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

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

Magnetic resonance imaging based kidney volume assessment for risk stratification in pediatric autosomal dominant polycystic kidney disease.

Introduction: In the pediatric context, most children with autosomal dominant polycystic kidney disease (ADPKD) maintain a normal glomerular filtration rate (GFR) despite underlying structural kidney damage, highlighting the critical need for early intervention and predictive markers. Due to the inverse relationship between kidney volume and kidney function, risk assessments have been presented on the basis of kidney volume. The aim of this study was to use magnetic resonance imaging (MRI)-based kidney volume assessment for risk stratification in pediatric ADPKD and to investigate clinical and genetic differences among risk groups. Methods: This multicenter, cross-sectional, and case-control study included 75 genetically confirmed pediatric ADPKD patients (5-18 years) and 27 controls. Kidney function was assessed by eGFR calculated from serum creatinine and cystatin C using the CKiD-U25 equation. Blood pressure was assessed by both office and 24-hour ambulatory measurements. Kidney volume was calculated from MRI using the stereological method. Total kidney volume was adjusted for the height (htTKV). Patients were stratified from A to E classes according to the Leuven Imaging Classification (LIC) using MRI-derived htTKV. Results: Median (Q1-Q3) age of the patients was 6.0 (2.0-10.0) years, 56% were male. There were no differences in sex, age, height-SDS, or GFR between the patient and control groups. Of the patients, 89% had PKD1 and 11% had PKD2 mutations. Non-missense mutations were 73% in PKD1 and 75% in PKD2. Twenty patients (27%) had hypertension based on ABPM. Median htTKV of the patients was significantly higher than controls (141 vs. 117 ml/m, p = 0.0003). LIC stratification revealed Classes A (38.7%), B (28%), C (24%), and D + E (9.3%). All children in class D + E and 94% in class C had PKD1 variants. Class D + E patients had significantly higher blood pressure values and hypertension compared to other classes (p > 0.05 for all). Discussion: This study distinguishes itself by using MRI-based measurements of kidney volume to stratify pediatric ADPKD patients into specific risk groups. It is important to note that PKD1 mutation and elevated blood pressure were higher in the high-risk groups stratified by age and kidney volume. Our results need to be confirmed in further studies.

Long-term Effects of Kidney Transplantation Compared With Dialysis on Intima-media Thickness in Children-Results From the 4C-T Study.

BACKGROUND: Children requiring kidney replacement therapy experience high burden of cardiovascular (CV) disease leading to increased mortality. Intima-media thickness (IMT) indicating atherosclerosis is a validated surrogate marker for future CV events. METHODS: We investigated the effect of different treatment modalities (dialysis, preemptive kidney transplantation (KTx), late KTx after dialysis) on IMT by multivariable linear mixed-effect modeling. Patients were enrolled in a prospective cohort study. RESULTS: A total of 261 analyzed children had a mean follow-up of 3 y. Children after preemptive and late KTx had lower levels of IMT when compared with dialysis. Using an interaction term, a significant progression of IMT over time was seen during dialysis (ß = 0.0053 mm/y, P   =  0.004). IMT before the start of therapy was the most influential determinant in all models. Low IMT was associated with maintenance steroid treatment after preemptive KTx. High IMT on dialysis was associated with higher systolic blood pressure, lower body mass index, lower serum albumin, and lower bicarbonate. CONCLUSIONS: IMT remained rather stable in children several years after KTx. In contrast, children on dialysis had higher IMT values, which increased over time. In these children, blood pressure control, calorie and protein intake, and acid-base homeostasis seem important. Taken together, children might profit from early transplantation to limit accumulation of CV risk.

Implication of transcription factor FOXD2 dysfunction in syndromic congenital anomalies of the kidney and urinary tract (CAKUT).

Congenital anomalies of the kidney and urinary tract (CAKUT) are the predominant cause for chronic kidney disease below age 30 years. Many monogenic forms have been discovered due to comprehensive genetic testing like exome sequencing. However, disease-causing variants in known disease-associated genes only explain a proportion of cases. Here, we aim to unravel underlying molecular mechanisms of syndromic CAKUT in three unrelated multiplex families with presumed autosomal recessive inheritance. Exome sequencing in the index individuals revealed three different rare homozygous variants in FOXD2, encoding a transcription factor not previously implicated in CAKUT in humans: a frameshift in the Arabic and a missense variant each in the Turkish and the Israeli family with segregation patterns consistent with autosomal recessive inheritance. CRISPR/Cas9-derived Foxd2 knockout mice presented with a bilateral dilated kidney pelvis accompanied by atrophy of the kidney papilla and mandibular, ophthalmologic, and behavioral anomalies, recapitulating the human phenotype. In a complementary approach to study pathomechanisms of FOXD2-dysfunction-mediated developmental kidney defects, we generated CRISPR/Cas9-mediated knockout of Foxd2 in ureteric bud-induced mouse metanephric mesenchyme cells. Transcriptomic analyses revealed enrichment of numerous differentially expressed genes important for kidney/urogenital development, including Pax2 and Wnt4 as well as gene expression changes indicating a shift toward a stromal cell identity. Histology of Foxd2 knockout mouse kidneys confirmed increased fibrosis. Further, genome-wide association studies suggest that FOXD2 could play a role for maintenance of podocyte integrity during adulthood. Thus, our studies help in genetic diagnostics of monogenic CAKUT and in understanding of monogenic and multifactorial kidney diseases.

