Interventions for idiopathic steroid-resistant nephrotic syndrome in children

Rituximab in combination with cyclosporine and steroid pulse therapy for childhood-onset multidrug-resistant nephrotic syndrome: a multicenter single-arm clinical trial (JSKDC11 trial)

BACKGROUND

Only 80% of children with idiopathic nephrotic syndrome respond well to glucocorticoid therapy. Multidrug-resistant nephrotic syndrome (MRNS) is associated with a poor kidney prognosis. Several retrospective studies have identified rituximab as an effective treatment for MRNS; however, prospective studies are required to assess its efficacy and safety.

METHODS

We conducted a multicenter, non-blinded, single-arm trial to investigate the efficacy and safety of rituximab in patients with childhood-onset MRNS who were resistant to cyclosporine and more than three courses of steroid pulse therapy. The enrolled patients received four 375 mg/m2 doses of rituximab in combination with baseline cyclosporine and steroid pulse therapy. The primary endpoint was a > 50% reduction in the urinary protein/creatinine ratio from baseline on day 169. Complete and partial remissions were also evaluated.

RESULTS

Six patients with childhood-onset MRNS were enrolled. All patients were negative for pathogenic variants of podocyte-related genes. On day 169, five patients (83.3%) showed a > 50% reduction in the urinary protein/creatinine ratio, two patients showed partial remission, and two patients showed complete remission. No deaths occurred and severe adverse events occurred in two patients (infection in one patient and acute kidney injury in one patient). Three patients needed treatment for moderate-to-severe infection.

CONCLUSIONS

The study treatment effectively reduced the urinary protein/creatinine ratio in patients with childhood-onset MRNS. The adverse events in this study were within the expected range; however, attention should be paid to the occurrence of infections.

Renin angiotensin aldosterone inhibitors in the treatment of proteinuria in children with congenital anomalies of the kidney and urinary tract: more evidence needed

INTRODUCTION

Congenital anomalies of the kidney and urinary tract (CAKUT) can be associated with proteinuria, possibly leading to a decline in kidney function. The aim of this review is to evaluate evidence on the efficacy of renin-angiotensin-aldosterone system inhibitors (RAASi) in children affected by CAKUT with proteinuria or chronic kidney disease (CKD).

AREAS COVERED

We conducted a bibliographic search between 1 December 2022 and 20 February 2023, including randomized controlled trials, case-control studies, observational studies, meta-analyses, and systematic reviews dealing with the efficacy of RAASi in reducing proteinuria and slowing the decline of kidney function in children.

EXPERT OPINION

RAASi are effective in reducing proteinuria and slowing CKD progression in many renal conditions; however, the efficacy of these drugs in patients affected by CAKUT with proteinuria is still unknown. While waiting for more evidence, when facing a child with CAKUT with isolated proteinuria or with proteinuria and CKD, a 6-12-month trial with RAASi with gradual increase to the maximal tolerated dose should be considered. If no improvement of proteinuria is obtained, the RAASi should be discontinued.

How Genetics Can Improve Clinical Practice in Chronic Kidney Disease: From Bench to Bedside

Chronic kidney disease (CKD) is considered a major global health problem with high socio-economic costs: the risk of CKD in individuals with an affected first degree relative has been found to be three times higher than in the general population. Genetic factors are known to be involved in CKD pathogenesis, both due to the possible presence of monogenic pathologies as causes of CKD, and to the role of numerous gene variants in determining susceptibility to the development of CKD. The genetic study of CKD patients can represent a useful tool in the hands of the clinician; not only in the diagnostic and prognostic field, but potentially also in guiding therapeutic choices and in designing clinical trials. In this review we discuss the various aspects of the role of genetic analysis on clinical management of patients with CKD with a focus on clinical applications. Several topics are discussed in an effort to provide useful information for daily clinical practice: definition of susceptibility to the development of CKD, identification of unrecognized monogenic diseases, reclassification of the etiological diagnosis, role of pharmacogenetics.

