Utility of kidney ultrasonography during initial evaluation of pediatric nephrotic syndrome.

BACKGROUND: Current guidelines note a gap in high-quality evidence regarding utility of kidney ultrasonography (KUS) during initial evaluation of nephrotic syndrome (NS) due to presumed minimal change disease (pMCD). However, KUS is frequently obtained at our institution. This retrospective chart review assessed incidence and impact of abnormal sonographic findings in these patients. METHODS: Patients 1-18 years, newly diagnosed at our institution with NS from pMCD between 2011 and 2021, were identified. Hypertension, urinalysis, kidney function, and steroid responsiveness data were collected. Imaging findings were abstracted from radiology reports. Clinical impact of KUS was defined by actions taken in response to KUS. RESULTS: A total of 173 patients identified with new NS; 98 met inclusion criteria. Of these, 54% had KUS during the initial encounter. Demographic and laboratory data did not differ between those with and without KUS. KUS were abnormal in 70% of studies: increased kidney echogenicity (39.6%) and nephromegaly (35.8%) were the most common abnormal findings. Other findings included decreased corticomedullary differentiation, lobular kidney contour, solitary simple kidney cyst, and mild unilateral hydronephrosis. Steroid resistance was not associated with either nephromegaly or abnormal echogenicity. CONCLUSIONS: Our data showed no clinically relevant ultrasound findings causing deviations from the standard of care for pMCD. There was no association between KUS findings and steroid resistance. These data suggest there is little to no benefit from routine KUS imaging in patients with pMCD upon initial presentation. A higher resolution version of the Graphical abstract is available as Supplementary information.

The association between dental caries and steroid-sensitive nephrotic syndrome in children.

BACKGROUND: Pathogenesis and relapse of steroid-sensitive nephrotic syndrome (SSNS) are primarily associated with infection. Dental caries is the most common chronic progressive oral infection in children. However, clinical studies of SSNS combined with dental caries in children are rare. METHODS: In our retrospective cohort study from January 2021 to June 2022, 145 children with SSNS were included in the baseline analysis and 105 in the follow-up analysis. The follow-up period was 1 year. The primary study endpoints were the relapse-free period and frequently relapsing nephrotic syndrome (FRNS). Secondary endpoints included the number and triggers of relapses and concomitant medications. RESULTS: The median age was 5.5 years, with a caries rate of 60.7%, the mean DMFT/dmft was 3.86, and the caries filling rate was 1.6%. Except for the lower proportion of high household income and high parental education observed in the caries group, no statistical differences were found when comparing the other baseline data with the non-caries group. The caries group had a shorter relapse-free period and a lower 1-year cumulative relapse-free survival rate (HR = 1.90, 95% CI 1.17-3.09, P = 0.009). Univariate regression analysis showed caries associated with FRNS (OR = 2.714, 95% CI 1.021-7.219, P = 0.045), but the correlation no longer remained in the multivariate analysis. Additionally, seven cases of caries-derived pulpal periapical inflammation triggered SSNS relapses. The caries group had more infection triggers and concomitant medication use. CONCLUSION: Dental caries and relapse of SSNS are potentially associated, but careful evaluation is needed.

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.

New insights from the genetic work-up in early onset nephrotic syndrome: report from a registry in western India.

BACKGROUND: Eighty-five percent of infants with congenital nephrotic syndrome (CNS) and 66% with infantile NS (INS) are likely to have a monogenic etiology. There exists a significant genetic variability between different regions and ethnic groups. This study aimed to determine the genetic defects in children with CNS and INS by establishing a registry in western India. METHODS: In this cross-sectional study, pediatric nephrologists from 13 private and government institutions shared relevant clinical data and details of the genetic evaluation of children presenting with NS within the first year of life. RESULTS: The median age at presentation was 9 months (range 1-23, IQR 3-13 months), history of consanguinity between parents existed in 14 patients (34%), family history of similar illness in 6 (15%), and extra-renal manifestations in 17 (41%). Twenty-five (61%) were confirmed to have a monogenic etiology. NPHS1 gene was the most implicated (9/25) followed by PLCE1 (5/25). There were 12 variants of uncertain significance (VUS) involving 10 genes (10/25, 40%), and no definite genetic abnormality was found in 4 (25%). A re-analysis of these VUS attempted 2-3 years later facilitated reclassification of 7/12 (58%); increasing the diagnostic yield from 61 to 68.2%. CONCLUSIONS: Consistent with worldwide data, variants in NPHS1 gene were the most common cause of NS in infancy; however, PLCE1 was implicated more frequently in our cohort. NUP93 and COL4A3 were reported in early onset NS for the first time. Reclassification of VUS should be attempted, if feasible, since it may lead to a useful revision of diagnosis.

