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Vivarelli M, Barratt J, Beck LH, Fakhouri F, Gale DP, Goicoechea de Jorge E, Mosca M, Noris M, Pickering MC, Susztak K, Thurman JM, Cheung M, King JM, Jadoul M, Winkelmayer WC, Smith RJH. The role of complement in kidney disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference. Kidney Int 2024:S0085-2538(24)00389-2. [PMID: 38844295 DOI: 10.1016/j.kint.2024.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 04/25/2024] [Accepted: 05/22/2024] [Indexed: 06/22/2024]
Abstract
Uncontrolled complement activation can cause or contribute to glomerular injury in multiple kidney diseases. Although complement activation plays a causal role in atypical hemolytic uremic syndrome and C3 glomerulopathy, over the past decade, a rapidly accumulating body of evidence has shown a role for complement activation in multiple other kidney diseases, including diabetic nephropathy and several glomerulonephritides. The number of available complement inhibitor therapies has also increased during the same period. In 2022, Kidney Diseases: Improving Global Outcomes (KDIGO) convened a Controversies Conference, "The Role of Complement in Kidney Disease," to address the expanding role of complement dysregulation in the pathophysiology, diagnosis, and management of various glomerular diseases, diabetic nephropathy, and other forms of hemolytic uremic syndrome. Conference participants reviewed the evidence for complement playing a primary causal or secondary role in progression for several disease states and considered how evidence of complement involvement might inform management. Participating patients with various complement-mediated diseases and caregivers described concerns related to life planning, implications surrounding genetic testing, and the need for inclusive implementation of effective novel therapies into clinical practice. The value of biomarkers in monitoring disease course and the role of the glomerular microenvironment in complement response were examined, and key gaps in knowledge and research priorities were identified.
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Affiliation(s)
- Marina Vivarelli
- Laboratory of Nephrology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
| | - Jonathan Barratt
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Laurence H Beck
- Section of Nephrology, Department of Medicine, Boston Medical Center Boston, Massachusetts, USA; Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, USA
| | - Fadi Fakhouri
- Department of Nephrology, Centre Hospitalier Universitaire, Nantes, France; INSERM UMR S1064, Nantes, France
| | - Daniel P Gale
- Department of Renal Medicine, University College London, UK
| | - Elena Goicoechea de Jorge
- Department of Immunology, Ophthalmology and ORL, Complutense University, Madrid, Spain; Research Institute Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Marta Mosca
- Department of Clinical and Experimental Medicine-Rheumatology Unit, University of Pisa, Pisa, Italy
| | - Marina Noris
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Ranica, Italy
| | - Matthew C Pickering
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College, Hammersmith Campus, London, UK
| | - Katalin Susztak
- Department of Medicine and Nephrology, Albert Einstein College Medicine, Bronx, New York, USA
| | - Joshua M Thurman
- Division of Nephrology and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | | | | | - Michel Jadoul
- Cliniques Universitaires Saint Luc, Université Catholique de Louvain, Brussels, Belgium
| | - Wolfgang C Winkelmayer
- Selzman Institute for Kidney Health, Section of Nephrology, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
| | - Richard J H Smith
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA; Department of Internal Medicine, Division of Nephrology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA; Department of Pediatrics Division of Nephrology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
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2
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Watanabe-Kusunoki K, Anders HJ. Balancing efficacy and safety of complement inhibitors. J Autoimmun 2024; 145:103216. [PMID: 38552408 DOI: 10.1016/j.jaut.2024.103216] [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: 12/20/2023] [Revised: 03/17/2024] [Accepted: 03/26/2024] [Indexed: 05/15/2024]
Abstract
Complement inhibitors have been approved for several immune-mediated diseases and they are considered the next paradigm-shifting approach in the treatment of glomerulonephritis. The hierarchical organization of the complement system offers numerous molecular targets for therapeutic intervention. However, complement is an integral element of host defense and therefore complement inhibition can be associated with serious infectious complications. Here we give a closer look to the hierarchical complement system and how interfering with proximal versus distal or selective versus unselective molecular targets could determine efficacy and safety. Furthermore, we propose to consider the type of disease, immunological activity, and patient immunocompetence when stratifying patients, e.g., proximal/unselective targets for highly active and potentially fatal diseases while distal and selective targets may suit more chronic disease conditions with low or moderate disease activity requiring persistent complement blockade in patients with concomitant immunodeficiency. Certainly, there exists substantial promise for anti-complement therapeutics. However, balancing efficacy and safety will be key to establish powerful treatment effects with minimal adverse events, especially when complement blockade is continued over longer periods of time in chronic disorders.
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Affiliation(s)
- Kanako Watanabe-Kusunoki
- Renal Division, Department of Medicine IV, Ludwig-Maximilians (LMU) University Hospital, LMU Munich, Germany; Department of Rheumatology, Endocrinology and Nephrology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Hans-Joachim Anders
- Renal Division, Department of Medicine IV, Ludwig-Maximilians (LMU) University Hospital, LMU Munich, Germany.
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3
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Del Vecchio L, Allinovi M, Comolli S, Peiti S, Rimoldi C, Locatelli F. Drugs in Development to Treat IgA Nephropathy. Drugs 2024; 84:503-525. [PMID: 38777962 DOI: 10.1007/s40265-024-02036-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2024] [Indexed: 05/25/2024]
Abstract
IgA nephropathy is a common glomerulonephritis consequent to the autoimmune response to aberrant glycosylated immunoglobulin (Ig) A antibodies. Although it has historically been considered a benign disease, it has since become clear that a substantial percentage of patients reach end-stage kidney failure over the years. Several therapeutic attempts have been proposed, with systemic steroids being the most prevalent, albeit burdened by possible serious adverse events. Thanks to the more in-depth knowledge of the pathogenesis of IgA nephropathy, new treatment targets have been identified and new drugs developed. In this narrative review, we summarise the molecules under clinical development for the treatment of IgA nephropathy. As a search strategy, we used PubMed, Google, ClinicalTrials.gov and abstracts from recent international congresses. TRF budesonide and sparsentan are the two molecules at a more advanced stage, just entering the market. Other promising agents are undergoing phase III clinical development. These include anti-APRIL and anti-BLyS/BAFF antibodies and some complement inhibitors. Other new possible strategies include spleen tyrosine kinase inhibitors, anti-CD40 ligands and anti-CD38 antibodies. In an era increasingly characterised by 'personalised medicine' and 'precision therapy' approaches and considering that the potential therapeutic armamentarium for IgA nephropathy will be very broad in the near future, the identification of biomarkers capable of helping the nephrologist to select the right drug for the right patient should be the focus of future studies.
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Affiliation(s)
| | - Marco Allinovi
- Nephrology, Dialysis and Transplantation Unit, Careggi University Hospital, Florence, Italy
| | - Stefania Comolli
- Department of Nephrology and Dialysis, ASST Sette Laghi, Varese, Italy
| | - Silvia Peiti
- Department of Nephrology and Dialysis, ASST Lariana, Como, Italy
| | | | - Francesco Locatelli
- Past Director of the Department of Nephrology and Dialysis, ASST Lecco, Lecco, Italy
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4
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Caravaca-Fontán F, Gutiérrez E, Sevillano ÁM, Praga M. Targeting complement in IgA nephropathy. Clin Kidney J 2023; 16:ii28-ii39. [PMID: 38053977 PMCID: PMC10695513 DOI: 10.1093/ckj/sfad198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Indexed: 12/07/2023] Open
Abstract
Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Recent years have witnessed significant improvements in the understanding of the pathogenesis of IgAN and particularly, the pathogenic role of complement activation. The alternative complement pathway is the major complement cascade activator in IgAN, and glomerular C3 deposition has been shown to correlate with disease progression. In addition, several studies have provided insight into the pathogenic role of factor H-related proteins -1 and -5 in IgAN, as independent players in complement dysregulation. The lectin pathway has also been shown to be associated with the severity of IgAN. Glomerular deposition of C4d has been associated with increased histologic disease activity, faster decline in estimated glomerular filtration rate and higher risk of kidney failure. On the other hand, although overlooked in the Oxford classification, numerous studies have shown that the coexistence of thrombotic microangiopathy in IgAN is a significant indicator of a poorer prognosis. All the breakthroughs in the understanding of the contributing role of complement in IgAN have paved the way for the development of new complement-targeted therapies in this disease. Several ongoing trials are evaluating the efficacy of new agents against factor B (iptacopan, Ionis-FB-LRX), C3 (pegcetacoplan), factor D (vemircopan, pelecopan), C5 (ravulizumab, cemdisiran) and C5a receptor 1 (avacopan). In this study, we provide a comprehensive review of the role of complement in IgAN, including the emerging mechanisms of complement activation and the promising potential of complement inhibitors as a viable treatment option for IgAN.
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Affiliation(s)
- Fernando Caravaca-Fontán
- Department of Nephrology, Instituto de Investigación Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Eduardo Gutiérrez
- Department of Nephrology, Hospital Universitario 12 de Octubre (imas12), Madrid, Spain
| | - Ángel M Sevillano
- Department of Nephrology, Hospital Universitario 12 de Octubre (imas12), Madrid, Spain
| | - Manuel Praga
- Department of Nephrology, Instituto de Investigación Hospital 12 de Octubre (imas12), Madrid, Spain
- Department of Medicine, Complutense University, Madrid, Spain
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5
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Tang B, Yang X. Clinical advances in immunotherapy for immune-mediated glomerular diseases. Clin Exp Med 2023; 23:4091-4105. [PMID: 37889398 PMCID: PMC10725396 DOI: 10.1007/s10238-023-01218-7] [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: 08/25/2023] [Accepted: 10/09/2023] [Indexed: 10/28/2023]
Abstract
BACKGROUND AND OBJECTIVE Due to the suboptimal therapeutic efficacy and potential adverse effects associated with traditional immunosuppressive medications, there has been an increasing emphasis on the development and utilization of immunotherapies. This paper aims to provide clinicians with valuable insights for selecting appropriate therapeutic approaches and contribute to the development of novel immunotherapeutic drugs. MAIN BODY This paper categorizes the immunotherapeutic drugs that are used for the treatment of immune-mediated glomerular diseases into three groups: immunotherapies targeting antigen-presenting cells (anti-CD80), immunotherapies targeting T/B cells (anti-CD20, anti-CD22, BAFF and APRIL inhibitors, CD40-CD40L inhibitors, proteasome inhibitors, Syk inhibitors, and Btk inhibitors), and immunotherapies targeting the complement system (C5 inhibitors, C5a/C5aR inhibitors, C3 inhibitors, MASP2 inhibitors, factor B inhibitors, and factor D inhibitors). The article then provides a comprehensive overview of advances related to these immunotherapeutic drugs in clinical research. CONCLUSION Certain immunotherapeutic drugs, such as rituximab, belimumab, and eculizumab, have exhibited notable efficacy in treating specific immune-mediated glomerular diseases, thereby providing novel therapeutic approaches for patients. Nonetheless, the efficacy of numerous immunotherapeutic drugs remains to be substantiated.
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Affiliation(s)
- Bihui Tang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, Hubei, China
| | - Xiao Yang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, Hubei, China.
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6
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Kang Y, Xu B, Shi S, Zhou X, Chen P, Liu L, Li Y, Leng Y, Lv J, Zhu L, Zhang H. Mesangial C3 Deposition, Complement-Associated Variant, and Disease Progression in IgA Nephropathy. Clin J Am Soc Nephrol 2023; 18:1583-1591. [PMID: 37651123 PMCID: PMC10723908 DOI: 10.2215/cjn.0000000000000290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/25/2023] [Indexed: 09/01/2023]
Abstract
BACKGROUND IgA nephropathy is the most common primary GN worldwide, with dominant deposition of IgA and co-deposits of complement component 3 (C3). Phenotypes and progression of IgA nephropathy varies among different ethnic populations, while patients with IgA nephropathy from Asia showed more severe clinical phenotypes, active kidney lesions, and rapid progression. Our previous genome-wide association study identified complement factor H ( CFH ) variant rs6677604, tightly linked with the deletion of CFH -related protein 3 and CFH -related protein 1 genes ( ΔCFHR3-1 ), as IgA nephropathy susceptible variant, and additionally revealed its effect on complement regulation in IgA nephropathy. METHODS To further explore the effect of rs6677604 on IgA nephropathy progression, here we enrolled a Chinese IgA nephropathy cohort of 1781 patients with regular follow-up for analysis. The rs6677604 genotype was measured, and the genotype-phenotype correlation was analyzed using the t test, the chi-squared test, or the nonparametric test, and the association between rs6677604 genotype or mesangial C3 deposition and IgA nephropathy prognosis was analyzed using Kaplan-Meier analysis and Cox regression. RESULTS We found that patients with rs6677604-GG genotype had a stronger intensity of mesangial C3 deposition than those with the rs6677604-AA/AG genotype. Patients with IgA nephropathy who had stronger intensity of C3 deposition manifested with more severe clinical and pathological manifestations, including lower eGFR and higher Oxford-M/S/T/C (mesangial hypercellularity, endocapillary cellularity, segmental sclerosis, interstitial fibrosis/tubular atrophy, and crescent) scores. In the survival analysis, stronger intensity of mesangial C3 deposition, but not rs6677604-GG genotypes, was associated with poor long-term kidney outcome in IgA nephropathy. CONCLUSIONS We found that in Chinese patients with IgA nephropathy, variant rs6677604 was associated with mesangial C3 deposition, and mesangial C3 deposition, but not rs6677604, was associated with IgA nephropathy severity and progression.
