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Chen X, Wang J, Wang J, Ye J, Di P, Dong C, Lei H, Wang C. Several Potential Serum Proteomic Biomarkers for Diagnosis of Osteoarticular Tuberculosis Based on Mass Spectrometry. Clin Chim Acta 2023:117447. [PMID: 37353136 DOI: 10.1016/j.cca.2023.117447] [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: 12/21/2022] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/25/2023]
Abstract
BACKGROUND Osteoarticular tuberculosis is one of the extrapulmonary tuberculosis (EPTB) diseases, which is mainly caused by infection of Mycobacterium tuberculosis (MTB) in bone and joints. The limitation of current clinical test methods is leading to a high misdiagnosis rate and affecting the treatment and prognosis. This study aims to search serum biomarkers that can assist in the diagnosis of osteoarticular tuberculosis. METHODS Proteomics can serve as an important method in the discovery of disease biomarkers. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyze proteins in 90 serum samples, which were collected from June 2020 to December 2021, then evaluated by statistical analysis to screen potential biomarkers. After that, potential biomarkers were validated by ELISA and diagnostic models were also established for observation of multi-index diagnostic efficacy. RESULTS 118 differential expressed proteins (DEPs) were obtained in serum after statistical analysis. After the diagnostic efficacy evaluation and clinical verification, inter-alpha-trypsin inhibitor heavy chain H2 (ITIH2), complement factor H-related protein 2 (CFHR2), complement factor H-related protein 3 (CFHR3) and complement factor H-related protein 5 (CFHR5) were found as potential biomarkers, with 0.7167 (95%CI: 0.5846-0.8487), 0.8600 (95%CI: 0.7701-0.9499), 0.8150 (95%CI: 0.6998-0.9302), and 0.9978 (95%CI: 0.9918-1.0040) AUC value, respectively. The remaining DEPs except CFHR5 were constructed as diagnostic models, the diagnostic model contained CFHR2 and CFHR3 had good diagnostic efficacy with 0.942 (95%CI: 0.872-0.980) AUC value compared to other models. CONCLUSION This study provides a reference for the discovery of serum protein markers for osteoarticular tuberculosis diagnosis, and the screened DEPs can also provide directions for subsequent pathogenesis research.
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Affiliation(s)
- Ximeng Chen
- Medical School of Chinese PLA, No.28 Fuxing Road, Haidian District, Beijing, China; Department of Clinical Laboratory Medicine, The First Medical Center, Chinese PLA General Hospital, No.28 Fuxing Road, Haidian District, Beijing, China
| | - Jianan Wang
- Medical School of Chinese PLA, No.28 Fuxing Road, Haidian District, Beijing, China; Department of Clinical Laboratory Medicine, The First Medical Center, Chinese PLA General Hospital, No.28 Fuxing Road, Haidian District, Beijing, China
| | - Jinyang Wang
- Department of Clinical Laboratory Medicine, The First Medical Center, Chinese PLA General Hospital, No.28 Fuxing Road, Haidian District, Beijing, China
| | - Jingyun Ye
- Department of Clinical Laboratory Medicine, The First Medical Center, Chinese PLA General Hospital, No.28 Fuxing Road, Haidian District, Beijing, China
| | - Ping Di
- Department of Clinical Laboratory Medicine, The First Medical Center, Chinese PLA General Hospital, No.28 Fuxing Road, Haidian District, Beijing, China
| | - Chang Dong
- Department of Clinical Laboratory Medicine, The Eighth Medical Center, Chinese PLA General Hospital, No.17A Heishanhu Road, Haidian District, Beijing, China
| | - Hong Lei
- Department of Clinical Laboratory Medicine, The Eighth Medical Center, Chinese PLA General Hospital, No.17A Heishanhu Road, Haidian District, Beijing, China.
| | - Chengbin Wang
- Department of Clinical Laboratory Medicine, The First Medical Center, Chinese PLA General Hospital, No.28 Fuxing Road, Haidian District, Beijing, China.
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Rodríguez de Córdoba S. Genetic variability shapes the alternative pathway complement activity and predisposition to complement-related diseases. Immunol Rev 2023; 313:71-90. [PMID: 36089777 PMCID: PMC10086816 DOI: 10.1111/imr.13131] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The implementation of next-generation sequencing technologies has provided a sharp picture of the genetic variability in the components and regulators of the alternative pathway (AP) of the complement system and has revealed the association of many AP variants with different rare and common diseases. An important finding that has emerged from these analyses is that each of these complement-related diseases associate with genetic variants altering specific aspects of the activation and regulation of the AP. These genotype-phenotype correlations have provided valuable insights into their pathogenic mechanisms with important diagnostic and therapeutic implications. While genetic variants in coding regions and structural variants are reasonably well characterized and occasionally have been instrumental to uncover unknown features of the complement proteins, data about complement expressed quantitative trait loci are still very limited. A crucial task for future studies will be to identify these quantitative variations and to determine their impact in the overall activity of the AP. This is fundamental as it is now clear that the consequences of genetic variants in the AP are additive and that susceptibility or resistance to disease is the result of specific combinations of genetic variants in different complement components and regulators ("complotypes").
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Peters K. Physiology and pathology of the C3 amplification cycle: A retrospective. Immunol Rev 2023; 313:217-224. [PMID: 36408746 PMCID: PMC10099761 DOI: 10.1111/imr.13165] [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: 11/22/2022]
Abstract
The C3 "Tickover" hypothesis, a mechanism whereby the host maintains constant surveillance of potential invading pathogens, targeting them for elimination through amplified C3b generation and C3-dependent effector mechanisms, was proposed by the late Professor Peter Lachmann in 1973. This unique insight came from a combined understanding of the complement system as it was then defined and the nature of the disease process in rare complement deficiencies and complement-driven diseases. In this review, I give a personal perspective of how understanding of "Tickover" has developed in the subsequent 50 years, culminating in the introduction into the clinic of therapeutic agents designed to combat amplification-driven disease.
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Renner B, Laskowski J, Poppelaars F, Ferreira VP, Blaine J, Antonioli AH, Hannan JP, Kovacs JM, van Kooten C, You Z, Pickering MC, Holers VM, Thurman JM. Factor H related proteins modulate complement activation on kidney cells. Kidney Int 2022; 102:1331-1344. [PMID: 36063874 PMCID: PMC9691546 DOI: 10.1016/j.kint.2022.07.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 07/04/2022] [Accepted: 07/27/2022] [Indexed: 01/13/2023]
Abstract
Complement activation at a particular location is determined by the balance of activating and inhibitory proteins. Factor H is a key regulator of the alternative pathway of complement, and genetic or acquired impairments in Factor H are associated with glomerular injury. The human Factor H-related proteins (FHRs) comprise a family of five proteins that are structurally related to Factor H. Variations in the genes or expression levels of the FHRs are also associated with glomerular disease, although the mechanisms of glomerular protection/injury are incompletely understood. To explore the role of the FHRs on complement regulation/dysregulation in the kidney, we expressed and purified recombinant murine FHRs (FHRs A, B, C and E). These four distinct FHRs contain binding regions with high amino acid sequence homology to binding regions within Factor H, but we observed different interactions of the FHRs with Factor H binding ligands, including heparin and C3d. There was differential binding of the FHRs to the resident kidney cell types (mesangial, glomerular endothelial, podocytes, and tubular epithelial). All four FHRs caused complement dysregulation on kidney cell surfaces in vitro, although the magnitude of the effect differed among the FHRs and also varied among the different kidney cells. However, only FHR E caused glomerular complement dysregulation when injected in vivo but did not exacerbate injury when injected into mice with ischemic acute kidney injury, an alternative pathway-mediated model. Thus, our experiments demonstrate that the FHRs have unique, and likely context-dependent, effects on the different cell types within the kidney.
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Affiliation(s)
- Brandon Renner
- Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Jennifer Laskowski
- Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Felix Poppelaars
- Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Judith Blaine
- Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | | | - Jonathan P Hannan
- Molecular Biophysics Program and Department of Biochemistry, University of Colorado, Boulder, Colorado, USA
| | - James M Kovacs
- Department of Chemistry and Biochemistry, University of Colorado Springs, Colorado Springs, Colorado, USA
| | - Cees van Kooten
- Department of Nephrology, Leiden University Medical Center, Leiden, the Netherlands
| | - Zhiying You
- Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Matthew C Pickering
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, London, UK
| | - V Michael Holers
- Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Joshua M Thurman
- Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA.
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5
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Unraveling Structural Rearrangements of the CFH Gene Cluster in Atypical Hemolytic Uremic Syndrome Patients Using Molecular Combing and Long-Fragment Targeted Sequencing. J Mol Diagn 2022; 24:619-631. [PMID: 35398599 DOI: 10.1016/j.jmoldx.2022.02.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/01/2022] [Accepted: 02/25/2022] [Indexed: 11/22/2022] Open
Abstract
Complement factor H (CFH) and its related proteins have an essential role in regulating the alternative pathway of the complement system. Mutations and structural variants (SVs) of the CFH gene cluster, consisting of CFH and its five related genes (CFHR1-5), have been reported in renal pathologies as well as in complex immune diseases like age-related macular degeneration and systemic lupus erythematosus. SV analysis of this cluster is challenging because of its high degree of sequence homology. Following first-line next-generation sequencing gene panel sequencing, we applied Genomic Vision's Molecular Combing Technology to detect and visualize SVs within the CFH gene cluster and resolve its structural haplotypes completely. This approach was tested in three patients with atypical hemolytic uremic syndrome and known SVs and 18 patients with atypical hemolytic uremic syndrome or complement factor 3 glomerulopathy with unknown CFH gene cluster haplotypes. Three SVs, a CFH/CFHR1 hybrid gene in two patients and a rare heterozygous CFHR4/CFHR1 deletion in trans with the common CFHR3/CFHR1 deletion in a third patient, were newly identified. For the latter, the breakpoints were determined using a targeted enrichment approach for long DNA fragments (Samplix Xdrop) in combination with Oxford Nanopore sequencing. Molecular combing in addition to next-generation sequencing was able to improve the molecular genetic yield in this pilot study. This (cost-)effective approach warrants validation in larger cohorts with CFH/CFHR-associated disease.
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6
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Vivarelli M, van de Kar N, Labbadia R, Diomedi-Camassei F, Thurman JM. A clinical approach to children with C3 glomerulopathy. Pediatr Nephrol 2022; 37:521-535. [PMID: 34002292 DOI: 10.1007/s00467-021-05088-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 03/28/2021] [Accepted: 04/20/2021] [Indexed: 11/28/2022]
Abstract
C3 glomerulopathy is a relatively new clinical entity that represents a challenge both to diagnose and to treat. As new therapeutic agents that act as complement inhibitors become available, many with an oral formulation, a better understanding of this disease and of the underlying complement dysregulation driving it has become increasingly useful to optimize patient care. Moreover, recent advances in research have clarified the role of complement in other glomerular diseases in which its role was less established, namely in immune-complex membranoproliferative glomerulonephritis (IC-MPGN), ANCA-vasculitis, IgA nephropathy, and idiopathic membranous nephropathy. Complement inhibitors are being studied in adult and adolescent clinical trials for these indications. This review summarizes current knowledge and future perspectives on every aspect of the diagnosis and management of C3 glomerulopathy and elucidates current understanding of the role of complement in this condition and in other glomerular diseases in children. An overview of ongoing trials involving therapeutic agents targeting complement in glomerular diseases is also provided.
