1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Wu Z, Zhang Z, Zhou S, Xie M, Liu L, Luo C, Zheng F, Qiu W, Wang Y, Zhang J. ERK1/2-dependent activity of SOX9 is required for sublytic C5b-9-induced expression of FGF1, PDGFα, and TGF-β1 in rat Thy-1 nephritis. Int Immunopharmacol 2024; 127:111372. [PMID: 38118314 DOI: 10.1016/j.intimp.2023.111372] [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: 10/19/2023] [Revised: 12/04/2023] [Accepted: 12/11/2023] [Indexed: 12/22/2023]
Abstract
Mesangial proliferative glomerulonephritis (MsPGN) and its related rat model Thy-1 nephritis (Thy-1N) are associated with C5b-9 deposition and are characterized by proliferation of glomerular mesangial cell (GMC) and expansion of extracellular matrix (ECM) expansion, alongside overexpression of multiple growth factors. Although fibroblast growth factor 1 (FGF1), platelet-derived growth factor alpha (PDGFα), and transforming growth factor beta 1 (TGF-β1) are well known for their proproliferative and profibrotic roles, the molecular mechanisms responsible for regulating the expression of these growth factors have not been thoroughly elucidated. In this study, we found that sublytic C5b-9 induction of sex-determining region Y-box 9 (SOX9) transactivated FGF1, PDGFα, and TGF-β1 genes in GMCs, resulting in a significant increase in their mRNA and protein levels. Besides, sublytic C5b-9 induction of activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) phosphorylated SOX9 at serine 181 and serine 64, which enhanced SOX9's ability to transactivate FGF1, PDGFα, and TGF-β1 genes in GMCs. Furthermore, we demonstrated that inhibiting ERK1/2 activation or silencing either ERK1/2 or SOX9 gene led to reduced SOX9 phosphorylation, decreased generation of FGF1, PDGFα, and TGF-β1, and ameliorated glomerular injury in rat Thy-1N. Overall, these findings suggest that expression of FGF1, PDGFα, and TGF-β1 is promoted by ERK1/2-mediated phosphorylation of SOX9, which may provide a valuable insight into the pathogenesis of MsPGN and offer a potential target for the development of novel treatment strategies for MsPGN.
Collapse
Affiliation(s)
- Zhijiao Wu
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Zhiwei Zhang
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Sicheng Zhou
- School of Pediatrics, Nanjing Medical University, Nanjing, China
| | - Mengxiao Xie
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Longfei Liu
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Can Luo
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Feixiang Zheng
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Wen Qiu
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China; Key Laboratory of Immune Microenvironment and Disease, Nanjing Medical University, Nanjing, China; National Health Commission Key Laboratory of Antibody Techniques, Nanjing Medical University, Nanjing, China
| | - Yingwei Wang
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China; Key Laboratory of Immune Microenvironment and Disease, Nanjing Medical University, Nanjing, China; National Health Commission Key Laboratory of Antibody Techniques, Nanjing Medical University, Nanjing, China
| | - Jing Zhang
- Department of Immunology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China; Key Laboratory of Immune Microenvironment and Disease, Nanjing Medical University, Nanjing, China; National Health Commission Key Laboratory of Antibody Techniques, Nanjing Medical University, Nanjing, China.
