Congenital Anomalies of the Kidney and the Urinary Tract (CAKUT)

A Pilot Comparative Study between Creatinine- and Cystatin-C-Based Equations to Estimate GFR and Kidney Ultrasound Percentiles in Children with Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies affecting the kidneys present significant challenges in pediatric nephrology, needing precise methods for assessing renal function and guiding therapeutic intervention. Bedside Schwartz formula with the cystatin-C-based Full Age Spectrum formula and Chronic Kidney Disease in Children (CKiD) U 25 formula used in estimating glomerular filtration rate (eGFR) and also to assess if the eGFR in association with kidney length percentiles can be a monitoring parameter for the progression of chronic kidney disease in children with congenital anomalies of the kidney and urinary tract (CAKUT). A total of 64 pediatric patients (median age at diagnostic was 12 months with an interquartile range of 2 to 60) were diagnosed with congenital anomalies in the kidney and urinary tract between June 2018 and May 2023 at "Louis Turcanu" Emergency Hospital for Children in Timisoara, Romania. Baseline characteristics, CAKUT types, associated pathologies, CKD staging, and eGFR using creatinine and cystatin C were analyzed. The mean age at the moment of examination was 116.50 months; (65, 180). Chronic kidney disease staging revealed a predominance of patients in CKD stages G1 and A1. Analysis of eGFR methods revealed a small mean difference between eGFR estimated by creatinine and cystatin C, with a moderate-strong positive correlation observed between the eGFR and ultrasound parameters. Using cystatin-C-based formulas for eGFR, in conjunction with ultrasound measurements, may offer reliable insights into renal function in pediatric patients with congenital anomalies affecting the kidney and urinary tract. However, the economic aspect must be taken into consideration because cystatin C determination is approximately eight times more expensive than that of creatinine. An interdisciplinary approach is crucial for managing patients with CAKUT.

Fortuitous detection of adult malrotated ectopic kidney during acute appendicitis: A unique case report

INTRODUCTION AND IMPORTANCE

Renal ectopia, a rare congenital anomaly, can occur in various body regions and may be associated with other abnormalities. It is often asymptomatic, commonly found incidentally, as in our 70-year-old patient during appendicitis exploration. This case highlights the importance of recognizing renal ectopia and associated anomalies, such as vascular abnormalities and renal malrotation, which may predispose patients to potential complications and require vigilant monitoring for urinary tract infections and lithiasis events, as well as potential challenges during laparoscopic surgical procedures, as in our appendectomy case.

CASE PRESENTATION

A 70-year-old female presented with right iliac fossa pain and elevated inflammatory markers. Abdominopelvic CT scan confirmed uncomplicated appendicitis and revealed a right ectopic and malrotated kidney. Laparoscopic appendectomy was performed without complications. Postoperative recovery was uneventful, and discharge occurred one day post-procedure. A four-week follow-up was scheduled to monitor for urinary infection and stone formation, with initiation of hygienic and dietary measures.

CLINICAL DISCUSSION

Renal ectopia, a congenital anomaly, frequently positions the kidneys in the pelvic region. Iliac ectopias are often confused with pelvic or abdominal ectopias. Ectopic kidneys can result in complications like vesicoureteral reflux, urinary tract infections, or kidney stones. Despite being typically left-sided, our patient presented with right-sided renal ectopia with malrotation. Despite lacking urinary symptoms, a urological consultation was advised due to the potential risk of infection or kidney stones. Surgical intervention is reserved for complication management.

CONCLUSION

Renal ectopia, a rare congenital anomaly, can be asymptomatic but often coincides with other renal or vascular issues. Early detection and accurate imaging are essential, emphasizing clinical vigilance and interdisciplinary collaboration for better patient care.

A preliminary study of the miRNA restitution effect on CNV-induced miRNA downregulation in CAKUT

BACKGROUND

The majority of CAKUT-associated CNVs overlap at least one miRNA gene, thus affecting the cellular levels of the corresponding miRNA. We aimed to investigate the potency of restitution of CNV-affected miRNA levels to remediate the dysregulated expression of target genes involved in kidney physiology and development in vitro.

METHODS

Heterozygous MIR484 knockout HEK293 and homozygous MIR185 knockout HEK293 cell lines were used as models depicting the deletion of the frequently affected miRNA genes by CAKUT-associated CNVs. After treatment with the corresponding miRNA mimics, the levels of the target genes have been compared to the non-targeting control treatment. For both investigated miRNAs, MDM2 and PKD1 were evaluated as common targets, while additional 3 genes were investigated as targets of each individual miRNA (NOTCH3, FIS1 and APAF1 as hsa-miR-484 targets and RHOA, ATF6 and CDC42 as hsa-miR-185-5p targets).

RESULTS

Restitution of the corresponding miRNA levels in both knockout cell lines has induced a change in the mRNA levels of certain candidate target genes, thus confirming the potential to alleviate the CNV effect on miRNA expression. Intriguingly, HEK293 WT treatment with investigated miRNA mimics has triggered a more pronounced effect, thus suggesting the importance of miRNA interplay in different genomic contexts.

CONCLUSIONS

Dysregulation of multiple mRNA targets mediated by CNV-affected miRNAs could represent the underlying mechanism behind the unresolved CAKUT occurrence and phenotypic variability observed in CAKUT patients. Characterizing miRNAs located in CNVs and their potential to become molecular targets could eventually help in understanding and improving the management of CAKUT.

Increased incidence of renal and urinary tract anomalies among individuals with fetal alcohol spectrum disorders (FASD)

BACKGROUND

Fetal alcohol spectrum disorders (FASD) in a spectrum of neurodevelopmental conditions resulting from prenatal alcohol exposure (PAE). Animal models have confirmed the toxic effects of PAE on the kidneys and urinary tract, yet the evidence from human studies is contradictory. The purpose of this study was to establish the incidence of renal and urinary tract anomalies (RUTA), impaired kidney function, and hypertension among patients with FASD.

METHODS

Children from the FASD Diagnostic Center with FASD diagnosis (FAS, pFAS, or ARND) were offered participation in the study. The control group consisted of patients from the Gastroenterology Department of the same hospital. The patients underwent renal and urinary tract ultrasound examination. The serum creatinine level was also evaluated and the blood pressure was taken twice. Polish OLAF charts were used to determine the percentiles of blood pressure.

RESULTS

The incidence of kidney and urinary tract defects in the study group was significantly higher than in the control group (OR: 2.64 [1.60-4.34]). The kidney size among FASD patients was significantly lower (73 mm [60-83] vs. 83 mm [70-96]; p < .001) when compared to the control group. No differences were observed in the estimated glomerular filtration rate. In the study group, significantly lower systolic blood, diastolic blood pressure, percentile of systolic pressure, and diastolic pressure were observed.

CONCLUSIONS

RUTA occurred more frequently among patients with FASD compared to the control group, and decreased kidney size was also demonstrated among patients with FASD. However, impaired kidney function and the risk of hypertension were not observed.

Congenital anomalies of the kidney and urinary tract: defining risk factors of disease progression and determinants of outcomes

Congenital anomalies of the kidney and urinary tract (CAKUT) result from disruptions in normal kidney and urinary tract development during fetal life and collectively represent the most common cause of kidney failure in children worldwide. The antenatal determinants of CAKUT are diverse and include mutations in genes responsible for normal nephrogenesis, alterations in maternal and fetal environments, and obstruction within the normal developing urinary tract. The resultant clinical phenotypes are complex and depend on the timing of the insult, the penetrance of underlying gene mutations, and the severity and timing of obstruction related to the sequence of normal kidney development. Consequently, there is a broad spectrum of outcomes for children born with CAKUT. In this review, we explore the most common forms of CAKUT and those most likely to develop long-term complications of their associated kidney malformations. We discuss the relevant outcomes for the different forms of CAKUT and what is known about clinical characteristics across the CAKUT spectrum that are risk factors of long-term kidney injury and disease progression.

Prevalence of and risk factors for chronic kidney disease in ten metropolitan areas of China: a cross-sectional study using three kidney damage markers

INTRODUCTION

To estimate the up-to-date prevalence of chronic kidney disease among the health check-up population in economically developed areas of China using estimated glomerular filtration rate, urinary albumin creatinine ratio, and kidney ultrasound.

