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Andeen NK, Hou J. Diagnostic Challenges and Emerging Pathogeneses of Selected Glomerulopathies. Pediatr Dev Pathol 2024:10935266241237656. [PMID: 38576387 DOI: 10.1177/10935266241237656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Recent progress in glomerular immune complex and complement-mediated diseases have refined diagnostic categories and informed mechanistic understanding of disease development in pediatric patients. Herein, we discuss selected advances in 3 categories. First, membranous nephropathy antigens are increasingly utilized to characterize disease in pediatric patients and include phospholipase A2 receptor (PLA2R), Semaphorin 3B (Sema3B), neural epidermal growth factor-like 1 (NELL1), and protocadherin FAT1, as well as the lupus membranous-associated antigens exostosin 1/2 (EXT1/2), neural cell adhesion molecule 1 (NCAM1), and transforming growth factor beta receptor 3 (TGFBR3). Second, we examine advances in techniques for paraffin and light chain immunofluorescence (IF), including the former's function as a salvage technique and their necessity for diagnosis in adolescent cases of membranous-like glomerulopathy with masked IgG kappa deposits (MGMID) and proliferative glomerulonephritis with monotypic Ig deposits (PGNMID), respectively. Finally, progress in understanding the roles of complement in pediatric glomerular disease is reviewed, with specific attention to overlapping clinical, histologic, and genetic or functional alternative complement pathway (AP) abnormalities among C3 glomerulopathy (C3G), infection-related and post-infectious GN, "atypical" post-infectious GN, immune complex mediated membranoproliferative glomerulonephritis (IC-MPGN), and atypical hemolytic uremic syndrome (aHUS).
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Affiliation(s)
- Nicole K Andeen
- Oregon Health & Science University, Department of Pathology and Laboratory Medicine, Portland, OR, USA
| | - Jean Hou
- Cedars-Sinai Medical Center, Department of Pathology, Los Angeles, CA, USA
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Pal D, Inamdar N, Kaur P, Singhal M, Lal A, Gorsi U, Nada R, Kohli HS, Kumar V, Ramachandran R. Augmented mannose-binding lectin levels in primary membranous nephropathy: A pilot study. Nephrology (Carlton) 2024. [PMID: 38511256 DOI: 10.1111/nep.14293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/25/2024] [Accepted: 03/08/2024] [Indexed: 03/22/2024]
Abstract
There is evidence to suggest that M-type phospholipase A2 (PLA2R) antibodies activate the mannose-binding lectin (MBL) cascade, resulting in glomerular damage and proteinuria in patients with primary membranous nephropathy (PMN). Furthermore, there are few reports indicating that aberrant MBL activation is associated with endothelial dysfunction and accelerated atherosclerosis. While PMN is a common cause of adult nephrotic syndrome, and patients are at increased risk of cardiovascular disease (CVD), there is a lack of research that explores the factors that contribute to this condition. This study aims to determine the MBL levels in PMN and their relation to the clinical activity and endothelial dysfunction in PMN. The MBL levels of 22 biopsy-confirmed PMN patients were assessed at baseline and after 6 months of immunosuppressive therapy. In order to evaluate endothelial dysfunction in PMN patients, flow-mediated vasodilation (FMD) was measured at baseline and after treatment. A total of 22 healthy controls were included in this study to measure MBL levels and FMD. A significant difference was observed between MBL levels in PMN patients and healthy controls (p < .01). MBL levels decreased significantly after immunosuppressive therapy (p = .04). The baseline MBL levels and FMD levels exhibited a strong correlation (Spearman correlation coefficient [ρ] = 0.51: p = .01). In conclusion, the study signals the activation of the MBL cascade and its association with endothelial dysfunction in PMN patients.
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Affiliation(s)
- Deeksha Pal
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Neeraj Inamdar
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Prabhjot Kaur
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Manphool Singhal
- Department of Radiodiagnosis, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Anupam Lal
- Department of Radiodiagnosis, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Ujjwal Gorsi
- Department of Radiodiagnosis, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Ritambhra Nada
- Department of Histopathology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Harbir S Kohli
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Vinod Kumar
- Department of Dermatology, Venereology & Leprosy, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Raja Ramachandran
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
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Yang L, Wang G, Ye N, Xu X, Cheng W, Sun L, Dong H, Kong L, Zhao X, Geng Y, Cheng H. Clinicopathological and prognostic characteristics of idiopathic membranous nephropathy with dual antigen positivity. Front Immunol 2024; 14:1297107. [PMID: 38250076 PMCID: PMC10796489 DOI: 10.3389/fimmu.2023.1297107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 12/11/2023] [Indexed: 01/23/2024] Open
Abstract
Background Idiopathic membranous nephropathy (IMN) is the most common pathological type in adults with nephrotic syndrome. Many target antigens have been discovered. However, dual antigen-positive IMN patients are very rare, with only a few such cases being briefly described in various studies. There is no specific study on the clinicopathological and prognostic characteristics of dual antigen-positive IMN patients, and the disease characteristics of such patients remain unclear. Methods Immunohistochemical staining of PLA2R, THSD7A, and NELL-1 was conducted on kidney tissue samples obtained from patients diagnosed with IMN. Simultaneously, the presence of corresponding serum antibodies was determined. Patients exhibiting positivity for dual antigens were included in the study, identified either through tissue staining or serum antibody detection. We retrospectively collected their clinical, pathological, and follow-up data and measured their serum antibody levels at multiple time points. Additionally, the same type of dual antigen-positive IMN cases reported in the literature were reviewed to extract clinical, pathological, and prognostic information. We compared the data for all of the above dual antigen-positive and PLA2R single-positive IMN cases at our center. Results We identified 6 IMN patients with dual antigen positivity at our center, approximately 0.7% of whole MN series; the previous literature reports 43 IMN patients with dual antigen positivity, the proportion ranged from 0.2% to 2.8%. The IgG1 positivity rate in the renal tissue of the dual antigen-positive patients at our center was significantly lower than that of dual antigen-positive patients previously reported (16.7% vs. 100.0%, p=0.015), but there was no significant difference in clinical or prognostic aspects. Patients with dual antigen positivity reported at our center and in the literature were combined and compared with PLA2R single-positive IMN reported at our center. Compared with PLA2R single-positive IMN patients, dual antigen-positive IMN patients had a higher renal tissue IgG1 positivity rate (58.3% vs. 22.3%, p=0.016), and the time required to achieve remission was longer [13.5 (3.3,35.0) vs. 3.0 (1.0,8.0), p=0.052]. Overall, The changes in urine protein were consistent with the changes in serum PLA2R antibody levels in dual antigen-positive IMN patients. Conclusions For patients with primary membranous nephropathy who did not attain remission following prolonged treatment, multiple target antigen staining should still be actively performed, even with positivity for the PLA2R target antigen.
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Affiliation(s)
- Lei Yang
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Guoqin Wang
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Nan Ye
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Xiaoyi Xu
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Wenrong Cheng
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Lijun Sun
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Hongrui Dong
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Lingqiang Kong
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Xiaoyi Zhao
- Division of Nephrology, Affiliated Hospital of Chifeng University, Neimenggu, China
| | - Yanqiu Geng
- Division of Nephrology, The Third Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Hong Cheng
- Beijing Anzhen Hospital, Capital Medical University, Beijing, China
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Guo Y, Ren M, Wang Y, Zhai Z, Yu L, Wang L, Tang L. Effect of rituximab in patients with PLA2R-associated membranous nephropathy and malignancy. Int Immunopharmacol 2024; 126:111327. [PMID: 38056198 DOI: 10.1016/j.intimp.2023.111327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/16/2023] [Accepted: 11/28/2023] [Indexed: 12/08/2023]
Abstract
INTRODUCTION Phospholipase A2 receptor (PLA2R)-associated membranous nephropathy (MN) is a common cause of nephrotic syndrome in nondiabetic adults who are also within the common age group for malignancy. How to treat patients with PLA2R-associated MN and malignancy effectively and safely still requires careful consideration. The aim of our study was to examine the outcomes and safety of rituximab (RTX) in these patients. METHODS Retrospective analysis of clinical data was performed on 15 patients with PLA2R-associated MN and malignancy. Patients were followed every 1-3 months for a minimum of 24 months. Clinical data were collected, including CD19+ B cells, anti-PLA2R antibodies, 24-hour urinary protein, serum albumin, and serum creatinine. The percentage of patients who achieved clinical remission and immunological remission was also measured. RESULTS Among these 15 patients, 14 patients with solid tumors received treatment for malignant diseases with complete resection. One patient received chemotherapy for chronic myeloid leukemia, and achieved complete remission 36 months before the diagnosis of MN. There were 6 (40.00 %) patients who achieved complete remission and 14 (93.33 %) patients who achieved complete or partial remission at the last visit after RTX treatment. At the last visit, patients were clinically improved, as evidenced by significant improvements in anti-PLA2R antibody titer [2.00 (2.00, 2.00) vs 35.25 (11.18, 91.58) RU/ml, P = 0.002], 24-hour urine protein [0.39 (0.11, 2.28) vs 9.22 (4.47, 14.73) g/d, P = 0.001], and serum albumin [38.15 (34.80, 43.20) vs 23.70 (18.70, 25.70) g/L, P = 0.001]. During the follow-up, the renal function of those patients remained stable. Recurrence of malignant tumors or the occurrence of new tumor events were not observed. CONCLUSION In this single-center retrospective study with a small sample size, RTX therapy might be an effective and safe treatment in patients with PLA2R-associated MN and malignancy.
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Affiliation(s)
- Yanhong Guo
- Department of Nephropathy, the First Affiliated Hospital of Zhengzhou University, No. 1 East Jianshe Road, Zhengzhou 450052, Henan, China.
| | - Mingjing Ren
- Department of Nephropathy, the First Affiliated Hospital of Zhengzhou University, No. 1 East Jianshe Road, Zhengzhou 450052, Henan, China
| | - Yulin Wang
- Department of Nephropathy, the First Affiliated Hospital of Zhengzhou University, No. 1 East Jianshe Road, Zhengzhou 450052, Henan, China
| | - Zihan Zhai
- Department of Nephropathy, the First Affiliated Hospital of Zhengzhou University, No. 1 East Jianshe Road, Zhengzhou 450052, Henan, China
| | - Lu Yu
- Department of Nephropathy, the First Affiliated Hospital of Zhengzhou University, No. 1 East Jianshe Road, Zhengzhou 450052, Henan, China
| | - Liuwei Wang
- Department of Nephropathy, the First Affiliated Hospital of Zhengzhou University, No. 1 East Jianshe Road, Zhengzhou 450052, Henan, China
| | - Lin Tang
- Department of Nephropathy, the First Affiliated Hospital of Zhengzhou University, No. 1 East Jianshe Road, Zhengzhou 450052, Henan, China.
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Chen Y, Xu Y, Chen S, Yu Y, Zhu X, Chen J. The application of podocyte antigen PLA2R and anti-PLA2R antibody in the diagnosis and treatment of membranous nephropathy. Ren Fail 2023; 45:2264939. [PMID: 37814415 PMCID: PMC10566392 DOI: 10.1080/0886022x.2023.2264939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 09/25/2023] [Indexed: 10/11/2023] Open
Abstract
BACKGROUND The application of podocyte antigen M-type phospholipase A2 receptor (PLA2R, GAg) and serum anti-PLA2R antibody (SAb) in predicting the prognosis of membrane nephropathy (MN) was controversial. METHOD 328 biopsy-proven MN patients were divided into three phenotypes, 182 MN patients with GAg+/SAb+, 118 MN patients with GAg+/SAb-, and 28 MN patients with GAg-/SAb-. The baseline clinicopathological characteristics, therapy response, and prognosis were compared among the three groups. Cox regression analysis was performed to assess predictors of remission. Anti-PLA2R antibody was analyzed by receiver operating characteristic curve to find the optimal titer for MN diagnosis. RESULT Lower eGFR (p = 0.009), higher UPCR (p < 0.001), and lower serum albumin (p < 0.001) were observed in GAg+/SAb+ MN patients, compared to GAg+/SAb- MN patients. More GAg+/SAb+ MN patients received cyclophosphamide (CTX) combined with glucocorticoids and calcineurin inhibitors (CNI) based therapy than the other two groups (p = 0.015 and p = 0.023, respectively). No significant difference was observed among the three groups in terms of complete remission, relapse, and developing ESRD. SAb+ status was an independent predictor for no remission (hazard ratio 1.378, 95% confidence interval 1.023 to 1.855; p = 0.035). The optimal cutoff value for anti-PLA2R antibody to predict MN was 2.055 RU/mL (sensibility 0.802, specificity 0.970). CONCLUSION GAg+/SAb+ MN patients were related to more severe clinical manifestations and more requisition of immunosuppressive treatment. Positive anti-PLA2R antibody was an independent predictor for no remission. An anti-PLA2R antibody above 2.055 RU/mL can be a suggestive indicator of MN diagnosis in patients with proteinuria.
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Affiliation(s)
- Yang Chen
- Kidney Disease Center, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Kidney Disease Prevention and Control Technology, Hangzhou, Zhejiang, China
- National Key Clinical Department of Kidney Diseases, Hangzhou, Zhejiang, China
- Institute of Nephrology, Zhejiang University, Hangzhou, Zhejiang, China
- Zhejiang Clinical Research Center of Kidney and Urinary System Disease, Hangzhou, Zhejiang China
| | - Ying Xu
- Kidney Disease Center, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Kidney Disease Prevention and Control Technology, Hangzhou, Zhejiang, China
- National Key Clinical Department of Kidney Diseases, Hangzhou, Zhejiang, China
- Institute of Nephrology, Zhejiang University, Hangzhou, Zhejiang, China
- Zhejiang Clinical Research Center of Kidney and Urinary System Disease, Hangzhou, Zhejiang China
| | - Siyu Chen
- Kidney Disease Center, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Kidney Disease Prevention and Control Technology, Hangzhou, Zhejiang, China
- National Key Clinical Department of Kidney Diseases, Hangzhou, Zhejiang, China
- Institute of Nephrology, Zhejiang University, Hangzhou, Zhejiang, China
- Zhejiang Clinical Research Center of Kidney and Urinary System Disease, Hangzhou, Zhejiang China
| | - Yedong Yu
- Kidney Disease Center, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Kidney Disease Prevention and Control Technology, Hangzhou, Zhejiang, China
- National Key Clinical Department of Kidney Diseases, Hangzhou, Zhejiang, China
- Institute of Nephrology, Zhejiang University, Hangzhou, Zhejiang, China
- Zhejiang Clinical Research Center of Kidney and Urinary System Disease, Hangzhou, Zhejiang China
- Zhejiang Provincial People’s Hospital, Hangzhou, Zhejiang, China
| | - Xueling Zhu
- The Department of Infectious Diseases, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Jianghua Chen
- Kidney Disease Center, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
- Key Laboratory of Kidney Disease Prevention and Control Technology, Hangzhou, Zhejiang, China
- National Key Clinical Department of Kidney Diseases, Hangzhou, Zhejiang, China
- Institute of Nephrology, Zhejiang University, Hangzhou, Zhejiang, China
- Zhejiang Clinical Research Center of Kidney and Urinary System Disease, Hangzhou, Zhejiang China
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Abstract
Membranous nephropathy (MN) is a common cause of nephrotic syndrome (NS) in adults and if untreated can progress to endstage kidney disease. Factors considered to place a patient at high or very high risk for progression include elevated serum creatinine at baseline, declining kidney function, persistent heavy proteinuria (>8 g/24 h), or persistent NS, presence of life-threatening complications related to NS (such as venous thromboembolic events), or very high anti-PLA2R antibody titers (>150 RU/ml). Patients who are at high or very high risk of progression should be treated with immunosuppression therapy to induce remission of proteinuria and to avoid progressive loss of kidney function. Traditional forms of immunosuppression for patients with MN have included the use of cyclic courses of corticosteroids with cyclophosphamide or calcineurin inhibitors. These forms of therapy are associated with significant toxicity, e.g. corticosteroids (infections, diabetes, weight gain), cyclophosphamide (infertility, severe leukopenia, malignancy), and calcineurin inhibitors (hypertension, nephrotoxicity). The introduction of anti-CD20+ B-cell therapies in the late 1990s has changed the landscape. In this article we will argue that anti-CD20+ B therapy should be the treatment of choice for patients at high/very high risk of progression when considering its efficacy and side-effect profile.