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Affiliation(s)
- Marina Vivarelli
- Division of Nephrology and Dialysis, Department of Pediatric Subspecialties, Bambino Gesù Pediatric Hospital IRCCS, Piazza S Onofrio 4, 00165, Rome, Italy.
| | - Nicole van de Kar
- Department of Pediatric Nephrology, Amalia Children's Hospital, Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Raffaella Labbadia
- Division of Nephrology and Dialysis, Department of Pediatric Subspecialties, Bambino Gesù Pediatric Hospital IRCCS, Piazza S Onofrio 4, 00165, Rome, Italy
| | | | - Joshua M Thurman
- Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
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7
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Piras R, Breno M, Valoti E, Alberti M, Iatropoulos P, Mele C, Bresin E, Donadelli R, Cuccarolo P, Smith RJH, Benigni A, Remuzzi G, Noris M. CFH and CFHR Copy Number Variations in C3 Glomerulopathy and Immune Complex-Mediated Membranoproliferative Glomerulonephritis. Front Genet 2021; 12:670727. [PMID: 34211499 PMCID: PMC8240960 DOI: 10.3389/fgene.2021.670727] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/14/2021] [Indexed: 11/13/2022] Open
Abstract
C3 Glomerulopathy (C3G) and Immune Complex-Mediated Membranoproliferative glomerulonephritis (IC-MPGN) are rare diseases characterized by glomerular deposition of C3 caused by dysregulation of the alternative pathway (AP) of complement. In approximately 20% of affected patients, dysregulation is driven by pathogenic variants in the two components of the AP C3 convertase, complement C3 (C3) and Factor B (CFB), or in complement Factor H (CFH) and Factor I (CFI), two genes that encode complement regulators. Copy number variations (CNVs) involving the CFH-related genes (CFHRs) that give rise to hybrid FHR proteins also have been described in a few C3G patients but not in IC-MPGN patients. In this study, we used multiplex ligation-dependent probe amplification (MLPA) to study the genomic architecture of the CFH-CFHR region and characterize CNVs in a large cohort of patients with C3G (n = 103) and IC-MPGN (n = 96) compared to healthy controls (n = 100). We identified new/rare CNVs resulting in structural variants (SVs) in 5 C3G and 2 IC-MPGN patients. Using long-read single molecule real-time sequencing (SMRT), we detected the breakpoints of three SVs. The identified SVs included: 1) a deletion of the entire CFH in one patient with IC-MPGN; 2) an increased number of CFHR4 copies in one IC-MPGN and three C3G patients; 3) a deletion from CFHR3-intron 3 to CFHR3-3'UTR (CFHR34 - 6 Δ) that results in a FHR3-FHR1 hybrid protein in a C3G patient; and 4) a CFHR31 - 5-CFHR410 hybrid gene in a C3G patient. This work highlights the contribution of CFH-CFHR CNVs to the pathogenesis of both C3G and IC-MPGN.
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Affiliation(s)
- Rossella Piras
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Matteo Breno
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Elisabetta Valoti
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Marta Alberti
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | | | - Caterina Mele
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Elena Bresin
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Roberta Donadelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Paola Cuccarolo
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Ariela Benigni
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
| | - Marina Noris
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo, Italy
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8
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Malik TH, Gitterman DP, Lavin DP, Lomax-Browne HJ, Hiemeyer EC, Moran LB, Boroviak K, Cook HT, Gilmore AC, Mandwie M, Ahmad A, Alexander IE, Logan GJ, Marchbank KJ, Bradley A, Pickering MC. Gain-of-function factor H-related 5 protein impairs glomerular complement regulation resulting in kidney damage. Proc Natl Acad Sci U S A 2021; 118:e2022722118. [PMID: 33753502 PMCID: PMC8020653 DOI: 10.1073/pnas.2022722118] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Genetic variation within the factor H-related (FHR) genes is associated with the complement-mediated kidney disease, C3 glomerulopathy (C3G). There is no definitive treatment for C3G, and a significant proportion of patients develop end-stage renal disease. The prototypical example is CFHR5 nephropathy, through which an internal duplication within a single CFHR5 gene generates a mutant FHR5 protein (FHR5mut) that leads to accumulation of complement C3 within glomeruli. To elucidate how abnormal FHR proteins cause C3G, we modeled CFHR5 nephropathy in mice. Animals lacking the murine factor H (FH) and FHR proteins, but coexpressing human FH and FHR5mut (hFH-FHR5mut), developed glomerular C3 deposition, whereas mice coexpressing human FH with the normal FHR5 protein (hFH-FHR5) did not. Like in patients, the FHR5mut had a dominant gain-of-function effect, and when administered in hFH-FHR5 mice, it triggered C3 deposition. Importantly, adeno-associated virus vector-delivered homodimeric mini-FH, a molecule with superior surface C3 binding compared to FH, reduced glomerular C3 deposition in the presence of the FHR5mut. Our data demonstrate that FHR5mut causes C3G by disrupting the homeostatic regulation of complement within the kidney and is directly pathogenic in C3G. These results support the use of FH-derived molecules with enhanced C3 binding for treating C3G associated with abnormal FHR proteins. They also suggest that targeting FHR5 represents a way to treat complement-mediated kidney injury.
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Affiliation(s)
- Talat H Malik
- Centre for Inflammatory Disease, Imperial College London, London W12 0NN, United Kingdom
| | - Daniel P Gitterman
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom
| | - Deborah P Lavin
- Centre for Inflammatory Disease, Imperial College London, London W12 0NN, United Kingdom
| | - Hannah J Lomax-Browne
- Centre for Inflammatory Disease, Imperial College London, London W12 0NN, United Kingdom
| | - E Christina Hiemeyer
- Centre for Inflammatory Disease, Imperial College London, London W12 0NN, United Kingdom
| | - Linda B Moran
- North West London Pathology, Imperial College Healthcare National Health Service Trust, London W6 8RF, United Kingdom
| | - Katharina Boroviak
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom
| | - H Terence Cook
- Centre for Inflammatory Disease, Imperial College London, London W12 0NN, United Kingdom
| | - Alyssa C Gilmore
- Centre for Inflammatory Disease, Imperial College London, London W12 0NN, United Kingdom
| | - Mawj Mandwie
- Gene Therapy Research Unit, Children's Medical Research Institute and Sydney Children's Hospitals Network, The University of Sydney, NSW 2145 Westmead, Australia
| | - Amina Ahmad
- Gene Therapy Research Unit, Children's Medical Research Institute and Sydney Children's Hospitals Network, The University of Sydney, NSW 2145 Westmead, Australia
| | - Ian E Alexander
- Gene Therapy Research Unit, Children's Medical Research Institute and Sydney Children's Hospitals Network, The University of Sydney, NSW 2145 Westmead, Australia
- Discipline of Child and Adolescent Health, Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, NSW 2145 Westmead, Australia
| | - Grant J Logan
- Gene Therapy Research Unit, Children's Medical Research Institute and Sydney Children's Hospitals Network, The University of Sydney, NSW 2145 Westmead, Australia
| | - Kevin J Marchbank
- Translational and Clinical Research Institute, The Medical School, Newcastle University, Framlington Place, Newcastle-upon-Tyne NE2 4HH, United Kingdom
- National Renal Complement Therapeutics Centre, Newcastle-upon-Tyne NE1 4LP, United Kingdom
| | - Allan Bradley
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom
| | - Matthew C Pickering
- Centre for Inflammatory Disease, Imperial College London, London W12 0NN, United Kingdom;
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9
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Abstract
PURPOSE OF REVIEW In this review, we discuss recent studies showing the importance of the complement pathway in kidney disease. RECENT FINDINGS Recent findings in C3 glomerulopathy (C3G) include: acute postinfectious glomerulonephritis is characterised by the presence of antifactor B antibodies; human leukocyte antigen type, but not rare complement gene variation, is associated with primary immunoglobulin-associated membranoproliferative GN and C3G. Immunohistochemistry in C3G shows that factor H related protein 5 (FHR5) is the most prevalent complement protein and correlates with kidney function. A multicentre study supported the use of mycophenolate mofetil (MMF) in C3G even after a propensity matching analysis. In immunoglobulin A nephropathy (IgAN) several studies have emphasised the importance of complement. Imbalances of circulating FH and FHR1 and FHR5, which interfere with the regulatory functions of FH, associate with IgAN. Immunohistochemistry has shown associations between glomerular FHR5 deposition and C3 activation; glomerular FHR5 associated with clinical markers of IgAN severity. Data also suggest the lectin complement pathway contributes to IgAN severity. We also discuss complement activation in thrombotic microangiopathy and other kidney diseases. SUMMARY Complement activity can be detected in a wide range of kidney diseases and this provides pathogenic insight and potential for therapy with the ongoing development of several drugs directed at complement activation.
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10
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García-Fernández J, Vilches-Arroyo S, Olavarrieta L, Pérez-Pérez J, Rodríguez de Córdoba S. Detection of Genetic Rearrangements in the Regulators of Complement Activation RCA Cluster by High-Throughput Sequencing and MLPA. Methods Mol Biol 2021; 2227:159-178. [PMID: 33847941 DOI: 10.1007/978-1-0716-1016-9_16] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The regulators of complement activation (RCA) gene cluster in 1q31-1q32 includes most of the genes encoding complement regulatory proteins. Genetic variability in the RCA gene cluster frequently involve copy number variations (CNVs), a type of chromosome structural variation causing alterations in the number of copies of specific regions of DNA. CNVs in the RCA gene cluster often relate with gene rearrangements that result in the generation of novel genes, carrying internal duplications or deletions, and hybrid genes, resulting from the fusion or exchange of genetic material between two different genes. These gene rearrangements are strongly associated with a number of rare and common diseases characterized by complement dysregulation. Identification of CNVs in the RCA gene cluster is critical in the molecular diagnostic of these diseases. It can be done by bioinformatics analysis of DNA sequence data generated by massive parallel sequencing techniques (NGS, next generation sequencing) but often requires special techniques like multiplex ligation-dependent probe amplification (MLPA). This is because the currently used massive parallel DNA sequencing approaches do not easily identify all the structural variations in the RCA gene cluster. We will describe here how to use the MLPA assays and two computational tools to analyze NGS data, NextGENe and ONCOCNV, to detect CNVs and gene rearrangements in the RCA gene cluster.
