FCGG renal biopsy network : first epidemiological report on pediatric renal diseases

Objective: In 2016, a regional renal biopsy network was founded as a collaboration between renal pathologists and nephrologists in order to standardize diagnosis and therapy. Uniform renal biopsy request and renal biopsy report forms were introduced, together with a new comprehensive list of renal pathology diagnoses for coding. The 2017-2018 epidemiological data of the pediatric patients (age= 0-17 years) are presented. Methods: Following informed consent and in compliance with GDPR, data registration consists of basic patient and categorical renal data, semi-structured medical information of renal histopathology and the clinical renal disease. Results: In 2017-2018, 92 renal biopsies were reported in pediatric patients or 3.6 per 100,000 pediatric inhabitants per year. Three clinical patterns were equally represented: only proteinuria >1g/day; only hematuria; and combination of proteinuria and hematuria. Acute or chronic renal failure were rare. In the youngest age group (0-5 years; N=26) minimal change disease predominated, followed by Henoch-Schönlein nephritis. The middle age group (6-11 years; N=32) mainly presented with disease characterized by hematuria: IgA nephropathy, Henoch-Schönlein nephritis and Alport’s disease. A more diverse renal disease spectrum was present in the highest age group (12-18 years; N=34): IgA nephropathy, different forms of proliferative glomerulonephritis and of nephrotic syndrome of childhood. Patients with a Caucasian descent presented with IgA nephropathy, while a nephrotic syndrome was more common in those without a Caucasian descent. Alport’s disease was particularly diagnosed in female patients, IgA nephropathy in male patients, and the gender distribution was equal in minimal change disease. Conclusion: The FCGG network provides an better cross-talk between renal pathologists and nephrologists. For the first time, reliable estimates of pediatric renal diseases based on histology are available. Genetic analyses are not yet included. Efforts to coordinate clinical care of pediatric renal diseases are ongoin

FCGG Renal Biopsy Network: first epidemiological report on pediatric renal disease in Flanders

FCGG Renal Biopsy Network: first epidemiological report on pediatric renal diseases Sevasti Karamaria1, Johan De Meester2, Amélie Dendooven3, Elena Levtchenko4, Noel Knops4, Koen Van Hoeck5, Dominique Trouet5, Reiner Mauel6, Ben Sprangers7, Wim Laurens8, Johan Vande Walle1, on behalf of the FCGG – NBVN working group 1 Department of Pediatrics, UZ Gent, Ghent; 2NBVN, Antwerp; 3Pathology Department, UZ Gent, Ghent; 4Department of Pediatrics, UZ Leuven, Leuven; 5Departement of Pediatrics, UZ Antwerpen, Antwerp; 6Department of Pediatrics, UZ Brussel, Brussels; 7Department of Nephrology, UZ Leuven, Leuven; 8Department of Nephrology, AZ Nikolaas, Sint-Niklaas. Objective: In 2016, a regional renal biopsy network was founded as a collaboration between renal pathologists and nephrologists in order to standardize diagnosis and therapy. Uniform renal biopsy request and renal biopsy report forms were introduced, together with a new comprehensive list of renal pathology diagnoses for coding. The 2017-2018 epidemiological data of the pediatric patients (age= 0-17 years) are presented. Methods: Following informed consent and in compliance with GDPR, data registration consists of basic patient and categorical renal data, semi-structured medical information of renal histopathology and the clinical renal disease. Results: In 2017-2018, 92 renal biopsies were reported in pediatric patients or 3.6 per 100,000 pediatric inhabitants per year. Three clinical patterns were equally represented: only proteinuria >1g/day; only hematuria; and combination of proteinuria and hematuria. Acute or chronic renal failure were rare. In the youngest age group (0-5 years; N=26) minimal change disease predominated, followed by Henoch-Schönlein nephritis. The middle age group (6-11 years; N=32) mainly presented with disease characterized by hematuria: IgA nephropathy, Henoch-Schönlein nephritis and Alport’s disease. A more diverse renal disease spectrum was present in the highest age group (12-18 years; N=34): IgA nephropathy, different forms of proliferative glomerulonephritis and of nephrotic syndrome of childhood. Patients with a Caucasian descent presented with IgA nephropathy, while a nephrotic syndrome was more common in those without a Caucasian descent. Alport’s disease was particularly diagnosed in female patients, IgA nephropathy in male patients, and the gender distribution was equal in minimal change disease. Conclusion: The FCGG network provides an better cross-talk between renal pathologists and nephrologists. For the first time, reliable estimates of pediatric renal diseases based on histology are available. Genetic analyses are not yet included. Efforts to coordinate clinical care of pediatric renal diseases are ongoing

Fibroepithelial ureteral polyps as a cause of ureteropelvic junction obstruction in children: A case report

We present a ten-year-old boy with episodic left flank pain, vomiting and microscopic hematuria. Imaging showed hydronephrosis characteristic for ureteropelvic junction (UPJ) obstruction. Pyeloplasty revealed a ureteral polyp, histopathologic examination confirmed the diagnosis of a fibroepithelial polyp. Fibroepithelial polyps of the ureter are a rare cause of UPJ obstruction in children. The most common presentation is episodic flank pain and/or hematuria. Imaging can be guiding, but pre-operative diagnosis is difficult. After surgical resection recurrence is rare

The influence of decision-making in tree ring-based climate reconstructions.

