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Mao M, Zhou Y, Zhang X, Zhao XY, Wang CD, Chen P. Renin-angiotensin-aldosterone-system inhibitors increase the serum level of complement component 4 in patients with immunoglobulin A nephropathy. Int Immunopharmacol 2024; 130:111669. [PMID: 38387189 DOI: 10.1016/j.intimp.2024.111669] [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: 11/26/2023] [Revised: 01/28/2024] [Accepted: 02/06/2024] [Indexed: 02/24/2024]
Abstract
OBJECTIVE To investigate the impact of renin-angiotensin-aldosterone-system (RAAS) inhibitors on complement component 4 (C4) serum levels in patients with immunoglobulin A nephropathy (IgAN). METHODS A total of 423 patients diagnosed with IgAN at Shanxi Provincial People's Hospital, China, between 1 January 2017 and 31 December 2021 were divided into two groups, a RAAS inhibitor group and a non-RAAS inhibitor group, for comparative analysis. RESULTS The RAAS inhibitor group exhibited significantly increased C4 and eGFR levels and had a higher proportion of patients with hypertension compared with the non-RAAS inhibitor group. Serum C4 levels were positively correlated with 24-hour urine protein, serum C3 levels and blood uric acid levels but negatively correlated with eGFR levels. In addition, serum C4 levels were positively correlated with the severity of mesangial hypercellularity and interstitial/tubular injury. Through prognostic analysis, serum C4 was identified as an independent risk factor for the progression of IgAN. CONCLUSION Renin-angiotensin-aldosterone-system inhibitors can increase serum C4 levels in patients with IgAN and may represent an independent risk factor for disease progression.
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Affiliation(s)
- Min Mao
- Department of Nephrology, The Fifth Clinical Medical College of Shanxi Medical University (Shanxi Provincial People's Hospital), Taiyuan, China
| | - Yun Zhou
- Department of Nephrology, The Fifth Clinical Medical College of Shanxi Medical University (Shanxi Provincial People's Hospital), Taiyuan, China; Department of Nephrology, Shanxi Province Integrated TCM and WM Hospital, Taiyuan, China
| | - Xu Zhang
- Department of Nephrology, The Fifth Clinical Medical College of Shanxi Medical University (Shanxi Provincial People's Hospital), Taiyuan, China
| | - Xiao-Yu Zhao
- Department of Nephrology, The Fifth Clinical Medical College of Shanxi Medical University (Shanxi Provincial People's Hospital), Taiyuan, China
| | - Chen-Dan Wang
- Department of Nephrology, The Fifth Clinical Medical College of Shanxi Medical University (Shanxi Provincial People's Hospital), Taiyuan, China
| | - Ping Chen
- Department of Nephrology, The Fifth Clinical Medical College of Shanxi Medical University (Shanxi Provincial People's Hospital), Taiyuan, China.
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Zhang H, Rizk DV, Perkovic V, Maes B, Kashihara N, Rovin B, Trimarchi H, Sprangers B, Meier M, Kollins D, Papachristofi O, Milojevic J, Junge G, Nidamarthy PK, Charney A, Barratt J. Results of a randomized double-blind placebo-controlled Phase 2 study propose iptacopan as an alternative complement pathway inhibitor for IgA nephropathy. Kidney Int 2024; 105:189-199. [PMID: 37914086 DOI: 10.1016/j.kint.2023.09.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 08/30/2023] [Accepted: 09/27/2023] [Indexed: 11/03/2023]
Abstract
Targeting the alternative complement pathway is an attractive therapeutic strategy given its role in the pathogenesis of immunoglobulin A nephropathy (IgAN). Iptacopan (LNP023) is an oral, proximal alternative complement inhibitor that specifically binds to Factor B. Our randomized, double-blind, parallel-group adaptive Phase 2 study (NCT03373461) enrolled patients with biopsy-confirmed IgAN (within previous three years) with estimated glomerular filtration rates of 30 mL/min/1.73 m2 and over and urine protein 0.75 g/24 hours and over on stable doses of renin angiotensin system inhibitors. Patients were randomized to four iptacopan doses (10, 50, 100, or 200 mg bid) or placebo for either a three-month (Part 1; 46 patients) or a six-month (Part 2; 66 patients) treatment period. The primary analysis evaluated the dose-response relationship of iptacopan versus placebo on 24-hour urine protein-to-creatinine ratio (UPCR) at three months. Other efficacy, safety and biomarker parameters were assessed. Baseline characteristics were generally well-balanced across treatment arms. There was a statistically significant dose-response effect, with 23% reduction in UPCR achieved with iptacopan 200 mg bid (80% confidence interval 8-34%) at three months. UPCR decreased further through six months in iptacopan 100 and 200 mg arms (from a mean of 1.3 g/g at baseline to 0.8 g/g at six months in the 200 mg arm). A sustained reduction in complement biomarker levels including plasma Bb, serum Wieslab, and urinary C5b-9 was observed. Iptacopan was well-tolerated, with no reports of deaths, treatment-related serious adverse events or bacterial infections, and led to strong inhibition of alternative complement pathway activity and persistent proteinuria reduction in patients with IgAN. Thus, our findings support further evaluation of iptacopan in the ongoing Phase 3 trial (APPLAUSE-IgAN; NCT04578834).
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Affiliation(s)
- Hong Zhang
- Renal Division, Peking University First Hospital, Peking University Institute of Nephrology, Beijing, People's Republic of China.
| | - Dana V Rizk
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Vlado Perkovic
- University of New South Wales, Sydney, New South Wales, Australia
| | - Bart Maes
- Department of Nephrology, AZ Delta, Roeselare, Belgium
| | - Naoki Kashihara
- Department of Nephrology and Hypertension, Kawasaki Medical School, Kurashiki, Japan
| | - Brad Rovin
- Division of Nephrology, the Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Hernán Trimarchi
- Nephrology Service and Kidney Transplantation Unit, Hospital Británico de Buenos Aires, Buenos Aires, Argentina
| | - Ben Sprangers
- Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium; Department of Nephrology, University Hospitals Leuven, Leuven, Belgium
| | | | | | | | - Julie Milojevic
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Guido Junge
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | | | - Alan Charney
- Novartis Pharmaceuticals Corporation, East Hanover, New Jersey, USA
| | - Jonathan Barratt
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK; The John Walls Renal Unit, University Hospitals of Leicester NHS Trust, Leicester, UK
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Ștefan G, Jullien P, Masson I, Alamartine E, Mariat C, Maillard N. Circulating alternative pathway complement cleavage factor Bb is associated with vascular lesions and outcomes in IgA nephropathy. Nephrol Dial Transplant 2023; 38:ii11-ii18. [PMID: 37816675 DOI: 10.1093/ndt/gfad163] [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: 04/13/2023] [Indexed: 10/12/2023] Open
Abstract
BACKGROUND Complement alternative pathway (AP) activation is linked to immunoglobulin A nephropathy (IgAN) prognosis severity, but Bb fragment's role is unclear. We examined the relationship between serum Bb fragment concentration at IgAN diagnosis and disease activity and outcomes. METHODS This retrospective study included 125 biopsy-proven IgAN patients [age 39.9 years, 75% male, estimated glomerular filtration rate (eGFR) 82 ml/min, proteinuria 0.5 g/day] enrolled from 1984 to 2010 and followed for a minimum of 18 months. Monitoring continued until the last follow-up, end-stage kidney disease (ESKD) or death. Serum Bb fragment was measured using an enzyme-linked immunosorbent assay at diagnosis. Oxford classification and global optical score (GOS) were utilized for pathology assessment. RESULTS Patients were followed for a median of 16 years; 42% developed chronic kidney disease stage ≥3, 19% reached ESKD and 9% died. Serum Bb fragment concentration negatively correlated with eGFR values at the last follow-up and positively with vascular and tubular histopathological indices. In univariate Cox regression analyses, higher Bb fragment concentration was associated with ESKD alongside older age, increased body mass index, arterial hypertension, lower eGFR, higher proteinuria, E1, S1, T1-2, GOS and corticotherapy. Patients with Bb levels ≥14.3 μg/ml had shorter mean kidney survival time (19.5 versus 22.7 years, P = .07); after adjusting for progression risk factors, the association persisted [hazard ratio 4.76 (95% confidence interval 1.56-14.43)]. CONCLUSIONS Serum Bb fragment concentration at diagnosis may predict long-term IgAN outcomes, potentially due to AP activation at the endothelial surface. Further research is needed to confirm these results and evaluate Bb fragment's role in IgAN management.
