Mechanism of the antiproteinuric effect of cyclosporine in membranous nephropathy

Membranous nephropathy: Mechanistic insights and therapeutic perspectives

Membranous nephropathy (MN) is one of the most common causes of non-diabetic nephrotic syndrome in adults. About 80% of cases are renal limited (primary MN) and 20% are associated with other systemic diseases or exposures (secondary MN). Autoimmune reaction is the main pathogenic factor of MN, and the discovery of autoantigens including the phospholipase A₂ receptor and thrombospondin type-1 domain-containing protein 7A has led to new insights into the pathogenesis, they can induce humoral immune responses led by IgG₄ makes them suitable for the diagnosis and monitoring of MN. In addition, complement activation, genetic susceptibility genes and environmental pollution are also involved in MN immune response. In clinical practice, due to the spontaneous remission of MN, the combination of supportive therapy and pharmacological treatment is widely used. Immunosuppressive drugs are the cornerstone of MN treatment, and the dangers and benefits of this approach vary from person to person. In summary, this review provides a more comprehensive review of the immune pathogenesis, interventions and unresolved issues of MN in the hope of providing some new ideas for clinical and scientific researchers in the treatment of MN.

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.

Low-dose cyclosporine in treatment of membranous nephropathy with nephrotic syndrome: effectiveness and renal safety

BACKGROUND

To observe effectiveness and renal safety of long-term low-dose cyclosporine in idiopathic membranous nephropathy (IMN).

METHODS

Sixty-eight patients were enrolled in this prospective cohort study. Renal endpoint was defined as a decrease in eGFR ≥50% from baseline and a development of eGFR ≤60 ml/min/1.73m².

RESULTS

A cyclosporine dose of 2.0 ± 0.5 mg/kg/d and a prednisone of 0.3 ± 0.2 mg/kg/d were prescribed. The duration of cyclosporine treatment was 27 (3-80) months. The overall remission rate was 91% with a relapse rate of 42%. Fourteen patients had cyclosporine-related acute renal injury (CsA-ARI) within the first three months, and 16 patients had cyclosporine related chronic renal injury (CsA-CRI) within the first year. At the end of follow-up (50 ± 18 months), 16 patients (24%) reached renal endpoint. Presence of intimal fibrosis of small artery and higher time-averaged proteinuria were identified as independent risk factors for renal endpoint. RAS inhibition treatment decreased the risk of poor renal outcome. Patients in CsA-ARI group had the highest proteinuria at the third month, the highest time-average proteinuria and the highest proportion of cases reaching renal endpoint. Patients with CsA-CRI were of the oldest age and with the lowest baseline eGFR.

CONCLUSIONS

Low-dose cyclosporine is effective in treating IMN. CsA-ARI and no response in proteinuria during the first three months of cyclosporine treatment had the lowest benefit/risk ratio, and these patients should be switched to non-calcineurin-inhibitor based regimen. Patients of older age, with lower baseline eGFR, or having intimal sclerosis of small artery, are more likely to develop progressive renal dysfunction.

Treatment of membranous nephropathy: time for a paradigm shift

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

Use of Cyclosporine Therapy in Steroid Resistant Nephrotic Syndrome (SRNS): A Review

A chronic, progressive disorder Steroid Resistant Nephrotic Syndrome (SRNS) accounts for 10-20% of all children with Nephrotic Syndrome. It is a heterogeneous disorder comprised of persistent edema, proteinuria, hypoalbuminemia and hyperlipidemia. Treatment for steroid-resistant nephrotic syndrome (SRNS) is challenging and children who suffer from SRNS require aggressive treatment to achieve remission. Calcineurin inhibitors have been used more in an empirical manner than on the basis of clear rationale. It was in 1984 when cyclosporine was first considered for the treatment of steroid resistant nephrotic syndrome. Cyclosporin is a calcineurin inhibitor that suppresses immune response by downregulating the transcription of various cytokine genes. Till now many studies have been conducted to determine dosages, duration of therapy, side effects and advantages of cyclosporine. Treatment of SRNS remains a difficult challenge in pediatric nephrology.  Treatment should be individualized according to the underlying histopathology, and clinical and environmental conditions of the children. There is an urgent need to distinguish as soon as possible those patients who may benefit from prolonged immunosuppressive treatment from those who will not benefit from such treatment and who will just suffer from its major side effects. The emerging evidence that the majority of genetic forms of SRNS should receive symptomatic treatment only, should also be clinically tested and studies baring its significance should be evaluated in the future.

Nonimmunologic targets of immunosuppressive agents in podocytes

Proteinuria is a characteristic finding in glomerular diseases and is closely associated with renal outcomes. In addition, therapeutic interventions that reduce proteinuria improve renal prognosis. Accumulating evidence has demonstrated that podocytes act as key modulators of glomerular injury and proteinuria. The podocyte, or glomerular visceral epithelial cell, is a highly specialized and differentiated cell that forms interdigitated foot processes with neighboring podocytes, which are bridged together by an extracellular structure known as the "slit diaphragm" (SD). The SD acts as a size- and charge-selective barrier to plasma protein. Derangement of SD structure or loss of SD-associated protein results in podocyte injury and proteinuria. During the past decades, several immune-modulating agents have been used for the treatment of glomerular diseases and for the reduction of proteinuria. Interestingly, recent studies have demonstrated that immunosuppressive agents can have a direct effect on the SD-associated proteins and stabilize actin cytoskeleton in podocyte and have therefore introduced the concept of nonimmunologic mechanism of renoprotection by immunomodulators. This review focuses on the evidence that immuno-modulating agents directly target podocytes.

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.

