Long-term outcome of biopsy-proven, frequently relapsing minimal-change nephrotic syndrome in children

Impact of childhood nephrotic syndrome on obesity and growth: a prospective cohort study

BACKGROUND

Children with nephrotic syndrome are at risk of obesity and growth impairment from repeated steroid treatment. However, incidence and risk factors for obesity and short stature remain uncertain, which is a barrier to preventative care. Our aim was to determine risk, timing, and predictors of obesity and short stature among children with nephrotic syndrome.

METHODS

We evaluated obesity and longitudinal growth among children (1-18 years) enrolled in Insight into Nephrotic Syndrome: Investigating Genes, Health, and Therapeutics. We included children with nephrotic syndrome diagnosed between 1996-2019 from the Greater Toronto Area, Canada, excluding congenital or secondary nephrotic syndrome. Primary outcomes were obesity (body mass index Z-score ≥  + 2) and short stature (height Z-score ≤ -2). We evaluated prevalence of obesity and short stature at enrolment (< 1-year from diagnosis) and incidence during follow-up. Cox proportional hazards models determined the association between nephrotic syndrome classification and new-onset obesity and short stature.

RESULTS

We included 531 children with nephrotic syndrome (30% frequently relapsing by 1-year). At enrolment, obesity prevalence was 23.5%, 51.8% were overweight, and 4.9% had short stature. Cumulative incidence of new-onset obesity and short stature over median 4.1-year follow-up was 17.7% and 3.3% respectively. Children with frequently relapsing or steroid dependent nephrotic syndrome within 1-year of diagnosis were at increased risk of new-onset short stature (unadjusted hazard ratio 3.99, 95%CI 1.26-12.62) but not obesity (adjusted hazard ratio 1.56, 95%CI 0.95-2.56). Children with ≥ 7 and ≥ 15 total relapses were more likely to develop obesity and short stature, respectively.

CONCLUSIONS

Obesity is common among children with nephrotic syndrome early after diagnosis. Although short stature was uncommon overall, children with frequently relapsing or steroid dependent disease are at increased risk of developing short stature. Effective relapse prevention may reduce steroid toxicity and the risk of developing obesity or short stature.

The efficacy and safety of rituximab with or without glucocorticoid in inducing remission of MCD with different clinical presentations in adults: a retrospective study

Background

To investigate the efficacy and safety of rituximab (RTX) with or without glucocorticoid (GC) in inducing remission of minimal change disease (MCD) in adults.

Methods

Twenty-one adult MCD patients were included in the study. The patients were assigned to the following three groups according to their background before RTX treatment: an RTX single drug direct induction treatment group (Group A; n = 9), a short-term, low-dose GC combined with RTX induction treatment group (Group B; n = 4), and a short-term, adequate-dose GC-induced remission and RTX maintenance treatment group (Group C; n = 8). The primary endpoints were the time to induction of remission and the rate of clinical remission at 12 months.

Results

All patients achieved clinical remission, with 19 (90.48%) achieving complete remission (CR), and the median remission time was 4 (2.5, 12) weeks. Eight (88.89%) patients in Group A achieved CR, and the median remission time was 3 (2.25, 14) weeks. In Group B, three (75.00%) patients achieved CR, with a median remission time of 4 (4, 10) weeks. In Group C, eight (100.00%) patients achieved CR, and the median remission time was 3.5 (2, 4) weeks.

Conclusions

In MCD patients without acute kidney injury, adequate RTX alone or short-term combined treatment with low-dose GCs can effectively induce and maintain MCD remission. Adequate short-term GCs combined with RTX maintenance may be an effective alternative for MCD patients in context of acute kidney injury. There is a need to investigate different induction therapy regimens for the remission of MCD patients with different backgrounds.

Do patients with nephrotic syndrome have an increased risk of osteoporosis? A nationwide population-based retrospective cohort study in Taiwan

OBJECTIVES

To evaluate whether nephrotic syndrome (NS) and further corticosteroid (CS) use increase the risk of osteoporosis in Asian population during the period January 2000-December 2010.

DESIGN

Nationwide population-based retrospective cohort study.

SETTING

All healthcare facilities in Taiwan.

PARTICIPANTS

A total of 28 772 individuals were enrolled.

INTERVENTIONS

26 614 individuals with newly diagnosed NS between 2000 and 2010 were identified and included in out study. 26 614 individuals with no NS diagnosis prior to the index date were age matched as controls. Diagnosis of osteoporosis prior to the diagnosis of NS or the same index date was identified, age, sex and NS-associated comorbidities were adjusted.

PRIMARY OUTCOME MEASURE

To identify risk differences in developing osteoporosis among patients with a medical history of NS.

RESULTS

After adjusting for covariates, osteoporosis risk was found to be 3.279 times greater in the NS cohort than in the non-NS cohort, when measured over 11 years after NS diagnosis. Stratification revealed that age older than 18 years, congestive heart failure, hyperlipidaemia, chronic kidney disease, liver cirrhosis and NS-related disease including diabetes mellitus, hepatitis B infection, hepatitis C infection, lymphoma and hypothyroidism, increased the risk of osteoporosis in the NS cohort, compared with the non-NS cohort. Additionally, osteoporosis risk was significantly higher in NS patients with CS use (adjusted HR (aHR)=3.397). The risk of osteoporosis in NS patients was positively associated with risk of hip and vertebral fracture (aHR=2.130 and 2.268, respectively). A significant association exists between NS and subsequent risk for osteoporosis.

CONCLUSION

NS patients, particularly those treated with CS, should be evaluated for subsequent risk of osteoporosis.

Retrospective Cross-Sectional Study Reviewing the Effectiveness of Mycophenolate Mofetil on Saudi Children With Nephrotic Syndrome

Background Idiopathic nephrotic syndrome (INS) is the most common form of nephrotic syndrome (NS) in children. It is often associated with minimal change disease (MCD). Corticosteroid therapy is the initial treatment, but many patients experience relapses, leading to steroid-dependent nephrotic syndrome (SDNS) or frequently relapsing steroid-sensitive nephrotic syndrome (FR-SSNS). To avoid prolonged steroid use, mycophenolate mofetil (MMF) is used as an immunosuppressive alternative. MMF is safe and effective for treating SDNS and FR-SSNS in children, with studies showing reduced relapse rates. The current study aims to evaluate MMF's effectiveness and safety in Saudi children with NS and identify factors that affect its efficacy. Methods A retrospective cross-sectional study was conducted at King Abdullah Specialized Children's Hospital (KASCH) in Riyadh, Saudi Arabia. The study included children aged one to 14 years diagnosed with NS who received MMF therapy. Data were collected from medical records from 2000 to 2020. Ethical considerations were followed, and statistical analysis was performed using IBM SPSS Statistics for Windows, version 25 (released 2017; IBM Corp., Armonk, New York, United States). Baseline characteristics and responsiveness to MMF were examined. Results In our study, 45 participants (25 males, 20 females) with NS were treated with MMF. Most participants were steroid-dependent (84.44%) and had frequent relapses. MMF was effective in 84.4% of cases, with a significant reduction in relapse; the mean number of relapses decreased from 3.5 before MMF to 1.6 after MMF (p-value = 0.00002). Moreover, 40% of the participants were completely free of relapse after the introduction of MMF. The average duration of the MMF therapy was 45 months. Post-MMF side effects were rare but documented. Gastrointestinal symptoms were extremely rare. Elevated liver enzyme levels were reported in 8.88% (four cases) of the participants. Leukopenia, a more common adverse effect, was reported in 26.66% of cases during the MMF therapy. The average daily dose of steroid was reduced from 12.5 mg/day pre MMF to 2 mg/day post MMF with a p-value of 0.00229. Conclusion Our study evaluated the use of MMF in 45 participants with NS. We found that MMF was effective in 84.4% of cases, leading to a significant reduction in the number of relapses. Post-MMF side effects were relatively rare, except for leukopenia that was reported in 26.66%. In addition, the average rate of reduction of steroid exposure before and after MMF was significant. These findings suggest that MMF is a promising treatment option for children with NS and an alternative therapy to long-term steroid use, due to its safety and effectiveness, although close monitoring for potential side effects is essential.

Multi-population genome-wide association study implicates immune and non-immune factors in pediatric steroid-sensitive nephrotic syndrome

Pediatric steroid-sensitive nephrotic syndrome (pSSNS) is the most common childhood glomerular disease. Previous genome-wide association studies (GWAS) identified a risk locus in the HLA Class II region and three additional independent risk loci. But the genetic architecture of pSSNS, and its genetically driven pathobiology, is largely unknown. Here, we conduct a multi-population GWAS meta-analysis in 38,463 participants (2440 cases). We then conduct conditional analyses and population specific GWAS. We discover twelve significant associations-eight from the multi-population meta-analysis (four novel), two from the multi-population conditional analysis (one novel), and two additional novel loci from the European meta-analysis. Fine-mapping implicates specific amino acid haplotypes in HLA-DQA1 and HLA-DQB1 driving the HLA Class II risk locus. Non-HLA loci colocalize with eQTLs of monocytes and numerous T-cell subsets in independent datasets. Colocalization with kidney eQTLs is lacking but overlap with kidney cell open chromatin suggests an uncharacterized disease mechanism in kidney cells. A polygenic risk score (PRS) associates with earlier disease onset. Altogether, these discoveries expand our knowledge of pSSNS genetic architecture across populations and provide cell-specific insights into its molecular drivers. Evaluating these associations in additional cohorts will refine our understanding of population specificity, heterogeneity, and clinical and molecular associations.

