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.

Cardiovascular rhythmicity in overweight and obese children / Ritmicidade cardiovascular em crianças com sobrepeso e obesidade

Abstract Introduction: Obesity is thought to play a role in the disruption of cardiac rhythmicity in obese children, but this is mostly an unexplored field of investigation. We aimed to evaluate the impact of overweight and obesity on circadian and ultradian cardiovascular rhythmicity of prepubertal children, in comparison with normal weight counterparts. Methods: We performed a cross sectional study of 316 children, followed in the birth cohort Generation XXI (Portugal). Anthropometrics and 24-hour ambulatory blood pressure were measured and profiles were examined with Fourier analysis for circadian and ultradian blood pressure (BP) and heart rate (HR) rhythms. Results: Overweight/obese children presented more frequently a non-dipping BP pattern than normal weight counterparts (31.5% vs. 21.6%, p = 0.047). The prevalence of 24-hour mean arterial pressure (MAP) and 8-hour HR rhythmicity was significantly lower in obese children (79.3% vs. 88.0%, p = 0.038 and 33.3% vs. 45.2%, p = 0.031, respectively). The prevalence of the remaining MAP and HR rhythmicity was similar in both groups. No differences were found in the median values of amplitudes and acrophases of MAP and HR rhythms. Discussion: The alterations found in rhythmicity suggest that circadian and ultradian rhythmicity analysis might be sensitive in detecting early cardiovascular dysregulations, but future studies are needed to reinforce our findings and to better understand their long-term implications.

Resumo Introdução: Acredita-se que a obesidade desempenhe um papel na desregulação da ritmicidade cardíaca em crianças obesas, mas esse é um campo de investigação ainda pouco explorado. O objetivo deste trabalho foi avaliar o impacto do sobrepeso e da obesidade na ritmicidade cardiovascular circadiana e ultradiana de crianças pré-púberes, em comparação com crianças com peso normal. Métodos: Realizamos um estudo transversal com 316 crianças, acompanhadas na coorte de nascimentos Geração XXI (Portugal). Foram medidos dados antropométricos e a pressão arterial ambulatorial de 24 horas, e os perfis foram examinados com uma análise de Fourier para ritmos circadianos e ultradianos de pressão arterial (PA) e frequência cardíaca (FC). Resultados: Crianças com sobrepeso/obesidade apresentaram mais frequentemente um padrão de PA não-dipper em comparação com crianças com peso normal (31,5% vs. 21,6%; p = 0,047). A prevalência da pressão arterial média (PAM) de 24 horas e da ritmicidade da FC de 8 horas foi significativamente menor em crianças obesas (79,3% vs. 88,0%; p = 0,038 e 33,3% vs. 45,2%; p = 0,031, respectivamente). A prevalência das restantes ritmicidades da PAM e da FC foi semelhante em ambos os grupos. Não foram encontradas diferenças nos valores medianos das amplitudes e acrofases dos ritmos de PAM e FC. Discussão: As alterações encontradas na ritmicidade sugerem que a análise da ritmicidade circadiana e ultradiana pode ser sensível na detecção de desregulações cardiovasculares precoces, mas são necessários novos estudos para reforçar nossos achados e entender melhor suas implicações a longo prazo.

Outcome of infantile nephropathic cystinosis depends on early intervention, not genotype: A multicenter sibling cohort study.

Infantile nephropathic cystinosis (INC) is an inheritable lysosomal storage disorder characterized by lysosomal cystine accumulation, progressive kidney disease, and multiple extrarenal complications (ERCs). Cysteamine postpones the onset of end-stage kidney disease (ESKD) and reduces the incidence of ERCs; however, cysteamine is generally initiated upon establishment of the renal Fanconi syndrome (FS) and partial loss of kidney function, whereas data on long-term effects of cysteamine administered from neonatal age are lacking. An international multicenter retrospective cohort study of siblings with INC was set up to investigate the outcome in relation to age at initiation of cysteamine versus CTNS genotype, with attention to patients treated with cysteamine from neonatal age. None of the siblings treated from neonatal age (n = 9; age 10 ± 6 years) had reached ESKD, while 22% of their index counterparts (n = 9; age 14 ± 5 years) had commenced renal replacement therapy. Siblings treated with cysteamine from the onset of symptoms at a younger age compared with their index counterparts, reached ESKD at a significant older age (13 ± 3 vs. 10 ± 3 years, p = 0.002). In contrast, no significant difference in ERCs was observed between sibling and index patients, independently from the age at initiation of cysteamine. The CTNS genotype had no impact on the overall outcome in this cohort. In INC, presymptomatic treatment with cysteamine results in a better renal outcome in comparison to treatment initiated from the onset of symptoms. This justifies including cystinosis into newborn screening programs. SYNOPSIS: In infantile nephropathic cystinosis, presymptomatic treatment with cysteamine improves the renal outcome which justifies the inclusion of cystinosis into newborn screening programs.

