Membranous Nephropathy Patients Research Articles

Updated diagnostic and therapeutic management for membranous nephropathy.

Pioneering contributions in membranous nephropathy over the last decade have greatly enhanced our comprehension of its pathogenesis, diagnosis, and treatments, igniting renewed interest in this entity. This review provides an updated perspective on the diagnosis and therapeutic management of membranous nephropathy. The identification of antiphospholipase A2 receptor (PLA2R) antibodies in 50-80% of membranous nephropathy patients was a key breakthrough. High or increasing PLA2R antibody levels are linked to persistent nephrotic syndrome and the need for targeted treatment. Given the high specificity of PLA2R antibodies, a kidney biopsy may not be required for pure nephrotic syndrome cases with no comorbidities. Over the years, various target antigens and associated conditions have been identified in membranous nephropathy patients, leading to a reclassification of membranous nephropathy. Treatment approaches vary based on baseline characteristics and changes in proteinuria and PLA2R titers. Rituximab has emerged as the first-line therapy for most patients without severe risk factors, with other emerging therapies under development. Advances in the diagnosis and treatment of membranous nephropathy have moved the management towards a more precision-based approach, though further studies and new therapies are needed for a comprehensive management strategy.

Efficacy and safety of rituximab in patients with PLA2R associated membranous nephropathy and resolved HCV infection

Rituximab occasionally induces reactivation of hepatitis C virus (HCV) in patients with resolved HCV infection, sometimes with fatal consequences. As rituximab has become one of the first-line therapies for the treatment of phospholipase A2 receptor (PLA2R)-associated membranous nephropathy (MN) and is more widely used, there is a lack of studies reporting the effectiveness and safety of rituximab in patients with PLA2R-associated MN and resolved HCV infection. A single-center retrospective study was conducted on PLA2R-associated membranous nephropathy (MN) patients who were HCVAb positive but HCV-RNA negative and treated with rituximab. A total of 598 adult patients with PLA2R-associated MN who underwent rituximab therapy were screened. General clinical information, including gender, age, pathological data, and previous treatment plans, was collected from medical records. Routine blood tests, liver and kidney function assessments, blood lipid profiles, 24-h urine protein levels, anti-PLA2R antibody titers, circulating B-cell counts, and HCV viral loads were measured at the time of rituximab infusion and repeated at intervals of 1–3 months post-rituximab administration. A total of 8 patients were enrolled, with a median follow-up period of 19.00 (range: 16.00–25.25) months. Among the 8 patients, 5 were male, and the mean age was 50.13 ± 4.29 years. Histological findings indicated that tubuloreticular inclusions, mesangial deposits, intramembranous deposits, and subendothelial deposits were not observed in any of the 8 patients. The overall 1-year remission rate for these patients was 75%, accompanied by a significant reduction in proteinuria. Additionally, blood albumin levels increased significantly, and renal function remained stable. No increase in HCV viral load and stable liver function tests were observed throughout the entire follow-up period. This study suggested that on the basis of successful eradication of HCV virus with antiviral drugs, rituximab can effectively induce clinical remission of patients with PLA2R associated MN and resolved HCV infection, and does not lead to a significant increase in HCV virus load. However, this finding is based on a very small sample size and should be confirmed in larger clinical trials.

Specific antigen-based stratification of membranous nephropathy in patients after haematopoietic stem cell allotransplantation - a case series and literature review.

Nephrotic syndrome (NS) is a rare complication that can occur after haematopoietic stem cell transplantation (HSCT). In patients with membranous nephropathy (MN) who have undergone allogeneic HSCT, a new antigen called protocadherin FAT1 has been identified. Our objective is to present a case series of MN patients after HSCT with a novel antigen-based stratification. Patients who developed full-blown NS due to MN after an HSCT were enrolled in the University Hospital Centre Zagreb study. The first two patients were treated with an HSCT for acute myeloid leukaemia, and both developed NS after cessation of graft versus host disease (GVHD) prophylaxis. The first patient had reduced kidney function, while the second had completely preserved function. Kidney biopsy showed MN with only subepithelial deposits. A thorough examination revealed that there was no secondary cause of the disease. The patients achieved complete remission after undergoing immunosuppression treatment. The third patient underwent HSCT for acute lymphoblastic leukaemia. He developed both acute and chronic GVHD and also experienced avascular hip necrosis. After sixteen years, the patient developed NS with preserved kidney function. The kidney specimen showed membranous nephropathy (MN) with mesangial and subepithelial deposits. Extensive research was conducted, but no secondary cause for the MN was detected. All three cases tested negative for anti-PLA2R antibodies. Biopsy tissue samples were analysed using laser microdissection and tandem mass spectrometry of glomeruli for the detection of different specific antigens. Patients one and two tested positive for FAT1, whereas patient three tested positive for PCSK6. MN can develop at various time intervals after HSCT. Specific antigen testing can help establish the relationship between MN and HSCT. In the future, serum testing for anti-FAT1 antibodies in HSCT patients could be significant in diagnosing FAT1-associated MN, similar to how anti-PLA2R antibodies are significant in diagnosing PLA2R-associated MN.

