BACKGROUND: The efficacy of rituximab in steroid-resistant nephrotic syndrome (SRNS) is controversial. We previously reported that rituximab in combination with methylprednisolone pulse therapy (MPT) and immunosuppressants was associated with favorable outcomes. We determined risk factors for poor response following rituximab treatment, which remains unknown.
METHODS: This retrospective study included 45 patients with childhood-onset SRNS treated with rituximab across four pediatric kidney facilities. Treatment effects were categorized as complete remission (CR), partial remission (PR), and no remission (NR) at one year after rituximab treatment. The primary outcome was the rate of CR, PR, and NR. Risk factors for non-CR were calculated with multivariate logistic regression. Adverse events and the relationship between disease status at one year and long-term prognosis were also evaluated.
RESULTS: The rates of CR, PR, and NR at one year were 69%, 24%, and 7%, respectively. The median time from rituximab administration to CR was 90 days. The median follow-up period after rituximab administration was 7.4 years. In multivariate analysis, significant risk factors for poor response were the pathologic finding of focal segmental glomerular sclerosis and a long interval between SRNS diagnosis and rituximab administration. The rates of CR were 90.3% and 21.4% in patients receiving rituximab within and after 6 months following SRNS diagnosis, respectively (p < 0.001). Five patients developed chronic kidney disease stage G5, including 2 of the 11 patients with PR and all 3 patients with NR, whereas none of the 31 patients with CR developed chronic kidney disease stage G5.
CONCLUSIONS: Early administration of rituximab in combination with MPT and immunosuppressants might achieve favorable outcomes in patients with SRNS.

UNASSIGNED: Steroid-resistant nephrotic syndrome (SRNS) is the second most common cause of end-stage kidney disease in children, mostly associated with focal segmental glomerulosclerosis (FSGS). Advances in genomic science have enabled the identification of causative variants in 20-30% of SRNS patients.
UNASSIGNED: We used whole exome sequencing to explore the genetic causes of SRNS in children. Totally, 101 patients with SRNS and 13 patients with nephrotic proteinuria and FSGS were retrospectively enrolled in our hospital between 2018 and 2022. For the known monogenic causes analysis, we generated a known SRNS gene list of 71 genes through reviewing the OMIM database and literature.
UNASSIGNED: Causative variants were identified in 23.68% of our cohort, and the most frequently mutated genes in our cohort were WT1 (7/27), NPHS1 (3/27), ADCK4 (3/27), and ANLN (2/27). Five patients carried variants in phenocopy genes, including MYH9, MAFB, TTC21B, AGRN, and FAT4. The variant detection rate was the highest in the two subtype groups with congenital nephrotic syndrome and syndromic SRNS. In total, 68.75% of variants we identified were novel and have not been previously reported in the literature.
UNASSIGNED: Comprehensive genetic analysis is key to realizing the clinical benefits of a genetic diagnosis. We suggest that all children with SRNS undergo genetic testing, especially those with early-onset and extrarenal phenotypes.

Steroid-resistant nephrotic syndrome (SRNS) patients with genetic mutations most commonly have histology of focal segmental glomerulosclerosis (FSGS) and do not respond to immunosuppressive drugs. We report the molecular screening results of 18 pediatric SRNS cases presented to our nephrology clinic. Three pathogenic variants have been detected, two previously reported and one novel variant. The reported pathogenic variants have been detected in NPHS1 and NPHS2 genes. A novel pathogenic variant has been detected in the inverted formin 2 gene ( INF2 ) gene. We did not detect any variant of the WT1 gene. There were 13 males. Mean age of study participants at enrollment was 69 months. There were 12 cases of primary SRNS. The mean duration from onset of symptoms to SRNS diagnosis was 13 months. FSGS and minimal change disease (MCD) were present in the same number of cases. The response rate (complete or partial) to immunosuppressive drugs was seen in only one patient in the genetic SRNS group ( n  = 3), while the response rate in nongenetic cases ( n  = 15) was 80%. Two nonresponders in the genetic SRNS group had FSGS for histopathology and pathogenic variants (NPHS2 and INF2). The other three nonresponders in the nongenetic SRNS group had both FSGS ( n  = 1) and MCD ( n  = 2) histopathology. There were two deaths in the study cohort of the nongenetic SRNS group. This study highlights the screening of the SRNS cohort by a panel of extended genes rather focussing on the three most common genes ( NPHS1 , NPHS2 , and WT1 ). This further confirms the molecular etiology of SRNS in three cases and extends the list of pathogenic variants of genetic SRNS in the North Indian population. This is the first study in the eastern part of Uttar Pradesh in India.