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Affiliation(s)
- Ladan Zand
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
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Kakhsurueva PA, Kamyshova ES, Bobkova IN, Stavrovskaya EV, Rudenko TE, Andreeva EY. [Clinical significance of the determination of antibodies to thrombospondin type 1 containing domain 7A (THSD7A) in membranous nephropathy]. TERAPEVT ARKH 2023; 95:462-467. [PMID: 38158964 DOI: 10.26442/00403660.2023.06.202268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 08/14/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND Membranous nephropathy (MN) is an immunocomplex glomerular disease, which is the most common cause of nephrotic syndrome in adults. Numerous studies have established that autoantibodies against the target podocyte autoantigens, including the thrombospondin type 1 domain containing 7A (THSD7A), play a leading role in the development of idiopathic MN. AIM To evaluate the prevalence of anti-THSD7A autoantibodies (anti-THSD7A AB) in a group of Russian patients with MN. MATERIALS AND METHODS Serum titers of anti-THSD7A AB were tested in 61 patients with biopsy-proven MN and 12 healthy controls. RESULTS The prevalence of anti-THSD7A AB was not differing significantly in patients with MN and in the control group (110.9 [71.63; 210.62] and 159.25 [125.64; 231.97] pg/ml, respectively; p=0.111). When comparing subgroups of anti-PLA2R-negative patients and patients who did not receive immunosuppressive therapy with the control group, there were also no statistically significant differences in the Anti-THSD7A AB levels (p>0.05). In the MN group, 1 (1.6%) patient was anti-THSD7A-positive: a 60-year-old man with anti-PLA2R-negative MN and the presence of hormonally inactive adenomas of both adrenal glands and colon polyps (villous adenoma with focal moderate dysplasia, tubulo-villous and tubular adenoma with focal moderate severe dysplasia). CONCLUSION THSD7-associated MN is a rare variant of MN and is usually detected in PLA2R-negative patients. Screening for malignancies in THSD7A-positive MN patients is proposed.
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Affiliation(s)
- P A Kakhsurueva
- Sechenov First Moscow State Medical University (Sechenov University)
| | - E S Kamyshova
- Sechenov First Moscow State Medical University (Sechenov University)
| | - I N Bobkova
- Sechenov First Moscow State Medical University (Sechenov University)
| | - E V Stavrovskaya
- Sechenov First Moscow State Medical University (Sechenov University)
| | - T E Rudenko
- Sechenov First Moscow State Medical University (Sechenov University)
| | - E Y Andreeva
- Sechenov First Moscow State Medical University (Sechenov University)
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Wang JL, Sun YL, Kang Z, Zhang SK, Yu CX, Zhang W, Xie H, Lin HL. Anti-phospholipase A2 receptor-associated membranous nephropathy with human immunodeficiency virus infection treated with telitacicept: A case report. World J Clin Cases 2023; 11:5309-5315. [PMID: 37621578 PMCID: PMC10445080 DOI: 10.12998/wjcc.v11.i22.5309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/07/2023] [Accepted: 07/17/2023] [Indexed: 08/04/2023] Open
Abstract
BACKGROUND The co-occurrence of Anti-phospholipase A2 receptor-associated membranous nephropathy (anti-PLA2R-MN) and human immunodeficiency virus (HIV) infection is a rare clinical scenario, presenting significant challenges in terms of management and treatment. CASE SUMMARY A 32-year-old Chinese male diagnosed with HIV infection presented with a clinical history of proteinuria persisting for over two years. A kidney biopsy demonstrated subepithelial immune complex deposition and a thickened glomerular basement membrane, indicative of stage I-II membranous nephropathy. Immunofluorescence staining revealed granular deposition of PLA2R (3+) along the glomerular capillary loops, corroborated by a strongly positive anti-PLA2R antibody test (1:320). Initial treatment involving losartan potassium, rivaroxaban, tacrolimus, and rituximab was discontinued due to either poor effectiveness or the occurrence of adverse events. Following a regimen of weekly subcutaneous injections of telitacicept (160 mg), a marked decline in the 24 h urine protein was observed within a three-month period, accompanied by a rise in serum albumin level. No significant reductions in peripheral blood CD3+CD4+T and CD3+CD8+T cell counts were detected. The patient's physical and psychological conditions showed significant improvements, with no adverse events reported during the treatment course. CONCLUSION Telitacicept might offer a potential therapeutic avenue for patients diagnosed with anti-PLA2R-MN concomitant with HIV infection.
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Affiliation(s)
- Jin-Ling Wang
- Department of Nephrology, Dalian Renal Care Hospital, Dalian 116000, Liaoning Province, China
| | - Yan-Ling Sun
- Department of Nephrology, Dalian Renal Care Hospital, Dalian 116000, Liaoning Province, China
| | - Zhe Kang
- Department of Nephrology, Dalian Renal Care Hospital, Dalian 116000, Liaoning Province, China
| | - Sheng-Kun Zhang
- Department of Nephrology, Dalian Renal Care Hospital, Dalian 116000, Liaoning Province, China
| | - Chun-Xin Yu
- Department of Nephrology, Dalian Renal Care Hospital, Dalian 116000, Liaoning Province, China
| | - Wan Zhang
- Department of Nephrology, Dalian Renal Care Hospital, Dalian 116000, Liaoning Province, China
| | - Hua Xie
- Department of Nephrology, Dalian Renal Care Hospital, Dalian 116000, Liaoning Province, China
| | - Hong-Li Lin
- Department of Nephrology, The First Affiliated Hospital of Dalian Medical University, Dalian 116000, Liaoning Province, China
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Zhang XD, Lin CX, Cui Z, Gu QH, Yan BJ, Liu L, Song WC, Shi Y, Debiec H, Ronco P, Zhao MH. Mapping the T cell epitopes of the M-type transmembrane phospholipase A2 receptor in primary membranous nephropathy. Kidney Int 2023; 103:580-592. [PMID: 36549363 DOI: 10.1016/j.kint.2022.11.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 10/09/2022] [Accepted: 11/14/2022] [Indexed: 12/24/2022]
Abstract
The M-type phospholipase A2 receptor (PLA2R) is the major autoantigen of primary membranous nephropathy (MN). Despite many studies on B-cell epitopes recognized by antibodies, little is known about T-cell epitopes. Herein, we synthesized 123 linear peptides, each consisting of 15-22 amino acids with 8-12 amino acid overlaps, across ten domains of PLA2R. Their binding capacity to risk (DRB1∗1501, DRB1∗0301) and protective (DRB1∗0901, DRB1∗0701) HLA molecules was then assessed by flow cytometry. Proliferation of CD4+ T cells from patients with anti-PLA2R positive MN was analyzed after peptide stimulation. Cytokines produced by activated peripheral blood mononuclear cells were measured by cytometric bead arrays. We identified 17 PLA2R peptides that bound to both DRB1∗1501 and DRB1∗0301 molecules with high capacity. Some of these peptides showed decreased binding to heterozygous DRB1∗1501/0901 and DRB1∗0301/0701. Ten of the 17 peptides (CysR1, CysR10, CysR12, FnII-3, CTLD3-9, CTLD3-10, CTLD3-11, CTLD5-2-1, CTLD7-1 and CTLD7-2) induced significant proliferation of CD4+ T cells from patients with MN than cells from healthy individuals. Upon activation by these peptides, peripheral blood mononuclear cells from patients with MN produced higher levels of pro-inflammatory cytokines, predominantly IL-6, TNF-α, IL-10, IL-9 and IL-17. Thus, we mapped and identified ten peptides in the CysR, FnII, CTLD3, CTLD5, and CTLD7 domains of PLA2R as potential T-cell epitopes of MN. These findings are a first step towards developing peptide-specific immunotherapies.
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Affiliation(s)
- Xiao-Dan Zhang
- Renal Division, 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 CKD Prevention and Treatment, Ministry of Education of China, Beijing, China
| | - Cai-Xia Lin
- Renal Division, 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 CKD Prevention and Treatment, Ministry of Education of China, Beijing, China
| | - Zhao Cui
- Renal Division, 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 CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.
| | - Qiu-Hua Gu
- Renal Division, 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 CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; Department of Nephrology, Tianjin Medical University General Hospital, Tianjin, China
| | - Bing-Jia Yan
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, China
| | - Lei Liu
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing, China; Peking-Tsinghua Center for Life Sciences, Beijing, China
| | - Wen-Chao Song
- Department of Pharmacology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA; Institute for Translational Medicine and Therapeutics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Yi Shi
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Hanna Debiec
- Sorbonne Université, Paris, France; Institut National de la Santé et de la Recherche Médicale (Inserm), Unité Mixte de Recherche S1155, Paris, France
| | - Pierre Ronco
- Sorbonne Université, Paris, France; Institut National de la Santé et de la Recherche Médicale (Inserm), Unité Mixte de Recherche S1155, Paris, France; Department of Nephrology, Centre Hospitalier du Mans, Le Mans, France
| | - Ming-Hui Zhao
- Renal Division, 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 CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; Peking-Tsinghua Center for Life Sciences, Beijing, China
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10
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Shah M, DeLaat A, Cavanaugh C. Treatment of membranous nephropathy: Perspectives on current and future therapies. Front Nephrol 2023; 3:1110355. [PMID: 37675368 PMCID: PMC10479573 DOI: 10.3389/fneph.2023.1110355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 01/09/2023] [Indexed: 09/08/2023]
Abstract
Primary membranous nephropathy remains one of the most frequent causes of nephrotic syndrome in adults. It is an autoimmune disorder in which auto-antibodies target antigens at the podocytes cell membrane-basement membrane interface. Our understanding of membranous nephropathy has expanded dramatically as of late. After the initial discovery of the phospholipase A2 receptor auto-antibody in 2009, eight more antigens have been discovered. These discoveries have led to refinement in our understanding of the pathogenesis, diagnosis, and natural history of primary membranous nephropathy. Now, many experts advocate for redefining primary membranous nephropathy based on antigen, potentially shedding the primary and secondary nomenclature. Recently, therapies for primary membranous have also expanded. Immunosuppressive therapies like cyclophosphamide and rituximab, which primarily target B-cells, remain the cornerstone of therapy. However, there is still significant room for improvement, as many as 30-40% do not respond to this therapy according to recent trials. Additionally, drugs targeting complement, and other novel therapies are also under investigation. In this review we will discuss the available therapies for primary membranous nephropathy in light of recent clinic trials like GEMRITUX, MENTOR, RI-CYCLO, and STARMEN, as well as management strategies. While the last 10 years have seen a boom in our mechanistic understanding of this ever-diversifying disease, we are likely to see a similar boom in the therapeutic options in the years to come.
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Affiliation(s)
- Monarch Shah
- Division of Nephrology, University of Virginia, Charlottesville, VA, United States
| | - Andrew DeLaat
- Liberty University College of Osteopathic Medicine, Lynchburg, VA, United States
| | - Corey Cavanaugh
- Division of Nephrology, University of Virginia, Charlottesville, VA, United States
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11
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Fujishige S, Ogawa Y, Aoyagi H, Okamoto T. M-type phospholipase A2 receptor-associated membranous nephropathy in a patient with Noonan-like syndrome with loose anagen hair. Pediatr Int 2023; 65:e15643. [PMID: 37817399 DOI: 10.1111/ped.15643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 05/24/2023] [Accepted: 08/02/2023] [Indexed: 10/12/2023]
Affiliation(s)
- Shuta Fujishige
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan
- Department of Pediatrics, Obihiro Kyokai Hospital, Obihiro, Japan
| | - Yayoi Ogawa
- Hokkaido Renal Pathology Center, Sapporo, Japan
| | - Hayato Aoyagi
- Department of Pediatrics, Obihiro Kyokai Hospital, Obihiro, Japan
| | - Takayuki Okamoto
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Japan
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12
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Kotwica-Strzałek E, Janicki P, Dociak I, Niemczyk S. Manifestations of renal involvement in sarcoidosis - case series. Pol Merkur Lekarski 2022; 50:124-127. [PMID: 35436276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
UNLABELLED Renal involvement is observed in 30% of sarcoidosis cases, but the exact occurrence is unknown, and the current numbers are estimated to be underestimated. The most common manifestation of renal sarcoidosis is interstitial nephritis, but other presentations are also possible, with specific histopathological and laboratory findings. Glomerulopathies, nephrocalcinosis and nephrolithiasis are among the most commonly seen types of renal involvement. CASE REPORTS We would like to show a case series describing four patients with varying renal manifestations of sarcoidosis: membranous nephropathy, granulomatous interstitial nephritis, IgA nephropathy and chronic kidney disease. The diagnosis of sarcoidosis can precede, present simultaneously with or follow the onset of renal manifestations. Our patients also showcase varying clinical pictures of renal sarcoidosis with different changes in renal parameters. CONCLUSIONS The involvement of kidneys in sarcoidosis is multifaceted and may pose a diagnostic difficulty, and a diagnostic kidney biopsy is often needed. Chronic sarcoidosis patients should undergo regular screening for renal involvement to introduce proper management quickly and effectively.