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Affiliation(s)
- Yuqi Kang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Peking University Institute of Nephrology, Beijing, China; Key Laboratory of Renal Disease (Peking University), Beijing, China; National Health Commission, Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China; and State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, Beijing, China
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7
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Rajasekaran A, Green TJ, Renfrow MB, Julian BA, Novak J, Rizk DV. Current Understanding of Complement Proteins as Therapeutic Targets for the Treatment of Immunoglobulin A Nephropathy. Drugs 2023; 83:1475-1499. [PMID: 37747686 PMCID: PMC10807511 DOI: 10.1007/s40265-023-01940-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2023] [Indexed: 09/26/2023]
Abstract
Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide and a frequent cause of kidney failure. Currently, the diagnosis necessitates a kidney biopsy, with routine immunofluorescence microscopy revealing IgA as the dominant or co-dominant immunoglobulin in the glomerular immuno-deposits, often with IgG and sometimes IgM or both. Complement protein C3 is observed in most cases. IgAN leads to kidney failure in 20-40% of patients within 20 years of diagnosis and reduces average life expectancy by about 10 years. There is increasing clinical, biochemical, and genetic evidence that the complement system plays a paramount role in the pathogenesis of IgAN. The presence of C3 in the kidney immuno-deposits differentiates the diagnosis of IgAN from subclinical glomerular mesangial IgA deposition. Markers of complement activation via the lectin and alternative pathways in kidney-biopsy specimens are associated with disease activity and are predictive of poor outcome. Levels of select complement proteins in the circulation have also been assessed in patients with IgAN and found to be of prognostic value. Ongoing genetic studies have identified at least 30 loci associated with IgAN. Genes within some of these loci encode complement-system regulating proteins that can interact with immune complexes. The growing appreciation for the central role of complement components in IgAN pathogenesis highlighted these pathways as potential treatment targets and sparked great interest in pharmacological agents targeting the complement cascade for the treatment of IgAN, as evidenced by the plethora of ongoing clinical trials.
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Affiliation(s)
- Arun Rajasekaran
- Division of Nephrology, Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Todd J Green
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Matthew B Renfrow
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Bruce A Julian
- Division of Nephrology, Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jan Novak
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Dana V Rizk
- Division of Nephrology, Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
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8
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Duval A, Olagne J, Obrecht A, Vargas GG, Perrin P, Moulin B, Frémeaux-Bacchi V, Caillard S. Eculizumab as a therapeutic approach for severe crescentic recurrence of immunoglobulin A nephropathy after kidney transplantation. Am J Transplant 2023; 23:1626-1630. [PMID: 37268295 DOI: 10.1016/j.ajt.2023.05.031] [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: 03/02/2023] [Revised: 05/22/2023] [Accepted: 05/26/2023] [Indexed: 06/04/2023]
Abstract
Crescentic forms of immunoglobulin A nephropathy (IgAN) are rare but can be associated with rapid kidney failure and a high rate of end-stage renal disease despite immunosuppression therapy. Complement activation has emerged as a key driver of glomerular injury in IgAN. Therefore, complement inhibitors may be a rational treatment option in patients unresponsive to first-line immunosuppressive therapy. Here, we describe the case of a 24-year-old woman presenting with crescentic IgAN recurrence a few months after living kidney transplantation. Considering the dramatic graft failure accompanied by malignant hypertension and thrombotic microangiopathy features worsening after a first-line of high-dose steroids and 3 sessions of plasma exchanges, eculizumab was started as a rescue therapy. For the first time, the clinical response to eculizumab was highly successful, with a complete graft recovery without any relapse after 1 year of treatment. Further clinical studies are strongly needed to specify which patients might benefit from terminal complement blockade.
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Affiliation(s)
- Anna Duval
- Department of nephrology, dialysis and transplantation, University Hospital of Strasbourg, Strasbourg, Bas Rhin, France; Inserm UMRS 1109 Molecular Immuno Rheumatology, University of Strasbourg, Strasbourg, Bas Rhin, France; Inserm UMRS 1138, Complement and diseases, Cordeliers' research center, Paris, France.
| | - Jérôme Olagne
- Department of nephrology, dialysis and transplantation, University Hospital of Strasbourg, Strasbourg, Bas Rhin, France; Department of pathology, University Hospital of Strasbourg, Strasbourg, Bas Rhin, France
| | - Augustin Obrecht
- Department of nephrology, dialysis and transplantation, University Hospital of Strasbourg, Strasbourg, Bas Rhin, France
| | - Gabriela Gautier Vargas
- Department of nephrology, dialysis and transplantation, University Hospital of Strasbourg, Strasbourg, Bas Rhin, France
| | - Peggy Perrin
- Department of nephrology, dialysis and transplantation, University Hospital of Strasbourg, Strasbourg, Bas Rhin, France
| | - Bruno Moulin
- Department of nephrology, dialysis and transplantation, University Hospital of Strasbourg, Strasbourg, Bas Rhin, France; Inserm UMRS 1109 Molecular Immuno Rheumatology, University of Strasbourg, Strasbourg, Bas Rhin, France
| | - Véronique Frémeaux-Bacchi
- Inserm UMRS 1138, Complement and diseases, Cordeliers' research center, Paris, France; Service d'immunologie Biologique, Hôpital Européen Georges Pompidou, Assistance publique des Hôpitaux de Paris, Paris, France
| | - Sophie Caillard
- Department of nephrology, dialysis and transplantation, University Hospital of Strasbourg, Strasbourg, Bas Rhin, France; Inserm UMRS 1109 Molecular Immuno Rheumatology, University of Strasbourg, Strasbourg, Bas Rhin, France
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9
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Tesař V, Radhakrishnan J, Charu V, Barratt J. Challenges in IgA Nephropathy Management: An Era of Complement Inhibition. Kidney Int Rep 2023; 8:1730-1740. [PMID: 37705895 PMCID: PMC10496078 DOI: 10.1016/j.ekir.2023.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/01/2023] [Accepted: 06/12/2023] [Indexed: 09/15/2023] Open
Abstract
IgA nephropathy (IgAN) is the most common glomerular disease worldwide, with an estimated annual incidence of 25 per million adults. Despite optimized supportive care, some patients fail to achieve disease control and suffer progressive deterioration of kidney function. In this subpopulation of patients, the Kidney Disease: Improving Global Outcomes 2021 guidelines recommend consideration of corticosteroids; however, their use is associated with significant side effects. Ongoing clinical trials are expected to identify corticosteroid-sparing therapies to help improve treatment and prognosis for patients with IgAN. It has been well-documented that the complement system plays a significant role in IgAN pathogenesis, and several complement inhibitors are now entering late-stage clinical development. This review evaluates what we know about the role of complement in the pathophysiology of IgAN and considers how the availability of targeted complement inhibitors may impact future clinical practice. Key knowledge gaps are evaluated, and research opportunities are recommended to help guide clinical decision-making and optimize patient outcomes. Such gaps include evaluating the relative contribution of the alternative and lectin pathways to disease pathogenesis, and the importance of determining the dominant pathway driving IgAN progression. Continued research into the staining of complement proteins in kidney biopsies and identifying targeted biomarkers to assess disease progression and treatment responses will also be needed to support the implementation of newer therapies in clinical practice. Considering the future horizons for enhancing the care of patients with IgAN, tackling the outstanding challenges now will help prepare for the best possible future outcomes.
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Affiliation(s)
- Vladimir Tesař
- Department of Nephrology, Charles University, Prague, Czech Republic
| | | | - Vivek Charu
- Department of Pathology, Stanford University, Palo Alto, California, USA
| | - Jonathan Barratt
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
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10
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Cheung CK, Dormer JP, Barratt J. The role of complement in glomerulonephritis-are novel therapies ready for prime time? Nephrol Dial Transplant 2023; 38:1789-1797. [PMID: 36307926 DOI: 10.1093/ndt/gfac296] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Indexed: 08/01/2023] Open
Abstract
The complement system plays a key pathogenic role in glomerular diseases with a diverse range of aetiologies, including C3 glomerulopathy, immunoglobulin A nephropathy, membranous nephropathy, ANCA-associated vasculitis and lupus nephritis. Several novel therapies targeting complement activity have recently been developed, which have now been approved or are in the late stages of clinical development. In this review, potential benefits and challenges of targeting the complement system in glomerular disease are discussed. We summarize current understanding of the role of complement, and the novel targeted therapies that are being developed for the treatment of glomerular disease.
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Affiliation(s)
- Chee Kay Cheung
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - John P Dormer
- Department of Histopathology, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Jonathan Barratt
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
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11
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Guo Y, Zhang H, Yu X. A bibliometric analysis of complement in IgA nephropathy from 1991 to 2022. Front Pharmacol 2023; 14:1200193. [PMID: 37576817 PMCID: PMC10414182 DOI: 10.3389/fphar.2023.1200193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/17/2023] [Indexed: 08/15/2023] Open
Abstract
Introduction: IgA nephropathy is a common glomerular disease on a global scale, which has resulted in significant economic burdens. The complement system plays a vital role in enhancing the efficacy of antibodies and phagocytic cells in eliminating microbes and damaged cells, and promoting inflammation. Complement activation has been found to contribute to the progression of various renal diseases, including IgA nephropathy. Methods: In this study, a thorough analysis was conducted on publications related to complement in IgAN from 1991 to 2022, retrieved from the Web of Science Core Collection and Scopus database. The analysis focused on various aspects such as annual publications, country, institution, author, journal, keywords, and co-cited references, utilizing Citespace and Vosviewer. Results: A total of 819 publications were obtained, and while there were slight fluctuations in annual publications, an overall upward trend was observed. China, Japan and the United States were the leading countries in terms of publications, with China having the highest number of publications (201). Collaborative network analysis revealed that England, University of Alabama Birmingham, and Robert J Wyatt were the most influential country, institution, and author, respectively, in this field of research. Furthermore, the analysis of references and keywords indicated that complement activation contributes to IgAN, and immunosuppression in IgAN are a hot topic of research. Discussion: This study identifies current research hotspots and advanced tendencies in the study of complement in IgAN, providing scholars with crucial directions in this research area.
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Affiliation(s)
- Yun Guo
- The First Clinical Medical College, Guangdong Medical University, Zhanjiang, China
- Department of Nephrology, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | | | - Xueqing Yu
- The First Clinical Medical College, Guangdong Medical University, Zhanjiang, China
- Department of Nephrology, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
- Guangdong-Hong Kong Joint Laboratory on Immunological and Genetic Kidney Diseases, Guangzhou, China
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12
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Gentile M, Sanchez-Russo L, Riella LV, Verlato A, Manrique J, Granata S, Fiaccadori E, Pesce F, Zaza G, Cravedi P. Immune abnormalities in IgA nephropathy. Clin Kidney J 2023; 16:1059-1070. [PMID: 37398689 PMCID: PMC10310525 DOI: 10.1093/ckj/sfad025] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Indexed: 09/10/2023] Open
Abstract
Immunoglobulin A (IgA) nephropathy (IgAN) is the most common primary glomerulonephritis worldwide and it is characterized by mesangial IgA deposition. Asymptomatic hematuria with various degrees of proteinuria is the most common clinical presentation and up to 20%-40% of patients develop end-stage kidney disease within 20 years after disease onset. The pathogenesis of IgAN involves four sequential processes known as the "four-hit hypothesis" which starts with the production of a galactose-deficient IgA1 (gd-IgA1), followed by the formation of anti-gd-IgA1 IgG or IgA1 autoantibodies and immune complexes that ultimately deposit in the glomerular mesangium, leading to inflammation and injury. Although several key questions about the production of gd-IgA1 and the formation of anti-gd-IgA1 antibodies remain unanswered, a growing body of evidence is shedding light on the innate and adaptive immune mechanisms involved in this complex pathogenic process. Herein, we will focus on these mechanisms that, along with genetic and environmental factors, are thought to play a key role in disease pathogenesis.
