Evaluation of Daily Low-Dose Prednisolone During Upper Respiratory Tract Infection to Prevent Relapse in Children With Relapsing Steroid-Sensitive Nephrotic Syndrome: The PREDNOS 2 Randomized Clinical Trial

Corticosteroid therapy for nephrotic syndrome in children

BACKGROUND

In nephrotic syndrome, protein leaks from the blood into the urine through the glomeruli, resulting in hypoproteinaemia and generalised oedema. While most children with nephrotic syndrome respond to corticosteroids, 80% experience a relapsing course. Corticosteroids have reduced the death rate to around 3%; however, corticosteroids have well-recognised potentially serious adverse events such as obesity, poor growth, hypertension, diabetes mellitus, osteoporosis, cataracts, glaucoma and behavioural disturbances. This is an update of a review first published in 2000 and updated in 2002, 2005, 2007, 2015 and 2020.

OBJECTIVES

The aim of this review was to assess the benefits and harms of different corticosteroid regimens in children with steroid-sensitive nephrotic syndrome (SSNS). The benefits and harms of therapy were studied in two groups of children: 1) children in their initial episode of SSNS and 2) children who experience a relapsing course of SSNS.

SEARCH METHODS

We contacted the Information Specialist and searched the Cochrane Kidney and Transplant Register of Studies up to 9 July 2024 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 Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) performed in children (one to 18 years) during their initial or subsequent episode of SSNS, comparing different durations, total doses or other dose strategies using any corticosteroid agent.

DATA COLLECTION AND ANALYSIS

Summary estimates of effects were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

In this 2024 update, we included five new studies, resulting in 54 studies randomising 4670 children. Risk of bias methodology was often poorly performed, with only 31 studies and 28 studies respectively assessed to be at low risk for random sequence generation and allocation concealment. Ten studies were at low risk of performance bias (blinding of participants and personnel), and 12 studies were at low risk of detection bias (blinding of outcome assessment); nine of these studies were placebo-controlled RCTs. Twenty-seven studies (fewer than 50%) were at low risk for attrition bias, and 26 studies were at low risk for reporting bias (selective outcome reporting). In studies at low risk of selection bias evaluating children in their initial episode of SSNS, there is little or no difference in the number of children with frequent relapses when comparing two months of prednisone with three months or more (RR 0.96, 95% CI 0.83 to 1.10; 755 children, 5 studies; I2 = 0%; high certainty evidence) or when comparing three months with five to seven months of therapy (RR 0.99, 95% CI 0.74 to 1.33; 376 children, 3 studies; I2 = 35%; high certainty evidence). In analyses of studies at low risk of selection bias, there is little or no difference in the number of children with any relapse by 12 to 24 months when comparing two months of prednisone with three months or more (RR 0.93, 95% CI 0.81 to 1.06; 808 children; 6 studies; I2 = 47%) or when comparing three months with five to seven months of therapy (RR 0.88, 95% CI 0.70 to 1.11; 377 children, 3 studies; I2 = 53%). Little or no difference was noted in adverse events between the different treatment durations. Amongst children with relapsing SSNS, four small studies (177 children) utilising lower doses of prednisone compared with standard regimens found little or no differences between groups in the numbers with relapse (RR 1.01, 95% CI 0.85 to 1.20; I2 = 0%). A fifth study (117 children) reported little or no difference between two weeks and four weeks of alternate-day prednisone after remission with daily prednisone. A recent large, well-designed study with 271 children found that administering daily prednisone compared with alternate-day prednisone or no prednisone during viral infection did not reduce the risk of relapse. In contrast, four previous small studies in children with frequently relapsing disease had reported that daily prednisone during viral infections compared with alternate-day prednisone or no treatment reduced the risk of relapse.

AUTHORS' CONCLUSIONS

There are four well-designed studies randomising 823 children, which have demonstrated that there is no benefit of prolonging prednisone therapy beyond two to three months in the first episode of SSNS. Small studies in children with relapsing disease have identified no differences in efficacy using lower induction doses or shorter durations of prednisone therapy. Large, well-designed studies are required to confirm these findings. While previous small studies had suggested that changing from alternate-day to daily prednisone therapy at the onset of infection reduced the likelihood of relapse, a much larger and well-designed study found no reduction in the number relapsing when administering daily prednisone at the onset of infection.

