History of Childhood Kidney Disease and Risk of Adult End-Stage Renal Disease

Label-free investigation of infected acute pyelonephritis tissue by FTIR microspectroscopy with unsupervised and supervised analytical methods

Acute pyelonephritis (AP) is a severe urinary tract infection (UTI) syndrome with a large population of patients worldwide. Current approaches to confirming AP are limited to urinalysis, radiological imaging methods and histological assessment. Fourier transform infrared (FTIR) microspectroscopy is a promising label-free modality that can offer information about both morphological and molecular pathologic alterations from biological tissues. Here, FTIR microspectroscopy serves to investigate renal biological histology of a rat model with AP and classify normal cortex, normal medulla and infected acute pyelonephritis tissues. The spectra were experimentally collected by FTIR with an infrared Globar source through raster scanning procedure. Unsupervised analysis methods, including integrating, clustering and principal component analysis (PCA) were performed on such spectra data to form infrared histological maps of entire kidney section. In comparison to Hematoxylin & Eosin-stained results of the adjacent tissue sections, these infrared maps were proved to enable the differentiation of the renal tissue types. The results of both integration and clustering indicated that the concentration of amide II decreases in the infected acute pyelonephritis tissues, with an increased presence of nucleic acids and lipids. By means of PCA, the infected tissue was linearly separated from normal ones by plotting confident ellipses with the score values of the first and second principal components. Moreover, supervised analysis was performed based on the supported vector machines (SVM). Normal cortex, normal medulla and infected acute pyelonephritis tissues were classified by SVM models with the best accuracy of 96.11% in testing dataset. In addition, these analytical methods were further employed on synchrotron-based FTIR spectra data and successfully form high-resolution infrared histological maps of glomerulus and necrotic cell mass. This work demonstrates that FTIR microspectroscopy will be a powerful manner to investigate AP tissue and differentiate infected tissue from normal tissue in a renal infected model system.

[Current clinical application of glomerular filtration rate assessment methods in pediatric populations]

Glomerular filtration rate (GFR) is a critical indicator of renal function assessment, which exhibits age-dependency in children and may differ from adults under various disease conditions. In recent years, there has been a growing focus on GFR among scholars, with an increasing number of clinical studies dedicated to refining and optimizing GFR estimation to span all pediatric age groups. However, the methods and assessment equations for estimating GFR may vary under different disease conditions, affecting the accuracy and applicability of assessments. This article reviews the peculiarities of renal function in children, explores GFR measurement methods, and evaluates the application of various GFR assessment equations in pediatric clinical practice, providing a reference for clinical assessment of renal function in children.

Long-Term Kidney Outcomes in Children with Posterior Urethral Valves: A Population-Based Cohort Study

Key Points

Background

Posterior urethral valves represent the most common cause of lower urinary tract obstruction in male infants (approximately 1/4000 live births). Long-term kidney outcomes of posterior urethral valves remain uncertain. We aimed to determine the time-varying risk of major adverse kidney events (MAKE) following children with posterior urethral valves into adulthood.

Methods

A population-based retrospective cohort study of all male children (<2 years) diagnosed with posterior urethral valves between 1991 and 2021 in Ontario, Canada. Comparator cohorts were (1) male general population and (2) male children with pyeloplasty (both <2 years). The primary outcome was MAKE (death, long-term KRT [dialysis or kidney transplant], or CKD). Time to MAKE was analyzed using multivariable-adjusted Cox proportional hazards models. We censored for provincial emigration or administrative censoring (March 31, 2022).

Results

We included 727 children with posterior urethral valves, 855 pyeloplasty comparators, and 1,013,052 general population comparators. The median follow-up time was 16.6 years (Q1–3, 8.6–24.5) overall. Throughout follow-up, 32% of children with posterior urethral valves developed MAKE versus 1% of the general population and 6% of pyeloplasty comparators. Their adjusted hazard ratio for MAKE was 36.6 (95% confidence interval, 31.6 to 42.4) versus the general population. The risk of developing MAKE declined over the first 5 years after posterior urethral valves diagnosis but remained elevated for >30-year follow-up. Children with posterior urethral valves were also at higher risk of death, CKD, long-term KRT, hypertension, and AKI than the general population or pyeloplasty comparators.

Conclusions

Children with posterior urethral valves are at higher risk of adverse long-term kidney outcomes well into adulthood.

Outcome 10 years after Shiga toxin-producing E. coli (STEC)-associated hemolytic uremic syndrome: importance of long-term follow-up

BACKGROUND

Hemolytic uremic syndrome (HUS) is an important cause of acute kidney injury in children. HUS is known as an acute disease followed by complete recovery, but patients may present with kidney abnormalities after long periods of time. This study evaluates the long-term outcome of Shiga toxin-producing Escherichia coli-associated HUS (STEC-HUS) in pediatric patients, 10 years after the acute phase of disease to identify risk factors for long-term sequelae.

METHODS

Over a 6-year period, 619 patients under 18 years of age with HUS (490 STEC-positive, 79%) were registered in Austria and Germany. Long-term follow-up data of 138 STEC-HUS-patients were available after 10 years for analysis.

RESULTS

A total of 66% (n = 91, 95% CI 0.57-0.73) of patients fully recovered showing no sequelae after 10 years. An additional 34% (n = 47, 95% CI 0.27-0.43) presented either with decreased glomerular filtration rate (24%), proteinuria (23%), hypertension (17%), or neurological symptoms (3%). Thirty had sequelae 1 year after STEC-HUS, and the rest presented abnormalities unprecedented at the 2-year (n = 2), 3-year (n = 3), 5-year (n = 3), or 10-year (n = 9) follow-up. A total of 17 patients (36.2%) without kidney abnormalities at the 1-year follow-up presented with either proteinuria, hypertension, or decreased eGFR in subsequent follow-up visits. Patients needing extracorporeal treatments during the acute phase were at higher risk of presenting symptoms after 10 years (p < 0.05).

CONCLUSIONS

Patients with STEC-HUS should undergo regular follow-up, for a minimum of 10 years following their index presentation, due to the risk of long-term sequelae of their disease. An initial critical illness, marked by need of kidney replacement therapy or plasma treatment may help predict poor long-term outcome.

Evaluation of differential renal function in children - a comparative study between magnetic resonance urography and dynamic renal scintigraphy

BACKGROUND

Urinary system anomalies, both congenital and acquired, constitute a relatively common clinical problem in children. The main role of diagnostic imaging is to determine early diagnosis and support therapeutic decisions to prevent the development of chronic renal disease. The aim of this study was to evaluate the utility of magnetic resonance urography (MRU) in assessment of urinary system in children, by comparing differential renal function calculated using MRU with dynamic renal scintigraphy (DRS).

MATERIALS AND METHODS

The study group consisted of 46 patients aged 1 week to 17 years (median 7 (0.5; 13) years, 17 (37%) girls, 29 (63%) boys), who underwent dynamic renal scintigraphy due to various clinical reasons. All participants underwent MRU, which was used to measure differential renal function. Functional analysis was performed using dedicated external software (CHOP-fMRU and pMRI without prior knowledge of DRS results. MRU results acquired using pMRI were assessed for inter and intraobserver agreement.

RESULTS

Statistical analysis of the results showed excellent agreement between MRU and DRS in measuring differential renal function with Pearson correlation coefficient 0.987 for CHOP-fMRU and 0.971 for pMRI, p < 0.001. Interclass correlation coefficient (ICC) for these programs was 0.987 (95% CI 0.976-0.993) and 0.969 (95% CI 0.945-0.983) respectively, p < 0.001. The Bland-Altman 95% limits of agreement for CHOP-fMRU results vs. DRS was - 6.29-5.50 p.p. and for pMRI results vs. DRS - 9.15-9.63 p.p. The differential renal function measurements calculated in pMRI showed excellent intraobserver and interobserver agreement with ICC 0.996 (95% CI 0.994-0.998) and 0.992 (95% CI 0.986-0.996) respectively, p < 0.001.