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Affiliation(s)
- Ewa Kotwica-Strzałek
- Department of Internal Diseases, Nephrology and Dialysotherapy, Military Institute of Medicine, Warsaw, Poland; Department of Descriptive and Clinical Anatomy, Medical University of Warsaw, Poland
| | - Piotr Janicki
- Department of Internal Diseases, Nephrology and Dialysotherapy, Military Institute of Medicine, Warsaw, Poland
| | - Irena Dociak
- Department of Internal Diseases, Nephrology and Dialysotherapy, Military Institute of Medicine, Warsaw, Poland
| | - Stanisław Niemczyk
- Department of Internal Diseases, Nephrology and Dialysotherapy, Military Institute of Medicine, Warsaw, Poland
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13
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Zhao Y, Cai M, Jiang Z, Dong B, Yan Y, Wang Y, Zuo L. Association of serum mannose-binding lectin, anti-phospholipase A2 receptor antibody and renal outcomes in idiopathic membranous nephropathy and atypical membranous nephropathy: a single center retrospective cohort study. Ren Fail 2022; 44:428-433. [PMID: 35272568 PMCID: PMC8920381 DOI: 10.1080/0886022x.2022.2048016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Objectives Idiopathic membranous nephropathy (iMN) is a major cause of nephrotic syndrome. Atypical membranous nephropathy (aMN) is a new type of nephropathy in China, characterized by a ‘full-house’ on immunofluorescent examination, that is IgG, IgA, IgM, C3, C1q positive, but without clinical evidence of a secondary cause. Phospholipase A2 receptor (PLA2R) was the major target antigens in iMN patients. Activation of the mannose-binding lectin (MBL) pathway plays a vital role in the development of MN. Our objective was to investigate the role of PLA2R and MBL in the pathogenesis of iMN and aMN. Methods We conducted a retrospective observational study using propensity score matching by age, gender, and eGFR. All clinical, laboratory data, and follow-up data of the patients were collected. Serum levels of anti-PLA2R antibodies and MBL were tested. Results Finally, 30 iMN patients and 30 aMN patients were included, and 20 healthy controls were retrospectively collected in this study. The 24 h proteinuria level was higher and serum albumin was lower in anti-PLA2R (+) patients than in anti-PLA2R (−) patients in both iMN and aMN groups. In aMN patients, MBL levels were significantly higher in anti-PLA2R (+) patients than in anti-PLA2R (−) patients (p = .045). The serum level of anti-PLA2R positively correlated with no-remission in both iMN and aMN groups. Conclusions The complement lectin pathway has an association with the development of MN, especially in patients with positive anti-PLA2R antibodies. Serum MBL cannot differentiate between the two diseases. Serum MBL levels are not associated with clinical manifestations, nor with prognosis.
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Affiliation(s)
- Yuchao Zhao
- Department of Nephrology, Peking University People's Hospital, Beijing, China
| | - Meishun Cai
- Department of Nephrology, Peking University People's Hospital, Beijing, China
| | - Zhenbin Jiang
- Department of Nephrology, Peking University People's Hospital, Beijing, China
| | - Bao Dong
- Department of Nephrology, Peking University People's Hospital, Beijing, China
| | - Yu Yan
- Department of Nephrology, Peking University People's Hospital, Beijing, China
| | - Yina Wang
- Department of Nephrology, Peking University People's Hospital, Beijing, China
| | - Li Zuo
- Department of Nephrology, Peking University People's Hospital, Beijing, China
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Ishibuchi K, Iwakura T, Ema C, Nakagami D, Uchiyama Y, Kaneko M, Fukasawa H, Matsuyama T, Yasuda H, Furuya R. A Case of M-Type Phospholipase A2 Receptor-Associated Membranous Nephropathy With IgG4-Positive Cells Infiltration in the Interstitium. Clin Med Insights Case Rep 2022; 15:11795476221078635. [PMID: 35221739 PMCID: PMC8874188 DOI: 10.1177/11795476221078635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 12/30/2021] [Indexed: 11/16/2022] Open
Abstract
A 70-year-old man was referred to our department for evaluation of nephrotic syndrome. Renal biopsy revealed membranous nephropathy (MN). Immunohistochemical analysis demonstrated IgG4-positive staining in the glomeruli and interstitial cells. The presence of serum anti-phospholipase A2 receptor (PLA2R) antibody and enhanced staining of PLA2R in the glomeruli was noted. Computed tomography unidentified the extrarenal lesions of IgG4-related disease. He was diagnosed with PLA2R-associated MN possibly complicated with IgG4 related kidney disease (IgG4-RKD). Storiform fibrosis, a typical manifestation of IgG4-RKD, was not apparent. We herein describe a case of serologically and histologically confirmed PLA2R-associated MN with IgG4+ cell infiltration into the interstitium without any signs of IgG4-RD.
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Affiliation(s)
- Kento Ishibuchi
- Renal Division, Department of Internal Medicine, Iwata City Hospital, Iwata, Japan
| | - Takamasa Iwakura
- Renal Division, Department of Internal Medicine, Iwata City Hospital, Iwata, Japan.,First Department of Internal medicine, Division of Nephrology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Chiemi Ema
- First Department of Internal medicine, Division of Nephrology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Daisuke Nakagami
- Renal Division, Department of Internal Medicine, Iwata City Hospital, Iwata, Japan
| | - Yuri Uchiyama
- Renal Division, Department of Internal Medicine, Iwata City Hospital, Iwata, Japan
| | - Mai Kaneko
- Renal Division, Department of Internal Medicine, Iwata City Hospital, Iwata, Japan
| | - Hirotaka Fukasawa
- Renal Division, Department of Internal Medicine, Iwata City Hospital, Iwata, Japan
| | - Takashi Matsuyama
- First Department of Internal medicine, Division of Nephrology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Hideo Yasuda
- First Department of Internal medicine, Division of Nephrology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Ryuichi Furuya
- Renal Division, Department of Internal Medicine, Iwata City Hospital, Iwata, Japan
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15
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Al-Othman YA, Kroneman O, Kumar S, Li W, Kanaan HD, Liu ML, Qu H, Zhang PL. Resolving primary membranous glomerulopathy (MGN) reveals a dynamically metabolic pathway from sub-epithelium to glomerular basement membranes. Ultrastruct Pathol 2022; 46:122-129. [PMID: 35109758 DOI: 10.1080/01913123.2022.2035876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
In idiopathic (primary) membranous glomerulopathy (MGN), there is a phenomenon of subepithelial deposits (stages 1 and 2) transitioned to intramembranous deposits, with lucent resolving features (stages 3 and 4). This phenomenon has not been described in other types of immune complex mediated glomerulonephritis with either subendothelial or mesangial deposits. The goal of this study was to evaluate what unique immunostaining pattern could occur in primary MGNs with intramembranous resolving features. PLA2R and IgG4 immunostains were performed in 50 primary MGNs, and 39 secondary MGNs after the clinical history was reviewed. Primary MGNs with resolving features were further evaluated in detail. A total of 84% (42/50) of primary MGN cases had diffuse positive immunostaining for IgG4 in the glomeruli, and most of them were also positive for PLA2R staining. Eight of the remaining primary MGN cases (8/50) with positive PLA2R but negative IgG4 staining in the glomeruli had diffuse resolving features as observed by electron microscopy. All secondary MGNs were stained negatively for both IgG4 and PLA2R except for one case with positive IgG4 staining but negative staining for PLA2R. Our data indicate that IgG4 staining on paraffin tissue is a very reliable screening tool to confirm the presence of primary MGN. Primary MGN with PLA2R+/IgG4- stains were seen in those with intramembranous resolving features. This finding is consistent with the known weak-binding capacity of IgG4 to the glomerular basement membranes. The transitional phenomenon from PLA2R+/IgG4+ subepithelial deposits to PLA2R+/IgG4- intramembranous resolving deposits in primary MGN implies that there may be a continuous metabolic activity from podocyte to glomerular basement membrane.
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Affiliation(s)
- Yazan A Al-Othman
- Department of Pathology, Beaumont Laboratories, Beaumont Health, Royal Oak, MI, USA
| | - Olaf Kroneman
- Division of Nephrology, Beaumont Health, Royal Oak, MI, USA
| | - Sandeep Kumar
- Department of Pathology, Beaumont Laboratories, Beaumont Health, Royal Oak, MI, USA
| | - Wei Li
- Department of Pathology, Beaumont Laboratories, Beaumont Health, Royal Oak, MI, USA
| | - Hassan D Kanaan
- Department of Pathology, Beaumont Laboratories, Beaumont Health, Royal Oak, MI, USA
| | - Ming-Lin Liu
- Department of Dermatology, University of Pennsylvania, Philadelphia, PA, USA
| | - Hong Qu
- Department of Pathology, Ascension St. John Hospital, Detroit, MI, USA
| | - Ping L Zhang
- Department of Pathology, Beaumont Laboratories, Beaumont Health, Royal Oak, MI, USA
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16
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Tang H, Zhu R, Waldman M, Zhu Q. Structural determinants of the dominant conformational epitopes of phospholipase A2 receptor in primary membranous nephropathy. J Biol Chem 2022; 298:101605. [PMID: 35065076 DOI: 10.1016/j.jbc.2022.101605] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 12/27/2022] Open
Abstract
Anti-phospholipase A2 receptor autoantibody (PLA2R-Ab) plays a critical role in the pathogenesis of primary membranous nephropathy (PMN), an autoimmune kidney disease characterized by immune deposits in the glomerular subepithelial spaces and proteinuria. However, the mechanism of how PLA2R-Abs interact with the conformational epitope(s) of PLA2R has remained elusive. PLA2R is a single transmembrane helix receptor containing ten extracellular domains that begin with a CysR domain followed by a FnII and eight CTLD domains. Here, we examined the interactions of PLA2R-Ab with the full PLA2R protein, N-terminal domain truncations, and C-terminal domain deletions under either denaturing or physiological conditions. Our data demonstrate that the PLA2R-Abs against the dominant epitope (the N-terminal CysR-CTLD1 triple domain) possess weak cross-reactivities to the C-terminal domains beyond CTLD1. Moreover, both the CysR and CTLD1 domains are required to form a conformational epitope for PLA2R-Ab interaction, with FnII serving as a linker domain. Upon close examination, we also observed that patients with newly diagnosed PMN carry two populations of PLA2R-Abs in sera that react to the denatured CysR-CTLD3 (the PLA2R-Ab1) and denatured CysR-CTLD1 (the PLA2R-Ab2) domain complexes on Western blots, respectively. Furthermore, the PLA2R-Ab1 appeared at an earlier time point than PLA2R-Ab2 in patients, whereas the increased levels of PLA2R-Ab2 coincided with the worsening of proteinuria. In summary, our data support that an integrated folding of the three PLA2R N-terminal domains, CysR, FnII, and CTLD1, is a prerequisite to forming the PLA2R conformational epitope and that the dominant epitope-reactive PLA2R-Ab2 plays a critical role in PMN clinical progression.
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17
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Giannini G, Arend LJ. The Prevalence of Mesangial Electron-Dense Deposits in PLA2R-Positive Membranous Nephropathy. Nephron Clin Pract 2021; 146:167-171. [PMID: 34802007 DOI: 10.1159/000519912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/25/2021] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Membranous nephropathy (MN) is a common cause of nephrotic syndrome in adults and can be primary or secondary. The antigenic target of antibodies in 70% of primary cases is phospholipase A2 receptor (PLA2R). The presence or absence of mesangial electron-dense deposits has been used to distinguish between primary and secondary MN. Mesangial deposits suggest MN due to lupus, infection, or other causes, though they are reported to occur in approximately 10% of primary MN. Staining for PLA2R is now frequently used for confirming a diagnosis of primary MN. If mesangial deposits predict a secondary cause, they should be more frequent in PLA2R-negative biopsies. METHODS A review of institutional kidney biopsies between March 2017 and June 2020 identified all cases of MN. Cases with a diagnosis of lupus or near "full-house" staining by immunofluorescence microscopy (IF) were excluded. Light microscopy, IF, and electron microscopy (EM) were performed. PLA2R staining was performed by IF. EM for all cases was reviewed and electron-dense deposit location, distribution, and size were determined. RESULTS Ninety-three cases of MN were identified, of which 86 had both PLA2R staining and EM performed. Of these, 51 cases (59%) were positive for PLA2R and 35 (41%) were negative. Mesangial electron-dense deposits were present in 22 (25.6%) of the 86 cases, including 27.5% (14/51) of PLA2R-positive cases and 22.8% (8/35) of PLA2R-negative cases. No difference was seen in size or distribution of deposits, or other features considered suggestive of secondary MN. CONCLUSION PLA2R-negative cases were not more likely to have mesangial deposits than PLA2R-positive cases. Mesangial deposits should not be used as an indicator of secondary MN.
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Affiliation(s)
- Gabriel Giannini
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Lois J Arend
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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18
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Ramachandran R, Prabakaran R, Priya G, Nayak S, Kumar P, Kumar A, Kumar V, Agrawal N, Rathi M, Kohli HS, Nada R. Immunosuppressive Therapy in Primary Membranous Nephropathy with Compromised Renal Function. Nephron Clin Pract 2021; 146:138-145. [PMID: 34818240 DOI: 10.1159/000518609] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 07/19/2021] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Renal dysfunction at presentation is uncommon in primary membranous nephropathy (PMN). The data on the outcome of PMN patients with renal dysfunction at outset are scarce. The objective of the current study was to report the clinical outcomes of PMN patients with renal dysfunction. MATERIAL AND METHODS This prospective longitudinal observational study included PMN patients (both incident and treatment resistant) with an estimated glomerular filtration rate of <60 mL/min/1.73 m2. Immunosuppressive treatment was as per the unit's protocol. Patients were evaluated for proteinuria, creatinine, and serum albumin at monthly intervals for 6 months, then quarterly for a year, and then biannually. Both serum and tissue anti-PLA2R were performed at baseline. OUTCOME Percentage of patients achieving clinical remission. RESULTS Sixty-four adults met study criteria and were analysed. The median (IQR) age of the patients was 48 (40, 56) years. PMN was PLA2R related in 52 (81.3%) patients. Twenty-eight (43.8%) and 30 (46.9%) patients were in remission at 12 months and at the end of the study [median (IQR) follow up: 24 months (12, 35)], respectively. Eight (12.5%) had progressed to end-stage renal disease at the last follow-up. Median (IQR) baseline anti-PLA2R titre was 150.1 RU/mL (38.5, 308). Nineteen (61.3%) and 18 (58.1%) patients with >90% reduction in anti-PLA2R titres at 12 months were in clinical remission at 12 months and at the end of the follow-up, respectively. Both cyclical cyclophosphamide/steroids (cCYC/GC) and rituximab were equally effective in inducing remission, but rituximab had a favourable adverse event profile compared to cCYC/GC. CONCLUSION To conclude, both cCYC/GC and rituximab are equally effective in inducing remission of nephrotic state with compromised renal function due to PMN. Immunosuppression induces remission in up to 50% PMN patients with CKD-stage 3-4.
