Psychosocial and environmental risk factors of obesity and hypertension in children and adolescents-a literature overview.

Childhood obesity has become a worldwide epidemic in the 21st century. Its treatment is challenging and often ineffective, among others due to complex, often not obvious causes. Awareness of the existence and meaning of psychosocial and environmental risk factors seems to be an essential element in the prevention and treatment of obesity and its complications, especially arterial hypertension. In this review, we will discuss the role of that risk factors linking obesity and increased cardiovascular disorders including the role of nutritional factors (including the role of unhealthy diet, inadequate hydration), unhealthy behaviors (e.g. smoking, alcohol and drugs, sedentary behavior, low physical activity, disrupted circadian rhythms, sleep disorders, screen exposure), unfavorable social factors (such as dysfunctional family, bullying, chronic stress, mood disorders, depression, urbanization, noise, and environmental pollution), and finally differences in cardiovascular risk in girls and boys.

Human peritoneal tight junction, transporter and channel expression in health and kidney failure, and associated solute transport.

Next to the skin, the peritoneum is the largest human organ, essentially involved in abdominal health and disease states, but information on peritoneal paracellular tight junctions and transcellular channels and transporters relative to peritoneal transmembrane transport is scant. We studied their peritoneal localization and quantity by immunohistochemistry and confocal microscopy in health, in chronic kidney disease (CKD) and on peritoneal dialysis (PD), with the latter allowing for functional characterizations, in a total of 93 individuals (0-75 years). Claudin-1 to -5, and -15, zonula occludens-1, occludin and tricellulin, SGLT1, PiT1/SLC20A1 and ENaC were consistently detected in mesothelial and arteriolar endothelial cells, with age dependent differences for mesothelial claudin-1 and arteriolar claudin-2/3. In CKD mesothelial claudin-1 and arteriolar claudin-2 and -3 were more abundant. Peritonea from PD patients exhibited increased mesothelial and arteriolar claudin-1 and mesothelial claudin-2 abundance and reduced mesothelial and arteriolar claudin-3 and arteriolar ENaC. Transperitoneal creatinine and glucose transport correlated with pore forming arteriolar claudin-2 and mesothelial claudin-4/-15, and creatinine transport with mesothelial sodium/phosphate cotransporter PiT1/SLC20A1. In multivariable analysis, claudin-2 independently predicted the peritoneal transport rates. In conclusion, tight junction, transcellular transporter and channel proteins are consistently expressed in peritoneal mesothelial and endothelial cells with minor variations across age groups, specific modifications by CKD and PD and distinct associations with transperitoneal creatinine and glucose transport rates. The latter deserve experimental studies to demonstrate mechanistic links.Clinical Trial registration: The study was performed according to the Declaration of Helsinki and is registered at www.clinicaltrials.gov (NCT01893710).

Metabolic syndrome as risk factor for left ventricular hypertrophy in children with chronic kidney disease.

Background: The metabolic syndrome (MS), a cluster of clinical and biochemical abnormalities including insulin resistance, dyslipidemia and hypertension, is often diagnosed in chronic kidney disease (CKD) children. Left ventricular hypertrophy (LVH) is a major target organ damage in hypertension and an important cardiovascular risk factor in CKD patients. We aimed to identify the most significant risk factors of LVH in children with CKD. Methods: Children with CKD stage 1-5 were enrolled in the study. MS was diagnosed according to De Ferranti (DF) as ≥3 from 5 criteria. Ambulatory blood pressure measurements (ABPM) and echocardiographic evaluation were performed. LVH was defined as ≥95th percentile of LV mass index related to height and age. Clinical and laboratory parameters included: serum albumin, Ca, HCT, cystatin C, creatinine, estimated glomerular filtration rate (eGFR) based on Schwartz formula, triglycerides, high-density lipoprotein (HDL), proteinuria, BMI standard deviation score (SDS), height SDS, waist circumference, ABPM data. Results: 71 children (28 girls/43 boys) with median age 14.05 (25%-75%:10.03-16.30) years and median eGFR 66.75 (32.76-92.32) ml/min/1.73m2 were evaluated. CKD stage 5 was diagnosed in 11 pts (15.5%). MS (DF) was diagnosed in 20 pts (28.2%). Glucose ≥ 110 mg/dL was present in 3 pts (4.2%); waist circumference ≥75th pc in 16 pts (22.5%); triglycerides ≥ 100 mg/dL in 35 pts (49.3%); HDL < 50mg/dL in 31 pts (43.7%) and BP ≥ 90th pc in 29 pts (40.8%), respectively. LVH was detected in 21 (29.6%) children. In univariate regression the strongest risk factor for LVH was CKD stage 5 (OR 4.9, p=0.0019) and low height SDS (OR 0.43,p=0.0009). In stepwise multiple logistic regression analysis (logit model) of the most important risk factors for LVH in CKD children, only three were statistically significant predictors: 1)MS diagnosis based on DF criteria (OR=24.11; 95%CI 1.1-528.7; p=0.043; Chi2 = 8.38,p=0.0038); 2), high mean arterial pressure (MAP SDS) in ABPM (OR=2.812; 95%CI 1.057-7.48; p=0.038;Chi2 = 5.91, p=0.015) and 3) low height SDS (OR=0.078; 95%CI 0.013-0.486;p=0.006; Chi2 = 25.01, p<0.001). Conclusions: In children with chronic kidney disease LVH is associated with the cluster of multiple factors, among them the components of MS, hypertension, stage 5 CKD and growth deficit were the most significant.