CONCLUSIONS

The study showed no significant differences between magnetic resonance urography and dynamic renal scintigraphy in calculating differential renal function. It indicates high utility of MRU in the evaluation of urinary system in children.

Association between albumin-corrected anion gap level and the risk of acute kidney injury in intensive care unit

PURPOSE

This study was to investigate the association between albumin-corrected anion gap (AG) (ACAG) levels and the risk of acute kidney injury (AKI) in intensive care unit (ICU) patients.

METHODS

The ICU patients of this retrospective cohort study were collected from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database between 2008 and 2019. ACAG = AG + {4.4 - [albumin (g/dl)]} × 2.5. The incidence of AKI was determined using the Kidney Disease: Improving Global Outcomes (KDIGO) definition. The logistic regression model was used to evaluate the association between ACAG levels and the risk of AKI. Subgroup analyses were applied based on age, gender, mechanical ventilation, vasopressors, the Charlson comorbidity index (CCI), and the Simplified Acute Physiology Score II (SAPS II).

RESULTS

Totally, 5586 patients were enrolled, of which 1929 patients (34.53%) occurred AKI. The higher levels of ACAG were associated with the risk of AKI in ICU patients, with the odds ratio (OR) value being 1.23 [95% confidence interval (CI): 1.22-1.24, P = 0.005] in ACAG level between 16.5 and 19.5, and OR value being 1.20 (95% CI 1.16-1.24, P = 0.016) in ACAG level > 19.5. A higher ACAG level was associated with a higher risk of AKI in ICU patients aged < 65 years, in ICU patients of female gender, in ICU patients who used mechanical ventilation, in ICU patients who did not use vasopressors, in patients without cardiogenic shock, and in ICU patients with CCI ≥ 2, and SAPS II > 31 (all P < 0.05).

CONCLUSION

There is an association between ACAG level and the risk of AKI in ICU patients. A higher ACAG value in ICU patients should therefore receive more attention.

Ensuring our exstrophy-epispadias complex patients and families thrive

Individuals with bladder exstrophy-epispadias complex (EEC) need long-term integrated medical/surgical and psychosocial care. These individuals are at risk for medical and surgical complications and experience social and psychological obstacles related to their genitourinary anomaly. This care needs to be accessible, comprehensive, and coordinated. Multiple surgical interventions, reoccurring hospitalizations, urinary and fecal incontinence, extensive treatment regimens for continent diversions, genital differences, and sexual health implications affect the quality of life for the EEC patient. Interventions must include psychosocial support, medical literacy initiatives, behavioral health services, school and educational consultation, peer-to-peer opportunities, referrals to disease-specific camps, mitigation of adverse childhood events (ACEs), formal transition of care to adult providers, family and teen advisory opportunities, and clinical care coordination. The priority of long-term kidney health will necessitate strong collaboration among urology and nephrology teams. Given the rarity of these conditions, multi-center and global efforts are paramount in the trajectory of improving care for the EEC population. To achieve the highest standards of care and ensure that individuals with EEC can thrive in their environment, multidisciplinary and integrated medical/surgical and psychosocial services are imperative.

Adult survivors of childhood-onset steroid-dependent and steroid-resistant nephrotic syndrome treated with cyclosporine: a long-term single-center experience

BACKGROUND

Although evidence has confirmed that cyclosporine (CS) is efficacious against childhood-onset steroid-dependent and steroid-resistant nephrotic syndrome (SD/SRNS), some patients may continue to relapse during adulthood. However, predictive factors for adult active disease and kidney complications, such as chronic kidney disease (CKD) and hypertension, in this cohort remain unknown.

METHODS

We conducted a retrospective study on the long-term outcomes of 81 young adults with childhood-onset SD/SRNS treated with CS. The primary endpoint was the probability of active disease into adulthood. The secondary endpoint was the probability of developing kidney complications.

RESULTS

At the last follow-up (median age, 23.2 years; median disease duration, 15.8 years), 44 adult patients (54%) continued to have active disease, whereas 16 patients developed CKD or hypertension, respectively. The proportion of patients developing kidney complications was similar between the active disease and long-term remission groups. Young age at NS onset and history of relapse during the initial CS (median, 31 months) were independent predictive factors for active disease. Acute kidney injury at NS onset, focal segmental glomerulosclerosis, and irreversible CS nephrotoxicity were identified as risk factors for the development of CKD, whereas older age was identified as a risk factor for the development of CKD and hypertension.

CONCLUSIONS

More than 50% of adult survivors treated with CS continued to have active disease, and each 20% developed CKD or hypertension. A long-term follow-up is necessary for patients with SD/SRNS to identify the development of kidney complications later in adulthood that can be attributed to prior disease and CS treatment in childhood, irrespective of disease activity. A higher resolution version of the Graphical abstract is available as Supplementary information.

Comparison of clean catch and bag urine using LC-MS/MS proteomics in infants

BACKGROUND

Urinary proteomics identifies the totality of urinary proteins and can therefore help in getting an early and precise diagnosis of various pathological processes in the kidneys. In infants, non-invasive urine collection is most commonly accomplished with a urine bag or clean catch. The influence of those two collection methods on urinary proteomics was assessed in this study.

METHODS

Thirty-two urine samples were collected in infants using urine bag and clean catch within 24 h. Nine boys and seven girls with a mean age of 4.3 ± 2.9 months were included (5 × post-pyelonephritis, 10 × non-kidney disease, 1 × chronic kidney disease (CKD)). Liquid chromatography-mass spectrometry (LC-MS/MS) was performed in data-independent acquisition (DIA) mode. Protein identification and quantification were achieved using Spectronaut.

RESULTS

A total of 1454 urinary proteins were detected. Albumin and α-1-microglobulin were detected the most. The 18 top-abundant proteins accounted for 50% of total abundance. The number of proteins was slightly, but insignificantly higher in clean catch (957 ± 245) than in bag urine (876 ± 255). The median intensity was 1.2 × higher in the clean catch. Overall, differential detection of proteins was 29% between the collection methods; however, it diminished to 3% in the 96 top-abundant proteins. Pearson's correlation coefficient was 0.81 ± 0.11, demonstrating a high intraindividual correlation. A principal component analysis and a heat map showed clustering according to diagnoses and patients rather than to the collection method.

CONCLUSION

Urinary proteomics shows a high correlation with minor variation in low-abundant proteins between the two urine collection methods. The biological characteristics overrule this variation. Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information.

Implementation of a standardized clinical pathway in a dedicated posterior urethral valves clinic: short-term outcomes

BACKGROUND

To determine if the implementation of a posterior urethral valves (PUV) clinic and standardized management pathway improves the short-term kidney outcomes of infants with PUV.

METHODS

From 2016-2022, 50 consecutive patients were divided into groups after the implementation of the clinic (APUV, n = 29) and before (BPUV, n = 21) during a comparable timeframe. Assessed data included age at initial visit, timing and type of surgery, frequency of follow-up visits, medications, nadir creatinine, and development of CKD/kidney failure. Data are shown as median with interquartile range (IQR) and odds ratios (OR) with 95% confidence interval (CI).