Adult survivors of childhood-onset steroid-dependent and steroid-resistant nephrotic syndrome treated with cyclosporine: a long-term single-center experience.

BACKGROUND: Although evidence has confirmed that cyclosporine (CS) is efficacious against childhood-onset steroid-dependent and steroid-resistant nephrotic syndrome (SD/SRNS), some patients may continue to relapse during adulthood. However, predictive factors for adult active disease and kidney complications, such as chronic kidney disease (CKD) and hypertension, in this cohort remain unknown. METHODS: We conducted a retrospective study on the long-term outcomes of 81 young adults with childhood-onset SD/SRNS treated with CS. The primary endpoint was the probability of active disease into adulthood. The secondary endpoint was the probability of developing kidney complications. RESULTS: At the last follow-up (median age, 23.2 years; median disease duration, 15.8 years), 44 adult patients (54%) continued to have active disease, whereas 16 patients developed CKD or hypertension, respectively. The proportion of patients developing kidney complications was similar between the active disease and long-term remission groups. Young age at NS onset and history of relapse during the initial CS (median, 31 months) were independent predictive factors for active disease. Acute kidney injury at NS onset, focal segmental glomerulosclerosis, and irreversible CS nephrotoxicity were identified as risk factors for the development of CKD, whereas older age was identified as a risk factor for the development of CKD and hypertension. CONCLUSIONS: More than 50% of adult survivors treated with CS continued to have active disease, and each 20% developed CKD or hypertension. A long-term follow-up is necessary for patients with SD/SRNS to identify the development of kidney complications later in adulthood that can be attributed to prior disease and CS treatment in childhood, irrespective of disease activity. A higher resolution version of the Graphical abstract is available as Supplementary information.

Longitudinal analysis of blood pressure and lipids in childhood nephrotic syndrome.

BACKGROUND: In the current study, longitudinal BP and lipid measurements were examined in a NEPTUNE cohort of children with newly diagnosed nephrotic syndrome (cNEPTUNE). We hypothesized that hypertensive BP and dyslipidemia would persist in children with nephrotic syndrome, regardless of steroid treatment response. METHODS: A multi-center longitudinal observational analysis of data obtained from children < 19 years of age with new onset nephrotic syndrome enrolled in the Nephrotic Syndrome Study Network (cNEPTUNE) was conducted. BP and lipid data were examined over time stratified by disease activity and steroid exposure. Generalized estimating equation regressions were used to find determinants of hypertensive BP and dyslipidemia. RESULTS: Among 122 children, the prevalence of hypertensive BP at any visit ranged from 17.4% to 57.4%, while dyslipidemia prevalence ranged from 40.0% to 96.2% over a median of 30 months of follow-up. Hypertensive BP was found in 46.2% (116/251) of study visits during active disease compared with 31.0% (84/271) of visits while in remission. Dyslipidemia was present in 88.2% (120/136) of study visits during active disease and in 66.0% (101/153) while in remission. Neither dyslipidemia nor hypertensive BP were significantly different with/without medication exposure (steroids and/or CNI). In regression analysis, male sex and urine protein:creatinine ratio (UPC) were significant determinants of hypertensive BP over time, while eGFR was found to be a determinant of dyslipidemia over time. CONCLUSIONS: Results demonstrate persistent hypertensive BPs and unfavorable lipid profiles in the cNEPTUNE cohort regardless of remission status or concurrent steroid or calcineurin inhibitor treatment.