Relationship between age at initiation of cysteamine treatment, adherence with therapy, and glomerular kidney function in infantile nephropathic cystinosis.

Infantile nephropathic cystinosis, due to impaired transport of cystine out of lysosomes, occurs with an incidence of 1 in 100-200,000 live births. It is characterized by renal Fanconi syndrome in the first year of life and glomerular dysfunction progression to end-stage kidney disease by approximately 10 years of age. Treatment with oral cysteamine therapy helps preserve glomerular function, but affected individuals eventually require kidney replacement therapy. This is because glomerular damage had already occurred by the time a child is diagnosed with cystinosis, typically in the second year of life. We performed a retrospective multicenter study to investigate the impact of initiating cysteamine treatment within the first 2 months of life in some infants and comparing two different levels of adherence in patients diagnosed at the typical age. We collected 3983 data points from 55 patients born between 1997 and 2020; 52 patients with 1592 data points could be further evaluated. These data were first analyzed by dividing the patient cohort into three groups: (i) standard treatment start with good adherence, (ii) standard treatment start with less good adherence, and (iii) early treatment start. At every age, mean estimated glomerular filtration rate (eGFR) was higher in early-treated patients than in later-treated patients. Second, a generalized additive mixed model (GAMM) was applied showing that patients with initiation of treatment before 2 months of age are expected to have a 34 ml/min/1.73 m2 higher eGFR than patients with later treatment start while controlling for adherence and patients' age. These data strongly suggest that oral cysteamine treatment initiated within 2 months of birth preserves kidney function in infantile nephropathic cystinosis and provide evidence of the utility of newborn screening for this disease.

Lysozyme amyloidosis-a report on a large German cohort and the characterisation of a novel amyloidogenic lysozyme gene variant.

Lysozyme-derived (ALys) amyloidosis is a rare type of hereditary amyloidosis. Nine amyloidogenic variants and ∼30 affected families have been described worldwide. The most common manifestations are renal dysfunction, gastrointestinal tract symptoms, and sicca syndrome. We report on the clinical course of ten patients from six families representing one of the largest cohorts published so far. Seven patients carried the W64R variant showing the whole spectrum of ALys-associated symptoms. Two patients-a mother-son pair-carried a novel lysozyme variant, which was associated with nephropathy and peripheral polyneuropathy. In accordance with previous findings, the phenotype resembled within these families but did not correlate with the genotype. To gain insights into the effect of the variants at the molecular level, we analysed the structure of lysozyme and performed comparative computational predictions on aggregation propensity and conformational stability. Our study supports that decreased conformational stability is a key factor for lysozyme variants to be prone to aggregation. In summary, ALys amyloidosis is a very rare, but still heterogeneous disease that can manifest at an early age. Our newly identified lysozyme variant is associated with nephropathy and peripheral polyneuropathy. Further research is needed to understand its pathogenesis and to enable the development of new treatments.

Risk Factors for Early Dialysis Dependency in Autosomal Recessive Polycystic Kidney Disease.

