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Gross O, Haffner D, Schaefer F, Weber LT. SGLT2 inhibitors: approved for adults and cats but not for children with CKD. Nephrol Dial Transplant 2024; 39:907-909. [PMID: 38308509 DOI: 10.1093/ndt/gfae029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Indexed: 02/04/2024] Open
Affiliation(s)
- Oliver Gross
- Nephrology and Rheumatology, University Medical Center Goettingen, Goettingen, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Franz Schaefer
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Lutz T Weber
- Pediatric Nephrology, Children's and Adolescents' Hospital, University Hospital of Cologne, Faculty of Medicine, University of Cologne, Cologne, Germany
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2
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Zhao Y, Zheng Q, Xie J. Exploration of Gene Therapy for Alport Syndrome. Biomedicines 2024; 12:1159. [PMID: 38927366 PMCID: PMC11200676 DOI: 10.3390/biomedicines12061159] [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: 03/31/2024] [Revised: 05/04/2024] [Accepted: 05/14/2024] [Indexed: 06/28/2024] Open
Abstract
Alport syndrome is a hereditary disease caused by mutations in the genes encoding the alpha 3, alpha 4, and alpha 5 chains of type IV collagen. It is characterized by hematuria, proteinuria, progressive renal dysfunction, hearing loss, and ocular abnormalities. The main network of type IV collagen in the glomerular basement membrane is composed of α3α4α5 heterotrimer. Mutations in these genes can lead to the replacement of this network by an immature network composed of the α1α1α2 heterotrimer. Unfortunately, this immature network is unable to provide normal physical support, resulting in hematuria, proteinuria, and progressive renal dysfunction. Current treatment options for Alport syndrome include angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, which aim to alleviate glomerular filtration pressure, reduce renal injury, and delay the progression of renal dysfunction. However, the effectiveness of these treatments is limited, highlighting the need for novel therapeutic strategies and medications to improve patient outcomes. Gene therapy, which involves the use of genetic material to prevent or treat diseases, holds promise for the treatment of Alport syndrome. This approach may involve the insertion or deletion of whole genes or gene fragments to restore or disrupt gene function or the editing of endogenous genes to correct genetic mutations and restore functional protein synthesis. Recombinant adeno-associated virus (rAAV) vectors have shown significant progress in kidney gene therapy, with several gene therapy drugs based on these vectors reaching clinical application. Despite the challenges posed by the structural characteristics of the kidney, the development of kidney gene therapy using rAAV vectors is making continuous progress. This article provides a review of the current achievements in gene therapy for Alport syndrome and discusses future research directions in this field.
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Affiliation(s)
- Yafei Zhao
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; (Y.Z.); (Q.Z.)
- Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Qimin Zheng
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; (Y.Z.); (Q.Z.)
- Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jingyuan Xie
- Department of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; (Y.Z.); (Q.Z.)
- Institute of Nephrology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
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Mabillard H, Ryan R, Tzoumas N, Gear S, Sayer JA. Explaining Alport syndrome-lessons from the adult nephrology clinic. JOURNAL OF RARE DISEASES (BERLIN, GERMANY) 2024; 3:14. [PMID: 38745975 PMCID: PMC11088994 DOI: 10.1007/s44162-024-00036-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 02/15/2024] [Indexed: 05/16/2024]
Abstract
Alport syndrome is a genetic kidney disease that causes worsening of kidney function over time, often progressing to kidney failure. Some types of Alport syndrome cause other symptoms and signs, including hearing loss and eye abnormalities. Research now indicates that Alport syndrome (autosomal dominant inheritance) is the most common form. Alport syndrome can have X-linked or a rare form of autosomal recessive inheritance. Traditionally, a kidney biopsy was used to diagnose Alport syndrome, but genetic testing provides a more precise and less invasive means of diagnosis and reveals the underlying pattern of inheritance. At present, there are no specific curative treatments for Alport syndrome however there is a strong international effort in pursuit of future therapies. Currently, angiotensin-converting enzyme inhibitors (ACEi), or an angiotensin receptor blocker (ARB) if a patient cannot tolerate an ACEi, slow down the progression of kidney disease and can delay the onset of kidney failure by years. There are other potential treatments in research that potentially can help delay the onset of kidney issues. Early treatment of patients and identification of their at-risk relatives is a priority. People living with Alport syndrome and their doctors now benefit from an active international research community working on translating further treatments into clinical practice and providing up-to-date clinical guidelines.
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Affiliation(s)
- Holly Mabillard
- Renal Services, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle Upon Tyne, UK
| | - Rebecca Ryan
- Renal Services, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
| | - Nik Tzoumas
- Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Central Parkway, Newcastle Upon Tyne, UK
- Sunderland Eye Infirmary, Sunderland, UK
| | - Susie Gear
- Alport UK, Cirencester, Gloucestershire, UK
| | - John A. Sayer
- Renal Services, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle Upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle Upon Tyne, UK
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4
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Chavez E, Goncalves S, Rheault MN, Fornoni A. Alport Syndrome. ADVANCES IN KIDNEY DISEASE AND HEALTH 2024; 31:170-179. [PMID: 39004457 DOI: 10.1053/j.akdh.2024.02.004] [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: 07/19/2023] [Revised: 02/10/2024] [Accepted: 02/28/2024] [Indexed: 07/16/2024]
Abstract
Alport syndrome (AS) is characterized by progressive kidney failure, hematuria, sensorineural hearing loss, and ocular abnormalities. Pathogenic variants in the COL4A3-5 genes result in a defective deposition of the collagen IV α3α4α5 protomers in the basement membranes of the glomerulus in the kidney, the cochlea in the ear and the cornea, lens capsule and retina in the eye. The presence of a large variety of COL4A3-5 gene(s) pathogenetic variants irrespective of the mode of inheritance (X-linked, autosomal recessive, autosomal dominant, or digenic) with and without syndromic features is better defined as the "Alport spectrum disorder", and represents the most common cause of genetic kidney disease and the second most common cause of genetic kidney failure. The clinical course and prognosis of individuals with AS is highly variable. It is influenced by gender, mode of inheritance, affected gene(s), type of genetic mutation, and genetic modifiers. This review article will discuss the epidemiology, classification, pathogenesis, diagnosis, clinical course with genotype-phenotype correlations, and current and upcoming treatment of patients with AS. It will also review current recommendations with respect to when to evaluate for hearing loss or ophthalmologic abnormalities.
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Affiliation(s)
- Efren Chavez
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL.
| | - Stefania Goncalves
- Department of Otolaryngology-Head and Neck Surgery, University of Miami Miller School of Medicine, University of Miami Ear Institute, Miami, FL
| | - Michelle N Rheault
- Department of Pediatrics, University of Minnesota Masonic Children's Hospital, Minneapolis, MN
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL; Peggy and Harold Katz Family Drug Discovery Center, University of Miami Miller School of Medicine, Miami, FL.
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5
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Huang L, Zou J, Zhang Y, Gu J, Wu J, Zhang C. Human umbilical cord mesenchymal stem cell therapy for renal dysfunction in Alport syndrome: protocol for an open-label, single-arm trial in China. BMJ Open 2024; 14:e075138. [PMID: 38490657 PMCID: PMC10946359 DOI: 10.1136/bmjopen-2023-075138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 02/01/2024] [Indexed: 03/17/2024] Open
Abstract
INTRODUCTION Alport syndrome (AS) is one of the most common fatal hereditary renal diseases in human, with a high risk of progressing to end-stage renal disease without effective treatments. Mesenchymal stem cells (MSCs) have recently emerged as a promising therapeutic strategy for chronic kidney disease. However, the safety and therapeutic potential of MSC transfusion for patients with AS are still need to be confirmed. Therefore, we have designed a clinical trial to evaluate the hypothesis that intravenous infusion of human umbilical cord-derived MSC (hUC-MSC) is safe, feasible, and well-tolerated in children with AS. METHODS AND ANALYSIS We report the protocol of the first prospective, open-label, single-arm clinical trial to evaluate the safety and preliminary efficacy of hUC-MSC transfusion in children with early-stage AS. Paediatric patients diagnosed with AS who have persistent albuminuria will be candidates for screening. Twelve eligible patients are planned to recruit and will receive hUC-MSC infusions under close safety monitoring, and complete the efficacy assessments at scheduled follow-up visits. The primary endpoints include the occurrence of adverse events to assess safety and the albuminuria level for efficacy evaluation. Secondary endpoint assessments are based on haematuria and glomerular filtration measurements. Each patient's efficacy endpoints will be evaluated against their baseline levels. Additionally, the underlying mechanism of hUC-MSC therapy will be explored through transcriptomic and proteomic analysis of blood and urine samples. ETHICS AND DISSEMINATION The protocol (V.1.0, date 17 January 2015) was approved by the institutional review board of the Affiliated Taihe Hospital of Hubei University of Medicine (ethical approval 03 March 2015). Written informed consent will be obtained from the patient and/or guardians before study specific process. In addition to publication in a peer-reviewed scientific journal, a lay summary of study will be available for participants and the public on the Chinese Organization for Rare Disorders website (http://www.cord.org.cn/). TRIAL REGISTRATION NUMBER ISRCTN62094626.
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Affiliation(s)
- Li Huang
- Department of Pharmacy, Shenzhen Second People's Hospital, Shenzhen, Guangdong, China
| | - Jun Zou
- Hainan Women and Children's Medical Center, Haikou, Hainan, China
| | | | | | - Jianlong Wu
- Department of Pharmacy, Shenzhen Second People's Hospital, Shenzhen, Guangdong, China
| | - Che Zhang
- Department of Pharmacy, South China Hospital, Medical School, Shenzhen University, Shenzhen, Guangdong, China
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Madison J, Wilhelm K, Meehan DT, Gratton MA, Vosik D, Samuelson G, Ott M, Fascianella J, Nelson N, Cosgrove D. Ramipril therapy in integrin α1-null, autosomal recessive Alport mice triples lifespan: mechanistic clues from RNA-seq analysis. J Pathol 2024; 262:296-309. [PMID: 38129319 PMCID: PMC10872630 DOI: 10.1002/path.6231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 10/10/2023] [Accepted: 10/29/2023] [Indexed: 12/23/2023]
Abstract
The standard of care for patients with Alport syndrome (AS) is angiotensin-converting enzyme (ACE) inhibitors. In autosomal recessive Alport (ARAS) mice, ACE inhibitors double lifespan. We previously showed that deletion of Itga1 in Alport mice [double-knockout (DKO) mice] increased lifespan by 50%. This effect seemed dependent on the prevention of laminin 211-mediated podocyte injury. Here, we treated DKO mice with vehicle or ramipril starting at 4 weeks of age. Proteinuria and glomerular filtration rates were measured at 5-week intervals. Glomeruli were analyzed for laminin 211 deposition in the glomerular basement membrane (GBM) and GBM ultrastructure was analyzed using transmission electron microscopy (TEM). RNA sequencing (RNA-seq) was performed on isolated glomeruli at all time points and the results were compared with cultured podocytes overlaid (or not) with recombinant laminin 211. Glomerular filtration rate declined in ramipril-treated DKO mice between 30 and 35 weeks. Proteinuria followed these same patterns with normalization of foot process architecture in ramipril-treated DKO mice. RNA-seq revealed a decline in the expression of Foxc2, nephrin (Nphs1), and podocin (Nphs2) mRNAs, which was delayed in the ramipril-treated DKO mice. GBM accumulation of laminin 211 was delayed in ramipril-treated DKO mice, likely due to a role for α1β1 integrin in CDC42 activation in Alport mesangial cells, which is required for mesangial filopodial invasion of the subendothelial spaces of the glomerular capillary loops. Ramipril synergized with Itga1 knockout, tripling lifespan compared with untreated ARAS mice. © 2023 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Jacob Madison
- Boys Town National Research Hospital, Omaha, NE, USA
| | - Kevin Wilhelm
- Boys Town National Research Hospital, Omaha, NE, USA
| | | | | | - Denise Vosik
- Boys Town National Research Hospital, Omaha, NE, USA
| | | | - Megan Ott
- Boys Town National Research Hospital, Omaha, NE, USA
| | | | - Noa Nelson
- Boys Town National Research Hospital, Omaha, NE, USA
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Latta K. [Macrohematuria in children and adolescents]. UROLOGIE (HEIDELBERG, GERMANY) 2024; 63:149-157. [PMID: 38117295 DOI: 10.1007/s00120-023-02254-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/23/2023] [Indexed: 12/21/2023]
Abstract
Hematuria is usually only noticed early in the case of macrohematuria. In around half of affected children, macrohematuria is caused by a urinary tract infection. In all other cases, a careful diagnosis is required. In addition to a detailed medical history, this builds upon a precise examination of the urine (microscopy, quantitative determination of proteinuria [mg albumin/g creatinine in spontaneously voided urine]) and measurement of blood pressure. The work-up usually includes sonography as the primary imaging modality. Invasive diagnostic tests using cystoscopy are only necessary in exceptional cases. If there is evidence of glomerulonephritis, a kidney biopsy may be indicated. Careful attention should be given to persisting microhematuria (> 6 months) and Alport syndrome should be confirmed or ruled out. Heterozygotic Alport syndrome can also be a possible cause of chronic renal failure.
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Affiliation(s)
- Kay Latta
- Clementine Kinderhospital, Theobald Christ Str. 16, 60316, Frankfurt am Main, Deutschland.
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8
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Zhou MS, Lee CD, Lerman BJ, Strong A, LaRosa C. An Adolescent Boy With Hypoxia, Microscopic Hematuria, and Hypertension. Cureus 2024; 16:e52738. [PMID: 38384656 PMCID: PMC10880807 DOI: 10.7759/cureus.52738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2024] [Indexed: 02/23/2024] Open
Abstract
A 13-year-old boy presented with hypoxia, microscopic hematuria, and elevated blood pressures. Persistent microscopic hematuria and hypertension led to investigation of glomerular and non-glomerular causes of hematuria. After reviewing his clinical course, family history, and laboratory testing, an additional test was sent, revealing the diagnosis.
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Affiliation(s)
- Melissa S Zhou
- Pediatrics, Children's Hospital of Philadelphia, Philadelphia, USA
| | - Clement D Lee
- Pediatrics, Children's Hospital of Philadelphia, Philadelphia, USA
| | | | - Alanna Strong
- Genetics, Children's Hospital of Philadelphia, Philadelphia, USA
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9
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Rhode H, Lüse A, Tautkus B, Nabity M, John-Kroegel U, Weigel F, Dost A, Schitke J, Metzing O, Böckhaus J, Rubel D, Kiess W, Gross O. Urinary Protein-Biomarkers Reliably Indicate Very Early Kidney Damage in Children With Alport Syndrome Independently of Albuminuria and Inflammation. Kidney Int Rep 2023; 8:2778-2793. [PMID: 38106579 PMCID: PMC10719601 DOI: 10.1016/j.ekir.2023.09.028] [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: 07/25/2023] [Revised: 09/04/2023] [Accepted: 09/25/2023] [Indexed: 12/19/2023] Open
Abstract
Introduction Alport syndrome (AS) is a hereditary type IV collagen disease. It starts shortly after birth, without clinical symptoms, and progresses to end-stage kidney disease early in life. The earlier therapy starts, the more effectively end-stage kidney disease can be delayed. Clearly then, to ensure preemptive therapy, early diagnosis is an essential prerequisite. Methods To provide early diagnosis, we searched for protein biomarkers (BMs) by mass spectrometry in dogs with AS stage 0. At this very early stage, we identified 74 candidate BMs. Of these, using commercial enzyme-linked immunosorbent assays (ELISAs), we evaluated 27 in dogs and 28 in children, 50 with AS and 104 healthy controls. Results Most BMs from blood appeared as fractions of multiple variants of the same protein, as shown by their chromatographic distribution before mass spectrometry. Blood samples showed only minor differences because ELISAs rarely detect disease-specific variants. However, in urine , several proteins, individually or in combination, were promising indicators of very early and preclinical kidney injury. The BMs with the highest sensitivity and specificity were collagen type XIII, hyaluronan binding protein 2 (HABP2), and complement C4 binding protein (C4BP). Conclusion We generated very strong candidate BMs by our approach of first examining preclinical AS in dogs and then validating these BMs in children at early stages of disease. These BMs might serve for screening purposes for AS before the onset of kidney damage and therefore allow preemptive therapy.