Low risk of hepatitis B virus reactivation in membranous nephropathy patients with resolved infection undergoing rituximab-based regimens without antiviral prophylaxis

IntroductionPatients with resolved hepatitis B virus infection undergoing rituximab are at risk of hepatitis B virus reactivation without antiviral prophylaxis. However, the risk in such patients treated with rituximab-based regimens for membranous nephropathy is not clear. We evaluated the risk of hepatitis B virus reactivation in membranous nephropathy patients with resolved infection undergoing rituximab-based regimens without antiviral prophylaxis. MethodsClinical data of 51 membranous nephropathy patients with resolved hepatitis B virus infection undergoing rituximab-based regimens without antiviral prophylaxis were retrospectively analyzed. Among these, 21 patients were followed for more than 1 year after rituximab discontinuation. The clinical data collected aimed to assess patients’ responses and the risk of hepatitis B virus reactivation during and after rituximab treatment. Results30/51 (58.8 %) patients reached complete or partial remission at 12 months. None of the patients experienced HBsAg seroreversion during rituximab treatment. Alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase and total bilirubin levels, as well as the numbers of patients who exceeded the upper limits of normal for alkaline phosphatase and prothrombin time, did not show any statistically significant difference during rituximab-based therapy. Neither did the anti-HBs level, the number of patients with protective anti-HBs titers exceeding 10 U/L, nor the levels of CD19+ B cells, CD4+ T cells, CD8+ T cells, and natural killer cells. Among the 21 patients followed for 12 (ranging from 12 to 19) months after rituximab discontinuation, no hepatitis B virus reactivation was observed. The mean anti-HBs level and the number of patients with anti-HBs titers over 10 U/L did not show any statistically significant difference during the extended follow-up of 33 patient-years. Neither did the CD4+ T cell, CD8+ T cell, nor the natural killer cell counts. One patient presented with an ALT level that exceeded the baseline value by three times and reached above 100 U/L, accompanied by elevations in AST, GGT, and ALP levels. Meanwhile, the anti-HBs titer was 816.09 U/L, and HBsAg was negative. ConclusionThe administration of rituximab-based regimens in membranous nephropathy patients with hepatitis B virus resolved infection leads to a low risk of hepatitis B virus reactivation without antiviral prophylaxis. Patient’s immune status, drug combination, rituximab strategy should be fully evaluated when considering antiviral prophylaxis therapy.

Obinutuzumab in Difficult to Treat Phospholipase A2 Receptor Positive Membranous Nephropathy: Our Experience at a Tertiary Care Center in North India

Obinutuzumab is a glycoengineered type II anti-CD20 monoclonal antibody with superior B cell cytotoxicity compared to rituximab. Various case reports suggest that in refractory phospholipase A2 receptor (PLA2R) positive membranous nephropathy (MN) patients, Obinutuzumab led to immunologic remission and improvement in proteinuria. In the present case series, we present six cases of difficult-to-treat PLA2R-associated MN refractory to prednisolone, calcineurin inhibitor (CNI), cyclophosphamide, and rituximab but subsequently responded to Obinutuzumab. Five out of six cases showed partial /complete clinical remission and immunological remission (IR) with normalization of serum albumin and stable renal function. Though this drug’s long-term efficacy and impact remain unclear, it is being increasingly considered for PLA2R-associated MN resistant to standard therapy.

#2154 Rituximab in the treatment of PLA2R-associated membranous nephropathy: insights from a hospital centre experience

Abstract Background and Aims Rituximab (RTX) is recommended as the first-line therapy for PLA2R-associated Membranous Nephropathy in patients with a moderate to high risk of progressive loss of kidney function, according to the KDIGO 2021 guidelines. This recommendation is based on the superior long-term efficacy and improved safety profile of RTX. This study aims to assess the use of RTX for the treatment of for PLA2R-associated Membranous Nephropathy at a hospital centre. Method A retrospective study was conducted on patients diagnosed with PLA2R-associated Membranous Nephropathy who underwent their first RTX administration between 2017 and 2022 at a tertiary hospital centre. Exclusion criteria involved patients with less than 6 months of follow-up post-RTX. The study evaluated the occurrence of immune remission, clinical remission, as well as instances of immune and proteinuria relapse, and recorded any adverse events. Results A total of 11 patients were included, with 54.5% being male. The mean age was 60.4 ± 14.7 years, and the median disease duration 69.0 [8.0-87.0] months. The mean follow-up time post-RTX was 36.7 ± 23.3 months. Regarding the risk of progressive loss of kidney function, 8 patients were classified as high risk, 1 as moderate risk, and 2 as low risk. RTX served as the initial immunosuppressive therapy for only 3 patients. Additional immunosuppressive therapies post-RTX, including further RTX doses, were administrated in 63.6% (n = 7) of patients. No response was observed in 18.2% (n = 2). Immune remission was achieved in 81.8% (n = 9), mean time of 3.8 ± 1.4 months. Within this group 55.5% (n = 5) patients achieved complete remission, 22.2% (n = 2) experienced partial remission, and 22.2% (n = 2) maintained nephrotic proteinuria, with immune remission consistently preceding clinical remission. Relapses occurred in 45.5% (n = 5), at a mean time of 20.8 ± 13.5 months. Patients with lower serum albumin at time of RTX administration were more likely to experience non-response or relapse (T (9) = 2.51, p = 0.03), with a Youden Index cut-off of 3.2 g/dL, demonstrating a sensitivity of 100% and a specificity of 85.7%. Patients with anti-PLA2R exceeding 150 RU/mL exhibited no response or relapsed. Four patients (36.4%) remained free of relapses throughout the entire follow-up period, mean time of 22.8 ± 10.0 months, with 1 keeping RTX maintenance therapy. During the 6 months post-RTX, 36.4% (n = 4) of patients experienced adverse events. Conclusion Rituximab demonstrated both efficacy and safety in treating PLA2R-associated Membranous Nephropathy. However, lower serum albumin levels and anti-PLA2R > 150 RU/mL at time of RTX administration were associated with worse response. Given the substantial need for additional immunosuppression, and considering lower albumin values and higher anti-PLA2R titres as risk markers, it is recommended to closely monitor these patients. Anti-PLA2R titres showed a meaningful association with disease activity, preceding changes in proteinuria levels. Therefore, tracking disease progression through the measurement of anti-PLA2R titres not only guides clinical decisions but also enables a judicious approach to subsequent RTX administrations.