Comparison of glucocorticoids alone and combined with cyclosporine a in patients with IgA nephropathy: a prospective randomized controlled trial

OBJECTIVE

The aim of this study was to investigate the effects of two different treatment regimes in patients with IgA nephropathy (IgAN): steroids alone and in combination with a medium dose of cyclosporine A (CsA).

METHODS

Forty-eight IgAN patients 18-69 years of age with proteinuria >1.0 g/24 hours and an estimated glomerular filtration rate (eGFR) of >30 mL/min/1.73 m(2) were randomly given either steroids alone (methylprednisolone (MP) group; n=25) or steroids plus CsA treatment (combination group; n=23). The primary endpoint was the reduction of proteinuria by 50% or more of the baseline value. The secondary endpoint was an increase in the baseline serum creatinine level of 50% or a decrease in the baseline eGFR of 25%.

RESULTS

After 12 months of treatment, all patients in the combination group and 87.50% of the patients in the MP group reached the primary endpoint. The complete remission rates in the combination group and MP group were 50.0% and 45.83%, respectively. The level of urinary protein excretion declined from 3.17 ± 3.25 g/24 hours to 0.36 ± 0.23 g/24 hours (p<0.001) in the combination group and from 2.60 ± 2.03 g/24 hours to 0.53 ± 0.71 g/24 hours (p<0.001) in the MP group. Two patients in the combination group reached the secondary endpoint, with a decrease in the eGFR of 25% from the baseline value, while no patients in the MP group achieved this goal. The patients in the combination group exhibited significant improvements in the eGFR after nine months (90.16 ± 28.78 vs. 80.46 ± 22.73 mL/min.1.73 m(2), p=0.011), while the patients in the MP group showed significant increases in the eGFR after six months of treatment (92.18 ± 22.71 to 81.63 ± 18.36 mL/min/1.73 m(2), p=0.019). Four patients (8.33%) developed severe pneumonia during treatment.

CONCLUSION

Both the full dose of steroids alone and combined treatment with steroids and a medium dose of CsA remarkably reduced the levels of proteinuria and ameliorated the renal function in the IgAN patients. Infection was the most serious complication during the treatment.

Treatment of idiopathic membranous nephropathy

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

Upregulation of c-mip is closely related to podocyte dysfunction in membranous nephropathy

Membranous nephropathy is a glomerular disease typified by a nephrotic syndrome without infiltration of inflammatory cells or proliferation of resident cells. Although the cause of the disease is unknown, the primary pathology involves the generation of autoantibodies against antigen targets on the surface of podocytes. The mechanisms of nephrotic proteinuria, which reflect a profound podocyte dysfunction, remain unclear. We previously found a new gene, c-mip (c-maf-inducing protein), that was associated with the pathophysiology of idiopathic nephrotic syndrome. Here we found that c-mip was not detected in the glomeruli of rats with passive-type Heymann nephritis given a single dose of anti-megalin polyclonal antibody, yet immune complexes were readily present, but without triggering of proteinuria. Rats reinjected with anti-megalin develop heavy proteinuria a few days later, concomitant with c-mip overproduction in podocytes. This overexpression was associated with the downregulation of synaptopodin in patients with membranous nephropathy, rats with passive Heymann nephritis, and c-mip transgenic mice, while the abundance of death-associated protein kinase and integrin-linked kinase was increased. Cyclosporine treatment significantly reduced proteinuria in rats with passive Heymann nephritis, concomitant with downregulation of c-mip in podocytes. Thus, c-mip has an active role in the podocyte disorders of membranous nephropathy.

The KDIGO practice guideline on glomerulonephritis: reading between the (guide)lines--application to the individual patient

The KDIGO guideline for glomerulonephritis is designed to assist health-care providers in treating patients with glomerular diseases. A guideline is not a set of rules but is intended to allow the practitioner to make an informed decision based on the available evidence. Due to its general nature and the variability of strength of the available studies, it is often difficult to directly apply a guideline to the care of an individual patient. This commonly relates to the limited generalizability of the evidence, i.e., does not cover every clinical scenario. To underscore this point, we have introduced within the context of the glomerulonephritis guideline cases with specific features to illustrate the constant need for clinical judgment. These vignettes are intended to demonstrate how the best treatment plans should be individualized and take into account patient preference and clinical acumen, as well as the best available evidence.

Is the antiproteinuric effect of cyclosporine a independent of its immunosuppressive function in T cells?

The antiproteinuric effect of cyclosporine A(CsA) has been believed to result from its immunosuppressive effect on the transcription factor NFAT in T cells. However, current evidences supporting this hypothesis are missing. A recent study showed that CsA has a direct antiproteinuric effect on podocytes, suggesting a novel non-immunosuppressive mechanism for CsA's antiproteinuric effect. Conditional NFATc1 activation in podoyctes per se is sufficient to induce proteinuria in mice, indicating that NFAT activation in podocytes is a critical pathogenic molecular event leading to podocyte injury and proteinuria. Meanwhile, evidence showed that TRPC6-mediated Ca(2+) influx stimulates NFAT-dependent TRPC6 expression. Altogether, these advances in podocyte research indicate that calcineurin-NFAT signal or calcineurin-synaptopodin axis has a direct proteinuric effect on podocytes which raises the possibility of developing specific antiproteinuric drugs that lack the unwanted effects of calcineurin or NFAT inhibition.

Benefit and cost from the long-term use of cyclosporine-A in idiopathic membranous nephropathy

AIM

Idiopathic membranous nephropathy (IMN), the most common cause of nephrotic syndrome in adults, is usually treated by cyclosporin A (CsA). Estimation of the effectiveness of long-term use of CsA in the remission and relapse rate of nephrotic syndrome along with histological changes in repeat renal biopsies was the aim of the study.

METHODS

Thirty-two nephrotic patients with well-preserved renal function treated by prednisolone and CsA were studied. A repeat biopsy was performed in 18 patients with remission of nephrotic syndrome, after 24 months of treatment, to estimate the activity of the disease and features of CsA toxicity.