OBJECTIVE: To identify prenatal, perinatal, and postnatal risk factors for dialysis within the first year of life in children with autosomal recessive polycystic kidney disease (ARPKD) as a basis for parental counseling after prenatal and perinatal diagnosis. STUDY DESIGN: A dataset comprising 385 patients from the ARegPKD international registry study was analyzed for potential risk markers for dialysis during the first year of life. RESULTS: Thirty-six out of 385 children (9.4%) commenced dialysis in the first year of life. According to multivariable Cox regression analysis, the presence of oligohydramnios or anhydramnios, prenatal kidney enlargement, a low Apgar score, and the need for postnatal breathing support were independently associated with an increased hazard ratio for requiring dialysis within the first year of life. The increased risk associated with Apgar score and perinatal assisted breathing was time-dependent and vanished after 5 and 8 months of life, respectively. The predicted probabilities for early dialysis varied from 1.5% (95% CI, 0.5%-4.1%) for patients with ARPKD with no prenatal sonographic abnormalities to 32.3% (95% CI, 22.2%-44.5%) in cases of documented oligohydramnios or anhydramnios, renal cysts, and enlarged kidneys. CONCLUSIONS: This study, which identified risk factors associated with onset of dialysis in ARPKD in the first year of life, may be helpful in prenatal parental counseling in cases of suspected ARPKD.

Prevalence of Hypertension in Children with Early-Stage ADPKD.

BACKGROUND AND OBJECTIVES: Autosomal dominant polycystic kidney disease is the most common inheritable kidney disease, frequently thought to become symptomatic in adulthood. However, patients with autosomal dominant polycystic kidney disease may develop signs or symptoms during childhood, in particular hypertension. Although ambulatory BP monitoring is the preferred method to diagnose hypertension in pediatrics, data in children with autosomal dominant polycystic kidney disease are limited. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Our retrospective multicenter study was conducted to collect ambulatory BP monitoring recordings from patients with autosomal dominant polycystic kidney disease age <18 years old. Basic anthropometric parameters as well as data on kidney function, BP treatment, and kidney ultrasound were also collected. RESULTS: Data from 310 children with autosomal dominant polycystic kidney disease with a mean age of 11.5±4.1 years old were collected at 22 European centers. At the time when ambulatory BP monitoring was performed, 95% of children had normal kidney function. Reference data for ambulatory BP monitoring were available for 292 patients. The prevalence rates of children with hypertension and/or those who were treated with antihypertensive drugs were 31%, 42%, and 35% during daytime, nighttime, or the entire 24-hour cycle, respectively. In addition, 52% of participants lacked a physiologic nocturnal BP dipping, and 18% had isolated nocturnal hypertension. Logistic regression analysis showed a significant association between a categorical cyst score that was calculated on the basis of the number of cysts >1 cm per kidney and daytime hypertension (odds ratio, 1.70; 95% confidence interval, 1.21 to 2.4; P=0.002), nighttime hypertension (odds ratio, 1.31; 95% confidence interval, 1.05 to 1.63; P=0.02), or 24-hour hypertension (odds ratio, 1.39; 95% confidence interval, 1.08 to 1.81; P=0.01). Kidney length, expressed as SD score, was also significantly associated with nighttime hypertension (odds ratio, 1.23; 95% confidence interval, 1.06 to 1.42; P=0.10). CONCLUSIONS: These data indicate high prevalence of hypertension in children with autosomal dominant polycystic kidney disease starting at young ages.

Efficacy and Long-Term Safety of C.E.R.A. Maintenance in Pediatric Hemodialysis Patients with Anemia of CKD.

