Enalapril dosage in steroid-resistant nephrotic syndrome

Recessive variants in the intergenic NOS1AP-C1orf226 locus cause monogenic kidney disease responsive to anti-proteinuric treatment

In genetic disease, an accurate expression landscape of disease genes and faithful animal models will enable precise genetic diagnoses and therapeutic discoveries, respectively. We previously discovered that variants in NOS1AP , encoding nitric oxide synthase 1 (NOS1) adaptor protein, cause monogenic nephrotic syndrome (NS). Here, we determined that an intergenic splice product of N OS1AP / Nos1ap and neighboring C1orf226/Gm7694 , which precludes NOS1 binding, is the predominant isoform in mammalian kidney transcriptional and proteomic data. Gm7694 -/- mice, whose allele exclusively disrupts the intergenic product, developed NS phenotypes. In two human NS subjects, we identified causative NOS1AP splice variants, including one predicted to abrogate intergenic splicing but initially misclassified as benign based on the canonical transcript. Finally, by modifying genetic background, we generated a faithful mouse model of NOS1AP -associated NS, which responded to anti-proteinuric treatment. This study highlights the importance of intergenic splicing and a potential treatment avenue in a mendelian disorder.

Nephrotic Syndrome and Renin-angiotensin System: Pathophysiological Role and Therapeutic Potential

Idiopathic Nephrotic Syndrome (INS) is the most frequent etiology of glomerulopathy in pediatric patients and one of the most common causes of chronic kidney disease (CKD) and end-stage renal disease (ESRD) in this population. In this review, we aimed to summarize evidence on the pathophysiological role and therapeutic potential of the Renin-Angiotensin System (RAS) molecules for the control of proteinuria and for delaying the onset of CKD in patients with INS. This is a narrative review in which the databases PubMed, Web of Science, and Sci- ELO were searched for articles about INS and RAS. We selected articles that evaluated the pathophysiological role of RAS and the effects of the alternative RAS axis as a potential therapy for INS. Several studies using rodent models of nephropathies showed that the treatment with activators of the Angiotensin-Converting Enzyme 2 (ACE2) and with Mas receptor agonists reduces proteinuria and improves kidney tissue damage. Another recent paper showed that the reduction of urinary ACE2 levels in children with INS correlates with proteinuria and higher concentrations of inflammatory cytokines, although data with pediatric patients are still limited. The molecules of the alternative RAS axis comprise a wide spectrum, not yet fully explored, of potential pharmacological targets for kidney diseases. The effects of ACE2 activators and receptor Mas agonists show promising results that can be useful for nephropathies including INS.

Outcomes of steroid-resistant nephrotic syndrome in children not treated with intensified immunosuppression

BACKGROUND

The aim of the current PodoNet registry analysis was to evaluate the outcome of steroid-resistant nephrotic syndrome (SRNS) in children who were not treated with intensified immunosuppression (IIS), focusing on the potential for spontaneous remission and the role of angiotensin blockade on proteinuria reduction.

METHODS

Ninety-five pediatric patients who did not receive any IIS were identified in the PodoNet Registry. Competing risk analyses were performed on 67 patients with nephrotic-range proteinuria at disease onset to explore the cumulative rates of complete or partial remission or progression to kidney failure, stratified by underlying etiology (genetic vs. non-genetic SRNS). In addition, Cox proportional hazard analysis was performed to identify factors predicting proteinuria remission.

RESULTS

Eighteen of 31 (58.1%) patients with non-genetic SRNS achieved complete remission without IIS, with a cumulative likelihood of 46.2% at 1 year and 57.7% at 2 years. Remission was sustained in 11 children, and only two progressed to kidney failure. In the genetic subgroup (n = 27), complete resolution of proteinuria occurred very rarely and was never sustained; 6 (21.7%) children progressed to kidney failure at 3 years. Almost all children (96.8%) received proteinuria-lowering renin-angiotensin-aldosterone system (RAAS) antagonist treatment. On antiproteinuric treatment, partial remission was achieved in 7 of 31 (22.6%) children with non-genetic SRNS and 9 of 27 children (33.3%) with genetic SRNS.

CONCLUSION

Our results demonstrate that spontaneous complete remission can occur in a substantial fraction of children with non-genetic SRNS and milder clinical phenotype. RAAS blockade increases the likelihood of partial remission of proteinuria in all forms of SRNS. A higher resolution version of the Graphical abstract is available as Supplementary information.

Clinical Efficacy of Persian Medicine Diet Combined with Western Medicine-Based Diet on Proteinuria in Pediatric Nephrotic Syndrome: A Randomized Controlled Clinical Trial

Introduction

Nephrotic syndrome (NS) is a common chronic kidney disorder during childhood. The most important characteristic of this disease is proteinuria. The Persian medicine (PM) has important dietary recommendations for strengthening the kidney function and treatment of this disease. The aim of this study was to investigate the effect of a diet including PM recommendations and general principles of Western medicine.

Materials and Methods

Twenty children with nephrotic syndrome were randomly divided into intervention and control groups and monitored for one month. The control group received a diet based on the general principles of Western medicine. In the intervention group, in addition to the Western medicine diet, dietary recommendations of PM were also prescribed including the pomegranate (Cydonia oblonga mill.), quince (Cydonia oblonga mill.), and whole grains (wheat and barley). A 24-hour dietary questionnaire was applied and anthropometric and biochemical indices including spot urine protein (proteinuria), albumin (Alb), urea, creatinine (Cr), total cholesterol (TC), and triglyceride (TG) were measured before and after the study.

Results

The amount of protein intake reduced significantly in the diet of both groups but the differences between the two groups were not significant. Proteinuria reduced significantly in both the Western and PM groups; however, proteinuria was significantly lower in the Persian medicine group compared to the control group. TC and Cr levels reduced significantly in the intervention group, although the changes were not significant compared to the control group.

Conclusion

The results of this study showed that adding dietary recommendations of the Persian medicine to the general rules of the Western medicine diet reduced proteinuria and improved the combat against nephrotic syndrome.

Efficacy and Safety of ACE Inhibitor and Angiotensin Receptor Blocker Therapies in Primary Focal Segmental Glomerulosclerosis Treatment: A Systematic Review and Meta-analysis

Rationale and Objective

Angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy (renin-angiotensin-aldosterone system [RAAS] inhibitor) to control proteinuria in primary and genetic focal segmental glomerulosclerosis (FSGS) follows guidelines based on other proteinuria-related kidney diseases. There is no consensus on the efficacy and safety of RAAS inhibitor therapies in primary and genetic FSGS. This systematic review assessed the effects of RAAS inhibitor therapy on kidney outcomes in these patients.

Study Design

Systematic review of randomized controlled trials, interventional nonrandomized studies, observational studies, and retrospective studies.

Setting & Study Populations

Patients with primary and genetic FSGS.

Selection Criteria for Studies

PubMed, Cochrane Library, and Embase.

Data Extraction

2 investigators independently screened studies and extracted data.

Analytical Approach

Results were summarized as the ratio of means (ROM) between baseline and follow-up measurements or as the hazard ratio using random-effects models.

Results

30 publications were selected; 5 were controlled trials (4 randomized controlled trials). 8 assessed RAAS inhibitor monotherapy, while the rest studied RAAS inhibitors in combination with other drugs, mainly immunosuppressants. On average, a 32% proteinuria reduction (ROM, 0.68; 95% CI, 0.47-0.98) and no change in creatinine clearance (ROM, 0.95; 95% CI, 0.77-1.16) from baseline to the last reported follow-up was observed in patients treated with RAAS inhibitor monotherapy. When a RAAS inhibitor was combined with other drugs, a 72% proteinuria reduction was observed from baseline to the last reported follow-up (ROM, 0.24; 95% CI, 0.08-0.75). The published data did not allow for the assessment of the effects of RAAS inhibitor monotherapy on estimated glomerular filtration rate and end-stage kidney disease risks.

Limitations

Large study heterogeneity in design, patient populations, and treatment regimens. No access to individual patient-level data.

Conclusions

This review supports the tendency to observe a proteinuria reduction with RAAS inhibitors in patients with primary FSGS. RAAS inhibitor monotherapy was associated with maintained kidney function, as shown by no change in creatinine clearance. Strong evidence to quantify the effects of RAAS inhibitor monotherapy on end-stage kidney disease and glomerular filtration rate was lacking. Larger, well-designed clinical trials are needed to better understand the effects of RAAS inhibitors on primary FSGS.

