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Deleersnijder D, Knops N, Trouet D, Van Hoeck K, Karamaria S, Vande Walle J, Mauel R, Cools L, Meeus G, Dendooven A, De Meester J, Laurens W, Sprangers B. Epidemiology and clinicopathological characteristics of native kidney disease in children in Flanders, Belgium. Pediatr Nephrol 2022; 38:1533-1545. [PMID: 36227435 DOI: 10.1007/s00467-022-05719-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/07/2022] [Accepted: 08/02/2022] [Indexed: 10/17/2022]
Abstract
BACKGROUND The Flemish Collaborative Glomerulonephritis Group (FCGG) registry is a population-based kidney biopsy registry that has been including all native kidney biopsies performed in children in Flanders (Belgium), since 2017. METHODS From 2017 to 2020, 148 pediatric (< 18 years) native kidney biopsies were included. Each biopsy received a histopathological and final nephrological diagnosis, and concordance between both was assessed. Disease chronicity, summarized by the Mayo Clinic Chronicity Score, was determined on 122 biopsies with > 5 glomeruli. RESULTS Kidney biopsy rate was high (29.0 biopsies per million children per year), median age was 10.0 years (IQR 5.8-14.7), and boys predominated (56.1% males). A total of 140 biopsies (94.6%) showed a representative pathology result. Glomerular disease was most prevalent, with IgA nephropathy/IgA vasculitis (43 biopsies, 29.1%) and minimal change disease (MCD) (29 biopsies, 19.6%) being the overall most frequent diagnoses. In general, diagnostic concordance was high (80.7%). In Alport syndrome and focal segmental glomerulosclerosis (FSGS), concordance was lower, as the nephrological diagnosis was often determined by results of genetic analysis. Nephrotic syndrome was the most frequent indication for kidney biopsy (31.8%) and was mainly caused by MCD and FSGS. The degree of disease chronicity on kidney biopsies was generally low, although 27.3% of biopsies with a diagnosis of FSGS showed moderate-to-severe chronic damage. CONCLUSIONS The presented epidemiological findings validate data from previous European registry studies and may inspire kidney biopsy registries worldwide to implement novel features such as clinicopathological concordance and chronicity grading. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Dries Deleersnijder
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Louvain, Belgium. .,Division of Nephrology, University Hospitals Leuven, Louvain, Belgium.
| | - Noël Knops
- Pediatric Nephrology and Solid Organ Transplantation, University Hospitals Leuven, Louvain, Belgium.,Department of Development and Regeneration, KU Leuven, Louvain, Belgium
| | - Dominique Trouet
- Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Antwerp, Wilrijk, Belgium.,Department of Pediatric Nephrology, Antwerp University Hospital, Edegem, Belgium
| | - Koen Van Hoeck
- Department of Pediatric Nephrology, Antwerp University Hospital, Edegem, Belgium
| | - Sevasti Karamaria
- Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium.,Department of Pediatric Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Johan Vande Walle
- Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium.,Department of Pediatric Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Reiner Mauel
- Department of Pediatrics, University Hospital Brussels, Brussels, Belgium
| | - Louise Cools
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Louvain, Belgium
| | - Gert Meeus
- Department of Nephrology, AZ Groeninge Hospital, Kortrijk, Belgium
| | - Amélie Dendooven
- Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Antwerp, Wilrijk, Belgium.,Division of Pathology, University Hospital Ghent, Ghent, Belgium
| | - Johan De Meester
- Department of Nephrology and Dialysis, VITAZ Hospital, Sint-Niklaas, Belgium
| | - Wim Laurens
- Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium.,Department of Nephrology and Dialysis, VITAZ Hospital, Sint-Niklaas, Belgium
| | - Ben Sprangers
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Louvain, Belgium. .,Division of Nephrology, University Hospitals Leuven, Louvain, Belgium.