OBJECTIVE: The comparative safety and efficacy of maintenance mycophenolate mofetil (MMF) and cyclosporine (CYC) following rituximab (RTX) in children with steroid-resistance nephrotic syndrome are uncertain.
METHODS: Multicenter randomized controlled trial.
METHODS: Sixty-six children between 2 and 6 years of age with SRNS.
METHODS: Patients were randomized to receive either MMF 1000 mg/m2 /day (n = 32) or CYC 5 mg/kg/day (n = 34) for 12 months following RTX induction therapy (375 mg/m2 ) given as needed for B-cell count.
RESULTS: Complete remission and adverse events (AEs).
RESULTS: Complete remission was observed in 26 patients (83.1%) in the MMF group compared with 21 patients (61.7%) in the CYC group (p = 0.02). The median time to remission was shorter in the MMF group than in the CYC group (2.64 vs. 3.4 months; hazard ratio [HR], 0.61; 95% CI, 0.74-0.90, p = 0.03). The median time to first relapse was longer in the MMF group compared with the CYC group (10.8 vs. 8.0 months; HR, 1.12; 95% CI, 1.31-1.54, p = 0.01), and this was significantly correlated with the median time to B-cell recovery in the two groups (8.6 vs. 5.2 months in MMF and CYC, respectively, p = 0.02). The overall incidence of adverse drug events was lower in the MMF group compared with the CYC group (59.3% vs. 76.4%, p = 0.03).
CONCLUSIONS: MMF-RTX is superior to CYC-RTX in maintaining remission with fewer AEs in children with initial SRNS. Additional high-quality randomized control trials with long-term follow-up are needed to identify the long-term potential complications.

Steroid-resistant nephrotic syndrome (SRNS) is one of the major causes of end-stage kidney disease (ESKD) in children and young adults. For approximately 30% of children with SRNS results from a genetic cause. In this study, genotype-phenotype correlations in a cohort of 283 pediatric patients with SRNS or early-onset NS (nephrotic syndrome presenting within the first year of life) from 23 major pediatric nephrology centers in China were analyzed. All patients were performed with next-generation sequencing and Sanger sequencing. The overall mutation detection rate was 37.5% (106 of 283 patients). WT1 was the most frequently detected mutation, followed by NPHS1, NPHS2, and ADCK4, and these four major causative genes (WT1, NPHS1, NPHS2, and ADCK4) account for 73.6% of patients with monogenic SRNS. Thirteen of 106 individuals (12.3%) carried mutations in ADCK4 that function within the coenzyme Q10 biosynthesis pathway. In the higher frequently ADCK4-related SRNS, two mutations, c.737G>A (p.S246N) and c.748G>C (p.D250H), were the most prevalent. Our study provides not only definitive diagnosis but also facilitate available targeted treatment for SRNS, and prediction of prognosis and renal outcome. Our indications for genetic testing are patients with FSGS, initial SRNS, cases of positive family history or those with extra-renal manifestations.

