The influence of oxidative stress on cardiac remodeling in obese adolescents.

Oxidative stress seems to be an important link between obesity and cardiovascular disease. The aim of our study was to assess oxidative stress in obese patients stratified according to ambulatory blood pressure status and to determine independent predictors of abnormal left ventricular geometry.A cross-sectional study was conducted. A total of 113 obese participants referred for 24-h ambulatory blood pressure monitoring (ABPM) aged 9-19 years, and 29 healthy controls were enrolled. In addition to anthropometric and biochemical measurements, such as fasting serum levels of glucose, insulin, lipid profile, and oxidative biomarkers, ABPM and echocardiography were performed.According to ABPM results, obese subjects were split in two groups: 57 hypertensive and 56 normotensive. Both hypertensive and normotensive obese participants had higher levels of oxidative stress parameters (pro-oxidative/antioxidative balance and total oxidant status) compared with control group. Levels of superoxide anion (O2-) and sulfhydryl groups were higher in obese hypertensive participants as compared to obese normotensive and control groups. Abnormal left ventricular geometry among obese participants was independently associated with O2- (p = .006) and body mass index z score (p = .020), with no significant impact of gender, while age and systolic blood pressure exhibited interaction term for the outcome.The independent effect of oxidative mechanisms on left ventricular geometry appears to start in childhood. Oxidative stress occurs in obese adolescents prior to the development of sustained hypertension.

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.

Hypertension, lipoprotein subclasses and lipid transfer proteins in obese children and adolescents.

BACKGROUND: Obesity-related childhood hypertension is associated with disturbances of serum lipids, but less is known about distribution of lipoprotein subclasses and activities of proteins involved in reverse cholesterol transport in hypertensive obese children. Our objective was to determine low-density lipoprotein (LDL) and high-density lipoprotein (HDL) subclasses distribution and activities of lecithin:cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP) in hypertensive and non-hypertensive obese children. METHODS: A total of 40 hypertensive and 25 non-hypertensive obese children were enrolled. Lipoprotein subclasses were assessed by polyacrylamide gradient gel electrophoresis. LCAT and CETP activities were determined as a rate of formation and a rate of transfer of cholesteryl esters. RESULTS: Despite of comparable values of serum lipid parameters, a shift toward smaller LDL and HDL subclasses was observed in hypertensive compared to normotensive obese children. Activities of LCAT were similar, but proatherogenic CETP activities were significantly higher in the hypertensive group (p = 0.036). LCAT/net CETP ratio inversely correlated with relative proportion of small, dense LDL particles (ρ = -0.423; p = 0.025) in the group with hypertension. CONCLUSIONS: The results of our study demonstrated a tendency toward altered distribution of lipoprotein subclasses in favor of more proatherogenic particles in childhood hypertension. Also, hypertensive obese children had increased proatherogenic CETP activity.

Associated extrarenal vascular diseases may complicate the treatment and outcome of renovascular hypertension.

AIM: This studied reviewed renovascular hypertension (RVH) due to renal artery stenosis (RAS) in two Serbian paediatric centres from 2001 to 2013. METHODS: The patients' demographic data, underlying syndromes, blood pressure (BP), antihypertensive treatments and outcomes were reviewed. RESULTS: The incidence of RVH was 1.9 per million children per year during the study period, and there were 25 patients with RAS, aged 10.4 ± 5.2 years. At presentation, their mean blood pressure (BP) standard deviation scores were 6.9 ± 3.4 systolic and 5.2 ± 2.6 diastolic. BP loads on 24-hour ambulatory BP were 88 ± 14% systolic and 80 ± 29% diastolic. We found that 72% had fibromuscular dysplasia and 28% had underlying syndromes. RAS was unilateral in 64% and bilateral in 28%, and 8% had RAS of a single kidney. Antihypertensive treatment included antihypertensive drugs (100%), percutaneous transluminal angioplasty (92%), renal auto-transplantation (16%), surgical revascularisation (12%) and nephrectomy (12%). After 4.4 ± 3.6 years of follow-up, high BP was cured in 40% of the patients and 39.4% of the kidneys and improved in 48% (75.7%), with BP decreases of 20.3 ± 3.7% systolic and 16.3 ± 6.2% diastolic. CONCLUSION: Fibromuscular dysplasia was the most common cause of RVH in this study, and hypertension was cured or improved in 88% of the patients.