BACKGROUND AND OBJECTIVES: The study was conducted to identify a conversion factor for switching from previous erythropoiesis-stimulating agents (ESAs) to continuous erythropoietin receptor activator-methoxy polyethylene glycol-epoetin beta (C.E.R.A.) and to document the efficacy and long-term safety of C.E.R.A. in pediatric patients with anemia of CKD undergoing hemodialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this open-label, multicenter study, patients aged 6-17 years, with stable chronic anemia of CKD, undergoing hemodialysis received C.E.R.A. every 4 weeks, at a starting dose determined by previous weekly epoetin alfa/beta or darbepoetin dosing. After a 16-week dose-titration and a 4-week evaluation period, patients with stable hemoglobin could enter a 1-year optional safety extension. RESULTS: A total of 64 patients were enrolled. A conversion factor (4 µg every 4 weeks for each weekly dose of 125 IU epoetin alfa/beta or 0.55 µg darbepoetin) was identified that allowed patients to maintain hemoglobin within target levels on switching to C.E.R.A. from another ESA. Using this conversion factor, the adjusted mean change in hemoglobin from baseline to evaluation was -0.09 g/dl (95% confidence interval, -0.45 to 0.26); 81% of patients maintained hemoglobin within 10.0-12.0 g/dl and 75% maintained hemoglobin within 1.0 g/dl of baseline. Results were consistent across age groups (6-11 and 12-17 years) and previous ESA. Thirty-seven patients entered the safety extension period and 17 completed 73 weeks of treatment. Most withdrawals were for kidney transplantation. A total of 70% of patients had hemoglobin within 10.0-12.0 g/dl at last observation, and 62% were within ±1.0 g/dl of baseline. Safety was similar to studies in adult patients, with no new signal detected. CONCLUSIONS: Using a defined conversion factor, 4-weekly C.E.R.A. was efficacious in maintaining hemoglobin levels in pediatric patients with stable anemia of CKD undergoing hemodialysis, switching from maintenance treatment with epoetin alfa/beta or darbepoetin. Safety was consistent with the known C.E.R.A. safety profile in adults.

Presentation of pediatric Henoch-Schönlein purpura nephritis changes with age and renal histology depends on biopsy timing.

BACKGROUND: This study correlates the clinical presentation of Henoch-Schönlein purpura nephritis (HSPN) with findings on initial renal biopsy. METHODS: Data from 202 pediatric patients enrolled in the HSPN registry of the German Society of Pediatric Nephrology reported by 26 centers between 2008 and 2014 were analyzed. All biopsy reports were re-evaluated for the presence of cellular crescents or chronic pathological lesions (fibrous crescents, glomerular sclerosis, tubular atrophy >5%, and interstitial fibrosis >5%). RESULTS: Patients with HSPN with cellular glomerular crescents were biopsied earlier after onset of nephritis (median 24 vs 36 days, p = 0.04) than those without, whereas patients with chronic lesions were biopsied later (57 vs 19 days, p < 0.001) and were older (10.3 vs 8.6 years, p = 0.01) than those without. Patients biopsied more than 30 days after the onset of HSPN had significantly more chronic lesions (52 vs 22%, p < 0.001), lower eGFR (88 vs 102 ml/min/1.73m2, p = 0.01), but lower proteinuria (2.3 vs 4.5 g/g, p < 0.0001) than patients biopsied earlier. Children above 10 years of age had lower proteinuria (1.98 vs 4.58 g/g, p < 0.001), lower eGFR (86 vs 101 ml/min/1.73m2, p = 0.002) and were biopsied significantly later after onset of nephritis (44 vs 22 days, p < 0.001) showing more chronic lesions (45 vs 30%, p = 0.03). Proteinuria and renal function at presentation decreased with age. CONCLUSIONS: In summary, we find an age-dependent presentation of HSPN with a more insidious onset of non-nephrotic proteinuria, impaired renal function, longer delay to biopsy, and more chronic histopathological lesions in children above the age of 10 years. Thus, HSPN presents more like Immunoglobulin A (IgA) nephritis in older than in younger children.

Point shear wave elastography (pSWE) using Acoustic Radiation Force Impulse (ARFI) imaging: a feasibility study and norm values for renal parenchymal stiffness in healthy children and adolescents.