Distintos enfoques adoptados por los médicos para tratar la nefrolitiasis en pediatría: estudio basado en una encuesta / Different approaches among physicians to treat pediatric stone disease: a survey-based study

Introducción. Los pediatras, cirujanos y subespecialistas, como urólogos y nefrólogos pediátricos, participan en el diagnóstico y tratamiento de la nefrolitiasis pediátrica. El objetivo fue determinar los enfoques de distintas disciplinas y evaluar las diferencias en sus protocolos de diagnóstico y tratamiento habituales.Población y métodos. Cuestionario administrado a participantes de sesiones sobre nefrolitiasis en congresos nacionales en 2017 para evaluar las rutinas de diagnóstico y tratamiento de la nefrolitiasis entre distintas especialidades (cirujanos y pediatras) y subespecialidades (nefrólogos pediátricos y urólogos pediátricos).Resultados. Se analizaron 324 cuestionarios de 88 pediatras, 121 urólogos, 23 cirujanos pediátricos, 54 nefrólogos pediátricos y 38 urólogos pediátricos. Ambos grupos coincidieron en la necesidad de una evaluación metabólica. Para los cálculos ureterales distales ≥6 mm, los cirujanos preferían una ureteroscopía; los pediatras, una litotricia por ondas de choque (LOC) (p < 0,001); y los subespecialistas, una ureteroscopía (p = 0,636). Para los cálculos en la parte inferior de los cálices renales < 1 cm, los cirujanos y los subespecialistas preferían la LOC y los pediatras, la hidratación (p < 0,001; p = 0,371). Para los cálculos de entre 1,1 cm y 2 cm, los cirujanos preferían la cirugía retrógrada intrarrenal (CRIR) y la LOC, y los pediatras, la LOC (p = 0,001). Para los cálculos más grandes, los cirujanos y subespecialistas preferían la nefrolitotomía percutánea (NLP) y los pediatras, la LOC (p = 0,458; p = 0,001).Conclusión. Existen diferencias entre las disciplinas que participan activamente en el diagnóstico y tratamiento de la nefrolitiasis

Introduction. Pediatricians, surgeons and subspecialties as pediatric urology and nephrology are involved in the diagnosis and treatment of pediatric renal stone disease (RSD). The aim of this study was to determine diagnostic and treatment approaches, of different disciplines, and to assess differences in their routine diagnostic and treatment protocols.Population and methods. A questionnaire was designed and administered to the participants of the RSD sessions in national congresses of all disciplines in 2017 to evaluate the diagnostic and treatment routines of specialties (surgeons and pediatricians) and subspecialties (pediatric nephrologists and pediatric urologists) for RSD. Results. A total, of 324 questionnaires were analyzed, from 88 pediatricians (27 %), 121 urologists (37 %), 23 pediatric surgeons (7 %), 54 pediatric nephrologists (17 %), and 38 pediatric urologists (12 %). Both groups agreed on the necessity of metabolic evaluation. For distal ureter stones that were ≥ 6 mm; surgeons preferred ureteroscopy (URS), pediatricians preferred shock wave lithotripsy (SWL) (p < 0.001) and subspecialties preferred URS for the treatment (p = 0.636). For lower calix stones less than 1 cm surgeons and subspecialists preferred SWL, while pediatricians preferred hydration (p < 0.001, p = 0.371). For the stone between 1.1 and 2 cm, surgeons preferred intrarenal surgery (RIRS) and SWL, pediatricians preferred SWL (p = 0.001). For larger stones, surgeons and subspecialists preferred percutaneous nephrolithotomy (PCNL), and pediatricians preferred SWL (p = 0.458 p = 0.001). Pediatric urologist chose low-dose computerized tomography as a diagnostic radiologic evaluation (p = 0.029).Conclusion. There are differences between the disciplines who take an active role in diagnosis and treatment of RSD.