| |
Collapse
|
3
|
Marro J, Chetwynd AJ, Hawkes J, Northey SJ, Oni L. Urinary markers of the alternative and lectin complement pathway are increased in IgA vasculitis nephritis. Clin Kidney J 2023; 16:2703-2711. [PMID: 38046006 PMCID: PMC10689168 DOI: 10.1093/ckj/sfad236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Indexed: 12/05/2023] Open
Abstract
Background IgA vasculitis (IgAV) is the most common form of childhood vasculitis. Nephritis (IgAVN) occurs in 50% of patients and 1-2% progress to chronic kidney disease stage 5. The pathophysiology of nephritis remains largely unknown, but recent evidence suggests that the complement system may be involved. The aim of this cross-sectional study was to explore whether there is evidence of alternative and/or lectin complement pathway activation in children with IgAVN. Methods Children with IgAV were recruited and grouped according to proteinuria: IgAVN or IgAV without nephritis (IgAVwoN). Age and sex-matched healthy controls (HCs) were also recruited. Cross-sectional urine and plasma concentrations of complement factor D (CFD), factor B (CFB), and MBL-associated protease 1 (MASP-1) were performed using commercially available enzyme-linked immunoassays. Results A total of 50 children were included (IgAVN, n = 15; IgAVwoN, n = 20, HCs, n = 15). The mean age was 8.5 ± 3.7 years old, male:female ratio was 1:1. Urinary CFD and CFB concentrations were statistically significantly increased in children with IgAVN (3.5 ± 5.4 μg/mmol; 25.9 ± 26.5 μg/mmol, respectively) compared to both IgAVwoN (0.4 ± 0.4 μg/mmol, P = 0.002; 9.2 ± 11.5 μg/mmol, P = 0.004) and HCs (0.3 ± 0.2 μg/mmol, P < 0.001; 5.1 ± 6.0 μg/mmol, P < 0.001). No statistically significant difference was reported for the plasma concentrations of CFD and CFB. Urinary MASP-1 concentrations were statistically significantly increased in IgAVN (116.9 ± 116.7 ng/mmol) compared to HCs (41.4 ± 56.1 ng/mmol, P = 0.006) and plasma MASP-1 concentrations were increased in IgAVwoN (254.2 ± 23.3 ng/mL) compared to HCs (233.4 ± 6.6 ng/mL, P = 0.046). Conclusion There is evidence of complement pathway products in the urine of children with IgAVN that warrants further investigation.
Collapse
Affiliation(s)
- Julien Marro
- Department of Women's and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Andrew J Chetwynd
- Department of Women's and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
- Centre for Proteome Research, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Jennifer Hawkes
- Department of Women's and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Sarah J Northey
- Department of Women's and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Louise Oni
- Department of Women's and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
- Department of Paediatric Nephrology, Alder Hey Children's NHS Foundation Trust Hospital, Liverpool, UK
| |
Collapse
|
4
|
Ying S, Liu L, Luo C, Liu Y, Zhao C, Ge W, Wu N, Ruan Y, Wang W, Zhang J, Qiu W, Wang Y. Sublytic C5b-9 induces TIMP3 expression by glomerular mesangial cells via TRAF6-dependent KLF5 K63-linked ubiquitination in rat Thy-1 nephritis. Int Immunopharmacol 2023; 124:110970. [PMID: 37748221 DOI: 10.1016/j.intimp.2023.110970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/07/2023] [Accepted: 09/18/2023] [Indexed: 09/27/2023]
Abstract
Rat Thy-1 nephritis (Thy-1N) is an experimental model for studying human mesangioproliferative glomerulonephritis (MsPGN), and its pathological features are glomerular mesangial cell (GMC) proliferation and extracellular matrix (ECM) accumulation. Although we have confirmed that renal lesions of Thy-1N rats are sublytic C5b-9-dependent, and ECM accumulation is related to tissue inhibitor of matrix metalloproteinase (TIMP) inhibiting matrix metalloproteinase (MMP) activity, whether sublytic C5b-9 can induce TIMP production by GMC in Thy-1N rat and the underlying mechanism remains unclear. In the study, we proved that the expressions of TIMP3, krϋppel-like transcription factor 5 (KLF5) and tumor necrosis factor receptor-associated factor 6 (TRAF6) were simultaneously up-regulated both in the renal tissues of Thy-1N rats (in vivo) and in the GMC exposed to sublytic C5b-9 (in vitro). Further mechanism exploration discovered that KLF5 and TRAF6 as two upstream molecules could induce TIMP3 gene transcription through binding to the same region i.e., -1801nt to -1554nt (GGGGAGGGGC) and -228nt to -46nt (GCCCCGCCCC) of TIMP3 promoter. In the process, TRAF6 mediated KLF5 K63-linked ubiquitination at K99 and K100 enhancing KLF5 nuclear localization and binding to TIMP3 promoter, augmenting its gene activation. Furthermore, the experiments in vivo exhibited that silencing KLF5, TRAF6 or TIMP3 gene could markedly lessen renal KLF5 K63-linked ubiquitination or TIMP3 induction, ECM accumulation and other pathological changes of Thy-1N rats. Besides, the positive expressions of above-mentioned these proteins and ECM accumulation and their correlation in the renal tissues of MsPGN patients were also demonstrated. Overall, our findings implicate that KLF5 and TRAF6 play a promoting role in sublytic C5b-9-triggered TIMP3 gene transcription and expression, which might provide a novel mechanistic insight into rat Thy-1N and human MsPGN.
