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Philip R, Aouba A, Martin Silva N, Mariotte D, Hamidi H, Rhouni S, Darnige L, Dragon-Durey MA. Autoantibodies against complement proteins in patients with antiphospholipid syndrome: Prevalence and clinical associations. Eur J Immunol 2024:e2350832. [PMID: 38700064 DOI: 10.1002/eji.202350832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 05/05/2024]
Abstract
Seventy-seven patients with antiphospholipid syndrome were tested for autoantibodies against C1q, C3, FB, FH, and C4bp. Fifty-seven patients had at least one anti-complement antibody. IgM anti-FH positivity was associated with thrombosis when anti-C3 and anti-FB were, negatively or positively, associated with various noncriteria manifestations of antiphospholipid syndrome.
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Affiliation(s)
- Rémi Philip
- Department of Clinical Immunology and Internal Medicine, CHU of Caen Normandie, Caen, France
- INSERM UMRS 1138 Team "Inflammation, Complement and Cancer", Centre de Recherche des Cordeliers, Sorbonne Université, Université Paris Cité, Paris, France
- UNICAEN, CHU de Caen Normandie, Normandie University, Caen, France
| | - Achille Aouba
- Department of Clinical Immunology and Internal Medicine, CHU of Caen Normandie, Caen, France
- UNICAEN, CHU de Caen Normandie, Normandie University, Caen, France
| | - Nicolas Martin Silva
- Department of Clinical Immunology and Internal Medicine, CHU of Caen Normandie, Caen, France
| | - Delphine Mariotte
- Laboratory of Immunology and Histocompatibility, Department of Biology, CHU of Caen Normandie, Caen, France
| | - Houcine Hamidi
- INSERM UMRS 1138 Team "Inflammation, Complement and Cancer", Centre de Recherche des Cordeliers, Sorbonne Université, Université Paris Cité, Paris, France
- Laboratory of Immunology, Hôpital Européen Georges-Pompidou, Assistance Publique Hopitaux de Paris (APHP), Paris, France
| | - Sanae Rhouni
- Laboratory of Immunology, Hôpital Européen Georges-Pompidou, Assistance Publique Hopitaux de Paris (APHP), Paris, France
| | - Luc Darnige
- Hematology Department, Hôpital Européen Georges-Pompidou, Assistance Publique Hôpitaux de Paris, Centre-Université de Paris (APHP-CUP), Université Paris Cité, Innovative Therapies in Haemostasis, INSERM UMR-S1140, Paris, France
| | - Marie-Agnès Dragon-Durey
- INSERM UMRS 1138 Team "Inflammation, Complement and Cancer", Centre de Recherche des Cordeliers, Sorbonne Université, Université Paris Cité, Paris, France
- Laboratory of Immunology, Hôpital Européen Georges-Pompidou, Assistance Publique Hopitaux de Paris (APHP), Paris, France
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2
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Jensen M, Eickhoff MK, Persson F, Rossing P, Thiel S, Hansen SWK, Palarasah Y, Svenningsen P, Jensen BL. Effect of dapagliflozin on collectins and complement activation in plasma from patients with type 2 diabetes and albuminuria: Data from the DapKid cohort. Immunobiology 2024; 229:152797. [PMID: 38518448 DOI: 10.1016/j.imbio.2024.152797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 03/13/2024] [Accepted: 03/15/2024] [Indexed: 03/24/2024]
Abstract
BACKGROUND Sodium-glucose cotransporter 2 (SGLT- 2) inhibitors exert cardiovascular and kidney-protective effects in people with diabetes. Attenuation of inflammation could be important for systemic protection. The lectin pathway of complement system activation is linked to diabetic nephropathy. We hypothesized that SGLT-2 inhibitors lower the circulating level of pattern-recognition molecules of the lectin cascade and attenuate systemic complement activation. METHODS Analysis of paired plasma samples from the DapKid crossover intervention study where patients with type 2 diabetes mellitus (T2DM) and albuminuria were treated with dapagliflozin and placebo for 12 weeks (10 mg/day, n=36). ELISA was used to determine concentrations of collectin kidney 1 (CL-K1), collectin liver 1 (CL-L1), mannose-binding lectin (MBL), MBL-associated serine protease 2 (MASP-2), the anaphylatoxin complement factor 3a (C3a), the stable C3 split product C3dg and the membrane attack complex (sC5b-9). RESULTS As published before, dapagliflozin treatment lowered Hba1C from 74 (14.9) mmol/mol to 66 (13.9) mmol/mol (p<0.0001), and the urine albumin/creatinine ratio from 167.8 mg/g to 122.5 mg/g (p<0.0001). Plasma concentrations of CL-K1, CL-L1, MBL, and MASP-2 did not change significantly after dapagliflozin treatment (P>0.05) compared to placebo treatment. The plasma levels of C3a (P<0.05) and C3dg (P<0.01) increased slightly but significantly, 0.6 [0.2] units/mL and 76 [52] units/mL respectively, after dapagliflozin treatment. The C9-associated neoepitope in C5b-9 did not change in plasma concentration by dapagliflozin (P>0.05). CONCLUSION In patients with type 2 diabetes and albuminuria, SGLT-2 inhibition resulted in modest C3 activation in plasma, likely not driven by primary changes in circulating collectins and not resulting in changes in membrane attack complex. Based on systemic analyses, organ-specific local protective effects of gliflozins against complement activation cannot be excluded.
