Saliva monitoring of prednisolone in children with first onset steroid-sensitive nephrotic syndrome: Is it possible?

AIMS: Prednisolone is the cornerstone of treatment for idiopathic nephrotic syndrome in children, but is associated with marked side-effects. Therapeutic drug monitoring using saliva would be a patient-friendly option to monitor prednisolone treatment. To assess the feasibility of saliva monitoring, we described the pharmacokinetics (PK) of unbound prednisolone in plasma and saliva of children with first onset steroid-sensitive nephrotic syndrome (SSNS). METHODS: Children (age 2-16 years) with SSNS participating in a randomized, placebo-controlled trial with levamisole were treated with an 18-week tapering schedule of prednisolone. Five serial samples were collected at 4 (saliva) and 8 weeks (saliva and plasma) after first onset. A nonlinear mixed-effects model was used to estimate the PK parameters of unbound prednisolone and the saliva-to-plasma ratio. Monte Carlo simulations were performed to assess the predictive performance of saliva monitoring. RESULTS: From 39 children, 109 plasma and 275 saliva samples were available. Estimates (relative squared error) of unbound plasma clearance and volume of distribution were 93 (5%) L h-1 70 kg-1 and 158 (7%) L 70 kg-1, respectively. Typical saliva-to-plasma ratio was 1.30 (8%). Monte Carlo simulations demonstrated that on basis of 4 saliva samples and a single plasma sample unbound plasma area-under-the-concentration-time curve can be predicted within 20% imprecision in 79% of the patients compared to 87% based on 4 plasma samples. CONCLUSION: Saliva proved to be a reliable and patient-friendly option to determine prednisolone plasma exposure in children with SSNS. This opens opportunities for further PK and pharmacodynamics studies of prednisolone in a variety of paediatric conditions.

Health-related quality of life of children with first onset steroid-sensitive nephrotic syndrome.

This study assessed HRQoL and emotional and behavioral difficulties (EBD) and associated variables in children with first onset SSNS. While relapsing steroid-sensitive nephrotic syndrome (SSNS) in children is associated with lower health-related quality of life (HRQoL), little is known about first onset. Four weeks after onset, children (2-16 years) and/or their parents who participated in a randomized placebo-controlled trial, completed the Pediatric Quality of Life Inventory 4.0 (PedsQL) and Strengths and Difficulties Questionnaire (SDQ) to measure HRQoL and EBD, respectively. Total and subscale scores and the proportion of children with impaired HRQoL (> 1 SD below the mean of the reference group) or SDQ clinical scores (< 10th and > 90th percentile) were compared to the Dutch general population (reference group). Regression analyses were used to identify associated variables. Compared to the reference group, children 8-18 years reported significantly lower total HRQoL, and physical and emotional functioning. A large proportion (> 45%) of these children had impaired HRQoL. There were no differences in HRQoL between children 2-7 years and the reference group, except for higher scores on social functioning (5-7 years). Similar proportions of SSNS and reference children scored within the clinical range of SDQ subscales. Age, sex, and steroid side-effects were negatively associated with HRQol and/or EBD.   Conclusion: This study showed that HRQoL and EBD are affected in children of different ages with first onset SSNS. This calls for more awareness from healthcare providers and routinely monitoring of HRQoL and EBD in daily clinical care to prevent worsening of symptoms.   Clinical trial registry: Netherlands Trial Register ( https://trialsearch.who.int/ ; NTR7013), date of registration: 02 June 2018. What is Known: •  Health-related quality of life (HRQoL) is lower and emotional and behavioral difficulties (EBD) is more affected in children with frequently-relapsing and steroid-dependent nephrotic syndrome. What is New: •  HRQoL and EBD are affected in children with first onset steroid-sensitive nephrotic syndrome compared to a reference group of the Dutch general population. • To what extent HRQoL and EBD are affected depends on the age of the patient.

Levamisole suppresses activation and proliferation of human T cells by the induction of a p53-dependent DNA damage response.

