The use of plasma creatinine concentration for estimating glomerular filtration rate in infants, children, and adolescents

Postnatal urinary tract dilatation classification: improvement of the accuracy in predicting kidney injury

BACKGROUND

The grading of urinary tract dilatation (UTD) on postnatal sonography is a fundamental step to establish rational management for infants with antenatal hydronephrosis (ANH). The aim of this study was to compare the prediction accuracy of UTD grading systems for relevant clinical outcomes. In addition, we propose a refinement of the UTD classification by adding quantitative measurements and evaluate its impact on accuracy.

METHODS

Between 1989 and 2019, 447 infants diagnosed with isolated AHN were prospectively followed. The events of interest were surgical interventions and kidney injury. Comparison of performance of the grading systems and the impact on the accuracy of a modified UTD classification (including the size of the kidney parenchyma) was assessed by the area under the receiver-operating characteristic curve (AUC).

RESULTS

Of 447 infants, 131 (29%) underwent surgical intervention and 26 (5.8%) had developed kidney injury. The median follow-up time was 9 years (IQ range, 7-12 years). The performance for detecting the need for surgical intervention was excellent for all grading systems (AUC > 0.90). However, for predicting kidney injury, the modified UTD classification exhibited significant improvement in accuracy (AUC = 0.913, 95%CI, 0.883-0.937) as compared with UTD classification (AUC = 0.887, 95%CI, 0.854-0.915) (P = 0.027).

CONCLUSIONS

Our study confirms that the hydronephrosis grading systems provide excellent accuracy in discriminating patients who need surgical intervention among infants with AHN. Our findings suggest that the inclusion of kidney parenchymal thickness to UTD classification might increase the accuracy for predicting infants who may develop kidney injury. A higher resolution version of the Graphical abstract is available as Supplementary information.

Correlation between kidney sodium and potassium handling and the renin-angiotensin-aldosterone system in children with hypertensive disorders

BACKGROUND

Urine sodium and potassium are used as surrogate markers for dietary consumption in adults with hypertension, but their role in youth with hypertension and their association with components of the renin-angiotensin-aldosterone system (RAAS) are incompletely characterized. Some individuals with hypertension may have an abnormal RAAS response to dietary sodium and potassium intake, though this is incompletely described. Our objective was to investigate if plasma renin activity and serum aldosterone are associated with urine sodium and potassium in youth referred for hypertensive disorders.

METHODS

This pilot study was a cross-sectional analysis of baseline data from 44 youth evaluated for hypertensive disorders in a Hypertension Clinic. We recorded urine sodium and potassium concentrations normalized to urine creatinine, plasma renin activity, and serum aldosterone and calculated the sodium/potassium (UNaK) and aldosterone/renin ratios. We used multivariable generalized linear models to estimate the associations of renin and aldosterone with urine sodium and potassium.

RESULTS

Our cohort was diverse (37% non-Hispanic Black, 14% Hispanic), 66% were male, and median age was 15.3 years; 77% had obesity and 9% had a secondary etiology. Aldosterone was associated inversely with urine sodium/creatinine (β: -0.34, 95% CI -0.62 to -0.06) and UNaK (β: -0.09, 95% CI -0.16 to -0.03), and adjusted for estimated glomerular filtration rate and serum potassium.

CONCLUSIONS

Higher serum aldosterone levels, but not plasma renin activity, were associated with lower urine sodium/creatinine and UNaK at baseline in youth referred for hypertensive disorders. Further characterization of the RAAS could help define hypertension phenotypes and guide management. A higher resolution version of the Graphical abstract is available as supplementary information.

Impact of Lifestyle Modifications on Alterations in Lipid and Glycemic Profiles and Uric Acid Values in a Pediatric Population

Cardiometabolic risk factors are frequent in children and adolescents with excess weight. The aim of this study was to evaluate the effects of lifestyle modifications on alterations in lipid and glycemic profiles and uric acid values in a pediatric population at increased cardiovascular risk. The study involved 276 subjects with a mean age of 10.6 (2.3) years. Body mass index (BMI) z-score and biochemical parameters (serum low-density lipoprotein (LDL) cholesterol, triglycerides and uric acid and homeostasis model assessment to quantify insulin resistance (HOMA index)) were assessed at baseline and at the end of a median follow-up of 14.7 (12.4, 19.3) months. Throughout follow-up, all children received a non-pharmacological treatment based on increased physical activity, reduced sedentary activity and administration of a personalized, healthy and balanced diet. All children attended periodic quarterly control visits during follow-up. Multivariable statistical analyses showed that each BMI z-score point reduction at follow-up was associated with an 8.9 (95% CI −14.2; −3.6) mg/dL decrease in LDL cholesterol (p = 0.001), 20.4 (95% CI −30.0; −10.7) mg/dL in triglycerides (p < 0.001), 1.6 (95% CI −2.2; −1.0) in HOMA index (p < 0.001), and 0.42 (95% CI −0.66; −0.18) mg/dL in uric acid (p = 0.001) values. At each reduction of the BMI z-score by one point, the odds of presenting with insulin resistance and hyperuricemia at follow-up significantly decreased (OR 0.23, 95% CI 0.10−0.50, and OR 0.32, 95% CI 0.10−0.95, p < 0.001 and p < 0.05, respectively). Improvement of dietary habits and lifestyles may improve lipid and glycemic profiles and serum uric acid values in a pediatric population.

Recommendations for the diagnosis and management of Fabry disease in pediatric patients: a document from the Rare Diseases Committee of the Brazilian Society of Nephrology (Comdora-SBN)

Abstract Fabry disease (FD) is a genetic disease, with X-chromosome linked inheritance, due to variants in the GLA gene that encodes the α-galactosidase A (α-GAL) enzyme. The purpose of the present study was to create a consensus aiming to standardize the recommendations regarding the renal involvement of FD with guidelines on the diagnosis, screening, and treatment of pediatric patients. This consensus is an initiative of the Rare Diseases Committee (Comdora) of the Brazilian Society of Nephrology (SBN). Randomized controlled clinical studies and studies with real-life data added to the authors' experience were considered for this review. The result of this consensus was to help manage patient and physician expectations regarding treatment outcomes. Thus, this consensus document recommends the investigation of the pediatric family members of an index case, as well as cases with suggestive clinical signs. From the diagnosis, assess all possible FD impairments and grade through scales. From an extensive review of the literature including pediatric protocols and particularly evaluating pediatric cases from general studies, it can be concluded that the benefits of early treatment are great, especially in terms of neuropathic pain and renal impairment parameters and outweigh the possible adverse effects that were mainly manifested by infusion reactions.

Derivation and validation of urinary TIMP-1 for the prediction of acute kidney injury and mortality in critically ill children

BACKGROUND

Acute kidney injury (AKI) is associated with high morbidity and mortality. Multiple urinary biomarkers have been identified to be associated with the prediction of AKI and outcomes. However, the accuracy of these urinary biomarkers for AKI and associated outcomes has not been clearly defined, especially in heterogeneous populations. The aims of the study were to compare the ability of 10 existing or potential urinary biomarkers to predict AKI and pediatric intensive care unit (PICU) mortality and validate urinary tissue inhibitor of metalloproteinases-1 (uTIMP-1) as a better biomarker for early prediction in heterogeneous critically ill children.

METHODS

A derivation-validation approach with separate critically ill cohorts was designed. We first conducted a prospective cohort study to determine the ability of 10 urinary biomarkers serially measured in 123 children during the first 7 days of PICU stay to predict AKI and PICU mortality (derivation study) and further validated the better biomarker of uTIMP-1 in a separate cohort of 357 critically ill children (validation study). AKI diagnosis was based on KDIGO classification with serum creatinine and urine output. PICU mortality was defined as all-cause mortality.

RESULTS

In the derivation cohort, 17 of 123 (13.8%) children developed AKI stage 3 or died during the PICU stay, and both the initial and peak uTIMP-1 displayed the highest AUCs of 0.87 (0.79-0.94) and 0.90 (0.84-0.96), respectively, for predicting AKI stage 3 or death. In the validation cohort, 78 of 357 (21.8%) developed AKI during the first week after admission, and 38 (10.6%) died during the PICU stay. The initial uTIMP-1 level was validated to be independently associated with AKI (AOR = 2.88, 95% CI 1.97-4.21), severe AKI (AOR = 2.62, 95% CI 1.78-3.88), AKI stage 3 (AOR = 2.94, 95% CI 1.84-4.68) and PICU mortality (AOR = 1.92, 95% CI 1.11-3.30) after adjustment for potential confounders. The predictive values of uTIMP-1 for AKI, severe AKI, AKI stage 3 and PICU mortality were 0.80 (0.74-0.86), 0.83 (0.77-0.89), 0.84 (0.77-0.92) and 0.83 (0.76-0.89), respectively.

CONCLUSIONS

Urinary TIMP-1 levels have been identified and validated to be independently associated with AKI and PICU mortality in independent prospective cohorts and may be an early potential indicator of AKI and PICU mortality in critically ill children.

Early Renal Ultrasound in Patients with Congenital Solitary Kidney Can Guide Follow-Up Strategy Reducing Costs While Keeping Long-Term Prognostic Information

We aimed to evaluate the prognostic value of renal length (RL) > 2 standard deviation scores (SDS) measured by renal ultrasound (RUS), across infancy, childhood and adolescence, in identifying which patients with congenital solitary functioning kidney (CSFK) are at lower risk of developing kidney injury (KI). We also estimated the cost saving of integrating the current follow-up protocols with an early RUS algorithm (ERUSA). Fifty-six CSFK adult patients who were 1-3 months old at first observation of undergoing RUS were enrolled. KI was defined by hypertension and/or proteinuria and/or declined renal function. ERUSA was assessed by early (at 1-3 months of life) RUS and was retrospectively tested in our patients. ERUSA establishes that patients with RL > 2SDS at early RUS do not undergo further follow-ups. The others undergo another RUS at 1 year of age along with follow-ups according with current protocols, with the exception of RUS which could be no longer performed. Direct and indirect costs were calculated for each analysed protocol and the cost saving of applying ERUSA was calculated. None of the patients with early RL > 2SDS presented KI in adulthood. A RL > 2SDS was predictive of absence of KI only at 1-3 months (OR = infinity) and 1 year of age (OR = 0.13; 95%CI: 0.03-0.66; p = 0.01). ERUSA provided a total cost-sparing ranging from 38.6% to 55.3% among the analysed follow-up protocols. With ERUSA, no patients developing KI in adulthood were missed. In conclusion, only a RL > 2SDS at 1-3 months and 1 year of age predicted good prognosis in young adulthood. ERUSA can guide a cost-sparing follow-up strategy in CSFK patients while maintaining important long-term information.

