Primary membranous nephropathy: comprehensive review and historical perspective

Modified Huangqi Chifeng decoction alleviates podocyte injury on rat with experimental membranous nephropathy

OBJECTIVE

This study aims to investigate the therapeutic effects of modified Huangqi Chifeng decoction (MHCD) on proteinuria in membranous nephropathy (MN) and its potential protective effects on podocytes. Furthermore, we explored whether these effects are associated with the inhibition of the nuclear factor kappa-B (NF-κB) pathway.

METHODS

Passive Heymann nephritis (PHN) rat model was applied with a single tail vein injection of sheep anti-rat Fx1A serum (0.4 ml/100g). All rats were divided into four groups: normal group, PHN group, benazepril group (10 mg/kg), and MHCD group (12.5 g/kg), and were treated for 6 weeks. 24-hour urine protein levels and serum biochemical parameters were measured. Optical microscopy and transmission electron microscopy were performed to assess pathological changes in renal tissues. Additionally, the expression levels of IgG, C5b-9, nephrin, podocin, Wilms' tumor gene 1 (WT-1), and NF-κB p65 were evaluated.

RESULTS

PHN rats exhibited progressive proteinuria over time. However, MHCD treatment significantly reduced levels of proteinuria and triglyceride, while increased levels of albumin. Moreover, MHCD alleviated pathological damage in renal tissues, and reduced the expression of IgG and membrane attack complex (C5b-9). Immunohistochemistry analysis revealed that MHCD increased the expression of nephrin, podocin, and WT-1. Western blot analysis showed that MHCD increased the expression of nephrin and podocin while inhibiting the activation of NF-κB p65.

CONCLUSIONS

Our findings indicate that MHCD exert reno-protective effects in the experimental rat model of MN by alleviating podocyte damage and inhibiting the NF-κB pathway.

Sanqi Qushi formula ameliorates renal injury in experimental membranous nephropathy rats by inhibiting the MEK/ERK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Sanqi Qushi Formula (SQQS), a clinically validated derivative of the Sanqi oral solution, integrates principles of traditional Chinese medicine (TCM) to treat membranous nephropathy (MN). Its efficacy in reducing proteinuria and preserving renal function has been observed in clinical practice.

AIM OF THE STUDY

This study aims to elucidate the therapeutic mechanisms, active components, and pathway-specific effects of SQQS in MN, providing a scientific foundation for its clinical use.

MATERIALS AND METHODS

The components of SQQS were analyzed using UHPLC-MS/MS. A passive Heymann nephritis (PHN) rat model was induced by intravenous injection of anti-Fx1A serum. Rats received oral SQQS for 3 weeks, and urine/serum samples were collected to evaluate renal function and chemokine levels. Renal histopathology was assessed via immunofluorescence, PASM staining, and CD68 immunostaining. Network pharmacology integrated target prediction for SQQS compounds and differentially expressed genes from the Gene Expression Omnibus (GEO) database (MN patient glomeruli). Mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway proteins and epithelial-mesenchymal transition (EMT) markers were analyzed by western blotting (WB). Molecular docking and molecular dynamics simulations evaluated compound-MEK interactions. Human glomerular podocytes were treated with SQQS-derived compounds; viability and migration were assessed using cell counting kit-8 assay and scratch assays.

RESULTS

UHPLC-MS/MS identified 129 compounds in SQQS. SQQS treatment significantly reduced renal injury markers, glomerular IgG deposition, and basement membrane thickening in PHN rats. GEO database analysis revealed 839 upregulated and 166 downregulated genes in MN glomeruli. Network pharmacology implicated the tumor necrosis factor (TNF) pathway, with 10 upregulated targets (e.g., MAP2K1, MMP3, CXCL10). WB confirmed SQQS suppressed MEK/ERK phosphorylation and decreased MMP3 and α-SMA levels. Renal CD68+ macrophages and associated chemokines (CXCL10, CCL20) were reduced by SQQS. Methylnissolin-3-O-glucoside, a flavonoid from Astragalus mongholicus Bunge, dose-dependently inhibited TNF-α-induced MEK/ERK activation and migration. MEK agonists reversed methylnissolin-3-O-glucoside-mediated MEK/ERK suppression.

CONCLUSION

SQQS ameliorates MN progression by inhibiting the MEK/ERK pathway, suppressing EMT, and reducing macrophage recruitment, with methylnissolin-3-O-glucoside as a key bioactive component.

Detection and prognostic relevance of PLA2R epitopes in idiopathic membranous nephropathy: a simultaneous quantitative multiplex suspension array detection method

Objective

This study aimed to develop a multiplex suspension assay for the simultaneous quantitative detection of anti-cysteine-rich domain (anti-CysR)/C-type lectin domain 1 (CTLD1)/C-type lectin domain 6-8 (CTLD678)-immunoglobulin G4 (IgG4) antibodies of M-type phospholipase A2 receptor (PLA2R) in the serum samples of patients to evaluate the clinical application value of PLA2R epitope spreading in disease prognosis.

Methods

CysR, CTLD1 and CTLD678 antigen domains were coupled to three types of microspheres. The optimal dilution ratio of biotinylated anti-human IgG4 was identified, and a multiplex suspension assay was evaluated in terms of linearity, sensitivity, precision, specificity and recovery rate. Lastly, the relationship between epitope spreading and the severity of idiopathic membranous nephropathy was evaluated.

Results

The content of all three epitopes could be detected simultaneously within 2 h. The intra-assay precision ranged from 4.74% to 9.48%, and the inter-assay precision was between 5.13% and 13.92%. Specific experiments showed that the human IgA antibody did not cause a cross-reaction. The recovery rates ranged between 90% and 100%. The cut-off values of epitopes CysR, CTLD1 and CTLD678 between healthy individuals and patients were 6.30, 12.38 and 10.06 Ru/mL, respectively. Among them, the positive rates of epitopes CysR, CTLD1 and CTLD678 were 100%, 34% and 75%, respectively. In addition, Group 3 (CTLD1 response) accounted for 73% of the 12 patients who were not in remission. Meanwhile, when the concentration of CTLD1 exceeds 42.76 Ru/mL, the patient's prognosis may be poorer.

Conclusion

A multiplex suspension assay was developed for the simultaneous quantitative detection of anti-CysR/CTLD1/CTLD678-IgG4 antibodies. The epitope migration sequence of PLA2R molecules during disease progression may not follow a simple linear rule. Among them, the epitope CTLD1 is likely to exert the most significant influence on patient remission.

Obinutuzumab in Rituximab-resistant and recurrent membranous nephropathy: a case-series

BACKGROUND

Membranous nephropathy (MN) is a common cause of nephrotic syndrome in adults, with high risk of progression to end-stage kidney disease when untreated. Rituximab is commonly used in its treatment however many patients do not respond. Obinutuzumab is a novel anti-CD20 monoclonal antibody for which there is increasing observational evidence in treatment-resistant membranous nephropathy. The majority of evidence for its use relates to anti-phospholipase A2 receptor-(PLA2R) associated membranous nephropathy.

METHODS

This was a single-centre case-series of all patients at a tertiary nephrology centre in Melbourne, Australia, treated with Obinutuzumab for membranous nephropathy, between January 2023 and June 2024. All patients who received Obinutuzumab were included in this case-series, irrespective of PLA2R status.

RESULTS

Out of 5 patients with treatment-resistant membranous nephropathy, 3 had PLA2R-associated membranous nephropathy which had previously been refractory to, or relapsed on Rituximab therapy. All 3 patients with PLA2R-positive membranous nephropathy achieved complete immunological and clinical remission after receiving Obinutuzumab. The case of secondary PLA2R-negative membranous nephropathy only achieved partial remission after Obinutuzumab before unexpectedly dying from another cause. The case of recurrent PLA2R-associated membranous nephropathy in a renal allograft did not respond to Obinutuzumab.

CONCLUSION

This case-series supports the existing evidence in favour of Obinutuzumab for treatment-resistant PLA2R-associated membranous nephropathy. To our knowledge it is the first reported use of Obinutuzumab in sarcoidosis-associated membranous nephropathy.

Establishing a differential diagnosis model between primary membranous nephropathy and non-primary membranous nephropathy by machine learning algorithms

CONTEXT

Four algorithms with relatively balanced complexity and accuracy in deep learning classification algorithm were selected for differential diagnosis of primary membranous nephropathy (PMN).

OBJECTIVE

This study explored the most suitable classification algorithm for PMN identification, and to provide data reference for PMN diagnosis research.

METHODS

A total of 500 patients were referred to Luo-he Central Hospital from 2019 to 2021. All patients were diagnosed with primary glomerular disease confirmed by renal biopsy, contained 322 cases of PMN, the 178 cases of non-PMN. Using the decision tree, random forest, support vector machine, and extreme gradient boosting (Xgboost) to establish a differential diagnosis model for PMN and non-PMN. Based on the true positive rate, true negative rate, false-positive rate, false-negative rate, accuracy, feature work area under the curve (AUC) of subjects, the best performance of the model was chosen.

RESULTS

The efficiency of the Xgboost model based on the above evaluation indicators was the highest, which the diagnosis of PMN of the sensitivity and specificity, respectively 92% and 96%.

CONCLUSIONS

The differential diagnosis model for PMN was established successfully and the efficiency performance of the Xgboost model was the best. It could be used for the clinical diagnosis of PMN.

Obinutuzumab in untreated primary membranous nephropathy: An observational case series

BACKGROUND

As an initial treatment for primary membranous nephropathy (PMN), there remains a significant proportion of patients for whom rituximab is not fully effective. Here, we aimed to assess the effectiveness and safety of obinutuzumab as initial treatment in patients with PMN.

METHODS

In this observational case series, patients diagnosed with PMN and treated with obinutuzumab as initial treatment were included. Treatment response was assessed by 24-h urine total protein (24 h UTP) and serum albumin, and immunologic remission was assessed by phospholipase A2 receptor (PLA2R) antibodies.

