Kidney and urological involvement in Down syndrome: frequent, underestimated, but associated with impaired quality of life and risk of kidney failure.

Patients with Down syndrome (DS) are at risk of multiorgan dysfunction; kidney and urological impairment are common. This is due to a likely increased risk of congenital kidney and urological malformations (odds ratio of 4.5 compared to the general population in one study), more frequent associated comorbidities at risk of kidney dysfunction (such as prematurity in 9-24% of children, intrauterine growth retardation or low birth weight in 20%, and congenital heart disease in 44%), and more frequent lower urinary tract dysfunction (reported in 27-77% of children with DS). If present, malformations and comorbidities at risk of kidney dysfunction warrant regular kidney monitoring in addition to their treatment. Serum creatinine in children with DS has been shown to be higher than in the general population and asymptomatic hyperuricemia is reported in 12-33% of children or young adults with DS. Moreover cryptorchidism and testicular cancer are also more common and should be detected by clinical examination. Thus, persons with DS at risk of presenting kidney and urological impairment should be identified by prenatal ultrasonography, comorbidities at risk of kidney sequelae considered, and during regular medical follow-up, clinically examined and questioned to diagnose testicular anomalies and lower urinary tract dysfunction. This is of importance as such kidney and urological impairments are associated with impaired quality of life and mental health, and risk of kidney failure.

Hemodiafiltration for children with stage 5 chronic kidney disease: technical aspects and outcomes.

Despite significant medical and technical improvements in the field of dialysis, the morbidity and mortality among patients with chronic kidney disease (CKD) stage 5 on dialysis remains extremely high. Hemodiafiltration (HDF), a dialysis method that combines the two main principles of hemodialysis (HD) and hemofiltration-diffusion and convection-has had a positive impact on survival when delivered with a high convective dose. Improved outcomes with HDF have been attributed to the following factors: HDF removes middle molecular weight uremic toxins including inflammatory cytokines, increases hemodynamic stability, and reduces inflammation and oxidative stress compared to conventional HD. Two randomized trials in adults have shown improved survival with HDF compared to high-flux HD. A large prospective cohort study in children has shown that HDF attenuated the progression of cardiovascular disease, improved bone turnover and growth, reduced inflammation, and improved blood pressure control compared to conventional HD. Importantly, children on HDF reported fewer headaches, dizziness, and cramps; had increased physical activity; and improved school attendance compared to those on HD. In this educational review, we discuss the technical aspects of HDF and results from pediatric studies, comparing outcomes on HDF vs. conventional HD. Convective volume, the cornerstone of treatment with HDF and a key determinant of outcomes in adult randomized trials, is discussed in detail, including the practical aspects of achieving an optimal convective volume.

Dyslipidemia in children with chronic kidney disease-findings from the Cardiovascular Comorbidity in Children with Chronic Kidney Disease (4C) study.

BACKGROUND: Dyslipidemia is an important and modifiable risk factor for CVD in children with CKD. METHODS: In a cross-sectional study of baseline serum lipid levels in a large prospective cohort study of children with stage 3-5 (predialysis) CKD, frequencies of abnormal lipid levels and types of dyslipidemia were analyzed in the entire cohort and in subpopulations defined by fasting status or by the presence of nephrotic range proteinuria. Associated clinical and laboratory characteristics were determined by multivariable linear regression analysis. RESULTS: A total of 681 patients aged 12.2 ± 3.3 years with a mean eGFR of 26.9 ± 11.6 ml/min/1.73 m2 were included. Kidney diagnosis was classified as CAKUT in 69%, glomerulopathy in 8.4%, and other disorders in 22.6% of patients. Nephrotic range proteinuria (defined by a urinary albumin/creatinine ratio > 1.1 g/g) was present in 26.9%. Dyslipidemia was found in 71.8%, and high triglyceride (TG) levels were the most common abnormality (54.7%). Fasting status (38.9%) had no effect on dyslipidemia status. Except for a significant increase in TG in more advanced CKD, lipid levels and frequencies of dyslipidemia were not significantly different between CKD stages. Hypertriglyceridemia was associated with younger age, lower eGFR, shorter duration of CKD, higher body mass index (BMI-SDS), lower serum albumin, and higher diastolic blood pressure. CONCLUSIONS: Dyslipidemia involving all lipid fractions, but mainly TG, is present in the majority of patients with CKD irrespective of CKD stage or fasting status and is significantly associated with other cardiovascular risk factors.

