in the CKD-4 plus cationic ferritin group. Thus, our study demonstrates the accuracy and safety of CFE-MRI to detect whole kidney pathology allowing for the development of novel biomarkers of kidney disease and providing a foundation for future in vivo longitudinal studies in mouse models of AKI and CKD to track nephron fate.
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Affiliation(s)
- Jennifer R Charlton
- Department of Pediatrics, Division Nephrology, University of Virginia, Charlottesville, Virginia, USA.
| | - Yanzhe Xu
- ASU-Mayo Center for Innovative Imaging, School of Computing, Informatics, Decision Systems Engineering, Arizona State University, Tempe, Arizona, USA
| | - Teresa Wu
- ASU-Mayo Center for Innovative Imaging, School of Computing, Informatics, Decision Systems Engineering, Arizona State University, Tempe, Arizona, USA
| | - Kim A deRonde
- Department of Pediatrics, Division Nephrology, University of Virginia, Charlottesville, Virginia, USA
| | | | - Shourik Dutta
- School of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Gavin T Oxley
- University of Virginia, Charlottesville, Virginia, USA
| | | | - Helen P Cathro
- Department of Pathology University of Virginia, Charlottesville, Virginia, USA
| | - Nathan P Charlton
- Department of Toxicology, University of Virginia, Virginia, Charlottesville, USA
| | - Mark R Conaway
- Division of Translational Research and Applied Statistics Department of Public Health Sciences, University of Virginia, Charlottesville, Virginia, USA
| | - Edwin J Baldelomar
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Neda Parvin
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Kevin M Bennett
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri, USA
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17
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Sasaki T, Tsuboi N, Marumoto H, Okabayashi Y, Haruhara K, Kanzaki G, Koike K, Ogura M, Ninomiya T, Yokoo T. Nephron Number and Time to Remission in Steroid-Sensitive Minimal Change Disease. Kidney Med 2020; 2:559-568.e1. [PMID: 33094274 PMCID: PMC7568083 DOI: 10.1016/j.xkme.2020.05.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
RATIONALE & OBJECTIVE The response to corticosteroid therapy may differ among patients with minimal change disease (MCD). Previous studies have suggested that glomerular hypertrophy or low areal glomerular density in biopsy specimens, which may be related to fewer nephrons, is associated with such a difference. We examined the associations between nephron number and the therapeutic response to corticosteroids in patients with MCD. STUDY DESIGN Retrospective cohort study. SETTING & PARTICIPANTS 75 adult patients with a histologic diagnosis of MCD. EXPOSURE Nephron number per kidney estimated based on the combination of unenhanced computed tomography and nonsclerotic volumetric glomerular density in kidney biopsy specimens. OUTCOMES Complete remission and relapse following corticosteroid therapy. ANALYTICAL APPROACH Multivariable Cox proportional hazard analyses of associations between factors, including nephron number, and outcomes. RESULTS Mean age of patients was 45.9 years and 60.0% were men. Patients had an estimated glomerular filtration rate of 64.6 mL/min/1.73 m2 and proteinuria of 8.7 g/d. The estimated total number of nonsclerotic glomeruli ranged from 1.07 to 18.77 ×105 per kidney among all patients. There were no significant differences in total amounts or selectivity of urinary protein excretion at biopsy among the tertile groups categorized by nephron number. All patients responded to corticosteroid therapy, but those with fewer nephrons had a delayed achievement of complete remission. Multivariable Cox proportional hazard analyses identified nephron number as a significant independent explanatory variable for the achievement of complete remission, with a hazard ratio of 1.10 (95% CI, 1.02-1.19)/100,000 nephrons per kidney. Nephron number in these patients was not associated with achievement of partial remission or relapse following complete remission. LIMITATION Retrospective design and sampling bias of needle biopsy. CONCLUSIONS A small nephron number in patients with MCD is associated with longer time to complete remission.