RESULTS

Twelve patients with PMN receiving obinutuzumab as initial treatment were included. Over 6 months, a statistically significant reduction in 24 h UTP levels (p = 0.003) and an increase in serum albumin levels were observed (p < 0.001). By the 6-month follow-up, two patients (16.7%) achieved complete remission, eight (66.6%) reached partial remission, and two (16.7%) showed no remission. Immunological remission was observed in 44.4% of evaluable patients (n = 9) after 3 months, increasing to 100% (6/6) at 6 months. Except for cases 1, 2, and 3, the total B cell counts in the remaining patients fell to less than 5 cells/μL before the administration of the second dose of obinutuzumab, including seven patients with counts as low as 0 cells/μL. Mild to moderate treatment-related adverse events (TRAEs) were reported in 58.3% (7/12) of the patients. No serious TRAEs were reported.

CONCLUSIONS

Obinutuzumab demonstrates promising potential as an initial treatment for PMN, with good effectiveness and a manageable safety profile. Further large-scale prospective studies are needed to confirm these findings.

Potential Role of Mineralocorticoid Receptor Antagonists in Nondiabetic Chronic Kidney Disease and Glomerular Disease

Glomerular disease is a leading cause of CKD and ESKD. Although diabetic kidney disease is the most common cause of glomerular disease, nondiabetic causes include malignancy, systemic autoimmune conditions, drug effects, or genetic conditions. Nondiabetic glomerular diseases are rare diseases, with a paucity of high-quality clinical trials in this area. Furthermore, late referral can result in poor patient outcomes. This article reviews the current management of nondiabetic glomerular disease and explores the latest developments in drug treatment in this area. Current treatment of nondiabetic glomerular disease aims to manage complications (edema, hypertension, proteinuria, hyperlipidemia, hypercoagulability, and thrombosis) as well as target the underlying cause of glomerular disease. Treatment options include renin-angiotensin-aldosterone system inhibitors, statins/nonstatin alternatives, loop diuretics, anticoagulation agents, immunosuppressives, and lifestyle and dietary modifications. Effective treatment of nondiabetic glomerular disease is limited by heterogeneity and a lack of understanding of the disease pathogenesis. Sodium-glucose cotransporter-2 inhibitors and nonsteroidal mineralocorticoid receptor antagonists (ns-MRAs, such as finerenone), with their broad anti-inflammatory and antifibrotic effects, have emerged as valuable therapeutic options for a range of cardiorenal conditions, including CKD. ns-MRAs are an evolving drug class of particular interest for the future treatment of nondiabetic glomerular disease, and there is evidence that these agents may improve kidney prognosis in various subgroups of patients with CKD. The benefits offered by ns-MRAs may present an opportunity to reduce the progression of CKD from a spectrum of glomerular disease. Several novel ns-MRA are in clinical development for both diabetic and nondiabetic CKD.

A Clinicopathological Analysis of Membranous Nephropathy and Its Correlation With the Immunohistochemical Expression of Phospholipase A2 Receptor (PLA2R) in Renal Biopsies in a Tertiary Care Center

Background  Membranous nephropathy (MN) is the second most common adult-onset nephrotic syndrome worldwide. Traditionally, these were classified as primary and secondary, with primary causes showing higher positivity for various antigens, including M-type phospholipase A2 receptor (PLA2R), a key antigen located in the podocyte against which antibodies are directed. Aim The aim of this study is to analyze the cases diagnosed as MN with clinicopathological parameters and PLA2R positivity by immunohistochemistry in renal biopsies. Methods A retrospective observational study of 65 cases of MN diagnosed in renal biopsies by light microscopy and confirmed by ancillary studies from the Department of Pathology, Sri Ramachandra Medical College and Research Institute over a period of three years (2021-2023). The demographic profile and patient details were obtained from the hospital information system and archival case files. The description of categorical variables was expressed as frequency and percentage. The Chi-squared test and Fisher's exact test were employed to compare the distribution of qualitative variables between the groups. Results This case study includes 65 membranous nephropathy cases, of which 47.7% were diagnosed as primary MN and 52.3% as secondary MN. Of these, serum antinuclear antibody (ANA) positivity was seen in 80.6% of cases of primary MN and 58.8% of cases of secondary MN. Elevated serum C3/C4 levels were noted in 51.6% of primary MN and 47.1% of secondary MN (Ref. C3 = 90-180mg/dl; C4 = 10-40mg/dl). Immunofluorescence for IgG showed a nonspecific association between primary and secondary MN. Immunohistochemistry (IHC) for PLA2R showed positivity in 72.3% of primary MN cases and 27.7% of secondary MN cases. The Chi-squared test and Fisher's exact test showed statistical significance for these parameters. Conclusion This study signifies that primary MN is more frequently associated with positive immunohistochemical expression of PLA2R. These findings help in characterizing these cases as antigen-specific and have helped in the ongoing validation of PLA2R IHC as a diagnostic marker, which aids in monitoring the disease progression, remission, and recurrence. Despite the availability of various modalities for estimating the levels of anti-PLA2R, diagnostic challenges persist. Hence, most renal laboratories continue to adopt renal biopsy staining for IHC PLA2R to identify and monitor the disease progression.

Phase 1b/2a Study Assessing the Safety and Efficacy of Felzartamab in Anti-Phospholipase A2 Receptor Autoantibody-Positive Primary Membranous Nephropathy

Introduction

Primary membranous nephropathy (PMN) is most often caused by autoantibodies to phospholipase A2 receptor (PLA2R). M-PLACE (NCT04145440) is an open-label, phase 1b/2a study that assessed the safety and efficacy of the fully human anti-CD38 monoclonal antibody felzartamab in high-risk anti-PLA2R+ PMN.

Methods

Patients with newly diagnosed or relapsed PMN (cohort 1 [C1]; n = 18) or PMN refractory to immunosuppressive therapy (IST) (cohort 2 [C2]; n = 13) received 9 infusions of felzartamab 16 mg/kg in the 24-week treatment period, followed by a 28-week follow-up. The primary end point was the incidence and severity of treatment-emergent adverse events (TEAEs).

Results

A total of 31 patients were enrolled and received felzartamab. Twenty-seven patients (87.1%) had TEAEs, including infusion-related reactions (IRRs) (29.0%), hypogammaglobulinemia (25.8%), peripheral edema (19.4%), and nausea (16.1%). Five patients (16.1%) had serious TEAEs that all resolved. Immunologic response (anti-PLA2R titer reduction ≥50%) was achieved by 20 of 26 efficacy-evaluable patients (76.9%) (C1, 13/15 [86.7%]; C2, 7/11 [63.6%]). Anti-PLA2R titer reductions were rapid (week 1 response, 44.0%; response 7 months after last felzartamab dose [end of study, EOS], 53.8%). Partial proteinuria remission (urine protein-to-creatinine ratio [UPCR] reduction ≥50%, UPCR <3.0 g/g, and stable estimated glomerular filtration rate [eGFR]) was achieved by 9 of 26 patients (34.6%) (C1, 7/15 [46.7%]; C2, 2/11 [18.2%]) before or at EOS (median follow-up, 366 days). Serum albumin increased from baseline to EOS in 20 of 26 patients (76.9%) (C1, 12/15 [80.0%]; C2, 8/11 [72.7%]).

Conclusion

In this population with high-risk anti-PLA2R+ PMN, felzartamab was tolerated and resulted in rapid partial and complete immunologic responses and partial improvements in proteinuria and serum albumin in some patients.

Future embracing: exosomes driving a revolutionary approach to the diagnosis and treatment of idiopathic membranous nephropathy

Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults and is associated with high rates of end-stage renal disease. Early detection and precise interventions are crucial for improving patient prognosis and quality of life. However, the current diagnosis primarily relies on renal biopsies and traditional biomarkers, which have limitations. Additionally, targeted therapeutic strategies are lacking. Exosomes, small vesicles that facilitate intercellular communication, have emerged as potential noninvasive diagnostic markers due to their stability, diverse cargo, and rapid detectability. They also hold promise as carriers for gene and drug delivery, presenting innovative opportunities in renal disease prognosis and treatment. However, research on exosomes in the context of idiopathic membranous nephropathy (IMN) remains limited, with a focus on exploring urinary exosomes as IMN markers. In this review, we summarize the current status of MN diagnosis and treatment, highlight the fundamental characteristics of exosomes, and discuss recent advancements in their application to IMN diagnosis and therapy. We provide insights into the clinical prospects of exosomes in IMN and acknowledge potential challenges. This article aims to offer forward-looking insights into the future of exosome-mediated IMN diagnosis and treatment, indicating a revolutionary transformation in this field.

From Diagnosis to Dialysis: Managing Primary Membranous Nephropathy in a Patient Living With Human Immunodeficiency Virus (HIV)

Membranous nephropathy (MN) is a significant cause of nephrotic syndrome in adults, with both primary and secondary etiologies contributing to its pathogenesis. This case report explores the clinical course of a 69-year-old African American man with human immunodeficiency virus (HIV) who developed primary MN, progressing to end-stage renal disease (ESRD) despite treatment efforts. Initially diagnosed with IgA nephropathy and HIV-associated immune complex kidney disease (HIVICK), the patient later developed anti-phospholipase A2 receptor (anti-PLA2R) antibody-positive MN. Despite immunosuppressive therapy and partial remission with rituximab, non-adherence to treatment led to disease exacerbation and eventual hospitalization for acute heart failure and worsening renal function. A subsequent renal biopsy revealed severe interstitial fibrosis and tubular atrophy, limiting further therapeutic options. This case underscores the challenges in managing MN, particularly in high-risk patients with comorbidities such as HIV, and highlights the importance of adherence to treatment and tailored management strategies to optimize outcomes in this complex condition.