RESULTS

Complete remission of nephrotic syndrome was observed in 18 (56%) and partial remission in 10 patients (31%) after 12 months of treatment (total 87%). Relapses were observed in 39% and 60% of patients with complete and partial remission, respectively, and multiple relapses in 25% of patients, who showed gradual unresponsiveness to CsA and decline of renal function. Progression of stage of the disease and more severe glomerulosclerosis and tubulointerstitial injury were recognized in 55% and 61% of patients respectively. Features of CsA nephrotoxicity were not observed. The severity of histological changes was related to the time elapsed from the first biopsy (r = 0.452, P < 0.05).

CONCLUSION

Low doses of CsA with prednisolone induce remission of nephrotic syndrome in most idiopathic membranous nephropathy patients. Although typical features of CsA nephrotoxicity are not observed, significant deterioration of histological lesions occurs with time, even in patients with remission. Long-term use of CsA should be examined with caution.

Management of idiopathic membranous nephropathy

IMPORTANCE OF THE FIELD

Idiopathic membranous nephropathy (IMN) can have a variable natural course. Treatments able to induce remission can improve the long-term prognosis. However, the optimal therapy for IMN remains controversial.

AREA COVERED IN THIS REVIEW

We reviewed the historical and current literature from 1979 to 2010 regarding the natural course of IMN and the possible treatments giving special emphasis to randomized controlled trials and to more recent approaches.

WHAT THE READER WILL GAIN

The reader will gain a comprehensive review of the available treatments of IMN. A personal therapeutic algorithm for nephrotic patients with IMN is also provided.

TAKE HOME MESSAGE

At least five different treatments showed efficacy in many (but not all) patients with IMN.

Triple therapy with single daily dose of cyclosporine in Japanese patients with idiopathic membranous nephropathy

OBJECTIVE

The optimal therapeutic approach to patients with idiopathic membranous nephropathy (IMN) remains controversial. In this study, we assessed the efficacy of single daily dose cyclosporine (CsA) combined with low-dose prednisolone (PSL) and an angiotensin II receptor blocker (ARB) in patients with IMN.

METHODS

We studied 13 nephrotic patients (8 men, 5 women) with IMN diagnosed on biopsy. An initial single daily dose of 2 mg/kg, but not exceeding 150 mg, CsA was given for 12 months, tapered by a 25 mg reduction every 2 months. An initial twice-daily dose of 0.5 mg/kg PSL was given for 2 months and was also tapered. An ARB was given to all patients and the same dosage was used throughout the study. Patients were followed up for 6 to 66 months.

RESULTS

Nine patients achieved complete remission at 6.7±2.9 months, and incomplete remission was obtained in the remaining patients. After a follow-up period of 32.7±20.0 months, their serum creatinine and estimated glomerular filtration rate values were similar to baseline levels. The 9 patients who completed the treatment course have not relapsed. Moreover, there were no adverse effects requiring discontinuation of this triple therapy.

CONCLUSION

A single daily dose of CsA combined with a low dose of PSL and an ARB in new-onset nephrotic patients with IMN induced a high remission rate of nephrotic syndrome, with a low incidence of relapse and a low risk of adverse effects. The triple therapy and prospective follow-up shows potential as a treatment approach for patients with IMN.

Oral cyclophosphamide is on the verge of extinction as therapy for severe autoimmune diseases (especially lupus): should nephrologists care?

Some day we will have powerful targeted therapies for autoimmune diseases. Remission will be induced efficiently. Side effects will be mere ripples. Unfortunately, that day is not imminent. Current therapies are powerful but with unintended targets and side effects that can be equivalent to a sea change. For SLE, the current competition to select the 'gold standard' immunosuppressant has come down to two regimens: intravenous cyclophosphamide (IVCY, standard NIH protocol or its variations) versus oral mycophenolate (MMF). Until recently, IVCY reigned as the gold standard, a title it achieved through a curious journey that did not involve rigorous head-to-head competition. Oral cyclophosphamide (POCY) has not been invited to the current competition to select the gold standard immunosuppressant despite the substantial evidence that POCY can perform at least as well as IVCY or mycophenolate, and compared to IVCY, is far less expensive, easier for the patient, and maybe more effective in African-Americans. Here, we state the case for POCY as therapy for severe autoimmune diseases. We suggest that if POCY is allowed to compete, it will not disappoint.

Non-immunologic mechanisms of calcineurin inhibitors explain its antiproteinuric effects in genetic glomerulopathies

It has been reported (this issue Pediatric Nephrology) that cyclosporine A (CyA) therapy in combination with corticosteroids, angiotensin-converting enzyme inhibitor, and an angiotensin receptor blocker decreased proteinuria in three patients with nephrotic syndrome (NS) due to WT1 mutations. Treatment with calcineurin inhibitors were found to induce a partial remission of proteinuria in several other children with genetic forms of NS, such as mutation in the podocine and in the phospholipase C epsilon gene. CyA therapy has also been reported to be beneficial to patients with Alport syndrome. Recent data have shown that the antiproteinuric effect of CyA in these cases may be due to a non-immunologic mechanism. CyA exerts an antiproteinuria effect by preventing the degradation of the actin organizing protein synaptodpodin and by a downregulation of TRPC6. This mechanism leads to the stabilization of the actin cytoskeleton in the kidney podocytes. This beneficial effect of CyA is interesting, but long-term results regarding function and nephrotoxicity are still missing.

