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Angiotensin-converting enzyme inhibitors and angiotensin II type I receptor blockers delay progression of chronic kidney disease and have antiproteinuric effects beyond their effects on blood pressure. They are routinely used in adults; however, their efficacy and safety in children, in whom the causes of chronic kidney disease are significantly different relative to adults, is uncertain. Here we assessed an open-label extension of a previous 3-month blinded trial, in which the efficacy and tolerability of losartan was compared to placebo or amlodipine in 306 normotensive and hypertensive children with proteinuria. In this study, 268 children were re-randomized to losartan or enalapril and followed until 100 patients completed 3 years of follow-up for proteinuria and renal function. The least squares percent mean reduction from baseline in the urinary protein/creatinine ratio was 30.01% for losartan and 40.45% for enalapril. The least squares mean change from baseline in eGFR was 3.3 ml/min per 1.73 m2 for losartan and 7.0 ml/min per 1.73 m2 for enalapril. The incidence of specific adverse events such as hyperkalemia and renal dysfunction was low and similar in both groups. Both were generally well tolerated and, overall, fewer drug-related adverse events occurred with losartan than with enalapril. Thus, in children with proteinuria, losartan and enalapril significantly reduced proteinuria without any appreciable changes in eGFR, effects that were maintained throughout the study. Both losartan and enalapril were generally well tolerated. [ABSTRACT FROM AUTHOR]

Heparanase activity is dysregulated in children with steroid-sensitive nephrotic syndrome.Background.Immune cells express heparanase, an endoglycosidase, able to degrade heparan sulfate glycosaminoglycan (HSGAG) in the glomerular capillary wall (GCW) and potentially induce proteinuria. The aim of this study was to determine whether dysregulated heparanase expression is associated with the heavy proteinuria of childhood steroid-sensitive nephrotic syndrome (SSNS).Methods.Plasma and urinary heparanase activity and peripheral blood mononuclear cell (PBMC) mRNA heparanase levels[real-time polymerase chain reaction (PCR)] were measured in children with SSNS in relapse and remission. Plasma and urinary heparanase activity was determined in adult patients with nephrotic syndrome and in age- and gender-matched controls.Results.Plasma heparanase activity was reduced in SSNS with relapse (811.2 units) compared to remission (1147.96 units) (P= 0.003) and control subjects (1390.51 units) (P<0.001). In adult nephrotic syndrome, plasma heparanase activity was significantly lower in patients compared to controls. However, there was no difference between remission and relapse states. In children, urinary heparanase activity/urinary creatinine ratio was highest in SSNS relapse (14.26 units/mg) compared with remission (7.43 units/mg) (P= 0.016) and controls (2.29) (P<0.001). However, PBMC heparanase mRNA expression was not different between these three groups. In adult nephrotic syndrome, urinary heparanase activity/urinary creatinine levels were lower in both remission and relapse compared to controls and there was no difference between remission and relapse states.Conclusion.In childhood SSNS, there is a qualitative and quantitative difference in urinary heparanase activity expression that is not paralleled in adult nephrotic syndrom. These data suggest that dysregulated heparanase expression may play a significant role in the pathogenesis of SSNS, possibly through an abnormality in post-translational control of latent heparanase activation. [ABSTRACT FROM AUTHOR]

Focal segmental glomerulosclerosis (FSGS) is a histological lesion with many causes, including inherited genetic defects, with significant proteinuria being the predominant clinical finding at presentation. Mutations in COL4A3 and COL4A4 are known to cause Alport syndrome (AS), thin basement membrane nephropathy, and to result in pathognomonic glomerular basement membrane (GBM) findings. Secondary FSGS is known to develop in classic AS at later stages of the disease. Here, we present seven families with rare or novel variants in COL4A3 or COL4A4 (six with single and one with two heterozygous variants) from a cohort of 70 families with a diagnosis of hereditary FSGS. The predominant clinical finding at diagnosis was proteinuria associated with hematuria. In all seven families, there were individuals with nephrotic-range proteinuria with histologic features of FSGS by light microscopy. In one family, electron microscopy showed thin GBM, but four other families had variable findings inconsistent with classical Alport nephritis. There was no recurrence of disease after kidney transplantation. Families with COL4A3 and COL4A4 variants that segregated with disease represent 10% of our cohort. Thus, COL4A3 and COL4A4 variants should be considered in the interpretation of next-generation sequencing data from such patients. Furthermore, this study illustrates the power of molecular genetic diagnostics in the clarification of renal phenotypes. [ABSTRACT FROM AUTHOR]

