51
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Gurjar BS, Manikanta Sriharsha T, Bhasym A, Prabhu S, Puraswani M, Khandelwal P, Saini H, Saini S, Verma AK, Chatterjee P, Guchhait P, Bal V, George A, Rath S, Sahu A, Sharma A, Hari P, Sinha A, Bagga A. Characterization of genetic predisposition and autoantibody profile in atypical haemolytic-uraemic syndrome. Immunology 2018; 154:663-672. [PMID: 29485195 PMCID: PMC6050217 DOI: 10.1111/imm.12916] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 02/01/2018] [Accepted: 02/02/2018] [Indexed: 12/25/2022] Open
Abstract
We previously reported that Indian paediatric patients with atypical haemolytic-uraemic syndrome (aHUS) showed high frequencies of anti-complement factor H (FH) autoantibodies that are correlated with homozygous deletion of the genes for FH-related proteins 1 and 3 (FHR1 and FHR3) (FHR1/3-/- ). We now report that Indian paediatric aHUS patients without anti-FH autoantibodies also showed modestly higher frequencies of the FHR1/3-/- genotype. Further, when we characterized epitope specificities and binding avidities of anti-FH autoantibodies in aHUS patients, most anti-FH autoantibodies were directed towards the FH cell-surface anchoring polyanionic binding site-containing C-terminal short conservative regions (SCRs) 17-20 with higher binding avidities than for native FH. FH SCR17-20-binding anti-FH autoantibodies also bound the other cell-surface anchoring polyanionic binding site-containing region FH SCR5-8, at lower binding avidities. Anti-FH autoantibody avidities correlated with antibody titres. These anti-FH autoantibody characteristics did not differ between aHUS patients with or without the FHR1/3-/- genotype. Our data suggest a complex matrix of interactions between FHR1-FHR3 deletion, immunomodulation and anti-FH autoantibodies in the aetiopathogenesis of aHUS.
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Affiliation(s)
| | | | - Angika Bhasym
- Regional Centre for BiotechnologyFaridabadIndia
- Department of BiotechnologyManipal Academy of Higher EducationManipalIndia
| | - Savit Prabhu
- Paediatric Biology CentreTranslational Health Science and Technology InstituteFaridabadIndia
| | - Mamta Puraswani
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Priyanka Khandelwal
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Himanshi Saini
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Savita Saini
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | | | | | | | - Vineeta Bal
- National Institute of ImmunologyNew DelhiIndia
- Paediatric Biology CentreTranslational Health Science and Technology InstituteFaridabadIndia
| | - Anna George
- National Institute of ImmunologyNew DelhiIndia
| | - Satyajit Rath
- National Institute of ImmunologyNew DelhiIndia
- Paediatric Biology CentreTranslational Health Science and Technology InstituteFaridabadIndia
- Agharkar Research InstitutePuneIndia
| | - Arvind Sahu
- National Centre for Cell ScienceS. P. Pune University CampusPuneIndia
| | - Amita Sharma
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Pankaj Hari
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Aditi Sinha
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
| | - Arvind Bagga
- Department of PaediatricsAll India Institute of Medical SciencesNew DelhiIndia
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52
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Taylor RP, Lindorfer MA. Mechanisms of Complement-Mediated Damage in Hematological Disorders. Semin Hematol 2018; 55:118-123. [PMID: 30032747 DOI: 10.1053/j.seminhematol.2018.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 02/09/2018] [Indexed: 12/27/2022]
Abstract
The complement cascade is an ancient defense system that destroys and eliminates threats to normal homeostasis in the bloodstream and tissues. Although multiple controls keep complement in check to minimize innocent bystander injury to normal cells and tissues, defects in complement regulation due to mutations in, or autoantibodies to, complement control proteins underlie the pathogenesis of several hemolytic diseases including paroxysmal nocturnal hemoglobinuria, and atypical hemolytic uremic syndrome. In autoimmune hemolytic anemias complement plays an important role in erythrocyte destruction mediated by antierythrocyte antibodies. The pathogenic mechanisms of these hemolytic diseases are discussed, with an emphasis on pivotal steps in complement activation.
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Affiliation(s)
- Ronald P Taylor
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA.
| | - Margaret A Lindorfer
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA
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53
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Lorés-Motta L, Paun CC, Corominas J, Pauper M, Geerlings MJ, Altay L, Schick T, Daha MR, Fauser S, Hoyng CB, den Hollander AI, de Jong EK. Genome-Wide Association Study Reveals Variants in CFH and CFHR4 Associated with Systemic Complement Activation: Implications in Age-Related Macular Degeneration. Ophthalmology 2018; 125:1064-1074. [PMID: 29398083 DOI: 10.1016/j.ophtha.2017.12.023] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 11/07/2017] [Accepted: 12/13/2017] [Indexed: 01/03/2023] Open
Abstract
PURPOSE To identify genetic variants associated with complement activation, which may help to select age-related macular degeneration (AMD) patients for complement-inhibiting therapies. DESIGN Genome-wide association study (GWAS) followed by replication and meta-analysis. PARTICIPANTS AMD patients and controls (n = 2245). METHODS A GWAS on serum C3d-to-C3 ratio was performed in 1548 AMD patients and controls. For replication and meta-analysis, 697 additional individuals were genotyped. A model for complement activation including genetic and non-genetic factors was built, and the variance explained was estimated. Haplotype analysis was performed for 8 SNPs across the CFH/CFHR locus. Association with AMD was performed for the variants and haplotypes found to influence complement activation. MAIN OUTCOME MEASURES Normalized C3d/C3 ratio as a measure of systemic complement activation. RESULTS Complement activation was associated independently with rs3753396 located in CFH (Pdiscovery = 1.09 × 10-15; Pmeta = 3.66 × 10-21; β = 0.141; standard error [SE] = 0.015) and rs6685931 located in CFHR4 (Pdiscovery = 8.18 × 10-7; Pmeta = 6.32 × 10-8; β = 0.054; SE = 0.010). A model including age, AMD disease status, body mass index, triglycerides, rs3753396, rs6685931, and previously identified SNPs explained 18.7% of the variability in complement activation. Haplotype analysis revealed 3 haplotypes (H1-2 and H6 containing rs6685931 and H3 containing rs3753396) associated with complement activation. Haplotypes H3 and H6 conferred stronger effects on complement activation compared with the single variants (P = 2.53 × 10-14; β = 0.183; SE = 0.024; and P = 4.28 × 10-4; β = 0.144; SE = 0.041; respectively). Association analyses with AMD revealed that SNP rs6685931 and haplotype H1-2 containing rs6685931 were associated with a risk for AMD development, whereas SNP rs3753396 and haplotypes H3 and H6 were not. CONCLUSIONS The SNP rs3753396 in CFH and SNP rs6685931 in CFHR4 are associated with systemic complement activation levels. The SNP rs6685931 in CFHR4 and its linked haplotype H1-2 also conferred a risk for AMD development, and therefore could be used to identify AMD patients who would benefit most from complement-inhibiting therapies.
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Affiliation(s)
- Laura Lorés-Motta
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Constantin C Paun
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jordi Corominas
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Marc Pauper
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maartje J Geerlings
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lebriz Altay
- Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany
| | - Tina Schick
- Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany
| | - Mohamed R Daha
- Department of Nephrology, Leiden University Medical Center, Leiden, The Netherlands
| | - Sascha Fauser
- Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany; Roche Pharma Research and Early Development, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Carel B Hoyng
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anneke I den Hollander
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Eiko K de Jong
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
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54
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Wong EKS, Kavanagh D. Diseases of complement dysregulation-an overview. Semin Immunopathol 2018; 40:49-64. [PMID: 29327071 PMCID: PMC5794843 DOI: 10.1007/s00281-017-0663-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 11/01/2017] [Indexed: 02/07/2023]
Abstract
Atypical hemolytic uremic syndrome (aHUS), C3 glomerulopathy (C3G), and paroxysmal nocturnal hemoglobinuria (PNH) are prototypical disorders of complement dysregulation. Although complement overactivation is common to all, cell surface alternative pathway dysregulation (aHUS), fluid phase alternative pathway dysregulation (C3G), or terminal pathway dysregulation (PNH) predominates resulting in the very different phenotypes seen in these diseases. The mechanism underlying the dysregulation also varies with predominant acquired autoimmune (C3G), somatic mutations (PNH), or inherited germline mutations (aHUS) predisposing to disease. Eculizumab has revolutionized the treatment of PNH and aHUS although has been less successful in C3G. With the next generation of complement therapeutic in late stage development, these archetypal complement diseases will provide the initial targets.
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Affiliation(s)
- Edwin K S Wong
- The National Renal Complement Therapeutics Centre, aHUS Service, Building 26, Royal Victoria Infirmary, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP, UK.,Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - David Kavanagh
- The National Renal Complement Therapeutics Centre, aHUS Service, Building 26, Royal Victoria Infirmary, Queen Victoria Road, Newcastle upon Tyne, NE1 4LP, UK. .,Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK.
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55
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Sastre-Ibáñez M, Barreiro-González A, Gallego-Pinazo R, Dolz-Marco R, García-Armendariz B. Geographic atrophy: Etiopathogenesis and current therapies. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2018; 93:22-34. [PMID: 28886928 DOI: 10.1016/j.oftal.2017.07.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 06/30/2017] [Accepted: 07/05/2017] [Indexed: 06/07/2023]
Abstract
Geographic atrophy is characterized by severe visual deficit whose etiology and pathophysiology are yet to be elucidated. As a working hypothesis, oxidative damage could trigger a chronic inflammation in Bruch's membrane-RPE-choriocapillaris complex, mostly due to complement pathway overactivation. Some individuals with mutations in the complement system and other factors have diminished capacity in the modulation of the inflammatory response, which results in cell damage and waste accumulation. This accumulation of intracellular and extracellular waste products manifests as drusen and pigmentary changes that precede the atrophy of photoreceptors, RPE, choriocapillaris with an ischemic process with decreased choroid flow. All these processes can be detected as tomographic findings and autofluorescence signals that are useful in the evaluation of patients with atrophic AMD, which helps to establish an individualized prognosis. Anti-inflammatory, antioxidant and therapies that decrease the accumulation of toxins for the preservation of the RPE cells and photoreceptors are being investigated in order to slow down the progression of this disease.