Recurrent idiopathic membranous nephropathy: early diagnosis by protocol biopsies and treatment with anti-CD20 monoclonal antibodies

Membranous nephropathy (MN) recurs posttransplant in 42% of patients. We compared MN recurrence rates in a historical cohort transplanted between 1990 and 1999 and in a current cohort diagnosed by protocol biopsies, we analyzed the progression of the disease and we assessed the effects of anti-CD20 antibodies (Rituximab) on recurrent MN. The incidence of recurrent MN was similar in the historical (53%) and the current cohorts (41%), although in the later the diagnosis was made earlier (median, 4[2-21] months vs. 83[6-149], p = 0.002) and the disease was clinically milder. Twelve out of 14 patients (86%) with recurrent MN in the current cohort had progressive increases in proteinuria. Eight recipients were treated with Rituximab after their proteinuria increased from median, 211 mg/day (64-4898) at diagnosis to 4489 (898-13 855) (p = 0.038). Twelve months post-Rituximab, 75% of patients had either partial (PR) or complete remission (CR). After 24 months 6/7 (86%) had PR/CR and one patient relapsed. Posttreatment biopsies showed resorption of electron dense immune deposits in 6/7 cases and were negative for C3 (4/7) and IgG (3/7). Protocol biopsies allow early diagnosis of subclinical recurrent MN, which is often progressive. Treatment of recurrent MN with Rituximab is promising and should be evaluated in a prospective randomized controlled trial.

Idiopathic membranous nephropathy: management strategies

Treatment of idiopathic membranous nephropathy is based on a 'symptomatic' therapy that includes ACE inhibitors or angiotensin II receptor antagonists, and on an 'aetiological' therapy aimed at modulating underlying immunological mechanisms. The role of the latter is still debated given the usually indolent course of disease; furthermore, traditional immunosuppressants would not have an impact on patient and renal survival according to a systematic review of literature. However, up to 40% of untreated patients eventually develop end-stage renal disease and remission of nephrotic syndrome protects patients from related life-threatening complications and is the strongest positive prognostic factor for long-term kidney function. Therefore, immunosuppressive therapy seems to be rational in high-risk patients with nephrotic syndrome or deteriorating renal function. This article outlines a possible role for each 'aetiological' therapy on the basis of available evidence in order to provide some practical recommendations. The first-line therapy is based on a 6-month regimen of alternating corticosteroids and an alkylating agent ('Ponticelli' regimen), whereas oral ciclosporin and intramuscular corticotrophin (adrenocorticotrophic hormone) are alternatives that provide comparable results in terms of remission of proteinuria, with a different adverse effect profile. New drugs are emerging as potential treatments, such as mycophenolate mofetil, tacrolimus, intravenous immunoglobulins and rituximab. Specific settings, such as chronic renal failure or elderly age, require a careful balance between benefits and toxicity of immunosuppression. The tailor-made use of this repertoire of drugs can provide a tool to achieve remission of proteinuria and modify the natural course of idiopathic membranous nephropathy.

Controversies in the treatment of idiopathic membranous nephropathy

Optimum treatment of idiopathic membranous nephropathy is both controversial and challenging. The most extensively studied and frequently used immunosuppressive regimens for this disease comprise alkylating agents plus corticosteroids or ciclosporin. All of these treatment options have inherent problems: they are not effective in all patients, partial-rather than complete-remissions are common, adverse effects are worrisome, and relapses after treatment cessation remain problematic. Alternative immunosuppressive agents have been tested in an effort to overcome these unresolved issues. This paper reviews the available evidence regarding both established and new agents for the treatment of patients with idiopathic membranous nephropathy, with an emphasis on the results of the most recent clinical trials.

Treatment of focal segmental glomerulosclerosis with immunophilin modulation: when did we stop thinking about pathogenesis?

Nephrotic focal segmental glomerulosclerosis (FSGS) represents a difficult therapeutic challenge. FSGS has long been considered a subset of idiopathic nephrotic syndrome, lumping together FSGS and minimal change disease (MCD). The time-honored 'Shalhoub hypothesis' has led to treating FSGS as a T-cell-driven condition in which a lymphokine, considered without proof as being the 'glomerular permeability factor,' induces proteinuria and podocyte functional and structural derangement. This has led to trying, in addition to steroids, every new drug marketed in the field of organ transplantation, first cyclosporine (CsA) and then other immunophilin modulators. The fact that alkylating agents and mycophenolate mofetil have obtained a poor and inconstant favorable effect, and that rituximab may obtain remissions, although inconstantly, has not led to reconsidering the T-cell hypothesis. This wrong thinking has fostered innumerable, mostly uncontrolled, treatment trials with various immunosuppressive agents. In fact, clinicians have not considered the fact that some but not all immunophilin modulators may be effective as nonspecific antiproteinuric agents, rather than as immunosuppressive drugs, and that treatment success does not exclude a non-immunologic pathophysiology. Recent findings on the mode of action of CsA and FK-506 have lent support to this concept. This review should be considered as a plea to reconsider the pathogenesis of nephrotic FSGS, applying all efforts to the identification of the factor, or factors, responsible for nephrotic FSGS, and to fund treatment to counteract the 'factor,' rather than pursuing costly and non-evidence-based immunosuppressive therapeutic trials.

An update on the treatment options for focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is not a disease but a lesion initially affecting the podocyte. Various factors may induce 'secondary' FSGS, including defects in molecules that contribute to the podocyte slit diaphragm permselectivity to albumin. They do not represent indications for immunosuppression and require symptomatic treatment only, comprising angiotensin 2 and endothelin antagonists. Primary (idiopathic) FSGS is possibly but not certainly of immunologic origin, owing to an elusive glomerular permeability factor (GPF), explaining relapse on a renal transplant and justifying an immunosuppressive treatment. The best prognostic feature of primary nephrotic FSGS is its response to corticosteroids. Alkylating agents are mostly ineffective in steroid-resistant forms. An association of corticosteroids and cyclosporine A (CsA) remains the mainstay of treatment, with a good tolerability when CsA dosage is low. A definite advantage of tacrolimus on CsA has not yet been established. Sirolimus appears ineffective and potentially harmful. Azathioprine is not indicated. A number of mostly uncontrolled trials indicate that mycophenolate mofetil might find an adjunctive place in the treatment. Plasmapheresis is of no avail outside the special case of relapse in a transplanted kidney. Immunoabsorption of the GPF has not led to practical treatment options. Anecdotal reports on rituximab are as yet too few to determine whether this monoclonal anti-CD20 antibody will find a place in the treatment of primary FSGS.