Creatinine levels in French children with Down syndrome up to ten years old.

Assess creatinine levels in French children with Down syndrome (DS) on the basis of the relationship between creatinine levels and age. The study included 279 children with DS aged 0 to 10 years who had been regularly monitored between 2004 and 2021 in a single genetics department and who had had at least one creatinine measurement. The creatinine level curves were established by estimating the median and the quantiles of order 2.5 and 97.5% according to age. A Generalized Additive Model for Location, Scale, and Shape was used. The results showed higher creatinine levels in children with DS than in children from the general population.   Conclusion: The present results allow to propose an original chart of creatinine levels according to age in French children with DS, which should help optimize their medical management and improve the early detection of renal diseases. What is Known: • Creatinine is a product of muscle breakdown and depends on muscle mass and children with Down syndrome have muscle and growth characteristics that differ from those of the general paediatric population. • Serum creatinine values in Japanese children with DS are higher than those of children from the general Japanese population. What is New: • Creatinine values in French children with DS are higher than those of children from the general French population. • The proposed original chart for creatinine values according to age, specifically designed for individuals up to 10 years old, should serve for further investigation, prevention, and follow-up of children with DS.

Peritoneal transformation shortly after kidney transplantation in pediatric patients with preceding chronic peritoneal dialysis.

BACKGROUND: The unphysiological composition of peritoneal dialysis (PD) fluids induces progressive peritoneal fibrosis, hypervascularization and vasculopathy. Information on these alterations after kidney transplantation (KTx) is scant. METHODS: Parietal peritoneal tissues were obtained from 81 pediatric patients with chronic kidney disease stage 5 (CKD5), 72 children on PD with low glucose degradation product (GDP) PD fluids, and from 20 children 4-8 weeks after KTx and preceding low-GDP PD. Tissues were analyzed by digital histomorphometry and quantitative immunohistochemistry. RESULTS: While chronic PD was associated with peritoneal hypervascularization, after KTx vascularization was comparable to CKD5 level. Submesothelial CD45 counts were 40% lower compared with PD, and in multivariable analyses independently associated with microvessel density. In contrast, peritoneal mesothelial denudation, submesothelial thickness and fibrin abundance, number of activated, submesothelial fibroblasts and of mesothelial-mesenchymal transitioned cells were similar after KTx. Diffuse peritoneal podoplanin positivity was present in 40% of the transplanted patients. In subgroups matched for age, PD vintage, dialytic glucose exposure and peritonitis incidence, submesothelial hypoxia-inducible factor 1-alpha abundance and angiopoietin 1/2 ratio were lower after KTx, reflecting vessel maturation, while arteriolar and microvessel p16 and cleaved Casp3 were higher. Submesothelial mast cell count and interleukin-6 were lower, whereas transforming growth factor-beta induced pSMAD2/3 was similar as compared with children on PD. CONCLUSIONS: Peritoneal membrane damage induced with chronic administration of low-GDP PD fluids was less severe after KTx. While peritoneal microvessel density, primarily defining PD transport and ultrafiltration capacity, was normal after KTx and peritoneal inflammation less pronounced, diffuse podoplanin positivity and profibrotic activity were prevalent.

Daily practice evaluation of the paediatric set of a next-generation long-term haemodialysis machine.

BACKGROUND: From 2006 to 2020, 24% of children starting haemodialysis in France weighed < 20 kg. Most new-generation long-term haemodialysis machines do not propose paediatric lines anymore but Fresenius has validated two devices for use in children above 10 kg. Our aim was to compare the daily use of these two devices in children < 20 kg. METHODS: Retrospective single-center evaluation of daily practice with Fresenius 6008® machines, and low-volume paediatric sets (83 mL), as compared to 5008® machines with paediatric lines (108 mL). Each child was treated randomly with both generators. RESULTS: A total of 102 online haemodiafiltration sessions were performed over 4 weeks in five children (median body weight 12.0 [range 11.5-17.0] kg). Arterial aspiration and venous pressures were maintained respectively over - 200 mmHg and under 200 mmHg. For all children, blood flow and volume treated per session were lower with 6008® vs. 5008® (p < 0.001), median difference between the two devices being 21%. In the four children treated in post-dilution mode, substituted volume was lower with 6008® (p < 0.001, median difference: 21%). Effective dialysis time was not different between the two generators; however, the difference between total duration of session and dialysis effective time was slightly higher (p < 0.05) with 6008® for three patients, due to treatment interruptions. CONCLUSION: These results suggest that children between 11 and 17 kg should be treated with paediatric lines on 5008® if possible. They advocate for modification of the 6008 paediatric set to decrease resistance to blood flow. The possibility to use 6008® with paediatric lines in children below 10 kg deserves further studies.