Subcutaneous C.E.R.A. for the Maintenance Treatment of Anemia in Pediatric Patients With CKD: A Phase 2, Open-Label, Single-Arm, Multicenter Study.

RATIONALE & OBJECTIVE: The optimum starting dose of intravenous continuous erythropoietin receptor activator (C.E.R.A.) has been previously determined; this study ascertains the optimum starting dose of subcutaneous C.E.R.A. administration in pediatric patients. STUDY DESIGN: Phase 2, open-label, single-arm, multicenter study. SETTING & PARTICIPANTS: Patients aged 3 months to 17 years with renal anemia and chronic kidney disease (CKD; including those treated with maintenance dialysis and those not treated with dialysis) who were receiving maintenance treatment with erythropoiesis-stimulating agents (ESAs). INTERVENTION: Subcutaneous C.E.R.A. administration every 4 weeks (starting dose was based on defined conversion factors). OUTCOME: The primary outcome was the change in hemoglobin concentration between the baseline and evaluation period for each patient. Secondary efficacy measures and safety were also evaluated. RESULTS: Forty patients aged 0.4-17.7 years were enrolled. The study achieved its primary outcome: the mean change in hemoglobin concentration was an increase of 0.48g/dL; the 95% confidence interval (0.15-0.82) and standard deviation (±1.03) were within the prespecified boundaries (-1 to 1g/dL and<1.5g/dL, respectively). Mean hemoglobin concentrations were maintained within the target 10-12g/dL range in 24 of 38 patients and within±1g/dL of the baseline in 19 of 38 patients, and the median C.E.R.A. subcutaneous dose decreased over time. Efficacy in key subgroups (age group, dialysis type, prior ESA treatment) was consistent with the primary outcome. Thirty-eight patients completed the core period; 25 chose to enter the safety extension period. Safety was consistent with prior studies, with no new signals. LIMITATIONS: Single-arm and open-label study; small sample size. CONCLUSIONS: Pediatric patients with anemia secondary to CKD who were on, or not on, dialysis could be safely and effectively switched from maintenance ESAs to subcutaneous C.E.R.A. administered every 4 weeks, using defined dose-conversion factors to determine the optimum starting dose. FUNDING: F. Hoffmann-La Roche Ltd. TRIAL REGISTRATION: The SKIPPER trial registered at ClinicalTrials.gov with study number NCT03552393. PLAIN-LANGUAGE SUMMARY: Anemia, a complication of chronic kidney disease, is associated with poor quality of life and an increased risk of hospitalization and mortality. The current treatments for anemia include iron therapy and erythropoiesis-stimulating agents (ESAs); however, the relatively short half-lives of the ESAs epoetin alfa/beta or darbepoetin alfa may require more frequent dosing and hospital visits compared with the ESA known as continuous erythropoietin receptor activator (C.E.R.A.). A previous study demonstrated that children aged 5 years or more with anemia associated with chronic kidney disease who were on hemodialysis could be switched to intravenous C.E.R.A. from their existing epoetin alfa/beta or darbepoetin alfa treatment. This study provides evidence that subcutaneous C.E.R.A. can safely and effectively treat anemia in children, including those aged<5 years and regardless of whether they were on dialysis or the type of dialysis they received (peritoneal dialysis or hemodialysis).

Effects of uric acid-lowering therapy in patients with essential arterial hypertension.