#161 Single-Nucleus RNA-Seq of Human Kidney Biopsy Tissue Reveals Microstructure-Specific Similarities and Differences in Various Glomerulonephritis

Abstract Background and Aims Transcriptomic alterations in kidney diseases may lead to the discovery of novel biomarkers. Single-nucleus RNA-seq (SnSeq) is a valuable method for profiling the transcriptome of kidney-residing cells. Additional SnRNA-seq data is necessary, including cases of human biopsy-confirmed glomerulonephritis. Method We collected snap-frozen kidney biopsy tissues from 6 cases of IgA nephropathy (IgAN), 6 cases of minimal change disease, 6 cases of PLA2R-Ab positive membranous nephropathy, 3 cases of diabetic kidney disease, and 7 nephrectomy control cases. SnSeq was performed on the kidney tissues, and kidney cells were identified in the dataset through UMAP clustering. The proportions of each cell subcluster were compared between the study groups. Differentially expressed genes (DEGs) were identified. K-means clustering and Weighted Gene Co-expression Network Analysis (WGCNA) were performed. Results We successfully collected transcriptomic profiles of 55 615 cells from IgAN, 53 370 from minimal change disease, 53 495 from membranous nephropathy, 34 343 from diabetic kidney disease, and 66 161 from control cases. The SnSeq data successfully identified major kidney cell clusters, including a considerable number of glomerular cells such as podocytes, mesangial cells, endothelial cells, and others. DEGs were largely identified in podocytes and proximal tubule cells, as well as in other glomerular cells. K-means clustering identified diverse similarities and differences between the study groups for each cell type. We identified diverse cell type-specific but disease-common DEGs, particularly in the downregulated genes, suggesting that the studied diseases share similar destruction in kidney microstructure. In comparison, cell type-common but disease-specific DEGs were also identified, considering a common pathophysiologic mechanism may occur in total kidney cortex. Diseases that can feature nephrotic syndrome showed high expression of AVP receptors, suggesting the association with edema, or highly expressed renin-angiotensin-aldosterone pathway was noted in IgAN or diabetic kidney disease, which was not evident in minimal change disease or membranous nephropathy patients. The studied disease shared certain types of inflammatory pathways (e.g. interferon-alpha or TGF-beta) but some pathways were differently enriched according to the disease types. WGCNA analysis revealed gene modules that were highly correlated with age, proteinuria, and estimated GFR, regardless of the diagnosis subtype. Conclusion The current SnSeq data is, to date, the largest one, including biopsy-confirmed human kidney glomerulonephritis cases. The results identified disease-specific changes in specific cell types. Additionally, common transcriptomic alterations occurring following changes in estimated GFR, age, and proteinuria were investigated. The data may be a valuable resource for future research on glomerulonephritis biomarker development.

#2691 Treatment naive membranous nephropathy patients treated with rituximab in COVID19 era

Abstract Background and Aims Standard of care of high-risk idiopathic membranous nephropathy patients is immunosuppressive treatment with cyclophosphamide and corticosteroids or rituximab. Our aim was to assess outcome and safety of rituximab therapy in COVID19 era in comparison to modified Ponticelli protocol. Method In this retrospective study all adult patients with biopsy proven membranous nephropathy treated with rituximab as a first line therapy from 2020 till 2022 were enrolled and compared with MN patients treated with modified Ponticelli protocol from 2013 till 2020. Renal outcome was defined as composite of partial and complete remission defined according KDIGO guidelines. Except otherwise stated, data are shown as N (%) or median with interquartile range (IQR) and accompanied p levels. Results During the COVID 19 era, between 2020 and 2022, 8 MN patients were treated with rituximab as a first line therapy. One was lost from follow up and one had allergic infusion reaction and therefore was excluded from further analysis. Ten patients were treated with modified Ponticelli protocol. There was no difference in age (60 vs. 59 years; p = 0.669), gender (M 57.1 vs. 60%), BMI (26.3 vs. 29.1cm/kg; p = 0.906), systolic (140. vs. 150 mmHg; p = 0.161) or diastolic (90 vs. 91.5 mmHg; p = 0.230) blood pressure between rituximab and cyclophosphamide treated group. Also, there was no difference in proteinuria between rituximab and cyclophosphamide treated group (16.2 (5.7–31.3) vs. 8.7 (6.5–12.5) g/dU; p = 0.201) Patients treated with cyclophosphamide had lower eGFR compared with patients treated with rituximab (51 (34-79) vs. 93 (72-98) ml/min/1,73 m²; p = 0.005). At 6 months follow up only 2 (28.6%) in rituximab group and 6 (60%) in cyclophosphamide group achieved outcome defined as composite of complete and partial remission. At one year follow up, there was no difference in outcome between groups and all patients from rituximab group compared to 8 patients (88.9%) from cyclophosphamide group accomplished composite favorable renal outcome (p = 398). At the end of follow up, one year after cyclophosphamide therapy eGFR was better (57 (43-96) vs. 51 (34-79) ml/min/1,73 m²). Rituximab was safe in our cohort. Three (50%) of patients acquired SARS CoV2 infection and there was no adverse outcome regarding COVID 19 disease. Conclusion Cyclophosphamide is faster than rituximab in accomplishing remission of nephrotic syndrome and improves deteriorated kidney function. Nevertheless, at 1 year follow up rituximab efficiency is proven to be excellent. Cyclophosphamide should be reserved for MN patients with nephrotic syndrome with reduced glomerular filtration rate.

