Idiopathic Membranous Nephropathy: Outline and Rationale of a Treatment Strategy

Diosgenin protects against cationic bovine serum albumin-induced membranous glomerulonephritis by attenuating oxidative stress and renal inflammation via the NF-κB pathway

CONTEXT

Membranous glomerulonephritis (MGN) is a leading cause of nephrotic syndrome in adults. Diosgenin (DG) has been reported to exert antioxidative and anti-inflammatory effects.

OBJECTIVE

To investigate the renoprotective activity of DG in a cationic bovine serum albumin-induced rat model of MGN.

MATERIALS AND METHODS

Fourty male Sprague-Dawley rats were randomized into four groups. The MGN model was established and treated with a DG dose (10 mg/kg) and a positive control (TPCA1, 10 mg/kg), while normal control and MGN groups received distilled water by gavage for four consecutive weeks. At the end of the experiment, 24 h urinary protein, biochemical indices, oxidation and antioxidant levels, inflammatory parameters, histopathological examination, immunohistochemistry and immunoblotting were evaluated.

RESULTS

DG significantly ameliorated kidney dysfunction by decreasing urinary protein (0.56-fold), serum creatinine (SCr) (0.78-fold), BUN (0.71-fold), TC (0.66-fold) and TG (0.73-fold) levels, and increasing ALB (1.44-fold). DG also reduced MDA (0.82-fold) and NO (0.83-fold) levels while increasing the activity of SOD (1.56-fold), CAT (1.25-fold), glutathione peroxidase (GPx) (1.55-fold) and GSH (1.81-fold). Furthermore, DG reduced Keap1 (0.76-fold) expression, Nrf2 nuclear translocation (0.79-fold), and induced NQO1 (1.25-fold) and HO-1 (1.46-fold) expression. Additionally, DG decreased IL-2 (0.55-fold), TNF-α (0.80-fold) and IL-6 (0.75-fold) levels, and reduced protein expression of NF-κB p65 (0.80-fold), IKKβ (0.93-fold), p-IKKβ (0.89-fold), ICAM-1 (0.88-fold), VCAM-1 (0.91-fold), MCP-1 (0.88-fold) and E-selectin (0.87-fold), and also inhibited the nuclear translocation of NF-κB p65 (0.64-fold).

DISCUSSION AND CONCLUSIONS

The results suggest a potential therapeutic benefit of DG against MGN due to the inhibition of the NF-κB pathway, supporting the need for further clinical trials.

Development and External Validation of a Nomogram for Predicting the Effect of RTX on the Treatment of Membranous Nephropathy

Introduction

Rituximab (RTX) has been shown to be effective in inducing immunological remission in patients with membranous nephropathy (MN). Some patients required more than one course of RTX to achieve immunological remission. Identifying patients who need more courses of RTX to achieve immunological remission is beneficial for better physician-patient communication, the assessment of treatment course, and the evaluation of medical costs. This study aims to establish a practical model to predict the probability of immunological remission after receiving one cycle of RTX.

Methods

This study enrolled 106 patients from the First Affiliated Hospital of Zhengzhou University in the modeling group and 30 patients from Henan Provincial Hospital of Traditional Chinese Medicine in the external validation group. Patients in the modeling group were divided into responders or nonresponders according to whether they achieved immunological remission or not after following up for 6 months. A nomogram was established based on the results of logistic regression analysis. The predictive performance of the nomogram was evaluated by the area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCAs).

Results

In the modeling group, 75 (70.8%) patients achieved immunological remission within 6 months after receiving one cycle of RTX. Significant differences were observed between nonresponders and responders. Risk factors used in nomogram included PLA2R antibody, hemoglobin, and gender. The AUC value of nomogram was 0.797 (95% CI 0.701-0.894, P<0.001). The calibration curves demonstrated acceptable agreement between the predicted outcomes by the nomogram and the actual values. DCA curves showed good positive net benefits in the predictive model. The external validation also demonstrated the reliability of the prediction nomogram.

Conclusion

A predictive nomogram including PLA2R antibody, hemoglobin, and gender may provide a basis to predict the doses of RTX needed in MN patients.

Rituximab in patients with membranous nephropathy and kidney insufficiency

Introduction: Patients with membranous nephropathy and kidney insufficiency have an extremely high risk of progression to end-stage renal disease. Whether rituximab can effectively treat membranous nephropathy patients with renal dysfunction remains unknown at present. The aim of our study was to evaluate the effectiveness and safety of rituximab (RTX) in membranous nephropathy with kidney insufficiency.

Methods: We retrospectively analyzed the clinical data of 35 membranous nephropathy patients with kidney insufficiency administered in the First Affiliated Hospital of Zhengzhou University between January 2020 and December 2021. Patients were followed every 1–3 months for a total of 6 months. Clinical data were collected including anti-phospholipase A2 receptor antibody (anti-PLA2R antibody) quantification, 24-h urinary protein, serum albumin, and serum creatinine. The percentage of patients who achieved clinical remission was measured.

Results: There were 7 (20%) patients who achieved complete or partial response at 6 months after RTX treatment. After 6 months of treatment, patients were clinically improved as evidenced by significant improvements in anti- PLA2R antibody titer [7.70 (5.72, 16.72) vs. 59.20 (17.70, 187.50) RU/ml, p < 0.001], 24-h urine protein [7.04 (4.43, 8.90) vs. 10.15 (4.83, 13.57) g/d, p < 0.001], serum albumin [30.55 (24.97, 33.27) vs. 21.40 (16.75, 25.00)g/L, p < 0.001], serum creatinine [99.50 (75.25, 140.25) vs. 152.00 (134.50, 232.50) µmol/L, p = 0.022], and estimated glomerular filtration rate (eGFR) [78.29 (50.15, 101.55) vs. 41.12 (26.53, 51.41) ml/min/1.73 m², p = 0.045]. There were no significantly differences between responders and nonresponders in the baseline levels of anti-PLA2R antibodies, proteinuria, serum albumin, and renal function. After the RTX treatment, anti-PLA2R antibodies turned negative in all responders, but the antibody level persisted maintained positive in all but 5 nonresponders. The patients who achieved response maintained a stable kidney function during the study period, with eGFR 29.03 (28.76, 35.07) ml/min/1.73 m² before rituximab treatment and 62.73 (62.34, 63.13) ml/min/1.73 m² at the end of follow-up (p = 0.053).

Conclusion: RTX therapy might be an alternative treatment in reducing proteinuria and maintaining stable renal function among membranous nephropathy patients even with kidney insufficiency.

Therapies for Membranous Nephropathy: A Tale From the Old and New Millennia

Primary Membranous Nephropathy (PMN) is the most frequent cause of nephrotic syndrome in adults. If untreated, PMN can lead to end-stage renal disease; moreover, affected patients are at increased risk of complications typical of nephrotic syndrome such as fluid overload, deep vein thrombosis and infection. The association of PMN with HLA-DQA1 and the identification in around 70% of cases of circulating autoantibodies, mainly directed towards the phospholipase A2 receptor, supports the autoimmune nature of the disease. In patients not achieving spontaneous remission or in the ones with deteriorating kidney function and severe nephrotic syndrome, immunosuppression is required to increase the chances of achieving remission. The aim of this review is to discuss the evidence base for the different immunosuppressive regimens used for PMN in studies published so far; the manuscript also includes a section where the authors propose, based upon current evidence, their recommendations regarding immunosuppression in the disease, while highlighting the still significant knowledge gaps and uncertainties.

Negative anti-phospholipase A2 receptor antibody status at three months predicts remission in primary membranous nephropathy

Background

The value of anti-phospholipase A2 receptor antibody (anti-PLA2R ab) monitoring at 3 months after diagnosis in membranous nephropathy (MN) remains uncertain.

Methods

We retrospectively examined the outcome on 1 August 2020 of 59 adult patients (age 54 (44, 68) years, 69% male, SCr 1.0 (0.9, 1.3) mg/dL) diagnosed with MN (kidney biopsy, positive serum anti-PLA2R ab). The outcomes were: kidney survival; partial and/or complete remission.

Results

Most of the studied patients (97%) received immunosuppression, cyclophosphamide regimens were the most frequent (87%), followed by cyclosporine (10%). The median time to remission was 12.0 months and the cumulative remission rates were 34% at 6, 54% at 12, and 73% at 24 months. Forty (69%) patients had negative anti-PLA2R ab at 3 months, they had similar age, serum creatinine, albumin, proteinuria, and treatment with the group with positive ab at 3 months. In the Cox proportional hazard model, three months anti-PLA2R ab negativization (HR 0.4 (95%CI 0.1, 0.9)) was an independent predictor for remission, while baseline hypoalbuminemia (HR 3.0 (95%CI 1.5, 5.7)) was associated with absence of remission. Six (10%) patients died, mostly due to cardiovascular disease and infections. A total of five (9%) patients started dialysis. Mean kidney survival time was 50.3 months and there was no survival difference in relation to baseline anti-PLA2R ab titer (p .09) or 3 months negativization (p .8).