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Affiliation(s)
- Raja Ramachandran
- Department of Nephrology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Rudreshwar Prabakaran
- Department of Nephrology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Gnana Priya
- Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Saurabh Nayak
- Department of Nephrology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Pankaj Kumar
- Department of Community Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Ashwani Kumar
- Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Vinod Kumar
- Department of Dermatology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Neha Agrawal
- Department of Nephrology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Manish Rathi
- Department of Nephrology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Harbir Singh Kohli
- Department of Nephrology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Ritambhra Nada
- Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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19
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Vajgel G, Correia MRB, Costa CLC, Sette LH. Nephrology pictures: pemphigus vulgaris and membranous nephropathy. J Nephrol 2021; 35:1299-1301. [PMID: 34652719 DOI: 10.1007/s40620-021-01151-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 08/29/2021] [Indexed: 11/28/2022]
Affiliation(s)
- Gisele Vajgel
- Division of Nephrology, Hospital das Clinicas, Federal University of Pernambuco (UFPE), Av. Professor Moraes Rego, 1235, Cidade Universitaria, Recife, PE, 50670-901, Brazil.
| | | | - Camila L C Costa
- Division of Internal Medicine, Hospital dos Servidores do Estado de Pernambuco, Recife, Brazil
| | - Luis H Sette
- Division of Nephrology, Hospital das Clinicas, Federal University of Pernambuco (UFPE), Av. Professor Moraes Rego, 1235, Cidade Universitaria, Recife, PE, 50670-901, Brazil
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20
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Ramachandran R, Kumar V, Bharati J, Rovin B, Nada R, Kumar V, Rathi M, Jha V, Gupta KL, Kohli HS. Long-Term Follow-Up of Cyclical Cyclophosphamide and Steroids Versus Tacrolimus and Steroids in Primary Membranous Nephropathy. Kidney Int Rep 2021; 6:2653-2660. [PMID: 34622104 PMCID: PMC8484506 DOI: 10.1016/j.ekir.2021.07.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/19/2021] [Accepted: 07/26/2021] [Indexed: 11/19/2022] Open
Abstract
Introduction Kidney Disease: Improving Global Outcomes (KDIGO) 2012 recommends cyclical cyclophosphamide plus glucocorticoids (GC) (modified Ponticelli regimen) or calcineurin inhibitors (CNIs) such as tacrolimus (TAC) or cyclosporine as the first-line agents for the management of primary membranous nephropathy (PMN) that is resistant to antiproteinuric therapy with renin-angiotensin system blockers. However, the long-term outcome of patients treated with CNIs is not known. Methods We report the outcomes of 70 patients randomized 1:1 to receive modified Ponticelli regimen or TAC/GC for renin-angiotensin system–resistant PMN who were prospectively followed for 6 years. Patients were followed monthly for 12 months, then quarterly for 12 months, and then every 6 months through the end of 6 years. Results At the end of 6 years, 21 (61.76%) and 9 (28.12%) patients maintained relapse-free remission in modified Ponticelli regimen and TAC/GC groups, respectively (relative risk [RR]: 2.19, 95% confidence interval [CI]: 1.23 to 4.15), and 30 (88.23%) and 17 (53.12%) patients were in remission (including relapses) in modified Ponticelli regimen and TAC/GC groups (RR: 1.66; 95% CI: 1.21 to 2.45), respectively. There was no significant difference in the proportion of patients who had a 40% decline in the estimated glomerular filtration rate (eGFR), death, or end-stage kidney disease between the groups. None of the patients treated with modified Ponticelli regimen reported a solid organ or hematological malignancy. Conclusions To conclude, in the long-term, modified Ponticelli regimen is superior to TAC/GC as first-line therapy for the management of antiproteinuric-resistant PMN.
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Affiliation(s)
- Raja Ramachandran
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
- Correspondence: Raja Ramachandran, Department of Nephrology, PGIMER, Sector 12, Chandigarh, 160012, India.
| | - Vinod Kumar
- Department of Dermatology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Joyita Bharati
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Brad Rovin
- Division of Nephrology, Department of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Ritambhra Nada
- Department of Histopathology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Vivek Kumar
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Manish Rathi
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Vivekanand Jha
- George Institute for Global Health, UNSW, New Delhi, India
- School of Public Health, Imperial College, London, UK
- Manipal Academy of Higher Education, Manipal, India
| | - Krishan Lal Gupta
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Harbir Singh Kohli
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
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Affiliation(s)
- Weiwen Guo
- Department of Renal Medicine, Sengkang General Hospital, Medical Centre Level 9, 110 Sengkang E Way, Singapore, 544886, Singapore.
| | - Puay Hoon Tan
- Division of Pathology, Singapore General Hospital, Singapore, Singapore
| | - Shashidhar Baikunje
- Department of Renal Medicine, Sengkang General Hospital, Medical Centre Level 9, 110 Sengkang E Way, Singapore, 544886, Singapore
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Liu X, Xu W, Yu C, Wang M, Liu R, Xie R. Associations between m-type phospholipase A2 receptor,human leukocyte antigen gene polymorphisms and idiopathic membranous nephropathy. Bioengineered 2021; 12:8833-8844. [PMID: 34607530 PMCID: PMC8806941 DOI: 10.1080/21655979.2021.1987080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Primary membranous nephropathy, also known as idiopathic membranous nephropathy, is an autoimmune disease. As an autoimmune disease, genetic factors are essential in the pathogenesis of IMN. People pay more and more attention to genetics and bioinformatics. With the continuous improvement and development of high-throughput gene sequencing and genotyping technology, it has been confirmed that many genes and their single nucleotide polymorphisms are strongly correlated with IMN disease susceptibility. However, there are few studies on HLA-DQA1 and PLA2R gene polymorphisms and IMN susceptibility in China. The purpose of this study was to investigate whether PLA2R rs2715928 and rs16844715 are related to IMN, the correlation between five SNP loci of PLA2R and HLA-DQA1 and IMN, and the effect of gene-gene interaction among different genotypes of each locus on disease. In this study, 86 patients with IMN confirmed by renal biopsy in the first hospital of Harbin Medical University and 90 healthy controls were selected. All subjects were excluded from secondary membranous nephropathy, pregnant or breastfeeding women, severe primary disease of vital organs, severe infection, major surgery, and severe trauma. Seven selected SNP loci were genotyped using the IMLDR multiple SNP typing kit. Chi-square test and logistic regression were used to analyze the correlation between each SNP and IMN. The general clinical data and laboratory indicators of each subject were recorded, and the relationship between different genotypes and clinical manifestations was analyzed. Among the 7 SNP loci included in the study, except HLA-DQA1 rs2187668, the other 6 loci all met Hardy-Weiberg equilibrium test (P > 0.05). The allele distribution of PLA2R rs2715928 and rs16844715 was significantly different between the IMN group and the healthy control group, and it was closely related to IMN (P < 0.05). There was no statistical difference in the distribution of alleles of rs2715918 between the IMN group and the control group (P* > 0.05), and there was also statistical difference in the distribution of alleles of rs35771982, rs3749117, and rs4664308 between the IMN group and the healthy control group (P < 0.05).The C allele of rs16844715 (OR = 2.03, 95%CI: 1.29–3.19, P* = 0.0140) and the A allele of rs2715928 (OR = 3.18, 95%CI: 1.94–5.24, P* = 3.54E-5), G allele of rs35771982 (OR = 4.07, 95%CI: 2.34–7.08, P* = 4.96E-6), T allele of rs3749117 (OR = 4.07, 95%CI: 2.34–7.08, P* = 4.96E-6), the A allele of rs4664308 (OR = 2.63, 95%CI: 1.54–4.49, P* = 0.0028) was the risk gene of IMN.Through the establishment of different genetic models, we found that,in the additive model, the three SNPs of PLA2R rs2715928 (OR = 5.40, 95%CI: 1.77–16.50, P* = 0.0217) and rs35771982 (OR = 15.15, 95%CI: 2.92–78.48, P* = 0.0084), rs3749117 (OR = 15.15, 95%CI: 2.92–78.48, P* = 0.0084) had a strong correlation with IMN. In the stealth model,homozygous gene risk type of the five SNPs,PLA2R rs16844715 (OR = 2.52, 95%CI: 1.38–4.61, P* = 0.0189) and rs2715928 (OR = 4.30, 95%CI: 2.31–8.03, P* = 3.14E-5), rs35771982 (OR = 4.85, 95%CI: 5.53–9.31, P* = 1.42E-5), rs3749117 (OR = 4.85, 95%CI: 5.53–9.31, P* = 1.42E-5) and rs4664308 (OR = 3.16, 95%CI: 1.67–5.97, P* = 0.0028) had a strong correlation with IMN. The distribution of GT haplotypes and CC haplotypes of rs35771982 and rs3749117 and CA haplotypes and TG haplotypes of rs16844715 and rs4664308 were significantly different between IMN group and control group (P < 0.05). When GMDR software was used to establish a model to analyze the interaction between various SNP sites, it was found that the combination of GG genotype at rs35771982 and AA genotype at rs2715928 was the highest risk of disease. The risk genotypes of rs16844715, rs2715928 and rs4664308 had no effect on the clinical manifestations of IMN (P > 0.05). PLA2R rs2715928 and rs16844715 are associated with susceptibility to IMN. The C allele of rs16844715, the A allele of rs2715928, the G allele of rs35771982, the T allele of rs3749117, and the A allele of rs4664308 are the dangerous genes of IMN. The combination of GG genotype at rs35771982 and AA genotype at rs2715928 poses the greatest risk of disease. Haplotype may affect susceptibility to IMN. The risk genotype had no effect on the clinical manifestations of IMN.
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Affiliation(s)
- Xiaogang Liu
- Department of Nephrology, Shenzhen Hengsheng Hospital, 20 Yintian Rd, Shenzhen, Guangdong, People's Republic of China
| | - Weixi Xu
- Department of Nephrology, The 2nd Affiliated of Chengdu Medical College Nuclear Industry 416 Hospital, Chengdu, China
| | - Chengyuan Yu
- Department of Geriatric, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; the First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, China
| | - Mingao Wang
- Department of Nephrology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Ruichan Liu
- Department of Nephrology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Rujuan Xie
- Department of Nephrology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
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Mathew D, Gupta S, Ashman N. A case report of breast cancer and membranous nephropathy with positive anti phospholipase A2 receptor antibodies. BMC Nephrol 2021; 22:324. [PMID: 34592934 PMCID: PMC8482676 DOI: 10.1186/s12882-021-02511-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/26/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Testing for antibodies against podocyte phospholipase A2 receptor-1 (PLA2R) allows clinicians to accurately identify primary membranous nephropathy (MN). Secondary MN is associated with a spectrum of pathology including solid organ malignancy. PLA2R positivity in these patients occurs, although no case of PLA2R-positive MN has been definitively linked to cancer. CASE PRESENTATION We describe a case of biopsy-proven PLA2R-positive MN, in whom invasive ductal carcinoma of the breast was discovered. The patient underwent surgery and adjuvant chemotherapy (including cyclophosphamide) and went into a sustained complete remission of her nephrotic syndrome. DISCUSSION AND CONCLUSIONS Case series have reported PLA2R positivity in patients with solid organ malignancy associated MN. Our case is unusual as it is a breast malignancy, and the patients nephrotic syndrome and anti-PLA2Rab titres improved with treatment of the cancer. Here we report, to the best of our knowledge, the first case of oestrogen receptor-2 positive breast cancer associated with PLA2R positive MN in a young lady that was treated successfully by treating the malignancy.
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Affiliation(s)
- David Mathew
- Department of Nephrology, Royal London Hospital, Whitechapel Road, London, E1 1FR, UK.
| | - Sanjana Gupta
- Department of Nephrology, Royal London Hospital, Whitechapel Road, London, E1 1FR, UK
| | - Neil Ashman
- Department of Nephrology, Royal London Hospital, Whitechapel Road, London, E1 1FR, UK
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Angeletti A, Leventhal JS, Cravedi P. Membranous nephropathy: setting the bar for hypothesis-driven, selective therapies in nephrology. J Nephrol 2021; 34:561-3. [PMID: 32683657 DOI: 10.1007/s40620-020-00806-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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25
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Le WB, Shi JS, Fan Y, Gong SW. HLA Alleles and Prognosis of PLA2R-Related Membranous Nephropathy. Clin J Am Soc Nephrol 2021; 16:1221-1227. [PMID: 34083219 PMCID: PMC8455041 DOI: 10.2215/cjn.18021120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 05/05/2021] [Indexed: 02/04/2023]
Abstract
BACKGROUND AND OBJECTIVES Associations between HLA alleles and susceptibility to M-type phospholipase A2 receptor (PLA2R)-related membranous nephropathy have been well defined previously in Chinese patients. However, the relationships between HLA alleles and kidney outcome remain unclear. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Five HLA genes (DRB1, DQA1, DQB1, DRB3, and DRB5) were genotyped in a prospective cohort of 392 patients with PLA2R-related membranous nephropathy. The associations between HLA alleles and kidney outcomes were studied. RESULTS A total of 79 HLA alleles were identified in this study. Four HLA alleles, DRB1*13:01 (n=12; hazard ratio, 3.7; 95% confidence interval, 1.8 to 7.8; P<0.001), DQB1*06:03 (n=12; hazard ratio, 3.7; 95% confidence interval, 1.8 to 7.8; P<0.001), DRB1*04:05 (n=12; hazard ratio, 3.8; 95% confidence interval, 1.5 to 9.5; P=0.004), and DQB1*03:02 (n=21; hazard ratio, 3.1; 95% confidence interval, 1.4 to 6.7; P=0.005), were associated with a ≥40% eGFR decline during follow-up. DRB1*13:01 and DQB1*06:03 were tightly linked with each other. Forty-four of the 392 patients (11%) carried at least one of the four identified risk HLA alleles in this study. Compared with patients who were negative for all risk HLA alleles, those carrying at least one risk HLA allele had a significant risk of a ≥40% eGFR decline during follow-up (hazard ratio, 3.9; 95% confidence interval, 2.3 to 6.7; P<0.001). After adjusting for age, sex, proteinuria, albumin, eGFR, and anti-PLA2R antibody levels, multivariable Cox analysis showed that patients carrying any of the four risk HLA alleles remained associated with a higher risk of a ≥40% decline in eGFR (hazard ratio, 4.1; 95% confidence interval, 2.3 to 7.1; P<0.001). CONCLUSIONS Carrying any of the HLA alleles, DRB1*13:01/DQB1*06:03, DRB1*04:05, and DQB1*03:02, was independently associated with poor prognosis in Chinese patients with PLA2R-related membranous nephropathy.
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Affiliation(s)
- Wei-Bo Le
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Jing-Song Shi
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Yang Fan
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Si-Wen Gong
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, The First School of Clinical Medicine, Southern Medical University, Nanjing, China
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Meyer N, Cooper W, Kirwan P, Garsia R, Dunkley S, Gracey DM. Primary membranous glomerulonephritis with negative serum PLA2R in haemophilia A successfully managed with rituximab - case report and review of the literature. BMC Nephrol 2021; 22:268. [PMID: 34294065 PMCID: PMC8299630 DOI: 10.1186/s12882-021-02475-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 07/14/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) cause a wide range of glomerular pathologies. In people with haemophilia, transfusion-associated infections with these viruses are common and definitive pathological diagnosis in this population is complicated by the difficulty of safely obtaining a renal biopsy. Membranous nephropathy (MN) is a common cause of adult onset nephrotic syndrome occurring in both primary and secondary forms. Primary MN is associated with podocyte autoantibodies, predominantly against phospholipase A2 receptor (PLA2R). Secondary disease is often associated with viral infection; however, infrequently with HIV or HCV. Distinguishing these entities from each other and other viral glomerular disease is vital as treatment strategies are disparate. CASE PRESENTATION We present the case of a 48-year-old man with moderate haemophilia A and well-controlled transfusion-associated HCV and HIV coinfection who presented with sudden onset nephrotic range proteinuria. Renal biopsy demonstrated grade two membranous nephropathy with associated negative serum PLA2R testing. Light and electron microscopic appearances were indeterminant of a primary or secondary cause. Given his extremely stable co-morbidities, treatment with rituximab and subsequent angiotensin receptor blockade was initiated for suspected primary MN and the patient had sustained resolution in proteinuria over the following 18 months. Subsequent testing demonstrated PLA2R positive glomerular immunohistochemistry despite multiple negative serum results. CONCLUSIONS Pursuing histological diagnosis is important in complex cases of MN as the treatment strategies between primary and secondary vary significantly. Serum PLA2R testing alone may be insufficient in the presence of multiple potential causes of secondary MN.