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Affiliation(s)
- Micaela Gentile
- Translational Transplant Research Center and Department of Medicine, Icahn School of Medicine at Mount Sinai, NY, USA
- UO Nefrologia, Dipartimento di Medicina e Chirurgia, Università di Parma, Parma, Italy
| | - Luis Sanchez-Russo
- Translational Transplant Research Center and Department of Medicine, Icahn School of Medicine at Mount Sinai, NY, USA
| | - Leonardo V Riella
- Division of Nephrology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Alberto Verlato
- Translational Transplant Research Center and Department of Medicine, Icahn School of Medicine at Mount Sinai, NY, USA
| | - Joaquin Manrique
- Nephrology Service, Complejo Hospitalario de Navarra, Pamplona, Spain
| | - Simona Granata
- Nephrology, Dialysis and Transplantation Unit, University of Foggia, Foggia, Italy
| | - Enrico Fiaccadori
- UO Nefrologia, Dipartimento di Medicina e Chirurgia, Università di Parma, Parma, Italy
| | - Francesco Pesce
- Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari “A. Moro”, Bari, Italy
| | - Gianluigi Zaza
- Nephrology, Dialysis and Transplantation Unit, University of Foggia, Foggia, Italy
| | - Paolo Cravedi
- Translational Transplant Research Center and Department of Medicine, Icahn School of Medicine at Mount Sinai, NY, USA
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Erger F, Aryal RP, Reusch B, Matsumoto Y, Meyer R, Zeng J, Knopp C, Noel M, Muerner L, Wenzel A, Kohl S, Tschernoster N, Rappl G, Rouvet I, Schröder-Braunstein J, Seibert FS, Thiele H, Häusler MG, Weber LT, Büttner-Herold M, Elbracht M, Cummings SF, Altmüller J, Habbig S, Cummings RD, Beck BB. Germline C1GALT1C1 mutation causes a multisystem chaperonopathy. Proc Natl Acad Sci U S A 2023; 120:e2211087120. [PMID: 37216524 PMCID: PMC10235935 DOI: 10.1073/pnas.2211087120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 03/28/2023] [Indexed: 05/24/2023] Open
Abstract
Mutations in genes encoding molecular chaperones can lead to chaperonopathies, but none have so far been identified causing congenital disorders of glycosylation. Here we identified two maternal half-brothers with a novel chaperonopathy, causing impaired protein O-glycosylation. The patients have a decreased activity of T-synthase (C1GALT1), an enzyme that exclusively synthesizes the T-antigen, a ubiquitous O-glycan core structure and precursor for all extended O-glycans. The T-synthase function is dependent on its specific molecular chaperone Cosmc, which is encoded by X-chromosomal C1GALT1C1. Both patients carry the hemizygous variant c.59C>A (p.Ala20Asp; A20D-Cosmc) in C1GALT1C1. They exhibit developmental delay, immunodeficiency, short stature, thrombocytopenia, and acute kidney injury (AKI) resembling atypical hemolytic uremic syndrome. Their heterozygous mother and maternal grandmother show an attenuated phenotype with skewed X-inactivation in blood. AKI in the male patients proved fully responsive to treatment with the complement inhibitor Eculizumab. This germline variant occurs within the transmembrane domain of Cosmc, resulting in dramatically reduced expression of the Cosmc protein. Although A20D-Cosmc is functional, its decreased expression, though in a cell or tissue-specific manner, causes a large reduction of T-synthase protein and activity, which accordingly leads to expression of varied amounts of pathological Tn-antigen (GalNAcα1-O-Ser/Thr/Tyr) on multiple glycoproteins. Transient transfection of patient lymphoblastoid cells with wild-type C1GALT1C1 partially rescued the T-synthase and glycosylation defect. Interestingly, all four affected individuals have high levels of galactose-deficient IgA1 in sera. These results demonstrate that the A20D-Cosmc mutation defines a novel O-glycan chaperonopathy and causes the altered O-glycosylation status in these patients.
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Affiliation(s)
- Florian Erger
- Institute of Human Genetics, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50931Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, 50931Cologne, Germany
| | - Rajindra P. Aryal
- Division of Surgical Sciences, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA02215
| | - Björn Reusch
- Institute of Human Genetics, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50931Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, 50931Cologne, Germany
| | - Yasuyuki Matsumoto
- Division of Surgical Sciences, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA02215
| | - Robert Meyer
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, Rheinisch-Westfälische Technische Hochschule Aachen University, 52074Aachen, Germany
| | - Junwei Zeng
- Division of Surgical Sciences, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA02215
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510080Guangzhou, China
| | - Cordula Knopp
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, Rheinisch-Westfälische Technische Hochschule Aachen University, 52074Aachen, Germany
| | - Maxence Noel
- Division of Surgical Sciences, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA02215
| | - Lukas Muerner
- Division of Surgical Sciences, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA02215
- Institute of Pharmacology, University of Bern, 3010Bern, Switzerland
| | - Andrea Wenzel
- Institute of Human Genetics, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50931Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, 50931Cologne, Germany
| | - Stefan Kohl
- Children’s and Adolescents’ Hospital, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50937Cologne, Germany
| | - Nikolai Tschernoster
- Institute of Human Genetics, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50931Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, 50931Cologne, Germany
- Cologne Center for Genomics, University of Cologne, 50931Cologne, Germany
| | - Gunter Rappl
- Center for Molecular Medicine Cologne, University of Cologne, 50931Cologne, Germany
| | - Isabelle Rouvet
- Centre de Biotechnologie Cellulaire and CBC BioTec Biobank, Centre de Ressources Biologiques, Hospices Civils de Lyon, 69229Lyon, France
| | | | - Felix S. Seibert
- Medical Department I, University Hospital Marien Hospital Herne, Ruhr-University Bochum, 44625Herne, Germany
| | - Holger Thiele
- Cologne Center for Genomics, University of Cologne, 50931Cologne, Germany
| | - Martin G. Häusler
- Division of Neuropediatrics and Social Pediatrics, Department of Pediatrics, Medical Faculty, Rheinisch-Westfälische Technische Hochschule Aachen University, 52074Aachen, Germany
| | - Lutz T. Weber
- Children’s and Adolescents’ Hospital, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50937Cologne, Germany
| | - Maike Büttner-Herold
- Department of Nephropathology, Institute of Pathology, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), 91054Erlangen, Germany
| | - Miriam Elbracht
- Institute for Human Genetics and Genomic Medicine, Medical Faculty, Rheinisch-Westfälische Technische Hochschule Aachen University, 52074Aachen, Germany
| | - Sandra F. Cummings
- Division of Surgical Sciences, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA02215
| | - Janine Altmüller
- Center for Molecular Medicine Cologne, University of Cologne, 50931Cologne, Germany
- Cologne Center for Genomics, University of Cologne, 50931Cologne, Germany
- Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Core Facility Genomics, 10178Berlin, Germany
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125Berlin, Germany
| | - Sandra Habbig
- Children’s and Adolescents’ Hospital, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50937Cologne, Germany
| | - Richard D. Cummings
- Division of Surgical Sciences, Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA02215
| | - Bodo B. Beck
- Institute of Human Genetics, University Hospital Cologne, Faculty of Medicine, University of Cologne, 50931Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, 50931Cologne, Germany
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Trambas IA, Coughlan MT, Tan SM. Therapeutic Potential of Targeting Complement C5a Receptors in Diabetic Kidney Disease. Int J Mol Sci 2023; 24:ijms24108758. [PMID: 37240105 DOI: 10.3390/ijms24108758] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Diabetic kidney disease (DKD) affects 30-40% of patients with diabetes and is currently the leading cause of end-stage renal disease (ESRD). The activation of the complement cascade, a highly conserved element of the innate immune system, has been implicated in the pathogenesis of diabetes and its complications. The potent anaphylatoxin C5a is a critical effector of complement-mediated inflammation. Excessive activation of the C5a-signalling axis promotes a potent inflammatory environment and is associated with mitochondrial dysfunction, inflammasome activation, and the production of reactive oxygen species. Conventional renoprotective agents used in the treatment of diabetes do not target the complement system. Mounting preclinical evidence indicates that inhibition of the complement system may prove protective in DKD by reducing inflammation and fibrosis. Targeting the C5a-receptor signaling axis is of particular interest, as inhibition at this level attenuates inflammation while preserving the critical immunological defense functions of the complement system. In this review, the important role of the C5a/C5a-receptor axis in the pathogenesis of diabetes and kidney injuries will be discussed, and an overview of the status and mechanisms of action of current complement therapeutics in development will be provided.
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Affiliation(s)
- Inez A Trambas
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Melinda T Coughlan
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
| | - Sih Min Tan
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, VIC 3004, Australia
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Selvaskandan H, Gonzalez-Martin G, Barratt J, Cheung CK. IgA nephropathy: an overview of drug treatments in clinical trials. Expert Opin Investig Drugs 2022; 31:1321-1338. [PMID: 36588457 DOI: 10.1080/13543784.2022.2160315] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION IgA nephropathy (IgAN) is the commonest primary glomerulonephritis worldwide and may progress to end-stage kidney disease (ESKD) within a 10-20 year period. Its slowly progressive course has made clinical trials challenging to perform, however the acceptance of proteinuria reduction as a surrogate end point has significantly improved the feasibility of conducting clinical trials in IgAN, with several novel and repurposed therapies currently undergoing assessment. Already, interim results are demonstrating value to some of these, offering great hope to those with IgAN. AREAS COVERED This review explores the rationale, candidates, clinical precedents, and trial status of therapies that are currently or have recently been evaluated for efficacy in IgAN. All IgAN trials registered with the U.S. National Library of Medicine; ClinicalTrials.gov were reviewed. EXPERT OPINION For the first time, effective treatment options beyond supportive care are becoming available for those with IgAN. This is the culmination of commendable international efforts and signifies a new era for those with IgAN. As more therapies become available, future challenges will revolve around deciding which treatments are most appropriate for individual patients, which is likely to push IgAN into the realm of precision medicine.
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Affiliation(s)
- Haresh Selvaskandan
- John Walls Renal Unit, University Hospitals Leicester NHS Trust, Leicester, UK.,Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | | | - Jonathan Barratt
- John Walls Renal Unit, University Hospitals Leicester NHS Trust, Leicester, UK.,Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Chee Kay Cheung
- John Walls Renal Unit, University Hospitals Leicester NHS Trust, Leicester, UK.,Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
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王 梓, 张 军, 左 力, 王 悦, 李 文, 程 虹, 蔡 广, 裴 华, 王 利, 周 绪, 师 素, 刘 立, 吕 继, 张 宏. [Efficacy of plasma exchange in severe crescentic IgA nephropathy: A multicentered, cohort study]. BEIJING DA XUE XUE BAO. YI XUE BAN = JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2022; 54:1038-1046. [PMID: 36241249 PMCID: PMC9568402 DOI: 10.19723/j.issn.1671-167x.2022.05.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Indexed: 06/16/2023]
Abstract
OBJECTIVE To evaluate the efficacy of plasma exchange therapy on crescentic IgA nephropathy (IgAN). METHODS A retrospective analysis was performed in a cohort of patients with crescentic IgAN from January 2012 to September 2020 at 9 sites across China. Clinical and pathological data, as well as therapeutic regimens, were collected. In order to minimize the effect of potential confounders in baseline characteristics, propensity score matching using a 1 ∶1 ratio nearest neighbor algorithm was performed between the adjunctive plasma exchange therapy group and the intensive immunosuppressive therapy group. The primary outcome was end-stage of kidney disease (ESKD). Kaplan-Meier method was used to compare the difference in renal survival between the two groups. RESULTS A total of 95 crescentic IgAN patients with acute kidney disease were included in this study, including 37 (38.9%) patients receiving adjunctive plasma exchange therapy, and 58 (61.1%) patients receiving intensive immunosuppressive therapy. In the whole cohort, the baseline eGFR was 12.77 (7.28, 21.29) mL/(min·1.73 m2), 24-hour urinary protein quantification was 5.9 (4.0, 8.9) g, and crescent percentage was 64.71% (54.55%, 73.68%). In the study, 23 patients in each group were matched after propensity score matching The median follow-up time was 7 (1, 26) months. As a whole, 29 patients (63.0%) reached ESKD, including 16 patients (69.6%) in the adjunctive plasma exchange therapy group and 13 (56.5%) patients in the intensive immunosuppressive therapy group.. There were no stastical difference between the two groups in terms of baseline eGFR [14.30 (9.31, 17.58) mL/(min·1.73 m2) vs. 11.45 (5.59, 20.79) mL/(min·1.73 m2)], 24-hour urinary protein (7.4±3.4) g vs. (6.6±3.8) g, crescent percentage 64.49%±13.23% vs. 66.41%±12.65% and the proportion of patients received steroid therapy[23 (100.0%) vs. 21 (91.3%)] (All P>0.05). Kaplan-Meier survival analysis demonstrated that there was no significant difference in renal survival rate between the two groups (Log-rank test, P=0.933). CONCLUSION The adjunctive plasma exchange therapy in addition to conventional intense immunosuppressive therapy did not additionally improve the prognosis of crescentic IgA nephropathy.