Conclusions

Three months anti-PLA2R ab negativization seems to be a late predictor of remission, and lower serum albumin at diagnosis is an early marker for remission absence. Abbreviations: anti-P LA2R ab, anti-phospholipase A2 receptor antibody; eGFR, estimated glomerular filtration rate; ESKD, end stage kidney disease; MN, membranous nephropathy; NELL-1, neural epidermal growth factor-like 1 protein; RAAS: renin–angiotensin–aldosterone system; RBC: red blood cells; RRT, renal replacement therapy; T HSD7A, thrombospondin type-1 domain containing 7A

Efficacy and safety of tacrolimus monotherapy versus tacrolimus-corticosteroid combination therapy for idiopathic membranous nephropathy: A meta-analysis

OBJECTIVE

The objective of this meta-analysis was to compare the efficacy and safety of tacrolimus (TAC) monotherapy versus TAC-corticosteroid combination therapy in idiopathic membranous nephropathy (IMN) patients.

METHODS

Databases including PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure, and Wanfang database were searched from inception to January 10, 2021. Eligible studies comparing TAC monotherapy and TAC-corticosteroid combination therapy in IMN patients were included. Data were analysed using Review Manager Version 5.3.

RESULTS

Seven studies were included in the meta-analysis. One randomized controlled trial and six cohort studies involving 372 patients were identified. Compared with TAC monotherapy, TAC-corticosteroid had a higher total remission at the sixth month (odd ratio (OR) 0.49, 95% confidence interval (CI) 0.31-0.78, P < .01). The two therapy regimens had similar complete remission rates (OR 0.79, 95% CI 0.43-1.48, P = .47) at the sixth month and similar relapse rates (OR 1.44, 95% CI 0.70-2.92, P = .32). TAC-corticosteroid combination therapy had a higher incidence of infection (OR 0.38, 95% CI 0.18-0.81, P = .01). The two therapy regimens had similar incidences of gastrointestinal symptoms (OR 0.96, 95% CI 0.34-2.70, P = .93), abnormal aminotransferase (OR 0.90, 95% CI 0.34-2.38, P = .84), and glucose intolerance (OR 0.58, 95% CI 0.32-1.07, P = .08).

CONCLUSION

TAC-corticosteroid combination therapy had a higher total remission rate at the sixth month but had a higher incidence of infection than TAC monotherapy in the treatment of IMN. The two therapeutic regimens had similar relapse rates.

Immunosuppressive treatment for primary membranous nephropathy in adults with nephrotic syndrome

BACKGROUND

Primary membranous nephropathy (PMN) is a common cause of nephrotic syndrome in adults. Without treatment, approximately 30% of patients will experience spontaneous remission and one third will have persistent proteinuria. Approximately one-third of patients progress toward end-stage kidney disease (ESKD) within 10 years. Immunosuppressive treatment aims to protect kidney function and is recommended for patients who do not show improvement of proteinuria by supportive therapy, and for patients with severe nephrotic syndrome at presentation due to the high risk of developing ESKD. The efficacy and safety of different immunosuppressive regimens are unclear. This is an update of a Cochrane review, first published in 2004 and updated in 2013.

OBJECTIVES

The aim was to evaluate the safety and efficacy of different immunosuppressive treatments for adult patients with PMN and nephrotic syndrome.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 1 April 2021 with support from the Cochrane Kidney and Transplant Information Specialist using search terms relevant to this review. Studies in the Register were identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) investigating effects of immunosuppression in adults with PMN and nephrotic syndrome were included.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, quality assessment, and data synthesis were performed using Cochrane-recommended methods. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Sixty-five studies (3807 patients) were included. Most studies exhibited a high risk of bias for the domains, blinding of study personnel, participants and outcome assessors, and most studies were judged unclear for randomisation sequence generation and allocation concealment. Immunosuppressive treatment versus placebo/no treatment/non-immunosuppressive treatment In moderate certainty evidence, immunosuppressive treatment probably makes little or no difference to death, probably reduces the overall risk of ESKD (16 studies, 944 participants: RR 0.59, 95% CI 0.35 to 0.99; I² = 22%), probably increases total remission (complete and partial) (6 studies, 879 participants: RR 1.44, 95% CI 1.05 to 1.97; I² = 73%) and complete remission (16 studies, 879 participants: RR 1.70, 95% CI 1.05 to 2.75; I² = 43%), and probably decreases the number with doubling of serum creatinine (SCr) (9 studies, 447 participants: RR 0.46, 95% CI 0.26 to 0.80; I² = 21%). However, immunosuppressive treatment may increase the number of patients relapsing after complete or partial remission (3 studies, 148 participants): RR 1.73, 95% CI 1.05 to 2.86; I² = 0%) and may lead to a greater number experiencing temporary or permanent discontinuation/hospitalisation due to adverse events (18 studies, 927 participants: RR 5.33, 95% CI 2.19 to 12.98; I² = 0%). Immunosuppressive treatment has uncertain effects on infection and malignancy. Oral alkylating agents with or without steroids versus placebo/no treatment/steroids Oral alkylating agents with or without steroids had uncertain effects on death but may reduce the overall risk of ESKD (9 studies, 537 participants: RR 0.42, 95% CI 0.24 to 0.74; I² = 0%; low certainty evidence). Total (9 studies, 468 participants: RR 1.37, 95% CI 1.04 to 1.82; I² = 70%) and complete remission (8 studies, 432 participants: RR 2.12, 95% CI 1.33 to 3.38; I² = 37%) may increase, but had uncertain effects on the number of patients relapsing, and decreasing the number with doubling of SCr. Alkylating agents may be associated with a higher rate of adverse events leading to discontinuation or hospitalisation (8 studies 439 participants: RR 6.82, 95% CI 2.24 to 20.71; I² = 0%). Oral alkylating agents with or without steroids had uncertain effects on infection and malignancy. Calcineurin inhibitors (CNI) with or without steroids versus placebo/no treatment/supportive therapy/steroids We are uncertain whether CNI with or without steroids increased or decreased the risk of death or ESKD, increased or decreased total or complete remission, or reduced relapse after complete or partial remission (low to very low certainty evidence). CNI also had uncertain effects on decreasing the number with a doubling of SCr, temporary or permanent discontinuation or hospitalisation due to adverse events, infection, or malignancy. Calcineurin inhibitors (CNI) with or without steroids versus alkylating agents with or without steroids We are uncertain whether CNI with or without steroids increases or decreases the risk of death or ESKD. CNI with or without steroids may make little or no difference to total remission (10 studies, 538 participants: RR 1.01, 95% CI 0.89 to 1.15; I² = 53%; moderate certainty evidence) or complete remission (10 studies, 538 participants: RR 1.15, 95% CI 0.84 to 1.56; I² = 56%; low certainty evidence). CNI with or without steroids may increase relapse after complete or partial remission. CNI with or without steroids had uncertain effects on SCr increase, adverse events, infection, and malignancy. Other immunosuppressive treatments Other interventions included azathioprine, mizoribine, adrenocorticotropic hormone, traditional Chinese medicines, and monoclonal antibodies such as rituximab. There were insufficient data to draw conclusions on these treatments.

AUTHORS' CONCLUSIONS

This updated review strengthened the evidence that immunosuppressive therapy is probably superior to non-immunosuppressive therapy in inducing remission and reducing the number of patients that progress to ESKD. However, these benefits need to be balanced against the side effects of immunosuppressive drugs. The number of included studies with high-quality design was relatively small and most studies did not have adequate follow-up. Clinicians should inform their patients of the lack of high-quality evidence. An alkylating agent (cyclophosphamide or chlorambucil) combined with a corticosteroid regimen had short- and long-term benefits, but this was associated with a higher rate of adverse events. CNI (tacrolimus and cyclosporin) showed equivalency with alkylating agents however, the certainty of this evidence remains low. Novel immunosuppressive treatments with the biologic rituximab or use of adrenocorticotropic hormone require further investigation and validation in large and high-quality RCTs.

Tetrandrine may treat membranous glomerulopathy via P13K/Akt signaling pathway regulation: therapeutic mechanism validation using Heymann nephritis rat model

Membranous glomerulopathy (MGN) is an autoimmune kidney disease that is the primary cause of nephrotic syndrome (NS) in adults. Tetrandrine, a bisbenzylisoquinoline alkaloid, is known to have numerous pharmacological effects. In this study, network pharmacology analysis and experimental validation were conducted to analyze the mechanisms by which tetrandrine functions as a therapeutic intervention for MGN. A systematic network pharmacology method was applied to identify potential targets and determine the therapeutic mechanism of tetrandrine in MGN treatment. A Heymann nephritis (HN) rat model was developed to assess the therapeutic effects of tetrandrine on NS and validate the predicted molecular mechanisms. We obtained 86 potential targets of tetrandrine for the treatment of NS. In vivo experiments showed that tetrandrine could reduce the 24-h urine protein content, decrease glomerular basement membrane proliferation, and significantly decrease thylakoid stroma and cell proliferation in the HN rat kidney tissue. Moreover, tetrandrine suppressed kidney cell apoptosis and upregulated the expression of nephrin and podocin in HN model rats. qRT-PCR results revealed that tetrandrine inhibited IL-1β, TNFα, and MCP-1 levels in HN model rats. Western blot results indicated that tetrandrine can protect against MGN via the PI3K/Akt signaling pathway. Thus, by using a combination of network and experimental pharmacology methods, we demonstrate that tetrandrine can treat MGN via the PI3K/Akt signaling pathway and provide novel insights into the mechanisms underlying tetrandrine-mediated management of MGN.

Membranous nephropathy: Treatment outline and risk stratification

Membranous nephropathy (MN) is the most common cause of nephrotic syndrome in adult. However, the exact etiology and the best treatment approach are still unclear. It is imperative to understand the nature of and prognosis of MN before initiating treatment which may include disease specific therapy based on a careful risk-stratification approach.