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Affiliation(s)
- Heidrun Rhode
- Institute of Biochemistry I, Jena University Hospital, Jena, Germany
| | - Alexandra Lüse
- Institute of Biochemistry I, Jena University Hospital, Jena, Germany
| | - Bärbel Tautkus
- Institute of Biochemistry I, Jena University Hospital, Jena, Germany
| | - Mary Nabity
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, Texas, USA
| | | | | | - Axel Dost
- Department of Pediatrics, Jena University Hospital, Jena, Germany
| | - Julia Schitke
- Department of Pediatrics, Jena University Hospital, Jena, Germany
| | - Oliver Metzing
- Department of Pediatrics, Jena University Hospital, Jena, Germany
| | - Jan Böckhaus
- Clinics for Nephrology and Rheumatology, University Medical Center Göttingen, Göttingen, Germany
| | - Diana Rubel
- Clinics for Nephrology and Rheumatology, University Medical Center Göttingen, Göttingen, Germany
| | - Wieland Kiess
- Hospital for Children and Adolescents, University of Leipzig, Liebigstr. 20a, 04103 Leipzig, Germany
| | - Oliver Gross
- Clinics for Nephrology and Rheumatology, University Medical Center Göttingen, Göttingen, Germany
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Rheault MN, McLaughlin HM, Mitchell A, Blake LE, Devarajan P, Warady BA, Gibson KL, Lieberman KV. COL4A gene variants are common in children with hematuria and a family history of kidney disease. Pediatr Nephrol 2023; 38:3625-3633. [PMID: 37204491 DOI: 10.1007/s00467-023-05993-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/24/2023] [Accepted: 04/15/2023] [Indexed: 05/20/2023]
Abstract
BACKGROUND Inherited kidney diseases are a common cause of chronic kidney disease (CKD) in children. Identification of a monogenic cause of CKD is more common in children than in adults. This study evaluated the diagnostic yield and phenotypic spectrum of children who received genetic testing through the KIDNEYCODE sponsored genetic testing program. METHODS Unrelated children < 18 years of age who received panel testing through the KIDNEYCODE sponsored genetic testing program from September 2019 through August 2021 were included (N = 832). Eligible children met at least one of the following clinician-reported criteria: estimated GFR ≤ 90 ml/min/1.73 m2, hematuria, a family history of kidney disease, or suspected or biopsy confirmed Alport syndrome or focal segmental glomerulosclerosis (FSGS) in the tested individual or family member. RESULTS A positive genetic diagnosis was observed in 234 children (28.1%, 95% CI [25.2-31.4%]) in genes associated with Alport syndrome (N = 213), FSGS (N = 9), or other disorders (N = 12). Among children with a family history of kidney disease, 30.8% had a positive genetic diagnosis. Among those with hematuria and a family history of CKD, the genetic diagnostic rate increased to 40.4%. CONCLUSIONS Children with hematuria and a family history of CKD have a high likelihood of being diagnosed with a monogenic cause of kidney disease, identified through KIDNEYCODE panel testing, particularly COL4A variants. Early genetic diagnosis can be valuable in targeting appropriate therapy and identification of other at-risk family members. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Michelle N Rheault
- Masonic Children's Hospital, University of Minnesota, Minneapolis, MN, USA.
| | | | | | | | - Prasad Devarajan
- Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH, USA
| | - Bradley A Warady
- Children's Mercy Kansas City, University of Missouri-Kansas City, Kansas City, MO, USA
| | | | - Kenneth V Lieberman
- Joseph M. Sanzari Children's Hospital, Hackensack Meridian School of Medicine, Hackensack, NJ, USA
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Zeng M, Di H, Liang J, Liu Z. Effectiveness of renin-angiotensin-aldosterone system blockers in patients with Alport syndrome: a systematic review and meta-analysis. Nephrol Dial Transplant 2023; 38:2485-2493. [PMID: 37218713 DOI: 10.1093/ndt/gfad105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Indexed: 05/24/2023] Open
Abstract
BACKGROUND Although renin-angiotensin-aldosterone system (RAAS) blockers have been considered the primary treatment for patients with Alport syndrome (AS) for a decade, there is no comprehensive review with evidence-based analysis evaluating the effectiveness of RAAS blockers in AS. METHODS A systematic review and meta-analysis was performed of published studies that compared outcomes related to disease progression between patients with AS receiving RAAS blockers with those taking non-RAAS treatment. Outcomes were meta-analyzed using the random effects models. Cochrane risk-of-bias, Newcastle-Ottawa Scale and Grading of Recommendations Assessment, Development and Evaluation methodology (GRADE) assessment determined the certainty of evidence. RESULTS A total of eight studies (1182 patients) were included in the analysis. Overall, the risk of bias was low to moderate. Compared with non-RAAS treatment, RAAS blockers could reduce the rate of progression to end-stage kidney disease (ESKD) [four studies; hazard ratio (HR) 0.33, 95% confidence interval (CI) 0.24-0.45; moderate certainty evidence]. After stratified by genetic types, a similar benefit was detected: male X-linked AS (XLAS) (HR 0.32, 95% CI 0.22-0.48), autosomal recessive AS (HR 0.25, 95% CI 0.10-0.62), female XLAS and autosomal dominant AS (HR 0.40, 95% CI 0.21-0.75). In addition, RAAS blockers showed a clear gradient of benefit depending on the stage of disease at the initiation of treatment. CONCLUSION This meta-analysis suggested that RAAS blockers could be considered as a specific therapy to delay of ESKD for AS with any genetic type, especially at the early stage of the disease, and every further more-effective therapy would be advised to be applied on top of this standard of care.
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Affiliation(s)
- Mengyao Zeng
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Hongling Di
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Ju Liang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Zhihong Liu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
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12
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Klinkhammer BM, Boor P. Kidney fibrosis: Emerging diagnostic and therapeutic strategies. Mol Aspects Med 2023; 93:101206. [PMID: 37541106 DOI: 10.1016/j.mam.2023.101206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/25/2023] [Indexed: 08/06/2023]
Abstract
An increasing number of patients worldwide suffers from chronic kidney disease (CKD). CKD is accompanied by kidney fibrosis, which affects all compartments of the kidney, i.e., the glomeruli, tubulointerstitium, and vasculature. Fibrosis is the best predictor of progression of kidney diseases. Currently, there is no specific anti-fibrotic therapy for kidney patients and invasive renal biopsy remains the only option for specific detection and quantification of kidney fibrosis. Here we review emerging diagnostic approaches and potential therapeutic options for fibrosis. We discuss how translational research could help to establish fibrosis-specific endpoints for clinical trials, leading to improved patient stratification and potentially companion diagnostics, and facilitating and optimizing development of novel anti-fibrotic therapies for kidney patients.
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Affiliation(s)
| | - Peter Boor
- Institute of Pathology, RWTH Aachen University Hospital, Aachen, Germany; Electron Microscopy Facility, RWTH Aachen University Hospital, Aachen, Germany; Division of Nephrology and Immunology, RWTH Aachen University Hospital, Aachen, Germany.
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13
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Solanki KV, Hu Y, Moore BS, Abedi V, Avula V, Mirshahi T, Strande NT, Bucaloiu ID, Chang AR. The Phenotypic Spectrum of COL4A3 Heterozygotes. Kidney Int Rep 2023; 8:2088-2099. [PMID: 37849993 PMCID: PMC10577321 DOI: 10.1016/j.ekir.2023.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 07/17/2023] [Indexed: 10/19/2023] Open
Abstract
Introduction The penetrance and phenotypic spectrum of autosomal dominant Alport Syndrome (ADAS), affecting 1 in 106, remains understudied. Methods Using data from 174,418 participants in the Geisinger MyCode/DiscovEHR study, an unselected health system-based cohort with whole exome sequencing, we identified 403 participants who were heterozygous for likely pathogenic COL4A3 variants. Phenotypic data was evaluated using International Classification of Diseases (ICD) codes, laboratory data, and chart review. To evaluate the phenotypic spectrum of genetically-determined ADAS, we matched COL4A3 heterozygotes 1:5 to nonheterozygotes using propensity scores by demographics, hypertension, diabetes, and nephrolithiasis. Results COL4A3 heterozygotes were at significantly increased risks of hematuria, decreased estimated glomerular filtration rate (eGFR), albuminuria, and kidney failure (P < 0.05 for all comparisons) but not bilateral sensorineural hearing loss (P = 0.9). Phenotypic severity was more severe for collagenous domain glycine missense variants than protein truncating variants (PTVs). For example, patients with Gly695Arg (n = 161) had markedly increased risk of dipstick hematuria (odds ratio [OR] 9.50; 95% confidence interval [CI]: 6.32, 14.28) and kidney failure (OR 7.02; 95% CI: 3.48, 14.16) whereas those with PTVs (n = 119) had moderately increased risks of dipstick hematuria (OR 1.64; 95% CI: 1.03, 2.59) and kidney failure (OR 3.44; 95% CI: 1.28, 9.22). Less than a third of patients had albuminuria screening completed, and fewer than 1 of 3 were taking inhibitors of the renin-angiotensin-aldosterone system. Conclusion This study demonstrates a wide spectrum of phenotypic severity in ADAS due to COL4A3 with phenotypic variability by genotype. Future studies are needed to evaluate the impact of earlier diagnosis, appropriate evaluation, and treatment of ADAS.
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Affiliation(s)
- Kaushal V Solanki
- Center for Kidney Health Research, Geisinger, Danville, Pennsylvania, USA
| | - Yirui Hu
- Department of Population Health Sciences, Geisinger, Danville, Pennsylvania, USA
| | - Bryn S Moore
- Department of Genomic Health, Geisinger, Danville, Pennsylvania, USA
| | - Vida Abedi
- Department of Public Health Sciences, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania, USA; Road, Tarrytown, New York, USA
| | - Venkatesh Avula
- Department of Genomic Health, Geisinger, Danville, Pennsylvania, USA
| | - Tooraj Mirshahi
- Department of Genomic Health, Geisinger, Danville, Pennsylvania, USA
| | - Natasha T Strande
- Department of Genomic Health, Geisinger, Danville, Pennsylvania, USA
- Autism and Developmental Medicine Institute, Geisinger, Danville, Pennsylvania, USA
| | - Ion D Bucaloiu
- Department of Nephrology, Geisinger, Danville, Pennsylvania, USA
| | - Alexander R Chang
- Center for Kidney Health Research, Geisinger, Danville, Pennsylvania, USA
- Department of Population Health Sciences, Geisinger, Danville, Pennsylvania, USA
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14
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Levy M, Bazak L, Lev-El N, Greenberg R, Kropach N, Basel-Salmon L, Maya I. Potential Founder Variants in COL4A4 Identified in Bukharian Jews Linked to Autosomal Dominant and Autosomal Recessive Alport Syndrome. Genes (Basel) 2023; 14:1854. [PMID: 37895203 PMCID: PMC10606019 DOI: 10.3390/genes14101854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/12/2023] [Accepted: 09/22/2023] [Indexed: 10/29/2023] Open
Abstract
BACKGROUND Alport syndrome is a hereditary disorder caused by pathogenic variants in the COL4A gene, which can be inherited in an autosomal recessive, dominant, or X-linked pattern. In the Bukharian Jewish population, no founder pathogenic variant has been reported in COL4A4. METHODS The cohort included 38 patients from 22 Bukharian Jewish families with suspected Alport syndrome who were referred the nephrogenetics clinic between 2012 and 2022. The study collected demographic, clinical, and genetic data from electronic medical records, which were used to evaluate the molecular basis of the disease using Sanger sequencing, and next-generation sequencing. RESULTS Molecular diagnosis was confirmed in 20/38 patients, with each patient having at least one of the three disease-causing COL4A4 variants detected: c.338G A (p.Gly1008Arg), and c.871-6T>C. In addition, two patients were obligate carriers. Overall, there were 17 heterozygotes, 2 compound heterozygotes, and 3 homozygotes. Each variant was detected in more than one unrelated family. All patients had hematuria with/without proteinuria at referral, and the youngest patient with proteinuria (age 5 years) was homozygous for the c.338G>A variant. End-stage renal disease was diagnosed in two patients at the age of 38 years, a compound heterozygote for c.338G>A and c.871-6T>C. Hearing deterioration was detected in three patients, the youngest aged 40 years, all of whom were heterozygous for c.338G>A. CONCLUSION This study unveils three novel disease-causing variants, c.3022G>A, c.871-6T>C, and c.338G>A, in the COL4A4 gene that are recurrent among Jews of Bukharian ancestry, and cause Alport syndrome in both dominant and recessive autosomal inheritance patterns.
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Affiliation(s)
- Michal Levy
- The Raphael Recanati Genetic Institute, Rabin Medical Center, Petah Tikva 49100, Israel (N.L.-E.); (L.B.-S.); (I.M.)
- School of Medicine, Tel Aviv University, Tel Aviv P.O.B 39040, Israel
| | - Lily Bazak
- The Raphael Recanati Genetic Institute, Rabin Medical Center, Petah Tikva 49100, Israel (N.L.-E.); (L.B.-S.); (I.M.)
| | - Noa Lev-El
- The Raphael Recanati Genetic Institute, Rabin Medical Center, Petah Tikva 49100, Israel (N.L.-E.); (L.B.-S.); (I.M.)
| | - Rotem Greenberg
- The Raphael Recanati Genetic Institute, Rabin Medical Center, Petah Tikva 49100, Israel (N.L.-E.); (L.B.-S.); (I.M.)
| | - Nesia Kropach
- School of Medicine, Tel Aviv University, Tel Aviv P.O.B 39040, Israel
- Pediatric Genetics Unit, Schneider Children’s Medical Center, Petah Tikva 4920235, Israel
| | - Lina Basel-Salmon
- The Raphael Recanati Genetic Institute, Rabin Medical Center, Petah Tikva 49100, Israel (N.L.-E.); (L.B.-S.); (I.M.)
- School of Medicine, Tel Aviv University, Tel Aviv P.O.B 39040, Israel
- Felsenstein Medical Research Center, Petach Tikva 4920235, Israel
| | - Idit Maya
- The Raphael Recanati Genetic Institute, Rabin Medical Center, Petah Tikva 49100, Israel (N.L.-E.); (L.B.-S.); (I.M.)