A comparison of the clinical characteristics of pediatric urolithiasis patients with positive and negative molecular diagnoses

PURPOSE

To compare the clinical characteristics of pediatric urolithiasis patients with positive and negative molecular diagnoses.

METHODS

The clinical characteristics corresponding to pediatric urolithiasis patients that had undergone exome sequencing at our hospital between January 2016 and May 2021 were collected. Genetic analysis results were used to separate patients into positive and negative molecular diagnosis groups. Multivariate logistic regression analyses adjusted for visiting age, sex, ethnicity, province, and body mass index were used to compare differences in medical history, diagnostic imaging findings, and renal function between individuals with and without molecular diagnoses.

RESULTS

In total, 194 patients with pediatric urolithiasis of unknown etiology underwent exome sequencing and were included in the present study, of whom 63 obtained urolithiasis-related molecular diagnoses. Relative to cases without a molecular diagnosis, those with a positive molecular diagnosis were more likely to be associated with a positive family history (OR 2.84, 95% CI 1.29-6.29, p = 0.008), consanguineous parents (OR 24.7, 95% CI 1.34-454, p = 0.002), early onset (OR 1.26, 95% CI 1.09-1.45, p < 0.001), nephrocalcinosis (OR 10.6, 95% CI 3.06-36.6, p < 0.001), cast stone (OR 18.9, 95% CI 4.40-81.1, p < 0.001), multiple stones (OR 13.9, 95% CI 6.39-30.2, p < 0.001), bilateral stones (OR 7.04, 95% CI 3.47-14.2, p < 0.001), a lower estimated glomerular filtration rate (OR 1.17, 95% CI 1.07-1.28, p < 0.001), and chronic kidney disease (OR 26.9, 95% CI 1.42-526, p < 0.001).

CONCLUSION

A positive family history, consanguineous parents, early onset, nephrocalcinosis, severe stone burden, and impaired renal function are signals of concern that are suggestive of inherited urolithiasis.

Establishment and application of population pharmacokinetics model of vancomycin in infants with meningitis

BACKGROUND

To establish a population pharmacokinetics (PPK) model of vancomycin (VCM) for dose individualization in Chinese infants with meningitis.

METHODS

We collected the data of 82 children with meningitis in hospital from July 2014 to June 2016. The initial vancomycin dosage regimen for children was 10 or 15 mg/kg for q12 h, q8 h or q6 h. Serum concentrations were determined by Viva-E Analyzer before and after the fifth administration. The PPK model was developed by nonlinear mixed-effect model software, assessed by the bootstrap method and then tested in 20 infant patients.

RESULTS

The VCM clearance (CL) was increased by body weight (WT) and decreased by blood urea nitrogen (BUN). Pharmacokinetic parameters of VCM were not influenced by co-administered drugs. The trough concentrations of VCM were accurately predicted by the PPK model, with the prediction errors less than 32%.

CONCLUSION

A new individual strategy for VCM regimens was proposed and validated by the PPK model.

Presentation, treatment, and outcome of renovascular hypertension below 2 years of age

Renovascular hypertension in most cases requires endovascular treatment and/or surgery. This is technically much more difficult in small children and there is very limited published knowledge in this age group. We here present treatment and outcome of young children with renovascular hypertension at our institution. Children below 2 years of age, with renovascular hypertension between January 1998 and March 2020 were retrospectively reviewed. Demographics and treatment modalities were noted. Primary outcome was blood pressure within a week after the procedures and at last available visit. Sixty-six angiographies were performed in 34 patients. Median age at time of first angiography was 1.03 (interquartile range (IQR) 0.4-1.4) years and systolic blood pressure at presentation 130 (IQR 130-150) mm Hg. Thirty-eight percent (13/34) of children were incidentally diagnosed and 18% (6/34) presented with heart failure. Twenty-six (76%) children had main renal artery stenosis and 17 (50%) mid-aortic syndrome. Seventeen (50%) children showed intrarenal, six (18%) mesenteric, and three (9%) cerebrovascular involvement. Twenty patients underwent 45 percutaneous transluminal angioplasty procedures and seven children surgeries. In 44% of the 16 patients who underwent only percutaneous transluminal angioplasty blood pressure was normalized, 38% had improvement on same or decreased treatment and 19% showed no improvement. Complications were seen in 7.5% (5/66) of angiographies. In four of the seven (57%) children who underwent surgery blood pressure was normalized, two had improved (29%) and one unchanged (14%) blood pressure.

CONCLUSION

In small children with renovascular hypertension below the age of 2 years, percutaneous transluminal angioplasty caused significant improvement in blood pressure with low complication profile. Surgery can be recommended where percutaneous transluminal angioplasty and medical treatments failed.

WHAT IS KNOWN

• Renovascular hypertension is diagnosed in all age groups from a few weeks of life until adulthood. • Both angioplasty and surgery are significantly more difficult to perform in small children and the published information on short and long-term outcome in these children is very scarce.

WHAT IS NEW

• Children below the age of two years can safely and successfully undergo selective renal angiography and also safely be treated with angioplasty. • We here present a large group of babies and infants where angioplasty and in some cases surgery effectively and safely improved their blood pressure.

Evaluation of renal replacement therapy in children and adolescents in the state of Amazonas, Brazil

Abstract Objective: To describe the characteristics of stage-5 chronic kidney disease (CKD) children and adolescents undergoing renal replacement therapy (RRT) in Amazonas, Brazil, estimating the frequencies of current and new cases, describing the presence of anemia and bone metabolism disorders. Methods: Thirty-five patients aged 7 to 19 years-old on hemodialysis (HD) or peritoneal dialysis (PD) were studied between June 2018 and April 2019. The frequencies of current and new cases were estimated based on the 0 to 19 years-old population of Amazonas, in the same period. Data were collected about the underlying cause and diagnosis of CKD, dialysis, and biochemical analysis. Results: The frequencies of current and new cases were 24 and 15 patients per million people of compatible age (pmpca), respectively. The causes of CKD were nephrotic syndrome (22.8%), nephritic syndrome (14.3%), and neurogenic bladder (14.3%); in 48.6%, the cause was unknown/not investigated. Ten patients underwent renal biopsy, seven with segmental and focal glomerulosclerosis. The majority (80%) were on HD, with an average kt/V of 1.4, and in 51.4% the vascular access was the double lumen catheter. Hypocalcemia was found in 82.8% of patients, hyperphosphatemia in 57.2%, vitamin D insufficiency or deficiency in 60%, and altered parathyroid hormone values in 48.6%. Hemoglobin was low in 80%, with absolute/functional iron deficiency in 28.6%. Conclusions: In children and adolescents of Amazonas, Brazil, we found 24 pmpca with stage-5 CKU currently in RRT and 16.3 pmpca per year of new cases requiring RRT. Most patients were adolescents on HD, half without a causal diagnosis of CKD, with a high frequency of anemia and bone metabolism disorder.

Etiology of Kidney Diseases With Proteinuria in the Gambia/West Africa

In West Africa, kidney diseases are frequently seen, but diagnostic and therapeutic options are poor due to limited access to specialized facilities. To unravel the etiology and develop clinical guidelines, we collected clinical data and results of kidney biopsies in 121 pediatric and mostly young adult patients with edema and proteinuria in The Gambia. Workup included clinical examination, urine and serum analysis, and kidney biopsy findings. Selected cases were treated with steroids.

RESULTS

The median age was 14.9 years (range 1.8-52.0) at presentation. The most frequent underlying histologies were post-infectious glomerulonephritis (PIGN) in 38%, focal-segmental glomerulosclerosis (FSGS) in 30%, minimal change nephrotic syndrome (MCNS) in 15%, and membranous glomerulonephritis (MGN) in 10% of cases. Patients with PIGN were significantly younger and had less proteinuria and higher serum albumin levels than the other three. Infected scabies was seen more often in cases with PIGN. Clinical parameters could not distinguish patients with FSGS, MCNS, and MGN. Steroid response was prompt in patients with MCNS (remission in 10/10 cases) compared to FSGS (4/19) and MGN (0/4). In summary, the clinical histopathological correlation allows a better approach to therapy and can be the basis for urgently needed interventional studies in steroid-resistant cases.

Serum Cystatin C Levels Are Associated With Obesity in Adolescents Aged 14-17 Years

BACKGROUND

The association between serum cystatin C levels and obesity has not been fully explored in adolescents. This study aimed to explore the association between serum cystatin C levels and obesity in adolescents of different sexes.

METHODS

We conducted a cross-sectional study including 481 adolescents aged 14-17 years. Cystatin C level was measured by immunoassay. Health examinations data, biochemical parameters, and questionnaire information were collected. The restricted cubic spline model analyzed the association between cystatin C levels and obesity in boys and girls.

RESULTS

Boys exhibited significantly higher cystatin C levels than girls, with a mean level of 0.97 ± 0.10 mg/L in boys and 0.86 ± 0.09 mg/L in girls (P < 0.001). The restricted cubic spline model suggested that low or high cystatin C levels were associated with an increased risk of obesity in boys, whereas only higher cystatin C levels were associated with an increased risk of obesity in girls.

CONCLUSIONS

A U-shaped correlation was observed between serum cystatin C levels and the risk of obesity in boys. However, in girls, the risk of obesity showed a trend of initially increase and then decrease with increasing cystatin C levels. Longitudinal studies should be conducted to further investigate the diagnostic potential of cystatin C in the progression of early obesity in adolescents of different sexes.

