Carotid artery intima-media thickness and distensibility in children and adolescents: reference values and role of body dimensions

Carotid intima-media thickness (cIMT) and carotid artery distensibility are reliable screening methods for vascular alterations and the assessment of cardiovascular risk in adult and pediatric cohorts. We sought to establish an international reference data set for the childhood and adolescence period and explore the impact of developmental changes in body dimensions and blood pressure (BP) on carotid wall thickness and elasticity. cIMT, the distensibility coefficient, the incremental modulus of elasticity, and the stiffness index β were assessed in 1155 children aged 6 to 18 years and sex-specific reference charts normalized to age or height were constructed from 1051 nonobese and nonhypertensive children. The role of body dimensions, BP, and family history, as well as the association between cIMT and distensibility, was investigated. cIMT increased and distensibility decreased with age, height, body mass index, and BP. A significant sex difference was apparent from the age of 15 years. Age- and height-normalized cIMT and distensibility values differed in children who are short or tall for their age. By stepwise multivariate analysis, standardized systolic BP and body mass index were independently positively associated with cIMT SD scores (SDS). Systolic BP SDS independently predicted all distensibility measures. Distensibility coefficient SDS was negatively and β SDS positively associated with cIMT SDS, whereas incremental modulus of elasticity was independent of cIMT. Morphological and functional aspects of the common carotid artery are particularly influenced by age, body dimensions, and BP. The reference charts established in this study allow to accurately compare vascular phenotypes of children with chronic conditions with those of healthy children.

Mutation frequency of Familial Mediterranean Fever and evidence for a high carrier rate in the Turkish population

Familial Mediterranean Fever (FMF) is a recessive disorder characterised by episodes of fever and neutrophil-mediated serozal inflammation. The FMF gene (MEFV) was recently identified and four common mutations characterised. The aim of this study was to determine the carrier rate in the Turkish population and the mutation frequency in the clinically diagnosed FMF patients. We found a high frequency of carriers in the healthy Turkish population (20%). The distribution of the five most common MEFV mutations among healthy individuals (M694V 3%, M680I 5%, V726A 2%, M694I 0% and E148Q 12%) was significantly different (P<0.005) from that found in patients (M694V 51.55%, M680I 9.22%, V726A 2.88%, M694I 0.44% and E148Q 3.55%).

DGKE variants cause a glomerular microangiopathy that mimics membranoproliferative GN

Renal microangiopathies and membranoproliferative GN (MPGN) can manifest similar clinical presentations and histology, suggesting the possibility of a common underlying mechanism in some cases. Here, we performed homozygosity mapping and whole exome sequencing in a Turkish consanguineous family and identified DGKE gene variants as the cause of a membranoproliferative-like glomerular microangiopathy. Furthermore, we identified two additional DGKE variants in a cohort of 142 unrelated patients diagnosed with membranoproliferative GN. This gene encodes the diacylglycerol kinase DGKε, which is an intracellular lipid kinase that phosphorylates diacylglycerol to phosphatidic acid. Immunofluorescence confocal microscopy demonstrated that mouse and rat Dgkε colocalizes with the podocyte marker WT1 but not with the endothelial marker CD31. Patch-clamp experiments in human embryonic kidney (HEK293) cells showed that DGKε variants affect the intracellular concentration of diacylglycerol. Taken together, these results not only identify a genetic cause of a glomerular microangiopathy but also suggest that the phosphatidylinositol cycle, which requires DGKE, is critical to the normal function of podocytes.

Cardiovascular Phenotypes in Children with CKD: The 4C Study

BACKGROUND AND OBJECTIVES

Cardiovascular disease is the most important comorbidity affecting long-term survival in children with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Cardiovascular Comorbidity in Children with CKD Study is a multicenter, prospective, observational study in children ages 6-17 years old with initial GFR of 10-60 ml/min per 1.73 m2. The cardiovascular status is monitored annually, and subclinical cardiovascular disease is assessed by noninvasive measurements of surrogate markers, including the left ventricular mass index, carotid intima-media thickness, and central pulse wave velocity. We here report baseline data at study entry and an explorative analysis of variables associated with surrogate markers.