A single-center, open label, randomized, controlled study of hydroxychloroquine sulfate in the treatment of low risk PLA2R-associated membranous nephropathy

OBJECTIVE

To evaluate the efficacy and safety of hydroxychloroquine sulfate (HCQ) in the treatment of low risk phospholipase A2 receptor (PLA2R)-associated membranous nephropathy (MN).

METHODS

A total of 110 patients with low risk PLA2R-associated MN were included in the study. Patients who met the inclusion and exclusion criteria were assigned randomly to two groups: the HCQ treatment group and the control group. The control group received standard supportive treatment according to the guidelines, while the HCQ treatment group received HCQ in addition to the supportive treatment. The clinical data of the patients were analyzed, with comparisons made at baseline and during the six-month follow-up period. Any adverse reactions were recorded.

RESULTS

The baseline data were comparable between the HCQ treatment group and the control group. At the end of the six-month follow-up period, the reductions in urine protein excretion and serum PLA2R antibody titer were more notable in the HCQ treatment group than those in the control group, with these differences being statistically significant (p < 0.05). Compared to the control group, the HCQ treatment group had fewer patients who were converted from low risk to moderate-to-high risk (p = 0.084). There were also no severe adverse reactions in the HCQ treatment group.

CONCLUSION

In patients with low risk PLA2R-associated MN, adequate supportive therapy combined with HCQ is superior to supportive therapy alone in controlling proteinuria and reducing serum PLA2R antibody titers. Additionally, our study demonstrated that the incidence of adverse reactions did not increase.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Registry (Registration No.: ChiCTR1900021757, Date of registration: 2019-03-08).

Membranous nephropathy: pathogenesis and treatments

Membranous nephropathy (MN), an autoimmune disease, can manifest at any age and is among the most common causes of nephrotic syndrome in adults. In 80% of cases, the specific etiology of MN remains unknown, while the remaining cases are linked to drug use or underlying conditions like systemic lupus erythematosus, hepatitis B virus, or malignancy. Although about one-third of patients may achieve spontaneous complete or partial remission with conservative management, another third face an elevated risk of disease progression, potentially leading to end-stage renal disease within 10 years. The identification of phospholipase A2 receptor as the primary target antigen in MN has brought about a significant shift in disease management and monitoring. This review explores recent advancements in the pathophysiology of MN, encompassing pathogenesis, clinical presentations, diagnostic criteria, treatment options, and prognosis, with a focus on emerging developments in pathogenesis and therapeutic strategies aimed at halting disease progression. By synthesizing the latest research findings and clinical insights, this review seeks to contribute to the ongoing efforts to enhance our understanding and management of this challenging autoimmune disorder.

Meta-analysis of the effects of CYP3A5*3 gene polymorphisms on tacrolimus blood concentration and effectiveness in Chinese patients with membranous nephropathy

Objective

The study aimed to systematically evaluate the relationship between CYP3A5*3 gene polymorphisms and the blood concentration and effectiveness of tacrolimus (TAC) in patients with membranous nephropathy (MN).

Methods

PubMed, Cochrane Library, Embase, Web of Science, China Biomedical, China National Knowledge Infrastructure, Wanfang, Vipshop, ReadShow, Clinical Trials Registry, and other databases were searched. Studies on the relationship between CYP3A5*3 gene polymorphism and TAC blood concentration in MN patients were collected, and meta-analysis was performed using Stata 16 software.

Results

A total of eight publications were included in the study, including 498 MN patients. CYP3A5*3 gene polymorphisms are associated with tacrolimus blood levels in patients with MN. The results of the relationship between CYP3A5*3 genotype polymorphisms and tacrolimus blood trough concentrations of the AA + AG genotype were lower than those of the GG genotype at ≤1 month [WMD = -2.08, 95% CI (-2.57, -1.59), p < 0.001] and 1-6 months [WMD = -0.63, 95% CI (-0.98, -0.27), p < 0.001]; however, they were not statistically significant at ≥6 months (p = 0.211). Furthermore, the subgroup analysis revealed that the dose-adjusted concentration of tacrolimus (C0/D) of the AA + AG genotype was lower than that of the GG genotype at ≤1 month [SMD = -1.93, 95% CI (-2.79, -1.08), p < 0.001], 1-6 months [SMD = -2.25, 95% CI (-2.71, -1.79), p < 0.001], and ≥6 months [SMD = -2.36, 95% CI (-2.86, -1.86), p < 0.001]. In addition, there was no statistically significant difference in effectiveness between the two groups at 3, 6, and 12 months of TAC administration (p > 0.05).

Conclusion

Serum TAC concentrations in MN patients were correlated with CYP3A5*3 genotype polymorphisms. Detection of the CYP3A5*3 genotype before the administration of TAC may provide some clinical value for optimizing the treatment of MN patients.

Systematic Review Registration

https://inplasy.com/, identifier [INPLASY202430083].

Potential therapeutic targets for membranous nephropathy: proteome-wide Mendelian randomization and colocalization analysis

Background

The currently available medications for treating membranous nephropathy (MN) still have unsatisfactory efficacy in inhibiting disease recurrence, slowing down its progression, and even halting the development of end-stage renal disease. There is still a need to develop novel drugs targeting MN.

Methods

We utilized summary statistics of MN from the Kiryluk Lab and obtained plasma protein data from Zheng et al. We performed a Bidirectional Mendelian randomization analysis, HEIDI test, mediation analysis, Bayesian colocalization, phenotype scanning, drug bank analysis, and protein-protein interaction network.

Results

The Mendelian randomization analysis uncovered 8 distinct proteins associated with MN after multiple false discovery rate corrections. Proteins related to an increased risk of MN in plasma include ABO [(Histo-Blood Group Abo System Transferase) (WR OR = 1.12, 95%CI:1.05-1.19, FDR=0.09, PPH4 = 0.79)], VWF [(Von Willebrand Factor) (WR OR = 1.41, 95%CI:1.16-1.72, FDR=0.02, PPH4 = 0.81)] and CD209 [(Cd209 Antigen) (WR OR = 1.19, 95%CI:1.07-1.31, FDR=0.09, PPH4 = 0.78)], and proteins that have a protective effect on MN: HRG [(Histidine-Rich Glycoprotein) (WR OR = 0.84, 95%CI:0.76-0.93, FDR=0.02, PPH4 = 0.80)], CD27 [(Cd27 Antigen) (WR OR = 0.78, 95%CI:0.68-0.90, FDR=0.02, PPH4 = 0.80)], LRPPRC [(Leucine-Rich Ppr Motif-Containing Protein, Mitochondrial) (WR OR = 0.79, 95%CI:0.69-0.91, FDR=0.09, PPH4 = 0.80)], TIMP4 [(Metalloproteinase Inhibitor 4) (WR OR = 0.67, 95%CI:0.53-0.84, FDR=0.09, PPH4 = 0.79)] and MAP2K4 [(Dual Specificity Mitogen-Activated Protein Kinase Kinase 4) (WR OR = 0.82, 95%CI:0.72-0.92, FDR=0.09, PPH4 = 0.80)]. ABO, HRG, and TIMP4 successfully passed the HEIDI test. None of these proteins exhibited a reverse causal relationship. Bayesian colocalization analysis provided evidence that all of them share variants with MN. We identified type 1 diabetes, trunk fat, and asthma as having intermediate effects in these pathways.

Conclusions

Our comprehensive analysis indicates a causal effect of ABO, CD27, VWF, HRG, CD209, LRPPRC, MAP2K4, and TIMP4 at the genetically determined circulating levels on the risk of MN. These proteins can potentially be a promising therapeutic target for the treatment of MN.

Giant retinal pigment epithelium tears with membranous nephropathy: a case report and literature review

BACKGROUND

Kidney and eye diseases may be closely linked. Tears of the retinal pigment epithelium (RPE) have been reported to be related to kidney diseases, such as IgA nephropathy and light-chain deposition disease. However, pigment epithelium tears associated with membranous nephropathy have not been reported or systematically analysed.

CASE PRESENTATION

A 68-year-old man presented with decreased right eye visual acuity. Optical coherence tomography (OCT) revealed cystic macular edema, localized serous detachment of the retina and loss of the outer retinal structure in the right eye and retinal pigment epithelium detachment (PED) combined with serous detachment of the retina in the left eye. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) revealed giant RPE tears in the right eye and exudative age-related macular degeneration in the left eye. The patient also suffered from severe membranous nephropathy-autoimmune glomerulonephritis. Renal biopsy immunofluorescence revealed a roughly granular pattern, with immunoglobulin G (IgA), immunoglobulin G (IgG), IgM, complement C3(Components 3), λ light chain and κ light chain subepithelial staining.

CONCLUSIONS

It is hypothesized that severe membranous nephropathy caused immune complex deposition on the surface of Bruch membrane, resulting in weakened adhesion between the RPE and Bruch membrane and impaired RPE pump function, combined with age-related macular degeneration, leading to giant RPE tears in the right eye. Close attention should be given to the ocular condition of patients with membranous nephropathy to facilitate timely treatment and avoid serious consequences.

Traditional Chinese medicine for idiopathic membranous nephropathy: A systematic review and meta-analysis

Background

Idiopathic membranous nephropathy (IMN) is a rare autoimmune disorder that causes nephrotic syndromes in adults. Conventional immunosuppressive therapies often exhibit limited efficacy in achieving remission and may result in notable adverse reactions, warranting the exploration of novel therapeutic approaches for IMN treatment. Traditional Chinese medicine (TCM), which is extensively used for kidney disease management, is a promising alternative.

Objective

This study aimed to examine the safety and efficacy of TCM alone or in combination with Western medicine for the management of patients diagnosed with IMN.