Hyperuricemia and Associated Factors in Children with Chronic Kidney Disease: A Cross-Sectional Study

Background: Hyperuricemia is increasingly recognized as a risk factor for chronic kidney disease (CKD) just in adults. The purpose of this study was to investigate the clinical characteristics of hyperuricemia and its associated factors in Chinese children with CKD at a single center. Methods: A cross-sectional study of 170 CKD children collected from the Department of Nephrology, The Zhejiang University Children’s Hospital was conducted. The clinical data, including anthropometric data, blood pressure measurements, and biochemical parameters, were recorded and analyzed retrospectively. The factors associated with hyperuricemia in CKD children were evaluated by Pearson and Spearman correlation analysis and multiple logistic regression analysis. Results: The mean age was 9.79 ± 4.10 years, and 72 (42.35%) were girls. Higher blood urea nitrogen (BUN), serum creatinine, cystatin C, D-dimer, lower hemoglobin, albumin, and estimated glomerular filtration rate (eGFR) were significantly associated with higher serum uric acid (SUA). In multiple logistic regression analysis, anemia and higher BUN were both positively associated factors, whereas eGFR ≥ 90 mL/min/1.73 m² was a negatively associated factor for subjects with SUA ≥ 390 µmol/L (6.5 mg/dL). Conclusions: SUA was significantly associated with kidney risk factors in CKD children. Monitoring and controlling SUA, Hb, BUN, and Scr levels in CKD children may help to prevent the progression of CKD.

Role of magnetic resonance diffusion weighted imaging in diagnosis of diabetic nephropathy in children living with type 1 diabetes mellitus

OBJECTIVES

Diabetic nephropathy is a serious and a common complication of diabetes that can lead to end stage renal disease among children living with type 1 diabetes, thus an early and accurate method of diagnosis that allows timely intervention is of high importance. This study aimed to evaluate the role of magnetic resonance diffusion weighted imaging in diagnosis of diabetic nephropathy in children with type 1 diabetes.

METHODS

This prospective, observational, case control study included 30 children with type 1 diabetes and 30 matched healthy controls attending the outpatient clinics in Mansoura University Children's Hospital. All were subjected to magnetic resonance DWI of the renal parenchyma and their glomerular filtration rate (GFR) was estimated, along with micro albumin in 24 h urine collection and HbA1c in patients with diabetes.

RESULTS

Children with diabetes who were positive for microalbuminuria had significantly lower apparent diffusion coefficient value compared to Children with diabetes who were negative for microalbuminuria (p = 0.034) as well as controls (p = 0.001). Among children with type 1 diabetes, apparent diffusion coefficient had significant positive correlation with estimated glomerular filtration rate (r = 0.491, p = 0.006) and negative correlation with microalbuminuria (r = -0.437, p = 0.016).

CONCLUSION

Magnetic resonance DWI of the renal parenchyma is correlated with estimated glomerular filtration rate (eGFR) in children with type 1 diabetes and can detect GFR deterioration even in presence of normal albumin excretion.

Obesity Facts and Their Influence on Renal Function Across the Life Span

Obesity is a chronic disease, with a rapidly increasing prevalence worldwide. Body mass index (BMI) provides the most useful population-level measure of overweight and obesity. For adults, overweight is defined as a BMI (Kg/m²) ≥ 25, and obesity as a BMI ≥ 30, for non-Asians and ≥ 27.5 for Asians. Abdominal obesity can be defined as a waist circumference equal to or higher than 102 cm for men and ≥88 cm for women. The definition of children and adolescents BMI changes with age and sex. Obesity may be exogenous or endogenous obesity, the latter is multifactorial and predominantly manifested during childhood. Presently, overweight and obesity are linked to more deaths worldwide than underweight. The total kidney glomerular filtration rate (GFR) is determined by the sum of nephrons and the GFR within each nephron or single nephron GFR. In clinical practice, GFR is more frequently calculated by GFR estimating equations based upon the plasma levels of creatinine, cystatin C, or both. The measured value of plasma creatinine is strongly influenced by non-GFR factors, by its tubular and gastrointestinal secretion, and by the problems associated with the lack of standardization of creatinine's laboratory assay discrediting it as an ideal GFR biomarker. Unlike creatinine, cystatin C plasma levels are mainly determined by GFR. Obesity may affect the kidney, via development of systemic arterial hypertension and/or diabetes mellitus, or directly, by ectopic accumulation of adipose tissue in the kidney. As obesity is a clinical condition associated with altered body composition, creatinine may not be the ideal biomarker for GFR measurement in obese individuals.

Estimation of body surface area in neonates, infants, and children using body weight alone

BACKGROUND

The aim of this study was to use Body Surface Area (BSA) data calculated with the Mosteller equation to test potential new equations that estimate BSA using Body Weight (BW) alone in children aged 0-18 years.Mosteller's equation, the golden standard at our hospital, was used to calculate the BSA in infants and children aged 0-18 years using BW and height data from 27,440 hospital visits by 20,635 patients over one year.

METHODS

The best fit of three nonlinear regression equations (third-order polynomial, Meeh-type, and modified Boyd self-adjusting-type) to a plot of the calculated Mosteller BSA values versus BW was then investigated. The correlation between the BSA values estimated by these equations and the Mosteller BSA values was established by the Spearman rank correlation test. Bias and precision were evaluated as outlined by Sheiner and Beal. Measured and estimated BSA values were compared using the Eksborg plot.

RESULTS

The estimated BSA values from all three equations and the BSA values from the Mosteller equation were closely correlated (P < .0001). The third-order polynomial and Meeh-type equations overestimated BSA by 0.13% and 0.40%, respectively, while the Boyd self-adjusted-type equation underestimated BSA by 0.060%. For the entire pediatric population, the best fit was obtained with the Meeh-type equation: 99.2% of the Meeh/Mosteller BSA ratios were within the range of 0.9-1.1 when compared with 98.3% and 97.2% for the polynomial and Boyd-type equations, respectively.

CONCLUSION

A single Meeh-type equation can be used to predict the results of Mosteller equation when H is not available with high precision and accuracy in children aged 0-18 years, including term neonates. We now plan to include the results of this study in CPOE systems in Sweden to improve drug dosage in all children.

Are we losing awareness of other infections due to the fear of coronavirus disease-2019 and MIS-C?

INTRODUCTION

Multisystem inflammatory syndrome in children (MIS-C) is a rarely seen severe complication of coronavirus disease-2019 (COVID-19). Although fever is one of the indispensable symptoms, other infections should be considered in the differential diagnosis during the pandemic.

CASE REPORT

An 8-year-old and a 16-year-old female patient were admitted with fever, vomiting, headache. Both had fulfilled the criteria and were diagnosed with MIS-C. However, they both had remarkable persistent costovertebral angle tenderness, which was unexpected in MIS-C. In Case-1, urine analysis showed microscopic hematuria without pyuria, and urine culture showed no bacterial growth. Case-2 had microscopic hematuria and pyuria with Escherichia coli growth in urine culture. Contrast-enhanced computed tomography showed wedge-shaped hypodense multiple lesions in bilateral kidneys for Case-1, in the right kidney for Case-2. They diagnosed acute focal bacterial nephritis (AFBN).

CONCLUSIONS

The diagnostic criteria of MIS-C can overlap with the symptoms of other severe septic infections such as AFBN, which is a rare urinary tract infection, diagnosed by imaging of localized renal inflammatory mass-like or wedge-shaped lesion. A detailed anamnesis and careful physical examination may help differential diagnosis.

A genome‑wide scan to locate regions associated with familial vesicoureteral reflux

Vesicoureteral reflux (VUR) is a congenital malformation carrying a high risk of recurrent urinary tract infections (UTI) and, at worst, chronic renal failure. Familial clustering implies a genetic etiology, but studies during the past few decades have demonstrated a causal gene variant in <10% of patients with VUR. The aim of the present study was to search for fully or partially shared ancestral haplotypes in 14 families from south-western Sweden with at least three affected members. High-density single nucleotide polymorphism microarray was used for genotyping prior to analysis with a compatibility matching method developed in-house, and the analysis of copy number variations (CNV). No single unique haplotype was revealed to be shared by the families, thereby excluding a common ancestry and founder mutations as a probable cause of VUR. After evaluation of haplotypes shared by subsets of families, a haplotype shared by nine families was found to be of particular interest. This haplotype, located at chromosomal region 4q21.21, harbours two tentative candidate genes (bone morphogenetic protein 3 and fibroblast growth factor 5), both expressed in metanephros and with known functions during nephrogenesis. As to CNV, only one family had a specific CNV shared by all affected members. This was a focal deletion at 5q31.1 including follistatin-like 4, a gene without a previous known connection to VUR. These data demonstrated the genetic heterogeneity of VUR and indicated that an interaction of environmental and genetic factors, including non-coding and epigenetic regulators, all contribute to the complexity of VUR.

Continuous infusion of piperacillin-tazobactam significantly improves target attainment in children with cancer and fever

Background

Children with febrile neutropenia commonly exhibit alterations of pharmacokinetic (PK) parameters, leading to decreased β‐lactam concentrations.

Aims

This study evaluated piperacillin PK and probability of target attainment (PTA) with continuous infusion of piperacillin‐tazobactam, in order to optimize the dosing regimen.

Methods

This prospective PK study included children with cancer, aged 1–17 years, who were treated with piperacillin‐tazobactam for suspected or verified infection. A piperacillin‐tazobactam loading dose (100 mg/kg) was administered followed by continuous infusion (300 mg/kg/day). The unbound fraction of piperacillin was quantified by high‐performance liquid chromatography and PK were described using population PK modeling. PK data was used to update and extend a previous PK model built on data following intermittent administration. Monte Carlo simulations were performed to assess PTA for targets of 100% time above the minimum inhibitory concentration (100% fT > MIC) and 50% fT > 4xMIC.

Results

We included 68 fever episodes among 38 children with a median (IQR) age of 6.5 years and body weight of 27.4 kg (15.1–54.0). A three‐compartment model adequately described the concentration‐time data. Median (95% confidence interval) estimates for clearance and piperacillin concentration at steady state were 14.2 L/h/70 kg (13.0; 15.3) and 47.6 mg/L (17.2; 129.5), respectively. Body weight or lean body weight was significantly associated with the PK parameters, and body weight was integrated in the final PK model. Based on piperacillin exposure, continuous infusion was the only dosing regimen to achieve optimal PTA for the P. aeruginosa breakpoint (16 mg/L) with the target of 100% fT > MIC, and a daily dose of 300 mg/kg reached optimal PTA. The strict target of 50% fT > 4xMIC (64 mg/L) was not feasibly attained by any dosing regimen at recommended doses.

Conclusion

Unlike conventional piperacillin intermittent administration and extended infusion regimens, continuous infusion allows the target of 100% fT > MIC to be reached for children with febrile neutropenia.