RESULTS

APUV had higher rates of prenatal diagnoses (12/29 vs. 1/21; p = 0.0037), earlier initial surgical intervention (8 days; IQR 0, 105 vs. 33 days; IQR 4, 603; p < 0.0001), and higher rates of primary diversions (10/29 vs. 0/21; p = 0.0028). Standardized management led to earlier initiation of alpha blockers (326 days; IQR 6, 860 vs. 991; IQR 149, 1634; p = 0.0019) and anticholinergics (57 days; IQR 3, 860 vs. 1283 days; IQR 477, 1718; p < 0.0001). Nadir creatinine was reached at earlier ages in APUV (105 days; IQR 2, 303 vs. 164 days; IQR 21, 447; p = 0.0192 BPUV). One patient progressed to CKD5 in APUV compared to CKD3, CKD5 and one transplant in BPUV.

CONCLUSION

Implementing the PUV clinic with standardized treatment expedited postnatal management and resulted in a higher number of cases detected prenatally, a shift in primary treatment, younger ages at initial treatment, reduced time to nadir creatinine, and timely initiation of supportive medications. A higher resolution version of the Graphical abstract is available as Supplementary information.

Recessive CHRM5 variant as a potential cause of neurogenic bladder

Neurogenic bladder is caused by disruption of neuronal pathways regulating bladder relaxation and contraction. In severe cases, neurogenic bladder can lead to vesicoureteral reflux, hydroureter, and chronic kidney disease. These complications overlap with manifestations of congenital anomalies of the kidney and urinary tract (CAKUT). To identify novel monogenic causes of neurogenic bladder, we applied exome sequencing (ES) to our cohort of families with CAKUT. By ES, we have identified a homozygous missense variant (p.Gln184Arg) in CHRM5 (cholinergic receptor, muscarinic, 5) in a patient with neurogenic bladder and secondary complications of CAKUT. CHRM5 codes for a seven transmembrane-spanning G-protein-coupled muscarinic acetylcholine receptor. CHRM5 is shown to be expressed in murine and human bladder walls and is reported to cause bladder overactivity in Chrm5 knockout mice. We investigated CHRM5 as a potential novel candidate gene for neurogenic bladder with secondary complications of CAKUT. CHRM5 is similar to the cholinergic bladder neuron receptor CHRNA3, which Mann et al. published as the first monogenic cause of neurogenic bladder. However, functional in vitro studies did not reveal evidence to strengthen the status as a candidate gene. Discovering additional families with CHRM5 variants could help to further assess the genes' candidate status.

Development of a Family-Centered Communication Tool for Kidney Health in Premature Infants: Qualitative Focus Group Study Using Human-Centered Design Methodology

BACKGROUND

Premature infants are at increased risk of kidney-related complications, including acute kidney injury (AKI) and chronic kidney disease (CKD). The risk of CKD in prematurely born infants is underrecognized by health care teams and caregivers. Understanding how to communicate the risk of CKD to caregivers is essential for longitudinal clinical follow-up and adherence.

OBJECTIVE

This study aimed to determine family caregiver attitudes toward kidney health and risk communication during a neonatal intensive care admission. We also sought to understand caregiver preferences for the communication of information surrounding the risk of CKD in premature infants.

METHODS

We augmented standard qualitative group sessions with human-centered design methods to assess parent preferences and clinician perspectives. Caregivers recruited had a prematurely born child who spent time in the neonatal intensive care unit at Riley Hospital for Children in Indianapolis, Indiana, and experienced AKI or another kidney complication, which put them at risk for future CKD. We used a variety of specific design methods in these sessions, including card sorting, projective methods, experience mapping, and constructive methods.

RESULTS

A total of 7 clinicians and 8 caregivers participated in 3 group sessions. Caregivers and clinicians readily acknowledged barriers to and drivers of long-term kidney monitoring as well as opportunities for communication of the risk of long-term kidney disease. Caregivers' primary concerns were for both the type and depth of information conveyed as well as the time at which it was communicated. Participants emphasized the importance of collaboration between the hospital care team and the primary care provider. Participant input was synthesized into several prototype concepts and, ultimately, into a rough prototype of a website and an informational flyer.

CONCLUSIONS

Caregivers of premature infants are open to communication about kidney health during their neonatal admission. The next phase of this work will translate caregivers' preferences into family-centered communication tools and test their efficacy in the neonatal intensive care unit.

Use of Female External Urinary Catheters in a Burn Intensive Care Unit: Benefits and Challenges

BACKGROUND

Burn patients have a relatively high rate of indwelling Foley catheter use because of their need for complex fluid management and wound care. However, Foley catheter use is associated with risks, including urinary tract infection. For female patients, an external urinary catheter is an alternative.

OBJECTIVES

To evaluate the use of female external urinary catheters in a burn intensive care unit and to develop a standard protocol.

METHODS

This study involved female patients admitted to a burn intensive care unit from 2017 to 2020. An initiative to increase the use of female external urinary catheters was begun in 2019. A retrospective review of medical records was used to determine rates of indwelling and external catheter use and of catheter-associated urinary tract infection before and after implementation of the initiative.

RESULTS

Of 77 female burn patients admitted to the unit between 2019 and 2020, 56 (73%) required indwelling Foley catheterization, a significant decrease from 94% before the initiative (P = .002). The mean duration of indwelling Foley catheter use decreased significantly from 19.4 days to 10.47 days (P = .049). Female external urinary catheters were used in 21 patients (27%). No patients with female external urinary catheters contracted urinary tract infections, compared with 9 patients with indwelling Foley catheters.

CONCLUSION

The use of female external urinary catheters may help reduce the risk of urinary tract infection in female burn patients. Further research is needed to refine the protocol for use of these devices and determine their safety profile.

The spectrum and changes of biopsy-proven kidney diseases in Chinese children

AIM

The study aimed to investigate the spectrum of biopsy-proven kidney disease in Chinese children.

METHODS

Records of children 0-17 years old who underwent native kidney biopsy from June 1st, 2013 to December 31st, 2018 in the national inpatients' database of China were analyzed. Biopsy-proven kidney diseases of different sex, age groups, and diagnosis, and the changing patterns of kidney disease compared with the previous study were analyzed.

RESULTS

A total of 21,311 patients from 232 hospitals with a median age of 11.34 years were included. Immunoglobulin A vasculitis with nephritis (IgAVN) was the most common pathological finding [29.17%, 95% confidence interval (confidence interval, CI) = 28.56-29.78], followed by IgA nephropathy (IgAN) (22.70%, 95% CI = 22.14-23.27). IgAN was the most common finding in patients with hematuria (60.75%, 95% CI = 58.83-62.65], proteinuria (33.43%, 95% CI = 30.54-36.42), and hematuria plus proteinuria (62.77%, 95% CI = 56.19-69.02). Minimal change disease was the most common finding (40.69%, 95% CI = 39.41-41.98) in nephrotic syndrome. The proportion of IgAVN in patients with biopsy-proven glomerular disease increased year by year during 2013-2018 (p for trend < 0.001) and was higher than that of 2004-2014 [29.41% (95% CI = 29.10-29.72) in 2013-2018 vs. 13.35% (95% CI = 12.97-13.73) 2004-2014, p < 0.001]. The proportion of hepatitis B virus associated nephritis during 2013-2018 was lower than that of  2004-2014 [0.44% (95% CI = 0.36-0.54) in 2013-2018 vs. 0.87% (95% CI = 0.67-1.10) in 2004-2014, p < 0.001].

CONCLUSIONS

IgAVN and IgAN were the most common types of pathological findings in children who underwent kidney biopsies from 2013 to 2018. The pathological spectrum of kidney biopsy changed over time.

