Search

Emergency departments (EDs) often rely on urinalysis (UA) to rapidly identify urinary tract infections (UTIs) in children. However, the suboptimal test characteristics of UA can lead to false-positive results. Novel urinary biomarkers may increase the diagnostic precision of UA. In this study, we compared the concentrations of 6 pre-selected proteins: BH3 interacting domain death agonist (BID), B-cell lymphoma 6 protein, ras GTPase-activating protein 1, cathepsin S (CTSS), 3-hydroxyanthranilate 3,4-dioxygenase, and transgelin-2. In a pediatric ED, we prospectively enrolled 167 children with UA and urine culture collected. Pyuria was defined as either ≥ 5 white blood cells per high-power field on microscopy or positive leukocyte esterase (LE). The urine culture was considered positive if it yielded ≥ 50,000 colony-forming units per milliliter of any single urinary pathogen. Urine protein levels were measured by enzyme-linked immunosorbent assay and normalized to urine creatinine. BID was significantly higher in the UTI group compared to the culture-negative pyuria group with a mean ratio of 1.42 (95% confidence interval (CI), 1.15, 1.76) when uncorrected for creatinine concentration. When corrected for creatinine concentration, CTSS was significantly elevated in the UTI group compared to the culture-negative pyuria group with a mean ratio of 2.11 (95% CI, 1.39, 3.21). BID and CTSS concentrations were elevated in the urine of children with UTI compared to those with culture-negative pyuria. These proteins deserve further research into their utility to serve as novel biomarkers for UTI.

Urinary tract infections (UTI), associated with vesicoureteral reflux (VUR), can lead to chronic kidney disease. Genetic alterations in the innate immune defenses contribute to UTI risk. We investigated a novel gene, Dachsous Cadherin-Related 1 ( DCHS1), in children with UTI. We determined absolute DNA copy number (CN) of DCHS1 in children with UTI. In this case-control study, we utilized multiple complementary methods to determine the genomic CN of DCHS1. Children with ( n = 370) and without ( n = 71) VUR from two well-phenotyped clinical trials of UTI were copy-typed and compared to 491 healthy controls with no known history of VUR or UTI. Less than 1% of controls had a single copy of DCHS1, while 31% of children with UTI and no VUR and 7% of children with UTI and VUR had a single copy of the DCHS1 gene. Using immunostaining, we localized expression postnatally to the bladder and renal epithelia. Mice were also challenged with two uropathogenic Escherichia coli strains, and Dchs1 mRNA was quantified. This study represents the first report of DCHS1 in association with pediatric UTI. We hypothesize that its role in innate immunity is critical to lower urinary tract defense. Further investigation is required to determine the role of DCHS1 in innate immunity.

Background: The 2011 American Academy of Pediatrics clinical practice guideline recommends when to obtain renal and bladder ultrasound (RBUS) and voiding cystourethrography (VCUG) following febrile urinary tract infection (UTI) for children age 2–24 months. However, there is not consensus about when to obtain imaging in neonates. The objective of this study is to evaluate UTI diagnostic criteria along with RBUS and VCUG in neonates admitted to the NICU in the first 3 months of life. Methods: A retrospective electronic medical record review was performed of neonates admitted to Nationwide Children's Hospital system NICUs between January 2010 and December 2014 with UTI as a primary or secondary diagnosis. Urine culture results were evaluated versus established UTI criteria and renal US and VCUG results were compared. Results: Of 81 patients with a straight catheterized urine culture obtained, 28 patients met laboratory criteria for diagnosis of UTI and all but 4 had a RBUS. Urine cultures had an equal distribution of Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, and Coagulase negative staphylococcus. RBUS showed dilation of the collecting system in 37.5% of patients with UTI compared to 41.3% without UTI. VCUG showed vesicourteral reflux (VUR) on 41.7% of those with UTI compared to 34.8% without UTI. For patients with UTI, the sensitivity of RBUS for VUR on VCUG was 60% with CI [0.17, 0.93] and specificity was 43% with CI [0.12, 0.80]. In patients without UTI, sensitivity of RBUS for VUR on VCUG was 63% with CI [0.26, 0.90] and specificity was 71% with CI [0.42, 0.90]. Conclusions: Fewer than half of neonates that were diagnosed clinically with UTI met laboratory criteria for a UTI. Positive urine cultures grew a wide variety of organisms. The sensitivity of renal ultrasound for VUR is only about 60%. Key Words: cystitis, cystourethrogram, ultrasound, urinalysis