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.

Immunological Impact of a Gluten-Free Dairy-Free Diet in Children With Kidney Disease: A Feasibility Study

Kidney disease affects 10% of the world population and is associated with increased mortality. Steroid-resistant nephrotic syndrome (SRNS) is a leading cause of end-stage kidney disease in children, often failing standard immunosuppression. Here, we report the results of a prospective study to investigate the immunological impact and safety of a gluten-free and dairy-free (GF/DF) diet in children with SRNS. The study was organized as a four-week summer camp implementing a strict GF/DF diet with prospective collection of blood, urine and stool in addition to whole exome sequencing WES of DNA of participants. Using flow cytometry, proteomic assays and microbiome metagenomics, we show that GF/DF diet had a major anti-inflammatory effect in all participants both at the protein and cellular level with 4-fold increase in T regulatory/T helper 17 cells ratio and the promotion of a favorable regulatory gut microbiota. Overall, GF/DF can have a significant anti-inflammatory effect in children with SRNS and further trials are warranted to investigate this potential dietary intervention in children with SRNS.

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.

Focal Segmental Glomerulosclerosis: State-of-the-Art and Clinical Perspective

Focal segmental glomerulosclerosis (FSGS) is a histological pattern of glomerular injury, rather than a single disease, that is caused by diverse clinicopathological entities with different mechanisms of injury with the podocyte as the principal target of lesion, leading to the characteristic sclerotic lesions in parts (i.e., focal) of some (i.e., segmental) glomeruli. The lesion of FSGS has shown an increasing prevalence over the past few decades and is considered the most common glomerular cause leading to ESKD. Primary FSGS, which usually presents with nephrotic syndrome, is thought to be caused by circulating permeability factors that have a main role in podocyte foot process effacement. Secondary forms of FSGS include maladaptive FSGS secondary to glomerular hyperfiltration such as in obesity or in cases of loss in nephron mass, virus-associated FSGS, and drug-associated FSGS that can result in direct podocyte injury. Genetic FSGS is increasingly been recognized and a careful evaluation of patients with atypical primary or secondary FSGS should be performed to exclude genetic causes. Unlike primary FSGS, secondary and genetic forms of FSGS do not respond to immunosuppression and tend not to recur after kidney transplantation. Distinguishing primary FSGS from secondary and genetic causes has a prognostic significance and is crucial for an appropriate management. In this review, we examine the pathogenesis, clinical approach to distinguish between the different causes, and current recommendations in the management of FSGS.

Treatment of nephrotic syndrome: going beyond immunosuppressive therapy

It is indisputable that immunosuppressive therapy and pathological diagnosis of renal biopsy have greatly improved the prognosis of childhood nephrotic syndrome. Unfortunately, there is no "one-size-fits-all" approach for precise patient stratification and treatment when facing the huge challenges posed by steroid-resistant nephrotic syndrome (SRNS). But genomic medicine has brought a glimmer of light, and the cognition of SRNS has entered a new stage. Based on this, identification of single genetic variants of SRNS has recognized the key role of podocyte injury in its pathogenesis. Targeted treatment of podocyte injury is paramount, and immunosuppressant with podocyte-targeted therapy seems to be more suitable as the first choice for SRNS, that is, we need to pay attention to their additional non-immunosuppressive effects. In the same way, other effect factors of nephrotic syndrome and the related causes of immunosuppressive therapy resistance require us to select reasonable and targeted non-immunosuppressive therapies, instead of only blindly using steroids and immunosuppressants, which may be ineffective and bring significant side effects. This article provides a summary of the clinical value of identification of genetic variants in podocytes and non-immunosuppressive therapy for nephrotic syndrome in children.

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.

Efficacy and safety of cyclosporine a for patients with steroid-resistant nephrotic syndrome: a meta-analysis

BACKGROUND

The purpose of this study was to determine efficacy and safety of cyclosporine A (CsA) for patients with steroid-resistant nephrotic syndrome (SRNS).