Background. Children with minimal change nephrotic syndrome (MCNS) receive repeated courses of high dose oral prednisolone. No previous study has investigated the impact of this on final bone mineral density (BMD). Young adults previously reported in a large follow-up study of children with MCNS were invited to participate in a cross-sectional study. Areal BMD (aBMD) of the spine (L1-4), left femoral neck, and total left hip was measured using dual x-ray absorptiometry (DXA), and volumetric BMD (vBMD) of the distal radius was measured by pQCT. BMD results were compared with reference data provided by the manufacturers of the densitometers. Methods. Thirty-four (24 male) of the original cohort of 62 participated in the study. The mean (SD) final height Z score of the cohort was –0.45 (0.92) ( P= 0.007) and mean BMI Z score 1.62 (1.53) ( P < 0.0001). Results. There was a highly significant reduction in distal radial trabecular vBMD; the mean Z score was –0.95 (0.99) and T score –1.04 (1.01) (both P < 0.0001); however, there was no reduction in distal radial total vBMD, the mean Z score being 0.00 (0.95) and T score −0.08 (0.99), ( P= 0.99 and 0.66, respectively). The aBMD of the lumbar spine and femoral neck also showed a reduction in T scores [−0.45 (1.27), P= 0.045 and −0.49 (0.86), P= 0.002, respectively], but not Z scores [−0.37 (1.28) and −0.15 (0.87), respectively, both P= NS]. Total hip aBMD was not different from the control population. Conclusion. Adult survivors of childhood MCNS have a significant reduction in forearm trabecular vBMD, placing them at increased fracture risk at this site. [ABSTRACT FROM AUTHOR]

Trials in children with chronic kidney disease do not consistently report outcomes that are critically important to patients and caregivers. This can diminish the relevance and reliability of evidence for decision making, limiting the implementation of results into practice and policy. As part of the Standardized Outcomes in Nephrology-Children and Adolescents (SONG-Kids) initiative, we convened 2 consensus workshops in San Diego, California (7 patients, 24 caregivers, 43 health professionals) and Melbourne, Australia (7 patients, 23 caregivers, 49 health professionals). This report summarizes the discussions on the identification and implementation of the SONG-Kids core outcomes set. Four themes were identified; survival and life participation are common high priority goals, capturing the whole child and family, ensuring broad relevance across the patient journey, and requiring feasible and valid measures. Stakeholders supported the inclusion of mortality, infection, life participation, and kidney function as the core outcomes domains for children with chronic kidney disease., (Copyright © 2020. Published by Elsevier Inc.)

Steroid Resistant Nephrotic Syndrome (SRNS) in children and young adults has differing etiologies with monogenic disease accounting for 2.9-30% in selected series. Using whole exome sequencing we sought to stratify a national population of children with SRNS into monogenic and non-monogenic forms, and further define those groups by detailed phenotypic analysis. Pediatric patients with SRNS were identified via a national United Kingdom Renal Registry. Whole exome sequencing was performed on 187 patients, of which 12% have a positive family history with a focus on the 53 genes currently known to be associated with nephrotic syndrome. Genetic findings were correlated with individual case disease characteristics. Disease causing variants were detected in 26.2% of patients. Most often this occurred in the three most common SRNS-associated genes: NPHS1, NPHS2, and WT1 but also in 14 other genes. The genotype did not always correlate with expected phenotype since mutations in OCRL, COL4A3, and DGKE associated with specific syndromes were detected in patients with isolated renal disease. Analysis by primary/presumed compared with secondary steroid resistance found 30.8% monogenic disease in primary compared with none in secondary SRNS permitting further mechanistic stratification. Genetic SRNS progressed faster to end stage renal failure, with no documented disease recurrence post-transplantation within this cohort. Primary steroid resistance in which no gene mutation was identified had a 47.8% risk of recurrence. In this unbiased pediatric population, whole exome sequencing allowed screening of all current candidate genes. Thus, deep phenotyping combined with whole exome sequencing is an effective tool for early identification of SRNS etiology, yielding an evidence-based algorithm for clinical management., (Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

Background: Significant variability exists in the outcome of renal parenchymal inflammation following urinary tract infection (UTI) in childhood as some children experience renal parenchymal scarring (RPS) while others do not scar. Since TGF-beta1 is pro-fibrotic, we examined the role of this cytokine in RPS following UTI., Methods: Five polymorphisms of the TGF-beta1 gene were investigated as well as the relationship between these polymorphisms and TGF-beta1 production by peripheral blood mononuclear cells (PBMC) in vitro. DNA was isolated from 91 children shown to have developed RPS, 43 children with no evidence of scarring (NS) following UTI, and 171 healthy controls. Genotyping was performed by restriction fragment length polymorphism (RFLP). PBMC were isolated from a subgroup of 24 patients from the total population. Cells were stimulated with LPS + PMA + PHA and then TGF-beta1 production was determined by ELISA., Results: Comparing the NS with the RPS group, there was an increase in the -800 GA genotypes (18.6 vs. 7.4%, P=0.05; chi2) and the Leu10-->Pro CT (62.8 vs. 41.5%, P=0.021), and a decrease in the -509 TT genotype (0.0 vs. 8.5%, P=0.049). PBMC TGF-beta1 production was higher in those patients with the -800 GG compared to those with a GA genotype stimulation index [stimulated/unstimulated TGF-beta1 levels were 1.54 interquartile range (IQR) 1.42 to 1.75 vs. 1.19, IQR 0.94 to 1.51, P=0.031]., Conclusions: There is an association between the TGF-beta1 -800 GA, -509 TT and Leu10-->Pro CT genotypes and the presence or absence of RPS. The low TGF-beta1 producer status of the -800 GA genotype may protect against the development of a pro-fibrotic pathology.