AIMS: To evaluate the applicability of point shear wave elastography (pSWE) for measuring renal parenchymal stiffness in healthy children and adolescents and to establish norm values for shear wave speed (SWS) using two ARFI methods and ultrasound probes. MATERIAL AND METHODS: We prospectively investigated 264 children (43.9% males). pSWE (Virtual TouchTM Quantification and Virtual TouchTM Imaging Quantification (VTQ and VTIQ; Siemens, Germany)) was performed in the renal cortex of 528 healthy kidneys using a 1-6 MHz convex and a 4-9 MHz linear ultrasound probe in ventrolateral and dorsal examinations. Feasibility and reproducibility of pSWE measurements were evaluated. SWS values were analysed with regard to age, body dimensions, kidney volume and measuring depth. RESULTS: pSWE measurements were successful in >95% of subjects using the low and in <60% using the high-frequency probe. Mean SWS values (m/s) differed by method and probe: 2.10±0.43 (VTQ1-6MHz, convex, ventrolateral), 2.30±0.37 (VTQ1-6MHz, convex, dorsal), 1.58±0.44 (VTQ4-9MHz, linear, dorsal) and 1.96±0.27 (VTIQ4-9MHz, linear, dorsal). SWS was positively correlated with age, weight and body height, but independent of sex, BMI, or kidney volume and depth. CONCLUSIONS: pSWE (VTQ) is a feasible method to evaluate renal parenchymal stiffness in children of all ages. SWS values are age and weight dependent and differ significantly between high- and low-frequency probes. High-frequency probes and VTIQ should only be used in children <10 years.

Association of Serum Soluble Urokinase Receptor Levels With Progression of Kidney Disease in Children.

Importance: Conventional methods to diagnose and monitor chronic kidney disease (CKD) in children, such as creatinine level and cystatin C-derived estimated glomerular filtration rate (eGFR) and assessment of proteinuria in spot or timed urine samples, are of limited value in identifying patients at risk of progressive kidney function loss. Serum soluble urokinase receptor (suPAR) levels strongly predict incident CKD stage 3 in adults. Objective: To determine whether elevated suPAR levels are associated with renal disease progression in children with CKD. Design, Setting, and Participants: Post hoc analysis of 2 prospectively followed up pediatric CKD cohorts, ie, the ESCAPE Trial (1999-2007) and the 4C Study (2010-2016), with serum suPAR level measured at enrollment and longitudinal eGFR measured prospectively. In the 2 trials, a total of 898 children were observed at 30 (ESCAPE Trial; n = 256) and 55 (4C Study; n = 642) tertiary care hospitals in 13 European countries. Renal diagnoses included congenital anomalies of the kidneys and urinary tract (n = 637 [70.9%]), tubulointerstitial nephropathies (n = 92 [10.2%]), glomerulopathies (n = 69 [7.7%]), postischemic CKD (n = 42 [4.7%]), and other CKD (n = 58 [6.5%]). Total follow-up duration was up to 7.9 years, and median follow-up was 3.1 years. Analyses were conducted from October 2016 to December 2016. Exposures: Serum suPAR level was measured at enrollment, and eGFR was measured every 2 months in the ESCAPE Trial and every 6 months in the 4C Study. The primary end point of CKD progression was a composite of 50% eGFR loss, eGFR less than 10 mL/min/1.73 m2, or initiation of renal replacement therapy. Main Outcomes and Measures: The primary end point in this study was renal survival, defined as a composite of 50% loss of GFR that persisted for at least 1 month, the start of renal replacement therapy, or an eGFR less than 10 mL/min/1.73 m2. Results: Of the 898 included children, 560 (62.4%) were male, and the mean (SD) patient age at enrollment was 11.9 (3.5) years. The mean (SD) eGFR was 34 (16) mL/min/1.73 m2. The 5-year end point-free renal survival was 64.5% (95% CI, 57.4-71.7) in children with suPAR levels in the lowest quartile compared with 35.9% (95% CI, 28.7-43.0) in those in the highest quartile (P < .001). By multivariable analysis, the risk of attaining the end point was higher in children with glomerulopathies and increased with age, blood pressure, proteinuria, and lower eGFR at baseline. In patients with baseline eGFR greater than 40 mL/min/1.73 m2, higher log-transformed suPAR levels were associated with a higher risk of CKD progression after adjustment for traditional risk factors (hazard ratio, 5.12; 95% CI, 1.56-16.7; P = .007). Conclusions and Relevance: Patients with high suPAR levels were more likely to have progression of their kidney disease. Further studies should determine whether suPAR levels can identify children at risk for future CKD.

Quantitative Histomorphometry of the Healthy Peritoneum.