T-cell receptor diversity in minimal change disease in the NEPTUNE study

BACKGROUND

Minimal change disease (MCD) is the major cause of childhood idiopathic nephrotic syndrome, which is characterized by massive proteinuria and debilitating edema. Proteinuria in MCD is typically rapidly reversible with corticosteroid therapy, but relapses are common, and children often have many adverse events from the repeated courses of immunosuppressive therapy. The pathobiology of MCD remains poorly understood. Prior clinical observations suggest that abnormal T-cell function may play a central role in MCD pathogenesis. Based on these observations, we hypothesized that T-cell responses to specific exposures or antigens lead to a clonal expansion of T-cell subsets, a restriction in the T-cell repertoire, and an elaboration of specific circulating factors that trigger disease onset and relapses.

METHODS

To test these hypotheses, we sequenced T-cell receptors in fourteen MCD, four focal segmental glomerulosclerosis (FSGS), and four membranous nephropathy (MN) patients with clinical data and blood samples drawn during active disease and during remission collected by the Nephrotic Syndrome Study Network (NEPTUNE). We calculated several T-cell receptor diversity metrics to assess possible differences between active disease and remission states in paired samples.

RESULTS

Median productive clonality did not differ between MCD active disease (0.0083; range: 0.0042, 0.0397) and remission (0.0088; range: 0.0038, 0.0369). We did not identify dominant clonotypes in MCD active disease, and few clonotypes were shared with FSGS and MN patients.

CONCLUSIONS

While these data do not support an obvious role of the adaptive immune system T-cells in MCD pathogenesis, further study is warranted given the limited sample size. A higher resolution version of the Graphical abstract is available as Supplementary information.

Vitamin D supplementation in children and young adults with persistent proteinuria secondary to glomerular disease

BACKGROUND

Vitamin D deficiency is common in glomerular disease. Supplementation may be ineffective due to ongoing urinary losses of vitamin D binding protein. We sought to determine if daily cholecalciferol supplementation would increase vitamin D concentrations in children with glomerular disease and persistent proteinuria, without adverse effects.

METHODS

Eighteen participants at least 5 years of age with primary glomerular disease and urine protein:creatinine ratio ≥ 0.5 were enrolled from four pediatric nephrology practices to receive cholecalciferol supplementation: 4,000 IU or 2,000 IU per day for serum 25 hydroxyvitamin vitamin D (25OHD) concentrations < 20 ng/mL and 20 ng/mL to < 30 ng/mL, respectively. Measures of vitamin D and mineral metabolism were obtained at baseline and weeks 6 and 12. Multivariable generalized estimating equation (GEE) regression estimated mean percent changes in serum 25OHD concentration.

RESULTS

Median baseline 25OHD was 12.8 ng/mL (IQR 9.3, 18.9) and increased to 27.8 ng/mL (20.5, 36.0) at week 6 (p < 0.001) without further significant increase at week 12. A total of 31% of participants had a level ≥ 30 ng/mL at week 12. Supplementation was stopped in two participants at week 6 for mildly elevated calcium and phosphorus, respectively, with subsequent declines in 25OHD of > 20 ng/mL. In the adjusted GEE model, 25OHD was 102% (95% CI: 64, 141) and 96% (95% CI: 51, 140) higher versus baseline at weeks 6 and 12, respectively (p < 0.001).

CONCLUSION

Cholecalciferol supplementation in vitamin D deficient children with glomerular disease and persistent proteinuria safely increases 25OHD concentration. Ideal dosing to fully replete 25OHD concentrations in this population remains unknown.

CLINICAL TRIAL

NCT01835639. A higher resolution version of the Graphical abstract is available as Supplementary information.

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

Idiopathic nephrotic syndrome is the most frequent pediatric glomerular disease, affecting from 1.15 to 16.9 per 100,000 children per year globally. It is characterized by massive proteinuria, hypoalbuminemia, and/or concomitant edema. Approximately 85-90% of patients attain complete remission of proteinuria within 4-6 weeks of treatment with glucocorticoids, and therefore, have steroid-sensitive nephrotic syndrome (SSNS). Among those patients who are steroid sensitive, 70-80% will have at least one relapse during follow-up, and up to 50% of these patients will experience frequent relapses or become dependent on glucocorticoids to maintain remission. The dose and duration of steroid treatment to prolong time between relapses remains a subject of much debate, and patients continue to experience a high prevalence of steroid-related morbidity. Various steroid-sparing immunosuppressive drugs have been used in clinical practice; however, there is marked practice variation in the selection of these drugs and timing of their introduction during the course of the disease. Therefore, international evidence-based clinical practice recommendations (CPRs) are needed to guide clinical practice and reduce practice variation. The International Pediatric Nephrology Association (IPNA) convened a team of experts including pediatric nephrologists, an adult nephrologist, and a patient representative to develop comprehensive CPRs on the diagnosis and management of SSNS in children. After performing a systematic literature review on 12 clinically relevant PICO (Patient or Population covered, Intervention, Comparator, Outcome) questions, recommendations were formulated and formally graded at several virtual consensus meetings. New definitions for treatment outcomes to help guide change of therapy and recommendations for important research questions are given.

Skeletal Outcomes in Children and Young Adults with Glomerular Disease

BACKGROUND

Children with glomerular disease have unique risk factors for compromised bone health. Studies addressing skeletal complications in this population are lacking.

METHODS

This retrospective cohort study utilized data from PEDSnet, a national network of pediatric health systems with standardized electronic health record data for more than 6.5 million patients from 2009 to 2021. Incidence rates (per 10,000 person-years) of fracture, slipped capital femoral epiphysis (SCFE), and avascular necrosis/osteonecrosis (AVN) in 4598 children and young adults with glomerular disease were compared with those among 553,624 general pediatric patients using Poisson regression analysis. The glomerular disease cohort was identified using a published computable phenotype. Inclusion criteria for the general pediatric cohort were two or more primary care visits 1 year or more apart between 1 and 21 years of age, one visit or more every 18 months if followed >3 years, and no chronic progressive conditions defined by the Pediatric Medical Complexity Algorithm. Fracture, SCFE, and AVN were identified using SNOMED-CT diagnosis codes; fracture required an associated x-ray or splinting/casting procedure within 48 hours.

RESULTS

We found a higher risk of fracture for the glomerular disease cohort compared with the general pediatric cohort in girls only (incidence rate ratio [IRR], 1.6; 95% CI, 1.3 to 1.9). Hip/femur and vertebral fracture risk were increased in the glomerular disease cohort: adjusted IRR was 2.2 (95% CI, 1.3 to 3.7) and 5 (95% CI, 3.2 to 7.6), respectively. For SCFE, the adjusted IRR was 3.4 (95% CI, 1.9 to 5.9). For AVN, the adjusted IRR was 56.2 (95% CI, 40.7 to 77.5).

CONCLUSIONS

Children and young adults with glomerular disease have significantly higher burden of skeletal complications than the general pediatric population.

A Clinical Response-Adjusted Steroid Treatment Protocol for Children With Newly Diagnosed Idiopathic Nephrotic Syndrome

RATIONALE & OBJECTIVE

Prednisone protocols for children with idiopathic nephrotic syndrome (INS) are generally similar in dose and duration, despite wide variations in time to response. We assessed the feasibility of a novel clinical treatment protocol characterized by a shorter duration and lower cumulative dose for children with early clinical response.

STUDY DESIGN

Nonrandomized pilot clinical trial.

SETTING & PARTICIPANTS

The study population included 59 children with newly diagnosed INS treated between 2014 and 2019 who responded to treatment within 8 days.

INTERVENTION

The intervention group (n = 27) was treated with a response-adjusted protocol during which responders received an 8-week course of tapering doses of prednisone. The usual care group (n =32) was treated with the standard protocol (prednisone, 60 mg/m²/24 hours for 6 weeks, followed by 40 mg/m²/48 hours for 4 weeks, followed by a slow taper for a total of 24 weeks).

OUTCOME

Consent rate, cumulative prednisone dose, the development of frequently relapsing or steroid-dependent nephrotic syndrome (FRNS or SDNS, respectively), relapses per year, treatment with steroid-sparing therapies, and adverse effects of steroid therapy over 3 years of follow-up observation.

RESULTS

The consent rate was 88%. The mean cumulative steroid dose for the initial treatment was 70 mg/kg and 141 mg/kg (P < 0.001) in the intervention and usual care groups, respectively. None of the patients in the intervention group relapsed while on faster steroid taper down. The occurrence of FRNS and SDNS in the intervention group was not statistically different than in the usual care group, hazard ratios were 0.80 (95% CI, 0.37-1.73) and 0.61 (95% CI, 0.30-1.27), respectively. The proportions of relapse-free patients were similar (P = 0.5), and adverse steroid events did not differ between the groups.

LIMITATIONS

Lack of randomization and small sample size.

CONCLUSIONS

These findings demonstrate the feasibility of a shortened duration of steroid dosing for INS when patients demonstrate an initial clinical response to treatment. A larger study is needed to characterize the relative efficacy and toxicity of this novel treatment regimen.

FUNDING

This study received no funding.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCTO2649413.

Benign and malignant proliferation in idiopathic nephrotic syndrome: a French cohort study

BACKGROUND

There seems to be a possible link between nephrotic syndrome (NS) and lymphoproliferative syndrome, but it remains poorly understood.