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Deleersnijder D, Laurens W, De Meester J, Cleenders E, Dendooven A, Lerut E, De Vriese AS, Dejagere T, Helbert M, Hellemans R, Koshy P, Maes B, Pipeleers L, Van Craenenbroeck AH, Van Laecke S, Vande Walle J, Couttenye MM, Meeus G, Sprangers B, De Rycke A, Bogaert AM, Woestenburg A, Denys B, Maes B, Peeters D, Vanbelleghem H, Donck J, Scharpé J, De Clippeleir N, Colson A, Meyvis K, Vandepitte K, Reyns LM, Peeters J, Decupere M, Helbert M, Zeegers M, Neirynck N, Bernaert P, Dejagere T, Lemahieu W, Sprangers B, Pipeleers L, Hellemans R, Van Laecke S, Knops N, Levtchenko E, Walle JV, Karamaria S, Van Hoeck K, Trouet D, Mauel R, Dendooven A, Hoorens A, Van Dorpe J, Praet M, Geers C, Lerut E, Koshy P, Roskams T, Aydin S, Siozopoulou V, Schelfhout AM, De Raeve H, Steenkiste E, Dedeurwaerdere F, Dalle I, Cokelaere K, Deloose S, De Paepe P, Van Eyken P. Clinicopathological characteristics and disease chronicity in native kidney biopsies in Flanders. Clin Kidney J 2022; 16:125-137. [PMID: 36726429 PMCID: PMC9871845 DOI: 10.1093/ckj/sfac208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Indexed: 02/04/2023] Open
Abstract
Background The Flemish Collaborative Glomerulonephritis Group (FCGG) registry provides complete population data on kidney disease epidemiology in the region of Flanders (Belgium), as it captures all native kidney biopsies performed in its population of 6.5 million inhabitants. Methods From 2017 until 2019, 2054 adult kidney biopsies were included from 26 nephrology centers (one biopsy per patient). Data on nephrotic and nephritic syndrome were available in 1992 and 2026 biopsies, respectively. In a subgroup of 898 biopsies containing ≥10 glomeruli from 2018 to 2019, disease chronicity was graded using the Mayo Clinic Chronicity Score (MCCS). The association between clinical variables and MCCS was determined using simple and multiple linear regression models. Results Nephrotic syndrome (present in 378 patients, 19.0%) was most frequently caused by minimal change disease in younger patients (18-44 years), membranous nephropathy in older patients (45-74 years) and amyloidosis in the elderly (>75 years). Nephritic syndrome (present in 421 patients, 20.8%) was most frequently caused by immunoglobulin A nephropathy (IgAN) in younger patients (18-64 years) and ANCA-associated vasculitis (AAV) in older patients (>64 years). AAV and IgAN were the most frequent underlying diagnoses in biopsies in which crescents were identified. In multivariable analysis, acute and chronic kidney disease and diagnoses of diabetic kidney disease, nephrosclerosis and hyperoxaluria/hypercalcemic nephropathy were associated with the highest MCCS increases. Conclusions The FCGG registry validates data from previous Western European registries and provides a snapshot of disease chronicity in the whole biopsied Flemish population.
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Affiliation(s)
| | | | - Johan De Meester
- Department of Nephrology and Dialysis, VITAZ Hospital, Sint-Niklaas, Belgium
| | - Evert Cleenders
- Department of Microbiology, Immunology and Transplantation, Nephrology and Renal Transplantation Research Group, KU Leuven, Leuven, Belgium
| | - Amélie Dendooven
- Division of Pathology, University Hospital Ghent, Ghent, Belgium,Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Wilrijk, Belgium
| | - Evelyne Lerut
- Department of Imaging and Pathology, KU Leuven, Leuven, Belgium,Department of Pathology, University Hospitals Leuven, Leuven, Belgium
| | - An S De Vriese
- Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium,Department of Nephrology and Infectious Diseases, AZ Sint-Jan, Brugge, Belgium
| | - Tom Dejagere
- Department of Nephrology, Jessa Hospital, Hasselt, Belgium
| | - Mark Helbert
- Department of Nephrology, ZNA Middelheim Hospital, Antwerp, Belgium
| | - Rachel Hellemans
- Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Wilrijk, Belgium,Department of Nephrology, Antwerp University Hospital, Edegem, Belgium
| | - Priyanka Koshy
- Department of Pathology, University Hospitals Leuven, Leuven, Belgium
| | - Bart Maes
- Department of Nephrology, AZ Delta, Roeselare, Belgium
| | - Lissa Pipeleers
- Department of Nephrology, University Hospital Brussels, Brussels, Belgium
| | - Amaryllis H Van Craenenbroeck
