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Filippone EJ, Gulati R, Farber JL. Contemporary review of IgA nephropathy. Front Immunol 2024; 15:1436923. [PMID: 39188719 PMCID: PMC11345586 DOI: 10.3389/fimmu.2024.1436923] [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: 05/22/2024] [Accepted: 07/02/2024] [Indexed: 08/28/2024] Open
Abstract
IgA nephropathy (IgAN) is considered the most common primary glomerulonephritis worldwide with a predilection for Asian-Pacific populations and relative rarity in those of African descent. Perhaps 20%-50% of patients progress to kidney failure. The pathogenesis is incompletely understood. Mesangial deposition of immune complexes containing galactose-deficient IgA1 complexed with anti-glycan IgG or IgA antibodies results in mesangial cell activation and proliferation, inflammatory cell recruitment, complement activation, and podocyte damage. Diagnosis requires a biopsy interpreted by the Oxford criteria. Additional pathologic features include podocytopathy, thrombotic microangiopathy, and C4d staining. Biomarkers predicting adverse outcomes include proteinuria, reduced GFR, hypertension, and pathology. Acceptable surrogate endpoints for therapeutic trials include ongoing proteinuria and rate of eGFR decline. The significance of persisting hematuria remains uncertain. The mainstay of therapy is supportive, consisting of lifestyle modifications, renin-angiotensin inhibition (if hypertensive or proteinuric), sodium-glucose-transporter 2 inhibition (if GFR reduced or proteinuric), and endothelin-receptor antagonism (if proteinuric). Immunosuppression should be considered for those at high risk after maximal supportive care. Corticosteroids are controversial with the most positive results observed in Chinese. They carry a high risk of serious side effects. Similarly, mycophenolate may be most effective in Chinese. Other immunosuppressants are of uncertain benefit. Tonsillectomy appears efficacious in Japanese. Active areas of investigation include B-cell inhibition with agents targeting the survival factors BAFF and APRIL and complement inhibition with agents targeting the alternate pathway (Factors B and D), the lectin pathway (MASP-2), and the common pathway (C3 and C5). Hopefully soon, the who and the how of immunosuppression will be clarified, and kidney failure can be forestalled.
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Affiliation(s)
- Edward J. Filippone
- Division of Nephrology, Department of Medicine, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, United States
| | - Rakesh Gulati
- Division of Nephrology, Department of Medicine, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, United States
| | - John L. Farber
- Department of Pathology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, United States
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Vaz de Castro PAS, Amaral AA, Almeida MG, Selvaskandan H, Barratt J, Simões E Silva AC. Examining the association between serum galactose-deficient IgA1 and primary IgA nephropathy: a systematic review and meta-analysis. J Nephrol 2024:10.1007/s40620-023-01874-8. [PMID: 38427309 DOI: 10.1007/s40620-023-01874-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 12/26/2023] [Indexed: 03/02/2024]
Abstract
BACKGROUND IgA nephropathy (IgAN) is a common primary glomerular disease. The O-glycosylation status of IgA1 plays a crucial role in disease pathophysiology. The level of poorly-O-galactosylated IgA1, or galactose-deficient IgA1 (Gd-IgA1), has also been identified as a potential biomarker in IgAN. We sought to examine the value of serum Gd-IgA1 as a biomarker in IgAN, by investigating its association with clinical, laboratory, and histopathological features of IgAN. METHODS The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations and was registered in PROSPERO (CRD42021287423). The literature search was conducted in PubMed, Web of Science, Cochrane, and Scopus, and the selected articles were evaluated for eligibility based on predefined criteria. The methodological quality of the studies was assessed using the Newcastle-Ottawa Scale. Statistical analysis was performed to calculate effect sizes and assess heterogeneity among the studies. RESULTS This review analyzed 29 out of 1,986 studies, conducted between 2005 and 2022, with participants from multiple countries. Gd-IgA1 levels were not associated with age and gender, while associations with hypertension, hematuria, and proteinuria were inconsistent. In the meta-analyses, a correlation between serum Gd-IgA1 and estimated glomerular filtration rate was identified, however, the relationships between Gd-IgA1 levels and chronic kidney disease (CKD) stage and progression to kidney failure were inconsistent. CONCLUSIONS Serum Gd-IgA1 levels were not associated with validated prognostic risk factors, but were negatively correlated with kidney function. Further research in larger studies using standardized assays are needed to establish the value of Gd-IgA1 as a prognostic risk factor in IgAN.
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Affiliation(s)
- Pedro Alves Soares Vaz de Castro
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Arthur Aguiar Amaral
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Mariana Godinho Almeida
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | - Haresh Selvaskandan
- The Mayer IgA Nephropathy Laboratories, University of Leicester, Leicester, UK
| | - Jonathan Barratt
- The Mayer IgA Nephropathy Laboratories, University of Leicester, Leicester, UK.
- Department of Cardiovascular Sciences, University of Leicester, University Road, Leicester, LE1 7RH, UK.
| | - Ana Cristina Simões E Silva
- Interdisciplinary Laboratory of Medical Investigation, Unit of Pediatric Nephrology, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
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Qin Y, Yu Z, Wu H, Wang A, Wang F, Wang D, Jia Q, Yuan J, Xing Y, Zhang Y, Zhao J, Sun S. Prognostic factors affecting long-term outcomes in patients with concurrent IgA nephropathy and membranous nephropathy. Heliyon 2024; 10:e23436. [PMID: 38187325 PMCID: PMC10770449 DOI: 10.1016/j.heliyon.2023.e23436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 11/30/2023] [Accepted: 12/04/2023] [Indexed: 01/09/2024] Open
Abstract
Background The incidence of concurrent immunoglobulin A nephropathy and membranous nephropathy (cIgAN/MN) is low and rarely reported, and the prognosis of patients with cIgAN/MN remains unclear. This study was designed to compare the clinical and prognostic characteristics of cIgAN/MN with IgAN and MN and to identify crucial factors influencing the outcomes of patients with cIgAN/MN. Methods We included biopsy-proven cIgAN/MN patients between December 2012 and December 2020 at Xijing Hospital. In the same period, propensity score matching was employed to select an equal number of IgAN and MN patients according to the following criteria: age, sex, and follow-up time. The primary endpoint was defined as a composite of eGFR decline ≥30 %, end-stage renal disease, or death. The patient survival rate was examined using Kaplan-Meier survival curves. Univariate and multivariate Cox regression analysis models were utilized to identify the risk factors affecting renal prognosis. Results A total of 135 patients were finally included in this study and 35 (25.9 %) reached the primary endpoint. The median follow-up time of cIgAN/MN was 45.9 (24.0, 72.0) months. Compared to the IgAN group, the cIgAN/MN group exhibited a lower cumulative incidence rate of composite renal endpoints (P = 0.044), while no significant difference was found between MN and cIgAN/MN patients (P = 0.211). Univariate Cox analysis revealed that mean arterial pressure, serum potassium, blood urea nitrogen, serum IgA, segmental glomerulosclerosis (S1), and MN staging were associated with an increased risk of renal composite endpoints. The multivariate Cox regression analysis of clinical variables plus histological lesion scoring demonstrated that potassium (HR = 14.350, 95 % CI 2.637-78.090, P = 0.002), serum IgA (HR = 1.870, 95 % CI 1.109-3.153, P = 0.019), and S1 (HR = 11.965, 95 % CI 2.166-66.105, P = 0.004) were independent risk factors influencing renal outcomes in cIgAN/MN patients. Conclusion The prognosis of cIgAN/MN patients may exhibit an intermediate pattern between IgAN and MN, leaning towards being more similar to MN in certain aspects. Within the cIgAN/MN cohort, potassium, and serum IgA may be more predictive of rapid progression of renal endpoints, and S1 may indicate a more aggressive disease course.