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11
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Medjeral-Thomas NR, O'Shaughnessy MM. Complement in IgA Nephropathy: The Role of Complement in the Pathogenesis, Diagnosis, and Future Management of IgA Nephropathy. Adv Chronic Kidney Dis 2020; 27:111-119. [PMID: 32553243 DOI: 10.1053/j.ackd.2019.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 12/12/2022]
Abstract
Immunoglobulin A (IgA) nephropathy (IgAN) is an important cause of chronic and end-stage kidney disease. IgAN pathogenesis is incompletely understood. In particular, we cannot adequately explain the heterogeneity in clinical and histologic features and severities that characterizes IgAN. This limits patient stratification to appropriate and effective treatments and the development of disease-targeted therapies. Studies of the role of the alternative, lectin, and terminal complement pathways in IgAN have enhanced our understanding of disease pathogenesis and inform the development of novel diagnostic and therapeutic strategies. For example, recent genetic, serologic, and immunohistologic evidence suggests that imbalances between the main alternative complement pathway regulator protein (factor H) and competitor proteins that deregulate complement activity (factor H-related proteins 1 and 5, FHR1, and FHR5) associate with IgAN severity: a relative abundance of FHR1 and FHR5 amplifies complement-dependent inflammation and exacerbates kidney injury. Ongoing characterization of the mechanisms by which complement activity contributes to IgAN pathogenesis will facilitate the development of complement-based diagnostic techniques, biomarkers of disease activity and severity, and novel targeted therapies.
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12
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Zipfel PF, Wiech T, Stea ED, Skerka C. CFHR Gene Variations Provide Insights in the Pathogenesis of the Kidney Diseases Atypical Hemolytic Uremic Syndrome and C3 Glomerulopathy. J Am Soc Nephrol 2020; 31:241-256. [PMID: 31980588 PMCID: PMC7003313 DOI: 10.1681/asn.2019050515] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Sequence and copy number variations in the human CFHR-Factor H gene cluster comprising the complement genes CFHR1, CFHR2, CFHR3, CFHR4, CFHR5, and Factor H are linked to the human kidney diseases atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy. Distinct genetic and chromosomal alterations, deletions, or duplications generate hybrid or mutant CFHR genes, as well as hybrid CFHR-Factor H genes, and alter the FHR and Factor H plasma repertoire. A clear association between the genetic modifications and the pathologic outcome is emerging: CFHR1, CFHR3, and Factor H gene alterations combined with intact CFHR2, CFHR4, and CFHR5 genes are reported in atypical hemolytic uremic syndrome. But alterations in each of the five CFHR genes in the context of an intact Factor H gene are described in C3 glomerulopathy. These genetic modifications influence complement function and the interplay of the five FHR proteins with each other and with Factor H. Understanding how mutant or hybrid FHR proteins, Factor H::FHR hybrid proteins, and altered Factor H, FHR plasma profiles cause pathology is of high interest for diagnosis and therapy.
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Affiliation(s)
- Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany;
- Institute of Microbiology, Friedrich-Schiller-University, Jena, Germany; and
| | - Thorsten Wiech
- Section of Nephropathology, Institute of Pathology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Emma D Stea
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
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Sugawara Y, Kato H, Yoshida Y, Fujisawa M, Kokame K, Miyata T, Akioka Y, Miura K, Hattori M, Nangaku M. Novel CFHR2-CFHR1 Hybrid in C3 Glomerulopathy Identified by Genomic Structural Variation Analysis. Kidney Int Rep 2019; 4:1759-1762. [PMID: 31844814 PMCID: PMC6895660 DOI: 10.1016/j.ekir.2019.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 09/05/2019] [Accepted: 09/09/2019] [Indexed: 11/24/2022] Open
Affiliation(s)
- Yuka Sugawara
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Hideki Kato
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Yoko Yoshida
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Madoka Fujisawa
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Koichi Kokame
- Department of Molecular Pathogenesis, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Toshiyuki Miyata
- Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Yuko Akioka
- Department of Pediatric Nephrology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan
| | - Kenichiro Miura
- Department of Pediatric Nephrology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan
| | - Motoshi Hattori
- Department of Pediatric Nephrology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
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14
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Regulation of regulators: Role of the complement factor H-related proteins. Semin Immunol 2019; 45:101341. [PMID: 31757608 DOI: 10.1016/j.smim.2019.101341] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/07/2019] [Accepted: 10/24/2019] [Indexed: 01/15/2023]
Abstract
The complement system, while being an essential and very efficient effector component of innate immunity, may cause damage to the host and result in various inflammatory, autoimmune and infectious diseases or cancer, when it is improperly activated or regulated. Factor H is a serum glycoprotein and the main regulator of the activity of the alternative complement pathway. Factor H, together with its splice variant factor H-like protein 1 (FHL-1), inhibits complement activation at the level of the central complement component C3 and beyond. In humans, there are also five factor H-related (FHR) proteins, whose function is poorly characterized. While data indicate complement inhibiting activity for some of the FHRs, there is increasing evidence that FHRs have an opposite role compared with factor H and FHL-1, namely, they enhance complement activation directly and also by competing with the regulators FH and FHL-1. This review summarizes the current stand and recent data on the roles of factor H family proteins in health and disease, with focus on the function of FHR proteins.
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15
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Abstract
Glomerulonephritis (GN) refers to a group of renal diseases affecting the glomeruli due to the damage mediated by immunological mechanisms. A large proportion of the disease manifestations are caused by disturbances in the complement system. They can be due to genetic errors, autoimmunity, microbes or abnormal immunoglobulins, like modified IgA or paraproteins. The common denominator in most of the problems is an overactive or misdirected alternative pathway complement activation. An assessment of kidney function, amount of proteinuria and hematuria are crucial elements to evaluate, when glomerulonephritis is suspected. However, the cornerstones of the diagnoses are renal biopsy and careful examination of the complement abnormality. Differential diagnostics between the various forms of GN is not possible based on clinical features, as they may vary greatly. This review describes the known mechanisms of complement dysfunction leading to different forms of primary GN (like IgA glomerulonephritis, dense deposit disease, C3 glomerulonephritis, post-infectious GN, membranous GN) and differences to atypical hemolytic uremic syndrome. It also covers the basic elements of etiology-directed therapy and prognosis of the most common forms of GN. Common principles in the management of GN include treatment of hypertension and reduction of proteinuria, some require immunomodulating treatment. Complement inhibition is an emerging treatment option. A thorough understanding of the basic disease mechanism and a careful follow-up are needed for optimal therapy.
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Affiliation(s)
- Kati Kaartinen
- Department of Nephrology, Abdominal Center, Helsinki University Central Hospital, Helsinki, Finland
| | - Adrian Safa
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - Soumya Kotha
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - Giorgio Ratti
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - Seppo Meri
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, Helsinki, Finland; HUSLAB, Helsinki University Central Hospital, Helsinki, Finland.
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16
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Complement Activation in Progression of Chronic Kidney Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1165:423-441. [PMID: 31399977 DOI: 10.1007/978-981-13-8871-2_20] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Chronic kidney disease (CKD) is a public health problem worldwide, with increasing incidence and prevalence. The mechanisms underlying the progression to end-stage renal disease (ESRD) is not fully understood. The complement system was traditionally regarded as an important part of innate immunity required for host protection against infection and for maintaining host hemostasis. However, compelling evidence from both clinical and experimental studies has strongly incriminated complement activation as a pivotal pathogenic mediator of the development of multiple renal diseases and progressive replacement of functioning nephrons by fibrosis. Both anaphylatoxins, i.e., C3a and C5a, and membrane attack complex (MAC) contribute to the damage that occurs during chronic renal progression through various mechanisms including direct proinflammatory and fibrogenic activity, chemotactic effect, activation of the renal renin-angiotensin system, and enhancement of T-cell immunity. Evolving understanding of the mechanisms of complement-mediated renal injury has led to the emergence of complement-targeting therapeutics. A variety of specific antibodies and inhibitors targeting complement components have shown efficacy in reducing disease in animal models. Moreover, building on these advances, targeting complement has gained encouraging success in treating patients with renal diseases such as atypical hemolytic uremic syndrome (aHUS). Nevertheless, it still requires a great deal of effort to develop inhibitors that can be applied to treat more patients effectively in routine clinical practice.
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17
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Medjeral-Thomas NR, Moffitt H, Lomax-Browne HJ, Constantinou N, Cairns T, Cook HT, Pickering MC. Glomerular Complement Factor H-Related Protein 5 (FHR5) Is Highly Prevalent in C3 Glomerulopathy and Associated With Renal Impairment. Kidney Int Rep 2019; 4:1387-1400. [PMID: 31701048 PMCID: PMC6829196 DOI: 10.1016/j.ekir.2019.06.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/30/2019] [Accepted: 06/10/2019] [Indexed: 12/19/2022] Open
Abstract
Introduction Therapeutic agents that target complement are increasingly available for glomerular diseases. However, the mechanisms linking glomerular complement deposition with inflammation and damage are incompletely understood. Complement factor H-related protein 5 (FHR5) interacts with complement C3 and is considered to promote activation. Circulating and glomerular FHR5 associates with IgA nephropathy and abnormal FHR5 associates with familial C3 glomerulopathy (C3G). We characterized glomerular FHR5 staining in C3G and assessed its relationships with histological features of glomerular injury and clinical outcome. Methods We developed FHR5 staining protocols for formalin-fixed paraffin-embedded (FFPE) renal tissue and applied them to surplus biopsy sections from a C3G cohort. Results Glomerular FHR5 was highly prevalent in native and transplant C3G and correlated with glomerular C3 and C5b-9 staining. Glomerular FHR5 staining correlated negatively with estimated glomerular filtration rate (eGFR) (P = 0.04, difference of medians 19.7 ml/min per 1.73 m2; 95% confidence interval [CI] 1.1-43.0) and positively with a membranoproliferative glomerulonephritis pattern at diagnostic biopsy (odds ratio 18; 95% CI 1.6-201; P = 0.049). Glomerular FHR5 staining intensity positively correlated with glomerular complement C3b/iC3b/C3c (Pearson's correlation coefficient [R] = 0.59; P = 0.0008), C3dg (R = 0.47; P = 0.02) and C5b9 (R = 0.44, P = 0.02). Conclusions Glomerular FHR5 is highly prevalent in C3G, interacts with glomerular C3, and is associated with markers of disease severity. Glomerular FHR5 likely exacerbates complement-mediated glomerular damage in C3G and its interaction with glomerular complement might be exploited to target complement therapeutic agents.