METHODS

Healthcare data from 38,093 subjects in 10 megalopolises of China who had an annual health check-up in 2021 were used. The overall and stratified prevalence of chronic kidney disease by sex, age, region and comorbidity group was reported. The association between chronic kidney disease and covariates of demographics, and comorbidities were analyzed in the multivariable-adjusted logistic regression model.

RESULTS

A total of 3837 CKD cases were detected meeting any of the three CKD diagnostic criteria, with a crude prevalence of 10.1% in the study population. Using one criterion of decreased glomerular filtration rate, albuminuria and kidney structural abnormalities alone detected 204 (5.3%), 3289 (85.7%) and 563 (14.7%) cases, respectively. The addition of kidney ultrasound detected 427 (11.1%) structural abnormality cases without decreased GFR and albuminuria. The most common abnormalities were renal masses, hydronephrosis due to obstruction and congenital anomalies of kidney and urinary tract. Female, older age, low city-tier, hypertension, diabetes, obesity, hypertriglyceridemia as well as early disease stages such as pre-hypertension, impaired fasting glucose and overweight were significantly associated with chronic kidney disease.

CONCLUSION

Kidney ultrasound helps to amplify the detection of CKD patients, which is a supplement to kidney function and urine protein.

Unraveling recurrent urinary tract infection in adulthood: a rare case report of unilateral partial duplex collecting system with ureterocele

Introduction

Duplication of the renal collecting system, known as the duplex collecting system, is a common congenital anomaly of the urinary tract. It can be partial or complete and affects 0.7-4% of the population, with a higher incidence in females. Ureteroceles are cystic dilations of the distal ureter and are often asymptomatic, particularly in adults.

Case presentation

The authors present a case of a newly diagnosed partial duplex collecting system of the left kidney and left intravesical ureterocele, which was diagnosed for the first time at the age of 47 years, along with a history of symptoms suggestive of recurrent urinary tract infection and a urethral calculus which was surgically managed 5 years ago.

Clinical discussion

The presence of a duplex collecting system can be observed even in males, with the possibility of recurrent urinary tract infection and the rare occurrence of an intravesical ureterocele. While ureteroceles are typically considered a congenital condition, they can also be diagnosed in adults.

Conclusion

A partial duplex collecting system of the left kidney with left intravesical ureterocele in the age of 47 years in a male is a rare occurrence. Diagnosis and management of such urological cases can be challenging especially in a resource limited setting, which can be mitigated by awareness of unusual presentations, proper antenatal care, and access to proper diagnostic tools.

Sex differences in children operated with pyeloplasty for pelvoureteric junction obstruction

PURPOSE

Pelvoureteric junction obstruction (UPJO) is a common cause of hydronephrosis in children but no previous studies have evaluated differences between boys and girls operated with pyeloplasty. This study aimed to evaluate potential differences between sexes in children operated with pyeloplasty for PUJO in terms of presentation, surgery, and long-term results.

METHODS

Data was retrospectively collected from all children operated on with pyeloplasty between January 2002 and December 2020. Data contained several variables covering presentation, surgery, and long-term results.

RESULTS

In total, 194 patients were included of which 126 (64.9%) were boys. There were no significant differences in prenatal findings, pelvic dilation on ultrasound, function of the affected kidney, surgical method, obstruction type, resolution of hydronephrosis, or improvement of function. Boys presented with pain more often than girls (47.4 vs 25.0%, p < 0.01) while girls were more prone to infections preoperatively (17.2 vs 7.0%, p = 0.04). All nine patients requiring reoperation were boys (p = 0.03).

CONCLUSION

Girls with UPJO seem to experience infections as presenting symptoms more often than boys, while boys significantly more often present with pain. There is also a higher percentage of boys needing reoperation.

Principles of Zebrafish Nephron Segment Development

Nephrons are the functional units which comprise the kidney. Each nephron contains a number of physiologically unique populations of specialized epithelial cells that are organized into discrete domains known as segments. The principles of nephron segment development have been the subject of many studies in recent years. Understanding the mechanisms of nephrogenesis has enormous potential to expand our knowledge about the basis of congenital anomalies of the kidney and urinary tract (CAKUT), and to contribute to ongoing regenerative medicine efforts aimed at identifying renal repair mechanisms and generating replacement kidney tissue. The study of the zebrafish embryonic kidney, or pronephros, provides many opportunities to identify the genes and signaling pathways that control nephron segment development. Here, we describe recent advances of nephron segment patterning and differentiation in the zebrafish, with a focus on distal segment formation.

Factors associated with clinically apparent congenital urethra anomalies among pediatric patients attending Muhimbili National Hospital, Dar Es Salaam, Tanzania

Background

Despite the clinically apparent congenital urethra anomalies being one of the common causes of admission in pediatric urology, yet little is known about its associated factors, especially in third world countries. Understanding associated factors of clinically apparent congenital urethra anomalies is important in prevention and in genetic counseling that may help in reducing the incidence of their occurrence.

Methods

Hospital-based cross-sectional prospective study conducted among pediatric patients admitted to pediatric surgery unit at Muhimbili National Hospital from July 2021 to March 2022. Socio-demographic and clinical characteristics were collected from participant’s parent or guardian. Patients were examined thoroughly for clinically apparent congenital urethra anomalies and associated genital-urinary tract anomalies. Analysis was done using SPPS version 23 with descriptive statistics for categorical variables and univariate and multivariate logistic regression for association between presence of clinically apparent urethra anomaly and associated factors at 95% CI. A p-value of < 5 was considered statistically significant.

Results

Overall proportion of clinically apparent urethra anomaly was 24.4% (94 out of 386) with hypospadias being the commonest anomaly (23.6%); others were epispadias in 2 patients (0.5%) and bladder exstrophy in one patient (0.3%). Among hypospadias cases, sub-coronal (37.4%) and mid-shaft (29.6%) were the most prevalent. About 9.6% had associated anomalies cryptorchidism being the commonest in 8 (8.5%) patients. There was no any factor that was independently associated with development of clinically apparent congenital urethra anomalies. However, folic acid supplementation, maternal hypertension, environmental exposure to pesticides and familial history of congenital urethra anomalies were related to higher proportion of the anomalies despite no any significant relationship detected.

Conclusion

Hypospadias is the commonest clinically apparent congenital urethra anomalies with cryptorchidism being the most prevalent associated genital-urinary tract anomaly. No associated factor has shown significant relationship with clinically apparent congenital urethra anomalies; however, attention is called to maternal hypertension, environmental exposure, especially pesticides and familial history of congenital urethra anomalies for detailed study. Proper examination of newborns is encouraged for early detection of such anomalies and hence planning for early intervention.

Modeling Podocyte Ontogeny and Podocytopathies with the Zebrafish

Podocytes are exquisitely fashioned kidney cells that serve an essential role in the process of blood filtration. Congenital malformation or damage to podocytes has dire consequences and initiates a cascade of pathological changes leading to renal disease states known as podocytopathies. In addition, animal models have been integral to discovering the molecular pathways that direct the development of podocytes. In this review, we explore how researchers have used the zebrafish to illuminate new insights about the processes of podocyte ontogeny, model podocytopathies, and create opportunities to discover future therapies.

Traumatic renal injury revealing a horseshoe kidney: A case report

Having a kidney disease is a major risk factor of renal injury during blunt traumas. We present a case of abdominal blunt trauma due to motor-vehicle accident in a 48 year old male patient. Abdominal computed tomography scan showed a high-volume retroperitoneal hematoma with rupture in the isthmus of the horseshoe kidney with active contrast-enhanced extravasation. He underwent a partial nephrectomy of the left lower pole.

A Spectrum of Congenital Anomalies of the Kidney and Urinary Tract (CAKUT)-Diagnostic Utility of Perinatal Autopsy

OBJECTIVE

To describe the spectrum of congenital renal anomalies and emphasize the critical role of comprehensive autopsy examination in identifying CAKUT, especially of lower urinary tract malformations correlating with prenatal imaging methods.

