Controlled trial of methylprednisolone and chlorambucil in idiopathic membranous nephropathy

An Updated Review of Membranous Nephropathy

Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in adults. The discovery of phospholipase A2 receptor (PLA2R) as a target antigen has led to a paradigm shift in the understanding and management of MN. At present, serum PLA2R antibodies are used for diagnosis, prognostication, and guiding treatment. Now, with the discovery of more than 20 novel target antigens, antigen mapping is almost complete. The clinical association of certain antigens provides clues for clinicians, such as the association of nerve epidermal growth factor-like 1 with malignancies and indigenous medicines. Serum antibodies are detected for most target antigens, except exostosin 1 and 2 and transforming growth factor-beta receptor 3, but their clinical utility is yet to be defined. Genome-wide association studies and studies investigating environmental factors, such as air pollution, shed more light on the underpinnings of MN. The standard therapy of MN diversified from cyclical cyclophosphamide and steroids to include rituximab and calcineurin inhibitors over the past decades. Here, we provide a cutting-edge review of MN, focusing on genetics, immune system and environmental factors, novel target antigens and their clinical characteristics, and currently available and emerging novel therapies in MN.

Complement activation and effector pathways in membranous nephropathy

Complement activation has long been recognized as a central feature of membranous nephropathy (MN). Evidence for its role has been derived from the detection of complement products in biopsy tissue and urine from patients with MN and from mechanistic studies primarily based on the passive Heymann nephritis model. Only recently, more detailed insights into the exact mechanisms of complement activation and effector pathways have been gained from patient data, animal models, and in vitro models based on specific target antigens relevant to the human disease. These data are of clinical relevance, as they parallel the recent development of numerous specific complement therapeutics for clinical use. Despite efficient B-cell depletion, many patients with MN achieve only partial remission of proteinuria, which may be explained by the persistence of subepithelial immune complexes and ongoing complement-mediated podocyte injury. Targeting complement, therefore, represents an attractive adjunct treatment for MN, but it will need to be tailored to the specific complement pathways relevant to MN. This review summarizes the different lines of evidence for a central role of complement in MN and for the relevance of distinct complement activation and effector pathways, with a focus on recent developments.

The thickness of glomerular basement membrane predicts complete remission in primary membranous nephropathy

Objective: Glomerular basement membrane (GBM) thickening is a typical and essential histopathological characteristic for the diagnosis of primary membranous nephropathy (PMN). The present study aimed to explore the relationship between GBM thickness and treatment response in PMN patients.Methods: A total of 128 patients with nephrotic syndrome concurrent with PMN were studied. The highest GBM thickness was measured from at least five glomerular capillary loops using an electron microscope, and the mean value was obtained. Patients were categorized into three groups according to the tertiles of GBM thickness as follows: Group 1 (GBM thickness ≤ 1100 nm, n = 48), Group 2 (1100 nm < GBM thickness ≤ 1300 nm, n = 40), Group 3 (GBM thickness >1300 nm, n = 40). Clinicopathological features and treatment response were compared among the three groups. The associations of GBM thickness with complete remission (CR) were assessed by Cox proportional hazard analyses and a cubic spline curve.Results: During a median follow-up period of 25.80 months, 69 (53.9%) patients achieved CR. Kaplan-Meier analysis showed that the non-CR probability was significantly higher in the highest tertile of GBM thickness (p˂0.001). Univariate Cox proportional hazard analysis indicated that GBM thickness was associated with CR (HR per SD 0.617, 95% CI [0.471-0.809], p˂0.001). After adjusting for age, duration of PMN, estimated glomerular filtration rate (eGFR), urinary protein excretion, grade of C3 deposition, and titer of serum anti-phospholipase A2 receptor (PLA2R) antibody, GBM thickness remained an independent predictor of CR (HR per SD 0.580, 95% CI [0.436-0.772], p˂0.001). Further multivariable-adjusted restricted cubic spline analysis confirmed a significant reverse linear association between GBM thickness and CR (p for nonlinear = 0.1261).Conclusions: GBM thickness is an independent risk factor of CR. PMN patients with an increased level of GBM thickening at diagnosis have a lower probability of achieving CR.

The place of cyclical therapy for the treatment of membranous nephropathy in the era of rituximab

Primary membranous nephropathy (MN) is the most frequent cause of nephrotic syndrome in adults, due to a variety of autoantibodies, most frequently against phospholipase A2 receptor (PLA2R). In severe cases or when spontaneous remission is not achieved, immunosuppression is required. Cyclical therapy, based on glucocorticoids and cyclophosphamide on alternate months for 6 months, has proven effective to induce remission and reduce the risk of end-stage renal disease. Since the early 2000s, rituximab (RTX) has emerged as a key player in the management of MN, showing overall comparable effectiveness and likely better safety compared with the cyclical regimen, despite the lack of adequately powered trials comparing the two approaches head to head. For these reasons, RTX is now considered the agent of choice for most patients with MN. However, there are still uncertainties. Around 20-40% of patients are resistant to RTX, especially in the setting of high anti-PLA2R levels, and this drug remains relatively unexplored in patients with the most severe disease. In these scenarios, although the expanding therapeutic armamentarium is probably going to provide further options, the cyclical regimen still plays a key role as a safety net. The aim of this article is to illustrate the role of cyclical therapy in the RTX era.

Anti-CD20 should be the first-line treatment in high-risk membranous nephropathy

Membranous nephropathy (MN) is a common cause of nephrotic syndrome (NS) in adults and if untreated can progress to endstage kidney disease. Factors considered to place a patient at high or very high risk for progression include elevated serum creatinine at baseline, declining kidney function, persistent heavy proteinuria (>8 g/24 h), or persistent NS, presence of life-threatening complications related to NS (such as venous thromboembolic events), or very high anti-PLA2R antibody titers (>150 RU/ml). Patients who are at high or very high risk of progression should be treated with immunosuppression therapy to induce remission of proteinuria and to avoid progressive loss of kidney function. Traditional forms of immunosuppression for patients with MN have included the use of cyclic courses of corticosteroids with cyclophosphamide or calcineurin inhibitors. These forms of therapy are associated with significant toxicity, e.g. corticosteroids (infections, diabetes, weight gain), cyclophosphamide (infertility, severe leukopenia, malignancy), and calcineurin inhibitors (hypertension, nephrotoxicity). The introduction of anti-CD20+ B-cell therapies in the late 1990s has changed the landscape. In this article we will argue that anti-CD20+ B therapy should be the treatment of choice for patients at high/very high risk of progression when considering its efficacy and side-effect profile.

Immunosuppressive therapy for progressive idiopathic membranous nephropathy: a cost-effectiveness analysis in China

BACKGROUND

This study aims to evaluate the cost-effectiveness of immunosuppressive therapy for patients with progressive idiopathic membranous nephropathy (IMN) from the Chinese healthcare system perspective.

METHODS

To estimate the cost-effectiveness of four regimens namely cyclophosphamide, cyclosporine, rituximab and tacrolimus-rituximab in treatment of IMN recommended by the updated Kidney Disease: Improving Global Outcomes (KDIGO) guideline 2021, a Markov model with five discrete states (active disease, remission, dialysis, kidney transplant and death) based on IMN patients aged 50 or above over a 30-years time horizon was constructed. Total costs were imputed from the Chinese healthcare system perspective, and health outcomes were converted into quality-adjusted life years (QALYs). The incremental cost-effectiveness ratio (ICER) was used to describe the results. The willingness-to-pay (WTP) threshold was set at $12,044 (China's 2021 Gross Domestic Product per capita). Sensitivity analyses were performed to test the uncertainties of the results.