- Department of Nephrology, University Hospitals Leuven, Leuven, Belgium,Department of Microbiology, Immunology and Transplantation, Nephrology and Renal Transplantation Research Group, KU Leuven, Leuven, Belgium
| | - Steven Van Laecke
- Renal Division, Department of Internal Medicine, Ghent University Hospital, Ghent, Belgium
| | - Johan Vande Walle
- Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium,Department of Pediatric Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Marie M Couttenye
- Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Wilrijk, Belgium,Department of Nephrology, Antwerp University Hospital, Edegem, Belgium
| | - Gert Meeus
- Department of Nephrology, AZ Groeninge Hospital, Kortrijk, Belgium
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Laurens W, Deleersnijder D, Dendooven A, Lerut E, De Vriese AS, Dejagere T, Helbert M, Hellemans R, Koshy P, Maes B, Pipeleers L, Van Craenenbroeck AH, Van Laecke S, Walle JV, Coutteneye MM, De Meester J, Sprangers B, De Vriese A, De Rycke A, Bogaert AM, Woestenburg A, Denys B, Maes B, Peeters D, Vanbelleghem H, Donck J, Scharpé J, De Clippeleir N, Vanparys J, Meyvis K, Vandepitte K, Reyns LM, Verresen L, Decupere M, Helbert M, Zeegers M, Neirynck N, Bernaert P, Dejagere T, Lemahieu W, Sprangers B, Pipeleers L, Hellemans R, Van Laecke S, Levtchenko E, Karamaria S, Van Hoeck K, Trouet D, Mauel R, Dendooven A, Hoorens A, Van Dorpe J, Praet M, Geers C, Lerut E, Koshy P, Roskams T, Aydin S, Siozopoulou V, Schelfhout AM, De Raeve H, Steenkiste E, Dedeurwaerdere F, Dalle I, Cokelaere K, Deloose S, De Paepe P, Van Eyken P. Epidemiology of native kidney disease in Flanders: results from the FCGG kidney biopsy registry. Clin Kidney J 2022; 15:1361-1372. [PMID: 35756729 PMCID: PMC9217646 DOI: 10.1093/ckj/sfac033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Indexed: 11/30/2022] Open
Abstract
Background The Flemish Collaborative Glomerulonephritis Group (FCGG) registry is the first population-based native kidney biopsy registry in Flanders, Belgium. In this first analysis, we report on patient demographics, frequency distribution and incidence rate of biopsied kidney disease in adults in Flanders. Methods From January 2017 to December 2019, a total of 2054 adult first native kidney biopsies were included. A ‘double diagnostic coding’ strategy was used, in which every biopsy sample received a histopathological and final clinical diagnosis. Frequency distribution and incidence rate of both diagnoses were reported and compared with other European registries. Results The median age at biopsy was 61.1 years (interquartile range, 46.1–71.7); male patients were more prevalent (62.1%) and biopsy incidence rate was 129.3 per million persons per year. Immunoglobulin A nephropathy was the most frequently diagnosed kidney disease (355 biopsies, 17.3% of total) with a similar frequency as in previously published European registries. The frequency of tubulointerstitial nephritis (220 biopsies, 10.7%) and diabetic kidney disease (154 biopsies, 7.5%) was remarkably higher, which may be attributed to changes in disease incidence as well as biopsy practices. Discordances between histopathological and final clinical diagnoses were noted and indicate areas for improvement in diagnostic coding systems. Conclusions The FCGG registry, with its ‘double diagnostic coding’ strategy, provides useful population-based epidemiological data on a large Western European population and allows subgroup selection for future research.
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Affiliation(s)
- Wim Laurens
- Department of Nephrology and Dialysis, AZ Nikolaas Hospital, Sint-Niklaas, Belgium
- Department of Internal Medicine and Pediatrics, Ghent University, Belgium
| | - Dries Deleersnijder
- Department of Microbiology, Immunology and Transplantation, Laboratory of Molecular Immunology, Rega Institute, KU Leuven, Leuven, Belgium
- Division of Nephrology, University Hospitals Leuven, Leuven, Belgium
| | - Amélie Dendooven
- Division of Pathology, University Hospital Ghent, Ghent, Belgium
- Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Wilrijk, Belgium
| | - Evelyne Lerut
- Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
- Department of Pathology, University Hospitals Leuven, Leuven, Belgium
| | - An S De Vriese
- Department of Internal Medicine and Pediatrics, Ghent University, Belgium
- Division of Nephrology and Infectious Diseases, AZ Sint-Jan, Brugge, Belgium
| | - Tom Dejagere