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Affiliation(s)
- M Sastre-Ibáñez
- Servicio de Oftalmología, Hospital Clínico San Carlos, Madrid, España.
| | - A Barreiro-González
- Servicio de Oftalmología, Hospital Universitario y Politécnico La Fe, Valencia, España
| | - R Gallego-Pinazo
- Servicio de Oftalmología, Hospital Universitario y Politécnico La Fe, Valencia, España
| | - R Dolz-Marco
- Servicio de Oftalmología, Hospital Universitario y Politécnico La Fe, Valencia, España
| | - B García-Armendariz
- Servicio de Oftalmología, Hospital Universitario y Politécnico La Fe, Valencia, España
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56
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Iyer A, Xu W, Reid RC, Fairlie DP. Chemical Approaches to Modulating Complement-Mediated Diseases. J Med Chem 2017; 61:3253-3276. [DOI: 10.1021/acs.jmedchem.7b00882] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Abishek Iyer
- Centre for Inflammation and Disease Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Weijun Xu
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Robert C. Reid
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - David P. Fairlie
- Centre for Inflammation and Disease Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
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57
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Cserhalmi M, Csincsi ÁI, Mezei Z, Kopp A, Hebecker M, Uzonyi B, Józsi M. The Murine Factor H-Related Protein FHR-B Promotes Complement Activation. Front Immunol 2017; 8:1145. [PMID: 28974948 PMCID: PMC5610720 DOI: 10.3389/fimmu.2017.01145] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 08/30/2017] [Indexed: 12/03/2022] Open
Abstract
Factor H-related (FHR) proteins consist of varying number of complement control protein domains that display various degrees of sequence identity to respective domains of the alternative pathway complement inhibitor factor H (FH). While such FHR proteins are described in several species, only human FHRs were functionally investigated. Their biological role is still poorly understood and in part controversial. Recent studies on some of the human FHRs strongly suggest a role for FHRs in enhancing complement activation via competing with FH for binding to certain ligands and surfaces. The aim of the current study was the functional characterization of a murine FHR, FHR-B. To this end, FHR-B was expressed in recombinant form. Recombinant FHR-B bound to human C3b and was able to compete with human FH for C3b binding. FHR-B supported the assembly of functionally active C3bBb alternative pathway C3 convertase via its interaction with C3b. This activity was confirmed by demonstrating C3 activation in murine serum. In addition, FHR-B bound to murine pentraxin 3 (PTX3), and this interaction resulted in murine C3 fragment deposition due to enhanced complement activation in mouse serum. FHR-B also induced C3 deposition on C-reactive protein, the extracellular matrix (ECM) extract Matrigel, and endothelial cell-derived ECM when exposed to mouse serum. Moreover, mouse C3 deposition was strongly enhanced on necrotic Jurkat T cells and the mouse B cell line A20 by FHR-B. FHR-B also induced lysis of sheep erythrocytes when incubated in mouse serum with FHR-B added in excess. Altogether, these data demonstrate that, similar to human FHR-1 and FHR-5, mouse FHR-B modulates complement activity by promoting complement activation via interaction with C3b and via competition with murine FH.
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Affiliation(s)
- Marcell Cserhalmi
- MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Ádám I Csincsi
- MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Zoltán Mezei
- MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Anne Kopp
- Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Mario Hebecker
- Junior Research Group for Cellular Immunobiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Jena, Germany
| | - Barbara Uzonyi
- MTA-ELTE Immunology Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Mihály Józsi
- MTA-ELTE Lendület Complement Research Group, Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
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58
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Complement factor H in AMD: Bridging genetic associations and pathobiology. Prog Retin Eye Res 2017; 62:38-57. [PMID: 28928087 DOI: 10.1016/j.preteyeres.2017.09.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 09/08/2017] [Accepted: 09/13/2017] [Indexed: 01/28/2023]
Abstract
Age-Related Macular Degeneration (AMD) is a complex multifactorial disease characterized in its early stages by lipoprotein accumulations in Bruch's Membrane (BrM), seen on fundoscopic exam as drusen, and in its late forms by neovascularization ("wet") or geographic atrophy of the Retinal Pigmented Epithelial (RPE) cell layer ("dry"). Genetic studies have strongly supported a relationship between the alternative complement cascade, in particular the common H402 variant in Complement Factor H (CFH) and development of AMD. However, the functional significance of the CFH Y402H polymorphism remains elusive. In this article, we critically review the literature surrounding the functional significance of this polymorphism. Furthermore, based on our group's studies we propose a model in which CFH H402 affects CFH binding to heparan sulfate proteoglycans leading to accelerated lipoprotein accumulation in BrM and drusen progression. We also review the literature on the role of other complement components in AMD pathobiologies, including C3a, C5a and the membrane attack complex (MAC), and on transgenic mouse models developed to interrogate in vivo the effects of the CFH Y402H polymorphism.
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59
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60
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Blatt AZ, Pathan S, Ferreira VP. Properdin: a tightly regulated critical inflammatory modulator. Immunol Rev 2017; 274:172-190. [PMID: 27782331 PMCID: PMC5096056 DOI: 10.1111/imr.12466] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The complement alternative pathway is a powerful arm of the innate immune system that enhances diverse inflammatory responses in the human host. Key to the effects of the alternative pathway is properdin, a serum glycoprotein that can both initiate and positively regulate alternative pathway activity. Properdin is produced by many different leukocyte subsets and circulates as cyclic oligomers of monomeric subunits. While the formation of non‐physiological aggregates in purified properdin preparations and the presence of potential properdin inhibitors in serum have complicated studies of its function, properdin has, regardless, emerged as a key player in various inflammatory disease models. Here, we review basic properdin biology, emphasizing the major hurdles that have complicated the interpretation of results from properdin‐centered studies. In addition, we elaborate on an emerging role for properdin in thromboinflammation and discuss the potential utility of properdin inhibitors as long‐term therapeutic options to treat diseases marked by increased formation of platelet/granulocyte aggregates. Finally, we describe the interplay between properdin and the alternative pathway negative regulator, Factor H, and how aiming to understand these interactions can provide scientists with the most effective ways to manipulate alternative pathway activation in complex systems.
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Affiliation(s)
- Adam Z Blatt
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Sabina Pathan
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA.
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61
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Roumenina LT, Rayes J, Frimat M, Fremeaux-Bacchi V. Endothelial cells: source, barrier, and target of defensive mediators. Immunol Rev 2017; 274:307-329. [PMID: 27782324 DOI: 10.1111/imr.12479] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Endothelium is strategically located at the interface between blood and interstitial tissues, placing thus endothelial cell as a key player in vascular homeostasis. Endothelial cells are in a dynamic equilibrium with their environment and constitute concomitantly a source, a barrier, and a target of defensive mediators. This review will discuss the recent advances in our understanding of the complex crosstalk between the endothelium, the complement system and the hemostasis in health and in disease. The first part will provide a general introduction on endothelial cells heterogeneity and on the physiologic role of the complement and hemostatic systems. The second part will analyze the interplay between complement, hemostasis and endothelial cells in physiological conditions and their alterations in diseases. Particular focus will be made on the prototypes of thrombotic microangiopathic disorders, resulting from complement or hemostasis dysregulation-mediated endothelial damage: atypical hemolytic uremic syndrome and thrombotic thrombocytopenic purpura. Novel aspects of the pathophysiology of the thrombotic microangiopathies will be discussed.
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Affiliation(s)
- Lubka T Roumenina
- INSERM UMRS 1138, Cordeliers Research Center, Université Pierre et Marie Curie (UPMC-Paris-6) and Université Paris Descartes Sorbonne Paris-Cité, Paris, France.
| | - Julie Rayes
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Marie Frimat
- INSERM UMR 995, Lille, France.,Nephrology Department, CHU Lille, Lille, France
| | - Veronique Fremeaux-Bacchi
- INSERM UMRS 1138, Cordeliers Research Center, Université Pierre et Marie Curie (UPMC-Paris-6) and Université Paris Descartes Sorbonne Paris-Cité, Paris, France.,Assistance Publique - Hôpitaux de Paris, Service d'Immunologie Biologique, Hôpital Européen Georges Pompidou, Paris, France
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62
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Ding Y, Zhao W, Zhang T, Qiang H, Lu J, Su X, Wen S, Xu F, Zhang M, Zhang H, Zeng C, Liu Z, Chen H. A haplotype in CFH family genes confers high risk of rare glomerular nephropathies. Sci Rep 2017; 7:6004. [PMID: 28729648 PMCID: PMC5519609 DOI: 10.1038/s41598-017-05173-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 05/24/2017] [Indexed: 12/15/2022] Open
Abstract
Despite distinct renal lesions, a series of rare glomerular nephropathies are reportedly mediated by complement overactivation. Genetic variations in complement genes contribute to disease risk, but the relationship of genotype to phenotype has not been straightforward. Here, we screened 11 complement genes from 91 patients with atypical hemolytic uremic syndrome (aHUS), C3 glomerulopathy (C3G) and membranoproliferative glomerulonephritis type I (MPGN I), and identified the concomitant presence of three missense variations located within the human complement Factor H (CFH) gene cluster. The three variations, rs55807605, rs61737525 and rs57960694, have strong linkage disequilibrium; subsequent haplotype analysis indicated that ATA increased the susceptibility of these renal diseases. In silico analysis, the CFHR3 rs61737525-T risk allele altered the physical and structural properties and generated a reduction in binding affinity of the CFHR3/C3b complex. Surface plasmon resonance (SPR) binding analysis further demonstrated the substitution induced a decrease of two orders of magnitude in C3b-binding properties, with a declined cofactor activity in fluid phase. These data suggest that the haplotype carrying the causative allele behaves as a partial C3 convertase deficiency, predisposing individuals to diverse pathologic lesions underlying complement overactivation. Such genotype-phenotype discrepancies allow better understanding about these nephropathies mediated by genetic complement disorders.
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Affiliation(s)
- Yin Ding
- Devision of Nephrology, Jinling Hospital, Southern Medical University, Nanjing, 210016, China.,National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210016, China
| | - Weiwei Zhao
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210016, China
| | - Tao Zhang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210016, China
| | - Hao Qiang
- Center of Drug Discovery, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Jianping Lu
- Devision of Nephrology, Jinling Hospital, Southern Medical University, Nanjing, 210016, China.,National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210016, China
| | - Xin Su
- Center of Drug Discovery, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Shuzhen Wen
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210016, China
| | - Feng Xu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210016, China
| | - Mingchao Zhang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210016, China
| | - Haitao Zhang
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210016, China
| | - Caihong Zeng
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210016, China
| | - Zhihong Liu
- Devision of Nephrology, Jinling Hospital, Southern Medical University, Nanjing, 210016, China. .,National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210016, China.
| | - Huimei Chen
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210016, China.
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63
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Liu J, Hoh J. Loss of Complement Factor H in Plasma Increases Endothelial Cell Migration. J Cancer 2017; 8:2184-2190. [PMID: 28819420 PMCID: PMC5560135 DOI: 10.7150/jca.19452] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 04/22/2017] [Indexed: 02/06/2023] Open
Abstract
Tumor growth depends on angiogenesis, the growth of new blood vessels. Complement factor H (CFH) is a plasma glycoprotein that functions as a regulator of the complement system. The aim of this study is to delineate the role of CFH in angiogenesis. A conditional null allele of the Cfh gene was generated in C57BL/6J mice by flanking the exon 3 with loxP sites. The Cfhflox/flox mice were crossed with Rosa26-Cre mice to obtain the mice homozygotes of Cfh deletion (Cfh-/-). The Cfh-/- mice were examined by in vivo angiogenesis assays. Mouse endothelial cells were treated with media containing 5% of mouse plasma from the wildtype or Cfh-/- mice and assayed for proliferation, viability and migration. The Cfh-/- mice did not display any obvious abnormalities. They demonstrated a pro-angiogenic phenotype in matrigel plug assay, but not in aorta ring assay. In vitro, loss of Cfh in plasma does not affect proliferation or viability, but significantly increases migration of mouse endothelial cells. Our findings suggest that plasma CFH inhibits angiogenesis by reduction of endothelial cell migration. Thus the mutation of CFH might lead to excessive tumor angiogenesis.
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Affiliation(s)
- Ju Liu
- Medical Research Center, Shandong Provincial Qianfoshan Hospital, Shandong University, 16766 Jingshi Road, Jinan, Shandong China 250014
| | - Josephine Hoh
- Department of Epidemiology and Public Health, Yale University, 60 College Street, New Haven, CT 06520, USA
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Ipe TS, Lim J, Reyes MA, Ero M, Leveque C, Lewis B, Kain J. An extremely rare splice site mutation in the gene encoding complement factor I in a patient with atypical hemolytic uremic syndrome. J Clin Apher 2017; 32:584-588. [PMID: 28455885 DOI: 10.1002/jca.21549] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/03/2017] [Accepted: 04/04/2017] [Indexed: 11/11/2022]
Abstract
BACKGROUND Atypical hemolytic uremic syndrome (aHUS) is a rare disease characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney failure. The disease is difficult to diagnose due to its similarity with other hematologic disorders, such as thrombotic thrombocytopenic purpura (TTP). However, genetic mutations are found in 50-70% of patients with aHUS and can be useful in its diagnosis. STUDY DESIGN AND METHODS A 40-year-old male presented to our hospital with acute kidney injury, evidenced by high creatinine levels (8.3 mg/dL) and kidney biopsy results. The patient was preliminarily diagnosed with TTP and therapeutic plasma exchange (TPE) was initiated. After four treatments, TPE was discontinued due to lack of ADAMTS13 activity and inhibitor assay results that were not consistent with TTP, improved hematologic laboratory results, and aHUS genetic testing results. RESULTS Next-generation sequencing showed a rare mutation at a splice site in the gene encoding complement factor I (CFI). Implication of this mutation in aHUS has not been previously described. Treatment with eculizumab reduced creatinine levels below 4.0 mg/dL, and the patient remained on maintenance dosage of eculizumab (1200 mg/14 days) to prevent aHUS recurrence. CONCLUSION An extremely rare, heterozygous mutation in the gene encoding CFI likely affecting splicing was associated for the first time with aHUS. Sequencing was critical for rapid diagnosis and subsequent timely treatment with eculizumab, which resulted in improved renal function.