OBJECTIVES: Asymptomatic hyperuricemia (AHU) is elevated serum uric acid (UA) without symptoms. This study aimed to determine the effects of AHU treatment with allopurinol on selected hypertension-mediated organ damage (HMOD) indices in patients with uncomplicated essential arterial hypertension (AH). METHODS: Patients aged 30-70 years with AHU and AH grade 1-2 with adequate blood pressure (BP) control, without previous urate-lowering therapy (ULT), were divided into two groups: (a) ULT (receiving allopurinol) and (b) control (age- and sex-matched patients without ULT). Both received a UA-lowering diet. BP (office, 24 h and central), echocardiographic parameters, carotid intima-media thickness (IMT) and lab tests [high-sensitivity C-reactive protein (hs-CRP)] were measured at baseline and at 6 months follow-up. RESULTS: Of 100 participants, 87 (44 ULT, 43 controls) completed the study. At 6 months follow-up, there was a greater reduction in serum UA concentration in the ULT group than in the control group. Patients receiving allopurinol had significant reductions in office systolic and diastolic BP, central systolic BP, pulse pressure, IMT (0.773 ± 0.121 vs. 0.752 ± 0.13 mm, P = 0.044) and hs-CRP (3.36 ± 2.73 vs. 2.74 ± 1.91 mg/L, P = 0.028) compared to controls. Multivariate regression analysis revealed the independent relationship between reduction in IMT and UA lowering (P < 0.026). CONCLUSION: In patients with AH and AHU, treatment with allopurinol leads to improvement in BP control and reduction in HMOD intensity, in particular IMT. The decrease in hs-CRP concentration associated with ULT may have a beneficial effect on a patient's long-term prognosis.

The Role of Complement Component C3 Activation in the Clinical Presentation and Prognosis of IgA Nephropathy-A National Study in Children.

The aim of the study was to evaluate the influence of the intensity of mesangial C3 deposits in kidney biopsy and the serum C3 level on the clinical course and outcomes of IgAN in children. The study included 148 children from the Polish Pediatric IgAN Registry, diagnosed based on kidney biopsy. Proteinuria, creatinine, IgA, C3 were evaluated twice in the study group, at baseline and the end of follow-up. Kidney biopsy was categorized using the Oxford classification, with a calculation of the MEST-C score. The intensity of IgA and C3 deposits were rated from 0 to +4 in immunofluorescence microscopy. The intensity of mesangial C3 > +1 deposits in kidney biopsy has an effect on renal survival with normal GFR in children with IgAN. A reduced serum C3 level has not been a prognostic factor in children but perhaps this finding should be confirmed in a larger group of children.

IgA vasculitis nephritis clinical course and kidney biopsy - national study in children.

The aim of the study was to investigate the relationship between the severity of typical clinical symptoms, severity of histopathological lesions in kidney biopsies in IgA vasculitis nephritis (IgAVN) and to propose indications for kidney biopsy in children. MATERIAL AND METHODS: This retrospective study enrolled 106 patients, included in the IgAVN registry of Polish children, diagnosed by kidney biopsy. Renal and extrarenal symptoms at onset of the disease were analyzed. Biopsy results were assessed using Oxford classifications (MEST-C). The patients were divided into 3 groups depending on the severity of proteinuria: A-nephrotic proteinuria with hematuria; B-non-nephrotic proteinuria with hematuria; C-isolated hematuria. RESULTS: The first symptoms of nephropathy were observed at the 0.7 (1-128.4) months from the onset of extrarenal symptoms. Kidney biopsy was performed on 39 (6-782) days after the onset of nephropathy symptoms. MEST-C score 4 or 5 was significantly more frequent in children from group A than in groups B and C. Significantly higher mean MEST-C score was found in patients with abdominal symptoms than without. In group A: S0 and T0 we found in significantly shorter time to kidney biopsy than in S1, T1-2 p < 0.05) and in group B the significantly shorter time in T0 compare to T1-2 p < 0.05). The ROC analysis shows that S1 changes appear in kidney biopsies in group A with cut off 21 days (AUC 0,702, p = 0.004, sensitivity 0.895 specificity 0.444) T1-2 changes after 35 days (AUC 0.685, p = 0.022, sensitivity 0.750, specificity 0.615), and in goupn B T1-2 cut off is 74 days (AUC 0,738, p = 0.002, sensitivity 0.667, specificity 0.833). CONCLUSIONS: In childhood IgAVN, the severity of changes in the urine is clearly reflected in the result of a kidney biopsy. The biopsy should be performed in patients with nephrotic proteinuria no later than 3 weeks after the onset of this symptom in order to promptly apply appropriate treatment and prevent disease progression. Accompanying abdominal symptoms predispose to higher MESTC score.