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Affiliation(s)
- Yunlong Qin
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
- Department of Nephrology, Bethune International Peace Hospital, Shijiazhuang, China
| | - Zixian Yu
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Hao Wu
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Anjing Wang
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Fang Wang
- Department of Nephrology, Bethune International Peace Hospital, Shijiazhuang, China
| | - Di Wang
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Qing Jia
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Jinguo Yuan
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Yan Xing
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Yumeng Zhang
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Jin Zhao
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Shiren Sun
- Department of Nephrology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
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Luo HL, He C, Xue H, Li M, Ji L, Xia Y. Serum human epididymis protein 4 is associated with disease severity in patients with IgA nephropathy. Clin Biochem 2024; 123:110701. [PMID: 38048899 DOI: 10.1016/j.clinbiochem.2023.110701] [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: 09/08/2023] [Revised: 11/30/2023] [Accepted: 12/01/2023] [Indexed: 12/06/2023]
Abstract
BACKGROUND Human epididymis protein 4 (HE4) is a promising tumor biomarker primarily utilized for the detection of ovarian cancer. However, its potential as a novel diagnostic indicator for immunoglobulin A nephropathy (IgAN) remains unknown. The objective of this study was to investigate the feasibility of serum HE4 as a novel biomarker for patients with IgAN. METHODS This study enrolled a total of 89 hospitalized patients with IgAN at Peking University Shenzhen Hospital between July 2020 and December 2022, along with 60 healthy control subjects matched for sex and age without evidence of comorbidities. Serum HE4 levels were measured using the Abbott Alinity automated immune analyzer, and the correlation between serum HE4 levels and biochemical markers of renal damage as well as clinicopathologic features in IgAN patients were analyzed. RESULTS In this study, serum HE4 levels were significantly elevated in patients with IgAN compared to healthy controls (116.43 ± 103.61 pmol/L vs. 35.57 ± 9.33 pmol/L, p < 0.001). There was a positive correlation between serum HE4 levels and blood urea nitrogen (r = 0.58, p < 0.001), creatinine (r = 0.73, p < 0.001), cystatin C (r = 0.82, p < 0.001), β2-microglobulin (r = 0.77, p < 0.001), α1-microglobulin (r = 0.75, p < 0.001), and glomerulosclerosis ratio (r = 0.56, p < 0.001). Conversely, a negative correlation was observed between serum HE4 levels and hemoglobin (r = -0.42, p < 0.001), albumin (r = -0.44, p < 0.001) and estimated glomerular filtration rate (eGFR) (r = -0.83, p < 0.001). In HE4+ IgAN patients, a higher glomerulosclerosis ratio (p < 0.01) and lower eGFR levels (p < 0.001) were observed compared to HE4- patients. Furthermore, patients with higher pathological classification grade also had higher serum HE4 levels. CONCLUSIONS Serum HE4 levels were significantly associated with both renal function and the pathological classification of patients with IgAN, indicating that HE4 may serve as a promising biomarker for assessing the severity of IgAN.
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Affiliation(s)
- Hou-Long Luo
- Department of Laboratory Medicine, Peking University Shenzhen Hospital, Shenzhen, China
| | - Chen He
- School of Medical Technology, Guangdong Medical University, Dongguan, China
| | - Hao Xue
- Department of Laboratory Medicine, Peking University Shenzhen Hospital, Shenzhen, China
| | - Mingyang Li
- Department of Laboratory Medicine, Peking University Shenzhen Hospital, Shenzhen, China
| | - Ling Ji
- Department of Laboratory Medicine, Peking University Shenzhen Hospital, Shenzhen, China.
| | - Yong Xia
- Department of Laboratory Medicine, Peking University Shenzhen Hospital, Shenzhen, China.
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Caravaca-Fontán F, Gutiérrez E, Sevillano ÁM, Praga M. Targeting complement in IgA nephropathy. Clin Kidney J 2023; 16:ii28-ii39. [PMID: 38053977 PMCID: PMC10695513 DOI: 10.1093/ckj/sfad198] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Indexed: 12/07/2023] Open
Abstract
Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Recent years have witnessed significant improvements in the understanding of the pathogenesis of IgAN and particularly, the pathogenic role of complement activation. The alternative complement pathway is the major complement cascade activator in IgAN, and glomerular C3 deposition has been shown to correlate with disease progression. In addition, several studies have provided insight into the pathogenic role of factor H-related proteins -1 and -5 in IgAN, as independent players in complement dysregulation. The lectin pathway has also been shown to be associated with the severity of IgAN. Glomerular deposition of C4d has been associated with increased histologic disease activity, faster decline in estimated glomerular filtration rate and higher risk of kidney failure. On the other hand, although overlooked in the Oxford classification, numerous studies have shown that the coexistence of thrombotic microangiopathy in IgAN is a significant indicator of a poorer prognosis. All the breakthroughs in the understanding of the contributing role of complement in IgAN have paved the way for the development of new complement-targeted therapies in this disease. Several ongoing trials are evaluating the efficacy of new agents against factor B (iptacopan, Ionis-FB-LRX), C3 (pegcetacoplan), factor D (vemircopan, pelecopan), C5 (ravulizumab, cemdisiran) and C5a receptor 1 (avacopan). In this study, we provide a comprehensive review of the role of complement in IgAN, including the emerging mechanisms of complement activation and the promising potential of complement inhibitors as a viable treatment option for IgAN.