- School of Medicine, Tel Aviv University, Tel Aviv P.O.B 39040, Israel
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15
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Zhu Z, Rosenkranz KA, Kusunoki Y, Li C, Klaus M, Gross O, Angelotti ML, Antonelli G, Cirillo L, Romagnani P, Bouteldja N, Sadr AV, Bülow RD, Boor P, Anders HJ. Finerenone Added to RAS/SGLT2 Blockade for CKD in Alport Syndrome. Results of a Randomized Controlled Trial with Col4a3-/- Mice. J Am Soc Nephrol 2023; 34:1513-1520. [PMID: 37428955 PMCID: PMC10482061 DOI: 10.1681/asn.0000000000000186] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 06/22/2023] [Indexed: 07/12/2023] Open
Abstract
SIGNIFICANCE STATEMENT We hypothesized that triple therapy with inhibitors of the renin-angiotensin system (RAS), sodium-glucose transporter (SGLT)-2, and the mineralocorticoid receptor (MR) would be superior to dual RAS/SGLT2 blockade in attenuating CKD progression in Col4a3 -deficient mice, a model of Alport syndrome. Late-onset ramipril monotherapy or dual ramipril/empagliflozin therapy attenuated CKD and prolonged overall survival by 2 weeks. Adding the nonsteroidal MR antagonist finerenone extended survival by 4 weeks. Pathomics and RNA sequencing revealed significant protective effects on the tubulointerstitium when adding finerenone to RAS/SGLT2 inhibition. Thus, triple RAS/SGLT2/MR blockade has synergistic effects and might attenuate CKD progression in patients with Alport syndrome and possibly other progressive chronic kidney disorders. BACKGROUND Dual inhibition of the renin-angiotensin system (RAS) plus sodium-glucose transporter (SGLT)-2 or the mineralocorticoid receptor (MR) demonstrated additive renoprotective effects in large clinical trials. We hypothesized that triple therapy with RAS/SGLT2/MR inhibitors would be superior to dual RAS/SGLT2 blockade in attenuating CKD progression. METHODS We performed a preclinical randomized controlled trial (PCTE0000266) in Col4a3 -deficient mice with established Alport nephropathy. Treatment was initiated late (age 6 weeks) in mice with elevated serum creatinine and albuminuria and with glomerulosclerosis, interstitial fibrosis, and tubular atrophy. We block-randomized 40 male and 40 female mice to either nil (vehicle) or late-onset food admixes of ramipril monotherapy (10 mg/kg), ramipril plus empagliflozin (30 mg/kg), or ramipril plus empagliflozin plus finerenone (10 mg/kg). Primary end point was mean survival. RESULTS Mean survival was 63.7±10.0 days (vehicle), 77.3±5.3 days (ramipril), 80.3±11.0 days (dual), and 103.1±20.3 days (triple). Sex did not affect outcome. Histopathology, pathomics, and RNA sequencing revealed that finerenone mainly suppressed the residual interstitial inflammation and fibrosis despite dual RAS/SGLT2 inhibition. CONCLUSION Experiments in mice suggest that triple RAS/SGLT2/MR blockade may substantially improve renal outcomes in Alport syndrome and possibly other progressive CKDs because of synergistic effects on the glomerular and tubulointerstitial compartments.
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Affiliation(s)
- Zhihui Zhu
- Division of Nephrology, Department of Medicine IV, Hospital of the Ludwig-Maximilians-University, Munich, Germany
- Center of Structural Heart Disease, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Karoline A.T. Rosenkranz
- Division of Nephrology, Department of Medicine IV, Hospital of the Ludwig-Maximilians-University, Munich, Germany
| | - Yoshihiro Kusunoki
- Division of Nephrology, Department of Medicine IV, Hospital of the Ludwig-Maximilians-University, Munich, Germany
| | - Chenyu Li
- Division of Nephrology, Department of Medicine IV, Hospital of the Ludwig-Maximilians-University, Munich, Germany
| | - Martin Klaus
- Division of Nephrology, Department of Medicine IV, Hospital of the Ludwig-Maximilians-University, Munich, Germany
| | - Oliver Gross
- Clinic of Nephrology and Rheumatology, University Medical Centre Goettingen, Goettingen, Germany
| | - Maria-Lucia Angelotti
- Department of Biomedical Experimental and Clinical Sciences “Mario Serio,” University of Florence, Florence, Italy
| | - Giulia Antonelli
- Department of Biomedical Experimental and Clinical Sciences “Mario Serio,” University of Florence, Florence, Italy
| | - Luigi Cirillo
- Department of Biomedical Experimental and Clinical Sciences “Mario Serio,” University of Florence, Florence, Italy
- Nephrology and Dialysis Unit, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Paola Romagnani
- Department of Biomedical Experimental and Clinical Sciences “Mario Serio,” University of Florence, Florence, Italy
- Nephrology and Dialysis Unit, Meyer Children's Hospital IRCCS, Florence, Italy
| | - Nassim Bouteldja
- Institute of Pathology, RWTH University Hospital Aachen, Aachen, Germany; Division of Nephrology and Immunology, RWTH University Hospital Aachen, Aachen, Germany
| | - Alireza Vafaei Sadr
- Institute of Pathology, RWTH University Hospital Aachen, Aachen, Germany; Division of Nephrology and Immunology, RWTH University Hospital Aachen, Aachen, Germany
| | - Roman D. Bülow
- Institute of Pathology, RWTH University Hospital Aachen, Aachen, Germany; Division of Nephrology and Immunology, RWTH University Hospital Aachen, Aachen, Germany
| | - Peter Boor
- Institute of Pathology, RWTH University Hospital Aachen, Aachen, Germany; Division of Nephrology and Immunology, RWTH University Hospital Aachen, Aachen, Germany
| | - Hans-Joachim Anders
- Division of Nephrology, Department of Medicine IV, Hospital of the Ludwig-Maximilians-University, Munich, Germany
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16
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Nozu K, Resontoc LPR, Hooman N, Vasudevan A, Ding J, Kang HG. Investigation of the current situation regarding diagnosis and treatment of Alport syndrome in Asian countries: results of survey of the Asian Paediatric Nephrology association (AsPNA) tubular and inherited working group. Clin Exp Nephrol 2023; 27:776-780. [PMID: 37289334 PMCID: PMC10432360 DOI: 10.1007/s10157-023-02358-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 05/02/2023] [Indexed: 06/09/2023]
Abstract
BACKGROUND Alport syndrome is one of the most common inherited kidney diseases worldwide. A genetic test or kidney biopsy is necessary for a definite diagnosis of this disease, and an accurate diagnosis system for this disease is highly desired in each country. However, the current situation in Asian countries is not clear. Therefore, the tubular and inherited disease working group of the Asian Pediatric Nephrology Association (AsPNA) aimed to assess the current situation of diagnosis and treatment for Alport syndrome in Asia. METHODS The group conducted an online survey among the members of AsPNA in 2021-2022. Collected data included the number of patients for each inheritance mode, availability of gene tests or kidney biopsy, and treatment strategies for Alport syndrome. RESULTS A total of 165 pediatric nephrologists from 22 countries in Asia participated. Gene test was available in 129 institutes (78%), but the cost was still expensive in most countries. Kidney biopsy was available in 87 institutes (53%); however, only 70 can access electron microscopy, and 42 can conduct type IV collagen α5 chain staining. Regarding treatment, 140 centers use renin-angiotensin system (RAS) inhibitors (85%) for Alport syndrome patients. CONCLUSIONS This study result might suggest that the system is underdeveloped enough to diagnose all Alport syndrome patients in most Asian countries. However, once diagnosed with Alport syndrome, most of them were treated with RAS inhibitors. These survey results can be used to address knowledge, diagnostic system, and treatment strategy gaps and improve the Alport patients' outcomes in Asian countries.
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Affiliation(s)
- Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-Cho, Chuo, Kobe, Hyogo, 650-0017, Japan.
| | - Lourdes Paula Real Resontoc
- Division of Pediatric Nephrology, College of Medicine, University of the Philippines-Philippine General Hospital, Manila, Philippines
| | - Nakysa Hooman
- Ali Asghar Clinical Research Development Center, Department of Pediatrics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Anil Vasudevan
- Department of Pediatric Nephrology, St John's Medical College Hospital, Bengaluru, India
| | - Jie Ding
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Hee Gyung Kang
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, South Korea
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17
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Deltas C, Papagregoriou G, Louka SF, Malatras A, Flinter F, Gale DP, Gear S, Gross O, Hoefele J, Lennon R, Miner JH, Renieri A, Savige J, Turner AN. Genetic Modifiers of Mendelian Monogenic Collagen IV Nephropathies in Humans and Mice. Genes (Basel) 2023; 14:1686. [PMID: 37761826 PMCID: PMC10530214 DOI: 10.3390/genes14091686] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/09/2023] [Accepted: 08/17/2023] [Indexed: 09/29/2023] Open
Abstract
Familial hematuria is a clinical sign of a genetically heterogeneous group of conditions, accompanied by broad inter- and intrafamilial variable expressivity. The most frequent condition is caused by pathogenic (or likely pathogenic) variants in the collagen-IV genes, COL4A3/A4/A5. Pathogenic variants in COL4A5 are responsible for the severe X-linked glomerulopathy, Alport syndrome (AS), while homozygous or compound heterozygous variants in the COL4A3 or the COL4A4 gene cause autosomal recessive AS. AS usually leads to progressive kidney failure before the age of 40-years when left untreated. People who inherit heterozygous COL4A3/A4 variants are at-risk of a slowly progressive form of the disease, starting with microscopic hematuria in early childhood, developing Alport spectrum nephropathy. Sometimes, they are diagnosed with benign familial hematuria, and sometimes with autosomal dominant AS. At diagnosis, they often show thin basement membrane nephropathy, reflecting the uniform thin glomerular basement membrane lesion, inherited as an autosomal dominant condition. On a long follow-up, most patients will retain normal or mildly affected kidney function, while a substantial proportion will develop chronic kidney disease (CKD), even kidney failure at an average age of 55-years. A question that remains unanswered is how to distinguish those patients with AS or with heterozygous COL4A3/A4 variants who will manifest a more aggressive kidney function decline, requiring prompt medical intervention. The hypothesis that a subgroup of patients coinherit additional genetic modifiers that exacerbate their clinical course has been investigated by several researchers. Here, we review all publications that describe the potential role of candidate genetic modifiers in patients and include a summary of studies in AS mouse models.
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Affiliation(s)
- Constantinos Deltas
- School of Medicine, University of Cyprus, Nicosia 2109, Cyprus
- biobank.cy Center of Excellence in Biobanking and Biomedical Research, University of Cyprus, Nicosia 2109, Cyprus
| | - Gregory Papagregoriou
- biobank.cy Center of Excellence in Biobanking and Biomedical Research, University of Cyprus, Nicosia 2109, Cyprus
| | - Stavroula F. Louka
- biobank.cy Center of Excellence in Biobanking and Biomedical Research, University of Cyprus, Nicosia 2109, Cyprus
| | - Apostolos Malatras
- biobank.cy Center of Excellence in Biobanking and Biomedical Research, University of Cyprus, Nicosia 2109, Cyprus
| | - Frances Flinter
- Clinical Genetics Department, Guy’s & St Thomas’ NHS Foundation Trust, London SE1 9RT, UK
| | - Daniel P. Gale
- Department of Renal Medicine, University College London, London NW3 2PF, UK
| | | | - Oliver Gross
- Clinic for Nephrology and Rheumatology, University Medicine Goettingen, 37075 Goettingen, Germany
| | - Julia Hoefele
- Institute of Human Genetics, Klinikum Rechts der Isar, School of Medicine & Health, Technical University Munich, 81675 Munich, Germany
| | - Rachel Lennon
- Wellcome Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9WU, UK
| | - Jeffrey H. Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Alessandra Renieri
- Medical Genetics, University of Siena, 53100 Siena, Italy
- Med Biotech Hub and Competence Center, Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy
- Genetica Medica, Azienda Ospedaliero-Universitaria Senese, 53100 Siena, Italy
| | - Judy Savige
- Department of Medicine (Melbourne Health and Northern Health), The University of Melbourne, Parkville, VIC 3052, Australia
| | - A. Neil Turner
- Renal Medicine, Royal Infirmary, University of Edinburgh, Edinburgh EH16 4UX, UK
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18
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Hu Y, Liang L, Liu S, Kung JY, Banh HL. Angiotensin-converting enzyme inhibitor induced cough compared with placebo, and other antihypertensives: A systematic review, and network meta-analysis. J Clin Hypertens (Greenwich) 2023; 25:661-688. [PMID: 37417783 PMCID: PMC10423763 DOI: 10.1111/jch.14695] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 07/08/2023]
Abstract
Studies have shown that angiotensin converting enzyme inhibitors (ACEIs) are superior in primary and secondary prevention for cardiac mortality and morbidity to angiotensin receptor blocker (ARBs). One of the common side effects from ACEI is dry cough. The aims of this systematic review, and network meta-analysis are to rank the risk of cough induced by different ACEIs and between ACEI and placebo, ARB or calcium channel blockers (CCB). We performed a systematic review, and network meta-analysis of randomized controlled trials to rank the risk of cough induced by each ACEI and between ACEI and placebo, ARB or CCB. A total of 135 RCTs with 45,420 patients treated with eleven ACEIs were included in the analyses. The pooled estimated relative risk (RR) between ACEI and placebo was 2.21 (95% CI: 2.05-2.39). ACEI had more incidences of cough than ARB (RR 3.2; 95% CI: 2.91, 3.51), and pooled estimated of RR between ACEI and CCB was 5.30 (95% CI: 4.32-6.50) Moexipril ranked as number one for inducing cough (SUCRA 80.4%) and spirapril ranked the least (SUCRA 12.3%). The order for the rest of the ACEIs are as follows: ramipril (SUCRA 76.4%), fosinopril (SUCRA 72.5%), lisinopril (SUCRA 64.7%), benazepril (SUCRA 58.6%), quinapril (SUCRA 56.5%), perindopril (SUCRA 54.1%), enalapril (SUCRA 49.7%), trandolapril (SUCRA 44.6%) and, captopril (SUCRA 13.7%). All ACEI has the similar risk of developing a cough. ACEI should be avoided in patients who have risk of developing cough, and an ARB or CCB is an alternative based on the patient's comorbidity.
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Affiliation(s)
- Yiyun Hu
- Department of PharmacySecond Xiangya Hospital of Central South UniversityChangshaChina
| | - Ling Liang
- Department of CardiologyThe Third Clinical Medical College, Fujian Medical UniversityFuzhouChina
- Department of CardiologyThe First Affiliated Hospital of Xiamen UniversityXiamenChina
| | - Shuang Liu
- Medical Affairs Management DepartmentSecond Xiangya Hospital of Central South UniversityChangshaChina
| | - Janice Y. Kung
- University of Alberta, John W. Scott Health Sciences LibraryEdmontonCanada
| | - Hoan Linh Banh
- Faculty of Medicine and DentistryDepartment of Family MedicineUniversity of AlbertaEdmontonCanada
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19
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Alharbi SA, Alshenqiti AM, Asiri AH, Alqarni MA, Alqahtani SA. The Role of Genetic Testing in Pediatric Renal Diseases: Diagnostic, Prognostic, and Social Implications. Cureus 2023; 15:e44490. [PMID: 37664254 PMCID: PMC10471834 DOI: 10.7759/cureus.44490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2023] [Indexed: 09/05/2023] Open
Abstract
Pediatric renal diseases vary widely and are linked to high morbidity and mortality; hence, early diagnosis is vital. Presently, genetic testing is being incorporated into the standard of care for children and their families with kidney disease, primarily as a diagnostic tool. In the present review, we aim to collect all potential evidence from relevant studies that reported the role of genetic testing in pediatric renal disease diagnostic, prognostic, and social implications. We have conducted both electronic and manual searches within PubMed, the Cochrane Library, Web of Science, and Scopus to find relevant studies. Studies from the years 2013-2023 were included. Case reports with limited sample sizes and no descriptive statistics, along with review papers and meta-analyses, were excluded from this review. Quality assessment for all included studies was performed. The pooled diagnostic yields were calculated using the common effect and random effect models utilizing the R program (R Foundation for Statistical Computing, Vienna, Austria). The pooled result for the diagnostic yield as per the common effect model is a pooled proportion of 0.42 (42%) 95% confidence interval (CI): [0.39,0.44], while with the random effects model the pooled proportion is 0.43 (43%) 95% CI: [0.31,0.57]. The diagnostic yield for the included studies ranged from 78.10% to 16.8%. The spectrum of kidney diseases included nephrolithiasis/nephrocalcinosis, glomerular diseases, cystic kidney disease, ciliopathies, tubulopathies, chronic kidney disease, and congenital anomalies of the kidneys and urinary tracts (CAKUT), while hematuria and proteinuria were reported by two studies and autosomal recessive and autosomal dominant idiopathic kidney disease was reported by only one study. Genetic testing validates clinical diagnosis and aids in tailoring management strategies; hence, a more precise treatment plan is developed and unnecessary investigations are avoided, which is crucial in the case of children during routine nephrology clinic visits. Genetic counselling is of the utmost importance, so all ethical and social concerns related to genetic testing are addressed in addition to patient satisfaction.