Tacrolimus in the treatment of idiopathic nephrotic syndrome

The immunosuppressant tacrolimus (FK-506) is a calcineurin inhibitor with a widespread use for the prevention of graft rejection in transplantation medicine. Tacrolimus inhibits the activation of an essential transcription factor for the transcription of cytokine genes in T cells leading to a decreased production of cytokines such as IL-2 and IFN-gamma. As T-cell activation plays a crucial role in the pathogenesis of inflammatory glomerular diseases, there is an increasing number of reports on the use of tacrolimus in nephrotic syndrome. In idiopathic nephrotic syndrome, corticosteroid treatment constitutes the first-line therapy to achieve remission. In the case of steroid resistance or steroid dependence, alternative immunosuppressive strategies are needed. Cyclophosphamide and ciclosporin are well-established drugs in this condition. The present article reviews the pharmacodynamics, pharmacokinetics, safety and clinical efficacy of tacrolimus in steroid-resistant and steroid-dependent nephrotic syndrome.

Cellular pharmacodynamics of immunosuppressive drugs for individualized medicine

The therapeutic effects of immunosuppressive drugs are known to deviate largely between patients, but efficient strategies for the differentiation of patients who show clinical resistance to immunosuppressive therapies have not been established. Accordingly, a considerable number of patients receive treatment with immunosuppressive drugs despite the onset of serious side effects and poor responses. Cellular pharmacodynamics of immunosuppressive drugs in vitro using peripheral lymphocytes derived from each patient, an attractive way to distinguish resistant patients, is respected and has been applied to the carrying out of individualized immunosuppressive therapy. In this article, I summarize experimental procedures for assaying immune cell responses to immunosuppressive drugs in vitro, and highlight the relationship between cellular sensitivity to immunosuppressive drugs and the therapeutic efficacy of drugs in organ transplantation and several immunological disorders. I will also overview the molecular mechanisms and genetic bases for cellular and clinical resistance to immunosuppressive drugs. Lastly, the future clinical prospects for the application of in vitro drug sensitivity tests for "patient-tailored" immunosuppressive therapies are discussed.

[Proteinuria]

Several health organizations recommend that people be regularly checked for proteinuria to detect and treat kidney disease before it progresses. Proteinuria detected by a simple dipstick test should be confirmed by a quantitative measurement to assess persistent proteinuria. Most proteins are too big to pass through the kidneys' filters into the urine unless the kidneys are damaged. Markers of kidney damage in addition to proteinuria include abnormalities in the urine sediment, ultrasound of the kidneys and estimation of kidney function (creatinemia to calculate glomerular filtration rate). These assessments provide clues to the type (diagnosis) of chronic kidney disease and will the risk for developing progressive kidney failure. Thus, early detection of kidney disease will result in a more timely introduction of therapy that may slow the course of kidney disease. Microalbuminuria (albumin excretion above the normal range) that a marker of microvascular lesions in diabetes and hypertension is associated with a worth cardiovascular prognosis. Level of proteinuria in excess of 3,0 g/d in glomerular disease strongly determines the extent of kidney damage and renal prognosis.

Bacterial superantigen TSST-1 attenuates suppressive efficacy of glucocorticoids and calcineurin inhibitors against blastogenesis of peripheral blood mononuclear cells from patients with antineutrophil cytoplasmic antibody-associated vasculitis and nephrosis

Successful immunosuppressive therapy is critical for the treatment of patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis and nephrosis. However, a considerable number of patients have shown clinical resistance to therapy. Bacterial infection might influence the clinical response of patients to immunosuppressive drugs, but few studies have been carried out to investigate the effect of bacterial superantigens on the efficacy of the drugs in these patients. We evaluated the suppressive efficacy of prednisolone, methylprednisolone, cyclosporine, and tacrolimus on the blastogenesis of PBMCs obtained from 12 ANCA-associated vasculitis patients (ANCA patients), eight patients with nephrotic syndrome, and eight healthy subjects. PBMC-stimulation index was calculated from the formula: [3H]thymidine incorporated in the presence of stimulant (dpm)/[3H]thymidine incorporated in the absence of stimulant (dpm). In vitro drug concentrations giving 50% inhibition (IC50s) of PBMC blastogenesis stimulated with concanavalin A (con A) or toxic shock syndrome toxin 1 (TSST-1) derived from Staphylococcus aureus (S. aureus) were calculated. The IC50 values for the four drugs evaluated in TSST-1-stimulated PBMCs were significantly higher than those evaluated in con A-stimulated PBMCs in both ANCA patients and nephrosis patients (p<0.012-0.044). Whereas, the IC50 values for these immunosuppressive drugs, except methylprednisolone, were not significantly different between con A- and TSST-1-stimulated PBMCs in healthy subjects. The stimulation index was not significantly different between the con A- and TSST-1-stimulated PBMCs in either of the subject groups. These observations raise the possibility that TSST-1 induced by S. aureus infection attenuates the clinical efficacy of glucocorticoids and calcineurin inhibitors in ANCA patients and nephrosis patients.