Urinary kidney injury molecule-1 rapid test predicts acute kidney injury in extremely low-birth-weight neonates.

BACKGROUND: The new urinary and serum biomarkers are discovered and are being investigated. With them we can diagnose acute kidney injury (AKI) faster and more precisely and they also have a significant role in the outcome prediction. METHODS: The study included 22 extremely low-birth-weight neonates who were hospitalized in the neonatal intensive care units. They were divided into two groups based on serum creatinine (SCr) level-with and without AKI. Detection and quantification of urinary kidney injury molecule-1 (uKIM-1) was done on the third day of life, using commercially available KIM-1 rapid test. Subsequently, measurements were repeated only in subjects who were diagnosed with AKI, at different values of SCr. RESULTS: Logistic regression analysis showed that AKI is an independent risk factor for mortality. In a group of neonates with AKI, 50% of neonates administered the KIM-1 rapid test showed positive findings. KIM-1 rapid test was positive in patients with a wide range of SCr levels (range of 78.73-385 µmol/l), but all subjects had oliguria and died in the next 24 h. CONCLUSION: KIM-1 is a significant predictor of death. On the other hand, our study failed to prove that KIM-1 rapid test has any significance for early prediction of AKI.

Genetic abnormalities and prognosis in patients with congenital and infantile nephrotic syndrome.

BACKGROUND: Congenital nephrotic syndrome (CNS) and infantile nephrotic syndrome (INS) are caused primarily by mutations in genes that encode structural and regulatory proteins of the glomerular filtration barrier. The aim of this study was to determine genotype-phenotype correlations and prognosis in patients with CNS and INS. METHODS: NPHS1, NPHS2, LAMB2 and the eighth and ninth exons of WT1 were sequenced in 80 and 22 patients with CNS and INS, respectively. Genotype-phenotype correlations and survival were evaluated. RESULTS: Causative mutations were identified in 64.7 % of patients, of which NPHS1 mutations were the most common (37.4 %). The mutation detection rate was twofold higher in CNS patients than in INS patients (72.5 vs. 36.2 %). The most commonly mutated gene in CNS patients was NPHS1 (46.3 %) versus NPHS2 (13.6 %) and WT1 (13.6 %) in INS patients. NPHS2 mutations, female patients with NPHS1 mutations, and NPHS1 mutations affecting the transmembrane or intracellular domains of nephrin were associated with longer survival. CONCLUSIONS: Based on our present findings, the likelihood of identification of a genetic cause decreases with increasing age at diagnosis. The underlying genetic abnormality should be identified as early as possible, as this knowledge will facilitate clinicians in their prognostic prediction and enable patients to receive appropriate genetic counseling.

Glomerular nestin expression: possible predictor of outcome of focal segmental glomerulosclerosis in children.

BACKGROUND: A high prevalence of chronic kidney disease among children with focal segmental glomerulosclerosis (FSGS) leads to a permanent quest for good predictors of kidney dysfunction. Thus, we carried out a retrospective cohort study in order to examine known clinical and morphological predictors of adverse outcome, as well as to investigate glomerular nestin expression as a potential new early predictor of kidney dysfunction in children with FSGS. Relationships between nestin expression and clinical and morphological findings were also investigated. METHODS: Among 649 renal biopsy samples, obtained from two children's hospitals, FSGS was diagnosed in 60 children. Thirty-eight patients, who met the criteria for this study, were followed up for 9.0 ± 5.2 years. Using Kaplan-Meier and Cox's regression analysis, potential clinical and morphological predictors were applied in two models of prediction: after disease onset and after the biopsy. RESULTS: The present study revealed the following significant predictors of kidney dysfunction: patients' ages at disease onset, as well as age at biopsy, resistance to corticosteroid treatment, serum creatinine level, urine protein/creatinine ratio, vascular involvement, tubular atrophy, interstitial fibrosis, and decreased glomerular nestin expression. CONCLUSIONS: The most important finding of our study is that nestin can be used as a potential new early morphological predictor of kidney dysfunction in childhood onset of FSGS, since nestin has been obviously decreased in both sclerotic and normal glomeruli seen by light microscopy.