METHODS

Retrospective analyses of CAKUT diagnosed at fetal autopsy were analyzed over a 7-y period and correlated with prenatal imaging findings.

RESULT

Among the 255 fetal autopsies, 45 cases were detected with CAKUT. Isolated (27%), syndromic CAKUT (51%), and CAKUT associated with other system anomalies (22%) were found. Hydronephrosis, followed by cystic renal diseases and agenesis were the common renal malformations. The gastrointestinal tract (GIT) was the commonest system associated with CAKUT. Among the syndromic CAKUT, the urorectal septum malformation (URSM) was the most frequent one, followed by VACTER-L, acrorenal syndrome, and OEIS complex. When correlating prenatal USG and autopsy findings, a significant change in final diagnosis was observed in 60% of cases.

CONCLUSION

Extrarenal malformations and syndromic associations of CAKUT predominated over isolated ones. Detection of lower urinary tract anomalies in CAKUT is difficult through antenatal imaging methods if associated with oligohydramnios. In these circumstances, the perinatal autopsy has a significant role in arriving at the final diagnosis which guides the clinician in predicting the recurrence risk and the need for genetic workup.

Analysis of the operational status of the three-level referral system for urologic ultrasound screening and risk factors for renal pelvic dilatation in high-risk children

Background

Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) are the primary cause of end-stage renal disease in children, early diagnosis and treatment can significantly improve the kidney function. Among CAKUT, renal pelvis dilatation (RPD) due to various causes has the highest detection rate, which can be detected early by postnatal ultrasound screening. Since 2010, the Children's Hospital of Fudan University (CHFU), together with the Minhang District Maternal and Child Health Hospital (MCH) and Community Health Centres (CHCs) of Minhang District has created a three-level referral system for urological ultrasound screening. This study aims to describe the operation of a three-level referral system for ultrasound screening of CAKUT and to select risk factors of RPD in high-risk children.

Methods

The operation of the three-level referral system was assessed by analyzing the screening volume, screening rate, referral rate, and follow-up rate; risk factors of RPD in high-risk children were selected by chi-square test and multivariate logistic regression.

Results

A total of 16,468 high-risk children were screened in ten years, and the screening volume was maintained at about 1,500 cases per year; the screening rate showed a linear increase, from 36.8% in 2010 to 98.2% in 2019; the referral rate from the CHCs to the MCH was 89.9% significantly higher after 2015 than that of 84.7% from 2010 to 2015; the follow-up rate after 2015 was 71.0% significantly higher than that of 46.3% from 2010 to 2015. Multivariate logistic regression analysis showed that the risk of RPD was 1.966 times higher in males than in females, and the risk of moderate to severe RPD was 2.570 times higher in males than in females; the risk of RPD in preterm children was 1.228 times higher than that of full-term children; and the risk of RPD was 1.218 times higher in twins than in singles.

Conclusions

The screening volume of the three-level referral system has remained stable over a decade, with significantly higher screening, referral, and follow-up rates. Males, preterm, and twins are risk factors of RPD in high-risk children; males are also risk factors for moderate to severe RPD in high-risk children.

Congenital anomalies of the kidney and urinary tract (CAKUT) in critically ill infants: a multicenter cohort study

BACKGROUND

The aim of the study was to determine the prevalence of congenital anomalies of the kidney and urinary tract (CAKUT) in the neonatal intensive care unit (NICU) and to evaluate risk factors associated with worse outcomes. We hypothesized that infants with CAKUT with extra-renal manifestations have higher mortality.

METHODS

This is a cohort study of all inborn infants who were diagnosed with any form of CAKUT discharged from NICUs managed by the Pediatrix Medical Group from 1997 to 2018. Logistic and linear regression models were used to analyze risk factors associated with in-hospital mortality.

RESULTS

The prevalence of CAKUT was 1.5% among infants hospitalized in 419 NICUs. Among the 13,383 infants with CAKUT analyzed, median gestational age was 35 (interquartile range [IQR] 31-38) weeks and median birth weight was 2.34 (IQR 1.54-3.08) kg. Overall in-hospital mortality for infants with CAKUT was 6.8%. Oligohydramnios (adjusted odds ratio [aOR] 4.5, 95% confidence interval [CI] 2.2-9.1, p < 0.001), extra-renal anomalies (aOR 2.5, 95% CI 2.0-3.1, p < 0.001), peak SCr (aOR 1.02, 95% CI 1.01-1.03, p < 0.001) and exposure to nephrotoxic medications (aOR 1.4, 95% CI 1.1-1.7, p = 0.01) were associated with increased mortality, while a history of urological surgery or intervention was associated with lower mortality (aOR 0.6, 95% CI 0.4-0.7, p < 0.001).

CONCLUSIONS

Infants hospitalized in the NICU who have CAKUT and the independent risk factors for mortality (e.g., oligohydramnios and presence of extra-renal anomalies) require close monitoring, minimizing of exposure to nephrotoxic drugs, and timely urological surgery or intervention. A higher resolution version of the Graphical abstract is available as Supplementary information.

Modeling development of genitourinary birth defects to understand disruption due to changes in gene dosage

Genitourinary development is a delicately orchestrated process that begins in the embryo. Once complete, the genitourinary system is a collection of functionally disparate organs spread throughout the abdominal and pelvic regions. These distinct organs are interconnected through an elaborate duct system which aggregates the organs' products to a common exit point. The complicated nature of the genitourinary system makes it highly susceptible to developmental disruptions that produce anomalies. In fact, genitourinary anomalies are among the most common class of human birth defects. Aside from congenital anomalies of the kidney and urinary tract (CAKUT), for males, these birth defects can also occur in the penis (hypospadias) and testis (cryptorchism), which impact male fertility and male mental health. As genetic technology has advanced, it has become clear that a subset of cases of genitourinary birth defects are due to gene variation causing dosage changes in critical regulatory genes. Here we first review the parallels between human and mouse genitourinary development. We then demonstrate how translational research leverages mouse models of human gene variation cases to advance mechanistic understanding of causation in genitourinary birth defects. We close with a view to the future highlighting upcoming technologies that will provide a deeper understanding of gene variation affecting regulation of genitourinary development, which should ultimately advance treatment options for patients.

Initial observational management of hydronephrosis in infants with reduced differential renal function and non-obstructive drainage parameters

INTRODUCTION

Hydronephrosis secondary to ureteropelvic junction (UPJ) obstruction is a common finding in infants with prenatally-diagnosed hydronephrosis and often results in pyeloplasty due to obstructive drainage parameters and/or renal function compromise. However, little is known regarding the natural history of hydronephrosis with reduced differential renal function (DRF) but non-obstructive drainage.

OBJECTIVE

We sought to explore our experience with initial observational management of these patients.

STUDY DESIGN

A retrospective review of our institutional database of all diuretic MAG-3 renal scans obtained between 2000 and 2016 was performed. We included patients with antenatally-detected unilateral hydronephrosis ≥ SFU grade 2, first MAG-3 scan prior to 18months of age, DRF <40% and post-furosemide half-time (T1/2) <20 min. Exclusion criteria were: hydroureter, VUR, solitary kidney, duplication anomalies. Outcomes of interest were a progression of T1/2 ≥ 20 min and/or further decline in DRF >5%.