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Affiliation(s)
- Takaya Sasaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Hirokazu Marumoto
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Yusuke Okabayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kotaro Haruhara
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Go Kanzaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kentaro Koike
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Makoto Ogura
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Toshiharu Ninomiya
- Department of Epidemiology and Public Health, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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Van den Berge BT, Maas RJ. Nephron Number as Predictor of Corticosteroid Response in Adult Minimal Change Disease. Kidney Med 2020; 2:520-522. [PMID: 33090125 PMCID: PMC7568060 DOI: 10.1016/j.xkme.2020.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Bartholomeus T Van den Berge
- Department of Nephrology, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Pathology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Rutger J Maas
- Department of Nephrology, Radboud University Medical Center, Nijmegen, the Netherlands
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19
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Dietary Protein Intake and Single-Nephron Glomerular Filtration Rate. Nutrients 2020; 12:nu12092549. [PMID: 32842498 PMCID: PMC7551595 DOI: 10.3390/nu12092549] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 08/17/2020] [Accepted: 08/20/2020] [Indexed: 12/25/2022] Open
Abstract
High protein intake can increase glomerular filtration rate (GFR) in response to excretory overload, which may exacerbate the progression of kidney disease. However, the direct association between glomerular hemodynamic response at the single-nephron level and dietary protein intake has not been fully elucidated in humans. In the present study, we evaluated nutritional indices associated with single-nephron GFR (SNGFR) calculated based on corrected creatinine clearance (SNGFRCr). We retrospectively identified 43 living kidney donors who underwent enhanced computed tomography and kidney biopsy at the time of donation at Jikei University Hospital in Tokyo from 2007 to 2018. Total nephron number was estimated with imaging-derived cortical volume and morphometry-derived glomerular density. SNGFRCr was calculated by dividing the corrected creatinine clearance by the number of non-sclerosed glomeruli (NglomNSG). The mean (± standard deviation) NglomNSG/kidney and SNGFRCr were 685,000 ± 242,000 and 61.0 ± 23.9 nL/min, respectively. SNGFRCr was directly associated with estimated protein intake/ideal body weight (p = 0.005) but not with body mass index, mean arterial pressure, albumin, or sodium intake. These findings indicate that greater protein intake may increase SNGFR and lead to glomerular hyperfiltration.
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20
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Rasała J, Szczot M, Kościelska-Kasprzak K, Szczurowska A, Poznański P, Mazanowska O, Małkiewicz B, Dębiński P, Krajewska M, Kamińska D. Computed Tomography Parameters and Estimated Glomerular Filtration Rate Formulas for Peridonation Living Kidney Donor Assessment. Transplant Proc 2020; 52:2278-2283. [PMID: 32505497 DOI: 10.1016/j.transproceed.2020.03.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/02/2020] [Accepted: 03/30/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Renal function is usually described by the estimated glomerular filtration rate (eGFR). The standard method used for living kidney donor evaluation in our center is the 24-hour urine creatinine clearance (CrCl) and kidney morphology assessment with computed tomography (CT). The aim of the study was the analysis of the correlation of CrCl with 15 published eGFR formulas and morphologic CT parameters to choose the most accurate kidney function estimation method before and after donation. METHODS The study included 39 living donors (18 male and 21 female, aged 32-69 years; mean age, 51.4 [SD, 9.7] years). The eGFR was estimated using Cockcroft-Gault, Modification of Diet in Renal Disease 7, Modification of Diet in Renal Disease 4, Chronic Kidney Disease Epidemiology Collaboration, Mayo Clinic, Nankivell, Bjornsson, Davis-Chandler, Edward-Whyte, Walser, Gates, Hull, Jelliffe-1, Jelliffe-2, or Mawer formulas and correlated with CrCl. CT parameters (kidney dimensions, volume, vascularization) were compared with eGFR formulas. RESULTS The 25% to 34% (mean, 28.5% [SD, 2.3%]) decrease in eGFR after donation and its 1.5% to 5.0% (mean, 3.2% [SD, 1.0%]) increase over a year were observed. Cockcroft-Gault, Bjornsson, Hull, and Mawer equations (all including serum creatinine, age, sex, and body mass) correlated with predonation CrCl (r = 0.54, 0.53, 0.53, and 0.56, respectively; P < .001). From CT parameters, renal cortex volume correlated with CrCl (r = 0.48, P = .002) as well as the 4 abovementioned equations before donation (r = 0.65, 0.61, 0.64, and 0.74, respectively; P < .001) and during the postdonation period (12-month r = 0.59, 0.54, 0.57, and 0.70 respectively; P < .002). CONCLUSIONS The eGFR calculated with equations combining serum creatinine, age, sex, and body mass as well as renal cortex volume are predictive of pre- and postdonation kidney function.