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Affiliation(s)
- Nicholas R Medjeral-Thomas
- Centre for Inflammatory Disease, Division of Immunology and Inflammation, Department of Medicine, Imperial College London, UK
| | - Hilary Moffitt
- Centre for Inflammatory Disease, Division of Immunology and Inflammation, Department of Medicine, Imperial College London, UK
| | - Hannah J Lomax-Browne
- Centre for Inflammatory Disease, Division of Immunology and Inflammation, Department of Medicine, Imperial College London, UK
| | - Nicholas Constantinou
- Centre for Inflammatory Disease, Division of Immunology and Inflammation, Department of Medicine, Imperial College London, UK
| | - Tom Cairns
- Renal and Transplant Centre, Imperial College Healthcare NHS Trust, UK
| | - H Terence Cook
- Centre for Inflammatory Disease, Division of Immunology and Inflammation, Department of Medicine, Imperial College London, UK
| | - Matthew C Pickering
- Centre for Inflammatory Disease, Division of Immunology and Inflammation, Department of Medicine, Imperial College London, UK
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18
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Corvillo F, Okrój M, Nozal P, Melgosa M, Sánchez-Corral P, López-Trascasa M. Nephritic Factors: An Overview of Classification, Diagnostic Tools and Clinical Associations. Front Immunol 2019; 10:886. [PMID: 31068950 PMCID: PMC6491685 DOI: 10.3389/fimmu.2019.00886] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/05/2019] [Indexed: 12/18/2022] Open
Abstract
Nephritic factors comprise a heterogeneous group of autoantibodies against neoepitopes generated in the C3 and C5 convertases of the complement system, causing its dysregulation. Classification of these autoantibodies can be clustered according to their stabilization of different convertases either from the classical or alternative pathway. The first nephritic factor described with the capacity to stabilize C3 convertase of the alternative pathway was C3 nephritic factor (C3NeF). Another nephritic factor has been characterized by the ability to stabilize C5 convertase of the alternative pathway (C5NeF). In addition, there are autoantibodies against assembled C3/C5 convertase of the classical and lectin pathways (C4NeF). These autoantibodies have been mainly associated with kidney diseases, like C3 glomerulopathy and immune complex-associated-membranoproliferative glomerulonephritis. Other clinical situations where these autoantibodies have been observed include infections and autoimmune disorders such as systemic lupus erythematosus and acquired partial lipodystrophy. C3 hypocomplementemia is a common finding in all patients with nephritic factors. The methods to measure nephritic factors are not standardized, technically complex, and lack of an appropriate quality control. This review will be focused in the description of the mechanism of action of the three known nephritic factors (C3NeF, C4NeF, and C5NeF), and their association with human diseases. Moreover, we present an overview regarding the diagnostic tools for its detection, and the main therapeutic approach for the patients with nephritic factors.
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Affiliation(s)
- Fernando Corvillo
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER U754), Madrid, Spain
| | - Marcin Okrój
- Department of Medical Biotechnology, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland
| | - Pilar Nozal
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER U754), Madrid, Spain.,Immunology Unit, La Paz University Hospital, Madrid, Spain
| | - Marta Melgosa
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain.,Pediatric Nephrology Unit, La Paz University Hospital, Madrid, Spain
| | - Pilar Sánchez-Corral
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER U754), Madrid, Spain
| | - Margarita López-Trascasa
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain.,Departamento de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
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19
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Ng MSY, McClymont K, McCallum N, Dua R, Holman K, Bennetts B, Ho G, Patel C, Mallett AJ. CFHR5 Nephropathy in a Greek-Cypriot Australian Family: Ancestry-Informed Precision Medicine. Kidney Int Rep 2018; 3:1222-1228. [PMID: 30197990 PMCID: PMC6127413 DOI: 10.1016/j.ekir.2018.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- Monica S Y Ng
- Kidney Health Service, Royal Brisbane and Women's Hospital, Brisbane, Australia.,Faculty of Medicine, The University of Queensland, Brisbane, Australia
| | - Kelly McClymont
- Department of Histopathology, Sullivan Nicolaides Pathology, Brisbane, Australia
| | - Naomi McCallum
- Electron Microscopy Unit, Pathology Queensland, Royal Brisbane & Women's Hospital, Brisbane, Australia
| | - Rahul Dua
- Mater Private Hospital, Townsville, Australia
| | - Katherine Holman
- Department of Molecular Genetics, The Children's Hospital at Westmead, Sydney, Australia
| | - Bruce Bennetts
- Department of Molecular Genetics, The Children's Hospital at Westmead, Sydney, Australia.,Disciplines of Genetic Medicine and Paediatrics and Child Health, The University of Sydney, Sydney, Australia
| | - Gladys Ho
- Department of Molecular Genetics, The Children's Hospital at Westmead, Sydney, Australia
| | - Chirag Patel
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Andrew J Mallett
- Kidney Health Service, Royal Brisbane and Women's Hospital, Brisbane, Australia.,Faculty of Medicine, The University of Queensland, Brisbane, Australia
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20
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van Beek AE, Kamp A, Kruithof S, Nieuwenhuys EJ, Wouters D, Jongerius I, Rispens T, Kuijpers TW, Gelderman KA. Reference Intervals of Factor H and Factor H-Related Proteins in Healthy Children. Front Immunol 2018; 9:1727. [PMID: 30116238 PMCID: PMC6082937 DOI: 10.3389/fimmu.2018.01727] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 07/12/2018] [Indexed: 01/06/2023] Open
Abstract
Complement is activated as part of the innate immune defense against invading pathogens. Also, it helps to remove apoptotic debris and immune complexes from the circulation. Impaired complement function due to aberrant plasma levels of complement proteins may be indicative for complement-mediated diseases or can be involved in susceptibility for infections. To determine whether plasma levels are abnormal, reference intervals (RIs) are used from adult healthy donors. Since many complement-mediated diseases have an onset during childhood, it is important to know whether these RIs can be extrapolated to children. RIs of Factor H (FH), the crucial fluid-phase regulator, and the FH-related proteins (FHRs), its homologous counterparts, are unknown in healthy children. While FH is measured to diagnose and monitor therapy of patients with atypical hemolytic uremic syndrome, recent studies also implicated increased plasma levels of FHRs in disease. Here, we investigated the levels of FH and FHRs in healthy children using recently developed specific ELISAs. We found that levels of FH, FHR-2, and FHR-3 were equal to those found in healthy adults. Levels of FHR-4A and FHR-5 were lower in children than in adults. However, only the FHR-5 levels associated with age. The RIs of these FH family proteins now serve to support the interpretation of plasma levels in prospective and retrospective studies that can be used for routine diagnostic and monitoring purposes including pediatric patient samples.
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Affiliation(s)
- Anna E van Beek
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands.,Department of Pediatric Hematology, Immunology and Infectious Diseases, Emma Children's Hospital, Academic Medical Centre, Amsterdam, Netherlands
| | - Angela Kamp
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Simone Kruithof
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | | | - Diana Wouters
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Ilse Jongerius
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Theo Rispens
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Taco W Kuijpers
- Department of Pediatric Hematology, Immunology and Infectious Diseases, Emma Children's Hospital, Academic Medical Centre, Amsterdam, Netherlands.,Department of Blood Cell Research, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
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21
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Sánchez-Corral P, Pouw RB, López-Trascasa M, Józsi M. Self-Damage Caused by Dysregulation of the Complement Alternative Pathway: Relevance of the Factor H Protein Family. Front Immunol 2018; 9:1607. [PMID: 30050540 PMCID: PMC6052053 DOI: 10.3389/fimmu.2018.01607] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 06/28/2018] [Indexed: 12/13/2022] Open
Abstract
The alternative pathway is a continuously active surveillance arm of the complement system, and it can also enhance complement activation initiated by the classical and the lectin pathways. Various membrane-bound and plasma regulatory proteins control the activation of the potentially deleterious complement system. Among the regulators, the plasma glycoprotein factor H (FH) is the main inhibitor of the alternative pathway and its powerful amplification loop. FH belongs to a protein family that also includes FH-like protein 1 and five factor H-related (FHR-1 to FHR-5) proteins. Genetic variants and abnormal rearrangements involving the FH protein family have been linked to numerous systemic and organ-specific diseases, including age-related macular degeneration, and the renal pathologies atypical hemolytic uremic syndrome, C3 glomerulopathies, and IgA nephropathy. This review covers the known and recently emerged ligands and interactions of the human FH family proteins associated with disease and discuss the very recent experimental data that suggest FH-antagonistic and complement-activating functions for the FHR proteins.
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Affiliation(s)
- Pilar Sánchez-Corral
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain
| | - Richard B Pouw
- Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - Margarita López-Trascasa
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Center for Biomedical Network Research on Rare Diseases (CIBERER), Madrid, Spain.,Department of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
| | - Mihály Józsi
- Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary.,MTA-SE Research Group of Immunology and Hematology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
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22
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Goicoechea de Jorge E, López Lera A, Bayarri-Olmos R, Yebenes H, Lopez-Trascasa M, Rodríguez de Córdoba S. Common and rare genetic variants of complement components in human disease. Mol Immunol 2018; 102:42-57. [PMID: 29914697 DOI: 10.1016/j.molimm.2018.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/06/2018] [Accepted: 06/08/2018] [Indexed: 12/21/2022]
Abstract
Genetic variability in the complement system and its association with disease has been known for more than 50 years, but only during the last decade have we begun to understand how this complement genetic variability contributes to the development of diseases. A number of reports have described important genotype-phenotype correlations that associate particular diseases with genetic variants altering specific aspects of the activation and regulation of the complement system. The detailed functional characterization of some of these genetic variants provided key insights into the pathogenic mechanisms underlying these pathologies, which is facilitating the design of specific anti-complement therapies. Importantly, these analyses have sometimes revealed unknown features of the complement proteins. As a whole, these advances have delineated the functional implications of genetic variability in the complement system, which supports the implementation of a precision medicine approach based on the complement genetic makeup of the patients. Here we provide an overview of rare complement variants and common polymorphisms associated with disease and discuss what we have learned from them.
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Affiliation(s)
- Elena Goicoechea de Jorge
- Department of Immunology, Complutense University, Madrid, Spain; Research Institute Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Alberto López Lera
- Research Institute Hospital Universitario La Paz (IdiPaz), Madrid, Spain; Ciber de Enfermedades Raras, Madrid, Spain
| | - Rafael Bayarri-Olmos
- Department of Clinical Immunology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Hugo Yebenes
- Ciber de Enfermedades Raras, Madrid, Spain; Molecular Pathology and Complement Genetics Unit. Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | | | - Santiago Rodríguez de Córdoba
- Ciber de Enfermedades Raras, Madrid, Spain; Molecular Pathology and Complement Genetics Unit. Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.