The evolution of the therapeutic approach to membranous nephropathy

Primary membranous nephropathy (MN) is a frequent cause of nephrotic syndrome (NS) in adults. In untreated patients, the outcome is variable, with one-third of the patients entering remission while the remaining ones show persisting proteinuria or progression to end-stage renal disease. Randomized clinical trials reported the efficacy of a 6-month regimen alternating intravenous and oral glucocorticoids with an alkylating agent every other month. The potential side effects of this regimen were limited by the fact that the use of glucocorticoids and alkylating agent did not exceed 3 months each. Two randomized trials with follow-ups (FU) up to 10 years provided assurance about the long-term efficacy and safety of this cyclical therapy. Calcineurin inhibitors have also been used successfully. However, in most responders, NS relapsed after the drug was withdrawn. Conflicting results have been reported with mycophenolate salts and adrenocorticotropic hormone. Observational studies reported good results with rituximab (RTX). Two controlled trials demonstrated the superiority of RTX over antiproteinuric therapy alone and cyclosporine. However, the FUs were relatively short and no randomized trial has been published against cyclical therapy. The available results, together with the discovery that most patients with MN have circulating antibodies against the phospholipase A2 receptor 1, support the use of cytotoxic drugs or RTX in MN. It is difficult to choose between these two different treatments. RTX is easier to use, but the FUs of the available studies are short, thus doubts remain about the long-term risk of relapses and the safety of repeated administrations of RTX.

Efficacy and safety of tacrolimus monotherapy versus cyclophosphamide-corticosteroid combination therapy for idiopathic membranous nephropathy: A meta-analysis

OBJECTIVE

The objective of this meta-analysis was to compare the efficacy and safety of tacrolimus (TAC) monotherapy versus cyclophosphamide (CTX)-corticosteroid combination therapy in idiopathic membranous nephropathy (IMN) patients.

METHODS

Databases including the PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure, and Wanfang databases were searched from inception to October 20, 2020. Eligible studies comparing TAC monotherapy and CTX-corticosteroid combination therapy in IMN patients were included. Data were analyzed using Review Manager Version 5.3.

RESULTS

Nine studies were included in the meta-analysis. One randomized controlled trial and eight cohort studies involving 442 patients were identified. Compared with CTX-corticosteroid combination therapy for IMN, TAC monotherapy had higher complete remission (CR) at month 6 (odds ratio [OR] 2.18, 95% confidence interval [CI] 1.35-3.50, P < .01). The 2 therapeutic regimens had similar partial remission (OR 0.69, 95% CI 0.45-1.04, P = .08), total remission (OR 1.38, 95% CI 0.85-2.23, P = 0.19) at month 6, and similar CR (OR 1.64, 95% CI 0.84-3.19, P = .15), partial remission (OR 0.71, 95% CI 0.37-1.38, P = 0.31), and total remission (OR 1.29, 95% CI 0.55-3.01, P = .56) after 1 year. The relapse rate of the TAC group was higher than that of the CTX group, but the difference was not statistically significant (OR 1.85, 95% CI 0.75-4.53, P = .18). There was no difference between the 2 therapeutic regimens concerning glucose intolerance (OR 1.15, 95% CI 0.61-2.14, P = .67), acute renal failure (OR 1.14, 95% CI 0.39-3.33, P = .81), or tremors (OR 4.39, 95% CI 0.75-25.67, P = .10). Incidences of gastrointestinal symptoms (OR 0.29, 95% CI 0.10-0.79, P = .02), infection (OR 0.18, 95% CI 0.08-0.39, P < 0.01), leukopenia (OR 0.14, 95% CI 0.04-0.51, P < .01), and abnormal aminotransferase (OR 0.31, 95% CI 0.13-0.77, P = .01) in the TAC group were all lower than those in the CTX group. Subgroup analysis showed that there was no significant difference between the TAC group and the CTX combined with corticosteroid 0.8 to 1 mg/kg/day group concerning CR at month 6 (P > .05). There was no significant difference between the TAC group and the CTX combined with corticosteroid 0.5 mg/kg/day group concerning abnormal aminotransferase (P > .05).

CONCLUSION

TAC monotherapy is comparable to CTX-corticosteroid combination therapy for renal remission in IMN patients. TAC monotherapy had a higher CR in the early stage and had fewer drug-related adverse effects. The relapse rate of TAC monotherapy was higher than that of CTX-corticosteroid combination therapy, but the difference was not significant.

Herbal Medicine "Shulifenxiao" Formula for Nephrotic Syndrome of Refractory Idiopathic Membranous Nephropathy

Background: Treatment for adult patients with refractory idiopathic membranous nephropathy (RIMN) by conventional immunosuppressive regimens is not satisfactory. This study aims to evaluate the effectiveness of Chinese herbal medicine, Shulifenxiao formula, as a promising regimen.

Methods: A total of 31 RIMN patients resistant to corticosteroid or immunosuppressive agents were retrospectively analyzed. Shulifenxiao treatment lasted a minimum of 12°months in all patients and extended to 24°months in 11 patients. The primary outcomes [the complete remission (CR) and partial remission (PR)] and secondary outcomes (the serum creatinine and estimated glomerular filtration rate (eGFR) levels) were measured at 6, 12, 18, and 24°months.

Results: The data provided an average follow-up of 21 ± 9.16°months from baseline. The remission was attained in 25/31 patients (80.7%: CR 29.0% and PR 51.6%) at 12°months and in 10/11 patients (90.9%: CR 54.6% and PR 36.4%) at 24°months, respectively. Proteinuria reduced from 6.02 g/d at baseline to 0.98 g/d at 12°months (p < 0.001) and to 0.27 g/d at 24°months (p = 0.003); serum albumin increased from 28 g/L to 37.2 g/L at 12°months (p < 0.001) and to 41.3 g/L at 24°months (p = 0.003); eGFR improved from 100.25 ml/min/1.73 m² to 118.39 ml/min/1.73 m² at 6°months (p < 0.001) and finally to 111.62 ml/min/1.73 m²at 24°months (p = 0.008). Only two patients developed subsequent relapse.

Conclusion: Shulifenxiao formula as a clinical cocktail therapy serves as an alternative therapeutic option for steroid and immunosuppressant-resistant RIMN patients, with a favourable safety profile, though further studies are warranted.

Clinical Trial registration:http://www.chictr.org.cn, Chinese Clinical Trials Registry [ChiCTR1800019351].

Effectiveness and safety of cyclophosphamide or tacrolimus therapy for idiopathic membranous nephropathy

BACKGROUND

Guidelines recommend classical combined therapy of steroid and cyclophosphamide (CYC) for patients with idiopathic membranous nephropathy (IMN), while it is associated with severe adverse effects.

AIMS

We conducted an observational and retrospective study to evaluate the effectiveness and safety of steroids plus tacrolimus (TAC) versus steroids plus CYC for IMN.

METHODS

A total of 203 kidney-biopsy-proven IMN patients was enrolled in this study. One group (n = 142) received steroid combined with intravenous CYC (750 mg/m² body surface) and the other group (n = 61) received steroid combined with oral TAC (target blood concentration of 4-8 ng/mL). The primary outcomes were achievement of remission. The secondary end-points included incidence of adverse events, relapse rates, 24 h urinary protein (UP), serum albumin, serum creatinine and estimated glomerular filtration rate.

RESULTS

Over the 18-month observation period, the study suggested that the remission rates at the first 3 months were significantly higher in TAC group than in CYC group (72.1% vs 54.9%, P < 0.05). Although the cumulative incidence of serious and non-serious adverse events was not different significantly between the two groups, the incidence after first 3 months was lower in TAC group. Levels of 24-h UP and serum albumin improved in the TAC group more than in the CYC group (P < 0.05) over the observed period.

CONCLUSIONS

Because of its short-term effectiveness and long-term safety profile, steroid plus TAC might be a better option for IMN.

Effectiveness and safety of cyclophosphamide or tacrolimus therapy for idiopathic membranous nephropathy

Background: Guidelines recommend combined therapy of glucocorticoid and cyclophosphamide (CYC) for patients with idiopathic membranous nephropathy (IMN), while it is associated with severe adverse effects. We conducted a retrospective study to evaluate the effectiveness and safety of glucocorticoid plus tacrolimus (TAC) for IMN.

Methods: Two hundred and three kidney-biopsy-proven IMN patients were enrolled in this study. One group (n = 142) received glucocorticoid combined with intravenous CYC (750 mg/m² body surface) and the other group (n = 61) received glucocorticoid combined with oral TAC (target blood concentration of 4–8 ng/mL). The primary outcomes were achievement of remission and incidence of adverse events. The secondary end points included relapse rates, 24 h urinary protein (UP), serum albumin, serum creatinine and estimated glomerular filtration rate.

Results: Over the 18-month observation period, the study suggested that the remission rates at the first 3 months were significantly higher in TAC group than in CYC group (72.1% versus 54.9%, p < .05). Although the cumulative incidence of serious and non-serious adverse events was not different significantly between the two groups, the incidence after first 3 months was lower in TAC group. 24hUP and serum albumin improved in TAC group more than the CYC group (p < .05) over the observed period.

Conclusion: Because of its short-term effectiveness and long-term safety profile, glucocorticoid plus TAC might be a better option for IMN.