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Affiliation(s)
- Fernando Caravaca-Fontán
- Department of Nephrology, Instituto de Investigación Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Eduardo Gutiérrez
- Department of Nephrology, Hospital Universitario 12 de Octubre (imas12), Madrid, Spain
| | - Ángel M Sevillano
- Department of Nephrology, Hospital Universitario 12 de Octubre (imas12), Madrid, Spain
| | - Manuel Praga
- Department of Nephrology, Instituto de Investigación Hospital 12 de Octubre (imas12), Madrid, Spain
- Department of Medicine, Complutense University, Madrid, Spain
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6
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Cattran DC, Floege J, Coppo R. Evaluating Progression Risk in Patients With Immunoglobulin A Nephropathy. Kidney Int Rep 2023; 8:2515-2528. [PMID: 38106572 PMCID: PMC10719597 DOI: 10.1016/j.ekir.2023.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/05/2023] [Accepted: 09/08/2023] [Indexed: 12/19/2023] Open
Abstract
The highly variable rate of decline in kidney function in patients with immunoglobulin A nephropathy (IgAN) provides a major clinical challenge. Predicting which patients will progress to kidney failure, and how quickly, is difficult. Multiple novel therapies are likely to be approved in the short-term, but clinicians lack the tools to identify patients most likely to benefit from specific treatments at the right time. Noninvasive and validated markers for selecting at-risk patients and longitudinal monitoring are urgently needed. This review summarizes what is known about demographic, clinical, and histopathologic prognostic markers in the clinician's toolkit, including the International IgAN Prediction Tool. We also briefly review what is known on these topics in children and adolescents with IgAN. Although helpful, currently used markers leave clinicians heavily reliant on histologic features from the diagnostic kidney biopsy and standard clinical data to guide treatment choice, and very few noninvasive markers reflect treatment efficacy over time. Novel prognostic and predictive markers are under clinical investigation, with considerable progress being made in markers of complement activation. Other areas of research are the interplay between gut microbiota and galactose-deficient IgA1 expression; microRNAs; imaging; artificial intelligence; and markers of fibrosis. Given the rate of therapeutic advancement, the remaining gaps in biomarker research need to be addressed. We finish by describing our route to clinical utility of predictive and prognostic markers in IgAN. This route will provide us with the chance to improve IgAN prognosis by using robust, clinically practical markers to inform patient care.
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Affiliation(s)
| | - Jürgen Floege
- Division of Nephrology and Clinical Immunology, RWTH Aachen University, Aachen, Germany
| | - Rosanna Coppo
- Fondazione Ricerca Molinette, Regina Margherita Hospital, Turin, Italy
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Rajasekaran A, Green TJ, Renfrow MB, Julian BA, Novak J, Rizk DV. Current Understanding of Complement Proteins as Therapeutic Targets for the Treatment of Immunoglobulin A Nephropathy. Drugs 2023; 83:1475-1499. [PMID: 37747686 PMCID: PMC10807511 DOI: 10.1007/s40265-023-01940-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2023] [Indexed: 09/26/2023]
Abstract
Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide and a frequent cause of kidney failure. Currently, the diagnosis necessitates a kidney biopsy, with routine immunofluorescence microscopy revealing IgA as the dominant or co-dominant immunoglobulin in the glomerular immuno-deposits, often with IgG and sometimes IgM or both. Complement protein C3 is observed in most cases. IgAN leads to kidney failure in 20-40% of patients within 20 years of diagnosis and reduces average life expectancy by about 10 years. There is increasing clinical, biochemical, and genetic evidence that the complement system plays a paramount role in the pathogenesis of IgAN. The presence of C3 in the kidney immuno-deposits differentiates the diagnosis of IgAN from subclinical glomerular mesangial IgA deposition. Markers of complement activation via the lectin and alternative pathways in kidney-biopsy specimens are associated with disease activity and are predictive of poor outcome. Levels of select complement proteins in the circulation have also been assessed in patients with IgAN and found to be of prognostic value. Ongoing genetic studies have identified at least 30 loci associated with IgAN. Genes within some of these loci encode complement-system regulating proteins that can interact with immune complexes. The growing appreciation for the central role of complement components in IgAN pathogenesis highlighted these pathways as potential treatment targets and sparked great interest in pharmacological agents targeting the complement cascade for the treatment of IgAN, as evidenced by the plethora of ongoing clinical trials.
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Affiliation(s)
- Arun Rajasekaran
- Division of Nephrology, Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Todd J Green
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Matthew B Renfrow
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Bruce A Julian
- Division of Nephrology, Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jan Novak
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Dana V Rizk
- Division of Nephrology, Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
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Lin Z, Feng L, Zeng H, Lin X, Lin Q, Lu F, Wang L, Mai J, Fang P, Liu X, Tan Q, Zou C. Nomogram for the prediction of crescent formation in IgA nephropathy patients: a retrospective study. BMC Nephrol 2023; 24:262. [PMID: 37667217 PMCID: PMC10478467 DOI: 10.1186/s12882-023-03310-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 08/25/2023] [Indexed: 09/06/2023] Open
Abstract
BACKGROUND The 2017 Oxford classification of immunoglobulin A nephropathy (IgAN) recently reported that crescents could predict a worse renal outcome. Early prediction of crescent formation can help physicians determine the appropriate intervention, and thus, improve the outcomes. Therefore, we aimed to establish a nomogram model for the prediction of crescent formation in IgA nephropathy patients. METHODS We retrospectively analyzed 200 cases of biopsy-proven IgAN patients. Least absolute shrinkage and selection operator(LASSO) regression and multivariate logistic regression was applied to screen for influencing factors of crescent formation in IgAN patients. The performance of the proposed nomogram was evaluated based on Harrell's concordance index (C-index), calibration plot, and decision curve analysis. RESULTS Multivariate logistic analysis showed that urinary protein ≥ 1 g (OR = 3.129, 95%CI = 1.454-6.732), urinary red blood cell (URBC) counts ≥ 30/ul (OR = 3.190, 95%CI = 1.590-6.402), mALBU ≥ 1500 mg/L(OR = 2.330, 95%CI = 1.008-5.386), eGFR < 60ml/min/1.73m2(OR = 2.295, 95%CI = 1.016-5.187), Serum IgA/C3 ratio ≥ 2.59 (OR = 2.505, 95%CI = 1.241-5.057), were independent risk factors for crescent formation. Incorporating these factors, our model achieved well-fitted calibration curves and a good C-index of 0.776 (95%CI [0.711-0.840]) in predicting crescent formation. CONCLUSIONS Our nomogram showed good calibration and was effective in predicting crescent formation risk in IgAN patients.
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Affiliation(s)
- Zaoqiang Lin
- Department of Nephrology, Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, China
| | - Liuchang Feng
- Department of Nephrology, Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, China
| | - Huan Zeng
- Department of Nephrology, Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, China
| | - Xuefei Lin
- Department of Nephrology, Jiujiang Hospital of Traditional Chinese Medicine, Jiujiang, China
| | - Qizhan Lin
- Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Fuhua Lu
- Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Lixin Wang
- Department of Hemodialysis, Guangzhou Charity Hospital, Guangzhou, China
| | - Jianling Mai
- Department of Hemodialysis, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Pingjun Fang
- Department of Hemodialysis, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Xusheng Liu
- Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Qinxiang Tan
- Department of Nephrology, Shenzhen Hospital, Beijing University of Chinese Medicine, Shenzhen, China.
| | - Chuan Zou
- Department of Nephrology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.