CARPEDIEM® for continuous kidney replacement therapy in neonates and small infants: a French multicenter retrospective study.

BACKGROUND: The Cardio-Renal Pediatric Dialysis Emergency Machine (CA.R.P.E.D.I.E.M.®) device is a continuous kidney replacement therapy (CKRT) equipment dedicated to neonates and small infants. This study aimed to assess the effectiveness, feasibility, outcomes, and technical considerations relating to CARPEDIEM® use. METHODS: This retrospective multicenter study included 19 newborns and six infants receiving CARPEDIEM® in five French pediatric and neonatal intensive care units. Laboratory parameters were collected at the initiation and end of the first CARPEDIEM® session. Results are presented as median [IQR] (range). RESULTS: At initiation, age was 4 days [2-13] (1-1134) with a body weight of 3.3 kg [2.5-4] (1.3-11.1). Overall, 131 sessions and 2125 h of treatment were performed. Treatment duration per patient was 42 h [24-91] (8-557). Continuous veno-venous hemofiltration (CVVH) was performed in 20 children. Blood flow rate was 8 mL/kg/min [6-9] (3-16). The effluent flow rate for CVVH was 74 mL/kg/h [43-99] (28-125) and net ultrafiltration (UF) 6 mL/kg/h [2-8] (1-12). In the five children treated by hemodialysis, the blood and dialysate flow rates were 6 mL/kg/min [5-7] (4-7) and 600 mL/h [300-600] (120-600), respectively, while session duration was 8 h [6-12] (2-24). Most infants required a catheter between 4.5 and 6.5 French. Hemodynamic instability with a need for volume replacement occurred in 31 sessions (23%). Thrombocytopenia was observed in 29 sessions (22%). No hemorrhage occurred; all the patients survived the sessions, but only eight patients (32%) were alive at hospital discharge. CONCLUSIONS: These data confirm that the use of CARPEDIEM® is safe and effective in critically ill neonates and infants. A higher resolution version of the Graphical abstract is available as Supplementary information.

Diagnosis and management of mineral and bone disorders in infants with CKD: clinical practice points from the ESPN CKD-MBD and Dialysis working groups and the Pediatric Renal Nutrition Taskforce.

BACKGROUND: Infants with chronic kidney disease (CKD) form a vulnerable population who are highly prone to mineral and bone disorders (MBD) including biochemical abnormalities, growth retardation, bone deformities, and fractures. We present a position paper on the diagnosis and management of CKD-MBD in infants based on available evidence and the opinion of experts from the European Society for Paediatric Nephrology (ESPN) CKD-MBD and Dialysis working groups and the Pediatric Renal Nutrition Taskforce. METHODS: PICO (Patient, Intervention, Comparator, Outcomes) questions were generated, and relevant literature searches performed covering a population of infants below 2 years of age with CKD stages 2-5 or on dialysis. Clinical practice points (CPPs) were developed and leveled using the American Academy of Pediatrics grading matrix. A Delphi consensus approach was followed. RESULTS: We present 34 CPPs for diagnosis and management of CKD-MBD in infants, including dietary control of calcium and phosphate, and medications to prevent and treat CKD-MBD (native and active vitamin D, calcium supplementation, phosphate binders). CONCLUSION: As there are few high-quality studies in this field, the strength of most statements is weak to moderate, and may need to be adapted to individual patient needs by the treating physician. Research recommendations to study key outcome measures in this unique population are suggested. A higher resolution version of the Graphical abstract is available as Supplementary information.

Technical requirements and devices available for long-term hemodialysis in children-mind the gap!