Acute dialysis in children: results of a European survey.

The number of children with acute kidney injury (AKI) requiring dialysis is increasing. To date, systematic analysis has been largely limited to critically ill children treated with continuous renal replacement therapy (CRRT). We conducted a survey among 35 European Pediatric Nephrology Centers to investigate dialysis practices in European children with AKI. Altogether, the centers perform dialysis in more than 900 pediatric patients with AKI per year. PD and CRRT are the most frequently used dialysis modalities, accounting for 39.4% and 38.2% of treatments, followed by intermittent HD (22.4%). In units treating more than 25 cases per year and in those with cardiothoracic surgery programs, PD is the most commonly chosen dialysis modality. Also, nearly one quarter of centers, in countries with a gross domestic product below $35,000/year, do not utilize CRRT at all. Dialysis nurses are exclusively in charge of CRRT management in 45% of the cases and pediatric intensive care nurses in 25%, while shared management is practiced in 30%. In conclusion, this survey indicates that the choice of treatment modalities for dialysis in children with AKI in Europe is affected by the underlying ethiology of the disease, organization/set-up of centers and socioeconomic conditions. PD is utilized as often as CRRT, and also intermittent HD is a commonly applied treatment option. A prospective European AKI registry is planned to provide further insights on the epidemiology, management and outcomes of dialysis in pediatric AKI.

The importance of fetuin-A in vascular calcification in children with chronic kidney disease.

BACKGROUND: The status of the cardiovascular (CV) system in children with chronic kidney disease (CKD) is significantly influenced by increasing stiffness of the arterial wall. This largely depends on the shortage of local and systemic inhibitors of soft tissue calcification. OBJECTIVES: The aim of the study was to evaluate the role of fetuin-A in conjunction with other factors in the progressive hardening of the vascular wall in these children. We examined serum fetuin-A concentrations in relation to renal function, dialysis modality, and other clinical and biochemical markers promoting vascular calcification. MATERIAL AND METHODS: Twenty children on peritoneal dialysis (PD), 20 on hemodialysis (HD), 36 treated conservatively, and 26 healthy subjects were enrolled into a cross-sectional study. In all children, fetuin-A and numerous clinical and biochemical parameters were measured. RESULTS: The fetuin-A concentration was significantly lower in children on hemodialysis (HD) vs children on peritoneal dialysis (PD), conservatively treated subjects, and the control group. In sick children, fetuinA concentration negatively correlated with dialysis vintage, PWV/ht, phosphate concentration, calcium phosphate product (CaxP), cumulative doses of calcium, and vitamin D3. In the whole study population, fetuin-A negatively correlated with blood pressure (BP), pulse wave velocity indexed to height (PWV/ht), intact parathyroid hormone (iPTH), high sensitivity C-reactive protein (hsCRP), and cholesterol concentrations. CONCLUSIONS: In children with CKD, the decreased concentration of fetuin-A is related to other vascular calcification risk factors. Serum fetuin-A concentration may play a role in the identification of vascular disease risk factors in this population.

[Body fat measurements using bioelectrical impedance in pediatric patientstreated with hematopoietic cell transplantation]. / Pomiary tkanki tluszczowej z zastosowaniem bioimpedancji elektrycznej u dzieci leczonych przeszczepieniem komórek krwiotwórczych.

INTRODUCTION: In patients who have undergone hematopoietic cell transplantation (HCT), the metabolic syndrome may develop without obesity defined by Body Mass Index (BMI). AIM OF THE STUDY: The aim of the study was to compare body fat parameters measured using bioelectrical impedance (BIA) and using standard parameters of obesity in patients treated with HCT and healthy controls. MATERIAL AND METHODS: We compared body fat (BF) and body fat percentage (BF%) measured using BIA in 44 patients before HCT and 28 patients after HCT, versus 26 controls. We also compared BMI and other BIA parameters in these groups of patients. RESULTS: The differences in BF and BF% between the patients before HCT and controls were not significant, while both BF and BF% were significantly lower in patients after HCT than in the control group. No significant differences in standard clinical obesity parameters were found in the patients before HCT, and in the patients after HCT, compared with the controls. The differences in other BIA parameters between the patients before HCT and the controls were not significant, while in the patients after HCT some parameters were significantly lower. CONCLUSION: Significant differences in BF and BF% in the patients after HCT compared with healthy controls suggest that BIA may be useful in screening for body fat abnormalities in patients after HCT.