Idiopathic Nephrotic Syndrome in Pediatrics: An Up-to-date

BACKGROUND

Idiopathic or Primary Nephrotic Syndrome (INS) is a common glomerular disease in pediatric population, characterized by proteinuria, edema and hypoalbuminemia with variable findings in renal histopathology.

OBJECTIVE

This review aims to summarize current data on the etiopathogenesis diagnosis, protocols of treatment and potential therapeutic advances in INS.

METHODS

This narrative review searched for articles on histopathology, physiopathology, genetic causes, diagnosis and treatment of INS in pediatric patients. The databases evaluated were PubMed and Scopus.

RESULTS

INS is caused by an alteration in the permeability of the glomerular filtration barrier with unknown etiology. There are several gaps in the etiopathogenesis, response to treatment and clinical course of INS that justify further investigation. Novel advances include the recent understanding of the role of podocytes in INS and the identification of genes associated with the disease. The role of immune system cells and molecules has also been investigated. The diagnosis relies on clinical findings, laboratory exams and renal histology for selected cases. The treatment is primarily based on steroids administration. In case of failure, other medications should be tried. Recent studies have also searched for novel biomarkers for diagnosis and alternative therapeutic approaches.

CONCLUSION

The therapeutic response to corticosteroids still remains the main predictive factor for the prognosis of the disease. Genetic and pharmacogenomics tools may allow the identification of cases not responsive to immunosuppressive medications.

Steroid-resistant Nephrotic Syndrome in Children: A Mini-review on Genetic Mechanisms, Predictive Biomarkers and Pharmacotherapy Strategies

Steroid-resistant nephrotic syndrome (SRNS) constitutes the second most frequent cause of chronic kidney disease in childhood. The etiology of SRNS remains largely unknown and no standardized treatment exists. Recent advances in genomics have helped to build understanding of the molecular mechanisms and pathogenesis of the disease. The genetic polymorphisms in genes encoding proteins which are involved in the pharmacokinetics and pharmacodynamics of glucocorticoids (GCs) partially account for the different responses between patients with nephrotic syndrome. More importantly, single-gene causation in podocytes-associated proteins was found in approximately 30% of SRNS patients. Some potential biomarkers have been tested for their abilities to discriminate against pediatric patients who are sensitive to GCs treatment and patients who are resistant to the same therapy. This article reviews the recent findings on genetic mechanisms, predictive biomarkers and current therapies for SRNS with the goal to improve the management of children with this syndrome.

Hypomethylation of NLRP3 gene promoter discriminates glucocorticoid-resistant from glucocorticoid-sensitive idiopathic nephrotic syndrome patients

Abstract

To assess whether NLRP3 gene promoter methylation was able to discriminate glucocorticoid (GC)‐resistant from GC‐sensitive idiopathic nephrotic syndrome (INS), patients with minimal change disease (MCD) or focal segmental glomerulosclerosis (FSGS), we measured the methylation level of NLRP3 promoter in DNA from peripheral blood cells of 10 adult patients with GC‐resistant FSGS already in hemodialysis and 18 patients with GC‐sensitive INS (13 MCD/5 FSGS) and in 21 pediatric patients with INS with MCD/FSGS before starting any treatment. Association of NLRP3 inflammasome with GC resistance was recapitulated in vitro in monocytic cell lines (THP‐1 and U937). In both adults and pediatric patients, NLRP3 promoter methylation was significantly reduced in GC‐resistant compared with GC‐sensitive patients. Indeed, NLRP3 methylation distinguished GC‐resistant and GC‐sensitive patients (area under the receiver operating characteristic curve [AUROC] 86.7% in adults, p = 0.00019, and 73.5% in children, p = 0.00097). NLRP3 knock‐down augmented sensitivity to GCs in THP‐1 cells, whereas NLRP3 inflammasome activation lowered GC receptor concentration, increasing GC resistance in U937 cells. Our results uncovered a new biological mechanism by which patients with INS may acquire GC resistance, that could be used in future as a novel noninvasive diagnostic tool.

Current understandings in treating children with steroid-resistant nephrotic syndrome

Steroid-resistant nephrotic syndrome (SRNS) remains a challenge for paediatric nephrologists. SRNS is viewed as a heterogeneous disease entity including immune-based and monogenic aetiologies. Because SRNS is rare, treatment strategies are individualized and vary among centres of expertise. Calcineurin inhibitors (CNI) have been effectively used to induce remission in patients with immune-based SRNS; however, there is still no consensus on treating children who become either CNI-dependent or CNI-resistant. Rituximab is a steroid-sparing agent for patients with steroid-sensitive nephrotic syndrome, but its efficacy in SRNS is controversial. Recently, several novel monoclonal antibodies are emerging as treatment option, but their efficacy remains to be seen. Non-immune therapies, such as angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers, have been proven efficacious in children with SRNS and are recommended as adjuvant agents. This review summarizes and discusses our current understandings in treating children with idiopathic SRNS.

Pharmacology of enalapril in children: a review

Enalapril is an angiotensin-converting enzyme (ACE) inhibitor that is used for the treatment of (paediatric) hypertension, heart failure and chronic kidney diseases. Because its disposition, efficacy and safety differs across the paediatric continuum, data from adults cannot be automatically extrapolated to children. This review highlights paediatric enalapril pharmacokinetic data and demonstrates that these are inadequate to support with certainty an age-related effect on enalapril/enalaprilat pharmacokinetics. In addition, our review shows that evidence to support effective and safe prescribing of enalapril in children is limited, especially in young children and heart failure patients; studies in these groups are either absent or show conflicting results. We provide explanations for observed differences between age groups and indications, and describe areas for future research.

IPNA clinical practice recommendations for the diagnosis and management of children with steroid-resistant nephrotic syndrome

Idiopathic nephrotic syndrome newly affects 1-3 per 100,000 children per year. Approximately 85% of cases show complete remission of proteinuria following glucocorticoid treatment. Patients who do not achieve complete remission within 4-6 weeks of glucocorticoid treatment have steroid-resistant nephrotic syndrome (SRNS). In 10-30% of steroid-resistant patients, mutations in podocyte-associated genes can be detected, whereas an undefined circulating factor of immune origin is assumed in the remaining ones. Diagnosis and management of SRNS is a great challenge due to its heterogeneous etiology, frequent lack of remission by further immunosuppressive treatment, and severe complications including the development of end-stage kidney disease and recurrence after renal transplantation. A team of experts including pediatric nephrologists and renal geneticists from the International Pediatric Nephrology Association (IPNA), a renal pathologist, and an adult nephrologist have now developed comprehensive clinical practice recommendations on the diagnosis and management of SRNS in children. The team performed a systematic literature review on 9 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, formulated recommendations and formally graded them at a consensus meeting, with input from patient representatives and a dietician acting as external advisors and a voting panel of pediatric nephrologists. Research recommendations are also given.

Rituximab therapy for refractory steroid-resistant nephrotic syndrome in children

Patients with steroid-resistant nephrotic syndrome (SRNS) who develop resistance to immunosuppressive agents, defined as refractory SRNS, have poor renal outcomes. Although the chimeric anti-CD20 monoclonal antibody rituximab has shown efficacy for frequently relapsing nephrotic syndrome and steroid-dependent nephrotic syndrome, its efficacy for refractory SRNS remains uncertain due to limited data. According to previous case reports, 50.4% of patients with refractory SRNS showed clinical improvements after rituximab treatment. Remission rates in patients with initial steroid resistance and late steroid resistance were 43.9 and 57.7%, respectively, and 41.5 and 63.6% in patients with focal segmental glomerulosclerosis and minor glomerular abnormalities, respectively. However, various factors (race, disease severity, number of rituximab doses, concomitant treatments, and observation period) differed among these observational studies and their consensus may also have been affected by potential publication bias. Rituximab monotherapy may have some degree of efficacy and lead to satisfactory outcomes in a subset of patients with refractory SRNS. However, administration of concomitant treatments during rituximab-mediated B cell depletion, such as methylprednisolone pulse therapy, daily oral prednisolone therapy, and immunosuppressive agents, may lead to better outcomes in these patients. Large-scale, multi-center prospective studies are needed to evaluate the efficacy and safety of such regimens.

Interventions for idiopathic steroid-resistant nephrotic syndrome in children

BACKGROUND

The majority of children who present with their first episode of nephrotic syndrome achieve remission with corticosteroid therapy. Children who fail to respond to corticosteroids in the first episode of nephrotic syndrome (initial resistance) or develop resistance after one or more responses to corticosteroids (delayed resistance) may be treated with immunosuppressive agents including calcineurin inhibitors (CNI) (cyclosporin or tacrolimus) and with non-immunosuppressive agents such as angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB). However, response to these agents is limited so newer agents are being assessed for efficacy. This is an update of a review first published in 2004 and updated in 2006, 2010 and 2016.