RESULT

Compared with cyclophosphamide, both cyclosporine (incremental cost $28,337.09, incremental QALY-1.63) and tacrolimus-rituximab (incremental cost $28,324.13, incremental QALY -0.46) were considered at strictly dominated for their negative values in QALYs, and the ICER value of rituximab was positive (incremental cost $9,162.19, incremental QALY 0.44). Since the ICER of rituximab exceeds the pre-determined threshold, cyclophosphamide was likely to be the best choice for the treatment of IMN within the acceptable threshold range. The results of the sensitivity analysis revealed that the model outcome was mostly affected by the probability of remission in rituximab. In a probabilistic sensitivity analysis, cyclophosphamide had 62.4% probability of being cost-effective compared with other regimens when the WTP was $12,044 per QALY. When WTP exceeded $18,300, rituximab was more cost-effective than cyclophosphamide.

CONCLUSION

Compared with cyclosporine, rituximab and tacrolimus-rituximab, our model results indicated that cyclophosphamide represented the most cost-effective regimen for patients with progressive IMN in China.

Comparative analysis of the efficacy of different treatments for idiopathic membranous nephropathy: a retrospectively real-world study

BACKGROUND

This study aimed to explore the clinical efficacy of different treatment regimens for idiopathic membranous nephropathy (IMN).

METHODS

Patients with IMN were retrospectively analyzed by dividing into two groups: glucocorticoids combined with cyclophosphamide group (GC + CYC) and glucocorticoids combined with calcineurin inhibitor group (GC + CNIs). After 1 year of treatment, those who found that the initial treatment was not effective were switched to another regimen. Patients continued to be followed up for at least 1 year to observe the treatment effects of different treatment regimens.

RESULTS

This study found that the rate of complete and partial remission (CR + PR) in the GC + CYC and GC + CNIs groups was 76.19 vs. 82.63% after 1 year of follow-up (p > .05). In the GC + CYC and GC + CNIs groups, 27.78 and 11.95% of the patients switched treatment regimens, respectively. After 2 years of follow-up, the CR + PR rate was significantly higher in the change to GC + CNIs group after the switch compared to before the switch (80.00 vs. 31.43%, p < .001). It was also significantly higher in the change to GC + CYC group compared to before the switch (68.42 vs. 31.58%, p = .023). The recurrence rate was significantly higher in the maintain GC + CNIs and change to GC + CNIs groups than in the maintain GC + CYC and change to GC + CYC groups (25.14 vs 6.36%, p < .001). The disengagement rate from immunotherapy was significantly higher in the maintain GC + CYC group and the change to GC + CYC group than in the maintain GC + CNIs group and the change to GC + CNIs group (76.36% vs 29.71%, p < .001). High titer of anti-phospholipase A2 receptor (anti-PLA2R) antibody (95%CI: 0.199-0.947, p = .036) and serum C3 (95%CI: 0.030-0.570, p = .007) were independent risk factors, while serum IgG (95%CI: 1.000-1.331, p = .050) was a favorable factor for achieving CR. Anti-PLA2R antibody was the independent risk factor that affected the worse renal condition (p = .023).

CONCLUSIONS

Timely change of treatment regimen can significantly enhance therapeutic effect. Compared with patients administered with CYC, those administered with CNIs were less likely to leave treatment and had a higher recurrence rate.

Primary membranous nephropathy: an endless story

Primary membranous nephropathy (PMN) is an autoimmune disease caused by the attack of autoantibodies against podocyte antigens leading to the in situ production of immune complexes. However, the etiology is unknown and the pathogenesis is still far from being completely elucidated. MN is prevalently idiopathic or primary, but in about 20-30% of cases it is secondary to chronic infections, systemic diseases, exposure to drugs, or malignancy. The differentiation between primary and secondary MN may be difficult, particularly when MN precedes signs and symptoms of the original disease, as in some cases of cancer or systemic lupus erythematosus. The natural course of PMN is variable, but in the long term 40-60% of patients with nephrotic syndrome progress to end-stage renal disease (ESRD) or die from thrombotic or cardiovascular events. PMN is a treatable disease. Patients with asymptomatic proteinuria should receive supportive care. Immunosuppressive treatments should be given to patients with nephrotic syndrome or risk of progression. The most frequently adopted treatments rely on cyclical therapy alternating steroids with a cytotoxic agent every other month, i.e., rituximab at different doses, or calcineurin inhibitors plus low-dose steroids. A good rate of response may be obtained but relapses can occur. Randomized controlled trials, with adequate size, long-term follow-up, and fair definition of endpoints are needed to identify treatment with the best therapeutic index.

Immunosuppressive treatment for idiopathic membranous nephropathy: An updated network meta-analysis

This network meta-analysis (NMA) aims to investigate the efficacy and safety of different pharmacological treatments for idiopathic membranous nephropathy (IMN). Thirty-four relevant studies were extracted from PubMed, Embase, Cochrane database, and MEDLINE. Treatment with tacrolimus (TAC), cyclophosphamide (CTX), mycophenolate mofetil, chlorambucil (CHL), cyclosporin A (CSA), steroids, rituximab (RTX), and conservative therapy were compared. Outcomes were measured using remission rate and incidence of side effects. Summary estimates were expressed as the odds ratio (OR) and 95% confidence intervals (CIs). The quality of findings was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach. In the direct meta-analysis for comparison of complete remission (CR) rate, the curative effect of RTX is inferior to CTX (OR 0.37; CI 0.18, 0.75). In the NMA of CR rate, the results showed that the curative effects of CTX, CHL, and TAC were significantly higher than those of the control group. The efficacy of RTX is not inferior to the CTX (OR 0.81; CI 0.32, 2.01), and the level of evidence was moderate; CSA was not as effective as RTX, and the difference was statistically significant with moderate evidence (OR 2.98, CI 1.00, 8.91). In summary, we recommend CTX and RTX as the first-line drug for IMN treatment.

Membranous nephropathy: Clearer pathology and mechanisms identify potential strategies for treatment

Primary membranous nephropathy (PMN) is one of the common causes of adult-onset nephrotic syndrome and is characterized by autoantibodies against podocyte antigens causing in situ immune complex deposition. Much of our understanding of the disease mechanisms underpinning this kidney-limited autoimmune disease originally came from studies of Heymann nephritis, a rat model of PMN, where autoantibodies against megalin produced a similar disease phenotype though megalin is not implicated in human disease. In PMN, the major target antigen was identified to be M-type phospholipase A2 receptor 1 (PLA2R) in 2009. Further utilization of mass spectrometry on immunoprecipitated glomerular extracts and laser micro dissected glomeruli has allowed the rapid discovery of other antigens (thrombospondin type-1 domain-containing protein 7A, neural epidermal growth factor-like 1 protein, semaphorin 3B, protocadherin 7, high temperature requirement A serine peptidase 1, netrin G1) targeted by autoantibodies in PMN. Despite these major advances in our understanding of the pathophysiology of PMN, treatments remain non-specific, often ineffective, or toxic. In this review, we summarize our current understanding of the immune mechanisms driving PMN from animal models and clinical studies, and the implications on the development of future targeted therapeutic strategies.