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Affiliation(s)
- Tina S Ipe
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas
| | - Jooeun Lim
- Machaon Diagnostics, Oakland, California
| | - Meredith Anne Reyes
- Department of Pathology and Laboratory Medicine, Baylor College of Medicine, Houston, Texas
| | - Mike Ero
- Machaon Diagnostics, Oakland, California
| | - Christopher Leveque
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas
| | | | - Jamey Kain
- Machaon Diagnostics, Oakland, California
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Challis RC, Ring T, Xu Y, Wong EKS, Flossmann O, Roberts ISD, Ahmed S, Wetherall M, Salkus G, Brocklebank V, Fester J, Strain L, Wilson V, Wood KM, Marchbank KJ, Santibanez-Koref M, Goodship THJ, Kavanagh D. Thrombotic Microangiopathy in Inverted Formin 2 -Mediated Renal Disease. J Am Soc Nephrol 2017; 28:1084-1091. [PMID: 27974406 PMCID: PMC5373440 DOI: 10.1681/asn.2015101189] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 10/19/2016] [Indexed: 12/26/2022] Open
Abstract
The demonstration of impaired C regulation in the thrombotic microangiopathy (TMA) atypical hemolytic uremic syndrome (aHUS) resulted in the successful introduction of the C inhibitor eculizumab into clinical practice. C abnormalities account for approximately 50% of aHUS cases; however, mutations in the non-C gene diacylglycerol kinase-ε have been described recently in individuals not responsive to eculizumab. We report here a family in which the proposita presented with aHUS but did not respond to eculizumab. Her mother had previously presented with a post-renal transplant TMA. Both the proposita and her mother also had Charcot-Marie-Tooth disease. Using whole-exome sequencing, we identified a mutation in the inverted formin 2 gene (INF2) in the mutational hotspot for FSGS. Subsequent analysis of the Newcastle aHUS cohort identified another family with a functionally-significant mutation in INF2 In this family, renal transplantation was associated with post-transplant TMA. All individuals with INF2 mutations presenting with a TMA also had aHUS risk haplotypes, potentially accounting for the genetic pleiotropy. Identifying individuals with TMAs who may not respond to eculizumab will avoid prolonged exposure of such individuals to the infectious complications of terminal pathway C blockade.
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Affiliation(s)
- Rachel C Challis
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | - Troels Ring
- Department of Nephrology, Aalborg University Hospital and
| | - Yaobo Xu
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | - Edwin K S Wong
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | | | - Ian S D Roberts
- Department of Cellular Pathology, Oxford University Hospitals National Health Service Trust, Oxford, United Kingdom
| | - Saeed Ahmed
- Department of Nephrology, City Hospitals Sunderland National Health Service Foundation Trust, Sunderland, United Kingdom
| | - Michael Wetherall
- Department of Pathology, Gateshead Health National Health Service Foundation Trust, Gateshead, United Kingdom
| | - Giedrius Salkus
- Department of Pathology, Aalborg University Hospital, Aalborg, Denmark
| | - Vicky Brocklebank
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | | | - Lisa Strain
- National Renal Complement Therapeutics Centre, Northern Molecular Genetics Service and
| | - Valerie Wilson
- National Renal Complement Therapeutics Centre, Northern Molecular Genetics Service and
| | - Katrina M Wood
- Department of Cellular Pathology, Newcastle upon Tyne Hospitals National Health Service Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Kevin J Marchbank
- Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Timothy H J Goodship
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
| | - David Kavanagh
- National Renal Complement Therapeutics Centre, Institutes of *Genetic Medicine and
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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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67
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Reversal of threatening blindness after initiation of eculizumab in Purtscher-like retinopathy secondary to atypical hemolytic uremic syndrome. Int Ophthalmol 2017; 38:399-407. [PMID: 28275964 PMCID: PMC5876418 DOI: 10.1007/s10792-017-0470-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 02/13/2017] [Indexed: 12/21/2022]
Abstract
Purtscher-like retinopathy, a rare manifestation of systemic thrombotic microangiopathy, is a potentially visually debilitating condition with no effective proven treatment. Distinct pathogenic pathways have been proposed as etiological factors. We revisit the etiology of Purtscher-like retinopathy based on the rapid response and profound visual improvement after initiation of systemic intravenous eculizumab, an inhibitor of the complement cascade, in a patient with Purtscher-like retinopathy secondary to familial atypical hemolytic uremic syndrome (aHUS) due to a mutation in complement factor H. We hypothesize that the efficacy of eculizumab in this patient provides evidence for pathogenic events in the retina similar to those encountered in the renal microvasculature of aHUS patients, namely complement-mediated thromboembolization as a result of activation of the complement cascade in endothelial cells with release of tissue factor and development and amplification of a procoagulant state. To the best of our knowledge, this is the first report in the literature of eculizumab as an effective therapeutic strategy in Purtscher-like retinopathy.
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68
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Ferluga J, Kouser L, Murugaiah V, Sim RB, Kishore U. Potential influences of complement factor H in autoimmune inflammatory and thrombotic disorders. Mol Immunol 2017; 84:84-106. [PMID: 28216098 DOI: 10.1016/j.molimm.2017.01.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 01/01/2023]
Abstract
Complement system homeostasis is important for host self-protection and anti-microbial immune surveillance, and recent research indicates roles in tissue development and remodelling. Complement also appears to have several points of interaction with the blood coagulation system. Deficiency and altered function due to gene mutations and polymorphisms in complement effectors and regulators, including Factor H, have been associated with familial and sporadic autoimmune inflammatory - thrombotic disorders, in which autoantibodies play a part. These include systemic lupus erythematosus, rheumatoid arthritis, atypical haemolytic uremic syndrome, anti-phospholipid syndrome and age-related macular degeneration. Such diseases are generally complex - multigenic and heterogeneous in their symptoms and predisposition/susceptibility. They usually need to be triggered by vascular trauma, drugs or infection and non-complement genetic factors also play a part. Underlying events seem to include decline in peripheral regulatory T cells, dendritic cell, and B cell tolerance, associated with alterations in lymphoid organ microenvironment. Factor H is an abundant protein, synthesised in many cell types, and its reported binding to many different ligands, even if not of high affinity, may influence a large number of molecular interactions, together with the accepted role of Factor H within the complement system. Factor H is involved in mesenchymal stem cell mediated tolerance and also contributes to self-tolerance by augmenting iC3b production and opsonisation of apoptotic cells for their silent dendritic cell engulfment via complement receptor CR3, which mediates anti-inflammatory-tolerogenic effects in the apoptotic cell context. There may be co-operation with other phagocytic receptors, such as complement C1q receptors, and the Tim glycoprotein family, which specifically bind phosphatidylserine expressed on the apoptotic cell surface. Factor H is able to discriminate between self and nonself surfaces for self-protection and anti-microbe defence. Factor H, particularly as an abundant platelet protein, may also modulate blood coagulation, having an anti-thrombotic role. Here, we review a number of interaction pathways in coagulation and in immunity, together with associated diseases, and indicate where Factor H may be expected to exert an influence, based on reports of the diversity of ligands for Factor H.
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Affiliation(s)
- Janez Ferluga
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UB8 3PH, United Kingdom
| | - Lubna Kouser
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UB8 3PH, United Kingdom
| | - Valarmathy Murugaiah
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UB8 3PH, United Kingdom
| | - Robert B Sim
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Uday Kishore
- Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UB8 3PH, United Kingdom.
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69
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Abstract
Haemolytic uraemic syndrome (HUS) is defined by the simultaneous occurrence of nonimmune haemolytic anaemia, thrombocytopenia and acute renal failure. This leads to the pathological lesion termed thrombotic microangiopathy, which mainly affects the kidney, as well as other organs. HUS is associated with endothelial cell injury and platelet activation, although the underlying cause may differ. Most cases of HUS are associated with gastrointestinal infection with Shiga toxin-producing enterohaemorrhagic Escherichia coli (EHEC) strains. Atypical HUS (aHUS) is associated with complement dysregulation due to mutations or autoantibodies. In this review, we will describe the causes of HUS. In addition, we will review the clinical, pathological, haematological and biochemical features, epidemiology and pathogenetic mechanisms as well as the biochemical, microbiological, immunological and genetic investigations leading to diagnosis. Understanding the underlying mechanisms of the different subtypes of HUS enables tailoring of appropriate treatment and management. To date, there is no specific treatment for EHEC-associated HUS but patients benefit from supportive care, whereas patients with aHUS are effectively treated with anti-C5 antibody to prevent recurrences, both before and after renal transplantation.
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Affiliation(s)
- Diana Karpman
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Sebastian Loos
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Ramesh Tati
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Ida Arvidsson
- Department of Pediatrics, Clinical Sciences Lund, Lund University, Lund, Sweden
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70
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Liszewski MK, Java A, Schramm EC, Atkinson JP. Complement Dysregulation and Disease: Insights from Contemporary Genetics. ANNUAL REVIEW OF PATHOLOGY 2017; 12:25-52. [PMID: 27959629 PMCID: PMC6020056 DOI: 10.1146/annurev-pathol-012615-044145] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The vertebrate complement system consists of sequentially interacting proteins that provide for a rapid and powerful host defense. Nearly 60 proteins comprise three activation pathways (classical, alternative, and lectin) and a terminal cytolytic pathway common to all. Attesting to its potency, nearly half of the system's components are engaged in its regulation. An emerging theme over the past decade is that variations in these inhibitors predispose to two scourges of modern humans. One, occurring most often in childhood, is a rare but deadly thrombomicroangiopathy called atypical hemolytic uremic syndrome. The other, age-related macular degeneration, is the most common form of blindness in the elderly. Their seemingly unrelated clinical presentations and pathologies share the common theme of overactivity of the complement system's alternative pathway. This review summarizes insights gained from contemporary genetics for understanding how dysregulation of this powerful innate immune system leads to these human diseases.
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Affiliation(s)
- M Kathryn Liszewski
- Division of Rheumatology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110;
| | - Anuja Java
- Division of Nephrology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | | | - John P Atkinson
- Division of Rheumatology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110;
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71
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Murine systemic thrombophilia and hemolytic uremic syndrome from a factor H point mutation. Blood 2017; 129:1184-1196. [PMID: 28057640 DOI: 10.1182/blood-2016-07-728253] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 12/22/2016] [Indexed: 01/07/2023] Open
Abstract
Complement plays a key role in host defense, but its dysregulation can cause autologous tissue injury. Complement activation is normally controlled by regulatory proteins, including factor H (FH) in plasma and membrane cofactor protein (MCP) on the cell surface. Mutations in FH and MCP are linked to atypical hemolytic uremic syndrome, a type of thrombotic microangiopathy (TMA) that causes renal failure. We describe here that disruption of FH function on the cell surface can also lead to disseminated complement-dependent macrovascular thrombosis. By gene targeting, we introduced a point mutation (W1206R) into murine FH that impaired its interaction with host cells but did not affect its plasma complement-regulating activity. Homozygous mutant mice carrying this mutation developed renal TMA as well as systemic thrombophilia involving large blood vessels in multiple organs, including liver, lung, spleen, and kidney. Approximately 30% of mutant mice displayed symptoms of stroke and ischemic retinopathy, and 48% died prematurely. Genetic deficiency of complement C3 and factor D prevented both the systemic thrombophilia and renal TMA phenotypes. These results demonstrate a causal relationship between complement dysregulation and systemic angiopathy and suggest that complement activation may contribute to various human thrombotic disorders involving both the micro- and macrovasculature.