- Department of Nephrology, Jessa Hospital, Hasselt, Belgium
| | - Mark Helbert
- Department of Nephrology, ZNA Middelheim Hospital, Antwerp, Belgium
| | - Rachel Hellemans
- Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Wilrijk, Belgium
- Department of Nephrology, Antwerp University Hospital, Edegem, Belgium
| | - Priyanka Koshy
- Department of Pathology, University Hospitals Leuven, Leuven, Belgium
| | - Bart Maes
- Department of Nephrology, AZ Delta, Roeselare, Belgium
| | - Lissa Pipeleers
- Department of Nephrology, University Hospital Brussels, Brussels, Belgium
| | - Amaryllis H Van Craenenbroeck
- Division of Nephrology, University Hospitals Leuven, Leuven, Belgium
- Department of Microbiology, Immunology and Transplantation, Nephrology and Renal Transplantation Research Group, KU Leuven, Leuven, Belgium
| | - Steven Van Laecke
- Renal Division, Department of Internal Medicine, Ghent University Hospital, Ghent, Belgium
| | - Johan Vande Walle
- Department of Internal Medicine and Pediatrics, Ghent University, Belgium
- Department of Pediatric Nephrology, Ghent University Hospital, Ghent, Belgium
| | - Marie M Coutteneye
- Laboratory of Experimental Medicine and Pediatrics, University of Antwerp, Wilrijk, Belgium
- Department of Nephrology, Antwerp University Hospital, Edegem, Belgium
| | - Johan De Meester
- Department of Nephrology and Dialysis, AZ Nikolaas Hospital, Sint-Niklaas, Belgium
| | - Ben Sprangers
- Department of Microbiology, Immunology and Transplantation, Laboratory of Molecular Immunology, Rega Institute, KU Leuven, Leuven, Belgium
- Division of Nephrology, University Hospitals Leuven, Leuven, Belgium
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Laurens W, De Meester J, Sprangers B, Van Laecke S, Amélie D, Evelyne L, Vande Walle J, An DV, Pipeleers L, Bart M, Mark H, Hellemans R, Tom D. P0114BENEFITS AND CHALLENGES OF A RENAL BIOPSY REGISTRY AND NETWORK - FCGG EXPERIENCE. Nephrol Dial Transplant 2020. [DOI: 10.1093/ndt/gfaa142.p0114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background and Aims
End December 2016, a renal biopsy network in the Flemish region (Belgium) was founded as a collaboration between the renal pathologists and nephrologists. This FCGG network introduced a uniform renal biopsy request form, a well-structured report form of the renal pathology examination and a comprehensive list of renal pathology diagnoses.
Method
Following informed consent [99.5%] and in compliance with GDPR, the registration of the renal biopsies consists of basic categorical renal data, structured renal pathology information and the final clinical renal disease.
Results
In 2017 and 2018, 1385 renal biopsies were registered – 10.5 per million inhabitants per year; in addition, 28 patients had a repeat biopsy in the same time frame (2%). Of the pediatric patients ( age < 18 years; N=92; 6.6%), 23 had IgA nephropathy, 20 a minimal change disease and 15 another type of glomerulonephritis. The biopsy was reported as normal or non-diagnostic in 15 patients (16%) – the majority was clinically considered as glomerulonephritis. The spectrum of the adult population was quite similar across gender and age groups: 56% glomerulonephritis [= IgA nephropathy [19%] + FSGS [8%] + pauci-immune glomerulonephritis [7%] + other GN [22%] ), 10% tubulo-interstitial nephritis, 7% acute tubular necrosis [ATN], 7% diabetes mellitus, and 7% nephroangiosclerosis. Exceptions are pauci-immune glomerulonephritis as the most important renal disease in women aged 65 years and older, and lupus nephritis as the second most important glomerulonephritis in women aged 18-44 years. Only a small percentage of adult renal biopsies yielded no result (7%), clinically interpreted as glomerulonephritis in 50% of the cases.
Conclusion
The FCGG network has provided a more intense collaboration between renal pathologists and nephrologists mainly by standardizing the renal biopsy reading and reporting across all centers. More precise estimates of the prevalent renal diseases were provided for the first time; however, in order to get full information, renal diseases diagnosed by other techniques ( serology, genetic analysis ) should also be collected in the future. Efforts will be done to coordinate the clinical care of renal diseases, particularly the more rare renal diseases, and to offer access to new therapeutic molecules or new schemes, through this super-regional network.