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Affiliation(s)
- Sultan A Alharbi
- Department of Pediatrics, Prince Mohammed Bin Abdulaziz Hospital, Madinah, SAU
| | | | - Ali H Asiri
- Department of Pediatrics, Khamis Mushait Maternity and Children Hospital, Khamis Mushait, SAU
| | - Musaed A Alqarni
- Department of Pediatrics, Khamis Mushait Maternity and Children Hospital, Khamis Mushait, SAU
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20
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Bonebrake L. When Should Dialysis Be Started in Children and Young Adults with Kidney Failure? Clin J Am Soc Nephrol 2023; 18:983-984. [PMID: 37368491 PMCID: PMC10564344 DOI: 10.2215/cjn.0000000000000224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
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21
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Shanks J, Butler G, Cheng D, Jayasinghe K, Quinlan C. Clinical and diagnostic utility of genomic sequencing for children referred to a Kidney Genomics Clinic with microscopic haematuria. Pediatr Nephrol 2023; 38:2623-2630. [PMID: 36715773 DOI: 10.1007/s00467-022-05846-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 11/17/2022] [Accepted: 12/05/2022] [Indexed: 01/31/2023]
Abstract
BACKGROUND Microscopic haematuria in children is associated with the risk of progression to chronic kidney disease. Genetic disease is an important potential aetiology. Genomic sequencing presents the most effective diagnostic route for these conditions, but access remains inequitable internationally. METHODS We conducted a retrospective review of the electronic medical records of a Kidney Genomics Clinic (KGC) from January 2016 to December 2021. RESULTS Sixty patients were referred to the KGC with haematuria over this period. Forty-three percent of patients had analysis of a limited haematuria panel (COL4A1, COL4A3, COL4A4, COL4A5, MYH9) with 58% receiving a genetic diagnosis. Forty-two percent of referred patients had further analysis of genes implicated in the development of kidney disease, and 36% received a diagnosis. Eight percent of patients underwent cascade testing for a known familial variant, and all received a diagnosis. Children with the highest levels of haematuria (> 500 × 106/L red blood cells) had the highest diagnostic yield (67%). Proteinuria, defined as a urinary protein to creatinine ratio > 20, increased the diagnostic yield from 31 to 65%. Importantly, negative genetic analysis can still have significant clinical utility for patients by altering surveillance and further management; the genetic result had clinical utility in 60% of patients. CONCLUSIONS Our KGC review highlights the substantial clinical utility and diagnostic yield of genomic analysis for microscopic haematuria in paediatric patients. Whilst the management of variants of uncertain significance can be challenging, a multidisciplinary team including genetic counselling can help ensure these patients are followed up meaningfully. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Josiah Shanks
- Department of Nephrology, Royal Children's Hospital, Melbourne, Australia.
- Digital Health, Melbourne Children's Centre for Health Analytics, Melbourne, Australia.
- Kidney Flagship, Murdoch Children's Research Institute, Melbourne, Australia.
| | - Grainne Butler
- Department of Nephrology, Royal Children's Hospital, Melbourne, Australia
- Digital Health, Melbourne Children's Centre for Health Analytics, Melbourne, Australia
- Kidney Flagship, Murdoch Children's Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Daryl Cheng
- Digital Health, Melbourne Children's Centre for Health Analytics, Melbourne, Australia
| | - Kushani Jayasinghe
- Kidney Flagship, Murdoch Children's Research Institute, Melbourne, Australia
| | - Catherine Quinlan
- Department of Nephrology, Royal Children's Hospital, Melbourne, Australia
- Digital Health, Melbourne Children's Centre for Health Analytics, Melbourne, Australia
- Kidney Flagship, Murdoch Children's Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
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22
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Cosgrove D, Gratton MA, Madison J, Vosik D, Samuelson G, Meehan D, Delimont D, Phillips G, Smyth B, Pramparo T, Jarocki D, Nguyen M, Komers R, Jenkinson C. Dual inhibition of the endothelin and angiotensin receptor ameliorates renal and inner ear pathologies in Alport mice. J Pathol 2023; 260:353-364. [PMID: 37256677 PMCID: PMC10330771 DOI: 10.1002/path.6087] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 03/08/2023] [Accepted: 04/04/2023] [Indexed: 06/01/2023]
Abstract
Alport syndrome (AS), a type IV collagen disorder, leads to glomerular disease and, in some patients, hearing loss. AS is treated with inhibitors of the renin-angiotensin system; however, a need exists for novel therapies, especially those addressing both major pathologies. Sparsentan is a single-molecule dual endothelin type-A and angiotensin II type 1 receptor antagonist (DEARA) under clinical development for focal segmental glomerulosclerosis and IgA nephropathy. We report the ability of sparsentan to ameliorate both renal and inner ear pathologies in an autosomal-recessive Alport mouse model. Sparsentan significantly delayed onset of glomerulosclerosis, interstitial fibrosis, proteinuria, and glomerular filtration rate decline. Sparsentan attenuated glomerular basement membrane defects, blunted mesangial filopodial invasion into the glomerular capillaries, increased lifespan more than losartan, and lessened changes in profibrotic/pro-inflammatory gene pathways in both the glomerular and the renal cortical compartments. Notably, treatment with sparsentan, but not losartan, prevented accumulation of extracellular matrix in the strial capillary basement membranes in the inner ear and reduced susceptibility to hearing loss. Improvements in lifespan and in renal and strial pathology were observed even when sparsentan was initiated after development of renal pathologies. These findings suggest that sparsentan may address both renal and hearing pathologies in Alport syndrome patients. © 2023 Travere Therapeutics, Inc and The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Dominic Cosgrove
- Center for Sensory Neuroscience, Boys Town National Research Hospital, Omaha, NE, USA
| | - Michael Anne Gratton
- Department of Otolaryngology, Washington University in St. Louis, St. Louis, MO, USA
| | - Jacob Madison
- Center for Sensory Neuroscience, Boys Town National Research Hospital, Omaha, NE, USA
| | - Denise Vosik
- Center for Sensory Neuroscience, Boys Town National Research Hospital, Omaha, NE, USA
| | - Gina Samuelson
- Center for Sensory Neuroscience, Boys Town National Research Hospital, Omaha, NE, USA
| | - Daniel Meehan
- Center for Sensory Neuroscience, Boys Town National Research Hospital, Omaha, NE, USA
| | - Duane Delimont
- Center for Sensory Neuroscience, Boys Town National Research Hospital, Omaha, NE, USA
| | - Grady Phillips
- Department of Otolaryngology, Washington University in St. Louis, St. Louis, MO, USA
| | - Brendan Smyth
- Department of Otolaryngology, Washington University in St. Louis, St. Louis, MO, USA
| | | | - Diana Jarocki
- Department of Otolaryngology, Washington University in St. Louis, St. Louis, MO, USA
| | - Mai Nguyen
- Travere Therapeutics, San Diego, CA, USA
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Savige J, Weinstock BA. What patients want to know about genetic testing for kidney disease. Front Med (Lausanne) 2023; 10:1201712. [PMID: 37342499 PMCID: PMC10277795 DOI: 10.3389/fmed.2023.1201712] [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: 04/07/2023] [Accepted: 05/03/2023] [Indexed: 06/23/2023] Open
Abstract
Previously, genetic kidney disease was often recognised when family members shared clinical features. Now, many genetic kidney diseases are diagnosed when testing demonstrates a pathogenic variant in a gene associated with the disease. Detection of a genetic variant also identifies the mode of inheritance, and suggests family members at risk. The genetic diagnosis has additional advantages for patients and their doctors even when no specific treatment is available since it often indicates likely complications in other organs, the clinical course, and management strategies. Generally, informed consent is required for genetic testing because the result provides "certainty" with implications for the patient, and their family, and possibly for employment, and for life and medical insurance, as well as having social, ethical, and financial consequences. Patients want to be provided with a copy of their genetic test result in a format that is comprehensible and to have the result explained. Their at-risk family members should be sought out and offered genetic testing too. Patients who allow the sharing of their anonymised results in registries help advance everyone's understanding of these diseases and expedite a diagnosis in other families. Patient Support Groups not only help normalise the disease but also educate patients, and update them on recent advances and new treatments. Some registries encourage patients to themselves submit their genetic variants, clinical features and response to treatment. More and more often, patients may volunteer for clinical trials of novel therapies including some that depend on a genetic diagnosis or variant type.
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Affiliation(s)
- Judy Savige
- Department of Medicine (Melbourne Health and Northern Health), Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia
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Boeckhaus J, Mohr L, Dihazi H, Tönshoff B, Weber LT, Pape L, Latta K, Fehrenbach H, Lange-Sperandio B, Kettwig M, Staude H, König S, John-Kroegel U, Gellermann J, Hoppe B, Galiano M, Haffner D, Rhode H, Gross O. Ratio of Urinary Proteins to Albumin Excretion Shifts Substantially during Progression of the Podocytopathy Alport Syndrome, and Spot Urine Is a Reliable Method to Detect These Pathologic Changes. Cells 2023; 12:cells12091333. [PMID: 37174733 PMCID: PMC10177071 DOI: 10.3390/cells12091333] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 04/12/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023] Open
Abstract
The urinary albumin- and protein-to-creatinine ratios (UACR and UPCR, respectively) are key endpoints in most clinical trials assessing risk of progression of chronic kidney disease (CKD). For the first time, the current study compares the UACR versus the UPCR head-to-head at early stages of CKD, taking use of the hereditary podocytopathy Alport syndrome (AS) as a model disease for any CKD. Urine samples originated from the prospective randomized, controlled EARLY PRO-TECT Alport trial (NCT01485978). Urine samples from 47 children with confirmed diagnoses of AS at very early stages of CKD were divided according to the current stage of AS: stage 0 (UACR < 30 mg/g), stage 1 (30-300 mg/g) or stage 2 (>300 mg/g). The range of estimated glomerular filtration rate was 75-187.6 mL/min. The mean age was 10.4 ± 4.5 years. In children at stage 0, proteinuria in spot urine, confirmed in 24 h urine, was almost ten times higher than albuminuria (106.4 ± 42.2 vs. 12.5 ± 9.7; p < 0.05); it was "only" about three times higher in stage 1 (328.5 ± 210.1 vs. 132.3 ± 80.5; p < 0.05) and almost equal in stage 2 (1481.9 ± 983.4 vs. 1109.7 ± 873.6; p = 0.36). In 17 children, UACRs and UPCRs were measured simultaneously in 24 h urine and spot urine in the same study visit. Interestingly, the UACR (and UPCR) in 24 h urine vs. in spot urine varied by less than 10% (266.8 ± 426.4 vs. 291.2 ± 530.2). In conclusion, our study provides the first evidence that in patients with normal glomerular filtration rate (GFR) and low amounts of albuminuria, especially in children with podocytopathies such as AS, measuring the UACR and UPCR in spot urine is a reliable and convenient alternative to 24 h urine collection. Our study advocates both the UACR and the UPCR as relevant diagnostic biomarkers in future clinical trials in children with glomerular diseases because the UPCR seems to be a very significant parameter at very early stages of podocytopathies. The German Federal Ministry of Education and Research funded this trial (01KG1104).
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Affiliation(s)
- Jan Boeckhaus
- Clinic for Nephrology and Rheumatology, University Medical Center Goettingen, 37075 Goettingen, Germany
| | - Lea Mohr
- Clinic for Nephrology and Rheumatology, University Medical Center Goettingen, 37075 Goettingen, Germany
| | - Hassan Dihazi
- Clinic for Nephrology and Rheumatology, University Medical Center Goettingen, 37075 Goettingen, Germany
| | - Burkhard Tönshoff
- Department of Pediatrics I, University Children's Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Lutz T Weber
- Pediatric Nephrology, Children's and Adolescents' Hospital, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50937 Cologne, Germany
| | - Lars Pape
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, 30625 Hannover, Germany
- Department of Pediatrics II, University Childrens' Hospital, University of Duisburg-Essen, 45147 Essen, Germany
| | - Kay Latta
- Clementine Kinderhospital Frankfurt, 60316 Frankfurt, Germany
| | - Henry Fehrenbach
- Pediatric Nephrology, Children's Hospital, 87700 Memmingen, Germany
| | | | - Matthias Kettwig
- Clinic of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Hagen Staude
- Pediatric Nephrology, University Children's Hospital Rostock, 18057 Rostock, Germany
| | - Sabine König
- University Children's Hospital Münster, 48149 Münster, Germany
| | - Ulrike John-Kroegel
- Division of Pediatric Nephrology, University Children's Hospital, 07743 Jena, Germany
| | - Jutta Gellermann
- Pediatric Nephrology, Charité Children's Hospital, 10117 Berlin, Germany
| | - Bernd Hoppe
- Division of Pediatric Nephrology, Department of Pediatrics, University of Bonn, 53121 Bonn, Germany
| | - Matthias Galiano
- Department of Pediatrics and Adolescent Medicine, University Hospital, Friedrich-Alexander-University Erlangen, 91054 Erlangen, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, 30625 Hannover, Germany
| | - Heidrun Rhode
- Department of Internal Medicine I, Cardiology, Angiology, Intensive Medical Care, University Hospital Jena, Am Klinikum 1, 07747 Jena, Germany
| | - Oliver Gross
- Clinic for Nephrology and Rheumatology, University Medical Center Goettingen, 37075 Goettingen, Germany
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Solanki KV, Hu Y, Moore BS, Abedi V, Avula V, Mirshahi T, Strande NT, Bucaloiu ID, Chang AR. The Phenotypic Spectrum of COL4A3 Heterozygotes. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.04.11.23288298. [PMID: 37163122 PMCID: PMC10168410 DOI: 10.1101/2023.04.11.23288298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Most data on Alport Syndrome (AS) due to COL4A3 are limited to families with autosomal recessive AS or severe manifestations such as focal segmental glomerulosclerosis (FSGS). Using data from 174,418 participants in the Geisinger MyCode/DiscovEHR study, an unselected health system-based cohort with whole exome sequencing, we identified 403 participants (0.2%) who were heterozygous for likely pathogenic COL4A3 variants. Phenotypic data was evaluated using International Classification of Diseases (ICD) codes, laboratory data, and chart review. To evaluate the phenotypic spectrum of genetically-determined autosomal dominant AS, we matched COL4A3 heterozygotes 1:5 to non-heterozygotes using propensity scores by demographics, hypertension, diabetes, and nephrolithiasis. COL4A3 heterozygotes were at significantly increased risks of hematuria, decreased estimated glomerular filtration rate (eGFR), albuminuria, and end-stage kidney disease (ESKD) (p<0.05 for all comparisons) but not bilateral sensorineural hearing loss (p=0.9). Phenotypic severity tended to be more severe among patients with glycine missense variants located within the collagenous domain. For example, patients with Gly695Arg (n=161) had markedly increased risk of dipstick hematuria (OR 9.47, 95% CI: 6.30, 14.22) and ESKD diagnosis (OR 7.01, 95% CI: 3.48, 14.12) whereas those with PTVs (n=119) had moderately increased risks of dipstick hematuria (OR 1.63, 95% CI: 1.03, 2.58) and ESKD diagnosis (OR 3.43, 95% CI: 1.28, 9.19). Less than a third of patients had albuminuria screening completed, and fewer than 1/3 were taking inhibitors of the renin-angiotensin-aldosterone system (RAASi). Future studies are needed to evaluate the impact of earlier diagnosis, appropriate evaluation, and treatment of ADAS.