Levamisole (LMS) is a small molecule used in the treatment of idiopathic nephrotic syndrome (INS). The pathogenesis of INS remains unknown, but evidence points toward an immunological basis of the disease. Recently, LMS has been shown to increase the relapse-free survival in INS patients. While LMS has been hypothesized to exert an immunomodulatory effect, its mechanism of action remains unknown. Here, we show that LMS decreased activation and proliferation of human T cells. T-cell activation-associated cytokines such as IL-2, TNF-α, and IFN-γ were reduced upon LMS treatment, whereas IL-4 and IL-13 were increased. Gene expression profiling confirmed that the suppressive effects of LMS as genes involved in cell cycle progression were downregulated. Furthermore, genes associated with p53 activation were upregulated by LMS. In agreement, LMS treatment resulted in p53 phosphorylation and increased expression of the p53 target gene FAS. Accordingly, LMS sensitized activated T cells for Fas-mediated apoptosis. LMS treatment resulted in a mid-S phase cell cycle arrest accompanied by γH2AX-foci formation and phosphorylation of CHK1. Our findings indicate that LMS acts as an immunosuppressive drug that directly affects the activation and proliferation of human T cells by induction of DNA damage and the activation of a p53-dependent DNA damage response.

Distress in parents of children with first-onset steroid-sensitive nephrotic syndrome.

BACKGROUND: Steroid-sensitive nephrotic syndrome (SSNS) is associated with a relapsing-remitting course that can be stressful for parents. As little is known of parental distress at the first onset of SSNS, this study aims to describe parental distress and everyday problems in mothers and fathers of a child with newly diagnosed SSNS participating in a randomized controlled trial of levamisole added to corticosteroids. METHODS: To assess distress, the Distress Thermometer for Parents (DT-P) was used, which includes questions on distress (thermometer score 0-10, ≥ 4 "clinical distress") and presence of everyday problems in six domains: practical, social, emotional, physical, cognitive, and parenting. The DT-P was completed 4 weeks after the onset of SSNS. Total sum and individual items of everyday problems were compared with reference data from mothers and fathers of the Dutch general population. RESULTS: There was no difference in clinically elevated parental distress between SSNS mothers (n = 37) and fathers (n = 25) and reference parents. Compared to reference fathers, fathers of a child with SSNS scored significantly higher on emotional problems (P = 0.030), while mothers experienced more parenting problems (P = 0.002). Regression analyses showed that lower parental age and having a girl with SSNS were significantly associated with more practical problems and higher distress thermometer scores, respectively. CONCLUSIONS: Four weeks after onset, SSNS mothers and fathers experience equal distress as reference parents. However, both parents endorsed significantly more everyday problems. Therefore, monitoring parental distress, even in the first weeks of the disease, could contribute to timely interventions and prevent worsening of problems. CLINICAL TRIAL REGISTRY: Dutch Trial Register ( https://onderzoekmetmensen.nl/en/trial/27331 ). A higher resolution version of the Graphical abstract is available as Supplementary information.

Incidence of idiopathic nephrotic syndrome during the Covid-19 pandemic in the Paris area (France) and in the Netherlands.