#2427 A multi-targeted treatment approach to induce early remission in high-risk primary membranous nephropathy

Abstract Background and Aims A considerable proportion of primary membranous nephropathy (PMN) patients do not achieve early clinical remission with current immunosuppression regimens. The goal of the study was to evaluate efficacy and safety of the multi-targeted treatment regimen including rituximab, cyclophosphamide, and corticosteroids (all administered at low cumulative doses) (RCP) in PMN with antibodies to the phospholipase A2 receptor (anti-PLA2R). Method The study enrolled 30 high- or very-high risk PMN patients with persistent nephrotic syndrome (NS) and elevated anti-PLA2R in a prospective single-arm study of RCP treatment. The experimental protocol consisted of a single intravenous infusion of RTX (375 mg/m2) and methylprednisolone (500 mg), followed by oral prednisolone (1 mg/kg) tapered rapidly at 10 mg per week and discontinued at week 49. An additional RTX infusion at the same dose was given during weeks 8-12, 20-24, and 32-36 if complete remission was not achieved and peripheral CD19+ cell exceeded 5 cells/μl. Four intravenous infusions of CYC were administered at a dose of 7.5 mg/kg every other week, in weeks 1, 3, 5, and 7. The effectiveness of RCP was compared to that of historic controls who received either rituximab-based therapy (RTX, n = 15) or cyclosporine+corticosteroids (CSA, n = 42). The primary outcomes measured were complete clinical remission (CR), overall remission (OR, which combines complete and partial remission) at month 12 after treatment initiation, and the time to clinical remission. Cox regression models were used to analyse the effect of RCP therapy on the probability of remission. Furthermore, we conducted comparative time-to-remission analyses in the RCP group and controls after propensity score (PS) matching. Results The RCP group exhibited higher OR and CR rates at 12 months (97% and 60%) compared to the RTX group (60% and 7%, P≤0.009) and the CSA group (50% and 24%, P≤0.003) (Fig. 1A,B). The median time to OR was shorter in the RCP group (2.8 (1.6–3.9) months) than in the RTX group (7.1 (3.4–17.5) months, P = 0.008) and the CSA group (7.3 (6.0–13.6) months, P < 0.001) (Fig. 1A). In the adjusted Cox regression, the hazard ratios for OR and CR attainment for RCP compared to other treatments were 5.2 (95% CI: 2.8–9.6) and 4.8 (95% CI: 2.2–10.3), respectively. These results were confirmed by comparative analyses of propensity score-matched groups. Only one serious adverse event (SAE) occurred in the RCP group during the 56 patient-year follow-up. Conclusion RCP therapy is considered effective and safe for inducing early remission in high-risk PMN patients.

#2229 miR-186, a potential noninvasive diagnostic biomarker of Membranous nephropathy in urinary microparticles

Abstract Background and Aims Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome, and is associated with podocyte damage and proteinuria. Invasive biopsy is the gold-standard diagnostic method for this disease. The use of specific biomarkers, such as microparticles (MPs) originating from damaged podocytes released in a patient's urine, has been proposed as an early, noninvasive, and repetitive diagnostic method. According to the previous studies, MPs derived from podocytes are present in the urine of patients with different glomerulonephritis, such as diabetic nephropathy, lupus nephritis, renal injury in preeclampsia, and renovascular hypertensive disorders. The analysis of urinary microparticle-derived miRNAs from patients with kidney diseases can help detect diagnostic biomarkers. This study aimed to analyze podocyte damage-related miRNAs in MN, miR-30c, miR-135, and miR-18 in the urinary MP of MN patients to identify appropriate candidate biomarkers for MN Method Urine samples from 30 patients with membranous nephropathy and 16 healthy individuals were collected to extract podocyte MPs using ultracentrifugation. Characterization of these particles was determined using the specific protein marker of MPs, TSG-101, and the podocyte-specific marker Nephrin, by western blotting, and SEM was used to check the size and morphology. The expression levels of microRNAs extracted from podocyte MPs, miR-30c, miR-135, and miR-186, were also evaluated by real-time PCR. Results The evaluation of the characteristics of MPs showed that there were many particles with a size of more than 100 nm in the urine sample, and there were higher levels of the specific markers TSG-101 and Nephrin in the urine samples of MGN patients than in the control samples (P < 0.001). The expression level of miR-186 was compared between the three studied groups and based on the results of the expression of this miRNA in the group of membranous nephropathy patients compared to healthy people group, there was a significant increase in expression (P = 0.000) Conclusion This study showed that although the expression levels of miR-186 in podocyte MPs samples extracted from the urine of patients with MN were significantly changed compared to the studied controls, more studies should be performed to determine the diagnostic values.