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Affiliation(s)
- Gabriel Ștefan
- Service de Néphrologie, Hôpital Nord CHU Saint Etienne, Saint Etienne, France
- University of Medicine and Pharmacy "Carol Davila", Nephrology Department, Bucharest, Romania
| | - Perrine Jullien
- Service de Néphrologie, Hôpital Nord CHU Saint Etienne, Saint Etienne, France
- Groupe Immunité muqueuse et agents pathogènes (GIMAP, team 15 CIRI INSERM U1111/UMR5108), Saint Etienne, France
| | - Ingrid Masson
- Service de Néphrologie, Hôpital Nord CHU Saint Etienne, Saint Etienne, France
- Groupe Immunité muqueuse et agents pathogènes (GIMAP, team 15 CIRI INSERM U1111/UMR5108), Saint Etienne, France
| | - Eric Alamartine
- Service de Néphrologie, Hôpital Nord CHU Saint Etienne, Saint Etienne, France
- Groupe Immunité muqueuse et agents pathogènes (GIMAP, team 15 CIRI INSERM U1111/UMR5108), Saint Etienne, France
| | - Christophe Mariat
- Service de Néphrologie, Hôpital Nord CHU Saint Etienne, Saint Etienne, France
- Groupe Immunité muqueuse et agents pathogènes (GIMAP, team 15 CIRI INSERM U1111/UMR5108), Saint Etienne, France
| | - Nicolas Maillard
- Service de Néphrologie, Hôpital Nord CHU Saint Etienne, Saint Etienne, France
- Groupe Immunité muqueuse et agents pathogènes (GIMAP, team 15 CIRI INSERM U1111/UMR5108), Saint Etienne, France
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Shi DC, Feng SZ, Zhong Z, Cai L, Wang M, Fu DY, Yu XQ, Li M. Functional variant rs12614 in CFB confers a low risk of IgA nephropathy by attenuating complement alternative pathway activation in Han Chinese. Front Immunol 2022; 13:973169. [PMID: 36311737 PMCID: PMC9606215 DOI: 10.3389/fimmu.2022.973169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 09/26/2022] [Indexed: 12/14/2022] Open
Abstract
Activation of the alternative pathway (AP) of complement is thought to play an important role in Immunoglobin A nephropathy (IgAN). Our previous study showed that rs4151657 within the complement factor B (CFB) gene increased the risk of IgAN. The protein encoded by the CFB gene is an initial factor that promotes AP activation. The aim of this study was to investigate whether other variants of CFB confer susceptibility to IgAN and elucidate their potential roles in AP activation. A total of 1,350 patients with IgAN and 1,420 healthy controls were enrolled and five tag single-nucleotide polymorphisms were selected for genotyping. The levels of key AP components, such as CFB, complement factor H and complement split product C3a, were measured by enzyme-linked immunosorbent assay. Molecular docking and molecular dynamic simulation were carried out to characterize the mutation of residues in the protein structure and the dynamic properties of wide type and mutation models of CFB protein. The allele-specific effect on CFB expression and its binding affinity to C3b were investigated through cell transfection and surface plasmon resonance analysis, respectively. We found that rs12614 significantly reduced the risk of IgAN (OR = 0.69, 95% CI = 0.52-0.91, P = 0.009), and the rs12614-T (R32W mutation) was correlated with lower CFB levels, higher serum C3 level, and less mesangial C3 deposition in patients with IgAN. The structural model showed that the R32W mutation reduced the structural stability of CFB protein. Furthermore, in vitro study revealed that rs12614-T decreased the expression of CFB and reduced its binding affinity to C3b by four-fold compared with rs12614-C. In conclusion, the rs12614-T in CFB was associated with low risk of IgAN probably by attenuating AP activation.
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Affiliation(s)
- Dian-Chun Shi
- Department of Nephrology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- NHC Key Laboratory of Clinical Nephrology (Sun Yat-sen University) and Guangdong Provincial Key Laboratory of Nephrology, Guangzhou, China
- Division of Nephrology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Shao-Zhen Feng
- Department of Nephrology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- NHC Key Laboratory of Clinical Nephrology (Sun Yat-sen University) and Guangdong Provincial Key Laboratory of Nephrology, Guangzhou, China
| | - Zhong Zhong
- Department of Nephrology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- NHC Key Laboratory of Clinical Nephrology (Sun Yat-sen University) and Guangdong Provincial Key Laboratory of Nephrology, Guangzhou, China
| | - Lu Cai
- Department of Nephrology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- NHC Key Laboratory of Clinical Nephrology (Sun Yat-sen University) and Guangdong Provincial Key Laboratory of Nephrology, Guangzhou, China
| | - Meng Wang
- Department of Nephrology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- NHC Key Laboratory of Clinical Nephrology (Sun Yat-sen University) and Guangdong Provincial Key Laboratory of Nephrology, Guangzhou, China
| | - Dong-Ying Fu
- Department of Nephrology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- NHC Key Laboratory of Clinical Nephrology (Sun Yat-sen University) and Guangdong Provincial Key Laboratory of Nephrology, Guangzhou, China
| | - Xue-Qing Yu
- Department of Nephrology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- NHC Key Laboratory of Clinical Nephrology (Sun Yat-sen University) and Guangdong Provincial Key Laboratory of Nephrology, Guangzhou, China
- Division of Nephrology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Ming Li
- Department of Nephrology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- NHC Key Laboratory of Clinical Nephrology (Sun Yat-sen University) and Guangdong Provincial Key Laboratory of Nephrology, Guangzhou, China
- Division of Nephrology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
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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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6
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Ji FP, Wen L, Zhang YP, Liu EP, Wen JG. Serum complement factor B is associated with disease activity and progression of idiopathic membranous nephropathy concomitant with IgA nephropathy. Int Urol Nephrol 2021; 54:1287-1294. [PMID: 34585312 DOI: 10.1007/s11255-021-02997-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 09/19/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Few studies have reported the roles of the complement system in concomitant idiopathic membranous nephropathy and IgA nephropathy (IMN-IgAN). Complement factor B (CFB) is a crucial factor that involved in the alternative complement pathway. We aimed to evaluate the association between disease activity (eGFR, anti-PLA2R antibody levels and 24 h urinary protein excretion), progression and serum CFB levels of IMN-IgAN patients. METHODS In total, 39 IMN-IgAN patients (median follow-up, 46.6 months), 99 IMN patients and 92 IgAN patients participated in this study. The disease progression event was defined as end-stage renal disease (ESRD) or a 30% decline in estimated glomerular filtration rate (eGFR). The serum CFB concentration was measured by enzyme-linked immunosorbent assay. RESULTS Serum CFB levels were lower in IMN-IgAN patients than in patients with IgAN only (P < .001). Serum CFB levels correlated positively with serum creatinine levels, anti-PLA2R antibody levels and 24 h urinary protein excretion (P < .05). Kaplan-Meier analysis revealed that IMN-IgAN patients with high serum CFB levels had a significantly lower cumulative renal survival rate than patients with low levels (log-rank test, P = .009). Multivariate Cox regression analysis showed that high baseline serum CFB levels were significantly associated with poor renal outcome in patients with IMN-IgAN (HR: 2.727, 95% CI 1.076-6.913, P = .034). CONCLUSION High serum CFB levels correlated with increased serum creatinine, anti-PLA2R antibody and urinary protein excretion as well as poor renal prognosis in patients with IMN-IgAN, indicating that serum CFB may be a marker of disease activity and progression.