Rituximab versus steroids and cyclophosphamide for the treatment of primary membranous nephropathy: protocol of a pilot randomised controlled trial

INTRODUCTION

Primary membranous nephropathy (MN) is a common cause of nephrotic syndrome in adults. The disease may have different long-term outcomes. After 10 years of follow-up, 35%-50% of the untreated patients with persistent nephrotic syndrome may die or progress to end stage renal disease. The 2012 KDIGO (Kidney Disease Improving Global Outcomes) guidelines recommend that initial therapy should consist of alternating steroids and an alkylating agent for 6 months. Recent observational studies showed that the anti-CD20 antibody rituximab may be effective in inducing remission. We designed a pilot multicentre randomised trial to inform the design of a larger trial testing the efficacy and safety of treatment with steroids and cyclophosphamide versus rituximab in patients with primary MN and heavy proteinuria (>3.5 g/24 hours).

METHODS AND ANALYSIS

This pilot, open-label, two-parallel-arm, randomised clinical trial will enrol 70 patients with primary MN and heavy proteinuria. Patients will be randomised in a 1:1 ratio to either the intervention arm (rituximab) or the active comparator arm (corticosteroid/alkylating-agent therapy). The study will provide estimates of the probability of complete remission of proteinuria and risk of serious side effects at 12 months to inform the design of a larger trial. We will also assess the recruitment potential of each participating centre to address study feasibility.

ETHICS AND DISSEMINATION

The trial received ethics approval from the local ethics boards. We will publish pilot data to inform the design of a larger clinical trial.

TRIAL REGISTRATION NUMBERS

NCT03018535; 2011-006115-59.

Renoprotective Effects Of Isoliquiritin Against Cationic Bovine Serum Albumin-Induced Membranous Glomerulonephritis In Experimental Rat Model Through Its Anti-Oxidative And Anti-Inflammatory Properties

Background

Membranous glomerulonephritis (MGN) is a nephrotic syndrome which shows the symptoms of heavy proteinuria and immune complex deposition in glomerular sub-epithelial space and finally leads to chronic kidney disease. Isoliquiritin (ILQ) is a flavonoid with a wide range of pharmacological properties, including antioxidant and anti-inflammatory activity. The present study was undertaken to investigate the possible mechanisms by which ILQ ameliorates cationic bovine serum albumin (C-BSA) induced MGN in rat model.

Methods

The MGN condition was confirmed by the 24 hr proteinuria and ILQ (10 mg/kg/bw/day) or TPCA-1 (10 mg/kg/bw/day; IKKβ inhibitor) was administered to successfully induce rats for 4 weeks.

Results

The present study revealed that MGN rats treated with ILQ showed significantly ameliorated kidney dysfunction and histopathological changes in kidneys. ILQ treated MGN rats alleviated the oxidative stress and were presented with increased anti-oxidative status in kidneys. Furthermore, ILQ treatment to MGN rats showed anti-oxidative effects through the prominent stimulation of Nrf2 signaling pathway and inhibition of Keap1, which consequently increases the Nrf2 nuclear translocation and thereby induces expression of NQO1 and HO-1. In addition, ILQ-treated MGN rats demonstrated anti-inflammatory effects by inhibiting NF-κB signaling pathway through decreased mRNA and protein expressions of NF-κB p65, IKKβ, COX-2, iNOS, p38-MAPK, p-p38-MAPK, TNF-α, IL-1β, IL-8, ICAM-1, E-selectin and VCAM-1 and reduced the nuclear translocation of NF-κB p65.

Conclusion

The protective effect of ILQ on MGN can be explained by its anti-oxidative and anti-inflammatory activities, which in turn due to the activation of Nrf2 and downregulation of NF-κB pathway.

Clinical outcomes and effects of treatment in older patients with idiopathic membranous nephropathy

BACKGROUND/AIMS

Membranous nephropathy (MN) is the most common primary glomerular disease diagnosed in older patients. Few reports describe the clinical outcomes in older patients with idiopathic MN.

METHODS

The outcomes of 135 patients with histologically proven MN were analyzed. 'Older' was defined as 60 years of age or older at the time of the renal biopsy. The rates of complete remission (CR), progression to end-stage renal disease (ESRD) and infection were compared between older and younger patients.

RESULTS

The cumulative event rate for achieving CR was inferior (p = 0.012) and that for requiring renal replacement was higher (p = 0.015) in older patients, and they had a greater risk of infection (p = 0.005). Older age was a significant predictor of a lower rate of CR (adjusted odds ratio [OR], 0.51; 95% confidence interval [CI], 0.26 to 0.98), and was a robust predictor of infection (adjusted OR, 5.27; 95% CI, 1.31 to 21.20). Conservative treatment was associated with a lower remission rate (p = 0.036) and corticosteroid treatment was less effective in achieving CR (p = 0.014), in preventing progression to ESRD (p = 0.013) and in reducing infection (p = 0.033) in older patients. Cyclosporine treatment had similar clinical outcomes with regard to CR, ESRD progression, and infection in older patients.

CONCLUSION

Older age was independently associated with inferior rates of CR and greater risk of infection. Treatment modalities affected the outcomes of older patients differently in that cyclosporine treatment is predicted to be more useful than corticosteroids.

Efficacy and safety of tacrolimus-based treatment for nephrotic idiopathic membranous nephropathy in young adults: A retrospective study

In China, the prevalence of idiopathic membranous nephropathy (IMN) is increasing with a younger age of onset. From January 2012 to October 2018, biopsy-proven nephrotic IMN patients aged between 15 and 40 in Taian City Central Hospital treated with tacrolimus (TAC) were retrospectively analyzed. Twelve-month follow-up data were collected. A total of 86 patients were enrolled in this study. Forty patients in the TAC group received TAC monotherapy with an initial dose of 0.05 to 0.1 mg/kg/day. Forty-six patients in the TAC + Pred group received TAC combined with oral prednisone (0.5 mg/kg/day initially). Remission rate, relapse rate, and adverse events in the two groups were assessed. Total remission (TR) rates at the end of the 3rd, 6th, and 12th month were 15%, 35%, and 77.5% (TAC group) and 28.3%, 56.5%, and 80.4% (TAC + Pred group), respectively. Compared with the TAC group, the TAC + Pred group had higher complete remission rates at the end of the 6th and 12th month, and TR rate at the 6th month was significantly higher. Twenty-four-hour urinary protein excretion, serum albumin and estimated glomerular filtration rate between the two groups were comparable during the follow-up. Decrease in proteinuria was significantly greater in the TAC + Pred group. No significant difference of relapse rate was found between the two groups. Adverse effects in the two groups were mild and controllable. Both TAC monotherapy and TAC combined with medium-dose prednisone are effective and safe for young adults with nephrotic IMN, while TAC + Pred regimen brings more benefits.

Clinical and pathological features of idiopathic membranous nephropathy in young people

AIM

To investigate the clinico-pathological features of idiopathic membranous nephropathy (IMN) in youth.

METHODS

Patients with biopsy-proven IMN in Peking University Third Hospital from May 2015 to October 2017 (n = 147) were enrolled in this study. Patients were divided into youth (≤35 years old), middle-age (35-65 years old) and elderly group (>65 years old) accordingly. Medical records of patients were retrospectively analyzed.

RESULTS

Youth group exhibited shorter duration from onset to biopsy (3.49 ± 4.25 months in youth vs 8.71 ± 12.24 months in elderly) and milder clinical presentations in terms of less proteinuria and higher serum albumin (P < 0.05). Furthermore, lower anti-phospholipase A2 receptor (PLA2R) antibody titre (65.36 ± 101.14 RU/mL in youth vs 137.45 ± 215.12 RU/mL in middle-age), less C3 deposits (35.14% in youth vs 65.00% in elderly) and higher 6-month remission rate (63.64% in youth vs 36.00% in middle-age) were observed in youth (P < 0.05). Multiple linear regression confirmed C3 deposits (P = 0.005) and anti-PLA2R (P = 0.040) were independent factors influencing proteinuria, and age is an independent influencing factor for time from onset to biopsy (P = 0.043). Older age (OR = 2.044, 95% CI: 1.073-3.896, P = 0.030) and higher anti-PLA2R (OR = 1.413, 95% CI: 1.020-1.959, P = 0.038) were significantly associated with non-remission by 6 months.

CONCLUSION

Younger patients with IMN tend to have rapider onset and quicker remission than older patients. Milder clinical presentations in youth are associated with lower anti-PLA2R antibody titre and less C3 deposits.

Does cyclophosphamide still play a role in glomerular diseases?

Cyclophosphamide is a prodrug that is converted to inactive carboxy-cyclophosphamide, acrolein and phosphoramide mustard, an agent that adds alkyl groups to oxygen and nitrogen atoms of guanine, one of the four nitrogen bases that form the DNA nucleotides, causing DNA cross-links and introducing DNA breaks. These cytotoxic and mutagenic effects mainly occur in proliferating cells. Repair mechanisms may prevent DNA damage in quiescent cells, but they may be insufficient to contrast the side effects of cyclophosphamide if high doses of the drug are used. Most adverse events are dose- and age-dependent. Phosphoramide mustard can cause bone marrow toxicity, gonadal toxicity, and may favor the development of leukemia, bladder cancer and other types of malignancy. Acrolein can produce hemorrhagic cystitis and even bladder fibrosis when given for prolonged periods. A number of precautional measures should be taken to prevent these untoward events. In particular, long-term administration and high doses of cyclophosphamide should be avoided whenever possible. Today the indications to cyclophosphamide in glomerular diseases are more restricted than in the past, but the drug is still used as a steroid-sparing agent in steroid-sensitive minimal change disease and focal segmental glomerulosclerosis. In membranous nephropathy, cyclophosphamide, alternated or associated with corticosteroids, proved to be beneficial in obtaining remission of nephrotic syndrome and preserving renal function. Cyclophosphamide is considered as a first-line treatment for rapidly progressive glomerulonephritis and the hectic phases of lupus nephritis. In conclusion, cyclophosphamide is a cheap drug that may be useful in a number of glomerular diseases but it may lead to severe side effects. A close monitoring of blood count and clinical conditions, as well as low cumulative doses of cyclophosphamide are strongly recommended when using the drug in patients with renal diseases.