[Epidemiology of childhood chronic kidney diseases]

Major advances have been made in the management of children with chronic kidney disease (CKD) over the past 30 years. However, existing epidemiological data mainly relies on registries of chronic kidney replacement therapy. The incidence and prevalence of earlier stages of CKD remain largely unknown, but rare population-based studies suggest that the prevalence of all stages CKD may be as high as 1 % of the pediatric population. Congenital disorders including renal hypodysplasia and uropathy (CAKUT) and hereditary nephropathies account for one-half to two-thirds of childhood CKD cases in high-income countries, whereas acquired nephropathies predominate in developing countries. CKD progression is slower in children with congenital disorders than in those with glomerular nephropathy, and other risk factors for progression have also been identified. Children with CKD have poorer health-related quality of life when compared to healthy children. While survival of children with CKD has continuously improved over time, mortality remains 20 to 30 times higher than in the general pediatric population.

CAKUT: A Pediatric and Evolutionary Perspective on the Leading Cause of CKD in Childhood

The global prevalence of chronic kidney disease (CKD) is increasing rapidly, due to increasing environmental stressors through the life cycle. Congenital anomalies of kidney and urinary tract (CAKUT) account for most CKD in children, with a spectrum that can lead to kidney failure from early postnatal to late adult life. A stressed fetal environment can impair nephrogenesis, now recognized as a significant risk factor for the development of adult CKD. Congenital urinary tract obstruction is the leading cause of CKD due to CAKUT and can itself impair nephrogenesis as well as contribute to progressive nephron injury. Early diagnosis by ultrasonography in fetal life by an obstetrician/perinatologist can provide important information for guiding prognosis and future management. This review focuses on the critical role played by the pediatrician in providing timely evaluation and management of the patient from the moment of birth to the transfer to adult care. In addition to genetic factors, vulnerability of the kidney to CKD is a consequence of evolved modulation of nephron number in response to maternal signaling as well as to susceptibility of the nephron to hypoxic and oxidative injury. Future advances in the management of CAKUT will depend on improved biomarkers and imaging techniques.

Kidney function outcomes in patients after complete primary repair of bladder exstrophy and penopubic epispadias: Results from the international bladder exstrophy consortium

INTRODUCTION

Historically, repair of bladder exstrophy (BE) is associated with compromise to the upper tracts; the single stage repair of BE was considered to exacerbate risks of kidney impairment.

OBJECTIVE

We aim to evaluate the risk of upper urinary tract deterioration or chronic kidney disease after the complete primary repair of exstrophy (CPRE).

STUDY DESIGN

As part of the U.S.-India Multi-institutional Bladder Exstrophy Collaboration, we prospectively performed data collection on all patients managed at the Civil Hospital, Ahmedabad from 2010 to 2020. All patients who underwent primary or redo BE or primary penopubic epispadias (PE) repair using CPRE were included. Data on annual VCUG and DMSA, serum creatinine and cystatin-C, urinary albumin, and creatinine were aggregated.

RESULTS

72/104 patients who underwent CPRE at a median age of 1.7 years (IQR: 1.1-4.6) were included: 43(60%) patients with primary BE, 17(24%) with redo BE, and 12(17%) with primary PE. At a median follow-up of 4 years (IQR: 3-6), the overall median eGFR was 105 for BE, and 128 ml/min for PE. 14(19%) patients had eGFR<90, and 22(31%) had microalbuminuria. 21(30%) patients had kidney scarring in DMSA and 31(44%) had VUR. Multivariate analysis showed that neither kidney scarring nor VUR could predict the presence of eGFR<90 or microalbuminuria. Of 72 patients, 2 (3%) patients had dry intervals >3 h, 9 (13%) patients have dry intervals of 1-3 h and 44 (61%) patients had dry intervals <1 h during follow-up. We found that kidney function outcomes (i.e., eGFR and microalbuminuria) were not associated with continence status (p = 0.3).

DISCUSSION

In this series, we report a 5% incidence of CKD stage 2 or above that was not impacted by continence status. Furthermore, a 40% incidence of VUR and a 30% incidence of kidney scarring during follow-up was observed within this cohort, neither of which had a significant impact on renal function deterioration (i.e, decline in eGFR), but underscores the need for close kidney surveillance in children that have undergone bladder exstrophy repair.

CONCLUSIONS

Modern CPRE technique for the repair of BE may increase the risk of kidney scarring in the intermediate-term follow-up, however, this finding does not correlate with low eGFR and presence of albuminuria inpatients. Therefore, close follow-up with serial kidney function measurements is warranted and necessary after CPRE.

The effect of ureteropelvic junction obstruction and pyeloplasty on somatic growth during infancy

Background

Evidence regarding the impact of perinatal ureteropelvic junction obstruction (UPJO) and surgical correction during infancy, on somatic growth are scarce. Understanding these impacts could help advise parents and aid in treatment decision making.

Objectives

To assess the impact of unilateral UPJO and surgical correction on somatic growth in infants diagnosed antenatally and treated during infancy.

Design

A retrospective bi-institutional analysis of somatic growth in patients under 2 years who underwent dismembered pyeloplasty for the treatment of UPJO was conducted.

Methods

We evaluated patients who were diagnosed with unilateral hydronephrosis during pre-natal ultrasound screening for detection of fetal anomalies between May 2015 and October 2020. The height and weight of patients who were diagnosed with UPJO were recorded at the age of 1 month, time of surgery, and 6 months after surgery. Standard deviation scores (SDSs) for height and weight were calculated and compared.

Results

Forty-eight patients under the age of 2 years were included in the analysis. Median age and weight at pyeloplasty were 6.9 months and 7.5 kg. At 1 month, the median SDS for weight in the entire cohort was -0.30 [interquartile range (IQR): -1.0 to 0.63] and the median SDS for height was -0.26 (IQR: -1.08 to 0.52). In 22.9% of patients (11/48), weight and height were below -1 age-appropriate standard deviations, and 6.3% (3/48) were below -2 standard deviations, suggesting growth restriction. When comparing SDS for the entire cohort, there was no significant difference corelated to measurement time or effect of surgery. In the growth restricted cohort, we found a significant improvement in linear growth for height, which was demonstrated between birth and surgery as well as after surgery.

Conclusion

Infants with unilateral UPJO diagnosed antenatally as a single anomaly may be at an increased risk of somatic growth restriction in comparison with the general population. In children with growth restriction at time of birth, height seems to improve regardless of surgical treatment. Pyeloplasty during infancy does not seem to negatively affect somatic growth. These findings can be used to counsel parents regarding the potential effects of UPJO and pyeloplasty.

The association of perfluoroalkyl substances (PFAS) exposure and kidney function in Korean adolescents using data from Korean National Environmental Health Survey (KoNEHS) cycle 4 (2018–2020): a cross-sectional study

Background

Perfluoroalkyl substances (PFAS) are chemicals widely used in various products in everyday life. Due to its unique strong binding force, the half-life of PFAS is very long, so bioaccumulation and toxicity to the human body are long-standing concerns. In particular, effects on kidney function have recently emerged and there are no studies on the effect of PFAS on kidney function through epidemiological investigations in Korea. From 2018 to 2020, the Korean National Environmental Health Survey (KoNEHS) cycle 4, conducted an epidemiological investigation on the blood concentration of PFAS for the first time in Korea. Based on this data, the relationship between PFAS blood concentration and kidney function was analyzed for adolescents.

Methods

We investigated 5 types of PFAS and their total blood concentration in 811 middle and high school students, living in Korea and included in KoNEHS cycle 4, and tried to find changes in kidney function in relation to PFAS concentration. After dividing the concentration of each of the 5 PFAS and the total concentration into quartiles, multivariable linear regression was performed to assess the correlation with kidney function. The bedside Schwartz equation was used as an indicator of kidney function.