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Affiliation(s)
- Feng Ping Ji
- Pediatric Urodynamic Centre, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.,Department of Urology, First Affiliated Hospital of Zhengzhou University, Jianshe East Road No.1, Zhengzhou, 450052, China
| | - Lu Wen
- Department of Nephrology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Yan Ping Zhang
- Pediatric Urodynamic Centre, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.,Department of Urology, First Affiliated Hospital of Zhengzhou University, Jianshe East Road No.1, Zhengzhou, 450052, China
| | - Er Peng Liu
- Pediatric Urodynamic Centre, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.,Department of Urology, First Affiliated Hospital of Zhengzhou University, Jianshe East Road No.1, Zhengzhou, 450052, China
| | - Jian Guo Wen
- Pediatric Urodynamic Centre, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China. .,Department of Urology, First Affiliated Hospital of Zhengzhou University, Jianshe East Road No.1, Zhengzhou, 450052, China.
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7
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Faria B, Canão P, Cai Q, Henriques C, Matos AC, Poppelaars F, Gaya da Costa M, Daha MR, Silva R, Pestana M, Seelen MA. Arteriolar C4d in IgA Nephropathy: A Cohort Study. Am J Kidney Dis 2020; 76:669-678. [PMID: 32439421 DOI: 10.1053/j.ajkd.2020.03.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 03/10/2020] [Indexed: 12/20/2022]
Abstract
RATIONALE & OBJECTIVE Glomerular C4d (C4dG) as an indicator of the lectin pathway of complement activation in immunoglobulin A nephropathy (IgAN) has been associated with more severe kidney damage. Recent studies have suggested that vascular lesions in IgAN biopsy specimens with complement deposition are also associated with disease progression. We aimed to study the clinical significance of arteriolar C4d (C4dA) in IgAN kidney biopsy tissue. STUDY DESIGN Retrospective cohort study. SETTING & PARTICIPANTS Kidney biopsy specimens from 126 adults with IgAN diagnosed by Oxford classification criteria were stained using immunohistochemistry and classified according to C4dG and C4dA deposition. Additionally, vascular lesions including acute and chronic microangiopathy, arteriolar hyalinosis, and arterial intima fibrosis were characterized. PREDICTOR C4dA. OUTCOME Progressive kidney disease, defined as a decline in estimated glomerular filtration rate by≥50% or occurrence of kidney failure. ANALYTICAL APPROACH The association of C4dA and C4dG with baseline clinical and histologic characteristics, as well as progressive kidney disease, were assessed with survival analysis using multivariable Cox regression analysis. RESULTS C4dA was identified in 21 (17%) patients and was associated with mean arterial pressure, arterial intima fibrosis, and chronic microangiopathy. C4dA was also significantly associated with C4dG and both were associated with progressive kidney disease. In regression analysis, C4dA remained significantly associated with progressive kidney disease after adjusting for other significant predictors, including baseline estimated glomerular filtration rate, mean arterial pressure, and the presence of crescents. LIMITATIONS Findings based on the retrospective evaluation of a single center's experience, limited number of events, a small number of patients with a broad range of kidney disease stages, and use of immunohistochemistry rather than immunofluorescence to detect C4d. CONCLUSIONS C4dA is a potential biomarker for disease progression in IgAN. It should be further investigated in larger cohorts to determine the value of C4dA in improving prediction of IgAN disease progression.
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Affiliation(s)
- Bernardo Faria
- Nephrology and Infectious Disease R&D Group, INEB, Institute of Investigation and Innovation in Health (i3S), University of Porto, Porto, Portugal; Division of Nephrology, Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
| | - Pedro Canão
- Department of Anatomic Pathology, Centro Hospitalar Universitário São João, Porto
| | - Qingqing Cai
- Division of Nephrology, Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Carla Henriques
- School of Technology and Management, Polytechnic Institute of Viseu, Viseu; Centre for Mathematics, University of Coimbra (CMUC), Coimbra
| | - Ana Cristina Matos
- School of Technology and Management, Polytechnic Institute of Viseu, Viseu; Centre for Research in Digital Services and CISeD, Viseu, Portugal
| | - Felix Poppelaars
- Division of Nephrology, Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Mariana Gaya da Costa
- Division of Nephrology, Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Mohamed R Daha
- Division of Nephrology, Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Department of Nephrology, University of Leiden, Leiden University Medical Center, Leiden, the Netherlands
| | - Roberto Silva
- Division of Nephrology, Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Manuel Pestana
- Nephrology and Infectious Disease R&D Group, INEB, Institute of Investigation and Innovation in Health (i3S), University of Porto, Porto, Portugal; Division of Nephrology, Centro Hospitalar Universitário São João and Department of Medicine, Faculty of Medicine of Porto University, Porto, Portugal
| | - Marc A Seelen
- Division of Nephrology, Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
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8
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van Essen MF, Ruben JM, de Vries APJ, van Kooten C. Role of properdin in complement-mediated kidney diseases. Nephrol Dial Transplant 2020; 34:742-750. [PMID: 30053164 DOI: 10.1093/ndt/gfy233] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Indexed: 12/15/2022] Open
Abstract
As part of the innate immune system, the complement system is an important mechanism in our first line of defence, but it can also contribute to the onset of various diseases. In renal diseases, the dysregulation of the complement system is often caused by mutations in-and autoantibodies directed against-members of the complement system, and contributes to disease onset and severity. As the only known positive regulator of the complement system, the role of properdin in complement-mediated diseases is largely unknown. In this review, we provide an overview of the detection of properdin in kidney biopsies and urine, serum or plasma samples from patients with complement-mediated renal diseases, such as immune complex-mediated glomerulonephritis and C3 glomerulopathy. Advances towards a better understanding of the role of properdin in (local) complement activation will provide insight into its potential role and offer opportunities to improve diagnosis and therapeutic interventions.
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Affiliation(s)
- Mieke F van Essen
- Division of Nephrology and Transplant Medicine, Department Of Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Jurjen M Ruben
- Division of Nephrology and Transplant Medicine, Department Of Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Aiko P J de Vries
- Division of Nephrology and Transplant Medicine, Department Of Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Cees van Kooten
- Division of Nephrology and Transplant Medicine, Department Of Medicine, Leiden University Medical Center, Leiden, The Netherlands
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Abstract
Glomerulonephritis (GN) refers to a group of renal diseases affecting the glomeruli due to the damage mediated by immunological mechanisms. A large proportion of the disease manifestations are caused by disturbances in the complement system. They can be due to genetic errors, autoimmunity, microbes or abnormal immunoglobulins, like modified IgA or paraproteins. The common denominator in most of the problems is an overactive or misdirected alternative pathway complement activation. An assessment of kidney function, amount of proteinuria and hematuria are crucial elements to evaluate, when glomerulonephritis is suspected. However, the cornerstones of the diagnoses are renal biopsy and careful examination of the complement abnormality. Differential diagnostics between the various forms of GN is not possible based on clinical features, as they may vary greatly. This review describes the known mechanisms of complement dysfunction leading to different forms of primary GN (like IgA glomerulonephritis, dense deposit disease, C3 glomerulonephritis, post-infectious GN, membranous GN) and differences to atypical hemolytic uremic syndrome. It also covers the basic elements of etiology-directed therapy and prognosis of the most common forms of GN. Common principles in the management of GN include treatment of hypertension and reduction of proteinuria, some require immunomodulating treatment. Complement inhibition is an emerging treatment option. A thorough understanding of the basic disease mechanism and a careful follow-up are needed for optimal therapy.
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Affiliation(s)
- Kati Kaartinen
- Department of Nephrology, Abdominal Center, Helsinki University Central Hospital, Helsinki, Finland
| | - Adrian Safa
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - Soumya Kotha
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - Giorgio Ratti
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - Seppo Meri
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; Department of Bacteriology and Immunology, Translational Immunology Research Program, University of Helsinki, Helsinki, Finland; HUSLAB, Helsinki University Central Hospital, Helsinki, Finland.