BACKGROUND: The aetiology of idiopathic nephrotic syndrome (INS) remains partially unknown. Viral infections have been associated with INS onset. Since we observed fewer first onset INS cases during the Covid-19 pandemic, we hypothesised that lower INS incidence was the result of lockdown measures. Therefore, the aim of this study was to evaluate the incidence of childhood INS before and during the COVID-19 pandemic in two independent European INS cohorts. METHODS: Children with new INS in the Netherlands (2018-2021) and Paris area (2018-2021) were included. We estimated incidences using census data for each region. Incidences were compared using two proportion Z-tests. RESULTS: A total of 128 and 324 cases of first onset INS were reported in the Netherlands and Paris area, respectively, corresponding to an annual incidence of 1.21 and 2.58 per 100,000 children/year. Boys and young children (< 7 years) were more frequently affected. Incidence before and during the pandemic did not differ. When schools were closed, incidence was lower in both regions: 0.53 vs. 1.31 (p = 0.017) in the Netherlands and 0.94 vs. 2.63 (p = 0.049) in the Paris area. During peaks of hospital admissions for Covid-19, no cases were reported in the Netherlands or Paris area. CONCLUSIONS: Incidence of INS before and during the Covid-19 pandemic was not different, but when schools were closed during lockdown, incidence was significantly lower. Interestingly, incidences of other respiratory viral infections were also reduced as was air pollution. Together, these results argue for a link between INS onset and viral infections and/or environmental factors. A higher resolution version of the Graphical abstract is available as Supplementary information.

Circulating Permeability Factors in Focal Segmental Glomerulosclerosis: In V itro Detection.

Introduction: The recurrence of proteinuria after kidney transplantation in patients with focal segmental glomerulosclerosis (FSGS) is considered proof of the presence of circulating permeability factors (CPFs). The aim of this study is to demonstrate the presence of plasma CPFs using series of in vitro assays. Methods: Podocytes and endothelial cells (glomerular microvascular endothelial cells [GMVECs]) were incubated with plasma from FSGS patients with presumed CPFs in relapse and remission and from steroid-resistant nephrotic syndrome (SRNS), steroid-sensitive nephrotic syndrome (SSNS), membranous nephropathy (MN), and healthy controls (hCtrls). Cell viability, podocyte actin cytoskeleton architecture, and reactive oxygen species (ROS) formation with or without ROS scavenger were investigated by Cell Counting Kit-8 assay, immunofluorescence staining, and CM-H2DCFDA probing, respectively. Results: Presumed CPF-containing plasma causes a series of events in podocytes but not in GMVECs. These events include actin cytoskeleton rearrangement and excessive formation of ROS, which results in podocyte loss. These effects were solely observed in response to CPF plasma collected during relapse, but not in response to plasma of hCtrls, or patients with SRNS, SSNS, and MN. The copresence of dimethylthiourea, a scavenger of ROS, abolished the aforementioned effects of CPF plasma. Conclusion: We provide a panel of in vitro bioassays to measure podocyte injury and predict the presence of CPFs in plasma of patients with nephrotic syndrome (NS), providing a new framework for monitoring CPF activity that may contribute to future NS diagnostics or used for disease monitoring purposes. Moreover, our findings suggest that the inhibition of ROS formation or facilitating rapid ROS scavenging may exert beneficial effects in patients with CPFs.

The Use of Patient-Reported Outcome Measures in Daily Clinical Practice of a Pediatric Nephrology Department.

(1) Background: Health-related quality of life (HRQoL) is lower in patients with chronic kidney disease (CKD) compared to the general population. In 2011, the KLIK PROM portal was implemented in the Emma Children's Hospital to monitor and discuss HRQoL in daily care. This study describes and assesses the implementation and use of the KLIK PROM portal in the pediatric nephrology department. (2) Methods: CKD patients (self-report, if 8-18 years of age) and their parents (proxy-report, if 1-8 years) were invited to complete HRQoL patient-reported outcome measures (PROMs): TNO-AZL Preschool children Quality Of Life (TAPQOL) or Pediatric Quality of Life Inventory for Children (PedsQL). The PROMs were completed before and discussed during outpatient consultations. The adaptation rate-the proportion of patients/parents who were invited and completed at least one PROM-was calculated. Reported HRQoL scores of CKD patients were compared to the general population. (3) Results: In total, 142 patients (proxy- and self-report) were invited, 112 patients completed at least one PROM (adaptation rate 79%). Patients (n = 84 with informed consent for scientific use) with CKD reported lower HRQoL and HRQoL was more often impaired compared to the general Dutch population. (4) Conclusions: The implementation of KLIK was successful and its use is feasible for daily care. Using KLIK, HRQoL problems can be easily identified and monitored.