Acute pyelonephritis is frequently associated with metabolic acidosis. We previously reported that metabolic acidosis stimulates expression of hypoxia-inducible factor (HIF)-1α-induced target genes such as stromal derived factor-1 and cathelicidin, an antimicrobial peptide. Since the collecting duct (CD) plays a pivotal role in regulating acid-base homeostasis and is the first nephron segment encountered by an ascending microbial infection, we examined the contribution of HIF-1α to innate immune responses elicited by acid loading of an M-1 immortalized mouse CD cell line. Acid loading of confluent M-1 cells was achieved by culture in pH 6.8 medium supplemented with 5-( N-ethyl- N-isopropyl)-amiloride to block Na+/H+ exchange activity for 24 h. Acid loading induced antimicrobial peptide [cathelicidin and β-defensin (Defb2 and Defb26)] mRNA expression and M-1 cell resistance to uropathogenic Escherichia coli infection to an extent similar to that obtained by inhibition of HIF prolyl hydroxylases, which promote HIF-1α protein degradation. The effect of acid loading on M-1 cell resistance to uropathogenic E. coli infection was reduced by inhibition of HIF-1α (PX-478), and, in combination with prolyl hydroxylase inhibitors, acidosis did not confer additional resistance. Thus, metabolic stress of acidosis triggers HIF-1α-dependent innate immune responses in CD (M-1) cells. Whether pharmacological stabilization of HIF prevents or ameliorates pyelonephritis in vivo warrants further investigation.

Hospital readmissions experienced by kidney transplant recipients may be secondary to a range of conditions, including infections and rejection episodes. The objective was to identify trends in patients with kidney transplant complications, in regard to hospital discharges, ED visits, and charges over the years available from 1993 to 2015. Using the Healthcare Cost and Utilization Project database, trends were identified in hospitalizations, emergency department visits, and charges from 1993 to 2015 for complications following kidney transplantation. Hospital discharges have significantly increased over time and at a faster rate than the increase in number of kidney transplants performed, while emergency department visits numbers and rates remain unchanged. The type of kidney transplant complications experienced were analyzed by incidence and proportion of total charges. Rejection made up the largest proportion of hospitalizations and of total cost in patients suffering from kidney transplant complications. Improved immunosuppression regimens have resulted in longer allograft survival. We speculate that the overlap between infection and rejection is compounding and contributing to graft injury and thus, it is important to try to prevent and/or properly identify those episodes as well in order to improve graft survival.

Ribonuclease 7 (RNase 7) is an antimicrobial peptide that prevents urinary tract infections (UTI); however, it is yet unknown how RNASE7 genetic variations affect its antimicrobial activity and its mitigation of UTI risk. This study determined whether the RNASE7 SNP rs1263872 is more prevalent in children with UTI and defined how rs1263872 affects RNase 7’s antimicrobial activity against uropathogenic E. coli (UPEC). We performed genotyping for rs1263872 in 2 national UTI cohorts, including children enrolled in the Randomized Intervention for Children with Vesicoureteral Reflux trial or the Careful Urinary Tract Infection Evaluation study. Genotypes from these cohorts were compared with those of female controls with no UTI. To assess whether rs1263872 affects RNase 7’s antimicrobial activity, we generated RNase 7 peptides and genetically modified urothelial cultures encoding wild-type RNase 7 and its variant. Compared with controls, girls in both UTI cohorts had an increased prevalence of the RNASE7 variant. Compared with the missense variant, wild-type RNase 7 peptide showed greater bactericidal activity against UPEC. Wild-type RNase 7 overexpression in human urothelial cultures reduced UPEC invasive infection compared with mutant overexpression. These results show that children with UTI have an increased prevalence of RNASE7 rs1263872, which may increase UTI susceptibility by suppressing RNase 7’s antibacterial activity.