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Affiliation(s)
- Mia Jensen
- Unit of Cardiovascular and Renal Research, Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark.
| | | | | | - Peter Rossing
- Steno Diabetes Center Copenhagen, Herlev, Denmark; University of Copenhagen, Department of Clinical Medicine, Copenhagen, Denmark
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Søren W K Hansen
- Unit for Cancer and Inflammation Research, Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Yaseelan Palarasah
- Unit for Cancer and Inflammation Research, Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Per Svenningsen
- Unit of Cardiovascular and Renal Research, Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Boye L Jensen
- Unit of Cardiovascular and Renal Research, Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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Vasilev V, Artero MR, Petkova M, Mihaylova G, Dragon-Durey MA, Radanova M, Roumenina LT. Clinical Relevance of Anti-C3 and Anti-C4 Autoantibodies in Lupus Nephritis. Kidney Int Rep 2024; 9:1429-1440. [PMID: 38707805 PMCID: PMC11068950 DOI: 10.1016/j.ekir.2024.01.052] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/25/2024] [Accepted: 01/29/2024] [Indexed: 05/07/2024] Open
Abstract
Introduction Complement system overactivation is pivotal in lupus nephritis (LN) pathophysiology. Considering that anti-C3 autoantibodies play a significant role in LN pathophysiology, we explored them as disease activity biomarkers and compared them to the ones against the homologous protein, C4. Methods We investigated the presence of anti-C3 and anti-C4 IgG autoantibodies in a LN cohort (N = 85 patients) and monitored their changes over time. We correlated autoantibody presence with clinical parameters. We conducted cross-sectional and longitudinal analyses (N = 295 samples, 8 years follow-up) to explore associations between autoantibodies and disease progression. Antigen-specific anti-C3 or anti-C4 IgG were purified from plasma by affinity chromatography and their reactivity was tested for cross-reactivity against purified C3 or C4 by enzyme-linked immunosorbent assay (ELISA). Results The reactivity against C3 was independent of C4. Our study revealed distinct roles for anti-C3 and anti-C4 in LN. Anti-C3 IgG exhibited stronger clinical correlations than anti-C4, showing associations with hypocomplementemia, anti-dsDNA, class IV LN, and active disease according to British Isles Lupus Assessment Group (BILAG) renal score. In a longitudinal analysis, anti-C3 positivity at initial sampling predicted present and future disease exacerbation alone and even better when combined with anti-dsDNA, as indicated by a transition to BILAG category A. Conclusion Our research provides insights into anti-C3/C3b and anti-C4 autoantibodies in LN, revealing that they are often not cross-reactive. Anti-C3 utility as disease activity biomarkers is underscored by its stronger clinical associations and predictive value for future flares. Combining anti-C3 and anti-dsDNA out-performs the 2 factors alone, suggesting that the incorporation of anti-C3/C3b quantification into routine clinical practice could improve LN management.
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Affiliation(s)
- Vasil Vasilev
- Clinic of Nephrology, University Hospital - “Tzaritza Yoanna – ISUL”, Medical University of Sofia, Sofia, Bulgaria
| | - Mikel Rezola Artero
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Team Inflammation, complement and cancer, Paris, France
- Department of Bacteriology and Immunology, Haartman Institute, and Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - Marijana Petkova
- Clinic of Nephrology, University Hospital - “Tzaritza Yoanna – ISUL”, Medical University of Sofia, Sofia, Bulgaria
| | - Galya Mihaylova
- Department of Biochemistry, Molecular Medicine and Nutrigenomics, Medical University of Varna, Varna, Bulgaria
| | - Marie-Agnes Dragon-Durey
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Team Inflammation, complement and cancer, Paris, France
- Laboratoire d'Immunologie, Hôpital Européen Georges Pompidou, APHP, Paris, France; Université de Paris, Paris, France
| | - Maria Radanova
- Department of Biochemistry, Molecular Medicine and Nutrigenomics, Medical University of Varna, Varna, Bulgaria
| | - Lubka T. Roumenina
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Team Inflammation, complement and cancer, Paris, France
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Revel M, Rezola Artero M, Hamidi H, Grunenwald A, Blasco L, Vano YA, Marie Oudard S, Sanchez-Salas R, Macek P, Rodriguez Sanchez L, Cathelineau X, Vedié B, Sautes-Fridman C, Herman Fridman W, Roumenina LT, Dragon-Durey MA. Humoral complementomics - exploration of noninvasive complement biomarkers as predictors of renal cancer progression. Oncoimmunology 2024; 13:2328433. [PMID: 38487624 PMCID: PMC10939156 DOI: 10.1080/2162402x.2024.2328433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 03/06/2024] [Indexed: 03/17/2024] Open
Abstract