RESULTS

Of 704 patients with unilateral hydronephrosis, 91 had DRF≤40%, of which 29 (18 boys, 11 girls) met our inclusion criteria and were followed for a mean of 2.8 years (1.4 months-6.6 years). Mean age at first sonogram was 2.3 months. 2 patients had SFU grade 2, 16 had grade 3, and 9 had grade 4 hydronephrosis, and 2 unknown grade. Median half-time on initial MAG-3 scan across all patients was 10 min (3-20 min). Initial MAG3 scan was performed at a median of 2.3 months of age (0.3-17 months). 22/29 patients had >1 MAG3 scan. Of the 7 remaining, 5 were lost to follow-up and 2 demonstrated improvement in hydronephrosis. Worsening drainage occurred in 10/22(45%), median final T1/2 was 45.5 min 8 of these underwent pyeloplasty and 2 were lost to follow up. 4/22 patients (18%) had progressive decline in DRF (mean 8.3%, range 6-10%). 3/4 maintained non-obstructive drainage patterns and stable/improved hydronephrosis, and 1 underwent pyeloplasty. 13/18 remaining patients had stable DRF and 5 had improvement in DRF. 7(39%) of these underwent surgery for worsening drainage (Summary Figure). Overall, 7/29(24%) patients had sufficient resolution of hydronephrosis to be discharged from our care, 8(28%) are under continued observation, 9(31%) underwent pyeloplasty, and 5(17%) were lost to follow-up. In the observational group [median follow-up 4.5 years (3.7-6.6 years)], all 8 demonstrated improved non-obstructive drainage (T1/2 <20 minutes) and/or improvement in hydronephrosis. 4/10(40%) with DRF <35% underwent pyeloplasty versus 5/19(26%) with DRF 35-40%(p=0.67).

CONCLUSION

Initial observational management of unilateral hydronephrosis with reduced DRF and nonobstructive drainage is recommended as most kidneys maintain nonobstructive drainage and do not demonstrate further decline in DRF. Even when DRF decreases, the majority remain non-obstructive. Worsening drainage over time more often leads to the decision for pyeloplasty rather than change in DRF.

Acute kidney injury in pediatrics: an overview focusing on pathophysiology

Acute kidney injury (AKI) is defined as an abrupt decline in glomerular filtration rate, with increased serum creatinine and nitrogenous waste products due to several possible etiologies. Incidence in the pediatric population is estimated to be 3.9 per 1,000 hospitalizations, and prevalence among children admitted to intensive care units is 26.9%. Despite being a condition with important incidence and morbimortality, further evidence on pathophysiology and management among the pediatric population is still lacking. This narrative review aimed to summarize and discuss current data on AKI pathophysiology in the pediatric population, considering all the physiological particularities of this age range and common etiologies. Additionally, we reported current diagnostic tools, novel biomarkers, and newly proposed medications that have been studied with the aim of early diagnosis and appropriate treatment of AKI in the future.

Oxidative stress: An essential factor in the process of arteriovenous fistula failure

For more than half a century, arteriovenous fistula (AVFs) has been recognized as a lifeline for patients requiring hemodialysis (HD). With its higher long-term patency rate and lower probability of complications, AVF is strongly recommended by guidelines in different areas as the first choice for vascular access for HD patients, and its proportion of application is gradually increasing. Despite technological improvements and advances in the standards of postoperative care, many deficiencies are still encountered in the use of AVF related to its high incidence of failure due to unsuccessful maturation to adequately support HD and the development of neointimal hyperplasia (NIH), which narrows the AVF lumen. AVF failure is linked to the activation and migration of vascular cells and the remodeling of the extracellular matrix, where complex interactions between cytokines, adhesion molecules, and inflammatory mediators lead to poor adaptive remodeling. Oxidative stress also plays a vital role in AVF failure, and a growing amount of data suggest a link between AVF failure and oxidative stress. In this review, we summarize the present understanding of the pathophysiology of AVF failure. Furthermore, we focus on the relation between oxidative stress and AVF dysfunction. Finally, we discuss potential therapies for addressing AVF failure based on targeting oxidative stress.

High-grade cervical dysplasia in a woman with uterine didelphys: A case report

•

Simultaneous malformations of the genital and urinary tracts present a higher risk of genital cancers.

•

Carcinomas of the genital tract and genitourinary malformations are separately relatively common but coexistence is rare.

•

We describe a case of high-grade dysplasia in the left cervix of a woman with a uterine didelphys and urinary malformations.

•

Multi-disciplinary international Project ECHO tumor boards can provide guidance in the management of difficult cases.

The combination of lower genital tract carcinomas with genitourinary malformations is a rare occurrence. The purpose of this report is to describe the case of high-grade cervical dysplasia of the left cervix of a woman with a uterine didelphys and additional urinary tract malformations.

Duplex Kidney Anomalies and Associated Pathologies in Children: A Single-Center Retrospective Review

Introduction: Duplex renal collecting systems are one of the most common congenital anomalies of the urinary tract. The exact prevalence of this anomaly is difficult to ascertain because most patients are asymptomatic, and the abnormality is frequently detected incidentally. The aim of this study is to retrospectively review the demographic characteristics and different clinical presentations, related pathology, and treatment methods of patients with duplex system anomaly who applied to our institution, with a literature review.

Methods: This is a retrospective study, performed at the Department of Pediatric Urology and Pediatric Surgery, Umraniye Training and Research Hospital, a tertiary center, from 2010 to 2021. Age, gender, presenting symptoms, and associated anomalies were determined in all patients. Asymptomatic patients with variants of duplex kidney anomaly detected incidentally did not require any surgical intervention. Necessary surgical interventions were performed depending on the pathologies of other symptomatic patients associated with duplex kidney anomaly variants.

Results: A total of 239 patients had duplex systems. The patients were divided into two groups according to their age, 0-24 months (newborn and infant) and over 24 months. There were 45 (18.8%) patients in the 1st group and 194 (81.1%) patients in the 2nd group. It was seen that the most common symptom in 85 (35.6%) patients was urinary tract infection (UTI). It was observed that 5 (2%) patients had no symptoms and were detected during routine screening. When comorbidities detected with the duplex system were examined, the most common ones were antenatal hydronephrosis 23 (9.6%). Ureterocele excision was performed in ten patients, laparoscopic heminephrectomy was performed in six patients, and ureteroneocystostomy was performed in one patient.

Conclusions: It is important that magnetic resonance urography (MRU) duplex renal collecting systems, which is a current imaging method used in the evaluation of the duplex system, provide detailed information about the morphology and function and are useful in the evaluation of associated anomalies. Diagnosis and treatment before it becomes symptomatic or results in further kidney damage are important for the preservation of renal function in advanced follow-ups.

Lower pole anatomy of horseshoe kidney and complete ureteral duplication: Anatomic and radiologic study applied to endourology

Purpose:

To analyze the 3-dimensional intrarenal anatomy of horseshoe kidneys (HK) and kidney with complete ureteral duplication (CUD), in polyester resin endocasts of the collecting system and in patients submitted to 3D computerized tomography scan (CT-scan).

Materials and Methods:

We analyzed seven 3-dimensional polyester resin endocasts of the kidney collecting system obtained from 6 fresh adult cadavers (4 with unilateral CUD and 2 with horseshoe kidney) and CT-scan reconstruction images of kidneys from 24 patients: 6 patients with HK, 8 with CUD and 10 patients without renal anomalies that were used as controls. We analyzed the spatial distribution of the calices, the infundibula diameters, the angle between the lower infundibulum and the renal pelvis (LIP) and the angle between the lower infundibulum and the inferior minor calyces (LIICA). Measurements of the width and length of the inferior infundibulum and the infundibula of the minor calyces, as well as the angles (LIP and LIICA) were made with the aid of the LibreOffice 6.3 software. The data were analyzed with the IBM^® SPSS^® Statistics.

Results:

There was no statistical difference in the inferior pole measurements between the groups with anomalies and the control group, both in polyester resin endocasts and CT-scan reconstruction images for LIP. When we compared the LIP in the CT-scan between HK versus CUD (p= 0.003), and HK versus the control group (p= 0.035), we observed statistical difference.

Conclusions:

The knowledge of spatial anatomy of lower pole is of utmost importance during endourologic procedures in patients with kidney anomalies. In the present study we observed that horseshoe kidneys had more restrictive anatomic factors in lower pole than the complete ureteral duplication.

A rare case report of Edwards syndrome with immature teratoma in submandibular region and literature review

Trisomy 18 (Edward syndrome) was first described by Edwards et al. in 1960. The condition is the second most common autosomal trisomy syndrome in males. The prevalence in infants is estimated as 1/6000-1/8000. Those affected have a high mortality rate – only 4% may survive their first year.

The study illustrates the first reported case of Edwards syndrome with immature teratoma in submandibular region.