METHODS

This multicentric and retrospective study focuses on children, who developed idiopathic NS and malignant or benign proliferation between 2000 and 2021.

RESULTS

Eleven patients were included, with a median age of 4 years. Only one had a steroid-resistant nephrotic syndrome (SRNS). The maintenance therapy before the proliferation was in majority tacrolimus or mycophenolate mofetil (MMF), but three patients did not receive treatments. The proliferation was mainly a Hodgkin's lymphoma (45%) or a lymphoproliferative disease (36%), in a median time after the NS of two years. Viruses were found in seven cases (EBV in five cases and HHV-8 in two).

CONCLUSION

The association between proliferative syndrome and idiopathic NS may not be fortuitous, possibly with a common lymphocytic disturbance. Genetic analyses could improve the comprehension of these manifestations in the future. A higher resolution version of the Graphical abstract is available as Supplementary information.

Rituximab May Have Positive Effect on Refractory Nephrotic Syndrome: A Meta-Analysis of Randomized Trials

Purpose

This study was aimed at demonstrating the role of rituximab (RTX) on the influence of nephrotic syndrome (NS) and on urinary protein which was not significant.

Methods

The clinical randomized controlled trials were performed by eight databases. Meanwhile, the confidence interval (CI) of either relative risk or mean difference was set to 95%. Besides, the heterogeneity of the research results is tested by I 2.

Results

A total of 1658 references were found using the search method. This meta-analysis will be done by the ultimately eight different studies. Each study is described as random controlled trial. According to these eight studies, the remission of test group and control group was quite higher (OR: 1.60; 95% Cl: 1.17, 2.20; P < 0.01) than the control group, serum albumin (SMD: 4.19; 95% Cl: 1.49, 6.89; P < 0.01), and urine protein (SMD: 0.79; 95% Cl: -0.64, 2.22; P = 0.28). Despite the fact that the remission rate's funnel plot was asymmetrically distributed, Egger's test and Begg's test revealed no probable publish bias.

Conclusion

The results of this study suggest that rituximab (RTX) may be effective in RNS, as evidenced by remission rates and serum albumin. However, the effect on urinary protein was not significant. The clear evidence is missing in this literature. Therefore, large sample, multicenter, low risk of bias clinical studies, as well as basic medical research, is needed.

Optimizing the corticosteroid dose in steroid-sensitive nephrotic syndrome

The use of corticosteroids in the treatment of steroid-sensitive nephrotic (SSNS) syndrome in children has evolved surprisingly slowly since the ISKDC consensus over 50 years ago. From a move towards longer courses of corticosteroid to treat the first episode in the 1990s and 2000s, more recent large, well-designed randomized controlled trials (RCTs) have unequivocally shown no benefit from an extended course, although doubt remains whether this applies across all age groups. With regard to prevention of relapses, daily ultra-low-dose prednisolone has recently been shown to be more effective than low-dose alternate-day prednisolone. Daily low-dose prednisolone for a week at the time of acute viral infection seems to be effective in the prevention of relapses but the results of a larger RCT are awaited. Recently, corticosteroid dosing to treat relapses has been questioned, with data suggesting lower doses may be as effective. The need for large RCTs to address the question of whether corticosteroid doses can be reduced was the conclusion of the authors of the recent corticosteroid therapy for nephrotic syndrome in children Cochrane update. This review summarizes development in thinking on corticosteroid use in SSNS and makes suggestions for areas that merit further scrutiny.

Duration of initial prednisolone therapy for first episode of childhood nephrotic syndrome based on time to response

BACKGROUND

The duration of initial corticosteroid therapy in newly diagnosed Idiopathic nephrotic syndrome (INS) is about 3 months. Our study was designed to test the feasibility of a shorter duration of corticosteroid therapy in newly diagnosed INS who show a quicker response.

METHODS

Patients who responded within 10 days (Group A) received 8 weeks of corticosteroid therapy as compared to 12-14 weeks of standard therapy in those who responded between >10 days to 28 days (Group B), and follow up for 52 weeks. The primary endpoint is time to first relapse after treatment completion. (NCT03878914, March 18, 2019).

RESULTS

A total of 33 children with INS were enrolled and the follow-up data were analyzed. The clinical and laboratory characteristics of patients in both groups were similar. No significant difference was found in time to first relapse [65(14.5, 159) days for Group A vs. 28(17, 61.5) days for Group B, P = 0.371], the incidence of frequently relapsing nephrotic syndrome [6/18 (33.3%) vs. 5/10(50%), P = 0.644] or requirement for alternative immunosuppressant [4/18 (22.2%) vs. 1/10 (10%), P = 0.769]. Group A received similar corticosteroid dose compare with Group B (3511 ± 2421 mg/m² vs. 4117 ± 2556 mg/m², P = 0.524). Frequency and severity of corticosteroid-related complications was similar in both groups.

CONCLUSIONS

The time to first relapse and the number of relapses per patient were comparable between the two groups. However, more patients in Group A relapsed and the mean total dose of prednisolone for the study period was very similar between the two groups.

Population-based identification and temporal trend of children with primary nephrotic syndrome: The Kaiser Permanente nephrotic syndrome study

INTRODUCTION

Limited population-based data exist about children with primary nephrotic syndrome (NS).

METHODS

We identified a cohort of children with primary NS receiving care in Kaiser Permanente Northern California, an integrated healthcare delivery system caring for >750,000 children. We identified all children <18 years between 1996 and 2012 who had nephrotic range proteinuria (urine ACR>3500 mg/g, urine PCR>3.5 mg/mg, 24-hour urine protein>3500 mg or urine dipstick>300 mg/dL) in laboratory databases or a diagnosis of NS in electronic health records. Nephrologists reviewed health records for clinical presentation and laboratory and biopsy results to confirm primary NS.

RESULTS

Among 365 cases of confirmed NS, 179 had confirmed primary NS attributed to presumed minimal change disease (MCD) (72%), focal segmental glomerulosclerosis (FSGS) (23%) or membranous nephropathy (MN) (5%). The overall incidence of primary NS was 1.47 (95% Confidence Interval:1.27-1.70) per 100,000 person-years. Biopsy data were available in 40% of cases. Median age for patients with primary NS was 6.9 (interquartile range:3.7 to 12.9) years, 43% were female and 26% were white, 13% black, 17% Asian/Pacific Islander, and 32% Hispanic.

CONCLUSION

This population-based identification of children with primary NS leveraging electronic health records can provide a unique approach and platform for describing the natural history of NS and identifying determinants of outcomes in children with primary NS.

Human or Chimeric Monoclonal Anti-CD20 Antibodies for Children with Nephrotic Syndrome: A Superiority Randomized Trial

BACKGROUND

The chimeric anti-CD20 monoclonal antibody rituximab is effective in steroid-dependent and calcineurin inhibitor-dependent forms of nephrotic syndrome, but many patients relapse at 1 year. Because ofatumumab, a fully human anti-CD20 monoclonal antibody, has a more extended binding site and higher affinity to CD20 compared with rituximab, it might offer superior efficacy in these patients.

METHODS

We designed a single-center randomized clinical trial to compare the long-term efficacy of ofatumumab versus rituximab in children and young adults with nephrotic syndrome maintained in remission with prednisone and calcineurin inhibitors. We randomized 140 children and young adults (aged 2-24 years) to receive intravenous ofatumumab (1.50 mg/1.73 m²) or rituximab (375 mg/m²). After infusions, oral drugs were tapered and withdrawn within 60 days. The primary outcome was relapse at 1 year, which was analyzed following the intent-to-treat principle. The secondary endpoint was relapse within 24 months from infusion, on the basis of urine dipstick and confirmed by a urine protein-to-creatinine ratio <200.

RESULTS

At 12 months, 37 of 70 (53%) participants who received ofatumumab experienced relapse versus 36 of 70 (51%) who received rituximab (odds ratio [OR], 1.06; 95% confidence interval [95% CI], 0.55 to 2.06). At 24 months, 53 of 70 (76%) participants who received ofatumumab experienced relapse, versus 46 of 70 (66%) who received rituximab (OR, 1.6; 95% CI, 0.8 to 3.3). The two groups exhibited comparable B cell subpopulation reconstitution and did not differ in adverse events.

CONCLUSIONS

A single dose of ofatumumab was not superior to a single dose of rituximab in maintaining remission in children with steroid-dependent and calcineurin inhibitor-dependent nephrotic syndrome.

CLINICAL TRIAL REGISTRATION NUMBERS

ClinicalTrials.gov (NCT02394119) and https://www.clinicaltrialsregister.eu/ctr-search/search (2015-000624-28).

Steroid Minimization in Adults with Minimal Change Disease

Background

Minimal change disease (MCD) causes approximately 10% of nephrotic syndrome in adults. While glucocorticoids (GCs) effectively induce remission in MCD, the disease has a high relapse rate (50-75%), and repeated exposure to GCs is often required. The adverse effects of GCs are well recognized and commonly encountered with the high doses and recurrent courses used in MCD.

Summary

In this review, we will discuss the standard therapy of MCD in adults and then describe new therapeutic options in induction therapy and treatment of relapses in MCD, minimizing the exposure to GCs.

Key Messages

Steroid minimization strategies may decrease adverse effects in the treatment of MCD.