Pneumococcal carriage and serotype distribution in children with nephrotic syndrome.

BACKGROUND: Patients with nephrotic syndrome (NS) are at a higher risk of developing invasive pneumococcal disease (IPD). Pneumococcal carriage studies are helpful tools for detecting potentially infectious serotypes and guiding immunization efforts. Pneumococcal nasopharyngeal colonization is common, and IPD can easily occur in an immunosuppressed state. Limited information is available regarding the frequency of pneumococcal carriage in individuals with NS. The aim of this study was to evaluate pneumococcal carriage and serotype distribution in children with NS. METHODS: Pneumococcal carriage was detected by real-time PCR assays from nasopharyngeal swab samples from 98 children with NS, and 100 healthy controls. Isolates were serotyped by real-time PCR. RESULTS: The pneumococcal carriage rate was 44.9% in children with NS. Regarding the recommendation about pneumococcal immunization in children with NS, the vaccination rate was low. Also, non-PCV13 serotypes have been detected in at least 25% of PCV13-vaccinated children. There is no statistically significant difference in total pneumococcal carriage rate, PCV13 serotype carriage rate, or non-PCV13 serotype carriage rate between children with NS and healthy controls (p > 0.05 for all). CONCLUSIONS: The pneumococcal carriage rate was similar between children with NS and healthy controls. However, because children with NS have an increased risk for IPD, the serotype distribution of children with NS can demonstrate the improved protection offered by new pneumococcal vaccines. Regular monitoring for IPD is crucial for assessing the evolving sero-epidemiology of pneumococcal infections and evaluating the effectiveness of vaccines for children with NS.

Prevalence and associated factors of infection in children with nephrotic syndrome aged 2-18 years in the northwest and east Amhara region, Ethiopia: a multi-center cross-sectional retrospective study.

BACKGROUND: Infection is the most common complication of pediatric patients with nephrotic syndrome. The factors associated with infection in nephrotic syndrome are lacking. The objective of the study was to identify the prevalence and associated factors among children with nephrotic syndrome aged 2 to 18 years. METHODS: We conducted a hospital-based retrospective cross-sectional study. The data collector installed an Epi5 collector electronic data-collecting tool from Google Play. Then, we exported the data to Stata version 15.1 for analysis. The mean, standard deviation, frequency, and percentage were used for descriptive statistics. The logistic regression model was used to identify the factors associated with infection. RESULTS: In this study, the prevalence of infection among nephrotic syndrome children is 39.8% (95%CI: 30.7, 49.7). The types of infection identified were pneumonia, urinary tract infection, diarrheal disease, cutaneous fungal infection, intestinal parasitic infection, and sepsis. The presence of hematuria increased the odds of infection by 5-times. On the other hand, low level of serum albumin increased the odds of infection by 7%. Being a rural resident increased the odds of infection by 3.3-times as compared to urban. CONCLUSIONS: Serum albumin level, presence of hematuria, and rural residence were significantly associated with infection. We recommended a longitudinal incidence study on large sample size at multicenter to strengthen this finding.

Hypothyroidism among children and adolescents with nephrotic syndrome in Mulago National Referral Hospital, Kampala, Uganda; a cross-sectional study.