The need for area under the curve measurements in the field of ganciclovir therapeutic drug monitoring in children: a case report

Background

Ganciclovir pharmacokinetics is characterized by a high variability in drug exposure. Usually, monitoring of ganciclovir exposure is performed by measuring trough concentration. However, due to the specificity of pediatric pharmacokinetics, trough concentration measurements may not be a relevant surrogate of ganciclovir exposure. Area under the curve of concentration (AUC) may be a more appropriate biomarker.

Case presentation

We report the case of 3.6-year-old boy with Emberger syndrome with a cytomegalovirus reactivation occurring after allogenic hematopoietic stem cell transplantation. After a few days of treatment with intravenous ganciclovir, sub-therapeutic trough ganciclovir concentrations were measured (< 0.5 µg/mL) and viral load still increased. Ganciclovir dosage was increased by two-fold to deal with this treatment failure. Trough concentrations remained sub-therapeutic. The patient had hematologic disorder therefore it was decided to estimate ganciclovir AUC to assess more accurately drug exposure before any further dosage modification. AUC_0–12 h was measured at 51 μg h/mL, which was within the therapeutic range (40–60 μg h/mL). Afterward, viral load decreased and became undetectable.

Conclusions

This case report highlights that monitoring ganciclovir exposure based on AUC should be performed to tailor drug dosage in order to improve treatment efficacy and safety in pediatric patients.

A Prospective Cohort Study on Serum Sodium and Clinical Outcome in Pediatric Nontraumatic Coma

OBJECTIVE

To study the serum sodium level and clinical outcome in pediatric nontraumatic coma.

METHODS

A prospective cohort study was conducted in a tertiary care pediatric intensive care unit (PICU) from September 2015 to June 2016. Children aged < 13 y with nontraumatic coma [modified-Glasgow Coma Scale (m-GCS) score ≤ 8 or fall of ≥ 3 from baseline within 24 h of admission] were included. Children who received intravenous fluids for > 24 h, those with developmental delay, or died within 24 h of admission were excluded. The serum sodium profile (mEq/L) in the first 72 h and clinical outcome [mortality, length of stay in mechanical ventilation, PICU, and hospital] were studied.

RESULTS

Eighty patients [Died n = 26 and Survived n = 54] were enrolled. Median [interquartile range (IQR)] age and m-GCS were 21 (4-78) mo and 9 (7-11), respectively. The mean [standard deviation (SD)] Pediatric Risk of Mortality-III (PRISM-III) was 17.7 (4). The most common etiology was acute central nervous system (CNS) infections (30%, n = 24) followed by an intracranial bleed (11.3%, n = 9). Mean (Standard error, SE) sodium levels and fluctuation of serum sodium from baseline up to 72 h were similar between nonsurvivors and survivors [140.8 (1.3) vs. 139.6 (0.8), p = 0.421] and [1.2 (0.3) vs. 0.8 (0.2), p = 0.307], respectively. On multivariate analysis, the need for vasoactive therapy was an independent predictor of mortality [adjusted odds ratio = 20.78, 95% CI 4.24-101.85, p = < 0.001, R² = 0.62].

CONCLUSION

Mean serum sodium within normal range and fluctuation of serum sodium of 0.8 to 1.2 mEq/L over 72 h was not associated with poor outcomes in pediatric nontraumatic coma. Vasoactive therapy was an independent predictor of mortality.

Increasing prevalence of hypertension during long-term follow-up in children with autosomal dominant polycystic kidney disease

INTRODUCTION

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease. Kidney cysts form over the course of the disease and kidney function slowly declines, usually leading to kidney failure in middle to late adulthood. However, some symptoms, such as hypertension or proteinuria, can be present at an earlier age. In this study, we aimed to quantify early complications in children over time.

METHODS

All 69 children with ADPKD from our pediatric nephrology center who met inclusion criteria (follow-up ≥ 1 year and ≥ 2 recorded visits) were studied. Analysis of changes in kidney size, cyst count, estimated glomerular filtration rate (eGFR), urinary protein excretion, and blood pressure was performed.

RESULTS

The median time of follow-up was 6.3 years (range 8.4-14.8). Over the follow-up, kidneys grew from 109 to 115% of expected length (p < 0.0001), number of cysts increased at a rate of 0.8 cyst/kidney/year, and the prevalence of hypertension increased significantly from 20 to 38% (p < 0.015). The eGFR and absolute urinary protein excretion remained stable.

CONCLUSIONS

This study shows that children with ADPKD suffer from increasing prevalence of hypertension during the course of the disease parallel to the increasing number of kidney cysts and size despite normal and stable kidney function and proteinuria. A higher resolution version of the Graphical abstract is available as Supplementary information.

Optimization of Personalized Amlodipine Dosing Strategies for Children Based on Pharmacokinetic Data from Chinese Male Adults and PBPK Modeling

For children, a special population who are continuously developing, a reasonable dosing strategy is the key to clinical therapy. Accurate dose predictions can help maximize efficacy and minimize pain in pediatrics. Methods: This study collected amlodipine pharmacokinetics (PK) data from 236 Chinese male adults and established a physiological pharmacokinetic (PBPK) model for adults using GastroPlus™. A PBPK model of pediatrics is constructed based on hepatic-to-body size and enzyme metabolism, used similar to the AUC_0-∞ to deduce the optimal dosage of amlodipine for children aged 1–16 years. A curve of continuous administration for 2-, 6-, 12-, 16-, and 25-year-olds and a personalized administration program for 6-year-olds were developed. Results: The results show that children could not establish uniform allometric amplification rules. The optimal doses were 0.10 mg·kg⁻¹ for ages 2–6 years and −0.0028 × Age + 0.1148 (mg/kg) for ages 7–16 years, r = 0.9941. The trend for continuous administration was consistent among different groups. In a 6-year-old child, a maintenance dose of 2.30 mg was used to increase the initial dose by 2.00 mg and the treatment dose by 1.00 mg to maintain stable plasma concentrations. Conclusions: A PBPK model based on enzyme metabolism can accurately predict the changes in the pharmacokinetic parameters of amlodipine in pediatrics. It can be used to support the optimization of clinical treatment plans in pediatrics.

Vancomycin-induced nephrotoxicity in non-intensive care unit pediatric patients

Previous data suggested several risk factors for vancomycin-induced nephrotoxicity (VIN), including higher daily dose, long-term use, underlying renal disease, intensive care unit (ICU) admission, and concomitant use of nephrotoxic medications. We conducted this study to investigate the prevalence and risk factors of VIN and to estimate the cut-off serum trough level for predicting acute kidney injury (AKI) in non-ICU pediatric patients. This was a retrospective, observational, single-center study at Samsung Medical Center tertiary hospital, located in Seoul, South Korea. We reviewed the medical records of non-ICU pediatric patients, under 19 years of age with no evidence of previous renal insufficiency, who received vancomycin for more than 48 h between January 2009 and December 2018. The clinical characteristics were compared between patients with AKI and those without to identify the risk factors associated with VIN, and the cut-off value of serum trough level to predict the occurrence of VIN was calculated by the Youden's index. Among 476 cases, 22 patients (4.62%) developed AKI. The Youden's index indicated that a maximum serum trough level of vancomycin above 24.35 μg/mL predicted VIN. In multivariate analysis, longer hospital stay, concomitant use of piperacillin-tazobactam and serum trough level of vancomycin above 24.35 μg/mL were associated independently with VIN. Our findings suggest that concomitant use of nephrotoxic medication and higher serum trough level of vancomycin might be associated with the risk of VIN. This study suggests that measuring serum trough level of vancomycin can help clinicians prevent VIN in pediatric patients.

Association between Multimorbidity and Kidney Function among Patients with Non-Dialysis-Dependent CKD

Aim: Individuals with chronic kidney disease (CKD) have a high prevalence of comorbidities, including cardiovascular disease (CVD) and its risk factors. However, epidemiological results to assess the association between multimorbidity and kidney function among the CKD population remains limited.

Methods: We performed a cross-sectional analysis of the association between 23 comorbid conditions and reduced kidney function in 4,476 patients with non-dialysis-dependent CKD enrolled in a multicenter cohort in Japan. Reduced kidney function was defined as an estimated glomerular filtration rate of ≤ 60 mL/min/1.73 m².

Results: The mean age of patients was 67 years (male, 56.0%). The prevalence of hypertension, diabetes mellitus, dyslipidemia, prior CVD, cancer, and bone fracture, which are the major comorbidities, was 83.3%, 28.7%, 45.9%, 23.3%, 12.7%, and 6.3%, respectively. Multivariable-adjusted analyses revealed that age, male sex, hypertension, dyslipidemia, prior CVD, body mass index, urinary protein excretion, and underlying kidney disease were independent factors associated with reduced kidney function. Importantly, the odds ratios (ORs) for reduced kidney function increased linearly as the number of major comorbid conditions increased (OR for 1–2 conditions: 2.22, 95% confidence interval [CI]: 1.65–2.97; OR for 3–4 conditions: 3.04, 95% CI: 2.12–4.37; OR for ≥ 5 conditions: 4.37, 95% CI: 1.75–10.9). The upward trend in OR was more pronounced with cardiovascular comorbidities but not significant with non-cardiovascular comorbidities.

Conclusions: In conclusion, we observed an independent association between cardiovascular comorbidity and its risk factors and reduced kidney function. The results of this study highlight the importance of managing multimorbidity among patients with CKD.

Pharmacokinetics, Pharmacodynamics, and Therapeutic Drug Monitoring of Valganciclovir and Ganciclovir in Transplantation

Ganciclovir and valganciclovir are first choice drugs for the prevention and treatment of cytomegalovirus infection and disease in solid organ and stem cell transplant recipients. Only a few studies on the pharmacokinetics and exposure/efficacy or exposure/safety relationships of ganciclovir and valganciclovir in transplant recipients have been published so far, and there are still controversies about the exposure parameter to use for therapeutic drug monitoring (TDM). We performed an extensive literature review of the clinical pharmacokinetics data, the exposure/effect relationships in terms of efficacy and safety, and the available tools for valganciclovir and ganciclovir TDM in adults and pediatrics transplant recipients. The pharmacokinetics of ganciclovir and valganciclovir is well described in adults and children, and a high interindividual variability is commonly observed. In contrast, the drug pharmacodynamics has been poorly described in adults and barely in children. The average 24-hour area under the concentration-time curve (AUC_0-24h ) seems to be the best predictor of efficacy and toxicity. The benefit of TDM remains controversial in adult patients but should be considered in children due to higher interindividual variability and lower probability of target attainment. Several bayesian estimators based on limited sampling strategies have been developed with this aim and may be used in clinical practice for the AUC-based individual dose adjustment of ganciclovir and valganciclovir.