Results

As a result of multivariable linear regression, when observing a change in kidney function according to the increase in the concentration of each of the 5 PFAS and their total, a significant decrease in kidney function was confirmed in some or all quartiles.

Conclusions

In this cross-sectional study of Korean adolescents based on KoNEHS data, a negative correlation between serum PFAS concentration and kidney function was found. A well-designed longitudinal study and continuous follow-up are necessary.

Febrile Urinary Tract Infections in Children: The Role of High Mobility Group Box-1

BACKGROUND

Differentiating between febrile lower urinary tract infection (LUTI) and acute pyelonephritis (APN) is crucial for prompt clinical management. We investigated whether the high mobility group box-1 (HMGB1) could be a useful biomarker in differentiating between LUTI or APN.

METHODS

We enrolled seventy-four pediatric patients with suspected LUTI/APN, according to the positive or negative renal scintigraphy (DMSA) scan. If the first DMSA findings were abnormal, a second DMSA was performed after six months. Voiding cystourethrography ruled out vesicoureteral reflux (VUR).

RESULTS

Higher serum (s) HMGB1 levels characterized the APN group when compared to LUTI patients (13.3 (11.8-14.3) versus 5.9 (5.2-6.8) ng/mL, p: 0.02), whereas there were no differences according to urine (u) HMGB1 values. sHMGB1 correlated with C-reactive protein (CRP) levels (β = 0.47; p: 0.02). Receiver operating characteristic curves identified the best diagnostic profile for detecting APN. sHMGB1 area under the curve was different from CRP (p: 0.01) and white blood cells (p: 0.003). After multivariate analyses, VUR (HR:4.81) and sHMGB1 (HR 1.16; p: 0.006) were independently associated with the risk of renal scarring development.

CONCLUSIONS

sHMGB1 could represent a marker to differentiate APN from LUTI. Measurement of sHMGB1 could select children for early intervention or long-term follow-up.

A Water-Soluble AIEgen for Noninvasive Diagnosis of Kidney Fibrosis via SWIR Fluorescence and Photoacoustic Imaging

Early diagnosis of renal fibrosis is crucially significant on account of its worldwide prevalent tendency. Optical imaging in the near-infrared window has been recognized as an appealing technique for the timely detection of renal dysfunction. However, formulating a contrast agent that allows early monitoring of renal fibrosis and concurrently renally clearable in a normal group is still challenging. Herein, a nanosized fluorophore with aggregation-induced emission (AIE) features, namely AIE-4PEG550 NPs, is well-tailored and amenable to longitudinal visualization of the fibrosis progression specifically in the early-stage via short-wave infrared (SWIR, 900-1700 nm) fluorescence and photoacoustic bimodal imaging. The small size (≈26 nm), renally filtrable molecular weight (3.3 kDa), high renal clearance efficiency (93.1 ± 1.7% excretion through the kidneys within 24 h), outstanding imaging performance, and good biocompatibility, together make AIE-4PEG550 NPs remarkably impressive and far superior to clinical diagnostic assays. The finding in this study would provide a blueprint for the next generation of diagnostic agents for the extent of renal fibrosis.

Comparative study of open, laparoscopic and endoscopic treatments of intermediate grade vesicoureteral reflux in children

BACKGROUND

Low-grade vesicoureteral-reflux (VUR) are rather treated by endoscopic injection, whereas open or laparoscopic procedures are mainly performed for high-grade VURs. Management of intermediate grades is controversial and no study focused on grade III to date. This study aims to compare the results of open, laparoscopic, and endoscopic approaches in children with grade III VUR.

METHODS

A multicenter comparative retrospective study included children with grade III VUR operated for febrile urinary tract infections (UTIs) from 2007 to 2016. Children without UTI, with reflux of other grades, neurological bladder, duplex system, posterior urethral valves, and bladder exstrophy were excluded. Success was defined as no recurrence of febrile UTI and was presented as event-free survival curves.

RESULTS

Out of 806 children operated of VUR, 171 met the inclusion criteria (114 females). Seventy-seven children (45%) underwent an open Cohen procedure, 35 (21%) a laparoscopic Lich-Gregoir and 59 (34%) a submucosal endoscopic injection according to the centers' preference. The mean follow-up was 64 months (24-132). Groups were not different for age, sex, and circumcision status. Compared to Cohen procedure, recurrences of febrile UTI were more frequent after laparoscopic treatment (p = 0,02, 8/35) and endoscopic treatment (p = 0.001, 16/59). Redosurgery was also more frequent after laparoscopy (n = 2) and endoscopic injection (n = 14) than after open surgery (n = 0, p < 0.001).

CONCLUSION

Recurrent febrile UTIs and redosurgery are more frequent after endoscopic and laparoscopic procedures in grade III VUR than open reimplantation. Whether the lower morbidity of laparoscopic or endoscopic approaches balances the risk of recurrent febrile UTI remains to be determined for intermediate grade reflux.

The scope of treatment of pediatric IgA vasculitis nephritis and its outcome: a Pediatric Nephrology Research Consortium study

BACKGROUND

IgA vasculitis (IgAV) is the most common type of vasculitis in children. There is a lack of consensus for management of significant IgAV nephritis (IgAVN). This study was designed to identify the most used treatment options and describe their efficacy.

METHODS

This is a multicenter retrospective study of children age 1-21 years with IgAVN who were managed for at least 6 months by a nephrologist. Subjects with at least microscopic hematuria and proteinuria and/or decreased kidney function were enrolled. Kidney outcome was assessed by eGFR and urine protein/creatinine (UPC) ratios at 2-4 weeks, 3, 6, and 12 months post-diagnosis.

RESULTS

A total of 128 subjects with median age of 7 years (range 2-18) were included. Of these, 69 subjects had kidney biopsy with crescents detected in 53%. AKI (P = 0.039), nephrosis (P = 0.038), and crescents on biopsy (P = 0.013) were more likely in older patients. Patients with UPC > 1 mg/mg were more likely to get a kidney biopsy (P < 0.001) and to be treated with steroids ± immunosuppressive (IS) agents (P = 0.001). Sixty-six percent of patients were treated with steroids and/or IS agents for variable durations. Anti-metabolite agents were the most common IS agents used with variability in dosing and duration. At 12 months, most subjects had a normal eGFR (79%) (median 123, range 68-207 mL/min/1.73 m²) and no proteinuria (median UPC 0.15, range 0.01-4.02 mg/mg).

CONCLUSIONS

IS agents are frequently used in managing IgAVN associated with heavy proteinuria, nephrosis, and/or AKI. Prospective studies are needed to determine indications and needed duration of IS therapy. A higher resolution version of the Graphical abstract is available as Supplementary information.

Regulation of nephron progenitor cell lifespan and nephron endowment

Low nephron number - resulting, for example, from prematurity or developmental anomalies - is a risk factor for the development of hypertension, chronic kidney disease and kidney failure. Considerable interest therefore exists in the mechanisms that regulate nephron endowment and contribute to the premature cessation of nephrogenesis following preterm birth. The cessation of nephrogenesis in utero or shortly after birth is synchronized across multiple niches in all mammals, and is coupled with the exhaustion of nephron progenitor cells. Consequently, no nephrons are formed after the cessation of developmental nephrogenesis, and lifelong renal function therefore depends on the complement of nephrons generated during gestation. In humans, a tenfold variation in nephron endowment between individuals contributes to differences in susceptibility to kidney disease; however, the mechanisms underlying this variation are not yet clear. Salient advances in our understanding of environmental inputs, and of intrinsic molecular mechanisms that contribute to the regulation of cessation timing or nephron progenitor cell exhaustion, have the potential to inform interventions to enhance nephron endowment and improve lifelong kidney health for susceptible individuals.