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Affiliation(s)
| | - Yirui Hu
- Department of Population Health Sciences, Geisinger, Danville, PA
| | - Bryn S Moore
- Department of Genomic Health, Geisinger, Danville, PA
| | - Vida Abedi
- Department of Public Health Sciences, College of Medicine, The Pennsylvania State University, Hershey, PA
| | | | | | - Natasha T Strande
- Department of Genomic Health, Geisinger, Danville, PA
- Autism and Developmental Medicine Institute, Geisinger, Danville, PA
| | | | - Alexander R Chang
- Center for Kidney Health Research, Geisinger, Danville, PA
- Department of Population Health Sciences, Geisinger, Danville, PA
- Regeneron Genetics Center, Sawmill Road, Tarrytown, NY
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26
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Gregorio VD, Caparali B, Shojaei A, Ricardo S, Barua M. Alport Syndrome: Clinical Spectrum and Therapeutic Advances. Kidney Med 2023; 5:100631. [PMID: 37122389 PMCID: PMC10131117 DOI: 10.1016/j.xkme.2023.100631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023] Open
Abstract
Alport syndrome is a hereditary disorder characterized by kidney disease, ocular abnormalities, and sensorineural hearing loss. Work in understanding the cause of Alport syndrome and the molecular composition of the glomerular basement membrane ultimately led to the identification of COL4A3, COL4A4 (both on chromosome 2q36), and COL4A5 (chromosome Xq22), encoding the α3, α4, and α5 chains of type IV collagen, as the responsible genes. Subsequent studies suggested that autosomal recessive Alport syndrome and males with X-linked Alport syndrome have more severe disease, whereas autosomal dominant Alport syndrome and females with X-linked Alport syndrome have more variability. Variant type is also influential-protein-truncating variants in autosomal recessive Alport syndrome or males with X-linked Alport syndrome often present with severe symptoms, characterized by kidney failure, extrarenal manifestations, and lack of the α3-α4-α5(IV) network. By contrast, mild-moderate forms from missense variants display α3-α4-α5(IV) in the glomerular basement membrane and are associated with protracted kidney involvement without extrarenal manifestations. Regardless of type, therapeutic intervention for kidney involvement is focused on early initiation of angiotensin-converting enzyme inhibitors. There are several therapies under investigation including sodium/glucose cotransporter 2 inhibitors, aminoglycoside analogs, endothelin type A antagonists, lipid-modifying drugs, and hydroxychloroquine, although targeting the underlying defect through gene therapy remains in preclinical stages.
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Alge JL, Bekheirnia N, Willcockson AR, Qin X, Scherer SE, Braun MC, Bekheirnia MR. Variants in genes coding for collagen type IV α-chains are frequent causes of persistent, isolated hematuria during childhood. Pediatr Nephrol 2023; 38:687-695. [PMID: 35759000 DOI: 10.1007/s00467-022-05627-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 05/04/2022] [Accepted: 05/06/2022] [Indexed: 01/19/2023]
Abstract
BACKGROUND Children with persistent, isolated microscopic hematuria typically undergo a limited diagnostic workup and are monitored for signs of kidney disease in long-term longitudinal follow-up, which can delay diagnosis and allow disease progression in some cases. METHODS To determine the clinical utility of genetic screening in this population, we performed targeted genetic testing using a custom, 32-gene next-generation sequencing panel for progressive kidney disease on children referred to the Texas Children's Hospital Pediatric Nephrology clinic for persistent, microscopic hematuria (n = 30; cohort 1). Patients with microscopic hematuria identified by urinalysis on at least two separate occasions were eligible for enrollment, but those with other evidence of kidney disease were excluded. Results were analyzed for sequence variants using the American College of Medical Genetics and Genomics (ACMG) guideline for data interpretation and were validated using a secondary analysis of a dataset of children with hematuria and normal kidney function who had undergone genetic testing as part of an industry-sponsored program (cohort 2; n = 67). RESULTS In cohort 1 33% of subjects (10/30) had pathogenic or likely pathogenic (P/LP) variants in the type IV collagen genes (COL4A3/A4/A5), and 10% (3/30) had variants of uncertain significance in these genes. The high diagnostic rate in type IV collagen genes was confirmed in cohort 2, where 27% (18/67) of subjects had P/LP variants in COL4A3/A4/A5 genes. CONCLUSIONS Children with persistent, isolated microscopic hematuria have a high likelihood of having pathogenic variants in type IV collagen genes and genetic screening should be considered. A higher resolution version of the Graphical abstract is available as Supplementary information.
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Affiliation(s)
- Joseph L Alge
- Department of Pediatrics, Division of Pediatric Nephrology, Baylor College Medicine, Houston, TX, 77030, USA
| | - Nasim Bekheirnia
- Department of Pediatrics, Division of Pediatric Nephrology, Baylor College Medicine, Houston, TX, 77030, USA
| | | | - Xiang Qin
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Steven E Scherer
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Michael C Braun
- Department of Pediatrics, Division of Pediatric Nephrology, Baylor College Medicine, Houston, TX, 77030, USA
| | - Mir Reza Bekheirnia
- Department of Pediatrics, Division of Pediatric Nephrology, Baylor College Medicine, Houston, TX, 77030, USA. .,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.
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Vaisitti T, Bracciamà V, Faini AC, Brach Del Prever GM, Callegari M, Kalantari S, Mioli F, Romeo CM, Luca M, Camilla R, Mattozzi F, Gianoglio B, Peruzzi L, Amoroso A, Deaglio S. The role of genetic testing in the diagnostic workflow of pediatric patients with kidney diseases: the experience of a single institution. Hum Genomics 2023; 17:10. [PMID: 36782285 PMCID: PMC9926680 DOI: 10.1186/s40246-023-00456-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/03/2023] [Indexed: 02/15/2023] Open
Abstract
PURPOSE Inherited kidney diseases are among the leading causes of kidney failure in children, resulting in increased mortality, high healthcare costs and need for organ transplantation. Next-generation sequencing technologies can help in the diagnosis of rare monogenic conditions, allowing for optimized medical management and therapeutic choices. METHODS Clinical exome sequencing (CES) was performed on a cohort of 191 pediatric patients from a single institution, followed by Sanger sequencing to confirm identified variants and for family segregation studies. RESULTS All patients had a clinical diagnosis of kidney disease: the main disease categories were glomerular diseases (32.5%), ciliopathies (20.4%), CAKUT (17.8%), nephrolithiasis (11.5%) and tubular disease (10.5%). 7.3% of patients presented with other conditions. A conclusive genetic test, based on CES and Sanger validation, was obtained in 37.1% of patients. The highest detection rate was obtained for ciliopathies (74.4%), followed by nephrolithiasis (45.5%), tubular diseases (45%), while most glomerular diseases and CAKUT remained undiagnosed. CONCLUSIONS Results indicate that genetic testing consistently used in the diagnostic workflow of children with chronic kidney disease can (i) confirm clinical diagnosis, (ii) provide early diagnosis in the case of inherited conditions, (iii) find the genetic cause of previously unrecognized diseases and (iv) tailor transplantation programs.
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Affiliation(s)
- Tiziana Vaisitti
- Immunogenetics and Transplant Biology Service, University Hospital "Città della Salute e della Scienza di Torino", Via Santena 19, 10126, Turin, Italy. .,Department of Medical Sciences, University of Turin, Via Nizza 52, 10126, Turin, Italy.
| | - Valeria Bracciamà
- Immunogenetics and Transplant Biology Service, University Hospital “Città della Salute e della Scienza di Torino”, Via Santena 19, 10126 Turin, Italy
| | - Angelo Corso Faini
- Immunogenetics and Transplant Biology Service, University Hospital "Città della Salute e della Scienza di Torino", Via Santena 19, 10126, Turin, Italy.
| | - Giulia Margherita Brach Del Prever
- Immunogenetics and Transplant Biology Service, University Hospital “Città della Salute e della Scienza di Torino”, Via Santena 19, 10126 Turin, Italy
| | - Martina Callegari
- Immunogenetics and Transplant Biology Service, University Hospital “Città della Salute e della Scienza di Torino”, Via Santena 19, 10126 Turin, Italy
| | - Silvia Kalantari
- Immunogenetics and Transplant Biology Service, University Hospital “Città della Salute e della Scienza di Torino”, Via Santena 19, 10126 Turin, Italy
| | - Fiorenza Mioli
- Immunogenetics and Transplant Biology Service, University Hospital “Città della Salute e della Scienza di Torino”, Via Santena 19, 10126 Turin, Italy
| | - Carmelo Maria Romeo
- Immunogenetics and Transplant Biology Service, University Hospital “Città della Salute e della Scienza di Torino”, Via Santena 19, 10126 Turin, Italy
| | - Maria Luca
- Immunogenetics and Transplant Biology Service, University Hospital “Città della Salute e della Scienza di Torino”, Via Santena 19, 10126 Turin, Italy
| | - Roberta Camilla
- Pediatric Nephrology Dialysis and Transplantation, University Hospital “Città della Salute e della Scienza di Torino”, Turin, Italy
| | - Francesca Mattozzi
- Pediatric Nephrology Dialysis and Transplantation, University Hospital “Città della Salute e della Scienza di Torino”, Turin, Italy
| | - Bruno Gianoglio
- Pediatric Nephrology Dialysis and Transplantation, University Hospital “Città della Salute e della Scienza di Torino”, Turin, Italy
| | - Licia Peruzzi
- Pediatric Nephrology Dialysis and Transplantation, University Hospital “Città della Salute e della Scienza di Torino”, Turin, Italy
| | - Antonio Amoroso
- Immunogenetics and Transplant Biology Service, University Hospital “Città della Salute e della Scienza di Torino”, Via Santena 19, 10126 Turin, Italy ,grid.7605.40000 0001 2336 6580Department of Medical Sciences, University of Turin, Via Nizza 52, 10126 Turin, Italy
| | - Silvia Deaglio
- Immunogenetics and Transplant Biology Service, University Hospital “Città della Salute e della Scienza di Torino”, Via Santena 19, 10126 Turin, Italy ,grid.7605.40000 0001 2336 6580Department of Medical Sciences, University of Turin, Via Nizza 52, 10126 Turin, Italy
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Ruggenenti P. The CARDINAL Trial of Bardoxolone Methyl in Alport Syndrome: When Marketing Interests Prevail over Patients Clinical Needs. Nephron Clin Pract 2023; 147:465-469. [PMID: 36731435 DOI: 10.1159/000529471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 01/18/2023] [Indexed: 02/04/2023] Open
Abstract
CONTEXT Alport syndrome (AS) is a hereditary chronic kidney disease (CKD) with X-linked, autosomal, and digenic patterns of transmission. Sieving dysfunction of the glomerular basement membrane caused by congenitally defective type IV collagen results in persistent proteinuria, hematuria, and progressive renal dysfunction. There are no disease-specific medications and treatment is based on conservative interventions in particular with renin-angiotensin-aldosterone-system (RAAS) inhibitors. Subject of Review: Evidence that AS is accompanied by glomerular and tubular inflammatory changes and that bardoxolone methyl exerts anti-inflammatory effects through suppression of NF-kB and activation of transcription of antioxidant and anti-inflammatory genes, provided a justification for the CARDINAL study, a prospective, randomized controlled trial testing the potential renoprotective effect of bardoxolone methyl in 157 adolescent or adult patients with AS. The authors concluded that bardoxolone methyl preserved estimated glomerular filtration rate (eGFR) relative to placebo at 48 and 100 weeks after randomization. However, exactly the same number of patients (n = 3) in each group developed kidney failure. Second Opinion: Despite alarming safety signals from previous trials in type 2 diabetics with CKD (increased hospitalizations for heart failure, fatal and nonfatal cardiovascular events, liver toxicity, and increased blood pressure and albuminuria), major marketing interests encouraged the drug manufacturer to pursue this line of research. Finding that type IV collagen gene mutations account for nearly one-third of cases of hereditary glomerulopathies implies that the population of potential target-patients could probably be much larger than estimated. Moreover, any new medication approved for AS might receive orphan drug designation which might be associated with shortened time to approval, monetary benefits, and a period of market exclusivity. In actual facts, CARDINAL failed to demonstrate any nephro-protective effect of bardoxolone methyl and found an increase in liver enzymes in 70 of the 77 (90.9%) bardoxolone-treated patients consistent with chronic liver toxicity. Indeed, in Zucker diabetic fatty rats treated with an analog of bardoxolone methyl, elevations of liver aminotransferases were associated with enhanced liver weight, severe and diffuse hepatocyte vacuolization, swelling, and degeneration. Moreover, bardoxolone-induced increase in eGFR was associated with a concomitant increase in geometric mean urinary albumin/creatinine ratio, a finding consistent with worsening glomerular hyperfiltration. Considering also the consequent increase in the biomechanical strain on the fragile Alport glomerular basement membrane, this hemodynamic effect is expected to translate into accelerated renal disease progression (consistently with evidence that a bardoxolone methyl analog worsened proteinuria, glomerulosclerosis, and tubular damage in Zucker diabetic fatty rats). These concerns induced the Food and Drug Administration to reject the new drug application for bardoxolone methyl submitted by Reata Pharmaceuticals, Inc. with the proposed indication to slow CKD progression in AS patients 12 years of age and older. Thus, bardoxolone methyl is devoid of any nephro-protective effect and is associated with significant heart, liver, and renal toxicity in patients with CKD, including those with AS. Because of these safety signals, it should not be used in this clinical context. Research programs could explore the potential clinical applications, even outside the kidney field, of novel NF erythroid 2-like 2 modulators devoid of bardoxolone methyl toxicity.
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Affiliation(s)
- Piero Ruggenenti
- Clinical Research Center for Rare Diseases "Aldo e Cele Daccò", Istituto di Ricerche Farmacologiche Mario Negri IRCCS, and Unit of Nephrology, Azienda Socio-Sanitaria Territoriale (ASST) Papa Giovanni XXIII, Bergamo, Italy
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Friedrich S, Groll A, Ickstadt K, Kneib T, Pauly M, Rahnenführer J, Friede T. Regularization approaches in clinical biostatistics: A review of methods and their applications. Stat Methods Med Res 2023; 32:425-440. [PMID: 36384320 PMCID: PMC9896544 DOI: 10.1177/09622802221133557] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A range of regularization approaches have been proposed in the data sciences to overcome overfitting, to exploit sparsity or to improve prediction. Using a broad definition of regularization, namely controlling model complexity by adding information in order to solve ill-posed problems or to prevent overfitting, we review a range of approaches within this framework including penalization, early stopping, ensembling and model averaging. Aspects of their practical implementation are discussed including available R-packages and examples are provided. To assess the extent to which these approaches are used in medicine, we conducted a review of three general medical journals. It revealed that regularization approaches are rarely applied in practical clinical applications, with the exception of random effects models. Hence, we suggest a more frequent use of regularization approaches in medical research. In situations where also other approaches work well, the only downside of the regularization approaches is increased complexity in the conduct of the analyses which can pose challenges in terms of computational resources and expertise on the side of the data analyst. In our view, both can and should be overcome by investments in appropriate computing facilities and educational resources.