Long-term health-related quality of life outcomes of adults with pediatric onset of frequently relapsing or steroid-dependent nephrotic syndrome

BACKGROUND

Long-term psychosocial outcomes and health-related quality of life (HRQOL) in adults with pediatric onset of frequently relapsing or steroid-dependent idiopathic nephrotic syndrome (FRNS or SDNS) remain to be determined.

METHODS

In this prospective cohort study, 59 adults with pediatric onset of FRNS/SDNS and persistent active glomerular disease in adulthood completed the GEDEPAC-2 questionnaire exploring 11 well-being domains. Data were compared to the French general population (FGP) with standardized incidence ratio ([SIR]; adjusted for period, age, gender). Regression models were performed to identify predictive factors of psychosocial well-being.

RESULTS

In 82% of cases, the questionnaire was completed while the participants (n = 59; 47 men; median age = 32 years; median number of relapses = 13) were in complete remission (under specific therapy in 76% of cases). Participants had higher educational degree than in the FGP (SIR = 6.3; p < 0.01) and more frequently a managerial occupation (SIR = 3.1; p < 0.01). Social integration was acceptable with regard to marital status and experience of sexual intercourse, but experiences of discrimination were far more frequent (SIR = 12.5; p < 0.01). The SF-12 mental component summary (MCS) score was altered (Z-score = - 0.6; p < 0.01) and mean multidimensional fatigue inventory (MFI-20) global fatigue score appeared high (12). Transfer from pediatric to adult healthcare was followed by a period of discontinued care for 33% of participants. Multivariate analysis revealed a close relationship between MFI-20, physical health, and MCS.

CONCLUSIONS

This study shows that pediatric onset FRNS and SDNS may have a long-term negative impact on mental HRQOL and highlights the impact of fatigue, which is often not adequately considered in routine care.

Adult survivors of idiopathic childhood onset nephrotic syndrome

Like many pediatric chronic health conditions, idiopathic childhood onset nephrotic syndrome (iCONS) and late effects of iCONS medical management may continue to impact the affected population in adulthood. Approximately 15% of adult survivors of steroid-sensitive iCONS continue to relapse. Long-term kidney health is associated with steroid response patterns as well as pathology findings of FSGS, tubulointerstitial fibrosis, tubular atrophy, and global glomerulosclerosis. Long-term cardiovascular disease burden is largely unknown in adult survivors, but risk factors starting in childhood, including hypertension, dyslipidemia, and obesity, are common in iCONS. Reproductive health concerns, including azo-/oligospermia and successful pregnancies, are largely related to prior exposure to cytotoxic therapies. Additional investigations are needed to complete the assessment and initiate the mitigation of the late effects of treatment-sensitive and treatment-resistant iCONS.

Consolidation Treatment and Long-Term Prognosis of Rituximab in Minimal Change Disease and Focal Segmental Glomerular Sclerosis

Purpose

There is currently a lack of studies investigating long-term prognosis and the necessity of further rituximab (RTX) consolidation treatment for minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS). The aim of this study was to evaluate the efficacy of RTX for these diseases and to investigate whether a consolidation treatment can lower risks of relapse and reinforce long-term remission.

Patients and Methods

A retrospective study was conducted. The relapse and remission of 70 patients treated with 1 course of RTX treatment (4 infusions of 375 mg/m2) over a median follow-up time of 27 months (12–60 months) were analyzed. The rates of patients that were able to achieve non-relapse for a duration of 24 months between RTX consolidation therapy and non-consolidation therapy were compared.

Results

There were 67 cases (95.71%) of remission and 3 cases (4.29%) of non-remission. The average number of relapses decreased from 3.7±2.5 times before the treatment to 0.8±1.8 times after treatment (P <0.001). The average avannual number of relapses decreased from 1.3±1.2 times/year to 0.2±0.3 times/year (P <0.001). The results from the Cox proportional-hazards model showed that the risk of relapse in patients who received RTX non-consolidation treatment was significantly higher than those with consolidation treatment (odds ratios (OR) 20.9, 95% confidence intervals (CI) OR 5.7–75.7, p<0.001). The 24-month relapse-free rate was also significantly higher in patients with consolidation therapy compared with non-consolidation therapy (86.36% vs 25%, p<0.001). No adverse events were recorded.

Conclusion

RTX is highly effective in treating MCD and FSGS, and RTX consolidation therapy may be recommended to reinforce long-term remissions.

A systematic overview of the spermatotoxic and genotoxic effects of methotrexate, ganciclovir and mycophenolate mofetil

INTRODUCTION

Immunosuppressant drugs are increasingly being used in the reproductive years. Theoretically, such medications could affect fetal health either through changes in the sperm DNA or through fetal exposure caused by a presence in the seminal fluid. This systematic overview summarizes existing literature on the spermatotoxic and genotoxic potentials of methotrexate (MTX), a drug widely used to treat rheumatic and dermatologic diseases, and mycophenolate mofetil (MMF), which alone or supplemented with ganciclovir (GCV) may be crucial for the survival of organ transplants.

MATERIAL AND METHODS

The systematic overview was performed in accordance with the PRISMA guidelines: A systematic literature search of the MEDLINE and Embase databases was done using a combination of relevant terms to search for studies on spermatotoxic or genotoxic changes related to treatment with MTX, GCV or MMF. The search was restricted to English language literature, and to in vivo animal studies (mammalian species) and clinical human studies.

RESULTS

A total of 102 studies were identified, hereof 25 human and 77 animal studies. For MTX, human studies of immunosuppressive dosages show transient effect on sperm quality parameters, which return to reference values within 3 months. No human studies have investigated the sperm DNA damaging effect of MTX, but in other organs the genotoxic effects of immunosuppressive doses of MTX are fluctuating. In animals, immunosuppressive and cytotoxic doses of MTX adversely affect sperm quality parameters and show widespread genotoxic damages in various organs. Cytotoxic doses transiently change the DNA material in all cell stages of spermatogenesis in rodents. For GCV and MMF, data are limited and the results are indeterminate, for which reason spermatotoxic and genotoxic potentials cannot be excluded.

CONCLUSIONS

Data from human and animal studies indicate transient spermatotoxic and genotoxic potentials of immunosuppressive and cytotoxic doses of MTX. There are a limited number of studies investigating GCV and MMF.

Prevalence and predictors of ocular complications among children undergoing nephrotic syndrome treatment in a resource-limited setting

Background

Nephrotic syndrome is the most common glomerulopathy among children aged 2–18 years and high dose corticosteroids are the backbone of its management. Potentially blinding ocular complications often result from nephrotic syndrome and/or its treatment. We conducted a study to determine the prevalence and predictors of ocular complications among children undergoing nephrotic syndrome treatment at Mulago National Referral Hospital.

Methods

This was a cross-sectional study conducted for three [3] months at the pediatric renal unit of Mulago National Referral Hospital (MNRH). Data from a consecutive sample of 100 children was collected using a semi-structured questionnaire, entered into Epi-data 4.4.2 and exported to STATA 14 for analysis at univariate, bivariate and multivariate levels. A robust Poisson regression model was used to identify predictors of ocular complications.

Results

Out of 100 patients examined, 80(80%) had ocular complications. The median age was 10 (IQR: 7–12) and 52 (52%) were girls. The most frequent complications were hypertrichosis and refractive errors in 71% (95%CI 61.1–79.6) and 56% (95%CI 45.7–65.9) of the patients respectively. Age above 10 years was the predictor for ocular complications with a RR = 1.37 (95%CI:1.14–1.64) p = 0.001.

Conclusions

We found a high prevalence of ocular complications among children with nephrotic syndrome in this tertiary hospital. The predictor of ocular complications was age greater than 10 years. We recommend that all children with nephrotic syndrome undergo a baseline ocular examination prior to commencement of treatment and be reviewed periodically by an ophthalmologist.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01817-6.

Effects of Chlorine Gas Exposure and Associated Factors on Spirometric Parameters in Detergent Industry Workers: a Four-Year Cross-Sectional Study

BACKGROUND

This study aimed to determine the effects of chlorine gas exposure and the associated factors on spirometric parameters among detergent industry workers in Semnan, Iran.

MATERIALS AND METHODS

This four-year cross-sectional study was concocted on 100 workers of two detergent factories in Semnan, Iran. Two questionnaires were used for data collection. The first questionnaire included demographic and occupational information, and the second questionnaire included spirometric parameters, such as forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC ratio, peak expiratory flow (PEF), and PEF 25-75%. The spirometric parameters were measured over four consecutive years by a trained technician. Next, to determine the effects of chlorine gas exposure and its associated factors on spirometric parameters, a generalized estimating equation (GEE) model was used. The correlation structure of GEE was considered to be autoregressive 1 (AR-1). Analyses were performed in STATA version 14.

RESULTS

All spirometric parameters showed a decreasing trend during 2012-2015. The GEE model showed a significant association between chlorine gas exposure and all spirometric parameters; the beta-coefficients for the effect of exposure (year) on FVC, FEV1, FEV1/FVC ratio, PEF, and PEF 25-75% were -4.51, -6.46, -4.27, -6.09, and -10.29, respectively. Also, this model demonstrated a significant association between smoking and FEV1, PEF, and PEF 25-75%; the beta-coefficients for the effect of smoking on these parameters were -5.64, -8.88, and -5.75, respectively. Additionally, the GGE model showed a significant association between the body mass index (BMI) and FVC and FEV1 (P<0.05); the beta-coefficients for the effect of BMI on these two parameters were - 0.59 and -0.48, respectively.