Manejo de la nefropatía membranosa idiopática con ciclofosfamida endovenosa

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

Immunosuppression therapy for idiopathic membranous nephropathy: systematic review with network meta-analysis

BACKGROUND

Idiopathic membranous nephropathy is a common cause of nephrotic syndrome in adults. The Kidney Disease Improving Global Outcomes guidelines recommend rituximab or cyclophosphamide and steroids, or calcineurin inhibitor-based therapy. However, there have been few or no head-to-head comparisons of the relative efficacy and safety of different immunosuppression regimens. We conducted a network meta-analysis to evaluate the comparative efficacy and safety of available immunosuppression strategies compared to cyclophosphamide in adults with idiopathic membranous nephropathy.

METHODS

We performed a systematic search of MEDLINE, Embase and CENTRAL for randomized controlled trials in the treatment of adults with idiopathic membranous nephropathy. The primary outcome was complete remission. Secondary outcomes were kidney failure, partial remission, estimated glomerular filtration rate, doubling of serum creatinine, proteinuria, serious adverse events, discontinuation of treatment, serious infection and bone marrow suppression.

RESULTS

Cyclophosphamide had uncertain effects on inducing complete remission when compared to rituximab (OR 0.35, CI 0.10-1.24, low certainty evidence), mycophenolate mofetil (OR 1.81, CI 0.69-4.71, low certainty), calcineurin inhibitor (OR 1.26, CI 0.61-2.63, low certainty) or steroid monotherapy (OR 2.31, CI 0.62-8.52, low certainty). Cyclophosphamide had a higher probability of inducing complete remission when compared to calcineurin inhibitor plus rituximab (OR 4.45, CI 1.04-19.10, low certainty). Compared to other immunosuppression strategies, there was limited evidence that cyclophosphamide had different effects on other pre-specified outcomes.

CONCLUSIONS

The comparative effectiveness and safety of immunosuppression strategies compared to cyclophosphamide is uncertain in adults with idiopathic membranous nephropathy.

Strategies Towards Antigen-Specific Treatments for Membranous Nephropathy

Membranous nephropathy (MN) is a rare but potentially severe autoimmune disease and a major cause of nephrotic syndrome in adults. Traditional treatments for patients with MN include steroids with alkylating agents such as cyclophosphamide or calcineurin inhibitors such as cyclosporine, which have an undesirable side effect profile. Newer therapies like rituximab, although superior to cyclosporine in maintaining disease remission, do not only affect pathogenic B or plasma cells, but also inhibit the production of protective antibodies and therefore the ability to fend off foreign organisms and to respond to vaccination. These are undesired effects of general B or plasma cell-targeted treatments. The discovery of several autoantigens in patients with MN offers the great opportunity for more specific treatment approaches. Indeed, such treatments were recently developed for other autoimmune diseases and tested in different preclinical models, and some are about to jump to clinical practice. As such treatments have enormous potential to enhance specificity, efficacy and compatibility also for MN, we will discuss two promising strategies in this perspective: The elimination of pathogenic antibodies through endogenous degradation systems and the depletion of pathogenic B cells through chimeric autoantibody receptor T cells.

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.

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.

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.

Membranous Nephropathy: It Is Time to Go Back to the Future

CONTEXT

Membranous nephropathy (MN) is an immune-mediated glomerular disease that can lead to nephrotic syndrome and progressive kidney function loss. The cyclic steroid-cyclophosphamide regimen (the modified Ponticelli protocol) and the monoclonal anti-CD20 antibody rituximab have been advocated as effective therapies to improve renal outcomes, but a direct comparison of these treatments had never been carried out in a prospective study. Subject of Review: Scolari et al. [J Am Soc Nephrol. 2021;32:972-82] recently reported the results of a pilot randomized controlled trial (RI-CYCLO) designed to provide direct estimates of the effect of rituximab (1 g × 2) compared to the cyclic steroid-cyclophosphamide regimen in 74 patients with MN. The proportion of patients with complete remission at 12 months was higher in the cyclic regimen arm than that of rituximab (32 and 16%, respectively), but the difference was not statistically significant in intention-to-treat analyses. Interestingly, differences in the cumulative incidence of complete and partial remissions between treatment arms progressively reduced over the follow-up and became virtually nonexistent from 24 months (>80% in both groups). The frequency of serious and nonserious adverse events was similar between the 2 treatment arms. Infusion reactions and drug discontinuation were more common with rituximab, while infections and leukopenia were more frequently observed with the cyclic regimen. The risk of cancer was similar in the 2 allocation groups, but the limited follow-up length did not allow to draw definitive conclusions. Independent of treatment allocation, 18% of patients experienced at least 1 relapse after achieving complete or partial remission. Second Opinion: Notwithstanding the intrinsic limitations of a pilot study, the RI-CYCLO trial represents an important milestone in the treatment of MN. Findings from this study support the hypothesis that the cyclic regimen and rituximab may have comparable efficacy in inducing disease remission over the long term. Considering its potentially better-albeit not yet formally proven-long-term safety profile, rituximab could be considered as a first-line therapy for most patients with MN. Several questions remain to be addressed, including rituximab ideal dose and its efficacy in patients with a significant reduction in glomerular filtration rate. In light of RI-CYCLO results, a large-scale trial to assess rituximab noninferiority to the cyclic regimen would require the enrollment of thousands of patients, and it would be probably unfeasible within a reasonable time frame. In our opinion, resources should be allocated to provide an answer to the pressing matter of treatment nonresponse and intolerance, which may be addressed in the near future with novel therapeutic strategies.

Perspectives in membranous nephropathy

The identification of the phospholipase A2 receptor 1 (PLA2R) and thrombospondin type-1 domain-containing protein 7A (THSD7A) as podocyte antigens in adult patients with membranous nephropathy (MN) has strongly impacted both experimental and clinical research on this disease. Evidence has been furnished that podocyte-directed autoantibodies can cause MN, and novel PLA2R- and THSD7A-specific animal models have been developed. Today, measurement of serum autoantibody levels and staining of kidney biopsies for the target antigens guides MN diagnosis and treatment worldwide. Additionally, anti-PLA2R antibodies have been proven to be valuable prognostic biomarkers in MN. Despite these impressive advances, a variety of questions regarding the disease pathomechanisms, clinical use of antibody measurement, and future treatments remain unanswered. In this review, we will outline recent advances made in the field of MN and discuss open questions and perspectives with a focus on novel antigen identification, mechanisms of podocyte injury, clinical use of antibody measurement to guide diagnosis and treatment, and the potential of innovative, pathogenesis-based treatment strategies.

Rituximab or Cyclophosphamide in the Treatment of Membranous Nephropathy: The RI-CYCLO Randomized Trial

BACKGROUND

A cyclic corticosteroid-cyclophosphamide regimen is the first-line therapy for membranous nephropathy. Compared with this regimen, rituximab therapy might have a more favorable safety profile, but a head-to-head comparison is lacking.

METHODS

We randomly assigned 74 adults with membranous nephropathy and proteinuria >3.5 g/d to rituximab (1 g) on days 1 and 15, or a 6-month cyclic regimen with corticosteroids alternated with cyclophosphamide every other month. The primary outcome was complete remission of proteinuria at 12 months. Other outcomes included determination of complete or partial remission at 24 months and occurrence of adverse events.