Methods

This study employed a systematic search of English and Chinese electronic databases to identify randomized controlled trials (RCTs) that examined the application of TCM in the treatment of IMN. RCTs that met the predetermined inclusion and exclusion criteria and assessed the safety and efficacy of TCM alone or in combination with Western medicine in patients with IMN were included in the analysis. The methodological quality of the included studies was evaluated by using a risk-of-bias tool. All statistical analyses were performed using the RevMan software (version 5.4.2). The evidence was evaluated on the https://www.gradepro.org/website.

Results

This study included 29 randomized controlled trials (RCTs) involving 1982 patients with moderate methodological quality that met the inclusion criteria. The results showed that, compared to Western medicine alone therapy, the use of TCM alone or in combination with Western medicine significantly improved total remission (TR) rate (risk ratios [RR] 1.38, 95% confidence interval [CI] 1.29-1.46, I2 = 0%, P < 0.00001), complete remission (CR) rate (RR 1.78, 95% CI 1.48-2.15, I2 = 0, P < 0.00001), partial remission (PR) rate (RR 1.27, 95% CI 1.161.40, I2 = 0%, P < 0.00001), and serum albumin (ALB) levels (MD: 4.05, 95% CI: 3.02-5.09, I2 = 91%, P < 0.00001). TCM alone or in combination with Western medicine also reduced proteinuria levels (mean difference [MD]: 1.05, 95% CI: 1.30 to -0.79, I2 = 95%, P < 0.00001), serum creatinine (SCr) levels (MD: 7.47, 95% CI: 13.70 to -1.24, I2 = 97%, P = 0.02), and serum antibodies against M-type phospholipase A2 receptor levels (aPLA2Rab) (MD: 19.24, 95% CI: 33.56 to -4.93, I2 = 87%, P = 0.008). Moreover, the efficacy of combined TCM and Western medicine is superior to that of Western medicine alone in reducing the incidence of infection, hepatotoxicity, and thrombosis. Although the primary and secondary outcomes were consistent, the evidence was generally moderate.

Conclusion

The results of this study suggest that TCM alone or in combination with Western medicine may be a feasible alternative therapeutic approach for the treatment of IMN. Nevertheless, additional, rigorously designed, high-quality, and extensive clinical trials are imperative to provide substantial evidence regarding the effectiveness of TCM in managing IMN.

Recurrence of Idiopathic Membranous Nephropathy in the Kidney Allograft: A Systematic Review

INTRODUCTION

The recurrence of idiopathic membranous nephropathy (iMN) after kidney transplantation is common, although its exact clinical significance remains unclear. This systematic review aims to elucidate the effects of iMN recurrence on graft survival.

MATERIALS AND METHODS

A literature search was performed by systematically searching Medline, Scopus, Web of Science, and Google Scholar from inception. Cohort studies examining iMN recurrence after kidney transplantation were deemed eligible. Meta-analysis was performed by fitting random-effects models.

RESULTS

Twelve (12) articles published from 1995 to 2016 reporting on 139 transplant patients with recurrent iMN were included. The median time of the diagnosis of recurrent iMN was 18 months during follow-up from 35 to 120 months. Risk factors for iMN recurrence in the renal allograft are a positive serum test for anti-PLA2R antibodies pretransplant, female sex, younger age, high proteinuria pretransplant, the longest interval from initial disease to end-stage chronic kidney disease, and the combination of alleles HLA DQA1 05:01 and HLA DQB1 02:01. In the pretransplant period, 37 (26.61%) patients had a positive serum test and 18 (12.94%) patients had a positive biopsy stain for anti-PLA2R antibodies. The sensitivity of the pretransplant positive serum test for these antibodies ranges from 57% to 85.30% and the specificity is 85.10-100%. A total of 81.80% of patients who received rituximab as treatment for iMN recurrence achieved complete and partial remission, while 18.20% had no response to treatment. iMN recurrence was not associated with significantly different rates of graft loss (odds ratio = 1.03, 95% CI: 0.52-2.04, p = 0.524, I2 = 0.00%). Recurrence of iMN was not associated with increased risk of graft loss independently of whether patients were treated with rituximab (OR: 0.98, 95% CI: 0.39-2.50, I2: 0%) or not (OR: 1.22, 95% CI: 0.58-2.59, I2: 3.8%). Patients with iMN recurrence who achieved remission had significantly reduced risk of graft loss (OR: 0.14, 95% CI: 0.03 to 0.73).

CONCLUSION

The main outcome from this systematic review is that there is no statistically significant difference in graft survival in patients with iMN recurrence compared to those without recurrence in long-term follow-up. The achievement of remission is associated with significantly reduced risk of graft loss.

Anti-Idiotypic mRNA Vaccine to Treat Autoimmune Disorders

The 80+ existing autoimmune disorders (ADs) affect billions with little prevention or treatment options, except for temporary symptomatic management, leading to enormous human suffering and a monumental financial burden. The autoantibodies formed in most ADs have been identified, allowing the development of novel anti-idiotypic antibodies to mute the autoantibodies using vaccines. Nucleoside vaccines have been successfully tested as antigen-specific immunotherapies (ASI), with mRNA technology offering multi-epitope targeting to mute multiple autoantibodies. This paper proposes using mRNA technology to produce anti-idiotypic antibodies with broad effectiveness in preventing and treating them. This paper delves into the state-of-the-art mRNA design strategies used to develop novel ASIs by selecting appropriate T cell and B cell epitopes to generate anti-idiotypic antibodies. The low cost and fast development of mRNA vaccines make this technology the most affordable for the global control of ADs.

Downregulation of TRPC6 regulates ERK1/2 to prevent sublytic C5b‑9 complement complex‑induced podocyte injury through activating autophagy

Idiopathic membranous nephropathy (IMN) is a common glomerular disease, in which 50-60% of patients can progress to end-stage renal disease within 10-20 years, seriously endangering human health. Podocyte injury is the direct cause of IMN. Sublytic C5b-9 complement complex induces damage in podocytes' structure and function. In sublytic C5b-9 treated podocytes, the expression of canonical transient receptor potential 6 (TRPC6) is increased. However, the specific mechanism of TRPC6 in sublytic C5b-9 treated podocytes is unclear. The present study aimed to reveal the effect and mechanism of TRPC6 on sublytic C5b-9-induced podocytes. Normal human serum was stimulated using zymosan to form C5b-9. A lactate dehydrogenase release assay was used to examine C5b-9 cytotoxicity in podocytes. The RNA and protein expression levels were analyzed using reverse transcription-quantitative PCR, western blotting and immunofluorescent assay, respectively. Cell Counting Kit-8 assay and flow cytometry were carried out to test the viability and apoptosis of podocytes, respectively. Transmission electron microscopy was used to observe autophagic vacuole. F-actin was tested through phalloidin staining. Sublytic C5b-9 was deposited and TRPC6 expression was boosted in podocytes stimulated through zymosan activation serum. Knockdown of TRPC6 raised the viability and reduced the apoptosis rate of sublytic C5b-9-induced podocytes. Meanwhile, transfection of small-interfering (si)TRPC6 facilitated autophagy progression and enhanced the activation of cathepsin B/L in sublytic C5b-9-induced podocytes. The phosphorylation level of ERK1/2 was receded in siTRPC6 and sublytic C5b-9 co-treated podocytes. Moreover, the addition of the ERK1/2 activator partially reversed the effect of TRPC6 inhibition on sublytic C5b-9-induced podocytes. TRPC6 knockdown reduced the damage of sublytic C5b-9 to podocytes by weakening the ERK1/2 phosphorylation level to activate autophagy. These results indicated that targeting TRPC6 reduced the injury of sublytic C5b-9 on podocytes.

Collagen IV of basement membranes: II. Emergence of collagen IVα345 enabled the assembly of a compact GBM as an ultrafilter in mammalian kidneys

The collagen IVα345 (Col-IVα345) scaffold, the major constituent of the glomerular basement membrane (GBM), is a critical component of the kidney glomerular filtration barrier. In Alport syndrome, affecting millions of people worldwide, over two thousand genetic variants occur in the COL4A3, COL4A4, and COL4A5 genes that encode the Col-IVα345 scaffold. Variants cause loss of scaffold, a suprastructure that tethers macromolecules, from the GBM or assembly of a defective scaffold, causing hematuria in nearly all cases, proteinuria, and often progressive kidney failure. How these variants cause proteinuria remains an enigma. In a companion paper, we found that the evolutionary emergence of the COL4A3, COL4A4, COL4A5, and COL4A6 genes coincided with kidney emergence in hagfish and shark and that the COL4A3 and COL4A4 were lost in amphibians. These findings opened an experimental window to gain insights into functionality of the Col-IVα345 scaffold. Here, using tissue staining, biochemical analysis and TEM, we characterized the scaffold chain arrangements and the morphology of the GBM of hagfish, shark, frog, and salamander. We found that α4 and α5 chains in shark GBM and α1 and α5 chains in amphibian GBM are spatially separated. Scaffolds are distinct from one another and from the mammalian Col-IVα345 scaffold, and the GBM morphologies are distinct. Our findings revealed that the evolutionary emergence of the Col-IVα345 scaffold enabled the genesis of a compact GBM that functions as an ultrafilter. Findings shed light on the conundrum, defined decades ago, whether the GBM or slit diaphragm is the primary filter.

Prognostic prediction of idiopathic membranous nephropathy using interpretable machine learning

BACKGROUND

Established prognostic models of idiopathic membranous nephropathy (IMN) were limited to traditional modeling methods and did not comprehensively consider clinical and pathological patient data. Based on the electronic medical record (EMR) system, machine learning (ML) was used to construct a risk prediction model for the prognosis of IMN.

METHODS

Data from 418 patients with IMN were diagnosed by renal biopsy at the Fifth Clinical Medical College of Shanxi Medical University. Fifty-nine medical features of the patients could be obtained from EMR, and prediction models were established based on five ML algorithms. The area under the curve, recall rate, accuracy, and F1 were used to evaluate and compare the performances of the models. Shapley additive explanation (SHAP) was used to explain the results of the best-performing model.