Pathogens causing urinary tract infections in infants: a European overview by the ESCAPE study group.

UNLABELLED: Knowledge of the distribution spectrum of causative organisms and their resistance patterns has become a core requirement for the rational and effective management of urinary tract infections. In the context of a prospective trial on the use of antibiotic prophylaxis in infants with underling kidney malformations, we conducted an online survey among paediatric nephrologists on positive urine cultures (July 2010-June 2012) from both hospitalized and non-hospitalized infants under 24 months of age. We collected 4745 urine cultures (UCs) at 18 units in 10 European countries. Escherichia coli was the most frequent bacterium isolated from UCs; however, in 10/16 hospitals and in 6/15 community settings, E. coli was isolated in less than 50% of the total positive UCs. Other bacterial strains were Klebsiella, Enterococcus, Proteus and Pseudomonas not only from hospital settings. E. coli showed a high resistance to amoxicillin and trimethoprim and variable to cephalosporin. Nitrofurantoin had a good rate of efficacy, with 11/16 hospitals and 11/14 community settings reporting a resistance lower than 5%. CONCLUSION: E. coli is the most common organism causing UTIs in infants; however, other bacterial strains are frequently isolated. As a result, antibiotic prophylaxis should be more elastic and adaptable over time in order to guarantee maximum efficacy.

Genotype-phenotype associations in WT1 glomerulopathy.

WT1 mutations cause a wide spectrum of renal and extrarenal manifestations. Here we evaluated disease prevalence, phenotype spectrum, and genotype-phenotype correlations of 61 patients with WT1-related steroid-resistant nephrotic syndrome relative to 700 WT1-negative patients, all with steroid-resistant nephrotic syndrome. WT1 patients more frequently presented with chronic kidney disease and hypertension at diagnosis and exhibited more rapid disease progression. Focal segmental glomerulosclerosis was equally prevalent in both cohorts, but diffuse mesangial sclerosis was largely specific for WT1 disease and was present in 34% of cases. Sex reversal and/or urogenital abnormalities (52%), Wilms tumor (38%), and gonadoblastoma (5%) were almost exclusive to WT1 disease. Missense substitutions affecting DNA-binding residues were associated with diffuse mesangial sclerosis (74%), early steroid-resistant nephrotic syndrome onset, and rapid progression to ESRD. Truncating mutations conferred the highest Wilms tumor risk (78%) but typically late-onset steroid-resistant nephrotic syndrome. Intronic (KTS) mutations were most likely to present as isolated steroid-resistant nephrotic syndrome (37%) with a median onset at an age of 4.5 years, focal segmental glomerulosclerosis on biopsy, and slow progression (median ESRD age 13.6 years). Thus, there is a wide range of expressivity, solid genotype-phenotype associations, and a high risk and significance of extrarenal complications in WT1-associated nephropathy. We suggest that all children with steroid-resistant nephrotic syndrome undergo WT1 gene screening.

Early biomarkers of renal injury and protective effect of erythropoietin on kidneys of asphyxiated newborn rats.

BACKGROUND: The aims of this study were to determine which of the two biomarkers of renal injury, kidney injury molecule-1 or cystatin C, is more sensitive and to evaluate whether erythropoietin protects kidneys injured by perinatal asphyxia. METHODS: Animals were split into three groups designated as follows: AE, pups that survived perinatal asphyxia and subsequently received 2.5 µg (0.1 ml) of darbepoetin-α (i.p.); A, the pups that survived perinatal asphyxia and received 0.1 ml of 0.9% NaCl; and C, control group. The pups were killed at different ages of life (6 h, 24 h, 48 h, 7 d, and 14 d of age; 10 rats in each subgroup). Immunohistopathological evaluation of kidneys was performed. RESULTS: At 48 h and on days 7 and 14, absolute injury scores were significantly lower in group AE as measured by both biomarkers. Cystatin C expression was the most intensive 6 h after the hypoxic event (average value of absolute injury score was 2.82) and declined over time. Expression of kidney injury molecule-1 was less intensive, with the average value of absolute injury score being 2.02 at 6 h and 2.105 at 24 h; the peak value (2.155) was recorded 48 h after the hypoxic event. CONCLUSION: Erythropoietin has a protective effect on hypoxic kidneys. Cystatin C is more sensitive as an early biomarker of acute kidney injury in comparison with kidney injury molecule-1.