CONCLUSION

The spirometric parameters showed a decreasing trend over time among detergent industry workers; this decline was more remarkable among individuals with a history of smoking. Therefore, it seems necessary to implement screening programs and periodic active examinations for these workers.

Biopsy or Biomarker? Children With Minimal Change Disease Have a Distinct Profile of Urinary Epidermal Growth Factor

Background: In this study, the profile of urinary EGF excretion (uEGF/uCreat) was mapped in children presenting with prolonged proteinuria or with nephrotic syndrome refractory to or dependent of steroids. We investigated whether uEGF/uCreat could be linked to the underlying biopsy result, taking into account its response to immunosuppressive medication and to ACE inhibition, as well as genetic predisposition. Methods: Ninety-eight pediatric patients with initial presentation of nephrotic syndrome or prolonged proteinuria were included in this study, along with 49 healthy controls and 20 pediatric Alport patients. All patients had a normal kidney function and were normotensive during the course of the study, whether or not under ACE inhibition. In repeated urine samples, uEGF was measured and concentration was normalized by urine creatinine. In order to compare diagnosis on kidney biopsy, genetic predisposition and response of uEGF/uCreat to immunosuppression and to ACE inhibition, uEGF/uCreat is studied in a linear mixed effects model. Results: Patients with Minimal Change Disease (MCD) showed a significantly different profile of uEGF/uCreat in comparison to healthy children, as well as compared to patients with Focal Segmental Glomerulosclerosis (FSGS) or another glomerulopathy on kidney biopsy. The response of uEGF/uCreat to ACE inhibition was absent in minimal change disease and contrasted with an impressive beneficial effect of ACE inhibition on uEGF/uCreat in FSGS and other proteinuric glomerulopathies. Absence of a genetic predisposition was also associated with a significantly lower uEGF/uCreat. Conclusions: Despite preserved kidney function, children with a proteinuric or nephrotic glomerular disease on kidney biopsy show a significantly lower uEGF/uCreat, indicative of early tubulo-interstitial damage, which appears reversible under ACE inhibition in any underlying glomerulopathy except in minimal change disease. In view of the distinct profile of uEGF/uCreat in minimal change disease compared to other glomerulopathies, and the link between genetic predisposition and uEGF/uCreat, our study suggests that uEGF/uCreat can be a helpful tool to decide on the need for a renal biopsy in order to differentiate minimal change disease from other proteinuric glomerular diseases.

Systematic Review and Meta-Analysis of Rituximab for Steroid-Dependent or Frequently Relapsing Nephrotic Syndrome in Children

Objective: To explore the effectiveness and safety of rituximab (RTX) for steroid-dependent or frequently relapsing nephrotic syndrome via a systematic review and meta-analysis. Methods: All the literature about RTX therapy for childhood nephrotic syndrome (NS) on PubMed, Web of Science, Cochrane Library, EMBASE, and Chinese biomedical literature database published before November 1, 2019, were conducted and selected according to the preset criteria. The Cochrane bias risk assessment tool was used to evaluate the quality of the literature included. The outcome data were analyzed by RevMan 5.3 software. Results: There were six RCT studies that met the inclusion criteria with a moderate quality after evaluation. At the end of the treatment, the relapse rate of NS in the RTX group reduced significantly when compared with that in the control group [odds ratio (OR) = 0.11, 95% confidence interval (CI) (0.03, 0.43), p = 0.001]. The number of patients in the RTX group used less steroid or/and calcineurin inhibitors significantly than that in the control group [OR = 0.05, 95% CI (0.01, 0.28), p = 0.0007]. For children who were steroid-dependent, RTX treatment significantly reduced the dosage of the steroid, compared with that in control [standardized mean difference (SMD) = -1.49, 95% CI (-2.00, -0.99), p < 0.00001]. There was no significant reduction in protein excretion between the two groups [SMD = -0.33, 95% CI (-0.71, 0.04), p = 0.08]. Fewer serious adverse reactions of RTX in the six studies were reported and most adverse events were mild. Conclusion: RTX is effective and safe for children with steroid-dependent or frequently relapsing nephrotic syndrome. Systematic Review Registration: Identifier: CRD 42020150933. https://www.crd.york.ac.uk/prospero/. This review has been registered to the PROSPERO on 27 Feb 2020.

Pediatric idiopathic steroid-sensitive nephrotic syndrome: diagnosis and therapy -short version of the updated German best practice guideline (S2e) - AWMF register no. 166-001, 6/2020

Idiopathic nephrotic syndrome is the most frequent glomerular disease in children in most parts of the world. Children with steroid-sensitive nephrotic syndrome (SSNS) generally have a good prognosis regarding the maintenance of normal kidney function even in the case of frequent relapses. The course of SSNS is often complicated by a high rate of relapses and the associated side effects of repeated glucocorticoid (steroid) therapy. The following recommendations for the treatment of SSNS are based on the comprehensive consideration of published evidence by a working group of the German Society for Pediatric Nephrology (GPN) based on the systematic Cochrane reviews on SSNS and the guidelines of the KDIGO working group (Kidney Disease - Improving Global Outcomes).

Time to Relapse and Its Predictors among Children with Nephrotic Syndrome in Comprehensive Specialized Hospitals, Tigray, Ethiopia, 2019

Background

Relapse in children with nephrotic syndrome leads to a variety of complications due to prolonged treatment and potential dependency on steroids. However, there is no study conducted to determine the incidence and predictive factors of relapse for nephrotic syndrome in Ethiopia, especially in children. Thus, this study aimed to assess the incidence of relapse and its predictors among children with nephrotic syndrome in Ethiopia.

Methods

A retrospective study was conducted by reviewing all charts of children with an initial diagnosis of the nephrotic syndrome in tertiary hospitals from 2011 to 2018. Charts of children with a diagnosis of steroid-resistant cases were excluded. The extraction tool was used for data collection, Epi-data manager V-4.4.2 for data entry, and Stata V-14 for cleaning and analysis. Kaplan-Meier curve, log-rank test, life table, and crude hazard ratios were used to describe the data and adjusted hazard ratios with 95% CI and P value for analysis. Median relapse time, incidence rate of relapse, and cumulative relapse probabilities at a certain time interval were computed. Bivariable and multivariate analyses were performed using the Cox proportional hazard regression to identify the factors associated with relapse. Any variable at P < 0.25 in the bivariable analysis was transferred to multivariate analysis. Then, the adjusted hazard ratio with 95% CI and P ≤ 0.05 was used to report the association and to test the statistical significance, respectively. Finally, texts, tables, and graphs were used to present the results. Results and Conclusion. Majority, 64.5% (40/66), of relapses were recorded in the first 12 months of follow-up. The incidence rate of relapse was 42.6 per 1000 child-month-observations with an overall 1454 child-month-observations and the median relapse time of 16 months. Having undernutrition [AHR = 3.44; 95% CI 1.78-6.65], elevated triglyceride [AHR = 3.37; 95% CI 1.04-10.90], decreased serum albumin level [AHR = 3.51; 95% CI 1.81-6.80], and rural residence [AHR = 4.00; 95% CI 1.49-10.76] increased the hazard of relapse. Conclusion and Recommendation. Relapse was higher in the first year of the follow-up period. Undernutrition, hypoalbuminemia, hypertriglyceridemia, and being from rural areas were independent predictors of relapse. A focused evaluation of those predictors during the initial diagnosis of the disease is compulsory.

ACTN4 Mediates SEPT14 Mutation-Induced Sperm Head Defects

Septins (SEPTs) are highly conserved GTP-binding proteins and the fourth component of the cytoskeleton. Polymerized SEPTs participate in the modulation of various cellular processes, such as cytokinesis, cell polarity, and membrane dynamics, through their interactions with microtubules, actin, and other cellular components. The main objective of this study was to dissect the molecular pathological mechanism of SEPT14 mutation-induced sperm head defects. To identify SEPT14 interactors, co-immunoprecipitation (co-IP) and nano-liquid chromatography-mass spectrometry/mass spectrometry were applied. Immunostaining showed that SEPT14 was significantly localized to the manchette structure. The SEPT14 interactors were identified and classified as (1) SEPT-, (2) microtubule-, (3) actin-, and (4) sperm structure-related proteins. One interactor, ACTN4, an actin-holding protein, was selected for further study. Co-IP experiments showed that SEPT14 interacts with ACTN4 in a male germ cell line. SEPT14 also co-localized with ACTN4 in the perinuclear and manchette regions of the sperm head in early elongating spermatids. In the cell model, mutated SEPT14 disturbed the localization pattern of ACTN4. In a clinical aspect, sperm with mutant SEPT14, SEPT14^A123T (p.Ala123Thr), and SEPT14^I333T (p.Ile333Thr), have mislocalized and fragmented ACTN4 signals. Sperm head defects in donors with SEPT14 mutations are caused by disruption of the functions of ACTN4 and actin during sperm head formation.