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Xie M, Zhu Y, Wang X, Ren J, Guo H, Huang B, Wang S, Wang P, Liu Y, Liu Y, Zhang J. Predictive prognostic value of glomerular C3 deposition in IgA nephropathy. J Nephrol 2023; 36:495-505. [PMID: 35781866 DOI: 10.1007/s40620-022-01363-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/23/2022] [Indexed: 10/17/2022]
Abstract
BACKGROUND IgAN is the most common primary glomerulonephritis worldwide. However, the pathogenesis of IgAN remains unknown. Currently, there is evidence that C3 deposition plays a role in disease development. This study aimed to investigate clinical, pathological features, and prognosis of adult IgAN patients with C3 deposition, as well as explore the role of complement activation in disease progression. METHODS A total of 821 patients with biopsy-proven IgAN were included in this study. Patients were divided into three different groups according to their C3 deposition intensity. Clinical and pathological characteristics were compared between groups. Logistic analysis was used to estimate the relationship between C3 deposition and the Oxford scoring system. Univariate and multivariate Cox proportional hazard regression models were used to analyze the effect of the presence of C3 deposits on the prognosis of patients with IgA nephropathy. Kaplan-Meier survival analysis was used to evaluate the cumulative incidence of renal progression between groups. RESULTS Patients with C3 deposition exhibited more severe clinical and pathological features and had a higher score according to the Oxford scoring system. With the increasing intensity of C3 deposition, patients present more hematuria, crescents, heavier interstitial inflammatory cell infiltration and a higher score on segmental sclerosis lesions. Logistic regression identified a positive relationship between C3 deposition and histopathology. Univariate and multivariate Cox regression indicated that C3 deposition was an independent risk factor for IgAN severity. The Kaplan-Meier survival curves indicated that patients with positive C3 deposition had a worse prognosis compared to those without C3 deposition. CONCLUSIONS Patients with positive glomerular C3 deposition presented with more severe clinical and histopathological characteristics and a higher score on the Oxford scoring system. With the increasing intensity of C3 deposition, IgAN patients were more likely to present with high level of microscopic hematuria, fibrous crescents, interstitial inflammatory cell infiltration, and a higher score on segmental sclerosis lesions. C3 deposition at the time of renal biopsy is likely an independent risk factor for IgA nephropathy severity and progression.
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Affiliation(s)
- Minhua Xie
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan, China
| | - Yuze Zhu
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan, China
| | - Xutong Wang
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan, China
| | - Jingjing Ren
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan, China
| | - Haonan Guo
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan, China
| | - Bo Huang
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan, China
| | - Shulei Wang
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan, China
| | - Peiheng Wang
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan, China
| | - Yiming Liu
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan, China
| | - Yingchun Liu
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan, China
| | - Junjun Zhang
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
- Research Institute of Nephrology, Zhengzhou University, Zhengzhou, Henan, China.
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Mizerska-Wasiak M. How to take advantage of easily available biomarkers in patients with IgA nephropathy: IgA and C3 in serum and kidney biopsies. Pediatr Nephrol 2022; 38:1439-1448. [PMID: 35916957 DOI: 10.1007/s00467-022-05644-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 05/03/2022] [Accepted: 05/24/2022] [Indexed: 11/30/2022]
Abstract
IgA nephropathy (IgAN) is the most common glomerulonephritis worldwide. It is diagnosed based on clinical and histological features including predominant IgA deposits in kidney biopsy. The multi-hit theory, based on the production of GDIgA1 and anti-GDIgA1 antibodies, and complement activation via alternative and lectin pathways and also a genetic tendency are crucial in the pathogenesis of IgAN. The aim of the present review is to summarize the utility of routine diagnostic tests in IgA nephropathy, such as IgA and C3 in serum and kidney biopsy specimens, for predicting the disease progression. The paper also contains data on new markers used in the diagnosis and prognosis of IgA nephropathy.
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11
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Mizerska-Wasiak M, Płatos E, Cichoń-Kawa K, Demkow U, Pańczyk-Tomaszewska M. The Usefulness of Vanin-1 and Periostin as Markers of an Active Autoimmune Process or Renal Fibrosis in Children with IgA Nephropathy and IgA Vasculitis with Nephritis-A Pilot Study. J Clin Med 2022; 11:jcm11051265. [PMID: 35268356 PMCID: PMC8911128 DOI: 10.3390/jcm11051265] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 01/25/2023] Open
Abstract
This study aimed to evaluate the usefulness of vanin-1 and periostin in urine as markers of the autoimmune process in kidneys and renal fibrosis in IgA nephropathy (IgAN) and IgA vasculitis with nephritis (IgAVN). From a group of 194 patients from the Department of Pediatrics and Nephrology, who were included in the Polish Pediatric Registry of IgAN and IgAVN, we qualified 51 patients (20 with IgAN and 31 with IgAVN) between the ages of 3 and 17, diagnosed based on kidney biopsy, for inclusion in the study. All of the patients received glucocorticosteroids, immunosuppressive drugs, or renoprotective therapy. The control group consisted of 18 healthy individuals. The concentration of vanin was significantly higher in the IgAN and IgAVN groups than in the control group. The concentration of vanin/creatinine correlates positively with the level of IgA and negatively with the serum level of C3 at the end of the observation. Urinary vanin-1 concentration may be useful as a marker of the active autoimmune process in IgAN and IgAVN in children, but the study needs confirmation on a larger group of children, along with evaluation of the dynamics of this marker. Urinary periostin is not a good marker for children with IgAN and IgAVN, especially in stage 1 and 2 CKD.
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Affiliation(s)
- Małgorzata Mizerska-Wasiak
- Department of Pediatrics and Nephrology, Medical University of Warsaw, 02-091 Warsaw, Poland; (K.C.-K.); (M.P.-T.)
- Correspondence:
| | - Emilia Płatos
- Science Students’ Association at the Department of Pediatrics and Nephrology, Medical University of Warsaw, 02-091 Warsaw, Poland;
| | - Karolina Cichoń-Kawa
- Department of Pediatrics and Nephrology, Medical University of Warsaw, 02-091 Warsaw, Poland; (K.C.-K.); (M.P.-T.)
| | - Urszula Demkow
- Department of Laboratory Diagnostics and Clinical Immunology of Developmental Age, Medical University of Warsaw, 02-091 Warsaw, Poland;
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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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Is complement the main accomplice in IgA nephropathy? From initial observations to potential complement-targeted therapies. Mol Immunol 2021; 140:1-11. [PMID: 34601376 DOI: 10.1016/j.molimm.2021.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 09/01/2021] [Accepted: 09/17/2021] [Indexed: 12/22/2022]
Abstract
IgA Nephropathy (IgAN) is the main cause of primary glomerulonephritis, globally. This disease is associated with a wide range of clinical presentations, variable prognosis and a spectrum of histological findings. More than fifty years after its first description, this heterogeneity continues to complicate efforts to understand the pathogenesis. Nevertheless, involvement of the complement system in IgAN was identified early on. Dysfunction of the immunoglobulin A (IgA) system, the principal offender in this disease, including modification of isoforms and glycoforms of IgA1, the nature of immune complexes and autoantibodies to galactose deficient IgA1 might all be responsible for complement activation in IgAN. However, the specific mechanisms engaging complement are still under examination. Research in this domain should allow for identification of patients that may benefit from complement-targeted therapy, in the foreseeable future.