RESULTS

A total of 737 patients were screened from October of 2009 to August of 2011 in 55 centers in 12 European countries, and baseline data were analyzed in 688 patients. Sixty-four percent had congenital anomalies of the kidney and urinary tract; 26.1% of children had uncontrolled hypertension (24-hour ambulatory BP monitoring; n=545), and the prevalence increased from 24.4% in CKD stage 3 to 47.4% in CKD stage 5. The prevalence of left ventricular hypertrophy was higher with each CKD stage, from 10.6% in CKD stage 3a to 48% in CKD stage 5. Carotid intima-media thickness was elevated in 41.6%, with only 10.8% of patients displaying measurements below the 50th percentile. Pulse wave velocity was increased in 20.1%. The office systolic BP SD score was the single independent factor significantly associated with all surrogate markers of cardiovascular disease. The intermediate end point score (derived from the number of surrogate marker measurements >95th percentile) was independently associated with a diagnosis of congenital anomalies of the kidney and urinary tract, time since diagnosis of CKD, body mass index, office systolic BP, serum phosphorus, and the hemoglobin level.

CONCLUSIONS

The baseline data of this large pediatric cohort show that surrogate markers for cardiovascular disease are closely associated with systolic hypertension and stage of CKD.

The Cardiovascular Comorbidity in Children with Chronic Kidney Disease (4C) study: objectives, design, and methodology

BACKGROUND AND OBJECTIVES

Children and adolescents with chronic kidney disease (CKD) are at high risk for cardiovascular morbidity and mortality. A systemic arteriopathy and cardiomyopathy has been characterized in pediatric dialysis patients by the presence of morphologic and functional abnormalities.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Cardiovascular Comorbidity in Children with CKD (4C) Study is a multicenter, prospective, observational study aiming to recruit more than 600 children, aged 6 to 17 years, with initial GFR of 10 to 45 ml/min per 1.73 m(2). The prevalence, degree, and progression of cardiovascular comorbidity as well as its association with CKD progression will be explored through longitudinal follow-up. The morphology and function of the heart and large arteries will be monitored by sensitive noninvasive methods and compared with aged-matched healthy controls. Multiple clinical, anthropometric, biochemical, and pharmacologic risk factors will be monitored prospectively and related to the cardiovascular status. A whole-genome association study will be performed to identify common genetic variants associated with progression of cardiovascular alterations and/or renal failure. Monitoring will be continued as patients reach end-stage renal disease and undergo different renal replacement therapies.

RESULTS

While cardiovascular morbidity in adults is related to older age and additional risk factor load (e.g., diabetes), the role of CKD-specific factors in the initiation and progression of cardiac and vascular disease are likely to be characterized with greater sensitivity in the pediatric age group.

CONCLUSIONS

The 4C study is expected to provide innovative insight into cardiovascular and renal disease progression in CKD.

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.

Disease severity in children and adolescents with familial Mediterranean fever: a comparative study to explore environmental effects on a monogenic disease

BACKGROUND

Worldwide, familial Mediterranean fever (FMF) is the most common autoinflammatory disease. It has been suggested that environmental factors affect the phenotype as some patients do not develop the complication of secondary amyloidosis.

OBJECTIVE

To analyse whether disease severity in Turkish children with FMF, living in Turkey and Germany is different.

PATIENTS AND METHODS

A total of 55 Turkish children living in Turkey were compared with 45 Turkish children born and raised in Germany. Mean age among the group from Turkey and Germany was 42.2 and 44.29 months, respectively. M694V was the leading mutation in both groups. The severity scores were compared with two scoring systems, modified according to published paediatric data for dosage.

RESULTS

There was no significant difference between the mean C-reactive protein and erythrocyte sedimentation rate levels of the two groups. According to the modified Sheba Center score, 78.2% of patients from the group living in Turkey had a severe course compared with 34.1% from the group living in Germany. The modified score of Pras et al also showed more severe disease in the patients from Turkey. The difference between the two groups for both scoring systems were significant (both p<0.05).

CONCLUSIONS

We believe the modified scores that we introduce can be widely used for children. Our results suggest that the environment affects the phenotype of a monogenic disease of the innate inflammatory pathway.