Successful use of cyclosporin A in severe Schönlein-Henoch nephritis resistant to both methylprednisolone pulse and azathioprine

Schönlein-Henoch nephritis (SHN) usually presents with micro-haematuria or mild proteinuria but can be associated with heavy proteinuria and nephrotic or acute nephritic syndrome. Although the treatment of SHN is still under debate, it has been suggested that cyclosporin A (CsA) may be beneficial in children with severe SHN, as reported by Ronkainen et al. (Pediatr Nephrol 18:1138-1142, 2003) and Someya et al. (Pediatr Int 46:111-113, 2004). However, histological effects of CsA on severe SHN had not been evaluated in their evaluations. We report the successful use of CsA in a male patient with severe SHN with nephrotic-range proteinuria, who failed to respond to methylprednisolone pulse and azathioprine therapy.

Idiopathic Membranous Nephropathy: Outline and Rationale of a Treatment Strategy

Idiopathic membranous nephropathy is a common cause of nephrotic syndrome. The treatment of patients with idiopathic membranous nephropathy is heavily debated. Based on literature data and our own experience, we propose a rational treatment strategy. Patients with renal insufficiency (serum creatinine level > 1.5 mg/dL [> 135 micromol/L]) are at greatest risk for the development of end-stage renal disease and should receive immunosuppressive therapy. In patients with normal renal function (serum creatinine level < 1.5 mg/dL [< 135 micromol/L]), risk for developing end-stage renal disease can be estimated by measuring urinary excretion of beta2-microglobulin or alpha1-microglobulin and immunoglobulin G. For low-risk patients, a wait-and-see policy is advised. High-risk patients likely benefit from immunosuppressive therapy. Currently, combinations of steroids with chlorambucil or cyclophosphamide are the best studied. We prefer cyclophosphamide in view of its fewer side effects. Cyclosporine may be an alternative option in patients with well-preserved renal function, although long-term data are lacking. Other immunosuppressive agents, such as mycophenolate mofetil or rituximab, currently are under study; however, data are insufficient to support their routine use.

Treatment of focal segmental glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is not a disease, but a lesion affecting the podocyte. Secondary FSGS may be due to a host of various factors, and patients are rarely nephrotic, requiring symptomatic treatment only. The best prognostic feature of nephrotic FSGS is its response to corticosteroids. Some forms are most likely of immunological origin, relapse in a renal transplant and justify immunosuppressive treatment. In a growing number of cases, genetic profiling of molecules that contribute to the podocyte slit diaphragm permselectivity to albumin has identified defects that do not represent indications for immunosuppression. In the other forms, corticosteroids and cyclosporin A (CsA) remain the mainstay of treatment, with better efficacy when CsA is associated with steroids. The renal tolerability of CsA is reasonably good when the dosage is low. CsA dependency is not constant. Alkylating agents are reluctantly indicated in steroid-sensitive forms, which are rare. They are mostly ineffective in steroid-resistant forms. Tacrolimus seems a promising therapy with low toxicity, but it is usual for dependency on the drug to occur. Sirolimus seems to be ineffective. Azathioprine is not considered indicated, despite rare reports with favourable results, which would deserve further controlled trials. Recent publications indicate that mycophenolate mofetil might usefully find a place in the treatment. Plasmapheresis is of no avail outside the special case of relapse in a transplanted kidney. Immunoabsorption of the elusive substance that causes the nephrotic syndrome and its relapse on a transplant has not led to practical treatment options.

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, 30-40% of patients progress toward end-stage renal failure (ESRF) within 5-15 years.

OBJECTIVES

To assess the benefits and harms of immunosuppressive treatment for IMN in adults.

SEARCH STRATEGY

We searched the Cochrane Renal Group Specialised Register (December 2003), The Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 4, 2003), MEDLINE and Pre-MEDLINE (1966 - December 2003), EMBASE (1980 - December 2003), reference lists of nephrology textbooks, review articles, prospective trial registers, relevant trials and abstracts from nephrology scientific meetings and the internet without language restriction. We also contacted principal investigators of controlled studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing any immunosuppressive interventions for the treatment of IMN in adults.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed and extracted information. Information was collected on method, participants, interventions and outcomes (death, ESRF, proteinuria, serum creatinine, GRF, remission, adverse events).

MAIN RESULTS

A total of 18 trials with 1025 patients were included. No differences were found when we combined data of all treatment categories as a group and compared them with placebo or no treatment. Oral glucocorticoids. No beneficial effect on any of the end points chosen for efficacy was observed. Alkylating agents showed a significant beneficial effect on complete remission (RR 2.37, 95%CI 1.32 to 4.25, P = 0.004) but not on partial remission (RR 1.22, 95%CI 0.63 to 2.35, P = 0.56) or complete or partial remission (RR 1.55, 95%CI 0.72 to 3.34, P = 0.27). Cyclophosphamide treatment resulted in significantly lower rate of discontinuations due to adverse events as compared to chlorambucil (RR 2.34, 95%CI 1.25 to 4.39, P = 0.008). There was no evidence of clinically relevant differences in favour of cyclosporin and there was insufficient data on anti-proliferative agents.

REVIEWERS' CONCLUSIONS

This review failed to show any long-term effect of immunosuppressive treatment on patient and/or renal survival. There was an increased number of discontinuations due to adverse events in immunosuppressive treatment groups. Within the class of alkylating agents there is weak evidence supporting the efficacy of cyclophosphamide as compared to chlorambucil. On the other hand, cyclophosphamide had fewer side effects leading to patient withdrawal than chlorambucil.

Cyclosporine A and chlorambucil in the treatment of idiopathic focal segmental glomerulosclerosis

BACKGROUND

The therapy of nephrotic syndrome in focal segmental glomerulosclerosis (FSGS) is still a matter of controversy.