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An Update on the Current State of Management and Clinical Trials for IgA Nephropathy. J Clin Med 2021; 10:jcm10112493. [PMID: 34200024 PMCID: PMC8200196 DOI: 10.3390/jcm10112493] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 12/31/2022] Open
Abstract
IgA nephropathy remains the most common primary glomerular disease worldwide. It affects children and adults of all ages, and is a leading cause of end-stage kidney disease, making it a considerable public health issue in many countries. Despite being initially described over 50 years ago, there are still no disease specific treatments, with current management for most patients being focused on lifestyle measures and renin-angiotensin-aldosterone system blockade. However, significant advances in the understanding of its pathogenesis have been made particularly over the past decade, leading to great interest in developing new therapeutic strategies, and a significant rise in the number of interventional clinical trials being performed. In this review, we will summarise the current state of management of IgAN, and then describe major areas of interest where new therapies are at their most advanced stages of development, that include the gut mucosal immune system, B cell signalling, the complement system and non-immune modulators. Finally, we describe clinical trials that are taking place in each area and explore future directions for translational research.
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IgA Vasculitis and IgA Nephropathy: Same Disease? J Clin Med 2021; 10:jcm10112310. [PMID: 34070665 PMCID: PMC8197792 DOI: 10.3390/jcm10112310] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/17/2021] [Accepted: 05/19/2021] [Indexed: 12/14/2022] Open
Abstract
Many authors suggested that IgA Vasculitis (IgAV) and IgA Nephropathy (IgAN) would be two clinical manifestations of the same disease; in particular, that IgAV would be the systemic form of the IgAN. A limited number of studies have included sufficient children or adults with IgAN or IgAV (with or without nephropathy) and followed long enough to conclude on differences or similarities in terms of clinical, biological or histological presentation, physiopathology, genetics or prognosis. All therapeutic trials available on IgAN excluded patients with vasculitis. IgAV and IgAN could represent different extremities of a continuous spectrum of the same disease. Due to skin rash, patients with IgAV are diagnosed precociously. Conversely, because of the absence of any clinical signs, a renal biopsy is practiced for patients with an IgAN to confirm nephropathy at any time of the evolution of the disease, which could explain the frequent chronic lesions at diagnosis. Nevertheless, the question that remains unsolved is why do patients with IgAN not have skin lesions and some patients with IgAV not have nephropathy? Larger clinical studies are needed, including both diseases, with a common histological classification, and stratified on age and genetic background to assess renal prognosis and therapeutic strategies.
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Wang M, Lv J, Chen P, Yu G, Shi S, Liu L, Zhou X, Xu D, Zhao M, Zhang H. Associations of ABO blood type and galactose-deficient immunoglobulin A1 with adverse outcomes in patients with IgA nephropathy. Nephrol Dial Transplant 2021; 36:288-294. [PMID: 31603230 DOI: 10.1093/ndt/gfz171] [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: 04/14/2019] [Accepted: 07/16/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Both ABO blood group antigens and pathogenic immunoglobulin A1 (IgA1) in patients with IgA nephropathy (IgAN) are influenced by modifications of N-acetylgalactosamine and galactose. The purpose of this study was to assess whether ABO blood type is associated with galactose-deficient IgA1 (Gd-IgA1) in the progression of kidney disease in patients with IgAN. METHODS We enrolled 1313 IgAN patients with a median of 44 months follow-up and measured the plasma Gd-IgA1 levels. Multivariate Cox regression models were used to estimate the association between all variables and adverse outcomes. Using the propensity score matching method, 718 IgAN patients with blood type either A or B were selected, and their data were used to assess the association of blood type and Gd-IgA1/serum complement 3 (sC3) with outcomes. RESULTS We found that the risk of adverse outcomes was significantly higher in patients with blood type A than in those with type B (hazard ratio = 1.82, 95% confidence interval 1.23-2.71; P = 0.003) after multivariate adjustment. The Gd-IgA1 levels showed trends similar to the multivariate-adjusted event-free curves for the blood types. However, this higher risk of adverse outcomes in type A than in type B patients was no longer significant after the addition of Gd-IgA1/sC3 to the model. CONCLUSIONS IgAN patients with blood type A had a higher risk of adverse outcomes than those with type B, and this risk was associated with Gd-IgA1/sC3. Thus, the ABO blood type may provide a reference for the prognostic factors for individuals with IgAN.
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Affiliation(s)
- Manliu Wang
- Renal Division, Department of Medicine, 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 of China, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Jicheng Lv
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Pei Chen
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Guizhen Yu
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Sufang Shi
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Lijun Liu
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Xujie Zhou
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Damin Xu
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Minghui Zhao
- Renal Division, Department of Medicine, 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 of China, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Hong Zhang
- Renal Division, Department of Medicine, 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 of China, Beijing, China
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17
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Dincer D, Tanacan E, Erdogan FG, Gurler A. The utility of immunoglobulin A/complement 3 and immunoglobulin G/immunoglobulin M ratios in the assessment of disease activation in patients with Behçet disease. Autoimmunity 2021; 54:176-180. [PMID: 33834897 DOI: 10.1080/08916934.2021.1906865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Pathogenesis of Behçet disease (BD) has not yet been clearly revealed and there is no ideal test for the estimation of disease activation at present. This study aimed to assess the efficiencies of IgG/IgM and IgA/C3 ratios in determining activation of BD. METHOD This retrospective cohort study consisted of 140 patients with BD. Patients were divided into two groups: (1) active BD (n = 89) and (2) inactive BD (n = 51) and were compared in terms of demographic features, clinical characteristics and laboratory test results. IgA/C3 and IgG/IgM ratios were compared according to organ system involvement; receiver operating characteristic (ROC) curve analysis was performed in order to assess the performance of IgA/C3 and IgG/IgM ratios in determining patient disease status. RESULTS Significantly higher levels of erythrocyte sedimentation rate, C-reactive protein, IgA, G, C4, IgA/C3, IgG/IgM ratios (p = .007 for IgA and p < .001 for others) and significantly lower levels of IgM and C3 were observed in patients with active BD (p < .001). The IgG/IgM ratio was significantly higher in patients with vascular involvement (p = .017) and the IgA/C3 ratio was significantly higher in patients with arthritis (p = .007). Cut-off values of 0.019 (70.8% sensitivity, 62% specificity) and 7.08 (84.3% sensitivity, 80% specificity) were determined for IgA/C3 and IgG/IgM ratios, respectively. CONCLUSION IgA/C3 and IgG/IgM ratios may be used as additional parameters for the assessment of BD status.