Tumour necrosis factor alpha G-->A -238 and G-->A -308 polymorphisms in juvenile idiopathic arthritis

OBJECTIVES

To study G-->A -238 and G-->A -308 polymorphisms in the promoter region of the tumour necrosis factor (TNF) alpha gene in patients with juvenile idiopathic arthritis (JIA). We analysed whether there were any associations between these polymorphisms and the type of JIA and/or the clinical course of the disease in two populations.

METHODS

The first group consisted of 51 Turkish JIA patients and the second consisted of 159 JIA patients from the Czech Republic. Healthy individuals (93 and 100) from each country served as controls. Subgroups of JIA were defined according to the Durban criteria. The course of the disease was defined on the basis of the physician's global evaluation of disease activity, the swollen and tender joint count and the erythrocyte sedimentation rate.

RESULTS

In both JIA cohorts, the distribution of genotypes was not significantly different among the types of JIA. The G-->A -238 polymorphism did not have an effect on the patients' outcome in either group. The G-->A -308 polymorphism was significantly associated with a poor outcome in the Turkish group (P=0.005) but there was no association in the Czech patients. Some features of JIA in Turkish patients differed from those in Czech patients.

CONCLUSIONS

Genetic differences may accompany the phenotypic differences found in the Turkish group. Although larger numbers of patients are clearly needed to verify this, we suggest that the G-->A -308 polymorphism may be operative in defining disease outcome in selected groups.

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.

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.

Reno-vascular hypertension in childhood: a nationwide survey

Renovascular disease accounts for 8-10% of all cases of paediatric hypertension, whereas, in adults, its incidence is approximately 1%. The Turkish Paediatric Hypertension Group aimed to create the first registry database for childhood renovascular hypertension in Turkey. Twenty of the 28 paediatric nephrology centres in Turkey responded to the survey and reported 45 patients (27 girls, 18 boys) with renovascular hypertension between 1990 and 2005. The age at presentation ranged from 20 days to 17 years. The mean blood pressure at the diagnosis was 169/110 mmHg. Chief complaints of symptomatic patients were headache (38%), seizure (18%), epistaxis (4%), growth retardation (4%), cognitive dysfunction (4%), polyuria (2%), palpitation (2%), and hemiplegia (2%). Renovascular hypertension was found incidentally in 11 children. The diagnosis of renovascular hypertension was established with conventional angiography in 39 patients, MR angiography in three, CT angiography in two, and captopril diethylene triamine penta-acetic acid (DTPA) scintigraphy in one patient. Twenty-one children had bilateral renal artery stenosis and 24 had unilateral renal artery stenosis. Of these, 14 (31%) had fibromuscular dysplasia; 12 (27%) Takayasu's arteritis; six (13%) neurofibromatosis; two (5%) Williams syndrome; one (2%) Kawasaki disease; one (2%) mid-aortic syndrome; one (2%) extrinsic compression to the renal artery, and eight (18%) unspecified bilateral renal artery stenosis. Hypertension was controlled with antihypertensive drugs in 17 patients. Percutaneous transluminal angioplasty (PTRA) or surgery had to be performed in 28 patients: PTRA in 16 patients, PTRA + surgery in one patient and surgery in 11 patients (four nephrectomies). The importance of vasculitic disease, especially Takayasu's arteritis, should not be underestimated in children with renovascular hypertension.

Performance of Different Diagnostic Criteria for Familial Mediterranean Fever in Children with Periodic Fevers: Results from a Multicenter International Registry

OBJECTIVE

Our aims were to validate the pediatric diagnostic criteria in a large international registry and to compare them with the performance of previous criteria for the diagnosis of familial Mediterranean fever (FMF).

METHODS

Pediatric patients with FMF from the Eurofever registry were used for the validation of the existing criteria. The other periodic fevers served as controls: mevalonate kinase deficiency (MKD), tumor necrosis factor receptor-associated periodic syndrome (TRAPS), cryopyrin-associated periodic syndrome (CAPS), aphthous stomatitis, pharyngitis, adenitis syndrome (PFAPA), and undefined periodic fever from the same registry. The performances of Tel Hashomer, Livneh, and the Yalcinkaya-Ozen criteria were assessed.