Despite the progress of anti-cancer treatment, the prognosis of many patients with solid tumors is still dismal. Reliable noninvasive biomarkers are needed to predict patient survival and therapy response. Here, we propose a Humoral Complementomics approach: a work-up of assays to comprehensively evaluate complement proteins, activation fragments, and autoantibodies targeting complement proteins in plasma, which we correlated with the intratumoral complement activation, and/or local production, focusing on localized and metastatic clear cell renal cell carcinoma (ccRCC). In two prospective ccRCC cohorts, plasma C2, C5, Factor D and properdin were elevated compared to healthy controls, reflecting an inflammatory phenotype that correlated with plasma calprotectin levels but did not associate with CRP or with patient prognosis. Conversely, autoantibodies against the complement C3 and the reduced form of FH (a tumor neo-epitope reported in lung cancer) correlated with a favorable outcome. Our findings pointed to a specific group of patients with elevated plasma C4d and C1s-C1INH complexes, indicating the initiation of the classical pathway, along with elevated Ba and Bb, indicating alternative pathway activation. Boostrapped Lasso regularized Cox regression revealed that the most predictive complement biomarkers were elevated plasma C4d and Bb levels at the time of surgery, which correlated with poor prognosis. In conclusion, we propose Humoral Complementomics as an unbiased approach to study the global state of the complement system in any pathological plasma sample and disease context. Its implementation for ccRCC revealed that elevated C4d and Bb in plasma are promising prognostic biomarkers, correlating with shorter progression-free survival.
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Affiliation(s)
- Margot Revel
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, Inflammation, Complement and Cancer team, Paris, France
| | - Mikel Rezola Artero
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, Inflammation, Complement and Cancer team, Paris, France
- Department of Bacteriology and Immunology, Haartman Institute, and Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - Houcine Hamidi
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, Inflammation, Complement and Cancer team, Paris, France
- Laboratoire d’Immunologie, Hôpital Européen Georges Pompidou, APHP, Paris, France
| | - Anne Grunenwald
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, Inflammation, Complement and Cancer team, Paris, France
- Department of Nephrology and Hemodialysis, Service de néphrologie - hémodialyse, Poissy, France
| | - Loris Blasco
- Laboratoire d’Immunologie, Hôpital Européen Georges Pompidou, APHP, Paris, France
| | - Yann A. Vano
- Hôpital Européen Georges-Pompidou, Oncology Department, Assistance Publique Hopitaux de Paris, Université Paris Cité, Paris, France
| | - Stephane Marie Oudard
- Hôpital Européen Georges-Pompidou, Oncology Department, Assistance Publique Hopitaux de Paris, Université Paris Cité, Paris, France
| | | | - Petr Macek
- Department of Urology Institut Mutualiste Montsouris, Paris, France
| | | | | | - Benoit Vedié
- Hôpital Européen Georges-Pompidou, Department of Biochemistry, Assistance Publique Hopitaux de Paris, Paris, France
| | - Catherine Sautes-Fridman
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, Inflammation, Complement and Cancer team, Paris, France
- Equipe labellisée Ligue contre le Cancer, Paris
| | - Wolf Herman Fridman
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, Inflammation, Complement and Cancer team, Paris, France
- Equipe labellisée Ligue contre le Cancer, Paris
| | - Lubka T. Roumenina
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, Inflammation, Complement and Cancer team, Paris, France
| | - Marie-Agnes Dragon-Durey
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, Inflammation, Complement and Cancer team, Paris, France
- Laboratoire d’Immunologie, Hôpital Européen Georges Pompidou, APHP, Paris, France
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Abstract
Uncontrolled alternative pathway activation is the primary driver of several diseases, and it contributes to the pathogenesis of many others. Consequently, diagnostic tests to monitor this arm of the complement system are increasingly important. Defects in alternative pathway regulation are strong risk factors for disease, and drugs that specifically block the alternative pathway are entering clinical use. A range of diagnostic tests have been developed to evaluate and monitor the alternative pathway, including assays to measure its function, expression of alternative pathway constituents, and activation fragments. Genetic studies have also revealed many disease-associated variants in alternative pathway genes that predict the risk of disease and prognosis. Newer imaging modalities offer the promise of non-invasively detecting and localizing pathologic complement activation. Together, these various tests help in the diagnosis of disease, provide important prognostic information, and can help guide therapy with complement inhibitory drugs.
