Immunosuppressive treatment for idiopathic membranous nephropathy in adults with nephrotic syndrome

Efficacy and Safety of Mizoribine in comparison with Cyclophosphamide for Treatment of Refractory Nephrotic Syndrome: Protocol for a Multi-center, Controlled, Open-label, Randomized Controlled Trial (Preprint)

BACKGROUND

Nephrotic syndrome that is resistant to steroidal therapy is termed refractory nephrotic syndrome (RNS), a condition that is associated with an increased risk of end-stage renal disease (ESRD). Immunosuppressants are utilized to treat RNS, however prolonged may lead to significant adverse effects. Mizoribine (MZR) is a novel agent used in long-term immunosuppressive therapy that has few adverse effects, but data on its long-term use in patients with RNS are unavailable.

OBJECTIVE

We propose a trial to examine the efficacy and safety of MZR compared to cyclophosphamide (CYC) in Chinese adult patients with RNS.

METHODS

This is a multi-center, randomized, controlled interventional study with a screening phase (1 week) and a treatment phase (52 weeks). This study was reviewed and approved by the Medical Ethics Committees of all 34 medical centers. Patients with RNS consented to participation, and were enrolled and randomized into an MZR group or a CYC group (1:1 ratio), with each group receiving tapering doses of oral corticosteroids. Participants were assessed for adverse effects and collection of laboratory results at 8 visits during the treatment phase on week-4, week-8, week-12, week-16, week-20, week-32, week-44, and week-52 (exit visit). Participants were able to withdraw voluntarily and investigators were required to remove patients when there were safety concerns or deviations from protocol.

RESULTS

The study started in November 2014, and was completed in March 2019. A total of 239 participants from 34 hospitals in China were enrolled. Data analysis is completed. The results are waiting to be finalized by Center for Drug Evaluation.

CONCLUSIONS

The purpose of the current study is to evaluate the efficacy and safety of MZR in comparison with CYC for treatment of RNS in Chinese adult patients with glomerular diseases. It is the longest lasting and largest randomized controlled trial to examine MZR in Chinese patients. The results can help determine whether RNS should be considered as an additional indication for MZR treatment in China.

CLINICALTRIAL

ClinicalTrials.gov Register, NCT02257697. Registered 2014-10-01, https://clinicaltrials.gov/ct2/show/NCT02257697?term=MZR&rank=2.

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

Purpose

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

Patients and Methods

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

Results

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

Conclusion

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

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.

Redox State of Human Serum Albumin and Inflammatory Biomarkers in Hemodialysis Patients with Secondary Hyperparathyroidism During Oral Calcitriol Supplementation for Vitamin D

Background:

Hemodialysis (HD) patients with secondary Hyperparathyroidism (s-HPT) are exposed to increased inflammation and oxidative stress. In HD patients, oxidized albumin is a reliable marker of oxidative stress and its clinical significance has been rarely studied.

Objective:

The objective of this study was to evaluate Cys34 Human Serum Albumin (HSA) as oxidative stress biomarker in HD patients with s-HPT and its relationship with inflammation on bone turnover markers during oral calcitriol supplementation for vitamin D.

Patients and Methods:

Fifteen stable hemodialysis patients with s-HPT (mean age 48.67±8.15, 11 males and 4 females) were used in the experiment to receive calcitriol treatment for 16 weeks (0.25mcg or 0.5 mcg once a day according to serum level of Ca and P for each). The changes in the serum biochemical parameters (Ca, P, ALP, and iPTH), inflammatory markers (CRP and IL-6 levels) and serum oxidative stress condition (SOD, IS and albumin ratio HNA/HMA) were evaluated before and at 8 and 16 weeks of calcitriol treatment. The correlations between those factors were studied.

Results:

All patients responded to oral calcitriol therapy, with a significant decrease in the serum iPTH. The results showed that calcitriol could effectively suppress iPTH secretion with a significant elevation of serum Ca and P but ALP remained unchanged during the study. It can also effectively reduce the inflammatory markers (CRP and IL-6), while increasing the oxidative markers (SOD and IS). Oxidative albumin ratio HNA/HMA showed a significant (p=0.001) reduction after 16 weeks of calcitriol treatment and the redox state of HSA showed a positive prediction for hyperparathyroidism and for inflammation.

Conclusion:

The redox state of HSA could be used as a predictor for monitoring hyperparathyroidism and inflammation during calcitriol treatment by retarding albumin oxidation in HD patients with secondary hyperparathyroidism.