Children requiring long-term kidney replacement therapy are a "rare disease" cohort. While the basic technical requirements for hemodialysis (HD) are similar in children and adults, key aspects of the child's cardiovascular anatomy and hemodynamic specifications must be considered. In this article, we describe the technical requirements for long-term HD therapy for children and the devices that are currently available around the world. We highlight the characteristics and major technical shortcomings of permanent central venous catheters, dialyzers, dialysis machines, and software available to clinicians who care for children. We show that currently available HD machines are not equipped with appropriately small circuits and sensitive control mechanisms to perform safe and effective HD in the youngest patients. Manufacturers limit their liability, and health regulatory agencies permit the use of devices, only in children according to the manufacturers' pre-specified weight limitations. Although registries show that 6-23% of children starting long-term HD weigh less than 15 kg, currently, there is only one long-term HD device that is cleared for use in children weighing 10 to 15 kg and none is available and labelled for use in children weighing less than 10 kg anywhere in the world. Thus, many children are being treated "off-label" and are subject to interventions delivered by medical devices that lack pediatric safety and efficacy data. Moreover, recent improvements in dialysis technology offered to adult patients are denied to most children. We, in turn, advocate for concerted action by pediatric nephrologists, industry, and health regulatory agencies to increase the development of dedicated HD machines and equipment for children.

Pediatric ANCA vasculitis: clinical presentation, treatment, and outcomes in a French retrospective study.

BACKGROUND: Pediatric ANCA vasculitis is a rare group of diseases with a scarcity of data in children. Annual incidence appeared to increase in the last several years, placing higher interest in the clinical and therapeutical outcomes of the disorder. Also, the growing use of rituximab questions the latest outcomes in these diseases. We therefore conducted a retrospective study to better understand the current characteristics, management, and the latest outcomes of the disorder. METHODS: We conducted a 9-year retrospective study of 46 children in 14 different centers across France to describe their clinical and laboratory presentations, therapeutic regimens, and kidney outcome. RESULTS: P-ANCA appeared to be a potential marker for higher relapse risk. Compared to adults, we found that ear-nose-throat presentations were frequent (45.7%) and more severe. Despite an evolution in the treatment management, kidney outcome remained poor with a substantial proportion of chronic kidney disease (54.8% at 1 year). Mortality stays low with 3 patients (6.5%) deceased at the end of our study. CONCLUSION: Clinical presentation was as previously described and time to diagnosis remains long. P-ANCA is a statistically significant marker for increased relapse risk. We observed a modification in the treatment regimens over the past several years with a growing use of rituximab and a decreasing use of cyclophosphamide. Despite these changes, kidney outcome remains poor and prospective studies should be conducted to assess the most appropriate therapeutic modality for each patient. A higher resolution version of the Graphical abstract is available as Supplementary information.

Sodium intake and urinary losses in children on dialysis: a European multicenter prospective study.

BACKGROUND: Sodium (Na) balance is unexplored in dialyzed children. We assessed a simplified sodium balance (sNaB) and its correlates in pediatric patients receiving maintenance dialysis. METHODS: Patients < 18 years old on hemodialysis (HD) or peritoneal dialysis (PD) in six European Pediatric Dialysis Working Group centers were recruited. sNaB was calculated from enteral Na, obtained by a 3-day diet diary, Na intake from medications, and 24-h urinary Na (uNa). Primary outcomes were systolic blood pressure and diastolic blood pressure standard deviation scores (SBP and DBP SDS), obtained by 24-h ambulatory blood pressure monitoring or office BP according to age, and interdialytic weight gain (IDWG). RESULTS: Forty-one patients (31 HD), with a median age of 13.3 (IQR 5.2) years, were enrolled. Twelve patients (29.3%) received Na-containing drugs, accounting for 0.6 (0.7) mEq/kg/day. Median total Na intake was 1.5 (1.1) mEq/kg/day, corresponding to 60.6% of the maximum recommended daily intake for healthy children. Median uNa and sNaB were 0.6 (1.8) mEq/kg/day and 0.9 (1.7) mEq/kg/day, respectively. The strongest independent predictor of sNaB in the cohort was urine output. In patients receiving HD, sNaB correlated with IDWG, pre-HD DBP, and first-hour refill index, a volume index based on blood volume monitoring. sNaB was the strongest predictor of IDWG in multiple regression analysis (ß = 0.63; p = 0.005). Neither SBP SDS nor DBP SDS correlated with sNaB. CONCLUSIONS: Na intake is higher than uNa in children on dialysis, and medications may be an important source of Na. sNaB is best predicted by urine output in the population, and it is a significant independent predictor of IDWG in children on HD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Nutritional and Anthropometric Indices in Children Receiving Haemodiafiltration vs Conventional Haemodialysis - The HDF, Heart and Height (3H) Study.