[B-type natriuretic peptide as a marker of cardiac dysfunction in children with chronic kidney disease]. / Peptyd natriuretyczny typu B jako marker uszkodzenia serca u dzieci z przewlekla choroba nerek.

Left ventricular hypertrophy is the most common organ damage in children with chronic kidney disease (CKD). AIM: The aim of the study was to assess the usefulness of B-type natriuretic peptide (BNP) as a marker of heart injury in children with CKD. MATERIALS AND METHODS: We included 66 children (41 boys and 25 girls) aged 0.7 to 18.6 (median 11.6) years with CKD stage 1-5. The concentrations of urea, creatinine, cystatin C and BNP in blood serum were assessed, and the estimated glomerular filtration rate (eGFR) was calculated from the Schwartz and Filler formulas. Patients were divided into groups depending on the CKD stage [group 1: CKD stages 1 + 2 (GFR> 60 ml/min/1.73 m2), group 2: stage 3 (GFR = 30-59 ml/min/1.73 m2), group 3: CKD stage 4 (GFR 15-29 ml/min/ 1.73 m2), group 4 - stage 5 (dialyzed children)]. On the basis of echocardiography, the left ventricular mass (LVM) was calculated, which was indexed for height (left ventricular mass index, LVMI). Left ventricular hypertrophy (LVH) was diagnosed if the LVMI value was > 95th percentile for sex and age. RESULTS: Depending on the CKD stage the median BNP concentrations for group 1, group 2, group 3, and group 4 were 2.5 pg/ml, 6.0 pg/ml, 9.3 pg/ml and 18.0 pg/ml, and the LVH prevalence 27.3%, 33.3%, 60.0% and 63.6% , respectively. Significant correlations between BNP concentration and LVH expressed by LVMI (R=0.256, p=0.038), creatinine (R=0.453, p<0.001), cystatin (R=0.494, p<0.001) and eGFR (R=-0.473, p<0.001) were found. CONCLUSIONS: In children with chronic kidney disease, BNP is an indicator of heart failure correlating with renal function parameters and left ventricular mass index.

Neutral pH and low-glucose degradation product dialysis fluids induce major early alterations of the peritoneal membrane in children on peritoneal dialysis.

The effect of peritoneal dialysates with low-glucose degradation products on peritoneal membrane morphology is largely unknown, with functional relevancy predominantly derived from experimental studies. To investigate this, we performed automated quantitative histomorphometry and molecular analyses on 256 standardized peritoneal and 172 omental specimens from 56 children with normal renal function, 90 children with end-stage kidney disease at time of catheter insertion, and 82 children undergoing peritoneal dialysis using dialysates with low-glucose degradation products. Follow-up biopsies were obtained from 24 children after a median peritoneal dialysis of 13 months. Prior to dialysis, mild parietal peritoneal inflammation, epithelial-mesenchymal transition and vasculopathy were present. After up to six and 12 months of peritoneal dialysis, blood microvessel density was 110 and 93% higher, endothelial surface area per peritoneal volume 137 and 95% greater, and submesothelial thickness 23 and 58% greater, respectively. Subsequent peritoneal changes were less pronounced. Mesothelial cell coverage was lower and vasculopathy advanced, whereas lymphatic vessel density was unchanged. Morphological changes were accompanied by early fibroblast activation, leukocyte and macrophage infiltration, diffuse podoplanin presence, epithelial mesenchymal transdifferentiation, and by increased proangiogenic and profibrotic cytokine abundance. These transformative changes were confirmed by intraindividual comparisons. Peritoneal microvascular density correlated with peritoneal small-molecular transport function by uni- and multivariate analysis. Thus, in children on peritoneal dialysis neutral pH dialysates containing low-glucose degradation products induce early peritoneal inflammation, fibroblast activation, epithelial-mesenchymal transition and marked angiogenesis, which determines the PD membrane transport function.

Thrombomodulin as a New Marker of Endothelial Dysfunction in Chronic Kidney Disease in Children.