Podocytopathies

Podocytopathies are kidney diseases in which direct or indirect podocyte injury drives proteinuria or nephrotic syndrome. In children and young adults, genetic variants in >50 podocyte-expressed genes, syndromal non-podocyte-specific genes and phenocopies with other underlying genetic abnormalities cause podocytopathies associated with steroid-resistant nephrotic syndrome or severe proteinuria. A variety of genetic variants likely contribute to disease development. Among genes with non-Mendelian inheritance, variants in APOL1 have the largest effect size. In addition to genetic variants, environmental triggers such as immune-related, infection-related, toxic and haemodynamic factors and obesity are also important causes of podocyte injury and frequently combine to cause various degrees of proteinuria in children and adults. Typical manifestations on kidney biopsy are minimal change lesions and focal segmental glomerulosclerosis lesions. Standard treatment for primary podocytopathies manifesting with focal segmental glomerulosclerosis lesions includes glucocorticoids and other immunosuppressive drugs; individuals not responding with a resolution of proteinuria have a poor renal prognosis. Renin-angiotensin system antagonists help to control proteinuria and slow the progression of fibrosis. Symptomatic management may include the use of diuretics, statins, infection prophylaxis and anticoagulation. This Primer discusses a shift in paradigm from patient stratification based on kidney biopsy findings towards personalized management based on clinical, morphological and genetic data as well as pathophysiological understanding.

Rituximab versus cyclophosphamide as first steroid-sparing agent in childhood frequently relapsing and steroid-dependent nephrotic syndrome

BACKGROUND

Approximately 50% of children with steroid-sensitive nephrotic syndrome (SSNS) will suffer from frequent relapses or steroid dependency, prompting the use of so-called steroid-sparing drugs. In this pilot study, we compare the efficacy and safety of rituximab to oral cyclophosphamide as first-line steroid-sparing medications.

METHODS

A prospective open-label non-randomized study of children with frequent relapsing or steroid-dependant SSNS. Exclusion criteria were steroid-resistant disease, prescription of immunosuppressive agents other than prednisolone or levamisole, evidence of impaired kidney function, leucopenia, or active infection. The recruited children were allocated either to the oral cyclophosphamide (3 mg/kg/day for 8 weeks) or intravenous rituximab treatment (two doses of 375 mg/m²/dose, 2 weeks apart) and were monitored for relapses and side effects for 12 months.

RESULTS

Forty-six subjects were included from two centers; 27 received cyclophosphamide and 19 received rituximab. One-year relapse-free survival was reached in 17 (58.6%) patients treated with cyclophosphamide compared to 16 (84.2%) with rituximab (adjusted HR 0.36; 95% CI 0.09-1.45; p = 0.151). The mean interval to relapse was 6.9 months in the cyclophosphamide group (N = 10) and 6.3 months in the rituximab group (N = 3). Both treatments were associated with a significant (p < 0.001) reduction in prescribed dose of oral alternate-day steroid from 1.02 to 0.36 mg/kg (cyclophosphamide) and 0.86 to 0.08 mg/kg (rituximab). Importantly, a significantly (p = 0.003) higher percentage of patients achieved complete withdrawal of steroid within 3 months of commencing study treatment in the rituximab (73.7%) versus cyclophosphamide (29.6%) group. Transient leucopenia was the most frequent adverse effect observed in the cyclophosphamide group (18.5%) and one patient (3.4%) had acute hepatotoxicity besides severe leucopenia and neutropenia in the 7th week of treatment with complete recovery with the withdrawal of cyclophosphamide and maintenance of remission. A minor infusion-related reaction in the form of a generalized macular skin rash was observed in one patient (5%) in the rituximab group.

CONCLUSIONS

Rituximab is non-inferior to cyclophosphamide and safe as a first-line steroid-sparing agent in children with SSNS. A larger multicenter study is required to assess superiority over cyclophosphamide. Graphical abstract.

Review on long-term non-renal complications of childhood nephrotic syndrome

BACKGROUND

Nephrotic syndrome (NS) is the most common glomerular childhood disease. A body of literature has described the long-term renal prognosis of childhood-onset idiopathic NS. However, the nonrenal outcomes have not been studied as much.

AIM

We aimed to discuss the long-term non-renal outcomes of childhood NS, highlighting studies with a follow-up period of more than 10 years.

RESULTS

We reviewed the literature and found that a number of immunosuppressive agents have stopped inflammation, stabilised the podocyte cytoskeleton and reduce proteinuria. However, prolonged treatment has frequently been associated with a high risk of renal and non-renal complications in patients with a complicated disease course, defined as frequent relapses or steroid dependency. Non-renal complications may include impaired longitudinal growth and pubertal development, undesirable fertility outcomes, ocular complications, bone mineral diseases and potential malignancies.

CONCLUSION

This review discusses and summarises the non-renal outcomes of idiopathic childhood NS.

Therapeutic Response to Corticosteroids Remains a Valid Approach to Initial Management of Children With Idiopathic Nephrotic Syndrome

Complete remission of idiopathic nephrotic syndrome (INS) in response to corticosteroids has been widely adopted as an indicator of satisfactory long-term outcomes in pediatric patients. The approach was based on the results of studies conducted in the 1960s and 1970s. The studies found that corticosteroid-responsive minimal change disease (MCD) was the most frequent diagnosis in INS patients. In more recent years, studies have reported increased frequency of focal segmental glomerulosclerosis (FSGS) and primary corticosteroid resistance without a corresponding increase of FSGS. It became unclear whether withholding kidney biopsy before treatment with corticosteroids is still the best management practice. We performed a retrospective chart review at the UPMC Children's Hospital of Pittsburgh and identified patients who were referred for evaluation of edema or proteinuria between 2002 and 2014. We identified 114 pediatric patients with INS who were treated initially with a corticosteroid (prednisone or prednisolone) 2 mg/kg (max 60 mg)/day for 4-6 weeks followed by 2 mg/kg (max 60 mg) every other day for 4-6 weeks and had not received a corticosteroid-sparing agent before completing at least 8 weeks of the initial therapy. Corticosteroid resistance in pediatric INS patients was independently associated with the black race, older age at presentation (>8 years), and female sex. The majority of blacks who were resistant to corticosteroids had a tissue diagnosis of MCD. Among the whites who were steroid-resistant, MCD and FSGS were diagnosed in similar proportions of cases. Thus, the tissue diagnosis in could not predict the response to corticosteroids. Nineteen percent of whites with FSGS were steroid-sensitive and none of the blacks with FSGS responded to corticosteroids. These data suggest that the histologic diagnosis of FSGS could not rule out response to corticosteroids, at least, in the white patient population. In summary, our data demonstrate that at this time, the therapeutic response to corticosteroids continues to be a valid approach for the initial evaluation and therapy of children diagnosed with INS at our center. Future studies should evaluate the mechanisms of changing characteristics of pediatric INS. The specific role of patient demographics, ethnicity, as well as genetic and environmental factors could be evaluated by a prospective, multicenter study.

Urinary Epidermal Growth Factor as a Marker of Disease Progression in Children With Nephrotic Syndrome

Introduction

Childhood-onset nephrotic syndrome has a variable clinical course. Improved predictive markers of long-term outcomes in children with nephrotic syndrome are needed. This study tests the association between baseline urinary epidermal growth factor (uEGF) excretion and longitudinal kidney function in children with nephrotic syndrome.

Methods

The study evaluated 191 participants younger than 18 years enrolled in the Nephrotic Syndrome Study Network, including 118 with their first clinically indicated kidney biopsy (68 minimal change disease; 50 focal segmental glomerulosclerosis) and 73 with incident nephrotic syndrome without a biopsy. uEGF was measured at baseline for all participants and normalized by the urine creatinine (Cr) concentration. Renal epidermal growth factor (EGF) mRNA was measured in the tubular compartment microdissected from kidney biopsy cores from a subset of patients. Linear mixed models were used to test if baseline uEGF/Cr and EGF mRNA expression were associated with change in estimated glomerular filtration rate (eGFR) over time.

Results

Higher uEGF/Cr at baseline was associated with slower eGFR decline during follow-up (median follow-up = 30 months). Halving of uEGF/Cr was associated with a decrease in eGFR slope of 2.0 ml/min per 1.73 m² per year (P < 0.001) adjusted for age, race, diagnosis, baseline eGFR and proteinuria, and APOL1 genotype. In the biopsied subgroup, uEGF/Cr was correlated with EGF mRNA expression (r = 0.74; P < 0.001), but uEGF/Cr was retained over mRNA expression as the stronger predictor of eGFR slope after multivariable adjustment (decrease in eGFR slope of 1.7 ml/min per 1.73 m² per year per log₂ decrease in uEGF/Cr; P < 0.001).

Conclusion

uEGF/Cr may be a useful noninvasive biomarker that can assist in predicting the long-term course of kidney function in children with incident nephrotic syndrome.

Bone Health in Glomerular Kidney Disease

PURPOSE OF REVIEW

To summarize the literature regarding alterations in bone health in patients with glomerular kidney disease and highlight areas in need of additional investigation.

RECENT FINDINGS

There is mounting evidence that children and adults with glomerular conditions, with or without compromised kidney function, comprise a distinct subgroup of patients with unique risk factors for altered bone health. Patients with glomerular kidney disease are exposed to both disease-related and treatment-related factors that affect bone structure and function. In addition to chronic kidney disease-related risk factors for impaired bone health, high rates of exposure to osteotoxic medications, varying degrees of systemic inflammation, and altered vitamin D metabolism may contribute to compromised bone health in individuals with glomerular disease. Further study is needed to better understand these risk factors and the complex interaction between the immune system and bone cells in glomerular disease.