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72
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Keir LS, Firth R, Aponik L, Feitelberg D, Sakimoto S, Aguilar E, Welsh GI, Richards A, Usui Y, Satchell SC, Kuzmuk V, Coward RJ, Goult J, Bull KR, Sharma R, Bharti K, Westenskow PD, Michael IP, Saleem MA, Friedlander M. VEGF regulates local inhibitory complement proteins in the eye and kidney. J Clin Invest 2017; 127:199-214. [PMID: 27918307 PMCID: PMC5199702 DOI: 10.1172/jci86418] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 10/28/2016] [Indexed: 12/15/2022] Open
Abstract
Outer retinal and renal glomerular functions rely on specialized vasculature maintained by VEGF that is produced by neighboring epithelial cells, the retinal pigment epithelium (RPE) and podocytes, respectively. Dysregulation of RPE- and podocyte-derived VEGF is associated with neovascularization in wet age-related macular degeneration (ARMD), choriocapillaris degeneration, and glomerular thrombotic microangiopathy (TMA). Since complement activation and genetic variants in inhibitory complement factor H (CFH) are also features of both ARMD and TMA, we hypothesized that VEGF and CFH interact. Here, we demonstrated that VEGF inhibition decreases local CFH and other complement regulators in the eye and kidney through reduced VEGFR2/PKC-α/CREB signaling. Patient podocytes and RPE cells carrying disease-associated CFH genetic variants had more alternative complement pathway deposits than controls. These deposits were increased by VEGF antagonism, a common wet ARMD treatment, suggesting that VEGF inhibition could reduce cellular complement regulatory capacity. VEGF antagonism also increased markers of endothelial cell activation, which was partially reduced by genetic complement inhibition. Together, these results suggest that VEGF protects the retinal and glomerular microvasculature, not only through VEGFR2-mediated vasculotrophism, but also through modulation of local complement proteins that could protect against complement-mediated damage. Though further study is warranted, these findings could be relevant for patients receiving VEGF antagonists.
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Affiliation(s)
- Lindsay S. Keir
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Rachel Firth
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Lyndsey Aponik
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Daniel Feitelberg
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Susumu Sakimoto
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Edith Aguilar
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
| | - Gavin I. Welsh
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Anna Richards
- Queens Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Yoshihiko Usui
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
- Tokyo Medical University Hospital, Tokyo, Japan
| | - Simon C. Satchell
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Valeryia Kuzmuk
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Richard J. Coward
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Jonathan Goult
- Centre for Cellular and Molecular Physiology, University of Oxford, United Kingdom
| | - Katherine R. Bull
- Centre for Cellular and Molecular Physiology, University of Oxford, United Kingdom
| | - Ruchi Sharma
- National Eye Institute, NIH, Bethesda, Maryland, USA
| | - Kapil Bharti
- National Eye Institute, NIH, Bethesda, Maryland, USA
| | - Peter D. Westenskow
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
- The Lowy Medical Research Institute, La Jolla, California, USA
| | | | - Moin A. Saleem
- Academic Renal Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Martin Friedlander
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, USA
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Abstract
Recent advances in our understanding of the disease pathology of membranoproliferative glomerulonephritis has resulted in its re-classification as complement C3 glomerulopathy (C3G) and immune complex-mediated glomerulonephritis (IC-GN). The new consensus is based on its underlying pathomechanism, with a key pathogenetic role for the complement alternative pathway (AP), rather than on histomorphological characteristics. In C3G, loss of AP regulation leads to predominant glomerular C3 deposition, which distinguishes C3G from IC-GN with predominant immunoglobulin G staining. Electron microscopy further subdivides C3G into C3 glomerulonephritis and dense deposit disease depending on the presence and distribution pattern of electron-dense deposits within the glomerular filter. Mutations or autoantibodies affecting the function of AP activators or regulators, in particular the decay of the C3 convertase (C3 nephritic factor), have been detected in up to 80 % of C3G patients. The natural outcome of C3G is heterogeneous, but 50 % of patients progress slowly and reach end-stage renal disease within 10-15 years. The new classification not only marks significant advancement in the pathogenic understanding of this rare disease, but also opens doors towards more specific treatment with the potential for improved outcomes.
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Affiliation(s)
- Magdalena Riedl
- Cell Biology Program of the Research Institute, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada
- Department of Paediatrics, Innsbruck Medical University, Innsbruck, Austria
| | - Paul Thorner
- Department of Pediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Christoph Licht
- Cell Biology Program of the Research Institute, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
- Division of Nephrology, The Hospital for Sick Children, Toronto, ON, Canada.
- Department of Paediatrics, University of Toronto, Toronto, ON, Canada.
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74
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Salvadori M, Bertoni E. Complement related kidney diseases: Recurrence after transplantation. World J Transplant 2016; 6:632-645. [PMID: 28058212 PMCID: PMC5175220 DOI: 10.5500/wjt.v6.i4.632] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 10/26/2016] [Accepted: 11/17/2016] [Indexed: 02/05/2023] Open
Abstract
The recurrence of renal disease after renal transplantation is becoming one of the main causes of graft loss after kidney transplantation. This principally concerns some of the original diseases as the atypical hemolytic uremic syndrome (HUS), the membranoproliferative glomerulonephritis (MPGN), in particular the MPGN now called C3 glomerulopathy. Both this groups of renal diseases are characterized by congenital (genetic) or acquired (auto-antibodies) modifications of the alternative pathway of complement. These abnormalities often remain after transplantation because they are constitutional and poorly influenced by the immunosuppression. This fact justifies the high recurrence rate of these diseases. Early diagnosis of recurrence is essential for an optimal therapeutically approach, whenever possible. Patients affected by end stage renal disease due to C3 glomerulopathies or to atypical HUS, may be transplanted with extreme caution. Living donor donation from relatives is not recommended because members of the same family may be affected by the same gene mutation. Different therapeutically approaches have been attempted either for recurrence prevention and treatment. The most promising approach is represented by complement inhibitors. Eculizumab, a monoclonal antibody against C5 convertase is the most promising drug, even if to date is not known how long the therapy should be continued and which are the best dosing. These facts face the high costs of the treatment. Eculizumab resistant patients have been described. They could benefit by a C3 convertase inhibitor, but this class of drugs is by now the object of randomized controlled trials.
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75
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Goodship THJ, Cook HT, Fakhouri F, Fervenza FC, Frémeaux-Bacchi V, Kavanagh D, Nester CM, Noris M, Pickering MC, Rodríguez de Córdoba S, Roumenina LT, Sethi S, Smith RJH. Atypical hemolytic uremic syndrome and C3 glomerulopathy: conclusions from a "Kidney Disease: Improving Global Outcomes" (KDIGO) Controversies Conference. Kidney Int 2016; 91:539-551. [PMID: 27989322 DOI: 10.1016/j.kint.2016.10.005] [Citation(s) in RCA: 420] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 10/10/2016] [Accepted: 10/20/2016] [Indexed: 02/06/2023]
Abstract
In both atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy (C3G) complement plays a primary role in disease pathogenesis. Herein we report the outcome of a 2015 Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference where key issues in the management of these 2 diseases were considered by a global panel of experts. Areas addressed included renal pathology, clinical phenotype and assessment, genetic drivers of disease, acquired drivers of disease, and treatment strategies. In order to help guide clinicians who are caring for such patients, recommendations for best treatment strategies were discussed at length, providing the evidence base underpinning current treatment options. Knowledge gaps were identified and a prioritized research agenda was proposed to resolve outstanding controversial issues.
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Affiliation(s)
| | - H Terence Cook
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College Hammersmith Campus, London, UK
| | - Fadi Fakhouri
- INSERM, UMR-S 1064, and Department of Nephrology and Immunology, CHU de Nantes, Nantes, France
| | - Fernando C Fervenza
- Department of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | | | - David Kavanagh
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Carla M Nester
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA; Division of Nephrology, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Marina Noris
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Clinical Research Center for Rare Diseases "Aldo e Cele Daccò," Ranica, Bergamo, Italy
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Department of Medicine, Imperial College Hammersmith Campus, London, UK
| | - Santiago Rodríguez de Córdoba
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain; Centro de Investigación Biomédica en Enfermedades Raras, Madrid, Spain
| | - Lubka T Roumenina
- Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche S1138, Complément et Maladies, Centre de Recherche des Cordeliers, Paris, France; Université Paris Descartes Sorbonne Paris-Cité, Paris, France; Université Pierre et Marie Curie (UPMC-Paris-6), Paris, France
| | - Sanjeev Sethi
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA; Division of Nephrology, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
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76
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Abstract
Antiphospholipid syndrome (APS) is a hypercoagulable state characterized by arterial and venous thromboses and pregnancy morbidity in the presence of antiphospholipid antibodies. Although warfarin remains the main therapeutic choice in APS, there is still concern about its efficacy, safety, and patient compliance. Patients with refractory APS to conventional therapy as well as patients with non-classical manifestations of APS may have alternative treatment approaches. APS pathogenesis has been further elucidated over the past years identifying new molecules as potential new treatment targets. This review summarizes available data from in vitro and animal models and clinical studies on the role of new potential treatment approaches including new oral anticoagulants and immunoregulatory agents: direct thrombin or factor Xa inhibitors, hydroxychloroquine, statins, B cell inhibition, complement inhibition, peptide therapy, nuclear factor κB and p38 mitogen-activated kinase inhibitors, defibrotide, abciximab, mTOR inhibitor, and other potential targets. Large multicenter prospective studies of well-characterized APS patients are needed to assess the efficacy and safety profile of these potential treatment alternatives.
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Affiliation(s)
- Danieli Andrade
- Rheumatology Department, University of São Paulo, Av. Dr. Arnaldo 455, Third Floor, Room 3109, São Paulo, Brazil
| | - Maria Tektonidou
- First Department of Propaedeutic Internal Medicine, Joint Academic Rheumatology Programme, National and Kapodistrian University of Athens, Athens, Greece.
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77
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Association among Complement Factor H Autoantibodies, Deletions of CFHR, and the Risk of Atypical Hemolytic Uremic Syndrome. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:ijerph13121209. [PMID: 27929404 PMCID: PMC5201350 DOI: 10.3390/ijerph13121209] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/22/2016] [Accepted: 11/25/2016] [Indexed: 12/02/2022]
Abstract
To evaluate the association among complement factor H-related (CFHRs) gene deficiency, complement factor H (CFH) autoantibodies, and atypical hemolytic uremic syndrome (aHUS) susceptibility. EMBASE, PubMed, and the ISI Web of Science databases were searched for all eligible studies on the relationship among CFHRs deficiency, anti-FH autoantibodies, and aHUS risk. Eight case-control studies with 927 cases and 1182 controls were included in this study. CFHR1 deficiency was significantly associated with an increased risk of aHUS (odds ratio (OR) = 3.61, 95% confidence interval (95% CI), 1.96, 6.63, p < 0.001), while no association was demonstrated in individuals with only CFHR1/R3 deficiency (OR = 1.32, 95% CI, 0.50, 3.50, p = 0.56). Moreover, a more significant correlation was observed in people with both FH-anti autoantibodies and CFHR1 deficiency (OR = 11.75, 95% CI, 4.53, 30.44, p < 0.001) in contrast to those with only CFHR1 deficiency. In addition, the results were essentially consistent among subgroups stratified by study quality, ethnicity, and gene detection methods. The present meta-analysis indicated that CFHR1 deletion was significantly associated with the risk of aHUS, particularly when combined with anti-FH autoantibodies, indicating that potential interactions among CFHR1 deficiency and anti-FH autoantibodies might impact the risk of aHUS.