Crossed fused renal ectopia: Diagnosis and prognosis as a single-center experience

BACKGROUND

Crossed fused renal ectopia (CFRE) is a rare congenital malformation. Renal bladder ultrasound (RBUS) is a good tool for establishing the diagnosis, however, additional imaging with a voiding cystourethrogram (VCUG) and dimercaptosuccinic acid scan (DMSA) might be required. We assessed the need for postnatal evaluation and the long-term consequences in patients with this diagnosis.

METHODS

A retrospective review of the records of all patients diagnosed with CFRE between 2004 and 2014 was done. We included all patients who underwent postnatal evaluation with RBUS, DMSA and VCUG. Long-term radiological and functional outcomes were assessed.

RESULTS

A total of 29 patients with CFRE were identified. Majority of cases were detected antenatally (79%) and left to right crossed ectopia constituted the majority of cases (65%). RBUS revealed associated hydronephrosis (HN) in 11 patients (38%). DMSA scans confirmed the diagnosis in all patients and showed impaired renal function in 10 ectopic kidneys (34%). Vesicoureteral reflux was detected in 12 patients (41%); one third of them needed surgical intervention. Extra-urinary anomalies were present in 14 patients (48%) mainly of cardiac origin. After a mean follow-up of 4.5 years, 4 patients (14%) with extra-urinary anomalies developed chronic kidney disease and two of them died.

CONCLUSIONS

Crossed fused renal ectopia is commonly associated with both urinary and extraurinary malformations. Postnatal RBUS is usually sufficient for diagnosis, however, additional imaging may aid for confirming the diagnosis and detection of associated urinary anomalies. Presence of extra-urinary malformations with crossed fused ectopia carries a higher risk of morbidity.

TYPE OF THE STUDY

Retrospective study [diagnostic/prognostic study].

LEVEL OF EVIDENCE

Level IV.

Pediatric onco-nephrology: time to spread the word : Part I: early kidney involvement in children with malignancy

Onco-nephrology has been a growing field within the adult nephrology scope of practice. Even though pediatric nephrologists have been increasingly involved in the care of children with different forms of malignancy, there has not been an emphasis on developing special expertise in this area. The fast pace of discovery in this field, including the development of new therapy protocols with their own kidney side effects and the introduction of the CD19-targeted chimeric antigen receptor T cell (CAR-T) therapy, has introduced new challenges for general pediatric nephrologists because of the unique effects of these treatments on the kidney. Moreover, with the improved outcomes in children receiving cancer therapy come an increased number of survivors at risk for chronic kidney disease related to both their cancer diagnosis and therapy. Therefore, it is time for pediatric onco-nephrology to take its spot on the expanding subspecialties map in pediatric nephrology.

A Population Pharmacokinetic Modeling Approach to Determine the Efficacy of Intravenous Amikacin in Children with Cystic Fibrosis

BACKGROUND

In children with cystic fibrosis (CF), the currently recommended amikacin dose ranges between 30 and 35 mg/kg/d; however, data supporting this dosing efficacy are lacking. In this article, the objectives were to develop a nonparametric pharmacokinetic population model for amikacin in children with CF and investigate the efficacy and toxicity at different dose rates for distinct minimum inhibitory concentration (MIC) clinical breakpoints using Monte Carlo simulations.

METHODS

Data from 94 children with CF (613 serum concentrations) from the Bordeaux University Hospital's CF-centre were analyzed. After determination of nonparametric pharmacokinetic population model parameters and associated influent covariates in Pmetrics, 1000 Monte Carlo simulations were performed for 7 different dose rates between 30 and 60 mg/kg/d, to predict the probability of obtaining peak serum amikacin ≥10 × MIC and trough level ≤2.5 mg/L, for MIC values between 1 and 16 mg/L.

RESULTS

The median (min-max) age and weight were 10 (0.3-17) years and 29 (6-71) kg, respectively, with only 2 children younger than 1 year of age. Body weight and creatinine clearance significantly impacted the amikacin volume of distribution and clearance. The mean relative bias/root mean squared error between observed and individual predicted concentrations was -0.68%/8.1%. Monte Carlo simulations showed that for sensitive bacteria with MICs ≤ 4, 30 mg/kg/d was most appropriate for a 100% success rate; for bacteria with MICs ≥ 8 [eg, Pseudomonas aeruginosa (MICamikacin = 8)], a dose of at least 40 mg/kg/d allowed a high success probability (90%), with a trough level below 2.5 mg/L.

CONCLUSIONS

For intermediate pathogens, a dose of at least 40 mg/kg/d can improve efficacy, with an acceptable calculated residual trough level in cases of normal or hyperfiltration. Because amikacin undergoes renal clearance, which is immature until 1 year of age, dosing recommendations for this age group may be markedly high, warranting cautious interpretation.

Renal biopsy in children with IgA vasculitis

Introduction

Henoch-Schönlein purpura nephritis (HSN) is defined as Henoch-Schönlein purpura with kidney involvement, including hematuria and/or proteinuria. The aim of this study was to evaluate the data of HSN patients who underwent renal biopsy, and compare the main clinical and laboratory parameters that may affect renal biopsy findings, treatment protocols, and short- and long-term outcome of those patients.

Methods

Biopsies performed in 72 HSN patients between January 2007 to January 2017 were retrospectively evaluated. They were divided into two groups according to renal biopsy classification of the International Study of Kidney Disease in Children. Renal outcome, clinical and laboratory parameters, treatment protocols, and outcome were compared between groups. Short- and long-term follow-up of patients were evaluated.

Results

Of 72 patients, 47 were male (65.3%) and 44 (61.1%) were ≤10 years of age. Neutrophil-lymphocyte ratio was found higher in patients with scrotal involvement (p=0.042). Short-term unfavorable outcome was significantly higher in patients with scrotal involvement (p=0.038). Patients with hypertension and decreased creatinine clearance were found to have more unfavorable outcomes in long-term follow-up (p=0.029, p=0.040).

Conclusion

Cyclosporin-A and cyclophosphamide could be effective in steroid unresponsive HSN patients. Patients with scrotal involvement, decreased creatinine clearance, and hypertension should be closely monitored for sequelae of HSN.

Hyperuricemia Is an Early and Relatively Common Feature in Children with HNF1B Nephropathy but Its Utility as a Predictor of the Disease Is Limited

Background: Hyperuricemia is recognized as an important feature of nephropathy, associated with a mutation in the hepatocyte nuclear factor-1B (HNF1B) gene, and could serve as a useful marker of the disease. However, neither a causal relationship nor its predictive value have been proven. The purpose of this study was to assess this in children with renal malformations, both with (mut+) and without HNF1B mutations (mut-). Methods: We performed a retrospective analysis of clinical characteristics of pediatric patients tested for HNF1B mutations, collected in a national registry. Results: 108 children were included in the study, comprising 43 mut+ patients and 65 mut- subjects. Mean sUA was higher and hyperuricemia more prevalent (42.5% vs. 15.4%) in HNF1B carriers. The two groups were similar with respect to respect to age, sex, anthropometric parameters, hypertension, and renal function. Renal function, fractional excretion of uric acid and parathyroid hormone level were independent predictors of sUA. The potential of hyperuricemia to predict mutation was low, and addition of hyperuricemia to a multivariate logistic regression model did not increase its accuracy. Conclusions: Hyperuricemia is an early and common feature of HNF1B nephropathy. A strong association of sUA with renal function and parathyroid hormone limits its utility as a reliable marker to predict HNF1B mutation among patients with kidney anomalies.

Spectrum of Mutations in Pediatric Non-glomerular Chronic Kidney Disease Stages 2-5

Renal hypodysplasia and cystic kidney diseases, the common non-glomerular causes of pediatric chronic kidney disease (CKD), are usually diagnosed by their clinical and imaging characteristics. The high degree of phenotypic heterogeneity, in both conditions, makes the correct final diagnosis dependent on genetic testing. It is not clear, however, whether the frequencies of damaged alleles vary among different ethnicities in children with non-glomerular CKD, and this will influence the strategy used for genetic testing. In this study, 69 unrelated children (40 boys, 29 girls) of predominantly Han Chinese ethnicity with stage 2-5 non-glomerular CKD caused by suspected renal hypodysplasia or cystic kidney diseases were enrolled and assessed by molecular analysis using proband-only targeted exome sequencing and array-comparative genomic hybridization. Targeted exome sequencing discovered genetic etiologies in 33 patients (47.8%) covering 10 distinct genetic disorders. The clinical diagnoses in 13/48 patients (27.1%) with suspected renal hypodysplasia were confirmed, and two patients were reclassified carrying mutations in nephronophthisis (NPHP) genes. The clinical diagnoses in 16/20 patients (80%) with suspected cystic kidney diseases were confirmed, and one patient was reclassified as carrying a deletion in the hepatocyte nuclear factor-1-beta gene (HNF1B). The diagnosis of one patient with unknown non-glomerular disease was elucidated. No copy number variations were identified in the 20 patients with negative targeted exome sequencing results. NPHP genes were the most common disease-causing genes in the patients with disease onsets above 6 years of age (14/45, 31.1%). The children with stage 2 and 3 CKD at onset were found to carry causative mutations in paired box gene 2 (PAX2) and HNF1B gene (11/24, 45.8%), whereas those with stage 4 and 5 CKD mostly carried causative mutations in NPHP genes (19/45, 42.2%). The causative genes were not suspected by the kidney imaging patterns at disease onset. Thus, our data show that in Chinese children with non-glomerular renal dysfunction caused by renal hypodysplasia and cystic kidney diseases, the common causative genes vary with age and CKD stage at disease onset. These findings have the potential to improve management and genetic counseling of these diseases in clinical practice.