Clinical and Histological Features of Phospholipase A2 Receptor-Associated and Thrombospondin Type-I Domain-containing 7A-Associated Idiopathic Membranous Nephropathy: A Single Center Retrospective Study from China

Background

M-type phospholipase A2 receptor (PLA2R) was identified as the major target antigen in idiopathic membranous nephropathy (IMN). Another target antigen, namely thrombospondin type-1 domain-containing 7A (THSD7A), was recently detected in approximately 10% of non-PLA2R-associated IMN. In this single center retrospective study, clinical and histological features of PLA2R-associated and THSD7A-associated IMN patients were evaluated.

Material/Methods

A total of 192 IMN patients, who were receiving no glucocorticoids or immunosuppressant before renal biopsy, were enrolled in this study and followed for a median duration of 25.5 months. IMN with enhanced glomerular PLA2R and THSD7A staining by immunohistochemistry (IHC) were designated as PLA2R-associated IMN and THSD7A-associated IMN respectively. Serum anti-PLA2R and anti-THSD7A antibodies levels were assessed by enzyme linked immunosorbent assay and indirect immunofluorescence testing in PLA2R-associated and THSD7A-associated IMN.

Results

Of 192 IMN patients, 164 patients (85.4%) had PLA2R-associated IMN and 3 patients (1.6%) had THSD7A-associated IMN. Compared with non-PLA2R-associated IMN patients, the 24-hour urinary protein levels were significantly higher (P=0.008), whereas, the proteinuria remission rates were significantly lower (P=0.03) in PLA2R-associated IMN patients. No pathological differences were found between PLA2R-associated IMN and non-PLA2R-associated IMN. Among 3 THSD7A-associated IMN patients, 1 patient had elevated serum anti-THSD7A antibody levels, which was below detectable levels after achieving partial proteinuria remission with combined glucocorticoid and cyclosporine treatment.

Conclusions

Compared with non-PLA2R-associated IMN patients in our cohort, PLA2R-associated IMN patients presented with more severe proteinuria and lower remission rates after treatment, with no distinct histological differences. Glomerular expression of PLA2R could be a useful marker to indicate the severity, treatment response, and prognosis of IMN.

Retrospective analysis of tacrolimus combined with Tripterygium wilfordii polyglycoside for treating idiopathic membranous nephropathy

BACKGROUND

Idiopathic membranous nephropathy (IMN) is one of the most common adult nephrotic syndromes. Some patients with this disorder require immunosuppressive therapy. This retrospective case series was performed to assess the effects of tacrolimus (TAC) combined with Tripterygium wilfordii polyglycoside (TWG) in treating IMN.

METHODS

From January 2015 to August 2016, kidney-biopsy-proven IMN patients treated with TAC in the Chinese PLA General Hospital were screened. Data were retrieved from the patients' medical records. The first efficacy evaluation index was remission rate (complete remission and partial remission), and the secondary efficacy evaluation indices included relapse rate, proteinuria, serum albumin and estimated glomerular filtration rate (eGFR). Adverse events were also assessed.

RESULTS

The included patients' treatments were tacrolimus monotherapy (TAC group, n = 33), tacrolimus combined with methylprednisolone (MP) (TAC + MP group, n = 24) and tacrolimus combined with Tripterygium wilfordii polyglycoside (TAC + TWG group, n = 21). The remission rates of the TAC, TAC + MP, and TAC + TWG groups in the 10th month were 54.5, 62.5, and 85.7%, respectively (TAC + TWG group vs TAC group, P = 0.037, TAC + TWG group vs TAC + MP group, P = 0.125). Moreover, the complete remission rates of the TAC, TAC + MP, and TAC + TWG groups in the 10th month were 21.2, 20.8, and 57.1%, respectively (TAC + TWG group vs TAC group, P = 0.007, TAC + TWG group vs TAC + MP group, P = 0.012). Compared with the TAC group, the TAC + TWG group had a higher remission rate during these ten months (log-rank, P = 0.005). Compared with the TAC and TAC + MP groups, the TAC + TWG group had a higher complete remission rate (log-rank, P = 0.019 and log-rank, P = 0.005, respectively).

CONCLUSION

This retrospective study showed that TAC combined with TWG may be effective for treating IMN. Further randomized controlled trials (RCTs) are needed to assess the efficacy and safety of TAC combined with TWG.

Inhibition of tumor necrosis factor signaling attenuates renal immune cell infiltration in experimental membranous nephropathy

Idiopathic membranous nephropathy (MN) is an autoimmune-mediated glomerulonephritis and the most common cause of idiopathic nephrotic syndrome in adult humans. A tumor necrosis factor α (TNF-α)-mediated inflammatory response via TNF receptor 1 (TNFR1) and TNFR2 has been proposed as a pathogenic factor. In this study, we assessed the therapeutic response to blocking TNF signaling in experimental MN. Murine MN was induced experimentally by cationic bovine serum albumin (cBSA); phosphate-buffered saline was used in control mice. In MN mice, TNF was inhibited by etanercept blocking of TNFR1/TNFR2 or the preligand assembly domain fusion protein (PLAD.Fc), a small fusion protein that can preferentially block TNFR1 signaling. Disease severity and possible mechanisms were assessed by analyzing the metabolic and histopathology profiles, lymphocyte subsets, immunoglobulin production, oxidative stress, and apoptosis. cBSA-induced MN mice exhibited typical nephrotic syndrome and renal histopathology. MN mice given etanercept or PLAD.Fc did not exhibit significant reduction of proteinuria, amelioration of glomerular lesions, or attenuation of immune complex deposition. Immune cell subsets, serum immunoglobulin levels, production of reactive oxygen species, and cell apoptosis in the kidney were not altered by TNF inhibition. By contrast, MN mice receiving etanercept or PLAD.Fc exhibited significantly decreased infiltration of immune cells into the kidney. These results show that the therapeutic effects of blocking TNFR1 and/or TNFR2 signaling in experimental MN are not clinically effective. However, TNF signaling inhibition significantly attenuated renal immune cell infiltration in experimental MN.

Treatment of primary membranous nephropathy: where are we now?

In the last 10 years, basic science and clinical research have made important contributions to the understanding and management of primary membranous nephropathy (MN). The identification of antibodies directed against the M-type phospholipase A₂ receptor (PLA2R) and thrombospondin type-1 domain-containing 7A protein have added a new perspective on diagnosis, monitoring the immunological activity, predicting prognosis and guiding therapy in patients with primary MN. Mounting evidence suggests that quantification and follow-up of antiPLA2R Abs levels can help in assessing prognosis and evaluate the response to treatment. The kidney disease improving global outcomes guidelines published in 2012 have not been updated. New data on the use of rituximab suggest it should be considered as a potential initial therapy in the treatment of patients with primary MN.

Treatment of membranous nephropathy: time for a paradigm shift

In patients with membranous nephropathy, alkylating agents (cyclophosphamide or chlorambucil) alone or in combination with steroids achieve remission of nephrotic syndrome more effectively than conservative treatment or steroids alone, but can cause myelotoxicity, infections, and cancer. Calcineurin inhibitors can improve proteinuria, but are nephrotoxic. Most patients relapse after treatment withdrawal and can become treatment dependent, which increases the risk of nephrotoxicity. The discovery of nephritogenic autoantibodies against podocyte M-type phospholipase A2 receptor (PLA₂R) and thrombospondin type-1 domain- containing protein 7A (THSD7A) antigens provides a clear pathophysiological rationale for interventions that specifically target B-cell lineages to prevent antibody production and subepithelial deposition. The anti-CD20 monoclonal antibody rituximab is safe and achieves remission of proteinuria in approximately two-thirds of patients with membranous nephropathy. In those with PLA₂R-related disease, remission can be predicted by anti-PLA₂R antibody depletion and relapse by antibody re-emergence into the circulation. Thus, integrated evaluation of serology and proteinuria could guide identification of affected patients and treatment with individually tailored protocols. Nonspecific and toxic immunosuppressive regimens will fall out of use. B-cell modulation by rituximab and second-generation anti-CD20 antibodies (or plasma cell-targeted therapy in anti-CD20 resistant forms of disease) will lead to a novel therapeutic paradigm for patients with membranous nephropathy.

Single-dose Rituximab Therapy for Refractory Idiopathic Membranous Nephropathy: A Single-center Experience

To date, a recognized treatment for refractory membranous nephropathy (MN) has not been established. Recently, several reports have indicated the efficacy of rituximab as a novel treatment option. However, only a few published accounts exist of rituximab therapy for idiopathic MN (IMN) in the Asian population. We present the cases of three IMN patients who were treated with single-dose rituximab after they showed no response to conventional therapies, including corticosteroids, cyclosporine, cyclophosphamide, mizoribine, and mycophenolate mofetil. Although one case showed no response, a complete or incomplete remission was achieved in the other two cases. Rituximab may therefore be a beneficial treatment option for IMN.