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78
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Abstract
The complement (C) cascade is an ancient system of proteins whose primary role is to initiate and modulate immune responses. During C activation, circulating proteins are cleaved and nascent cleavage fragments participate in a broad range of downstream innate and adaptive immune functions. Although the majority of these functions are either homeostatic or protective, a large body of experimental and clinical evidence also highlights a central role for the C system in the pathogenesis of many types of glomerular disease. From classic pathway activation in lupus nephritis to alternative pathway dysregulation in C3 glomerulopathy, our understanding of the spectrum of C involvement in kidney disease has expanded greatly in recent years. However, the characteristics that make the glomerulus so uniquely susceptible to C-mediated injury are not fully understood, and this remains an area of ongoing investigation. Several C inhibitors have been approved for clinical use, and additional C inhibitory drugs are in development. The use of these drugs in patients with kidney disease will expand our understanding of the benefits and limitations of C inhibition.
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Affiliation(s)
- Joshua M. Thurman
- Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado; and
| | - Carla M. Nester
- Stead Family Department of Pediatrics and
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa
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79
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Tan PL, Bowes Rickman C, Katsanis N. AMD and the alternative complement pathway: genetics and functional implications. Hum Genomics 2016; 10:23. [PMID: 27329102 PMCID: PMC4915094 DOI: 10.1186/s40246-016-0079-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 06/08/2016] [Indexed: 12/22/2022] Open
Abstract
Age-related macular degeneration (AMD) is an ocular neurodegenerative disorder and is the leading cause of legal blindness in Western societies, with a prevalence of up to 8 % over the age of 60, which continues to increase with age. AMD is characterized by the progressive breakdown of the macula (the central region of the retina), resulting in the loss of central vision including visual acuity. While its molecular etiology remains unclear, advances in genetics and genomics have illuminated the genetic architecture of the disease and have generated attractive pathomechanistic hypotheses. Here, we review the genetic architecture of AMD, considering the contribution of both common and rare alleles to susceptibility, and we explore the possible mechanistic links between photoreceptor degeneration and the alternative complement pathway, a cascade that has emerged as the most potent genetic driver of this disorder.
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Affiliation(s)
- Perciliz L Tan
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Catherine Bowes Rickman
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA.,Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, 27710, USA
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, 27710, USA. .,Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA.
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80
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Ueda Y, Gullipalli D, Song WC. Modeling complement-driven diseases in transgenic mice: Values and limitations. Immunobiology 2016; 221:1080-90. [PMID: 27371974 DOI: 10.1016/j.imbio.2016.06.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/07/2016] [Accepted: 06/09/2016] [Indexed: 12/15/2022]
Abstract
Remarkable advances have been made over past decades in understanding the pathogenesis of complement-mediated diseases. This has led to development of new therapies for, and in some cases re-classification of, complement-driven diseases. This success is due to not only insight from human patients but also studies using transgenic animal models. Animal models that mimic human diseases are useful tools to understand the mechanism of disease and develop new therapies but there are also limitations due to species differences in their complement systems. This review provides a summary of transgenic animal models for three human diseases that are at the forefront of anti-complement therapy, paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy (C3G). They are discussed here as examples to highlight the values and limitations of animal modeling in complement-driven diseases.
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Affiliation(s)
- Yoshiyasu Ueda
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - Damodar Gullipalli
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, United States
| | - Wen-Chao Song
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, United States.
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81
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Berger BE. The Alternative Pathway of Complement and the Evolving Clinical-Pathophysiological Spectrum of Atypical Hemolytic Uremic Syndrome. Am J Med Sci 2016; 352:177-90. [PMID: 27524217 DOI: 10.1016/j.amjms.2016.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 03/31/2016] [Accepted: 05/03/2016] [Indexed: 01/31/2023]
Abstract
Complement-mediated atypical hemolytic uremic syndrome (aHUS) comprises approximately 90% of cases of aHUS, and results from dysregulation of endothelial-anchored complement activation with resultant endothelial damage. The discovery of biomarker ADAMTS13 has enabled a more accurate diagnosis of thrombotic thrombocytopenic purpura (TTP) and an appreciation of overlapping clinical features of TTP and aHUS. Given our present understanding of the pathogenic pathways involved in aHUS, it is unlikely that a specific test will be developed. Rather the use of biomarker data, complement functional analyses, genomic analyses and clinical presentation will be required to diagnose aHUS. This approach would serve to clarify whether a thrombotic microangiopathy present in a complement-amplifying condition arises from the unmasking of a genetically driven aHUS versus a time-limited complement storm-mediated aHUS due to direct endothelial damage in which no genetic predisposition is present. Although both scenarios result in the phenotypic expression of aHUS and involve the alternate pathway of complement activation, long-term management would differ.
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Affiliation(s)
- Bruce E Berger
- School of Medicine, Case Western Reserve University, Cleveland, Ohio.
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82
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Brady TM, Pruette C, Loeffler LF, Weidemann D, Strouse JJ, Gavriilaki E, Brodsky RA. Typical Hus: Evidence of Acute Phase Complement Activation from a Daycare Outbreak. ACTA ACUST UNITED AC 2016; 1. [PMID: 27413789 PMCID: PMC4940046 DOI: 10.21767/2472-5056.100011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The clinical manifestations of typical hemolytic uremic syndrome (HUS) encompass a wide spectrum. Despite the potentially severe sequelae from this syndrome, treatment approaches remain supportive. We present the clinical course of a child who contracted Shiga toxin-positive E. coli (STEC) from a daycare center during an outbreak. Utilizing the modified Ham test which is a rapid, serum-based functional assay used to detect activation of the alternative pathway of complement as observed in atypical HUS, patient sera revealed evidence of increased complement activation in the acute phase of the syndrome but not after resolution. Further, this complement activation was attenuated by eculizumab in vitro, an effect that was replicated in vitro utilizing Shiga toxin as a stimulus of complement activation in normal serum. Our report suggests that complement blockade may be effective in the treatment of STEC-HUS when initiated early in the disease. Given the epidemic nature of the disease that limits the feasibility of randomized clinical trials, further studies are needed to determine the value of early eculizumab treatment in STEC-HUS.
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Affiliation(s)
- Tammy M Brady
- Division of Pediatric Nephrology, Johns Hopkins University School of Medicine, USA
| | - Cozumel Pruette
- Division of Pediatric Nephrology, Johns Hopkins University School of Medicine, USA
| | - Lauren F Loeffler
- Division of Pediatric Nephrology, Johns Hopkins University School of Medicine, USA
| | - Darcy Weidemann
- Division of Pediatric Nephrology, Children's Mercy Hospital, Kansas City, MO, USA
| | - John J Strouse
- Division of Pediatric Hematology Johns Hopkins University School of Medicine, USA; Division of Hematology, Johns Hopkins University School of Medicine, USA
| | - Eleni Gavriilaki
- Division of Hematology, Johns Hopkins University School of Medicine, USA
| | - Robert A Brodsky
- Division of Hematology, Johns Hopkins University School of Medicine, USA
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83
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Coppo R, Bonaudo R, Peruzzi RL, Amore A, Brunati A, Romagnoli R, Salizzoni M, Galbusera M, Gotti E, Daina E, Noris M, Remuzzi G. Liver transplantation for aHUS: still needed in the eculizumab era? Pediatr Nephrol 2016; 31:759-68. [PMID: 26604087 DOI: 10.1007/s00467-015-3278-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/28/2015] [Accepted: 10/28/2015] [Indexed: 12/25/2022]
Abstract
BACKGROUND The risk of disease recurrence after a kidney transplant is high in patients with atypical hemolytic uremic syndrome (aHUS) and mutations in the complement factor H (FH) gene (CFH). Since FH is mostly produced by the liver, a kidney transplant does not correct the genetic defect. The anti-C5 antibody eculizumab prevents post-transplant aHUS recurrence, but it does not cure the disease. Combined liver-kidney transplantation has been performed in few patients with CFH mutations based on the rationale that liver replacement provides a source of normal FH. METHODS We report the 9-year follow-up of a child with aHUS and a CFH mutation, including clinical data, extensive genetic characterization, and complement profile in the circulation and at endothelial level. The outcome of kidney and liver transplants performed separately 3 years apart are reported. RESULTS The patient showed incomplete response to plasma, with relapsing episodes, progression to end-stage renal disease, and endothelial-restricted complement dysregulation. Eculizumab prophylaxis post-kidney transplant did not achieve sustained remission, leaving the child at risk of disease recurrence. A liver graft given 3 years after the kidney transplant completely abrogated endothelial complement activation and allowed eculizumab withdrawal. CONCLUSIONS Liver transplant may definitely cure aHUS and represents an option for patients with suboptimal response to eculizumab.
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Affiliation(s)
- Rosanna Coppo
- Nephrology Dialysis and Transplantation, AOU Città della Salute e della Scienza di Torino, Turin and Fondazione Ricerca Molinette, Regina Margherita Hospital, Turin, Italy
| | - Roberto Bonaudo
- Nephrology Dialysis and Transplantation, AOU Città della Salute e della Scienza di Torino, Turin and Fondazione Ricerca Molinette, Regina Margherita Hospital, Turin, Italy
| | - R Licia Peruzzi
- Nephrology Dialysis and Transplantation, AOU Città della Salute e della Scienza di Torino, Turin and Fondazione Ricerca Molinette, Regina Margherita Hospital, Turin, Italy
| | - Alessandro Amore
- Nephrology Dialysis and Transplantation, AOU Città della Salute e della Scienza di Torino, Turin and Fondazione Ricerca Molinette, Regina Margherita Hospital, Turin, Italy
| | - Andrea Brunati
- Liver Transplantation Center, General Surgery Unit 2U, AOU Città della Salute e della Scienza di Torino, Molinette Hospital, University of Turin , Turin, Italy
| | - Renato Romagnoli
- Liver Transplantation Center, General Surgery Unit 2U, AOU Città della Salute e della Scienza di Torino, Molinette Hospital, University of Turin , Turin, Italy
| | - Mauro Salizzoni
- Liver Transplantation Center, General Surgery Unit 2U, AOU Città della Salute e della Scienza di Torino, Molinette Hospital, University of Turin , Turin, Italy
| | - Miriam Galbusera
- Clinical Research Center for Rare Diseases "Aldo e Cele Daccò", IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Villa Camozzi, 3-24020, Ranica (Bergamo), Italy.,Centro Anna Maria Astori, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Eliana Gotti
- Unit of Nephrology and Dialysis, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy
| | - Erica Daina
- Clinical Research Center for Rare Diseases "Aldo e Cele Daccò", IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Villa Camozzi, 3-24020, Ranica (Bergamo), Italy
| | - Marina Noris
- Clinical Research Center for Rare Diseases "Aldo e Cele Daccò", IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Villa Camozzi, 3-24020, Ranica (Bergamo), Italy.