BACKGROUND: Nephrotic syndrome (NS) is the commonest glomerular disease among children. It is characterized by heavy proteinuria and is a risk factor for hypothyroidism in the affected children. Hypothyroidism is of concern because it affects the physical and intellectual development of children and adolescents. This study sought to establish the prevalence and factors associated with hypothyroidism among children and adolescents with NS. METHODS: A cross-sectional design was used to study 70 children and adolescents aged 1-19 years diagnosed with nephrotic syndrome and being followed up in the kidney clinic in Mulago National Referral Hospital. Questionnaires were used to collect patients' socio-demographics and clinical information. A blood sample was taken for analysis for thyroid stimulating hormone (TSH) and free thyroxine (FT4), renal function tests and serum albumin. Hypothyroidism included both overt and subclinical forms. Overt hypothyroidism was defined as TSH level > 10 mU/L and FT4 < 10pmol/L, or FT4 < 10pmol/l with normal TSH, or TSH < 0.5mU/l. Sub-clinical hypothyroidism was defined as TSH ranging between 5 and10 mU/L with normal age appropriate FT4 levels. Urine samples were collected and taken for a dipstick examination. The data was analyzed using STATA version 14. The Bayesian Logistic regression analysis approach was used to estimate odds ratios (OR) and their associated 95% credible intervals. All predictor variables with p value < 0.05 at frequentist statistical analysis were considered significant. RESULTS: The mean age (standard deviation) of participants was 9 years (3.8). There were more males; 36 of 70 (51.4%). The prevalence of hypothyroidism was 23% (16/70 participants). Of the 16 children with hypothyroidism, 3 (18.7%) had overt hypothyroidism while 13 had subclinical hypothyroidism. Only low serum albumin was found to be strongly associated with hypothyroidism; Bayesian OR 132.57 (CI 9.13-567.10) with a frequentist OR of 37 and a p value of 0.001. CONCLUSION: The prevalence of hypothyroidism among children and adolescent with nephrotic syndrome attending Mulago Hospital paediatric kidney clinic was 23%. Hypoalbuminemia was found to be associated with hypothyroidism. Therefore, children and adolescents that have severely low levels of serum albumin should be screened for hypothyroidism and linked to endocrinologists for care.

Risk factors and renal outcomes of AKI in children with secondary steroid-resistant nephrotic syndrome.

BACKGROUND: Acute kidney injury (AKI) is increasingly prevalent in children with nephrotic syndrome (NS). It is associated with adverse outcomes in NS, especially steroid-resistant nephrotic syndrome (SRNS). The incidence, risk factors and outcomes of AKI in secondary SRNS remain undefined. The main objectives of this study were to determine the risk factors and prognosis of AKI in hospitalized children with secondary SRNS. MATERIAL AND METHODS: This retrospective study was conducted from January 2014 to December 2019, involving 172 hospitalizations with secondary SRNS admitted to the First Affiliated Hospital of Sun Yat-sen University. AKI was defined and classified in accordance with the 2012 Kidney Disease Improving Global Outcomes (KDIGO) guidelines. RESULTS: AKI was found in 67 (39.0%) of 172 hospitalizations with secondary SRNS. Average age of onset in our group is 4.4 (3.1, 6.7) years with AKI and 3.7 (1.8, 5.6) years without AKI. Urea nitrogen level is 5.9 (4.1, 10.0) mmol/L with AKI and 5.1 (3.7, 7.0) mmol/L. Uric acid level is 446.0 (340.0, 567.0) umol/L with AKI and 401.0 (303.0, 496.0) umol/L. 24-h urinary protein level is 4.14 (2.9, 6.5) g with AKI and 2.5 (1.3, 5.3) without AKI. Multivariate logistic regression revealed that infection (OR = 5.287; 95% confidence interval, 2.349 to 11.899; p < 0.001), age at onset (OR = 1.180; 95% confidence interval, 1.032 to 1.349; p = 0.015) and uric acid level (OR = 1.003; 95% confidence interval, 1.000 to 1.006; p = 0.031) were significantly associated with the development of AKI in children with secondary SRNS. Among 72 children with secondary SRNS, six went to end-stage kidney disease (ESKD). Children in the AKI group were more likely to progress to ESKD compared with children in the non-AKI group (p = 0.017) with a median follow-up of 48.5months. CONCLUSION: AKI occurred in 39.0% of total hospitalizations associated with secondary SRNS. Risk factors including infection, age of onset, and uric acid level are associated with AKI in children with secondary SRNS. Furthermore, AKI was identified as a risk factor for the progression of secondary SRNS to ESKD.

Histopathologic Characteristics of Childhood Nephrotic Syndrome in a Tertiary Health Facility in Nigeria.