Efficacy and safety of long-course tacrolimus treatment for idiopathic membranous nephropathy

The aim of the present study was to observe the efficacy and safety of long-course treatment with tacrolimus combined with low-dose corticosteroids for idiopathic membranous nephropathy (IMN). A total of 76 patients with IMN diagnosed by renal biopsy between March 2012 and January 2016 form The First People's Hospital of Changzhou (Changzhou, China) were selected and randomly divided into a short-course group and a long-course group (each, n=38). Patients in the short-course group were treated with hormone combined with tacrolimus for 12 months, whereas those in the long-course group received the same treatment for 24 months. The efficacy, safety and recurrence of the two groups of patients were observed, and serum ALB, urine protein, Scr and blood glucose were assessed once a month for 24 months by measuring blood biochemistry. A total of 11 patients exhibited adverse effects, 6 of whom were serious and as such were excluded from the study. In the short-course group, 8 of 35 patients demonstrated complete remission (CR), 17 patients exhibited partial remission (PR) and the remaining 10 patients had no remission (NR); however the disease recurred in 8 patients following treatment. In the long-course group, 16 of 35 patients exhibited CR, 14 patients demonstrated PR and the remaining 5 patients had NR. Furthermore, the disease recurred in 4 patients following treatment. Significant differences were observed in urine protein and serum ALB at 18 and 24 months following treatment between the two groups while Scr and blood glucose had no significant differences at any time point. It was concluded that long-course tacrolimus combined with low-dose hormone effectively treats idiopathic membranous nephropathy and that therapy demonstrated a relatively high remission rate, and the recurrence rate of the disease is low.

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.

Immunosuppression for progressive membranous nephropathy: a UK randomised controlled trial

BACKGROUND

Membranous nephropathy leads to end-stage renal disease in more than 20% of patients. Although immunosuppressive therapy benefits some patients, trial evidence for the subset of patients with declining renal function is not available. We aimed to assess whether immunosuppression preserves renal function in patients with idiopathic membranous nephropathy with declining renal function.

METHODS

This randomised controlled trial was undertaken in 37 renal units across the UK. We recruited patients (18-75 years) with biopsy-proven idiopathic membranous nephropathy, a plasma creatinine concentration of less than 300 μmol/L, and at least a 20% decline in excretory renal function measured in the 2 years before study entry, based on at least three measurements over a period of 3 months or longer. Patients were randomly assigned (1:1:1) by a random number table to receive supportive treatment only, supportive treatment plus 6 months of alternating cycles of prednisolone and chlorambucil, or supportive treatment plus 12 months of ciclosporin. The primary outcome was a further 20% decline in renal function from baseline, analysed by intention to treat. The trial is registered as an International Standard Randomised Controlled Trial, number 99959692.

FINDINGS

We randomly assigned 108 patients, 33 of whom received prednisolone and chlorambucil, 37 ciclosporin, and 38 supportive therapy alone. Two patients (one who received ciclosporin and one who received supportive therapy) were ineligible, so were not included in the intention-to-treat analysis, and 45 patients deviated from protocol before study end, mostly as a result of minor dose adjustments. Follow up was until primary endpoint or for minimum of 3 years if primary endpoint was not reached. Risk of further 20% decline in renal function was significantly lower in the prednisolone and chlorambucil group than in the supportive care group (19 [58%] of 33 patients reached endpoint vs 31 [84%] of 37, hazard ratio [HR] 0·44 [95% CI 0·24-0·78]; p=0·0042); risk did not differ between the ciclosporin (29 [81%] of 36) and supportive treatment only groups (HR 1·17 [0·70-1·95]; p=0·54), but did differ significantly across all three groups (p=0·003). Serious adverse events were frequent in all three groups but were higher in the prednisolone and chlorambucil group than in the supportive care only group (56 events vs 24 events; p=0·048).

INTERPRETATION

For the subset of patients with idiopathic membranous nephropathy and deteriorating excretory renal function, 6 months' therapy with prednisolone and chlorambucil is the treatment approach best supported by our evidence. Ciclosporin should be avoided in this subset.

FUNDING

Medical Research Council, Novartis, Renal Association, Kidney Research UK.

Immunosuppression for membranous nephropathy: a systematic review and meta-analysis of 36 clinical trials

BACKGROUND AND OBJECTIVES

The efficacy and safety of immunosuppression for idiopathic membranous nephropathy (IMN) with nephrotic syndrome are still controversial. A systematic review and meta-analysis of randomized controlled trials (RCTs) was performed.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Cochrane Library, PUBMED, EMBASE, Chinese Database, and Clinical Trial Registries (June 2012) were searched to identify RCTs investigating the effect of immunosuppression on adults with IMN and nephrotic syndrome.