METHODS

The Cochrane Library and PubMed were searched to extract the associated studies on Oct 10, 2018, and the meta-analysis method was used to pool and analyze the applicable investigations included in this study. The P(opulation) I(ntervention) C(omparison) O(utcome) of the study were defined as follows: P: Patients with SRNS; I: treated with CsA, cyclophosphamide (CYC), tacrolimus (TAC) or placebo/not treatment (P/NT); C: CsA vs. placebo/nontreatment (P/NT), CsA vs. CYC, CsA vs. TAC; O: complete remission (CR), total remission (TR; complete or partial remission (PR)), urine erythrocyte number, proteinuria levels, albumin, proteinuria, serum creatinine, and plasma cholesterol, etc. Data were extracted and pooled using RevMan 5.3.

RESULTS

In the therapeutic regimen of CsA vs. placebo/nontreatment (P/NT), the results indicated that the CsA group had high values of CR, TR, and low values of proteinuria, serum creatinine, and plasma cholesterol when compared with those in the placebo group. In comparing CsA vs. cyclophosphamide (CYC), the results indicated that the CsA group had higher TR than the CYC group. In comparing CsA vs. tacrolimus (TAC), the results revealed insignificant differences in CR, and TR between the CsA and TAC groups. The safety of CsA was also assessed. The incidence of gum hyperplasia in CsA group was higher than that in the P/NT group, with no differences in incidence of infections or hypertension between CsA and P/NT groups. There was no difference in the incidence of hypertension between the CsA and TAC groups.

CONCLUSIONS

CsA is an effective and safe agent in the therapy of patients with SRNS.

Association of low birth weight and prematurity with clinical outcomes of childhood nephrotic syndrome: a prospective cohort study

BACKGROUND

Low birth weight (LBW)/prematurity have been proposed as risk factors for the development of kidney disease in adulthood. Whether there is an association between LBW/prematurity and poor renal outcomes in childhood onset nephrotic syndrome remains unknown.

METHODS

Children with nephrotic syndrome diagnosed between 1 and 18 years of age were followed prospectively from 1996 to 2016 at The Hospital for Sick Children (N = 377). LBW/prematurity was defined as birth weight < 2500 g or gestational age < 36 weeks. Normal birth weight (NBW) was defined as birth weight ≥ 2500 g. Measures evaluating clinical course of nephrotic syndrome include initial steroid-resistant nephrotic syndrome (SRNS), time to first relapse, and frequently relapsing nephrotic syndrome. Kaplan-Meier survival analysis, logistic regression, and Cox proportional hazards regression were used to determine the association of LBW/prematurity with clinical outcomes.

RESULTS

Median birth weights in LBW/premature (n = 46) and NBW (n = 331) children were 2098 g (interquartile range [IQR] 1700-2325 g) and 3317 g (IQR 2977-3685 g), respectively. Odds of having SRNS were 3.78 (95% confidence interval [CI] 1.28-11.21) times higher among LBW/premature children than NBW children. An 8% decrease in odds of developing SRNS was observed for every 100 g increase in birth weight (adjusted odds ratio [OR] 0.92; 95% CI 0.86-0.98). Median time to first relapse did not differ (hazard ratio [HR] 0.89; 95% CI 0.53-1.16).

CONCLUSIONS

LBW/premature children were more likely to develop SRNS but did not have a difference in time to first relapse with NBW children. Understanding the impact and mechanism of birth weight and steroid-resistant disease needs further study.