RESULTS

The FMF group included 339 patients. The control group consisted of 377 patients (53 TRAPS, 45 MKD, 32 CAPS, 160 PFAPA, 87 undefined periodic fevers). Patients with FMF were correctly diagnosed using the Yalcinkaya-Ozen criteria with a sensitivity rate of 87.4% and a specificity rate of 40.7%. On the other hand, Tel Hashomer and Livneh criteria displayed a sensitivity of 45.0 and 77.3%, respectively. Both of the latter criteria displayed a better specificity than the Yalcinkaya-Ozen criteria: 97.2 and 41.1% for the Tel Hashomer and Livneh criteria, respectively. The overall accuracy for the Yalcinkaya-Ozen criteria was 65 and 69.6% (using 2 and 3 criteria), respectively. Ethnicity and residence had no effect on the performance of the Yalcinkaya-Ozen criteria.

CONCLUSION

The Yalcinkaya-Ozen criteria yielded a better sensitivity than the other criteria in this international cohort of patients and thus can be used as a tool for FMF diagnosis in pediatric patients from either the European or eastern Mediterranean region. However, the specificity was lower than the previously suggested adult criteria.

Effects of Hemodiafiltration versus Conventional Hemodialysis in Children with ESKD: The HDF, Heart and Height Study

BACKGROUND

Hypertension and cardiovascular disease are common in children undergoing dialysis. Studies suggest that hemodiafiltration (HDF) may reduce cardiovascular mortality in adults, but data for children are scarce.

METHODS

The HDF, Heart and Height study is a nonrandomized observational study comparing outcomes on conventional hemodialysis (HD) versus postdilution online HDF in children. Primary outcome measures were annualized changes in carotid intima-media thickness (cIMT) SD score and height SD score.

RESULTS

We enrolled 190 children from 28 centers; 78 on HD and 55 on HDF completed 1-year follow-up. The groups were comparable for age, dialysis vintage, access type, dialysis frequency, blood flow, and residual renal function. At 1 year, cIMT SD score increased significantly in children on HD but remained static in the HDF cohort. On propensity score analysis, HD was associated with a +0.47 higher annualized cIMT SD score compared with HDF. Height SD score increased in HDF but remained static in HD. Mean arterial pressure SD score increased with HD only. Factors associated with higher cIMT and mean arterial pressure SD-scores were HD group, higher ultrafiltration rate, and higher β2-microglobulin. The HDF cohort had lower β2-microglobulin, parathyroid hormone, and high-sensitivity C-reactive protein at 1 year; fewer headaches, dizziness, or cramps; and shorter postdialysis recovery time.

CONCLUSIONS

HDF is associated with a lack of progression in vascular measures versus progression with HD, as well as an increase in height not seen in the HD cohort. Patient-related outcomes improved among children on HDF correlating with improved BP control and clearances. Confirmation through randomized trials is required.

Carbamazepine poisoning: treatment with plasma exchange

Lethal cases due to carbamazepine overdose have been reported. There are contradicting reports about the efficiency of hemodialysis, hemoperfusion and plasmapheresis for the treatment of carbamazepine poisoning. We present a case of carbamazepine intoxication successfully managed with plasma exchange. The patient was a 15-year-old girl. On admission there was no evidence of trauma, Glascow Coma Scale scored 6. Further questioning of the parents revealed the patient had taken at least 23 tablets of Tegretol (4.6 g) 6 h before the admission. The carbamazepine level was 190 micromol/l. Orogastric lavage was followed by activated charcoal. Within 20 h after admission there was no improvement in her neurological status. It was thus decided to perform plasmapheresis. At the end of the procedure she started to respond to verbal stimuli. Carbamazepine level immediately after the procedure was 101 micromol/l, and at the 36th, 60th and 84th hours were 72, 33 and 20 micromol/l, respectively. The patient was discharged on the fourth day. We have not observed any rebound in our patient. Thus we suggest that simple plasma exchange by plasma replacement is a cheaper and effective method for the treatment of intoxication with carbamazepine or similar drugs.

Follow-up results of patients with ADCK4 mutations and the efficacy of CoQ10 treatment

BACKGROUND

ADCK4-related glomerulopathy is an important differential diagnosis in adolescents with steroid-resistant nephrotic syndrome (SRNS) and/or chronic kidney disease (CKD) of unknown origin. We screened adolescent patients to determine the frequency of ADCK4 mutation and the efficacy of early CoQ10 administration.