The peritoneum plays an essential role in preventing abdominal frictions and adhesions and can be utilized as a dialysis membrane. Its physiological ultrastructure, however, has not yet been studied systematically. 106 standardized peritoneal and 69 omental specimens were obtained from 107 patients (0.1-60 years) undergoing surgery for disease not affecting the peritoneum for automated quantitative histomorphometry and immunohistochemistry. The mesothelial cell layer morphology and protein expression pattern is similar across all age groups. Infants below one year have a thinner submesothelium; inflammation, profibrotic activity and mesothelial cell translocation is largely absent in all age groups. Peritoneal blood capillaries, lymphatics and nerve fibers locate in three distinct submesothelial layers. Blood vessel density and endothelial surface area follow a U-shaped curve with highest values in infants below one year and lowest values in children aged 7-12 years. Lymphatic vessel density is much lower, and again highest in infants. Omental blood capillary density correlates with parietal peritoneal findings, whereas only few lymphatic vessels are present. The healthy peritoneum exhibits major thus far unknown particularities, pertaining to functionally relevant structures, and subject to substantial changes with age. The reference ranges established here provide a framework for future histomorphometric analyses and peritoneal transport modeling approaches.

Aortic Pulse Wave Velocity in Healthy Children and Adolescents: Reference Values for the Vicorder Device and Modifying Factors.

BACKGROUND: Aortic pulse wave velocity (PWV), an indicator of arterial stiffness, independently predicts cardiovascular mortality risk in adults. Arterial stiffening advances with age and seems accelerated in children with certain disease conditions such as chronic kidney disease or diabetes. The Vicorder, an oscillometric device to measure PWV, has been validated in children, but reference values in a large pediatric cohort, association to carotid stiffness and influence of individual and family risk factors have not been determined. METHODS: Pulse waves were captured in 1,003 healthy children (aged 6-18 years) in 6 centers and gender-specific reference data normalized to age/height were constructed. In 589 children carotid distensibility and intima media thickness were measured. Gestational and family history was reported. RESULTS: PWV correlated with age (r = 0.57, P < 0.0001) with significant gender-related differences starting at age 9. Further significant correlations were seen for height, weight, body mass index, blood pressure, pulse pressure, and heart rate. Independent predictors for PWV in a multivariate regression analysis were gender, age, height, weight, mean arterial pressure, and heart rate. Risk factors for higher PWV included small for gestational age at birth, secondhand smoking, parental hypertension, and obesity. PWV showed weak correlations with 2 of the carotid distensibility measures, but not with intima media thickness. CONCLUSION: This study defines reference values for PWV captured by the Vicorder device in children and adolescents and reveals associations with potential cardiovascular risk factors in a healthy population. Gender-specific percentiles for age/height will allow for the assessment of pediatric cohorts using this oscillometric method.

Renal replacement therapy for rare diseases affecting the kidney: an analysis of the ERA-EDTA Registry.

BACKGROUND: In recent years, increased efforts have been undertaken to address the needs of patients with rare diseases by international initiatives and consortia devoted to rare disease research and management. However, information on the overall prevalence of rare diseases within the end-stage renal disease (ESRD) population is limited. The aims of this study were (i) to identify those rare diseases within the ERA-EDTA Registry for which renal replacement therapy (RRT) is being provided and (ii) to determine the prevalence and incidence of RRT for ESRD due to rare diseases, both overall and separately for children and adults. METHODS: The Orphanet classification of rare disease was searched for rare diseases potentially causing ESRD, and these diagnosis codes were mapped to the corresponding ERA-EDTA primary renal disease codes. Thirty-one diagnoses were defined as rare diseases causing ESRD. RESULTS: From 1 January 2007 to 31 December 2011, 7194 patients started RRT for a rare disease (10.6% children). While some diseases were exclusively found in adults (e.g. Fabry disease), primary oxalosis, cystinosis, congenital anomalies of the kidney and urinary tract (CAKUT) and medullary cystic kidney disease affected young patients in up to 46%. On 31 December 2011, 20 595 patients (12.4% of the total RRT population) were on RRT for ESRD caused by a rare disease. The point prevalence was 32.5 per million age-related population in children and 152.0 in adults. Only 5.8% of these patients were younger than 20 years; however, 57.7% of all children on RRT had a rare disease, compared with only 11.9% in adults. CAKUT and focal segmental glomerulosclerosis were the most prevalent rare disease entities among patients on RRT. CONCLUSIONS: More than half of all children and one of nine adults on RRT in the ERA-EDTA Registry suffer from kidney failure due to a rare disease, potentially with a large number of additional undiagnosed or miscoded cases. Comprehensive diagnostic assessment and the application of accurate disease classification systems are essential for improving the identification and management of patients with rare kidney diseases.