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Affiliation(s)
- Joshua M. Thurman
- Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Veronique Fremeaux-Bacchi
- Assistance Publique-Hôpitaux de Paris, European Hospital Georges Pompidou, Department of Immunology Biology and INSERM UMRS1138, Centre de Recherche des Cordeliers, Team "Inflammation, Complement and Cancer", Paris, France
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6
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Zarantonello A, Revel M, Grunenwald A, Roumenina LT. C3-dependent effector functions of complement. Immunol Rev 2023; 313:120-138. [PMID: 36271889 PMCID: PMC10092904 DOI: 10.1111/imr.13147] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
C3 is the central effector molecule of the complement system, mediating its multiple functions through different binding sites and their corresponding receptors. We will introduce the C3 forms (native C3, C3 [H2 O], and intracellular C3), the C3 fragments C3a, C3b, iC3b, and C3dg/C3d, and the C3 expression sites. To highlight the important role that C3 plays in human biological processes, we will give an overview of the diseases linked to C3 deficiency and to uncontrolled C3 activation. Next, we will present a structural description of C3 activation and of the C3 fragments generated by complement regulation. We will proceed by describing the C3a interaction with the anaphylatoxin receptor, followed by the interactions of opsonins (C3b, iC3b, and C3dg/C3d) with complement receptors, divided into two groups: receptors bearing complement regulatory functions and the effector receptors without complement regulatory activity. We outline the molecular architecture of the receptors, their binding sites on the C3 activation fragments, the cells expressing them, the diversity of their functions, and recent advances. With this review, we aim to give an up-to-date analysis of the processes triggered by C3 activation fragments on different cell types in health and disease contexts.
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Affiliation(s)
- Alessandra Zarantonello
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Margot Revel
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Anne Grunenwald
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
| | - Lubka T Roumenina
- Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, Université de Paris, Paris, France
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7
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Complement C3 Regulates Inflammatory Response and Monocyte/Macrophage Phagocytosis of Streptococcus agalactiae in a Teleost Fish. Int J Mol Sci 2022; 23:ijms232415586. [PMID: 36555227 PMCID: PMC9779060 DOI: 10.3390/ijms232415586] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/28/2022] [Accepted: 09/02/2022] [Indexed: 12/14/2022] Open
Abstract
The complement system is composed of a complex protein network and is pivotal to innate immunity. Complement 3 (C3) is a critical protein in the complement cascade and participates in complement activation and immune defense. In this study, C3 from Nile tilapia (Oreochromis niloticus) was cloned and its function in resisting pathogen infection was characterized. The full length of OnC3 open reading frame is 4974 bp, encoding 1657 aa, and the predicted protein mass weight is 185.93 kDa. The OnC3 amino acid sequence contains macroglobulin domains. The expression pattern of OnC3 mRNA in the tissues of healthy fish was detected, with the highest in the liver and the lowest in the muscle. After challenged with Streptococcus agalactiae and Aeromonas hydrophila, the expression of OnC3 mRNA was significantly up-regulated in the liver, spleen, and head kidney. Further, the recombinant OnC3 protein alleviated the inflammatory response and pathological damage of tissues after infected with S. agalactiae. Moreover, the OnC3 promoted the phagocytosis of monocytes/macrophages to S. agalactiae. The data obtained in this study provide a theoretical reference for in-depth understanding of C3 in host defense against bacterial infection and the immunomodulatory roles in teleost fish.
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Emre C, Do KV, Jun B, Hjorth E, Alcalde SG, Kautzmann MAI, Gordon WC, Nilsson P, Bazan NG, Schultzberg M. Age-related changes in brain phospholipids and bioactive lipids in the APP knock-in mouse model of Alzheimer's disease. Acta Neuropathol Commun 2021; 9:116. [PMID: 34187579 PMCID: PMC8244172 DOI: 10.1186/s40478-021-01216-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 06/08/2021] [Indexed: 12/19/2022] Open
Abstract
Sustained brain chronic inflammation in Alzheimer’s disease (AD) includes glial cell activation, an increase in cytokines and chemokines, and lipid mediators (LMs), concomitant with decreased pro-homeostatic mediators. The inflammatory response at the onset of pathology engages activation of pro-resolving, pro-homeostatic LMs followed by a gradual decrease. We used an APP knock-in (App KI) AD mouse that accumulates β-amyloid (Aβ) and presents cognitive deficits (at 2 and 6 months of age, respectively) to investigate LMs, their precursors, biosynthetic enzymes and receptors, glial activation, and inflammatory proteins in the cerebral cortex and hippocampus at 2-, 4-, 8- and 18-month-old in comparison with wild-type (WT) mice. We used LC-mass-spectrometry and MALDI molecular imaging to analyze LMs and phospholipids, and immunochemistry for proteins. Our results revealed an age-specific lipid and cytokine profile, and glial activation in the App KI mice. Despite an early onset of Aβ pathology, pro-inflammatory and pro-resolving LMs were prominently increased only in the oldest age group. Furthermore, the LM biosynthetic enzymes increased, and their receptor expression decreased in the aged App KI mice. Arachidonic acid (AA)-containing phospholipid molecular species were elevated, correlating with decreased cPLA2 activity. MALDI molecular imaging depicted differential distribution of phospholipids according to genotype in hippocampal layers. Brain histology disclosed increased microglia proliferation starting from young age in the App KI mice, while astrocyte numbers were enhanced in older ages. Our results demonstrate that the brain lipidome is modified preferentially during aging as compared to amyloid pathology in the model studied here. However, alterations in phospholipids signal early pathological changes in membrane composition.