RESULTS

This review was an update (36 RCTs, 1762 participants) of the 2004 version (18 RCTs, 1025 participants). Immunosuppression significantly reduced all-cause mortality or ESRD (15 RCTs, 791 participants; risk ratio, 0.58 [95% confidence interval, 0.36-0.95]; P=0.03). However, the result was not consistent when prespecified subgroup analyses were undertaken. Immunosuppression increased complete or partial remission (CR + PR) (16 RCTs, 864 participants; 1.31 [1.01-1.70]; P=0.04) but resulted in more withdrawals or hospitalizations (16 RCTs, 880 participants; 5.35 [2.19-13.02]; P=0.002). Corticosteroids combined with alkylating agents significantly reduced all-cause mortality or ESRD (8 RCTs, 448 participants; 0.44 [0.26-0.75]; P=0.002) and increased CR + PR (7 RCTs, 422 participants; 1.46 [1.13-1.89]; P=0.004) but led to more adverse events (4 RCTs, 303 participants; 4.20 [1.15-15.32]; P=0.03). Cyclophosphamide was safer than chlorambucil (3 RCTs, 147 participants; 0.48 [0.26-0.90]; P=0.02). Cyclosporine and mycophenolate mofetil failed to show superiority over alkylating agents. Tacrolimus and adrenocorticotropic hormone significantly reduced proteinuria.

CONCLUSIONS

Alkylating agents plus corticosteroids had long-term and short-term benefits for adult IMN, but resulted in more withdrawals or hospitalizations.

Rituximab therapy in nephrotic syndrome: implications for patients' management

Rituximab offers an alternative to current immunosuppressive therapies for difficult-to-treat nephrotic syndrome. The best outcomes are seen in patients with steroid-dependent nephrotic syndrome who have failed to respond to multiple therapies. By contrast, the benefits of rituximab therapy are limited in patients with steroid-resistant nephrotic syndrome, particularly those with focal segmental glomerulosclerosis (FSGS). Therapy with plasma exchange and one or two doses of rituximab has shown success in patients with recurrent FSGS. Young patients and those with normal serum albumin at recurrence of nephrotic syndrome are most likely to respond to rituximab therapy. A substantial proportion of rituximab-treated patients with idiopathic membranous nephropathy show complete or partial remission of proteinuria, and reduced levels of phospholipase A(2) receptor autoantibodies, which are implicated in the pathogenesis of this disorder. Successful rituximab therapy induces prolonged remission and enables discontinuation of other medications without substantially increasing the risk of infections and other serious adverse events. However, the available evidence of efficacy of rituximab therapy is derived chiefly from small case series and requires confirmation in prospective, randomized, controlled studies that define the indications for use and predictors of response to this therapy.

Immunosuppressive treatment for nephrotic idiopathic membranous nephropathy: a meta-analysis based on Chinese adults

Background

Idiopathic membranous nephropathy (IMN) is the most common pathological type for nephrotic syndrome in adults in western countries and China. The benefits and harms of immunosuppressive treatment in IMN remain controversial.

Objectives

To assess the efficacy and safety of different immunosuppressive agents in the treatment of nephrotic syndrome caused by IMN.

Methods

PubMed, EMBASE, Cochrane Library and wanfang, weipu, qinghuatongfang, were searched for relevant studies published before December 2011. Reference lists of nephrology textbooks, review articles were checked. A meta-analysis of randomized controlled trials (RCTs) meeting the criteria was performed using Review Manager.

Main Results

17 studies were included, involving 696 patients. Calcineurin inhibitors had a better effect when compared to alkylating agents, on complete remission (RR 1.61, 95% CI 1.13, to 2.30 P = 0.008), partial or complete remission (effective) (CR/PR, RR 1.29, 95% CI 1.09 to 1.52 P = 0.003), and fewer side effects. Among calcineurin inhibitors, tacrolimus (TAC) was shown statistical significance in inducing more remissions. When compared to cyclophosphamide (CTX), leflunomide (LET) showed no beneficial effect, mycophenolate mofetil (MMF) showed significant beneficial on effectiveness (CR/PR, RR: 1.41, 95% CI 1.16 to 1.72 P = 0.0006) but not significant on complete remission (CR, RR: 1.38, 95% CI 0.89 to 2.13 P = 0.15).

Conclusions

This analysis based on Chinese adults and short duration RCTs suggested calcineurin inhibitors, especially TAC, were more effective in proteinuria reduction in IMN with acceptable side effects. Long duration RCTs were needed to confirm the long-term effects of those agents in nephrotic IMN.

Glomerular disease search filters for Pubmed, Ovid Medline, and Embase: a development and validation study

BACKGROUND

Tools to enhance physician searches of Medline and other bibliographic databases have potential to improve the application of new knowledge in patient care. This is particularly true for articles about glomerular disease, which are published across multiple disciplines and are often difficult to track down. Our objective was to develop and test search filters for PubMed, Ovid Medline, and Embase that allow physicians to search within a subset of the database to retrieve articles relevant to glomerular disease.