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Affiliation(s)
- Nicholas Meyer
- Department of Renal Medicine, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.
| | - Wendy Cooper
- Tissue Pathology and Diagnostic Oncology, NSW Health Pathology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.,Central Clinical School, Faculty of Medicine, University of Sydney, Sydney, NSW, Australia.,School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Paul Kirwan
- Electron Microscopy Unit, Department of Anatomical Pathology, Concord Repatriation General Hospital, Concord, NSW, Australia
| | - Roger Garsia
- Department of Immunology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - Scott Dunkley
- Institute of Haematology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - David M Gracey
- Department of Renal Medicine, Royal Prince Alfred Hospital, Camperdown, NSW, Australia.,Central Clinical School, Faculty of Medicine, University of Sydney, Sydney, NSW, Australia
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Ramachandran R, Nayak S, Kumar V, Kumar A, Agrawal N, Bansal R, Tiewsoh K, Nada R, Rathi M, Kohli HS. Primary membranous nephropathy in children and adolescents: a single-centre report from South Asia. Pediatr Nephrol 2021; 36:1217-1226. [PMID: 33108509 DOI: 10.1007/s00467-020-04798-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 07/26/2020] [Accepted: 09/23/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND Unlike adults, primary membranous nephropathy (PMN) comprises only 1-2% of childhood nephrotic syndrome. The clinical behaviour of PMN in children is not explicit and we report upon clinical presentation and outcome. METHODS This prospective study includes children and adolescents (< 20 years) with biopsy-proven PMN without secondary causes. Anti-PLA2R assessment: before and after completing therapy. OUTCOME percentage of patients achieving remission. RESULTS Study cohort included 48 (M:F ratio 1.1:1) patients and median age 17 (IQR 15-18) years, with 35 (72.9%) PLA2R related. Median interval from symptom onset to presentation was 5 months, where median proteinuria, serum albumin and creatinine were 4.9 g/day, 2.1 g/dL and 0.63 mg/dL, respectively. Forty-seven patients received immunosuppressive therapy, with various agents used as first-line therapy: cyclical CYC/GC (53.1%), CNI/GC (21.3%), rituximab (14.9%), prednisolone alone (4.3%), azathioprine (4.3%) and mycophenolate mofetil (2.1%). Median follow-up was 29 (14, 59) months. At 6 months, 11 (24.4%) and 17 (37.7%) had complete remission (CR) or partial remission (PR), while at last follow-up (median 29 months), 20 (45.4%) and 14 (31.8%) had CR and PR respectively. No significant differences in outcome were observed with different agents. A total of 60% patients treated with rituximab as first line/for relapsing disease, and all cases with resistant disease receiving rituximab had CR or PR at last follow-up. PLA2R antibody presence was associated with clinical outcome. CONCLUSIONS Three-quarters of PMN in children and adolescents is PLA2R related and two-thirds respond to immunosuppressive therapy. Rituximab is a promising agent to manage PMN in children. Anti-PLA2R is associated with clinical outcomes.
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Affiliation(s)
- Raja Ramachandran
- Department of Nephrology, Postgraduate Institute of Medical Education & Research, Chandigarh, India.
| | - Saurabh Nayak
- Department of Nephrology, Postgraduate Institute of Medical Education & Research, Chandigarh, India
| | - Vinod Kumar
- Department of Dermatology, Postgraduate Institute of Medical Education & Research, Chandigarh, India
| | - Ashwani Kumar
- Department of Histopathology, Postgraduate Institute of Medical Education & Research, Chandigarh, India
| | - Neha Agrawal
- Department of Nephrology, Postgraduate Institute of Medical Education & Research, Chandigarh, India
| | - Ritika Bansal
- Department of Nephrology, Postgraduate Institute of Medical Education & Research, Chandigarh, India
| | - Karalanglin Tiewsoh
- Division of Pediatric Nephrology, Department of Paediatrics, Postgraduate Institute of Medical Education & Research, Chandigarh, India
| | - Ritambhra Nada
- Department of Histopathology, Postgraduate Institute of Medical Education & Research, Chandigarh, India
| | - Manish Rathi
- Department of Nephrology, Postgraduate Institute of Medical Education & Research, Chandigarh, India
| | - Harbir Singh Kohli
- Department of Nephrology, Postgraduate Institute of Medical Education & Research, Chandigarh, India
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28
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Lerner GB, Virmani S, Henderson JM, Francis JM, Beck LH. A conceptual framework linking immunology, pathology, and clinical features in primary membranous nephropathy. Kidney Int 2021; 100:289-300. [PMID: 33857571 DOI: 10.1016/j.kint.2021.03.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/07/2021] [Accepted: 03/25/2021] [Indexed: 12/22/2022]
Abstract
Primary membranous nephropathy is a leading cause of adult nephrotic syndrome. The field took a major step forward with the identification of phospholipase A2 receptor (PLA2R) as a target antigen in the majority of cases and with the ability to measure circulating autoantibodies to PLA2R. Since then, the existence of additional target antigens such as thrombospondin type-1 domain-containing 7A, exostosin 1 and 2, neural EGFL like 1, and semaphorin 3B has been demonstrated. The ability to detect and monitor levels of circulating autoantibodies has opened a new window onto the humoral aspect of primary membranous nephropathy. Clinicians now rely on clinical parameters such as proteinuria, as well as levels of circulating autoantibodies against PLA2R and the results of immunofluorescence staining for PLA2R within kidney biopsy tissue, to guide the management of this disease. The relationship between immunologic and clinical disease course is consistent, but not necessarily intuitive. In addition, kidney biopsy provides only a single snapshot of disease that needs to be interpreted in light of changing clinical and serological findings. A clear understanding of these dynamic parameters is essential for staging, treatment, and management of this disease. This review aims to shed light on current knowledge regarding the development and time course of changes in the serum levels of autoantibodies against PLA2R, proteinuria, and histological findings that underlie the pathophysiology of primary membranous nephropathy.
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Affiliation(s)
- Gabriel B Lerner
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Samarth Virmani
- Department of Internal Medicine, University of Central Florida College of Medicine, Gainesville, Florida, USA
| | - Joel M Henderson
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston Medical Center, Boston, Massachusetts, USA
| | - Jean M Francis
- Department of Medicine, Section of Nephrology, Boston University School of Medicine, Boston Medical Center, Boston, Massachusetts, USA
| | - Laurence H Beck
- Department of Medicine, Section of Nephrology, Boston University School of Medicine, Boston Medical Center, Boston, Massachusetts, USA.
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Arghiani M, Zamani BH, Nazemian F, Samadi S, Afsharian MS, Habibzadeh M, Eslami S, Sabbagh MG. A cohort study of membranous nephropathy, primary or secondary. BMC Nephrol 2021; 22:138. [PMID: 33874909 PMCID: PMC8056567 DOI: 10.1186/s12882-021-02338-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 04/05/2021] [Indexed: 11/26/2022] Open
Abstract
Background Although IgG4 deposit against phospholipase A2 receptor (anti-PLA2R) is predominantly presented in the renal biopsy of patients with primary membranous nephropathy (MN), its diagnostic value of this immune complex has not been fully established. Methods In this cohort study, 108 biopsy-proven MN patients with proteinuria were evaluated during two years follow up and were divided into primary and secondary groups. Renal biopsy specimens were pathologically assessed for IgG4 and PLA2R depositions by immunohistochemistry (IHC). Therefore, the relationships between staining severity, MN type and total proteinuria in all patients were determined. Results Of 108 patients, 73.1% had primary MN and 26.9% were diagnosed as secondary form. IHC staining in patients with primary MN was positive for PLA2R in 76 (96.2%) and IgG4 in 68 (86.1%). Cases with positive PLA2R expression had a significantly higher rate among patients with mild to moderate stages (P = 0.03). No significant relationship was found between intensity of PLA2R and IgG4 deposits with proteinuria and serum creatinine. Based on our data, double positivity/negativity of PLA2R and IgG4 expression adds prominent information to the clinical data and were found to be useful and robust biomarkers for detection of primary MN patients with high sensitivity and specificity (97.1 and 96.3% respectively, PPV = 98.5% and NPV = 92.9%). Conclusions Simultaneously expression of PLA2R and IgG4 in renal biopsy specimens of patients with MN could possibly be used as a potential diagnostic method to distinguish primary from secondary MN and also pathological severity of the disease. Supplementary Information The online version contains supplementary material available at 10.1186/s12882-021-02338-6.
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Affiliation(s)
- Maryam Arghiani
- Kidney Transplantation Complications Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Boshra Hasan Zamani
- Kidney Transplantation Complications Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Fatemeh Nazemian
- Kidney Transplantation Complications Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Sara Samadi
- Kidney Transplantation Complications Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Student research committee, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | | | - Saeid Eslami
- Department of medical informatics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mahin Ghorban Sabbagh
- Kidney Transplantation Complications Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
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30
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Abstract
The identification of the phospholipase A2 receptor 1 (PLA2R) and thrombospondin type-1 domain-containing protein 7A (THSD7A) as podocyte antigens in adult patients with membranous nephropathy (MN) has strongly impacted both experimental and clinical research on this disease. Evidence has been furnished that podocyte-directed autoantibodies can cause MN, and novel PLA2R- and THSD7A-specific animal models have been developed. Today, measurement of serum autoantibody levels and staining of kidney biopsies for the target antigens guides MN diagnosis and treatment worldwide. Additionally, anti-PLA2R antibodies have been proven to be valuable prognostic biomarkers in MN. Despite these impressive advances, a variety of questions regarding the disease pathomechanisms, clinical use of antibody measurement, and future treatments remain unanswered. In this review, we will outline recent advances made in the field of MN and discuss open questions and perspectives with a focus on novel antigen identification, mechanisms of podocyte injury, clinical use of antibody measurement to guide diagnosis and treatment, and the potential of innovative, pathogenesis-based treatment strategies.
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31
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Lutz J. Pathophysiology, diagnosis, and treatment of membranous nephropathy. Nephrol Ther 2021; 17S:S1-S10. [PMID: 33910688 DOI: 10.1016/j.nephro.2021.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 03/23/2021] [Indexed: 11/20/2022]
Abstract
Nephrotic syndrome is in adult patients mainly due to membranous nephropathy (MN) characterized by thickening of the glomerular basement membrane (GBM) and immune complex formation between podocytes and the GBM. Autoantibodies directed against the M-type phospholipase A2 receptor (PLA2R) and thrombospondin 1 domain-containing 7 A (THSD7A) can be used as diagnostic biomarkers. THSD7A seems to be of direct pathogenic significance as is suggested by experimental models and plasmapheresis in humans. Recently, further antigens like NELL-1 (neural tissue encoding protein with EGF-like repeats-1), exostosin 1 and 2 have been discovered. Thus, MN should be classified into antibody positive and antibody negative MN. More specific immunosuppressive treatments directed against B-cells and antibody production like rituximab have been introduced in addition to already existing immunosuppressive protocols including steroids, chlorambucil, cyclophosphamide, and calcineurin inhibitors. Antibody removal using immunoadsorption or plasmapheresis leads to short-term reduction in proteinuria and might be indicated only in patients with very severe proteinuria and complications. Studies are needed to identify a more specific immunosuppression directed against the production and effects of autoantibodies in order to protect the kidneys from autoimmune mediated tissue damage and to identify patients who require an immunosuppressive treatment, as the remission rate is high in patients with MN.
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Affiliation(s)
- Jens Lutz
- Medical Clinic, Nephrology-Infectious Diseases, Central Rhine hospital group, Gemeinschaftsklinikum Mittelrhein, Koblenzer Straße 115-155, 56073 Koblenz, Germany.
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32
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Gu Y, Xu H, Tang D. Mechanisms of Primary Membranous Nephropathy. Biomolecules 2021; 11:513. [PMID: 33808418 DOI: 10.3390/biom11040513] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 12/11/2022] Open
Abstract
Membranous nephropathy (MN) is an autoimmune disease of the kidney glomerulus and one of the leading causes of nephrotic syndrome. The disease exhibits heterogenous outcomes with approximately 30% of cases progressing to end-stage renal disease. The clinical management of MN has steadily advanced owing to the identification of autoantibodies to the phospholipase A2 receptor (PLA2R) in 2009 and thrombospondin domain-containing 7A (THSD7A) in 2014 on the podocyte surface. Approximately 50–80% and 3–5% of primary MN (PMN) cases are associated with either anti-PLA2R or anti-THSD7A antibodies, respectively. The presence of these autoantibodies is used for MN diagnosis; antibody levels correlate with disease severity and possess significant biomarker values in monitoring disease progression and treatment response. Importantly, both autoantibodies are causative to MN. Additionally, evidence is emerging that NELL-1 is associated with 5–10% of PMN cases that are PLA2R- and THSD7A-negative, which moves us one step closer to mapping out the full spectrum of PMN antigens. Recent developments suggest exostosin 1 (EXT1), EXT2, NELL-1, and contactin 1 (CNTN1) are associated with MN. Genetic factors and other mechanisms are in place to regulate these factors and may contribute to MN pathogenesis. This review will discuss recent developments over the past 5 years.
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Moszczuk B, Kiryluk K, Pączek L, Mucha K. Membranous Nephropathy: From Research Bench to Personalized Care. J Clin Med 2021; 10:jcm10061205. [PMID: 33799372 PMCID: PMC7998937 DOI: 10.3390/jcm10061205] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/15/2021] [Accepted: 03/08/2021] [Indexed: 12/13/2022] Open
Abstract
Membranous nephropathy is a glomerulopathy that causes nephrotic syndrome and, in at least a third of cases, lasting end-stage kidney disease (ESKD). It is also a rare case of revolutionary changes in our understanding of the disease, that translates from scientific findings to real diagnosis and treatment recommendations in less than ten years. In this review we present: (1) a short history and traditional approach to patients with membranous nephropathy, (2) current recommendations and treatment options that have emerged in recent years, (3) findings of new studies, with a particular focus on serological/immunological methods, genomic and proteomic studies, still requiring validation. With further development in this field, membranous nephropathy may become one of the first nephrological conditions that apply a truly personalized approach with the omission of invasive measures such as kidney biopsy.
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Affiliation(s)
- Barbara Moszczuk
- Department of Immunology, Transplantology and Internal Diseases, Medical University of Warsaw, 02-006 Warsaw, Poland; (B.M.); (L.P.)
- Department of Clinical Immunology, Medical University of Warsaw, 02-006 Warsaw, Poland
| | - Krzysztof Kiryluk
- Department of Medicine, Division of Nephrology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA;
| | - Leszek Pączek
- Department of Immunology, Transplantology and Internal Diseases, Medical University of Warsaw, 02-006 Warsaw, Poland; (B.M.); (L.P.)