OBJECTIVES

To evaluate the benefits and harms of different interventions used in children with idiopathic nephrotic syndrome, who do not achieve remission following four weeks or more of daily corticosteroid therapy.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies to 17 September 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are 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) and quasi-RCTs were included if they compared different immunosuppressive agents or non-immunosuppressive agents with placebo, prednisone or other agent given orally or parenterally in children aged three months to 18 years with steroid-resistant nephrotic syndrome (SRNS). Studies, which enrolled children and adults but in which paediatric data could not be separated from adult data, were also included.

DATA COLLECTION AND ANALYSIS

Two authors independently searched the literature, determined study eligibility, assessed risk of bias and extracted data. For dichotomous outcomes, results were expressed as risk ratios (RR) and 95% confidence intervals (CI). For continuous outcomes, results were expressed as mean difference (MD) and 95% CI. Data were pooled using the random effects model. The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

Twenty-five studies (1063 participants) were included. Fourteen studies were at low risk of bias for sequence generation and allocation concealment. Five and 19 studies were at low risk of performance and detection bias. Fourteen, 14 and 13 studies were at low risk of attrition bias, reporting bias and other bias respectively. Cyclosporin compared with placebo or no treatment may increase the number of participants who achieve complete remission (4 studies, 74 participants: RR 3.50, 95% CI 1.09 to 11.20) or complete or partial remission (4 studies, 74 children: RR 3.15, 95% CI 1.04 to 9.57) by 6 months (low certainty evidence). It is uncertain whether cyclosporin increases the likelihood of worsening hypertension or reduces the likelihood of end-stage kidney disease (very low certainty evidence). CNI compared with IV cyclophosphamide (CPA) may increase the number of participants with complete or partial remission at 3 to 6 months (2 studies, 156 children: RR 1.98, 95% CI 1.25 to 3.13) (low certainty evidence) and probably reduces the number with treatment failure (non response, serious infection, persistently elevated creatinine (1 study, 124 participants: RR 0.32, 95% CI 0.18 to 0.58) (moderate certainty evidence) with little or no increase in serious infections (1 study, 131 participants: RR 0.49, 95% CI 0.16 to 1.56) (moderate certainty evidence). Tacrolimus compared with cyclosporin may make little or no difference to the number who achieve complete or partial remission (2 studies, 58 participants: RR 1.05, 95% CI 0.87 to 1.25) (low certainty evidence) or in the number with worsening hypertension (2 studies, 58 participants: RR 0.41, 95% CI 0.08 to 2.15) (low certainty evidence). Cyclosporin compared with mycophenolate mofetil (MMF) and dexamethasone probably makes little or no difference to the number who achieve complete or partial remission (1 study, 138 participants: RR 2.14, 95% CI 0.87 to 5.24) (moderate certainty evidence) and makes little or no difference to the number dying (1 study, 138 participants: RR 2.14, 95% CI 0.87 to 5.24) or with 50% reduction in glomerular filtration rate (GFR) (1 study, 138 participants: RR 2.29, 95% CI 0.46 to 11.41) (low certainty evidence). Among children, who have achieved complete remission, tacrolimus compared with MMF may increase the number of children who maintain complete or partial response for 12 months (1 study, 60 children: RR 2.01, 95% CI 1.32 to 3.07) (low certainty evidence). Oral CPA with prednisone compared with prednisone alone may make little or no difference to the number who achieve complete remission (2 studies, 84 children: RR 1.06, 95% CI 0.61 to 1.87) (low certainty evidence). IV CPA compared with oral CPA (2 studies, 61 children: RR 1.58, 95% CI 0.65 to 3.85) and IV compared with oral CPA plus IV dexamethasone (1 study, 49 children: RR 1.13, 95% CI 0.65 to 1.96) may make little or no difference to the number who achieve complete remission (low certainty evidence). It is uncertain whether rituximab and cyclosporin compared with cyclosporin increases the likelihood of remission because the certainty of the evidence is very low. It is uncertain whether adalimumab or galactose compared with conservative therapy increases the likelihood of remission because the certainty of the evidence is very low. Two studies reported that ACEi may reduce proteinuria in children with SRNS. One study reported that the dual angiotensin II and endothelin Type A receptor antagonist, sparsentan, may reduce proteinuria more effectively than the angiotensin receptor blocker, irbesartan.

AUTHORS' CONCLUSIONS

To date RCTs have demonstrated that CNIs may increase the likelihood of complete or partial remission compared with placebo/no treatment or CPA. For other regimens assessed, it remains uncertain whether the interventions alter outcomes because the certainty of the evidence is low. Further adequately powered, well designed RCTs are needed to evaluate other regimens for children with idiopathic SRNS. Since SRNS represents a spectrum of diseases, future studies should enrol children from better defined groups of patients with SRNS.

Treatment of steroid-resistant nephrotic syndrome in the genomic era

The pathogenesis of steroid-resistant nephrotic syndrome (SRNS) is not completely known. Recent advances in genomics have elucidated some of the molecular mechanisms and pathophysiology of the disease. More than 50 monogenic causes of SRNS have been identified; however, these genes are responsible for only a small fraction of SRNS in outbred populations. There are currently no guidelines for genetic testing in SRNS, but evidence from the literature suggests that testing should be guided by the genetic architecture of the disease in the population. Notably, most genetic forms of SRNS do not respond to current immunosuppressive therapies; however, a small subset of patients with monogenic SRNS will achieve partial or complete remission with specific immunomodulatory agents, presumably due to non-immunosuppressive effects of these agents. We suggest a pragmatic approach to the therapy of genetic SRNS, as there is no evidence-based algorithm for the management of the disease.

Evidence for a role of angiotensin converting enzyme 2 in proteinuria of idiopathic nephrotic syndrome

Introduction: Renin angiotensin system (RAS) plays a role in idiopathic nephrotic syndrome (INS). Most studies investigated only the classical RAS axis. Therefore, the aims of the present study were to evaluate urinary levels of RAS molecules related to classical and to counter-regulatory axes in pediatric patients with INS, to compare the measurements with levels in healthy controls and to search for associations with inflammatory molecules, proteinuria and disease treatment. Subjects and methods: This cross-sectional study included 31 patients with INS and 19 healthy controls, matched for age and sex. Patients and controls were submitted to urine collection for measurement of RAS molecules [Ang II, Ang-(1-7), ACE and ACE2] by enzyme immunoassay and cytokines by Cytometric Bead Array. Findings in INS patients were compared according to proteinuria: absent (<150 mg/dl, n = 15) and present (≥150 mg/dl, n = 16). Results: In comparison to controls, INS patients had increased Ang II, Ang-(1-7) and ACE, levels while ACE2 was reduced. INS patients with proteinuria had lower levels of ACE2 than those without proteinuria. ACE2 levels were negatively correlated with 24-h-proteinuria. Urinary concentrations of MCP-1/CCL2 were significantly higher in INS patients, positively correlated with Ang II and negatively with Ang-(1-7). ACE2 concentrations were negatively correlated with IP-10/CXCL-10 levels, which, in turn, were positively correlated with 24-h-proteinuria. Conclusion: INS patients exhibited changes in RAS molecules and in chemokines. Proteinuria was associated with low levels of ACE2 and high levels of inflammatory molecules.

Management of steroid-resistant nephrotic syndrome in children and adolescents

More than 85% of children and adolescents (majority between 1-12 years old) with idiopathic nephrotic syndrome show complete remission of proteinuria following daily treatment with corticosteroids. Patients who do not show remission after 4 weeks' treatment with daily prednisolone are considered to have steroid-resistant nephrotic syndrome (SRNS). Renal histology in most patients shows presence of focal segmental glomerulosclerosis, minimal change disease, and (rarely) mesangioproliferative glomerulonephritis. A third of patients with SRNS show mutations in one of the key podocyte genes. The remaining cases of SRNS are probably caused by an undefined circulating factor. Treatment with calcineurin inhibitors (ciclosporin and tacrolimus) is the standard of care for patients with non-genetic SRNS, and approximately 70% of patients achieve a complete or partial remission and show satisfactory long-term outcome. Additional treatment with drugs that inhibit the renin-angiotensin axis is recommended for hypertension and for reducing remaining proteinuria. Patients with SRNS who do not respond to treatment with calcineurin inhibitors or other immunosuppressive drugs can show declining kidney function and are at risk for end-stage renal failure. Approximately a third of those who undergo renal transplantation show recurrent focal segmental glomerulosclerosis in the allograft and often respond to combined treatment with plasma exchange, rituximab, and intensified immunosuppression.