Levamisole causes a transient increase in plasma creatinine levels but does not affect kidney function based on cystatin C.

BACKGROUND: In pediatric patients treated with levamisole to prevent relapses of idiopathic nephrotic syndrome (INS), a transient and non-progressive rise in creatinine levels has been observed. It has been suggested that levamisole affects tubular secretion of creatinine. However, other potential mechanisms - nephrotoxicity and interference with the analytical assay for creatinine - have never been thoroughly investigated. METHODS: In three steroid-sensitive nephrotic syndrome (SSNS) patients with elevated plasma creatinine levels, treated with levamisole 2.5 mg/kg every other day, serum cystatin C was determined. The glomerular filtration rate (GFR) was estimated using the full age spectrum for creatinine and the full age spectrum for cystatin C equations. Interference of levamisole with the enzymatic creatinine assay was tested using spare human plasma of different creatinine concentrations spiked with levamisole (4, 20, and 100 µM). RESULTS: Three patients who received levamisole with elevated plasma creatinine levels had normal serum cystatin C levels and corresponding estimated GFR. There was no assay interference. CONCLUSION: Levamisole increases plasma creatinine levels, which is most probably due to impaired tubular secretion of creatinine since there was no assay interference and patients had normal eGFR based on serum cystatin C. However, interference of metabolites of levamisole could not be excluded. To monitor GFR, cystatin C in addition to creatinine should be used and be measured before and during levamisole use.

Incidence and Relapse of Idiopathic Nephrotic Syndrome: Meta-analysis.

CONTEXT: Idiopathic nephrotic syndrome (INS) in children is a disease with considerable morbidity, yet the incidence and risk for relapse have not been systematically reviewed. OBJECTIVE: To estimate the overall pooled weighted incidence and risk for relapse of INS in children. DATA SOURCES: Medline and Embase (until December 2020). STUDY SELECTION: All studies reporting incidence (per 100 000 children per year) and/or risk for relapse (the proportion of patients who experience ≥1 relapse) of INS in children (age: <18 years) were eligible. DATA EXTRACTION: After quality assessment, data were extracted: study (design, localization, and sample size) and patient (age, sex, steroid response, and ethnicity) characteristics, incidence, and risk for relapse. RESULTS: After screening, 73 studies were included for analysis (27 incidence, 54 relapse). The overall pooled weighted estimate and corresponding prediction interval (PI) of the incidence was 2.92 (95% PI: 0.00-6.51) per 100 000 children per year. Higher incidences were found in non-Western countries (P < .001). Incidence tended to be lower in white children, but this was not significant. The overall pooled weighted estimate of the risk for relapse was 71.9% (95% PI: 38.8-95.5). Between 1945 and 2011, incidence did not change (P = .39), yet the risk for relapse decreased significantly (P = .024), from 87.4% to 66.2%. LIMITATIONS: There was no full-text availability (n = 33), considerable heterogeneity, and limited studies from Africa, Latin America, and Asia. CONCLUSIONS: INS has a low incidence with ethnic variation but high risk for relapse. Although corticosteroids have significantly reduced the risk for relapse, it remains unacceptably high, underscoring the need for alternative treatment strategies.

Development and Validation of a Highly Sensitive Liquid Chromatography-Tandem Mass Spectrometry Technique to Determine Levamisole in Plasma and Saliva.