Collapse
Affiliation(s)
- Shuai Ying
- Department of Immunology, and Key Laboratory of Immunological Environment and Disease, Nanjing Medical University, Nanjing, China
| | - Longfei Liu
- Department of Central Laboratory, The Affiliated Huaian No. 1 People's Hospital, Nanjing Medical University, Huai'an, China
| | - Can Luo
- Department of Immunology, and Key Laboratory of Immunological Environment and Disease, Nanjing Medical University, Nanjing, China
| | - Yu Liu
- Department of Microbiology and Immunology, Jiangsu Health Vocational College, Nanjing, China
| | - Chenhui Zhao
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Wen Ge
- Department of Immunology, and Key Laboratory of Immunological Environment and Disease, Nanjing Medical University, Nanjing, China
| | - Ningxia Wu
- Department of Immunology, and Key Laboratory of Immunological Environment and Disease, Nanjing Medical University, Nanjing, China
| | - Yuting Ruan
- Department of Immunology, and Key Laboratory of Immunological Environment and Disease, Nanjing Medical University, Nanjing, China
| | - Weiming Wang
- Department of Immunology, and Key Laboratory of Immunological Environment and Disease, Nanjing Medical University, Nanjing, China
| | - Jing Zhang
- Department of Immunology, and Key Laboratory of Immunological Environment and Disease, Nanjing Medical University, Nanjing, China; Key Laboratory of Antibody Technology of Ministry of Health, Nanjing Medical University, Nanjing, China
| | - Wen Qiu
- Department of Immunology, and Key Laboratory of Immunological Environment and Disease, Nanjing Medical University, Nanjing, China; Key Laboratory of Antibody Technology of Ministry of Health, Nanjing Medical University, Nanjing, China.
| | - Yingwei Wang
- Department of Immunology, and Key Laboratory of Immunological Environment and Disease, Nanjing Medical University, Nanjing, China; Key Laboratory of Antibody Technology of Ministry of Health, Nanjing Medical University, Nanjing, China.
| |
Collapse
|
5
|
Lv Y, Fu R, Peng XJ, Wang Y, Yin TT, Deng YQ. Comparative study on clinicopathological features and prognosis of IgA vasculitis nephritis and IgA nephropathy in children. BMC Pediatr 2023; 23:423. [PMID: 37620917 PMCID: PMC10464207 DOI: 10.1186/s12887-023-04243-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 08/11/2023] [Indexed: 08/26/2023] Open
Abstract
BACKGROUND IgA vasculitis nephritis (IgAVN) and IgA nephropathy (IgAN) share several clinical and pathological characteristics, though distinctions also exist. Their interrelation, however, remains undefined. This study investigates the clinicopathological divergences and prognostic disparities in pediatric patients with IgAVN and IgAN. METHODS Our study encompasses 809 pediatric patients with IgAVN and 236 with IgAN, all of whom underwent kidney biopsy. We utilized the Semiquantitative Classification (SQC) scoring system to juxtapose the pathologies of the two conditions, and performed a COX regression analysis to examine factors influencing their prognoses. RESULTS Both patient groups demonstrated a predominance of males. A seasonality was observed, with a higher incidence of IgAN in the summer, and IgAVN in the fall (P < 0.0001). Patients with IgAN exhibited more severe tubulointerstitial injury, higher chronicity index, and total biopsy scores compared to those with IgAVN (P < 0.0001). Mesangial deposition intensity of complement C3, and the rate of pure IgA deposition, were found to be greater in patients with IgAVN compared to those with IgAN (P < 0.0001). The intensity of IgA deposition was also significantly higher in IgAVN patients (P = 0.003). IgAVN demonstrated a superior prognosis, with a higher rate of kidney remission (P < 0.0001). COX regression analysis indicated that interstitial fibrosis, as identified in the SQC pathology system, was associated with the prognosis of both conditions. Furthermore, the findings suggest that IgA deposition levels (IgA + + and IgA + + +) could potentially influence the prognosis of IgAVN. CONCLUSIONS Compared to IgAVN, IgAN manifests more severely with regard to renal impairment, interstitial damage, and prognosis. The disparities in immune complex deposition levels and locations within the kidneys support the hypothesis of IgAVN and IgAN as distinct diseases. Interstitial fibrosis may serve as a key pathological indicator within the SQC system associated with kidney prognosis in children with IgAVN and IgAN. The degree of IgA deposition could also be linked with the prognosis of IgAVN.