Demographics of paediatric renal replacement therapy in Europe: a report of the ESPN/ERA-EDTA registry.

BACKGROUND: The ESPN/ERA-EDTA Registry collects data on European children with end-stage renal disease receiving renal replacement therapy (RRT) who are listed on national and regional renal registries in Europe. In this paper we report on the analysis of demographic data collected from 2009 to 2011. METHODS: Data on primary renal disease, incidence, prevalence, 4-year survival, transplantation rate and causes of death in paediatric patients receiving RRT were extracted from the ESPN/ERA-EDTA Registry for 37 European countries. RESULTS: The incidence of RRT in paediatric patients in Europe during the study period was 5.5 cases per million age-related population (pmarp) in patients aged 0-14 years and varied markedly between countries (interquartile range 3.4-7.0 years). The prevalence of RRT was 27.9 pmarp and increased with age, with 67 % of prevalent patients living with a functioning graft. The probability of receiving a transplant within 4 years was 76.9 % and was lowest in patients aged 0-4 years (68.9 %). Mortality in paediatric patients treated with RRT was 55-fold higher than that of the general EU paediatric population. Overall survival at 4 years was 93.7 %, with the poorest survival in patients aged 0-4 years and in patients starting on dialysis. Infections (19.9 %) were the primary cause of death in European paediatric RRT patients. CONCLUSION: Considerable variation exists in the current demographics of children treated with RRT across Europe.

Combined NGS approaches identify mutations in the intraflagellar transport gene IFT140 in skeletal ciliopathies with early progressive kidney Disease.

Ciliopathies are genetically heterogeneous disorders characterized by variable expressivity and overlaps between different disease entities. This is exemplified by the short rib-polydactyly syndromes, Jeune, Sensenbrenner, and Mainzer-Saldino chondrodysplasia syndromes. These three syndromes are frequently caused by mutations in intraflagellar transport (IFT) genes affecting the primary cilia, which play a crucial role in skeletal and chondral development. Here, we identified mutations in IFT140, an IFT complex A gene, in five Jeune asphyxiating thoracic dystrophy (JATD) and two Mainzer-Saldino syndrome (MSS) families, by screening a cohort of 66 JATD/MSS patients using whole exome sequencing and targeted resequencing of a customized ciliopathy gene panel. We also found an enrichment of rare IFT140 alleles in JATD compared with nonciliopathy diseases, implying putative modifier effects for certain alleles. IFT140 patients presented with mild chest narrowing, but all had end-stage renal failure under 13 years of age and retinal dystrophy when examined for ocular dysfunction. This is consistent with the severe cystic phenotype of Ift140 conditional knockout mice, and the higher level of Ift140 expression in kidney and retina compared with the skeleton at E15.5 in the mouse. IFT140 is therefore a major cause of cono-renal syndromes (JATD and MSS). The present study strengthens the rationale for IFT140 screening in skeletal ciliopathy spectrum patients that have kidney disease and/or retinal dystrophy.

Genetic screening in adolescents with steroid-resistant nephrotic syndrome.

Genetic screening paradigms for congenital and infantile nephrotic syndrome are well established; however, screening in adolescents has received only minor attention. To help rectify this, we analyzed an unselected adolescent cohort of the international PodoNet registry to develop a rational screening approach based on 227 patients with nonsyndromic steroid-resistant nephrotic syndrome aged 10-20 years. Of these, 21% had a positive family history. Autosomal dominant cases were screened for WT1, TRPC6, ACTN4, and INF2 mutations. All other patients had the NPHS2 gene screened, and WT1 was tested in sporadic cases. In addition, 40 sporadic cases had the entire coding region of INF2 tested. Of the autosomal recessive and the sporadic cases, 13 and 6%, respectively, were found to have podocin-associated nephrotic syndrome, and 56% of them were compound heterozygous for the nonneutral p.R229Q polymorphism. Four percent of the sporadic and 10% of the autosomal dominant cases had a mutation in WT1. Pathogenic INF2 mutations were found in 20% of the dominant but none of the sporadic cases. In a large cohort of adolescents including both familial and sporadic disease, NPHS2 mutations explained about 7% and WT1 4% of cases, whereas INF2 proved relevant only in autosomal dominant familial disease. Thus, screening of the entire coding sequence of NPHS2 and exons 8-9 of WT1 appears to be the most rational and cost-effective screening approach in sporadic juvenile steroid-resistant nephrotic syndrome.