Association of insurance status with chronic kidney disease stage at diagnosis in children

BACKGROUND

Whether medical insurance impacts the timely diagnosis in chronic kidney disease (CKD) children is unknown. We aim to examine the extent to which insurance is associated with access to timely diagnosis and different stages of CKD among a large population of children in China.

METHODS

A retrospective, cross-sectional study based on China's national hospitalized record database was carried out. Children aged 0-17 years diagnosed as CKD stages 1-5 between June 1, 2013, and December 31, 2018, were included. A diagnosis of advanced CKD stage (CKD stage 4 or 5) was the primary outcome. Multivariable logistic regression model adjusted for age, sex, cross-regional hospitalization, year of diagnosis, and cause of CKD was used to assess the association between insurance status and the stage of CKD when diagnosed.

RESULTS

A total of 10,256 children (median [interquartile range, IQR] age, 12.4 [7.9, 15.4] years) were included. There were 4716 (46.0%) uninsured children in the included population. The insurance coverage was highest in children 13-17 years old (60.9%). The hospitalized charge was highest in stage 5 uninsured children (median [IQR], ¥13,000.89 [7640.63, 24,585.00]). More uninsured children are diagnosed in CKD stage 4 or 5 (48.1%) than insured children (47.5%). Uninsured children had higher odds (odds ratio [OR] 1.20, [95% CI, 1.08-1.32]) of receiving a diagnosis of CKD stage 4 or 5 compared with insured children.

CONCLUSIONS

Lack of medical insurance was associated with a more advanced stage of CKD when diagnosed in hospitalized children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Advanced chronic kidney disease among UK children

The UK Renal Registry currently collects information on UK children with kidney failure requiring long-term kidney replacement therapy (KRT), which supports disease surveillance and auditing of care and outcomes; however, data are limited on children with chronic kidney disease (CKD) not on KRT.

METHODS

In March 2020, all UK Paediatric Nephrology centres submitted data on children aged <16 years with severely reduced kidney function as of December 2019, defined as an estimated glomerular filtration rate <30 mL/min/1.73 m2.

RESULTS

In total, 1031 children had severe CKD, the majority of whom (80.7%) were on KRT. The overall prevalence was 81.2 (95% CI 76.3 to 86.3) per million of the age-related population.

CONCLUSIONS

The prevalence of severe CKD among UK children is largely due to a high proportion of children on long-term KRT. Expanding data capture to include children with CKD before reaching failure will provide greater understanding of the CKD burden in childhood.

Research features between Urology and Nephrology authors in articles regarding UTI related to CKD, HD, PD, and renal transplantation

BACKGROUND

A urinary tract infection (UTI) is one of the most common types of infections affecting the urinary tract. When bacteria enter the bladder or kidney and multiply in the urine, a URI can occur. The urethra is shorter in women than in men, which makes it easier for bacteria to reach the bladder or kidneys and cause infection. A comparison of the research differences between Urology and Nephrology (UN) authors regarding UTI pertaining to the 4 areas (i.e., Chronic Kidney Disease, Hemodialysis, Peritoneal Dialysis, and Renal Transplantation [CHPR]) is thus necessary. We propose and verify 2 hypotheses: CHPR-related articles on UTI have equal journal impact factors (JIFs) in research achievements (RAs) and UN authors have similar research features (RFs).

METHODS

Based on keywords associated with UTI and CHPR in titles, subject areas, and abstracts since 2013, we obtained 1284 abstracts and their associated metadata (e.g., citations, authors, research institutes, departments, countries of origin) from the Web of Science core collection. There were 1030 corresponding and first (co-first) authors with hT-JIF-indices (i.e., JIF was computed using hT-index rather than citations as usual). The following 5 visualizations were used to present the author's RA: radar, Sankey, time-to-event, impact beam plot, and choropleth map. The forest plot was used to distinguish RFs by observing the proportional counts of keyword plus in Web of Science core collection between UN authors.

RESULTS

It was observed that CHPR-related articles had unequal JIFs (χ2 = 13.08, P = .004, df = 3, n = 1030) and UN departments had different RFs (Q = 53.24, df = 29, P = .004). In terms of countries, institutes, departments, and authors, the United States (hT-JIF = 38.30), Mayo Clinic (12.9), Nephrology (19.14), and Diana Karpman (10.34) from Sweden had the highest hT-JIF index.

CONCLUSION

With the aid of visualizations, the hT-JIF-index and keyword plus were demonstrated to assess RAs and distinguish RFs between UN authors. A replication of this study under other topics and in other disciplines is recommended in the future, rather than limiting it to UN authors only, as we did in this study.

Nomogram Prediction Model of Serum Chloride and Sodium Ions on the Risk of Acute Kidney Injury in Critically Ill Patients

Purpose

This study aims to investigate the effect of serum chloride and sodium ions on AKI occurrence in ICU patients, and further constructs a prediction model containing these factors to explore the predictive value of these ions in AKI.

Methods

The clinical information of patients admitted to ICU of Beijing Friendship Hospital Affiliated to Capital Medical University was collected for retrospective analysis. Logistic regression analysis was used to analyzing the influencing factors. A nomogram for predicting AKI risk was constructed with R software and validated by repeated sampling. Afterwards, the effectiveness and accuracy of the model were tested and evaluated.

Results

A total of 446 cases met the requirements of this study, of which 178 developed AKI during their stay in ICU, with an incidence rate of 39.9%. Hypernatremia, heart failure, sepsis, APACHE II score, and initial creatinine value and BE value at ICU admission before the diagnosis of AKI were identified as independent risk factors for developing AKI during ICU stay. These predictors were incorporated into the nomogram of AKI risk in critically ill patients, which was constructed by using R software. Receiver operating characteristic curve analysis was further used and showed that the area under the curve of the model was 0.7934 (95% CI 0.742–0.8447), indicating that the model had an ideal value. Finally, further evaluated its clinical effectiveness. The clinical effect curve and decision curve showed that most areas of the decision curve of this model were greater than 0, indicating that this model owned a certain clinical effectiveness.

Conclusion

The nomogram based on hypernatremia, heart failure, sepsis, APACHE II score, and initial creatinine and BE value in ICU can predict the individualized risk of AKI with satisfactory distinguishability and accuracy.

Risk factors for childhood chronic kidney disease: a population-based study

BACKGROUND

The population-based prevalence and risk factors of childhood chronic kidney disease (CKD) are not well-defined. We ascertained childhood CKD epidemiology and perinatal risk factors, based on a large computerized medical record database that covers most of southern Israel's population.

METHODS

Pre- and post-natal records of 79,374 eligible children (with at least one serum creatinine test) born during 2001-2015 were analyzed. "Ever-CKD" was defined as ≥ 2 estimated glomerular filtration rate (eGFR) values < 60 ml/min/1.73 m² beyond age 2 years, more than 3 months apart. The last CKD status was determined on March 2019.

RESULTS

Of 82 (0.1%) patients with ever-CKD, 35 (42.7%) had their first abnormal eGFR identified already at age 2 years. In multiple logistic regression analysis, congenital anomalies of kidney and urinary tract (CAKUT)-related diagnoses, glomerulopathy, maternal oligohydramnios, small for gestational age, prematurity (under 34 weeks), post-term delivery, and small for gestational age at birth were significant risk factors for ever-CKD (odds ratio (95% confidence interval): 44.34(26.43-74.39), 64.60(32.42-128.70), 5.54(3.01-10.19), 2.02(1.25-3.28), 4.45(2.13-9.28), 2.96(1.28-6.86 and 2.02(1.25-3.28), respectively). Seventy children with ever-CKD (85.4%) had a depressed eGFR (< 90 ml/min/1.73 m²) on the last assessment (current-CKD), yielding a prevalence of 882/million.