Nephropathic cystinosis: an international consensus document.

Cystinosis is caused by mutations in the CTNS gene (17p13.2), which encodes for a lysosomal cystine/proton symporter termed cystinosin. It is the most common cause of inherited renal Fanconi syndrome in young children. Because of its rarity, the diagnosis and specific treatment of cystinosis are frequently delayed, which has a significant impact on the overall prognosis. In this document, we have summarized expert opinions on several aspects of the disease to improve knowledge and provide guidance for diagnosis and treatment.

Bleeding complications in pediatric ABO-incompatible kidney transplantation.

BACKGROUND: ABO-incompatible renal transplantation (ABOi-RTx) following preconditioning with immunoadsorption (IA) and rituximab is a promising approach to facilitate living-related RTx. However, clinical experience is limited in pediatric patients. METHODS: Three patients underwent living-related ABOi-RTx in our center. Preoperative IA was performed six, ten and 11 times in patient one, two and three, respectively, to achieve isoagglutinin titers of ≤1:8 on the day of transplantation; rituximab was administered once. The immunosuppressive regimen further comprised tacrolimus, mycophenolate, methylprednisolone and basiliximab; immunoglobulin G (IgG) was infused on the day of ABOi-RTx. RESULTS: All three patients achieved normal renal function within 2-6 days post-RTx. Major postoperative bleeding occurred in two patients, with one requiring repeated blood transfusions and the other a surgical revision 4 h after RTx, despite local citrate anticoagulation use during the preoperative IA procedures in the latter patient. A pyelonephritis-associated increase of the isoagglutinin IgG/IgM titers to 1:64/1:128 led to a biopsy-proven acute humoral rejection in the third patient, which was treated successfully with plasma exchange and methylprednisolone pulses. The estimated glomerular filtration rate at 18, 8 and 23 months post-RTx was 96, 52 and 74 ml/min/1.73 m(2), respectively. CONCLUSIONS: ABOi-RTx can successfully be performed in pediatric patients after preconditioning with quadruple immunosuppression, rituximab and IA. Caution is required regarding bleeding complications, which are most likely due to the unspecific binding of coagulation factors during repeated IA.

Timing and outcome of renal replacement therapy in patients with congenital malformations of the kidney and urinary tract.

BACKGROUND AND OBJECTIVES: Congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of ESRD in children, but the proportion of patients with individual CAKUT entities progressing to ESRD during adulthood and their long-term clinical outcomes are unknown. This study assessed the age at onset of renal replacement therapy (RRT) and patient and renal graft survival in patients with CAKUT across the entire age range. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Patients with CAKUT were compared with age-matched patients who were undergoing RRT for other renal disorders on the basis of data from the European Renal Association-European Dialysis and Transplant Association Registry. Competing risk and Cox regression analyses were conducted. RESULTS: Of 212,930 patients commencing RRT from 1990 to 2009, 4765 (2.2%) had renal diagnoses consistent with CAKUT. The proportion of incident RRT patients with CAKUT decreased from infancy to childhood and then increased until age 15-19 years, followed by a gradual decline throughout adulthood. Median age at RRT start was 31 years in the CAKUT cohort and 61 years in the non-CAKUT cohort (P<0.001). RRT was started earlier (median, 16 years) in patients with isolated renal dysplasia than in those with renal hypoplasia and associated urinary tract disorders (median, 29.5-39.5 years). Patients with CAKUT survived longer than age- and sex-matched non-CAKUT controls because of lower cardiovascular mortality (10-year survival rate, 76.4% versus 70.7%; P<0.001). CONCLUSIONS: CAKUT leads to ESRD more often at adult than pediatric age. Treatment outcomes differ from those of acquired kidney diseases and vary within CAKUT subcategories.