Underweight, overweight and obesity in paediatric dialysis and renal transplant patients.

BACKGROUND: The prevalence of childhood overweight is rising worldwide, but in children on renal replacement therapy (RRT) a poor nutritional status is still the primary concern. We aimed to study the prevalence of, and factors associated with, underweight and overweight/obesity in the European paediatric RRT population. Moreover, we assessed the evolution of body mass index (BMI) after the start of RRT. METHODS: We included 4474 patients younger than 16 years from 25 countries of whom BMI data, obtained between 1995 and 2010, were available within the European Society for Paediatric Nephrology/European Renal Association-European Dialysis and Transplant Association Registry. Prevalence estimates for under- and overweight/obesity were calculated using age and sex-specific criteria of the World Health Organization (WHO, 0-1 year olds) and the International Obesity Task Force cut-offs (2-15 year olds). RESULTS: The prevalence of underweight was 3.5%, whereas 20.8% of the patients were overweight and 12.5% obese. Factors associated with being underweight were receiving dialysis treatment and infant age. Among transplanted recipients, a very short stature (OR: 1.64, 95% CI: 1.40-1.92) and glucocorticoid treatment (OR: 1.23, 95% CI: 1.03-1.47) were associated with a higher risk of being overweight/obese. BMI increased post-transplant, and a lower BMI and a higher age at the start of RRT were associated with greater BMI changes during RRT treatment. CONCLUSIONS: Overweight and obesity, rather than underweight, are highly prevalent in European children on RRT. Short stature among graft recipients had a strong association with overweight, while underweight appears to be only a problem in infants. Our findings suggest that nutritional management in children receiving RRT should focus as much on the prevention and treatment of overweight as on preventing malnutrition.

L-FABP can be an early marker of acute kidney injury in children.

BACKGROUND: Acute kidney injury (AKI) is a common postoperative complication following cardiopulmonary bypass (CPB) surgery. New biomarkers to identify patients with early AKI (before increases in serum creatinine) are needed to facilitate appropriate treatment. This study aimed to test the role of urinary liver fatty-acid-binding protein (L-FABP) as an early biomarker for AKI in children undergoing CPB surgery. METHODS: This is a case-control study of children undergoing CPB. AKI was defined as 50 % increase in serum creatinine at 48 h after surgery. For each patient, five serum and urine samples were obtained corresponding to time 0 h (presurgery) and 2, 6, 24, and 48 h after surgery. RESULTS: Twenty-seven patients, median age 360 days, were enrolled. AKI developed in 11 patients (41 %); three needed renal replacement therapy (peritoneal dialysis); there were two deaths. There were significant differences between patients with and without AKI in L-FABP levels at 2, 6, and 48 h after surgery, length of hospital stay, and CPB time; there were no differences in gender, patient age, and body weight. L-FABP was normalized to urinary creatinine concentration at all time points, with area under the receiver operator curve (AUC ROC) 0.867 at 2 and 6 h postoperatively. Correlation coefficient between L-FABP and length of hospital stay after surgery was statistically significant (r = 0.722, p value = 0.000). CONCLUSIONS: Our results suggest that urinary L-FABP can be used to diagnose AKI earlier than rise in serum creatinine in children undergoing CPB.

Hyperlipidemia, oxidative stress, and intima media thickness in children with chronic kidney disease.