#1267 Exostosin 1- and 2-positive membranous nephropathy in Chinese patients

Abstract Background and Aims The exostosin 1 and 2 (EXT1/2) complex was recently identified as a potential antigen associated with systemic autoimmunity in PLA2R-negative membranous nephropathy patients. There are currently no reports of circulating anti-EXT1/2 antibodies and no clinical studies of EXT1/2-positive membranous nephropathy in the Chinese population. Method Immunohistochemical staining for PLA2R, THSD7A and NELL-1 was performed in 1442 consecutive patients with biopsy-proven MN from January 2011 to December 2019 at Beijing Anzhen Hospital. A total of 201 MN patients were PLA2R-, THSD7A- and NELL-1-negative and enrolled in the study. Patient medical records were reviewed for clinical data, including demographics, laboratory tests, treatment, and follow-up. The glomerular expression of EXT1 and EXT2 was screened. The anti-EXT1 and anti-EXT2 antibodies were also detected in the sera of patients with EXT1/2–positive membranous nephropathy by western blot, ELISA and immunoprecipitation separately. Clinical and pathologic features were comparable between PLA2R-, THSD7A- and NELL-1-negative patients with EXT1/2 or without EXT1/2 positive. Results Among these 201 patients, 19 of 83 (22.9%) with lupus membranous nephropathy (class 5 and class 5+3/4), and 13 of 118 (11.0%) with nonlupus membranous nephropathy exhibited positive EXT1/2 staining. Thirteen patients with EXT1/2-positive non-LMN had no definitive secondary cause, but 7 patients (53.8%, 7/13) were seropositive for ANA. Baseline anti–double-stranded DNA antibody and serum antinuclear antibody positivity were independent predictors of glomerular EXT1/2-positive expression in patients with lupus membranous nephropathy (pure class 5, class 5 + 3/4) and nonlupus membranous nephropathy, respectively. In 32 patients with EXT1/2-positive MN, 22 patients with available serum samples collected at the time of biopsy were tested for anti-EXT1 and anti-EXT2 antibodies. Sixteen patients were positive for antibodies. According to the molecular weight of positive bands, we speculated that 5 patients were positive for both anti-EXT1 and anti-EXT2 antibodies, 11 patients were positive only for anti-EXT1 antibodies, and no patients were positive only for anti-EXT2 antibodies. There were no significantly differences between the characteristics of 22 EXT1/2-positive MN patients with or without antibody seropositivity. Two patients with EXT1/2-positive membranous nephropathy underwent repeated renal biopsies. When the pathological type changed to lupus nephritis (LN) or the LN worsened clinically, the renal tissue staining intensity of EXT1/2 increased. Renal EXT1/2 staining positivity occurred earlier than the diagnosis of lupus. Conclusion This is the first study to detect circulating anti-EXT1/2 antibodies, and the functional significance should be further studied. The renal EXT1/2 staining positive was earlier than diagnosis of lupus. whether the level of serum EXT1/2 antibody can be used as a predictor for disease progression and prognosis needs to be further evaluated in larger sample studies.

#2653 Long term renal outcome of patients with idiopathic membranous nephropathy – Croatian single center cohort

Abstract Background and Aims Membranous nephropathy (MN) is the most prevalent cause of nephrotic syndrome in adult population. Our aim was to assess long term renal outcome of primary membranous nephropathy patients. Method In this retrospective study adult patients with biopsy proven membranous nephropathy from 2000 till 2015 with follow up of at least 5 years from UHC Zagreb were included. Extensive clinical workup was done to exclude patients with secondary MN. Except otherwise stated, data are shown as N (%) or median with interquartile range (IQR) and accompanied p levels. Results Between 2000 and 2015, 48 patients were diagnosed to have idiopathic/primary membranous nephropathy, out of which 33 (68%) MN patients had follow up of at least 5 years and where further analyzed. They were predominantly male 20 (60.6%) of average age of 52 years (min – max 19 - 76). High risk MN patient 25 (75%) were treated with immunosuppressive therapy, dominantly with cyclophosphamide and corticosteroids. During the median follow up of 10 (7 – 14) years, 19 (57%) accomplished complete remission and 11 (33%) partial remission. One (3%) patient did not achieve remission and 2 (6.1%) were in relapse of nephrotic syndrome at last follow up. Proteinuria significantly decreased (6.2 (3.3 – 10.9) vs. 0.2 (0.14 – 0,90); p < 0.001) and there was no significant change in creatinine level (87 (42.8 – 101.5) vs. 93 (68.5 – 140.5; p = 0.332)). In follow up there were 5 (15%) carcinomas detected; one of each origin (colon, pancreas, lung, prostate, lymph nodes) approximately 7,8 years after the diagnose of MN. Limitation of this study could be selection bias but there was no difference in renal function at presentation of all MN patients and those who had at least 5 years follow up. Conclusion Renal long-term outcome of patients with idiopathic MN in our cohort was excellent. Nevertheless, there is high prevalence of cancer and therefore regular screening for cancer disease should take place in this population of patients. Also, drugs with cancerogenic potential should be avoided, as well as bear in mind cumulative dose of drugs applied.

Development of a nomogram for membranous nephropathy prediction in patients with primary Sjögren's syndrome: a 6-year retrospective study.