Collapse
Affiliation(s)
- Yan Lv
- Department of Nephrology, Jiangxi Provincial Children's Hospital, Nanchang, China
- Nanchang University, Nanchang, Jiangxi Province, China
| | - Rui Fu
- Department of Nephrology, Jiangxi Provincial Children's Hospital, Nanchang, China
| | - Xiao-Jie Peng
- Department of Nephrology, Jiangxi Provincial Children's Hospital, Nanchang, China.
| | - Ying Wang
- Nanchang University, Nanchang, Jiangxi Province, China
| | - Ting-Ting Yin
- Nanchang University, Nanchang, Jiangxi Province, China
| | - Yan-Qing Deng
- Nanchang University, Nanchang, Jiangxi Province, China
| |
Collapse
|
6
|
Kronbichler A, Bajema I, Geetha D, Säemann M. Novel aspects in the pathophysiology and diagnosis of glomerular diseases. Ann Rheum Dis 2022; 82:585-593. [PMID: 36535746 DOI: 10.1136/ard-2022-222495] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022]
Abstract
Immune deposits/complexes are detected in a multitude of tissues in autoimmune disorders, but no organ has attracted as much attention as the kidney. Several kidney diseases are characterised by the presence of specific configurations of such deposits, and many of them are under a 'shared care' between rheumatologists and nephrologists. This review focuses on five different diseases commonly encountered in rheumatological and nephrological practice, namely IgA vasculitis, lupus nephritis, cryoglobulinaemia, anti-glomerular basement membrane disease and anti-neutrophil cytoplasm-antibody glomerulonephritis. They differ in disease aetiopathogenesis, but also the potential speed of kidney function decline, the responsiveness to immunosuppression/immunomodulation and the deposition of immune deposits/complexes. To date, it remains unclear if deposits are causing a specific disease or aim to abrogate inflammatory cascades responsible for tissue damage, such as neutrophil extracellular traps or the complement system. In principle, immunosuppressive therapies have not been developed to tackle immune deposits/complexes, and repeated kidney biopsy studies found persistence of deposits despite reduction of active inflammation, again highlighting the uncertainty about their involvement in tissue damage. In these studies, a progression of active lesions to chronic changes such as glomerulosclerosis was frequently reported. Novel therapeutic approaches aim to mitigate these changes more efficiently and rapidly. Several new agents, such as avacopan, an oral C5aR1 inhibitor, or imlifidase, that dissolves IgG within minutes, are more specifically reducing inflammatory cascades in the kidney and repeat tissue sampling might help to understand their impact on immune cell deposition and finally kidney function recovery and potential impact of immune complexes/deposits.