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23
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Yang Y, Denton H, Davies OR, Smith-Jackson K, Kerr H, Herbert AP, Barlow PN, Pickering MC, Marchbank KJ. An Engineered Complement Factor H Construct for Treatment of C3 Glomerulopathy. J Am Soc Nephrol 2018; 29:1649-1661. [PMID: 29588430 PMCID: PMC6054357 DOI: 10.1681/asn.2017091006] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 02/26/2018] [Indexed: 01/06/2023] Open
Abstract
Background C3 glomerulopathy (C3G) is associated with dysregulation of the alternative pathway of complement activation, and treatment options for C3G remain limited. Complement factor H (FH) is a potent regulator of the alternative pathway and might offer a solution, but the mass and complexity of FH makes generation of full-length FH far from trivial. We previously generated a mini-FH construct, with FH short consensus repeats 1-5 linked to repeats 18-20 (FH1-5^18-20), that was effective in experimental C3G. However, the serum t1/2 of FH1-5^18-20 was significantly shorter than that of serum-purified FH.Methods We introduced the oligomerization domain of human FH-related protein 1 (denoted by R1-2) at the carboxy or amino terminus of human FH1-5^18-20 to generate two homodimeric mini-FH constructs (FHR1-2^1-5^18-20 and FH1-5^18-20^R1-2, respectively) in Chinese hamster ovary cells and tested these constructs using binding, fluid-phase, and erythrocyte lysis assays, followed by experiments in FH-deficient Cfh-/- mice.Results FHR1-2^1-5^18-20 and FH1-5^18-20^R1-2 homodimerized in solution and displayed avid binding profiles on clustered C3b surfaces, particularly FHR1-2^1-5^18-20 Each construct was >10-fold more effective than FH at inhibiting cell surface complement activity in vitro and restricted glomerular basement membrane C3 deposition in vivo significantly better than FH or FH1-5^18-20 FH1-5^18-20^R1-2 had a C3 breakdown fragment binding profile similar to that of FH, a >5-fold increase in serum t1/2 compared with that of FH1-5^18-20, and significantly better retention in the kidney than FH or FH1-5^18-20Conclusions FH1-5^18-20^R1-2 may have utility as a treatment option for C3G or other complement-mediated diseases.
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Affiliation(s)
- Yi Yang
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Harriet Denton
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Kate Smith-Jackson
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Heather Kerr
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | - Andrew P Herbert
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | - Paul N Barlow
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | | | - Kevin J Marchbank
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK;
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24
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Santoro D, Siligato R, Vadalà C, Lucanto M, Cristadoro S, Conti G, Buemi M, Costa S, Sabadini E, Magazzù G. C3 glomerulopathy in cystic fibrosis: a case report. BMC Nephrol 2018; 19:73. [PMID: 29592796 PMCID: PMC5875003 DOI: 10.1186/s12882-018-0880-y] [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: 03/13/2017] [Accepted: 03/20/2018] [Indexed: 11/25/2022] Open
Abstract
Background C3 glomerulonephritis is a rare glomerulopathy characterized at renal biopsy by C3 deposition, alone or with scanty immunoglobulins, as well as by an electron-dense material in mesangium, subendothelial and subepithelial space. An abnormal systemic activation of the alternative pathway of the complement cascade is responsible for the development of the disease if triggered by several possible environmental conditions. We report the first case in literature of a patient affected by cystic fibrosis and C3GN. Case presentation Our case involves a young woman with cystic fibrosis, who had persistent microscopic hematuria, proteinuria and hypocomplementemia C3 for over three months. Renal biopsy confirmed the diagnosis of C3 glomerulopathy. Complement system dysregulation was tested and resulted in a strong terminal pathway activation proved by high levels of sC5b-9 complex, amounting to 1588 ng/ml (normal value < 400 ng/ml). Next generation sequencing (NGS) showed polymorphism in CFH (p.V62I in SCR1) and THBD (p.A473V), already known as pathogenic for C3GN, as well as a mutation in C3 (p.R102G) associated only with age-related macular degeneration (AMD) so far. Treatment was based on ACE inhibitors and kidney function is currently stable (GFR 50 ml/min, serum creatinine 1.7). Conclusions The co-existence of C3 glomerulopathy in a patient with CF, which is characterized by chronic infection/inflammation, makes this case an interesting model of chronic altered systemic activation of the alternative pathway of the complement cascade.
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Affiliation(s)
- Domenico Santoro
- Department of Clinical and Experimental Medicine, University of Messina, Via Faranda, 2-98123, Messina, Italy.
| | - Rossella Siligato
- Department of Clinical and Experimental Medicine, University of Messina, Via Faranda, 2-98123, Messina, Italy
| | - Carmela Vadalà
- Department of Clinical and Experimental Medicine, University of Messina, Via Faranda, 2-98123, Messina, Italy
| | - Mariacristina Lucanto
- Unit of Pediatric Gastroenterology and Cystic Fibrosis, University of Messina, Messina, Italy
| | - Simona Cristadoro
- Unit of Pediatric Gastroenterology and Cystic Fibrosis, University of Messina, Messina, Italy
| | - Giovanni Conti
- Unit of Pediatric Nephrology and Rheumatology, University of Messina, Messina, Italy
| | - Michele Buemi
- Department of Clinical and Experimental Medicine, University of Messina, Via Faranda, 2-98123, Messina, Italy
| | - Stefano Costa
- Unit of Pediatric Gastroenterology and Cystic Fibrosis, University of Messina, Messina, Italy
| | | | - Giuseppe Magazzù
- Unit of Pediatric Gastroenterology and Cystic Fibrosis, University of Messina, Messina, Italy
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25
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Spartà G, Gaspert A, Neuhaus TJ, Weitz M, Mohebbi N, Odermatt U, Zipfel PF, Bergmann C, Laube GF. Membranoproliferative glomerulonephritis and C3 glomerulopathy in children: change in treatment modality? A report of a case series. Clin Kidney J 2018; 11:479-490. [PMID: 30094012 PMCID: PMC6070093 DOI: 10.1093/ckj/sfy006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/27/2017] [Indexed: 12/11/2022] Open
Abstract
Background Membranoproliferative glomerulonephritis (MPGN) with immune complexes and C3 glomerulopathy (C3G) in children are rare and have a variable outcome, with some patients progressing to end-stage renal disease (ESRD). Mutations in genes encoding regulatory proteins of the alternative complement pathway and of complement C3 (C3) have been identified as concausative factors. Methods Three children with MPGN type I, four with C3G, i.e. three with C3 glomerulonephritis (C3GN) and one with dense deposit disease (DDD), were followed. Clinical, autoimmune data, histological characteristics, estimated glomerular filtration rate (eGFR), proteinuria, serum C3, genetic and biochemical analysis were assessed. Results The median age at onset was 7.3 years and the median eGFR was 72 mL/min/1.73 m2. Six children had marked proteinuria. All were treated with renin-angiotensin-aldosterone system (RAAS) blockers. Three were given one or more immunosuppressive drugs and two eculizumab. At the last median follow-up of 9 years after diagnosis, three children had normal eGFR and no or mild proteinuria on RAAS blockers only. Among four patients without remission of proteinuria, genetic analysis revealed mutations in complement regulator proteins of the alternative pathway. None of the three patients with immunosuppressive treatment achieved partial or complete remission of proteinuria and two progressed to ESRD and renal transplantation. Two patients treated with eculizumab revealed relevant decreases in proteinuria. Conclusions In children with MPGN type I and C3G, the outcomes of renal function and response to treatment modality show great variability independent from histological diagnosis at disease onset. In case of severe clinical presentation at disease onset, early genetic and biochemical analysis of the alternative pathway dysregulation is recommended. Treatment with eculizumab appears to be an option to slow disease progression in single cases.
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Affiliation(s)
- Giuseppina Spartà
- Pediatric Nephrology Unit, University Children's Hospital Zurich, Zurich, Switzerland
| | - Ariana Gaspert
- Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland
| | - Thomas J Neuhaus
- Children's Hospital of Lucerne, Cantonal Hospital Lucerne, Lucerne, Switzerland
| | - Marcus Weitz
- Pediatric Nephrology Unit, University Children's Hospital Zurich, Zurich, Switzerland
| | - Nilufar Mohebbi
- Division of Nephrology, University Hospital Zurich, Zurich, Switzerland
| | - Urs Odermatt
- Nephrology Unit, Cantonal Hospital Lucerne, Lucerne, Switzerland
| | - Peter F Zipfel
- Leibniz Institute for Natural Product Research and Infection Biology e. V. Hans-Knöll-Institute, Jena, Germany.,Friedrich Schiller University, Jena, Germany
| | - Carsten Bergmann
- Bioscientia Center of Human Genetics, Ingelheim am Rhein, Germany
| | - Guido F Laube
- Pediatric Nephrology Unit, University Children's Hospital Zurich, Zurich, Switzerland
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26
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Rudnick RB, Chen Q, Stea ED, Hartmann A, Papac-Milicevic N, Person F, Wiesener M, Binder CJ, Wiech T, Skerka C, Zipfel PF. FHR5 Binds to Laminins, Uses Separate C3b and Surface-Binding Sites, and Activates Complement on Malondialdehyde-Acetaldehyde Surfaces. THE JOURNAL OF IMMUNOLOGY 2018; 200:2280-2290. [PMID: 29483359 DOI: 10.4049/jimmunol.1701641] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 01/30/2018] [Indexed: 12/17/2022]
Abstract
Factor H related-protein 5 (CFHR5) is a surface-acting complement activator and variations in the CFHR5 gene are linked to CFHR glomerulonephritis. In this study, we show that FHR5 binds to laminin-521, the major constituent of the glomerular basement membrane, and to mesangial laminin-211. Furthermore, we identify malondialdehyde-acetaldehyde (MAA) epitopes, which are exposed on the surface of human necrotic cells (Homo sapiens), as new FHR5 ligands. Using a set of novel deletion fragments, we show that FHR5 binds to laminin-521, MAA epitopes, heparin, and human necrotic cells (HUVECs) via the middle region [short consensus repeats (SCRs) 5-7]. In contrast, surface-bound FHR5 contacts C3b via the C-terminal region (SCRs8-9). Thus, FHR5 uses separate domains for C3b binding and cell surface interaction. MAA epitopes serve as a complement-activating surface by recruiting FHR5. The complement activator FHR5 and the complement inhibitor factor H both bind to oxidation-specific MAA epitopes and FHR5 competes with factor H for binding. The C3 glomerulopathy-associated FHR21-2-FHR5 hybrid protein is more potent in MAA epitope binding and activation compared with wild-type FHR5. The implications of these results for pathology of CFHR glomerulonephritis are discussed. In conclusion, we identify laminins and oxidation-specific MAA epitopes as novel FHR5 ligands and show that the surface-binding site of FHR5 (SCRs5-7) is separated from the C3b binding site (SCRs8-9). Furthermore, FHR5 competes with factor H for binding to MAA epitopes and activates complement on these modified structures.