BACKGROUND: The roles of dyslipidemia and oxidative stress in the early phases of atherosclerosis were tested in children with chronic kidney disease (CKD). Intima media thickness of common carotid arteries (cIMT) is used as a measure of early atherosclerosis. METHODS: Fifty-two pediatric CKD patients were enrolled in the study (10 with chronic renal failure [CRF], 22 with a renal transplant [RT], 20 with chronic hemodialysis (cHD) patients, and 36 healthy children (control group, CG). Lipid status, oxidative stress, and paraoxonase 1 (PON1) status were assessed. cIMT was measured by ultrasound, adjusted for age and sex, and presented as standard deviation scores (SDS). RESULTS: Children with CKD had disturbed lipid content, which was most pronounced in cHD children, with higher free cholesterol and triglycerides compared with healthy children. Oxidative stress was markedly increased (malodialdehyde [MDA, µmol/L]: CRF 1.50 ± 0.26, RT 1.55 ± 0.40, cHD 1.77 ± 0.34, CG 0.97 ± 0.33, p < 0.001) and antioxidative defense was compromised (superoxide dismutase [SOD, U/L]: CG 120 ± 21, CRF 84 ± 25, RT 93 ± 12, cHD 119 ± 37, p < 0.001). Multiple linear regression analysis showed that a model that included disease duration, blood pressure, urea, lipid, and oxidative status parameters accounted for more than 90% of the variability of cIMT-SDS. CONCLUSIONS: Early atherosclerosis in CKD children is caused, at least in part, by dyslipidemia and oxidative stress. Monitoring of vessel wall changes, along with assessment of oxidative stress status and high density lipoprotein (HDL) functionality is necessary to ensure better therapeutic strategies for delaying atherosclerotic changes in their asymptomatic phase.

Granulomatosis with polyangiitis (Wegener's granulomatosis) in children: report of three cases with cutaneous manifestations and literature review.

Granulomatosis with polyangiitis (GPA), also known as Wegener's granulomatosis, is a rare disease in childhood. Of 39 GPA patients that we diagnosed during a 20-year period, only 3 (7.7%) were younger than 18 years. We report the course of GPA in three girls whose disease started at the ages of 16, 11, and 6 years. All had cutaneous manifestations: the first had necrotizing vasculitis, the second had palpable purpura, and the third had right upper-eyelid edema and infiltration and proptosis caused by extraocular pseudotumor, initially histologically misdiagnosed as orbital immunoglobulin G4 (IgG4)-related disease. Unlike with skin vasculitis and glomerulonephritis, upper-airway and orbital inflammation were resistant to immunosuppressive therapy. Our report emphasizes that children presenting with cutaneous vasculitis, chronic eyelid swelling, sinusitis, or hoarseness should be tested for antineutrophil cytoplasmic antibodies. We emphasize that the upper-eyelid edema and infiltration, with histologic characteristics of orbital IgG4-related disease, may be the initial presentation of localized GPA in children, a feature that, until now, has been described only in adults.

Strict blood-pressure control and progression of renal failure in children.

BACKGROUND: Although inhibition of the renin-angiotensin system delays the progression of renal failure in adults with chronic kidney disease, the blood-pressure target for optimal renal protection is controversial. We assessed the long-term renoprotective effect of intensified blood-pressure control among children who were receiving a fixed high dose of an angiotensin-converting-enzyme (ACE) inhibitor. METHODS: After a 6-month run-in period, 385 children, 3 to 18 years of age, with chronic kidney disease (glomerular filtration rate of 15 to 80 ml per minute per 1.73 m(2) of body-surface area) received ramipril at a dose of 6 mg per square meter of body-surface area per day. Patients were randomly assigned to intensified blood-pressure control (with a target 24-hour mean arterial pressure below the 50th percentile) or conventional blood-pressure control (mean arterial pressure in the 50th to 95th percentile), achieved by the addition of antihypertensive therapy that does not target the renin-angiotensin system; patients were followed for 5 years. The primary end point was the time to a decline of 50% in the glomerular filtration rate or progression to end-stage renal disease. Secondary end points included changes in blood pressure, glomerular filtration rate, and urinary protein excretion. RESULTS: A total of 29.9% of the patients in the group that received intensified blood-pressure control reached the primary end point, as assessed by means of a Kaplan-Meier analysis, as compared with 41.7% in the group that received conventional blood-pressure control (hazard ratio, 0.65; confidence interval, 0.44 to 0.94; P=0.02). The two groups did not differ significantly with respect to the type or incidence of adverse events or the cumulative rates of withdrawal from the study (28.0% vs. 26.5%). Proteinuria gradually rebounded during ongoing ACE inhibition after an initial 50% decrease, despite persistently good blood-pressure control. Achievement of blood-pressure targets and a decrease in proteinuria were significant independent predictors of delayed progression of renal disease. CONCLUSIONS: Intensified blood-pressure control, with target 24-hour blood-pressure levels in the low range of normal, confers a substantial benefit with respect to renal function among children with chronic kidney disease. Reappearance of proteinuria after initial successful pharmacologic blood-pressure control is common among children who are receiving long-term ACE inhibition. (ClinicalTrials.gov number, NCT00221845.)