A 33-year-old multigravida had a normal antenatal course until 36 weeks of gestation. Two hours after delivery, the baby was transported to a neonatal ward, where several malformations were described: a tumour formation the size of a walnut in the right submandibular region, ear abnormality, micrognathia with high arched palate, overlapping fingers, and feet deformities. A genetic test was performed which confirmed trisomy 18. After 26 days of assisted ventilation and oxygen therapy, the newborn developed hyaline-membrane disease, dilatation of the pulmonary artery and the right side of the heart, thrombosis of the right atrium and these conditions were determined to be the cause of death.

The autopsy and histological examination confirmed the aforementioned malformations finding also a kidney with duplicated collecting system on the right and ectopic ureter in the left kidney. The submandibular tumour was determined to be immature teratoma.

Conclusion: This is the first presented case in the literature of a newborn with Edwards syndrome combined with immature teratoma.

Challenges in genetic counseling for congenital anomalies of the kidneys and urinary tract (CAKUT) spectrum

Objectives

Congenital anomalies of the kidneys and urinary tract (CAKUT) are one of the most common sets of congenital defects. Bilateral renal agenesis is a severe presentation of the CAKUT spectrum.

Case presentation

We report on two families who presented with recurrent pregnancies affected with bilateral renal agenesis and negative family histories. Likely pathogenic variants in the GREB1L gene were identified in the affected pregnancies and subsequently in their asymptomatic fathers. The first familial variant was identified by a multi-gene CAKUT panel and the second by whole exome sequencing. Renal ultrasound showed the father in family 1 had asymptomatic unilateral pelvic kidney and the father in family 2 had no apparent renal anomalies.

Conclusions

Recent identification of genes responsible for CAKUT allows for genetic testing of affected families. Identification of the genetic etiology of CAKUT cases has multiple benefits including accurate risk assessment and reproductive options. Genetic counseling around CAKUT is challenging due to the extreme variability in presentation of the disorders.

Multidisciplinary approaches for elucidating genetics and molecular pathogenesis of urinary tract malformations

Advances in clinical diagnostics and molecular tools have improved our understanding of the genetically heterogeneous causes underlying congenital anomalies of kidney and urinary tract (CAKUT). However, despite a sharp incline of CAKUT reports in the literature within the past 2 decades, there remains a plateau in the genetic diagnostic yield that is disproportionate to the accelerated ability to generate robust genome-wide data. Explanations for this observation include (i) diverse inheritance patterns with incomplete penetrance and variable expressivity, (ii) rarity of single-gene drivers such that large sample sizes are required to meet the burden of proof, and (iii) multigene interactions that might produce either intra- (e.g., copy number variants) or inter- (e.g., effects in trans) locus effects. These challenges present an opportunity for the community to implement innovative genetic and molecular avenues to explain the missing heritability and to better elucidate the mechanisms that underscore CAKUT. Here, we review recent multidisciplinary approaches at the intersection of genetics, genomics, in vivo modeling, and in vitro systems toward refining a blueprint for overcoming the diagnostic hurdles that are pervasive in urinary tract malformation cohorts. These approaches will not only benefit clinical management by reducing age at molecular diagnosis and prompting early evaluation for comorbid features but will also serve as a springboard for therapeutic development.

Kidney Failure in Bardet-Biedl Syndrome

The aim of this study was to explore kidney failure (KF) in Bardet–Biedl syndrome (BBS), focusing on high‐risk gene variants, demographics, and morbidity. We employed the Clinical Registry Investigating BBS (CRIBBS) to identify 44 (7.2%) individuals with KF out of 607 subjects. Molecularly confirmed BBS was identified in 37 KF subjects and 364 CRIBBS registrants. KF was concomitant with recessive causal variants in 12 genes, with BBS10 the most predominant causal gene (26.6%), while disease penetrance was highest in SDCCAG8 (100%). Two truncating variants were present in 67.6% of KF cases. KF incidence was increased in genes not belonging to the BBSome or chaperonin‐like genes (p < 0.001), including TTC21B, a new candidate BBS gene. Median age of KF was 12.5 years, with the vast majority of KF occurring by 30 years (86.3%). Females were disproportionately affected (77.3%). Diverse uropathies were identified, but were not more common in the KF group (p = 0.672). Kidney failure was evident in 11 of 15 (73.3%) deaths outside infancy. We conclude that KF poses a significant risk for premature morbidity in BBS. Risk factors for KF include female sex, truncating variants, and genes other than BBSome/chaperonin‐like genes highlighting the value of comprehensive genetic investigation.

World Federation for Ultrasound in Medicine Review Paper: Incidental Findings during Obstetrical Ultrasound

Although the prevalence of incidental findings revealed during an obstetric ultrasound examination is low, the findings may include adnexal and cervical masses, uterine or urinary congenital malformations, free fluid in the pouch of Douglas or tortuous vessels (varices). Adnexal masses are the most common finding and vary in imaging characteristics. They are mainly unilateral, cystic masses with a low risk of malignancy that are treated conservatively. The International Ovarian Tumor Analysis scoring models may be helpful in differentiating benign from malignant masses. For those masses >5 cm, follow-up is recommended, and resection could be considered to avoid risk of torsion, rupture and hemorrhage, which may compromise pregnancy outcome. Uterine masses such as fibroids are commonly diagnosed early in the first trimester and should be followed up during pregnancy to evaluate any changes. Transabdominal and transvaginal ultrasound is the first-line test for the diagnosis of such incidentalomas; however, magnetic resonance ultrasound may have a useful role in excluding malignancy potential. As a result of their low frequency and the lack of good evidence, there are no specific guidelines on the management of incidentalomas detected at obstetric scans. Their management should follow the related general guidelines for ovarian, cervical and uterine masses, with individualized management depending on the pregnancy status.

Ultrasound-Based Renal Parenchymal Area and Kidney Function Decline in Infants With Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies of the kidney and urinary tract are the leading cause of chronic kidney disease in children. Noninvasive imaging biomarkers that predict chronic kidney disease progression in early infancy are needed. We performed a pilot study nested in the prospective Chronic Kidney Disease in Children cohort study to determine the association between renal parenchymal area (RPA) on first post-natal renal ultrasound and change in estimated glomerular filtration rate (eGFR) in children with congenital anomalies of the kidney and urinary tract. Among 14 participants, 78.6% were males, the median age at the time of the ultrasound was 3.4 months (interquartile range, 1.3-7.9 mo), and the median total RPA z-score at baseline was -1.01 (interquartile range, -2.39 to 0.52). After a median follow-up period of 7.4 years (interquartile range, 6.8-8.2 y), the eGFR decreased from a median of 49.4 mL/min per 1.73 m² at baseline to 29.4 mL/min per 1.73 m², an annual eGFR percentage decrease of -4.68%. Lower RPA z-scores were correlated weakly with a higher annual decrease in eGFR (Spearman correlation, 0.35; 95% confidence interval, -0.25 to 0.76). This pilot study shows the feasibility of obtaining RPA from a routine ultrasound and suggests that a lower baseline RPA may be associated with a greater decrease in eGFR over time. Further studies with larger patient cohorts are needed to confirm this association.

Access to treatment for chronic kidney disease by children and adolescents in Brazil

BACKGROUND

This study aimed to identify main factors associated with child and adolescent access to chronic kidney disease (CKD) treatment in Brazil.

METHODS

Multi-center cross-sectional study conducted in eight pediatric nephrology centers across all Brazilian geographic regions. Information was collected on characteristics associated with referral and treatment of patients with CKD. The following outcomes were analyzed as follows: (1) age at first consultation, and (2) time elapsed between referral and treatment at the specialized service.

RESULTS

Three hundred thirty-five children were assessed. Variables associated with age at first consultation were as follows: CAKUT (HR=1.7; 95%CI 1.3-2.2, p<0.01); private health plan (HR=1.54; 95%CI 1.06-2.23, p=0.02); modified Medical Outcomes Study Social Support Survey mMOS-SS score (HR=1.02; 95%CI 1.00-1.03, p=0.024); maternal age (HR=0.96; 95%CI 0.95-0.97, p<0.01); and number of siblings in the household (HR=0.86; 95%CI 0.79-0.83, p<0.01). Significant variables associated with time elapsed between referral and treatment at the specialized service were as follows: each additional occupant sharing the household (HR=0.94; 95%CI:0.89-0.99, p=0.02), residing in the Northeast (HR=0.81; 95%CI:0.67-0.98, p=0.03) and having someone to take them to the physician (HR=1.36; 95%CI 1.07-1.74, p=0.01). The median time interval between patient referral and treatment by the service was 11 days (IQR 10-31).