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Affiliation(s)
- Ramona B Rudnick
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany
| | - Qian Chen
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany
| | - Emma Diletta Stea
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany
| | - Andrea Hartmann
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany
| | - Nikolina Papac-Milicevic
- Clinical Department of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, 1090 Vienna, Austria.,Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Fermin Person
- Institute of Pathology, University Hospital Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Michael Wiesener
- Department of Nephrology and Hypertension, Friedrich-Alexander University of Erlangen-Nuremberg, 91054 Erlangen, Germany; and
| | - Christoph J Binder
- Clinical Department of Medical and Chemical Laboratory Diagnostics, Medical University of Vienna, 1090 Vienna, Austria.,Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Thorsten Wiech
- Institute of Pathology, University Hospital Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany
| | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany; .,Department Microbiology, Friedrich-Schiller-University, 07745 Jena, Germany
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27
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Medjeral-Thomas NR, Troldborg A, Constantinou N, Lomax-Browne HJ, Hansen AG, Willicombe M, Pusey CD, Cook HT, Thiel S, Pickering MC. Progressive IgA Nephropathy Is Associated With Low Circulating Mannan-Binding Lectin-Associated Serine Protease-3 (MASP-3) and Increased Glomerular Factor H-Related Protein-5 (FHR5) Deposition. Kidney Int Rep 2017; 3:426-438. [PMID: 29725647 PMCID: PMC5932138 DOI: 10.1016/j.ekir.2017.11.015] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/16/2017] [Accepted: 11/21/2017] [Indexed: 12/16/2022] Open
Abstract
Introduction IgA nephropathy (IgAN) is characterized by glomerular deposition of galactose-deficient IgA1 and complement proteins and leads to renal impairment. Complement deposition through the alternative and lectin activation pathways is associated with renal injury. Methods To elucidate the contribution of the lectin pathway to IgAN, we measured the 11 plasma lectin pathway components in a well-characterized cohort of patients with IgAN. Results M-ficolin, L-ficolin, mannan-binding lectin (MBL)-associated serine protease (MASP)-1 and MBL-associated protein (MAp) 19 were increased, whereas plasma MASP-3 levels were decreased in patients with IgAN compared with healthy controls. Progressive disease was associated with low plasma MASP-3 levels and increased glomerular staining for C3b/iC3b/C3c, C3d, C4d, C5b-9, and factor H-related protein 5 (FHR5). Glomerular FHR5 deposition positively correlated with glomerular C3b/iC3b/C3c, C3d, and C5b-9 deposition, but not with glomerular C4d. These observations, together with the finding that glomerular factor H (fH) deposition was reduced in progressive disease, are consistent with a role for fH deregulation by FHR5 in renal injury in IgAN. Conclusion Our data indicate that circulating MASP-3 levels could be used as a biomarker of disease severity in IgAN and that glomerular staining for FHR5 could both indicate alternative complement pathway activation and be a tissue marker of disease severity.
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Affiliation(s)
| | - Anne Troldborg
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark
| | - Nicholas Constantinou
- Centre for Complement and Inflammation Research, Imperial College London, London, UK
| | - Hannah J Lomax-Browne
- Centre for Complement and Inflammation Research, Imperial College London, London, UK
| | | | - Michelle Willicombe
- Renal and Transplant Centre, Imperial College Healthcare NHS Trust, London, UK
| | - Charles D Pusey
- Renal and Vascular Inflammation Section, Imperial College London, London, UK
| | - H Terence Cook
- Centre for Complement and Inflammation Research, Imperial College London, London, UK
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Imperial College London, London, UK
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28
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van Beek AE, Pouw RB, Brouwer MC, van Mierlo G, Geissler J, Ooijevaar-de Heer P, de Boer M, van Leeuwen K, Rispens T, Wouters D, Kuijpers TW. Factor H-Related (FHR)-1 and FHR-2 Form Homo- and Heterodimers, while FHR-5 Circulates Only As Homodimer in Human Plasma. Front Immunol 2017; 8:1328. [PMID: 29093712 PMCID: PMC5651247 DOI: 10.3389/fimmu.2017.01328] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 09/29/2017] [Indexed: 01/11/2023] Open
Abstract
The complement factor H-related (FHR) proteins are hypothesized to fine-tune the regulatory role of complement factor H (FH) in the alternative pathway of the complement system. Moreover, FHR-1, FHR-2, and FHR-5 have been proposed to be dimers, which further complicates accurate analysis. As FHRs are highly similar among themselves and toward FH, obtaining specific reagents for quantification of serum levels and functional analysis is challenging. In this study, we generated antibodies and developed ELISAs to measure FHR-1, FHR-2, and FHR-5 in serum. We used both recombinant and serum-derived proteins to show that four dimers occur in human circulation: homodimers of FHR-1, FHR-2, and FHR-5, as well as FHR-1/FHR-2 heterodimers. Heterodimers containing FHR-5 were not found. In individuals with homozygous CFHR1 deletions or compound heterozygous CFHR2 missense/nonsense mutations identified in this study, the respective FHR-1 and FHR-2 homo- and heterodimers were absent. Using FRET, we found that recombinant FHR dimers exchange monomers rapidly. This was confirmed ex vivo, using FHR-1- and FHR-2-deficient sera. Of all FHR dimers, FHR-5/5 homodimers demonstrated strong binding affinity toward heparin. Specific ELISAs demonstrated that serum levels of FHR-1/1, FHR-1/2, FHR-2/2, and FHR-5/5 dimers were low compared to FH, which circulates at a 10- to 200-fold molar excess. In summary, FHR-1, FHR-2, and FHR-5 homodimerize, with FHR-1 and FHR-2 forming heterodimers as well, and equilibrate quickly in plasma.
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Affiliation(s)
- Anna E van Beek
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands.,Department of Pediatric Hematology, Immunology and Infectious Diseases, Emma Children's Hospital, Academic Medical Centre, Amsterdam, Netherlands
| | - Richard B Pouw
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands.,Department of Pediatric Hematology, Immunology and Infectious Diseases, Emma Children's Hospital, Academic Medical Centre, Amsterdam, Netherlands
| | - Mieke C Brouwer
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Gerard van Mierlo
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Judy Geissler
- Department of Blood Cell Research, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Pleuni Ooijevaar-de Heer
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Martin de Boer
- Department of Blood Cell Research, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Karin van Leeuwen
- Department of Blood Cell Research, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Theo Rispens
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Diana Wouters
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands
| | - Taco W Kuijpers
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, Netherlands.,Department of Pediatric Hematology, Immunology and Infectious Diseases, Emma Children's Hospital, Academic Medical Centre, Amsterdam, Netherlands
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29
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Abstract
The role of the complement factor H-related (FHR) proteins in homeostasis, pathogen defense, and autoimmune disease has recently attracted considerable interest. We highlight the exciting research that has contributed to our understanding of the FHR protein family. Unlike factor H, a potent negative regulator of complement C3 activation, the FHR proteins appear to promote C3 activation. These data have important implications for understanding complement-mediated diseases because, depending on the context, the balance between the actions of factor H and the FHR proteins determines the degree of complement activation.
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Affiliation(s)
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Imperial College, London, UK
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30
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A novel CFHR1-CFHR5 hybrid leads to a familial dominant C3 glomerulopathy. Kidney Int 2017; 92:876-887. [PMID: 28729035 DOI: 10.1016/j.kint.2017.04.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 04/14/2017] [Accepted: 04/28/2017] [Indexed: 11/23/2022]
Abstract
The intrinsic similarity shared between the members of the complement factor H family, which comprises complement factor H and five complement factor H-related (CFHR) genes, leads to various recombination events. In turn these events lead to deletions of some genes or abnormal proteins, which are found in patients with atypical hemolytic uremic syndrome or C3 glomerulopathies. Here we describe a novel genetic rearrangement generated from a heterozygous deletion spanning 146 Kbp involving multiple CFHR genes leading to a CFHR1-R5 hybrid protein. This deletion was found in four family members presenting with a familial dominant glomerulopathy histologically classified as an overlap of dense deposit disease and C3 glomerulonephritis. Affected patients exhibited permanently low C3 and factor B levels and high amounts of activation fragments sC5b9 and Bb, indicating a systemic alternative pathway dysregulation. The abnormal protein, characterized by Western blot and immunoprecipitation, was shown to circulate in association with CFHR1 and CFHR2, attributable to its two N-terminal dimerization motifs. The presence of this protein is associated with a perturbation of Factor H activity on the C3 convertase decay. Thus, our study highlights the role of CFHRs in the physiopathology of C3 glomerulopathies and stresses the importance of screening CFHRs in all familial C3 glomerulopathies. Such hybrids described till now were always associated with familial forms.
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31
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Medjeral-Thomas NR, Lomax-Browne HJ, Beckwith H, Willicombe M, McLean AG, Brookes P, Pusey CD, Falchi M, Cook HT, Pickering MC. Circulating complement factor H-related proteins 1 and 5 correlate with disease activity in IgA nephropathy. Kidney Int 2017; 92:942-952. [PMID: 28673452 PMCID: PMC5611987 DOI: 10.1016/j.kint.2017.03.043] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 03/23/2017] [Accepted: 03/30/2017] [Indexed: 12/21/2022]
Abstract
IgA nephropathy (IgAN) is a common cause of chronic kidney disease and end-stage renal failure, especially in young people. Due to a wide range of clinical outcomes and difficulty in predicting response to immunosuppression, we need to understand why and identify which patients with IgAN will develop progressive renal impairment. A deletion polymorphism affecting the genes encoding the complement factor H-related protein (FHR)-1 and FHR-3 is robustly associated with protection against IgAN. Some FHR proteins, including FHR-1 and FHR-5, antagonize the ability of complement factor H (fH), the major negative regulator of the complement alternative pathway, to inhibit complement activation on surfaces, a process termed fH deregulation. From a large cohort of patients, we demonstrated that plasma FHR-1 and the FHR-1/fH ratio were elevated in IgAN and associated with progressive disease. Plasma FHR-1 negatively correlated with eGFR but remained elevated in patients with IgAN with normal eGFR. Serum FHR5 was slightly elevated in IgAN but did not correlate with eGFR. Neither FHR5 levels nor the FHR-5/fH ratio was associated with progressive disease. However, higher serum FHR-5 levels were associated with a lack of response to immunosuppression, the presence of endocapillary hypercellularity, and histology scores of disease severity (the Oxford Classification MEST score). Thus, FHR-1 and FHR-5 have a role in IgAN disease progression.
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Affiliation(s)
| | | | - Hannah Beckwith
- Centre for Complement and Inflammation Research, Imperial College London, UK
| | - Michelle Willicombe
- Renal and Transplant Centre, Imperial College Healthcare NHS Trust, London, UK
| | - Adam G McLean
- Renal and Transplant Centre, Imperial College Healthcare NHS Trust, London, UK
| | - Paul Brookes
- Histocompatibility & Immunogenetics, Imperial College Healthcare NHS Trust, London, UK
| | - Charles D Pusey
- Renal and Vascular Inflammation Section, Imperial College London, UK
| | - Mario Falchi
- Department of Twin Research and Genetic Epidemiology, King's College London, UK
| | - H Terence Cook
- Centre for Complement and Inflammation Research, Imperial College London, UK
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Imperial College London, UK.
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32
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Abstract
C3 glomerulopathy is a recently defined entity that encompasses a group of kidney diseases caused by abnormal control of complement activation with deposition of complement component C3 in glomeruli leading to variable glomerular inflammation. Before the recognition of the unique pathogenesis of these cases, they were variably classified according to their morphological features. C3 glomerulopathy accounts for roughly 1% of all renal biopsies. Clear definition of this entity has allowed a better understanding of its pathogenesis and clinical course and is likely to lead to the design of rational therapies over the next few years.