An open label non-inferiority randomized controlled trial evaluated alternate day prednisolone given daily during infections vs. levamisole in frequently relapsing nephrotic syndrome

Initial therapies for children with frequently relapsing nephrotic syndrome include alternate-day prednisolone that is given daily during infections, or levamisole. In this open label, non-inferiority trial, 160 patients, 2 to 18-years-old with frequent relapses, were randomly assigned to receive either prednisolone (0.5-0.7 mg/kg/alternate-day, given daily during infections), or levamisole (2-2.5 mg/kg/alternate-days) for one-year. Patients with relapses on alternate day prednisolone at over 1 mg/kg, prior use of potent steroid-sparing therapies, eGFR under 60 ml/min/1.73 m2 and significant steroid toxicity were excluded. Primary outcome was the proportion of patients with frequent relapses, defined as three-relapses in one-year, or two-relapses within six-months if associated with significant steroid toxicity or loss to follow up. Eighty patients each were randomized to receive prednisolone and levamisole. Baseline features showed preponderance of young patients presenting within two-years of disease onset. On intention-to-treat analysis, frequent relapses were more common in patients administered prednisolone (40% versus 22.5%; risk difference 17.5%; 95% confidence interval 3.4-31.6%). Prednisolone was not non-inferior to levamisole in preventing frequent relapses. However, the two groups showed similar proportions of patients in sustained remission, comparable frequency of relapses, and low frequency of adverse events. The decline in steroid requirement from baseline was higher in the levamisole group. Per-protocol analysis showed similar results. These results have implications for choice of therapy for frequently relapsing nephrotic syndrome. Although therapy with alternate-day prednisolone was not non-inferior to levamisole in preventing frequent relapses, both therapies were effective in other outcome measures. Thus, levamisole was relatively steroid-sparing and may be preferred in patients at risk of steroid toxicity.

The extrafollicular B cell response is a hallmark of childhood idiopathic nephrotic syndrome

The efficacy of the B cell-targeting drug rituximab (RTX) in childhood idiopathic nephrotic syndrome (INS) suggests that B cells may be implicated in disease pathogenesis. However, B cell characterization in children with INS remains limited. Here, using single-cell RNA sequencing, we demonstrate that a B cell transcriptional program poised for effector functions represents the major immune perturbation in blood samples from children with active INS. This transcriptional profile was associated with an extrafollicular B cell response marked by the expansion of atypical B cells (atBCs), marginal zone-like B cells, and antibody-secreting cells (ASCs). Flow cytometry of blood from 13 children with active INS and 24 healthy donors confirmed the presence of an extrafollicular B cell response denoted by the expansion of proliferating RTX-sensitive extrafollicular (CXCR5-) CD21low T-bet+ CD11c+ atBCs and short-lived T-bet+ ASCs in INS. Together, our study provides evidence for an extrafollicular origin for humoral immunity in active INS.

Single- versus Divided-Dose Prednisolone for the First Episode of Nephrotic Syndrome in Children: An Open-Label RCT

BACKGROUND

Early morning single-dose prednisolone has a hypothetical advantage of less hypothalamic-pituitary-adrenal (HPA) axis suppression, but lack of robust evidence has resulted in variation in practice, with divided-dose prednisolone still commonly used. We conducted this open-label randomized control trial to compare HPA axis suppression between single-dose or divided-dose prednisolone among children with first episode of nephrotic syndrome.

METHODS

Sixty children with first episode of nephrotic syndrome were randomized (1:1) to receive prednisolone (2 mg/kg per day), either as single or two divided doses for 6 weeks, followed by single alternative daily dose of 1.5 mg/kg for 6 weeks. The Short Synacthen Test was conducted at 6 weeks, with HPA suppression defined as postadrenocorticotropic hormone cortisol <18 µ mg/dl.

RESULTS

Four children (single=1 and divided dose=3) did not attend the Short Synacthen Test and were hence excluded from analysis. Remission was induced in all, and no relapse postremission was noted during the 6+6 weeks of steroid therapy. After 6 weeks of daily steroids, HPA suppression was greater in divided (100%) versus single dose (83%) ( P = 0.02). Time to remission and final relapse rates were similar, but for those children who relapsed within 6 months of follow-up period, time to first relapse was shorter for divided dose (median 28 versus 131 days) P = 0.002.