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Affiliation(s)
- Didem Dincer
- Department of Dermatology and Veneorology, Ufuk University, Ankara, Turkey
| | - Efsun Tanacan
- Department of Dermatology and Veneorology, Ufuk University, Ankara, Turkey
| | - F Gulru Erdogan
- Department of Dermatology and Veneorology, Ufuk University, Ankara, Turkey
| | - Aysel Gurler
- Department of Dermatology and Veneorology, Ufuk University, Ankara, Turkey
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Lang Y, Song S, Zhao L, Yang Y, Liu T, Shen Y, Wang W. Serum IgA/C3 ratio and glomerular C3 staining predict progression of IgA nephropathy in children. Transl Pediatr 2021; 10:666-672. [PMID: 33880336 PMCID: PMC8041611 DOI: 10.21037/tp-21-90] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND This retrospective study aimed to evaluate the significance of serum immunoglobulin A/complement 3 (IgA/C3) ratio and glomerular C3 staining at the onset of disease for predicting progression of IgA nephropathy in children. METHODS A total of 41 children with IgA nephropathy were allocated to two groups according to proteinuria (proteinuria <50 mg/kg/day group and proteinuria ≥50 mg/kg/day group) to compare their clinical data. Receiver operating characteristic (ROC) curves were used to evaluate the optimal cutoff value of serum IgA/C3 ratio in two groups. According to the optimal cutoff value of serum IgA/C3 ratio and glomerular C3 staining, the children were divided into four groups: Group A (serum IgA/C3 ratio <2.025 and glomerular C3 staining <2.0); Group B (serum IgA/C3 ratio ≥2.025 and glomerular C3 staining <2.0); Group C (serum IgA/C3 ratio <2.025 and glomerular C3 staining ≥2.0); and Group D (serum IgA/C3 ratio ≥2.025 and glomerular C3 staining ≥2.0). Then, the risk factors [including proteinuria and glomerular filtration rate (GFR) and pathological findings] were compared in these 4 groups at onset of IgA nephropathy. RESULTS Serum IgA/C3 ratio in the proteinuria <50 mg/kg/day group was significantly higher compared to the proteinuria ≥50 mg/kg/day group (P<0.01). According to ROC curves, the optimal cutoff value for the IgA/C3 ratio was 2.025 in two groups. At onset of IgA nephropathy, patients with IgA/C3 ratio <2.025 were predicted with nephrotic range proteinuria. When glomerular C3 staining was at the same level (glomerular C3 staining <2.0), GFR was significantly lower in group B (serum IgA/C3 ratio ≥2.025) compared with group A (serum IgA/C3 ratio <2.025). When serum IgA/C3 ratio was at the same level (serum IgA/C3 ratio <2.025), GFR was significantly lower in group C (glomerular C3 staining ≥2.0) compared with group A (glomerular C3 staining <2.0). Pathological findings and MEST (Oxford classification of IgA nephropathy) scores did not differ among the 4 groups at onset of the disease. CONCLUSIONS Serum IgA/C3 ratio and glomerular C3 staining may be useful markers of the progression of IgA nephropathy in children, but not good markers for pathological findings at the onset of disease.
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Affiliation(s)
- Yuanyuan Lang
- Department of Clinical Laboratory, Tianjin Children's Hospital, Tianjin, China
| | - Shaona Song
- Department of Nephrology, Tianjin Children's Hospital, Tianjin, China
| | - Linsheng Zhao
- Department of Pathology, Tianjin Children's Hospital, Tianjin, China
| | - Yi Yang
- Department of Clinical Laboratory, Tianjin Children's Hospital, Tianjin, China
| | - Tao Liu
- NHC Key Laboratory of Critical Care Medicine, Tianjin First Central Hospital, Tianjin, China
| | - Yongming Shen
- Department of Clinical Laboratory, Tianjin Children's Hospital, Tianjin, China
| | - Wenhong Wang
- Department of Nephrology, Tianjin Children's Hospital, Tianjin, China
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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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Chen P, Yu G, Zhang X, Xie X, Wang J, Shi S, Liu L, Lv J, Zhang H. Plasma Galactose-Deficient IgA1 and C3 and CKD Progression in IgA Nephropathy. Clin J Am Soc Nephrol 2019; 14:1458-1465. [PMID: 31511226 PMCID: PMC6777583 DOI: 10.2215/cjn.13711118] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 07/26/2019] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Increased circulating galactose-deficient IgA1 and subsequently complement activation both play important roles in the pathophysiology of IgA nephropathy. However, their relationship to disease severity and progression remains unclear. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We assessed 1210 participants in a cohort study of biopsy-proven IgA nephropathy at Peking University First Hospital. Plasma concentrations of galactose-deficient IgA1 and complement component C3 were measured at the time of biopsy. We tested associations of galactose-deficient IgA1 and galactose-deficient IgA1/C3 ratio with CKD progression event, defined as ESKD or 50% decline in eGFR, using Cox proportional hazards models and restricted cubic splines. RESULTS After a median follow-up of 43 months (interquartile range, 24-76 months), 172 (14%) participants reached the CKD progression event. The association of galactose-deficient IgA1 levels and CKD progression event showed a nonlinear relationship. The risk of CKD progression events was greater with higher plasma galactose-deficient IgA1 levels but reached a plateau when galactose-deficient IgA1>325 U/ml, whereas the risk of CKD progression events monotonically increased with higher galactose-deficient IgA1/C3 ratio. After adjustment for traditional risk factors (demographics, eGFR, proteinuria, hypertension, Oxford pathologic score, and corticosteroids/immunosuppressive therapy), higher levels of galactose-deficient IgA1/C3 ratio were independently associated with CKD progression event (per natural log-transformed [galactose-deficient IgA1/C3], hazard ratio, 2.03; 95% confidence interval [95% CI], 1.25 to 3.29; P=0.004). In reference to the first quartile of the galactose-deficient IgA1/C3 ratio, hazard ratios were 1.71 (95% CI, 1.01 to 2.89) for the second quartile, 1.55 (95% CI, 0.91 to 2.63) for the third quartile, and 2.17 (95% CI, 1.33 to 3.56) for the fourth quartile. CONCLUSIONS In IgA nephropathy, plasma galactose-deficient IgA1/C3 ratio was associated with CKD progression event independent of clinical and biopsy characteristics.