The Evaluation of a 19-Year-Old With Hypertension and Proteinuria: A Case Report

A 19-year-old male presented to the clinic and was found to be prehypertensive and have proteinuria on urine testing. He was subsequently diagnosed with focal segmental glomerulosclerosis (FSGS). Initial workup for pediatric hypertension includes urinalysis, chemistry panel, lipid panel, and renal ultrasound. Abnormalities on urinalysis, including proteinuria, hypercholesterolemia, and low serum albumin in children are characteristic of nephrotic disease. FSGS is a type of kidney pathology that often contributes to nephrotic disease and results from a variety of causes. For the primary care provider, being aware of the guidelines for pediatric hypertension screening and evaluation is important as 20% of children with hypertensive disease are due to kidney disease. FSGS is the third leading cause of end-stage renal disease in children aged 12 to 19 years, and its incidence was found to be rising in a study of Olmsted County, MN residents. Treatment to complete or partial remission of the proteinuria can slow the progression of renal disease. In this case report, we will discuss the evaluation of pediatric hypertension workup with proteinuria, specifically due to FSGS, and review current management strategies.

Prospects of genetic testing for steroid-resistant nephrotic syndrome in Nigerian children: a narrative review of challenges and opportunities

The prevalence of childhood steroid-resistant nephrotic syndrome (SRNS) ranges from 35% to 92%. This steroid resistance among Nigerian children also reflects underlying renal histopathology, revealing a rare minimal-change disease and a varying burden of membranoproliferative glomerulonephritis and focal segmental glomerulosclerosis (FSGS). FSGS tends to progress to end-stage kidney disease, which requires dialysis and/or renal transplantation. While knowledge of the molecular basis of NS is evolving, recent data support the role of mutant genes that otherwise maintain the structural and functional composition of the glomerular filtration barrier to account for many monogenic forms of FSGS. With the advent of next-generation sequencing, >39 genes are currently associated with SRNS, and the number is likely to increase in the near future. Monogenic FSGS is primarily resistant to steroids, and this foreknowledge obviates the need for steroids, other immunosuppressive therapy, and renal biopsy. Therefore, a multidisciplinary collaboration among cell biologists, molecular physiologists, geneticists, and clinicians holds prospects of fine-tuning the management of SRNS caused by known mutant genes. This article describes the genetics of NS/SRNS in childhood and also gives a narrative review of the challenges and opportunities for molecular testing among children with SRNS in Nigeria. For these children to benefit from genetic diagnosis, Nigeria must aspire to have and develop the manpower and infrastructure required for medical genetics and genomic medicine, leveraging on her existing experiences in genomic medicine. Concerted efforts can be put in place to increase the number of enrollees in Nigeria’s National Health Insurance Scheme (NHIS). The scope of the NHIS can be expanded to cater for the expensive bill of genetic testing within or outside the structure of the National Renal Care Policy proposed by Nigerian nephrologists.

Childhood nephrotic syndrome at the University of Abuja Teaching Hospital, Abuja, Nigeria: a preliminary report supports high steroid responsiveness

The response to steroid in childhood nephrotic syndrome (CNS) varies across geographical regions, depending on aetiology, genetics, and the underlying pathology. Recently, there is an increasing steroid responsiveness among Nigerian children with nephrotic syndrome (NS). This is the first report of CNS at the University of Abuja Teaching Hospital, Gwagwalada, Abuja, Nigeria, between 15th January 2016 and 30th June 2018. Prednisolone was administered to all the children with NS according to the regimen of the International Study of Kidney Disease in Children. There were 46 children aged 17 months to 18 years, including 37 males and 9 females. The peak age was 6-10 years with a mean age of 8.2 ± 4.4 years. Forty-one (89.1%) had idiopathic NS (INS). Secondary NS occurred in five (10.9%) children with hepatitis B infection, sickle cell anaemia, haemolytic-uraemic syndrome, and post-infectious glomerulonephritis (two cases). Plasmodium malariae was not seen. Overall, steroid-sensitive NS (SSNS) was seen in 34 (73.9%) and in 32 (78%) with INS. Five (16.7%) of the 30 with SSNS relapsed on follow-up. Twelve (26.1%) were resistant to steroid (steroid-resistant NS, SRNS). Renal biopsies in five SRNS revealed focal segmental glomerulosclerosis in three, minimal change lesion in one, and severe interstitial fibrosis/glomerulosclerosis in another one. Four (8.7%) children who had SRNS died. A child with SRNS is surviving on renal transplant from a living-unrelated donor. The study supports the notion that steroid responsiveness is increasing among ethnic black Nigerian children. Pre-treatment renal biopsy may be unwarranted.