Acute Kidney Injury and Renal Tubular Damage in Children With Type 1 Diabetes Mellitus Onset

CONTEXT

Acute kidney injury (AKI) and renal tubular damage (RTD), especially if complicated by acute tubular necrosis (ATN), could increase the risk of later chronic kidney disease. No prospective studies on AKI and RTD in children with type1diabetes mellitus (T1DM) onset are available.

OBJECTIVES

To evaluate the AKI and RTD prevalence and their rate and timing of recovery in children with T1DM onset.

DESIGN

Prospective study.

SETTINGS AND PATIENTS

185 children were followed up after 14 days from T1DM onset. The patients who did not recover from AKI/RTD were followed-up 30 and 60 days later.

MAIN OUTCOME MEASURES

AKI was defined according to the KDIGO criteria. RTD was defined by abnormal urinary beta-2-microglobulin and/or neutrophil gelatinase-associated lipocalin and/or tubular reabsorption of phosphate < 85% and/or fractional excretion of Na (FENa) > 2%. ATN was defined by RTD+AKI, prerenal (P)-AKI by AKI+FENa < 1%, and acute tubular damage (ATD) by RTD without AKI.

RESULTS

Prevalence of diabetic ketoacidosis (DKA) and AKI were 51.4% and 43.8%, respectively. Prevalence of AKI in T1DM patients with and without DKA was 65.2% and 21.1%, respectively; 33.3% reached AKI stage 2, and 66.7% of patients reached AKI stage 1. RTD was evident in 136/185 (73.5%) patients (32.4% showed ATN; 11.4%, P-AKI; 29.7%, ATD). All patients with DKA or AKI presented with RTD. The physiological and biochemical parameters of AKI and RTD were normal again in all patients. The former within 14 days and the latter within 2months.

CONCLUSIONS

Most patients with T1DM onset may develop AKI and/or RTD, especially if presenting with DKA. Over time the physiological and biochemical parameters of AKI/RTD normalize in all patients.

Mean of creatinine clearance and urea clearance examined over 1 h estimates glomerular filtration rate accurately and precisely in children

AIM

Accurate and precise estimation of glomerular filtration rate (GFR) is essential in kidney disease. We evaluated the usefulness of the mean of creatinine clearance (C_Cr ) and urea clearance (C_UN ) examined over a 1-h urine collection period (1-h (C_Cr  + C_UN )/2) in a retrospective, cross-sectional study across two centres, as a relatively simple method for estimating GFR in children.

METHODS

Children aged ≤18 years who underwent inulin clearance (C_In ) tests were eligible. Two clearance values were obtained during a 2-h test consisting of two periods of 1 h each. The mean clearance in two periods was defined as 1-h clearance. 1-h (C_Cr  + C_UN )/2, 1-h C_Cr , 1-h C_UN and GFR estimated by Cr-based and cystatin C (CysC)-based formulas for Japanese children were compared with C_In . Bland-Altman plots were used to evaluate correlations. The primary outcome measure was the correlation between 1-h (C_Cr  + C_UN )/2 and C_In .

RESULTS

Fifty-three children were analysed. Their median age was 10.9 (interquartile range [IQR] 5.3-14.2) years, and median C_In and 1-h (C_Cr  + C_UN )/2 were 77.0 (IQR: 51.5-95.1) and 81.0 (IQR: 64.1-97.7) ml/min/1.73 m² , respectively. Percentage difference of C_In and 1-h (C_Cr  + C_UN )/2 in the Bland-Altman plot was -11.2% (95% confidence interval - 15.3% - -7.1%), with 95% lower and upper limits of agreement of -40.3% and 18.0%, respectively. Thus, 1-h (C_Cr  + C_UN )/2 was 1.12 times C_In .

CONCLUSION

1 h (C_Cr  + C_UN )/2 was almost concordant with C_In . 1-h (C_Cr  + C_UN )/2 can estimate GFR accurately and precisely, making it a simple and speedy test for use in clinical practice.

Optimizing Meropenem Therapy for Severe Nosocomial Infections in Neonates

Meropenem pharmacokinetics in neonates exhibits large interindividual variability due to developmental changes occurring during the first month of life. The objective was to characterize meropenem pharmacokinetics through a population approach to determine effective dosing recommendations in neonates with severe nosocomial infections. Three blood samples from forty neonates were obtained once steady-state blood levels were achieved and plasma concentrations were determined with a validated chromatographic method. Data were used to develop and validate the one-compartment with first-order elimination population pharmacokinetic model obtained by non-linear mixed effect modeling. The final model was Clearance (L/h) = 2.23 × Creatinine Clearance (L/h) and Volume of distribution(L) = 6.06 × Body Surface Area(m²) × (1 + 0.60 if Fluticasone comedication). Doses should be adjusted based on said covariates to increase the likelihood of achieving therapeutic targets. This model explains 12.9% of the interindividual variability for meropenem clearance and 19.1% for volume of distribution. Stochastic simulations to establish initial dosing regimens to maximize the time above the MIC showed that the mean probabilities to achieve the PK/PD target (PTA) for microorganisms with a MIC of 2 and 8 µg/mL were 0.8 and 0.7 following i.v. bolus of 250 and 500 mg/m²/dose q8h, respectively. Meropenem extended 4h infusion would improve PTA in neonates with augmented creatinine clearance.

Clinical characteristics of childhood acute tubulointerstitial nephritis

BACKGROUND

Acute tubulointerstitial nephritis (ATIN) is a rare cause of acute kidney injury in children that can lead to chronic kidney disease. The aim of this study was to describe the presenting features, etiology, and clinical characteristics of childhood ATIN, and to evaluate treatment modalities and renal outcomes.

METHODS

The study included 38 patients who had been diagnosed with ATIN, were younger than 18 years old, and were admitted for at least 6 months of follow up.

RESULTS

The median age at diagnosis was 13.1 years (range 1.2-16.6 years). The female / male ratio was 1.37. The most common symptoms were abdominal pain (65.7%) and nausea / vomiting (55.2%). Twenty-three of the patients had a history of drug intake (60.5%), and the most active drugs in the etiology were non-steroidal anti-inflammatory drugs (56.5%). Eleven patients were given steroid therapy due to severe kidney involvement and rapid increases in serum creatinine values, and ten of those patients were drug-related ATIN cases. Other patients were given symptomatic treatment. Four patients needed several sessions of dialysis due to the severity of their acute renal failure. The follow-up creatinine and estimated glomerular filtration rate levels were not statistically different between the symptomatic and corticosteroid treated groups (P > 0.05).

CONCLUSIONS

Although our study was unable to show the beneficial effect of corticosteroid therapy on the extent of renal recovery, the use of steroids may be preferable in severe nephritis because of the rapid recovery of estimated glomerular filtration rate with corticosteroid therapy.

Thoroughly Validated Bayesian Estimator and Limited Sampling Strategy for Dose Individualization of Ganciclovir and Valganciclovir in Pediatric Transplant Recipients

BACKGROUND AND OBJECTIVE

Given a high pharmacokinetic inter-individual variability and a low exposure target achievement, ganciclovir (GCV) therapeutic drug monitoring is sometimes used in children. We aimed to develop and validate Bayesian estimators based on limited sampling strategies for the estimation of GCV area under the concentration-time curve from 0 to 24 h in pediatric transplant recipients treated with valganciclovir (VGCV) or GCV.

METHODS

Solid organ transplant or stem-cell transplant recipients who received GCV or VGCV and had available GCV concentrations per standard of care were retrospectively included in this study for pharmacokinetic modeling and development of Bayesian estimators using the iterative two-stage Bayesian method. Validation datasets included additional child recipients of a solid organ transplant or stem-cell transplant, and child recipients of a kidney or liver transplant enrolled in a previous study. Various combinations of three or two sampling times, applicable in clinical practice, were assessed based on the relative mean bias, standard deviation, and the root mean square error in a development dataset and three independent validation datasets.

RESULTS

In the development dataset, the mean bias/standard deviation/root mean square error for the 1 h/2 h/3 h and 1 h/3 h limited sampling strategies were - 1.4%/9.3%/9.1% and - 3.5%/12.2%/12.3%, respectively for GCV, while for VGCV, the mean bias/standard deviation/root mean square error for the 1 h/2 h/6 h and 1 h/6 h limited sampling strategies were 0.7%/13.5%/13.3% and - 0.1%/12.1%/11.8%, respectively. In the independent validation datasets, seven (13%) and five (14%) children would have had misclassifications of their exposure using these Bayesian estimators and limited sampling strategies for VGCV and GCV, respectively.

CONCLUSIONS

Three plasma samples collected at 1 h/2 h/3 h and 1 h/2 h/6 h post-dose for GCV and VGCV respectively, are sufficient to accurately determine GCV area under the concentration-time curve from 0 to 24 h for pharmacokinetic-enhanced therapeutic drug monitoring.

Population Pharmacokinetics and Outcomes of Critically Ill Pediatric Patients Treated with Intravenous Colistin at Higher Than Recommended Doses

Limited pharmacokinetic (PK) data suggest that currently recommended pediatric dosages of colistimethate sodium (CMS) by the Food and Drug Administration and European Medicines Agency may lead to suboptimal exposure, resulting in plasma colistin concentrations that are frequently <2 mg/liter. We conducted a population PK study in 17 critically ill patients 3 months to 13.75 years (median, 3.3 years) old who received CMS for infections caused by carbapenem-resistant Gram-negative bacteria. CMS was dosed at 200,000 IU/kg/day (6.6 mg colistin base activity [CBA]/kg/day; 6 patients), 300,000 IU/kg/day (9.9 mg CBA/kg/day; 10 patients), and 350,000 IU/kg/day (11.6 mg CBA/kg/day; 1 patient). Plasma colistin concentrations were determined using ultraperformance liquid chromatography combined with electrospray ionization-tandem mass spectrometry. Colistin PK was described by a one-compartment disposition model, including creatinine clearance, body weight, and the presence or absence of systemic inflammatory response syndrome (SIRS) as covariates (P < 0.05 for each). The average colistin plasma steady-state concentration (C_ss,avg) ranged from 1.11 to 8.47 mg/liter (median, 2.92 mg/liter). Ten patients had C_ss,avg of ≥2 mg/liter. The presence of SIRS was associated with decreased apparent clearance of colistin (47.8% of that without SIRS). The relationship between the number of milligrams of CBA per day needed to achieve each 1 mg/liter of plasma colistin C_ss,avg and creatinine clearance (in milliliters per minute) was described by linear regression with different slopes for patients with and without SIRS. Nephrotoxicity, probably unrelated to colistin, was observed in one patient. In conclusion, administration of CMS at the above doses improved exposure and was well tolerated. Apparent clearance of colistin was influenced by creatinine clearance and the presence or absence of SIRS.