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10
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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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11
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Pan M, Zhou Q, Zheng S, You X, Li D, Zhang J, Chen C, Xu F, Li Z, Zhou Z, Zhang J. Serum C3/C4 ratio is a novel predictor of renal prognosis in patients with IgA nephropathy: a retrospective study. Immunol Res 2019; 66:381-391. [PMID: 29850970 DOI: 10.1007/s12026-018-8995-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
IgA nephropathy (IgAN) is an autoimmune disease associated with complement activation. It is unclear whether the ratio of serum C3 and C4 concentrations (C3/C4 ratio) can predict renal outcomes in IgAN patients. A total of 1503 patients diagnosed with IgAN via renal biopsy were recorded in this study. Poor renal outcomes were defined as > 50% decrease in the baseline estimated glomerular filtration rate (eGFR) or development of end-stage renal disease (ESRD) during follow-up. In total, 712 patients meeting the exclusion/inclusion criteria were selected, and the mean follow-up period was 40.6 (12.34) months. Patients with decreased C3/C4 ratios displayed significantly more severe clinical characteristics and renal pathological features and a higher proportion of poor renal outcomes and ESRD. The optimal multivariate Cox regression models identified the C3/C4 ratio (hazard ratio (HR) 0.63, 95% CI 0.5-0.9), serum uric acid (HR 1.58, 95% CI 1.2-2.2), serum creatinine (HR 1.3, 95% CI 1.1-1.6), systolic blood pressure (HR 1.57, 95% CI 1.2-2.0) and T score (relative to T0, T1: HR 1.96, 95% CI 1.1-3.7, T2: HR 3.03, 95% CI 1.6-5.9) as strong predictors of poor renal outcomes. Subgroup analysis showed that patients with low C3/C4 ratios benefited from glucocorticoids or other immunosuppressive agents (hazard ratio 0.30 and 0.18, 95% CI 0.13-0.72 and 0.07-0.46, respectively). Serum C3/C4 ratios may be an independent novel predictor of renal outcomes in IgAN patients. Decreased C3/C4 ratios suggest poor renal outcomes and the potential to benefit from aggressive immunosuppressive therapies.
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Affiliation(s)
- Min Pan
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - QiongXiu Zhou
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - ShuBei Zheng
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - XiaoHan You
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - Duo Li
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - Ji Zhang
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - ChaoSheng Chen
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - FeiFei Xu
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - ZhanYuan Li
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - ZhiHong Zhou
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - JianNa Zhang
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Nanbaixiang, Ouhai District, Wenzhou, Zhejiang, 325000, People's Republic of China.
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12
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Ouyang Y, Zhu L, Shi M, Yu S, Jin Y, Wang Z, Ma J, Yang M, Zhang X, Pan X, Ren H, Wang W, Zhang H, Xie J, Chen N. A Rare Genetic Defect of MBL2 Increased the Risk for Progression of IgA Nephropathy. Front Immunol 2019; 10:537. [PMID: 30967869 PMCID: PMC6438956 DOI: 10.3389/fimmu.2019.00537] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 02/27/2019] [Indexed: 12/23/2022] Open
Abstract
The aim of this study was to investigate the association between lectin pathway-related genetic variations and progression in IgA nephropathy. Biopsy-proven IgAN patients with eGFR ≥15 ml/min/1.73 m2 at baseline and a minimum follow-up of 12-months were enrolled. A total of 1,007 patients and 121 healthy controls were enrolled from two Chinese renal centers. The discovery cohort consisted of 606 patients, and the validation cohort consisted of 401 patients. First, promoters, all exons and their boundary regions of MBL2 and FCN2 were sequenced in 50 patients, and then 37 variations were identified. Of these variations, 7 expression-associated variations were selected and genotyped in the whole discovery cohort. We found that rs1800450 in MBL2 and rs7851696 in FCN2 were associated with an increased risk for ESRD as well as serum MBL or L-ficolin levels. However, only rs1800450 was successively validated for its association with ESRD (HR, 15.91; 3.27-77.34; P = 0.001) in the fully adjusted model in the validation cohort. In addition, 2.7% of patients, and 2.5% of healthy controls carried rs1800450-AA. IgAN patients with rs1800450-AA lacked expression of MBL in both serum and renal tissue and had more severe tubulointerstitial damage. Furthermore, a combined effect of rs1800450-AA with a previously reported clinical risk score was observed in which patients with both a high clinical risk score (≥1%) and rs1800450-AA had a strikingly increased 10-years ESRD risk by 37.1-fold (7.17 to 192.13-fold). In summary, IgAN patients carrying MBL2 rs1800450-AA have a high risk for renal function deterioration, probably due to inactivation of the complement MBL pathway.
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Affiliation(s)
- Yan Ouyang
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Li Zhu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
| | - Manman Shi
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shuwen Yu
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuanmeng Jin
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhaohui Wang
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jun Ma
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Meng Yang
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoyan Zhang
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoxia Pan
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hong Ren
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weiming Wang
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hong Zhang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
| | - Jingyuan Xie
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Nan Chen
- Department of Nephrology, Institute of Nephrology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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13
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Michels MAHM, Volokhina EB, van de Kar NCAJ, van den Heuvel LPWJ. The role of properdin in complement-mediated renal diseases: a new player in complement-inhibiting therapy? Pediatr Nephrol 2019; 34:1349-1367. [PMID: 30141176 PMCID: PMC6579773 DOI: 10.1007/s00467-018-4042-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 07/31/2018] [Accepted: 08/03/2018] [Indexed: 12/16/2022]
Abstract
Properdin is known as the only positive regulator of the complement system. Properdin promotes the activity of this defense system by stabilizing its key enzymatic complexes: the complement alternative pathway (AP) convertases. Besides, some studies have indicated a role for properdin as an initiator of complement activity. Though the AP is a powerful activation route of the complement system, it is also involved in a wide variety of autoimmune and inflammatory diseases, many of which affect the kidneys. The role of properdin in regulating complement in health and disease has not received as much appraisal as the many negative AP regulators, such as factor H. Historically, properdin deficiency has been strongly associated with an increased risk for meningococcal disease. Yet only recently had studies begun to link properdin to other complement-related diseases, including renal diseases. In the light of the upcoming complement-inhibiting therapies, it is interesting whether properdin can be a therapeutic target to attenuate AP-mediated injury. A full understanding of the basic concepts of properdin biology is therefore needed. Here, we first provide an overview of the function of properdin in health and disease. Then, we explore its potential as a therapeutic target for the AP-associated renal diseases C3 glomerulopathy, atypical hemolytic uremic syndrome, and proteinuria-induced tubulointerstitial injury. Considering current knowledge, properdin-inhibiting therapy seems promising in certain cases. However, knowing the complexity of properdin's role in renal pathologies in vivo, further research is required to clarify the exact potential of properdin-targeted therapy in complement-mediated renal diseases.