RESULTS

At 12 months, six of 37 patients (16%) randomized to rituximab and 12 of 37 patients (32%) randomized to the cyclic regimen experienced complete remission (odds ratio [OR], 0.4; 95% CI, 0.13 to 1.23); 23 of 37 (62%) receiving rituximab and 27 of 37 (73%) receiving the cyclic regimen had complete or partial remission (OR, 0.61; 95% CI, 0.23 to 1.63). At 24 months, the probabilities of complete and of complete or partial remission with rituximab were 0.42 (95% CI, 0.26 to 0.62) and 0.83 (95% CI, 0.65 to 0.95), respectively, and 0.43 (95% CI, 0.28 to 0.61) and 0.82 (95% CI, 0.68 to 0.93), respectively, with the cyclic regimen. Serious adverse events occurred in 19% of patients receiving rituximab and in 14% receiving the cyclic regimen.

CONCLUSIONS

This pilot trial found no signal of more benefit or less harm associated with rituximab versus a cyclic corticosteroid-cyclophosphamide regimen in the treatment of membranous nephropathy. A head-to-head, pragmatic comparison of the cyclic regimen versus rituximab may require a global noninferiority trial.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Rituximab versus Steroids and Cyclophosphamide in the Treatment of Idiopathic Membranous Nephropathy (RI-CYCLO), NCT03018535.

Pathophysiology, diagnosis, and treatment of membranous nephropathy

Nephrotic syndrome is in adult patients mainly due to membranous nephropathy (MN) characterized by thickening of the glomerular basement membrane (GBM) and immune complex formation between podocytes and the GBM. Autoantibodies directed against the M-type phospholipase A2 receptor (PLA2R) and thrombospondin 1 domain-containing 7 A (THSD7A) can be used as diagnostic biomarkers. THSD7A seems to be of direct pathogenic significance as is suggested by experimental models and plasmapheresis in humans. Recently, further antigens like NELL-1 (neural tissue encoding protein with EGF-like repeats-1), exostosin 1 and 2 have been discovered. Thus, MN should be classified into antibody positive and antibody negative MN. More specific immunosuppressive treatments directed against B-cells and antibody production like rituximab have been introduced in addition to already existing immunosuppressive protocols including steroids, chlorambucil, cyclophosphamide, and calcineurin inhibitors. Antibody removal using immunoadsorption or plasmapheresis leads to short-term reduction in proteinuria and might be indicated only in patients with very severe proteinuria and complications. Studies are needed to identify a more specific immunosuppression directed against the production and effects of autoantibodies in order to protect the kidneys from autoimmune mediated tissue damage and to identify patients who require an immunosuppressive treatment, as the remission rate is high in patients with MN.

Efficacy and cost of different treatment in patients with idiopathic membranous nephropathy: A network meta-analysis and cost-effectiveness analysis

BACKGROUND

Idiopathic membranous nephropathy (IMN) is the most common pathological type of adult nephrotic syndrome. However, the treatments for IMN patients had not been compared from the perspectives of therapeutic effect and pharmacoeconomics. Therefore, a network meta-analysis and a cost-effectiveness analysis were conducted to find the optimum treatment for IMN patients.

METHODS

Randomized controlled trials (RCTs) which compared the treatments including cyclophosphamide (CTX), mycophenolate mofetil (MMF), cyclosporine (CsA), tacrolimus (TAC), leflunomide (LEF), chlorambucil (CLB) and rituximab (RTX) for patients with IMN were reviewed. The complete and partial remission rates were extracted and then compared by network meta-analysis. The surface under the cumulative ranking area (SUCRA) was calculated to rank the remission rate for all treatments. Then, the cost-effectiveness analysis was performed to compared the incremental cost-effectiveness ratio (ICER) of different treatments.

RESULTS

A total of 75 articles with 4806 participants were included according to the inclusion and exclusion criteria. Compared with the glucocorticoids (GC) group, CTX + GC (95%RR 1.02,1.76), CsA + GC (95%RR 1.11,2.13) and TAC + GC (95%RR 1.44,2.59) were associated with a significantly higher rate of complete remission. TAC + GC were most likely to be ranked the best (SUCRA of 92.1%). From the perspective of the cost-effectiveness analysis in China, the ICER of LEF + GC to CTX + GC was $30616.336 per unit utility, and that of TAC + GC to CTX + GC was $670475.210 per unit utility. And the ICER of CTX + GC to LEF + GC in the UK was $-65680.879 per unit utility.

CONCLUSIONS

CTX + GC was the cheapest treatment with obvious curative effect in China, while LEF + GC was a cost-effective alternative to CTX + GC. The remission rate of TAC + GC was highest despite the high single-dose cost.

Increased incidence and improved prognosis of glomerulonephritis: a national 30-year study

Background

While there are many cross-sectional studies of glomerulonephritis (GN) incidence, changes in incidence over time, particularly in the 21st century have received less attention. Similarly, little is known about temporal changes in GN prognosis. The presence in Denmark of comprehensive registries for renal biopsy results, end-stage renal disease (ESRD), comorbidity and mortality permit these questions to be addressed.

Methods

Data for all renal biopsies in Denmark between 1985 and 2014 were extracted from the Danish Renal Biopsy Registry and Patobank registries. The date of first dialysis or transplantation was extracted from the Danish Nephrology Registry for those patients developing ESRD. Dates of death and presence of chronic comorbid conditions at date of biopsy were extracted from the National Patient Registry. The incidence of GN, adjusted to the 2013 European standard population, was calculated. ESRD incidence and mortality were calculated, both in absolute terms and after correction for age, comorbidity and presence of renal tubulointerstitial fibrosis.

Results

The incidence rose from 33.3 patients per million (ppm)/year in 1985–94 to 46.5 ppm in 2005–14. The increase could in part be related to changes in renal biopsy policy. Large increases in Anti-neutropil cytoplasmic antibody (ANCA) vasculitis (ANCAV) (3.1–7.7 ppm/year) and focal segmental glomerulosclerosis (FSGS) (1.5–5.7 ppm/year) incidence were noted. The biopsy-proven prevalence of GN in 2014 was 748 ppm of which 155 ppm were being treated with dialysis or transplantation. Adjusted ESRD incidence fell by 25% during the study period, mortality by 62% and combined ESRD/mortality by 46%. The fall in ESRD incidence was limited to minimal change GN, FSGS, membranous GN and lupus nephritis, while reductions in mortality, and the combination of ESRD and/or death, were seen for nearly all GN diagnoses.

Conclusions

This study suggests that the incidence of GN has generally increased between 1985 and 2014, but some of the increase may be related to changes in renal biopsy policy. Major increases in FSGS and ANCAV incidence have occurred. The prognosis of GN, both as regards ESRD and mortality, has improved.