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Affiliation(s)
- Sarah Friedrich
- Institute of Mathematics, University of
Augsburg, Augsburg, Germany
- Centre for Advanced Analytics and Predictive Sciences, University of
Augsburg, Augsburg, Germany
| | - Andreas Groll
- Department of Statistics, TU Dortmund
University, Dortmund, Germany
| | - Katja Ickstadt
- Department of Statistics, TU Dortmund
University, Dortmund, Germany
| | - Thomas Kneib
- Chair of Statistics and Campus Institute Data Science,
Georg-August-University Göttingen,
Göttingen, Germany
| | - Markus Pauly
- Department of Statistics, TU Dortmund
University, Dortmund, Germany
| | | | - Tim Friede
- Department of Medical Statistics, University Medical Center
Göttingen, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site
Göttingen, Göttingen, Germany
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31
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Sun L, Kuang XY, Zhang J, Huang WY. Hydroxychloroquine Ameliorates Hematuria in Children with X-Linked Alport Syndrome: Retrospective Case Series Study. Pharmgenomics Pers Med 2023; 16:145-151. [PMID: 36874354 PMCID: PMC9976585 DOI: 10.2147/pgpm.s394290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/17/2023] [Indexed: 03/07/2023] Open
Abstract
Purpose As a rare collagen type IV hereditary kidney disease, X-linked Alport syndrome (XLAS) is the most common form of Alport syndrome, the prevalence of which is estimated at 1:10,000 of the population, four times higher than the prevalence rate of autosomal recessive Alport syndrome. To describe a series of eight XLAS children with persistent hematuria and proteinuria and the clinical outcomes after hydroxychloroquine (HCQ) treatment to assess its efficacy as early intervention. Patients and Methods The study retrospectively analysed 8 patients with persistent hematuria and proteinuria at different onset ages who were diagnosed with XLAS and been treated with HCQ. The urinary erythrocyte count, urinary albuminn were measured. Descriptive statistics were used to estimate the patients' responses to HCQ treatment after one month, three months, and six months. Results After the first month, the three months, and the six months of HCQ treatment, the urinary erythrocyte counts of four, seven, and eight children were significantly reduced; the decreasing proteinuria was found in two, four, and five children. Only one child with increasing proteinuria was found after 1-month HCQ treatment. This proteinuria was maintained after 3-month HCQ treatment but decreased to minor after 6-month HCQ treatment. Conclusion We present the first potential efficacy of HCQ treatment in XLAS with hematuria and persistent proteinuria. It suggested that HCQ could be an effective treatment to ameliorate hematuria and proteinuria.
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Affiliation(s)
- Lei Sun
- Department of Nephrology and Rheumatology, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Xin-Yu Kuang
- Department of Nephrology and Rheumatology, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Jing Zhang
- Department of Nephrology and Rheumatology, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Wen-Yan Huang
- Department of Nephrology and Rheumatology, Shanghai Children's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China
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Ponticelli C, Calatroni M, Moroni G. Anti-glomerular basement membrane vasculitis. Autoimmun Rev 2023; 22:103212. [PMID: 36252931 DOI: 10.1016/j.autrev.2022.103212] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/11/2022] [Indexed: 12/27/2022]
Abstract
Antiglomerular basement membrane disease (anti-GBM) is a rare life-threatening autoimmune vasculitis that involves small vessels and it is characterized by circulating autoantibodies directed against type IV collagen antigens expressed in glomerular and alveolar basement membrane. The typical clinical manifestations are the rapidly progressive glomerulonephritis and the alveolar hemorrhage. The diagnosis is usually confirmed by the detection of anti-GBM circulating antibodies. If not rapidly recognized, anti-GBM disease can lead to end stage kidney disease (ESKD). An early diagnosis and prompt treatment with immunosuppressive therapies and plasmapheresis are crucial to prevent a poor outcome. In this review, we discuss the primary form of anti-GBM (the so called Goodpasture syndrome) but also cases associated with other autoimmune diseases such as antineutrophil-cytoplasmic-antibody (ANCA) vasculitis, membranous nephropathy, IgA nephritis and systemic lupus erythematosus (SLE), as well as the few cases of anti-GBM vasculitis complicating kidney transplantation in the Alport syndrome.
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Affiliation(s)
| | - Marta Calatroni
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072, Pieve Emanuele, Milan, Italy; Nephrology and Dialysis Division, IRCCS Humanitas Research Hospital, Via Manzoni 56, 20089, Rozzano, Milan, Italy.
| | - Gabriella Moroni
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072, Pieve Emanuele, Milan, Italy; Nephrology and Dialysis Division, IRCCS Humanitas Research Hospital, Via Manzoni 56, 20089, Rozzano, Milan, Italy
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Quinlan C, Jayasinghe K. Bardoxolone Methyl for Alport Syndrome: Opportunities and Challenges. Clin J Am Soc Nephrol 2022; 17:1713-1715. [PMID: 36411059 PMCID: PMC9718019 DOI: 10.2215/cjn.12491022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Catherine Quinlan
- Department of Nephrology, Royal Children’s Hospital, Melbourne, Australia
- Kidney Regeneration, Murdoch Children’s Research Institute, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
- Melbourne Genomics Health Alliance, Melbourne, Australia
| | - Kushani Jayasinghe
- Kidney Regeneration, Murdoch Children’s Research Institute, Melbourne, Australia
- Melbourne Genomics Health Alliance, Melbourne, Australia
- Department of Nephrology, Monash Health, Melbourne, Australia
- Department of Medicine, Monash University, Melbourne, Australia
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Novel and Founder Pathogenic Variants in X-Linked Alport Syndrome Families in Greece. Genes (Basel) 2022; 13:genes13122203. [PMID: 36553470 PMCID: PMC9778032 DOI: 10.3390/genes13122203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/08/2022] [Accepted: 11/18/2022] [Indexed: 11/27/2022] Open
Abstract
Alport syndrome (AS) is the most frequent monogenic inherited glomerulopathy and is also genetically and clinically heterogeneous. It is caused by semi-dominant pathogenic variants in the X-linked COL4A5 (NM_000495.5) gene or recessive variants in the COL4A3/COL4A4 (NM_000091.4/NM_000092.4) genes. The disease manifests in early childhood with persistent microhematuria and can progress to proteinuria and kidney failure in adolescence or early adulthood if left untreated. On biopsy, pathognomonic features include alternate thinning, thickening and lamellation of the glomerular basement membrane (GBM), in the presence of podocyte foot process effacement. Although previous studies indicate a prevalence of AS of about 1/50,000, a recent publication reported a predicted rate of pathogenic COL4A5 variants of 1/2320. We herewith present 98 patients (40 M/58 F) from 26 Greek families. We are selectively presenting the families segregating the X-linked form of AS with pathogenic variants in the COL4A5 gene. We found 21 different pathogenic variants, 12 novel: eight glycine and one proline substitutions in the collagenous domain, one cysteine substitution in the NC1 domain, two premature termination of translation codons, three splicing variants, one 5-bp insertion/frameshift variant, one indel-frameshift variant and four gross deletions. Notably, patients in six families we describe here and three families we reported previously, carried the COL4A5-p.G624D substitution, a founder defect encountered all over Europe which is hypomorphic with mostly milder symptomatology. Importantly, on several occasions, the correct genetic diagnosis reclassified patients as patients with AS, leading to termination of previous immunosuppressive/cyclosporine A therapy and a switch to angiotensin converting enzyme inhibitors (ACEi). With the understanding that all 98 patients span a wide range of ages from infancy to late adulthood, 15 patients (11 M/4 F) reached kidney failure and 11 (10 M/1 F) received a transplant. The prospects of avoiding lengthy diagnostic investigations and erroneous medications, and the advantage of delaying kidney failure with very early administration of renin-angiotensin-aldosterone system (RAAS) blockade, highlights the importance of timely documentation of AS by genetic diagnosis.
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Di H, Zhang J, Gao E, Zheng C, Huang X, Wang Q, Yu X, Liu Z. Dissecting the genotype-phenotype correlation of COL4A5 gene mutation and its response to renin-angiotensin-aldosterone system blockers in Chinese male patients with Alport syndrome. Nephrol Dial Transplant 2022; 37:2487-2495. [PMID: 35020912 DOI: 10.1093/ndt/gfac002] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Alport syndrome (AS) is an inherited type IV collagen-related disorder with an irreversible tendency to progress to end-stage renal disease (ESRD). X-linked AS (XLAS) is caused by mutations in the COL4A5 gene. The aim of this study was to investigate the effects of underlying mutations on clinical manifestations and the response to therapy in XLAS. METHODS We conducted a retrospective cohort study of 187 Chinese male patients with XLAS confirmed by pathological examination and genetic analysis. The Kaplan-Meier method and Cox proportional hazards model were used to assess the age and risk of progression to ESRD under different genotypes and treatment conditions. RESULTS A strong relationship between transcript type and renal outcome was observed, with the median age of ESRD onset being 22 years for truncating mutations and 39 years for non-truncating mutations. The response of affected patients to renin-angiotensin-aldosterone system (RAAS) blockers was genotype-associated. This therapy delayed the onset of ESRD by 16 years in patients with non-truncating mutations and 3 years in patients with truncating mutations. The efficacy of RAAS blockers functioned in a time-dependent manner, with a 7% reduction in the risk of progression to ESRD per each 6-month increase in treatment duration [hazard ratio 0.93 (95% confidence interval 0.89-0.96); P < 0.001]. CONCLUSIONS Clinical features and response to RAAS blockers were observed to be strongly correlated with the genotypes of male XLAS patients. Genotyping of COL4A5 gene mutations is essential and is a useful tool to assess the prognosis of AS patients.
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Affiliation(s)
- Hongling Di
- National Clinical Research Center of Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Jiahui Zhang
- Key Laboratory of Biosystems Homeostasis and Protection of the Ministry of Education, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China
| | - Erzhi Gao
- National Clinical Research Center of Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Chunxia Zheng
- National Clinical Research Center of Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Xianghua Huang
- National Clinical Research Center of Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Qing Wang
- National Clinical Research Center of Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Xiaomin Yu
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, Zhejiang, China
| | - Zhihong Liu
- National Clinical Research Center of Kidney Diseases, Affiliated Jinling Hospital, Medical School of Nanjing University, Nanjing, China
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36
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Boeckhaus J, Hoefele J, Riedhammer KM, Nagel M, Beck BB, Choi M, Gollasch M, Bergmann C, Sonntag JE, Troesch V, Stock J, Gross O. Lifelong effect of therapy in young patients with the COL4A5 Alport missense variant p.(Gly624Asp): a prospective cohort study. Nephrol Dial Transplant 2022; 37:2496-2504. [PMID: 35022790 DOI: 10.1093/ndt/gfac006] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Angiotensin-converting enzyme inhibitors (ACEis) have evolved as a first-line therapy for delaying end-stage renal failure (ESRF) in Alport syndrome (AS). The present study tested the hypothesis of a superior nephroprotective potential of an early ACEi intervention, examining a cohort with the COL4A5 missense variant p.(Gly624Asp). METHODS In this observational cohort study (NCT02378805), 114 individuals with the identical gene variant were explored for age at ESRF and life expectancy in correlation with treatment as endpoints. RESULTS All 13 untreated hemizygous patients developed ESRF (mean age 48.9 ± 13.7 years), as did 3 very late treated hemizygotes (51.7 ± 4.2 years), with a mean life expectancy of 59.2 ± 9.6 years. All 28 earlier-treated [estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2] hemizygous patients were still alive and still had not reached ESRF. Therapy minimized the annual loss of their GFR, similar to the annual loss in healthy individuals. Of 65 heterozygotes, 4 untreated individuals developed ESRF at an age of 53.3 ± 20.7 years. None of the treated heterozygous females developed ESRF. CONCLUSIONS For the first time, this study shows that in AS, early therapy in individuals with missense variants might have the potential to delay renal failure for their lifetime and thus to improve life expectancy and quality of life without the need for renal replacement therapy. Some treated patients have reached their retirement age with still-functioning kidneys, whereas their untreated relatives have reached ESRF at the same or a younger age. Thus, in children with glomerular haematuria, early testing for Alport-related gene variants could lead to timely nephroprotective intervention.
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Affiliation(s)
- Jan Boeckhaus
- Clinic for Nephrology and Rheumatology, University Medical Center Göttingen, Göttingen, Germany
| | - Julia Hoefele
- Institute of Human Genetics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Korbinian M Riedhammer
- Institute of Human Genetics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Department of Nephrology, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Mato Nagel
- Center for Nephrology and Metabolic Medicine, Weisswasser, Germany
| | - Bodo B Beck
- Institute of Human Genetics, Center for Molecular Medicine Cologne, and Center for Rare and Hereditary Kidney Disease, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Mira Choi
- Department of Nephrology and Medical Intensive Care, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Maik Gollasch
- Department of Internal and Geriatric Medicine, University Medicine Greifswald, Greifswald, Germany.,Experimental and Clinical Research Center, Charité University Medicine Berlin, Berlin, Germany
| | - Carsten Bergmann
- Department of Medicine, Nephrology, University Hospital Freiburg, Germany.,Medizinische Genetik Mainz, Limbach Genetics, Mainz, Germany
| | - Joseph E Sonntag
- Clinic for Nephrology and Rheumatology, University Medical Center Göttingen, Göttingen, Germany
| | - Victoria Troesch
- Clinic for Nephrology and Rheumatology, University Medical Center Göttingen, Göttingen, Germany
| | - Johanna Stock
- Clinic for Nephrology and Rheumatology, University Medical Center Göttingen, Göttingen, Germany
| | - Oliver Gross
- Clinic for Nephrology and Rheumatology, University Medical Center Göttingen, Göttingen, Germany
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37
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Kashtan CE. Genetic testing and glomerular hematuria-A nephrologist's perspective. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:399-403. [PMID: 35775584 PMCID: PMC9796064 DOI: 10.1002/ajmg.c.31987] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/25/2022] [Accepted: 06/19/2022] [Indexed: 01/29/2023]
Abstract
Alport syndrome is an inherited disorder of the kidneys that results from variants in three collagen IV genes-COL4A3, COL4A4, and COL4A5. Early diagnosis and pharmacologic intervention can delay the progression of chronic kidney disease and the onset of kidney failure in patients with Alport syndrome. This article describes the evolution of approaches to the diagnosis and early treatment of Alport syndrome.
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Affiliation(s)
- Clifford E. Kashtan
- Division of Pediatric NephrologyUniversity of Minnesota Medical SchoolMinneapolisMinnesotaUSA
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38
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Kumagai N, Matsumoto Y, Kondoh T, Ikezumi Y. A novel COL4A5 splicing variant causing X-linked Alport syndrome: A case report. Hum Genome Var 2022; 9:30. [PMID: 36045115 PMCID: PMC9433376 DOI: 10.1038/s41439-022-00209-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 07/24/2022] [Accepted: 07/30/2022] [Indexed: 01/11/2023] Open
Abstract
Alport syndrome is a hereditary disorder characterized by renal impairment, hearing loss, and ocular symptoms and is caused by COL4A3, COL4A4, and COL4A5 mutations. Here, we report the case of 3-year-old boy with isolated hematuria detected in routine preventative urinary screening conducted in 3-year-old children. He carried a novel variant, NM_033380.3:c. 1032 + 1 G > A, which caused a splicing abnormality in COL4A5. He was diagnosed with X-linked Alport syndrome.