CONCLUSIONS

CKD is more prevalent among children in southern Israel than previously reported, even after excluding those with aborted-CKD. Prenatal conditions increase the risk to develop CKD in childhood. Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information.

Mechanisms of Post-critical Illness Cardiovascular Disease

Prolonged critical care stays commonly follow trauma, severe burn injury, sepsis, ARDS, and complications of major surgery. Although patients leave critical care following homeostatic recovery, significant additional diseases affect these patients during and beyond the convalescent phase. New cardiovascular and renal disease is commonly seen and roughly one third of all deaths in the year following discharge from critical care may come from this cluster of diseases. During prolonged critical care stays, the immunometabolic, inflammatory and neurohumoral response to severe illness in conjunction with resuscitative treatments primes the immune system and parenchymal tissues to develop a long-lived pro-inflammatory and immunosenescent state. This state is perpetuated by persistent Toll-like receptor signaling, free radical mediated isolevuglandin protein adduct formation and presentation by antigen presenting cells, abnormal circulating HDL and LDL isoforms, redox and metabolite mediated epigenetic reprogramming of the innate immune arm (trained immunity), and the development of immunosenescence through T-cell exhaustion/anergy through epigenetic modification of the T-cell genome. Under this state, tissue remodeling in the vascular, cardiac, and renal parenchymal beds occurs through the activation of pro-fibrotic cellular signaling pathways, causing vascular dysfunction and atherosclerosis, adverse cardiac remodeling and dysfunction, and proteinuria and accelerated chronic kidney disease.

Definition, diagnosis and clinical management of non-obstructive kidney dysplasia: a consensus statement by the ERKNet Working Group on Kidney Malformations

Kidney dysplasia is one of the most frequent causes of chronic kidney failure in children. While dysplasia is a histological diagnosis, the term 'kidney dysplasia' is frequently used in daily clinical life without histopathological confirmation. Clinical parameters of kidney dysplasia have not been clearly defined, leading to imprecise communication amongst healthcare professionals and patients. This lack of consensus hampers precise disease understanding and the development of specific therapies. Based on a structured literature search, we here suggest a common basis for clinical, imaging, genetic, pathological and basic science aspects of non-obstructive kidney dysplasia associated with functional kidney impairment. We propose to accept hallmark sonographic findings as surrogate parameters defining a clinical diagnosis of dysplastic kidneys. We suggest differentiated clinical follow-up plans for children with kidney dysplasia and summarize established monogenic causes for non-obstructive kidney dysplasia. Finally, we point out and discuss research gaps in the field.

Epidemiology of pediatric chronic kidney disease/kidney failure: learning from registries and cohort studies

Although the concept of chronic kidney disease (CKD) in children is similar to that in adults, pediatric CKD has some peculiarities, and there is less evidence and many factors that are not clearly understood. The past decade has witnessed several additional registry and cohort studies of pediatric CKD and kidney failure. The most common underlying disease in pediatric CKD and kidney failure is congenital anomalies of the kidney and urinary tract (CAKUT), which is one of the major characteristics of CKD in children. The incidence/prevalence of CKD in children varies worldwide. Hypertension and proteinuria are independent risk factors for CKD progression; other factors that may affect CKD progression are primary disease, age, sex, racial/genetic factors, urological problems, low birth weight, and social background. Many studies based on registry data revealed that the risk factors for mortality among children with kidney failure who are receiving kidney replacement therapy are younger age, female sex, non-White race, non-CAKUT etiologies, anemia, hypoalbuminemia, and high estimated glomerular filtration rate at dialysis initiation. The evidence has contributed to clinical practice. The results of these registry-based studies are expected to lead to new improvements in pediatric CKD care.

Predicting factors of clinically significant urological anomalies after initial urinary tract infection among 2- to 24-month-old children

AIM

To find more effective criteria to identify clinically significant urological anomalies after initial urinary tract infection among children.

METHODS

Children aged 2-24 months with an initial urinary tract infection were consecutively recruited in a Japanese hospital from 2013 to 2019. Voiding cystourethrography, 99mTc dimercaptosuccinic acid scan and ultrasound were intended to perform for all cases. Clinically significant urological anomalies were defined as high-grade vesicoureteral reflux, obstructive and abnormal urinary tract lesions, need for surgical intervention, renal hypoplasia and scarring. Using classification and regression tree analysis, we sought the associated factors. We developed new criteria with these factors, retrospectively applied them to the original data, and calculated the sensitivity and specificity.

RESULTS

One hundred sixty-seven patients were eligible, and 39 had clinically significant urological anomalies. Classification and regression tree analysis showed that the associated factors were non-E. coli infections, serum creatinine levels and ultrasound abnormalities. When the gold standards were performed on children with non-E. coli infections or serum creatinine levels ≥0.21 mg/dl, sensitivity and specificity were 0.82 and 0.68, respectively.

CONCLUSION

The criteria including non-E. coli infections and high-normal or higher serum creatinine levels may efficiently predict clinically significant urological anomalies after initial urinary tract infections.

Prenatal Hydronephrosis: Bridging Pre- and Postnatal Management

Urinary tract dilation (UTD), including hydronephrosis (HN) is the most common prenatally detected anomaly and affects up to 1-2% of pregnancies. Postnatally, it resolves without surgical intervention in approximately 75-80% of children, however this may take several years to occur, necessitating repeated clinic visits and additional invasive testing for many. For the remainder, a surgical intervention will be offered to relieve obstruction or to correct vesicoureteral reflux. During the monitoring period, many of these infants will be offered continuous antibiotic prophylaxis for the prevention of urinary tract infections, however this remains a controversial topic among pediatric urologists and nephrologists. Herein, we present an up-to-date review of the early management of prenatally detected UTD including timing of postnatal imaging, the use of antibiotics, when circumcision may be beneficial and long term outcomes of the most common HN etiologies. We also propose a decision making tool to help guide the care of infants with UTD. This article is protected by copyright. All rights reserved.

Fifteen-minute consultation: how to identify and treat children with acute kidney injury

Acute kidney injury (AKI) is under-recognised in children and neonates. It is associated with increased mortality and morbidity along with an increased incidence of chronic kidney disease in adulthood. It is important that paediatricians are able to recognise AKI quickly, enabling prompt treatment of reversible causes. In this article, we demonstrate an approach to recognising paediatric AKI, cessation of nephrotoxic medication, appropriate investigations and the importance of accurately assessing fluid status. The mainstay of treatment is attempting to mimic the kidneys ability to provide electrolyte and fluid homeostasis; this requires close observation and careful fluid management. We discuss referral to paediatric nephrology and the importance of long-term follow-up. We present an approach to AKI through case-presentation.

The impact of biological sex on diseases of the urinary tract

Biological sex, being female or male, broadly influences diverse immune phenotypes, including immune responses to diseases at mucosal surfaces. Sex hormones, sex chromosomes, sexual dimorphism, and gender differences all contribute to how an organism will respond to diseases of the urinary tract, such as bladder infection or cancer. Although the incidence of urinary tract infection is strongly sex biased, rates of infection change over a lifetime in women and men, suggesting that accompanying changes in the levels of sex hormones may play a role in the response to infection. Bladder cancer is also sex biased in that 75% of newly diagnosed patients are men. Bladder cancer development is shaped by contributions from both sex hormones and sex chromosomes, demonstrating that the influence of sex on disease can be complex. With a better understanding of how sex influences disease and immunity, we can envision sex-specific therapies to better treat diseases of the urinary tract and potentially diseases of other mucosal tissues.