BACKGROUND: The "HDF-Heart-Height" study showed that haemodiafiltration (HDF) is associated with improved growth compared to conventional haemodialysis (HD). We report a post-hoc analysis of this study assessing the effect of extracorporeal dialysis therapies on nutritional indices. METHODS: 107 children were included in the baseline cross-sectional analysis, of whom 79 (43 HD, 36 HDF) completed the 12-month follow-up. Height (Ht), optimal 'dry' weight (Wt), and body mass index (BMI) standard deviations scores (SDS), waist-to-hip ratio, des-acyl ghrelin (DAG), adiponectin, leptin, insulin-like growth factor-1 (IGF-1)-SDS and insulin were measured. RESULTS: The levels of nutritional indices were comparable between HDF and HD patients at baseline and 12-month. On univariable analyses Wt-SDS positively correlated with leptin and IGF-1-SDS, and negatively with DAG, while Ht-SDS of the overall cohort positively correlated with IGF1-SDS and inversely with DAG and adiponectin. On multivariable analyses, higher 12-month Ht-SDS was inversely associated with baseline DAG (beta = -0.13 per 500 higher; 95%CI -0.22, -0.04; P = .004). Higher Wt-SDS at 12-month was positively associated with HDF modality (beta = 0.47 vs HD; 95%CI 0.12-0.83; P = .01) and inversely with baseline DAG (beta = -0.18 per 500 higher; 95%CI -0.32, -0.05; P = .006). Growth Hormone (GH) treated patients receiving HDF had higher annualized increase in Ht SDS compared to those on HD. CONCLUSIONS: In children on HD and HDF both Wt- and Ht-SDS independently correlated with lower baseline levels of the anorexygenic hormone DAG. HDF may attenuate the resistance to GH, but further studies are required to examine the mechanisms linking HDF to improved growth.

Findings from 4C-T Study demonstrate an increased cardiovascular burden in girls with end stage kidney disease and kidney transplantation.

Mortality in children with kidney failure is higher in girls than boys with cardiovascular complications representing the most common causes of death. Pulse wave velocity (PWV), a measure of vascular stiffness, predicts cardiovascular mortality in adults. Here, PWV in children with kidney failure undergoing kidney replacement therapy was investigated to determine sex differences and potential contributing factors. Two-hundred thirty-five children (80 girls; 34%) undergoing transplantation (150 pre-emptive, 85 with prior dialysis) having at least one PWV measurement pre- and/or post-transplantation from a prospective cohort were analyzed. Longitudinal analyses (median/maximum follow-up time of 6/9 years) were performed for PWV z-scores (PWVz) using linear mixed regression models and further stratified by the categories of time: pre-kidney replacement therapy and post-transplantation. PWVz significantly increased by 0.094 per year and was significantly higher in girls (PWVz +0.295) compared to boys, independent of the underlying kidney disease. During pre-kidney replacement therapy, an average estimated GFR decline of 4 ml/min/1.73 m2 per year was associated with a PWVz increase of 0.16 in girls only. Higher diastolic blood pressure and low density lipoprotein were independently associated with higher PWVz during pre-kidney replacement therapy in both sexes. In girls post-transplantation, an estimated GFR decline of 4ml/min/1.73m2 per year pre-kidney replacement therapy and a longer time (over 12 months) to transplantation were significantly associated with higher PWVz of 0.22 and of 0.57, respectively. PWVz increased further after transplantation and was positively associated with time on dialysis and diastolic blood pressure in both sexes. Thus, our findings demonstrate that girls with advanced chronic kidney disease are more susceptible to develop vascular stiffening compared to boys, this difference persist after transplantation and might contribute to higher mortality rates seen in girls with kidney failure.

Rituximab as induction therapy in pediatric kidney transplantation: A single-center experience in four patients.