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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, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands
| | - Elena B. Volokhina
- Radboud Institute for Molecular Life Sciences, Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands ,Department of Laboratory Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands
| | - Nicole C. A. J. van de Kar
- Radboud Institute for Molecular Life Sciences, Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands
| | - Lambertus P. W. J. van den Heuvel
- Radboud Institute for Molecular Life Sciences, Department of Pediatric Nephrology, Amalia Children’s Hospital, Radboud University Medical Center, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands ,Department of Laboratory Medicine, Radboud University Medical Center, Geert Grooteplein Zuid 10, PO Box 9101, 6525 GA Nijmegen, The Netherlands ,Department of Pediatrics/Pediatric Nephrology and Department of Development & Regeneration, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium
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14
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Zhu L, Guo WY, Shi SF, Liu LJ, Lv JC, Medjeral-Thomas NR, Lomax-Browne HJ, Pickering MC, Zhang H. Circulating complement factor H-related protein 5 levels contribute to development and progression of IgA nephropathy. Kidney Int 2018; 94:150-158. [PMID: 29759419 DOI: 10.1016/j.kint.2018.02.023] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 01/19/2018] [Accepted: 02/08/2018] [Indexed: 11/25/2022]
Abstract
IgA nephropathy (IgAN) is a disease associated with activation of the complement system. But the factors influencing complement activation in IgAN are not fully understood. Complement factor H (FH) is an essential negative regulator of complement C3 activation. Complement factor H-related protein (FHR)-5 shares high sequence similarity with factor H. However, unlike factor H, on binding to activated C3 it enables further activation to proceed. Previously, we reported the contribution of rare variants of the CFHR5 gene to IgAN susceptibility. Here we compared circulating levels of FHR-5 in 1126 patients with IgAN and regular follow-up with those of 153 unrelated healthy individuals to explore the relationship of FHR-5 levels with IgAN development and progression. Circulating FHR-5 levels were significantly elevated in patients with IgAN compared to healthy individuals (median 4.55 [interquartile range 3.58 to 5.85] μg/ml vs 3.19 [interquartile range 2.55 to 3.92] μg/ml). Higher circulating FHR-5 levels were associated with a lower estimated glomerular filtration rate, hypertension, and severe Oxford-T and Oxford-C scores. High FHR-5 levels were independently and significantly associated with a risk of developing either a 30% decline in the estimated glomerular filtration rate or end-stage renal disease (hazard ratio, per standard deviation increment of natural square root transformed FHR-5 of 1.226; 95% confidence interval: 1.106-1.359). Thus, the circulating FHR-5 level is an independent risk factor for IgAN progression.
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Affiliation(s)
- Li Zhu
- Renal Division, Department of Medicine, Peking University First Hospital, China; Peking University Institute of Nephrology, 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 of China
| | - Wei-Yi Guo
- Renal Division, Department of Medicine, Peking University First Hospital, China; Peking University Institute of Nephrology, 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 of China
| | - Su-Fang Shi
- Renal Division, Department of Medicine, Peking University First Hospital, China; Peking University Institute of Nephrology, 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 of China
| | - Li-Jun Liu
- Renal Division, Department of Medicine, Peking University First Hospital, China; Peking University Institute of Nephrology, 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 of China
| | - Ji-Cheng Lv
- Renal Division, Department of Medicine, Peking University First Hospital, China; Peking University Institute of Nephrology, 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 of China
| | | | - Hannah J Lomax-Browne
- Centre for Complement and Inflammation Research, Imperial College London, London, UK
| | - Matthew C Pickering
- Centre for Complement and Inflammation Research, Imperial College London, London, UK
| | - Hong Zhang
- Renal Division, Department of Medicine, Peking University First Hospital, China.
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15
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Pan M, Zhang J, Li Z, Jin L, Zheng Y, Zhou Z, Zhen S, Lu G. Increased C4 and decreased C3 levels are associated with a poor prognosis in patients with immunoglobulin A nephropathy: a retrospective study. BMC Nephrol 2017; 18:231. [PMID: 28697742 PMCID: PMC5505039 DOI: 10.1186/s12882-017-0658-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 07/05/2017] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND An association between serum complement levels and poor renal prognosis in patients with immunoglobulin A nephropathy (IgAN) remains controversial. METHODS We conducted a retrospective study examining the relationship between serum complement levels and prognosis in patients with IgAN. Between 2009 and 2013, patients with biopsy-confirmed IgAN were identified from the Second Affiliated Hospital of Wenzhou Medical College, China, and various parameters were documented during follow-up until 2015. The definition of the primary endpoint was a decrease of estimated glomerular filtration rate (eGFR) more than 30% from their baseline levels. RESULTS A total of 403 patients (55.3% female, average 33.7 months of follow-up) were identified and enrolled, with the primary endpoint occurring in 39 (9.8%) patients. Among the patients selected, 202 (50.1%) received corticosteroid treatment alone or in combination with another immunosuppressant (GS group), while others did not receive immunosuppressive treatment (non-GS group). The incidence of the primary endpoint was slightly lower in the GS group compared to the non-GS group (7.0% versus 12.6%, p = 0.06). Multivariate Cox proportional-hazard regression analyses, adjusting for age, systolic and diastolic blood pressure, 24-h urine protein, and immunosuppressive therapy, showed that serum complement 4 (C4) levels (hazard ratio [HR] 2.4, 95% confidence interval [CI] 1.6-3.8, p < 0.001) and serum complement 3 (C3) levels (HR 0.6, 95% CI 0.2-0.6, p < 0.001) were significantly associated with a poor prognosis among patients with IgAN. CONCLUSIONS We demonstrated that an increase in serum C4, as well as a decrease in C3, was an important outcome determinant for patients with IgAN. Testing serum C3 and C4 levels might assist in predicting renal outcomes among these patients.
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Affiliation(s)
- Min Pan
- Department of Nephrology, The First Affiliated Hospital of Soochow University, 88 Shizi St., Suzhou, 215006, Jiangsu, People's Republic of China.,Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Ji Zhang
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Zhanyuan Li
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Lingwei Jin
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Yu Zheng
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Zhihong Zhou
- Department of Nephrology, The Second Affiliated Hospital & Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Su Zhen
- Department of Nephrology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People's Republic of China
| | - Guoyuan Lu
- Department of Nephrology, The First Affiliated Hospital of Soochow University, 88 Shizi St., Suzhou, 215006, Jiangsu, People's Republic of China.
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16
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Zhang YM, Zhou XJ, Zhang H. What Genetics Tells Us About the Pathogenesis of IgA Nephropathy: The Role of Immune Factors and Infection. Kidney Int Rep 2017; 2:318-331. [PMID: 29142962 PMCID: PMC5678660 DOI: 10.1016/j.ekir.2017.02.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 02/07/2017] [Accepted: 02/08/2017] [Indexed: 02/04/2023] Open
Abstract
Immunoglobulin A nephropathy (IgAN) is the most common type of primary glomerulonephritis, which is characterized by IgA1-containing immune-deposits in the glomerular mesangium. The epidemiologic observations of familial clustering as well as ethnic and regional discrepancies indicate a genetic component to IgAN. Large, international, genome-wide association studies have identified several susceptibility genes and loci for IgAN, many of which have been implicated in immune regulation and are shared with other autoimmune diseases. Notably, increasing numbers of genes involved in mucosal immunity have been detected; such genes may impact the susceptibility and progression of IgAN through interaction with environmental stimuli (especially infection). Here, we discuss the innate and adaptive immune mechanisms that drive protective immunity against pathogens. Our goal is to provide a representative overview of the synergistic roles between genetic predisposition and infection in IgAN pathogenesis. We anticipate that these results will provide potential therapeutic agents and advances in precision medicine.