METHODS

We performed a prospective randomized study of the treatment of nephrotic syndrome due to FSGS. We compared 2 specific treatment protocols to assess the effect of treatment on proteinuria and renal function. Fifty-seven patients were randomly assigned to 2 groups: group 1 (n = 34) received steroids and cyclosporine, and group 2 (n = 23) received steroids and chlorambucil for 6 months. When treatment was refractory to chlorambucil, the patients in this group were treated with cyclosporine. Creatinine, blood urea nitrogen, proteinuria, lipids, and arterial hypertension were monitored at regular intervals.

RESULTS

Patients showed a mean serum creatinine of 1.5 +/- 0.2 mg/dL (132.6 +/- 17.7 micromol/L) and proteinuria of 4.8 +/- 2.8 g/24 h with no differences between the groups. At the end of the chlorambucil therapy, patients in group 2 had creatinine levels of 1.8 +/- 0.6 mg/dL (159.1 +/- 53 micromol/L) and proteinuria levels of 3.4 +/- 1 g/24 h. All patients in this group were given cyclosporine. After 4 years the mean creatinine level in group 1 was 1.7 +/- 0.4 mg/dL (150.3 +/- 35.4 micromol/L) and the proteinuria level was 2.5 +/- 1 g/24 h. In group 2, the mean creatinine level was 1.9 +/- 0.6 mg/dL (168 +/- 53 micromol/L) (not significant [NS]) and the mean proteinuria level was 2.3 +/- 1.1 g/24 h (NS). Full remission occurred in 23% of the patients in group 1 (n = 8) and 17% of the patients in group 2 (n = 4; NS). Partial remission was observed in 38% of the patients in group 1 (n = 13) and 48% in group 2 (n = 11; NS). The number of patients who developed end-stage renal disease was comparable in both groups: 4 of 34 patients in group 1 after 2.5 +/- 0.8 years, and 5 of 23 patients in group 2 (NS).

CONCLUSION

Additional treatment with chlorambucil was found to be ineffective in FSGS. Patients responded to treatment with steroids or cyclosporine, but additional treatment with chlorambucil did not improve the patient's outcome. Future studies must focus on the long-term prognosis of these patients.

Management of nephrotic syndrome in children

Idiopathic childhood nephrotic syndrome generally has a favorable long-term prognosis. Prompt administration of and improved guidelines for monitoring therapy have decreased morbidity and mortality. The treatment goal is to induce prompt remission while minimizing complications and adverse events. Aggressive therapy induces remission and decreases the frequency of relapse in most patient populations; however, such treatment often results in unnecessary toxicity. We critically assessed the current clinical evidence that supports each pharmacologic therapy. For each drug regimen, the risks and monitoring parameters required to reduce complications and optimize therapy are discussed. Some of the treatments are the common corticosteroid approaches, cytotoxic therapies (chlorambucil, cyclophosphamide), cyclosporine, less frequently used drugs (e.g., levamisole), and experimental therapies. Further studies are needed to identify the most effective and least toxic therapeutic regimens for inducing and maintaining remission in children with nephrotic syndrome.

Mycophenolate mofetil and cyclosporine therapy in membranous nephropathy

Idiopathic membranous nephropathy (IMN) remains one of the most common causes of the nephrotic syndrome (NS) in adults. Although the natural history is extremely variable, approximately two thirds of the patients will have persistent high-grade proteinuria and/or develop renal failure over a decade of observation. On the other hand, the remaining third of patients will remit spontaneously and potentially toxic therapy should be avoided in this group. Our capacity to predict which patient will progress at an early stage of the disease has improved substantially in the past 10 years. We present the data from studies of cyclosporine (CSA) and mycophenolate mofetil (MMF) treatment of IMN with their level of evidence in support of efficacy. In addition, based on data related to predicting prognosis, we assign a risk for progression category to the trial patients at entry into these studies. The data are presented in this format so the reader will be able to better discern the risk benefit of treatment within each category and the rationale for our subsequent grade of recommendation for the use of these agents in IMN. CSA has been shown in randomized controlled trials in both the medium and high risk of progression categories of IMN patients to improve proteinuria and preserve renal function at least in the short term in up to two thirds of patients. Other studies suggest prolonged therapy beyond 6 months to 1 year may reduce the high relapse rate after CSA treatment supporting more long-term, continuous, or combination therapy in IMN treatment. The data in favor of MMF treatment of this disease is much weaker and are derived from pilot studies. Only one report applied MMF specifically to IMN patients. In these medium to high risk of progression patients, approximately one-half had a 50% reduction in their baseline proteinuria without a significant alteration in their serum creatinine level. MMF's role as a single agent or as adjunctive therapy in the treatment of IMN needs more rigorous evaluation.

Developments in the Immunotherapy of Glomerular Disease

Glomerular diseases span a broad spectrum of clinical syndromes, with varied clinical manifestations, underlying etiologies, and pathogenic mechanisms. They can be secondary to underlying infectious, toxic, environmental, or drug exposures, or present as “primary entities.” In the latter case, most glomerular diseases are thought to be due to autoimmune dysregulation, and their treatment is primarily immunosuppressive. The armamentarium for immunomodulation includes corticosteroids, alkylating agents, anti-metabolites, calcineurin inhibitors, and new biological agents designed to block specific inflammatory pathways. The choice of therapy for an individual patient must be based on the specific character of the glomerular disease and its acuity and severity, as well as the patient’s comorbidities, history of prior exposure to immunosuppressive drugs, and risk factors for developing complications of the disease or its treatment. The complexities of such therapy can best be addressed by an experienced team of care givers in which the clinical pharmacist can help minimize, if not eliminate, potential sources of drug induced toxicities and adverse effects. This article will describe the major agents and modalities used in the management of the most common glomerular diseases.