Endothelial dysfunction (ED) and oxidative stress are potential new pathomechanisms of cardiovascular diseases in patients with chronic kidney disease (CKD). The aim of the study was to assess the association between endothelial dysfunction, oxidative stress biomarkers, and cardiovascular risk factors in children with CKD. Serum oxidized LDL (oxLDL), protein carbonyl group, urea, creatinine, cystatin C, thrombomodulin, asymmetric dimethylarginine (ADMA), von Willebrand factor, brain natriuretic peptide (BNP), lipids, high sensitivity C-reactive protein, intercellular adhesion molecule-1 levels, and albuminuria were measured. Anthropometric, ambulatory blood pressure (BP) measurements and echocardiography were performed. The studied group consisted of 59 patients aged 0.7-18.6 (mean 11.1) years with stages 1 to 5 CKD. Thrombomodulin strongly correlated with creatinine (R = 0.666; p < 0.001), cystatin C (R = 0.738; p < 0.001), BNP (R = 0.406; p = 0.001), ADMA (R = 0.353; p = 0.01), oxLDL (R = 0.340; p = 0.009), 24-hour systolic (R = 0.345; p = 0.011) and mean (R = 0.315; p < 0.05) BP values, and left ventricular mass index (LVMI, R = 0.293; p = 0.024) and negatively with estimated glomerular filtration rate (R = -0.716; p < 0.001). In children with CKD, TM strongly depended on kidney function parameters, oxLDL levels, and 24-hour systolic and mean BP values. Thrombomodulin seems to be a valuable marker of ED in CKD patients, correlating with CKD stage as well as oxidative stress, BP values, and LVMI.

Clinical and molecular genetic characterization of a male patient with Sensenbrenner syndrome (cranioectodermal dysplasia) and biallelic WDR35 mutations.

BACKGROUND: Sensenbrenner syndrome (cranioectodermal dysplasia, CED) is a very rare autosomal recessive ciliopathy first described by Judith Sensenbrenner in 1975. CED is a complex disorder characterized by craniofacial, skeletal, and ectodermal abnormalities. The clinical symptoms are variable and the CED phenotype may present intrafamilial and interfamilial differences. Sensenbrenner syndrome belongs to a group of ciliary chondrodysplasias and is a genetically heterogeneous disease. Mutations in six genes: IFT122, WDR35, IFT43, WDR19, IFT52, and IFT140 have been associated with this disorder. All known CED genes encode proteins that are part of the intraflagellar transport complex, which plays an important role in the assembly and maintenance of cilia. CASE: We report a on 2-year-old male patient affected by Sensenbrenner syndrome. Dysmorphic features included short stature with rhizomelic shortening of limbs, short fingers, narrow chest, high forehead, epicanthal folds, telecanthus, broad nasal bridge, low-set ears, sparse hair, and widely space teeth. Craniosynostosis was surgically corrected at the age of 4 months. The patient presented chronic renal disease. Nephrologic picture showed early stages of nephronophthisis. Psychomotor development was apparently normal. Molecular analysis of the affected individual revealed compound heterozygosity for a novel nonsense p.(Arg113*) and a missense p.(Asp841Val) variant in the WDR35 gene. CONCLUSIONS: The observations of the CED patient in this study provide additional clinical data and expand the molecular spectrum of Sensenbrenner syndrome. Moreover, the two variants identified in the proband provide further evidence for the WDR35 mutations as the most common cause of this rare syndrome.

Low renal but high extrarenal phenotype variability in Schimke immuno-osseous dysplasia.

Schimke immuno-osseous dysplasia (SIOD) is a rare multisystem disorder with early mortality and steroid-resistant nephrotic syndrome (SRNS) progressing to end-stage kidney disease. We hypothesized that next-generation gene panel sequencing may unsurface oligosymptomatic cases of SIOD with potentially milder disease courses. We analyzed the renal and extrarenal phenotypic spectrum and genotype-phenotype associations in 34 patients from 28 families, the largest SMARCAL1-associated nephropathy cohort to date. In 11 patients the diagnosis was made unsuspectedly through SRNS gene panel testing. Renal disease first manifested at median age 4.5 yrs, with focal segmental glmerulosclerosis or minimal change nephropathy on biopsy and rapid progression to end-stage kidney disease (ESKD) at median age 8.7 yrs. Whereas patients diagnosed by phenotype more frequently developed severe extrarenal complications (cerebral ischemic events, septicemia) and were more likely to die before age 10 years than patients identified by SRNS-gene panel screening (88 vs. 40%), the subgroups did not differ with respect to age at proteinuria onset and progression to ESKD. Also, 10 of 11 children diagnosed unsuspectedly by Next Generation Sequencing were small at diagnosis and all showed progressive growth failure. Severe phenotypes were usually associated with biallelic truncating mutations and milder phenotypes with biallelic missense mutations. However, no genotype-phenotype correlation was observed for the renal disease course. In conclusion, while short stature is a reliable clue to SIOD in children with SRNS, other systemic features are highly variable. Our findings support routine SMARCAL1 testing also in non-syndromic SRNS.