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Affiliation(s)
- 梓 王
- 北京大学第一医院肾内科,北京大学肾脏疾病研究所,卫生部肾脏疾病重点实验室,慢性肾脏病防治教育部重点实验室(北京大学),中国医学科学院免疫介导肾病诊治创新单元,北京 100034Renal Division, Peking University First Hospital; Institute of Nephrology, Peking University; Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Research Units of Diagnosis and Treatment of lmmune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing 100191, China
| | - 军军 张
- 郑州大学附属第一医院肾内科,郑州 450052Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - 力 左
- 北京大学人民医院肾内科,北京 100044Department of Nephrology, Peking University People's Hospital, Beijing 100044, China
| | - 悦 王
- 北京大学第三医院肾内科,北京 100191Department of Nephrology, Peking University Third Hospital, Beijing 100191, China
| | - 文歌 李
- 中日友好医院肾内科,北京 100029Department of Nephrology, China-Japan Friendship Hospital, Beijing 100029, China
| | - 虹 程
- 首都医科大学附属北京安贞医院肾内科,北京 10029Division of Nephrology, Beijing Anzhen Hospital, Capital Medical University, Beijing 10029, China
| | - 广研 蔡
- 中国人民解放军总医院肾内科,北京 100853Department of Nephrology, Chinese PLA General Hospital, Beijing 100853, China
| | - 华颖 裴
- 河北医科大学第二医院肾内科,石家庄 050000Renal Division, Department of Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - 利华 王
- 山西医科大学第二医院肾内科,太原 030001Renal Division, Shanxi Medical University Second Affiliated Hospital, Taiyuan 030001, China
| | - 绪杰 周
- 北京大学第一医院肾内科,北京大学肾脏疾病研究所,卫生部肾脏疾病重点实验室,慢性肾脏病防治教育部重点实验室(北京大学),中国医学科学院免疫介导肾病诊治创新单元,北京 100034Renal Division, Peking University First Hospital; Institute of Nephrology, Peking University; Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Research Units of Diagnosis and Treatment of lmmune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing 100191, China
| | - 素芳 师
- 北京大学第一医院肾内科,北京大学肾脏疾病研究所,卫生部肾脏疾病重点实验室,慢性肾脏病防治教育部重点实验室(北京大学),中国医学科学院免疫介导肾病诊治创新单元,北京 100034Renal Division, Peking University First Hospital; Institute of Nephrology, Peking University; Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Research Units of Diagnosis and Treatment of lmmune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing 100191, China
| | - 立军 刘
- 北京大学第一医院肾内科,北京大学肾脏疾病研究所,卫生部肾脏疾病重点实验室,慢性肾脏病防治教育部重点实验室(北京大学),中国医学科学院免疫介导肾病诊治创新单元,北京 100034Renal Division, Peking University First Hospital; Institute of Nephrology, Peking University; Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Research Units of Diagnosis and Treatment of lmmune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing 100191, China
| | - 继成 吕
- 北京大学第一医院肾内科,北京大学肾脏疾病研究所,卫生部肾脏疾病重点实验室,慢性肾脏病防治教育部重点实验室(北京大学),中国医学科学院免疫介导肾病诊治创新单元,北京 100034Renal Division, Peking University First Hospital; Institute of Nephrology, Peking University; Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Research Units of Diagnosis and Treatment of lmmune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing 100191, China
| | - 宏 张
- 北京大学第一医院肾内科,北京大学肾脏疾病研究所,卫生部肾脏疾病重点实验室,慢性肾脏病防治教育部重点实验室(北京大学),中国医学科学院免疫介导肾病诊治创新单元,北京 100034Renal Division, Peking University First Hospital; Institute of Nephrology, Peking University; Key Laboratory of Renal Disease, Ministry of Health of China; Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Research Units of Diagnosis and Treatment of lmmune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing 100191, China
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Specific immune biomarker monitoring in two children with severe IgA nephropathy and successful therapy with immunoadsorption in a rapidly progressive case. Pediatr Nephrol 2022; 37:1597-1603. [PMID: 34997322 DOI: 10.1007/s00467-021-05381-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 10/01/2021] [Accepted: 11/04/2021] [Indexed: 10/19/2022]
Abstract
BACKGROUND Childhood IgA nephropathy (cIgAN) is one of the most common primary glomerulonephritides with the potential to evolve to kidney failure. IgAN is an autoimmune disease involving 3 key factors: galactose-deficient IgA1 (Gd-IgA1), anti-IgA1 autoantibodies, and soluble (s)CD89 IgA Fc receptor. These molecules and immune complexes have been described recently as potential biomarkers of disease progression in childhood IgAN but their evolution in time under immunosuppressive treatment remains unknown. METHODS We performed a prospective study of two proliferative cIgAN patients by sequentially biomonitoring immune IgA complexes (sCD89-IgA, IgG-IgA), sCD89, and Gd-IgA1 and correlating them with clinical and histological outcome after treatment. RESULTS After patient 1's treatment, a decrease in sCD89-IgA, IgG-IgA, and free sCD89 was linked to a decrease in proteinuria whereas eGFR (estimated glomerular filtration rate) and Gd-IgA1 levels remained stable. Patient 1 received tacrolimus and monthly intramuscular steroid injections of Kenacort for 10 months. At the end, a relapse induced an increase in proteinuria consistent with an increase of the 3 biomarkers. Patient 2 displayed rapidly progressive IgAN with crescents in more than 90% of glomeruli and received intense immunosuppression treatment associated with the immunoadsorption (IA) approach. During IA, proteinuria decreased rapidly, as well as levels of CD89-IgA, IgG-IgA, sCD89, and Gd-IgA1 biomarkers. After discontinuation of IA, proteinuria increased as well as IgG-IgA complexes whereas sCD89-IgA and sCD89 remained low. Further re-intensification of IA and addition of cyclophosphamide improved proteinuria again with reduced IgG-IgA. A second biopsy was performed showing a reduction of extracapillary proliferation to 6% of glomeruli and only 9% glomerulsoclerosis. CONCLUSIONS In conclusion, sequential biomonitoring of Gd-IgA1, IgA-immune complexes, and sCD89 in cIgAN was found to be valuable, by correlating with clinical features and glomerular proliferative lesions in cIgAN. These biomarkers could represent useful tools to evaluate kidney injury without repeat kidney biopsies.
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Efficacy and safety of artesunate for patients with IgA nephropathy: a study protocol for a multicenter, double-blind, randomized, placebo-controlled trial. Trials 2022; 23:444. [PMID: 35614482 PMCID: PMC9134594 DOI: 10.1186/s13063-022-06336-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 02/15/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND IgA nephropathy is the most common glomerular disease and is a common cause of progression to end-stage renal disease in patients with kidney diseases. Proteinuria levels are critical for the prognosis of patients with IgA nephropathy, but many patients are still unable to effectively control their proteinuria levels after receiving RAAS blockers. Antimalarial drugs have shown good efficacy in the treatment of kidney disease in previous studies; however, there have been no strictly designed randomized controlled trials to confirm the clinical efficacy of artesunate for treating IgA nephropathy patients. Therefore, we designed this clinical trial to compare the effect of artesunate versus placebo in patients with IgA nephropathy. METHODS This study is a randomized, double-blind, three-group-parallel, placebo-controlled clinical trial. One hundred and twenty eligible IgA nephropathy patients at risk of progression will be randomly divided into the artesunate 100-mg group, artesunate 50-mg group, and placebo group. Changes in proteinuria and renal function will be measured 6 months after the intervention. The levels of Gd-IgA1 and anti-Gd-IgA1 in the patient's blood will also be tested to explore the possible immune mechanisms. DISCUSSION Clinical evidence supporting artesunate treatment of IgA nephropathy is currently lacking, and we expect that the results of this trial will provide high-quality clinical evidence for artesunate as a treatment option for IgA nephropathy in the future. TRIAL REGISTRATION Chinese Clinical Trial Registry ChiCTR2000038104 . Registered on 10 September 2020.
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New Insights into the Treatment of Glomerular Diseases: When Mechanisms Become Vivid. Int J Mol Sci 2022; 23:ijms23073525. [PMID: 35408886 PMCID: PMC8998908 DOI: 10.3390/ijms23073525] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 03/18/2022] [Accepted: 03/22/2022] [Indexed: 12/23/2022] Open
Abstract
Treatment for glomerular diseases has been extrapolated from the experience of other autoimmune disorders while the underlying pathogenic mechanisms were still not well understood. As the classification of glomerular diseases was based on patterns of juries instead of mechanisms, treatments were typically the art of try and error. With the advancement of molecular biology, the role of the immune agent in glomerular diseases is becoming more evident. The four-hit theory based on the discovery of gd-IgA1 gives a more transparent outline of the pathogenesis of IgA nephropathy (IgAN), and dysregulation of Treg plays a crucial role in the pathogenesis of minimal change disease (MCD). An epoch-making breakthrough is the discovery of PLA2R antibodies in the primary membranous nephropathy (pMN). This is the first biomarker applied for precision medicine in kidney disease. Understanding the immune system’s role in glomerular diseases allows the use of various immunosuppressants or other novel treatments, such as complement inhibitors, to treat glomerular diseases more reasonable. In this era of advocating personalized medicine, it is inevitable to develop precision medicine with mechanism-based novel biomarkers and novel therapies in kidney disease.
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20
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Werion A, Rondeau E. Application of C5 inhibitors in glomerular diseases in 2021. Kidney Res Clin Pract 2022; 41:412-421. [PMID: 35354244 PMCID: PMC9346396 DOI: 10.23876/j.krcp.21.248] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 01/17/2022] [Indexed: 11/04/2022] Open
Abstract
The complement pathway is an essential mechanism in innate immunity, but it is also involved in multiple pathologies. For kidney diseases, strong evidence of a dysregulation in the alternative pathway in atypical hemolytic uremic syndrome (aHUS) led to the use of eculizumab, the first anti-C5 inhibitor available in clinical practice. Intensive fundamental research resulted in the development of subsequent new drugs, such as long-acting C5 inhibitors, oral medications, or antagonists of C5aR, the receptor for C5a. New data in the domain of C5-inhibition in glomerular diseases are still limited and mainly focus on 1) the efficacy of ravulizumab, a long-acting C5 inhibitor in aHUS, and 2) the use of avacopan, a C5aR antagonist, in antineutrophil cytoplasmic antibody vasculitis. Several new studies ongoing or planned for the next few years will evaluate the efficacy of C5 inhibition in secondary thrombotic microangiopathy, C3 glomerulopathy, membranous nephropathy, or immunoglobulin A nephropathy.
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Affiliation(s)
- Alexis Werion
- Intensive Care and Acute Nephrology Department, SINRA, Hospital Tenon, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Eric Rondeau
- Intensive Care and Acute Nephrology Department, SINRA, Hospital Tenon, Assistance Publique-Hôpitaux de Paris, Paris, France
- Correspondence: Eric Rondeau Intensive Care and Acute Nephrology Department, SINRA, Hospital Tenon, Rue de la Chine 4, 75020 Paris, France. E-mail:
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21
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Chan M, Hanna MG, Willard N, Treece A, Dixon BP. Hypocomplementemic Atypical IgA Vasculitis: A Case Report. Front Pediatr 2022; 10:886371. [PMID: 35757129 PMCID: PMC9218267 DOI: 10.3389/fped.2022.886371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/13/2022] [Indexed: 12/02/2022] Open
Abstract
IgA vasculitis (IgAV, also known as Henoch-Schönlein purpura or HSP) is a vasculitis of small vessels involving multiple organs, particularly of the joints, gastrointestinal tract, skin, and kidneys. Growing laboratory evidence has shown that complement plays a key role in the pathogenesis of IgAV, although direct evidence of this association in patients is lacking. We report a child with IgAV associated with clinical features of hypertension, nephrotic range proteinuria, acute kidney injury, and low serum C3, with histopathologic findings on renal biopsy of membranoproliferative glomerulonephritis with C3 and IgA co-dominance, and extensive complement derangements. This case report suggests that complement modifies the pathogenesis of IgAV, and further investigation into complement-targeted therapy in cases of refractory IgAV may be beneficial.
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Affiliation(s)
- Melvin Chan
- Department of Pediatric Nephrology, Children's Hospital Colorado, Aurora, CO, United States
| | - Melisha Gayle Hanna
- Department of Pediatric Nephrology, Children's Hospital Colorado, Aurora, CO, United States
| | - Nicholas Willard
- Department of Pathology, School of Medicine, University of Colorado, Aurora, CO, United States
| | - Amy Treece
- Department of Pathology, School of Medicine, University of Colorado, Aurora, CO, United States
| | - Bradley Patton Dixon
- Department of Pediatric Nephrology, Children's Hospital Colorado, Aurora, CO, United States
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22
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Freiwald T, Afzali B. Renal diseases and the role of complement: Linking complement to immune effector pathways and therapeutics. Adv Immunol 2021; 152:1-81. [PMID: 34844708 PMCID: PMC8905641 DOI: 10.1016/bs.ai.2021.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The complement system is an ancient and phylogenetically conserved key danger sensing system that is critical for host defense against pathogens. Activation of the complement system is a vital component of innate immunity required for the detection and removal of pathogens. It is also a central orchestrator of adaptive immune responses and a constituent of normal tissue homeostasis. Once complement activation occurs, this system deposits indiscriminately on any cell surface in the vicinity and has the potential to cause unwanted and excessive tissue injury. Deposition of complement components is recognized as a hallmark of a variety of kidney diseases, where it is indeed associated with damage to the self. The provenance and the pathophysiological role(s) played by complement in each kidney disease is not fully understood. However, in recent years there has been a renaissance in the study of complement, with greater appreciation of its intracellular roles as a cell-intrinsic system and its interplay with immune effector pathways. This has been paired with a profusion of novel therapeutic agents antagonizing complement components, including approved inhibitors against complement components (C)1, C3, C5 and C5aR1. A number of clinical trials have investigated the use of these more targeted approaches for the management of kidney diseases. In this review we present and summarize the evidence for the roles of complement in kidney diseases and discuss the available clinical evidence for complement inhibition.