METHODS

A total of 146 index patients aged 10-18 years, with newly diagnosed non-nephrotic proteinuria, nephrotic syndrome, or chronic renal failure and end-stage kidney disease (ESKD) of unknown etiology were screened for ADCK4 mutation.

RESULTS

Twenty-eight individuals with bi-allelic mutation from 11 families were identified. Median age at diagnosis was 12.4 (interquartile range [IQR] 8.04-19.7) years. Upon first admission, all patients had albuminuria and 18 had CKD (6 ESKD). Eight were diagnosed either through the screening of family members following index case identification or during genetic investigation of proteinuria in an individual with a history of a transplanted sibling. Median age of these 8 patients was 21.5 (range 4.4-39) years. CoQ10 supplementation was administered following genetic diagnosis. Median estimated glomerular filtration rate (eGFR) just before CoQ10 administration was 140 (IQR 117-155) ml/min/1.73m², proteinuria was 1,008 (IQR 281-1,567) mg/m²/day. After a median follow-up of 11.5 (range 4-21) months following CoQ10 administration, proteinuria was significantly decreased (median 363 [IQR 175-561] mg/m²/day, P=0.025), whereas eGFR was preserved (median 137 [IQR 113-158] ml/min/1.73m², P=0.61).

CONCLUSIONS

ADCK4 mutations are one of the most common causes of adolescent-onset albuminuria and/or CKD of unknown etiology in Turkey. CoQ10 supplementation appears efficacious at reducing proteinuria, and may thereby be renoprotective.

FMF50: a score for assessing outcome in familial Mediterranean fever

BACKGROUND

Colchicine is the main treatment for familial Mediterranean fever (FMF). However, biological agents and other treatments are available for patients who are unable to receive optimal treatment.

OBJECTIVE

To develop outcome criteria that define response to treatment.

METHODS

Two rounds of Delphi exercise were followed by a consensus conference enabling the definition of the criteria to be employed. Data for patients with FMF responding and resistant to their treatment were obtained from the FMF Arthritis Vasculitis and Orphan disease Research in paediatric rheumatology (FAVOR) website. The suggested criteria were analysed and validated in this patient cohort. Sensitivity/specificity measures and the ability of the score to discriminate between patients with active and inactive disease via the best cut-off score were calculated by a receiver operating characteristic analysis.

RESULTS

Compliance with the maximum dose of the drug was considered essential for evaluation of the patients. Seven criteria were suggested in the consensus conference. The performance of each criterion, in differentiating between resistant and responsive patients, was tested. The final set of criteria was defined as at least 50% improvement in five of six criteria, without worsening in any one defined response to treatment with a very high sensitivity and specificity. The items of this FMF50 included: 1. Percentage change in the frequency of attacks with the treatment. 2. Percentage change in the duration of attacks with the treatment. 3. Patients/parents' global assessment of disease severity (10 cm visual analogue scale (VAS)). 4. Physicians' global assessment of disease severity (10 cm VAS). 5. Percentage change in arthritis attacks with the treatment. 6. Percentage change in C-reactive protein, erythrocyte sedimentation rate or serum amyloid A level with the treatment.

CONCLUSIONS

The FMF50 produced is a user-friendly measurement tool to guide physicians and can be used in clinical trials.

Abnormal circadian blood pressure regulation in children born preterm

OBJECTIVE

To assess a possible relationship between prematurity and casual blood pressure (BP) by means of 24-hour ambulatory BP monitoring (ABPM).

STUDY DESIGN

ABPM was performed in 41 children aged 5 to 17 years who were born prematurely with (n = 11) or without intrauterine growth restriction, and in 27 matched children who were born at term with a birth weight appropriate for gestational age.

RESULTS

Although BP did not differ between the preterm group and control subjects during the daytime, nocturnal standardized systolic BP was elevated (P < .05) and a lack of nocturnal decrease was more prevalent in the preterm children compared with the control subjects (73% versus 41%, P = .01). The difference was caused by a marked increase of nighttime systolic BP in the light-for-date children (1.17 +/- 0.61 standard deviation scores; P < .01), although preterm children with appropriate weight (0.33 +/- 1.00) were not different from control subjects (0.09 +/- 0.73). Nighttime BP standard deviation scores were closely correlated with standardized heart rate, compatible with a role of sympathetic hyperactivation.