BACKGROUND: Globally, the predominant histopathologic characteristic of childhood nephrotic syndrome has been minimal change nephropathy (MCN). However, some studies from Africa and Nigeria have revealed otherwise. It is imperative that this pattern is re-examined from time to time given changing disease and environmental dynamics from place to place. OBJECTIVE: This study aimed to determine the histopathological characteristics of childhood nephrotic syndrome in Ilorin, northcentral Nigeria. METHODS: A prospective study of all new patients aged 2-14 years who presented with clinical features of nephrotic syndrome between January 2010 to December 2023 at the University of Ilorin Teaching Hospital, Ilorin was carried out. All eligible patients underwent renal biopsy. RESULTS: A total of 47 children with nephrotic syndrome were biopsied comprising of 21 males and 26 females making an M: F ratio of 1:1.2. The age range of subjects was 2-14 years with a mean of 7.8 ±3.6 years. The most common histological type of nephrotic syndrome was minimal change nephrotic syndrome (MCNS) which occurred in 35(74.5%) children followed by membranoproliferative glomerulonephritis (MPGN) in 5(10.6%) and focal segmental glomerulosclerosis (FSGS) in 2(4.3%). Of the 35 MCNS patients, 31(88.6%) were steroid sensitive while 4(11.4%) were steroid resistant. CONCLUSION: The predominant histopathological characteristic of childhood nephrotic syndrome was minimal change nephrotic syndrome, which was mostly steroid-sensitive.

CONTEXTE: Au niveau mondial, la principale caractéristique histopathologique du syndrome néphrotique de l'enfant a été la néphropathie à lésions minimales (NLM). Cependant, certaines études en Afrique et au Nigeria ont montré des résultats différents. Il est essentiel de réévaluer ce modèle régulièrement en raison de l'évolution des maladies et de l'environnement d'un endroit à l'autre. OBJECTIF: Cette étude visait à déterminer les caractéristiques histopathologiques du syndrome néphrotique de l'enfant à Ilorin, dans le nord-centre du Nigeria. MÉTHODES: Une étude prospective de tous les nouveaux patients âgés de 2 à 14 ans présentant des signes cliniques de syndrome néphrotique entre janvier 2010 et décembre 2023 à l'hôpital universitaire d'Ilorin, à Ilorin, a été réalisée. Tous les patients éligibles ont subi une biopsie rénale. RÉSULTATS: Au total, 47 enfants atteints du syndrome néphrotique ont été biopsiés, dont 21 garçons et 26 filles, soit un ratio H/F de 1/1,2. La tranche d'âge des sujets était de 2 à 14 ans avec une moyenne de 7,8 ± 3,6 ans. Le type histologique le plus fréquent du syndrome néphrotique était la néphropathie à lésions minimales (NLM), obser vée chez 35 (74,5 %) enfants, suivie de la glomérulonéphrite membranoproliférative (GMPN) chez 5 (10,6 %) et du sclérose segmentaire et focale (SSF) chez 2 (4,3 %). Parmi les 35 patients atteints de NLM, 31 (88,6 %) étaient cortico-sensibles et 4 (11,4 %) cortico-résistants. CONCLUSION: La principale caractéristique histopathologique du syndrome néphrotique de l'enfant était la néphropathie à lésions minimales, qui était principalement cortico-sensible. MOTS-CLÉS: Syndrome néphrotique, Enfant, Histopathologie, Nigeria.

Steroid induced ocular complications in idiopathic nephrotic syndrome: a cross sectional single center study.

Objective: To screen children receiving steroids to identify ocular complications and their prevalence. METHODS: The cross-sectional study was conducted at the Paediatric Nephrology and Ophthalmology departments of the Sindh Institute of Urology and Transplantation, Karachi, from May to October 2022, and comprised patients who received at least 1500mg cumulative steroid dose for a minimum of 3 months. They were screened for steroidsensitive or steroid-resistant nephrotic syndrome. Ocular examinations, including visual acuity, intraocular pressure, slit-lamp biomicroscopy, lens examination and fundus evaluation, were performed. Data was analysed using SPSS 22. RESULTS: Of the 124 subjects with mean age 8.15±2.03 years (range: 6-12 years), 64(51.6%) were boys. Steroidsensitive nephrotic syndrome was present in 97(78%) cases. The mean cumulative steroid dose was 3999.31±1564.22mg. Overall, 36(29%) children developed ocular complications. Blood pressure, number of relapses and the duration of treatment were significantly associated (p<0.05). Conclusion: Refractive errors were the most frequent side effects/complication seen among children with nephrotic syndrome who received prolonged corticosteroids.