Urinary Volatile Organic Compounds as Potential Biomarkers in Idiopathic Membranous Nephropathy

OBJECTIVE

To detect urinary volatile organic compounds (VOCs) in patients with idiopathic membranous nephropathy (iMN) and normal controls, and to examine whether or not urinary VOCs can act as biomarkers for the diagnosis of iMN independent of renal biopsy.

MATERIALS AND METHODS

Gas chromatography/mass spectrometry (GC/MS) was used to assess the urine collected from 63 iMN patients and 15 normal controls. The statistical methods of principal component analysis and partial least squares discriminant analysis were performed to process the final data in Common Data Format which were converted from GC/MS data.

RESULTS

Six VOCs in the urine samples of iMN patients exhibited significant differences from those of normal controls: carbamic acid monoammonium salt, 2-pentanone, 2,4-dimethyl-pentanal, hydrogen azide, thiourea, and 4-heptanone were significantly higher than in controls (p < 0.05).

CONCLUSIONS

Six urinary VOCs were isolated from patients with iMN using GC/MS. The analysis of urinary VOCs using GC/MS could be developed into a non-invasive method for the detection of iMN.

Synthetic ACTH in High Risk Patients with Idiopathic Membranous Nephropathy: A Prospective, Open Label Cohort Study

New therapeutic agents are warranted in idiopathic membranous nephropathy. Synthetic ACTH may be advantageous with reported remission rates up to 85% and few side effects. We conducted a prospective open label cohort study from 2008 till 2010 (NCT00694863). We prospectively selected patients with idiopathic membranous nephropathy and high risk for progression (defined as βeta-2-microglobulin (β2m) excretion of >500 ng/min). For comparison, we selected matched historical controls treated with cyclophosphamide. The prospectively selected patients received intramuscular injections of synthetic ACTH during 9 months (maximal dose 1 mg twice a week). The primary endpoints concerned the feasibility and incidence of remissions as a primary event. Secondary endpoints included side effects of treatment and the incidence of remissions and relapses at long-term follow-up. Twenty patients (15 men) were included (age 54±14 years, serum creatinine 104 μmol/l [IQR 90–113], urine protein:creatinine ratio 8.7 g/10 mmol creatinine [IQR 4.3–11.1]). Seventeen patients (85%) completed treatment. 97% of injections were administered correctly. Cumulative remission rate was 55% (complete remission in 4 patients, partial remission 7 patients). In a group of historical controls treated with cyclophosphamide and steroids, 19 of 20 patients (95%) developed a remission (complete remission in 13 patients, partial remission in 6 patients) (p<0.01). The main limitation of our study is its small size and the use of a historical control group. We show that treatment with intramuscular injections of synthetic ACTH is feasible. Our data suggest that synthetic ACTH is less effective than cyclophosphamide in inducing a remission in high risk patients with idiopathic membranous nephropathy. The use of synthetic ACTH was also associated with many adverse events. Therefore, we advise against synthetic ACTH as standard treatment in membranous nephropathy.

A Multicenter Randomized Controlled Trial of Rituximab versus Cyclosporine in the Treatment of Idiopathic Membranous Nephropathy (MENTOR)

BACKGROUND

Idiopathic membranous nephropathy remains the leading cause of nephrotic syndrome in Caucasian adults. Immunosuppressive therapy with cyclosporine (CSA) is often successful in reducing proteinuria, but its use is associated with a high relapse rate. Rituximab, a monoclonal antibody that specifically targets CD20 on the surface of B-cells, is effective in achieving a complete remission of proteinuria in patients with idiopathic membranous nephropathy. However, whether rituximab is as effective as CSA in inducing and maintaining complete or partial remission of proteinuria in these patients is unknown. The membranous nephropathy trial of rituximab (MENTOR) hypothesizes that B-cell targeting with rituximab is non-inferior to CSA in inducing long-term remission of proteinuria.

METHODS AND DESIGN

Patients with idiopathic membranous nephropathy, proteinuria ≥5 g/24 h, and a minimum of 3 months of Angiotensin-II blockade will be randomized into a 12-month treatment period with i.v. rituximab, 1,000 mg (2 infusions, 14 days apart; repeated at 6 months if a substantial reduction in proteinuria (equal to or >25%) is seen at 6 months) or oral CSA 3.5-5 mg/kg/day for 6 months (continued for another 6 months if a substantial reduction in proteinuria (equal to or >25%) is seen at 6 months). The efficacy of treatment will be assessed by the remission status (based on changes in proteinuria) at 24 months from randomization. Patient safety will be assessed via collection of adverse event data and evaluation of pre- and posttreatment laboratory data. At the 6-month post-randomization visit, patients who have been randomized to either CSA or rituximab but who do not have a reduction in proteinuria ≥25% (confirmed on repeat measurements within 2 weeks) will be considered treatment failures and exit the study.

DISCUSSION

This study will test for the first time whether treatment with rituximab is non-inferior to CSA in inducing long-term remission (complete or partial) of proteinuria in patients with idiopathic membranous nephropathy.

Resveratrol ameliorates renal damage, increases expression of heme oxygenase-1, and has anti-complement, anti-oxidative, and anti-apoptotic effects in a murine model of membranous nephropathy

Background

Idiopathic membranous nephropathy (MN) is an autoimmune-mediated glomerulonephritis and a common cause of nephrotic syndrome in adults. There are limited available treatments for MN. We assessed the efficacy of resveratrol (RSV) therapy for treatment of MN in a murine model of this disease.

Methods

Murine MN was experimentally induced by daily subcutaneous administration of cationic bovine serum albumin, with phosphate-buffered saline used in control mice. MN mice were untreated or given RSV. Disease severity and pathogenesis was assessed by determination of metabolic and histopathology profiles, lymphocyte subsets, immunoglobulin production, oxidative stress, apoptosis, and production of heme oxygenase-1 (HO1).

Results

MN mice given RSV had significantly reduced proteinuria and a marked amelioration of glomerular lesions. RSV also significantly attenuated immunofluorescent staining of C3, although there were no changes of serum immunoglobulin levels or immunocomplex deposition in the kidneys. RSV treatment of MN mice also reduced the production of reactive oxygen species (ROS), reduced cell apoptosis, and upregulated heme oxygenase 1 (HO1). Inhibition of HO1 with tin protoporphyrin IX partially reversed the renoprotective effects of RSV. The HO1 induced by RSV maybe via Nrf2 signaling.

Conclusion

Our results show that RSV increased the expression of HO1 and ameliorated the effects of membranous nephropathy in a mouse model due to its anti-complement, anti-oxidative, and anti-apoptotic effects. RSV appears to have potential as a treatment for MN.

Kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin as prognostic markers in idiopathic membranous nephropathy

Background

Urinary excretion of alpha-1-microglobulin and beta-2-microglobulin reflects tubular damage and predicts outcome in patients with idiopathic membranous nephropathy with reasonable accuracy. Urinary kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin are novel biomarkers of tubular damage. We investigated if these markers could improve prediction of outcome in idiopathic membranous nephropathy.

Methods

We measured kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin in urine samples from patients with idiopathic membranous nephropathy, who had nephrotic proteinuria and normal renal function. Excretion of alpha-1-microglobulin and beta-2-microglobulin had been measured previously. Progression was defined as a serum creatinine rise >30%, a rise in serum creatinine to an absolute value of ≥135  µmol/L, or a clinical decision to start immunosuppressive therapy. Remission was defined as proteinuria <3.5 g/day and >50% reduction from baseline.

Results

Sixty-nine patients were included. Median follow-up was 35 months (interquartile range 18–63 months). Progression occurred in 30 patients (44%), and spontaneous remission in 36 (52%). Kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin excretion rates were significantly correlated with each other, and with alpha-1-microglobulin and beta-2-microglobulin. The areas under the receiver operating characteristic curves for progression were 0.75 (0.62–0.87) for kidney injury molecule-1 and 0.74 (0.62–0.87) for neutrophil gelatinase-associated lipocalin. In multivariate analysis with either alpha-1-microglobulin and beta-2-microglobulin, kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin did not independently predict outcome.

Conclusion

Kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin excretion rates correlated with excretion rates of other tubular damage markers and predicted outcome in patients with idiopathic membranous nephropathy. They did not add prognostic value compared to measurement of either alpha-1-microglobulin or beta-2-microglobulin.

A 10-year follow-up of idiopathic membranous nephropathy patients on steroids and cyclophosphamide: a case series

The studies of idiopathic membranous nephropathy (IMN) require sufficiently long duration of follow-up to understand the effect of treatment on the development of end-stage renal disease (ESRD) in IMN. The aim was to assess the remission rates with steroids and cyclophosphamide regimen for IMN at the end of 10 years of follow-up. A prospective, open-label study performed in Nephrology department of a state run tertiary care centre in a southern state of India. Adult (age >18 years) patients with biopsy-proven IMN of at least 6-month duration were included in the study. Patients received a 6-month course of alternate months of steroid and cyclophosphamide. The patients were followed for 10 years. Study end points were doubling of serum creatinine, development of ESRD, or death. A total of 58 IMN patients were recruited from 1997 to 2001. Out of 58 patients included, only 48 patients could complete the treatment schedule in six months. The remission rate at the end of 10 years was 58.6% (34 in 58 patients). The probability of dialysis-free survival in our study was 89.6% at the end of 10 years follow-up. The regimen of steroids and cyclophosphamide in IMN had a remission rates not as high as reported before. It was associated with high relapse rates and more infections.