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Affiliation(s)
- H Terence Cook
- Department of Medicine, Imperial College London, Hammersmith, London, UK
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33
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Kousios A. Does complement Factor H-Related protein 5 Nephropathy (Troodos Nephropathy) protect from rickettsial infections? Med Hypotheses 2017; 98:76-80. [DOI: 10.1016/j.mehy.2016.11.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 11/25/2016] [Indexed: 10/20/2022]
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34
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Familial C3 glomerulonephritis caused by a novel CFHR5-CFHR2 fusion gene. Mol Immunol 2016; 77:89-96. [PMID: 27490940 DOI: 10.1016/j.molimm.2016.07.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 07/10/2016] [Accepted: 07/12/2016] [Indexed: 11/23/2022]
Abstract
C3 glomerulopathy (C3G) is an ultra-rare complement-mediated renal disease characterized histologically by the predominance of C3 deposition within in the glomerulus. Familial cases of C3G are extremely uncommon and offer unique insight into the genetic drivers of complement dysregulation. In this report, we describe a patient who presented with C3G. Because a relative carried the same diagnosis, we sought an underlying genetic commonality to explain the phenotype. As part of a comprehension genetic screen, we completed multiplex ligation-dependent probe amplification across the complement factor H related region and identified amplification alterations consistent with a genomic rearrangement. Using comparative genomic hybridization, we narrowed and then cloned the rearrangement breakpoints thereby defining a novel fusion gene that is translated into a serum protein comprised of factor H related-5 (short consensus repeats 1 and 2) and factor H-related-2 (short consensus repeats 1-4). These data highlight the role of factor H related proteins in the control of complement activity and illustrate how perturbation of that control leads to C3G.
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35
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Abstract
C3 glomerulopathy (C3G) describes a spectrum of glomerular diseases defined by shared renal biopsy pathology: a predominance of C3 deposition on immunofluorescence with electron microscopy permitting disease sub-classification. Complement dysregulation underlies the observed pathology, a causal relationship that is supported by well described studies of genetic and acquired drivers of disease. In this article, we provide an overview of the features of C3G, including a discussion of disease definition and a review of the causal role of complement. We discuss molecular markers of disease and how biomarkers are informing our evolving understanding of underlying pathology. Research advances are laying the foundation for complement inhibition as a targeted approach to treatment of C3G.
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36
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Salvadori M, Rosso G. Reclassification of membranoproliferative glomerulonephritis: Identification of a new GN: C3GN. World J Nephrol 2016; 5:308-320. [PMID: 27458560 PMCID: PMC4936338 DOI: 10.5527/wjn.v5.i4.308] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 03/31/2016] [Accepted: 05/27/2016] [Indexed: 02/06/2023] Open
Abstract
This review revises the reclassification of the membranoproliferative glomerulonephritis (MPGN) after the consensus conference that by 2015 reclassified all the glomerulonephritis basing on etiology and pathogenesis, instead of the histomorphological aspects. After reclassification, two types of MPGN are to date recognized: The immunocomplexes mediated MPGN and the complement mediated MPGN. The latter type is more extensively described in the review either because several of these entities are completely new or because the improved knowledge of the complement cascade allowed for new diagnostic and therapeutic approaches. Overall the complement mediated MPGN are related to acquired or genetic cause. The presence of circulating auto antibodies is the principal acquired cause. Genetic wide association studies and family studies allowed to recognize genetic mutations of different types as causes of the complement dysregulation. The complement cascade is a complex phenomenon and activating factors and regulating factors should be distinguished. Genetic mutations causing abnormalities either in activating or in regulating factors have been described. The diagnosis of the complement mediated MPGN requires a complete study of all these different complement factors. As a consequence, new therapeutic approaches are becoming available. Indeed, in addition to a nonspecific treatment and to the immunosuppression that has the aim to block the auto antibodies production, the specific inhibition of complement activation is relatively new and may act either blocking the C5 convertase or the C3 convertase. The drugs acting on C3 convertase are still in different phases of clinical development and might represent drugs for the future. Overall the authors consider that one of the principal problems in finding new types of drugs are both the rarity of the disease and the consequent poor interest in the marketing and the lack of large international cooperative studies.
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37
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Distinct roles for the complement regulators factor H and Crry in protection of the kidney from injury. Kidney Int 2016; 90:109-22. [PMID: 27165610 DOI: 10.1016/j.kint.2016.02.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 02/23/2016] [Accepted: 02/25/2016] [Indexed: 12/29/2022]
Abstract
Mutations in the complement regulatory proteins are associated with several different diseases. Although these mutations cause dysregulated alternative pathway activation throughout the body, the kidneys are the most common site of injury. The susceptibility of the kidney to alternative pathway-mediated injury may be due to limited expression of complement regulatory proteins on several tissue surfaces within the kidney. To examine the roles of the complement regulatory proteins factor H and Crry in protecting distinct renal surfaces from alternative pathway mediated injury, we generated mice with targeted deletions of the genes for both proteins. Surprisingly, mice with combined genetic deletions of factor H and Crry developed significantly milder renal injury than mice deficient in only factor H. Deficiency of both factor H and Crry was associated with C3 deposition at multiple locations within the kidney, but glomerular C3 deposition was lower than that in factor H alone deficient mice. Thus, factor H and Crry are critical for regulating complement activation at distinct anatomic sites within the kidney. However, widespread activation of the alternative pathway reduces injury by depleting the pool of C3 available at any 1 location.
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38
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Muff-Luett M, Nester CM. The Genetics of Ultra-Rare Renal Disease. J Pediatr Genet 2016; 5:33-42. [PMID: 27617140 DOI: 10.1055/s-0036-1572515] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 12/02/2015] [Indexed: 12/14/2022]
Abstract
The complement-mediated renal diseases are a group of ultra-rare renal diseases that disproportionately affect children and young adults and frequently lead to irreversible renal failure. Genetic mutations in alternate pathway of complement genes are pathomechanistically involved in a significant number of these unique diseases. Here, we review our current understanding of the role of genetics in the primary complement-mediated renal diseases affecting children, with a focus on atypical hemolytic uremic syndrome and C3 glomerulopathy. Also, included is a brief discussion of the related diseases whose relationship to complement abnormality has been suspected but not yet confirmed. Advances in genetics have transformed both treatment and outcomes in these historically difficult to treat, highly morbid diseases.
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Affiliation(s)
- Melissa Muff-Luett
- Division of Pediatric Nephrology, University of Nebraska Medical Center, Omaha, Nebraska, United States
| | - Carla M Nester
- Division of Pediatric Nephrology, Dialysis and Transplantation, Stead Family Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States; Molecular Otolaryngology and Renal Research Laboratory, University of Iowa, Iowa City, Iowa, United States
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39
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De Vriese AS, Sethi S, Van Praet J, Nath KA, Fervenza FC. Kidney Disease Caused by Dysregulation of the Complement Alternative Pathway: An Etiologic Approach. J Am Soc Nephrol 2015; 26:2917-29. [PMID: 26185203 DOI: 10.1681/asn.2015020184] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Kidney diseases caused by genetic or acquired dysregulation of the complement alternative pathway (AP) are traditionally classified on the basis of clinical presentation (atypical hemolytic uremic syndrome as thrombotic microangiopathy), biopsy appearance (dense deposit disease and C3 GN), or clinical course (atypical postinfectious GN). Each is characterized by an inappropriate activation of the AP, eventuating in renal damage. The clinical diversity of these disorders highlights important differences in the triggers, the sites and intensity of involvement, and the outcome of the AP dysregulation. Nevertheless, we contend that these diseases should be grouped as disorders of the AP and classified on an etiologic basis. In this review, we define different pathophysiologic categories of AP dysfunction. The precise identification of the underlying abnormality is the key to predict the response to immune suppression, plasma infusion, and complement-inhibitory drugs and the outcome after transplantation. In a patient with presumed dysregulation of the AP, the collaboration of the clinician, the renal pathologist, and the biochemical and genetic laboratory is very much encouraged, because this enables the elucidation of both the underlying pathogenesis and the optimal therapeutic approach.
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Affiliation(s)
- An S De Vriese
- Division of Nephrology, AZ Sint-Jan Brugge-Oostende AV, Brugge, Belgium; and
| | | | - Jens Van Praet
- Division of Nephrology, AZ Sint-Jan Brugge-Oostende AV, Brugge, Belgium; and
| | - Karl A Nath
- Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota
| | - Fernando C Fervenza
- Nephrology and Hypertension, Mayo Clinic College of Medicine, Rochester, Minnesota
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Yuste C, Gutierrez E, Sevillano AM, Rubio-Navarro A, Amaro-Villalobos JM, Ortiz A, Egido J, Praga M, Moreno JA. Pathogenesis of glomerular haematuria. World J Nephrol 2015; 4:185-95. [PMID: 25949932 PMCID: PMC4419128 DOI: 10.5527/wjn.v4.i2.185] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 12/19/2014] [Accepted: 12/29/2014] [Indexed: 02/06/2023] Open
Abstract
Haematuria was known as a benign hallmark of some glomerular diseases, but over the last decade, new evidences pointed its negative implications on kidney disease progression. Cytotoxic effects of oxidative stress induced by hemoglobin, heme, or iron released from red blood cells may account for the tubular injury observed in human biopsy specimens. However, the precise mechanisms responsible for haematuria remain unclear. The presence of red blood cells (RBCs) with irregular contours and shape in the urine indicates RBCs egression from the glomerular capillary into the urinary space. Therefore glomerular haematuria may be a marker of glomerular filtration barrier dysfunction or damage. In this review we describe some key issues regarding epidemiology and pathogenesis of haematuric diseases as well as their renal morphological findings.
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Zipfel PF, Skerka C, Chen Q, Wiech T, Goodship T, Johnson S, Fremeaux-Bacchi V, Nester C, de Córdoba SR, Noris M, Pickering M, Smith R. The role of complement in C3 glomerulopathy. Mol Immunol 2015; 67:21-30. [PMID: 25929733 DOI: 10.1016/j.molimm.2015.03.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/09/2015] [Accepted: 03/10/2015] [Indexed: 12/12/2022]
Abstract
C3 glomerulopathy describes a spectrum of disorders with glomerular pathology associated with C3 cleavage product deposition and with defective complement action and regulation (Fakhouri et al., 2010; Sethi et al., 2012b). Kidney biopsies from these patients show glomerular accumulation or deposition of C3 cleavage fragments, but no or minor deposition of immunoglobulins (Appel et al., 2005; D'Agati and Bomback, 2012; Servais et al., 2007; Sethi and Fervenza, 2011). At present the current situation asks for a better definition of the underlining disease mechanisms, for precise biomarkers, and for a treatment for this disease. The complement system is a self activating and propelling enzymatic cascade type system in which inactive, soluble plasma components are activated spontaneously and lead into an amplification loop (Zipfel and Skerka, 2009). Activation of the alternative pathway is spontaneous, occurs by default, and cascade progression leads to amplification by complement activators. The system however is self-controlled by multiple regulators and inhibitors, like Factor H that control cascade progression in fluid phase and on surfaces. The activated complement system generates a series of potent effector components and activation products, which damage foreign-, as well as modified self cells, recruit innate immune cells to the site of action, coordinate inflammation and the response of the adaptive immune system in form of B cells and T lymphocytes (Kohl, 2006; Medzhitov and Janeway, 2002; Ogden and Elkon, 2006; Carroll, 2004; Kemper and Atkinson, 2007; Morgan, 1999; Muller-Eberhard, 1986; Ricklin et al., 2010). Complement controls homeostasis and multiple reactions in the vertebrate organism including defense against microbial infections (Diaz-Guillen et al., 1999; Mastellos and Lambris, 2002; Nordahl et al., 2004; Ricklin et al., 2010). In consequence defective control of the spontaneous self amplifying cascade or regulation is associated with numerous human disorders (Ricklin and Lambris, 2007; Skerka and Zipfel, 2008; Zipfel et al., 2006). Understanding the exact action and regulation of this sophisticated homeotic cascade system is relevant to understand disease pathology of various complement associated human disorders. Furthermore this knowledge is relevant for a better diagnosis and appropriate therapy. At present diagnosis of C3 glomerulopathy is primarily based on the kidney biopsy, and histological, immmunohistological and electron microscopical evaluation (D'Agati and Bomback, 2012; Fakhouri et al., 2010; Medjeral-Thomas et al., 2014a,b; Sethi et al., 2012b). The challenge is to define the actual cause of the diverse glomerular changes or damages, to define how C3 deposition results in the reported glomerular changes, the location of the cell damage and the formation of deposits.