Factors predicting the recovery from acute kidney injury in children with primary nephrotic syndrome

BACKGROUND

The prognosis of acute kidney injury (AKI) varies in children with nephrotic syndrome (NS), data on factors predicting the recovery and recurrence of AKI in children with NS are limited. This study aimed to explore the possible factors predicting the recovery from and recurrence of AKI in children with primary NS.

METHODS

Children with primary NS complicated with AKI from 1993 to 2017 in a single centre were reviewed retrospectively. The clinical pictures and possible factors predicting the recovery from and recurrence of AKI in children with primary NS were investigated.

RESULTS

Sixty-eight episodes of AKI in 59 children with NS were analysed: 88.2% of AKI recovered within 3 months, and 2.9% of AKI did not recover after 3 months. Survival analysis revealed that leucocyturia is significantly related to the AKI recovery time (P = 0.001), and children with leucocyturia [22 (4, 79) days] recovered significantly slower than did children without leucocyturia [12.0 (2, 39) days]. Renal tubular and interstitial injury were prominent in children with leucocyturia, and 11.9% of children with index AKI experienced the recurrence of AKI.

CONCLUSIONS

Most episodes of AKI that occurred in children with NS recovered completely. Leucocyturia is a significant factor predicting the recovery time of AKI.

LAMB2 novel variant c.2885-9 C>A affects RNA splicing in a minigene assay

Background

Both Pierson syndrome (PS) and isolated nephrotic syndrome can be caused by LAMB2 biallelic pathogenic variants. Only 15 causative splicing variants in the LAMB2 gene have been reported. However, the pathogenicity of most of these variants has not been verified, which may lead to incorrect interpretation of the functional consequence of these variants.

Methods

Using high‐throughput DNA sequencing and Sanger sequencing, we detected variants in a female with clinically suspected PS. A minigene splicing assay was performed to assess the effect of LAMB2 intron 20 c.2885‐9C>A on RNA splicing. We also performed the immunohistochemical analysis of laminin beta‐2 in kidney tissues.

Results

Two novel LAMB2 heteroallelic variants were found: a paternally inherited variant c.2885‐9C>A in intron 20 and a maternally inherited variant c. 3658C>T (p. (Gln1220Ter)). In vitro minigene assay showed that the variant c.2885‐9C>A caused erroneous integration of a 7 bp sequence into intron 20. Immunohistochemical analysis revealed the absence of glomerular expression of laminin beta‐2, the protein encoded by LAMB2.

Conclusion

We demonstrated the impact of a novel LAMB2 intronic variant on RNA splicing using the minigene assay firstly. Our results extend the mutational spectrum of LAMB2.

Long-Term Outcome of Secondary Steroid-Resistant Nephrotic Syndrome in Chinese Children

Introduction

Secondary steroid-resistant nephrotic syndrome (SRNS) refers to the condition when patients with initial steroid-sensitive nephrotic syndrome develop steroid resistance in subsequent relapses. Long-term outcomes of secondary SRNS in children are uncertain.

Methods

This was a single-center retrospective study of 56 children with secondary SRNS between 2006 and 2016. The survival curve was estimated using the Kaplan-Meier method. Independent risk factors for end-stage renal disease (ESRD) were determined using Cox proportional hazards model.

Results

The median time from nephrotic syndrome onset to secondary SRNS was 7.8 months. Biopsy results at diagnosis secondary SRNS showed that 64.3% of cases were minimal change disease (MCD). No remission was observed in seven (12.5%) patients within the first year. The mean follow-up time was 7.8 ± 3.2 years. Eight patients were clinically cured, one died before ESRD, 10 reached ESRD, and 75.0% (3 of 4) of patients recurred post-transplantation. The 10-year ESRD-free survival rate was 85.8%. No response to intensified immunosuppression (IIS) in the first year was the independent predictor for ESRD. Repeat biopsies were performed in 20 cases, revealing that the reclassification from MCD to mesangial hypercellularity and focal segmental glomerulosclerosis (FSGS) in two when secondary steroid resistance appeared, from MCD and mesangial hypercellularity to FSGS in seven who developed multidrug resistance, and from FSGS to MCD and mesangial hypercellularity in two with favorable outcomes.

Conclusions

The long-term outcome in children with secondary SRNS was heterogeneous, and no response to IIS in the first year was the independent predictor for ESRD. In patients with repeat biopsy, changes in histological appearance to FSGS were associated with multidrug resistance.

Longitudinal growth patterns and final height in childhood-onset systemic lupus erythematosus

Patients with childhood-onset systemic lupus erythematosus (cSLE) are at risk of becoming short adults. To evaluate the growth patterns and risk factors of short final height, a retrospective study was conducted in 97 patients (87 females, 90%) with cSLE who grew from the time of diagnosis and reached their final height. The primary outcome was the final height. Participants were divided into participants with short final height (final height standard deviation score (HSDS) < - 2, n = 22, 23%) and participants with normal final height (final HSDS ≥ - 2, n = 75, 77%). At diagnosis, the mean age was 11.3 ± 2.4 years and HSDS was - 0.5 ± 1.3. The participants reached the final height of 1.51 ± 0.08 m (final HSDS - 1.3 ± 0.1) at mean age of 16.2 ± 2.3 years. The HSDS of participants with short final height steadily declined throughout the course of SLE (p = 0.02), and were significantly lower than participants with normal final height at any time point (p < 0.001). In participants with normal final height, HSDS significantly declined from baseline until 2 years after diagnosis (p = 0.01), and then became stable thereafter. The independent risk factors for short final height were the male sex, short stature at diagnosis, low body weight at final height, and cumulative corticosteroid dose.Conclusion: A substantial number of the participants with cSLE became short adults. Adequate nutrition and corticosteroid minimization should be emphasized in patients at high risk for short final height. What is known? • Growth failure is common in SLE due to many risk factors including chronic inflammation, malnutrition, and long-term use of corticosteroids. • In comparison to growth failure, final height is a better indicator of growth as the prevalence of growth failure is variable depending on definitions, patient age and pubertal status. What is new? • Nearly one fourth of children with SLE have short final height. • The independent risk factors for short final height were the male sex, short stature at diagnosis, low body weight at final height, and cumulative corticosteroid dose.

Non-invasive fibrosis assessments of non-alcoholic fatty liver disease associated with low estimated glomerular filtration rate among CKD patients: the Fukuoka Kidney disease Registry Study

BACKGROUND

A growing body of evidence has shown that non-alcoholic fatty liver disease (NAFLD) is associated with chronic kidney disease (CKD). Non-invasive fibrosis assessments of NAFLD such as Fibrosis-4 (FIB-4) index and NAFLD fibrosis score (NFS) have been developed to substitute liver biopsy. Little is known about the association between FIB-4 index or NFS and the components of CKD.

METHODS

In the present cross-sectional study, we assessed of 3640 Japanese CKD patients. We examined the association between FIB-4index or NFS and the odds of having low estimated glomerular filtration rate (eGFR) defined as eGFR < 60 mL/min/1.73 m² or albuminuria defined as urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g. Patients were divided into quartiles according to their baseline FIB-4 index and NFS levels. Linear and logistic regression analysis were conducted, with adjustment for potential confounding factors.

RESULTS

FIB-4 index and NFS were negatively associated with eGFR, but not UACR, after adjustment for potential confounding factors. Both FIB-4 index and NFS were significantly associated with low eGFR after adjustment for potential confounding factors. Meanwhile, in the multivariable-adjusted model, no associations were found between FIB-4 index or NFS and albuminuria. The addition of FIB-4 index or NFS to the established clinical CKD risk factors improved diagnostic accuracy of prevalence of low eGFR. We also found that there was a significant trend of higher FIB-4 index and NFS with more advanced renal fibrosis using the kidney biopsy data.

CONCLUSIONS

Higher non-invasive fibrosis assessments of NAFLD were associated with higher odds of decreased eGFR.

Age- and sex-dependent clinical equations to estimate glomerular filtration rates in children and young adults with chronic kidney disease

Using data (2655 observations from 928 participants) from the Chronic Kidney Disease in Children Study, we developed and internally validated new glomerular filtration rate estimating equations for clinical use in children and young adults: two forms of K × [heigh(ht) / serum creatinine(sCr)] and two forms of K × [1 / cystatin C(cysC)]. For each marker, one equation used a sex-dependent K; in the other, K is sex-and age-dependent. Glomerular filtration rate (GFR) was measured directly by plasma iohexol disappearance. The equations using ht⁄sCr had sex-specific constants of 41.8 for males and 37.6 for females. In the age- dependent models, K increased monotonically for children 1-18 years old and was constant for young adults 18-25 years. For males, K ranged from 35.7 for one-year-olds to 50.8 for those 18 and older. For females, the values of K ranged from 33.1 to 41.4. Constant K values for cystatin-C equations were 81.9 for males and 74.9 for females. With age-dependency, K varied non-monotonically with the highest values at age 15 for males (K of 87.2) and 12 years for females (K of 79.9). Use of an age-dependent K with ht/sCr models reduced average bias, notably in young children and young adults; age-dependent cystatin-C models produced similar agreement to using a constant K in children under 18 years, but reduced bias in young adults. These age-dependent proposed equations were evaluated alongside estimated GFRs from 11 other published equations for pediatrics and young adults. Only our proposed equations yielded non- significant bias and within 30% accuracy values greater than 85% in both the pediatric and young adult subpopulations.

Serum uric acid and blood pressure among adolescents: data from the Nutrition and Health Survey in Taiwan (NAHSIT) 2010-2011

PURPOSE

Elevated serum uric acid (UA) is frequently observed in adults with high blood pressure (BP); however, data from adolescents are limited. We examined the association between serum UA and BP in a nationally representative sample of Taiwan adolescents.

MATERIAL AND METHODS

Some 1384 participants, aged 14-19 years, from the Nutrition and Health Survey in Taiwan 2010-2011 were included for the study. Elevated BP was defined as systolic or diastolic BP ≥120/80 mmHg. The analyses examined the relationship between serum UA and BP using linear regression and odds ratios of having an elevated BP using logistic regression.