Epidemiology of chronic kidney disease in children in Serbia.

BACKGROUND: The epidemiological information from well-defined populations regarding childhood chronic kidney disease (CKD), particularly those concerning non-terminal stages, are scanty. The epidemiology of CKD in children is often based on renal replacement therapy (RRT) data, which means that a considerable number of children in earlier stages of CKD are missed as they will reach end-stage renal disease (ESRD) in adulthood. Here, we report the basic epidemiological data on childhood CKD in Serbia, gathered over the 10-year period of activity of the Serbian Pediatric Registry of Chronic Kidney Disease. METHODS: Since 2000-09, data on incidence, prevalence, aetiology, treatment modalities and outcome of children aged 0-18 years, with CKD Stages 2-4 and CKD Stage 5, were collected by reporting index cases from paediatric centres. RESULTS: Three hundred and thirty-six children were registered (211 boys, 125 girls, male/female ratio 1.7). The median age at registration was 9.0 years [interquartile range (IQR) 3-13]. Median follow-up was 4.0 years (IQR, 1-9). The median glomerular filtration rate (GFR) at the time of the registration was 39.6 mL/min/1.73m(2) (IQR, 13.8-65.4). Median annual incidence of CKD 2-5 stages was 14.3 per million age-related population (p.m.a.r.p.), while those of CKD 2-4 or CKD 5 were 9.1 and 5.7 p.m.a.r.p., respectively. The median prevalence of CKD 2-5 was 96.1 p.m.a.r.p., 52.8 p.m.a.r.p. in CKD 2-4 and 62.2 p.m.a.r.p. in CKD 5. The main causes of CKD were congenital anomalies of kidney and urinary tract and hereditary nephropathies. Kidney survival was the worst in children with glomerular diseases and in those with advanced CKD. Haemodialysis was the most common first modality of RRT. Mortality rate was 4.5%, mainly due to cardiovascular and infectious complications. CONCLUSIONS: Epidemiology of paediatric CKD in Serbia is similar to that reported from developed European countries. The knowledge of the epidemiology of earlier stages of CKD is essential for both institution of renoprotective therapy and planning of RRT, a fact of paramount importance in countries with limited resources.

Lipoproteins and cholesterol homeostasis in paediatric nephrotic syndrome patients.

Introduction: The aim of this study was to investigate lipoprotein particle distributions and the likelihood of achieving cholesterol homeostasis in the remission phase of nephrotic syndrome (NS) in paediatric patients. We hypothesized that lipoprotein particle distributions moved toward less atherogenic profile and that cholesterol homeostasis was achieved. Materials and methods: Thirty-three children, 2 to 9 years old with NS were recruited. Blood sampling took place both in the acute phase and during remission. Serum low-density lipoprotein particles (LDL) and high-density lipoprotein particles (HDL) were separated using non-denaturing polyacrylamide gradient gel (3-31%) electrophoresis. Serum non-cholesterols sterols (NCSs), desmosterol, lathosterol, 7-dehydrocholesterol (7-DHC), campesterol and ß-sitosterol were measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Results: All patients had desirable serum HDL cholesterol concentrations during remission. The dominant lipoprotein diameters and LDL subclass distribution did not change significantly during follow-up. In contrast, HDL lipoprotein particle distribution shifted towards larger particles. The absolute concentration of desmosterol was significantly lower during remission (P = 0.023). ß-sitosterol concentration markedly increased during remission (P = 0.005). Desmosterol/ß-sitosterol (P < 0.001) and 7-DHC/ß-sitosterol (P = 0.005) ratios significantly declined during disease remission. Conclusions: Favourable changes in the serum lipid profiles, HDL particle subclass distribution and cholesterol metabolism in paediatric patients with NS during remission took place. For the first time, we found that cholesterol homeostasis changed in favour of increased cholesterol absorption during disease remission. Nevertheless, complete cholesterol homeostasis was not achieved during disease remission.