Nephritis is a life-threatening complication of primary Sjögren's syndrome (pSS), with membranous nephropathy (MN) being prevalent. Renal biopsy is the gold standard for MN diagnosis, but it is invasive and cannot be repeatedly performed. This study aimed to develop a nomogram for the prediction of MN in patients with pSS. This retrospective study included patients with pSS admitted to the Rheumatology and Immunology Department of the First Affiliated Hospital of China Medical University between January 2015 and January 2021.A nomogram was developed using multivariable logistic regression analysis and evaluated using receiver operating characteristic (ROC) curve analysis. Bootstrap resampling analysis (1,000 times) was performed to evaluate the nomogram for discrimination and the calibration curve for consistency. A total of 237 patients with pSS [aged 53.00 (44.00, 61.00) years] were included, with 35 pSS-MN patients. Based on clinical practice and multivariable logistic regression analysis, seven variables associated with pSS-MN were selected, including white blood cells, creatine, complement 3, rheumatoid factor, antinuclear antibodies, anti-SSA antibody, and interstitial lung disease. The area under the ROC curve was 0.860 (95% confidence interval: 0.796-0.919), indicating good predictive power. In addition, the nomogram exhibited excellent performance, as demonstrated by the calibration curve and decision curve analysis. This study developed a risk prediction nomogram for MN in patients with pSS, with high predictive power. It may be used to improve the management of patients with pSS.

Combined Serologic and Genetic Risk Score and Prognostication of Phospholipase A2 receptor-Associated Membranous Nephropathy.

The aim of this study was to test whether a combined risk score on the basis of genetic risk and serology can improve the prediction of kidney failure in phospholipase A2 receptor (PLA2R)-associated primary membranous nephropathy. We performed a retrospective analysis of 519 biopsy-proven PLA2R-associated primary membranous nephropathy patients with baseline eGFR ≥25 ml/min per 1.73 m 2 . The combined risk score was calculated by combining the genetic risk score with PLA2R ELISA antibody titers. The primary end point was kidney disease progression defined as a 50% reduction in eGFR or kidney failure. Cox proportional hazard regression analysis and C-statistics were applied to compare the performance of PLA2R antibody, genetic risk score, and combined risk score, as compared with clinical factors alone, in predicting primary outcomes. The median age was 56 years (range, 15-82 years); the male-to-female ratio was 1:0.6, the median eGFR at biopsy was 99 ml/min per 1.73 m 2 (range: 26-167 ml/min per 1.73 m 2 ), and the median proteinuria was 5.3 g/24 hours (range: 1.5-25.8 g/24 hours). During a median follow-up of 67 (5-200) months, 66 (13%) had kidney disease progression. In Cox proportional hazard regression models, PLA2R antibody titers, genetic risk score, and combined risk score were all individually associated with kidney disease progression with and without adjustments for age, sex, proteinuria, eGFR, and tubulointerstitial lesions. The best-performing clinical model to predict kidney disease progression included age, eGFR, proteinuria, serum albumin, diabetes, and tubulointerstitial lesions (C-statistic 0.76 [0.69-0.82], adjusted R 2 0.51). Although the addition of PLA2R antibody titer improved the performance of this model (C-statistic: 0.78 [0.72-0.84], adjusted R 2 0.61), replacing PLA2R antibody with the combined risk score improved the model further (C-statistic: 0.82 [0.77-0.87], adjusted R 2 0.69, difference of C-statistics with clinical model=0.06 [0.03-0.10], P < 0.001; difference of C-statistics with clinical-serologic model=0.04 [0.01-0.06], P < 0.001). In patients with PLA2R-associated membranous nephropathy, the combined risk score incorporating inherited risk alleles and PLA2R antibody enhanced the prediction of kidney disease progression compared with PLA2R serology and clinical factors alone.

Development of Drug Efficacy Testing Platform for Glomerulonephritis.

We developed a 3D glomeruli tissue chip for glomerulonephritis (GN) testing, featuring a gravity-driven glomerular filtration barrier (GFB) with human podocytes and endothelial cells with a bidirectional flow in the bottom channel. Using puromycin-induced GN, we observed decreased cell viability, increased albumin permeability, and reduced WT1 and nephrin compared to the normal GFB. Tacrolimus restored cell viability, reduced albumin permeability, and increased WT1 expression. Using serum from five membranous nephropathy (MN) patients, we created MN models using a GFB-mimicking chip. A notable decline in cell viability was observed in the serum-induced MN1 and MN2 models. However, tacrolimus restored it. Albumin permeability was reduced in the MN1, MN2, and MN5 models by tacrolimus treatment. MN1 displayed the best clinical response to tacrolimus, exhibiting increased expression of WT1 in chip-based evaluations after tacrolimus treatment. We successfully evaluated the efficacy of tacrolimus using puromycin-induced and serum-induced GN models on a chip that mimicked the structure and function of the GFB. The GFB-mimicking chip holds promise as a personalized platform for assessing drug efficacy using patient serum samples.

Clinicopathological characteristics and outcomes of PLA2R related idiopathic membranous nephropathy in patients with seronegative PLA2R antibodies