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Affiliation(s)
- Pei Chen
- Renal Division, Department of Medicine, 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; and.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Guizhen Yu
- Renal Division, Department of Medicine, 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; and.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Xue Zhang
- Renal Division, Department of Medicine, 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; and.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Xinfang Xie
- Renal Division, Department of Medicine, 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; and.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Jinwei Wang
- Renal Division, Department of Medicine, 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; and.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Sufang Shi
- Renal Division, Department of Medicine, 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; and.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Lijun Liu
- Renal Division, Department of Medicine, 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; and.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Jicheng Lv
- Renal Division, Department of Medicine, 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; and.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
| | - Hong Zhang
- Renal Division, Department of Medicine, 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; and.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment (Peking University), Ministry of Education, Beijing, China
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Relationship between complement deposition and the Oxford classification score and their combined effects on renal outcome in immunoglobulin A nephropathy. Nephrol Dial Transplant 2019; 35:2103-2137. [DOI: 10.1093/ndt/gfz161] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 07/09/2019] [Indexed: 12/30/2022] Open
Abstract
Abstract
Background
Complement activation has been highlighted in immunoglobulin (Ig) A nephropathy pathogenesis. However, whether the complement system can affect the downstream phenotype of IgA nephropathy remains unknown. Herein, we investigated the association of mesangial C3 deposition with the Oxford classification and their joint effects on worsening kidney function.
Methods
We investigated 453 patients with biopsy-proven IgA nephropathy. C3 deposition was defined as an immunofluorescence intensity of C3 ≥2+ within the mesangium. The subjects were classified according to the combination of C3 deposition and Oxford classification lesions. The primary endpoint was a composite of ≥30% decline in the estimated glomerular filtration rate or an increase in proteinuria ≥3.5 g/g during follow-up.
Results
Among the Oxford classification lesions, mesangial hypercellularity (M1), segmental glomerulosclerosis (S1) and tubulointerstitial fibrosis (T1–2) and crescentic lesion significantly correlated with C3 deposition. During a median follow-up of 33.0 months, the primary endpoint occurred more in patients with M1, S1, T1–2 and mesangial C3 deposition than in those without. In individual multivariable-adjusted Cox analyses, the presence of M1, S1, T1–2 and C3 deposition was significantly associated with higher risk of reaching primary endpoint. In the combined analyses of C3 deposition and the Oxford classification lesions, the hazard ratios for the composite outcome were significantly higher in the presence of C3/M1, C3/S1 and C3/crescent than in the presence of each lesion alone.
Conclusions
Complement deposition can strengthen the significance of the Oxford classification, and the presence of both components portends a poorer prognosis in IgA nephropathy.
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22
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Jia M, Zhu L, Zhai YL, Chen P, Xu BY, Guo WY, Shi SF, Liu LJ, Lv JC, Zhang H. Variation in complement factor H affects complement activation in immunoglobulin A vasculitis with nephritis. Nephrology (Carlton) 2019; 25:40-47. [PMID: 30838755 DOI: 10.1111/nep.13580] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND Immunoglobulin A (IgA) vasculitis with nephritis (IgAVN) and IgA nephropathy (IgAN) are widely considered as related diseases. Considerable evidences support the notion of involvement of complement activation in both IgAVN and IgAN. Our previous studies identified a genetic variant in complement factor H (CFH), rs6677604, as an IgAN-susceptible variant by genome-wide association study, and further confirmed its linkage to CFHR3-1Δ and proved its influence on complement activation and thereby on IgAN susceptibility. AIM To explore the role of rs6677604 in complement activation of IgAVN. METHODS In this study, we enrolled 632 patients with IgAVN, 1178 patients with IgAN and 902 healthy controls. The genotype of rs6677604 was measured by TaqMan allele discrimination assays or was extracted from genome-wide association study data. RESULTS The frequency of the rs6677604-A allele was significantly higher in IgAVN than in IgAN. However, no significant differences were observed between IgAVN and the controls. Higher complement factor H (FH) levels were observed in IgAVN than IgAN, and positive correlation between circulating FH and C3 levels was present in IgAVN. In both IgAVN and IgAN, rs6677604-A was associated with less intensity of glomerular C3 deposits. In agreement with the higher frequency of rs6677604-A in IgAVN, the glomerular C3 deposits of patients with IgAVN were less intense than those in IgAN. CONCLUSION Our findings suggest that genetic variation in CFH (rs6677604) is involved in the phenotype of complement activation in both IgAVN and IgAN. Moreover, rs6677604 might contribute to the difference of complement activation intensity between IgAVN and IgAN.
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Affiliation(s)
- Meng Jia
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Li Zhu
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Ya-Ling Zhai
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Pei Chen
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Bo-Yang Xu
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Wei-Yi Guo
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Su-Fang Shi
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Li-Jun Liu
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Ji-Cheng Lv
- Renal Division, Department of Medicine, 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 of China, Beijing, China
| | - Hong Zhang
- Renal Division, Department of Medicine, 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 of China, Beijing, China
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23
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Gong WY, Liu M, Luo D, Liu FN, Yin LH, Li YQ, Zhang J, Peng H. High serum IgA/C3 ratio better predicts a diagnosis of IgA nephropathy among primary glomerular nephropathy patients with proteinuria ≤ 1 g/d: an observational cross-sectional study. BMC Nephrol 2019; 20:150. [PMID: 31039758 PMCID: PMC6492345 DOI: 10.1186/s12882-019-1331-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 04/08/2019] [Indexed: 11/22/2022] Open
Abstract
Background The serum immunoglobulin A (IgA)/C3 ratio is considered to be an effective predictor of IgA nephropathy (IgAN). This study sought to explore the diagnostic value of the IgA/C3 ratio in IgAN among primary glomerular nephropathy patients in China. Methods We recruited 1095 biopsy-diagnosed primary glomerular nephropathy patients, including 757 IgAN patients and 338 non-IgAN patients. Patient demographics, serum immunological indices, and other clinical examinations were measured. IgAN cases were propensity score matched (PSM) to non-IgAN cases on the logit of the propensity score using nearest neighbor matching in a 1:1 fashion, with a caliper of 0.02 with no replacements, according to age, gender, BMI, proteinuria level, and estimated glomerular filtration rate (eGFR). Results We found that in both the full cohort and PSM cohort, the IgA/C3 ratio in the IgAN group was significantly higher than that of the non-IgAN group. The same results were also obtained with stratification by different levels of proteinuria and renal function. In the PSM cohort, there was no difference in IgA/C3 ratio in patients with IgAN between different proteinuria groups and different chronic kidney disease (CKD) groups. The area under the ROC curve (AUROC) of the IgA/C3 ratio in distinguishing IgAN among primary glomerular disease was 0.767 in the full cohort, and 0.734 in the PSM cohort. The highest AUROC of the IgA/C3 ratio was in the ≤1 g/d proteinuria group (0.801 in the full cohort, and 0.803 in the PSM cohort); however, there was no difference between all CKD groups. Meanwhile, the diagnostic accordance rate for the diagnosis of IgAN among all patients with an IgA/C3 ratio > 3.5304 was as high as 92.02% in the full cohort. IgAN was independently correlated with IgA/C3 ratio in the full cohort by multivariate logistic regression analysis. Conclusions The present study provides clear evidence that the IgA/C3 ratio is an effective predictor of IgA diagnosis, especially in patients with proteinuria ≤1 g/d. In order to study the effectiveness of this biomarker, and to determine a standardized cut-off value, additional multicenter large-scale studies are needed. Electronic supplementary material The online version of this article (10.1186/s12882-019-1331-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Wen-Yu Gong
- Division of Nephrology, Department of medicine, the First Affiliated Hospital, Jinan University, Guangzhou, 510630, Guangdong, China
| | - Man Liu
- Division of Gastroenterology and Hepatology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Dan Luo
- Division of Nephrology, Department of medicine, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, Guangdong, China
| | - Fan-Na Liu
- Division of Nephrology, Department of medicine, the First Affiliated Hospital, Jinan University, Guangzhou, 510630, Guangdong, China
| | - Liang-Hong Yin
- Division of Nephrology, Department of medicine, the First Affiliated Hospital, Jinan University, Guangzhou, 510630, Guangdong, China
| | - Yuan-Qing Li
- Division of Nephrology, Department of medicine, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, Guangdong, China
| | - Jun Zhang
- Division of Nephrology, Department of medicine, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, Guangdong, China.