Metabolic acidosis is common and associates with disease progression in children with chronic kidney disease.

Recent studies in adult chronic kidney disease (CKD) suggest that metabolic acidosis is associated with faster decline in estimated glomerular filtration rate (eGFR). Alkali therapies improve the course of kidney disease. Here we investigated the prevalence and determinants of abnormal serum bicarbonate values and whether metabolic acidosis may be deleterious to children with CKD. Associations between follow-up serum bicarbonate levels categorized as under 18, 18 to under 22, and 22 or more mmol/l and CKD outcomes in 704 children in the Cardiovascular Comorbidity in Children with CKD Study, a prospective cohort of pediatric patients with CKD stages 3-5, were studied. The eGFR and serum bicarbonate were measured every six months. At baseline, the median eGFR was 27 ml/min/1.73m2 and median serum bicarbonate level 21 mmol/l. During a median follow-up of 3.3 years, the prevalence of metabolic acidosis (serum bicarbonate under 22 mmol/l) was 43%, 60%, and 45% in CKD stages 3, 4, and 5, respectively. In multivariable analysis, the presence of metabolic acidosis as a time-varying covariate was significantly associated with log serum parathyroid hormone through the entire follow-up, but no association with longitudinal growth was found. A total of 211 patients reached the composite endpoint (ESRD or 50% decline in eGFR). In a multivariable Cox model, children with time-varying serum bicarbonate under 18 mmol/l had a significantly higher risk of CKD progression compared to those with a serum bicarbonate of 22 or more mmol/l (adjusted hazard ratio 2.44; 95% confidence interval 1.43-4.15). Thus, metabolic acidosis is a common complication in pediatric patients with CKD and may be a risk factor for secondary hyperparathyroidism and kidney disease progression.

Long-Term Outcome of Steroid-Resistant Nephrotic Syndrome in Children.

We investigated the value of genetic, histopathologic, and early treatment response information in prognosing long-term renal outcome in children with primary steroid-resistant nephrotic syndrome. From the PodoNet Registry, we obtained longitudinal clinical information for 1354 patients (disease onset at >3 months and <20 years of age): 612 had documented responsiveness to intensified immunosuppression (IIS), 1155 had kidney biopsy results, and 212 had an established genetic diagnosis. We assessed risk factors for ESRD using multivariate Cox regression models. Complete and partial remission of proteinuria within 12 months of disease onset occurred in 24.5% and 16.5% of children, respectively, with the highest remission rates achieved with calcineurin inhibitor-based protocols. Ten-year ESRD-free survival rates were 43%, 94%, and 72% in children with IIS resistance, complete remission, and partial remission, respectively; 27% in children with a genetic diagnosis; and 79% and 52% in children with histopathologic findings of minimal change glomerulopathy and FSGS, respectively. Five-year ESRD-free survival rate was 21% for diffuse mesangial sclerosis. IIS responsiveness, presence of a genetic diagnosis, and FSGS or diffuse mesangial sclerosis on initial biopsy as well as age, serum albumin concentration, and CKD stage at onset affected ESRD risk. Our findings suggest that responsiveness to initial IIS and detection of a hereditary podocytopathy are prognostic indicators of favorable and poor long-term outcome, respectively, in children with steroid-resistant nephrotic syndrome. Children with multidrug-resistant sporadic disease show better renal survival than those with genetic disease. Furthermore, histopathologic findings may retain prognostic relevance when a genetic diagnosis is established.

Modification of the Schwartz equations for children increases their accuracy at eGFR > 60 mL/min/1.73 m(2).