| | - Giuseppe Remuzzi
- Clinical Research Center for Rare Diseases "Aldo e Cele Daccò", IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Villa Camozzi, 3-24020, Ranica (Bergamo), Italy.,Centro Anna Maria Astori, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Science and Technology Park Kilometro Rosso, Bergamo, Italy.,Unit of Nephrology and Dialysis, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy.,Department of Biomedical Sciences of Health, University of Milan, Milan, Italy
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84
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Vernon KA, Ruseva MM, Cook HT, Botto M, Malik TH, Pickering MC. Partial Complement Factor H Deficiency Associates with C3 Glomerulopathy and Thrombotic Microangiopathy. J Am Soc Nephrol 2016; 27:1334-42. [PMID: 26374608 PMCID: PMC4849824 DOI: 10.1681/asn.2015030295] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 07/28/2015] [Indexed: 11/03/2022] Open
Abstract
The complement-mediated renal diseases C3 glomerulopathy (C3G) and atypical hemolytic uremic syndrome (aHUS) strongly associate with inherited and acquired abnormalities in the regulation of the complement alternative pathway (AP). The major negative regulator of the AP is the plasma protein complement factor H (FH). Abnormalities in FH result in uncontrolled activation of C3 through the AP and associate with susceptibility to both C3G and aHUS. Although previously developed FH-deficient animal models have provided important insights into the mechanisms underlying susceptibility to these unique phenotypes, these models do not entirely reproduce the clinical observations. FH is predominantly synthesized in the liver. We generated mice with hepatocyte-specific FH deficiency and showed that these animals have reduced plasma FH levels with secondary reduction in plasma C3. Unlike mice with complete FH deficiency, hepatocyte-specific FH-deficient animals developed neither plasma C5 depletion nor accumulation of C3 along the glomerular basement membrane. In contrast, subtotal FH deficiency associated with mesangial C3 accumulation consistent with C3G. Although there was no evidence of spontaneous thrombotic microangiopathy, the hepatocyte-specific FH-deficient animals developed severe C5-dependent thrombotic microangiopathy after induction of complement activation within the kidney by accelerated serum nephrotoxic nephritis. Taken together, our data indicate that subtotal FH deficiency can give rise to either spontaneous C3G or aHUS after a complement-activating trigger within the kidney and that the latter is C5 dependent.
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Affiliation(s)
- Katherine A Vernon
- Centre for Complement and Inflammation Research, Imperial College, London, United Kingdom
| | - Marieta M Ruseva
- Centre for Complement and Inflammation Research, Imperial College, London, United Kingdom
| | - H Terence Cook
- Centre for Complement and Inflammation Research, Imperial College, London, United Kingdom
| | - Marina Botto
- Centre for Complement and Inflammation Research, Imperial College, London, United Kingdom
| | - Talat H Malik
- Centre for Complement and Inflammation Research, Imperial College, London, United Kingdom
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Imperial College, London, United Kingdom
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85
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Iatropoulos P, Noris M, Mele C, Piras R, Valoti E, Bresin E, Curreri M, Mondo E, Zito A, Gamba S, Bettoni S, Murer L, Fremeaux-Bacchi V, Vivarelli M, Emma F, Daina E, Remuzzi G. Complement gene variants determine the risk of immunoglobulin-associated MPGN and C3 glomerulopathy and predict long-term renal outcome. Mol Immunol 2016; 71:131-142. [DOI: 10.1016/j.molimm.2016.01.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/21/2016] [Accepted: 01/23/2016] [Indexed: 01/13/2023]
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86
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Nozal P, Bernabéu-Herrero ME, Uzonyi B, Szilágyi Á, Hyvärinen S, Prohászka Z, Jokiranta TS, Sánchez-Corral P, López-Trascasa M, Józsi M. Heterogeneity but individual constancy of epitopes, isotypes and avidity of factor H autoantibodies in atypical hemolytic uremic syndrome. Mol Immunol 2016; 70:47-55. [DOI: 10.1016/j.molimm.2015.12.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 11/30/2015] [Accepted: 12/02/2015] [Indexed: 01/27/2023]
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87
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Loeven MA, Rops AL, Lehtinen MJ, van Kuppevelt TH, Daha MR, Smith RJ, Bakker M, Berden JH, Rabelink TJ, Jokiranta TS, van der Vlag J. Mutations in Complement Factor H Impair Alternative Pathway Regulation on Mouse Glomerular Endothelial Cells in Vitro. J Biol Chem 2016; 291:4974-81. [PMID: 26728463 DOI: 10.1074/jbc.m115.702506] [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: 11/04/2015] [Indexed: 01/28/2023] Open
Abstract
Complement factor H (FH) inhibits complement activation and interacts with glomerular endothelium via its complement control protein domains 19 and 20, which also recognize heparan sulfate (HS). Abnormalities in FH are associated with the renal diseases atypical hemolytic uremic syndrome and dense deposit disease and the ocular disease age-related macular degeneration. Although FH systemically controls complement activation, clinical phenotypes selectively manifest in kidneys and eyes, suggesting the presence of tissue-specific determinants of disease development. Recent results imply the importance of tissue-specifically expressed, sulfated glycosaminoglycans (GAGs), like HS, in determining FH binding to and activity on host tissues. Therefore, we investigated which GAGs mediate human FH and recombinant human FH complement control proteins domains 19 and 20 (FH19-20) binding to mouse glomerular endothelial cells (mGEnCs) in ELISA. Furthermore, we evaluated the functional defects of FH19-20 mutants during complement activation by measuring C3b deposition on mGEnCs using flow cytometry. FH and FH19-20 bound dose-dependently to mGEnCs and TNF-α treatment increased binding of both proteins, whereas heparinase digestion and competition with heparin/HS inhibited binding. Furthermore, 2-O-, and 6-O-, but not N-desulfation of heparin, significantly increased the inhibitory effect on FH19-20 binding to mGEnCs. Compared with wild type FH19-20, atypical hemolytic uremic syndrome-associated mutants were less able to compete with FH in normal human serum during complement activation on mGEnCs, confirming their potential glomerular pathogenicity. In conclusion, our study shows that FH and FH19-20 binding to glomerular endothelial cells is differentially mediated by HS but not other GAGs. Furthermore, we describe a novel, patient serum-independent competition assay for pathogenicity screening of FH19-20 mutants.
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Affiliation(s)
- Markus A Loeven
- From the Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Angelique L Rops
- From the Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Markus J Lehtinen
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, FIN-00290 Helsinki, Finland
| | - Toin H van Kuppevelt
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands
| | - Mohamed R Daha
- Department of Nephrology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands, and
| | - Richard J Smith
- Department of Internal Medicine and Otolaryngology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242
| | - Marinka Bakker
- From the Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Jo H Berden
- From the Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Ton J Rabelink
- Department of Nephrology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands, and
| | - T Sakari Jokiranta
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, FIN-00290 Helsinki, Finland
| | - Johan van der Vlag
- From the Department of Nephrology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands,
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88
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Phillips EH, Westwood JP, Brocklebank V, Wong EKS, Tellez JO, Marchbank KJ, McGuckin S, Gale DP, Connolly J, Goodship THJ, Kavanagh D, Scully MA. The role of ADAMTS-13 activity and complement mutational analysis in differentiating acute thrombotic microangiopathies. J Thromb Haemost 2016; 14:175-85. [PMID: 26559391 PMCID: PMC4737436 DOI: 10.1111/jth.13189] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Accepted: 10/25/2015] [Indexed: 01/10/2023]
Abstract
UNLABELLED ESSENTIALS: Molecular diagnostics has improved the differentiation of acute thrombotic microangiopathys (TMAs). Atypical hemolytic uremic syndrome may have features mimicking thrombotic thrombocytopenic purpura. We identified novel complement mutations and a high incidence of CD46, with favorable long term outcomes. Complement mutation analysis in TMA where the diagnosis is unclear and ADAMTS-13 activity is >10%. BACKGROUND Differentiation of acute thrombotic microangiopathy (TMA) at presentation has historically been dependent on clinical parameters. Confirmation of thrombotic thrombocytopenic purpura (TTP) is increasingly reliant on demonstrating deficient ADAMTS-13 activity. The identification of alternative complement pathway abnormalities in atypical hemolytic uremic syndrome (aHUS), along with the proven efficacy of terminal complement inhibitors in treatment, has increased the need for rapid differentiation of TTP from aHUS. OBJECTIVES We describe the clinical phenotype and nature of complement mutations in a cohort of aHUS patients referred as acute TMAs. PATIENTS/METHODS Fourteen consecutive aHUS patients were screened for mutations in C3, CD46, CFH, CFI, and CFB, as well as factor H (FH) antibodies. All aHUS patients had ADAMTS-13 activity > 10%. RESULTS Of 14 aHUS patients, 11 (79%) had platelet counts < 30 × 10(9) /L during the acute phase. Median presenting creatinine level was 295 μmol L(-1) , while five (36%) of 14 presented with a serum creatinine level < 200 μmol L(-1) . Alternative complement pathway mutations were detected in 9 (64%) of 14 patients, including CD46 mutations in five (36%) of 14 patients. Patients were identified with novel mutations in CFB and C3 that have not been previously reported. CONCLUSIONS We demonstrate that diagnostic differentiation based on platelet count and renal function is insufficient to predict an underlying complement mutation in some aHUS cases. Specifically, we demonstrate a high frequency of functionally significant CD46 mutations which may mimic TTP. ADAMTS-13 activity > 10% in a patient with a TMA should necessitate genetic screening for complement abnormalities.
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Affiliation(s)
- E. H. Phillips
- Department of HaematologyUniversity College LondonLondonUK
| | - J. P. Westwood
- Department of HaematologyUniversity College LondonLondonUK
| | - V. Brocklebank
- Institute of Genetic MedicineNewcastle UniversityNewcastle upon TyneUK
| | - E. K. S. Wong
- Institute of Genetic MedicineNewcastle UniversityNewcastle upon TyneUK
| | - J. O. Tellez
- Institute of Genetic MedicineNewcastle UniversityNewcastle upon TyneUK
| | - K. J. Marchbank
- Institute of Cellular MedicineNewcastle UniversityNewcastle upon TyneUK
| | - S. McGuckin
- Department of HaematologyUniversity College LondonLondonUK
| | - D. P. Gale
- Centre for NephrologyUniversity College LondonLondonUK
| | - J. Connolly
- Department of NephrologyRoyal Free HospitalLondonUK
| | - T. H. J. Goodship
- Institute of Genetic MedicineNewcastle UniversityNewcastle upon TyneUK
| | - D. Kavanagh
- Institute of Genetic MedicineNewcastle UniversityNewcastle upon TyneUK
| | - M. A. Scully
- Cardiometabolic ProgrammeNIHR/University College London Hospitals Biomedical Research CentreLondonUK
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89
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Ruseva MM, Peng T, Lasaro MA, Bouchard K, Liu-Chen S, Sun F, Yu ZX, Marozsan A, Wang Y, Pickering MC. Efficacy of Targeted Complement Inhibition in Experimental C3 Glomerulopathy. J Am Soc Nephrol 2015; 27:405-16. [PMID: 26047789 DOI: 10.1681/asn.2014121195] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 04/01/2015] [Indexed: 12/19/2022] Open
Abstract
C3 glomerulopathy refers to renal disorders characterized by abnormal accumulation of C3 within the kidney, commonly along the glomerular basement membrane (GBM). C3 glomerulopathy is associated with complement alternative pathway dysregulation, which includes functional defects in complement regulator factor H (FH). There is no effective treatment for C3 glomerulopathy. We investigated the efficacy of a recombinant mouse protein composed of domains from complement receptor 2 (CR2) and FH (CR2-FH) in two models of C3 glomerulopathy with either preexisting or triggered C3 deposition along the GBM. FH-deficient mice spontaneously develop renal pathology associated with abnormal C3 accumulation along the GBM and secondary plasma C3 deficiency. CR2-FH partially restored plasma C3 levels in FH-deficient mice 2 hours after intravenous injection. CR2-FH specifically targeted glomerular C3 deposits, reduced the linear C3 reactivity assessed with anti-C3 and anti-C3b/iC3b/C3c antibodies, and prevented further spontaneous accumulation of C3 fragments along the GBM. Reduction in glomerular C3d and C9/C5b-9 reactivity was observed after daily administration of CR2-FH for 1 week. In a second mouse model with combined deficiency of FH and complement factor I, CR2-FH prevented de novo C3 deposition along the GBM. These data show that CR2-FH protects the GBM from both spontaneous and triggered C3 deposition in vivo and indicate that this approach should be tested in C3 glomerulopathy.