BACKGROUND: The anti-CD20 rituximab is often used in the treatment of children with steroid-resistant nephrotic syndrome or EBV-induced post-transplant lymphoproliferative disorder. This single-center series reports the use of rituximab as induction therapy in pediatric kidney transplantation. METHODS: Four children who received rituximab as induction therapy for kidney transplantation since 2016 were retrospectively analyzed. Clinical and laboratory data were extracted from medical records. RESULTS: The patients (2 boys and 2 girls) were aged from 6.1 to 11.9 years and were treated with rituximab on the day of the transplantation procedure; all the transplants came from deceased donors. In all patients, rituximab was used because of positive EBV viral loads before kidney transplantation. Viral loads remained undetectable for the first 6 months after the transplantation procedure and remained below the 4.5 log threshold thereafter. After a median follow-up of 2.3 years, none of the patients displayed rejection or de novo donor-specific antibodies; the glomerular filtration rate remained above 70 ml/min/1.73 m2 . No post-transplant lymphoproliferative disorder was observed. CONCLUSION: The results suggest that rituximab can be used as induction therapy to prevent EBV replication and its complications in case of positive viral load prior to kidney transplantation.

Effects of Chronic Kidney Disease on Nanomechanics of the Endothelial Glycocalyx Are Mediated by the Mineralocorticoid Receptor.

Endothelial mechanics control vascular reactivity and are regulated by the mineralocorticoid receptor (MR) and its downstream target, the epithelial Na+ channel (ENaC). Endothelial dysfunction is a hallmark of chronic kidney disease (CKD), but its mechanisms are poorly understood. We hypothesized that CKD disrupts endothelial mechanics in an MR/ENaC-dependent process. METHODS: Primary human endothelial cells were cultured with uremic serum derived from children with stage 3-5 (predialysis) CKD or adult hemodialysis (HD) patients or healthy controls. The height and stiffness of the endothelial glycocalyx (eGC) and cortex were monitored by atomic force microscopy (AFM) using an ultrasensitive mechanical nanosensor. RESULTS: In a stage-dependent manner, sera from children with CKD induced a significant increase in eGC and cortex stiffness and an incremental reduction of the eGC height. AFM measurements were significantly associated with individual pulse wave velocity and serum concentrations of gut-derived uremic toxins. Serum from HD patients increased MR expression and mechanical stiffness of the endothelial cortex, an effect reversed by MR and ENaC antagonists, decreased eNOS expression and NO bioavailability, and augmented monocyte adhesion. CONCLUSION: These data indicate progressive structural damage of the endothelial surface with diminishing kidney function and identify the MR as a mediator of CKD-induced endothelial dysfunction.

Refining genotype-phenotype correlations in 304 patients with autosomal recessive polycystic kidney disease and PKHD1 gene variants.

Autosomal recessive polycystic kidney disease (ARPKD) is a severe disease of early childhood that is clinically characterized by fibrocystic changes of the kidneys and the liver. The main cause of ARPKD are variants in the PKHD1 gene encoding the large transmembrane protein fibrocystin. The mechanisms underlying the observed clinical heterogeneity in ARPKD remain incompletely understood, partly due to the fact that genotype-phenotype correlations have been limited to the association of biallelic null variants in PKHD1 with the most severe phenotypes. In this observational study we analyzed a deep clinical dataset of 304 patients with ARPKD from two independent cohorts and identified novel genotype-phenotype correlations during childhood and adolescence. Biallelic null variants frequently show severe courses. Additionally, our data suggest that the affected region in PKHD1 is important in determining the phenotype. Patients with two missense variants affecting amino acids 709-1837 of fibrocystin or a missense variant in this region and a null variant less frequently developed chronic kidney failure, and patients with missense variants affecting amino acids 1838-2624 showed better hepatic outcome. Variants affecting amino acids 2625-4074 of fibrocystin were associated with poorer hepatic outcome. Thus, our data expand the understanding of genotype-phenotype correlations in pediatric ARPKD patients and can lay the foundation for more precise and personalized counselling and treatment approaches.

Interleukin 17 acts in synergy with B cell-activating factor to influence B cell biology and the pathophysiology of systemic lupus erythematosus.

Studies have suggested involvement of interleukin 17 (IL-17) in autoimmune diseases, although its effect on B cell biology has not been clearly established. Here we demonstrate that IL-17 alone or in combination with B cell-activating factor controlled the survival and proliferation of human B cells and their differentiation into immunoglobulin-secreting cells. This effect was mediated mainly through the nuclear factor-kappaB-regulated transcription factor Twist-1. In support of the relevance of our observations and the potential involvement of IL-17 in B cell biology, we found that the serum of patients with systemic lupus erythematosus had higher concentrations of IL-17 than did the serum of healthy people and that IL-17 abundance correlated with the disease severity of systemic lupus erythematosus.