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Affiliation(s)
- Naonori Kumagai
- grid.256115.40000 0004 1761 798XDepartment of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan
| | - Yuji Matsumoto
- grid.256115.40000 0004 1761 798XDepartment of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan
| | - Tomomi Kondoh
- grid.256115.40000 0004 1761 798XDepartment of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan
| | - Yohei Ikezumi
- grid.256115.40000 0004 1761 798XDepartment of Pediatrics, School of Medicine, Fujita Health University, Toyoake, Japan
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39
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Ćomić J, Riedhammer KM, Günthner R, Schaaf CW, Richthammer P, Simmendinger H, Kieffer D, Berutti R, Tasic V, Abazi-Emini N, Nushi-Stavileci V, Putnik J, Stajic N, Lungu A, Gross O, Renders L, Heemann U, Braunisch MC, Meitinger T, Hoefele J. The multifaceted phenotypic and genotypic spectrum of type-IV-collagen-related nephropathy—A human genetics department experience. Front Med (Lausanne) 2022; 9:957733. [PMID: 36117978 PMCID: PMC9470833 DOI: 10.3389/fmed.2022.957733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/29/2022] [Indexed: 11/28/2022] Open
Abstract
Disease-causing variants in COL4A3-5 are associated with type-IV-collagen-related nephropathy, a genetically and phenotypically multifaceted disorder comprising Alport syndrome (AS) and thin basement membrane nephropathy (TBMN) and autosomal, X-linked and a proposed digenic inheritance. Initial symptoms of individuals with AS are microscopic hematuria followed by proteinuria leading to kidney failure (90% on dialysis < age 40 years). In contrast, individuals with TBMN, an outdated histology-derived term, present with microscopic hematuria, only some of them develop kidney failure (>50 years of age). An early diagnosis of type-IV-collagen-related nephropathy is essential for optimized therapy and slowing of the disease. Sixty index cases, in whom exome sequencing had been performed and with disease-causing variant(s) in COL4A3-5, were evaluated concerning their clinical tentative diagnosis and their genotype. Of 60 reevaluated individuals with type-IV-collagen-related nephropathy, 72% had AS, 23% TBMN and 5% focal segmental glomerulosclerosis (FSGS) as clinical tentative diagnosis. The FSGS cases had to be re-classified as having type-IV-collagen-related nephropathy. Twelve percent of cases had AS as clinical tentative diagnosis and a monoallelic disease-causing variant in COL4A3/4 but could not be classified as autosomal dominant AS because of limited or conflicting clinical data. This study illustrates the complex clinical and genetic picture of individuals with a type IV-collagen-related nephropathy indicating the need of a refined nomenclature and the more interdisciplinary teamwork of clinicians and geneticists as the key to optimized patient care.
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Affiliation(s)
- Jasmina Ćomić
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
- Department of Nephrology, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Korbinian M. Riedhammer
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
- Department of Nephrology, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Roman Günthner
- Department of Nephrology, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Christian W. Schaaf
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
- Department of Nephrology, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Patrick Richthammer
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Hannes Simmendinger
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Donald Kieffer
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Riccardo Berutti
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Velibor Tasic
- University Children's Hospital, Medical Faculty of Skopje, Skopje, North Macedonia
| | - Nora Abazi-Emini
- University Children's Hospital, Medical Faculty of Skopje, Skopje, North Macedonia
| | | | - Jovana Putnik
- Institute for Mother and Child Health Care of Serbia “Dr. Vukan Čupić”, Department of Nephrology, University of Belgrade, Faculty of Medicine, Belgrade, Serbia
| | - Nataša Stajic
- Institute for Mother and Child Health Care of Serbia “Dr. Vukan Čupić”, Department of Nephrology, University of Belgrade, Faculty of Medicine, Belgrade, Serbia
| | - Adrian Lungu
- University Children's Hospital, Medical Faculty of Skopje, Skopje, North Macedonia
| | - Oliver Gross
- Clinic of Nephrology and Rheumatology, University Medical Center Göttingen, University of Göttingen, Göttingen, Germany
| | - Lutz Renders
- Department of Nephrology, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Uwe Heemann
- Department of Nephrology, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Matthias C. Braunisch
- Department of Nephrology, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Julia Hoefele
- Institute of Human Genetics, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
- *Correspondence: Julia Hoefele
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Ateya AM, El Hakim I, Shahin SM, El Borolossy R, Kreutz R, Sabri NA. Effects of Ramipril on Biomarkers of Endothelial Dysfunction and Inflammation in Hypertensive Children on Maintenance Hemodialysis: the SEARCH Randomized Placebo-Controlled Trial. Hypertension 2022; 79:1856-1865. [PMID: 35686561 DOI: 10.1161/hypertensionaha.122.19312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Hypertension, endothelial dysfunction, and inflammation are associated with increased cardiovascular mortality in end-stage kidney disease. We evaluated the effects of ACE (angiotensin-converting enzyme) inhibition on biomarkers of endothelial dysfunction and inflammation in hypertensive children with end-stage kidney disease on maintenance hemodialysis. METHODS In a randomized, double-blind, placebo-controlled trial, 135 (72 males/63 females) children and adolescents (age 7-15 years) were randomly assigned to treatment with either 2.5 mg once daily ramipril (n=68) or placebo (n=67) for 16 weeks. Primary outcome were the serum concentrations of asymmetrical dimethylarginine, a marker of endothelial dysfunction and hs-CRP (high-sensitivity C-reactive protein), a marker of inflammation. Changes in IL-6 (interleukin-6), TNF-α (tumor necrosis factor-alpha), systolic (S), and diastolic (D) blood pressure were secondary outcomes. Change in potassium levels and incidence of hyperkalemia were among the safety parameters. RESULTS Ramipril, but not placebo, significantly reduced serum levels of asymmetrical dimethylarginine (-79.6%; P<0.001), hs-CRP (-46.5%; P<0.001), IL-6 (-27.1%; P<0.001), and TNF-α (-51.7%; P<0.001). Systolic blood pressure and diastolic blood pressure were significantly lowered in both groups with a greater reduction in children receiving ramipril (median between-group differences -12.0 [95% CI -18.0 to -9.5] and -9.0 [95% CI -12.0 to -4.5]; P<0.001, respectively). Changes in asymmetrical dimethylarginine, hs-CRP, IL-6, or TNF-α in the ramipril group did not significantly correlate with blood pressure reductions. No severe cases of hyperkalemia or other serious treatment-associated adverse events were observed. CONCLUSIONS Ramipril improves biomarkers of endothelial dysfunction and inflammation in hypertensive children on maintenance hemodialysis in addition to its efficacious and safe potential to lower blood pressure. REGISTRATION URL: https://www. CLINICALTRIALS gov; Unique identifier: NCT04582097.
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Affiliation(s)
- Areej Mohamed Ateya
- Department of Clinical Pharmacy, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt (A.M.A., S.M.S., R.E.B., N.A.S.).,Charité - Universitätsmedizin Berlin, Institute of Clinical Pharmacology and Toxicology, Berlin, Germany (A.M.A., R.K.)
| | - Ihab El Hakim
- Department of Pediatrics, Faculty of Medicine, Ain Shams University, Cairo, Egypt (I.E.H.)
| | - Sara Mahmoud Shahin
- Department of Clinical Pharmacy, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt (A.M.A., S.M.S., R.E.B., N.A.S.)
| | - Radwa El Borolossy
- Department of Clinical Pharmacy, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt (A.M.A., S.M.S., R.E.B., N.A.S.)
| | - Reinhold Kreutz
- Charité - Universitätsmedizin Berlin, Institute of Clinical Pharmacology and Toxicology, Berlin, Germany (A.M.A., R.K.)
| | - Nagwa Ali Sabri
- Department of Clinical Pharmacy, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt (A.M.A., S.M.S., R.E.B., N.A.S.)
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41
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Anders HJ, Boor P. Predicting Future Outcomes from Kidney Biopsies with MCD/FSGS Lesions: Opportunities and Limitations. J Am Soc Nephrol 2022; 33:1233-1235. [PMID: 35728879 PMCID: PMC9257806 DOI: 10.1681/asn.2022040506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- Hans-Joachim Anders
- Renal Division, University Hospital of the Ludwig Maximilian, Munich, Germany
| | - Peter Boor
- Institute of Pathology, Department of Nephrology, RWTH University Hospital Aachen, Aachen, Germany
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42
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Gomes AM, Lopes D, Almeida C, Santos S, Malheiro J, Lousa I, Caldas Afonso A, Beirão I. Potential Renal Damage Biomarkers in Alport Syndrome—A Review of the Literature. Int J Mol Sci 2022; 23:ijms23137276. [PMID: 35806283 PMCID: PMC9266446 DOI: 10.3390/ijms23137276] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/24/2022] [Accepted: 06/28/2022] [Indexed: 02/01/2023] Open
Abstract
Alport syndrome (AS) is the second most common cause of inherited chronic kidney disease. This disorder is caused by genetic variants on COL4A3, COL4A4 and COL4A5 genes. These genes encode the proteins that constitute collagen type IV of the glomerular basement membrane (GBM). The heterodimer COL4A3A4A5 constitutes the majority of the GBM, and it is essential for the normal function of the glomerular filtration barrier (GFB). Alterations in any of collagen type IV constituents cause disruption of the GMB structure, allowing leakage of red blood cells and albumin into the urine, and compromise the architecture of the GFB, inducing inflammation and fibrosis, thus resulting in kidney damage and loss of renal function. The advances in DNA sequencing technologies, such as next-generation sequencing, allow an accurate diagnose of AS. Due to the important risk of the development of progressive kidney disease in AS patients, which can be delayed or possibly prevented by timely initiation of therapy, an early diagnosis of this condition is mandatory. Conventional biomarkers such as albuminuria and serum creatinine increase relatively late in AS. A panel of biomarkers that might detect early renal damage, monitor therapy, and reflect the prognosis would have special interest in clinical practice. The aim of this systematic review is to summarize the biomarkers of renal damage in AS as described in the literature. We found that urinary Podocin and Vascular Endothelial Growth Factor A are important markers of podocyte injury. Urinary Epidermal Growth Factor has been related to tubular damage, interstitial fibrosis and rapid progression of the disease. Inflammatory markers such as Transforming Growth Factor Beta 1, High Motility Group Box 1 and Urinary Monocyte Chemoattractant Protein- 1 are also increased in AS and indicate a higher risk of kidney disease progression. Studies suggest that miRNA-21 is elevated when renal damage occurs. Novel techniques, such as proteomics and microRNAs, are promising.
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Affiliation(s)
- Ana Marta Gomes
- Nephrology Department, Hospital Centre Vila Nova de Gaia/Espinho, 4434-502 Vila Nova de Gaia, Portugal; (A.M.G.); (D.L.); (C.A.)
- UMIB—Unit for Multidiscisciplinary Research on Biomedicine, Department of Nephrology, Dialysis and Transplantation, ICBAS—School of Medicine and Biomedical Sciences, University of Porto, Rua de Jorge Viterbo Ferreira n.º 228, 4050-313 Porto, Portugal; (S.S.); (J.M.)
| | - Daniela Lopes
- Nephrology Department, Hospital Centre Vila Nova de Gaia/Espinho, 4434-502 Vila Nova de Gaia, Portugal; (A.M.G.); (D.L.); (C.A.)
| | - Clara Almeida
- Nephrology Department, Hospital Centre Vila Nova de Gaia/Espinho, 4434-502 Vila Nova de Gaia, Portugal; (A.M.G.); (D.L.); (C.A.)
| | - Sofia Santos
- UMIB—Unit for Multidiscisciplinary Research on Biomedicine, Department of Nephrology, Dialysis and Transplantation, ICBAS—School of Medicine and Biomedical Sciences, University of Porto, Rua de Jorge Viterbo Ferreira n.º 228, 4050-313 Porto, Portugal; (S.S.); (J.M.)
- ITR, Laboratory for Integrative and Translational Research in Population Health, 4050-313 Porto, Portugal
- Nephrology Department, University Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal
| | - Jorge Malheiro
- UMIB—Unit for Multidiscisciplinary Research on Biomedicine, Department of Nephrology, Dialysis and Transplantation, ICBAS—School of Medicine and Biomedical Sciences, University of Porto, Rua de Jorge Viterbo Ferreira n.º 228, 4050-313 Porto, Portugal; (S.S.); (J.M.)
- ITR, Laboratory for Integrative and Translational Research in Population Health, 4050-313 Porto, Portugal
- Nephrology Department, University Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal
| | - Irina Lousa
- UCIBIO/REQUIMTE, Laboratory of Biochemistry, Department of Biological Sciences, Faculty Pharmacy, University of Porto, 4050-313 Porto, Portugal;
| | - Alberto Caldas Afonso
- Paediatrics Department, University Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal;
- European Rare Kidney Disease Centre (ERKNET)—Universitary Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal
| | - Idalina Beirão
- UMIB—Unit for Multidiscisciplinary Research on Biomedicine, Department of Nephrology, Dialysis and Transplantation, ICBAS—School of Medicine and Biomedical Sciences, University of Porto, Rua de Jorge Viterbo Ferreira n.º 228, 4050-313 Porto, Portugal; (S.S.); (J.M.)
- ITR, Laboratory for Integrative and Translational Research in Population Health, 4050-313 Porto, Portugal
- Nephrology Department, University Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal
- European Rare Kidney Disease Centre (ERKNET)—Universitary Hospital Centre of Porto (CHUP), 4099-001 Porto, Portugal
- Correspondence: or ; Tel.: +351-222077500
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Chavez E, Rodriguez J, Drexler Y, Fornoni A. Novel Therapies for Alport Syndrome. Front Med (Lausanne) 2022; 9:848389. [PMID: 35547199 PMCID: PMC9081811 DOI: 10.3389/fmed.2022.848389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 03/14/2022] [Indexed: 12/14/2022] Open
Abstract
Alport syndrome (AS) is a hereditary kidney disease associated with proteinuria, hematuria and progressive kidney failure. It is characterized by a defective glomerular basement membrane caused by mutations in type IV collagen genes COL4A3/A4/A5 which result in defective type IV collagen α3, α4, or α5 chains, respectively. Alport syndrome has three different patterns of inheritance: X-linked, autosomal and digenic. In a study of CKD of unknown etiology type IV collagen gene mutations accounted for the majority of the cases of hereditary glomerulopathies which suggests that AS is often underrecognized. The natural history and prognosis in patients with AS is variable and is determined by genetics and environmental factors. At present, no preventive or curative therapies exist for AS. Current treatment includes the use of renin-angiotensin-aldosterone system inhibitors which slow progression of kidney disease and prolong life expectancy. Ramipril was found in retrospective studies to delay the onset of ESKD and was recently demonstrated to be safe and effective in children and adolescents, supporting that early initiation of Renin Angiotensin Aldosterone System (RAAS) blockade is very important. Mineralocorticoid receptor blockers might be favorable for patients who develop "aldosterone breakthrough." While the DAPA-CKD trial suggests a beneficial effect of SGLT2 inhibitors in CKD of non-metabolic origin, only a handful of patients had Alport in this cohort, and therefore conclusions can't be extrapolated for the treatment of AS with SGLT2 inhibitors. Advances in our understanding on the pathogenesis of Alport syndrome has culminated in the development of innovative therapeutic approaches that are currently under investigation. We will provide a brief overview of novel therapeutic targets to prevent progression of kidney disease in AS. Our review will include bardoxolone methyl, an oral NRf2 activator; lademirsen, an anti-miRNA-21 molecule; sparsentan, dual endothelin type A receptor (ETAR) and angiotensin 1 receptor inhibitor; atrasentan, oral selective ETAR inhibitor; lipid-modifying agents, including cholesterol efflux transporter ATP-binding cassette A1 (ABCA1) inducers, discoidin domain receptor 1 (DDR1) inhibitors and osteopontin blocking agents; the antimalarial drug hydroxychloroquine; the antiglycemic drug metformin and the active vitamin D analog paricalcitol. Future genomic therapeutic strategies such as chaperone therapy, genome editing and stem cell therapy will also be discussed.
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Affiliation(s)
- Efren Chavez
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Juanly Rodriguez
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Yelena Drexler
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, United States.,Peggy and Harold Katz Family Drug Discovery Center, University of Miami Miller School of Medicine, Miami, FL, United States
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The 2019 and 2021 International Workshops on Alport Syndrome. Eur J Hum Genet 2022; 30:507-516. [PMID: 35260866 PMCID: PMC8904161 DOI: 10.1038/s41431-022-01075-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 02/04/2022] [Accepted: 02/14/2022] [Indexed: 01/27/2023] Open
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Cosgrove D, Madison J. Molecular and Cellular Mechanisms Underlying the Initiation and Progression of Alport Glomerular Pathology. Front Med (Lausanne) 2022; 9:846152. [PMID: 35223933 PMCID: PMC8863674 DOI: 10.3389/fmed.2022.846152] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 01/17/2022] [Indexed: 01/11/2023] Open
Abstract
Alport syndrome results from a myriad of variants in the COL4A3, COL4A4, or COL4A5 genes that encode type IV (basement membrane) collagens. Unlike type IV collagen α1(IV)2α2(IV)1 heterotrimers, which are ubiquitous in basement membranes, α3/α4/α5 have a limited tissue distribution. The absence of these basement membrane networks causes pathologies in some, but not all these tissues. Primarily the kidney glomerulus, the stria vascularis of the inner ear, the lens, and the retina as well as a rare link with aortic aneurisms. Defects in the glomerular basement membranes results in delayed onset and progressive focal segmental glomerulosclerosis ultimately requiring the patient to undergo dialysis and if accessible, kidney transplant. The lifespan of patients with Alport syndrome is ultimately significantly shortened. This review addresses the consequences of the altered glomerular basement membrane composition in Alport syndrome with specific emphasis on the mechanisms underlying initiation and progression of glomerular pathology.