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Affiliation(s)
- Marieta M Ruseva
- Centre for Complement and Inflammation Research, Imperial College, London, United Kingdom; and
| | - Tao Peng
- Alexion Pharmaceuticals, Cheshire, Connecticut
| | | | | | | | - Fang Sun
- Alexion Pharmaceuticals, Cheshire, Connecticut
| | - Zhao-Xue Yu
- Alexion Pharmaceuticals, Cheshire, Connecticut
| | | | - Yi Wang
- Alexion Pharmaceuticals, Cheshire, Connecticut
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Imperial College, London, United Kingdom; and
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91
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de Córdoba SR. Complement genetics and susceptibility to inflammatory disease. Lessons from genotype-phenotype correlations. Immunobiology 2015; 221:709-14. [PMID: 26004345 DOI: 10.1016/j.imbio.2015.05.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 05/06/2015] [Indexed: 10/23/2022]
Abstract
Different genome-wide linkage and association studies performed during the last 15 years have associated mutations and polymorphisms in complement genes with different diseases characterized by tissue damage and inflammation. These are complex disorders in which genetically susceptible individuals usually develop the pathology as a consequence of environmental triggers. Although complement dysregulation is a common feature of these pathologies, how the disease phenotype is determined is only partly understood. One way to advance understanding is to focus the research in the analysis of the peculiar genotype-phenotype correlations that characterize some of these diseases. I will review here how understanding the functional consequences of these disease-associated complement genetic variants is providing us with novel insights into the underpinning complement biology and a better knowledge of the pathogenic mechanisms underlying each of these pathologies. These advances have important therapeutic and diagnostic implications.
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92
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Martínez-Barricarte R, Heurich M, López-Perrote A, Tortajada A, Pinto S, López-Trascasa M, Sánchez-Corral P, Morgan BP, Llorca O, Harris CL, Rodríguez de Córdoba S. The molecular and structural bases for the association of complement C3 mutations with atypical hemolytic uremic syndrome. Mol Immunol 2015; 66:263-73. [PMID: 25879158 PMCID: PMC4503813 DOI: 10.1016/j.molimm.2015.03.248] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 03/18/2015] [Accepted: 03/24/2015] [Indexed: 01/28/2023]
Abstract
Mutations in C3 have been associated with aHUS and other glomerulopathies. aHUS-associated C3 mutants R592W, R161W, and I1157T impair regulation by MCP, but not by FH. EM analysis provides the structural basis for the functional impairment of the R161W and I1157T mutants. Data supports aHUS-associated C3 mutations selectively affect complement regulation on surfaces.
Atypical hemolytic uremic syndrome (aHUS) associates with complement dysregulation caused by mutations and polymorphisms in complement activators and regulators. However, the reasons why some mutations in complement proteins predispose to aHUS are poorly understood. Here, we have investigated the functional consequences of three aHUS-associated mutations in C3, R592W, R161W and I1157T. First, we provide evidence that penetrance and disease severity for these mutations is modulated by inheritance of documented “risk” haplotypes as has been observed with mutations in other complement genes. Next, we show that all three mutations markedly reduce the efficiency of factor I-mediated C3b cleavage when catalyzed by membrane cofactor protein (MCP), but not when catalyzed by factor H. Biacore analysis showed that each mutant C3b bound sMCP (recombinant soluble MCP; CD46) at reduced affinity, providing a molecular basis for its reduced cofactor activity. Lastly, we show by electron microscopy structural analysis a displacement of the TED domain from the MG ring in C3b in two of the C3 mutants that explains these defects in regulation. As a whole our data suggest that aHUS-associated mutations in C3 selectively affect regulation of complement on surfaces and provide a structural framework to predict the functional consequences of the C3 genetic variants found in patients.
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Affiliation(s)
- Rubén Martínez-Barricarte
- Centro Investigaciones Biológicas, Ramiro de Maeztu 9, 28040 Madrid, Spain; Ciber de Enfermedades Raras, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Meike Heurich
- Institute of Infection & Immunity, School of Medicine, Cardiff University Heath Park, Cardiff CF14 4XN, United Kingdom
| | | | - Agustin Tortajada
- Centro Investigaciones Biológicas, Ramiro de Maeztu 9, 28040 Madrid, Spain; Ciber de Enfermedades Raras, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Sheila Pinto
- Centro Investigaciones Biológicas, Ramiro de Maeztu 9, 28040 Madrid, Spain; Ciber de Enfermedades Raras, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Margarita López-Trascasa
- Unidad de Inmunología, Hospital Universitario La Paz-IdiPAZ, and Ciber de Enfermedades Raras. Paseo de la Castellana 261, 28046 Madrid, Spain
| | - Pilar Sánchez-Corral
- Unidad de Investigación, Hospital Universitario La Paz-IdiPAZ, and Ciber de Enfermedades Raras. Paseo de la Castellana 261, 28046 Madrid, Spain
| | - B Paul Morgan
- Institute of Infection & Immunity, School of Medicine, Cardiff University Heath Park, Cardiff CF14 4XN, United Kingdom
| | - Oscar Llorca
- Centro Investigaciones Biológicas, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Claire L Harris
- Institute of Infection & Immunity, School of Medicine, Cardiff University Heath Park, Cardiff CF14 4XN, United Kingdom
| | - Santiago Rodríguez de Córdoba
- Centro Investigaciones Biológicas, Ramiro de Maeztu 9, 28040 Madrid, Spain; Ciber de Enfermedades Raras, Ramiro de Maeztu 9, 28040 Madrid, Spain.
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93
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Yang S, McGookey M, Wang Y, Cataland SR, Wu HM. Effect of blood sampling, processing, and storage on the measurement of complement activation biomarkers. Am J Clin Pathol 2015; 143:558-65. [PMID: 25780008 DOI: 10.1309/ajcpxpd7zqxntial] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVES Recent studies have shown that complement hyperactivation contributes to development of thrombotic microangiopathy. The evaluation of complement biomarkers is known to be influenced by inappropriate specimen handling. However, there has been no study fully addressing this topic. METHODS Blood from each donor was subjected to 62 different handling conditions prior to complement assays. RESULTS Complement biomarkers (C4d/C3a/factor Bb/C5a/C5b-9) are stable at room temperature (RT) for up to 4 hours in whole blood containing citrate or EDTA. However, under similar conditions, levels of C4d and C3a were significantly higher in serum than those in plasma. Thawing of the samples on ice or at RT had no significant effect on complement levels. In contrast, thawing at 37°C resulted in striking increases in levels of the complement system in serum and citrated plasma but not in EDTA plasma. Up to four freeze/thaw cycles on ice or RT did not substantially increase the levels of C3a, factor Bb, C5a, and C5b-9 but had a significant effect on C4d. Long-term storage of citrated plasma at -80°C for up to 6 years had no significant effect on levels of complement factors. CONCLUSIONS The results from this study thus provide crucial guidelines for future investigations using complement biomarkers to define the role of complement system in disease.
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Affiliation(s)
- Shangbin Yang
- Department of Pathology and Internal Medicine, College of Medicine, The Ohio State University, Columbus
| | - Michael McGookey
- Department of Pathology and Internal Medicine, College of Medicine, The Ohio State University, Columbus
| | - Yi Wang
- Translational Medicine, Alexion Corporation, Cheshire, CT
| | - Spero R. Cataland
- Department of Pathology and Internal Medicine, College of Medicine, The Ohio State University, Columbus
| | - Haifeng M. Wu
- Department of Pathology and Internal Medicine, College of Medicine, The Ohio State University, Columbus
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94
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Pouw RB, Vredevoogd DW, Kuijpers TW, Wouters D. Of mice and men: The factor H protein family and complement regulation. Mol Immunol 2015; 67:12-20. [PMID: 25824240 DOI: 10.1016/j.molimm.2015.03.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 03/09/2015] [Accepted: 03/10/2015] [Indexed: 10/23/2022]
Abstract
For decades immunological research has relied, with variable success, on mouse models to investigate diseases and possible therapeutic interventions. With the approval of the first therapeutic antibody targeting complement, called eculizumab, as therapy in paroxysmal nocturnal hemoglobinuria (PNH) and more recently atypical hemolytic uremic syndrome (aHUS), the viability of targeting the complement system was demonstrated. The potent, endogenous complement regulators have become of increasing interest as templates for designing and developing new therapeutics. Recently, complement inhibitors based on (parts of) the human complement regulator factor H (FH) are being examined for therapeutic intervention in inflammatory conditions. The first step to evaluate the potency of a new drug is often testing it in a mouse model for the target disease. However, translating results to human conditions requires a good understanding of similarities and, more importantly, differences between the human and mouse complement system and particularly regulation. This review will provide a comprehensive overview of the complement regulator FH and its closely related proteins and current views on their role in mice and men.
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Affiliation(s)
- R B Pouw
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands; Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children's Hospital, Academic Medical Centre, Amsterdam, the Netherlands.
| | - D W Vredevoogd
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - T W Kuijpers
- Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children's Hospital, Academic Medical Centre, Amsterdam, the Netherlands; Department of Blood Cell Research, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - D Wouters
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner laboratory of the Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
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95
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Kavanagh D, Yu Y, Schramm EC, Triebwasser M, Wagner EK, Raychaudhuri S, Daly MJ, Atkinson JP, Seddon JM. Rare genetic variants in the CFI gene are associated with advanced age-related macular degeneration and commonly result in reduced serum factor I levels. Hum Mol Genet 2015; 24:3861-70. [PMID: 25788521 PMCID: PMC4459386 DOI: 10.1093/hmg/ddv091] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/09/2015] [Indexed: 12/13/2022] Open
Abstract
To assess a potential diagnostic and therapeutic biomarker for age-related macular degeneration (AMD), we sequenced the complement factor I gene (CFI) in 2266 individuals with AMD and 1400 without, identifying 231 individuals with rare genetic variants. We evaluated the functional impact by measuring circulating serum factor I (FI) protein levels in individuals with and without rare CFI variants. The burden of very rare (frequency <1/1000) variants in CFI was strongly associated with disease (P = 1.1 × 10−8). In addition, we examined eight coding variants with counts ≥5 and saw evidence for association with AMD in three variants. Individuals with advanced AMD carrying a rare CFI variant had lower mean FI compared with non-AMD subjects carrying a variant (P < 0.001). Further new evidence that FI levels drive AMD risk comes from analyses showing individuals with a CFI rare variant and low FI were more likely to have advanced AMD (P = 5.6 × 10−5). Controlling for covariates, low FI increased the risk of advanced AMD among those with a variant compared with individuals without advanced AMD with a rare CFI variant (OR 13.6, P = 1.6 × 10−4), and also compared with control individuals without a rare CFI variant (OR 19.0, P = 1.1 × 10−5). Thus, low FI levels are strongly associated with rare CFI variants and AMD. Enhancing FI activity may be therapeutic and measuring FI provides a screening tool for identifying patients who are most likely to benefit from complement inhibitory therapy.