Changes in Patterns of Infection Associated with Pediatric Idiopathic Nephrotic Syndrome: A Single-Center Experience in Japan.

OBJECTIVE: We studied infection rates and risk factors for infection in current patients with idiopathic nephrotic syndrome (INS). STUDY DESIGN: This retrospective cohort study included the clinical data for children with diagnosed INS in our center between January 2010 and December 2020. The infection rates and risk factors were analyzed. RESULTS: We enrolled 187 patients, including 85 cases with steroid-dependent/frequently relapsing nephrotic syndrome and 45 with steroid-resistant nephrotic syndrome. Infection was observed a total of 84 times in 55 patients (95.5 per 1000 person-years). Pneumonia was the most common infection (21 cases, 23.9 per 1000 person-years), followed by febrile neutropenia (12 cases, 13.7 per 1000 person-years), whereas peritonitis and bacteremia were observed in only 3 and 2 cases, respectively. The multivariate analyses by logistic regression showed that rituximab treatment was significantly associated with infections in pediatric INS (P = .001). The infection rate during the B-cell-depleted state with immunosuppressants (318 per 1000 person-years) was greater than that with normal B-cell count with immunosuppressants (109 per 1000 person-years) or without immunosuppressants (76 per 1000 person-years). CONCLUSION: Common infections, such as peritonitis and bacteremia, decreased, whereas infections associated with medication (eg, rituximab) increased. The rate of infection increases during B-cell depletion after treatments with rituximab and other immunosuppressants.

Twenty-four-Year Trends in Incidence and Mortality of Nephrotic Syndrome: A Population-Based Cohort Study.

BACKGROUND: With the increasing prevalence of risk factors for nephrotic syndrome, updated epidemiologic data on the syndrome are needed. We examined its age- and sex-specific incidence, histopathology, and mortality over 24 years. METHODS: This nationwide cohort study included all adults with first-time-recorded nephrotic syndrome in Denmark during 1995-2018 using the Danish National Patient Registry. We obtained data on age, sex, hospital-diagnosed comorbidities, and histopathologic findings. We computed overall, and age- and sex-specific, incidence rates of nephrotic syndrome, 1- and 5-year mortality by calendar period, and 1-year hazard ratios (HRs) of death using Cox models. RESULTS: We identified 3,970 adults with first-time nephrotic syndrome diagnosis. Incidence was highest in men and increased with age to 11.77 per 100,000 person-years (95% confidence interval [CI]: 10.21-13.32) in men aged 80+ years, and 6.56 per 100,000 person-years (95% CI: 5.71-7.41) in women aged 80+ years. Incidence of nephrotic syndrome increased from 3.35 per 100,000 person-years (95% CI: 3.12-3.58) in 1995-2000 to 4.30 per 100,000 person-years (95% CI: 4.05-4.54) in 2013-2018. Over time, 1-year mortality of nephrotic syndrome was stable at 13%-16%, but HR of death was 0.54 (95% CI: 0.42-0.69), adjusted for age, sex, and comorbidities, in 2013-2018 compared with 1995-2000. Subdistribution of glomerulopathies was stable over time with membranous nephropathy and minimal change disease being the most common. CONCLUSION: During 1995-2018, the incidence of recorded adult nephrotic syndrome increased slightly, and the adjusted mortality of nephrotic syndrome decreased markedly. Whether these findings reflect changes in epidemiology or awareness and coding of nephrotic syndrome, remains to be clarified.

Childhood nephrotic syndrome and the clinical profile of thromboembolism: a systematic review and meta-analysis.