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Affiliation(s)
| | - Jacob Madison
- Boys Town National Research Hospital, Omaha, NE, United States
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Rubel D, Boulanger J, Craciun F, Xu EY, Zhang Y, Phillips L, Callahan M, Weber W, Song W, Ngai N, Bukanov NO, Shi X, Hariri A, Husson H, Ibraghimov-Beskrovnaya O, Liu S, Gross O. Anti-microRNA-21 Therapy on Top of ACE Inhibition Delays Renal Failure in Alport Syndrome Mouse Models. Cells 2022; 11:cells11040594. [PMID: 35203245 PMCID: PMC8869926 DOI: 10.3390/cells11040594] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/28/2022] [Accepted: 02/03/2022] [Indexed: 02/01/2023] Open
Abstract
Col4a3−/− Alport mice serve as an animal model for renal fibrosis. MicroRNA-21 (miR-21) expression has been shown to be increased in the kidneys of Alport syndrome patients. Here, we investigated the nephroprotective effects of Lademirsen anti-miR-21 therapy. We used a fast-progressing Col4a3−/− mouse model with a 129/SvJ background and an intermediate-progressing F1 hybrid mouse model with a mixed genetic background, with angiotensin-converting enzyme inhibitor (ACEi) monotherapy in combination with anti-miR-21 therapy. In the fast-progressing model, the anti miR-21 and ACEi therapies showed an additive effect in the reduction in fibrosis, the decline of proteinuria, the preservation of kidney function and increased survival. In the intermediate-progressing F1 model, the anti-miR-21 and ACEi therapies individually improved kidney pathology. Both also improved kidney function and survival; however, the combination showed a significant additive effect, particularly for survival. RNA sequencing (RNA-seq) gene expression profiling revealed that the anti-miR-21 and ACEi therapies modulate several common pathways. However, anti-miR-21 was particularly effective at normalizing the expression profiles of the genes involved in renal tubulointerstitial injury pathways. In conclusion, significant additive effects were detected for the combination of anti-miR-21 and ACEi therapies on kidney function, pathology and survival in Alport mouse models, as well as a strong differential effect of anti-miR-21 on the renal expression of fibrotic factors. These results support the addition of anti-miR-21 to the current standard of care (ACEi) in ongoing clinical trials in patients with Alport syndrome.
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Affiliation(s)
- Diana Rubel
- Clinic for Nephrology and Rheumatology, University Medical Center Goettingen, 37075 Goettingen, Germany; (D.R.); (Y.Z.)
| | | | - Florin Craciun
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
| | - Ethan Y. Xu
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Excision BioTherapeutics, San Francisco, CA 94111, USA
| | - Yanqin Zhang
- Clinic for Nephrology and Rheumatology, University Medical Center Goettingen, 37075 Goettingen, Germany; (D.R.); (Y.Z.)
- Department of Pediatrics, Peking University First Hospital, Beijing 100034, China
| | - Lucy Phillips
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Abbvie Bioresearch Center, Worcester, MA 01605, USA
| | - Michelle Callahan
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
| | - William Weber
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Takeda Pharmaceuticals, Cambridge, MA 02139, USA
| | - Wenping Song
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
| | - Nicholas Ngai
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
| | - Nikolay O. Bukanov
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Janssen Pharmaceuticals, Boston, MA 02115, USA
| | - Xingyi Shi
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Novartis Institute for BioMedical Research, Boston, MA 02139, USA
| | - Ali Hariri
- Sanofi-Genzyme, Clinical Development, Cambridge, MA 02142, USA; (A.H.); (S.L.)
- Eloxx Pharmaceuticals, Watertown, MA 02140, USA
| | - Hervé Husson
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
| | - Oxana Ibraghimov-Beskrovnaya
- Sanofi-Genzyme Research and Development, Framingham, MA 02118, USA; (F.C.); (E.Y.X.); (L.P.); (M.C.); (W.W.); (W.S.); (N.N.); (N.O.B.); (X.S.); (H.H.); (O.I.-B.)
- Dyne Therapeutics, Waltham, MA 02451, USA
| | - Shiguang Liu
- Sanofi-Genzyme, Clinical Development, Cambridge, MA 02142, USA; (A.H.); (S.L.)
| | - Oliver Gross
- Clinic for Nephrology and Rheumatology, University Medical Center Goettingen, 37075 Goettingen, Germany; (D.R.); (Y.Z.)
- Correspondence: ; Tel.: +49-551-39-60488
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Widjaja A, Shekeran S, Adami E, Goh J, Tan J, Viswanathan S, Lim SY, Tan PH, Hubner N, Coffman T, Cook S. A Neutralizing IL-11 Antibody Improves Renal Function and Increases Lifespan in a Mouse Model of Alport Syndrome. J Am Soc Nephrol 2022; 33:718-730. [PMID: 35140116 PMCID: PMC8970448 DOI: 10.1681/asn.2021040577] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 01/07/2022] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Alport syndrome is a genetic disorder characterized by a defective glomerular basement membrane, tubulointerstitial fibrosis, inflammation, and progressive renal failure. IL-11 was recently implicated in fibrotic kidney disease but its role in Alport syndrome is unknown Methods: We determined IL-11 expression by molecular analyses and in an Alport syndrome mouse model. We assessed the effects of a neutralizing IL-11 antibody (X203) versus an IgG control in Col4a3-/- mice (lacking the gene encoding a type IV collagen component) on renal tubule damage, function, fibrosis, and inflammation. Effects on lifespan of X203, the IgG control, an angiotensin-converting enzyme inhibitor (ramipril), or ramipril+X203 were also studied. RESULTS In Col4a3 mice, as kidney failure advanced, renal IL-11 levels increased and IL-11 expression localized to tubular epithelial cells. The IL-11 receptor IL11RA is expressed in tubular epithelial cells and podocytes and is upregulated in tubular epithelial cells of Col4a3 mice. Administration of X203 reduced albuminuria, improved renal function, and preserved podocyte numbers and levels of key podocyte proteins that are reduced in Col4a3 mice; these effects were accompanied by reduced fibrosis and inflammation, attenuation of epithelial-tomesenchymal transition, and increased expression of regenerative markers. X203 attenuated pathogenic ERK and STAT3 pathways, which were activated in Col4a3 mice. Median lifespan of Col4a3 mice was prolonged 22% by ramapril, 44% with X203, and 99% with amipril+X203. CONCLUSIONS In an Alport syndrome mouse model, renal IL-11 is upregulated, and neutralization of IL-11 reduces epithelial-to-mesenchymal transition, fibrosis, and inflammation, while improving renal function. Anti-IL-11 combined with ACE inhibition synergistically extends lifespan. This suggests that a therapeutic approach targeting IL-11 holds promise for progressive kidney disease in Alport syndrome.
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Affiliation(s)
- Anissa Widjaja
- A Widjaja, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Shamini Shekeran
- S Shekeran, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Eleonora Adami
- E Adami, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Joyce Goh
- J Goh, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Jessie Tan
- J Tan, National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Sivakumar Viswanathan
- S Viswanathan, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Sze Yun Lim
- S Lim, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Puay Hoon Tan
- P Tan, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Norbert Hubner
- N Hubner, Cardiovascular and Metabolic Sciences, Max Delbruck Centre for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Thomas Coffman
- T Coffman, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Stuart Cook
- S Cook, Cardiovascular and Metabolic Disorders Program, Duke-NUS Medical School, Singapore, Singapore
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Voggel J, Mohr J, Nüsken KD, Dötsch J, Nüsken E, Alejandre Alcazar MA. Translational insights into mechanisms and preventive strategies after renal injury in neonates. Semin Fetal Neonatal Med 2022; 27:101245. [PMID: 33994314 DOI: 10.1016/j.siny.2021.101245] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Adverse perinatal circumstances can cause acute kidney injury (AKI) and contribute to chronic kidney disease (CKD). Accumulating evidence indicate that a wide spectrum of perinatal conditions interferes with normal kidney development and ultimately leads to aberrant kidney structure and function later in life. The present review addresses the lack of mechanistic knowledge with regard to perinatal origins of CKD and provides a comprehensive overview of pre- and peri-natal insults, including genetic predisposition, suboptimal nutritional supply, obesity and maternal metabolic disorders as well as placental insufficiency leading to intrauterine growth restriction (IUGR), prematurity, infections, inflammatory processes, and the need for life-saving treatments (e.g. oxygen supplementation, mechanical ventilation, medications) in neonates. Finally, we discuss future preventive, therapeutic, and regenerative directions. In summary, this review highlights the perinatal vulnerability of the kidney and the early origins of increased susceptibility toward AKI and CKD during postnatal life. Promotion of kidney health and prevention of disease require the understanding of perinatal injury in order to optimize perinatal micro- and macro-environments and enable normal kidney development.
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Affiliation(s)
- Jenny Voggel
- University of Cologne, Faculty of Medicine, University Hospital Cologne, Department of Pediatric and Adolescent Medicine, Germany; University of Cologne, Faculty of Medicine, University Hospital Cologne, Center for Molecular Medicine Cologne (CMMC), Germany
| | - Jasmine Mohr
- University of Cologne, Faculty of Medicine, University Hospital Cologne, Translational Experimental Pediatrics - Experimental Pulmonology, Department of Pediatric and Adolescent Medicine, Germany; University of Cologne, Faculty of Medicine, University Hospital Cologne, Center for Molecular Medicine Cologne (CMMC), Germany
| | - Kai-Dietrich Nüsken
- University of Cologne, Faculty of Medicine, University Hospital Cologne, Department of Pediatric and Adolescent Medicine, Germany
| | - Jörg Dötsch
- University of Cologne, Faculty of Medicine, University Hospital Cologne, Department of Pediatric and Adolescent Medicine, Germany
| | - Eva Nüsken
- University of Cologne, Faculty of Medicine, University Hospital Cologne, Department of Pediatric and Adolescent Medicine, Germany
| | - Miguel A Alejandre Alcazar
- University of Cologne, Faculty of Medicine, University Hospital Cologne, Translational Experimental Pediatrics - Experimental Pulmonology, Department of Pediatric and Adolescent Medicine, Germany; University of Cologne, Faculty of Medicine, University Hospital Cologne, Center for Molecular Medicine Cologne (CMMC), Germany; Excellence Cluster on Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Faculty of Medicine, University Hospital Cologne Cologne, Germany; Institute for Lung Health, University of Giessen and Marburg Lung Centre (UGMLC), Member of the German Centre for Lung Research (DZL), Gießen, Germany.
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49
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Omachi K, Kai H, Roberge M, Miner JH. Full-length and split-NanoLuc reporters identify pathogenic COL4A5 nonsense mutations susceptible to premature termination codon readthrough. iScience 2022; 25:103891. [PMID: 35243249 PMCID: PMC8866893 DOI: 10.1016/j.isci.2022.103891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 12/22/2021] [Accepted: 02/04/2022] [Indexed: 11/02/2022] Open
Abstract
Alport syndrome, a disease of kidney, ear, and eye, is caused by pathogenic variants in the COL4A3, COL4A4, or COL4A5 genes encoding collagen α3α4α5(IV) of basement membranes. Collagen IV chains that are truncated due to nonsense variants/premature termination codons (PTCs) cannot assemble into heterotrimers or incorporate into basement membranes. To investigate the feasibility of PTC readthrough therapy for Alport syndrome, we utilized two NanoLuc reporters in transfected cells: full-length for monitoring translation, and a split version for assessing readthrough product function. Full-length assays of 49 COL4A5 nonsense variants identified eleven as susceptible to PTC readthrough using various readthrough drugs. In split-NanoLuc assays, the predicted missense α5(IV) readthrough products of five nonsense mutations could heterotrimerize with α3(IV) and α4(IV). Readthrough was also observed in kidney cells from an engineered Col4a5 PTC mouse model. These results suggest that readthrough therapy is a feasible approach for a fraction of patients with Alport syndrome. NanoLuc fusion constructs identified COL4A5 mutants susceptible to PTC readthrough Readthrough enhancer and “designer” compounds promoted PTC readthrough Split-NanoLuc fusion constructs identified functional missense readthrough products Cultured Col4a5 nonsense mutant mouse kidney cells were susceptible to readthrough
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50
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Aoto Y, Horinouchi T, Yamamura T, Kondo A, Nagai S, Ishiko S, Okada E, Rossanti R, Sakakibara N, Nagano C, Awano H, Nagase H, Shima Y, Nakanishi K, Matsuo M, Iijima K, Nozu K. Last Nucleotide Substitutions of COL4A5 Exons Cause Aberrant Splicing. Kidney Int Rep 2022; 7:108-116. [PMID: 35005319 PMCID: PMC8720670 DOI: 10.1016/j.ekir.2021.10.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/08/2021] [Accepted: 10/11/2021] [Indexed: 12/23/2022] Open
Abstract
Introduction COL4A5 is a causative gene of X-linked Alport syndrome (XLAS). Male patients with XLAS with nonsense variants have the most severe phenotypes of early onset end-stage kidney disease (ESKD); those with splicing variants have middle phenotypes and those with missense variants have the mildest phenotypes. Therefore, genotyping for male patients with XLAS can be used to predict kidney prognosis. Single-base substitutions at the last nucleotide position in each exon are known to affect splicing patterns and could be splicing variants. Nevertheless, in XLAS, these variants are generally considered to be missense variants, without conducting a transcript analysis, which underestimates some patients as having mild phenotypes. This study aimed to investigate whether single-base substitutions at the last nucleotide position of COL4A5 exons cause aberrant splicing. Methods In total, 20 variants were found in the Human Gene Mutation Database (n = 14) and our cohort (n = 6). We performed functional splicing assays using a hybrid minigene analysis and in vivo transcript analyses of patients’ samples when available. Then, we investigated genotype–phenotype correlations for patients with splicing variants detected in this study by comparing data from our previous studies. Results Among the 20 variants, 17 (85%) caused aberrant splicing. Male patients with splicing variants had more severe phenotypes when compared with those with missense variants. Findings from the in vivo analyses for 3 variants were identical to those from the minigene assay. Conclusion Our study revealed that most single-base substitutions at the last nucleotide position of COL4A5 exons result in splicing variants, rather than missense variants, thereby leading to more severe phenotypes.
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Affiliation(s)
- Yuya Aoto
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomoko Horinouchi
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomohiko Yamamura
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Atsushi Kondo
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Sadayuki Nagai
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Shinya Ishiko
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Eri Okada
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Rini Rossanti
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Nana Sakakibara
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - China Nagano
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hiroyuki Awano
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hiroaki Nagase
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yuko Shima
- Department of Pediatrics, Wakayama Medical University, Wakayama, Japan
| | - Koichi Nakanishi
- Department of Child Health and Welfare (Pediatrics), Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Masafumi Matsuo
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan
| | - Kazumoto Iijima
- Hyogo Prefectural Kobe Children's Hospital, Hyogo, Japan.,Department of Advanced Pediatric Medicine, Kobe University Graduate School of Medicine, Hyogo, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
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