Steroid-resistant nephrotic syndrome (SRNS) is one of the major causes of end-stage renal disease (ESRD) in childhood and is mostly associated with focal segmental glomerulosclerosis (FSGS). More than 50 monogenic causes of SRNS or FSGS have been identified. Recently, the mutation detection rate in pediatric patients with SRNS has been reported to be approximately 30%. In this study, genotype-phenotype correlations in a cohort of 291 Korean pediatric patients with SRNS/FSGS were analyzed. The overall mutation detection rate was 43.6% (127 of 291 patients). WT1 was the most common causative gene (23.6%), followed by COQ6 (9.4%), NPHS1 (8.7%), NUP107 (7.1%), and COQ8B (6.3%). Mutations in COQ6, NUP107, and COQ8B were more frequently detected, and mutations in NPHS2 were less commonly detected in this cohort than in study cohorts from Western countries. The mutation detection rate was higher in patients with congenital onset, those who presented with proteinuria or chronic kidney disease/ESRD, and those who did not receive steroid treatment. Genetic diagnosis in patients with SRNS provides not only definitive diagnosis but also valuable information for decisions on treatment policy and prediction of prognosis. Therefore, further genotype-phenotype correlation studies are required.

BACKGROUND: Long-term outcomes of children with nephrotic syndrome have not been well described in the literature.
METHODS: Cross-sectional study data analysis of n = 43 patients with steroid-sensitive (SSNS) and n = 7 patients with steroid-resistant (SRNS) nephrotic syndrome were retrospectively collected; patients were clinically examined at a follow-up visit (FUV), on average 30 years after onset, there was the longest follow-up period to date.
RESULTS: The mean age at FUV was 33.6 years (14.4-50.8 years, n = 41). The mean age of patients with SSNS at onset was 4.7 years (median 3.8 years (1.2-14.5 years), the mean number of relapses was 5.8 (0 to 29 relapses). Seven patients (16.3%) had no relapses. Eleven patients were \"frequent relapsers\" (25.6%) and four patients still had relapses beyond the age of 18 years. Except of cataracts and arterial hypertension, there were no negative long-term outcomes and only one patient was using immunosuppressant therapy at FUV. 55% of patients suffered from allergies and 47.5% had hypercholesterolemia. Two patients suffered a heart attack in adulthood. A younger age at onset (< 4 years) was a risk factor for frequent relapses. An early relapse (within 6 months after onset) was a risk factor and a low birth weight was not a significant risk factor for a complicated NS course. The mean age of patients with SRNS at onset was 4.6 ± 4.4 years and 27.5 ± 9.9 years at FUV. Three patients received kidney transplantations.
CONCLUSIONS: The positive long-term prognosis of SSNS can reduce the concern of parents about the probability of the child developing a chronic renal disease during the clinical course after onset.

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.

BACKGROUND: 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).
CONCLUSIONS: 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.

This is a randomized, parallel group, active-controlled trial to compare the efficacy of intravenous cyclophosphamide (IVCP) with oral cyclophosphamide (OCP) in patients with steroid-resistant nephrotic syndrome (SRNS) in children. Fifty consecutive children with idiopathic SRNS were biopsied and then randomized to receive either OCP at a dose of 2 mg/kg/day for 12 weeks or IVCP at a dose of 500 mg/m2/month for 6 months. Both groups received tapering doses of oral steroids. The response was evaluated in terms of induction of complete remission (CR) or partial remission (PR), time to remit, and side effects. The groups were followed up to determine the duration of remission, percentage of patients who remain in sustained remission for more than 1 year after completion of therapy, change in steroid response status, progression to chronic kidney disease stage 3 or more. Of the fifty patients, OCP was given to 25 children and IVCP to 25 children. The demographic data, histopathology, biochemical profile, and duration of follow-up in the two groups were comparable. The rates of induction of CR were 52% versus 44% and of PR were 8% versus 8% in the intravenous (IV) and oral group, respectively. Time to remit was shorter with OCP than IVCP (53 days vs. 84.4 days). Incidence of side effects (both major and minor) was 36% in IVCP versus 20% in OCP group. The actuarial cumulative sustained remission in our study was 12% in IVCP compared with 16% in OCP at 1 year after completion of therapy. Twelve percent children in both the groups exhibited restoration of steroid sensitivity. Thus, in our study, overall, more than half of SRNS patients showed initial response to cyclophosphamide, but only one-fourth patients had sustained remission on follow-up. OCP and IVCP were equally efficacious and safe in idiopathic SRNS in children.