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Krzysztof Mucha
- Department of Immunology, Transplantology and Internal Diseases, Medical University of Warsaw, 02-006 Warsaw, Poland; (B.M.); (L.P.)
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
- Correspondence: or ; Tel.: +48-(22)-502-1641
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Abstract
Membranous nephropathy (MN) is a rare auto-immune disease where the glomerulus is targeted by circulating auto-antibodies mostly against podocyte antigens, which results in the formation of electron-dense immune complexes, activation of complement and massive proteinuria. MN is the most common cause of nephrotic syndrome in adults leading to severe thrombotic complications and kidney failure. This review is focused on the recent therapeutic and pathophysiological advances that occurred in the last two years. For a long time, we were lacking a head-to-head comparison between cyclophosphamide considered as the gold standard therapy and other medications, notably rituximab. Substantial progress has been achieved owing to three randomized controlled trials. MENTOR (Membranous Nephropathy Trial of Rituximab) and STARMEN (Sequential Therapy with Tacrolimus and Rituximab in Primary Membranous Nephropathy) conclusively established that calcineurin inhibitor-based regimens are slower to result in an immunologic response than rituximab or cyclophosphamide, achieve fewer complete clinical remissions, and are less likely to maintainremission. Rituximab Versus Steroids and Cyclophosphamide in the Treatment of Idiopathic Membranous Nephropathy (RI-CYCLO) suggested that competition between cyclophosphamide and rituximab remains open. Given the technological leap combining laser microdissection of glomeruli and mass spectrometry of solubilized digested proteins, four "new antigens" were discovered including NELL-1 and Semaphorin 3B in so-called primary MN, and exostosins 1 and 2 and NCAM 1 in lupus MN. NELL-1 is associated with about 8% of primary MN and is characterized by segmental immune deposits and frequent association with cancer (30%). Semaphorin 3B-associated MN usually occurs in children, often below the age of two years, where it is the main antigen, representing about 16% of non-lupus MN in childhood. Exostosins 1/2 and NCAM 1 are associated with 30% and 6% of lupus MN, respectively. Exostosins 1/2 (EXT1/2) staining is associated with a low rate of end-stage kidney disease (ESKD) even in mixed classes III/IV+V. These findings already lead to revisiting the diagnostic and therapeutic algorithms toward more personalized medicine.
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Affiliation(s)
- Pierre Ronco
- Unité Mixte de Recherche S1155, Institut National de la Santé et de la Recherche Médicale, Sorbonne Université, Université Pierre et Marie Curie Paris 06, Hôpital Tenon, 75020 Paris, France; (E.P.); (H.D.)
- Reference Center of Rare Disease-Idiopathic Nephrotic Syndrome, Hôpital Tenon, 75020 Paris, France
- Department of Nephrology, Centre Hospitalier du Mans, 72000 Le Mans, France
| | - Emmanuelle Plaisier
- Unité Mixte de Recherche S1155, Institut National de la Santé et de la Recherche Médicale, Sorbonne Université, Université Pierre et Marie Curie Paris 06, Hôpital Tenon, 75020 Paris, France; (E.P.); (H.D.)
- Reference Center of Rare Disease-Idiopathic Nephrotic Syndrome, Hôpital Tenon, 75020 Paris, France
- Day Hospital of Nephrology, Hôpital Tenon, Assistance Publique-Hôpitaux de Paris, 75020 Paris, France
| | - Hanna Debiec
- Unité Mixte de Recherche S1155, Institut National de la Santé et de la Recherche Médicale, Sorbonne Université, Université Pierre et Marie Curie Paris 06, Hôpital Tenon, 75020 Paris, France; (E.P.); (H.D.)
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Lwezaula BF, Ameh OI, Ekrikpo UE, Botha FC, Okpechi-Samuel US, Wearne N, Ronco P, Bello AK, Okpechi IG. Diagnostic performance of glomerular PLA2R and THSD7A antibodies in biopsy confirmed primary membranous nephropathy in South Africans. BMC Nephrol 2021; 22:15. [PMID: 33413188 PMCID: PMC7791976 DOI: 10.1186/s12882-020-02216-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 12/20/2020] [Indexed: 11/10/2022] Open
Abstract
Background: Serum and tissue-based tests using phospholipase A2 receptor 1 (PLA2R) and thrombospondin type-1 domain containing 7A (THSD7A) are established immune biomarkers for the diagnosis of primary membranous nephropathy (PMN). This study assessed the diagnostic performance of these biomarkers in the diagnosis of PMN in South Africans. Methods This was a cross-sectional analysis from a single centre in Cape Town, South Africa. Relevant biodata was collected from all patients. Histology, including slides for PLA2R and THSD7A were processed and assessed by typical microscopic and immunohistochemical features. Biopsy tissues of patients with membranous lupus nephritis (LN-V) and diabetic nephropathy (DN) were used as controls. The diagnostic accuracy for diagnosis of PMN using positive PLA2R and THSD7A were evaluated. Results Of the 88 patients included, 41 had PMN with a mean age of 44.5 ± 17.5 years and 61.0% were female. Histologically, PLA2R and THSD7A were only positive in the PMN group (51.2% and 4.9%, respectively) but negative in both control groups. The sensitivity of PLA2R and THSD7A for identifying PMN was 51.2% and 4.9%, respectively. The sensitivity of both tests together was 53.7% while the specificity and positive predictive values (PPV) for any of the tests (alone or in combination) was 100%. There was no difference in the sensitivity and specificity when using PLA2R alone compared to combining the two tests (p=0.32). Conclusion Glomerular staining of PLA2R and THSD7A could have potential diagnostic values in South Africans. This has implications on how immunotherapies can be initiated and used in these settings.
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Affiliation(s)
- Bingileki F Lwezaula
- Division of Nephrology and hypertension, University of Cape Town, Cape Town, South Africa.,Kidney and Hypertension Research Unit, University of Cape Town, Cape Town, South Africa.,Mount Meru Regional Referral Hospital, Arusha, Tanzania
| | - Oluwatoyin I Ameh
- Division of Nephrology, Zenith Medical & Kidney Centre, Gudu, Abuja, Nigeria
| | | | - Francois Cj Botha
- Pathcare Laboratories, George, South Africa.,Division of Anatomical pathology, University of Cape Town, Cape Town, South Africa
| | | | - Nicola Wearne
- Division of Nephrology and hypertension, University of Cape Town, Cape Town, South Africa.,Kidney and Hypertension Research Unit, University of Cape Town, Cape Town, South Africa
| | - Pierre Ronco
- Department of Nephrology and Dialysis, Assistance Publique-Hôpitaux de Paris, Tenon Hospital, Paris, France
| | - Aminu K Bello
- Department of Medicine, University of Alberta, Edmonton, Canada
| | - Ikechi G Okpechi
- Division of Nephrology and hypertension, University of Cape Town, Cape Town, South Africa. .,Kidney and Hypertension Research Unit, University of Cape Town, Cape Town, South Africa. .,Department of Medicine, University of Alberta, Edmonton, Canada.
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Guo Y, Wu X, Liu L, Zhang H, Yang L, Chen W. Efficacy of leflunomide combined with prednisone for the treatment of PLA2R-associated primary membranous nephropathy. Ren Fail 2020; 42:122-130. [PMID: 31957527 PMCID: PMC7006764 DOI: 10.1080/0886022x.2020.1713806] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Objective To evaluate the clinical efficacy and safety of leflunomide (LEF) combined with prednisone for the treatment of PLA2R-associated primary membranous nephropathy (PMN) and changes in anti-PLA2R antibody titers after treatment. Methods Sixty patients with nephrotic syndrome, biopsy-proven MN and anti-PLA2R antibody positivity were included in this study conducted from December 2017 to February 2019. The patients were randomly divided into an experimental group (n = 30) and a control group (n = 30). The patients in the experimental group were treated with LEF combined with prednisone, whereas the patients in the control group were treated with cyclophosphamide (CTX) combined with prednisone. We assessed 24-h urinary protein and serum albumin levels, kidney function markers, blood lipid levels and anti-PLA2R antibody titers before and after treatment. Adverse reactions during treatment were recorded. Results After 16 weeks of treatment, there were 2 cases of complete remission and 6 cases of partial remission in the experimental group, with a total effective rate of 26.67%. In the control group, there were 4 cases of complete remission and 8 cases of partial remission, with a total effective rate of 40% (p > .05). After 24 weeks of treatment, the total effective rates of the experimental and control groups were 66.67% and 76.67%, respectively (p > .05). There were no significant differences in 24-h urinary protein, serum albumin, kidney function marker or blood lipid levels between the two groups after treatment (p > .05). However, there were fewer adverse reactions in the experimental group than in the control group (p < .05). After treatment, serum anti-PLA2R antibody titers were clearly decreased in patients with complete remission and partial remission (p < .05), but these levels remained relatively high in patients without remission (p > .05). Conclusion LEF combined with prednisone has a certain efficacy for the treatment of PLA2R-associated PMN and provokes few adverse reactions. A large-sample randomized double-blind controlled study with a long follow-up period is needed to verify the efficacy of LEF combined with prednisone.
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Affiliation(s)
- Yaling Guo
- Department of Nephrology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, People's Republic of China
| | - Xueping Wu
- Department of Nephrology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, People's Republic of China
| | - Lei Liu
- Department of Nephrology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, People's Republic of China
| | - Haifeng Zhang
- Department of Nephrology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, People's Republic of China
| | - Lijuan Yang
- Department of Nephrology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, People's Republic of China
| | - Weidong Chen
- Department of Nephrology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, People's Republic of China
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Cuarental L, Valiño-Rivas L, Mendonça L, Saleem M, Mezzano S, Sanz AB, Ortiz A, Sanchez-Niño MD. Tacrolimus Prevents TWEAK-Induced PLA2R Expression in Cultured Human Podocytes. J Clin Med 2020; 9:E2178. [PMID: 32664235 DOI: 10.3390/jcm9072178] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/06/2020] [Accepted: 07/07/2020] [Indexed: 12/27/2022] Open
Abstract
Primary membranous nephropathy is usually caused by antibodies against the podocyte antigen membrane M-type phospholipase A2 receptor (PLA2R). The treatment of membranous nephropathy is not fully satisfactory. The calcineurin inhibitor tacrolimus is used to treat membranous nephropathy, but recurrence upon drug withdrawal is common. TNF superfamily members are key mediators of kidney injury. We have now identified key TNF receptor superfamily members in podocytes and explored the regulation of PLA2R expression and the impact of tacrolimus. Data mining of single cell transcriptomics and glomerular transcriptomics data identified TNFRSF12a/Fn14 as the highest expressed TNF receptor superfamily gene in human membranous nephropathy, and this was confirmed by immunohistochemistry that also identified NFκB activation in membranous nephropathy podocytes. Additionally, glomerular transcriptomics identified PLA2R1 expression as being increased in membranous nephropathy in the parenteral administration of the Fn14 ligand TWEAK increased podocyte PLA2R expression in mice. Furthermore, in cultured human podocytes, TWEAK increased the expression of PLA2R as well as the expression of other genes recently identified by GWAS as linked to membranous nephropathy: NFKB1 and IRF4. Interestingly, IRF4 encodes the FK506-binding protein 52 (FKBP52), a protein associated with tacrolimus. Tacrolimus prevented the increased expression of PLA2R, NFKB1 and IRF4 induced by TWEAK in cultured podocytes. In conclusion, TWEAK upregulates the expression of PLA2R and of other genes linked to membranous nephropathy in podocytes, and this is prevented by tacrolimus. An impact of tacrolimus on the expression of PLA2R and other genes in podocytes may underlie its efficacy in treating the disease as well as the frequent recurrence of nephrotic syndrome upon tacrolimus withdrawal.
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Subramanian P, Kumar H, Tiwari B, Barwad A, Bagchi S, Bagga A, Agarwal SK, Dinda AK, Singh G. Profile of Indian Patients With Membranous Nephropathy. Kidney Int Rep 2020; 5:1551-1557. [PMID: 32954080 PMCID: PMC7486174 DOI: 10.1016/j.ekir.2020.06.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/21/2020] [Accepted: 06/23/2020] [Indexed: 10/27/2022] Open
Abstract
Introduction The majority of primary membranous nephropathy (MN) cases are no longer considered idiopathic with the discovery of the podocytic autoantigens: phospholipase A2 receptor (PLA2R) and thrombospondin type 1 domain-containing 7A (THSD7A). Limited data on PLA2R-related MN in Indians exist in literature, and THSD7A-related MN remains undocumented in this population. We aimed to characterize the baseline PLA2R and THSD7A profile of adult and pediatric membranous nephropathy (MN) in a large Indian single-institution cohort. Methods A retrospective analysis of all cases of MN (primary and secondary) between 2014 and 2017 was performed with PLA2R direct immunofluorescence and THSD7A immunohistochemistry on the biopsies and anti-PLA2R enzyme-linked immunosorbent assay (ELISA) on baseline sera. Results MN constituted 10% of kidney biopsies received in the study period. A total of 216 cases with adequate tissue underwent PLA2R direct immunofluorescence, and 110 of them had available sera for PLA2R ELISA. Combining both testing methods, the prevalence of PLA2R-related primary MN was 72.8%, with moderate concordance between the 2 methods (kappa 0.61). PLA2R was also detected in 16.7% cases of secondary MN, most commonly lupus MN. THSD7A immunohistochemistry performed on 176 cases showed a prevalence of 3.4% in primary MN. One case of lupus MN was also positive for THSD7A. Dual positivity (PLA2R and THSD7A) was noted in 2 cases. The large pediatric cohort tested showed a prevalence of 44% of PLA2R based on tissue testing, whereas 1 case demonstrated THSD7A positivity. Conclusion This study in a large cohort of Indian patients demonstrates prevalence rates of PLA2R- and THSD7A-related MN similar to world literature, including the substantial cohort of pediatric MN. It also confirms variation in MN in the form of outliers within PLA2R (related to tissue and serum testing), dual positivity for PLA2R and THSD7A, and PLA2R/THSD7A-positive secondary MN.