CONCLUSION

There are potentially modifiable factors hampering access of children with CKD to specialized treatment. The importance of the role of social support for the two outcomes should serve as an alert for health managers and professionals to consider this aspect throughout all steps of the care process of children with CKD.

Bilateral pelvic kidneys with upper pole fusion and malrotation: a case report and review of the literature

BACKGROUND

The incidence of ectopic kidneys is 1:12,000 clinically and 1:900 postmortem. Patients with pelvic mal-rotated kidneys are more susceptible to recurrent urinary tract infections, recurrent renal stones, and renal injury. Fusion of the kidney lower poles is relatively common compared to other types of renal anomalies.

CASE PRESENTATION

We present the case of a 36-year-old Sudanese female patient who presented with a long history of recurrent urinary tract infections unresponsive to antibiotics. Ultrasound scan revealed bilateral pelvic kidneys. Computed tomography (CT) urography confirmed bilateral ectopic fused kidneys, with the left kidney mal-rotated (renal pelvis facing upwards and laterally). Kidney infection secondary to vesicoureteral reflux was diagnosed. Antibiotics were prescribed according to culture and sensitivity. The patient responded well to ciprofloxacin.

CONCLUSION

A history of recurrent urinary tract infections without an apparent cause is highly suggestive of renal anomaly and should be investigated expediently. Ultrasonography or CT imaging may be utilized to aid in diagnosis. Early recognition may help prevent the high risk of end-stage renal failure associated with anomalies.

Patterns of co-occurring birth defects among infants with hypospadias

INTRODUCTION

Hypospadias, one of the most common male genital birth defects, occurs in 1 out of every 200 male births in the United States and is increasing in prevalence globally.

OBJECTIVE

This study aimed to characterize the combinations of birth defects that co-occur with hypospadias more often than expected by chance, while accounting for the complex clustering patterns of congenital defects.

STUDY DESIGN

We analyzed cases with hypospadias and at least one additional co-occurring defect from the Texas Birth Defect Registry born between 1999 and 2014. For each combination, we calculated adjusted observed-to-expected (O/E) ratios, using Co-Occurring Defect Analysis (CODA).

RESULTS

Among 16,442 cases with hypospadias and without known syndromes, 2,084 (12.7%) had at least one additional defect. Many of the birth defect combinations within the highest adjusted O/E ratios included cardiac, musculoskeletal, and additional urogenital defects. For example, a top combination with an adjusted O/E of 139.0 included renal agenesis and dysgenesis, reduction defects of the upper limb, and other anomalies of upper limb (including shoulder girdle). High adjusted O/E ratios were also observed in combinations that included defects outside of the urogenital developmental field. For instance, the combination with the highest O/E ratio included buphthalmos, and congenital cataract and lens anomalies (adjusted O/E ratio: 192.9). Similar results were obtained when we restricted our analyses to cases with second- or third-degree hypospadias.

DISCUSSION

Many combinations in the top results were expected (e.g., multiple urogenital defects); however, some combinations with seemingly unrelated patterns of defects may suggest the presence of some etiologic mechanisms yet to be identified.

CONCLUSION

In summary, this study described patterns of co-occurring defect combinations with hypospadias that can inform further study and may provide insights for screening and diagnostic practices.

Congenital Anomalies of the Upper Urinary Tract: A Comprehensive Review

The upper urinary tract is the most common human system affected by congenital anomalies. Congenital anomalies of the kidneys and ureters comprise a wide spectrum of disorders ranging from simple variants with no clinical significance to complex anomalies that may lead to severe complications and end-stage renal disease. They may be classified as anomalies of renal form, which are subclassified as structural anomalies (eg, persistent fetal lobulation, hypertrophied column of Bertin, and dromedary hump) and fusion anomalies (eg, horseshoe kidney and pancake kidney); anomalies of renal position (eg, renal malrotation, simple renal ectopia, and crossed renal ectopia) and renal number (eg, renal agenesis and supernumerary kidney); and abnormalities in development of the urinary collecting system (eg, pyelocaliceal diverticulum, megacalycosis, ureteropelvic junction obstruction, duplex collecting system, megaureter, ectopic ureter, and ureterocele). US is usually the first imaging modality used because of its low cost, wide availability, and absence of ionizing radiation. Intravenous urography and voiding cystourethrography are also useful, mainly for characterization of the collecting system and vesicoureteral reflux. However, intravenous urography has been replaced by CT urography and MR urography. These imaging methods not only allow direct visualization of the collecting system but also demonstrate the function of the kidneys, the vascular anatomy, adjacent structures, and complications. Comprehension of congenital anomalies of the upper urinary tract is crucial for an accurate diagnosis and correct management. The authors discuss the spectrum of these anomalies, with emphasis on embryologic development, imaging findings, clinical manifestations, and complications. Online supplemental material is available for this article. ^©RSNA, 2021.

A Unique Case of Incomplete Bifid Ureter and Associated Arterial Variations

Introduction. Urogenital and vascular anomalies, including a left duplex kidney and a left aberrant renal artery that gave rise to the left ovarian artery, were observed in a 77-year-old female cadaver during a routine dissection. Description. A left aberrant renal artery, which gave rise to the left ovarian artery, was observed originating from the aorta 4 cm below the left renal artery. Two independent contributions to a bifid ureter were found originating from the hilum of the left kidney. These two contributions descended 12.4 cm and 10.6 cm, respectively, posterior to the left aberrant renal artery and lateral to the left ovarian artery before uniting anterior to the psoas major muscle to descend 12.7 cm to the bladder. Significance. While the duplex kidney is a relatively common congenital anomaly that can be asymptomatic, it can also potentially be associated with compression of renal vasculature or the ureter. Ureteral compression can then result in several pathologies including reflux, urinary tract infection (UTI), ureteropelvic junction obstruction, or hydronephrosis. Compression of renal and ovarian vasculature can result in altered blood flow to the kidney and ovary, potentially causing fibrosis, atrophy, or organ failure. Current imaging techniques alone are insufficient for correct diagnostics of such complications, and they must be supplemented with a thorough understanding of the respective anatomical variations.

Early Acute Kidney Injury in Preterm and Term Neonates: Incidence, Outcome, and Associated Clinical Features

BACKGROUND

Critically ill neonates are at high risk of kidney injury, mainly in the first days of life. Acute kidney injury (AKI) may be underdiagnosed due to lack of a uniform definition. In addition, long-term renal follow-up is limited.

OBJECTIVE

To describe incidence, etiology, and outcome of neonates developing AKI within the first week after birth in a cohort of NICU-admitted neonates between 2008 and 2018. Renal function at discharge in infants with early AKI was assessed.

METHODS AND SUBJECTS

AKI was defined as an absolute serum Cr (sCr) value above 1.5 mg/dL (132 μmol/L) after the first 24 h or as stage 2-3 of the NIDDK neonatal definition. Clinical data and outcomes were collected from medical records and retrospectively analyzed.

RESULTS

From January 2008 to December 2018, a total of 9,376 infants were admitted to the NICU of Wilhelmina Children's Hospital/UMC Utrecht, of whom 139 were diagnosed with AKI during the first week after birth. In 72 term infants, the most common etiology was perinatal asphyxia (72.2%), followed by congenital kidney and urinary tract malformations (CAKUT) (8.3%), congenital heart disease (6.9%), and sepsis (2.8%). Associated conditions in 67 preterm infants were medical treatment of a hemodynamic significant PDA (27.2%), -CAKUT (21%), and birth asphyxia (19.4%). Among preterm neonates and neonates with perinatal asphyxia, AKI was mainly diagnosed by the sCr >1.5 mg/dL criterion. Renal function at discharge improved in 76 neonates with AKI associated with acquired conditions. Neonates with stage 3 AKI showed increased sCr values at discharge. Half of these were caused by congenital kidney malformations and evolved into chronic kidney disease (CKD) later in life. Neurodevelopmental outcome (NDO) at 2 years was favorable in 93% of surviving neonates with detailed follow-up.