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.

[Epidemiology of pediatric chronic kidney disease]

Major advances have been made in the management of children with chronic kidney disease over the past 30 years. However, existing epidemiology data are primarily from kidney replacement therapy registries, and information available at earlier stages of chronic kidney disease is limited. The incidence and prevalence of chronic kidney disease stages 2 to 5 remain poorly understood. However, rare population-based studies suggest that the prevalence of all-stage chronic kidney disease may be as high as 1% of the pediatric population. Congenital disorders including congenital abnormalities of the kidney and urinary tract and hereditary nephropathies account for one-half to two-thirds of pediatric chronic kidney disease cases in middle and high-income countries, whereas acquired nephropathies seem to predominate in low-income countries. The progression of chronic kidney disease is slower in children with congenital disorders than in those with acquired nephropathy, particularly glomerular disease, resulting in a lower proportion of congenital abnormalities of the kidney and urinary tract as a cause of end-stage kidney disease compared to less advanced stages of chronic kidney disease. The incidence of kidney replacement therapy in the pediatric population ranged by country from 1 to 14 per million children of the same age in 2018 (approximately 8 per million children in France) in patients younger than 20 years. The prevalence of kidney replacement therapy in children under 20 years of age in 2018 ranged from 15-30 per million children in some Eastern European and Latin American countries to 100 per million children in Finland and the United States (56 per million children in France). Most children with end-stage kidney disease initiate kidney replacement therapy with dialysis (more frequently hemodialysis than peritoneal dialysis). In about 20% of cases, the initial kidney replacement therapy modality is a pre-emptive kidney transplantation. In high-income countries, 60-80% of prevalent children with end-stage kidney disease live with a functioning transplant (75% in France). While the survival of children with chronic kidney disease has continuously improved over time, mortality remains about 30 times higher than in the general pediatric population.

A Promising NIR-II Fluorescent Sensor for Peptide-Mediated Long-Term Monitoring of Kidney Dysfunction

Kidney disease is usually "silent" at the early stage but can lead to severe kidney failure later on. The development of bioimaging probes with rapid distribution and long-term retention in the kidney is significant for the precise diagnosis of renal diseases. Here, a strategy for the peptide-mediated delivery and long-term accumulation (>48 h) of second near-infrared window (NIR-II) fluorophores into the kidney is demonstrated. It is shown that both the hepatic-cleared organic molecules and fast renal-cleared ultrasmall nanoparticles can be retained in the kidney after conjugation to the peptide with high polarity. Moreover, a ROS-responsive activatable bilateral NIR-II sensor was designed based on the kidney targeting peptide, which enables both in vivo long-term kidney monitoring and in vitro urine analysis. The capability of the peptide-based sensor to detect early kidney injury and report on kidney dysfunctional progression is particularly crucial for chemotherapy regimen optimization and timely renoprotective intervention during medication.

Childhood risk factors for adulthood chronic kidney disease

Chronic kidney disease (CKD) is a major public health challenge, affecting as much as 8 to 18% of the world population. Identifying childhood risk factors for future CKD may help clinicians make early diagnoses and initiation of preventive interventions for CKD and its attendant comorbidities as well as monitoring for complications. The purpose of this review is to describe childhood risk factors that may predict development of overt kidney disease later in life. Currently, there are multiple childhood risk factors associated with future onset and progression of CKD. These risk factors can be grouped into five categories: genetic factors (e.g., monogenic or risk alleles), perinatal factors (e.g., low birth weight and prematurity), childhood kidney diseases (e.g., congenital anomalies, glomerular diseases, and renal cystic ciliopathies), childhood onset of chronic conditions (e.g., cancer, diabetes, hypertension, dyslipidemia, and obesity), and different lifestyle factors (e.g., physical activity, diet, and factors related to socioeconomic status). The available published information suggests that the lifelong risk for CKD can be attributed to multiple factors that appear already during childhood. However, results are conflicting on the effects of childhood physical activity, diet, and dyslipidemia on future renal function. On the other hand, there is consistent evidence to support follow-up of high-risk groups.

Prognosis and acute complications at the first onset of idiopathic nephrotic syndrome in children: a nationwide survey in Japan (JP-SHINE study)

BACKGROUND

Information on the epidemiology of idiopathic nephrotic syndrome (INS) in children, complications of INS and the side effects of steroid therapy is scarce.

METHODS

The Japanese Pediatric Survey Holding Information of Nephrotic Syndrome, a nationwide cohort study, was conducted by the Japanese Study Group of Renal Disease in Children and enrolled 2099 children with newly diagnosed INS between 1 January 2010 and 31 December 2012. We conducted a follow-up study of the complications during the first onset and the patients' prognosis in this cohort.

RESULTS

We obtained follow-up data on 999 children (672 males) with a median age at onset of 4.5 years [interquartile range (IQR) 2.8-9.4] and a median follow-up period of 4.1 years (IQR 2.5-5.1). At the first onset, 24% of patients experienced severe acute kidney injury (AKI), defined as a serum creatinine increase to a level two or more times the baseline. On logistic regression analysis, age, hematuria, severe hypoalbuminemia (serum albumin <1.0 g/dL) and severe bacterial infection were not independent factors, but female sex {hazard ratio [HR] 1.5 [95% confidence interval (CI) 1.1-1.7]} and hypertension [HR 4.0 (95% CI 2.6-6.0)] were significantly related to AKI. During the observation period, ocular hypertension requiring treatment occurred in 17.4% of patients, among which 0.4% received surgical treatment. Progression to frequently relapsing nephrotic syndrome/steroid-dependent nephrotic syndrome in 3 years was seen in 44.2% of the patients and was shown by the Cox regression analysis to be significantly related to younger age and days until remission at the first episode, but not to sex, hematuria, the minimum serum albumin level or AKI. Two patients died during the observation period. One patient showed progression to end-stage kidney disease.

CONCLUSION

Based on the results of a multicenter questionnaire survey, the overall survival and renal survival rates were found to be excellent. However, proper management of complications, particularly in AKI and ocular hypertension, is mandatory.

Nephron number and its determinants: a 2020 update

Studies of human nephron number have been conducted for well over a century and have uncovered a large variability in nephron number. However, the mechanisms influencing nephron endowment and loss, along with the etiology for the wide range among individuals are largely unknown. Advances in imaging technology have allowed investigators to revisit the principles of renal structure and physiology and their roles in the progression of kidney disease. Here, we will review the latest data on the influences impacting nephron number, innovations made over the last 6 years to understand and integrate renal structure and function, and new developments in the tools used to count nephrons in vivo.

Development of the metanephric kidney

The kidney plays an integral role in filtering the blood-removing metabolic by-products from the body and regulating blood pressure. This requires the establishment of large numbers of efficient and specialized blood filtering units (nephrons) that incorporate a system for vascular exchange and nutrient reabsorption as well as a collecting duct system to remove waste (urine) from the body. Kidney development is a dynamic process which generates these structures through a delicately balanced program of self-renewal and commitment of nephron progenitor cells that inhabit a constantly evolving cellular niche at the tips of a branching ureteric "tree." The former cells build the nephrons and the latter the collecting duct system. Maintaining these processes across fetal development is critical for establishing the normal "endowment" of nephrons in the kidney and perturbations to this process are associated both with mutations in integral genes and with alterations to the fetal environment.