Idiopathic nephrotic syndrome in children

The incidence of idiopathic nephrotic syndrome (NS) is 1·15-16·9 per 100 000 children, varying by ethnicity and region. The cause remains unknown but the pathogenesis of idiopathic NS is thought to involve immune dysregulation, systemic circulating factors, or inherited structural abnormalities of the podocyte. Genetic risk is more commonly described among children with steroid-resistant disease. The mainstay of therapy is prednisone for the vast majority of patients who are steroid responsive; however, the disease can run a frequently relapsing course, necessitating the need for alternative immunosuppressive agents. Infection and venous thromboembolism are the main complications of NS with also increased risk of acute kidney injury. Prognosis in terms of long-term kidney outcome overall is excellent for steroid-responsive disease, and steroid resistance is an important determinant of future risk of chronic or end-stage kidney disease.

Monogenic Causes of Proteinuria in Children

Glomerular disease is a common cause for proteinuria and chronic kidney disease leading to end-stage renal disease requiring dialysis or kidney transplantation in children. Nephrotic syndrome in children is diagnosed by the presence of a triad of proteinuria, hypoalbuminemia, and edema. Minimal change disease is the most common histopathological finding in children and adolescents with nephrotic syndrome. Focal segmental sclerosis is also found in children and is the most common pathological finding in patients with monogenic causes of nephrotic syndrome. Current classification system for nephrotic syndrome is based on response to steroid therapy as a majority of patients develop steroid sensitive nephrotic syndrome regardless of histopathological diagnosis or the presence of genetic mutations. Recent studies investigating the genetics of nephrotic syndrome have shed light on the pathophysiology and mechanisms of proteinuria in nephrotic syndrome. Gene mutations have been identified in several subcellular compartments of the glomerular podocyte and play a critical role in mitochondrial function, actin cytoskeleton dynamics, cell-matrix interactions, slit diaphragm, and podocyte integrity. A subset of genetic mutations are known to cause nephrotic syndrome that is responsive to immunosuppressive therapy but clinical data are limited with respect to renal prognosis and disease progression in a majority of patients. To date, more than 50 genes have been identified as causative factors in nephrotic syndrome in children and adults. As genetic testing becomes more prevalent and affordable, we expect rapid advances in our understanding of mechanisms of proteinuria and genetic diagnosis will help direct future therapy for individual patients.

Exploring the Clinical and Genetic Spectrum of Steroid Resistant Nephrotic Syndrome: The PodoNet Registry

Background: Steroid resistant nephrotic syndrome (SRNS) is a rare condition, accounting for 10-15% of all children with idiopathic nephrotic syndrome. SRNS can be caused by genetic abnormalities or immune system dysfunction. The prognosis of SRNS varies from permanent remission to progression to end-stage kidney disease, and post-transplant recurrence is common. Objectives: The PodoNet registry project aims to explore the demographics and phenotypes of immune-mediated and genetic forms of childhood SRNS, to assess genotype-phenotype correlations, to evaluate clinical management and long-term outcomes, and to search for novel genetic entities and diagnostic and prognostic biomarkers in SRNS. Methods: In 2009, an international registry for SRNS was established to collect retro- and prospective information on renal and extrarenal disease manifestations, histopathological and genetic findings and information on family history, pharmacotherapy responsiveness and long-term outcomes. To date, more than 2,000 patients have been enrolled at 72 pediatric nephrology centers, constituting the largest pediatric SRNS cohort assembled to date. Results: In the course of the project, traditional Sanger sequencing was replaced by NGS-based gene panel screening covering over 30 podocyte-related genes complemented by whole exome sequencing. These approaches allowed to establish genetic diagnoses in 24% of the patients screened, widened the spectrum of genetic disease entities presenting with SRNS phenotype (COL4A3-5, CLCN5), and contributed to the discovery of new disease causing genes (MYOE1, PTPRO). Forty two percent of patients responded to intensified immunosuppression with complete or partial remission of proteinuria, whereas 58% turned out multi-drug resistant. Medication responsiveness was highly predictive of a favorable long-term outcome, whereas the diagnosis of genetic disease was associated with a high risk to develop end-stage renal disease during childhood. Genetic SRNS forms were generally resistant to immunosuppressive treatment, justifying to avoid such pharmacotherapies altogether once a genetic diagnosis is established. Even symptomatic anti-proteinuric treatment with RAS antagonists seems to be challenging and of limited efficacy in genetic forms of SRNS. The risk of post-transplant disease recurrence was around 30% in non-genetic SRNS whereas it is negligible in genetic cases. Conclusion: In summary, the PodoNet Registry has collected detailed clinical and genetic information in a large SRNS cohort and continues to generate fundamental insights regarding demographic and etiological disease aspects, genotype-phenotype associations, the efficacy of therapeutic strategies, and long-term patient and renal outcomes including post-transplant disease recurrence.

Treatment of Genetic Forms of Nephrotic Syndrome

Idiopathic steroid-resistant nephrotic syndrome (SRNS) is most frequently characterized by focal segmental glomerulosclerosis (FSGS) but also other histological lesions, such as diffuse mesangial sclerosis. In the past two decades, a multitude of genetic causes of SRNS have been discovered raising the question of effective treatment in this cohort. Although no controlled studies are available, this review will discuss treatment options including pharmacologic interventions aiming at the attenuation of proteinuria in genetic causes of SRNS, such as inhibitors of the renin-angiotensin-aldosterone system and indomethacin. Also, the potential impact of other interventions to improve podocyte stability will be addressed. In this respect, the treatment with cyclosporine A (CsA) is of interest, since a podocyte stabilizing effect has been demonstrated in various experimental models. Although clinical response to CsA in children with genetic forms of SRNS is inferior to sporadic SRNS, some recent studies show that partial and even complete response can be achieved even in individual patients inherited forms of nephrotic syndrome. Ideally, improved pharmacologic and molecular approaches to induce partial or even complete remission will be available in the future, thus slowing or even preventing the progression toward end-stage renal disease.

Childhood nephrotic syndrome in tropical Africa: then and now

This descriptive and comparative review examines the changing epidemiology, treatment, renal and patient outcome of childhood nephrotic syndrome (NS) in tropical Africa (TpAfr). In the 1960s to 1980s, corticosteroid-resistant non-minimal change disease (nMCD) including quartan malaria nephropathy (QMN) was the dominant renal histopathology type. The overall incidence of NS was 0.35-1.34% of hospital admissions. Median age at onset of NS ranged between 4.0 and 12.0 years while the mean (SD) age range was 5.8 (3.8) to 10.3 (4.8) years across studies. The male: female ratio was 1.6:1.0. The overall mean (SD) incidence of idiopathic minimal change disease (MCD) [21.6 (18.6%)] compared with idiopathic nMCD [59.1 (25.7%)] demonstrates significant dominance of the latter (p = 0.0001). Post-1989, the following mean (SD) incidences of histopathological types were: MCD 20.4 (17.7%), focal segmental glomerulosclerosis 39.0 (26.3%), membranoproliferative glomerulonephritis 25.4 (16.8%), proliferative glomerulonephritis 16.7 (27.0%) and membranous nephropathy 7.4 (4.5%). While the mean (SD) proportion of steroid resistance (SR) [73.5 (19.2%)] was significantly greater than the mean complete remission (CR) [26.5 (19.2%)] during 1960-1989 (p=0.005), mean (SD) SR [27.4 (25.3%)] was significantly lower than mean (SD) CR [66.1 (28.0%)] post-1989 (p < 0.001). Unlike QMN, hepatitis B virus, HIV infection, sickle cell disease and systemic lupus erythematosus are now increasingly being associated with NS in TpAfr. Mean (SD) renal survival post-1989 was 58.3 (37.0%) while all-cause mortality was 9.8%. Children with NS now survive better than before, reflecting improved access to healthcare and transition to a clinical pattern favouring idiopathic NS and increased sensitivity to corticosteroids.