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Affiliation(s)
- Wim Laurens
- AZ Nikolaas, Nephrology & Dialysis, Sint-Niklaas, Belgium
| | | | - Ben Sprangers
- UZ Leuven, Nephrology, Dialysis & Transplantation, Leuven, Belgium
| | | | | | | | | | - De Vriese An
- AZ Sint-Jan, Nephrology & Dialysis, Brugge, Belgium
| | - Lissa Pipeleers
- UZ Brussel, Nephrology, Dialysis & Transplantation, Jette, Belgium
| | - Maes Bart
- AZ Delta, Nephrology & Dialysis, Roeselare, Belgium
| | - Helbert Mark
- ZNA Antwerpen, Nephrology & Dialysis, Antwerpen, Belgium
| | - Rachel Hellemans
- UZ Antwerpen, Nephrology, Dialysis & Transplantation, Edegem, Belgium
| | - Dejagere Tom
- Jessaziekenhuis, Nephrology & Dialysis, Hasselt, Belgium
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Dendooven A, Laurens W, Helbert M, De Paepe P, Lerut E, De Vriese A, Nguyen T. MP085DEVELOPMENT OF A NEW RENAL PATHOLOGY CODING LIST FOR THE FLEMISH RENAL BIOPSY (FCGG) REGISTRY. Nephrol Dial Transplant 2017. [DOI: 10.1093/ndt/gfx162.mp085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Macconi D, Laurens W, Paris S, Battaglia C, Bertani T, Remuzzi G, Remuzzi A. Selective dietary restriction of protein and calorie intakes prevents spontaneous proteinuria in male MWF rats. Exp Nephrol 1997; 5:404-13. [PMID: 9386977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND/AIMS Previous observations indicate that protein and calorie restrictions can affect the course of renal disease progression. We compared the effects of selective protein and calorie restriction on glomerular hemodynamics and proteinuria in a model of spontaneous glomerular injury in the rat. METHODS Three groups of male MWF rats were assigned to three different diets: standard diet (ST, 19% protein, 3.4 kcal/g), low protein (LP) and low calorie (LC). Proteinuria and systolic blood pressure were periodically measured. Glomerular hemodynamics and tuft volume were determined after 2 months of dietary treatment. RESULTS The effective mean protein intake was 3.4 +/- 0.4, 1.6 +/- 0.2, and 3.2 +/- 0.2 g/day/rat, respectively, for the ST, LP, and LC diets, while caloric intake averaged 60 +/- 7, 59 +/- 9, and 30 +/- 2 kcal/day/rat. Both LP and LC diets significantly prevented proteinuria (104 +/- 32, 36 +/- 9, and 18 +/- 8 mg/day, respectively, in the three groups). The systolic blood pressure was unaffected by the diets. The LC diet induced lower body and kidney weights than the ST diet. The glomerular filtration rate was slightly but significantly increased by the LP diet, but not by the LC diet (0.64 +/- 0.14, 0.81 +/- 0.08, and 0.67 +/- 0.12 ml/min, respectively, for ST, LP and LC diets). The glomerular hydraulic pressures were not affected by the diets. No differences were also observed in glomerular volume. The incidences of glomerulosclerosis and tubulointerstitial changes were comparable in ST and LP diets and completely absent in the LC diet group. CONCLUSION These results indicate that restriction of both protein and calorie intakes prevents spontaneous proteinuria in male MWF rats by preventing deterioration of glomerular perm-selective functions.
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Affiliation(s)
- D Macconi
- Mario Negri Institute for Pharmacological Research, Bergamo, Italy.
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Laurens W, Battaglia C, Foglieni C, De Vos R, Malanchini B, Van Damme B, Vanrenterghem Y, Remuzzi G, Remuzzi A. Direct podocyte damage in the single nephron leads to albuminuria in vivo. Kidney Int 1995; 47:1078-86. [PMID: 7783404 DOI: 10.1038/ki.1995.154] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The hypothesis that detachment of podocytes leads to albuminuria was tested by studying the single nephron albuminuria in vivo after injecting a saponin solution (0.6 mg/ml) in Bowman's space of superficial glomeruli, which produces selective damage of the podocytes, in female Munich-Wistar-Frömter rats. Animals were subsequently installed under a fluorescence microscope, a purified fluoresceinated rat albumin solution was intravenously injected and the passage of the fluorescent albumin was followed through the microscope. Of the 47 glomeruli injected with the saponin solution (in 6 animals) 46 became fluorescent within seconds with the fluorescence progressing from Bowman's space into the proximal tubule and then in the rest of the tubule. In superficial non-injected and control-injected glomeruli weak fluorescence could be detected only in the glomerular tuft and the peritubular capillaries. Tubuli injected with the saponin solution remained indistinguishable from non-injected tubuli. Electron microscopic study of the saponin-injected glomeruli confirmed the selective removal of podocytes. Immunogold electron microscopy confirmed that the intact albumin molecule effectively passed the glomerular capillary wall at the site where podocyte detachment had occurred. It is concluded that selective removal of podocytes at the single nephron level leads to albuminuria in vivo, and therefore podocytes play a crucial role in regulating the permeability of the glomerular capillary wall.
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Affiliation(s)
- W Laurens
- Mario Negri Institute for Pharmacological Research, Ospedali Riuniti di Bergamo, Italy
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