Hyperphosphatemia and Chronic Kidney Disease: A Major Daily Concern Both in Adults and in Children.

Hyperphosphatemia is common in chronic kidney disease (CKD). Often seen as the "silent killer" because of its dramatic effect on vascular calcifications, hyperphosphatemia explains, at least partly, the onset of the complex mineral and bone disorders associated with CKD (CKD-MBD), together with hypocalcemia and decreased 1-25(OH)2 vitamin D levels. The impact of CKD-MBD may be immediate with abnormalities of bone and mineral metabolism with secondary hyperparathyroidism and increased FGF23 levels, or delayed with poor growth, bone deformities, fractures, and vascular calcifications, leading to increased morbidity and mortality. The global management of CKD-MBD has been detailed in international guidelines for adults and children, however, with difficulties to obtain an agreement on the ideal PTH targets. The clinical management of hyperphosphatemia is a daily challenge for nephrologists and pediatric nephrologists, notably because of the phosphate overload in occidental diets that is mainly due to the phosphate "hidden" in food additives. The management begins with a dietary restriction of phosphate intake, and is followed by the use of calcium-based and non-calcium-based phosphate binders, and/or the intensification of dialysis. The objective of this review is to provide an overview of the pathophysiology of hyperphosphatemia in CKD, with a focus on its deleterious effects and a description of the clinical management of hyperphosphatemia in a more global setting of CKD-MBD.

Pediatric atypical hemolytic-uremic syndrome due to auto-antibodies against factor H: is there an interest to combine eculizumab and mycophenolate mofetil?

BACKGROUND: Atypical hemolytic and uremic syndrome (aHUS), a thrombotic micro-angiopathy (TMA) caused by deregulation in the complement pathway, is sometimes due to the presence of anti-complement factor H (CFH) auto-antibodies. The "standard" treatment for such aHUS combines plasma exchange therapy and immunosuppressive drugs. Eculizumab, a monoclonal antibody that blocks the terminal pathway of the complement cascade, could be an interesting alternative in association with an immunosuppressive treatment for maintenance regimen. CASE-DIAGNOSIS/TREATMENT: We report on two children, diagnosed with mildly severe aHUS due to anti-CFH antibodies, who were treated with the association eculizumab-mycophenolate mofetil (MMF). Neither side effects nor relapses were observed during the 3 years of follow-up; MMF was even progressively tapered and withdrawn successfully in one patient. CONCLUSIONS: The association of eculizumab and MMF appears to be an effective and safe option in pediatric cases of aHUS due to anti-CFH antibodies of mild severity.

Adherence to cysteamine in nephropathic cystinosis: A unique electronic monitoring experience for a better understanding. A prospective cohort study: CrYSTobs.

INTRODUCTION: In nephropathic cystinosis (NC), adherence to cysteamine remains challenging; poor adherence is worsening the disease progression with a decline of kidney function and increase of extrarenal morbidities. Our objective was to describe adherence to cysteamine in NC patients, using electronic monitoring systems. METHODS: Patients with confirmed NC, aged > 4 years and receiving oral cysteamine (short acting or delayed release formulation as standard of care) from 3 French reference centers, were included. Adherence to treatment was primarily assessed as the percentage of days with a good adherence score, adherence score rating from 0 (poor) to 2 (good). A descriptive analysis was performed after 1-year follow-up. RESULTS: Seventeen patients (10 girls, median age: 13.9 (5.4-33.0) years) were included. Median age at diagnosis was 17.0 (3.0-76.9) months and age at start of cysteamine was 21.0 (15.5-116.3) months. Median daily dose of cysteamine was 1.05 (0.55-1.63) g/m2/day. Over the year, the median percentage of days with a good adherence score was 80 (1-99)% decreasing to 68 (1-99)% in patients > 11 years old. The median of average number of hours covered by treatment in a day was 22.5 (6.1-23.9) versus 14.9 (9.2-20.5) hours for delayed release versus short acting cysteamine. CONCLUSION: Our data are the first describing a rather good adherence to cysteamine, decreasing in adolescents and adults. We described a potential interest of the delayed release formulation. Our data highlight the need for a multidisciplinary approach including therapeutic education and individualized approaches in NC patients transitioning to adulthood. Graphical abstract.