Long-Term Outcome of Steroid-Resistant Nephrotic Syndrome in Children

We investigated the value of genetic, histopathologic, and early treatment response information in prognosing long-term renal outcome in children with primary steroid-resistant nephrotic syndrome. From the PodoNet Registry, we obtained longitudinal clinical information for 1354 patients (disease onset at >3 months and <20 years of age): 612 had documented responsiveness to intensified immunosuppression (IIS), 1155 had kidney biopsy results, and 212 had an established genetic diagnosis. We assessed risk factors for ESRD using multivariate Cox regression models. Complete and partial remission of proteinuria within 12 months of disease onset occurred in 24.5% and 16.5% of children, respectively, with the highest remission rates achieved with calcineurin inhibitor-based protocols. Ten-year ESRD-free survival rates were 43%, 94%, and 72% in children with IIS resistance, complete remission, and partial remission, respectively; 27% in children with a genetic diagnosis; and 79% and 52% in children with histopathologic findings of minimal change glomerulopathy and FSGS, respectively. Five-year ESRD-free survival rate was 21% for diffuse mesangial sclerosis. IIS responsiveness, presence of a genetic diagnosis, and FSGS or diffuse mesangial sclerosis on initial biopsy as well as age, serum albumin concentration, and CKD stage at onset affected ESRD risk. Our findings suggest that responsiveness to initial IIS and detection of a hereditary podocytopathy are prognostic indicators of favorable and poor long-term outcome, respectively, in children with steroid-resistant nephrotic syndrome. Children with multidrug-resistant sporadic disease show better renal survival than those with genetic disease. Furthermore, histopathologic findings may retain prognostic relevance when a genetic diagnosis is established.

[Causes and treatment of systemic amyloidosis]

BACKGROUND

Systemic amyloidoses are rare protein deposition disorders, which are often diagnosed in an advanced stage of the disease due to non-specific symptoms. Any chronic inflammatory disease can lead to an AA-type amyloidosis.

AIM

This paper summarizes the current state of the art of diagnosis and treatment of AA amyloidosis and presents data from the past 10 years of our amyloidosis center.

MATERIAL AND METHODS

Our data represents an analysis of our cohort of patients with amyloidosis and a selective research in the PubMed database for AA amyloidosis.

RESULTS

The underlying diseases comprise autoinflammatory syndromes, polyarthritis, and chronic inflammatory bowel and lung diseases. Renal organ involvement is the most prevalent in AA amyloidosis. It can be detected early through the evaluation of proteinuria. The treatment depends on the individual underlying disease. Patients without an associated inflammatory disease are considered to have idiopathic AA amyloidosis and empiric treatment is mandatory.

DISCUSSION

Survival of this fatal disease has recently improved due to the new diagnostic tools and treatment options; however, early diagnosis plays a crucial role in the prevention of end-stage renal failure. New therapeutic strategies aim to remove existing amyloid deposits.

Interventions for idiopathic steroid-resistant nephrotic syndrome in children

BACKGROUND

The majority of children who present with their first episode of nephrotic syndrome achieve remission with corticosteroid therapy. Children who fail to respond may be treated with immunosuppressive agents including calcineurin inhibitors (cyclosporin or tacrolimus) and with non-immunosuppressive agents such as angiotensin-converting enzyme inhibitors (ACEi). Optimal combinations of these agents with the least toxicity remain to be determined. This is an update of a review first published in 2004 and updated in 2006 and 2010.

OBJECTIVES

To evaluate the benefits and harms of different interventions used in children with idiopathic nephrotic syndrome, who do not achieve remission following four weeks or more of daily corticosteroid therapy.

SEARCH METHODS

We searched Cochrane Kidney and Transplant's Specialised Register (up to 2 March 2016) through contact with the Information Specialist using search terms relevant to this review.

SELECTION CRITERIA

RCTs and quasi-RCTs were included if they compared different immunosuppressive agents or non-immunosuppressive agents with placebo, prednisone or other agent given orally or parenterally in children aged three months to 18 years with SRNS.

DATA COLLECTION AND ANALYSIS

Two authors independently searched the literature, determined study eligibility, assessed risk of bias and extracted data. For dichotomous outcomes, results were expressed as risk ratios (RR) and 95% confidence intervals (CI). Data were pooled using the random effects model.

MAIN RESULTS

Nineteen RCTs (820 children enrolled; 773 evaluated) were included. Most studies were small. Eleven studies were at low risk of bias for allocation concealment and only four studies were at low risk of performance bias. Fifteen, eight and 10 studies were at low risk of detection bias, attrition bias and reporting bias respectively. Cyclosporin when compared with placebo or no treatment significantly increased the number of children who achieved complete remission. However this was based on only eight children who achieved remission with cyclosporin compared with no children who achieved remission with placebo/no treatment in three small studies (49 children: RR 7.66, 95% CI 1.06 to 55.34). Calcineurin inhibitors significantly increased the number with complete or partial remission compared with IV cyclophosphamide (2 studies, 156 children: RR 1.98, 95% CI 1.25 to 3.13; I² = 20%). There was no significant differences in the number who achieved complete remission between tacrolimus versus cyclosporin (1 study, 41 children: RR 0.86, 95% CI 0.44 to 1.66), cyclosporin versus mycophenolate mofetil plus dexamethasone (1 study, 138 children: RR 2.14, 95% CI 0.87 to 5.24), oral cyclophosphamide with prednisone versus prednisone alone (2 studies, 91 children: RR 1.06, 95% CI 0.61 to 1.87), IV versus oral cyclophosphamide (1 study, 11 children: RR 3.13, 95% CI 0.81 to 12.06), IV cyclophosphamide versus oral cyclophosphamide plus IV dexamethasone (1 study, 49 children: RR 1.13, 95% CI 0.65 to 1.96), and azathioprine with prednisone versus prednisone alone (1 study, 31 children: RR 0.94, 95% CI 0.15 to 5.84). One study found no significant differences between three agents (cyclophosphamide, mycophenolate mofetil, leflunomide) used in combination with tacrolimus and prednisone. One study found no significant difference in the percentage reduction in proteinuria (31 children: -12; 95% CI -73 to 110) between rituximab with cyclosporin/prednisolone and cyclosporin/prednisolone alone. Two studies reported ACEi significantly reduced proteinuria.

AUTHORS' CONCLUSIONS

To date RCTs have demonstrated that calcineurin inhibitors increase the likelihood of complete or partial remission compared with placebo/no treatment or cyclophosphamide. For other regimens assessed, it remains uncertain whether the interventions alter outcomes because the certainty of the evidence is low. Further adequately powered, well designed RCTs are needed to evaluate other regimens for children with idiopathic SRNS. Since SRNS represents a spectrum of diseases, future studies should enrol children from better defined groups of patients with SRNS.

The non-immunosuppressive management of childhood nephrotic syndrome

Idiopathic nephrotic syndrome (INS) is one of the most common renal diseases found in the paediatric population and is associated with significant complications, including infection and thrombosis. A high proportion of children enter sustained remission before adulthood, and therapy must therefore mitigate the childhood complications, while minimising the long-term risk to health. Here we address the main complications of INS and summarise the available evidence and guidance to aid the clinician in determining the appropriate treatment for children with INS under their care. Additionally, we highlight areas where no consensus regarding appropriate management has been reached. In this review, we detail the reasons why routine prophylactic antimicrobial and antithrombotic therapy are not warranted in INS and emphasise the conservative management of oedema. When pharmacological intervention is required for the treatment of oedema, we provide guidance to aid the clinician in determining the appropriate therapy. Additionally, we discuss obesity and growth, fracture risk, dyslipidaemia and thyroid dysfunction associated with INS. Where appropriate, we describe how recent developments in research have identified potential novel therapeutic targets.

[Idiopathic Nephrotic Syndrome: recommendations of the Nephrology Branch of the Chilean Society of Pediatrics. Part two]

Idiopathic nephrotic syndrome is the most common glomerular disease in childhood, affecting 1 to 3 per 100,000 children under the age of 16. It most commonly occurs in ages between 2 and 10. Its cause is unknown, and its histology corresponds to minimal change disease in 90% of cases, or focal segmental glomerulosclerosis. Steroid-resistant nephrotic syndrome represents 10-20% of idiopathic nephrotic syndrome in pediatrics. It has a poor prognosis, and its management is a significant therapeutic challenge. Half of patients evolve to end-stage renal disease within 5 years, and are additionally exposed to complications secondary to persistent NS and to the adverse effects of immunosuppressive therapy. The primary goal of treatment is to achieve complete remission, but even a partial remission is associated with a better renal survival than the lack of response. This paper is the result of the collaborative effort of the Nephrology Branch of the Chilean Society of Pediatrics with aims at helping pediatricians and pediatric nephrologists to treat pediatric idiopathic nephrotic syndrome. In this second part, handling of steroid-resistant nephrotic syndrome as well as nonspecific therapies are discussed.