New Aspects of the Treatment of Nephrotic Syndrome

Abstract.The nephrotic syndrome, caused by glomerulonephritis, diabetes mellitus, or amyloidosis, is still a therapeutic challenge. Newer therapeutic approaches may be sought in the fields of immunosuppression, nonspecific supportive measures, heparinoid administration, and removal of a supposed glomerular basement membrane toxic factor. In immunosuppression, the newer drugs now used in organ transplantation (cyclosporine, tacrolimus, and mycophenolate mofetil) can also be used in the treatment of glomerulonephritis. In nonspecific supportive treatment, angiotensin II receptor antagonists are now used in addition to angiotensin-converting enzyme inhibitors. Positive effects of hydroxymethylglutaryl coenzyme A reductase inhibitors on the nephrotic syndrome have not yet been proven. Cyclooxygenase II inhibitors must be tested but probably have too many renal side effects, similar to those of nonsteroidal anti-inflammatory drugs. Heparinoids or glycosaminoglycans serve as polyanions and thus have protective effects on the negative charge of the glomerular basement membrane. They can now be administered as oral medications. The removal of a supposed glomerular basement membrane toxic factor that induces proteinuria has been attempted for 20 yr and now is usually performed using immunoadsorption. Especially in cases of recurrent nephrotic syndrome after renal transplantation for patients with glomerulonephritis, this approach has been successful in decreasing proteinuria, although in most cases its effect is not lasting but must be continuously renewed.

Plasma disappearance of albumin and impact of capillary thickness in idiopathic dilated cardiomyopathy and after heart transplantation

BACKGROUND-The increased plasma disappearance of albumin has previously been described in decompensated congestive heart failure (CHF); this disappearance normalized after diuretic treatment. Cardiac transplantation (HTX) and current medical treatment affect microvascular structure and function. We investigated the plasma disappearance of albumin and the impact of microvascular thickness and electrostatic properties in patients with compensated CHF and after HTX. METHODS AND RESULTS-The fraction of intravascular albumin that passes to the extravascular space per unit time, as determined from the plasma disappearance of intravenously injected (131)I-labeled albumin, was increased to 7.8+/-1.7% in 16 patients with CHF compared with 18 controls (6.5+/-1.9%, P<0.05); these levels normalized after HTX (5.8+/-2.6%, P<0.01, n=17). The change in ratio between (131)I-albumin and simultaneously injected negatively charged glycosylated (125)I-albumin (selectivity index, >1/hour in controls) was lower in patients with HTX (0.993+/-0. 022/hour) than in controls (1.008+/-0.019/hour; P<0.05), which indicated a relatively increased plasma disappearance of negatively charged albumin in HTX patients. Capillary basement membrane thickness was evaluated semiquantitatively from skin biopsies and showed no difference in the 3 groups (control, CHF, and HTX patients). However, in all 3 study groups, subjects with thicker capillary basement membranes had lower albumin escape rates (6.1+/-1. 8%, n=32, versus 7.6+/-2.6% in subjects without thickening of capillary basement membranes, n=19; P<0.05). CONCLUSIONS-The plasma disappearance of albumin increased in patients with compensated CHF and it normalized after HTX. The present normalized capillary basement thicknesses in patients with CHF and the direct association between this parameter and plasma albumin disappearance indicate that previous compensatory microvascular basement membrane growth results in restricted permeability. Microvascular electrostatic properties did not relate to plasma albumin disappearance.

Cyclosporin treatment of glomerular diseases

Cyclosporin is a potent immunosuppressive agent that has become the first line therapy in organ transplantation. Its efficacy has led to its use in a variety of immune-mediated glomerular diseases. A selection of controlled and uncontrolled trials has studied the effects of cyclosporin in patients with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), IgA nephropathy, membranoproliferative glomerulonephritis (MPGN) and lupus nephritis. We review the recent literature and suggest recommendations for using cyclosporin in these diseases, based on this evidence and our experience.

Long term treatment of IgA nephropathy with cyclosporine A

20-50% of patients with IgA nephropathy (IgAN) reach end-stage renal failure. Yet a standard treatment for those with progressive course and/or great proteinuria is lacking. We treated 6 patients with biopsy proven IgAN, proteinuria over 3.5 g/24 h and S-creatinine less than 200 micromol/L non-responding to corticosteroids administered for 3 months. They were given cyclosporine A (CsA) 5 mg/kg bw/day then titrated aiming at a serum concentration of 70-150 ng/mL for one year tapered to discontinuation in 9 months. Prednisone 5-10 mg on alternate days was given with CsA. Proteinuria (g/day) decreased from 4.66 +/- 0.43 to 1.38 +/- 0.29 (p < 0.01) after 1 month and to 0.59 +/- 0.14 (p < 0.001) after 1 year of treatment and remained lower than baseline 2 years from the beginning (1.44 +/- 0.27, p < 0.001). GFR (creatinine clearance) did not change during the first month (1.25 +/- 0.21 mL/s vs 1.38 +/- 0.29 mL/s), but decreased after 1 year (1.05 +/- 0.14 mL/s, p < 0.05). After two years it increased to 1.17 +/- 0.16, NS from baseline. We also calculated the ratio of proteinuria to the GFR (mg/L) to assess the role of hemodynamic changes in the decrease of proteinuria. This ratio was 53.80 + 6.47 before therapy, it decreased after 1 month (11.56 +/- 1.7, p < 0.05) and further after 1 year (6.78 + 1.45, p < 0.01). Three months after discontinuation it was still 14.32 +/- 1.00, p < 0.05 from baseline. In conclusion, CsA significantly lowered moderate to high proteinuria in 6 patients with IgAN. Significant decrease of the proteinuria/GFR ratio suggests some non-hemodynamic mechanism of CsA action. The therapy was well tolerated and side-effects were not so severe as to require CsA withdrawal.