CONCLUSIONS

Among children with first episode of nephrotic syndrome, single-dose and/or divided-dose prednisolone were equally effective in inducing remission with similar relapse rates, but single dose had less HPA suppression and longer time to first relapse.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

CTRI/2021/11/037940.

PODCAST

This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/CJASN/2023_10_09_CJN0000000000000216.mp3.

Childhood nephrotic syndrome

Idiopathic nephrotic syndrome is the most common glomerular disease in children. Corticosteroids are the cornerstone of its treatment, and steroid response is the main prognostic factor. Most children respond to a cycle of oral steroids, and are defined as having steroid-sensitive nephrotic syndrome. Among the children who do not respond, defined as having steroid-resistant nephrotic syndrome, most respond to second-line immunosuppression, mainly with calcineurin inhibitors, and children in whom a response is not observed are described as multidrug resistant. The pathophysiology of nephrotic syndrome remains elusive. In cases of immune-mediated origin, dysregulation of immune cells and production of circulating factors that damage the glomerular filtration barrier have been described. Conversely, up to a third of cases of steroid-resistant nephrotic syndrome have a monogenic origin. Multidrug resistant nephrotic syndrome often leads to kidney failure and can cause relapse after kidney transplant. Although steroid-sensitive nephrotic syndrome does not affect renal function, most children with steroid-sensitive nephrotic syndrome have a relapsing course that requires repeated steroid cycles with significant side-effects. To minimise morbidity, some patients require steroid-sparing immunosuppressive agents, including levamisole, mycophenolate mofetil, calcineurin inhibitors, anti-CD20 monoclonal antibodies, and cyclophosphamide. Close monitoring and preventive measures are warranted at onset and during relapse to prevent acute complications (eg, hypovolaemia, acute kidney injury, infections, and thrombosis), whereas long-term management requires minimising treatment-related side-effects. A subset of patients have active disease into adulthood.

KDOQI US Commentary on the 2021 KDIGO Clinical Practice Guideline for the Management of Glomerular Diseases

The KDIGO 2021 Clinical Practice Guideline for the Management of Glomerular Diseases represents the first update to this set of recommendations since the initial set of KDIGO guideline recommendations was published in 2012. The pace of growth in our molecular understanding of glomerular disease has quickened and a number of newer immunosuppressive and targeted therapies have been introduced since the original set of guideline recommendations, making such an update necessary. Despite these updates, many areas of controversy remain. In addition, further updates since the publication of KDIGO 2021 have occurred which this guideline does not encompass. With this commentary, the KDOQI work group has generated a chapter-by-chapter companion opinion article that provides commentary specific to the implementation of the KDIGO 2021 guideline in the United States.

Common Risk Variants in AHI1 Are Associated With Childhood Steroid Sensitive Nephrotic Syndrome

Introduction

Steroid-sensitive nephrotic syndrome (SSNS) is the most common form of kidney disease in children worldwide. Genome-wide association studies (GWAS) have demonstrated the association of SSNS with genetic variation at HLA-DQ/DR and have identified several non-HLA loci that aid in further understanding of disease pathophysiology. We sought to identify additional genetic loci associated with SSNS in children of Sri Lankan and European ancestry.

Methods

We conducted a GWAS in a cohort of Sri Lankan individuals comprising 420 pediatric patients with SSNS and 2339 genetic ancestry matched controls obtained from the UK Biobank. We then performed a transethnic meta-analysis with a previously reported European cohort of 422 pediatric patients and 5642 controls.

Results

Our GWAS confirmed the previously reported association of SSNS with HLA-DR/DQ (rs9271602, P = 1.12 × 10-27, odds ratio [OR] = 2.75). Transethnic meta-analysis replicated these findings and identified a novel association at AHI1 (rs2746432, P = 2.79 × 10-8, OR = 1.37), which was also replicated in an independent South Asian cohort. AHI1 is implicated in ciliary protein transport and immune dysregulation, with rare variation in this gene contributing to Joubert syndrome type 3.

Conclusions

Common variation in AHI1 confers risk of the development of SSNS in both Sri Lankan and European populations. The association with common variation in AHI1 further supports the role of immune dysregulation in the pathogenesis of SSNS and demonstrates that variation across the allele frequency spectrum in a gene can contribute to disparate monogenic and polygenic diseases.