CONCLUSION

During the first week after birth, AKI was seen in 1.5% of infants admitted to a level III NICU. Renal function at discharge had improved in most neonates with acquired AKI but not in infants diagnosed with stage 3 AKI. Long-term renal function needs further exploration, whereas NDO appears to be good.

Malrotation of an iliac ectopic kidney with pyelo-ureteral duplication: An incidental three-in-one congenital anomaly

Renal ectopia is a rare congenital anomaly that mostly occurs in the pelvic area. An ectopic kidney is usually associated with other anomalies such as a malrotation. We report the case of a 15-year-old male who consulted after a blunt abdominal trauma. A left iliac renal ectopia was incidentally discovered. This ectopic kidney was associated with a malrotation, and a pyelo-ureteral duplication. Iliac renal ectopia should be dissociated from other abdominal renal ectopias, and its association with other renal malformations should be further investigated.

High Activation of the AKT Pathway in Human Multicystic Renal Dysplasia

Multicystic renal dysplasia is a congenital cystic anomaly of the kidney caused by abnormal metanephric differentiation with immature tubules. It is surrounded by mesenchymal collars and islands of immature mesenchyma present between the cysts. The PI3K-AKT-mTOR signaling pathway is a key regulator involved in cell growth, proliferation, motility, survival, and apoptosis. Activation of the PI3K-AKT-mTOR pathway results in the survival and proliferation of tumor cells in many cancers. The aim of this study is to analyze the topographic expression of phospho-AKT, phospho-mTOR, and phospho-70S6K in renal development and in the multicystic dysplastic kidney (MCDK). A total of 17 fetal kidneys of development age from the first to the third trimester and 13 cases of pathological kidneys with MCDK were analyzed by immunohistochemistry in order to evaluate the expression of phospho-AKT (S473), phospho-mTOR, and phospho-70S6K. Phospho-AKT and phospho-mTOR were expressed early in renal development and in an identical manner for every structure derived from the ureteric bud, such as collecting ducts and urothelium. Phospho-p70S6K was expressed early in the urothelium and in glomerular mesangial cells. Later, their expressions differed according to the needs of cell proliferation and differentiation over time by becoming more selective. In MCDK, phospho-AKT, phospho-mTOR, and phospho-70S6K have the same profile: a high cytoplasmic expression in cystic epithelium, loose mesenchyma, and primitive tubes. This study demonstrates the essential and specific role of the PI3K-AKT-mTOR pathway in the formation of cysts in multicystic renal dysplasia.

Screening for Renal and Urinary Tract Anomalies in Asymptomatic First Degree Relatives of Children with Congenital Anomalies of the Kidney and Urinary Tract (CAKUT)

OBJECTIVE

To estimate the frequency of renal and urinary tract anomalies in first-degree relatives of children with Congenital anomalies of kidney and urinary tract (CAKUT).

METHODS

This descriptive study was conducted on parents and siblings of 138 children with CAKUT. Renal ultrasonogram, radionuclide diuretic renogram and micturating cysturethrogram were the tools used for screening these family members.

RESULTS

Asymptomatic first-degree relatives of 138 children [total of 270 first-degree relatives (95 fathers, 97 mothers and 78 siblings)] were screened, with new anomalies detected in 11 first-degree relatives (4% out of 270 first-degree relatives screened) from 11 families (7.9% out of 138 families screened). The anomalies detected were vesicoureteric reflux (VUR) (n = 2), non-obstructive non-refluxing hydronephrosis (n = 2), pelviureteral junction obstruction (PUJO) (n = 3), Duplex collecting system (n = 1), hypodysplastic kidney (n = 1), single kidney (n = 1) and horseshoe kidney (n = 1). Most of the anomalies were discordant to the index anomaly (66.6%). Among 95 fathers screened, 5 (5.2%) had renal anomalies. Among 97 mothers screened, 2 (2.1%) had renal anomalies. Among the 78 siblings screened, 4 (5.1%) had renal anomalies.

CONCLUSIONS

Familial clustering was noted in 7.9% of the 138 families (of the index cases) screened. The anomalies detected were mostly discordant to the index anomaly.

Horseshoe Kidney Blunt Trauma With Double Laceration: Endovascular Management

A 78-year-old male patient was admitted to our hospital after abdominal trauma. Contrast-enhanced computed tomography (CT) scan demonstrated a horseshoe kidney with a perinephric hematoma and evidence of arterial hemorrhage. An anomalous renal arterial anatomy was noted as well, with a renal artery originating from the left common iliac artery. He was successfully treated via an endovascular approach. Varying forms of vascularization may complicate angiographic treatment of patients with abdominal trauma in a setting of kidney anomalies. Obtaining and evaluating contrast-enhanced CT angiography can identify anomalous vessels and can be invaluable when deciding on the most appropriate interventional approach.

Comparative Proteome Analyses of Ureteropelvic Junction Obstruction and Surrounding Ureteral Tissue

Ureteropelvic junction (UPJ) obstruction is a common problem in children, but its etiology remains unclear. In this study, the proteome profiles of the obstructed segment and its surrounding distal and proximal parts were comparatively evaluated. Twelve children younger than 2 years of age with unilateral intrinsic UPJ obstruction were included. The excised operational tissue was divided into three parts immediately after resection: the obstructed part (Obst), the distal normal ureteral part (Dist), and the proximal part of the obstructed segment (Prox). Proteins extracted from the tissue samples were subjected to two-dimensional gel electrophoresis analysis to identify differentially regulated proteins. Spot analysis revealed that four proteins, namely tropomyosin beta and alpha-1 chains, actin and desmin, were upregulated in Obst in comparison to Dist. A similar analysis between Obst and Prox showed that heat shock protein beta-1 and carbonic anhydrase-1 were upregulated in Obst, while tropomyosin alpha 3 chain and ATP synthase beta were upregulated in Prox. The last comparative analysis between Dist and Prox revealed upregulation of annexin-A5 and annexin-A1 in Dist and vimentin, mitochondrial ATP synthase subunit-beta, peroxiredoxin-2, and apolipoprotein-A1 in Prox. Bioinformatics analysis using the STRING server indicated that the differentially regulated proteins, altogether, point to the changes occurring in muscle filament sliding pathway. When regulations occurring in each group were mutually compared, a change in lipase inhibition activity was detected by STRING. This is the first study scrutinizing changes occurring in protein profiles in UPJ.

Differential role of planar cell polarity gene Vangl2 in embryonic and adult mammalian kidneys

Planar cell polarity (PCP) pathway is crucial for tissue morphogenesis. Mutations in PCP genes cause multi-organ anomalies including dysplastic kidneys. Defective PCP signaling was postulated to contribute to cystogenesis in polycystic kidney disease. This work was undertaken to elucidate the role of the key PCP gene, Vangl2, in embryonic and postnatal renal tubules and ascertain whether its loss contributes to cyst formation and defective tubular function in mature animals. We generated mice with ubiquitous and collecting duct-restricted excision of Vangl2. We analyzed renal tubules in mutant and control mice at embryonic day E17.5 and postnatal days P1, P7, P30, P90, 6- and 9-month old animals. The collecting duct functions were analyzed in young and adult mutant and control mice. Loss of Vangl2 leads to profound tubular dilatation and microcysts in embryonic kidneys. Mechanistically, these abnormalities are caused by defective convergent extension (larger tubular cross-sectional area) and apical constriction (cuboidal cell shape and a reduction of activated actomyosin at the luminal surface). However, the embryonic tubule defects were rapidly resolved by Vangl2-independent mechanisms after birth. Normal collecting duct architecture and functions were found in young and mature animals. During embryogenesis, Vangl2 controls tubular size via convergent extension and apical constriction. However, rapidly after birth, PCP-dependent control of tubular size is switched to a PCP-independent regulatory mechanism. We conclude that loss of the Vangl2 gene is dispensable for tubular elongation and maintenance postnatally. It does not lead to cyst formation and is unlikely to contribute to polycystic kidney disease.