[Treatment of idiopathic nephrotic syndrome in children]

The annual incidence of the nephrotic syndrome has been estimated to be 1-3 per 100,000 children<16 year of age. In children, the most common cause of nephrotic syndrome is idiopathic nephrotic syndrome (INS). INS is defined by the presence of proteinuria and hypoalbuminemia and by definition is a primary disease. Renal biopsy study shows non-specific histological abnormalities of the kidney including minimal changes, focal and segmental glomerular sclerosis, and diffuse mesangial proliferation. Steroid therapy is applied in all cases of INS. Renal biopsy is usually not indicated before starting corticosteroid therapy. The majority of patients (80-90%) are steroid-responsive. Children with INS who do not achieve a complete remission with corticosteroid therapy commonly present focal and segmental glomerular sclerosis and require treatment with calcineurin inhibitors (cyclosporine or tacrolimus), mycophenolate mofetil or rituximab, plus renin-angiotensin system blockade. In this article we review the recent accepted recommendations for the treatment of children with INS.

Treatment of FSGS in Children

Focal segmental glomerulosclerosis (FSGS) is a pathologic condition that represents many disease entities. The goals of therapy are to cure the disease. When this is not possible, the secondary goals are to reduce proteinuria to avoid the complications of nephrotic syndrome and to delay progression of kidney disease. Proteinuria remission is one of the most important independent predictors of kidney survival. Children with FSGS who do not achieve partial or complete remission have a 50% risk of progression to ESRD within 5 years whereas those who enter complete remission have a 5-year kidney survival rate of 90%. Treatment of idiopathic FSGS commonly involves immune-based and nonimmunologic therapy options. This manuscript will review the current state of FSGS therapy for children.

Treatment of steroid-resistant nephrotic syndrome in children: new guidelines from KDIGO

Kidney Disease: Improving Global Outcomes (KDIGO) recently published the clinical practice guideline on glomerulonephritis (GN) to assist the practitioner caring for patients with GN. Chapter 4 of the guideline focuses on managing children aged 1-18 years with steroid-resistant nephrotic syndrome (SRNS), defined by an inability to achieve complete remission with corticosteroid therapy. Guideline development followed a thorough evidence review, and management recommendations and suggestions were based on the best available evidence. Limitations of the evidence, including the paucity of large-scale randomized controlled trials, are discussed. This article provides both the guideline recommendations and a brief review of relevant treatment trials related to each recommendation. This précis serves as a summary of the complete guidelines recently published.

Combined renin angiotensin blockade in childhood steroid-resistant nephrotic syndrome

BACKGROUND

Reduced proteinuria results in delayed deterioration of renal function and remission of proteinuria predicts a good long-term prognosis in steroid-resistant nephrotic syndrome (SRNS). The aim of this study was to analyze the effects of the combined angiotensin-converting enzyme inhibitor and angiotensin II receptor blocker in reducing proteinuria in SRNS.

METHODS

A prospective study of eight patients with SRNS was conducted at the Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University from September 2003 to December 2007. Enalapril was given at 0.1 mg/kg/day and was increased by 0.1 mg/kg/day every 4 weeks up to 0.6 mg/kg/day (maximum 40 mg/day) and 1 mg/kg/day of losartan was added for 4 weeks and stepped up to 2 mg/kg/day (maximum 100 mg/day) for another 4 weeks.

RESULTS

There were five boys (62.5%) and three girls (37.5%). The mean age at diagnosis was 8.3 ± 4.1 years (range 2.05-13 years) and age at enrollment was 11.7 ± 3.8 years (range 6-16 years). Renal histology revealed seven focal segmental glomerulosclerosis and one immunoglobulin M nephropathy. The results showed significant reduction on mean spot urine protein : creatinine ratio from 9.6 ± 2.3 to 3.6 ± 1.6 (P < 0.05) and 24-h urine protein from 182.8 ± 59.6 to 28.7 ± 8.2 mg/m(2) /h (P < 0.05). Urine protein reduction ratio at the end of the study was 50% (P= 0.08). Serum cholesterol, albumin, potassium, blood pressure and renal function had no significant change. No clinical and laboratory side-effects were reported.

CONCLUSION

Combined high-dose angiotensin II receptor blocker to high-dose angiotensin-converting enzyme inhibitor therapy is safe and effective in reducing proteinuria in childhood SRNS. However a large-scale study should be conducted to validate this result.

Renin-angiotensin-aldosterone system inhibitors in pediatric focal segmental glomerulosclerosis

BACKGROUND

Conventional immunosuppressive therapy for primary pediatric focal segmental glomerulosclerosis (FSGS) is potentially toxic and only moderate evidence supports its effectiveness. Renin-angiotensin-aldosterone (RAAS) inhibition monotherapy is anecdotally used in selected patients as an alternative to conventional therapy.

METHODS

We performed a retrospective cohort study of children with primary FSGS seen at a tertiary care academic hospital between 1986 and 2008. We classified patients into two groups based upon initial treatment: RAAS inhibition monotherapy (RIM) and conventional therapy (CT). The primary endpoint was progression to end-stage renal disease (ESRD). Secondary endpoints were remission of proteinuria, relapse, and death.

RESULTS

The cohort consisted of 67 patients. Mean baseline urine protein/creatinine ratio (Up/c) was 8.0 (5.2, 10.7) mg/mg, and mean baseline estimated glomerular filtration rate (eGFR) was 115.0 (101.8, 128.1) mL/min/1.73 m(2). Patients in the RIM group were more likely to have lower eGFR (100.8 mL/min/1.73 m(2) vs 132.9 mL/min/1.73 m(2), p = 0.01) and less proteinuria (4.4 vs.14.4, p < 0.01). Renal failure occurred in 22.9% of the RIM group vs 40.6% in the CT group (log-rank p = 0.07). After adjustment for African-American race, time period of presentation, baseline age, eGFR, and Up/c, patients in the RIM group had a 0.11 hazard ratio of progressing to renal failure compared with patients in the CT group (p < 0.01).

CONCLUSIONS

Children treated initially with RIM may have better outcomes than those treated with CT.

Interventions for idiopathic steroid-resistant nephrotic syndrome in children

BACKGROUND

The majority of children who present with their first episode of nephrotic syndrome achieve remission with corticosteroid therapy. Children who fail to respond may be treated with immunosuppressive agents including calcineurin inhibitors (cyclosporin or tacrolimus) and with non-immunosuppressive agents such as angiotensin-converting enzyme inhibitors (ACEi). Optimal combinations of these agents with the least toxicity remain to be determined.

OBJECTIVES

To evaluate the benefits and harms of interventions used to treat idiopathic steroid-resistant nephrotic syndrome (SRNS) in children.

SEARCH STRATEGY

Randomised controlled trials (RCTs) were identified from the Cochrane Renal Group's specialised register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and reference lists of articles.

SELECTION CRITERIA

RCTs and quasi-RCTs were included if they compared different immunosuppressive agents or non-immunosuppressive agents with placebo, prednisone or other agent given orally or parenterally in children aged three months to 18 years with SRNS.

DATA COLLECTION AND ANALYSIS

Two authors independently searched the literature, determined study eligibility, assessed quality and extracted data. For dichotomous outcomes, results were expressed as risk ratios (RR) and 95% confidence intervals (CI). Data were pooled using the random effects model.

MAIN RESULTS

Fourteen RCTs (449 children) were included. Cyclosporin when compared with placebo or no treatment significantly increased the number of children who achieved complete remission (three studies, 49 children: RR 7.66, 95% CI 1.06 to 55.34). Cyclosporin significantly increased the number with complete or partial remission compared with IV cyclophosphamide (one study, 32 children: RR 3.40, 95% CI 1.12 to 10.28). There was no significant difference in the number who achieved complete remission between oral cyclophosphamide with prednisone versus prednisone alone (two studies, 91 children: RR 1.06, 95% CI 0.61 to 1.87), IV versus oral cyclophosphamide (one study, 11 children: RR 3.13, 95% CI 0.81 to 12.06), IV cyclophosphamide versus oral cyclophosphamide with IV dexamethasone (one study, 49 children: RR 1.13, 95% CI 0.65 to 1.96), tacrolimus versus cyclosporin (one study, 41 children: RR 0.86, 95% CI 0.44 to 1.66) and azathioprine with prednisone versus prednisone alone (one study, 31 children: RR 0.94, 95% CI 0.15 to 5.84). ACEi significantly reduced proteinuria (two studies, 70 children). No studies were identified comparing high dose steroids and cyclosporin with single agents, placebo or no treatment.