RESULTS

In this study population, the mean age was 16.0 years, mean serum UA was 5.8 mg/dL, 22.5% were obese (body mass index ≥24 kg/m2) and 9.8% had an elevated BP. Compared to girls, boys are more likely to be obese and to have higher serum UA and BP. After full adjustments, systolic BP, diastolic BP and mean arterial pressure increased 0.45, 0.48 and 0.47 mmHg, respectively, for each 1-mg/dL increase in UA (p = 0.07, 0.03 and 0.02, respectively). The odds of having an elevated BP were 3.4 times higher in subjects of the upper tertile of serum UA than those of the lower tertile (p = 0.02).

CONCLUSION

Adolescents with factors as male, obesity, and UA ≥5.5 mg/dL were prone to have an elevated BP, regardless of age and family history of hypertension. The present study found that serum UA levels are significantly correlated to BP in Taiwanese adolescents.

Population Pharmacokinetic Study of Cefathiamidine in Infants With Augmented Renal Clearance

Objectives: Augmented renal clearance (ARC) of primarily renally eliminated antibacterial agents may result in subtherapeutic antibiotic concentrations and, as a consequence, worse clinical outcomes. Cefathiamidine is frequently used as empirical antimicrobial therapy in children with ARC, but pharmacokinetic studies in infants are lacking. This population pharmacokinetic study in infants with ARC was conducted to determine optimal dosing regimens of cefathiamidine.

Methods: The population pharmacokinetics was conducted in 20 infants treated with cefathiamidine. Plasma samples of cefathiamidine were collected using opportunistic sampling, and the concentrations were detected by UPLC-MS/MS. Data analysis was performed to determine pharmacokinetic parameters and to characterize pharmacokinetic variability of cefathiamidine using nonlinear mixed effects modelling (NONMEM) software program.

Results: The data (n = 36) from 20 infants (age range, 0.35–1.86 years) with ARC were fitted best with a 1-compartment model. Allometrically scaled weight and age as significant covariates influenced cefathiamidine pharmacokinetics. The median (range) values of estimated clearance and the volume of distribution were 0.22 (0.09–0.29) L/h/kg and 0.34 (0.24–0.41) L/kg, respectively. Monte Carlo simulations showed that the cefathiamidine doses of 100 mg/kg/day q12 h, 50 mg/kg/day q8 h and 75 mg/kg/day q6 h were chosen for bacteria with MIC 0.25, 0.5 and 2 mg/L, respectively.

Conclusion: The population pharmacokinetic model of cefathiamidine for infants with ARC was developed. The PTA - based dosing regimens were recommended based on the final model.

Determination of vancomycin exposure target and individualised dosing recommendations for neonates: model-informed precision dosing

INTRODUCTION

Few studies incorporating population pharmacokinetic/pharmacodynamic (Pop-PK/PD) modelling have been conducted to quantify the exposure target of vancomycin in neonates. A retrospective observational cohort study was undertaken in neonates to determine this target and dosing recommendations (chictr.org.cn, ChiCTR1900027919).

METHODS

A Pop-PK model was developed to estimate PK parameters. Causalities between acute kidney injury (AKI) occurrence and vancomycin use were verified using Naranjo criteria. Thresholds of vancomycin exposure in predicting AKI or efficacy were identified via classification and regression tree analysis. Associations between exposure thresholds and clinical outcomes, including AKI and efficacy, were analysed by logistic regression. Dosing recommendations were designed using Monte Carlo simulations based on the optimised exposure target.

RESULTS

Pop-PK modelling included 182 neonates with 411 observations. On covariate analysis, neonatal physiological maturation, renal function and concomitant use of vasoactive agents (VAS) significantly affected vancomycin PK. Seven cases of vancomycin-induced AKI were detected. Area under the concentration-time curve from 0-24 hours (AUC_0-24) ≥ 485 mg•h/L was an independent risk factor for AKI after adjusting for VAS co-administration. The clinical efficacy of vancomycin was analysed in 42 patients with blood culture-proven staphylococcal sepsis. AUC_0-24 to minimum inhibitory concentration (AUC_0-24/MIC) ≥ 234 was the only significant predictor of clinical effectiveness. Monte Carlo simulations indicated that regimens in Neonatal Formulary 7 and Red Book (2018) were unsuitable for all neonates.

CONCLUSION

An AUC_0-24 of 240-480 (assuming MIC = 1 mg/L) is a recommended exposure target of vancomycin in neonates. Model-informed dosing regimens are valuable in clinical practice.

Prevalence of and factors associated to chronic kidney disease and hypertension in a cohort of children with juvenile idiopathic arthritis

We evaluated chronic kidney disease (CKD) (proteinuria or estimated glomerular filtration rate < 60 mL/min/1.73 m2) or hypertension prevalence in 110 children with juvenile idiopathic arthritis (JIA). CKD and hypertension were clustered under the umbrella term of "renal injury". Median age at the last visit was 14 years. Nine out of 110 (8.1%) patients showed renal injury (8 hypertension, 1 proteinuria). Patients with renal injury presented higher age at last visit, longer duration of active JIA, shorter intervals free from JIA relapses, longer duration of non-steroidal anti-inflammatory drugs (NSAIDs) treatment but with similar cumulative NSAIDs dose and higher rate of methotrexate (MTX) prescription, longer time of MTX administration, and higher cumulative MTX dose compared to patients without renal injury. At the last visit, patients with and without renal injury presented similar prevalence of active disease. The cumulative proportion of patients free from renal injury at 240 months since JIA onset was 40.72% for all population; while the cumulative proportion was 23.7% for patients undergoing NSAIDs+MTX treatment and 100% for those undergoing NSAIDs (p = 0.039) treatment.Conclusion:About 8% of the children with JIA develop hypertension or CKD. The main risk factor was longer exposure to both NSAIDs and MTX due to a more severe form of the disease. What is Known •Anecdotal reports showed that rarely juvenile idiopathic arthritis (JIA) could present renal involvement due to prolonged and uncontrolled inflammation (renal amyloidosis) or to long exposure to anti-rheumatic drugs. •No cohort studies investigated renal health in children with JIA. What is new •About 8% of the children with JIA developed hypertension or chronic kidney disease. •The main risk factor was long exposure to non-steroidal anti-inflammatory drugs and methotrexate for patients suffering from a more severe form of the disease. •In JIA patients, periodic evaluation of renal function, blood pressure and proteinuria should be warranted.

Population pharmacokinetics of ganciclovir and valganciclovir in paediatric solid organ and stem cell transplant recipients

AIMS

Ganciclovir (GCV) and its prodrug valganciclovir (VGCV) are first-line agents to prevent and treat cytomegalovirus in transplant recipients. There is high pharmacokinetic (PK) interindividual variability and PK data are scarce, especially in paediatric stem cell transplant (SCT) recipients. We sought to determine the optimal GCV and VGCV dosing in transplanted children.

METHODS

We conducted a single-centre retrospective population PK (POPPK) study of IV GCV and enteral VGCV in paediatric solid organ transplant (SOT) and SCT recipients. We included children who were transplanted and had available plasma GCV concentrations, done per standard of care. POPPK analysis was performed using a nonlinear mixed effects modelling approach with NONMEM. Optimal dosing was determined based on the achievement of the surrogate efficacy target: GCV 24 h area under the concentration-time curve (AUC_0-24h ) of 40-60 mg.h.L^-1 .

RESULTS

Fifty children with a median [range] age of 7.5 years [0.5-17.4] contributed 580 PK samples. A two-compartment model with first-order absorption with a lag time and first-order elimination fit the data well. Creatinine clearance and body weight (WT) were significant covariates for GCV clearance (CL); and WT for the volumes of distribution. IV GCV 15-20 mg.kg^-1 .day^-1 divided every 12 hours achieved the highest probability of target achievement (PTA) (33.0-33.8%). Enteral VGCV 30 and 40 mg.kg^-1 .day^-1 divided every 12 hours in children 0-<6 years, and 6-18 years, respectively, achieved the highest PTA (29.1-33.0%).

CONCLUSION

This is the first POPPK model developed in children with either SOT or SCT. Concentration target achievement was low, suggesting a potential benefit for therapeutic drug monitoring to ensure optimal exposure.

Safety and diagnostic efficacy of gadoteridol for magnetic resonance imaging of the brain and spine in children 2 years of age and younger

BACKGROUND

Neonates and young children require efficacious magnetic resonance imaging (MRI) examinations but are potentially more susceptible to the short- and long-term adverse effects of gadolinium-based contrast agents due to the immaturity of their body functions.

OBJECTIVE

To evaluate the acute safety and diagnostic efficacy of gadoteridol (ProHance) for contrast-enhanced MRI of the central nervous system (CNS) in children ≤2 years of age.

MATERIALS AND METHODS

One hundred twenty-five children ≤2 years old (including 57 children <6 months old) who underwent contrast-enhanced MRI of the CNS with gadoteridol at 0.1 mmol/kg body weight were retrospectively enrolled at five imaging centers. Safety data were assessed for acute/subacute adverse events in the 48 h following gadoteridol administration and, when available, vital signs, electrocardiogram (ECG) and clinical laboratory values obtained from blood samples taken from 48 h before until 48 h following the MRI exam. The efficacy of gadoteridol-enhanced MRI compared to unenhanced MRI for disease diagnosis was evaluated prospectively by three blinded, unaffiliated readers.

RESULTS

Thirteen changes of laboratory values (11 mild, 1 moderate, 1 unspecified) were reported as adverse events in 7 (5.6%) patients. A relationship to gadoteridol was deemed possible though doubtful for two of these adverse events in two patients (1.6%). There were no clinical adverse events, no serious adverse events and no clinically meaningful changes in vital signs or ECG recordings. Accurate differentiation of tumor from non-neoplastic disease, and exact matching of specific MRI-determined diagnoses with on-site final diagnoses, was achieved in significantly more patients by each reader following the evaluation of combined pre- and post-contrast images compared to pre-contrast images alone (84.6-88.0% vs. 70.9-76.9%; P≤0.006 and 67.5-79.5% vs. 47.0-66.7%; P≤0.011, respectively).

CONCLUSION

Gadoteridol at 0.1 mmol/kg body weight is safe, well tolerated and effective for contrast-enhanced MRI of the CNS in children ≤2 years of age.