Background Idiopathic membranous nephropathy (IMN) with deposits of phospholipase A2 receptor (PLA2R) antigen in glomerular tissue (GAg+) but no circulating serum PLA2R antibody (SAb−) has been reported. However, little is known about the clinicopathological characteristics and prognosis of this subtype. Methods A total of 74 IMN patients with GAg + identified by kidney biopsy were enrolled in this study. We categorized patients into two groups based on the presence or absence of serum PLA2R antibody. Data on clinical features, pathological features, and outcomes were collected. Kaplan–Meier analysis of complete remission (CR) and partial remission (PR) comparing SAb−/GAg + and SAb+/GAg + patients. Cox proportional hazards models was used to examine factors associated with CR and PR. Results Among 74 IMN patients, 14 were SAb−/GAg+. Compared with SAb+/GAg + patients, SAb−/GAg + patients presented with higher levels of albumin, lower levels of cholesterol and low density lipoprotein cholesterol (all p < .01), but similar pathological manifestations of kidney biopsy. Multivariate logistic analyses indicated that low albumin (0.79 [95%CI: 0.66–0.95], p = .01) and high cholesterol (1.81 [95%CI: 1.02–3.19], p = .04) were correlated with seropositivity of PLA2R antibody. SAb−/GAg + patients exhibited a significantly higher probability of CR (p = .03) than patients who were SAb+/GAg+. However, no difference was found in the PR rate. Cox regression analyses showed that compared to SAb+/GAg + patients, SAb−/GAg + was more predictive of complete remission (4.28 [95%CI: 1.01–18.17], p = .04). Conclusion IMN with PLA2R staining on kidney biopsy but without serum PLA2R antibody has milder clinical manifestations and a better prognosis.

Defining the threshold: triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio's non-linear impact on tubular atrophy in primary membranous nephropathy.

Hyperlipidemia is common in primary membranous nephropathy (PMN) patients, and tubular atrophy (TA) is an unfavorable prognostic factor. However, the correlation between the triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio and TA is controversial. Therefore, our study aimed to investigate the association between the TG/HDL-C ratio and TA in PMN patients. We conducted a cross-sectional study and collected data from 363 PMN patients at Shenzhen Second People's Hospital from January 2008 to April 2023. The primary objective was to evaluate the independent correlation between the TG/HDL-C ratio and TA using binary logistic regression model. We used a generalized additive model along with smooth curve fitting and multiple sensitivity analyses to explore the relationship between these variables. Additionally, subgroup analyses were conducted to delve deeper into the results. Of the 363 PMN patients, 75 had TA (20.66%). The study population had a mean age of 46.598 ± 14.462 years, with 217 (59.78%) being male. After adjusting for sex, age, BMI, hypertension, history of diabetes, smoking, alcohol consumption, UPRO, eGFR, HB, FPG, and ALB, we found that the TG/HDL-C ratio was an independent risk factor for TA in PMN patients (OR=1.29, 95% CI: 1.04, 1.61, P=0.0213). A non-linear correlation was observed between the TG/HDL-C ratio and TA, with an inflection point at 4.25. The odds ratios (OR) on the left and right sides of this inflection point were 1.56 (95% CI: 1.17, 2.07) and 0.25 (95% CI: 0.04, 1.54), respectively. Sensitivity analysis confirmed these results. Subgroup analysis showed a consistent association between the TG/HDL-C ratio and TA, implying that factors such as gender, BMI, age, UPRO, ALB, hypertension and severe nephrotic syndrome had negligible effects on the link between the TG/HDL-C ratio and TA. Our study demonstrates a non-linear positive correlation between the TG/HDL-C ratio and the risk of TA in PMN patients, independent of other factors. Specifically, the association is more pronounced when the ratio falls below 4.25. Based on our findings, it would be advisable to decrease the TG/HDL-C ratio below the inflection point in PMN patients as part of treatment strategies.

MiR-664a-5p promotes experimental membranous nephropathy progression through HIPK2/Calpain1/GSα-mediated autophagy inhibition.

We previously found that miR-664a-5p is specifically expressed in urinary exosomes of idiopathic membranous nephropathy (IMN) patients. Homeodomain-interacting protein kinase 2 (HIPK2), a nuclear serine/threonine kinase, plays an important role in nephropathy. But the function of these factors and their connection in MN are unclear. To investigate the function and mechanism of miR-664a-5p in MN, the miR-664a-5p expression in HK-2 cells, exosomes, podocytes and renal tissues were studied, as well as cell growth and apoptosis of these cells, the binding of miR-664a-5p to HIPK2 mRNA, the levels of relative proteins and autophagy. The MN progression in MN mice model was also studied. Albumin increased the miR-664a-5p content and apoptosis of HK-2 cells, which was blocked by miR-664a-5p antagomir. miR-664a-5p bound to the 3' UTR of HIPK2 mRNA, resulting in the up-regulation of Calpain1, GSα shear and the inhibition of autophagy level. Autophagy inhibitor CQ blocked the protective effect of miR-664a-5p antagomir, HIPK2 overexpression, Calpain inhibitor SJA6017 on albumin-mediated injury. MiR-664a-5p from albumin-treated HK-2 cells could be horizontally transported to podocytes through exosomes. Exosomes from albumin-treated HK-2 cells promoted progression of MN mice, AAV-Anti-miR-664-5p (mouse homology miRNA) could improve them. Albumin increases the miR-664a-5p level and causes changes of HIPK2/Calpain1/GSα pathway, which leads to autophagy inhibition and apoptosis up-regulation of renal tubular epithelial cells. miR-664a-5p can horizontally enter podocytes through exosomes resulting in podocytes injury. Targeted inhibition of miR-664a-5p can reduce the apoptosis of renal tubule cells and podocytes, and may improve the MN progression.

Aggressive treatment may be needed for idiopathic membranous nephropathy with focal segmental glomerulosclerosis lesions.