Nephrotic syndrome (NS) is a common kidney disease of childhood, affecting 2-7 children per 100,000. A potentially life-threatening complication affecting children with NS is thromboembolism (TE). However, there remains a paucity of information regarding the burden of TE and its associated risk factors in this population. A systematic review was performed on observational studies examining TE events in children with NS, published in Medline, Embase, CINAHL, and CENTRAL, until May 2021. Meta-analyses were separately conducted on the prevalence of TE within articles exclusively studying children with congenital NS and among articles including all forms of NS. Out of 13,626 articles, 22 were included (14,290 children). The pooled prevalence of symptomatic TE among articles including patients with all forms of NS was 3.60% (95% CI 1.95-5.63), which increased to 8.70% (95% CI 5.11-12.96) in articles with exclusively congenital NS patients. Children with steroid-resistant NS were at a higher risk of TE compared to steroid-sensitive children (OR 4.40, 95% CI 1.34-15.59, p = 0.013). Focal segmental glomerulosclerosis was the most common histology present in patients with TE (51.2%). Children diagnosed with NS have a significant risk of TE, particularly in patients with congenital NS and steroid resistance. IMPACT: The prevalence of symptomatic thromboembolic (TE) events in children with nephrotic syndrome (NS) was 3.60% (95% CI 1.95-5.63), which increased more than two-fold in children with congenital NS to 8.70% (95% CI 5.11-12.96). Potential risk factors for TE events in this population include congenital forms of NS and steroid resistance. This review provides a better estimate of the prevalence of TE in children with NS, while identifying potentially higher-risk populations who may benefit from TE screening and thromboprophylaxis.

Hiding in plain sight: genetics of childhood steroid-resistant nephrotic syndrome in Sub-Saharan Africa.

Steroid-resistant nephrotic syndrome (SRNS) is the most severe form of childhood nephrotic syndrome with an increased risk of progression to chronic kidney disease stage 5. Research endeavors to date have identified more than 80 genes that are associated with SRNS. Most of these genes regulate the structure and function of the podocyte, the visceral epithelial cells of the glomerulus. Although individuals of African ancestry have the highest prevalence of SRNS, especially those from Sub-Saharan Africa (SSA), with rates as high as 30-40% of all cases of nephrotic syndrome, studies focusing on the characterization and understanding of the genetic basis of SRNS in the region are negligible compared with Europe and North America. Therefore, it remains unclear if some of the variants in SRNS genes that are deemed pathogenic for SRNS are truly disease causing, and if the leading causes of monogenic nephrotic syndrome in other populations are the same for children in SSA with SRNS. Other implications of this lack of genetic data for SRNS in the region include the exclusion of children from the region from clinical trials aimed at identifying potential novel therapeutic agents for this severe form of nephrotic syndrome. This review underlines a need for concerted efforts to advance the genetic basis of SRNS in children in SSA. Such endeavors will complement global efforts at understanding the genetic basis of nephrotic syndrome.

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.

Rituximab-associated hypogammaglobulinemia in children with idiopathic nephrotic syndrome: results of an ESPN survey.

BACKGROUND: There is paucity of information on rituximab-associated hypogammaglobulinemia (HGG) and its potential infectious consequences in children treated for idiopathic nephrotic syndrome (INS). METHODS: A survey was distributed by the European Society Pediatric Nephrology to its members. It addressed the screening and management practices of pediatric nephrology units for recognizing and treating RTX-associated HGG and its morbidity and mortality. Eighty-four centers which had treated an overall 1328 INS children with RTX responded. RESULTS: The majority of centers administered several courses of RTX and continued concomitant immunosuppressive therapy. Sixty-five percent of centers routinely screened children for HGG prior to RTX infusion, 59% during, and 52% following RTX treatment. Forty-seven percent had observed HGG prior to RTX administration, 61% during and 47% >9 months following treatment in 121, 210, and 128 subjects respectively. Thirty-three severe infections were reported among the cohort of 1328 RTX-treated subjects, of whom 3 children died. HGG had been recognized in 30/33 (80%) of them. CONCLUSIONS: HGG in steroid-dependent/frequently relapsing nephrotic syndrome (SDNS/FRNS) children is probably multifactorial and can be observed prior to RTX administration in children with SDNS/FRNS. Persistent HGG lasting >9 months from RTX infusion is not uncommon and may increase the risk of severe infections in this cohort. We advocate for the obligatory screening for HGG in children with SDNS/FRNS prior to, during, and following RTX treatment. Further research is necessary to identify risk factors for developing both HGG and severe infections before recommendations are made for its optimal management. A higher resolution version of the Graphical abstract is available as Supplementary information.