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Affiliation(s)
- Tilo Freiwald
- Immunoregulation Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Bethesda, MD, United States; Department of Nephrology, University Hospital Frankfurt, Goethe-University, Frankfurt am Main, Germany
| | - Behdad Afzali
- Department of Nephrology, University Hospital Frankfurt, Goethe-University, Frankfurt am Main, Germany.
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23
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Poppelaars F, Faria B, Schwaeble W, Daha MR. The Contribution of Complement to the Pathogenesis of IgA Nephropathy: Are Complement-Targeted Therapies Moving from Rare Disorders to More Common Diseases? J Clin Med 2021; 10:4715. [PMID: 34682837 PMCID: PMC8539100 DOI: 10.3390/jcm10204715] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/29/2022] Open
Abstract
Primary IgA nephropathy (IgAN) is a leading cause of chronic kidney disease and kidney failure for which there is no disease-specific treatment. However, this could change, since novel therapeutic approaches are currently being assessed in clinical trials, including complement-targeting therapies. An improved understanding of the role of the lectin and the alternative pathway of complement in the pathophysiology of IgAN has led to the development of these treatment strategies. Recently, in a phase 2 trial, treatment with a blocking antibody against mannose-binding protein-associated serine protease 2 (MASP-2, a crucial enzyme of the lectin pathway) was suggested to have a potential benefit for IgAN. Now in a phase 3 study, this MASP-2 inhibitor for the treatment of IgAN could mark the start of a new era of complement therapeutics where common diseases can be treated with these drugs. The clinical development of complement inhibitors requires a better understanding by physicians of the biology of complement, the pathogenic role of complement in IgAN, and complement-targeted therapies. The purpose of this review is to provide an overview of the role of complement in IgAN, including the recent discovery of new mechanisms of complement activation and opportunities for complement inhibitors as the treatment of IgAN.
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Affiliation(s)
- Felix Poppelaars
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands; (B.F.); (M.R.D.)
| | - Bernardo Faria
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands; (B.F.); (M.R.D.)
- Nephrology and Infectious Disease R&D Group, INEB, Institute of Investigation and Innovation in Health (i3S), University of Porto, 4200-135 Porto, Portugal
| | - Wilhelm Schwaeble
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK;
| | - Mohamed R. Daha
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, University of Groningen, 9700 AD Groningen, The Netherlands; (B.F.); (M.R.D.)
- Department of Nephrology, Leiden University Medical Center, University of Leiden, 2300 RC Leiden, The Netherlands
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24
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Wang Z, Xie X, Li J, Zhang X, He J, Wang M, Lv J, Zhang H. Complement Activation Is Associated With Crescents in IgA Nephropathy. Front Immunol 2021; 12:676919. [PMID: 34594322 PMCID: PMC8477028 DOI: 10.3389/fimmu.2021.676919] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction Crescents, especially those found at a percentage greater than 50%, are often associated with rapid progression of kidney disease in IgA nephropathy (IgAN). The mechanism of crescents forming in IgAN is still unclear. In this study, we aimed to evaluate whether excess complement activation participates in the formation of crescents in IgAN. Methods One hundred IgAN patients with various proportions of crescents—24 with 1%–24%, 27 with 25%–49%, 21 with 50%–74% 12 with more than 75%, and 16 without crescents—were included. Urinary concentrations of mannose-binding lectin (MBL), Bb, C4d, C3a, C5a, and soluble C5b-9 (sC5b-9) were measured at the time of biopsy. Receiver operating characteristic (ROC) curves were performed to evaluate predictive ability of renal survival for urine complement activation. In addition, historical C4d, C5b-9, and C3d were stained by immunohistochemistry. Results IgAN patients with more than 50% crescent formation showed higher complement activation levels than the other patients (urinary C3a/creatinine (C3a/Cr): 6.7295 ng/mg, interquartile range (IQR) 1.4652–62.1086 ng/mg vs. 0.1055 ng/mg, IQR 0–1.4089 ng/mg; urinary C5a/Cr: 15.6202 ng/mg, 4.3127–66.7347 ng/mg vs. 0.3280 ng/mg, IQR 0.0859–2.4439 ng/mg; urinary sC5b-9/Cr: 98.6357 ng/mg, 8.8058–1,087.4578 ng/mg vs. 1.4262 ng/mg, 0.0916–11.0858 ng/mg, all p-values <0.001). The levels of urinary MBL and C4d representing lectin complement pathway showed a linear association with the proportion of crescents (r = 0.457 and 0.562, respectively, both p-values <0.001). Combined urine complement products could increase the predictive ability compared with crescents alone from 0.904 to 0.944 (p = 0.062) with borderline significance. Moreover, the glomerular C4d deposition rate elevated with the increase of proportions of crescents. Conclusion Excess complement activation may be involved in the formation of crescents, especially diffuse crescent formation, in patients with IgAN. Urinary C4d correlated with the proportion of crescents and was a potential biomarker for disease monitoring in crescentic IgAN.
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Affiliation(s)
- Zi Wang
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.,Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Xinfang Xie
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.,Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Jingyi Li
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.,Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Xue Zhang
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.,Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Jiawei He
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.,Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Manliu Wang
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.,Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Jicheng Lv
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.,Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
| | - Hong Zhang
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China.,Research Units of Diagnosis and Treatment of Immune-Mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China
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25
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Is complement the main accomplice in IgA nephropathy? From initial observations to potential complement-targeted therapies. Mol Immunol 2021; 140:1-11. [PMID: 34601376 DOI: 10.1016/j.molimm.2021.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 09/01/2021] [Accepted: 09/17/2021] [Indexed: 12/22/2022]
Abstract
IgA Nephropathy (IgAN) is the main cause of primary glomerulonephritis, globally. This disease is associated with a wide range of clinical presentations, variable prognosis and a spectrum of histological findings. More than fifty years after its first description, this heterogeneity continues to complicate efforts to understand the pathogenesis. Nevertheless, involvement of the complement system in IgAN was identified early on. Dysfunction of the immunoglobulin A (IgA) system, the principal offender in this disease, including modification of isoforms and glycoforms of IgA1, the nature of immune complexes and autoantibodies to galactose deficient IgA1 might all be responsible for complement activation in IgAN. However, the specific mechanisms engaging complement are still under examination. Research in this domain should allow for identification of patients that may benefit from complement-targeted therapy, in the foreseeable future.
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26
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Huang X, Xu G. An Update on Targeted Treatment of IgA Nephropathy: An Autoimmune Perspective. Front Pharmacol 2021; 12:715253. [PMID: 34497518 PMCID: PMC8419281 DOI: 10.3389/fphar.2021.715253] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/10/2021] [Indexed: 02/06/2023] Open
Abstract
Immunoglobulin (Ig) A nephropathy (IgAN) is the commonest form of primary glomerulonephritis worldwide and is, considered a significant cause of end-stage renal disease in young adults. The precise pathogenesis of IgAN is unclear. The clinical and pathological features vary significantly between individuals and races, which makes treating IgAN difficult. Currently, the therapeutic strategies in IgAN are still optimal blood pressure control and proteinuria remission to improve the renal function in most cases. Immunosuppressive drugs such as corticosteroids can be considered in patients with persistent proteinuria and a high risk of renal function decline; however, they include a high toxicity profile. Therefore, the safety and selectivity of medications are critical concerns in the treatment of IgAN. Various pharmacological therapeutic targets have emerged based on the evolving understanding of the autoimmune pathogenesis of IgAN, which involves the immune response, mucosal immunity, renal inflammation, complement activation, and autophagy; treatments based on these mechanisms have been explored in preclinical and clinical studies. This review summarizes the progress concerning targeted therapeutic strategies and the relevant autoimmune pathogenesis in IgAN.
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Affiliation(s)
- Xin Huang
- Department of Nephrology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Gaosi Xu
- Department of Nephrology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
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27
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Peruzzi L, Coppo R. IgA vasculitis nephritis in children and adults: one or different entities? Pediatr Nephrol 2021; 36:2615-2625. [PMID: 33219450 DOI: 10.1007/s00467-020-04818-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/15/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022]
Abstract
The clinical features of the kidney involvement in immunoglobulin A (IgA) vasculitis (IgAVN) differ in children and adults for both clinical presentation and progression. IgAVN in children has mostly a self-limiting course and favorable resolution, while in adults the kidney involvement is frequently severe with unfavorable outcome. However, a subset of children is at risk of progression within the pediatric age or decades later in adulthood, particularly when the diagnosis and a prompt intervention are delayed. Factors predicting progression and outcome in the whole spectrum of age have been investigated in recent research, as well as the relationship between IgAVN and primary IgAN, which share the same pathology features, in the light of peculiar clinical differences and progression tendencies, and hence need for selective treatments. The search for a personalized treatment in children with IgAV and in different ages of life should rely on the identification of different risks for progression. This review will focus on recent studies which contribute to improve our knowledge in this still largely unclear area.
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Affiliation(s)
- Licia Peruzzi
- Fondazione Ricerca Molinette, Regina Margherita Hospital, Turin, Italy.,Pediatric Nephrology Unit, Regina Margherita Department, City of Health and Science University Hospital, Turin, Italy
| | - Rosanna Coppo
- Fondazione Ricerca Molinette, Regina Margherita Hospital, Turin, Italy.
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28
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Medjeral-Thomas NR, Cook HT, Pickering MC. Complement activation in IgA nephropathy. Semin Immunopathol 2021; 43:679-690. [PMID: 34379175 PMCID: PMC8551128 DOI: 10.1007/s00281-021-00882-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 07/23/2021] [Indexed: 11/25/2022]
Abstract
IgA nephropathy pathogenesis is incompletely understood, and this limits the development of disease-specific biomarkers and effective therapies. Evidence of complement activity in IgA nephropathy is well established. However, a growing body of research indicates complement activity is an important contributor to IgA nephropathy pathology. In particular, multiple associations have been identified between complement alternative, lectin and terminal pathway proteins and IgA nephropathy severity. Recently, we have also gained insight into possible mechanisms that could link glomerular IgA deposition, complement activity, glomerular inflammation and disease severity. Ongoing clinical trials of therapeutic complement inhibitors will provide insight into the importance of complement activity to IgA nephropathy pathogenesis. Further research into mechanisms of complement activity is essential to improving our understanding and management of patients with IgA nephropathy.
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Affiliation(s)
- Nicholas R Medjeral-Thomas
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, London, W12 0NN, UK.
| | - H Terence Cook
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, London, W12 0NN, UK
| | - Matthew C Pickering
- Centre for Inflammatory Disease, Department of Immunology and Inflammation, Imperial College London, London, W12 0NN, UK
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29
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Abstract
PURPOSE OF REVIEW IgA vasculitis (IgAV) is a rare and poorly understood systemic vasculitis in adults. Its diagnosis and treatment remain a challenge. Herein, we review the clinical manifestations, diagnosis, management, and prognosis of IgAV in adults. RECENT FINDINGS The clinical course of IgAV in adults appears to be different from pediatric IgAV, especially due to its higher risk of evolving into end-stage renal disease. Rising awareness and interest in adult-onset IgA vasculitis has resulted in recent increasing number of publications on different treatment experiences. However, there is still controversy over the role of glucocorticoid (GC) and different immunosuppressive therapies such as cyclophosphamide, rituximab, and mychophenolate mofetil for more severe IgAV. Data regarding potential benefits of targeting the mucosal immune system, toll-like receptors, complements, and tyrosine kinase inhibitors in the treatment of IgA nephropathy are emerging. High quality evidence or guidelines in the treatment of severe IgAV are lacking and there is still a great need for controlled trials.
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30
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Portilla D, Xavier S. Role of intracellular complement activation in kidney fibrosis. Br J Pharmacol 2021; 178:2880-2891. [PMID: 33555070 DOI: 10.1111/bph.15408] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/22/2021] [Accepted: 02/02/2021] [Indexed: 02/06/2023] Open
Abstract
Increased expression of complement C1r, C1s and C3 in kidney cells plays an important role in the pathogenesis of kidney fibrosis. Our studies suggest that activation of complement in kidney cells with increased generation of C3 and its fragments occurs by activation of classical and alternative pathways. Single nuclei RNA sequencing studies in kidney tissue from unilateral ureteral obstruction mice show that increased synthesis of complement C3 and C5 occurs primarily in renal tubular epithelial cells (proximal and distal), while increased expression of complement receptors C3ar1 and C5ar1 occurs in interstitial cells including immune cells like monocytes/macrophages suggesting compartmentalization of complement components during kidney injury. Although global deletion of C3 and macrophage ablation prevent inflammation and reduced kidney tissue scarring, the development of mice with cell-specific deletion of complement components and their regulators could bring further insights into the mechanisms by which intracellular complement activation leads to fibrosis and progressive kidney disease. LINKED ARTICLES: This article is part of a themed issue on Canonical and non-canonical functions of the complement system in health and disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.14/issuetoc.