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Affiliation(s)
- Julia Rasała
- Faculty of Medicine Wroclaw Medical University, Wrocław, Poland.
| | - Mikołaj Szczot
- Faculty of Medicine Wroclaw Medical University, Wrocław, Poland
| | | | - Agata Szczurowska
- Department of General Radiology, Interventional Radiology, and Neuroradiology, Wroclaw Medical University, Wrocław, Poland
| | - Paweł Poznański
- Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wrocław, Poland
| | - Oktawia Mazanowska
- Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wrocław, Poland
| | - Bartosz Małkiewicz
- Department of Urology and Oncological Urology, Wroclaw Medical University, Wrocław, Poland
| | - Paweł Dębiński
- Department of Urology and Oncological Urology, Wroclaw Medical University, Wrocław, Poland
| | - Magdalena Krajewska
- Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wrocław, Poland
| | - Dorota Kamińska
- Department of Nephrology and Transplantation Medicine, Wroclaw Medical University, Wrocław, Poland
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21
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Okabayashi Y, Tsuboi N, Sasaki T, Haruhara K, Kanzaki G, Koike K, Shimizu A, D'Agati VD, Yokoo T. Single-Nephron GFR in Patients With Obesity-Related Glomerulopathy. Kidney Int Rep 2020; 5:1218-1227. [PMID: 32775821 PMCID: PMC7403629 DOI: 10.1016/j.ekir.2020.05.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 04/28/2020] [Accepted: 05/04/2020] [Indexed: 02/07/2023] Open
Abstract
Introduction Obesity-related glomerulopathy (ORG) is a slowly progressive kidney disease occurring in association with obesity. It is characterized histopathologically by glomerulomegaly, likely caused by single-nephron hyperfiltration that has not been demonstrated in humans because of technical difficulty in measuring single-nephron glomerular filtration rate (SNGFR) in the clinical setting. Methods Total glomerular number per kidney, with or without global glomerulosclerosis, was estimated by the combination of cortical volume assessment via unenhanced computed tomography and biopsy-based stereology. Mean glomerular volume was calculated from the measured area of glomerular tufts. Both SNGFR and single-nephron urinary protein excretion (SNUPE) were estimated by dividing values for estimated glomerular filtration rate and urinary protein excretion by the number of nonsclerotic glomeruli. Living kidney donors were used as healthy controls. Results A total of 48 ORG patients with average nonsclerotic glomerular numbers of 456,000 ± 235,000 per kidney were included. The values for SNGFR in ORG patients with chronic kidney disease (CKD) stages 1 and 2 were higher than for nonobese and obese controls (97 ± 43 vs. 59 ± 21 vs. 64 ± 21 nl/min, respectively, P = 0.001). Nonsclerotic glomerular number decreased with advancing stages of renal functional impairment. The presence of ORG with more advanced CKD stages was associated with lower SNGFR and marked elevation in SNUPE levels, with no difference in the mean glomerular volume between the stages. Conclusions These results provide functional evidence for single-nephron hyperfiltration in patients with ORG, and identify compensatory failure to maintain effective SNGFR as a feature of advanced-stage ORG.
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Affiliation(s)
- Yusuke Okabayashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Nobuo Tsuboi
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Takaya Sasaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kotaro Haruhara
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Go Kanzaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kentaro Koike
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Akira Shimizu
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo, Japan
| | - Vivette D D'Agati
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York, USA
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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