Economic Evaluation of Using Daily Prednisolone versus Placebo at the Time of an Upper Respiratory Tract Infection for the Management of Children with Steroid-Sensitive Nephrotic Syndrome: A Model-Based Analysis

BACKGROUND

Childhood steroid-sensitive nephrotic syndrome is a frequently relapsing disease with significant short- and long-term complications, leading to high healthcare costs and reduced quality of life for patients. The majority of relapses are triggered by upper respiratory tract infections (URTIs) and evidence shows that daily low-dose prednisolone at the time of infection may reduce the risk of relapse.

OBJECTIVE

The aim of this study was to assess the cost effectiveness of a 6-day course of low-dose prednisolone at the start of a URTI when compared with placebo.

METHODS

A state-transition Markov model was developed to conduct a cost-utility analysis with the outcome measured in quality-adjusted life-years (QALYs). Resource use and outcome data were derived from the PREDNOS2 trial. The analysis was performed from a UK National Health Service perspective and the results were extrapolated to adulthood. Model parameter and structural uncertainty were assessed using sensitivity analyses.

RESULTS

The base-case results showed that administering low-dose prednisolone at the time of a URTI generated more QALYs and a lower mean cost at 1 year compared with placebo. In the long-term, low-dose prednisolone was associated with a cost saving (£176) and increased effectiveness (0.01 QALYs) compared with placebo and thus remained the dominant treatment option. These findings were robust to all sensitivity analyses.

CONCLUSION

A 6-day course of low-dose prednisolone at the time of a URTI in children with steroid-sensitive nephrotic syndrome has the potential to reduce healthcare costs and improve quality of life compared with placebo.

Pulmonary surfactants and the respiratory-renal connection in steroid-sensitive nephrotic syndrome of childhood

Steroid-sensitive nephrotic syndrome (SSNS) in childhood is usually due to minimal change disease (MCD). Unlike many glomerular conditions, SSNS/MCD is commonly precipitated by respiratory infections. Of interest, pulmonary inflammation releases surfactants in circulation which are soluble agonists of SIRPα, a podocyte receptor that regulates integrin signaling. Here, we characterized this pulmonary-renal connection in MCD and performed studies to determine its importance. Children with SSNS/MCD in relapse but not remission had elevated plasma surfactants and urinary SIRPα. Sera from relapsing subjects triggered podocyte SIRPα signaling via tyrosine phosphatase SHP-2 and nephrin dephosphorylation, a marker of podocyte activation. Further, addition of surfactants to MCD sera from patients in remission replicated these findings. Similarly, nasal instillation of toll-like receptor 3 and 4 agonists in mice resulted in elevated serum surfactants and their binding to glomeruli triggering proteinuria. Together, our data document a critical pulmonary-podocyte signaling pathway involving surfactants and SIRPα signaling in SSNS/MCD.

Short Course of Daily Prednisolone During Upper Respiratory Tract Infection for Children With Relapsing Steroid Sensitive Nephrotic Syndrome

PREDNOS 2 was a double blind placebo controlled trial done to investigate the use of daily low-dose prednisolone for the treatment of upper respiratory tract infection—related relapses. It evaluated 365 children with relapsing steroid-sensitive nephrotic syndrome with and without background immunosuppressive treatment at 122 pediatric departments in the UK from February 1, 2013, to January 31, 2020. At the beginning of an upper respiratory tract infection, children received 6 days of prednisolone, 15 mg/m² daily, or matching placebo preparation. Those already taking alternate-day prednisolone rounded their daily dose using trial medication to the equivalent of 15 mg/m² daily or their alternate-day dose, whichever was greater. The primary outcome was the incidence of first upper respi-ratory tract infection-related relapse. The modified intention-to-treat analysis population comprised 271 children (mean (SD) age, 7.6 (3.5) years; 64.2% male), with 134 in the prednisolone arm and 137 in the placebo arm. The number of patients experiencing an upper respiratory tract infection-related relapse was 56 (42.7%) in the predniso-lone arm and 58 (44.3%) in the placebo arm (adjusted risk difference, 0.02; 95% CI, 0.14 to 0.10; P =0.70). No evidence was found that the treatment effect differed according to background immuno-suppressive treatment. A post hoc subgroup analysis assessing the primary outcome in 54 children of South Asian ethnicity (risk ratio, 0.66; 95% CI, 0.40–1.10) vs 208 children of other ethnicity (risk ratio, 1.11; 95% CI, 0.81–1.54) found no difference in efficacy of intervention in those of South Asian ethnicity (test for interaction P=0.09). The authors concluded that, results of PREDNOS 2 suggest that administering 6 days of daily low-dose prednisolone at the time of an upper respiratory tract infection does not reduce the risk of relapse of nephrotic syndrome in children in the UK and further work is needed to study the inter-ethnic differences in the study response.