The purpose of this study was to analyze the clinical, pathological, prognostic features and treatment response of the coexistence of focal segmental glomerulosclerosis lesions with idiopathic membranous nephropathy. This is a two-center retrospective cohort study. Patients of idiopathic membranous nephropathy were enrolled and divided into two groups with or without focal segmental glomerulosclerosis lesions according to the renal biopsy. Laboratory data and pathological manifestation were compared. Renal phospholipase A2 receptor was detected by immunofluorescence. During the follow-up, the effects of different therapies and renal function were estimated. A total of 236 patients were finally enrolled in this study, of which 60 and 176 idiopathic membranous nephropathy patients were enrolled in the FSGS+ and FSGS- groups, respectively. The FSGS+ group showed a higher percentage of hypertension history (38.3 vs. 20.0%, p=0.004), with a significantly higher level of systolic pressure [137 (120, 160) mmHg vs. 130 (120, 140) mmHg, p=0.009]. Main laboratory findings, including serial albumin (20.4±7.8 g/L vs. 24.5±6.7 g/L, p<0.001), 24-h proteinuria [5.61 (3.10, 7.87) g/day vs. 3.82 (2.31, 5.79) g/day, p=0.002], serial creatinine [80.8 (65.8, 97.9) μmol/L vs. 72.0 (58.7, 84.9) μmol/L, p=0.003], and estimated glomerular filtration rate [86 (66, 101) mL/min/1.73 m2 vs. 95 (81, 108) mL/min/1.73 m2, p=0.007] showed significant differences between the two groups. Pathologically, patients with focal segmental glomerulosclerosis lesions appeared with a higher percentage of crescents, a more severe degree of interstitial fibrosis, and a higher level of membranous nephropathy stage. Renal phospholipase A2 receptor showed a relatively lower positive rate of only 75.0% in the FSGS+ group in comparison with the positive rate of 90.3% in the FSGS- group (p=0.031). The prognosis was generally similar between the two groups. Among patients who were given non-immunosuppression treatment, those with focal segmental glomerulosclerosis lesions took a relatively longer period of time to achieve complete remission (29.3±7.0 m vs. 15.4±8.9 m, p=0.025) and experienced a higher rate of renal function deterioration (37.5 vs. 5.4%, p=0.033) compared with the other ones. While among those receiving immunosuppression treatment, both groups received similar remission rates. Compared with FSGS- group, idiopathic membranous nephropathy with focal segmental glomerulosclerosis lesions represented more severe nephrotic syndrome and worse renal function. In view of the renal function decline during the follow-up, more aggressive treatment with the use of immunosuppressants should be considered for idiopathic membranous nephropathy patients with focal segmental glomerulosclerosis lesions.

A comparative urinary proteomic and metabolomic analysis between renal aa amyloidosis and membranous nephropathy with clinicopathologic correlations

Urinary omics has become a powerful tool for elucidating pathophysiology of glomerular diseases. However, no urinary omics analysis has been performed yet on renal AA amyloidosis. Here, we performed a comparative urine proteomic and metabolomic analysis between recently diagnosed renal AA amyloidosis (AA) and membranous nephropathy (MN) patients. Urine samples of 22 (8 AA, 8 MN and 6 healthy control) patients were analyzed with nLC-MS/MS and GC/MS for proteomic and metabolomic studies, respectively. Pathological specimens were scored for glomerulosclerosis and tubulointerstitial fibrosis grades. Functional enrichment analysis between AA and control groups showed enrichment in cell adhesion related sub-domains. Uromodulin (UMOD) was lower, whereas ribonuclease 1 (RNase1) and α-1-microglobulin/bikunin precursor (AMBP) were higher in AA compared to MN group. Correlations were demonstrated between UMOD-proteinuria (r = −0.48, p = 0.03) and AMBP-eGFR (r = −0.69, p = 0.003) variables. Metabolomic analysis showed myo-inositol and urate were higher in AA compared to MN group. A positive correlation was detected between RNase1 and urate independent of eGFR values (r = 0.63, p = 0.01). Enrichment in cell adhesion related domains suggested a possible increased urinary shear stress due to amyloid fibrils. UMOD, AMBP and myo-inositol were related with tubulointerstitial damage, whereas RNase1 and urate were believed to be related with systemic inflammation in AA amyloidosis. SignificanceUrinary omics studies have become a standard tool for biomarker studies. However, no urinary omics analysis has been performed yet on renal AA amyloidosis. Here, we performed a comparative urinary omics analysis between recently diagnosed renal AA amyloidosis (AA), membranous nephropathy (MN) patients and healthy controls. Pathological specimens were scored with glomerulosclerosis (G) and tubulointerstitial fibrosis (IF) grades to consolidate the results of the omics studies and correlation analyzes. Functional enrichment analysis showed enrichment in cell adhesion related sub-domains due to downregulation of cadherins; which could be related with increased urinary shear stress due to amyloid deposition and disruption of tissue micro-architecture. In comparative proteomic analyzes UMOD was lower, whereas RNase1 and AMBP were higher in AA compared to MN group. Whereas in metabolomic analyzes; myo-inositol, urate and maltose were higher in AA compared to MN group. Correlations were demonstrated between UMOD-proteinuria (r = −0.48, p = 0.03), AMBP-eGFR (r = −0.69, p = 0.003) and between RNase1-Urate independent of eGFR values (r = 0.63, p = 0.01). This study is the first comprehensive urinary omics analysis focusing on renal AA Amyloidosis to the best of our knowledge. Based on physiologic roles and clinicopathologic correlations of the molecules; UMOD, AMBP and myo-inositol were related with tubulointerstitial damage, whereas RNase1 and urate were believed to be increased with systemic inflammation and endothelial damage in AA amyloidosis.