RESULTS

One hundred and seventeen patients (28.0%) with IMN experienced adverse events, 28 of them had compound outcomes (ESRD or double serum creatinine (SCr)), and 89 had relapsed. The gradient boosting machine (LightGBM) model had the best performance, with the highest AUC (0.892 ± 0.052, 95% CI 0.840-0.945), accuracy (0.909 ± 0.016), recall (0.741 ± 0.092), precision (0.906 ± 0.027), and F1 (0.905 ± 0.020). Recursive feature elimination with random forest and SHAP plots based on LightGBM showed that anti-phospholipase A2 receptor (anti-PLA2R), immunohistochemical immunoglobulin G4 (IHC IgG4), D-dimer (D-DIMER), triglyceride (TG), serum albumin (ALB), aspartate transaminase (AST), β2-microglobulin (BMG), SCr, and fasting plasma glucose (FPG) were important risk factors for the prognosis of IMN. Increased risk of adverse events in IMN patients was correlated with high anti-PLA2R and low IHC IgG4.

CONCLUSIONS

This study established a risk prediction model for the prognosis of IMN using ML based on clinical and pathological patient data. The LightGBM model may become a tool for personalized management of IMN patients.

Correlation Analysis between Intrarenal Small Artery Intimal Thickening and Clinicopathological Features and Prognosis in Primary Membranous Nephropathy Patients

BACKGROUND

Primary membranous nephropathy (PMN) is the most common pathological type of nephrotic syndrome in adults. Intrarenal small artery intimal thickening can be observed in most renal biopsies. The purpose of this study was to investigate the association between intrarenal small artery intimal thickening and clinicopathological features and prognosis in PMN patients.

METHODS

Data were continuously collected from patients who were diagnosed with PMN in Shenzhen Second People's Hospital (The First Affiliated Hospital of Shenzhen University) from 2008 to 2021 for a retrospective cohort study. Regression analysis and survival analysis were used to analyze the relationship between intrarenal small artery intimal thickening and renal prognosis in PMN patients.

RESULTS

300 PMN patients were enrolled in this study, including 165 patients (55%) with intrarenal small artery intimal thickening. Patients with intimal thickening were older, with higher BMI, systolic blood pressure and diastolic blood pressure, serum uric acid, a higher proportion of hypertension, acute kidney injury, nephrotic syndrome, more urine protein, and lower eGFR. Multivariate Cox regression analysis showed that after adjusting for age, gender, hypertension, BMI, urine protein, eGFR, and the use of ACEI/ARB and hormone immunosuppressants, intimal thickening was a risk factor for renal prognosis in PMN patients (HR = 3.68, 95% CI 1.36-9.96, p < 0.05). Kaplan-Meier survival curve analysis showed that the incidence of reaching the renal composite outcome was higher in the intimal thickening group (p < 0.05).

CONCLUSION

The prognosis of PMN patients with intrarenal small artery intimal thickening is worse, so early intervention is very important for these patients.

Unusual Clinical Presentation of Nephrotic Syndrome With Significant Renal Vein Thrombosis in a Young Male: A Case Report and Literature Review

Primary membranous glomerulopathy is the most common cause of idiopathic nephrotic syndrome, with increasing recognition as an autoimmune-mediated disease. We present the case of a 31-year-old Hispanic male with no prior medical or family history, presenting with one month of dyspnea on exertion, lower extremity, and periorbital edema with a recent diagnosis of pulmonary embolism. Upon further imaging, renal vein thrombosis was discovered with significant lab dysfunction concerning nephrotic syndrome. Further, a workup of kidney biopsy and serum antibody levels revealed the cause to be anti-phospholipase A2 receptor (PLA2R)-mediated.

The Role of PLA2R in Primary Membranous Nephropathy: Do We Still Need a Kidney Biopsy?

Membranous nephropathy (MN) is the most prevalent cause of nephrotic syndrome amongst the non-diabetic adult population. A fifth of idiopathic nephrotic syndrome cases can be attributed to MN, rising to more than 40% in older patients over 60 years. Most MN cases are classified as being of a primary cause, where there is absence of a secondary disease process explaining its manifestation. Traditionally, the standard approach of diagnosing MN involves performing a kidney biopsy as histological evaluation offers not only conclusive evidence of the diagnosis but also provides valuable information regarding disease chronicity and the presence of any other kidney histopathological features. Nevertheless, kidney biopsy is an invasive procedure which poses risks for the patient including bleeding and pain and bears greater costs for the health system. The identification of the phospholipase A2 receptor (PLA2R) antigen in 2009 was a landmark discovery, one which has evolved our understanding of the disease processes in MN and subsequently our management approach of this condition. Antibodies against PLA2R (PLA2RAb) have since emerged as an attractive non-invasive test option to be applied for the diagnosis and prognostication of primary MN. However, much debate and unknowns remain about the accuracy and reliability of testing for PLA2RAb across various primary MN scenarios. We provide a review summarizing the historical journey of PLA2R in relation to its significance in primary MN and, more importantly, evidence emerging over the years which contemplated the role of PLA2RAb as a diagnostic and prognostic tool in primary MN.

The Prognostic Value of Anti-PLA2R Antibodies Levels in Primary Membranous Nephropathy

Anti-PLA2R antibodies (Ab) are a diagnostic and prognostic biomarker in primary membranous nephropathy (PMN). We assessed the relationship between the levels of anti-PLA2R Ab at diagnosis and different variables related to disease activity and prognosis in a western population of PMN patients. Forty-one patients with positive anti-PLA2R Ab from three nephrology departments in Israel were enrolled. Clinical and laboratory data were collected at diagnosis and after one year of follow-up, including serum anti-PLA2R Ab levels (ELISA) and glomerular PLA2R deposits on biopsy. Univariable statistical analysis and permutation-based ANOVA and ANCOVA tests were performed. The median [(interquartile range (IQR)) age of the patients was 63 [50-71], with 28 (68%) males. At the time of diagnosis, 38 (93%) of the patients had nephrotic range proteinuria, and 19 (46%) had heavy proteinuria (≥8 gr/24 h). The median [IQR] level of anti-PLA2R at diagnosis was 78 [35-183] RU/mL. Anti-PLA2R levels at diagnosis were correlated with 24 h proteinuria, hypoalbuminemia and remission after one year (p = 0.017, p = 0.003 and p = 0.034, respectively). The correlations for 24 h proteinuria and hypoalbuminemia remained significant after adjustment for immunosuppressive treatment (p = 0.003 and p = 0.034, respectively). Higher levels of anti-PLA2R Ab at diagnosis in patients with active PMN from a western population are associated with higher proteinuria, lower serum albumin and remission one year after the diagnosis. This finding supports the prognostic value of anti-PLA2R Ab levels and their possible use in stratifying PMN patients.

The efficacy and safety of Sanqi Qushi Granule in patients with idiopathic membranous nephropathy --protocol of a multicenter, randomized control trial (SQ-AUTUMN)

BACKGROUND

Adult nephropathy is mainly caused by idiopathic membranous nephropathy (IMN). In cases of proteinuria, Modified Ponticelli Regimens (MPR) are often successful. However, it can cause adverse side effects. Oral Sanqi Qushi Granule (SQG) with MPR is effective in patients with IMN. However, whether it can improve the remission rate of IMN and shorten the remission time is unknown. In this trial, SQG with MPR on IMN will be evaluated clinically for its efficacy and safety.

METHODS

We will randomly assign IMN patients who meet the criteria to receives SQG plus cyclical Cyclophosphamide (CTX)/steroids or with placebo plus cyclical CTX/steroids for 6 months. A 12-month follow-up will be conducted on them. Status of remission will be used to assess treatment efficacy.

DISCUSSION

This study aims to appraise whether treatment with SQG plus cyclical CTX/steroids is superior to placebo plus cyclical CTX/steroids in the remission rate of patients with adult IMN. Adverse events of SQG plus MPR will be also evaluated for further researches about Chinese Medicine and MPR on whether it can improve the remission rate of IMN in half a year and shorten the remission time and relieve adverse effects will also be clarified.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200061953 . Registered on 13 July 2022.

Efficacy of low or heavy rituximab‑based protocols and comparison with seven regimens in idiopathic membranous nephropathy: a systematic review and network meta-analysis

OBJECTIVE

Numerous studies have demonstrated the efficiency of tacrolimus + rituximab and rituximab in idiopathic membranous nephropathy (IMN). But optimal dosages of rituximab for IMN are still controversial. This network meta-analysis (NMA) was conducted to compare the efficacy of different rituximab dosages and other main treatments in IMN treatment.

METHODS

Randomized controlled trials (RCTs) and observational studies analyzing nine therapeutic regimens for IMN were included from some databases. Network comparisons were performed to analyze the rates of total remission (TR) and relapse rate. The surface under the cumulative ranking area (SUCRA) was calculated to rank interventions.

RESULTS

Twelve RCTs and 12 observational studies involving 1724 patients were pooled for comparison of 9 interventions. This NMA demonstrated steroids + tacrolimus was ranked first in the aspect of total remission at 6 months (92%) and 12 months (81.3%). The total remission rate associated with tacrolimus + rituximab increased rapidly between the sixth (SUCRA 22.5%) and the twelfth month (SUCRA 63.9%). Tacrolimus and cyclosporine A were associated with higher total remission at 6 months (78.8% and 65.4%, separately) and decreased at 12 months (58.1 and 34.9%, separately). Steroids + cyclophosphamide, rituximab (Heavy dose) and rituximab (Low dose) had stable remission rates at 6 (63.7%, 46.6%, and 19.4%) and 12 months (SUCRA 66.9%, 39.6%, and 28.8%). Tacrolimus and cyclosporine A were associated with a significantly higher risk of relapse than that with steroids + cyclophosphamide, rituximab (Heavy dose), and rituximab (Low dose).