Cyclophosphamide versus cyclosporine A therapy in steroid-resistant nephrotic syndrome: a retrospective study with a mean 5-year follow-up

Objective

To compare the clinical efficacy of cyclophosphamide (CTX) and cyclosporine A (CSA) in initial treatment of children with steroid-resistant nephrotic syndrome (SRNS).

Methods

Prospectively maintained databases were reviewed to retrospectively compare two cohorts with SRNS that received peroral administration of 2 to 2.5 mg/kg/d CTX for 3 to 6 months or 1 to 5 mg/kg/d CSA for 2 years until the primary analysis cut-off date during 2007 to 2011. The time to first on-study relapse of SRNS was the primary endpoint. The effective rate was the second endpoint.

Results

A total of 127 children with SRNS were included (CTX-treated cohort: n = 62; CSA-treated cohort: n = 65), with a mean 5-year follow-up. CTX-treated children showed a significantly delayed time to first on-study relapse of SRNS compared with CSA-treated children (hazard ratio 0.66, 95% confidence interval 0.32–1.75). The relapse rate (rate/year) in CTX-treated children (1.1 ± 0.1) at the 24-month follow-up was significantly higher than that with CSA (0.4 ± 0.2). This difference persisted until the final follow-up.

Conclusions

CSA is associated with a significantly lower relapse rate and significantly higher effective rate compared with CTX, especially in children with minimal change disease.

Adrenocortical Suppression in Children with Nephrotic Syndrome Treated with Low-Dose Alternate Day Corticosteroids

Corticosteroids form the mainstay of therapy for all forms of nephrotic syndrome. The long-term use of this medication is associated with serious side effects including adrenocortical suppression. The primary objective of this study was to identify adrenocortical suppression (assessed by single morning serum cortisol levels) in children with nephrotic syndrome on treatment with low-dose alternate day steroids. This cross-sectional study was conducted in the Department of Pediatrics in a tertiary care hospital from January 2014 to January 2015. Seventy children (1–18 years) with nephrotic syndrome (steroid sensitive and resistant) who were in remission and on low-dose alternate day steroids for at least 8 weeks or had received steroids of 2 mg/kg/d for at least 2 weeks in the last 1 year (infrequent relapsers) were enrolled. Relevant history was taken, clinical examination was done and blood samples were drawn for serum cortisol, lipid profile, kidney function tests, fasting blood sugar, glycated hemoglobin (HbA_1c), and serum albumin. Forty percent (28/70) children had adrenocortical suppression as assessed by low morning serum cortisol levels. The mean serum cortisol levels were 188 nmol/L and were significantly lower in frequently relapsing individuals (85.9 nmol/L) as compared to other types of nephrotic syndrome (P = 0.05). The prevalence of adrenocortical suppression was higher in steroid-resistant patients (57%) as compared to 28% in frequently relapsing and 11% in steroid-dependent patients. Fifty-seven percent of patients with adrenocortical suppression had short stature while 50% had obesity. All individuals had normal serum HbA_1c levels. The cumulative steroid doses and total duration of corticosteroid therapy were significantly higher in patients with adrenocortical suppression. Children with nephrotic syndrome treated with low-dose alternate day steroids have a high prevalence of adrenocortical suppression on screening with single morning cortisol sample. Those with frequently relapsing or steroid-resistant diseases are at a higher risk of suppression.

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.