Modern view on treatment of membranous nephropathy

Membranous nephropathy (MN) is the most common cause of nephrotic syndrome in adults. Since the moment of animal model creation and the recognition of podocytes damage as a key mechanism of MN development, the identification of antigens, first of all the phospholipase A2 receptor (PLA2R), and the development of methods of PLA2R autoantibodies detection and its monitoring opened a new era in the idiopathic MN (iMN) diagnosis, treatment and prognosis evaluation. MN continues to be actively studied in the new millennium, since a number of aspects of its pathogenesis still need to be clarified, and there is still no clear opinion on the iMN treatment optimal approach. Comprehensive clinical and serological assessment of patients with iMN can be the key to individual choice of treatment protocols. In patients with aPLA2R-positive iMN, the predictor of disease remission is the aPLA2R titer decrease or aPLA2R disappearance in the blood serum, and disease relapse is associated with the aPLA2R appearance ore increase of aPLA2R titer in the circulation. Studies which were conducted by today (GEMRITUX, MENTOR, STARMEN, NICE, etc.) confirmed the acceptable safety profile and effectiveness of iMN therapy by anti-CD20 monoclonal antibodies (rituximab): more than half of of iMN patients had remission of nephrotic syndrome or proteinuria decrease, remissions in anti-CD20 monoclonal antibodies treated patients were longer compared to traditional therapy. The obtained data allows us to consider rituximab and anti-CD20 antibody therapy of a new generation not only as an alternative to the more toxic treatment with cyclophosphane and calcineurin inhibitors, but as an independent promising direction of therapy for patients with IMN, which completely changes the paradigm of treatment of this glomerulopathy.

Comparative efficacy of 13 immunosuppressive agents for idiopathic membranous nephropathy in adults with nephrotic syndrome: a systematic review and network meta-analysis

OBJECTIVES

This study aimed to compare the effectiveness of 13 types of immunosuppressive agents used to treat idiopathic membranous nephropathy (IMN) in adults with nephrotic syndrome.

DESIGN

Systematic review and network meta-analysis.

DATA SOURCES

PubMed, EMbase, Cochrane Library, Web of Science, Clinical trials, SinoMed, Chinese Biomedicine, CNKI, WanFang and Chongqing VIP Information databases were comprehensively searched until February 2018.

ELIGIBILITY CRITERIA

Randomised clinical trials (RCTs) comparing the effects of different immunosuppressive treatments in adult patients with IMN and nephrotic syndrome were included, and all included RCTs had a study-duration of at least 6 months.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently screened articles, extracted data and assessed study quality. Standard pairwise meta-analysis was performed using DerSimonian-Laird random-effects model.

RESULTS

This study ultimately included 48 RCTs with 2736 patients and 13 immunosuppressive agents. The network meta-analysis results showed that most regimens, except for leflunomide (LEF), mizoribine (MZB) and steroids (STE), showed significantly higher probabilities of total remission (TR) when compared with non-immunosuppressive therapies (the control group),with risk ratios (RRs) of 2.71 (95% CI) 1.81 to 4.06)for tacrolimus+tripterygium wilfordii (TAC+TW), 2.16 (1.27 to 3.69) foradrenocorticotropic hormone, 2.02 (1.64 to 2.49) for TAC, 2.03 (1.13 to3.64) for azathioprine (AZA), 1.91 (1.46 to 2.50) for cyclosporine (CsA), 1.86 (1.44 to2.42) for mycophenolate mofetil (MMF), 1.85 (1.52 to 2.25) for cyclophosphamide (CTX),1.81 (1.10 to 2.98) for rituximab (RIT), 1.80 (1.38 to 2.33) for TW, 1.72 (1.35 to 2.19) for chlorambucil. As for 24 hours UTP, the direct andindirect comparisons showed that AZA (standard mean difference (SMD), -1.02(95% CI -1.90 to -0.15)), CsA (SMD, -0.70 (95% CI -1.33 to -0.08)),CTX (SMD, -1.01 (95% CI -1.44 to -0.58)), MMF (SMD, -0.98 (95% CI -1.64 to -0.32)), MZB (SMD, -0.97 (95% CI -1.90 to-0.04]), TAC (SMD, -1.16 (95% CI -1.72 to -0.60)) and TAC+TW(SMD, -2.03 (95% CI -2.94 to -1.12)) could significantly superior thancontrol, except for chlorambucil, LEF, RIT and STE. Thechanges of serum creatinine (Scr) was not significantly different between eachtreatments of immunosuppressive agents and the control, except for STE whichhas the possibility of increasing Scr (SMD, 1.00 (95% CI 0.36 to 1.64)).Comparisons among all treatments of immunosuppressive agents showed nostatistical significance in the outcome of relapse. A drenocorticotropichormone (85.1%) showed the lowest probability of relapse under the cumulativeranking curve values among all immunosuppressants. Infection,gastrointestinal symptoms, and bone marrow suppression were the common adverseevents associated with most of the immunosuppressive therapies.

CONCLUSIONS

This study demonstrates that TAC+TW, TAC and CTX are superior to other immunosuppressive agents in terms of TR and 24 hours UTP. Moreover, they are all at risk of infection, gastrointestinal symptoms, and myelosuppression. Furthermore, TAC could increase the risk of glucose intolerance or new-onset diabetes mellitus. Conversely, STE alone, LEF and MZB seem to have little advantage in clinical treatment of IMN.

PROSPERO REGISTRATION NUMBER

CRD42018094228.

Mycophenolate mofetil and tacrolimus versus tacrolimus alone for the treatment of idiopathic membranous glomerulonephritis: a randomised controlled trial

Background

Tacrolimus (TAC) is effective in treating membranous nephropathy (MN); however relapses are frequent after treatment cessation. We conducted a randomised controlled trial to examine whether the addition of mycophenolate mofetil (MMF) to TAC would reduce relapse rate.

Methods

Forty patients with biopsy proven idiopathic MN and nephrotic syndrome were randomly assigned to receive either TAC monotherapy (n = 20) or TAC combined with MMF (n = 20) for 12 months. When patients had been in remission for 1 year on treatment the MMF was stopped and the TAC gradually withdrawn in both groups over 6 months. Patients also received supportive treatment with angiotensin blockade, statins, diuretics and anticoagulation as needed. Primary endpoint was relapse rate following treatment withdrawal. Secondary outcomes were remission rate, time to remission and change in renal function.

Results

16/20 (80%) of patients in the TAC group achieved remission compared to 19/20 (95%) in the TAC/MMF group (p = 0.34). The median time to remission in the TAC group was 54 weeks compared to 40 weeks in the TAC/MMF group (p = 0.46). There was no difference in the relapse rate between the groups: 8/16 (50%) patients in the TAC group relapsed compared to 8/19 (42%) in the TAC/MMF group (p = 0.7). The addition of MMF to TAC did not adversely affect the safety of the treatment.

Conclusions

Addition of MMF to TAC does not alter the relapse rate of nephrotic syndrome in patients with MN.

Trial registration

This trial is registered with EudraCTN2008–001009-41. Trial registration date 2008-10-08.

Rituximab or Cyclosporine in the Treatment of Membranous Nephropathy

BACKGROUND

B-cell anomalies play a role in the pathogenesis of membranous nephropathy. B-cell depletion with rituximab may therefore be noninferior to treatment with cyclosporine for inducing and maintaining a complete or partial remission of proteinuria in patients with this condition.

METHODS

We randomly assigned patients who had membranous nephropathy, proteinuria of at least 5 g per 24 hours, and a quantified creatinine clearance of at least 40 ml per minute per 1.73 m² of body-surface area and had been receiving angiotensin-system blockade for at least 3 months to receive intravenous rituximab (two infusions, 1000 mg each, administered 14 days apart; repeated at 6 months in case of partial response) or oral cyclosporine (starting at a dose of 3.5 mg per kilogram of body weight per day for 12 months). Patients were followed for 24 months. The primary outcome was a composite of complete or partial remission of proteinuria at 24 months. Laboratory variables and safety were also assessed.