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Abstract
The complement cascade is an evolutionary ancient innate immune defense system, playing a major role in the defense against infections. Its function in maintaining host homeostasis on activated cells has been emphasized by the crucial role of its overactivation in ever growing number of diseases, such as atypical hemolytic uremic syndrome (aHUS), autoimmune diseases as systemic lupus erythematosus (SLE), C3 glomerulopathies (C3GN), age-related macular degeneration (AMD), graft rejection, Alzheimer disease, and cancer, to name just a few. The last decade of research on complement has extended its implication in many pathological processes, offering new insights to potential therapeutic targets and asserting the necessity of reliable, sensitive, specific, accurate, and reproducible biomarkers to decipher complement role in pathology. We need to evaluate accurately which pathway or role should be targeted pharmacologically, and optimize treatment efficacy versus toxicity. This chapter is an introduction to the role of complement in human diseases and the use of complement-related biomarkers in the clinical practice. It is a part of a book intending to give reliable and standardized methods to evaluate complement according to nowadays needs and knowledge.
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10
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Willrich MAV, Braun KMP, Moyer AM, Jeffrey DH, Frazer-Abel A. Complement testing in the clinical laboratory. Crit Rev Clin Lab Sci 2021; 58:447-478. [PMID: 33962553 DOI: 10.1080/10408363.2021.1907297] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The complement system is the human's first line of defense against microbial pathogens because of its important housekeeping and infection/inflammation roles. It is composed of a series of soluble and cell-bound proteins that are activated in a cascade effect, similar to the coagulation pathways. There are different pattern recognizing molecules that activate the complement system in response to stimuli or threats, acting through three initiation pathways: classical, lectin, and alternative. All three activation pathways converge at the C3 component and share the terminal pathway. The main outputs of the complement system action are lytic killing of microbes, the release of pro-inflammatory anaphylatoxins, and opsonization of targets. Laboratory testing is relevant in the setting of suspected complement deficiencies, as well as in the emerging number of diseases related to dysregulation (over-activation) of complement. Most common assays measure complement lytic activity and the different complement component concentrations. Specialized testing includes the evaluation of autoantibodies against complement components, activation fragments, and genetic studies. In this review, we cover laboratory testing for complement and the conditions with complement involvement, as well as current challenges in the field.
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Affiliation(s)
| | - Karin M P Braun
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Ann M Moyer
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - David H Jeffrey
- Exsera Biolabs, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, USA
| | - Ashley Frazer-Abel
- Exsera Biolabs, Department of Medicine, University of Colorado School of Medicine, Aurora, CO, USA
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11
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Abstract
Antibodies to autoantigens are implicated in a large number of diseases. Such autoantibodies may cause pathological activation of complement, an ancient humoral recognition and effector system of innate immunity; in addition, complement components or regulators may be target of autoantibodies and cause abnormal complement activation or function. Autoantibodies to complement proteins are in particular involved in kidney diseases. Those binding to complement convertase enzymes can cause enhanced stability of convertases and their increased resistance to regulation, thus promoting complement turnover. Here, we describe an ELISA method to detect factor B autoantibodies that bind to and stabilize the alternative complement pathway C3 convertase enzyme, C3bBb.
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Affiliation(s)
- Mihály Józsi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary.
| | - Barbara Uzonyi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
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12
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Radanova M, Roumenina LT, Vasilev V. Detection of Anti-C3b Autoantibodies by ELISA. Methods Mol Biol 2021; 2227:133-139. [PMID: 33847938 DOI: 10.1007/978-1-0716-1016-9_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Autoantibodies against complement proteins are involved in the pathological process of many diseases, including lupus nephritis, C3 glomerulopathies, and atypical hemolytic uremic syndrome. This method describes the detection of autoantibodies targeting the central complement component C3 by ELISA. These autoantibodies (IgG) are detected in up to 30% of the patients with lupus nephritis and more rarely in cases with C3 glomerulopathies. These autoantibodies recognize the active fragment C3b and have overt functional consequences. They enhance the formation of the C3 convertase and prevent the inactivation of C3b by Factor H and complement receptor 1. Moreover, they enhance the deposition of complement activation fragments on activator surfaces, such as apoptotic cells. The data currently available on the relations of anti-C3 autoantibodies with clinical, laboratory, and histological markers for activity of lupus nephritis, as well as the relations of anti-C3 with classical immunological markers for activity of autoimmune process in patients with lupus nephritis, such as hypocomplementemia and high levels of anti-dsDNA, could identify these autoantibodies as a potential marker for evaluation the activity of lupus nephritis. These autoantibodies correlate with the disease severity and can be used to identify patients with lupus nephritis who were prone to flare. Therefore, the detection of such autoantibodies could guide the clinicians to evaluate and predict the severity and to manage the therapy of lupus nephritis.