Daily low-dose prednisolone to prevent relapse of steroid-sensitive nephrotic syndrome in children with an upper respiratory tract infection: PREDNOS2 RCT

Background

Most children with steroid-sensitive nephrotic syndrome have relapses that are triggered by upper respiratory tract infections. Four small trials, mostly in children already taking maintenance corticosteroid in countries of different upper respiratory tract infection epidemiology, showed that giving daily low-dose prednisone/prednisolone for 5–7 days during an upper respiratory tract infection reduces the risk of relapse.

Objectives

To determine if these findings were replicated in a large UK population of children with relapsing steroid-sensitive nephrotic syndrome on different background medication or none.

Design

A randomised double-blind placebo-controlled trial, including a cost-effectiveness analysis.

Setting

A total of 122 UK paediatric departments, of which 91 recruited patients.

Participants

A total of 365 children with relapsing steroid-sensitive nephrotic syndrome (mean age 7.6 ± 3.5 years) were randomised (1 : 1) according to a minimisation algorithm based on background treatment. Eighty children completed 12 months of follow-up without an upper respiratory tract infection. Thirty-two children were withdrawn from the trial (14 prior to an upper respiratory tract infection), leaving a modified intention-to-treat analysis population of 271 children (134 and 137 children in the prednisolone and placebo arms, respectively).

Interventions

At the start of an upper respiratory tract infection, children received 6 days of prednisolone (15 mg/m2) or an equivalent dose of placebo.

Main outcome measures

The primary outcome was the incidence of first upper respiratory tract infection-related relapse following any upper respiratory tract infection over 12 months. The secondary outcomes were the overall rate of relapse, changes in background treatment, cumulative dose of prednisolone, rates of serious adverse events, incidence of corticosteroid adverse effects, change in Achenbach Child Behaviour Checklist score and quality of life. Analysis was by intention-to-treat principle. The cost-effectiveness analysis used trial data and a decision-analytic model to estimate quality-adjusted life-years and costs at 1 year, which were then extrapolated over 16 years.

Results

There were 384 upper respiratory tract infections and 82 upper respiratory tract infection-related relapses in the prednisolone arm, and 407 upper respiratory tract infections and 82 upper respiratory tract infection-related relapses in the placebo arm. The number of patients experiencing an upper respiratory tract infection-related relapse was 56 (42.7%) and 58 (44.3%) in the prednisolone and placebo arms, respectively (adjusted risk difference –0.024, 95% confidence interval –0.14 to 0.09; p = 0.70). There was no evidence that the treatment effect differed when data were analysed according to background treatment. There were no significant differences in secondary outcomes between treatment arms. Giving daily prednisolone at the time of an upper respiratory tract infection was associated with increased quality-adjusted life-years (0.9427 vs. 0.9424) and decreased average costs (£252 vs. £254), when compared with standard care. The cost saving was driven by background therapy and hospitalisations after relapse. The finding was robust to sensitivity analysis.

Limitations

A larger number of children than expected did not have an upper respiratory tract infection and the sample size attrition rate was adjusted accordingly during the trial.

Conclusions

The clinical analysis indicated that giving 6 days of daily low-dose prednisolone at the time of an upper respiratory tract infection does not reduce the risk of relapse of steroid-sensitive nephrotic syndrome in UK children. However, there was an economic benefit from costs associated with background therapy and relapse, and the health-related quality-of-life impact of having a relapse.

Future work

Further work is needed to investigate the clinical and health economic impact of relapses, interethnic differences in treatment response, the effect of different corticosteroid regimens in treating relapses, and the pathogenesis of individual viral infections and their effect on steroid-sensitive nephrotic syndrome.

Trial registration

Current Controlled Trials ISRCTN10900733 and EudraCT 2012-003476-39.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 3. See the NIHR Journals Library website for further project information.