Collapse
Affiliation(s)
- Andreas Kronbichler
- Department of Medicine, University of Cambridge, Cambridge, UK .,Vasculitis and Lupus Service, Addenbrooke's Hospital, Cambridge, UK
| | - Ingeborg Bajema
- Department of Pathology, Leiden University Medical Center, Leiden and Department of Pathology and Medical Biology, University of Groningen, University Medical Center, Groningen, The Netherlands
| | - Duvuru Geetha
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Marcus Säemann
- 6th Medical Department, Nephrology and Dialysis, Clinic Ottakring, Vienna, Austria.,Medical Faculty, Sigmund Freud University, Vienna, Austria
| |
Collapse
|
7
|
Brandwijk RJMGE, Michels MAHM, van Rossum M, de Nooijer AH, Nilsson PH, de Bruin WCC, Toonen EJM. Pitfalls in complement analysis: A systematic literature review of assessing complement activation. Front Immunol 2022; 13:1007102. [PMID: 36330514 PMCID: PMC9623276 DOI: 10.3389/fimmu.2022.1007102] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/13/2022] [Indexed: 11/13/2022] Open
Abstract
Background The complement system is an essential component of our innate defense and plays a vital role in the pathogenesis of many diseases. Assessment of complement activation is critical in monitoring both disease progression and response to therapy. Complement analysis requires accurate and standardized sampling and assay procedures, which has proven to be challenging. Objective We performed a systematic analysis of the current methods used to assess complement components and reviewed whether the identified studies performed their complement measurements according to the recommended practice regarding pre-analytical sample handling and assay technique. Results are supplemented with own data regarding the assessment of key complement biomarkers to illustrate the importance of accurate sampling and measuring of complement components. Methods A literature search using the Pubmed/MEDLINE database was performed focusing on studies measuring the key complement components C3, C5 and/or their split products and/or the soluble variant of the terminal C5b-9 complement complex (sTCC) in human blood samples that were published between February 2017 and February 2022. The identified studies were reviewed whether they had used the correct sample type and techniques for their analyses. Results A total of 92 out of 376 studies were selected for full-text analysis. Forty-five studies (49%) were identified as using the correct sample type and techniques for their complement analyses, while 25 studies (27%) did not use the correct sample type or technique. For 22 studies (24%), it was not specified which sample type was used. Conclusion A substantial part of the reviewed studies did not use the appropriate sample type for assessing complement activation or did not mention which sample type was used. This deviation from the standardized procedure can lead to misinterpretation of complement biomarker levels and hampers proper comparison of complement measurements between studies. Therefore, this study underlines the necessity of general guidelines for accurate and standardized complement analysis
Collapse
Affiliation(s)
| | - Marloes A. H. M. Michels
- Radboud Institute for Molecular Life Sciences, Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Nijmegen, Netherlands
| | - Mara van Rossum
- R&D Department, Hycult Biotechnology b.v., Uden, Netherlands
| | - Aline H. de Nooijer
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
| | - Per H. Nilsson
- Department of Immunology, University of Oslo and Oslo University Hospital Rikshospitalet, Oslo, Norway
- Linnaeus Centre for Biomaterials Chemistry, Linnaeus University, Kalmar, Sweden
- Department of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, Sweden
| | | | - Erik J. M. Toonen
- R&D Department, Hycult Biotechnology b.v., Uden, Netherlands
- *Correspondence: Erik J. M. Toonen,
| |
Collapse
|
8
|
Wright RD, Marro J, Northey SJ, Corkhill R, Beresford MW, Oni L. Urinary complement proteins are increased in children with IgA vasculitis (Henoch-Schönlein purpura) nephritis. Pediatr Nephrol 2022; 38:1491-1498. [PMID: 36227437 PMCID: PMC10060309 DOI: 10.1007/s00467-022-05747-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 09/08/2022] [Accepted: 09/08/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND Children with immunoglobulin A vasculitis (IgAV Henoch-Schönlein purpura) frequently encounter nephritis (IgAV-N) with 1-2% risk of kidney failure. The pathophysiology of IgAV-N is not fully understood with speculation that complement may contribute. The aim of this study was to identify whether urinary complement proteins are increased in children with IgAV-N. METHODS A cross-sectional prospective cohort of children with IgAV were recruited together with controls including healthy children and children with systemic lupus erythematosus (SLE). Patients were subdivided according to the presence of nephritis. Urinary C3, C4, C5, and C5a were measured by enzyme-linked immunosorbent assay (ELISA) and corrected for urinary creatinine. RESULTS The study included 103 children; 47 with IgAV (37 IgAV without nephritis, IgAVwoN; 10 IgAV-N), 30 SLE and 26 healthy children. Urinary complement C3, C4, and C5 were all statistically significantly increased in all children with IgAV compared to SLE patients (all p < 0.05). In patients with IgAV-N, urinary complement C3, C4, C5, C5a were all statistically significantly increased compared to IgAVwoN (C3 14.65 μg/mmol [2.26-20.21] vs. 2.26 μg/mmol [0.15-3.14], p = 0.007; C4 6.52 μg/mmol [1.30-9.72] vs. 1.37 μg/mmol [0.38-2.43], p = 0.04; C5 1.36 μg/mmol [0.65-2.85] vs. 0.38 μg/mmol [0.03-0.72], p = 0.005; C5a 101.9 ng/mmol [15.36-230.0] vs. 18.33 ng/mmol [4.27-33.30], p = 0.01). Using logistic regression, the urinary complement components produced an outstanding ability to discriminate between patients with and without nephritis in IgAV (AUC 0.92, p < 0.001). CONCLUSIONS Children with IgAV-N have evidence of increased complement proteins present in their urine that may indicate a pathological role and may allow treatment stratification. A higher resolution version of the Graphical abstract is available as Supplementary information.