Effect of Combined Gluten-Free, Dairy-Free Diet in Children With Steroid-Resistant Nephrotic Syndrome: An Open Pilot Trial

Introduction

Steroid-resistant nephrotic syndrome (SRNS) affects both children and adults and has a high rate of progression to end-stage renal disease. Although a subset of patients have well-characterized genetic mutation(s), in the majority of cases, the etiology is unknown. Over the past 50 years, a number of case reports have suggested the potential impact of dietary changes in controlling primary nephrotic syndrome, especially gluten and dairy restrictions.

Methods

We have designed a prospective, open-label, nonrandomized, pilot clinical trial, to study the effect of a gluten-free and dairy-free (GF/DF) diet in children with SRNS. The study will be organized as a 4-week summer camp to implement a GF/DF diet in a tightly controlled and monitored setting. Blood, urine, and stool samples will be collected at different time points during the study.

Results

The primary end point is a reduction of more than 50% in the urine protein:creatinine ratio. The secondary end points include changes in urine protein, kidney function, and serum albumin, as well as effects in immune activation, kidney injury biomarkers, and gut microbiome composition and function (metagenomic/metatranscriptomic).

Conclusion

This study will advance the field by testing the effect of dietary changes in patients with SRNS in a highly controlled camp environment. In addition, we hope the results will help to identify a responder profile that may guide the design of a larger trial for further investigation.

Genomic medicine for kidney disease

Technologies such as next-generation sequencing and chromosomal microarray have advanced the understanding of the molecular pathogenesis of a variety of renal disorders. Genetic findings are increasingly used to inform the clinical management of many nephropathies, enabling targeted disease surveillance, choice of therapy, and family counselling. Genetic analysis has excellent diagnostic utility in paediatric nephrology, as illustrated by sequencing studies of patients with congenital anomalies of the kidney and urinary tract and steroid-resistant nephrotic syndrome. Although additional investigation is needed, pilot studies suggest that genetic testing can also provide similar diagnostic insight among adult patients. Reaching a genetic diagnosis first involves choosing the appropriate testing modality, as guided by the clinical presentation of the patient and the number of potential genes associated with the suspected nephropathy. Genome-wide sequencing increases diagnostic sensitivity relative to targeted panels, but holds the challenges of identifying causal variants in the vast amount of data generated and interpreting secondary findings. In order to realize the promise of genomic medicine for kidney disease, many technical, logistical, and ethical questions that accompany the implementation of genetic testing in nephrology must be addressed. The creation of evidence-based guidelines for the utilization and implementation of genetic testing in nephrology will help to translate genetic knowledge into improved clinical outcomes for patients with kidney disease.

Cost analysis on the use of rituximab and calcineurin inhibitors in children and adolescents with steroid-dependent nephrotic syndrome

BACKGROUND

Rituximab (RTX) is increasingly being used in place of calcineurin inhibitors (CNI) in pediatric patients with steroid-dependent nephrotic syndrome (SDNS). However, despite its favorable safety profile, its unit cost is prohibitive. We therefore compared the healthcare costs associated with the use of both agents in a retrospective cohort.

METHODS

This study was a retrospective analysis of data retrieved from the medical charts and electronic databases of pediatric patients (age range 2-18 years) with SDNS who were treated with either CNI or RTX from January 2008 to December 2012 at Children's Hospital of New Orleans, Louisiana. The minimum follow-up period was 12 months.

RESULTS

Of the 18 patients whose medical data were analyzed, ten received RTX and eight were treated with CNI. The annualized healthcare cost for the rituximab group was $197,031 versus $189,857 (all values in US dollars) for the CNI group (p > 0.05). At the 12-month follow-up, more patients in the RTX group were in remission (40 vs. 25%). Duration of freedom from steroid use was longer in the RTX group, while body mass index was higher in the CNI arm (p > 0.05). No significant adverse events occurred in either group.

CONCLUSION

The expenditure for the RTX and CNI groups was comparable, but there were fewer clinical encounters in the former group, potentially reducing the burden of healthcare on the patient's family.