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Affiliation(s)
- Didier Portilla
- Department of Medicine and Center for Immunity and Regenerative Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Sandhya Xavier
- Department of Medicine and Center for Immunity and Regenerative Medicine, University of Virginia, Charlottesville, Virginia, USA
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31
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An Update on the Current State of Management and Clinical Trials for IgA Nephropathy. J Clin Med 2021; 10:jcm10112493. [PMID: 34200024 PMCID: PMC8200196 DOI: 10.3390/jcm10112493] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 12/31/2022] Open
Abstract
IgA nephropathy remains the most common primary glomerular disease worldwide. It affects children and adults of all ages, and is a leading cause of end-stage kidney disease, making it a considerable public health issue in many countries. Despite being initially described over 50 years ago, there are still no disease specific treatments, with current management for most patients being focused on lifestyle measures and renin-angiotensin-aldosterone system blockade. However, significant advances in the understanding of its pathogenesis have been made particularly over the past decade, leading to great interest in developing new therapeutic strategies, and a significant rise in the number of interventional clinical trials being performed. In this review, we will summarise the current state of management of IgAN, and then describe major areas of interest where new therapies are at their most advanced stages of development, that include the gut mucosal immune system, B cell signalling, the complement system and non-immune modulators. Finally, we describe clinical trials that are taking place in each area and explore future directions for translational research.
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32
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New therapeutic perspectives for IgA nephropathy in children. Pediatr Nephrol 2021; 36:497-506. [PMID: 32040630 DOI: 10.1007/s00467-020-04475-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 01/02/2020] [Accepted: 01/07/2020] [Indexed: 12/20/2022]
Abstract
Childhood IgA nephropathy (cIgAN) differs from the adult by having an abrupt clinical onset, often presenting as an acute attack that can progress to a chronic phase. No treatment guidelines have been established for the treatment of cIgAN. Given the severity of acute attack in children, and the number of life-years at stake, pediatricians prescribe immunosuppression in addition to renin-angiotensin system blockade. Non-specific immunosuppressors, such as corticosteroids, have systemic toxic effects, and given recent therapeutic advances in adult glomerulonephritis, new tailored strategies should be expected for children. The mucosal immune system has been highlighted as a key player in IgAN pathogenesis, and several biomarkers have been identified with a direct role in pathogenesis. In this review, we discuss current studies of conventional and novel therapeutic approaches for cIgAN.
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33
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Koopman JJE, van Essen MF, Rennke HG, de Vries APJ, van Kooten C. Deposition of the Membrane Attack Complex in Healthy and Diseased Human Kidneys. Front Immunol 2021; 11:599974. [PMID: 33643288 PMCID: PMC7906018 DOI: 10.3389/fimmu.2020.599974] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/21/2020] [Indexed: 12/11/2022] Open
Abstract
The membrane attack complex-also known as C5b-9-is the end-product of the classical, lectin, and alternative complement pathways. It is thought to play an important role in the pathogenesis of various kidney diseases by causing cellular injury and tissue inflammation, resulting in sclerosis and fibrosis. These deleterious effects are, consequently, targeted in the development of novel therapies that inhibit the formation of C5b-9, such as eculizumab. To clarify how C5b-9 contributes to kidney disease and to predict which patients benefit from such therapy, knowledge on deposition of C5b-9 in the kidney is essential. Because immunohistochemical staining of C5b-9 has not been routinely conducted and never been compared across studies, we provide a review of studies on deposition of C5b-9 in healthy and diseased human kidneys. We describe techniques to stain deposits and compare the occurrence of deposits in healthy kidneys and in a wide spectrum of kidney diseases, including hypertensive nephropathy, diabetic nephropathy, membranous nephropathy, IgA nephropathy, lupus nephritis, C3 glomerulopathy, and thrombotic microangiopathies such as the atypical hemolytic uremic syndrome, vasculitis, interstitial nephritis, acute tubular necrosis, kidney tumors, and rejection of kidney transplants. We summarize how these deposits are related with other histological lesions and clinical characteristics. We evaluate the prognostic relevance of these deposits in the light of possible treatment with complement inhibitors.
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Affiliation(s)
- Jacob J E Koopman
- Division of Renal Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
- Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Mieke F van Essen
- Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Helmut G Rennke
- Division of Renal Pathology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Aiko P J de Vries
- Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
| | - Cees van Kooten
- Division of Nephrology, Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands
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34
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Complement-mediated kidney diseases. Mol Immunol 2020; 128:175-187. [DOI: 10.1016/j.molimm.2020.10.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/16/2020] [Accepted: 10/19/2020] [Indexed: 12/19/2022]
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35
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Guo WY, Sun LJ, Dong HR, Wang GQ, Xu XY, Zhao ZR, Cheng H. Glomerular Complement Factor H-Related Protein 5 is Associated with Histologic Injury in Immunoglobulin A Nephropathy. Kidney Int Rep 2020; 6:404-413. [PMID: 33615066 PMCID: PMC7879122 DOI: 10.1016/j.ekir.2020.11.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/07/2020] [Accepted: 11/17/2020] [Indexed: 11/02/2022] Open
Abstract
Introduction Immunoglobulin A nephrology (IgAN), characterized by co-deposition of IgA and complement components, is an activation of complement system involved disease. Factor H-related protein 5 (FHR-5) antagonized the ability of factor H to negatively regulate C3 activation, which leads to overactivation of the alternative pathway. Here we explore the relationship of intensity of glomerular FHR-5 deposition and severity of IgAN. Methods Renal staining of FHR-5 was detected by immunofluorescence, and plasma FHR-5 was detected by enzyme-linked immunosorbent assay in 56 patients with IgAN. The relationship of intensity of glomerular FHR-5 and clinical and pathologic features of these patients were further analyzed. Results Glomerular staining for FHR-5 was observed in a predominantly mesangial pattern in 32 biopsy specimens (57.1%). FHR-5 co-deposited with IgA and C3c in glomerular mesangial and capillary area in patients with IgAN. Patients with IgAN with Oxford endocapillary hypercellularity (P = 0.007) and segmental glomerulosclerosis (P = 0.049) presented with greater intensity of FHR-5 deposition. There were more cases with 2+ and 3+ FHR-5 staining in cohorts of 2+ and 3-4+ mesangial C3 deposition (P = 0.034) and IgA deposition (P = 0.019). Interestingly, the glomerular FHR-5 depositions were more abundant in male versus female in patients with IgAN (P = 0.002). Besides, circulating FHR-5 levels were elevated in patients with IgAN compared with healthy control subjects. Plasma FHR-5 levels were significantly higher in patients with mesangial hypercellularity at diagnosis than those with nonmesangial hypercellularity. Conclusions We found that glomerular intensity of FHR-5 deposition could indicate the severity of histologic lesions of IgAN.
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Affiliation(s)
- Wei-Yi Guo
- Renal Division, Department of Medicine, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Li-Jun Sun
- Renal Division, Department of Medicine, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Hong-Rui Dong
- Renal Division, Department of Medicine, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Guo-Qin Wang
- Renal Division, Department of Medicine, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Xiao-Yi Xu
- Renal Division, Department of Medicine, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Zhi-Rui Zhao
- Renal Division, Department of Medicine, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Hong Cheng
- Renal Division, Department of Medicine, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
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He JW, Zhou XJ, Lv JC, Zhang H. Perspectives on how mucosal immune responses, infections and gut microbiome shape IgA nephropathy and future therapies. Am J Cancer Res 2020; 10:11462-11478. [PMID: 33052226 PMCID: PMC7545987 DOI: 10.7150/thno.49778] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/30/2020] [Indexed: 02/06/2023] Open
Abstract
Infections have been considered to play a critical role in the pathogenesis of IgA nephropathy (IgAN) because synpharyngitic hematuria is a common feature in IgAN. However, how infections participate in this process is still debated. More recent studies have also revealed that the alteration of the gut microbiome exerts a profound effect on host immune responses, contributing to the etiology or progression of autoimmunity. Considering IgA as the first line of defense against bacterial and viral antigens, this review evaluates the relationships among intestinal infections, gut microbiome, and IgA for a better understanding of the pathogenesis of IgAN. Moreover, as a prototype of IgA immunity, we provide detailed clarification of IgAN pathogenesis to shed light on other diseases in which IgA plays a role. Finally, we discuss potential therapies focusing on microbes and mucosal immune responses in IgAN.
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Gutiérrez E, Carvaca-Fontán F, Luzardo L, Morales E, Alonso M, Praga M. A Personalized Update on IgA Nephropathy: A New Vision and New Future Challenges. Nephron Clin Pract 2020; 144:555-571. [PMID: 32818944 DOI: 10.1159/000509997] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 07/08/2020] [Indexed: 11/19/2022] Open
Abstract
IgA nephropathy (IgAN) is the most common primary glomerulonephritis in the world among patients undergoing renal biopsy. Approximately 30% of patients with IgAN develop end-stage kidney disease 20 years after renal biopsy. It is a glomerulopathy with a very broad clinical presentation, making it difficult to stratify and treat. IgAN is characterized by dysregulation of the immune system, which causes an abnormal synthesis of IgA1 that is deglycosylated causing its mesangial deposition. IgAN pathogenesis is incompletely understood; the current multi-hit hypothesis of IgAN pathogenesis does not explain the range of glomerular inflammation and renal injury associated with mesangial IgA deposition. Although associations between IgAN and glomerular and circulating markers of complement activation are established, the mechanism of complement activation and contribution to glomerular inflammation and injury are not defined. On the other hand, the renal-gut connection can also play an important role in the pathogenesis of IgAN with possible therapeutic implications. In order to standardize the histological findings, the Oxford Classification has allowed clarifying renal lesions that confer potential risk of progression. Currently, except for the blockade of the renin-angiotensin-aldosterone system, no other therapies are available in clinical setting for the treatment of IgAN, although the range of new drugs under investigation is extensive. The incorporation in the next trials of clinical parameters such as the amount of hematuria and histological lesions may allow more personalized therapeutic approaches. To summarize, in recent years, several important efforts have taken place in the understanding of IgAN, but still, further studies are warranted to elucidate the best therapeutic strategies according to the risk to improve the prognosis of this entity.
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Affiliation(s)
- Eduardo Gutiérrez
- Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain, .,Department of Nephrology, Hospital Universitario 12 de Octubre, Madrid, Spain,
| | - Fernando Carvaca-Fontán
- Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Department of Medicine, Universidad Complutense de Madrid, Madrid, Spain
| | - Leonella Luzardo
- Department of Nephrology and Pathophysiology, School of Medicine, Universidad de la República, Montevideo, Uruguay
| | - Enrique Morales
- Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Department of Medicine, Universidad Complutense de Madrid, Madrid, Spain
| | - Marina Alonso
- Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Department of Pathological Anatomy, Hospital Universitario 12 de Octubre, Madrid, Spain
| | - Manuel Praga
- Instituto de Investigación Hospital 12 de Octubre (i+12), Madrid, Spain.,Department of Medicine, Universidad Complutense de Madrid, Madrid, Spain
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Infante B, Rossini M, Di Lorenzo A, Coviello N, Giuseppe C, Gesualdo L, Giuseppe G, Stallone G. Recurrence of immunoglobulin A nephropathy after kidney transplantation: a narrative review of the incidence, risk factors, pathophysiology and management of immunosuppressive therapy. Clin Kidney J 2020; 13:758-767. [PMID: 33123355 PMCID: PMC7577761 DOI: 10.1093/ckj/sfaa060] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 03/18/2020] [Indexed: 01/04/2023] Open
Abstract
Glomerulonephritis (GN) is the underlying cause of end-stage renal failure in 30–50% of kidney transplant recipients. It represents the primary cause of end-stage renal disease for 25% of the dialysis population and 45% of the transplant population. For patients with GN requiring renal replacement therapy, kidney transplantation is associated with superior outcomes compared with dialysis. Recurrent GN was previously considered to be a minor contributor to graft loss, but with the prolongation of graft survival, the effect of recurrent disease on graft outcome assumes increasing importance. Thus the extent of recurrence of original kidney disease after kidney transplantation has been underestimated for several reasons. This review aims to provide updated knowledge on one particular recurrent renal disease after kidney transplantation, immunoglobulin A nephropathy (IgAN). IgAN is one of the most common GNs worldwide. The pathogenesis of IgAN is complex and remains incompletely understood. Evidence to date is most supportive of a several hit hypothesis. Biopsy is mandatory not only to diagnose the disease in the native kidney, but also to identify and characterize graft recurrence of IgAN in the kidney graft. The optimal therapy for IgAN recurrence in the renal graft is unknown. Supportive therapy aiming to reduce proteinuria and control hypertension is the mainstream, with corticosteroids and immunosuppressive treatment tailored for certain subgroups of patients experiencing a rapidly progressive course of the disease with active lesions on renal biopsy and considering safety issues related to infectious complications.