Study protocol: multicenter double-blind, randomized, placebo-controlled trial of rituximab for the treatment of childhood-onset early-stage uncomplicated frequently relapsing or steroid-dependent nephrotic syndrome (JSKDC10 trial)

Background

Eighty percent of children with idiopathic nephrotic syndrome respond well to steroid therapy, but up to 50% of patients with steroid-sensitive nephrotic syndrome exhibit frequently relapsing (FRNS) or steroid-dependent nephrotic syndrome (SDNS). Several studies identified the chimeric anti-CD20 monoclonal antibody rituximab as an effective treatment for patients with complicated FRNS/SDNS. Recent studies suggested that rituximab could also be a first-line treatment for early-stage uncomplicated FRNS/SDNS, although further studies are required to confirm its efficacy and safety.

Methods/design

We are conducting a multicenter, double-blind, randomized placebo controlled trial to investigate the efficacy and safety of rituximab for the treatment of childhood-onset early-stage uncomplicated FRNS/SDNS. Patients will be allocated to receive two 375 mg/m² doses (maximum dose: 500 mg) of either rituximab or placebo. Investigators are permitted to request the disclosure of a subject’s allocation code if he or she exhibits treatment failure. Additionally, if placebo-treated subjects display early relapse (a sign of treatment failure), they have the option to receive rituximab in an unblinded phase. The primary endpoint is relapse-free survival during the observation period.

Discussion

The results will provide important data on the use of rituximab for patients with uncomplicated FRNS/SDNS. In the future, rituximab treatment will enable most patients with uncomplicated FRNS/SDNS to discontinue or reduce steroid therapy without relapse, and it is possible that rituximab could represent an immunosuppressive therapy for these diseases.

Trial registration

This trial was prospectively registered to the JMACCT Clinical Trials Registry on September 6, 2018 (Trial ID: JMA-IIA00380).

Levamisole in Children with Idiopathic Nephrotic Syndrome: Clinical Efficacy and Pathophysiological Aspects

Steroid sensitive nephrotic syndrome is one of the most common pediatric glomerular diseases. Unfortunately, it follows a relapsing and remitting course in the majority of cases, with 50% of all cases relapsing once or even more often. Most children with idiopathic nephrotic syndrome respond initially to steroid therapy, nevertheless repeated courses for patients with relapses induce significant steroid toxicity. Patients with frequent relapses or steroid dependency thus require alternative treatment, such as cyclophosphamide, cyclosporine, tacrolimus, mycophenolate mofetil, levamisole, or rituximab. To reduce the relapse rate, several drugs have been used. Among these, levamisole has been considered the least toxic and least expensive therapy. Several randomized controlled trials (RCT) showed that levamisole is effective in reducing the relapse risk in steroid sensitive forms of nephrotic syndrome with a low frequency of side effects. Levamisole is a synthetic imidazothiazole derivative with immune-modulatory properties. In this article, we review recent data from randomized trials and observational studies to assess the efficacy of levamisole in frequently relapsing nephrotic syndrome and steroid-dependent nephrotic syndrome.

Usefulness of mizoribine administration in children with frequently relapsing nephrotic syndrome, and the relationship between pharmacokinetic parameters and efficacy: a multicenter prospective cohort study in China

BACKGROUND

Mizoribine (MZR) is an immunosuppressant used to treat adult nephropathy. There is little experience with the drug in treating Chinese children with frequently relapsing nephrotic syndrome (FRNS). We investigated the efficacy and safety for treating MZR with FRNS. Furthermore, the relationship between efficacy and serum concentration was investigated.

METHODS

A prospective multicenter observational 12-month study was performed for evaluating the usefulness of MZR with FRNS. Serum MZR concentration was measured, and the relationships between pharmacokinetic parameters (C_max, AUC), number of relapses, and urinary protein were evaluated.

RESULTS

Eighty-two pediatric patients from four hospitals were treated with MZR and prednisone. MZR treatment significantly reduced the number of relapses and steroid doses. A correlation between pharmacokinetic parameters and relapses was observed, which fits well with the sigmoidal E_max model. Even in the relationship between pharmacokinetic parameters and urinary proteins, it was recognized that there was a threshold in the pharmacokinetic parameters for the therapeutic effect similar to the results obtained with the sigmoidal E_max model. Eleven patients (13.4%) experienced mild adverse events.

CONCLUSIONS

MZR therapy was effective in reducing the number of relapses and steroid doses. No severe adverse reactions were observed. Therapeutically effective serum concentrations were estimated to be C_max ≥ about 2 μg/mL or AUC ≥ about 10 μg h/mL. MZR and steroid treatment were effective and safe for pediatric FRNS.

Efficacy of low-dose daily versus alternate-day prednisolone in frequently relapsing nephrotic syndrome: an open-label randomized controlled trial

BACKGROUND

While patients with frequently relapsing nephrotic syndrome (FRNS) are initially treated with long-term alternate-day prednisolone, relapses and adverse effects are common. In an open-label randomized controlled trial, we compared the efficacy of therapy with low-dose daily to standard alternate-day prednisolone in reducing relapse rates over 12-month follow-up.

METHODS

Consecutive patients, aged 2-18 years, with FRNS were included. Following therapy of relapse, prednisolone was tapered to 0.75 mg/kg on alternate days. Stratifying for steroid dependence, patients were randomly assigned to prednisolone at 0.2-0.3 mg/kg daily or 0.5-0.7 mg/kg alternate day for 12 months. Relapses were treated with daily prednisolone, followed by return to intervention. Primary outcome was the incidence of relapses. Proportion with therapy failure (≥ 2 relapses in any 6 months or significant steroid toxicity) and sustained remission, cumulative prednisolone intake and adverse events were evaluated.

RESULTS

Patients receiving daily prednisolone (n = 30) showed significantly fewer relapses than those on alternate-day therapy (n = 31) (0.55 relapses/person-year versus 1.94 relapses/person-year; incidence rate ratio 0.28; 95% CI 0.15, 0.52). Daily therapy was associated with higher rates of sustained remission at 6 months (73.3 versus 48.4%) and 1 year (60 versus 31.6%; log rank p = 0.013), lower rates of treatment failure at 6 months (3.3 versus 32.8%) and 1 year (6.7 versus 57.4%; p < 0.0001), and lower prednisolone use (0.27 ± 0.07 versus 0.39 ± 0.19 mg/kg/day; p = 0.003). Three and two patients need to receive the study intervention to enable sustained remission and prevent treatment failure, respectively.

CONCLUSIONS

In patients with FRNS, daily administration of low-dose prednisolone is more effective than standard-dose alternate day therapy in lowering relapse rates, sustaining remission, and enabling steroid sparing.

Efficacy and safety of rituximab in childhood-onset, difficult-to-treat nephrotic syndrome: A multicenter open-label trial in Korea

BACKGROUND

The anti-CD20 monoclonal antibody rituximab (RTX) has been proposed as a rescue therapy for difficult-to-treat nephrotic syndrome (NS). We conducted a clinical trial to evaluate the efficacy and safety of RTX in children with difficult-to-treat NS dependent on or resistant to steroids and calcineurin inhibitors (CNIs).

METHODS

A multicenter open-label trial was performed at 8 major pediatric nephrology centers in Korea. The investigation consisted of a randomized controlled trial for steroid- and CNI-dependent NS (DDNS; randomization into the RTX group and the control group, at a ratio of 2:1) and a single-arm study of steroid and CNI-resistant NS (DRNS). DDNS patients in the RTX group and DRNS patients received a single dose of intravenous RTX (375 mg/m of body surface area) for B-cell depletion. A second RTX dose was administered at week 2 if the first dose failed to achieve depletion of CD19(+) cells. The primary endpoint was rate of maintaining remission at 6 months after treatment for DDNS and rate of remission achievement for DRNS.

RESULTS

Sixty-one children with DDNS were enrolled while in remission and randomized to the control group (21 patients) or the RTX group (40 patients). At 6 months after treatment, the remission rates were 74.3% in the RTX group and 31.3% in the control group (P = .003). The mean duration of remission maintenance was significantly higher in the RTX group than in the control group (9.0 vs 2.9 months, P = .004). Of the 23 patients with DRNS enrolled in the single-arm study and treated with RTX, 9 (39.1%) achieved partial or complete remission within 6 months. Depletion of B cells occurred in all patients with RTX therapy. Thirty patients (50.8% of 59 patients analyzed) experienced mild and transient infusion reaction during RTX administration, and most adverse events were mild.

CONCLUSIONS

RTX administration was safe and effective in patients with difficult-to-treat NS. One or 2 doses of RTX may be sufficient to deplete B cells and achieve better control of pediatric NS.

Continuous B-cell depletion in frequently relapsing, steroid-dependent and steroid-resistant nephrotic syndrome

Background

Patients with frequently relapsing (FR), steroid-dependent (SD) and steroid-resistant (SR) nephrotic syndrome are a therapeutic challenge with limited treatment options. Here, we retrospectively analyze the efficacy and safety of rituximab-induced continuous B-cell depletion in these populations.

Methods

Patients were included if they were at least 18 years of age and had FR, SD or SR minimal change disease (MCD) or primary focal segmental glomerulosclerosis (FSGS) and were treated with a strategy of continuous B-cell depletion. Partial remission (PR) was defined as a urinary protein:creatinine ratio (UPCR) of ≤3.5 g/g and a 50% reduction in the UPCR from baseline. Complete remission (CR) was defined as a UPCR ≤0.3 g/g.