METHODS

We used a diagnostic test assessment framework with development and validation phases. We read a total of 22,992 full text articles for relevance and assigned them to the development or validation set to define the reference standard. We then used combinations of search terms to develop 997,298 unique glomerular disease filters. Outcome measures for each filter included sensitivity, specificity, precision, and accuracy. We selected optimal sensitive and specific search filters for each database and applied them to the validation set to test performance.

RESULTS

High performance filters achieved at least 93.8% sensitivity and specificity in the development set. Filters optimized for sensitivity reached at least 96.7% sensitivity and filters optimized for specificity reached at least 98.4% specificity. Performance of these filters was consistent in the validation set and similar among all three databases.

CONCLUSIONS

PubMed, Ovid Medline, and Embase can be filtered for articles relevant to glomerular disease in a reliable manner. These filters can now be used to facilitate physician searching.

Membranous nephropathy in children: clinical presentation and therapeutic approach

The approach to the pediatric patient with membranous nephropathy (MN) can be challenging to the practitioner. The clinical presentation of the child with this histologic entity usually involves some degree of proteinuria ranging from persistent, subnephrotic-ranged proteinuria to overt nephrotic syndrome. Patients often have accompanying microscopic hematuria and may have azotemia or mild hypertension. Children presenting with nephrotic syndrome are often steroid resistant; as such, their biopsy for steroid-resistant nephrotic syndrome results in the diagnosis of MN. The practitioner treating MN in the pediatric patient must weigh the risks of immunosuppressive therapy against the benefits. In general, the child with subnephrotic proteinuria and normal renal function can likely be treated conservatively with angiotensin blockade (angiotensin-converting enzyme inhibitors or angiotensin receptor blockers) without the need for immunosuppressive therapy. Those with nephrotic syndrome are usually treated with steroids initially and often followed by alkylating agents (cyclophosphamide or chlorambucil). Calcineurin inhibitors may also be useful, but the relapse rate after their discontinuation remains high. The absence of controlled studies in children with MN makes treatment recommendations difficult, but until they are available, using the patient's clinical presentation and risk of disease progression appears to be the most prudent approach.

Familial membranous nephropathy: an X-linked genetic susceptibility?

BACKGROUND

Membranous nephropathy (MN) is the most common histological diagnosis in adults with nephrotic syndrome and a leading cause of end-stage kidney failure from glomerulonephritis. Little is known about the underlying aetiology, although anti-glomerular antibodies have been implicated. No specific underlying genetic defect has yet been identified.

METHODS

In a family with four members in three generations affected by primary MN, the serum of affected members and their mothers were assessed for anti-glomerular antibodies.

RESULTS

All four affected are male and connected through the maternal line, indicative of X-linked inheritance. Age of onset of nephrotic syndrome varied between 1 and 67 years of age, suggesting that a potential underlying gene may confer a genetic predisposition to MN, but other factors, genetic or environmental, are necessary to trigger the disease. Serologic studies revealed antibodies against glomerular and peritubular endothelial cells in the mother of the youngest patient.

CONCLUSIONS

We have identified the largest reported family with a potential X-linked susceptibility to MN. Foeto-maternal alloimmunization may have triggered the disease in the youngest individual. Considering that the majority of patients with sporadic MN are male, identification of an X-linked predisposing factor may have implications well beyond this family and could provide a target for treatment.

Contrasting roles of complement activation and its regulation in membranous nephropathy

The complement system is involved in defense against microorganisms, the processing of immune complexes and apoptotic debris, and the development of an appropriate immune response. Along with these physiologic effects, complement activation has the potential to result in tissue pathology. To limit this, various complement regulatory proteins (CRP) are present on host cells, including the glomerular podocyte. Experimental data from the Heymann nephritis (HN) rat model of human membranous nephropathy (MN) have shown that IgG antibodies in subepithelial immune deposits initiate complement activation and C5b-9-mediated damage of the overlying podocyte. Although IgG can activate the classical pathway, there also is evidence that alternative pathway activation occurs in MN, which could occur because of absent, dysfunctional, or inhibited podocyte CRP. Related to this are experimental data in HN showing the presence of antibodies that bind and inhibit podocyte CRP; although such antibodies have not been documented in human MN, a decrease in CR1 quantity on the podocyte has been observed. A s a result of a relative lack of CRP and the exposure of activating complement proteins to tubular cells, alternative complement pathway activation and C5b-9-mediated tubular injury can occur in MN and other proteinuric diseases. Overall, in a disease such as MN, the balance between complement regulation and activation is tipped toward its being activated. Therefore, a number of therapeutic approaches have been developed to counteract this, including recombinant forms of endogenous CRP and complement-inhibitory monoclonal antibodies. There is good reason to be optimistic that approaches to block complement activation will become viable therapy for human MN in the future.