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Affiliation(s)
- David Kavanagh
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Newcastle upon Tyne, UK
| | - Yi Yu
- Ophthalmic Epidemiology and Genetics Service, New England Eye Center, Tufts Medical Center, Boston, MA, USA
| | - Elizabeth C Schramm
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Michael Triebwasser
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Erin K Wagner
- Ophthalmic Epidemiology and Genetics Service, New England Eye Center, Tufts Medical Center, Boston, MA, USA
| | - Soumya Raychaudhuri
- Partners HealthCare Center for Personalized Genetic Medicine, Boston, MA, USA, Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA, Division of Genetics, Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA, USA, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK
| | - Mark J Daly
- Partners HealthCare Center for Personalized Genetic Medicine, Boston, MA, USA, Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA, Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, USA
| | - John P Atkinson
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Johanna M Seddon
- Ophthalmic Epidemiology and Genetics Service, New England Eye Center, Tufts Medical Center, Boston, MA, USA, Department of Ophthalmology, Tufts University School of Medicine, Boston, MA, USA and Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA, USA
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96
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Duvvari MR, Saksens NT, van de Ven JP, de Jong-Hesse Y, Schick T, Nillesen WM, Fauser S, Hoefsloot LH, Hoyng CB, de Jong EK, den Hollander AI. Analysis of rare variants in the CFH gene in patients with the cuticular drusen subtype of age-related macular degeneration. Mol Vis 2015; 21:285-92. [PMID: 25814826 PMCID: PMC4360166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 03/12/2015] [Indexed: 11/17/2022] Open
Abstract
PURPOSE Age-related macular degeneration (AMD) and cuticular drusen (CD), a clinical subtype of AMD, have been linked to genetic variants in the complement factor H (CFH) gene. In this study, we aimed to investigate the frequency of rare variants in the CFH gene in 180 cases with CD. In addition, we aimed to determine the frequency of a previously reported rare, highly penetrant CFH variant (p.Arg1210Cys) in a Dutch-German non-CD-type AMD case-control cohort, and to describe the phenotype of patients carrying the p.Arg1210Cys variant. METHODS Study subjects were selected from the European Genetic Database (EUGENDA), a joint AMD database of the Radboud University Medical Centre and the University Hospital of Cologne, and graded at the Cologne Image Reading Centre and Laboratory (CIRCL). Additionally, two CD cases were recruited from the VU Medical Centre in Amsterdam. The CFH gene was analyzed in 180 CD cases with Sanger sequencing. All identified variants were analyzed for potential damaging effects with prediction software tools Sorting Intolerant from Tolerant (SIFT) and Polymorphism Phenotyping (PolyPhen). In addition, we genotyped the p.Arg1210Cys variant in 813 non-CD type AMD cases and 1175 controls. RESULTS Sequencing identified 11 rare, heterozygous missense variants, one frameshift variant, and one splice acceptor site variant in 16 CD cases. The p.Arg1210Cys variant was identified in two CD cases but was not identified in our Dutch-German non-CD-type AMD case-control cohort. CONCLUSIONS The present study identified the presence of rare variants in the CFH gene in 16 (8.8%) of 180 patients with the CD subtype of AMD. The carriers of rare CFH variants displayed a significantly earlier age at onset than non-carriers (p=0.016). The rare missense variant p.Arg1210Cys was identified in two CD cases, but was not detected in 813 non-CD type AMD cases or in the 1,175 controls of our Dutch-German cohort. The current study suggests that the p.Arg1210Cys variant may be restricted to a subset of patients with the CD subtype of AMD. Detailed clinical phenotyping, including fluorescein angiography, of patients with AMD carrying the p.Arg1210Cys variant in other cohorts is required to confirm this finding.
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Affiliation(s)
- Maheswara R. Duvvari
- Department of Ophthalmology, Radboud University Medical Centre, Nijmegen, the Netherlands,Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Nicole T.M. Saksens
- Department of Ophthalmology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | | | | | - Tina Schick
- Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany
| | - Willy M. Nillesen
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Sascha Fauser
- Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany
| | - Lies H. Hoefsloot
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands,Department of Clinical Genetics, Erasmus Medical Centre, Rotterdam, the Netherlands
| | - Carel B. Hoyng
- Department of Ophthalmology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Eiko K. de Jong
- Department of Ophthalmology, Radboud University Medical Centre, Nijmegen, the Netherlands,Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Anneke I. den Hollander
- Department of Ophthalmology, Radboud University Medical Centre, Nijmegen, the Netherlands,Department of Human Genetics, Radboud University Medical Centre, Nijmegen, the Netherlands
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97
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Timmermans SAMEG, van Paassen P, Cohen Tervaert JW. Recent advances in the understanding of immune-mediated nephrotic syndrome: diagnostic and prognostic implications. Expert Rev Clin Immunol 2015; 11:489-500. [PMID: 25754988 DOI: 10.1586/1744666x.2015.1024659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Glomerular diseases with severe defects in glomerular permeability give rise to heavy proteinuria and can present as nephrotic syndrome. There are many different causes of the nephrotic syndrome and a renal biopsy is nearly always needed to elucidate the underlying disease. During the last decade, substantial advances have occurred in the understanding of the pathophysiological mechanisms involved in immune-mediated glomerular diseases. Here, we review the diagnostic and prognostic implications of recent progress on the understanding of membranous nephropathy, minimal change disease, focal segmental glomerulosclerosis, amyloidosis, IgA nephropathy and membranoproliferative glomerulonephritis.
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Affiliation(s)
- Sjoerd A M E G Timmermans
- Deptartment of Nephrology and Clinical Immunology, Maastricht University Medical Centre, Maastricht, The Netherlands
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98
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Langford-Smith A, Day AJ, Bishop PN, Clark SJ. Complementing the Sugar Code: Role of GAGs and Sialic Acid in Complement Regulation. Front Immunol 2015; 6:25. [PMID: 25699044 PMCID: PMC4313701 DOI: 10.3389/fimmu.2015.00025] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 01/12/2015] [Indexed: 01/15/2023] Open
Abstract
Sugar molecules play a vital role on both microbial and mammalian cells, where they are involved in cellular communication, govern microbial virulence, and modulate host immunity and inflammatory responses. The complement cascade, as part of a host's innate immune system, is a potent weapon against invading bacteria but has to be tightly regulated to prevent inappropriate attack and damage to host tissues. A number of complement regulators, such as factor H and properdin, interact with sugar molecules, such as glycosaminoglycans (GAGs) and sialic acid, on host and pathogen membranes and direct the appropriate complement response by either promoting the binding of complement activators or inhibitors. The binding of these complement regulators to sugar molecules can vary from location to location, due to their different specificities and because distinct structural and functional subpopulations of sugars are found in different human organs, such as the brain, kidney, and eye. This review will cover recent studies that have provided important new insights into the role of GAGs and sialic acid in complement regulation and how sugar recognition may be compromised in disease.
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Affiliation(s)
- Alex Langford-Smith
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester , Manchester , UK
| | - Anthony J Day
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester , Manchester , UK
| | - Paul N Bishop
- Centre for Hearing and Vision Research, Institute of Human Development, University of Manchester , Manchester , UK ; Centre for Advanced Discovery and Experimental Therapeutics, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust , Manchester , UK ; Manchester Academic Health Science Centre, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust , Manchester , UK ; Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust , Manchester , UK
| | - Simon J Clark
- Centre for Hearing and Vision Research, Institute of Human Development, University of Manchester , Manchester , UK ; Centre for Advanced Discovery and Experimental Therapeutics, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust , Manchester , UK
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99
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Wong EKS, Kavanagh D. Anticomplement C5 therapy with eculizumab for the treatment of paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome. Transl Res 2015; 165:306-20. [PMID: 25468487 DOI: 10.1016/j.trsl.2014.10.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 10/15/2014] [Accepted: 10/16/2014] [Indexed: 12/28/2022]
Abstract
The complement inhibitor eculizumab is a humanized monoclonal antibody against C5. It was developed to specifically target cleavage of C5 thus preventing release of C5a and activation of the terminal pathway. Paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS) are 2 diseases with distinctly different underlying molecular mechanisms. In PNH, progeny of hematopoietic stem cells that harbor somatic mutations lead to a population of peripheral blood cells that are deficient in complement regulators resulting in hemolysis and thrombosis. In aHUS, germline mutations in complement proteins or their regulators fail to protect the glomerular endothelium from complement activation resulting in thrombotic microangiopathy and renal failure. Critical to the development of either disease is activation of the terminal complement pathway. Understanding this step has led to the study of eculizumab as a treatment for these diseases. In clinical trials, eculizumab is proven to be effective and safe in PNH and aHUS.
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Affiliation(s)
- Edwin K S Wong
- Institute of Genetic Medicine, Newcastle University, Newcastle Upon Tyne, United Kingdom.
| | - David Kavanagh
- Institute of Genetic Medicine, Newcastle University, Newcastle Upon Tyne, United Kingdom
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100
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Watson R, Wearmouth E, McLoughlin AC, Jackson A, Ward S, Bertram P, Bennaceur K, Barker CE, Pappworth IY, Kavanagh D, Lea SM, Atkinson JP, Goodship THJ, Marchbank KJ. Autoantibodies to CD59, CD55, CD46 or CD35 are not associated with atypical haemolytic uraemic syndrome (aHUS). Mol Immunol 2015; 63:287-96. [PMID: 25150608 PMCID: PMC4452024 DOI: 10.1016/j.molimm.2014.07.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Accepted: 07/16/2014] [Indexed: 01/31/2023]
Abstract
Autoantibody formation against Factor H (FH) is found in 7-10% of patients who are diagnosed with atypical haemolytic uraemic syndrome (aHUS). These autoantibodies predominately target the C-terminal cell binding recognition domain of FH and are associated with absence of FHR1. Additional autoantibodies have also been identified in association with aHUS, for example autoantibodies to Factor I. Based on this, and that there are genetic mutations in other complement regulators and activators associated with aHUS, we hypothesised that other complement regulator proteins, particularly surface bound regulators in the kidney, might be the target for autoantibody formation in aHUS. Therefore, we assayed serum derived from 89 patients in the Newcastle aHUS cohort for the presence of autoantibodies to CD46 (membrane cofactor protein, MCP), CD55 (decay accelerating factor, DAF), CD35 (complement receptor type 1, CR1; TP10) and CD59. We also assayed 100 healthy blood donors to establish the normal levels of reactivity towards these proteins in the general population. Recombinant proteins CD46 and CD55 (purified from Escherichia coli) as well as soluble CR1 (CD35) and oligomeric C4BP-CD59 (purified from eukaryotic cell media) were used in ELISA to detect high responders. False positive results were established though Western blot and flow cytometric analysis. After excluding false positive responders to bacterial proteins in the CD46 and CD55 preparations, and responses to blood group antigens in CD35, we found no significant level of patient serum IgG reactivity with CD46, CD55, CD35 or CD59 above that detected in the normal population. These results suggest that membrane anchored complement regulators are not a target for autoantibody generation in aHUS.
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Affiliation(s)
- Rachael Watson
- Institutes of Cellular and Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Emma Wearmouth
- Institutes of Cellular and Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Amy-Claire McLoughlin
- Institutes of Cellular and Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Arthur Jackson
- Institutes of Cellular and Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Sophie Ward
- Institutes of Cellular and Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Paula Bertram
- Division of Rheumatology, Washington University School of Medicine, St. Louis, MO, USA
| | - Karim Bennaceur
- Institutes of Cellular and Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Catriona E Barker
- Institutes of Cellular and Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Isabel Y Pappworth
- Institutes of Cellular and Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - David Kavanagh
- Institutes of Cellular and Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Susan M Lea
- Sir William Dunn School of Pathology, University of Oxford, UK
| | - John P Atkinson
- Division of Rheumatology, Washington University School of Medicine, St. Louis, MO, USA
| | - Timothy H J Goodship
- Institutes of Cellular and Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Kevin J Marchbank
- Institutes of Cellular and Genetic Medicine, Newcastle University, Newcastle-upon-Tyne, UK.
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