Results

We identified 20 patients with MCD (n = 13) or FSGS (n = 7) who fulfilled the inclusion criteria. All patients had either SD (n = 12), SR (n = 7) or FR (n = 1) disease. Patients received a median of nine rituximab doses [interquartile range (IQR) 7.5, 11] and were treated for a median time of 28 months (IQR 23, 41). Prednisone was weaned from a median of 60 mg daily (IQR 40, 60) at rituximab initiation to 4.5 mg daily (IQR 0, 5.5) by 12 months. All patients achieved PR. CR occurred in 11 of 13 patients with FR or SD disease, but only 1 of 7 patients with SR disease (logrank P = 0.01). Four relapses occurred, all in patients with SR disease. Three serious infections occurred over 70.3 patient-years.

Conclusion

Continuous B-cell depletion is a therapeutic option in the management of complicated nephrotic syndrome. Additional studies are needed to clarify the utility of this strategy.

Calcineurin inhibitors and nephrotoxicity in children

BACKGROUND

Calcineurin inhibitors (CNIs) are commonly given to transplant recipients of kidneys and other solid organs and to patients with immune disorders, such as steroid-resistant nephrotic syndrome, steroid-dependent nephrotic syndrome, and frequent relapse nephrotic syndrome. Although CNIs remain the most effective available immunosuppressant agent, there is clinical concern regarding possible long-term nephrotoxicity. This concern is especially significant in children who have a longer life expectancy and greater growth rate.

DATA SOURCES

In this review, we analyzed the literatures to identify original articles that examined use of CNIs in children who received organ transplantation and nephropathy to assess the available evidence of their nephrotoxicity. PubMed, Elsevier, and Tompson ISI Web of Knowledge were searched for identifying relevant papers.

RESULTS

Clinical research supports the presence of CNI-related nephrotoxicity. However, some researchers have questioned the prevalence and seriousness of chronic CNIs nephrotoxicity, especially because the pathological lesions typically associated with long-term CNI use are nonspecific. Many researchers have focused on early markers of CNI nephrotoxicity, and the methods that may help prevent and manage nephrotoxicity.

CONCLUSIONS

Future research should focus on investigating early markers of CNI nephrotoxicity and strategies for improved immunosuppressant therapy, and developing alternative treatments. CNI-mediated nephrotoxicity should always be taken seriously in clinic.

Skeletal manifestations of renal disease in childhood

PURPOSE OF REVIEW

This review summarizes recent findings on musculoskeletal health in three chronic renal conditions of childhood: chronic kidney disease stages 2-5D, nephrotic syndrome, and urolithiasis. Findings with important clinical implications warranting further investigation are highlighted.

RECENT FINDINGS

Recent cohort studies have demonstrated a high burden of fracture and progressive deficits of cortical bone in children with chronic kidney disease. Lower cortical density is associated with incident fracture and may be an important therapeutic target. Parathyroid hormone and calcium are independent correlates of cortical density, and modifiable factors for fracture include parathyroid hormone and phosphate binder use. Children with nephrotic syndrome, even with normal renal function, have evidence of abnormal bone metabolism and structure, and vitamin D deficiency may be an important modifiable risk factor in this population. Urolithiasis has been associated with reduced bone mineral density and is increasingly common in children and adolescents. Population-based data found a significantly increased risk of fracture in adolescent males and young women.

SUMMARY

Recent findings substantiate concern regarding the particular vulnerability of the growing skeleton to chronic renal disease. Studies are needed to determine how to optimize assessment and management of bone health in children with these conditions, particularly in terms of calcium and vitamin D requirements, with the goal of improving childhood bone accrual for lifelong fracture prevention.

Nephrotic syndrome in infants and children: pathophysiology and management

Nephrotic syndrome is defined by nephrotic-range proteinuria (≥40 mg/m²/hour or urine protein/creatinine ratio ≥200 mg/mL or 3+ protein on urine dipstick), hypoalbuminaemia (<25 g/L) and oedema. This review focuses on the classification, epidemiology, pathophysiology, management strategies and prognosis of idiopathic nephrotic syndrome of childhood, and includes a brief overview of the congenital forms.

Long-term repeated rituximab treatment for childhood steroid-dependent nephrotic syndrome

BACKGROUND

Rituximab (RTX) can be used as a rescue therapy for steroid-dependent nephrotic syndrome (SDNS). However, the efficacy and safety of long-term, repeated use of RTX are not established. This study was conducted to assess the efficacy and safety of long-term, repeated RTX treatment in children.

METHODS

Eighteen consecutive child patients with SDNS who were treated with three or more cycles of RTX for one year or longer were recruited, and their medical records were retrospectively reviewed.

RESULTS

The patients were followed for 4.7 ± 1.9 years and received 5.2 ± 2.3 cycles of RTX over 2.8 ± 1.1 years. Approximately 70% of the additional RTX cycles were administered due to recovery of B-cells without relapse. The relapse rate decreased from 3.4 ± 2.0 per year initially to 0.4 ± 0.8 per year at the third year after RTX treatment. Approximately 10% of the RTX infusions were accompanied by mild infusion reactions. Eight patients showed sustained remission without any oral medication after the last cycle of RTX, while 10 patients had one or more episodes of relapse after the last cycle of RTX. The relapse rate in the latter group decreased from 2.8 ± 1.5 per year before RTX treatment to 1.3 ± 0.8 per year after cessation of RTX treatment. No significant differences in clinical parameters were found between the two groups.

CONCLUSION

This retrospective study showed that pre-emptive and long-term, repeated RTX treatment is relatively effective and safe in children with SDNS. However, well-designed prospective studies are needed to confirm these findings.

REducing STEroids in Relapsing Nephrotic syndrome: the RESTERN study- protocol of a national, double-blind, randomised, placebo-controlled, non-inferiority intervention study

INTRODUCTION

Oral corticosteroids are the first-line treatment for idiopathic childhood nephrotic syndrome. Most children experience several relapses, needing repeated courses of corticosteroid therapy. This exposes them to side effects and long-term complications. For most patients, long-term prognosis is for complete resolution of the disease over time and maintenance of normal kidney function. Therefore, it is vital to focus on minimising adverse events of the disease and its therapy. Unfortunately, no randomised controlled trials are available to determine the optimal corticosteroid treatment of an infrequent relapse of nephrotic syndrome. Recent studies show that treatment schedules for the first episode can safely be shortened to 2 months. The hypothesis of the REducing STEroids in Relapsing Nephrotic syndrome (RESTERN) study is that a 4-week reduction of alternate-day steroids after inducing remission is effective and safe, reduces steroid exposure by 35% on average and is therefore preferable.

METHODS AND ANALYSIS

The RESTERN study is a nationwide, double-blind, randomised, placebo-controlled, non-inferiority intervention study. Children aged 1-18 years with a relapse of steroid-sensitive nephrotic syndrome are eligible for this study. Study subjects (n=144) will be randomly assigned to either current standard therapy in the Netherlands or a reduced prednisolone schedule. The primary outcome of the RESTERN study is the time to first relapse after the final prednisolone dose. The secondary outcomes are the number or relapses, progression to frequent relapsing or steroid dependent nephrotic syndrome and the cumulative dosage of prednisolone during the study period.

ETHICS AND DISSEMINATION

This non-inferiority trial will be performed in accordance with the Declaration of Helsinki and has been approved by the medical ethical committee of Arnhem-Nijmegen and the Dutch Competent Authority (Central Committee on Research Involving Human Subjects, CCMO). After completion of this study, results will be published in national and international peer-reviewed scientific journals. Papers will be published according to CCMO guidelines. The final report will be made available to trial participants.

TRIAL REGISTRATION NUMBER

NTR5670, EudraCT no 2016-002430-76.

Glomerular Filtration Rate Trends During Follow-up in Children With Steroid-Sensitive Nephrotic Syndrome

BACKGROUND

Overall prognosis of children with steroid-sensitive nephrotic syndrome (SSNS) is regarded as generally favorable. However, only a few recent studies have evaluated changes in kidney function and blood pressure over time in children with SSNS.

OBJECTIVES

We describe clinical features of SSNS patients and characterize changes in calculated estimated glomerular filtration rate (eGFR) and use of antihypertensive medications during follow-up.

DESIGN

This is a retrospective cohort study.

SETTING

This study was conducted in a Canadian pediatric nephrology center.

PATIENTS

This study included patients aged 1 to 18 years with SSNS.

MEASUREMENTS

eGFR was calculated from recorded serum creatinine and height measurements using the modified Schwartz equation.

METHODS

eGFR was calculated at yearly intervals, and the trend of eGFR was assessed using linear mixed effects model. Patients were also evaluated for use of antihypertensive medications during follow-up.

RESULTS

Seventy-eight patients-median age, 3.2 years (interquartile range [IQR], 2.65) and median follow-up of 4.37 (IQR, 5.6)-were evaluated. Sixty-three (80.8%) had at least 1 relapse. Twenty-two (28.2%) and 20 (25.6%) were steroid dependent and frequently relapsing, respectively. Forty-three patients (55.1%) received at least 1 steroid-sparing agent, and of these, 18 (41.8%) received a calcineurin inhibitor. One patient had eGFR ≤90 mL/min/1.73 m² during observation. eGFR remained unchanged over the follow-up period in this cohort of patients. Four patients (5.1%) were on antihypertensive medications at the end of follow-up.

LIMITATIONS

Patients who had frequent relapses had more measurements available for serum creatinine and height, creating a sampling bias. The number of eGFR measurements was overall small, making it difficult to ascertain eGFR trend.

CONCLUSION

eGFR remained unchanged over time in this cohort, and a small proportion of patients required antihypertensive therapy at the end of follow-up. Our study highlights the needs for carefully constructed long-term observational studies of children with nephrotic syndrome.