RESULTS

A total of 130 patients underwent randomization. At 12 months, 39 of 65 patients (60%) in the rituximab group and 34 of 65 (52%) in the cyclosporine group had a complete or partial remission (risk difference, 8 percentage points; 95% confidence interval [CI], -9 to 25; P = 0.004 for noninferiority). At 24 months, 39 patients (60%) in the rituximab group and 13 (20%) in the cyclosporine group had a complete or partial remission (risk difference, 40 percentage points; 95% CI, 25 to 55; P<0.001 for both noninferiority and superiority). Among patients in remission who tested positive for anti-phospholipase A₂ receptor (PLA2R) antibodies, the decline in autoantibodies to anti-PLA2R was faster and of greater magnitude and duration in the rituximab group than in the cyclosporine group. Serious adverse events occurred in 11 patients (17%) in the rituximab group and in 20 (31%) in the cyclosporine group (P = 0.06).

CONCLUSIONS

Rituximab was noninferior to cyclosporine in inducing complete or partial remission of proteinuria at 12 months and was superior in maintaining proteinuria remission up to 24 months. (Funded by Genentech and the Fulk Family Foundation; MENTOR ClinicalTrials.gov number, NCT01180036.).

Primary membranous nephropathy: comprehensive review and historical perspective

Membranous nephropathy (MN) is the most common cause of nephrotic syndrome in non-diabetic Caucasian adults over 40 years of age. It has an estimated incidence of 8–10 cases per 1 million. Fifty per cent of patients diagnosed with primary MN continue to have nephrotic syndrome and 30% of patients may progress to end-stage renal disease over 10 years. Although it was recognised as a distinct clinic-pathological entity in 1940s by immunofluorescence and electron microscopy, the pathogenesis and treatment have become more apparent only in the last decade. Discovery of M-type phospholipase A2 receptor (PLA2R) antibodies and thrombospondin type 1 domain-containing 7A antibodies has given new perspectives in understanding the pathogenesis of the disease process. Anti-PLA2R antibody is the first serologic marker that has promising evidence to be used as a tool to prognosticate the course of the disease. More importantly, therapeutic agents such as rituximab and adrenocorticotropic hormone analogues are the newer therapeutic options that should be considered in the therapy of primary MN.

Clinical implications of pathological features of primary membranous nephropathy

Background

The clinical outcome varies considerably in primary membranous nephropathy (pMN). Risk factors for kidney prognosis include ageing, male gender, persistent heavy proteinuria, decreased eGFR at presentation, persistent elevation of anti-PLA2R antibodies, no remission, and so on. It was controversial whether the histopathological features of pMN could predict treatment response and kidney outcome.

Methods

A retrospective study was conducted in 371 patients with biopsy-proven pMN. Pathological parameters included immunofluorescence staining, membranous Churg’s stages, sclerosis, crescent, focal segmental sclerosis lesion, chronic and acute tubulointerstitial injury. The fluorescence intensity was determined: 0, negative; 1, weak; 2, moderate; 3, strong; 4, glaring. Chronic tubulointerstitial injury was graded by the involved area: 0, 0–5%; 1, 6–25%; 2, 26–50%; 3, > 50%.

Results

We found that patients with higher intensity of C3 staining, advanced membranous stage, and more severe chronic tubulointerstitial injury presented with higher positivity rate of anti-PLA2R antibodies, higher levels of urinary protein excretion and serum creatinine, and lower level of serum albumin. Univariate Cox regression analysis showed that severe (grade = 3) chronic tubulointerstitial injury was a risk factor to the kidney outcome of ESKD (HR = 61.02, 95%CI, 7.75–480.57, P < 0.001) and over 50% reduction of eGFR (HR = 4.43, 95%CI, 1.26–15.6, P = 0.021). Multivariate analysis demonstrated it as an independent risk factor to ESKD (HR = 25.77, 95% CI, 1.27–523.91, P = 0.035). None of the pathological parameters exerted any influence on treatment response (P > 0.05).

Conclusions

We found the prognostic role of chronic tubulointerstitial injury to the kidney outcome of pMN. This study highlighted the value of kidney biopsy under the widespread usage of anti-PLA2R antibodies for diagnosis and prognosis.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1011-5) contains supplementary material, which is available to authorized users.

Should we really STOP treating patients with IgA nephropathy with steroids?

IgA nephropathy (IgAN) is the most common primary glomerulonephritis all over the world. Once considered as a benign disease, today the scientific community is aware that a significant percentage of patients eventually progress to end-stage kidney disease (ESKD). The rate of progression is often very slow. Since 1980s, several therapeutic attempts have been made with steroids. Despite different molecules, doses, and lengths of treatment, the majority of uncontrolled and controlled studies found benefits in terms of proteinuria reduction and reduction of the risk of ESKD. This was obtained with reasonable safety and tolerability, especially when steroids are given at relatively low dose and for a period not exceeding 6 months. Recently, two randomized controlled trials have questioned the efficacy and safety of steroid therapy in IgAN. However, these trials have many drawbacks that are to be considered when interpreting the findings.

The Unpredictability of Idiopathic Membranous Nephropathy: An Illustrative Case Report

The case of a female patient with primary membranous nephropathy is presented. She was treated with corticosteroids and chlorambucil after conservative therapy had failed and went into remission for 5 years. Her nephrotic syndrome recurred but did not respond to the same regimen. She had another complete remission after treatment with corticosteroids and cyclosporine, but the nephrosis recurred after 7 years. Again, she failed to respond with retreatment of steroids plus cyclosporine. She was treated with alternate-day steroid plus mycophenolate and, once again, had a complete remission. She was maintained on low-dose mycophenolate for 7 more years. The mycophenolate had to be discontinued because of cytomegalovirus colitis. Treatment with ganciclovir abolished the colitis. She is still in remission 10 years later. The case is discussed with regard to current knowledge of the immune pathogenesis of membranous nephropathy as well as the unknowns of the immunogenesis of the disease.

Regional variations in immunosuppressive therapy in patients with primary nephrotic syndrome: the Japan nephrotic syndrome cohort study

BACKGROUND

The lack of high-quality clinical evidences hindered broad consensus on optimal therapies for primary nephrotic syndromes. The aim of the present study was to compare prevalence of immunosuppressive drug use in patients with primary nephrotic syndrome across 6 regions in Japan.

METHODS

Between 2009 and 2010, 380 patients with primary nephrotic syndrome in 56 hospitals were enrolled in a prospective cohort study [Japan Nephrotic Syndrome Cohort Study (JNSCS)], including 141, 151, and 38 adult patients with minimal change disease (MCD), membranous nephropathy (MN), and focal segmental glomerulosclerosis (FSGS), respectively. Their clinical characteristics were compared with those of patients registered in a large nationwide registry of kidney biopsies [Japan Renal Biopsy Registry (J-RBR)]. The regional prevalence of use of each immunosuppressive drug was assessed among adult MCD, MN, and FSGS patients who underwent immunosuppressive therapy in the JNSCS (n = 139, 127, and 34, respectively). Predictors of its use were identified using multivariable-adjusted logistic regression models.

RESULTS

The clinical characteristics of JNSCS patients were comparable to those of J-RBR patients, suggesting that the JNSCS included the representatives in the J-RBR. The secondary major immunosuppressive drugs were intravenous methylprednisolone [n = 33 (24.6%), 24 (19.7%), and 9 (28.1%) in MCD, MN, and FSGS, respectively] and cyclosporine [n = 25 (18.7%), 62 (50.8%), and 16 (50.0%), respectively]. The region was identified as a significant predictor of use of intravenous methylprednisolone in MCD and MN patients.