| | - Hui Peng
- Division of Nephrology, Department of medicine, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, Guangdong, China.
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24
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Rizk DV, Maillard N, Julian BA, Knoppova B, Green TJ, Novak J, Wyatt RJ. The Emerging Role of Complement Proteins as a Target for Therapy of IgA Nephropathy. Front Immunol 2019; 10:504. [PMID: 30941137 PMCID: PMC6433978 DOI: 10.3389/fimmu.2019.00504] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 02/25/2019] [Indexed: 12/28/2022] Open
Abstract
IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis worldwide and a common cause of end-stage renal disease. Evaluation of a kidney biopsy is necessary for diagnosis, with routine immunofluorescence microscopy revealing dominant or co-dominant IgA immunodeposits usually with complement C3 and sometimes IgG and/or IgM. IgA nephropathy reduces life expectancy by more than 10 years and leads to kidney failure in 20–40% of patients within 20 years of diagnosis. There is accumulating clinical, genetic, and biochemical evidence that complement plays an important role in the pathogenesis of IgA nephropathy. The presence of C3 differentiates the diagnosis of IgA nephropathy from the subclinical deposition of glomerular IgA. Markers for the activation of the alternative and mannan-binding lectin (MBL) pathways in renal-biopsy specimens are associated with disease activity and portend a worse renal outcome. Complement proteins in the circulation have also been evaluated in IgA nephropathy and found to be of prognostic value. Recently, genetic studies have identified IgA nephropathy-associated loci. Within these loci are genes encoding products involved in complement regulation and interaction with immune complexes. Put together, these data identify the complement cascade as a rational treatment target for this chronic kidney disease. Recent case reports on the successful use of humanized anti-C5 monoclonal antibody eculizumab are consistent with this hypothesis, but a better understanding of the role of complement in IgA nephropathy is needed to guide future therapeutic interventions.
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Affiliation(s)
- Dana V Rizk
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Nicolas Maillard
- Department of Nephrology, Dialysis, Transplantation, CHU de Saint-Etienne, GIMAP, EA3064, Université Jean Monnet, COMUE Université de Lyon, Rhône-Alpes, France
| | - Bruce A Julian
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Barbora Knoppova
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, United States.,Department of Immunology, Faculty of Medicine and Dentistry, Palacky University and University Hospital, Olomouc, Czechia
| | - Todd J Green
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Robert J Wyatt
- Department of Pediatrics, University of Tennessee Health Sciences Center, Memphis, TN, United States
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25
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Thompson A, Carroll K, A. Inker L, Floege J, Perkovic V, Boyer-Suavet S, W. Major R, I. Schimpf J, Barratt J, Cattran DC, S. Gillespie B, Kausz A, W. Mercer A, Reich HN, H. Rovin B, West M, Nachman PH. Proteinuria Reduction as a Surrogate End Point in Trials of IgA Nephropathy. Clin J Am Soc Nephrol 2019; 14:469-481. [PMID: 30635299 PMCID: PMC6419287 DOI: 10.2215/cjn.08600718] [Citation(s) in RCA: 137] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
IgA nephropathy (IgAN) is an important cause of ESKD for which there are no approved therapies. A challenge for evaluating treatments for IgAN is the usual long time course for progression to ESKD. The aim of this Kidney Health Initiative project was to identify surrogate end points that could serve as reliable predictors of a treatment's effect on long-term kidney outcomes in IgAN and be used as a basis for approval. Proteinuria was identified as the most widely recognized and well studied risk factor for progression to ESKD in IgAN. The workgroup performed a critical review of the data on proteinuria reduction as a surrogate end point for a treatment's effect on progression to ESKD in IgAN. Epidemiologic data indicate a strong and consistent relationship between the level and duration of proteinuria and loss of kidney function. Trial-level analyses of data from 13 controlled trials also show an association between treatment effects on percent reduction of proteinuria and treatment effects on a composite of time to doubling of serum creatinine, ESKD, or death. We conclude that data support the use of proteinuria reduction as a reasonably likely surrogate end point for a treatment's effect on progression to ESKD in IgAN. In the United States, reasonably likely surrogate end points can be used as a basis for accelerated approval of therapies intended to treat serious or life-threatening conditions, such as IgAN. The clinical benefit of products approved under this program would need to be verified in a postmarketing confirmatory trial.
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Affiliation(s)
- Aliza Thompson
- Division of Cardiovascular and Renal Products, Office of New Drugs, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland
| | | | | | - Jürgen Floege
- Division of Nephrology, RWTH University of Aachen, Aachen, Germany
| | - Vlado Perkovic
- The George Institute for Global Health, University of New South Wales, Sydney, Australia
| | - Sonia Boyer-Suavet
- Service de Néphrologie, Hôpital Pasteur, Centre Hospitalier Universitaire de Nice, Université Nice Sophia-Antipolis, Nice, France; Departments of
| | | | | | - Jonathan Barratt
- Infection, Inflammation and Immunity, University of Leicester, Leicester, UK
| | - Daniel C. Cattran
- University Health Network, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | - Heather N. Reich
- University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Brad H. Rovin
- The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Melissa West
- American Society of Nephrology, Washington, DC; and
| | - Patrick H. Nachman
- Division of Renal Diseases and Hypertension, University of Minnesota, Minneapolis, Minnesota
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