Membranous nephropathy: not just a disease for adults

Membranous nephropathy (MN) is an immune complex-mediated cause of the nephrotic syndrome that can occur in all age groups, from infants to the elderly. While systemic disorders such as hepatitis B infection or lupus may more frequently cause secondary MN in the younger population, primary or "idiopathic" MN has generally been considered a disease of adults. Recent progress in our understanding of primary disease was recently made when the target antigen in primary MN was identified as the M-type phospholipase A2 receptor (PLA2R). Circulating anti-PLA2R antibodies may serve both as a diagnostic tool for distinguishing primary from secondary disease and as a biomarker for monitoring the immunologic activity of this organ-specific autoimmune disease during treatment. Whereas definitive therapy for secondary forms of MN should be targeted at the underlying cause, immunosuppressive therapy is often necessary for primary disease. Alkylating agents in combination with corticosteroids, as well as calcineurin inhibitors (± steroids), are first line agents due to randomized controlled trials in an adult population with relatively long durations of follow-up. However, rituximab, mycophenolate and adrenocorticotropic hormone have shown promise in smaller and/or observational studies. The optimal therapy for children and adolescents with MN is less well defined.

Immunosuppressive treatment for idiopathic membranous nephropathy in adults with nephrotic syndrome

BACKGROUND

Idiopathic membranous nephropathy (IMN) is the most common form of nephrotic syndrome in adults. The disease shows a benign or indolent course in the majority of patients, with a rate of spontaneous complete or partial remission of nephrotic syndrome as high as 30% or more. Despite this, 30% to 40% of patients progress toward end-stage kidney disease (ESKD) within five to 15 years. The efficacy and safety of immunosuppression for IMN with nephrotic syndrome are still controversial. This is an update of a Cochrane review first published in 2004.

OBJECTIVES

The aim of this review was to evaluate the safety and efficacy of immunosuppressive treatments for adult patients with IMN and nephrotic syndrome. Moreover it was attempted to identify the best therapeutic regimen, when to start immunosuppression and whether the above therapies should be given to all adult patients at high risk of progression to ESKD or only restricted to those with impaired kidney function.

SEARCH METHODS

We searched Cochrane Renal Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Chinese databases, reference lists of articles, and clinical trial registries to June 2014. We also contacted principal investigators of some of the studies for additional information.

SELECTION CRITERIA

Randomised controlled trials (RCTs) investigating the effects of immunosuppression in adults with IMN and nephrotic syndrome.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, quality assessment, and data synthesis were performed using the Cochrane-recommended methods. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes.

MAIN RESULTS

Thirty nine studies with 1825 patients were included, 36 of these could be included in our meta-analyses. The data from two studies could not be extracted and one study was terminated due to poor accrual. Immunosuppression significantly reduced all-cause mortality or risk of ESKD ((15 studies, 791 patients): RR 0.58 (95% CI 0.36 to 0.95, P = 0.03) and risk of ESKD ((15 studies, 791 patients): RR 0.55, 95% CI 0.31 to 0.95, P = 0.03), increased complete or partial remission ((16 studies, 864 patients): RR 1.31, 95% CI 1.01 to 1.70, P = 0.04), and decreased proteinuria ((9 studies,(393 patients): MD -0.95 g/24 h, 95% CI -1.81 to -0.09, P = 0.03) at the end of follow-up (range 6 to 120 months). However this regimen was associated with more discontinuations or hospitalisations ((16 studies, 880 studies): RR 5.35, 95% CI 2.19 to 13.02), P = 0.0002). Combined corticosteroids and alkylating agents significantly reduced death or risk of ESKD ((8 studies, 448 patients): RR 0.44, 95% CI 0.26 to 0.75, P = 0.002) and ESKD ((8 studies, 448 patients): RR 0.45, 95% CI 0.25 to 0.81, P = 0.008), increased complete or partial remission ((7 studies, 422 patients): RR 1.46, 95% CI 1.13 to 1.89, P = 0.004) and complete remission ((7 studies, 422 patients): RR 2.32, 95% CI 1.61 to 3.32, P < 0.00001), and decreased proteinuria ((6 studies, 279 patients): MD -1.25 g/24 h, 95% CI -1.93 to -0.57, P = 0.0003) at the end of follow-up (range 9 to 120 months). In a population with an assumed risk of death or ESKD of 181/1000 patients, this regimen would be expected to reduce the number of patients experiencing death or ESKD to 80/1000 patients (range 47 to 136). In a population with an assumed complete or partial remission of 408/1000 patients, this regimen would be expected to increase the number of patients experiencing complete or partial remission to 596/1000 patients (range 462 to 772). However this combined regimen was associated with a significantly higher risk of discontinuation or hospitalisation due to adverse effects ((4 studies, 303 patients): RR 4.20, 95% CI 1.15 to 15.32, P = 0.03). Whether this combined therapy should be indicated in all adult patients at high risk of progression to ESKD or only restricted to those with deteriorating kidney function still remained unclear. Cyclophosphamide was safer than chlorambucil ((3 studies, 147 patients): RR 0.48, 95% CI 0.26 to 0.90, P = 0.02). There was no clear evidence to support the use of either corticosteroid or alkylating agent monotherapy. Cyclosporine and mycophenolate mofetil failed to show superiority over alkylating agents. Tacrolimus and adrenocorticotropic hormone significantly reduced proteinuria. The numbers of corresponding studies related to tacrolimus, mycophenolate mofetil, adrenocorticotropic hormone, azathioprine, mizoribine, and Tripterygium wilfordii are still too sparse to draw final conclusions.

AUTHORS' CONCLUSIONS

In this update, a combined alkylating agent and corticosteroid regimen had short- and long-term benefits on adult IMN with nephrotic syndrome. Among alkylating agents, cyclophosphamide was safer than chlorambucil. This regimen was significantly associated with more withdrawals or hospitalisations. It should be emphasised that the number of included studies with high-quality design was relatively small and most of included studies did not have adequate follow-up and enough power to assess the prespecified definite endpoints. Although a six-month course of alternating monthly cycles of corticosteroids and cyclophosphamide was recommended by the KDIGO Clinical Practice Guideline 2012 as the initial therapy for adult IMN with nephrotic syndrome, clinicians should inform their patients of the lack of high-quality evidence for these benefits as well as the well-recognised adverse effects of this therapy. Cyclosporine or tacrolimus was recommended by the KDIGO Clinical Practice Guideline 2012 as the alternative regimen for adult IMN with nephrotic syndrome; however, there was no evidence that calcineurin inhibitors could alter the combined outcome of death or ESKD.

Predictors of response and relapse in patients with idiopathic membranous nephropathy treated with tacrolimus

BACKGROUND

Although tacrolimus is recommended by KDIGO Clinical Practice Guideline for Glomerulonephritis for the treatment of idiopathic membranous nephropathy (MN), little is known about factors that influence response and relapse of the disease after tacrolimus therapy.

METHODS

Multicentre study that collected 122 MN patients with nephrotic syndrome and stable renal function treated with tacrolimus. Duration of treatment was 17.6 ± 7.2 months, including a full-dose and a tapering period.

RESULTS

The percentage of remission was 60, 78 and 84% after 6, 12 and 18 months of treatment, respectively. The amount of proteinuria at baseline significantly predicted remission, the lower the baseline proteinuria the higher the probability of remission. Only 10 patients (8%) received concomitantly corticosteroids, and their rate of remission was similar (80% at 18 months). Among responders, 42% achieved complete remission (CR) and 58% partial remission (PR). Almost half (44%) of the responder patients relapsed. The amount of proteinuria at the onset of tacrolimus tapering was significantly higher in relapsing patients. By multivariable analysis, the presence of a PR versus CR at the onset of tacrolimus tapering and a shorter duration of the tapering period significantly predicted relapses. Tolerance was good and the number of adverse events low.

CONCLUSIONS

Tacrolimus monotherapy is an effective and safe option for the treatment of MN with stable renal function. Relapses are frequent in patients with PR and can be partially prevented by a longer tapering period.

Chlorambucil-induced cytomegalovirus infection: a case report

INTRODUCTION

Chlorambucil is an alkylating agent used in combination with prednisolone for the treatment of idiopathic membranous nephropathy. Although chlorambucil is generally well-tolerated, it is a myelosuppresive drug that can cause several infections.

CASE PRESENTATION

We report the case of an 81-year-old Caucasian male presenting with idiopathic membranous nephropathy who developed fever, cough, dyspnea, pulmonary infiltrates, and abdominal pain shortly after the initiation of treatment with chlorambucil and corticosteroids for nephropathy. Virology tests for infectious diseases revealed a recent cytomegalovirus infection. Antiviral treatment (ganciclovir) resulted in full remission.

CONCLUSIONS

Cytomegalovirus infection should be considered in the differential diagnosis of respiratory symptoms and pulmonary infiltrates in patients treated with chlorambucil for nephrotic syndrome.

Smoking is a risk factor for the progression of idiopathic membranous nephropathy

Background

Multiple studies have shown cigarette smoking to be a risk factor for chronic kidney disease. However, it is unknown whether smoking similarly increases the risk for progression of membranous nephropathy.

Methods

This study used the Nagoya Nephrotic Syndrome Cohort Study (N-NSCS), including 171 patients with idiopathic membranous nephropathy (IMN) from 10 nephrology centers in Japan. The dose-response relationships between cigarette smoking and the outcomes were assessed by using multivariate Cox proportional hazards models adjusted for clinically relevant factors. The primary outcome was a 30% decline in the estimated glomerular filtration rate (eGFR). The secondary outcome was first complete remission (CR) of proteinuria.