BACKGROUND: Levamisole is used as a steroid-sparing drug for the treatment of frequently relapsing or steroid-dependent idiopathic nephrotic syndrome in children. As part of a large multicentre randomized controlled trial with levamisole, pharmacokinetic and pharmacodynamic parameters of levamisole in children with idiopathic nephrotic syndrome were investigated, as well as the feasibility of using saliva as an alternative and patient-friendly matrix for determining levamisole concentrations. In this study, the authors presented the development and validation of a highly sensitive method for determining levamisole in plasma and saliva using liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: In 100 µL samples, proteins were precipitated with 750 µL acetonitrile/methanol 420:80 (v/v) with levamisole-D5 as an internal standard. Calibration standards were prepared over a range of 0.1 ng/mL-50 ng/mL. To determine ultrafiltration efficiency, the ultrafiltrate was obtained by centrifuging blank plasma samples over the filter. Both filtered and nonfiltered samples were analyzed. RESULTS: For plasma, accuracy and within-run and between-run imprecision were between 95.0% and 100% and <14.5%, respectively, and for saliva, between 100.9% and 107.5%, and <13.3%. No significant matrix effects were observed. Samples were stable at benchtop for 24 hours and -80°C, for at least 14 months (stability experiments ongoing). The ultrafiltration efficiency of unbound concentrations in plasma was lower than 85% (58.9%) but stable, and, therefore, the observed concentration should be corrected. CONCLUSIONS: Based on observations, the developed measure can determine levamisole concentrations in participant saliva samples.

Prevention of relapses with levamisole as adjuvant therapy in children with a first episode of idiopathic nephrotic syndrome: study protocol for a double blind, randomised placebo-controlled trial (the LEARNS study).

INTRODUCTION: Idiopathic nephrotic syndrome (INS) is characterised by a high relapse rate up to 80% after initial response to standard therapy with corticosteroids. Steroid toxicity is common and causes a great burden of disease that negatively influences the health-related quality of life (HRQoL). Recently, studies have shown that levamisole, an anthelminthic drug, significantly improves relapse-free survival in children with frequent relapses or steroid dependency. Compared with other steroid-sparing drugs, levamisole has relatively few side effects. We hypothesise that adding levamisole to standard therapy with corticosteroids in children with a first episode of INS will prevent relapses, decrease cumulative dosage of steroids used and improve HRQoL. This paper presents the study protocol for the LEARNS study (LEvamisole as Adjuvant therapy to Reduce relapses of Nephrotic Syndrome). METHODS AND ANALYSIS: An international, double-blind, placebo-controlled randomised trial will be conducted in 20 participating hospitals in the Netherlands and Belgium. Participants (n=92) with a first episode of INS, aged 2-16 years, who achieve remission after 4 weeks of oral prednisolone will be randomly assigned (1:1) to receive either levamisole 2.5 mg/kg alternate day or placebo added to prednisolone (18-week tapering schedule) for a total of 24 weeks. Follow-up will be until 2 years after first presentation. Additionally, parents and/or children will fill out five HRQoL questionnaires. Primary outcome of the LEARNS study is occurrence of relapses within 12 months after first presentation. Secondary outcomes include time to first relapse, cumulative steroid dose after 2 years, safety parameters and quality of life scores. ETHICS AND DISSEMINATION: The trial was approved by the Medical Ethical Committee. Results of the study will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NL6826, 2017-001025-41.

Age-dependent differences in pulmonary host responses in ARDS: a prospective observational cohort study.

BACKGROUND: Results from preclinical studies suggest that age-dependent differences in host defense and the pulmonary renin-angiotensin system (RAS) are responsible for observed differences in epidemiology of acute respiratory distress syndrome (ARDS) between children and adults. The present study compares biomarkers of host defense and RAS in bronchoalveolar lavage (BAL) fluid from neonates, children, adults, and older adults with ARDS. METHODS: In this prospective observational study, we enrolled mechanical ventilated ARDS patients categorized into four age groups: 20 neonates (< 28 days corrected postnatal age), 29 children (28 days-18 years), 26 adults (18-65 years), and 17 older adults (> 65 years of age). All patients underwent a nondirected BAL within 72 h after intubation. Activities of the two main enzymes of RAS, angiotensin converting enzyme (ACE) and ACE2, and levels of biomarkers of inflammation, endothelial activation, and epithelial damage were determined in BAL fluid. RESULTS: Levels of myeloperoxidase, interleukin (IL)-6, IL-10, and p-selectin were higher with increasing age, whereas intercellular adhesion molecule-1 was higher in neonates. No differences in activity of ACE and ACE2 were seen between the four age groups. CONCLUSIONS: Age-dependent differences in the levels of biomarkers in lungs of ARDS patients are present. Especially, higher levels of markers involved in the neutrophil response were found with increasing age. In contrast to preclinical studies, age is not associated with changes in the pulmonary RAS.