Zinner syndrome mimicking bladder outlet obstruction managed with aspiration

Zinner syndrome is a rare cystic malformation of seminal vesicle which consists a triad of unilateral renal agenesis, ipsilateral seminal vesicle cyst, and ejaculatory duct obstruction. The usual presentation is between the third and fourth decades of life, with infertility being the most common complaint. Ultrasound, cystoscopy, and magnetic resonance tomography (MRI) can easily detect this condition. Treatment option varies according to the presenting symptoms of the patient. We present a case of a 19-year-old male with recurrent episodes of urinary tract infection (UTI) and poor urinary stream. On ultrasound examination, the patient was found to have absent right kidney with a cystic swelling noted to be arising from prostate or seminal vesicle region which was further confirmed on MRI examination. Cystoscopy reveals a bulge on the right side of the verumontanum abutting the neck of the bladder. An ultrasound-guided aspiration of the cyst was performed which relieved the symptoms of the patient. Cystic abnormalities of the seminal vesicle are very uncommon. Symptomatic cases may present as recurrent UTI, infertility, bladder outlet obstruction, and painful ejaculation. Surveillance may be the option in the absence of clinical manifestations. Interventions such as image-guided aspiration or surgical procedures are appropriate when conservative measures prove ineffective.

Histology Atlas of the Developing Mouse Urinary System With Emphasis on Prenatal Days E10.5-E18.5

Congenital abnormalities of the urinary tract are some of the most common human developmental abnormalities. Several genetically engineered mouse models have been developed to mimic these abnormalities and aim to better understand the molecular mechanisms of disease. This atlas has been developed as an aid to pathologists and other biomedical scientists for identification of abnormalities in the developing murine urinary tract by cataloguing normal structures at each stage of development. Hematoxylin and eosin- and immunohistochemical-stained sections are provided, with a focus on E10.5-E18.5, as well as a brief discussion of postnatal events in urinary tract development. A section on abnormalities in the development of the urinary tract is also provided, and molecular mechanisms are presented as supplementary material. Additionally, overviews of the 2 key processes of kidney development, branching morphogenesis and nephrogenesis, are provided to aid in the understanding of the complex organogenesis of the kidney. One of the key findings of this atlas is the histological identification of the ureteric bud at E10.5, as previous literature has provided conflicting reports on the initial point of budding. Furthermore, attention is paid to points where murine development is significantly distinct from human development, namely, in the cessation of nephrogenesis.

Three Optimized Methods for In Situ Quantification of Progenitor Cell Proliferation in Embryonic Kidneys Using BrdU, EdU, and PCNA

Background:

Nephron progenitor cells derived from the metanephric mesenchyme undergo a complex balance of self-renewal and differentiation throughout kidney development to give rise to the mature nephron. Cell proliferation is an important index of progenitor population dynamics. However, accurate and reproducible in situ quantification of cell proliferation within progenitor populations can be technically difficult to achieve due to the complexity and harsh tissue treatment required of certain protocols.

Objective:

To optimize and compare the performance of the 3 most accurate S phase–specific labeling methods used for in situ detection and quantification of nephron progenitor and ureteric bud cell proliferation in the developing kidney, namely, 5-bromo-2’-deoxyuridine (BrdU), 5-ethynyl-2’-deoxyuridine (EdU), and proliferating cell nuclear antigen (PCNA).

Methods:

Protocols for BrdU, EdU, and PCNA were optimized for fluorescence labeling on paraformaldehyde-fixed, paraffin-embedded mouse kidney tissue sections, with co-labeling of nephron progenitor cells and ureteric bud with Six2 and E-cadherin antibodies, respectively. Image processing and analysis, including quantification of proliferating cells, were carried out using free ImageJ software.

Results:

All 3 methods detect similar ratios of nephron progenitor and ureteric bud proliferating cells. The BrdU staining protocol is the lengthiest and most complex protocol to perform, requires tissue denaturation, and is most subject to interexperimental signal variability. In contrast, bound PCNA and EdU protocols are relatively more straightforward, consistently yield clear results, and far more easily lend themselves to co-staining; however, the bound PCNA protocol requires substantive additional postexperimental analysis to distinguish the punctate nuclear PCNA staining pattern characteristic of proliferating cells.

Conclusions:

All 3 markers exhibit distinct advantages and disadvantages in quantifying cell proliferation in kidney progenitor populations, with EdU and PCNA protocols being favored due to greater technical ease and reproducibility of results associated with these methods.

Prenatal genetic considerations of congenital anomalies of the kidney and urinary tract (CAKUT)

Congenital anomalies of the kidney and urinary tract (CAKUT) constitute 20% of all congenital malformations occurring in one in 500 live births. Worldwide, CAKUT are responsible for 40% to 50% of pediatric and 7% of adult end-stage renal disease. Pathogenic variants in genes causing CAKUT include monogenic diseases such as polycystic kidney disease and ciliopathies, as well as syndromes that include isolated kidney disease in conjunction with other abnormalities. Prenatal diagnosis most often occurs using ultrasonography; however, further genetic diagnosis may be made using a variety of testing strategies. Family history and pathologic examination can also provide information to improve the ability to make a prenatal diagnosis of CAKUT. Here, we provide a comprehensive overview of genetic considerations in the prenatal diagnosis of CAKUT disorders. Specifically, we discuss monogenic causes of CAKUT, associated ultrasound characteristics, and considerations for genetic diagnosis, antenatal care, and postnatal care.

Xenopus: Driving the Discovery of Novel Genes in Patient Disease and Their Underlying Pathological Mechanisms Relevant for Organogenesis

Frog model organisms have been appreciated for their utility in exploring physiological phenomena for nearly a century. Now, a vibrant community of biologists that utilize this model organism has poised Xenopus to serve as a high throughput vertebrate organism to model patient-driven genetic diseases. This has facilitated the investigation of effects of patient mutations on specific organs and signaling pathways. This approach promises a rapid investigation into novel mechanisms that disrupt normal organ morphology and function. Considering that many disease states are still interrogated in vitro to determine relevant biological processes for further study, the prospect of interrogating genetic disease in Xenopus in vivo is an attractive alternative. This model may more closely capture important aspects of the pathology under investigation such as cellular micro environments and local forces relevant to a specific organ's development and homeostasis. This review aims to highlight recent methodological advances that allow investigation of genetic disease in organ-specific contexts in Xenopus as well as provide examples of how these methods have led to the identification of novel mechanisms and pathways important for understanding human disease.

Incomplete bilateral duplication of the ureters identified during cytoreductive surgery for ovarian cancer: A case report

•

In adults, ureteral duplication is usually asymptomatic.

•

Ureteral anatomical varieties increase the possibility of iatrogenic injury.

•

Ureteral injuries may increase morbidity and even cause mortality.

•

If unilateral duplication is observed, bilateral duplication should be suspected.

Introduction

Incomplete bilateral ureteral duplication is a very rare condition. Ureteral duplication is often asymptomatic or may be associated with several urinary tract complications.

Case Report

We report a case of a 72- year- old Caucasian female who was referred to our clinic after she was diagnosed with FIGO IIIc ovarian cancer with peritoneal metastases. The patient underwent Cytoreductive Surgery plus Hyperthermic Intraperitoneal Chemotherapy. During the standard bilateral recognition of the ureters, intraoperatively, incomplete duplication of both of the ureters was identified. Bilaterally, the ureters were derived from a single renal parenchyma and duplication of the pyelocaliceal system in each kidney.

Discussion

The incomplete bilateral duplication of the ureters is a rare congenital renal abnormality. In a series of 51.880 autopsies ureteral duplication was observed in 0.66% of the cases, while in another autopsy series the ureteral duplication rate was 0.68%.

Conclusion

Anatomical varieties of the ureter are of utmost importance for the surgeons, because they increase the possibility of iatrogenic ureteral injury. Ureteral injuries are severe complications of pelvic operations and may increase morbidity and even cause mortality.