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Affiliation(s)
- Maria Radanova
- Department of Biochemistry, Molecular Medicine and Nutrigenomics, Medical University of Varna, Varna, Bulgaria.
| | - Lubka T Roumenina
- INSERM, UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, Université de Paris, Paris, France
| | - Vasil Vasilev
- Clinic of Nephrology, University Hospital-"Tzaritza Yoanna-ISUL", Medical University of Sofia, Sofia, Bulgaria
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13
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Kavvadas E. Autoantibodies specific for C1q, C3b, β2-glycoprotein 1 and annexins may amplify complement activity and reduce apoptosis-mediated immune suppression. Med Hypotheses 2020; 144:110286. [PMID: 33254588 DOI: 10.1016/j.mehy.2020.110286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/13/2020] [Accepted: 09/14/2020] [Indexed: 02/08/2023]
Abstract
Neoplastic cells hijack cell death pathways to evade the immune response. Phosphatidylserine, a marker of apoptotic cells, and its highly conserved bridging proteins, annexins and β2-glycoprotein I, facilitate the efficient removal of apoptotic and necrotic cells via tumor-associated phagocytes in a process called efferocytosis. Efferocytosis results in the clearance of dead and dying cells and local immune suppression. Neoplastic cells also have an increased capacity to activate complement. Complement may facilitate the silent removal of tumor cells and has a dual role in promoting and inhibiting tumor growth. Here I hypothesize that immune response-generating IgG autoantibodies that recognize opsonizing fragments C1q, C3b, and phosphatidylserine-binding proteins (annexins, β2-glycoprotein I) may reduce tumor growth. I propose that these autoantibodies induce a pro-inflammatory, cytotoxic tumor microenvironment. Further, I predict that autoantibodies can drive neoplastic cell phagocytosis in an Fc receptor-dependent manner and recruit additional complement, resulting in immune-stimulatory effects. Excessive complement activation and antibody-dependent cytotoxicity may stimulate anti-tumor responses, including damage to tumor vasculature. Here I provide insights that may aid the development of more effective therapeutic modalities to control cancer. Such therapeutic approaches should kill neoplastic cells and target their interaction with host immune cells. Thereby the pro-tumorigenic effect of dead cancer cells could be limited while inducing the anti-tumor potential of tumor-associated phagocytes.
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Affiliation(s)
- Efstathios Kavvadas
- 417 General Military Hospital NIMTS - Pathology Department, Monis Petraki 12, Postal Code: 11521, Athens, Greece.
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14
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Mihaylova G, Vasilev V, Kosturkova MB, Stoyanov GS, Radanova M. Long Non-Coding RNAs as New Biomarkers in Lupus Nephritis: A Connection Between Present and Future. Cureus 2020; 12:e9003. [PMID: 32775083 PMCID: PMC7402529 DOI: 10.7759/cureus.9003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE). LN often leads to kidney failure, affecting the quality of a patient's life. There are several classical biomarkers that assist nephrologists’ daily practice. For more than 50 years, anti-double stranded DNA antibodies and complement components C3 and C4 have been used for LN disease activity evaluation. The major obstacle in the usage of conventional biomarkers is that none of them have both high specificity and high sensitivity. Moreover, an invasive kidney biopsy is still the gold standard for renal involvement detection in SLE patients. Therefore, new non-invasive biomarkers are needed for the early and accurate establishment of LN. Among the promising candidates are long non-coding RNAs (lncRNAs). Their dysregulation appears to have predictive and diagnostic potential. Furthermore, these biomarkers like other conventional biomarkers give insight into the pathogenesis of LN. This review aims to summarize the available information on lncRNAs in SLE patients and to present their future opportunities to add to the conventional biomarkers in the diagnosis and monitoring of LN.