Late recovery of renal function by rituximab in a patient with Wegener's granulomatosis.

BACKGROUND: Rituximab has proven effective in the treatment of complicated granulomatosis with polyangiitis (Wegener's, GPA). Two controlled trials in adults demonstrated beneficial effects of rituximab compared to cyclophosphamide in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis to induce remission and to treat relapses. Pediatric experience with rituximab in GPA is limited; the impact on renal function is unknown. CASE-DIAGNOSIS/TREATMENT: We report a female adolescent with GPA and necrotizing glomerulonephritis that lead to end-stage renal disease (ESRD). After 22 months of peritoneal dialysis, she still experienced relapses and major treatment-associated adverse effects. After a single dose of rituximab, she rapidly achieved clinical remission and, unexpectedly, steadily recovered glomerular filtration rate, plateauing at 25 ml/min/1.73 m(2). Peritoneal dialysis could be discontinued for 16 months. CONCLUSIONS: This case documents a potent beneficial effect of rituximab on renal manifestation of GPA even in long-established ESRD.

IVIG and rituximab for treatment of chronic antibody-mediated rejection: a prospective study in paediatric renal transplantation with a 2-year follow-up.

Chronic antibody-mediated rejection (AMR) is the major cause of late renal allograft loss. There is, however, no established treatment for this condition. We report the results of a prospective pilot study on an antihumoral therapy (AHT) consisting of high-dose intravenous immunoglobulin G (IVIG) and rituximab in 20 paediatric renal transplant recipients. Donor-specific HLA antibodies (HLA DSA) were quantified by Luminex-based bead array technology. Loss of eGFR decreased significantly from 7.6 ml/min/1.73 m² during 6 months prior to AHT to 2.1 ml/min/1.73 m² (P = 0.0013) during 6 months after AHT. Fourteen patients (70%) responded: nine of nine patients (100%) without and five of 11 (45%) with transplant glomerulopathy (P = 0.014). C4d positivity in PTC decreased from 40 ± 18.5% in the index biopsy to 11.6 ± 12.2% (P = 0.002) in the follow-up biopsy. In four of nine biopsies (44%) C4d staining turned negative. During 2 years of follow-up, the median loss of eGFR in each of the four 6-month periods remained significantly lower compared with prior to AHT. Class I DSA declined in response to AHT by 61% (p = 0.044), class II DSA by 63% (p = 0.033) 12 months after intervention. AHT with IVIG and rituximab significantly reduces or stabilizes the progressive loss of transplant function in paediatric patients with chronic AMR over an observation period of 2 years, apparently by lowering circulating DSA and reducing intrarenal complement activation.

Determinants of blood pressure in preschool children: the role of parental smoking.

BACKGROUND: Hypertension is the leading risk factor for cardiovascular disease. Although accumulating evidence suggests tracking of blood pressure from childhood into adult life, there is little information regarding the relative contributions of genetic, prenatal, biological, behavioral, environmental, and social determinants to childhood blood pressure. METHODS AND RESULTS: Blood pressure and an array of potential anthropometric, prenatal, environmental, and familial risk factors for high blood pressure, including parental smoking habits, were determined as part of a screening project in 4236 preschool children (age 5.7 ± 0.4 years). Smoking was reported by 28.5% of fathers and 20.7% of mothers, and by both parents 11.9%. In addition to classic risk factors such as body mass index, prematurity, low birth weight, and parental hypertension, both systolic (+1.0 [95% confidence interval, +0.5 to +1.5] mm Hg; P=0.0001) and diastolic blood pressure (+0.5 [+0.03 to +0.9] mm Hg; P=0.03) were higher in children of smoking parents. Parental smoking independently affected systolic blood pressure (P=0.001) even after correction for other risk factors, such as body mass index, parental hypertension, or birth weight, increasing the likelihood of having a systolic blood pressure in the top 15% of the population by 21% (2% to 44%; P=0.02). CONCLUSIONS: In healthy preschool children, parental smoking is an independent risk factor for higher blood pressure, adding to other familial and environmental risk factors. Implementing smoke-free environments at home and in public places may provide a long-term cardiovascular benefit even to young children.