Results

During the observation period (median, 37 months; interquartile range, 16–71 months), 37 (21.6%) patients developed a 30% decline in eGFR and 2 (1.2%) progressed to ESRD. CR occurred in 103 (60.2%) patients. Multivariate Cox proportional hazards models revealed current smoking (adjusted hazard ratio [HR], 7.81 [95% confidence interval (CI), 3.17–19.7]), female sex (adjusted HR, 3.58 [95% CI, 1.87–8.00]), older age (adjusted HR, 1.71 [95% CI, 1.13–2.62] per 10 years), the number of cigarettes smoked daily (adjusted HR, 1.61 [95% CI, 1.23–2.09] per 10 cigarettes daily), and cumulative smoking of ≥40 pack-years (adjusted HR, 5.56 [95% CI, 2.17–14.6]) to be associated with a 30% decline in eGFR. However, smoking was not associated with CR.

Conclusion

Smoking is a significant and dose-dependent risk factor for IMN progression. All patients with IMN who smoke should be encouraged to quit.

Phosphotriesterase-related protein sensed albuminuria and conferred renal tubular cell activation in membranous nephropathy

Background

Membranous nephropathy (MN) is a common cause of nephrotic syndrome that may progress to end-stage renal disease (ESRD). The formation of MN involves the in situ formation of subepithelial immune deposits and leads to albuminuria; however, the underlying mechanism of how MN leads to ESRD remains unclear. The aim of this study was to investigate the expression and biological functions of phosphotriesterase-related protein (PTER) in MN.

Results

In the progression of MN, the expression of PTER increased significantly and was mainly expressed in the renal tubular cells. Both mRNA and protein expression levels of PTER were increased in a concentration- and time-dependent manner in the in vitro albuminuria tubular cell model. Silencing the expression of PTER by RNA interference diminished albuminuria-induced inflammatory and pro-fibrotic cytokines production.

Conclusions

Our findings reveal that PTER may sense albuminuria in the progression of MN, induce tubular cell activation and lead to ESRD.

Leflunomide plus oral prednisone in treatment of idiopathic membranous nephropathy: a retrospective clinical study of efficacy and safety

AIM

Treatment of idiopathic membranous nephropathy (IMN) remains a controversial issue. While clinical trials have shown that some immunosuppressants combined with glucocorticoid have a good efficacy on IMN patients. However, there is little data on leflunomide (LEF) in treatment of IMN.

METHODS

Records of every patient with biopsy-proven IMN in Department of Nephrology, the First Affiliated Hospital, Xi'an Jiaotong University from January 2005 to December 2011 (n=194) were retrospectively analyzed. Patients with nephrotic IMN were treated with LEF plus oral prednisone (n=32) for at least 12 months, whereas 31 patients who did not receive any immunosuppressants were used as controls.

RESULTS

Remission rates in the LEF group were 31.3%, 59.4%, 68.8% and 71.9% at 6, 9, 12 and 15 months, respectively, which were significantly higher than those in controls. In the LEF group, proteinuria decreased from 6.79 g/24 h at baseline to 5.63 g/24 h (P<0.01), 3.85 g/24 h (P<0.01) and 2.51 g/24 h (P<0.01) after treatment for 6, 9 and 12 months, respectively. Relapse occurred in five (21.7%) patients within a median of 14 months (range, 8-27) after cessation of LEF. No patients developed renal insufficiency during the therapeutic period. Multivariate analysis suggested that age negatively correlated with achievement of remission (odds ratio, 0.87; P<0.05). No serious adverse events were observed.

CONCLUSION

LEF plus oral prednisone may be an alternative treatment option in Chinese patients with nephrotic IMN.

Pathological predictors of renal outcomes in nephrotic idiopathic membranous nephropathy with decreased renal function

BACKGROUND AND OBJECTIVES

The outcome of idiopathic membranous nephropathy (IMN) in adults with nephrotic-range proteinuria and decreased renal function has seldom been described and the predictive value of pathological features is debated. This study aimed to describe the clinical course of this patient subgroup and to identify independently predictive pathological features.

MATERIALS AND METHODS

We evaluated 129 adults with biopsy-proven IMN diagnosed from 2002 to 2011. All patients had chronic kidney disease (CKD) stages 2-4 and nephrotic-range proteinuria (≥3.5 g/day). Primary outcomes were a 20 or 50 % decline in renal function, progression to end-stage renal disease (ESRD), or all-cause mortality.

RESULTS

Of 129 patients, 38 (30 %) presented with proteinuria ≥8.0 g/day and 37 (29 %) with CKD stages 3-4. Thirteen (10 %) presented with segmental sclerosis, 97 (75 %) with arteriosclerosis, 42 (33 %) with moderate-to-severe tubulointerstitial injury, and 86 (67 %) with C3 deposition. Over a median follow-up of 34 months (range 12-135), 51 patients (40 %) had a 20 % decline in renal function, 27 (21 %) a 50 % decline, 14 (11 %) developed ESRD, and 19 (15 %) died. Segmental sclerosis and tubulointerstitial injury but not arteriosclerosis or C3 deposition were independent risk factors for 20 and 50 % renal function decline and progression to ESRD.

CONCLUSIONS

Segmental sclerosis and tubulointerstitial injury predict renal outcomes independent of clinical data in nephrotic IMN patients with decreased renal function.

[Membranous nephropathy]

Membranous nephropathy is characterized by immune complex deposits on the outer side of the glomerular basement membrane. Activation of complement and of oxidation lead to basement membrane lesions. The most frequent form is idiopathic. At 5 and 10 years, renal survival is around 90 and 65% respectively. A prognostic model based on proteinuria, level and duration, progression of renal failure in a few months can refine prognosis. The urinary excretion of C5b-9, β2 and α1 microglobuline and IgG are strong predictors of outcome. Symptomatic treatment is based on anticoagulation in case of nephrotic syndrome, angiotensin conversion enzyme inhibitors, angiotensin II receptor blockers and statins. Immunosuppressive therapy should be discussed for patients having a high risk of progression. Corticoids alone has no indication. Treatment should include a simultaneous association or more often alternating corticoids and alkylant agent for a minimum of 6 months. Adrenocorticoid stimulating hormone and steroids plus mycophenolate mofetil may be equally effective. Steroids plus alkylant decrease the risk of end stage renal failure. Cyclosporine and tacrolimus decrease proteinuria but are associated with a high risk of recurrence at time of withdrawal and are nephrotoxic. Rituximab evaluated on open studies needs further evaluations to define its use.

Long-term outcomes in idiopathic membranous nephropathy using a restrictive treatment strategy

Recently published Kidney Disease Improving Global Outcomes (KDIGO) guidelines recommend limiting the use of immunosuppressive drugs in idiopathic membranous nephropathy to patients at the highest risk of kidney failure. However, recommendations are based on natural history rather than direct assessment of a restrictive treatment strategy. Here, we describe the long-term outcomes of treating a large cohort of patients with idiopathic membranous nephropathy according to a restrictive treatment policy. We analyzed data for 254 patients who visited our outpatient clinic between 1995 and 2009. All patients were treated with angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers. Immunosuppressive therapy was recommended in cases of deteriorating renal function or untreatable nephrotic syndrome. Primary outcomes for the present study were renal replacement therapy and death. Secondary outcomes included adverse events during follow-up and remission of proteinuria. In total, 124 patients (49%) received immunosuppressive therapy, which predominantly consisted of cyclophosphamide combined with steroids. Ten-year cumulative incidence rates were 3% for renal replacement therapy and 10% for death. Partial remission rates were 39%, 70%, and 83% after 1, 3, and 5 years, respectively; complete remission rates were 5%, 24%, and 38% at 1, 3, and 5 years, respectively. A serious adverse event occurred in 23% of all patients. The most notable complications were infections (17%), leukopenia (18%), cardiovascular events (13%), and malignancies (8%). In conclusion, the use of a restrictive treatment strategy in this cohort of patients with idiopathic membranous nephropathy yielded favorable outcomes while limiting the number of patients exposed to toxic drugs. These results support current KDIGO guidelines.

Treatment of idiopathic membranous nephropathy

Immunosuppressive treatment of patients with idiopathic membranous nephropathy (iMN) is heavily debated. The controversy is mainly related to the toxicity of the therapy and the variable natural course of the disease-spontaneous remission occurs in 40-50% of patients. The 2012 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for Glomerulonephritis provides guidance for the treatment of iMN. The guideline suggests that immunosuppressive therapy should be restricted to patients with nephrotic syndrome and persistent proteinuria, deteriorating renal function or severe symptoms. Alkylating agents are the preferred therapy because of their proven efficacy in preventing end-stage renal disease. Calcineurin inhibitors can be used as an alternative although efficacy data on hard renal end points are limited. In this Review, we summarize the KDIGO guideline and address remaining areas of uncertainty. Better risk prediction is needed to identify patients who will benefit from immunosuppressive therapy, and the optimal timing and duration of this therapy is unknown because most of the randomized controlled trials were performed in low-risk or medium-risk patients. Alternative therapies, directed at B cells, are under study. The discovery of anti-M type phospholipase A2 receptor-antibodies is a major breakthrough and we envisage that in the near future, antibody-driven therapy will enable more individualized treatment of patients with iMN.