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Affiliation(s)
| | - Hemanth Kumar
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Bipin Tiwari
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Adarsh Barwad
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Soumita Bagchi
- Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | - Arvind Bagga
- Division of Pediatric Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Sanjay Kumar Agarwal
- Department of Nephrology, All India Institute of Medical Sciences, New Delhi, India
| | - Amit Kumar Dinda
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Geetika Singh
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
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Kudose S, Santoriello D, Debiec H, Canetta PA, Bomback AS, Stokes MB, Batal I, Ronco P, D'Agati VD, Markowitz GS. The clinicopathologic spectrum of segmental membranous glomerulopathy. Kidney Int 2021; 99:247-55. [PMID: 32599086 DOI: 10.1016/j.kint.2020.06.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 05/05/2020] [Accepted: 06/04/2020] [Indexed: 01/12/2023]
Abstract
Membranous glomerulopathy (MGN) is characterized by global subepithelial immune deposits that stain most intensely by immunofluorescence for IgG. Here we describe the clinical and pathologic findings in a cohort of patients with MGN in which, by definition, only segmental immune deposits are present. This rare variant, termed segmental MGN (sMGN), is poorly characterized. We retrospectively identified all patients with sMGN diagnosed at Columbia University from January 2010 to October 2018, excluding those with systemic lupus erythematosus. Data on presenting features, pathologic findings, and outcomes were collected. Fifty cases of sMGN were identified, representing 2.5% of MGN. In 21 of 50 biopsies, there was an alternative, predominant disease process. The remaining 29 patients with isolated sMGN had a median creatinine of 0.97 mg/dl, median 24-hour urine protein 3.1 g/day, and 32% had nephrotic syndrome. Staining for NELL-1 (a protein kinase C binding protein) was positive in five of 17 cases. Staining for PLA2R, THSD7A, and exostosin 1 (autoantigens in primary MGN) was negative in all biopsies evaluated. Ultrastructural evaluation revealed predominantly early stage sMGN (stage 1 or 1-2 in 14/29). Follow-up was available for 21 of the 29 patients with isolated sMGN (median 12 months), including seven who received immunosuppression (primarily glucocorticoids). During follow-up, 86% had stable/improved kidney function and 45% achieved complete while 15% achieved partial remission. Among the 15 patients with isolated sMGN without full nephrotic syndrome, only two received immunosuppression; nonetheless, 50% achieved complete while 21% achieved partial remission. Thus, sMGN is a rare PLA2R-negative variant of MGN with 29% NELL-1 positivity and favorable prognosis, even in the absence of immunosuppressive treatment.
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Nishizawa Y, Honda K, Aoyama Y, Hosoda Y, Tamura T, Horimoto A, Omae K, Higuchi C, Sakura H, Nitta K, Ogawa T. Low-density lipoprotein apheresis for PLA2R-related membranous glomerulonephritis accompanied by IgG4-related tubulointerstitial nephritis. CEN Case Rep 2020; 9:395-403. [PMID: 32557252 DOI: 10.1007/s13730-020-00494-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 06/06/2020] [Indexed: 12/16/2022] Open
Abstract
IgG4-related disease preferentially involves the kidney by tubulointerstitial nephritis with IgG4-positive plasma cell filtration and/or membranous glomerulonephritis. We reported the case of a 68-year-old man with IgG4-related tubulointerstitial nephritis combined with antiphospholipase A2 receptor (PLA2R)-related membranous glomerulonephritis, in which distinguishing between idiopathic PLA2R-related and IgG4-related secondary membranous glomerulonephritis was difficult. We diagnosed him as having IgG4-related disease, based on a serum IgG4 level of 170 mg/dL and the presence of IgG4-related parotiditis. On renal biopsy, there was tubulointerstitial nephritis with IgG4-positive plasma cell filtration, which was compatible with IgG4-related disease and membranous glomerulonephritis, with concomitant positive staining for PLA2R on immunofluorescence microscopy. The renal function immediately recovered after steroid treatment, probably because of the improvement in the tubulointerstitial lesions, but his nephrotic syndrome was steroid-resistant. Low-density lipoprotein (LDL) apheresis therapy was effective for membranous glomerulonephritis and increased his serum albumin from 1.4 to 2.8 g/dL. Although IgG4-related kidney disease usually accompanies secondary membranous glomerulonephritis, the positive PLA2R staining suggested a concomitant primary membranous glomerulonephritis. The recent treatment strategy, including LDL apheresis, for primary and secondary membranous glomerulonephritis was discussed briefly in this report.
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Affiliation(s)
- Yoko Nishizawa
- Department of Medicine, Tokyo Women's Medical University Medical Center East, 2-1-10, Nishiogu, Arakawa, Tokyo, 116-8567, Japan.
| | - Kazuho Honda
- Department of Anatomy, Showa University School of Medicine, 1-5-8, Hatanodai, Shinagawa, Tokyo, 142-8555, Japan
| | - Yumi Aoyama
- Department of Medicine, Tokyo Women's Medical University Medical Center East, 2-1-10, Nishiogu, Arakawa, Tokyo, 116-8567, Japan
| | - Yumi Hosoda
- Department of Medicine, Tokyo Women's Medical University Medical Center East, 2-1-10, Nishiogu, Arakawa, Tokyo, 116-8567, Japan
| | - Tomomi Tamura
- Department of Medicine, Tokyo Women's Medical University Medical Center East, 2-1-10, Nishiogu, Arakawa, Tokyo, 116-8567, Japan
| | - Ai Horimoto
- Department of Medicine, Tokyo Women's Medical University Medical Center East, 2-1-10, Nishiogu, Arakawa, Tokyo, 116-8567, Japan
| | - Kiyotsugu Omae
- Department of Medicine, Tokyo Women's Medical University Medical Center East, 2-1-10, Nishiogu, Arakawa, Tokyo, 116-8567, Japan
| | - Chieko Higuchi
- Department of Medicine, Tokyo Women's Medical University Medical Center East, 2-1-10, Nishiogu, Arakawa, Tokyo, 116-8567, Japan
| | - Hiroshi Sakura
- Department of Medicine, Tokyo Women's Medical University Medical Center East, 2-1-10, Nishiogu, Arakawa, Tokyo, 116-8567, Japan
| | - Kosaku Nitta
- Department of Nephrology, Tokyo Women's Medical University, 8-1, Kawadacho, Shinjyuku, Tokyo, 162-8666, Japan
| | - Tetsuya Ogawa
- Department of Medicine, Tokyo Women's Medical University Medical Center East, 2-1-10, Nishiogu, Arakawa, Tokyo, 116-8567, Japan
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Ramachandran R, Kaundal U, Girimaji N, Rakha A, Rathi M, Gupta KL, Kohli HS, Jha V. Regulatory B Cells Are Reduced and Correlate With Disease Activity in Primary Membranous Nephropathy. Kidney Int Rep 2020; 5:872-878. [PMID: 32518869 PMCID: PMC7271006 DOI: 10.1016/j.ekir.2020.03.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 03/10/2020] [Accepted: 03/16/2020] [Indexed: 11/30/2022] Open
Abstract
Introduction Primary membranous nephropathy (PMN) is an autoimmune disease. Both T-regulatory cells (TREGs) and B-regulatory cells (BREGs) are decreased in patients with autoimmune disease. We evaluated the TREG and BREG population in patients of PMN treated with cyclical cyclophosphamide and steroid therapy (cCYC/GC). Methods Twenty-four patients with PMN resistant to a restrictive strategy and treated with cCYC/GC therapy and 10 healthy controls were enrolled. The proteinuria, serum creatinine, and serum albumin were tested at monthly intervals and blood samples were collected before starting cCYC/GC and at 6 and 8 (2 months wash out) months of therapy. The peripheral blood mononuclear cells (PBMCs) after staining with fluorochrome-conjugated antibodies were then subjected to flow cytometric analysis for detection of TREGs (CD3+CD4+CD25hiCD127loFoxP3+) and BREGs (CD19+CD5+CD1dhiIL10+). TREGs and BREGs are presented as the percentage of T and B cells, respectively. Cases with remission at month 18 were classified as responders, and those without any remission as nonresponders. Results Patients with PMN had a lower percentage of TREGs (P = 0.07) and BREGs compared with healthy controls (P = 0.0007). As compared with baseline, there was a significant increase in both BREGs (P = 0.001) and TREGs (P = 0.02) with the treatment (8 months). Patients who responded to therapy by 18 months had an increase in TREG (P = 0.05) and BREG (P = 0.0001) at month 8 compared with baseline. Conclusion As compared with healthy controls, patients with PMN displayed a lower percentage of BREGs. Both TREGs and BREGs significantly improved with disease-specific therapy. BREGs had an association with clinical activity.
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Affiliation(s)
- Raja Ramachandran
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Urvashi Kaundal
- Department of Translational and Regenerative Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Niveditha Girimaji
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Aruna Rakha
- Department of Translational and Regenerative Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Manish Rathi
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Krishnan L Gupta
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Harbir S Kohli
- Department of Nephrology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Vivekanand Jha
- The George Institute for Global Health, University of South Wales, New Delhi, India.,Manipal Academy of Higher Education, Manipal, India.,University of Oxford, Oxford, UK
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Nikolopoulou A, Teixeira C, Cook HT, Roufosse C, Cairns THD, Levy JB, Pusey CD, Griffith ME. Membranous nephropathy associated with viral infection. Clin Kidney J 2020; 14:876-883. [PMID: 33777370 PMCID: PMC7986439 DOI: 10.1093/ckj/sfaa026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 01/28/2020] [Indexed: 12/27/2022] Open
Abstract
Background Membranous nephropathy (MN) can be associated with hepatitis infection and less commonly with human immunodeficiency virus (HIV) infection. The significance of anti-phospholipase A2 receptor (PLA2R) and anti-thrombospondin type 1 domain-containing 7A (THSD7A) antibodies in this setting is unclear. Methods We describe the clinical, histopathological and outcome data of 19 patients with MN and hepatitis B virus (HBV), hepatitis C virus (HCV) or HIV infection identified through our renal biopsy database and the association with anti-PLA2R antibodies and anti-THSD7A antibodies. Results The cohort consisted of 19 patients, 8 male and 11 female, with a median age of 42 years (range 23–74). HBV infection was found in six cases, HCV in four and HIV in nine (two HIV patients had HBV co-infection and one HCV co-infection). PLA2R staining on biopsy was positive in 10/19 patients: 4 with HBV-MN, 3 with HCV-MN and 3 with HIV-MN and circulating anti-PLA2R antibodies were detected in 7/10 cases. THSD7A staining on biopsy was positive in three PLA2R-negative cases, one with HBV-MN and two with HIV-MN. Mean proteinuria was higher in the PLA2R-positive group and the median urinary protein:creatinine ratio (uPCR) was 963 mg/mmol (range 22–2406) compared with the PLA2R-negative group [median uPCR 548 mg/mmol (range 65–1898); P = 0.18 Mann–Whitney]. Spontaneous remission occurred in 6/19 patients and after-treatment remission occurred in 7/11 patients. Renal function was preserved in all but two patients who required haemodialysis 2 and 11 years from diagnosis. Conclusions We describe a cohort of patients with MN associated with viral infection, including rare cases of HIV-MN with PLA2R and THSD7A positivity. The mechanism of coincidental or viral-related MN needs to be investigated further.
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Affiliation(s)
- Aikaterini Nikolopoulou
- Renal Department, Imperial College Healthcare NHS Trust, London, UK.,Department of Immunology and Inflammation, Centre for Inflammatory Diseases, Imperial College, London, UK
| | - Catarina Teixeira
- Nephrology Department, Centro Hospitalar e Universitario de Coimbra, Coimbra, Portugal
| | - H Terry Cook
- Department of Immunology and Inflammation, Centre for Inflammatory Diseases, Imperial College, London, UK
| | - Candice Roufosse
- Department of Immunology and Inflammation, Centre for Inflammatory Diseases, Imperial College, London, UK
| | | | - Jeremy B Levy
- Renal Department, Imperial College Healthcare NHS Trust, London, UK
| | - Charles D Pusey
- Department of Immunology and Inflammation, Centre for Inflammatory Diseases, Imperial College, London, UK
| | - Megan E Griffith
- Renal Department, Imperial College Healthcare NHS Trust, London, UK
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Abstract
Membranous nephropathy (MN) is a common cause of nephrotic syndrome in adults. Over the last decade important research discoveries have revealed that most "idiopathic" cases are caused by autoantibodies to podocyte antigens including phospholipase A2 receptor (PLA2R) and thrombospondin type 1 domain containing 7A (THSD7A). In this review, we will discuss the histopathology of primary MN, recent revelations regarding pathogenesis, and ancillary tests.
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Affiliation(s)
- Qi Cai
- Department of Pathology, The University of Texas Southwestern Medical Center, 6201 Harry Hines Blvd. CUH 04.233, Dallas, TX 75390-9234, United States.
| | - Allen R Hendricks
- Department of Pathology, The University of Texas Southwestern Medical Center, 6201 Harry Hines Blvd. CUH 04.233, Dallas, TX 75390-9234, United States
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Hanset N, Esteve E, Plaisier E, Johanet C, Michel PA, Boffa JJ, Fievet P, Mesnard L, Morelle J, Ronco P, Dahan K. Rituximab in Patients With Phospholipase A2 Receptor-Associated Membranous Nephropathy and Severe CKD. Kidney Int Rep 2019; 5:331-338. [PMID: 32154454 PMCID: PMC7056852 DOI: 10.1016/j.ekir.2019.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 12/03/2019] [Accepted: 12/09/2019] [Indexed: 11/23/2022] Open
Abstract
Introduction Patients with phospholipase A2 receptor (PLA2R)–associated membranous nephropathy and stage 4 or 5 chronic kidney disease are at high risk of end-stage kidney disease. In recent years, rituximab (RTX) emerged as a safe and efficient treatment for patients with PLA2R-associated membranous nephropathy. Whether its use is also appropriate in patients with an estimated glomerular filtration rate <30 ml/min per 1.73 m2 has not been investigated. Methods We retrospectively reviewed characteristics and outcome of 13 patients with PLA2R-associated membranous nephropathy and stage 4 or 5 chronic kidney disease who received a total of 14 consecutive RTX treatments from January 2012 to March 2018. The treatment regimen consisted of either 2 weekly infusions of 375 mg/m2 or 2 RTX infusions of 1 g/d two weeks apart. When needed, the regimen was repeated to achieve immunological remission. Results The mean estimated glomerular filtration rate, serum albumin level, and urinary protein level at the first RTX infusion were 18 ± 7 ml/min per 1.73 m2, 25.2 ± 5.4 g/l, and 13.2 ± 7.5 g/d, respectively, with all patients being tested positive for serum PLA2R antibodies. Ten treatment courses led to an increase in estimated glomerular filtration rate and remission of nephrotic syndrome after a median follow-up of 40.8 months (interquartile range, 14.8–46.8). Conversely, 4 RTX treatments were unsuccessful, with patients requiring chronic hemodialysis within 1 year. The urinary albumin-to-protein ratio before treatment was predictive of renal response. Immunological remission occurred after 11 treatment courses and was associated with clinical response in 10 of 11 patients. Three patients experienced severe adverse events. Conclusion RTX seems effective and reasonably safe in PLA2R-associated membranous nephropathy with stage 4 or 5 chronic kidney disease. Immunological remission is associated with a good clinical outcome.