AIM: Estimation of eGFR in children with normal kidney function using the Schwartz equations results in underestimating real GFR. MATERIALS AND METHODS: We propose modification of three Schwartz equations - two based on creatinine concentration (eGFRScrBS bedside) and (eGFRScr) and one 3-marker based on creatinine, urea and cystatin C concentrations (eGFRS3M). The iohexol test (reference method) was performed 417 times in 353 children >2 years with mean GFR: 98 ± 31.6 ml/min/1.73m(2). The assessment included also the Filler and Zappitelli equations. The modification was performed using methods: (1) based on equation, eGFRcor = a [eGFR - T] + T, where T = 50, if eGFR > T, and a equals for: eGFRScrBS 1.4043, for eGFRScr 2.0048, for eGFRS3M 1.2951, and (2) based on correction of all coefficients of the original equation. RESULTS: For comparison of all the results and for children with GFR< 60, 60-90, 90-135 and > 135 ml/min/1.73m(2) the correlation coefficient, relative error (RE) and root mean square relative error (RMSRE) was employed and revealed improvement of RE from 25.9 to 6.8 and 3.9% (depending on the correction method) for eGFRScr; from 19 to 8.1 and 3.9% for eGFRScrBS and: from 11.6% to 2.0 and 2.3% for eGFRS3M (respectively). The RMSRE values changed from 30 to 21.3 and 19.8% for eGFRScr, from 25.1 to 21.6 and 19.8% for eGFRScrBS and from 19.1 to 15.8 and 15.3 % for eGFRS3M. CONCLUSIONS: Modifications of Schwartz equations at GFR > 60 ml/min/1.73m(2) significantly improves the accuracy of calculating eGFR. The 3-markers equation is more accurate and should be employed frequently.

Oxidative Stress Biomarkers and Left Ventricular Hypertrophy in Children with Chronic Kidney Disease.

Cardiovascular diseases remain the most frequent cause of morbidity and mortality in patients with chronic kidney disease (CKD). The aim of the study was to assess the association between oxidative stress biomarkers and cardiovascular risk factors and left ventricular hypertrophy in children with CKD. Material and Methods. The studied group consisted of 65 patients aged 1.4-18.6 (mean 11.2) years with stages 1 to 5 CKD. Serum oxidized low-density lipoprotein (oxLDL), protein carbonyl group, creatinine, cystatin C, albumin, lipids, high-sensitivity C-reactive protein, intercellular adhesion molecule-1, insulin, plasma renin activity, and aldosterone levels were measured. Patients were divided into groups depending on CKD stage. Anthropometric measurements, ambulatory blood pressure (BP) measurements, and echocardiography with left ventricular mass (LVM) calculation were performed. Results. Serum oxLDL strongly correlated with creatinine (R = 0.246; p = 0.048), cystatin C (R = 0.346; p = 0.006), total cholesterol (R = 0.500; p < 0.001), triglycerides (R = 0.524; p < 0.001), low-density lipoprotein concentrations (R = 0.456; p < 0.001), and 24 hour BP values of systolic (R = 0.492; p = 0.002), diastolic (R = 0.515; p < 0.001), and mean arterial pressure (R = 0.537; p < 0.001). A significant correlation between oxLDL levels and LVM z-scores (R = 0.299; p = 0.016) was found. Conclusions. Hypertension and dyslipidemia correlated with lipid oxidation in children with CKD. oxLDLs seem to be valuable markers of oxidative stress in CKD patients, correlating with left ventricular hypertrophy.

Favorable four-yr outcome after renal transplantation in a patient with complement factor H antibody and CFHR1/CFHR3 gene mutation-associated HUS.

UNLABELLED: aHUS is a clinical challenge for successful renal transplantation. CASE REPORT: A 14-yr-old girl lost her kidneys at the age of 7, due to CFH antibodies and CFH-related protein (CFHR1/CFHR3) homozygous deletion-associated aHUS. CFH, CFI, and MCP gene mutations were excluded. The patient was a candidate for renal transplantation despite persistent presence of CFH antibodies (up to 539 AU/mL). Treatment with MMF, IVIG, and repeated PF (n = 8) was introduced while being placed on urgent waiting list. Three years after aHUS onset, the patient underwent the deceased donor renal transplantation "under cover" of PF, as PF was performed directly prior to surgery and, then, PFs were repeated up to overall 14 sessions. Quadruple immunosuppression (basiliximab + tacrolimus + MMF + prednisolone) was used. Moderate symptoms of aHUS (hemolysis, low platelets, and low C3) were present within first seven days post-transplant and then normalized with PF therapy. The patient remained stable during four yr of further follow-up after transplantation. CONCLUSION: Specific pre- and post-transplant management allowed successful renal transplantation in a CFH antibody-positive patient.