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.

Efficacy and safety of immunosuppressive medications for steroid-resistant nephrotic syndrome in children: a systematic review and network meta-analysis

Background

Conventional meta-analyses and randomized controlled trials have shown inconsistent results regarding the efficacy of immunosuppressants for pediatric steroid-resistant nephrotic syndrome (SRNS).

Objective

To conduct a network meta-analysis aimed at evaluating the efficacy and safety of available immunosuppressive agents in pediatric patients with SRNS.

Study methods

MEDLINE, the Cochrane Central Register of Controlled Trials, and EMBASE were searched on January 2017. Data from randomized controlled trials (RCTs) were included. The main outcomes analyzed were efficacy [number/portion with complete remission (CR), number/portion with partial remission (PR), and total number/portion in remission (TR)] and safety [adverse secondary event (ASE) rates].

Results

A meta-analysis of 18 RCTs showed that tacrolimus was more efficacious for achieving CR than intravenous (i.v.) cyclophosphamide, mycophenolate mofetil (MMF), oral cyclophosphamide, leflunomide, chlorambucil, azathioprine, and plaebo/nontreatment (P/NT), and more efficacious than i.v. cyclophosphamide, oral cyclophosphamide, and P/NT in terms of TR outcomes. Cyclosporin was associated with a greater CR rate than i.v. cyclophosphamide, MMF, oral cyclophosphamide, chlorambucil, azathioprine, or P/NT, and associated with a greater TR rate than i.v. cyclophosphamide, oral cyclophosphamide, or P/NT. MMF was found to be more efficacious than i.v. cyclophosphamide and oral cyclophosphamide in terms of TR.

Conclusions

Tacrolimus and cyclosporine may be preferred initial treatments for children with SRNS. MMF may be another option for this patient population. Further studies of the efficacy and safety of these three drugs in children with SRNS should be pursued.

Pulsed Vincristine Therapy in Steroid-Resistant Nephrotic Syndrome

Steroid-resistant nephrotic syndrome (SRNS) poses a therapeutic challenge for the paediatric nephrologist. As relentless progression to renal failure occurs with continued proteinuria, such patients will be treated with different cytotoxic medications with variable success rates and side-effects. We present here our findings on administering the anticancer drug vincristine for SRNS patients at a single centre in Sri Lanka. Methods. Between 2002 and 2007, fifty-four children presenting with steroid and cyclophosphamide resistance were treated with vincristine at 1.5 mg/m² in weekly intravenous pulses for 8 weeks along with a tapering steroid regimen of 6 months. All patients were closely followed up for 5 years. Results. Of the 54 patients 39 were males and 15 were females (age range 3.5–11.6 years, median 6.1 years). At the end of the treatment course, 21 patients achieved complete remission while 7 had partial remission and no response was seen in 26 patients. Sustained remission at 6, 12, 24, and 60 months were 15 (27.78%), 11 (20.37%), 9 (16.67%), and 7 (12.96%), respectively. Most side-effects observed were reversible and no serious side-effects were noted during vincristine therapy. Conclusion. Although its therapeutic mechanisms in nephrotic syndrome are still not elucidated, vincristine appears to be a potent alternative that could be considered for treating SRNS.

New biologics in the treatment of rare glomerular diseases of childhood

Minimal change disease and focal segmental glomerulosclerosis are rare but important causes of end-stage kidney disease in children. Though their pathogenesis is still unclear, evidence of immune abnormalities provided the background for the use of immunosuppressive drugs, such as corticosteroids, calcineurin inhibitors, antiproliferative and alkylating agents. Unfortunately, these treatments fail to achieve a sustained remission in a significant portion of patients and are burdened by significant toxicities. Recent developments of new biologics, including anti-CD20 monoclonal antibodies rituximab and ofatumumab, offered the opportunity to selectively target immune cell subsets or activation pathways, leading to more effective and safer hypothesis-driven treatments.