CONCLUSION

Subtle abnormalities of BP regulation, indicated by a selective increase of nocturnal systolic BP, are present during childhood in subjects born prematurely, and are prominent in those with intrauterine growth restriction.

Rationale, design and objectives of ARegPKD, a European ARPKD registry study

BACKGROUND

Autosomal recessive polycystic kidney disease (ARPKD) is a rare but frequently severe disorder that is typically characterized by cystic kidneys and congenital hepatic fibrosis but displays pronounced phenotypic heterogeneity. ARPKD is among the most important causes for pediatric end stage renal disease and a leading reason for liver-, kidney- or combined liver kidney transplantation in childhood. The underlying pathophysiology, the mechanisms resulting in the observed clinical heterogeneity and the long-term clinical evolution of patients remain poorly understood. Current treatment approaches continue to be largely symptomatic and opinion-based even in most-advanced medical centers. While large clinical trials for the frequent and mostly adult onset autosomal dominant polycystic kidney diseases have recently been conducted, therapeutic initiatives for ARPKD are facing the challenge of small and clinically variable cohorts for which reliable end points are hard to establish.

METHODS/DESIGN

ARegPKD is an international, mostly European, observational study to deeply phenotype ARPKD patients in a pro- and retrospective fashion. This registry study is conducted with the support of the German Society for Pediatric Nephrology (GPN) and the European Study Consortium for Chronic Kidney Disorders Affecting Pediatric Patients (ESCAPE Network). ARegPKD clinically characterizes long-term ARPKD courses by a web-based approach that uses detailed basic data questionnaires in combination with yearly follow-up visits. Clinical data collection is accompanied by associated biobanking and reference histology, thus setting roots for future translational research.

DISCUSSION

The novel registry study ARegPKD aims to characterize miscellaneous subcohorts and to compare the applied treatment options in a large cohort of deeply characterized patients. ARegPKD will thus provide evidence base for clinical treatment decisions and contribute to the pathophysiological understanding of this severe inherited disorder.

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.

Chronic renal disease in children aged 5-18 years: a population-based survey in Turkey, the CREDIT-C study

BACKGROUND

Data on the epidemiology of chronic kidney disease (CKD), which is a serious health problem and refers to a condition related to irreversible kidney damage that further progress to end-stage renal disease in children, are insufficient and data that are available were based on hospital records. The aim of this nationwide, population-based field study was to determine the prevalence of CKD in children in Turkey and to evaluate the association between CKD and possible risk factors such as obesity and hypertension.

METHODS

The study was the paediatric stratum (3622 children aged 5-18 years) of the previously published population-based survey of Chronic REnal Disease In Turkey (CREDIT study). Medical data were collected through home visits and interviews between November 2007 and July 2008; height, weight and blood pressure were also measured. Serum creatinine, total cholesterol, uric acid and complete blood count were determined from 12-h fasting blood samples, and spot urine tests were performed for subjects who gave consent to laboratory evaluation.

RESULTS

Following adjustment according to gender, residence, age groups and geographical regions, the prevalence of children with estimated glomerular filtration rate (eGFR) <75 mL/min/1.73 m(2) was 0.94 [95% confidence interval (CI): 0.63-1.35], and the prevalence of children with CKD Stages 3-5 [National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (K/DOQI)] was 2600 (95% CI 1100-5100) per million age related population. The mean eGFR was found to increase with age; the ratios of children with eGFR <90 and <75 mL/min/1.73 m(2) were higher in younger age groups. The frequencies of overweight and obese children were 9.3 and 8.9%, respectively, and the mean eGFR was lower in patients with higher body mass index. The prevalence of hypertension and hypercholesterolaemia was 6.1 and 5.8%, respectively; the mean eGFR was lower in children with hypercholesterolaemia.

CONCLUSIONS

This is the first population-based CKD study performed in children aged 5-18 years. The prevalence of CKD in our study was 25-100 times greater than that found in previous hospital-based studies. Our data suggest that approaches focusing on patients in tertiary centres are likely to lead to patients being missed at early stages of CKD and that a vast majority of these children will never develop symptomatic CKD during childhood.