Relapse rate in children with nephrotic syndrome during the SARS-CoV-2 pandemic.

BACKGROUND: Viral upper respiratory tract infections trigger nephrotic syndrome relapses. Few data exist on the impact of the SARS-CoV-2 pandemic on the risk of relapse in children with idiopathic nephrotic syndrome (INS). METHODS: In a Belgian and Italian cohort of children with INS, we performed a retrospective analysis on the number and duration of relapses observed in 3 different periods in 2020: first COVID period, February 15-May 31; second COVID period, June 1-September 14; third COVID period, September 15-December 31. Relapse rates were compared to those of the previous 5 years (PRECOVID period). For the years 2019 and 2020, all causes and INS relapse-related hospitalizations were recorded. Hospitalizations and deaths due to SARS-CoV-2 infection were also recorded. In the Belgian cohort, SARS-CoV-2 serologies were performed. RESULTS: A total of 218 patients were enrolled, and 29 (13.3%) were diagnosed with new-onset INS during the COVID period. Relapse rates per 1000 person-days were as follows: 3.2 in the PRECOVID period, 2.7 in the first COVID period, 3.3 in the second COVID period, and 3.0 in the third COVID period. The incidence rate ratio for the total COVID period was 0.9 (95%CI 0.76 to 1.06; P = 0.21) as compared to the PRECOVID period. During 2020, both the proportion of patients hospitalized for recurrence (14.2% vs. 7.6% in 2019; P = 0.03) and the rate of hospitalization for recurrence (IRR 1.97 (95%CI 1.35 to 2.88); P = 0.013) were higher compared to 2019. In December 2020, anti-SARS-CoV-2 antibodies were detected in 31% of the Belgian cohort. Patients with positive and negative SARS-CoV-2 serology did not differ significantly in relapse rate (2.4 versus 4.2 per 1000 person-days). The number of new INS cases remained similar between 2020, 2019, and 2018. CONCLUSION: The first year of the SARS-CoV-2 pandemic did not significantly affect the relapse rate in children with INS. No serious infections were reported in this population of immunosuppressed patients. A higher resolution version of the Graphical abstract is available as Supplementary information.

Family functioning and quality of life among children with nephrotic syndrome during the first pandemic wave.

BACKGROUND: During the SARS-CoV-2 global pandemic, one of the longest lockdowns worldwide occurred in Ontario, Canada, during the first wave. For parents and children managing care at home and at risk for COVID-19, the impact on their psychosocial functioning is unknown. METHODS: A total of 122 families of children aged 2-18 years were enrolled as part of the prospective cohort of childhood nephrotic syndrome and completed a survey during the first wave of the pandemic (August 21-December 10), 2020. In a subset, 107 families had data available pre-pandemic to assess change. Validated measures included the McMaster Family Assessment Device (FAD) for parents and children ≥ 12 years for family functioning, the Patient Health Questionnaire for Depression and Anxiety (PHQ-4) for both parent and child, and Pediatric Quality of Life Inventory (PEDSQL™-V4) for children only. Scores were compared using Student's t-test or the Mann-Whitney U test, as appropriate. RESULTS: Among the 107 children, 71% were male with a mean age of 9 years old at the time of questionnaire completion, and the mean age of parents was 41 years old. Parents and children reported that family functioning improved during COVID (parent: p < 0.01; child: p = 0.05). Children's overall HRQOL declined (p = 0.04), specifically increased sleep disruption (p = 0.01). Increasing child age was associated with a greater sleep disruption (ß = - 1.6 [IQR: - 2.6, - 0.67]) and a related decrease in QOL (ß = - 1.0 [IQR: - 1.7, - 0.2]), adjusted for sex. CONCLUSIONS: Despite the positive effects of family dynamics during the first wave, there were negative effects of sleep disruptions and reduced quality of life in children, especially among older children. A higher resolution version of the Graphical abstract is available as Supplementary information.