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Affiliation(s)
- Yue-Miao Zhang
- Renal Division, Peking University First Hospital, Beijing, China.,Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Peking University, Ministry of Education, Beijing, China
| | - Xu-Jie Zhou
- Renal Division, Peking University First Hospital, Beijing, China.,Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Peking University, Ministry of Education, Beijing, China
| | - Hong Zhang
- Renal Division, Peking University First Hospital, Beijing, China.,Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Peking University, Ministry of Education, Beijing, China
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17
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Knoppova B, Reily C, Maillard N, Rizk DV, Moldoveanu Z, Mestecky J, Raska M, Renfrow MB, Julian BA, Novak J. The Origin and Activities of IgA1-Containing Immune Complexes in IgA Nephropathy. Front Immunol 2016; 7:117. [PMID: 27148252 PMCID: PMC4828451 DOI: 10.3389/fimmu.2016.00117] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 03/15/2016] [Indexed: 12/12/2022] Open
Abstract
IgA nephropathy (IgAN) is the most common primary glomerulonephritis, frequently leading to end-stage renal disease, as there is no disease-specific therapy. IgAN is diagnosed from pathological assessment of a renal biopsy specimen based on predominant or codominant IgA-containing immunodeposits, usually with complement C3 co-deposits and with variable presence of IgG and/or IgM. The IgA in these renal deposits is galactose-deficient IgA1, with less than a full complement of galactose residues on the O-glycans in the hinge region of the heavy chains. Research from the past decade led to the definition of IgAN as an autoimmune disease with a multi-hit pathogenetic process with contributing genetic and environmental components. In this process, circulating galactose-deficient IgA1 (autoantigen) is bound by antiglycan IgG or IgA (autoantibodies) to form immune complexes. Some of these circulating complexes deposit in glomeruli, and thereby activate mesangial cells and induce renal injury through cellular proliferation and overproduction of extracellular matrix components and cytokines/chemokines. Glycosylation pathways associated with production of the autoantigen and the unique characteristics of the corresponding autoantibodies in patients with IgAN have been uncovered. Complement likely plays a significant role in the formation and the nephritogenic activities of these complexes. Complement activation is mediated through the alternative and lectin pathways and probably occurs systemically on IgA1-containing circulating immune complexes as well as locally in glomeruli. Incidence of IgAN varies greatly by geographical location; the disease is rare in central Africa but accounts for up to 40% of native-kidney biopsies in eastern Asia. Some of this variation may be explained by genetically determined influences on the pathogenesis of the disease. Genome-wide association studies to date have identified several loci associated with IgAN. Some of these loci are associated with the increased prevalence of IgAN, whereas others, such as deletion of complement factor H-related genes 1 and 3, are protective against the disease. Understanding the molecular mechanisms and genetic and biochemical factors involved in formation and activities of pathogenic IgA1-containing immune complexes will enable the development of future disease-specific therapies as well as identification of non-invasive disease-specific biomarkers.
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Affiliation(s)
- Barbora Knoppova
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Immunology, Faculty of Medicine and Dentistry, Palacky University and University Hospital, Olomouc, Czech Republic
| | - Colin Reily
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Nicolas Maillard
- Université Jean Monnet, Saint Etienne, France
- PRES Université de Lyon, Lyon, France
| | - Dana V. Rizk
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Zina Moldoveanu
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jiri Mestecky
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Milan Raska
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Immunology, Faculty of Medicine and Dentistry, Palacky University and University Hospital, Olomouc, Czech Republic
| | - Matthew B. Renfrow
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Bruce A. Julian
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
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18
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19
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Implication of urinary complement factor H in the progression of immunoglobulin A nephropathy. PLoS One 2015; 10:e0126812. [PMID: 26035554 PMCID: PMC4452759 DOI: 10.1371/journal.pone.0126812] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 04/07/2015] [Indexed: 11/18/2022] Open
Abstract
Background After activation, the complement system is involved in the pathogenesis of Immunoglobulin A nephropathy (IgAN). Complement factor H (CFH) is a crucial inhibitory factor of the alternative pathway of the complement system. The study investigated the effects of urinary CFH levels on IgAN progression. Methods A total of 351patients with IgAN participated in this study. They were followed up for an average of 51.8±26.6 months. Renal outcome was defined as a composite endpoint, that included instances of end-stage renal disease (ESRD),≥ 50% decline in estimated glomerular filtration rate (eGFR) or doubling of plasma creatinine levels. Urinary CFH levels were measured by enzyme-linked immunosorbent assay and calculated as the ratio of urinary CFH over creatinine (uCFH/uCr). Results In the whole cohort, uCFH/uCr values were associated with disease progression either as continuous [log(uCFH/uCr)] or categorical traits (dichotomous and quartile variables) after adjusting for eGFR, proteinuria, mean arterial blood pressure, histological grading and immunosuppressive therapy in the Cox proportional hazard model. Kaplan-Meier analysis showed that higher uCFH/uCr values at baseline predicted worse renal outcome during follow-up (log-rank, P<0.001). Receiver operating characteristic curve (ROC) analysis showed that log(uCFH/uCr) had predictive value for renal outcome (area under curve [AUC]=0.745), and the AUC increased to 0.805 after being incorporated into baseline eGFR and proteinuria. In subgroup analysis with eGFR≥60 mL/min/1.73m2, log(uCFH/uCr) had better predictive value (AUC= 0.724, P=0.002) for renal outcome compared to eGFR (AUC = 0.582, P=0.259) and proteinuria (AUC = 0.615, P=0.114). Conclusions Urinary CFH levels are associated with renal function decline and increased urinary CFH levels are a risk factor for progression of IgA nephropathy.
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Moresco RN, Speeckaert MM, Delanghe JR. Diagnosis and monitoring of IgA nephropathy: the role of biomarkers as an alternative to renal biopsy. Autoimmun Rev 2015; 14:847-53. [PMID: 26026694 DOI: 10.1016/j.autrev.2015.05.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 05/20/2015] [Indexed: 12/13/2022]
Abstract
IgA nephropathy (IgAN) is the most prevalent form of chronic glomerulonephritis in the world. The underlying pathogenesis of this autoimmune disease comprises the formation of immune complexes, including glycan-specific IgA1 or IgG antibodies and an aberrant glycosylation of IgA1. Until now, anatomopathological analysis of renal biopsies is essential for the diagnosis of IgAN and different histological classification systems have been proposed, e.g. the Oxford classification. However, a percutaneous renal biopsy is frequently not performed for several reasons and the Oxford classification system has some limitations. Since the poor prognosis of IgAN patients is partly the result of a delayed diagnosis, there is an urgent need for reliable noninvasive biomarkers that might be applicable in routine clinical practice. This article reviews the advances on the understanding of the underlying pathophysiological mechanisms of IgAN and discusses in depth the recent development of new biomarkers, including the use of proteomics and microRNAs.
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Affiliation(s)
- Rafael N Moresco
- Department of Clinical Chemistry, Ghent University Hospital, Gent, Belgium; Department of Clinical and Toxicological Analysis, Federal University of Santa Maria, Santa Maria, Brazil
| | | | - Joris R Delanghe
- Department of Clinical Chemistry, Ghent University Hospital, Gent, Belgium.
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Faria B, Henriques C, Matos AC, Daha MR, Pestana M, Seelen M. Combined C4d and CD3 immunostaining predicts immunoglobulin (Ig)A nephropathy progression. Clin Exp Immunol 2015; 179:354-61. [PMID: 25267249 DOI: 10.1111/cei.12461] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2014] [Indexed: 11/30/2022] Open
Abstract
A number of molecules have been shown recently to be involved in the pathogenesis and progression of immunoglobulin (Ig)A nephropathy (IgAN). Among these, we have selected C4d (complement lectin pathway involvement), CD3 (T cell marker, traducing interstitial inflammation), transglutaminase 2 (TGase-2, involved in tissue fibrosis development) and p-extracelluar-regulated kinase (ERK)1/2 (protein kinase intracellular signaling molecule) to perform a panel of immunohistological biomarkers and assess its predictive value for disease progression. Immunohistochemical staining of these biomarkers was performed in paraffin sections from 74 renal biopsy cases with the clinical diagnosis of IgAN. Association between score analysis of these parameters and disease course was assessed through univariate and multivariate analysis, including baseline clinical and histological data. Univariate analysis showed that glomerular C4d, tubulointerstitial TGase2 and CD3 scores were associated with baseline proteinuria and disease progression. Multivariate analysis showed that only baseline estimated glomerular filtration rate (eGFR), C4d and CD3 were associated independently with progressive kidney disease (decline of at least 50% in the eGFR or progression to end-stage renal disease (ESRD) during the follow-up period). Establishing an accurate prediction model for IgAN progression is still a matter of research in clinical nephrology. The complement system, particularly lectin pathway activation, and T cell activation, have been shown previously to be potential modifiers of the disease course. Here we show that the combination of two histological biomarkers (C4d and CD3) can be a powerful predictor of IgAN progression and a potential useful tool for the clinical approach of this disease.