CONCLUSION

Use of intravenous methylprednisolone for MCD and MN differed geographically in Japan. Its efficacy should be further evaluated in a well-designed trial.

Low-dose rituximab is poorly effective in patients with primary membranous nephropathy

Background

The optimal dosing and the efficacy of rituximab for primary membranous nephropathy (PMN) has not been established. This multicentric prospective study evaluates the efficacy and safety of low-dose rituximab (RTX) therapy in patients with PMN in clinical practice.

Methods

Thirty-four consecutive patients with PMN and nephrotic syndrome were included and received RTX (375 mg/m2) once (18 patients) or twice (16 patients). RTX was the first-line therapy for 19 (56%) and the second line for 15 (44%) patients. All patients were followed for 12 months after RTX and 24 for at least 18 months (mean 23.9 ± 18.6 months).

Results

At 12 months, 5 patients (14.7%) achieved complete response, 10 (29.4%) partial and 19 (55.8%) no response. Response occurred ∼6 months after RTX. At 24 months, the clinical situation was unchanged: two non-responders achieved partial response and two responders relapsed. Responders had significantly higher baseline GFR and lower anti-PLA2R antibodies compared with non-responders. Outcome was similar between one or two doses of RTX (non-responders 55.5 versus 56%, respectively) and between patients who had received previous therapy versus those receiving RTX as first-line therapy (non-responders 40 versus 68%, respectively). In the 15 patients already treated, the response to RTX was comparable to that of previous therapies.

Conclusion

Low-dose RTX obtains remission in <50% of PMN patients. Probably, higher doses and longer treatments are needed to induce and maintain a response. The balance between the costs and benefits should guide the selection of the patient and the optimal dosage.

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.

Safety of Rituximab Compared with Steroids and Cyclophosphamide for Idiopathic Membranous Nephropathy

Guidelines recommend steroid plus cyclical cyclophosphamide (St-Cp) therapy for patients with idiopathic membranous nephropathy at high risk of progression to ESRD. Rituximab (Rtx) may be a safer alternative. In this retrospective, observational cohort study, we compared time to any adverse event (primary outcome); serious or nonserious events; partial and complete remission of the nephrotic syndrome; and a composite of doubling of serum creatinine, ESRD, or death between 100 Rtx-treated patients and 103 patients who received daily St-Cp We monitored patients with standardized protocols and adjusted for baseline characteristics by Cox regression. Over a median follow-up of 40 months, the Rtx group had significantly fewer adverse events than the St-Cp group (63 versus 173; P<0.001), both serious (11 versus 46; P<0.001) and nonserious (52 versus 127; P<0.001). Cumulative incidence of any first (35.5% versus 69.0%; P<0.001), serious (16.4% versus 30.2%; P=0.002), or nonserious (23.6% versus 60.8%; P<0.001) event was significantly lower with Rtx Adjusted hazard ratios (95% confidence intervals) between Rtx and St-Cp groups were 0.27 (0.16 to 0.44) for any first adverse event, 0.32 (0.15 to 0.68) for serious adverse events, and 0.23 (0.13 to 0.41) for nonserious adverse events. Although the cumulative incidence of partial remission was lower in the Rtx group, rates of complete remission and the composite renal end point did not differ significantly between groups. Because of its superior safety profile, we suggest that Rtx might replace St-Cp as first-line immunosuppressive therapy in patients with idiopathic membranous nephropathy and nephrotic syndrome.

Early initiation of immunosuppressive treatment in membranous nephropathy patients

BACKGROUND/PURPOSE

Suggestion for the management of idiopathic membranous nephropathy (IMN) includes 6 months of observation, followed with steroid plus alkylating agent. However, delayed immunosuppression exposes the kidneys to persistent damage. This study aimed to examine the benefit of early immunosuppression in IMN patients.

METHODS

A retrospective study was performed. From 1993 to 2013, 161 IMN patients were enrolled. Patients receiving immunosuppression within 6 months after diagnosis were classified as initial-treatment group, whereas other patients as initial-no-treatment group. The clinical outcomes and complication were examined.

RESULT

Patients in the initial-treatment group had lower serum albumin concentration, less diabetes, and were younger. Steroid monotherapy is the main immunosuppression (64.5%) in this group. The initial-treatment group had a higher complete and partial remission rate than the initial-no-treatment group 6 months (52.9% vs. 35.0%, p=0.05) and 12 months (71.1% vs. 45.0%, p=0.003) after diagnosis. A similar result was seen between initial-steroid monotherapy and initial-no-treatment patients. Early immunosuppression is an independent predictor of remission within 1 year [hazard ratio (HR)=2.09; 95% confidence interval (CI)=1.25-3.49; p=0.005] and estimated glomerular filtration rate (eGFR) decline over 50% during the follow-up. (HR=0.33; 95% CI=0.13-0.86; p=0.02). The initial-treatment group also had a low frequency of eGFR decline over 50% (p=0.001) and low combined end-stage renal disease/mortality (p=0.001) compared with the initial-no-treatment group, but without more immunosuppression-related complication.

CONCLUSION

In contrast to Western countries, early immunosuppression (even steroid monotherapy) in our patients is associated with better remission in the 1^st year and renal preserve. Further randomized controlled trials are needed to clarify the benefit of early immunosuppression in IMN patients, especially with oriental ethnic background.

The putative role of MALDI-MSI in the study of Membranous Nephropathy

Membranous Nephropathy (MN) is an immunocomplex mediated renal disease that represents one of the most frequent glomerulopathies worldwide. This glomerular disease can manifest as primary (idiopathic) or secondary and this distinction is crucial when choosing the most appropriate course of treatment. In secondary cases, the best strategy involves treating the underlying disease, whereas in primary forms, the identification of confirmatory markers of the idiopathic etiology underlining the process is requested by clinicians. Among those currently reported, the positivity to circulating antigens (PLA2R, IgG4 and THSD7A) was demonstrated in approximately 75% of iMN patients, while approximately 1 in 4 patients with iMN still lack a putative diagnostic marker. Ultimately, the discovery of biomarkers to help further stratify these two different forms of glomerulopathy seems mandatory. Here, MALDI-MSI was applied to FFPE renal biopsies from histologically diagnosed primary and secondary MN patients (n=20) in order to detect alterations in their tissue proteome. MALDI-MSI was able to generate molecular signatures of primary and secondary MN, with one particular signal (m/z 1459), identified as Serine/threonine-protein kinase MRCK gamma, being over-expressed in the glomeruli of primary MN patients with respect to secondary MN. Furthermore, a number of signals that could differentiate the different forms of iMN that were positive to PLA2R or IgG4 were detected, as well as a further set of signals (m/z 1094, 1116, 1381 and 1459) that could distinguish these patients from those who were negative to both. These signals could potentially represent future targets for the further stratification of iMN patients. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann.

Renal biopsy in patients over 75: 131 cases

INTRODUCTION

Demographic analysis shows the ageing of the global population and the consequent increase in the age of hospitalized subjects and of patients starting dialysis. Hence, interest in the feasibility, safety, and usefulness of renal biopsy in elderly patients is growing. We examined the data of 131 patients over the age of 75 who underwent renal biopsy. We analyzed the safety of the procedure, treatment, and outcomes.