Collapse
Affiliation(s)
- Rachael D Wright
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Member of Liverpool Health Partners, Eaton Road, Liverpool, L12 2AP, UK
| | - Julien Marro
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Member of Liverpool Health Partners, Eaton Road, Liverpool, L12 2AP, UK
| | - Sarah J Northey
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Member of Liverpool Health Partners, Eaton Road, Liverpool, L12 2AP, UK
| | - Rachel Corkhill
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Member of Liverpool Health Partners, Eaton Road, Liverpool, L12 2AP, UK
| | - Michael W Beresford
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Member of Liverpool Health Partners, Eaton Road, Liverpool, L12 2AP, UK
- Department of Paediatric Rheumatology, Alder Hey Children's NHS Foundation Trust, Member of Liverpool Health Partners, Liverpool, UK
| | - Louise Oni
- Department of Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Member of Liverpool Health Partners, Eaton Road, Liverpool, L12 2AP, UK.
- Department of Paediatric Nephrology, Alder Hey Children's NHS Foundation Trust, Member of Liverpool Health Partners, Eaton Road, Liverpool, L12 2AP, UK.
| |
Collapse
|
9
|
van Straalen KR, Dudink K, Aarts P, van der Zee HH, van den Bosch TPP, Giang J, Prens EP, Damman J. Complement activation in Hidradenitis suppurativa: Covert low-grade inflammation or innocent bystander? Front Immunol 2022; 13:953674. [PMID: 36211440 PMCID: PMC9535337 DOI: 10.3389/fimmu.2022.953674] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 08/04/2022] [Indexed: 11/13/2022] Open
Abstract
Hidradenitis suppurativa (HS) is a chronic auto-inflammatory skin disease with a complex and multifactorial pathogenesis involving both the innate and adaptive immune system. Despite limited evidence for local complement activation, conflicting results have been published on the role of systemic complement activation in HS. It was hypothesized that complement was consumed in highly inflamed HS skin, trapping complement from the circulation. Therefore, the aim of this study was to evaluate this local complement deposition in HS skin lesions using routine and commonly used complement antibodies.Direct immunofluorescence for C1q, C3c, C4d, C5b-9, and properdin was performed on frozen tissue sections of 19 HS patients and 6 controls. C5a receptor 1 (C5aR1) was visualized using immunohistochemistry.Overall, we found no significant local complement deposition in HS patients versus controls regarding C1q, C3c, C4d, C5b-9, or properdin on either vessels or immune cells. C5aR1 expression was exclusively found on immune cells, predominantly neutrophilic granulocytes, but not significantly different relatively to the total infiltrate in HS lesions compared with controls. In conclusion, despite not being able to confirm local complement depositions of C1q, C3c, C4d, or properdin using highly sensitive and widely accepted techniques, the increased presence of C5aR1 positive immune cells in HS suggests the importance of complement in the pathogenesis of HS and supports emerging therapies targeting this pathway.