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Affiliation(s)
- B Faria
- Nephrology and Infectious Disease R&D Group, INEB, I3S, University of Porto, Porto, Portugal; Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, Groningen, Netherlands
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Maillard N, Wyatt RJ, Julian BA, Kiryluk K, Gharavi A, Fremeaux-Bacchi V, Novak J. Current Understanding of the Role of Complement in IgA Nephropathy. J Am Soc Nephrol 2015; 26:1503-12. [PMID: 25694468 DOI: 10.1681/asn.2014101000] [Citation(s) in RCA: 212] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Complement activation has a role in the pathogenesis of IgA nephropathy, an autoimmune disease mediated by pathogenic immune complexes consisting of galactose-deficient IgA1 bound by antiglycan antibodies. Of three complement-activation pathways, the alternative and lectin pathways are involved in IgA nephropathy. IgA1 can activate both pathways in vitro, and pathway components are present in the mesangial immunodeposits, including properdin and factor H in the alternative pathway and mannan-binding lectin, mannan-binding lectin-associated serine proteases 1 and 2, and C4d in the lectin pathway. Genome-wide association studies identified deletion of complement factor H-related genes 1 and 3 as protective against the disease. Because the corresponding gene products compete with factor H in the regulation of the alternative pathway, it has been hypothesized that the absence of these genes could lead to more potent inhibition of complement by factor H. Complement activation can take place directly on IgA1-containing immune complexes in circulation and/or after their deposition in the mesangium. Notably, complement factors and their fragments may serve as biomarkers of IgA nephropathy in serum, urine, or renal tissue. A better understanding of the role of complement in IgA nephropathy may provide potential targets and rationale for development of complement-targeting therapy of the disease.
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Affiliation(s)
- Nicolas Maillard
- University of Alabama at Birmingham, Departments of Microbiology and Medicine, Birmingham, Alabama; Université Jean Monnet, Groupe sur l'immunité des Muqueuses et Agents Pathogènes, St. Etienne, Pôle de Recherche et d'Enseignement Supérieur, Université de Lyon, Lyon, France
| | - Robert J Wyatt
- University of Tennessee Health Science Center and Children's Foundation Research at the Le Bonheur Children's Hospital, Memphis, Tennessee
| | - Bruce A Julian
- University of Alabama at Birmingham, Departments of Microbiology and Medicine, Birmingham, Alabama
| | - Krzysztof Kiryluk
- Columbia University, Department of Medicine, New York, New York; and
| | - Ali Gharavi
- Columbia University, Department of Medicine, New York, New York; and
| | - Veronique Fremeaux-Bacchi
- Unité Mixte de Recherche en Santé 1138, Team "Complement and Diseases," Cordeliers Research Center, Paris, France
| | - Jan Novak
- University of Alabama at Birmingham, Departments of Microbiology and Medicine, Birmingham, Alabama;
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Tomino Y. Pathogenesis and treatment of chronic kidney disease: a review of our recent basic and clinical data. Kidney Blood Press Res 2014; 39:450-89. [PMID: 25501571 DOI: 10.1159/000368458] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2014] [Indexed: 12/30/2022] Open
Abstract
Chronic kidney disease (CKD) is a worldwide public health problem that affects millions of people from all racial and ethnic groups. At end of 2013, over 300,000 Japanese patients had maintenance dialysis therapy (JSDT). In Japan, the major causes of end stage kidney disease (ESKD) are chronic glomerulonephritis (particularly IgA nephropathy), type 2 diabetic nephropathy, and hypertensive nephrosclerosis. Hypertension is a major factor driving the progression of CKD to ESKD. Since many features of the pathogenesis of IgA nephropathy are still obscure, specific treatment is not yet available. However, efforts by investigators around the world have gradually clarified different aspects of the pathogenesis and treatment of IgA nephropathy. Today, around half of all diabetic patients in Japan receive medical treatment. Type 2 diabetic nephropathy is one of the major long-term microvascular complications occurring in nearly 40% of Japanese diabetic patients. The pathogenesis of diabetic nephropathy involves both genetic and environmental factors. However, the candidate genes related to the initiation and progression of the disorder are still obscure in patients with diabetic nephropathy. Regarding environmental factors, the toxicity of persistent hyperglycemia, reactive oxygen species, systemic and/or glomerular hypertension, dyslipidemia and complement are considered to play an important role. The first part of this review covers the pathogenesis of IgA nephropathy and type 2 diabetic nephropathy, and combines the clinicopathological findings in patients with our research on the ddY and KKA-y mouse models (spontaneous animal models for IgA nephropathy and diabetic nephropathy, respectively). In Japan, the major renal replacement therapies (RRT) are peritoneal dialysis (PD) and hemodialysis (HD). The second part of this review focuses on PD and HD. Based on our research findings from patients and as well as from animal models, we discuss strategies for the management of patients on PD and HD.
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Affiliation(s)
- Yasuhiko Tomino
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
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Zhu L, Zhai YL, Wang FM, Hou P, Lv JC, Xu DM, Shi SF, Liu LJ, Yu F, Zhao MH, Novak J, Gharavi AG, Zhang H. Variants in Complement Factor H and Complement Factor H-Related Protein Genes, CFHR3 and CFHR1, Affect Complement Activation in IgA Nephropathy. J Am Soc Nephrol 2014; 26:1195-204. [PMID: 25205734 DOI: 10.1681/asn.2014010096] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 07/18/2014] [Indexed: 12/17/2022] Open
Abstract
Complement activation is common in patients with IgA nephropathy (IgAN) and associated with disease severity. Our recent genome-wide association study of IgAN identified susceptibility loci on 1q32 containing the complement regulatory protein-encoding genes CFH and CFHR1-5, with rs6677604 in CFH as the top single-nucleotide polymorphism and CFHR3-1 deletion (CFHR3-1∆) as the top signal for copy number variation. In this study, to explore the clinical effects of variation in CFH, CFHR3, and CFHR1 on IgAN susceptibility and progression, we enrolled two populations. Group 1 included 1178 subjects with IgAN and available genome-wide association study data. Group 2 included 365 subjects with IgAN and available clinical follow-up data. In group 1, rs6677604 was associated with mesangial C3 deposition by genotype-phenotype correlation analysis. In group 2, we detected a linkage between the rs6677604-A allele and CFHR3-1∆ and found that the rs6677604-A allele was associated with higher serum levels of CFH and lower levels of the complement activation split product C3a. Furthermore, CFH levels were positively associated with circulating C3 levels and negatively associated with mesangial C3 deposition. Moreover, serum levels of the pathogenic galactose-deficient glycoform of IgA1 were also associated with the degree of mesangial C3 deposition in patients with IgAN. Our findings suggest that genetic variants in CFH, CFHR3, and CFHR1 affect complement activation and thereby, predispose patients to develop IgAN.
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Affiliation(s)
- Li Zhu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Ya-Ling Zhai
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Feng-Mei Wang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Ping Hou
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Ji-Cheng Lv
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Da-Min Xu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Su-Fang Shi
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Li-Jun Liu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Feng Yu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Ming-Hui Zhao
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - Ali G Gharavi
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York
| | - Hong Zhang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China; Institute of Nephrology, Peking University, Beijing, China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China; Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China;
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Sui W, Cui Z, Zhang R, Xue W, Ou M, Zou G, Chen J, Dai Y. Comparative proteomic analysis of renal tissue in IgA nephropathy with iTRAQ quantitative proteomics. Biomed Rep 2014; 2:793-798. [PMID: 25279147 DOI: 10.3892/br.2014.318] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 06/20/2014] [Indexed: 11/06/2022] Open
Abstract
Immunoglobulin (Ig) A nephropathy (IgAN) is the most common form of glomerulonephritis. In clinical practice, it is difficult to monitor the repeating relapse in patients suffering from IgAN, which usually occurs within 10 years of end-stage renal disease. In order to identify and quantify the total protein content in the renal tissue of patients with IgAN, isobaric tags for relative and absolute quantification (iTRAQ) technology was performed. iTRAQ coupled with multiple chromatographic fractionation and tandem mass spectrometry was used to analyze the total protein of normal renal tissue in IgAN and healthy patients. The individual proteins were identified by the Mascot search engine and any that were differentially expressed were monitored. A total of 574 different proteins were identified, and 287 proteins were up- or downregulated by >1 fold alteration in levels. The results showed that iTRAQ-based quantitative proteomic technology for the identification and relative quantitation of the renal tissue proteome is efficiently applicable. The differential expression of the proteome profiles for IgAN patients was determined. Further studies using large cohorts of patient samples with long-term clinical follow-up data should be conducted to evaluate the usefulness of the pathogenesis and novel biomarker candidates of IgAN, which may develop a novel technique for the diagnosis of IgAN.