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Affiliation(s)
- Barbara Infante
- Department of Medical and Surgical Sciences, Nephrology, Dialysis and Transplantation Unit, University of Foggia, Foggia, Italy
| | - Michele Rossini
- Department of Emergency and Organ Transplantation, Nephrology, Dialysis and Transplantation Unit, University of Bari "Aldo Moro", Bari, Italy
| | - Adelaide Di Lorenzo
- Department of Medical and Surgical Sciences, Nephrology, Dialysis and Transplantation Unit, University of Foggia, Foggia, Italy
| | - Nicola Coviello
- Department of Medical and Surgical Sciences, Nephrology, Dialysis and Transplantation Unit, University of Foggia, Foggia, Italy
| | - Castellano Giuseppe
- Department of Medical and Surgical Sciences, Nephrology, Dialysis and Transplantation Unit, University of Foggia, Foggia, Italy
| | - Loreto Gesualdo
- Department of Emergency and Organ Transplantation, Nephrology, Dialysis and Transplantation Unit, University of Bari "Aldo Moro", Bari, Italy
| | | | - Giovanni Stallone
- Department of Medical and Surgical Sciences, Nephrology, Dialysis and Transplantation Unit, University of Foggia, Foggia, Italy
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Abstract
PURPOSE OF REVIEW Complement system dysfunction in terms of upregulation, downregulation, or dysregulation can create an imbalance of both host defense and inflammatory response leading to autoimmunity. In this review, we aimed at describing the role of complement system in host defense to inflection and in autoimmunity starting from the evidence from primary and secondary complement system deficiencies. RECENT FINDINGS Complement system has a determinant role in defense against infections: deficiencies of complement components are associated with increased susceptibility to infections. Primary complement system deficiencies are rare disorders that predispose to both infections and autoimmune diseases. Secondary complement system deficiencies are the result of the complement system activation with consumption. Complement system role in enhancing risk of infective diseases in secondary deficiencies has been demonstrated in patients affected by systemic autoimmune disorders, mainly systemic lupus erythematosus and vasculitis. SUMMARY The relationship between the complement system and autoimmunity appears paradoxical as both the deficiency and the activation contribute to inducing autoimmune diseases. In these conditions, the presence of complement deposition in affected tissues, decreased levels of complement proteins, and high levels of complement activation fragments in the blood and vessels have been documented.
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Dumont C, Mérouani A, Ducruet T, Benoit G, Clermont MJ, Lapeyraque AL, Phan V, Patey N. Clinical relevance of membrane attack complex deposition in children with IgA nephropathy and Henoch-Schönlein purpura. Pediatr Nephrol 2020; 35:843-850. [PMID: 31932958 DOI: 10.1007/s00467-019-04445-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 11/26/2019] [Accepted: 12/03/2019] [Indexed: 11/26/2022]
Abstract
BACKGROUND IgA nephropathy (IgAN) and Henoch-Schönlein purpura are common glomerular disorders in children sharing the same histopathologic pattern of IgA deposits within the mesangium, even if their physiopathology may be different. Repeated exposure to pathogens induces the production of abnormal IgA1. The immune complex deposition in the renal mesangium in IgAN or potentially in small vessels in Henoch-Schönlein purpura induces complement activation via the alternative and lectin pathways. Recent studies suggest that levels of membrane attack complex (MAC) in the urine might be a useful indicator of renal injury. Because of the emerging availability of therapies that selectively block complement activation, the aim of the present study is to investigate whether MAC immunostaining might be a useful marker of IgA-mediated renal injury. METHODS We conducted immunohistochemistry analysis of the MAC on renal biopsies from 67 pediatric patients with IgAN and Henoch-Schönlein purpura. We classified their renal biopsies according to the Oxford classification, retrieved symptoms, biological parameters, treatment, and follow-up. RESULTS We found MAC expression was significantly related to impaired renal function and patients whose clinical course required therapy. MAC deposits tend to be more abundant in patients with decreased glomerular filtration rate (p = 0.02), patients with proteinuria > 0.750 g/day/1.73 m2, and with nephrotic syndrome. No correlation with histological alterations was observed. CONCLUSIONS We conclude that MAC deposition could be a useful additional indicator of renal injury in patients with IgAN and Henoch-Schönlein purpura, independent of other indicators.
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Affiliation(s)
- Camille Dumont
- Department of Pathology, CHU Sainte Justine, 3175 Chemin Côte Sainte Catherine, Montréal, Québec, H3T 1C5, Canada
| | - Aicha Mérouani
- Department of Nephrology, CHU Sainte-Justine, Université de Montréal, Montréal, Québec, Canada
| | - Thierry Ducruet
- Applied Clinical Research Unit, CHU Sainte-Justine, Université de Montréal, Montréal, Québec, Canada
| | - Geneviève Benoit
- Department of Nephrology, CHU Sainte-Justine, Université de Montréal, Montréal, Québec, Canada
| | - Marie-Josée Clermont
- Department of Nephrology, CHU Sainte-Justine, Université de Montréal, Montréal, Québec, Canada
| | - Anne Laure Lapeyraque
- Department of Nephrology, CHU Sainte-Justine, Université de Montréal, Montréal, Québec, Canada
| | - Véronique Phan
- Department of Nephrology, CHU Sainte-Justine, Université de Montréal, Montréal, Québec, Canada
| | - Natalie Patey
- Department of Pathology, CHU Sainte Justine, 3175 Chemin Côte Sainte Catherine, Montréal, Québec, H3T 1C5, Canada.
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Medjeral-Thomas NR, O'Shaughnessy MM. Complement in IgA Nephropathy: The Role of Complement in the Pathogenesis, Diagnosis, and Future Management of IgA Nephropathy. Adv Chronic Kidney Dis 2020; 27:111-119. [PMID: 32553243 DOI: 10.1053/j.ackd.2019.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 12/12/2022]
Abstract
Immunoglobulin A (IgA) nephropathy (IgAN) is an important cause of chronic and end-stage kidney disease. IgAN pathogenesis is incompletely understood. In particular, we cannot adequately explain the heterogeneity in clinical and histologic features and severities that characterizes IgAN. This limits patient stratification to appropriate and effective treatments and the development of disease-targeted therapies. Studies of the role of the alternative, lectin, and terminal complement pathways in IgAN have enhanced our understanding of disease pathogenesis and inform the development of novel diagnostic and therapeutic strategies. For example, recent genetic, serologic, and immunohistologic evidence suggests that imbalances between the main alternative complement pathway regulator protein (factor H) and competitor proteins that deregulate complement activity (factor H-related proteins 1 and 5, FHR1, and FHR5) associate with IgAN severity: a relative abundance of FHR1 and FHR5 amplifies complement-dependent inflammation and exacerbates kidney injury. Ongoing characterization of the mechanisms by which complement activity contributes to IgAN pathogenesis will facilitate the development of complement-based diagnostic techniques, biomarkers of disease activity and severity, and novel targeted therapies.
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42
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Management and treatment of glomerular diseases (part 1): conclusions from a kidney disease: improving global outcomes (KDIGO) controversies conference. ACTA ACUST UNITED AC 2020. [DOI: 10.36485/1561-6274-2020-24-2-22-41] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The Kidney Disease: Improving Global Outcomes (KDIGO) initiative organized a Controversies Conference on glomerular diseases in November 2017. The conference focused on the 2012 KDIGO guideline with the aim of identifying new insights into nomenclature, pathogenesis, diagnostic work-up, and, in particular, therapy of glomerular diseases since the guideline’s publication. It was the consensus of the group that most guideline recommendations, in particular those dealing with therapy, will need to be revisited by the guideline-updating Work Group. This report covers general management of glomerular disease, IgA nephropathy, and membranous nephropathy.
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Hu X, Feng J, Deng S, Tang J, Liao Z, Luo L, Luo L, Meng T, Gong G, Li X. Anaphylatoxins enhance Th9 cell recruitment via the CCL20-CCR6 axis in IgA nephropathy. J Nephrol 2020; 33:1027-1036. [PMID: 32036611 DOI: 10.1007/s40620-020-00708-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 01/31/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND CD4+ T cells are involved in the pathogenesis of immunoglobulin A nephropathy (IgAN); T helper (Th) 1, Th17 and Th22 cells promote the occurrence and amplification of inflammatory reactions, while regulatory T (Treg) cells produce the opposite effects. However, whether Th9 cells, a subset of CD4+ T cells, participate in IgAN development is still unknown. METHODS Human peripheral blood mononuclear cells (PBMCs) were isolated from IgAN patients for Th9 cells detection by flow cytometry. Wild-type (WT) mouse was used to establish an IgAN mouse model while C3aR and C5aR inhibitor treated IgAN mouse. Kidney disease and function was assessed by histology and albumin-to-creatinine ratio. C3aR and C5aR expression was examined by immunohistochemical (IHC) assay. Th9 cell proportions in the blood of IgAN mouse was detected. C3a, C5a and interleukin (IL)-9 levels were tested by ELISA. Moreover, co-culture system between human mesangial cells (HMCs) and CD4+ T cells were constructed with or without C3a, C5a and anti-CCL20 mAb stimulation for transwell assay to examine Th9 cell chemotaxis. RESULTS We observed the numbers of Th9 cell and the levels of IL-9 were increased in IgAN patients and IgAN mice. Furthermore, C3a and C5a level in serum and kidney, C3aR and C5aR expression was increased in IgAN mice compared to WT mice. Most interestingly, C3aR and C5aR inhibitor could reduce kidney damage, Th9 cell numbers and IL-9 levels. We also observed that C3a and C5a enhanced CCL20 production in HMCs. Notably, C3a and C5a also increased the recruitment of Th9 cells and IL-9 levels by HMCs through enhancing the CCL20-CCR6 pathway. CONCLUSIONS Our results support that C3a and C5a increase the production of CCL20 by HMCs and consequently augment Th9 cell recruitment and IL-9 levels, resulting in IgAN exacerbation.
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Affiliation(s)
- Xinyue Hu
- Department of Respiratory and Critical Care Medicine, Key Cite of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, China
| | - Juntao Feng
- Department of Respiratory and Critical Care Medicine, Key Cite of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, China
| | - Shuanglinzi Deng
- Department of Respiratory and Critical Care Medicine, Key Cite of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, China
| | - Jiale Tang
- Department of Nephrology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, China
| | - Zhonghua Liao
- Department of Nephrology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, China
| | - Lisha Luo
- Department of Respiratory and Critical Care Medicine, Key Cite of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, China
| | - Liying Luo
- Department of Nephrology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, China
| | - Ting Meng
- Department of Nephrology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, China
| | - Guanghui Gong
- Department of Pathology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, China
| | - Xiaozhao Li
- Department of Nephrology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, China.
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Floege J, Barbour SJ, Cattran DC, Hogan JJ, Nachman PH, Tang SCW, Wetzels JFM, Cheung M, Wheeler DC, Winkelmayer WC, Rovin BH. Management and treatment of glomerular diseases (part 1): conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference. Kidney Int 2020; 95:268-280. [PMID: 30665568 DOI: 10.1016/j.kint.2018.10.018] [Citation(s) in RCA: 162] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 10/10/2018] [Accepted: 10/24/2018] [Indexed: 01/10/2023]
Abstract
The Kidney Disease: Improving Global Outcomes (KDIGO) initiative organized a Controversies Conference on glomerular diseases in November 2017. The conference focused on the 2012 KDIGO guideline with the aim of identifying new insights into nomenclature, pathogenesis, diagnostic work-up, and, in particular, therapy of glomerular diseases since the guideline's publication. It was the consensus of the group that most guideline recommendations, in particular those dealing with therapy, will need to be revisited by the guideline-updating Work Group. This report covers general management of glomerular disease, IgA nephropathy, and membranous nephropathy.
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Affiliation(s)
- Jürgen Floege
- Division of Nephrology, Rheinisch-Westfälische Technische Hochschule University of Aachen, Aachen, Germany.
| | - Sean J Barbour
- British Columbia Provincial Renal Agency, Vancouver, British Columbia, Canada; Division of Nephrology, University of British Columbia, Vancouver, British Columbia, Canada; Centre for Health Evaluation and Outcomes Research, St. Paul's Hospital, Vancouver, British Columbia, Canada
| | - Daniel C Cattran
- Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Jonathan J Hogan
- Division of Nephrology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Patrick H Nachman
- Division of Renal Diseases and Hypertension, University of Minnesota, Minneapolis, Minnesota, USA
| | - Sydney C W Tang
- Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China
| | - Jack F M Wetzels
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | | | - Wolfgang C Winkelmayer
- Selzman Institute for Kidney Health, Section of Nephrology, Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
| | - Brad H Rovin
- Division of Nephrology, The Ohio State University, Wexner Medical Center, Columbus, Ohio, USA.