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Affiliation(s)
- Galya Mihaylova
- Biochemistry, Molecular Medicine and Nutrigenomics, Medical University of Varna, Varna, BGR
| | - Vasil Vasilev
- Nephrology, "Tsaritsa Yoanna - ISUL" University Hospital, Sofia, BGR
| | | | - George S Stoyanov
- General and Clinical Pathology/Forensic Medicine and Deontology, Medical University of Varna, Varna, BGR
| | - Maria Radanova
- Biochemistry, Molecular Medicine and Nutrigenomics, Medical University of Varna, Varna, BGR
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15
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Anti-complement factor H autoantibodies may be protective in lupus nephritis. Clin Chim Acta 2020; 508:1-8. [PMID: 32387092 DOI: 10.1016/j.cca.2020.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/22/2020] [Accepted: 05/04/2020] [Indexed: 01/28/2023]
Abstract
BACKGROUND This study aimed to investigate the role of anti-CFH autoantibodies in lupus nephritis based on a well-defined cohort. METHODS One hundred twenty patients with biopsy-proven active lupus nephritis were collected as the discovery cohort, sixty patients served as the validation cohort, thirty-four patients with SLE without renal involvement (NR-SLE) were as disease controls, and thirty healthy donors were also included. The anti-CFH autoantibodies and IgG subclasses were detected by ELISA, and epitopes were evaluated by western blot. Anti-CFH autoantibodies were purified by affinity chromatography column, and the interference on the biofunctions of CFH was further studied by the C3b binding assay and cofactor activity assay in vitro. RESULTS The prevalence of anti-CFH autoantibodies in lupus nephritis was significantly higher than that in healthy controls (8.3% (10/120) vs. 0% (0/30), P = 0.017), and no significant difference was found between the discovery and the validation group (8.3% (10/120) vs. 11.7% (7/60), P = 0.268) or the discovery and the NR-SLE group (8.3% (10/120) vs. 11.8% (4/34), P = 0.231). The subclass was mainly IgG2 (7/10), and major epitopes were in the middle (8/10 in SCRs 11-14) and N-terminal (7/10 in SCRs 1-4) regions of CFH. Patients with anti-CFH autoantibodies had a significantly lower prevalence of acute kidney injury (0% (0/10) vs. 40.0%(4/10), P = 0.025), lower serum creatinine levels (0.76 (0.40, 1.06) vs. 1.43 (0.46, 11.15), mg/dL, P = 0.023), and higher hemoglobin levels (113.8 ± 24.63 vs. 90.0 ± 22.53, g/L, P = 0.037) than those who were negative after further stratified analysis. A functional study showed that anti-CFH autoantibodies purified from patients with lupus nephritis could improve the binding between CFH and C3b, and also enhance the cofactor activity of CFH in vitro. CONCLUSIONS Anti-CFH autoantibodies were detected in patients with lupus nephritis in approximately 10% of patients with polyepitopes and IgG2 subclass predominance. Patients with anti-CFH autoantibodies presented with milder renal damage, and the purified autoantibodies could enhance the C3b binding and CFI cofactor activity of CFH in vitro, which suggested a protective role in the lupus nephritis.
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16
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Radanova M, Mihaylova G, Ivanova D, Daugan M, Lazarov V, Roumenina L, Vasilev V. Clinical and functional consequences of anti-properdin autoantibodies in patients with lupus nephritis. Clin Exp Immunol 2020; 201:135-144. [PMID: 32306375 DOI: 10.1111/cei.13443] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 12/18/2022] Open
Abstract
Properdin is the only positive regulator of the complement system. In this study, we characterize the prevalence, functional consequences and disease associations of autoantibodies against properdin in a cohort of patients with autoimmune disease systemic lupus erythematosus (SLE) suffering from lupus nephritis (LN). We detected autoantibodies against properdin in plasma of 22·5% of the LN patients (16 of 71) by enzyme-linked immunosorbent assay (ELISA). The binding of these autoantibodies to properdin was dose-dependent and was validated by surface plasmon resonance. Higher levels of anti-properdin were related to high levels of anti-dsDNA and anti-nuclear antibodies and low concentrations of C3 and C4 in patients, and also with histological signs of LN activity and chronicity. The high negative predictive value (NPV) of anti-properdin and anti-dsDNA combination suggested that patients who are negative for both anti-properdin and anti-dsDNA will not have severe nephritis. Immunoglobulin G from anti-properdin-positive patients' plasma increased the C3b deposition on late apoptotic cells by flow cytometry. Nevertheless, these IgGs did not modify substantially the binding of properdin to C3b, the C3 convertase C3bBb and the pro-convertase C3bB, evaluated by surface plasmon resonance. In conclusion, anti-properdin autoantibodies exist in LN patients. They have weak but relevant functional consequences, which could have pathological significance.
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Affiliation(s)
- M Radanova
- Department of Biochemistry, Molecular Medicine and Nutrigenomics, Medical University of Varna, Varna, Bulgaria
| | - G Mihaylova
- Department of Biochemistry, Molecular Medicine and Nutrigenomics, Medical University of Varna, Varna, Bulgaria
| | - D Ivanova
- Department of Biochemistry, Molecular Medicine and Nutrigenomics, Medical University of Varna, Varna, Bulgaria
| | - M Daugan
- INSERM, UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, Université de Paris, Paris, France
| | - V Lazarov
- Clinic of Nephrology, University Hospital "Tzaritza Yoanna, ISUL", Medical University of Sofia, Sofia, Bulgaria
| | - L Roumenina
- INSERM, UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, Université de Paris, Paris, France
| | - V Vasilev
- Clinic of Nephrology, University Hospital "Tzaritza Yoanna, ISUL", Medical University of Sofia, Sofia, Bulgaria
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17