CONCLUSIONS

For IMN in adults, steroids + tacrolimus was ranked first in the aspect of total remission, followed by steroids + cyclophosphamide and steroids + cyclosporine A. The TR associated with rituximab (Heavy and Low dosage) at 12 months was higher than that at 6 months. And rituximab (Heavy dose) achieves a higher rate of total remission than that of rituximab (Low dose).

From KDIGO 2012 towards KDIGO 2021 in idiopathic membranous nephropathy guidelines: what has changed over the last 10 years?

The recommendations in the Kidney Disease: Improving Global Outcomes (KDIGO) 2021 guidelines regarding Idiopathic Membranous Nephropathy (IMN) management include significant changes as compared to those published in 2012. According to the recent guidelines, a biopsy is not always needed for IMN diagnosis; since diagnosis can be allowed for by the detection of circulating antibodies against the M-type transmembrane phospholipase A2 receptor (anti-PLA2R). Moreover, alterations in anti-PLA2R concentrations, along with other serum and urinary markers, may guide further follow-up. The findings of numerous recent studies which compared different immunosuppressive treatments resulted in substantial changes in treatment indications in the KDIGO 2021 guidelines, suggesting the stratification of patients into four risk categories. The definition of resistant cases and relapses was likewise modified. All the above will lead to a more granular and personalized approach, whose results need to be tested over time. In this commentary, we discuss the changes in the 2012 and 2021 guidelines, adding information from the most recent literature.

Computer-aided diagnosis of primary membranous nephropathy using expert system

BACKGROUND

The diagnosis of primary membranous nephropathy (PMN) often depends on invasive renal biopsy, and the diagnosis based on clinical manifestations and target antigens may not be completely reliable as it could be affected by uncertain factors. Moreover, different experts could even have different diagnosis results due to their different experiences, which could further impact the reliability of the diagnosis. Therefore, how to properly integrate the knowledge of different experts to provide more reliable and comprehensive PMN diagnosis has become an urgent issue.

METHODS

This paper develops a belief rule-based system for PMN diagnosis. The belief rule base is constructed based on the knowledge of the experts, with 9 biochemical indicators selected as the input variables. The belief rule-based system is developed of three layers: (1) input layer; (2) belief rule base layer; and (3) output layer, where 9 biochemical indicators are selected as the input variables and the diagnosis result is provided as the conclusion. The belief rule base layer is constructed based on the knowledge of the experts. The final validation was held with gold pattern clinical cases, i.e., with known and clinically confirmed diagnoses.

RESULTS

134 patients are used in this study, and the proposed method is defined by its sensitivity, specificity, accuracy and area under curve (AUC), which are 98.0%, 96.9%, 97.8% and 0.93, respectively. The results of this study present a novel and effective way for PMN diagnosis without the requirement of renal biopsy.

CONCLUSIONS

Through analysis of the diagnosis results and comparisons with other methods, it can be concluded that the developed system could help diagnose PMN based on biochemical indicators with relatively high accuracy.

Evaluating Efficacy and Safety of Tacrolimus Treatment in Membranous Nephropathy: Results of a Retrospective Study of 182 Patients

Purpose

Tacrolimus is recommended by KDIGO Clinical Practice Guidelines as an initial therapy for the treatment of membranous nephropathy (MN). However, little is known about the factors that influence response and recurrence of the disease after tacrolimus therapy, and there are limited data regarding the duration of tacrolimus treatment. Here, we present a real-world retrospective cohort study of 182 MN patients treated with tacrolimus, aiming to assess the efficacy and safety of tacrolimus in the treatment of MN.

Patients and Methods

The clinical data of 182 patients with MN treated with tacrolimus and followed up for at least one year were analyzed retrospectively for the efficacy and safety of tacrolimus.

Results

The mean follow-up period was 27.3 (19.3-41.6) months. A total of 154 patients (84.6%) achieved complete or partial remission, and 28 patients (15.4%) did not. Multivariate Cox regression analysis showed that male and higher baseline BMI were independently associated with lower, while higher serum albumin was associated with higher probability of remission. Among the responders, 56 patients (36.4%) relapsed. After adjustments for age and sex, Cox regression analysis revealed that the longer period of full-dose tacrolimus was administered, the lower the incidence of relapse. However, high levels of serum creatinine and proteinuria at the onset of tacrolimus discontinuation were risk factors for relapse. During the treatment of tacrolimus, a decline in renal function (≥50% increase in serum creatinine after the onset of tacrolimus treatment) was the most common adverse reaction, observed in 20 (11.0%) patients, followed by elevated blood glucose and infection, but the latter two occurred mostly during treatment with tacrolimus plus corticosteroids.

Conclusion

Tacrolimus is effective in the treatment of MN, but the relapse rate is high. Clinical studies with larger sample sizes are needed to further explore the use of tacrolimus in the treatment of membranous nephropathy.

The Role of Heme Oxygenase-1 as an Immunomodulator in Kidney Disease

The protein heme oxygenase (HO)-1 has been implicated in the regulations of multiple immunological processes. It is well known that kidney injury is affected by immune mechanisms and that various kidney-disease forms may be a result of autoimmune disease. The current study describes in detail the role of HO-1 in kidney disease and provides the most recent observations of the effect of HO-1 on immune pathways and responses both in animal models of immune-mediated disease forms and in patient studies.

A low rate of end-stage kidney disease in membranous nephropathy: A single centre study over 2 decades

INTRODUCTION

Membranous nephropathy is the commonest cause of nephrotic syndrome in non-diabetic Caucasian adults over the age of 40 years. Primary membranous nephropathy is limited to the kidneys. Clinical management aims to induce remission, either spontaneously with supportive care, or with immunosuppression. Here, we describe the natural history of this condition in a large tertiary centre in the UK.

METHODS

178 patients with primary membranous nephropathy were identified over 2 decades. We collected data on demographics, baseline laboratory values, treatment received and outcomes including progression to renal replacement therapy and death. Analysis was performed on the whole cohort and specific subgroups. Univariate and multivariate Cox regression was also performed.

RESULTS

Median age was 58.3 years with 63.5% male. Median baseline creatinine was 90μmol/L and urine protein-creatinine ratio 664g/mol. Remission (partial or complete) was achieved in 134 (75.3%), either spontaneous in 60 (33.7%) or after treatment with immunosuppression in 74 (41.6%), and of these 57 (42.5%) relapsed. Progression to renal replacement therapy was seen in 10.1% (much lower than classically reported) with mortality in 29.8%. Amongst the whole cohort, those who went into remission had improved outcomes compared to those who did not go into remission (less progression to renal replacement therapy [4.5% vs 28%] and death [20.1% vs 67%]. Those classified as high-risk (based on parameters including eGFR, proteinuria, serum albumin, PLA2R antibody level, rate of renal function decline) also had worse outcomes than those at low-risk (mortality seen in 52.6% vs 10.8%, p<0.001). The median follow-up period was 59.5 months.

CONCLUSION

We provide a comprehensive epidemiologic analysis of primary membranous nephropathy at a large tertiary UK centre. Only 10.1% progressed to renal replacement therapy. For novelty, the KDIGO risk classification was linked to outcomes, highlighting the utility of this classification system for identifying patients most likely to progress.

An Unusual Progression of Membranous Nephropathy

Membranous glomerulopathy is one of the commonest causes of nephrotic syndrome and chronic renal insufficiency in adults. There has been documented evidence of a poorer prognosis with factors such as male gender, advanced age, increased blood pressure and persistent loss of proteins in the urine, but the overall prognosis of this condition is excellent. Herein, we present the case of a 20-year-old female patient who was diagnosed with primary membranous nephropathy. Normally, cases of primary membranous nephropathy have good outcomes with conservative management and immunosuppressants but our case had a worsening course and a delayed response even with immunosuppressive treatment. This case has been recorded due to its unusual presentation, unnatural course, and outcomes contrary to what is seen in routine clinical practice.

Histological Findings in Kidney Biopsies of Patients with Monoclonal Gammopathy—Always a Surprise

Background: The simultaneous occurrence of impaired kidney function and paraproteinemia is common in our constantly aging society. Both can be independent entities; however, renal insufficiency can also be caused by the paraprotein. We assessed all kidney biopsies in patients with monoclonal gammopathy in our clinic over the past 20 years and evaluated the histological results. Methods: Biopsies were systematically performed in nearly all patients with paraproteinemia and impaired kidney function (n = 178). The histological findings were systematically evaluated and correlated with the initial clinical diagnosis. Results: We found cast nephropathy (CN) in n = 66 (37.1%) biopsies, AL amyloidosis in n = 31 (17.4%) biopsies, monoclonal immunoglobulin deposition disease (MIDD) in n = 7 (3.9%) biopsies and other renal diseases (ORDs) in n = 74 (41.6%) biopsies. In the latter group, paraprotein-associated changes were found in 37 of 74 (50%) patients, whereas paraprotein-independent changes were found in the other half. Whereas, in the group of patients with MGUS, the findings were heterogenous, most of the patients with known multiple myeloma (MM) or B-NHL showed malignancy-associated changes in the kidney. The biopsy changed the diagnoses in a significant proportion of the patients: The group of patients with MM grew from 71 to 112 patients, whereas, in the MGUS group, only 31 of 44 patients remained. Conclusion: Kidney biopsies in patients with paraproteinemia and renal impairment show a wide range of findings that can lead to a change in diagnosis.