AUTHORS' CONCLUSIONS

Further adequately powered, well designed RCTs are needed to confirm the efficacy of cyclosporin and to evaluate other regimens for idiopathic SRNS including high dose steroids with cyclosporin.

Pharmacotherapeutic review and update of idiopathic nephrotic syndrome in children

AIM OF THE REVIEW

The therapeutic management of pediatric idiopathic nephrotic syndrome is still a challenge due to the large number of potentially effective pharmacological alternatives and the insufficient scientific evidence available. A bibliographic review was performed in order to identify the available pharmacological alternatives, as well as their place in therapy, and to analyze whether the treatment algorithm developed by the pediatric nephrology department of our hospital is consistent with the evidence published to date.

METHOD

A literature search was carried out on MEDLINE, through PubMed, using the medical subject heading (MeSH) nephrotic syndrome. The search was limited to review papers, meta-analyses, clinical practice guidelines, and randomized controlled trials performed on pediatric populations up to September 2009.

RESULTS

The treatment algorithm established in our hospital is consistent with the evidence available. Prednisone constitutes the first line treatment with evidence level Ia. When corticosteroids do not achieve remission, there are other therapeutic options that are not clearly positioned yet and further studies that provide more information on their comparative efficacy and safety are needed. These alternative therapeutic options are cyclosporine, mycophenolate mofetil, levamisol, cyclophosphamide and methylprednisolone, as independent strategies or as part of "Mendoza Protocol", tacrolimus and rituximab. Their sequence of introduction in the therapeutic scheme of NS is classified as evidence level IV and grade D recommendation.

CONCLUSION

The wide range of options available for the pharmacotherapeutic management of NS and the lack of evidence about the comparative efficacy and safety of the different therapeutic strategies, make its positioning rather difficult. Therefore each hospital needs to draw up protocols based not only on the small amount of evidence available, but also on the authorized indications, availability of the drugs, clinical experience, associated costs, and patient preferences with regard to the duration of treatment, incidence and type of adverse effects. Development of new randomized controlled trials should be encouraged and setting up national plans for the treatment of this pathology might be a good approach for this problem.

Management of childhood onset nephrotic syndrome

The therapeutic approach to childhood nephrotic syndrome is based on a series of studies that began with an international collaborative effort sponsored by the International Study of Kidney Disease in Children in 1967. The characteristics of children presenting with nephrotic syndrome have changed over recent decades with greater frequency of the challenging condition focal segmental glomerulosclerosis and a greater prevalence of obesity and diabetes mellitus, which may be resistant to glucocorticoids in the former and exacerbated by long-term glucocorticoid therapy in the latter 2 conditions. The Children's Nephrotic Syndrome Consensus Conference was formed to systematically review the published literature and generate a children's primary nephrotic syndrome guideline for use in educational, therapeutic, and research venues.

Long-term outcome of idiopathic steroid-resistant nephrotic syndrome: a multicenter study

Long-term outcome of idiopathic steroid-resistant nephrotic syndrome was retrospectively studied in 78 children in eight centers for the past 20 years. Median age at onset was 4.4 years (1.1-15.0 years) and the gender ratio was 1.4. Median follow-up period was 7.7 years (1.0-19.7 years). The disease in 45 patients (58%) was initially not steroid-responsive and in 33 (42%) it was later non-responsive. The main therapeutic strategies included administration of ciclosporine (CsA) alone (n = 29; 37%) and CsA + mycophenolate mofetil (n = 18; 23%). Actuarial patient survival rate after 15 years was 97%. Renal survival rate after 5 years, 10 years and 15 years was 75%, 58% and 53%, respectively. An age at onset of nephrotic syndrome (NS) > 10 years was the only independent predictor of end-stage renal disease (ESRD) in a multivariate analysis using a Cox regression model (P < 0.001). Twenty patients (26%) received transplants; ten showed recurrence of the NS: seven within 2 days, one within 2 weeks, and two within 3-5 months. Seven patients lost their grafts, four from recurrence. Owing to better management, kidney survival in idiopathic steroid-resistant nephrotic syndrome (SRNS) has improved during the past 20 years. Further prospective controlled trials will delineate the potential benefit of new immunosuppressive treatment.

[Mycophenolate mofetil and cyclosporine in the treatment of steroid-dependent nephrotic syndrome with frequent relapses]

We describe the case of an 8-year-old patient, with steroid-dependent minimal lesion nephrotic syndrome, with frequent relapses despite treatment with cyclosporine. After the switch to mycophenolate mofetil the patient had new relapses, and there was difficulty in controlling the disease. The reintroduction of cyclosporine combined with mycophenolate mofetil obtained an optimal response, with a longer relapse-free time. Due to their kinetic variability, the blood levels of both drugs were closely monitored during follow-up.

Therapies for steroid-resistant nephrotic syndrome

Between 10 and 20% of children with primary nephrotic syndrome are steroid-resistant (SRNS). From earlier studies in children with SRNS, we know that cyclosporin (with or without alternate-day prednisone) and cyclophosphamide (with pulse intravenous corticosteroids) result in comparable complete or partial remission rates of about 60%. An evaluation of the relative effectiveness of cyclophosphamide and cyclosporin has not been possible because of the absence of a head-to-head randomised trial. The Arbeitsgemeinschaft für Pädiatrische Nephrologie trial, published in this issue of Pediatric Nephrology, has filled this gap in our evidence base. Although there was no difference in the number of patients achieving complete remission, those patients receiving cyclosporin treatment were significantly more likely to achieve partial remission than those receiving intravenous cyclophosphamide. This result suggests that cyclosporin rather than cyclophosphamide should be used as first line therapy for children with SRNS.

Corticosteroid-resistant nephrotic syndrome with focal and segmental glomerulosclerosis : an update of treatment options for children

Corticosteroid-resistant nephrotic syndrome (CRNS) with focal and segmental glomerulosclerosis (FSGS) is a heterogeneous disorder and the most severe and frequent type of all glomerulopathies in children leading to end-stage renal failure. The podocyte is at the center of development and progress of FSGS; this unique cell type plays a major role in the integrity of glomerular structure and permeability. The rate of complete remission of CRNS after induction therapy using different immunosuppressant agents is reported to range between 30% and 84%, depending on the treatment schedule and on the underlying defects of FSGS. Children with genetic types of FSGS barely respond to immunosuppressant therapies and over-treatment prior to transplantation should be avoided. The response of children with an idiopathic type of FSGS to immunosuppressants is superior to those with genetic FSGS. However, many children with idiopathic FSGS do not enter complete remission if they are under-treated, for example, with short-term immunosuppressant monotherapies. If immunosuppressant treatment fails, these patients will have to undergo renal transplantation. However, as unknown pathogenetic mechanisms may persist, more than one-third of these patients with idiopathic FSGS develop a rapid recurrence of CRNS that responds poorly to further long-term therapeutic attempts. In contrast with previously published data, this review takes into account recently identified genetic etiologies of CRNS, and superior results with long-term combination therapy in idiopathic forms to avoid over- and under-treatment.

Evaluation and management of steroid-unresponsive nephrotic syndrome

PURPOSE OF REVIEW

Idiopathic nephrotic syndrome in children is commonly associated with minimal change disease and response to steroid therapy. Steroid-unresponsive nephrotic syndrome is often characterized by persistent proteinuria and progression to chronic kidney disease. Focal segmental glomerulosclerosis is the leading cause of steroid-unresponsive nephrotic syndrome in childhood. There is no uniformed consensus as to the treatment of steroid-unresponsive nephrotic syndrome. Advances in the pathogenesis, genetics and biomarkers or surrogate markers may be useful for the diagnosis and identification of patients with steroid-unresponsive nephrotic syndrome, severity of disease, progression and response to therapy.

RECENT FINDINGS

This review is intended to describe some of the recent changes in the epidemiology of steroid-unresponsive nephrotic syndrome, in particular focal segmental glomerulosclerosis, its pathogenesis and alternative therapies.

SUMMARY

Recent studies in both children and adults have shown an increase in the incidence of focal segmental sclerosis as a cause of steroid-unresponsive nephrotic syndrome. Advances in the pathogenesis and noninvasive methods of diagnosis may allow for the identification of steroid-responsive patients.