Collapse
Affiliation(s)
- K. R. van Straalen
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - K. Dudink
- Department of Dermatology, Erasmus University Medical Center Rotterdam, Rotterdam, Netherlands
| | - P. Aarts
- Department of Dermatology, Erasmus University Medical Center Rotterdam, Rotterdam, Netherlands
| | - H. H. van der Zee
- Department of Dermatology, Erasmus University Medical Center Rotterdam, Rotterdam, Netherlands
| | - T. P. P. van den Bosch
- Department of Pathology, Erasmus University Medical Center Rotterdam, Rotterdam, Netherlands
| | - J. Giang
- Department of Pathology, Maasstad Hospital, Rotterdam, Netherlands
| | - E. P. Prens
- Department of Dermatology, Erasmus University Medical Center Rotterdam, Rotterdam, Netherlands
- Laboratory for Experimental Immunodermatology, Department of Dermatology, Erasmus University Medical Center Rotterdam, Rotterdam, Netherlands
| | - J. Damman
- Department of Pathology, Erasmus University Medical Center Rotterdam, Rotterdam, Netherlands
- *Correspondence: J. Damman,
| |
Collapse
|
10
|
IgA vasculitis with nephritis: update of pathogenesis with clinical implications. Pediatr Nephrol 2022; 37:719-733. [PMID: 33818625 PMCID: PMC8490493 DOI: 10.1007/s00467-021-04950-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/17/2020] [Accepted: 01/14/2021] [Indexed: 12/13/2022]
Abstract
IgA vasculitis with nephritis (IgAVN) shares many pathogenetic features with IgA nephropathy (IgAN). The purpose of this review is to describe our current understanding of the pathogenesis of pediatric IgAVN, particularly as it relates to the four-hit hypothesis for IgAN. These individual steps, i.e., hits, in the pathogenesis of IgAN are (1) elevated production of IgA1 glycoforms with some O-glycans deficient in galactose (galactose-deficient IgA1; Gd-IgA1), (2) generation of circulating IgG autoantibodies specific for Gd-IgA1, (3) formation of pathogenic circulating Gd-IgA1-containing immune complexes, and (4) kidney deposition of the Gd-IgA1-IgG immune complexes from the circulation and induction of glomerular injury. Evidence supporting the four-hit hypothesis in the pathogenesis of pediatric IgAVN is detailed. The genetics, pediatric outcomes, and kidney histopathologic features and the impact of these findings on future treatment and potential biomarkers are discussed. In summary, the evidence points to the critical roles of Gd-IgA1-IgG immune complexes and complement activation in the pathogenesis of IgAVN. Future studies are needed to characterize the features of the immune and autoimmune responses that enable progression of IgA vasculitis to IgAVN.
Collapse
|
11
|
Abstract
PURPOSE OF REVIEW The purpose of this update is to summarize current knowledge on the pathophysiology of immunglobulin A (IgA) vasculitis nephritis (IgAVN) as well as to critically review evidence for established therapeutic regimes and available biomarkers. An additional purpose is to raise the discussion what could be done to further improve our understanding of IgAVN, identify patients at risk for adverse outcome and increase the evidence for therapy recommendations. RECENT FINDINGS Clinical and experimental studies have established the concept of a multilevel pathogenesis. Toll-like-receptor activation, B cell proliferation, micro-RNAs and complement activation have been identified or confirmed as potential therapeutic targets which can modify the course of the disease. Currently, kidney injury molecule-1, monocyte chemotactic protein-1, N-acetyl-β-glucosaminidase, and angiotensinogen are the most promising urinary biomarkers for early diagnosis of renal involvement in IgA vasculitis. SUMMARY Close surveillance of all IgAV patients for renal involvement is recommended. Given the multilevel pathogenesis, early treatment of even mild cases should be initiated. Further therapeutic options should be considered in case first-line therapy (mostly corticosteroids) has no effect. The evidence supporting current therapeutic regimes is predominantly based on expert opinion. Prospective studies are needed and should involve substances inhibiting B cell proliferation and complement activation.
Collapse
Affiliation(s)
- Eva Nüsken
- Pediatric Nephrology, Children's and Adolescents' Hospital, University Hospital of Cologne, Faculty of Medicine, University of Cologne, Köln, Germany
| | | |
Collapse
|
12
|
Urinary C5b-9 as a Prognostic Marker in IgA Nephropathy. J Clin Med 2022; 11:jcm11030820. [PMID: 35160271 PMCID: PMC8836759 DOI: 10.3390/jcm11030820] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/24/2022] [Accepted: 02/02/2022] [Indexed: 01/27/2023] Open
Abstract
C5b-9 plays an important role in the pathogenesis of immunoglobin A nephropathy (IgAN). We evaluated C5b-9 as a prognostic marker for IgAN. We prospectively enrolled 33 patients with biopsy-proven IgAN. We analyzed the correlation between baseline urinary C5b-9 levels, posttreatment changes in their levels, and clinical outcomes, including changes in proteinuria, estimated glomerular filtration rate (eGFR), and treatment response. Baseline urinary C5b-9 levels were positively correlated with proteinuria (r = 0.548, p = 0.001) at the time of diagnosis. Changes in urinary C5b-9 levels were positively correlated with changes in proteinuria (r = 0.644, p < 0.001) and inversely correlated with changes in eGFR (r = −0.410, p = 0.018) at 6 months after treatment. Changes in urinary C5b-9 levels were positively correlated with time-averaged proteinuria during the follow-up period (r= 0.461, p = 0.007) but were not correlated with the mean annual rate of eGFR decline (r = −0.282, p = 0.112). Baseline urinary C5b-9 levels were not a significant independent factor that could predict the treatment response in logistic regression analyses (odds ratio 0.997; 95% confidence interval, 0.993 to 1.000; p = 0.078). Currently, urinary C5b-9 is not a promising prognostic biomarker for IgAN, and further studies are needed.