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Affiliation(s)
- Nicolas Hanset
- Department of Nephrology and Dialysis, Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France.,Division of Nephrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.,Nephrology Day Hospital, Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France
| | - Emmanuel Esteve
- Department of Nephrology and Dialysis, Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France.,Sorbonne Université, Université Pierre-et-Marie-Curie Paris 06, Paris, France.,Unité Mixte de Recherche_S 1155, Institut National de la Santé Et de la Recherche Médicale, Paris, France
| | - Emmanuelle Plaisier
- Nephrology Day Hospital, Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France.,Sorbonne Université, Université Pierre-et-Marie-Curie Paris 06, Paris, France.,Unité Mixte de Recherche_S 1155, Institut National de la Santé Et de la Recherche Médicale, Paris, France.,Centre de Référence Maladies Rares "Syndrome Néphrotique Idiopathique de l'Enfant et de l'Adulte," Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France
| | - Catherine Johanet
- Department of Immunology, Assistance Publique - Hôpitaux de Paris, Hôpital Saint Antoine, Paris, France
| | - Pierre-Antoine Michel
- Department of Nephrology and Dialysis, Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France
| | - Jean-Jacques Boffa
- Department of Nephrology and Dialysis, Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France
| | - Patrick Fievet
- Department of Nephrology, Centre Hospitalier Laennec de Creil, Creil, France
| | - Laurent Mesnard
- Sorbonne Université, Université Pierre-et-Marie-Curie Paris 06, Paris, France.,Unité Mixte de Recherche_S 1155, Institut National de la Santé Et de la Recherche Médicale, Paris, France.,Department of Intensive Care Nephrology and Kidney Transplantation, Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France
| | - Johann Morelle
- Division of Nephrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Pierre Ronco
- Nephrology Day Hospital, Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France.,Sorbonne Université, Université Pierre-et-Marie-Curie Paris 06, Paris, France.,Unité Mixte de Recherche_S 1155, Institut National de la Santé Et de la Recherche Médicale, Paris, France.,Centre de Référence Maladies Rares "Syndrome Néphrotique Idiopathique de l'Enfant et de l'Adulte," Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France
| | - Karine Dahan
- Nephrology Day Hospital, Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France.,Centre de Référence Maladies Rares "Syndrome Néphrotique Idiopathique de l'Enfant et de l'Adulte," Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France
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Beck LH, Salant DJ. Refining Our Understanding of the PLA2R-Antibody Response in Primary Membranous Nephropathy: Looking Forward, Looking Back. J Am Soc Nephrol 2019; 31:8-11. [PMID: 31871252 DOI: 10.1681/asn.2019111195] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Laurence H Beck
- Renal Section, Department of Medicine, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts
| | - David J Salant
- Renal Section, Department of Medicine, Boston Medical Center and Boston University School of Medicine, Boston, Massachusetts
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Dong D, Fan TT, Wang YY, Zhang L, Song L, Zhang L. Relationship between renal tissues phospholipase A2 receptor and its serum antibody and clinical condition and prognosis of idiopathic membranous nephropathy: a meta-analysis. BMC Nephrol 2019; 20:444. [PMID: 31791262 PMCID: PMC6889699 DOI: 10.1186/s12882-019-1638-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 11/21/2019] [Indexed: 01/15/2023] Open
Abstract
Objective To investigate the correlation of M-type phospholipase A2 receptor (PLA2R) expression and serum anti-PLA2R antibody with the clinical parameters and prognosis of patients with idiopathic membranous nephropathy (IMN). Methods A literature search for relevant original articles published between January 2009 and October 2019 was conducted on domestic and foreign databases. RevMan 5.3 software was used for meta-analysis. Results Eighteen studies were included in this meta-analysis. There were 1235 anti-PLA2R antibody-positive and PLA2R-positive patients, and 407 serum anti-PLA2R antibody-negative and PLA2R-negative patients. Compared with negative group, patients in the serum PLA2R antibody -positive group had lower serum albumin [SMD = -1.11, 95% CI (− 1.82, − 0.40), P < 0.00001], higher age [MD = 2.71, 95% CI (1.94, 3.48), P < 0.00001], and lower estimated glomerular filtration rate (eGFR) [MD = -10.34, 95% CI (− 12.09, − 8.60), P < 0.00001]; no significant between-group difference was observed with respect to 24-h urine protein and serum creatinine. However, no significant difference was observed between renal tissues PLA2R -positive and -negative groups with respect to serum albumin, eGFR, serum creatinine, and 24-h urine protein. Remission rate in the serum anti-PLA2R antibody -positive group was lower than that in the -negative group [OR = 0.41, 95% CI (0.28, 0.61),P < 0.00001]; however, no significant between-group difference in this respect was observed between the renal tissue PLA2R-positive and -negative groups. In the serum anti-PLA2R antibody -positive group, the higher titer subgroup had lower remission rate [OR = 0.19, 95% CI (0.07, 0.55),P = 0.002]. No significant difference was observed between anti-PLA2R antibody -positive and -negative groups with respect to adverse events. Serum anti-PLA2R antibody titer did not affect the adverse event rate. Conclusion As compared to PLA2R, serum anti-PLA2R antibody is more closely related with IMN disease progression.
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Affiliation(s)
- Dan Dong
- Department of Nephrology, First Hospital of Jilin University, 71 Xinmin Street, Changchun, Jilin, 130021, People's Republic of China
| | - Ting-Ting Fan
- Department of Nephrology, First Hospital of Jilin University, 71 Xinmin Street, Changchun, Jilin, 130021, People's Republic of China.,Department of Nephrology, Binzhou People's Hospital, Binzhou, Shandong, People's Republic of China
| | - Ying-Ying Wang
- Department of Nephrology, Jining No.1 People's Hospital, Jining, Shandong, People's Republic of China
| | - Lu Zhang
- Department of Nephrology, First Hospital of Jilin University, 71 Xinmin Street, Changchun, Jilin, 130021, People's Republic of China
| | - Li Song
- Department of Nephrology, First Hospital of Jilin University, 71 Xinmin Street, Changchun, Jilin, 130021, People's Republic of China
| | - Li Zhang
- Department of Nephrology, First Hospital of Jilin University, 71 Xinmin Street, Changchun, Jilin, 130021, People's Republic of China.
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47
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Shirai S, Akiyama S, Kamijo-Ikemori A, Suzuki T, Ichikawa D, Koike J, Kimura K, Shibagaki Y. Membranous nephropathy associated with thrombospondin type-1 domain-containing 7A (THSD7A) in an adult woman with eosinophilia. CEN Case Rep 2020; 9:65-73. [PMID: 31705303 DOI: 10.1007/s13730-019-00430-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 10/20/2019] [Indexed: 11/29/2022] Open
Abstract
A 30-year-old woman on steroid therapy for eosinophilia presented with nephrotic syndrome during steroid tapering. She was diagnosed with membranous nephropathy (MN) stage II–III (positive for IgG1 and IgG4) by renal biopsy. There was no evidence of secondary MN. Her urinary protein level was controlled to 0.5 g/day or less, and her eosinophil count in white blood cell differential was stabilized at less than 10% without increasing the steroid dosage. The renal specimen did not show any enhanced granular expression of PLA2R along the glomerular basement membrane, and PLA2R was not detected in the patient’s serum. On retrospective analysis, enhanced granular staining for thrombospondin type-1 domain-containing 7A (THSD7A) in the glomeruli was detected in the biopsy, and anti-THSD7A IgG was detected in the serum using a commercial indirect immunofluorescence test (IFT). Based on these, the case was considered as THSD7A-associated MN with comorbid eosinophilia. The causal relationship between THSD7A-related MN and eosinophilia was unclear. However, a few cases of THSD7A-associated MN with eosinophilia have been reported, and further clarification on the relationship between THSD7A-related MN and eosinophilia is warranted.
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Cravedi P, Jarque M, Angeletti A, Favà À, Cantarelli C, Bestard O. Immune-Monitoring Disease Activity in Primary Membranous Nephropathy. Front Med (Lausanne) 2019; 6:241. [PMID: 31788474 PMCID: PMC6856075 DOI: 10.3389/fmed.2019.00241] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 10/14/2019] [Indexed: 01/03/2023] Open
Abstract
Primary membranous nephropathy (MN) is a glomerular disease mediated by autoreactive antibodies, being the main cause of nephrotic syndrome among adult patients. While the pathogenesis of MN is still controversial, the detection of autoantibodies against two specific glomerular antigens, phospholipase A2 receptor (PLA2R) and thrombospondin type 1 domain containing 7A (THSD7A), together with the beneficial effect of therapies targeting B cells, have highlighted the main role of autoreactive B cells driving this renal disease. In fact, the detection of PLA2R-specific IgG4 antibodies has resulted in a paradigm shift regarding the diagnosis as well as a better prediction of the progression and recurrence of primary MN. Nevertheless, some patients do not show remission of the nephrotic syndrome or do rapidly recur after immunosuppression withdrawal, regardless the absence of detectable anti-PLA2R antibodies, thus highlighting the need of other immune biomarkers for MN risk-stratification. Notably, the exclusive evaluation of circulating antibodies may significantly underestimate the magnitude of the global humoral memory immune response since it may exclude the role of antigen-specific memory B cells. Therefore, the assessment of PLA2R-specific B-cell immune responses using novel technologies in a functional manner may provide novel insight on the pathogenic mechanisms of B cells triggering MN as well as refine current immune-risk stratification solely based on circulating autoantibodies.
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Affiliation(s)
- Paolo Cravedi
- Renal Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Marta Jarque
- Experimental Nephrology Laboratory, Biomedical Research Institute of Bellvitge (IDIBELL), Barcelona, Spain
| | - Andrea Angeletti
- Nephrology, Dialysis and Renal Transplant Unit, Department of Experimental Diagnostic and Specialty Medicine (DIMES), St. Orsola Hospital, University of Bologna, Bologna, Italy
| | - Àlex Favà
- Experimental Nephrology Laboratory, Biomedical Research Institute of Bellvitge (IDIBELL), Barcelona, Spain
| | - Chiara Cantarelli
- UO Nefrologia, Dipartimento di Medicina e Chirurgia, Azienda Ospedaliero-Universitaria Parma, Parma, Italy
| | - Oriol Bestard
- Experimental Nephrology Laboratory, Biomedical Research Institute of Bellvitge (IDIBELL), Barcelona, Spain.,Kidney Transplant Unit, Nephrology Department, Bellvitge University Hospital, Barcelona University, Biomedical Research Institute of Bellvitge (IDIBELL), Barcelona, Spain
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49
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Zhang MF, Huang J, Zhang YM, Qu Z, Wang X, Wang F, Meng LQ, Cheng XY, Cui Z, Liu G, Zhao MH. Complement activation products in the circulation and urine of primary membranous nephropathy. BMC Nephrol 2019; 20:313. [PMID: 31399080 PMCID: PMC6688252 DOI: 10.1186/s12882-019-1509-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 07/31/2019] [Indexed: 12/19/2022] Open
Abstract
Background Complement activation plays a substantial role in the pathogenesis of primary membranous nephropathy (pMN). C5b-9, C3c, MBL, and factor B have been documented in the subepithelial immune deposits. However, the changing of complement activation products in circulation and urine is not clear. Methods We measured the circulating and urinary levels of C1q, MBL, C4d, Bb, properdin, C3a, C5a, and sC5b-9, in 134 patients with biopsy-proven pMN, by enzyme-linked immunosorbent assay. All the plasma values were corrected by eGFR and all the urinary values were corrected by urinary creatinine and urinary protein excretion. Anti-PLA2R antibodies were measured in all patients. Results The plasma complement activation products were elevated both in the patients with and without anti-PLA2R antibodies. C3a levels were remarkably increased in the circulation and urine, much higher than the elevated levels of C5a. C5b-9 was in normal range in plasma, but significantly higher in urine. The urinary C5a had a positive correlation with anti-PLA2R antibody levels and urinary protein. The plasma level of C4d was elevated, but C1q and MBL were comparable to healthy controls. Positive correlations were observed between plasma C4d/MBL and urinary protein, only in the patients with positive anti-PLA2R antibodies but not in those without. The plasma level of Bb was elevated and had positive correlation with urinary protein only in the patients without anti-PLA2R antibodies. Conclusion Complement activation products were remarkable increased in pMN and may serve as sensitive biomarkers of disease activity. The complement may be activated through lectin pathway with the existence of anti-PLA2R antibodies, while through alternative pathway in the absence of antibody.
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Affiliation(s)
- Mu-Fan Zhang
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, 100034, China.,Institute of Nephrology, Peking University, Beijing, 100034, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, China.,Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, 100034, China
| | - Jing Huang
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, 100034, China.,Institute of Nephrology, Peking University, Beijing, 100034, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, China.,Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, 100034, China
| | - Yi-Miao Zhang
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, 100034, China.,Institute of Nephrology, Peking University, Beijing, 100034, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, China.,Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, 100034, China
| | - Zhen Qu
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, 100034, China.,Institute of Nephrology, Peking University, Beijing, 100034, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, China.,Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, 100034, China
| | - Xin Wang
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, 100034, China.,Institute of Nephrology, Peking University, Beijing, 100034, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, China.,Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, 100034, China
| | - Fang Wang
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, 100034, China.,Institute of Nephrology, Peking University, Beijing, 100034, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, China.,Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, 100034, China
| | - Li-Qiang Meng
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, 100034, China.,Institute of Nephrology, Peking University, Beijing, 100034, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, China.,Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, 100034, China
| | - Xu-Yang Cheng
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, 100034, China.,Institute of Nephrology, Peking University, Beijing, 100034, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, China.,Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, 100034, China
| | - Zhao Cui
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, 100034, China. .,Institute of Nephrology, Peking University, Beijing, 100034, China. .,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, China. .,Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, 100034, China.
| | - Gang Liu
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, 100034, China.,Institute of Nephrology, Peking University, Beijing, 100034, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, China.,Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, 100034, China
| | - Ming-Hui Zhao
- Department of Medicine, Renal Division, Peking University First Hospital, Beijing, 100034, China.,Institute of Nephrology, Peking University, Beijing, 100034, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, 100034, China.,Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, 100034, China.,Peking-Tsinghua Center for Life Sciences, Beijing, China
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Fresquet M, Rhoden SJ, Jowitt TA, McKenzie EA, Roberts I, Lennon R, Brenchley PE. Autoantigens PLA2R and THSD7A in membranous nephropathy share a common epitope motif in the N-terminal domain. J Autoimmun 2019; 106:102308. [PMID: 31395435 PMCID: PMC7471840 DOI: 10.1016/j.jaut.2019.102308] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/19/2019] [Accepted: 07/24/2019] [Indexed: 12/11/2022]
Abstract
Patients with membranous nephropathy have autoantibodies against PLA2R (up to 80%), or THSD7A (up to 2%). We previously described the immunodominant epitope within PLA2R but epitopes in THSD7A are still unknown. To find anti-THSD7A sera for this study, we screened 1843 sera from biopsy-proven MN patients by ELISA and identified 22 sera as anti-THSD7A positive representing 1.2% of MN cases. Anti-THSD7A positive sera were further characterized by western blotting and slot blotting on THSD7A protein fragments and peptides. Real time interaction analyses and antibodies off-rate could be reliably determined using bio-layer interferometry. A signature motif in the N-terminal domain of THSD7A (T28mer) with sequence homology to the major PLA2R epitope (P28mer) was identified. B-cell epitope prediction analysis and homology modelling revealed this sequence to be antigenic and surface available suggesting it is accessible for the antibody to bind. All ten selected sera bound to the T28mer confirming this sequence as a dominant epitope in THSD7A. Reactivity to this sequence was lost following kallikrein protease cleavage within the predicted epitope. Importantly, cross-reactivity of both PLA2R and THSD7A autoantibodies was observed at the peptide but not the protein level. We propose that this common motif shared by both autoantigens could be an epitope involved in the initial B-cell triggering event in MN.
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Affiliation(s)
- M Fresquet
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - S J Rhoden
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - T A Jowitt
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - E A McKenzie
- Manchester Institute of Biotechnology, University of Manchester, UK
| | | | - R Lennon
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, University of Manchester, UK; Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - P E Brenchley
- Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
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