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Affiliation(s)
- Weiguo Sui
- Nephrology Department of the 181st Hospital, Guangxi Key Laboratory of Metabolic Diseases Research, Guilin, Guangxi 541002, P.R. China
| | - Zhenzhen Cui
- Nephrology Department of the 181st Hospital, Guangxi Key Laboratory of Metabolic Diseases Research, Guilin, Guangxi 541002, P.R. China ; The Life Science College, Guangxi Normal University, Guilin, Guangxi 541004, P.R. China
| | - Ruohan Zhang
- Nephrology Department of the 181st Hospital, Guangxi Key Laboratory of Metabolic Diseases Research, Guilin, Guangxi 541002, P.R. China
| | - Wen Xue
- Nephrology Department of the 181st Hospital, Guangxi Key Laboratory of Metabolic Diseases Research, Guilin, Guangxi 541002, P.R. China
| | - Minglin Ou
- Nephrology Department of the 181st Hospital, Guangxi Key Laboratory of Metabolic Diseases Research, Guilin, Guangxi 541002, P.R. China
| | - Guimian Zou
- Nephrology Department of the 181st Hospital, Guangxi Key Laboratory of Metabolic Diseases Research, Guilin, Guangxi 541002, P.R. China
| | - Jiejing Chen
- Nephrology Department of the 181st Hospital, Guangxi Key Laboratory of Metabolic Diseases Research, Guilin, Guangxi 541002, P.R. China
| | - Yong Dai
- Clinical Medical Research Center, The Second Clinical Medical College of Jinan University (Shenzhen People's Hospital), Shenzhen, Guangdong 518020, P.R. China
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Pathological scenario with the mannose-binding lectin in patients with IgA nephropathy. J Biomed Biotechnol 2012; 2012:476739. [PMID: 22566742 PMCID: PMC3335258 DOI: 10.1155/2012/476739] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2011] [Accepted: 01/26/2012] [Indexed: 02/03/2023] Open
Abstract
A deeper understanding of the mechanism of complement activation may help to elucidate the pathogenesis of IgA nephropathy (IgAN). Traditionally, the activation of an alternative pathway (AP) has been recognized as an enhancer mechanism of glomerular damage. This paper documents contemporary information concerning the possible pathological mechanisms of the lectin pathway (LP) in the circulation and in the glomerulus. The circulating initiator of LP activation is not fully understood. However, ligands for mannose-binding lectin (MBL) which are among the starter molecules of the LP are aberrant glycosylated molecules-containing immune complex. Recent reports have focused on N-glycans on secretory IgA as a candidate ligand. Mesangial deposits of MBL are seen in 25% of patients with IgAN. Mesangial deposits of MBL and C4 and/or C4 breakdown products are implicated as markers for disease progression of IgAN. On the other hand, patients with MBL deficiency tend to show better clinical presentation and lower levels of urinary protein and serum creatinine than MBL-sufficient patients. It is now recognized that involvement of AP and LP constitutes an additional mechanism for explaining the progression of IgAN.
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Onda K, Ohsawa I, Ohi H, Tamano M, Mano S, Wakabayashi M, Toki A, Horikoshi S, Fujita T, Tomino Y. Excretion of complement proteins and its activation marker C5b-9 in IgA nephropathy in relation to renal function. BMC Nephrol 2011; 12:64. [PMID: 22111871 PMCID: PMC3283454 DOI: 10.1186/1471-2369-12-64] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 11/23/2011] [Indexed: 12/18/2022] Open
Abstract
Background Glomerular damage in IgA nephropathy (IgAN) is mediated by complement activation via the alternative and lectin pathways. Therefore, we focused on molecules stabilizing and regulating the alternative pathway C3 convertase in urine which might be associated with IgAN pathogenesis. Methods Membrane attack complex (MAC), properdin (P), factor H (fH) and Complement receptor type 1 (CR1) were quantified in urine samples from 71 patients with IgAN and 72 healthy controls. Glomerular deposition of C5, fH and P was assessed using an immunofluorescence technique and correlated with histological severity of IgAN and clinical parameters. Fibrotic changes and glomerular sclerosis were evaluated in renal biopsy specimens. Results Immunofluorescence studies revealed glomerular depositions of C5, fH and P in patients with IgAN. Urinary MAC, fH and P levels in IgAN patients were significantly higher than those in healthy controls (p < 0.001), but CR1 was significantly lower than that in healthy controls (p < 0.001). Urinary MAC and fH levels were positively correlated with serum creatinine (sCr), urinary N-acetyl-β-D-glucosaminidase (u-NAG), urinary β2 microglobulin (u-Bm), urinary protein (p < 0.001), interstitial fibrosis (MAC: p < 0.01, fH: p < 0.05) and the percentage of global glomerular sclerosis (p < 0.01). Urinary P was positively correlated with u-NAG, u-Bm, and urinary protein (p < 0.01). Conclusions Complement activation occurs in the urinary space in IgAN and the measurement of levels of MAC and fH in the urine could be a useful indicator of renal injury in patients with IgAN.
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Affiliation(s)
- Kisara Onda
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
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Pathogenetic and therapeutic approaches to IgA nephropathy using a spontaneous animal model, the ddY mouse. Clin Exp Nephrol 2010; 15:1-7. [PMID: 21057848 DOI: 10.1007/s10157-010-0359-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 09/28/2010] [Indexed: 10/18/2022]
Abstract
IgA nephropathy is the most common primary chronic glomerulonephritis in the world and was first described by Berger et al. (J Urol Nephrol 74:694-695;1968). Histopathologically, IgA nephropathy is characterized by expansion of the glomerular mesangial matrix with mesangial cell proliferation. Glomeruli typically contain generalized diffuse granular mesangial deposits of IgA (mainly IgA1), IgG and C3. In advanced patients, global glomerular sclerosis, crescent formation and tubulo-interstitial fibrosis are marked in light microscopy. IgA nephropathy is generally considered to be an immune-complex mediated glomerulonephritis. Although more than 40 years have passed since this disease was firstly described, the pathogenesis/initiation factors of IgA nephropathy are still obscure. The objective of this review is to explain the pathogenesis and treatment based on our previous data of ddY mouse, a spontaneous animal model for IgA nephropathy.
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Zhang JJ, Jiang L, Liu G, Wang SX, Zou WZ, Zhang H, Zhao MH. Levels of urinary complement factor H in patients with IgA nephropathy are closely associated with disease activity. Scand J Immunol 2008; 69:457-64. [PMID: 19508377 DOI: 10.1111/j.1365-3083.2009.02234.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Factor H plays a key inhibitory role in control of the activation of alternative pathway of complement system. The aim of the study was to investigate the predictive value of factor H as a biomarker of renal injury in IgA nephropathy (IgAN). Urine factor H concentration from 202 patients was measured and compared with that of 60 healthy volunteers. Forty-eight patients fulfilled Haas-I or II (group 1), 60 fulfilled Haas-III (group 2) and 94 fulfilled Haas-IV or V (group 3). Co-deposition of factor H and C3b in kidneys were investigated using confocal microscope. The levels of urinary factor H, when expressed as a ratio of urinary creatinine, were significantly higher in groups 3 than group 1 and 2, also significantly higher in group 2 than group 1. In addition, the levels of urinary factor H were significantly higher in those with factor H deposition in the kidney than those without deposition. The levels of urinary factor H may be a useful biomarker to evaluate kidney injury in IgAN.
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Affiliation(s)
- J-J Zhang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
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