Manejo de la nefropatía membranosa idiopática con ciclofosfamida endovenosa

Introducción: las enfermedades glomerulares primarias ocupan la tercera causa de enfermedad renal crónica, siendo el origen más común de síndrome nefrótico en Colombia la nefropatía membranosa (NM). El tratamiento de la NM con ciclofosfamida endovenosa es una opción terapéutica, que no ha sido descrita en nuestra población. Objetivo: determinar la respuesta al tratamiento con ciclofosfamida endovenosa en la NM idiopática en el Hospital de San José de Bogotá en el periodo enero 2000 a enero 2019.  Metodología: estudio tipo serie de casos donde se incluyeron todos los pacientes adultos con diagnóstico de NM idiopática por biopsia renal tratados con ciclofosfamida endovenosa en el periodo descrito Resultados: ocho pacientes se incluyeron en el estudio de los cuales 50% eran mujeres, la mediana de edad de presentación fue 32,5 (RIQ:26-45) años. El 100% de los pacientes presentaron remisión parcial o completa, distribuidos así: 62,5% completa y 37,5% parcial. La mediana en el aumento de la tasa de filtración glomerular posterior al uso de ciclofosfamida endovenosa fue 9 (RIQ: 1-20,2) mL/min/1.73 m2. La sobrevida renal fue 100% y el porcentaje de recaída 12,5%. Conclusiones: el uso mensual de ciclofosfamida endovenosa es una opción en el manejo de la NM idiopática con un porcentaje de remisión parcial o completa de 100%, utilizando una dosis mediana acumulada de 93 (RIQ: 65,6-125) mg/k.     

Knockdown of circ_CDYL Contributes to Inhibit Angiotensin II-Induced Podocytes Apoptosis in Membranous Nephropathy via the miR-149-5p/TNFSF11 Pathway

ABSTRACT

Circular RNAs (circRNAs) have been verified as vital regulators in various diseases, including membranous nephropathy (MN). Therefore, the role of circ_CDYL in podocyte apoptosis and MN was investigated. The real-time quantitative polymerase chain reaction was performed to measure the expression of circ_CDYL, microRNA-149-5p (miR-149-5p), and tumor necrosis factor superfamily member 11 (TNFSF11) in podocytes. In addition, angiotensin II (Ang II) was used to induce apoptosis of podocytes. The apoptosis-related protein expression was quantified by western blot assay. The apoptosis of podocytes was evaluated by flow cytometry assay. The interaction relationship between miR-149-5p and circ_CDYL or TNFSF11 was confirmed by dual-luciferase reporter assay. Circ_CDYL was significantly overexpressed in MN patients and Ang II-induced podocytes compared with control groups. Importantly, loss-of-functional experiments indicated that knockdown of circ_CDYL protected podocytes from Ang II-induced apoptosis. MiR-149-5p was verified as target of circ_CDYL and negatively correlated with circ_CDYL expression in MN patients. Knockdown of circ_CDYL-mediated effects on Ang II-induced podocyte cells were abolished by silencing miR-149-5p. Besides, the upregulation of miR-149-5p could suppress apoptosis in Ang II-induced podocyte cells by targeting TNFSF11. Under Ang II stimulation, the upregulation of TNFSF11 could increase the expression of TNFSF11 and induce apoptosis in circ_CDYL-silencing podocytes. Our results confirmed that circ_CDYL specifically targeted miR-149-5p/TNFSF11 pathway to regulate Ang II-induced apoptosis in podocytes, which might be useful diagnostic biomarkers in MN.

The Association Between Serum Complement 4 and Kidney Disease Progression in Idiopathic Membranous Nephropathy: A Multicenter Retrospective Cohort Study

Introduction

Complement system plays an important role in the pathogenesis of idiopathic membranous nephropathy (IMN), however, the relationship between serum complement 4 (C4) and kidney disease progression in IMN is unclear. This study aims to investigate the association of serum C4 level with the risk of kidney disease progression among patients with IMN.

Methods

The retrospective cohort assessed 1,254 participants with biopsy-proven IMN from three centers in Xi ‘an, Shaanxi Province, China. Baseline serum C4 levels were measured at renal biopsy. The association between baseline serum C4 and the risk of renal function progression, defined as a 30% decline in renal function or end stage renal disease, was evaluated in Cox proportional hazards models.

Results

A total of 328 patients with IMN and nephrotic proteinuria were eligible, and 11.3% (37/328) of them attained the renal function progression events after a median follow-up of 51 months (37-59 months). After adjustment for other confounders, a higher value of serum C4 was independently associated with a higher risk of renal function progression event with a hazard ratio (HR) of 4.76 (95% confidence interval [95% CI], 1.77-12.79) per natural log-transformed C4. In reference to the low level of C4, the adjusted HRs were 2.72 (95% CI, 1.02-7.24) and 3.65 (95% CI, 1.39-9.60), respectively, for the median and high levels of C4 (P for trend=0.008). Additionally, the results were robust and reliable in the sensitivity and subgroup analyses.

Conclusion

Among patients with IMN and nephrotic proteinuria, serum C4 at renal biopsy is an independent predictor for kidney disease progression regardless of other confounders.

Clinical Evaluation of Antiphospholipase A2 Receptor IgG4 level and Its IgG4-to-IgG Ratio Based on Quantitative Immunoassays in Idiopathic Membranous Nephropathy

Background. Phospholipase A2 receptor (PLA2R), located at the membrane of glomerular podocyte, is the major autoantigen of idiopathic membranous nephropathy (IMN), and its antibodies with a predominant IgG4 subclass lead to pathological lesions. Further studies could be performed to validate the clinical values of PLA2R-IgG, PLA2R-IgG4, and PLA2R-IgG4-to-IgG ratios, as ultrasensitive and quantitative immunoassays for PLA2R antibodies have been well established in our previous work. Methods. A cohort of 58 IMN patients, 30 of whom were followed from 3 to 42 months, was assessed for serum PLA2R-IgG and -IgG4 levels, and the ratio of PLA2R-IgG4/-IgG combined with relative clinicopathological indicators. Results. Serum PLA2R-IgG4 level was significantly correlated with glomerular PLA2R staining. In addition, it was strongly correlated with PLA2R-IgG and its ratio. PLA2R-IgG and -IgG4 levels were both correlated with high-density lipoprotein and erythrocyte sedimentation rates. The ratio at the first diagnosis can predict the remission, and its efficacy overmatched PLA2R-IgG4. In the survival curves, negative results for the ratio or PLA2R-IgG4 at the first diagnosis demonstrated higher remission rates. Conclusion. Serum PLA2R-IgG4 concentration may replace renal PLA2R immunohistochemistry in IMN diagnosis. We propose that the PLA2R-IgG4-to-IgG ratio and PLA2R-IgG4 could be novel indicators for remission prediction in clinical practice.

Treatment resistant M-type phospholipase A2 receptor associated membranous nephropathy responds to obinutuzumab: a report of two cases

Background

Membranous Nephropathy (MN) is a common cause of nephrotic syndrome (NS) in adults. Recognition of MN as an antibody mediated autoimmune disease has enabled the introduction of anti-B-cell therapy. Rituximab, a type I anti-CD20 antibody has been used in the management of MN, but has a 35-45% failure rate. Obinutuzumab, a fully humanised type II anti-CD20 monoclonal antibody produces greater CD20 depletion and is superior to rituximab in the treatment of certain B-cell malignancies. In the two reports published to date involving nine patients with M-type phospholipase A2 receptor (PLA2R) associated MN (six of whom were rituximab resistant), treatment with obinutuzumab lead to immunological remission (IR) in 75% of patients, with improvement of proteinuria, normalisation of serum albumin and stable renal function in all patients.

Case presentation

We report on two cases of PLA2R-associated MN, two males aged 33 and 36-years, who presented with NS and bilateral sub massive pulmonary emboli requiring anticoagulation. Both were diagnosed serologically as PLA2R-associated MN where a renal biopsy was initially deferred due to bleeding risk on anticoagulation, but later confirmed. Both patients were refractory to multiple lines of therapy including rituximab, but achieved IR, normalistation of serum albumin, improved proteinuria and stable renal function with obinutuzumab.

Conclusions

Our cases add to the current limited literature on the successful use of obinutuzumab in PLA2R associated MN refractory to standard therapy including rituximab.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02761-3.

New Insights into the Treatment of Glomerular Diseases: When Mechanisms Become Vivid

Treatment for glomerular diseases has been extrapolated from the experience of other autoimmune disorders while the underlying pathogenic mechanisms were still not well understood. As the classification of glomerular diseases was based on patterns of juries instead of mechanisms, treatments were typically the art of try and error. With the advancement of molecular biology, the role of the immune agent in glomerular diseases is becoming more evident. The four-hit theory based on the discovery of gd-IgA1 gives a more transparent outline of the pathogenesis of IgA nephropathy (IgAN), and dysregulation of Treg plays a crucial role in the pathogenesis of minimal change disease (MCD). An epoch-making breakthrough is the discovery of PLA2R antibodies in the primary membranous nephropathy (pMN). This is the first biomarker applied for precision medicine in kidney disease. Understanding the immune system's role in glomerular diseases allows the use of various immunosuppressants or other novel treatments, such as complement inhibitors, to treat glomerular diseases more reasonable. In this era of advocating personalized medicine, it is inevitable to develop precision medicine with mechanism-based novel biomarkers and novel therapies in kidney disease.

Revisiting immunological and clinical aspects of membranous nephropathy

Idiopathic or primary membranous nephropathy (IMN) is one of the most frequent causes of nephrotic syndrome in adults and the elderly. It is characterized by a thickening of the wall of the glomerular capillaries due to the presence of immune complex deposits. 85% of membranous nephropathy cases are classified as primary or idiopathic (IMN). The rest are of secondary origin (SMN), caused by autoimmune conditions or malignant tumors as lung cancer, colon and melanomas. It is an organ-specific autoimmune disease in which the complement system plays an important role with the formation of the membrane attack complex (MAC; C5b-9), which produces an alteration of the podocyte structure. The antigen responsible for 70-80% of IMN is a podocyte protein called M-type phospholipase A2 receptor (PLA2R). More recently, another podocyte antigen has been identified, the "Thrombospondin type-1 domain-containing 7A" (THSD7A), which is responsible for 10% of the cases of negative IMN for anti- PLA2R.