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Affiliation(s)
- Peter F Zipfel
- Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany; Friedrich Schiller University Jena, Germany.
| | - Christine Skerka
- Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Qian Chen
- Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Thorsten Wiech
- Institute for Pathology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Tim Goodship
- Institute of Human Genetics, University of Newcastle upon Tyne, United Kingdom
| | - Sally Johnson
- Institute of Human Genetics, University of Newcastle upon Tyne, United Kingdom
| | - Veronique Fremeaux-Bacchi
- Assistance Publique-Hopitaux de Paris, Hospital European Georges-Pompidou and INSERM UMRS 1138, "Complement and Diseases" Team, Cordelier Research Center, Paris, France
| | - Clara Nester
- University of Iowa Carver College of Medicine, Otolaryngology, Iowa City, IA 52242, USA
| | - Santiago Rodríguez de Córdoba
- Departamento de Medicina Celular y Molecular, and Ciber de Enfermedades Raras, Centro de Investigaciones Biológicas, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Marina Noris
- Mario Negri Institute for Pharmacological Research, Ranica, Bergamo, Italy
| | | | - Richard Smith
- University of Iowa Carver College of Medicine, Otolaryngology, Iowa City, IA 52242, USA
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Abstract
'Membranoproliferative' describes glomerular injury characterized by capillary wall thickening and mesangial expansion owing to increased matrix deposition and hypercellularity. The presence of immune deposits is indicative of membranoproliferative glomerulonephritis (MPGN). Historically, MPGN was further classified into three types according to the appearance and site of the electron-dense deposits seen by electron microscopy, but it is now recognized that many cases show only deposition of the complement component C3, owing to abnormal control of the alternative pathway of complement activation-these cases are now classified as C3 glomerulopathies. Not all cases of C3 glomerulopathy, however, show an MPGN pattern. C3 glomerulopathies include dense deposit disease, which shows dense osmiophilic deposits, and C3 glomerulonephritis, which shows isolated deposits. In many cases, the genetic mutations or autoantibodies responsible for C3 deposition have been identified. Some patients in whom complement control is abnormal will accumulate small amounts of immunoglobulin in their glomeruli and so, in everyday practice, the morphological diagnosis of 'glomerulonephritis with dominant C3' is useful for identifying patients who require investigation of the complement pathway. The recognition that many cases of MPGN are C3 glomerulopathies and that the underlying cause can often be identified in immunoglobulin-associated cases means that the diagnosis of idiopathic MPGN is now very uncommon.
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Affiliation(s)
- H Terence Cook
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College, London W12 0NN, UK
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College, London W12 0NN, UK
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Zhang Y, Nester CM, Martin B, Skjoedt MO, Meyer NC, Shao D, Borsa N, Palarasah Y, Smith RJH. Defining the complement biomarker profile of C3 glomerulopathy. Clin J Am Soc Nephrol 2014; 9:1876-82. [PMID: 25341722 DOI: 10.2215/cjn.01820214] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND OBJECTIVES C3 glomerulopathy (C3G) applies to a group of renal diseases defined by a specific renal biopsy finding: a dominant pattern of C3 fragment deposition on immunofluorescence. The primary pathogenic mechanism involves abnormal control of the alternative complement pathway, although a full description of the disease spectrum remains to be determined. This study sought to validate and define the association of complement dysregulation with C3G and to determine whether specific complement pathway abnormalities could inform disease definition. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This study included 34 patients with C3G (17 with C3 glomerulonephritis [C3GN] and 17 with dense deposit disease [DDD]) diagnosed between 2008 and 2013 selected from the C3G Registry. Control samples (n=100) were recruited from regional blood drives. Nineteen complement biomarkers were assayed on all samples. Results were compared between C3G disease categories and with normal controls. RESULTS Assessment of the alternative complement pathway showed that compared with controls, patients with C3G had lower levels of serum C3 (P<0.001 for both DDD and C3GN) and factor B (P<0.001 for both DDD and C3GN) as well as higher levels of complement breakdown products including C3d (P<0.001 for both DDD and C3GN) and Bb (P<0.001 for both DDD and C3GN). A comparison of terminal complement pathway proteins showed that although C5 levels were significantly suppressed (P<0.001 for both DDD and C3GN) its breakdown product C5a was significantly higher only in patients with C3GN (P<0.05). Of the other terminal pathway components (C6-C9), the only significant difference was in C7 levels between patients with C3GN and controls (P<0.01). Soluble C5b-9 was elevated in both diseases but only the difference between patients with C3GN and controls reached statistical significance (P<0.001). Levels of C3 nephritic factor activity were qualitatively higher in patients with DDD compared with patients with C3GN. CONCLUSIONS Complement biomarkers are significantly abnormal in patients with C3G compared with controls. These data substantiate the link between complement dysregulation and C3G and identify C3G interdisease differences.
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Affiliation(s)
- Yuzhou Zhang
- Molecular Otolaryngology and Renal Research Laboratories
| | - Carla M Nester
- Molecular Otolaryngology and Renal Research Laboratories, Division of Nephrology, Department of Internal Medicine, Division of Nephrology, Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Bertha Martin
- Molecular Otolaryngology and Renal Research Laboratories, Department of Anatomy and Cell Biology, Graduate Program, and
| | - Mikkel-Ole Skjoedt
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Faculty of Health Sciences, University Hospital of Copenhagen, Copenhagen, Denmark; and
| | - Nicole C Meyer
- Molecular Otolaryngology and Renal Research Laboratories
| | - Dingwu Shao
- Molecular Otolaryngology and Renal Research Laboratories
| | - Nicolò Borsa
- Molecular Otolaryngology and Renal Research Laboratories
| | - Yaseelan Palarasah
- Department of Cancer and Inflammation, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, Division of Nephrology, Department of Internal Medicine, Division of Nephrology, Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa;
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Barbour TD, Ruseva MM, Pickering MC. Update on C3 glomerulopathy. Nephrol Dial Transplant 2014; 31:717-25. [PMID: 25326473 PMCID: PMC4848753 DOI: 10.1093/ndt/gfu317] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 09/10/2014] [Indexed: 02/06/2023] Open
Abstract
C3 glomerulopathy refers to a disease process in which abnormal control of complement activation, degradation or deposition results in predominant C3 fragment deposition within the glomerulus and glomerular damage. Recent studies have improved our understanding of its pathogenesis. The key abnormality is uncontrolled C3b amplification in the circulation and/or along the glomerular basement membrane. Family studies in which disease segregates with structurally abnormal complement factor H-related (CFHR) proteins demonstrate that abnormal CFHR proteins are important in some types of C3 glomerulopathy. This is currently thought to be due to the ability of these proteins to antagonize the major negative regulator of C3 activation, complement factor H (CFH), a process termed ‘CFH de-regulation’. Recent clinicopathological cohort studies have led to further refinements in case definition, culminating in a 2013 consensus report, which provides recommendations regarding investigation and treatment. Early clinical experience with complement-targeted therapeutics, notably C5 inhibitors, has also now been published. Here, we summarize the latest developments in C3 glomerulopathy.
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Affiliation(s)
- Thomas D Barbour
- Centre for Complement and Inflammation Research (CCIR), Division of Immunology and Inflammation, Department of Medicine, Imperial College London, London W12 0NN, UK
| | - Marieta M Ruseva
- Centre for Complement and Inflammation Research (CCIR), Division of Immunology and Inflammation, Department of Medicine, Imperial College London, London W12 0NN, UK
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research (CCIR), Division of Immunology and Inflammation, Department of Medicine, Imperial College London, London W12 0NN, UK
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Meyers KE, Liapis H, Atta MG. American Society of Nephrology clinical pathological conference. Clin J Am Soc Nephrol 2014; 9:818-28. [PMID: 24651072 DOI: 10.2215/cjn.12481213] [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: 11/23/2022]
Abstract
A 13-year-old girl presented with proteinuria and acute kidney failure. She was born at full term via cesarean delivery (due to nuchal cord), but there were no other prenatal or perinatal complications. In early childhood the patient had two hospitalizations at ages 4.5 and 9 years, respectively, the latter for pneumonia. She had no history of symptoms of kidney disease. She came to the hospital at age 12 years for routine bilateral molar extractions. She was treated with oral antibiotics and discharged after the procedure without complications. At age 13 years, 10 months after the molar extraction, she was seen by a pediatrician because of puffiness and increased BP. She had had respiratory symptoms 2 weeks before presentation. The pediatrician prescribed furosemide and amlodipine. A few days later, the patient returned to the pediatrician's office because of hand, ankle, and facial swelling and malaise. The pediatrician recommended hospitalization and the patient was admitted at this time.
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Affiliation(s)
- Kevin E Meyers
- The Children Hospital of Philadelphia and University of Pennsylvania, Philadelphia, Pennsylvania;, †Division of Anatomic and Molecular Pathology, Washington University School of Medicine, St. Louis, Missouri, ‡Division of Nephrology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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C3 glomerulopathy: consensus report. Kidney Int 2013; 84:1079-89. [PMID: 24172683 PMCID: PMC3842953 DOI: 10.1038/ki.2013.377] [Citation(s) in RCA: 411] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 05/30/2013] [Accepted: 06/20/2013] [Indexed: 02/06/2023]
Abstract
C3 glomerulopathy is a recently introduced pathological entity whose original definition was glomerular pathology characterized by C3 accumulation with absent or scanty immunoglobulin deposition. In August 2012, an invited group of experts (comprising the authors of this document) in renal pathology, nephrology, complement biology, and complement therapeutics met to discuss C3 glomerulopathy in the first C3 Glomerulopathy Meeting. The objectives were to reach a consensus on: the definition of C3 glomerulopathy, appropriate complement investigations that should be performed in these patients, and how complement therapeutics should be explored in the condition. This meeting report represents the current consensus view of the group.
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