European Society of Pediatric Nephrology survey on current practice regarding recurrent focal segmental glomerulosclerosis after pediatric kidney transplantation.

INTRODUCTION: Primary FSGS is an important cause of ESRD in children. FSGS recurrence after kidney transplantation is associated with early graft loss. No guidelines for treatment of FSGS recurrence exist. We conducted a survey to gain insight into variation of treatment between centers. METHODS: A survey was sent to all members of the ESPN on behalf of the "Renal Transplantation" and "Idiopathic Nephrotic Syndrome" working groups. RESULTS: Fifty-nine nephrologists from 31 countries responded, reporting 807 FSGS patients, with 241 (30%) FSGS recurrences after transplantation. Recurrence varied from 0% to 100% between respondents. Native nephrectomy before or during transplantation was performed, respectively, always (37%), never (39%), or on clinical indication (17%). Half of the respondents started preventive treatment before transplantation, using PF (n = 10); R (n = 4); PF or IA, plus R (n = 9); cyclosporine (n = 2); or unknown (n = 4). Immunosuppressive therapy for patients without known mutations consisted of a combination of steroids, tacrolimus/cyclosporine, and MMF, with or without IL-2R-blockade in, respectively, 61% and 86% of the respondents. Sixty-three percent applied a similar regimen to patients with known mutations. FSGS recurrence was treated with PF or IA, plus R by 66% of respondents; 54% observed no response. Complete remission in >50% of patients was reported by 41% of the respondents. DISCUSSION: FSGS recurrence after transplantation is common, but varies greatly between centers. We found great variability in preventive and therapeutic treatment regimens. Future research should focus on predisposing factors, including biopsy findings and genetic mutations, and standardized treatment.

Incidence and Mortality of Acute Respiratory Distress Syndrome in Children: A Systematic Review and Meta-Analysis.

OBJECTIVES: Our understanding of the acute respiratory distress syndrome in children is limited, and literature is dominated by investigations in adult patients. Recent preclinical studies suggest that the susceptibility to and severity of acute respiratory distress syndrome in children could differ from that in adults. We assessed the incidence and mortality of acute respiratory distress syndrome reported in children in studies published in the last two decades. DATA SOURCES: Medline, Embase, and CINAHL databases were searched up to August 2014. STUDY SELECTION: Articles reporting study data on population- or PICU-based incidence and mortality of acute respiratory distress syndrome in children (> 36 wk gestation and < 18 yr old) were selected. DATA EXTRACTION: Two authors independently collected data and assessed methodological quality and risk of bias of selected studies. Pooled estimates of incidence and mortality were calculated using random-effects models. To explore heterogeneity, influence of study characteristics, including median year of conduct, study location, inclusion and exclusion criteria, and study design and quality, was assessed by meta-regression analysis. DATA SYNTHESIS: Twenty-nine studies reported on incidence and 32 on mortality. Pooled weighted estimate of the population-based and PICU-based incidence of pediatric acute respiratory distress syndrome was 3.5 (95% CI, 2.2-5.7) cases per 100,000 person years and 2.3% (95% CI, 1.9-2.9), respectively. Pooled weighted mortality was 33.7% (95% CI, 28.6-39.7). There were no trends over time, but mortality was significantly associated with study location. CONCLUSIONS: This systematic review and meta-analysis shows a low incidence but a high mortality. Its results also indicate that both incidence and mortality of pediatric acute respiratory distress syndrome have not changed over the last two decades and that mortality depends on the geographic location of studies.