Comparison of cyclophosphamide and calcineurin inhibitors for idiopathic membranous nephropathy: A protocol for systematic review and meta-analysis

BACKGROUND

Idiopathic membranous nephropathy (IMN) is one of the leading causes of nephrotic syndrome in adults. We performed a protocol for systematic review and meta-analysis to compare the efficacy and safety of cyclophosphamide (CTX) with calcineurin inhibitors (CNIs) in the treatment of IMN.

METHODS

PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and 3 Chinese databases (WanFang Data, Chongqing VIP and China National Knowledge Infrastructure) were searched from inception through January 2022 to identify randomized controlled trials that compared CTX with CNIs for patients with IMN. Systematic review and meta-analysis of the data will be performed in RevMan software (version 5.3) according to the preferred reporting items of systematic reviews and meta-analysis guidelines. Two authors independently performed the literature searching, data extraction, and quality evaluation. Risk of bias was assessed using the Cochrane Risk of Bias Tool for randomized controlled trials.

RESULTS

The results will be submitted to a peer-reviewed journal once completed.

CONCLUSION

The conclusion of our research will provide evidence to help physicians to decide between CTX and CNIs therapy regimens for IMN patients.

OPEN SCIENCE FRAMEWORK REGISTRATION NUMBER

10.17605/OSF.IO/G584K.

Integrated UPLC-MS and Network Pharmacology Approach to Explore the Active Components and the Potential Mechanism of Yiqi Huoxue Decoction for Treating Nephrotic Syndrome

Background: Yiqi Huoxue Decoction (YQHXD) is a traditional Chinese medicine that promotes blood circulation, removes blood stasis, facilitates diuresis, and alleviates edema. It is composed of 10 herbal medicines and has extensive application in treating nephrotic syndrome (NS). However, the active components and the potential mechanism of YQHXD for treating NS remain unclear.

Methods: We set up a sensitive and rapid method based on Ultra-High Performance Liquid Chromatograph-Mass (UPLC-MS) to identify the compounds in YQHXD and constituents absorbed into the blood. Disease genes were collected through GeneCards, DisGeNET, and OMIM database. Genes of compounds absorbed into blood were predicted by the TCMSP database. We constructed Disease-Drug-Ingredient-Gene (DDIG) network using Cytoscape, established a Protein-protein interaction (PPI) network using String, Gene biological process (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was performed using DAVID. Cellular experiments were performed to validate the results of network pharmacology.

Result: A total of 233 compounds in YQHXD and 50 constituents absorbed into the blood of rats were identified. The 36 core targets in the PPI network were clustered in the phosphatidylinositol 3 kinase-RAC serine/threonine-protein kinase (PI3K-AKT) and nuclear factor kappa-B (NF-κB) signaling pathways. Luteolin, Wogonin, Formononetin, and Calycosin were top-ranking components as potentially active compounds.

Conclusion: The results of our studies show that YQHXD is able to enhance renal function, alleviate podocyte injury, and improve adriamycin nephrotic syndrome.

Treatment of Idiopathic Membranous Nephropathy for Moderate or Severe Proteinuria: A Systematic Review and Network Meta-Analysis

OBJECTIVE

Numerous studies have demonstrated that the efficacy of drugs differs in idiopathic membranous nephropathy (IMN) patients with moderate or high proteinuria. However, there is no systematic comparison confirming it. This network meta-analysis (NMA) was performed to respectively compare the efficacy of ten IMN treatments in patients with moderate and high proteinuria and compare the risk of adverse events with 10 IMN regimens.

METHODS

Randomized controlled trials (RCTs) and observational studies analyzing the main therapeutic regimens for IMN were included from some databases. Network comparisons were performed to analyze the rates of total remission (TR), bone marrow suppression, and gastrointestinal symptoms. The surface under the cumulative ranking area (SUCRA) was calculated to rank interventions.

RESULTS

Seventeen RCTs and eight observational studies involving 1778 patients were pooled for comparison of ten interventions. Steroid + tacrolimus (TAC) showed the highest probabilities of TR whether patients had severe proteinuria or not (SUCRA 89.5% and 88.9%, separately). Rituximab (RTX) was more beneficial for TR on patients with proteinuria <8 g/d (SUCRA 66.0%) and was associated with a lower risk of bone marrow suppression and gastrointestinal symptoms (SUCRA 21.7% and 21.4%, separately). TAC + RTX and steroids + cyclophosphamide induced the highest rates of bone marrow suppression (SUCRA 90.6% and 88.3%, separately) and gastrointestinal symptoms (SUCRA 86.0% and 72.1%, separately).

CONCLUSIONS

Steroids + TAC showed significant efficacy in patients with all degrees of proteinuria, while RTX was more effective in patients with moderate proteinuria and was safer in bone marrow suppression and gastrointestinal symptoms.

Retrospective analysis of Tripterygium wilfordii polyglycoside combined with angiotensin receptor blockers for the treatment of primary membranous nephropathy with sub-nephrotic proteinuria

INTRODUCTION

Primary membranous nephropathy (PMN) is one common cause of end-stage kidney disease. There is no optimal treatment for PMN patients with sub-nephrotic proteinuria currently. Tripterygium wilfordii polyglycoside (TWG) is a widely used traditional medicine in China and has been used to treat nephropathy for decades.

OBJECTIVE

To investigate the effect of TWG combined with angiotensin receptor blocker (ARB) on the treatment of PMN with sub-nephrotic proteinuria.

METHODS

Biopsy-proven sub-nephrotic PMN patients with normal kidney function and treated with TWG combined with ARB or ARB alone were retrospectively analyzed. The primary outcome was remission rate (complete or partial remission), and the secondary outcomes included proteinuria, serum albumin levels, estimated glomerular filtration rate (eGFR), relapse rate, and adverse events.

RESULTS

The clinical trial included 55 patients. The overall remission rates for the TWG + ARB and ARB groups after 9 months of treatment were 74.3% and 35%, respectively (p = 0.004). Moreover, the complete remission (CR) rate for the TWG + ARB and ARB groups in the 9th month were 45.7% and 15%, respectively (p = 0.044). Treatment with TWG + ARB was the independent predictor of complete remission of proteinuria (p = 0.048). Besides, the remission rate was higher in the TWG + ARB group than in the ARB group among patients who were positive for anti-phospholipase A2 receptor (PLA2R) antibodies (65.4% vs. 21.4%, p = 0.02).

CONCLUSIONS

These data demonstrate that TWG may be a promising treatment for PMN patients with sub-nephrotic proteinuria, whether anti-PLA2R antibody is positive or negative.

Urinary peptidomics reveals proteases involved in idiopathic membranous nephropathy

BACKGROUND

Idiopathic membranous nephropathy (IMN) is a cause of nephrotic syndrome that is increasing in incidence but has unclear pathogenesis. Urinary peptidomics is a promising technology for elucidating molecular mechanisms underlying diseases. Dysregulation of the proteolytic system is implicated in various diseases. Here, we aimed to conduct urinary peptidomics to identify IMN-related proteases.

RESULTS

Peptide fingerprints indicated differences in naturally produced urinary peptide components among 20 healthy individuals, 22 patients with IMN, and 15 patients with other kidney diseases. In total, 1,080 peptide-matched proteins were identified, 279 proteins differentially expressed in the urine of IMN patients were screened, and 32 proteases were predicted; 55 of the matched proteins were also differentially expressed in the kidney tissues of IMN patients, and these were mainly involved in the regulation of proteasome-, lysosome-, and actin cytoskeleton-related signaling pathways. The 32 predicted proteases showed abnormal expression in the glomeruli of IMN patients based on Gene Expression Omnibus databases. Western blot revealed abnormal expression of calpain, matrix metalloproteinase 14, and cathepsin S in kidney tissues of patients with IMN.

CONCLUSIONS

This work shown the calpain/matrix metalloproteinase/cathepsin axis might be dysregulated in IMN. Our study is the first to systematically explore the role of proteases in IMN by urinary peptidomics, which are expected to facilitate discovery of better biomarkers for IMN.

Effect of Mahuang Fuzi and Shenzhuo Decoction on Idiopathic Membranous Nephropathy: A Multicenter, Nonrandomized, Single-Arm Clinical Trial

Objective: To explore the clinical effect of Mahuang Fuzi and Shenzhuo Decoction on idiopathic membranous nephropathy.

Methods: This study is a multicenter, nonrandomized, single-arm clinical trial carried out as per the objective performance criteria, with the target being set at 35.0%. 184 cases of patients suffering from idiopathic membranous nephropathy with Shaoyin Taiyin syndrome were collected. These patients were treated with Mahuang Fuzi and Shenzhuo Decoction with a follow-up period of 3 years. The 24-hour urine protein and blood albumin were observed, and the remission rates of the patients were compared with the target.

Results: The mean follow-up time was 18 (12.5, 30) months, and the remission rate was 61.4%, which is a statistically significant difference from the target group of 35%. The remission rates for patients who had and had not used immunosuppressive therapy were 59.6 and 65.5%, respectively, but the difference was not statistically significant (p = 0.254). However, the albumin before the treatment and the course of treatment of the patients was significantly correlated with the disease remission (p < 0.05). However, the albumin before the treatment and the course of treatment of the patients was significantly correlated with the disease remission (p < 0.05). There were no significant changes in renal function before and after treatment, and no severe adverse events occurred during treatment.

Conclusion: Mahuang Fuzi and Shenzhuo Decoction have significant effects on idiopathic membranous nephropathy, and has the same effect on patients with membranous nephropathy who are newly treated as well as those who have been treated with immunosuppressive therapy without remission. In addition, the efficacy of this regimen is related to the albumin and the duration of the therapy, but not to 24-hour urine protein or other factors.