Tree-ring chronologies underpin the majority of annually-resolved reconstructions of Common Era climate. However, they are derived using different datasets and techniques, the ramifications of which have hitherto been little explored. Here, we report the results of a double-blind experiment that yielded 15 Northern Hemisphere summer temperature reconstructions from a common network of regional tree-ring width datasets. Taken together as an ensemble, the Common Era reconstruction mean correlates with instrumental temperatures from 1794-2016 CE at 0.79 (p < 0.001), reveals summer cooling in the years following large volcanic eruptions, and exhibits strong warming since the 1980s. Differing in their mean, variance, amplitude, sensitivity, and persistence, the ensemble members demonstrate the influence of subjectivity in the reconstruction process. We therefore recommend the routine use of ensemble reconstruction approaches to provide a more consensual picture of past climate variability

The North American tree-ring fire-scar network

Fire regimes in North American forests are diverse and modern fire records are often too short to capture important patterns, trends, feedbacks, and drivers of variability. Tree-ring fire scars provide valuable perspectives on fire regimes, including centuries-long records of fire year, season, frequency, severity, and size. Here, we introduce the newly compiled North American tree-ring fire-scar network (NAFSN), which contains 2562 sites, >37,000 fire-scarred trees, and covers large parts of North America. We investigate the NAFSN in terms of geography, sample depth, vegetation, topography, climate, and human land use. Fire scars are found in most ecoregions, from boreal forests in northern Alaska and Canada to subtropical forests in southern Florida and Mexico. The network includes 91 tree species, but is dominated by gymnosperms in the genus Pinus. Fire scars are found from sea level to >4000-m elevation and across a range of topographic settings that vary by ecoregion. Multiple regions are densely sampled (e.g., >1000 fire-scarred trees), enabling new spatial analyses such as reconstructions of area burned. To demonstrate the potential of the network, we compared the climate space of the NAFSN to those of modern fires and forests; the NAFSN spans a climate space largely representative of the forested areas in North America, with notable gaps in warmer tropical climates. Modern fires are burning in similar climate spaces as historical fires, but disproportionately in warmer regions compared to the historical record, possibly related to under-sampling of warm subtropical forests or supporting observations of changing fire regimes. The historical influence of Indigenous and non-Indigenous human land use on fire regimes varies in space and time. A 20th century fire deficit associated with human activities is evident in many regions, yet fire regimes characterized by frequent surface fires are still active in some areas (e.g., Mexico and the southeastern United States). These analyses provide a foundation and framework for future studies using the hundreds of thousands of annually- to sub-annually-resolved tree-ring records of fire spanning centuries, which will further advance our understanding of the interactions among fire, climate, topography, vegetation, and humans across North America

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

Abstract: 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

Caveolin-1 modulates the activity of the volume-regulated chloride channel

Caveolae are small invaginations of the plasma membrane that have recently been implicated in signal transduction. In the present study, we have investigated whether caveolins, the principal protein of caveolae, also modulate volume-regulated anion channels (VRACs).ICl,swell, the cell swelling-induced chloride current through VRACs, was studied in three caveolin-1-deficient cell lines: Caco-2, MCF-7 and T47D.Electrophysiological measurements showed that ICl,swell was very small in these cells and that transient expression of caveolin-1 restored ICl,swell. The caveolin-1 effect was isoform specific: caveolin-1β but not caveolin-1α upregulated VRACs. This correlated with a different subcellular distribution of caveolin-1α (perinuclear location) from caveolin-1β (perinuclear and peripheral).To explain the modulation of ICl,swell by caveolin-1 we propose that caveolin increases the availability of VRACs in the plasma membrane or, alternatively, that it plays a crucial role in the signal transduction cascade of VRACs

Screening for an underlying tubulopathy in children with growth failure, simply maths?

BACKGROUND: Involving pediatric nephrological input in the clinical diagnostic work-up of children with short stature, gave rise to the hypothesis that the presence of an underlying renal tubular disorder in children with short stature is possibly underestimated. This study focussed on the added value of calculated urinary fractional excretion (FE) in the early detection of tubular disorders in children with growth failure. METHODS: This trial was designed as an observational study analyzing the medical files of children between 5 and 16 years who had been referred for short stature to the pediatric endocrinology outpatient clinic at the University Hospital Antwerp between 25/01/2015 and 01/03/2019. Based on the laboratory results of the simultaneously taken blood and urine sample, the fractional excretions of Sodium, Chloride, Potassium, Calcium, Phosphate, and Magnesium were calculated. RESULTS: Of the 299 patients, 54 patients had at least one deviating fractional excretion value, requiring further investigation (control sample of blood and urine, kidney ultrasound or 24 h urine collection). Genetic screening for tubulopathies was performed in 19 patients. In 5 patients (1.7% of the total population) a tubulopathy was confirmed based on genetic analysis. CONCLUSION: This study explored the possibility of using fractional excretions as a screening test to obtain an earlier diagnosis of tubular disorders in children with short stature. Of the 299 patients, 5 patients were diagnosed with a genetically confirmed tubulopathy. Based on these results, we propose a flowchart for an additional work-up in all children with a deviating fractional excretion