Collapse
|
13
|
Comparison of Complement Pathway Activation in Autoimmune Glomerulonephritis. Kidney Int Rep 2022; 7:1027-1036. [PMID: 35571000 PMCID: PMC9091805 DOI: 10.1016/j.ekir.2022.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 01/27/2022] [Accepted: 02/04/2022] [Indexed: 12/11/2022] Open
Abstract
Introduction Methods Results Conclusion
Collapse
|
14
|
Comparison of clinical, pathological and long-term renal outcomes of children with Henoch-Schonlein purpura nephritis and IgA nephropathy. Int Urol Nephrol 2021; 54:1925-1932. [PMID: 34846620 DOI: 10.1007/s11255-021-03063-7] [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: 01/19/2021] [Accepted: 11/11/2021] [Indexed: 02/05/2023]
Abstract
PURPOSE To compare clinical, pathological, and long-term renal outcomes of children with Henoch-Schonlein purpura nephritis (HSPN) and IgA nephropathy (IgAN). METHODS The medical records of patients diagnosed as HSPN and IgAN during childhood were evaluated retrospectively. HSPN and IgAN groups were compared in terms of gender, age, upper respiratory infection history, blood pressure; presence of nephrotic and/or nephritic syndrome; hemoglobin level, leukocyte count, C-reactive protein (CRP), serum albumin (sAlb), creatinine, complement 3 (sC3), complement 4 (sC4) and immunoglobulin A (sIgA) levels; estimated glomerular filtration rate (eGFR) and proteinuria levels; and renal pathology findings at the onset of disease; total follow-up time; and blood pressure, eGFR and proteinuria levels at the last visit. RESULTS Fifty-four patients were enrolled in the study [38 (70%) HSPN and 16 (30%) IgAN]. The median follow-up time was 60.5 and 72.0 months in HSPN and IgAN groups, respectively (p > 0.05). The HSPN and IgAN groups were also not different in terms of gender, age at the onset; leukocyte count, eGFR, sC3-sC4-sIgA levels; and the presence of endocapillary, extracapillary and mesangial proliferation, tubular atrophy, interstitial fibrosis and IgA, IgM, C3 accumulation in renal tissue. Upper respiratory tract infection history was more common in children with IgAN (8/16 vs 8/38, p = 0.045). sAlb (3.96 ± 0.58 vs 4.40 ± 0.46 g/dL, p = 0.005), hemoglobin (12.1 ± 1.3 vs 13.3 ± 1.2 g/dL, p = 0.004,) and the incidence of mesangial IgG deposition (15/38 vs 11/16, p = 0.049) were lower, while CRP (16.3 ± 7.2 vs 7.8 ± 4.4 mg/L, p = 0.002) and proteinuria (72.1 ± 92.4 vs 34.2 ± 37.9 mg/m2/24 h, p = 0.041) was higher in HSPN group at the onset of disease. Proteinuria and eGFR were similar between the two groups at last visit. CONCLUSION Children with HSPN and IgAN have little clinical and histological differences in our population. The most prominent difference at presentation with nephritis was higher proteinuria in HSPN probably associated with inflammation due to systemic vasculitis. Long-term renal outcome was good in both HSPN and IgAN.
Collapse
|
15
|
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.
Collapse
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
| |
Collapse
|
16
|
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.
Collapse
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
| |
Collapse
|