Neonatal onset atypical hemolytic uremic syndrome successfully treated with eculizumab

BACKGROUND

Atypical hemolytic uremic syndrome (aHUS) is characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and renal impairment. Neonatal cases are extremely uncommon. Plasma therapy is the first choice therapy in patients with aHUS based on the belief of an underlying complement dysregulation. Alternatively, eculizumab, which targets complement 5, is used to block complement activation.

CASE-DIAGNOSIS/TREATMENT

Sudden onset macroscopic hematuria, hypertension, and bruises over the entire body were noted in a 5 day-old newborn. Investigations revealed hemolytic anemia, thrombocytopenia, renal impairment, and a low serum C3, leading to the diagnosis of aHUS. Fresh frozen plasma (FFP) infusions and peritoneal dialysis for acute kidney injury were initiated. This approach yielded full renal and hematological remission. The patient was discharged with FFP infusions, but subsequently developed three life-threatening disease recurrences at 1, 3, and 6 months of age. The last relapse presented with uncontrolled hypertension and impaired renal function while the patient was receiving FFP infusions. After the first dose of eculizumab, his renal and hematological parameters returned to normal and his blood pressure normalized. Genetic screening of the CFH gene revealed a novel homozygous p. Tyr1177Cys mutation.

CONCLUSION

Eculizumab can be considered as an alternative to plasma therapy in the treatment of specific patients with aHUS, even in infants.

Ataxia and peripheral neuropathy: rare manifestations in Henoch-Schönlein purpura

Henoch-Schönlein purpura (HSP) is a multisystemic vasculitis. Nervous system involvement is usually underestimated. Headaches, mental status changes and seizures are the most frequent neurologic symptoms. Ataxia and mononeuropathy are both very rare. We present an 11-year-old boy with HSP who suffered from ataxia during the initial presentation and peripheral neuropathy at the time of a relapse. Brainstem vasculitic involvement was shown by magnetic resonance imaging, while cranial tomography was normal. All the neurologic symptoms and signs resolved following bolus methylprednisolone administration. Ten months later he had a second course of HSP with skin and renal involvement. A percutaneous renal biopsy, which was performed due to persistent hematuria, revealed mesangial proliferation with IgA deposition. During that period the patient experienced pain and numbness in the right foot and leg; electromyography showed signs of mononeuritis multiplex involving the right posterior tibial nerve. The patient responded to steroid therapy.

Carotid intima-media thickness in children and young adults with renal transplant: Internal carotid artery vs. common carotid artery

Cardiovascular diseases are the main causes of morbidity and mortality following renal transplantation. Atherosclerotic structural changes, which can be detected by high-resolution B-mode ultrasonography, begin before clinical findings. However, little is known about the extent of these abnormalities in children after renal transplantation. We aimed to determine early structural changes of large arteries in renal transplant recipients without cardiovascular disease and to evaluate the role of clinical and laboratory features on IMT of carotid arteries. IMT and hemoglobin, serum levels of creatinine, acute phase proteins, lipid profile, and homocysteine were examined in 24 asymptomatic renal transplant recipients (median age 16.5 yr; range 8-25), and 20 healthy controls (median age 16 yr; range 9-24). CCA and ICA were evaluated in patients and controls with a high-resolution B-mode ultrasonography in multiple projections to optimize detection of carotid IMT. Measurement of IMT of both CCA [0.36 mm (range 0.16-0.48) vs. 0.28 mm (range 0.21-0.35), p < 0.001] and ICA [0.27 mm (range 0.16-0.48) vs. 0.22 mm (range 0.1-0.26), p < 0.001] were significantly higher in renal recipients than in healthy controls. Among several parameters assessed, only significant correlations were found between duration of CRF, duration of dialysis prior to transplantation and ICA-IMT (p = 0.06 and p = 0.02, respectively) and between mean past serum calcium-phosphorus ion product and CCA-IMT (p = 0.002). In conclusion, our observations indicate that vascular changes begin early in the course of CRF and are directly related to time on CRF and dialysis. These changes can be detected by measuring CCA/ICA-IMT ultrasonographically. We suggest that early renal transplantation can potentially avoid long-term cardiovascular events in children with end stage kidney disease.