Effects of antihypertensive drugs on blood pressure and proteinuria in childhood

BACKGROUND

Historically, there have been few drug trials for antihypertensive treatment in childhood and recommendations have been extrapolated from data obtained in adulthood. During the last decade an increased awareness of the risks of childhood hypertension stimulated clinical trials of antihypertensive agents in children.

OBJECTIVE

The aim of this article is to systematically review the studies published between 1995 and 2006 that deal with the effect of antihypertensive drugs on childhood hypertension or proteinuria.

METHODS

Medline, Current Contents, personal files and reference lists were used as data sources.

RESULTS

Fifty-two out of 79 initially found reports were excluded. Consequently 27 articles were retained for the final analysis. The blood pressure reduction was similar with angiotensin-converting enzyme inhibitors (10.7/8.1 mmHg), angiotensin II receptor antagonists (10.5/6.9 mmHg) and calcium-channel blockers (9.3/7.2 mmHg). In addition angiotensin-converting enzyme inhibitors (by 49%) and angiotensin II receptor antagonists (by 59%) significantly reduced pathological proteinuria.

CONCLUSIONS

The blood pressure reduction of angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists and calcium-channel blockers is almost identical. In children with pathological proteinuria angiotensin-converting enzyme inhibitors or angiotensin II antagonists are superior to calcium-channel blockers.

Remission of steroid- and CyA-resistant nephrotic syndrome using multiple drug immunosuppression

Nephrotic proteinuria in minimal change disease (MCD) is supposed to be due to a circulating factor of immunologic origin. End-stage renal failure occurs if both steroids and immunosuppressive drugs remain ineffective. Three children (2 years, 3 years, and 6 years of age) with secondary steroid-resistant nephrotic syndrome (NS) were included, as they remained resistant to 30 days of treatment with prednisone (60 mg/m(2) per day), three pulses of methylprednisolone (1 g/1.73 m(2)) followed by oral administration of CyA 7.5 mg/kg per day over 2 months, and 1 month of intravenous (i.v.) administration of cyclosporine (blood level 500-600 ng/ml). All three patients were partially responsive to methylprednisolone pulses, with an increase of serum albumin by 100%. They were treated with plasma exchanges, cyclophosphamide and cyclosporine A, both given orally, pefloxacin and methylprednisolone pulses followed by orally administered prednisone. All three patients went into remission within 2 to 5 weeks. The character of their NS changed to a steroid-sensitive one. There were no significant side effects from the therapy. They had normal renal function, normal blood pressure and no residual proteinuria. A combination of plasmapheresis and multiple immunosuppressive medications was effective in producing remission of minimal change NS in three children who were previously resistant to glucocorticoids and cyclosporine.

Progression of chronic renal failure in children with dysplastic kidneys

The aim of this study is to describe progression of chronic renal failure (CRF) in children with renal malformations and to study factors influencing this progression. We reviewed retrospectively 176 children with CRF secondary to renal dysplasia, reflux nephropathy or renal obstruction with at least 5 years of follow-up. Serum creatinine was recorded at least every third month, and an estimated glomerular filtration rate (eGFR) was calculated. Number of febrile urinary tract infections (UTI), blood pressure, albuminuria (UaUc), and number of functioning kidneys was also recorded. We found that the development of renal function could be separated into three time periods: (1) During the first years of life, 82% of the children showed early improvement of their kidney function, which lasted until a median age of 3.2 years (median improvement 6.3 ml/year). (2) From the age of 3.2 years until 11.4 years, 52.5% of the studied children showed a stable kidney function, whereas in 47.5%, kidney function immediately started to deteriorate. (3) Around puberty, 42.9% started deterioration in kidney function, whereas 57.1% even after puberty showed a stable function. Patients with UaUc >200 mg/mmol deteriorated faster (-6.5 ml/min per 1.73 m(2) per year compared with -1.5 ml/min per 1.73 m(2) per year) in those with UaUc <50 mg/mmol. Children with more than two febrile UTIs, hypertension or an eGFR at onset of less than 40 ml/min per 1.73 m(2) deteriorated faster than the others. Most children experienced early improvement of kidney function. The further prognosis, early or late deterioration of kidney function or stable function during the whole follow-up, was related to albuminuria, number of febrile UTIs, eGFR at onset of deterioration, hypertension and puberty.

Therapeutic approach to FSGS in children

Therapy of primary focal segmental glomerulosclerosis (FSGS) in children incorporates conservative management and immunosuppression regimens to control proteinuria and preserve kidney function. In long-term cohort studies in adults and children with primary FSGS, renal survival has been directly associated with degree of proteinuria control. This educational article reviews the current therapeutic approach toward children with primary FSGS.

Effect of fosinopril in children with steroid-resistant idiopathic nephrotic syndrome

We aimed to test if fosinopril reduces urinary protein excretion and alleviates renal tubular damage in normotensive children with steroid-resistant idiopathic nephrotic syndrome (SRINS). We also aimed to evaluate whether there are changes in steady-state blood pressure and serum concentrations of serum angiotensin-converting enzyme (ACE) and plasma renin activity or angiotensin II (AT-II) in children under this treatment. Forty-five normotensive patients with SRINS were randomly divided into two groups. Group I was treated with fosinopril and prednisone for 12 weeks, while group II was treated with prednisone alone for the same duration. The values of 24-h urinary protein excretion were 1.25+/-0.64 vs 2.52+/-0.56 g/24 h (P<0.05), 1.16+/-0.45 vs 2.42+/-0.24 g/24 h (P<0.05), and 1.10+/-0.41 vs 2.05+/-0.46 g/24 h (P<0.05) in group I and group II patients, respectively, at 4, 8, and 12 weeks. Patients in group I showed lower serum concentrations of urinary retinol-binding protein and beta(2)-microglobulin (P<0.01) at the end of the study, but the patients' blood pressure and components of the renin-angiotensin system (RAS) had no change during treatment. The result suggested that fosinopril significantly reduced proteinuria and alleviated renal tubular damage, but did not influence blood pressure and components of systemic RAS in normotensive children with SRINS.

Interventions for idiopathic steroid-resistant nephrotic syndrome in children

BACKGROUND

The majority of children who present with their first episode of nephrotic syndrome, achieve remission with corticosteroid therapy. Children who fail to respond may be treated with immunosuppressive agents such as cyclophosphamide, chlorambucil or cyclosporin, or with non-immunosuppressive agents such as ACE inhibitors. Optimal combinations of these agents with the least toxicity remain to be determined.

OBJECTIVES

To evaluate the benefits and harms of interventions used to treat idiopathic steroid resistant nephrotic syndrome (SRNS) in children.

SEARCH STRATEGY

Randomised controlled trials (RCTs) were identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, reference lists of articles and abstracts from conference proceedings. Date of most recent search: June 2005

SELECTION CRITERIA

RCTs and quasi-RCTs were included if they compared different immunosuppressive agents or non-immunosuppressive agents with placebo, prednisone or other agent given orally or parenterally in children aged three months to 18 years with SRNS.

DATA COLLECTION AND ANALYSIS

Two reviewers independently searched the literature, determined trial eligibility, assessed quality, extracted data and entered it in RevMan. For dichotomous outcomes, results were expressed as relative risk (RR) and 95% confidence intervals (CI). Data were pooled using the random effects model.

MAIN RESULTS

Eleven RCTs (312 children) were included. Cyclosporin when compared with placebo or no treatment significantly increased the number of children who achieved complete remission (three trials, 49 children: RR for persistent nephrotic syndrome 0.64, 95% CI, 0.47 to 0.88). There was no significant difference in the number of children who achieved complete remission between oral cyclophosphamide with prednisone and prednisone alone (two trials, 91 children: RR 1.01, 95% CI 0.74 to 1.36), between intravenous cyclophosphamide and oral cyclophosphamide (one study, 11 children: RR 0.09, 95% CI 0.01 to 1.39) and between azathioprine with prednisone and prednisone alone (one trial 31 children: RR 1.01, 95% CI 0.77 to 1.32). ACE inhibitors significantly reduced proteinuria (two trials, 70 children). After 12 weeks of treatment fosinopril reduced proteinuria by 0.95 g/24 h (95% CI -1.21 to -0.69). No RCTs were identified comparing combination regimens comprising high dose steroids, alkylating agents or cyclosporin with single agents, placebo or no treatment.

AUTHORS' CONCLUSIONS

Further adequately powered and well designed RCTs are needed to confirm the efficacy of cyclosporin and to evaluate other regimens for idiopathic SRNS including high dose steroids with alkylating agents or cyclosporin.