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Predictive value of mesangial C3 and C4d deposition in IgA nephropathy. Clin Immunol 2019; 211:108331. [PMID: 31899330 DOI: 10.1016/j.clim.2019.108331] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 12/24/2019] [Accepted: 12/30/2019] [Indexed: 12/22/2022]
Abstract
We aimed to determine the relative contribution of each complement (C3 and C4d) deposition to the progression of IgA nephropathy (IgAN). We enrolled a total of 380 patients with biopsy-confirmed IgAN. Mesangial deposition of C3(<2+ vs. ≥2+) and C4d(positive vs. negative) was evaluated by immunofluorescence staining and immunohistochemistry, respectively. Study endpoint was the composite of a 30% decline in eGFR or ESRD. The risk of reaching the primary outcome was significantly higher in patients having C3 ≥ 2+ and C4d(+) than in corresponding counterparts. Adding C3 deposition to clinical data acquired at kidney biopsy modestly increased the area under the receiver-operating characteristic curve, net reclassification improvement, and integrated discrimination improvement (IDI); adding C4d increased IDI only. In conclusion, mesangial C3 and C4d deposition was an independent risk factor for progression of IgAN. C3 showed better predictability than C4d, suggesting that lectin pathway alone has limited clinical prognostic value.
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Tortajada A, Gutierrez E, Pickering MC, Praga Terente M, Medjeral-Thomas N. The role of complement in IgA nephropathy. Mol Immunol 2019; 114:123-132. [PMID: 31351413 DOI: 10.1016/j.molimm.2019.07.017] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/16/2019] [Accepted: 07/16/2019] [Indexed: 12/22/2022]
Abstract
IgA nephropathy (IgAN) is common and often progresses to end stage renal disease. IgAN encompasses a wide range of histology and clinical features. IgAN pathogenesis is incompletely understood; the current multi-hit hypothesis of IgAN pathogenesis does not explain the range of glomerular inflammation and renal injury associated with mesangial IgA deposition. Although associations between IgAN and glomerular and circulating markers of complement activation are established, the mechanism of complement activation and contribution to glomerular inflammation and injury are not defined. Recent identification of specific complement pathways and proteins in severe IgAN cases had advanced our understanding of complement in IgAN pathogenesis. In particular, a growing body of evidence implicates the complement factor H related proteins 1 and 5 and lectin pathway as pathogenic in a subset of patients with severe disease. These data suggest complement deregulation and activity may be dominant drivers of renal injury in IgAN. Thereby, markers of complement activation may identify IgAN patients likely to progress to significant renal impairment and complement inhibition may emerge as an effective method of preventing and reducing glomerular injury in IgAN.
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Affiliation(s)
- Agustin Tortajada
- Department of Immunology, Ophthalmology and ENT, Complutense University School of Medicine and 12 de Octubre Health Research Institute (imas12), Madrid, Spain
| | - Eduardo Gutierrez
- Department of Nephrology, Research Institute Universitary Hospital 12 de Octubre (imas12), Madrid, Spain
| | | | - Manuel Praga Terente
- Department of Nephrology, Research Institute Universitary Hospital 12 de Octubre (imas12), Madrid, Spain
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Complement-mediated microangiopathy in IgA nephropathy and IgA vasculitis with nephritis. Mod Pathol 2019; 32:1147-1157. [PMID: 30936425 DOI: 10.1038/s41379-019-0259-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 02/18/2019] [Accepted: 02/18/2019] [Indexed: 12/20/2022]
Abstract
Complement factor C4d was recently observed in renal biopsies from patients who had IgA nephropathy and a poor prognosis. We previously reported that C4d is a common denominator in microangiopathies. In this retrospective cohort study, we investigated whether C4d is a marker of microangiopathy in both IgA nephropathy and IgA vasculitis with nephritis, and whether patients with C4d and microangiopathy have poor renal outcome. We examined 128 renal biopsies from adult and pediatric patients, including normotensive and hypertensive patients, who presented with IgA nephropathy or IgA vasculitis with nephritis. Biopsies were re-evaluated in accordance with the Oxford classification, scored for additional lesions, and stained for complement proteins using immunohistochemistry, including C4d and C5b-9. Clinical data were collected with a mean (±SD) follow-up period of 51 ± 39 months. Changes in estimated glomerular filtration rate over time were compared using linear mixed-effects models. Renal survival was analyzed using multivariable Cox regression. Microangiopathic lesions were present in 20% of all biopsies (23% and 9% of patients with IgA nephropathy and IgA vasculitis with nephritis, respectively). Microangiopathy was associated with C4d and C5b-9 deposits, a higher number of chronic lesions, and hypertension (all p < 0.05). Patients with C4d and microangiopathic lesions had significantly poorer renal survival than patients without these findings, corrected for hypertension (p < 0.01). In conclusion, patients with IgA nephropathy or IgA vasculitis with nephritis with a combination of C4d positivity and microangiopathy comprise a clinical subgroup with an increased number of chronic lesions, lower estimated glomerular filtration rate, and poorer renal survival, even when corrected for hypertension. These data suggest that complement activation is involved in the development of microangiopathy in patients with IgA nephropathy and IgA vasculitis with nephritis, and that complement-mediated microangiopathy contributes to disease progression.
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Yeo SC, Liu X, Liew A. Complement factor H gene polymorphism rs6677604 and the risk, severity and progression of IgA nephropathy: A systematic review and meta-analysis. Nephrology (Carlton) 2019; 23:1096-1106. [PMID: 29240274 DOI: 10.1111/nep.13210] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2017] [Indexed: 12/30/2022]
Abstract
AIM Studies reporting the association between complement factor H gene rs6677604 polymorphism and susceptibility to IgA nephropathy (IgAN) had yielded inconsistent results. We performed a systematic review and meta-analysis to clarify the association between rs6677604 and IgAN susceptibility, disease severity and chronic progression. METHODS A comprehensive database search was performed to identify eligible studies. Meta-analyses were performed for rs6677604 allele frequency, genotypes and the association with IgAN susceptibility. RESULTS 10 studies were included in the systematic review. Among them, four studies containing 10 distinct datasets (15,617 cases and 31,957 controls) were included in the meta-analysis. The pooled frequency of the minor allele (A) was significantly higher in Europeans than in Asians across both IgAN cases and controls, and the frequency of the minor allele (A) in IgAN cases was also significantly lower than that in controls across both European and Asian subgroups. Significant associations were detected between rs6677604 and risk of developing IgAN, when comparing allele A vs. G, genotype AA vs. GG, genotype AA vs. AG and genotype AG vs. GG. In analysis stratified by ethnicity, significant association was only observed in Europeans but not in Asians when comparing AA vs. GG or AA vs. AG. CONCLUSION Our pooled analysis showed a significant association between rs6677604-(A) allele and IgAN susceptibility, supporting the importance of complement activation in the pathogenesis of IgAN. The presence of rs6677604-(A) allele may be associated with a decreased the risk of IgAN in Europeans, but the association was not confirmed in Asians.
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Affiliation(s)
- See Cheng Yeo
- Department of Renal Medicine, Tan Tock Seng Hospital, Singapore, Singapore
| | - Xinyang Liu
- Department of Renal Medicine, Tan Tock Seng Hospital, Singapore, Singapore
| | - Adrian Liew
- Department of Renal Medicine, Tan Tock Seng Hospital, Singapore, Singapore
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Liu LJ, Yang YZ, Shi SF, Bao YF, Yang C, Zhu SN, Sui GL, Chen YQ, Lv JC, Zhang H. Effects of Hydroxychloroquine on Proteinuria in IgA Nephropathy: A Randomized Controlled Trial. Am J Kidney Dis 2019; 74:15-22. [PMID: 30922594 DOI: 10.1053/j.ajkd.2019.01.026] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 01/20/2019] [Indexed: 01/25/2023]
Abstract
RATIONALE & OBJECTIVE Despite optimization of renin-angiotensin-aldosterone system (RAAS) inhibition, patients with immunoglobulin A nephropathy (IgAN) and persistent proteinuria remain at risk for kidney failure. We evaluated the efficacy and safety of hydroxychloroquine (HCQ), an immunomodulator, when added to the treatment regimen of patients with IgAN. STUDY DESIGN Double-blind, randomized, placebo-controlled, phase 2 clinical trial. SETTING & PARTICIPANTS Participants had IgAN (proteinuria with protein excretion of 0.75-3.5g/d and estimated glomerular filtration rate>30mL/min/1.73m2) and were receiving optimized RAAS inhibitor therapy. INTERVENTIONS Patients were randomly assigned 1:1 to receive daily oral HCQ or a placebo for 6 months. OUTCOMES The primary outcome was percentage change in proteinuria between baseline and 6 months. RESULTS 60 participants (mean estimated glomerular filtration rate, 53.8mL/min/1.73m2; median urine protein excretion, 1.7g/d) were recruited and randomly assigned to receive HCQ (n=30) or placebo (n=30). Percentage change in proteinuria at 6 months was significantly different between the HCQ group and the placebo group (-48.4% [IQR, -64.2%, -30.5%] vs 10.0% [IQR, -38.7%, 30.6%]; P<0.001, respectively). At 6 months, median proteinuria level was significantly lower in the HCQ group than in the placebo group (0.9 [IQR, 0.6, 1.0] g/d vs 1.9 [IQR, 0.9, 2.6] g/d; P=0.002, respectively). No serious adverse events were recorded during the study in either study group. LIMITATIONS The short treatment period and lack of postwithdrawal observations limit conclusions about long-term renoprotective efficacy and safety. CONCLUSIONS HCQ in addition to optimized RAAS inhibition significantly reduced proteinuria in patients with IgAN over 6 months without evidence of adverse events. These findings require confirmation in larger treatment trials. FUNDING This study was supported by grants from a government entity, the Capital of Clinical Characteristics, and the Applied Research Fund. TRIAL REGISTRATION Registered at ClinicalTrials.gov with study number NCT02942381.
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Affiliation(s)
- Li-Jun Liu
- Renal Division, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China.
| | - Ya-Zi Yang
- Renal Division, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China
| | - Su-Fang Shi
- Renal Division, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China
| | - Yun-Fei Bao
- Renal Division, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China
| | - Chao Yang
- Renal Division, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China
| | - Sai-Nan Zhu
- Statistics Division, Peking University First Hospital, Beijing, PR China
| | - Gui-Li Sui
- Renal Division, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China
| | - Yu-Qing Chen
- Renal Division, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China
| | - Ji-Cheng Lv
- Renal Division, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China
| | - Hong Zhang
- Renal Division, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China
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Rizk DV, Maillard N, Julian BA, Knoppova B, Green TJ, Novak J, Wyatt RJ. The Emerging Role of Complement Proteins as a Target for Therapy of IgA Nephropathy. Front Immunol 2019; 10:504. [PMID: 30941137 PMCID: PMC6433978 DOI: 10.3389/fimmu.2019.00504] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 02/25/2019] [Indexed: 12/28/2022] Open
Abstract
IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis worldwide and a common cause of end-stage renal disease. Evaluation of a kidney biopsy is necessary for diagnosis, with routine immunofluorescence microscopy revealing dominant or co-dominant IgA immunodeposits usually with complement C3 and sometimes IgG and/or IgM. IgA nephropathy reduces life expectancy by more than 10 years and leads to kidney failure in 20–40% of patients within 20 years of diagnosis. There is accumulating clinical, genetic, and biochemical evidence that complement plays an important role in the pathogenesis of IgA nephropathy. The presence of C3 differentiates the diagnosis of IgA nephropathy from the subclinical deposition of glomerular IgA. Markers for the activation of the alternative and mannan-binding lectin (MBL) pathways in renal-biopsy specimens are associated with disease activity and portend a worse renal outcome. Complement proteins in the circulation have also been evaluated in IgA nephropathy and found to be of prognostic value. Recently, genetic studies have identified IgA nephropathy-associated loci. Within these loci are genes encoding products involved in complement regulation and interaction with immune complexes. Put together, these data identify the complement cascade as a rational treatment target for this chronic kidney disease. Recent case reports on the successful use of humanized anti-C5 monoclonal antibody eculizumab are consistent with this hypothesis, but a better understanding of the role of complement in IgA nephropathy is needed to guide future therapeutic interventions.
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Affiliation(s)
- Dana V Rizk
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Nicolas Maillard
- Department of Nephrology, Dialysis, Transplantation, CHU de Saint-Etienne, GIMAP, EA3064, Université Jean Monnet, COMUE Université de Lyon, Rhône-Alpes, France
| | - Bruce A Julian
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Barbora Knoppova
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, United States.,Department of Immunology, Faculty of Medicine and Dentistry, Palacky University and University Hospital, Olomouc, Czechia
| | - Todd J Green
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Robert J Wyatt
- Department of Pediatrics, University of Tennessee Health Sciences Center, Memphis, TN, United States
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