RESULTS

Histological diagnoses included: membranous glomerulonephritis (GN) 20.6%, crescentic GN 12.9%, IgAGN 10.6%, focal segmental glomerulosclerosis 9.1%, acute GN 4.5%, amyloidosis 9.1%, and acute tubular necrosis 3.8%. Mean glomerular obsolescence was 28.9 Â ± 27.9%. Mean age of the patients was 78.7 Â ± 5.73 years. At the time of biopsy, serum creatinine (SCr) was 4.47 Â ± 2.56 mg/dL and proteinuria was 4.82 Â ± 6.78 g/day. Targeted treatment was given to 51.9% of patients, 52.9% of whom had a good clinical response. Eight patients had clinically non-relevant side effects (11.7%). A positive response (defined as a more than 50% reduction of SCr, or by partial or complete remission of proteinuria) was observed in 36 patients (52.9%). 76 patients were monitored for 57 Â ± 9.89 months: 18 patients were on dialysis (follow-up 2.56 Â ± 3.61 months), 15 died (follow-up 58.5 Â ± 13.43 months), and 52 remained under nephrologic observation for 36 Â ± 31 months (SCr was 2.56 Â ± 0.75 mg/dL and proteinuria was 4.82 Â ± 6.78 g/day).

CONCLUSION

In our experience, renal biopsy is safe even in very elderly patients; it allowed targeted treatment in 51.9% of patients, 52.9% of whom had a good clinical response, possibly contributing to prolonged patient survival and improved quality of life.

Complete and Partial Remission as Surrogate End Points in Membranous Nephropathy

Absent a remission of proteinuria, primary membranous nephropathy (MN) can lead to ESRD over many years. Therefore, use of an earlier end point could facilitate the conduct of clinical trials. This manuscript evaluates complete remission (CR) and partial remission (PR) of proteinuria as surrogate end points for a treatment effect on ESRD in patients with primary MN with heavy proteinuria. CR is associated with a low relapse rate and excellent long-term renal survival, and it plausibly reflects remission of the disease process that leads to ESRD. Patients who achieve PR have better renal outcomes than those who do not but may have elevated relapse rates. How long PR must be maintained to yield a benefit on renal outcomes is also unknown. Hence, available data suggest that CR could be used as a surrogate end point in primary MN, whereas PR seems reasonably likely to predict clinical benefit. In the United States, surrogate end points that are reasonably likely to predict clinical benefit can be used as a basis for accelerated approval; treatments approved under this program must verify the clinical benefit in postmarketing trials. Additional analyses of the relationship between treatment effects on CR and PR and subsequent renal outcomes would inform the design of future clinical trials in primary MN.

Rituximab in Children with Steroid-Dependent Nephrotic Syndrome: A Multicenter, Open-Label, Noninferiority, Randomized Controlled Trial

Steroid-dependent nephrotic syndrome (SDNS) carries a high risk of toxicity from steroids or steroid-sparing agents. This open-label, noninferiority, randomized controlled trial at four sites in Italy tested whether rituximab is noninferior to steroids in maintaining remission in juvenile SDNS. We enrolled children age 1-16 years who had developed SDNS in the previous 6-12 months and were maintained in remission with high prednisone doses (≥0.7 mg/kg per day). We randomly assigned participants to continue prednisone alone for 1 month (control) or to add a single intravenous infusion of rituximab (375 mg/m(2); intervention). Prednisone was tapered in both groups after 1 month. For noninferiority, rituximab had to permit steroid withdrawal and maintain 3-month proteinuria (mg/m(2) per day) within a prespecified noninferiority margin of three times the levels among controls (primary outcome). We followed participants for ≥1 year to compare risk of relapse (secondary outcome). Fifteen children per group (21 boys; mean age, 7 years [range, 2.6-13.5 years]) were enrolled and followed for ≤60 months (median, 22 months). Three-month proteinuria was 42% lower in the rituximab group (geometric mean ratio, 0.58; 95% confidence interval, 0.18 to 1.95 [i.e., within the noninferiority margin of three times the levels in controls]). All but one child in the control group relapsed within 6 months; median time to relapse in the rituximab group was 18 months (95% confidence interval, 9 to 32 months). In the rituximab group, nausea and skin rash during infusion were common; transient acute arthritis occurred in one child. In conclusion, rituximab was noninferior to steroids for the treatment of juvenile SDNS.

Study of hypothalamic pituitary adrenal axis in patients of membranous nephropathy receiving modified Ponticelli regimen

Pulse methyl prednisolone followed by oral prednisolone and abrupt switch to chlorambucil/cyclophosphamide (Ponticelli/modified Ponticelli regimen) is used in patients with idiopathic membranous nephropathy. This therapy where steroids are stopped abruptly is unphysiologic and expected to have hypothalamic pituitary adrenal (HPA) axis suppression; however, this has not been evaluated. A total of 13 consecutive adult patients with idiopathic membranous nephropathy who had completed modified Ponticelli regimen were studied. The regimen included administration of pulse methylprednisolone 1 g for 3 days followed by oral prednisolone 0.5 mg/kg/day for 27 days followed by oral cyclophosphamide at a dose of 2 mg/kg/day for the next month. This was repeated for three courses. Patients who had received corticosteroids prior to therapy were excluded. The HPA axis was evaluated after 1 month of completing the last course of steroid therapy. The evaluation was done using a low-dose adrenocorticotropic hormone stimulation test. A single intravenous bolus dose of synacthen (1 μg) was given at 9.00 am and the serum cortisol levels were estimated by radioimmunoassay at 0, 30, and 60 min. A peak cortisol level of 550 nmol/L or higher was considered as normal. Mean baseline cortisol levels was 662.3 ± 294.6 nmol/L and peak cortisol level was 767 ± 304.4 nmol/L. A total of 6 patients (46.2%) had low basal cortisol levels, only 3 (23%) had both basal and peak cortisol levels < 550 nmol/L suggestive of HPA axis suppression. To conclude, 23% of patients had suppression of HPA axis after modified Ponticelli regimen.

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.

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.

Glomerular diseases: membranous nephropathy--a modern view

Membranous nephropathy (MN) is an autoimmune disease usually associated with a nephrotic syndrome and it may progress to ESRD in the long term. Its etiology is often unknown (idiopathic MN), whereas other cases have a recognizable etiology (secondary MN). In idiopathic MN, the glomerular lesions are mainly caused by autoantibodies against a podocyte membrane protein, the M-type of phospholipase A2 receptor 1. The natural course of idiopathic MN is quite varied with spontaneous complete or partial remissions a relatively common occurrence. Patients with asymptomatic non-nephrotic proteinuria seldom progress and need only conservative management. Those with persistent full-blown nephrotic syndrome and those with declining renal function are candidates for specific treatment with any of several regimens. Cyclical therapy with alternating monthly intravenous and oral glucocorticoids combined with a cytotoxic agent can induce remission and preserve renal function in the long term. Cyclosporine or tacrolimus can induce remission, but relapses are frequent after the drug withdrawal. Mycophenolate mofetil monotherapy seems to be ineffective, but may be beneficial when administered together with steroids. The experience with adrenocorticotropic hormone, natural or synthetic, is limited to a few studies with short-term follow-up, but high rates of remission can be seen after prolonged treatment. A high rate of remission and good tolerance have also been reported with rituximab. Patients with moderate renal insufficiency may also benefit from treatment, but at a price of frequent and serious side effects. With these limitations in mind, idiopathic MN may be considered a treatable disease in many patients.