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Corvillo F, Ceccarini G, Nozal P, Magno S, Pelosini C, Garrido S, López-Lera A, Moraru M, Vilches C, Fornaciari S, Gabbriellini S, Santini F, Araújo-Vilar D, López-Trascasa M. Immunological features of patients affected by Barraquer-Simons syndrome. Orphanet J Rare Dis 2020; 15:9. [PMID: 31924231 PMCID: PMC6954565 DOI: 10.1186/s13023-019-1292-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 12/29/2019] [Indexed: 01/16/2023] Open
Abstract
Background C3 hypocomplementemia and the presence of C3 nephritic factor (C3NeF), an autoantibody causing complement system over-activation, are common features among most patients affected by Barraquer-Simons syndrome (BSS), an acquired form of partial lipodystrophy. Moreover, BSS is frequently associated with autoimmune diseases. However, the relationship between complement system dysregulation and BSS remains to be fully elucidated. The aim of this study was to provide a comprehensive immunological analysis of the complement system status, autoantibody signatures and HLA profile in BSS. Thirteen subjects with BSS were recruited for the study. The circulating levels of complement components, C3, C4, Factor B (FB) and Properdin (P), as well as an extended autoantibody profile including autoantibodies targeting complement components and regulators were assessed in serum. Additionally, HLA genotyping was carried out using DNA extracted from peripheral blood mononuclear cells. Results C3, C4 and FB levels were significantly reduced in patients with BSS as compared with healthy subjects. C3NeF was the most frequently found autoantibody (69.2% of cases), followed by anti-C3 (38.5%), and anti-P and anti-FB (30.8% each). Clinical data showed high prevalence of autoimmune diseases (38.5%), the majority of patients (61.5%) being positive for at least one of the autoantibodies tested. The HLA allele DRB1*11 was present in 54% of BSS patients, and the majority of them (31%) were positive for *11:03 (vs 1.3% allelic frequency in the general population). Conclusions Our results confirmed the association between BSS, autoimmunity and C3 hypocomplementemia. Moreover, the finding of autoantibodies targeting complement system proteins points to complement dysregulation as a central pathological event in the development of BSS.
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Affiliation(s)
- Fernando Corvillo
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Paseo de la Castellana, 261, 28046, Madrid, Spain. .,Center for Biomedical Network Research on Rare Diseases (CIBERER U754), Madrid, Spain.
| | - Giovanni Ceccarini
- Obesity and Lipodystrophy Centre at the Endocrinology Unit, University Hospital of Pisa, Pisa, Italy
| | - Pilar Nozal
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Paseo de la Castellana, 261, 28046, Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER U754), Madrid, Spain.,Unit of Immunology, La Paz University Hospital, Madrid, Spain
| | - Silvia Magno
- Obesity and Lipodystrophy Centre at the Endocrinology Unit, University Hospital of Pisa, Pisa, Italy
| | - Caterina Pelosini
- Obesity and Lipodystrophy Centre at the Endocrinology Unit, University Hospital of Pisa, Pisa, Italy
| | - Sofía Garrido
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Paseo de la Castellana, 261, 28046, Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER U754), Madrid, Spain.,Unit of Immunology, La Paz University Hospital, Madrid, Spain
| | - Alberto López-Lera
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Paseo de la Castellana, 261, 28046, Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER U754), Madrid, Spain
| | - Manuela Moraru
- Immunogenetics and Histocompatibility, Instituto de Investigación Sanitaria Puerta de Hierro, Madrid, Spain
| | - Carlos Vilches
- Immunogenetics and Histocompatibility, Instituto de Investigación Sanitaria Puerta de Hierro, Madrid, Spain
| | | | | | - Ferruccio Santini
- Obesity and Lipodystrophy Centre at the Endocrinology Unit, University Hospital of Pisa, Pisa, Italy
| | - David Araújo-Vilar
- Thyroid and Metabolic Diseases Unit (U.E.T.eM.), Centro Singular de Investigación en Medicina Molecular e Enfermidades Crónicas (CIMUS-IDIS), School of Medicine, Universidad de Santiago de Compostela, Santiago de Compostela, Spain
| | - Margarita López-Trascasa
- Complement Research Group, Hospital La Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Paseo de la Castellana, 261, 28046, Madrid, Spain.,Universidad Autónoma de Madrid, Madrid, Spain
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18
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Zipfel PF, Wiech T, Rudnick R, Afonso S, Person F, Skerka C. Complement Inhibitors in Clinical Trials for Glomerular Diseases. Front Immunol 2019; 10:2166. [PMID: 31611870 PMCID: PMC6776600 DOI: 10.3389/fimmu.2019.02166] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/28/2019] [Indexed: 01/16/2023] Open
Abstract
Defective complement action is a cause of several human glomerular diseases including atypical hemolytic uremic syndrome (aHUS), anti-neutrophil cytoplasmic antibody mediated vasculitis (ANCA), C3 glomerulopathy, IgA nephropathy, immune complex membranoproliferative glomerulonephritis, ischemic reperfusion injury, lupus nephritis, membranous nephropathy, and chronic transplant mediated glomerulopathy. Here we summarize ongoing clinical trials of complement inhibitors in nine glomerular diseases and show which inhibitors are used in trials for these renal disorders (http://clinicaltrials.gov).
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Affiliation(s)
- Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany.,Friedrich-Schiller-University, Jena, Germany
| | - Thorsten Wiech
- Institute of Pathology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Ramona Rudnick
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Sara Afonso
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Fermin Person
- Institute of Pathology, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
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