Objectives: To describe variations in coronavirus disease 2019 (COVID-19) diagnosis by zip code race and ethnicity in Indiana.Methods: Cross-sectional evaluation of subjects with SARS-CoV-2 at Indiana University Health. We performed two separate analyses, first evaluating likelihood of COVID-19 diagnosis by race (Caucasian, African American, Asian, or other) and ethnicity (Hispanic vs. non-Hispanic) in the cohort encompassing the entire state of Indiana. Subsequently, patient data was geolocated with zip codes in Marion County and the immediate surrounding counties, and descriptive statistical analyses were used to calculate the number of COVID-19 cases per 10,000 persons for each of these zip codes.Results: Indiana had a total of 3,892 positive COVID-19 cases from January 1 to April 30, 2020. The odds of testing positive for COVID-19 were four-fold higher in African Americans than non-African Americans (OR 4.58, 95% CI 4.25–4.94, P < 0.0001). Increased COVID-19 cases per 10,000 persons were seen in zip codes with higher percentage of African American (median infection rate of 17.4 per 10,000 population in zip codes above median % African American compared to 6.7 per 10,000 population in zip codes below median % African American, with an overall median infection rate 9.9 per 10,000 population, P < 0.0001) or Hispanic residents (median infection rate of 15.9 per 10,000 population in zip codes above median % Hispanic compared to 7.0 per 10,000 population in zip codes below median % Hispanic, overall median infection rate 9.6 per 10,000 population, P < 0.0001).Conclusions: Individuals from zip codes with higher percentages of African American, Hispanic, foreign-born, and/or residents living in poverty are disproportionately affected by COVID-19. Urgent work is needed to understand and address the disproportionate burden of COVID-19 in minority communities and when economic disparities are present.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its associated disease COVID-19 (coronavirus disease 2019) has presented graduate medical education (GME) training programs with a unique set of challenges. One of the most pressing is how should hospital systems that rely on graduate medical residents provide appropriate care for patients while protecting trainees. This question is of particular concern as healthcare workers are at high risk of SARS-CoV-2 exposure.Objective: This cross-sectional study sought to assess the impact of hospital COVID-19 patient placement on pediatric graduate medical residents by comparing rates of SARS-CoV-2 seroconversion rates of residents who worked on designated COVID-19 teams and those who did not.Methods: Forty-four pediatric and medicine–pediatric residents at Riley Children's Hospital (Indianapolis, IN) were tested for SARS-CoV-2 immunoglobulin M (IgM) and IgG seroconversion in May 2020 using enzyme-linked immunosorbent assays (Abnova catalog no. KA5826), 2 months after the first known COVID-19 case in Indiana. These residents were divided into two groups: those residents who worked on designated COVID-19 teams, and those who did not. Groups were compared using χ2 or Fisher exact test for categorical variables, and continuous variables were compared using Student t testing.Results: Forty-four of 104 eligible residents participated in this study. Despite high rates of seroconversion, there was no difference in the risk of SARS-CoV-2 seroconversion between residents who worked on designated COVID-19 teams (26% or 8/31) and those who did not (31% or 4/13). Eleven of 44 residents (25%) tested positive for SARS-CoV-2 IgG, whereas only 5/44 (11.4%) tested positive for SARS-CoV-2 IgM, without a detectable difference between exposure groups.Conclusion: We did not observe a difference in SARS-CoV-2 seroconversion between different exposure groups. These data are consistent with growing evidence supporting the efficacy of personal protective equipment. Further population-based research on the role of children in transmitting the SARS-CoV-2 virus is needed to allow for a more evidence-based approach toward managing the COVID-19 pandemic.

Background:Acute kidney injury (AKI) due to urinary stone disease (USD) is rare in adults; AKI rates in children with USD may be higher, and emerging data links stones to chronic kidney disease (CKD) development in adults.Methods:This study is a retrospective analysis of USD patients at a single pediatric hospital system's emergency department (ED). Patients were initially identified by USD ICD codes; USD was then confirmed by imaging or physician documentation; patients had to have baseline creatinine (Cr) and Cr in the ED for comparison to be included. AKI was defined by Kidney Disease: Improving Global Outcomes (KDIGO), Acute Kidney Injury Network (AKIN), and Pediatric Risk, Injury, Failure, Loss, End Stage (pRIFLE).Results:Of the 589 total visits, 264/589 (45%) had data to evaluate for AKI, 23% were AKI(+) and 77% were AKI(–). pRIFLE was most common (82%) and 18% were only positive by AKIN/KDIGO. AKI(+) were more likely to be younger (16.7 vs. 17.4 years,p= 0.046) and more likely to present with vomiting {odds ratio [OR] [95% confidence interval (CI)]: 2.4 [1.4–4.3],p= 0.002}; also, the proportion of AKI(+) was significantly higher in p= 0.032, OR (95% CI): 2.0 (1.1–3.9)]. Urinary tract infection (UTI) and obstruction rates were similar between groups. AKI(+) patients had a significant OR p= 0.001).Conclusion:We have demonstrated a novel association between USD-induced renal colic and AKI in a group of young adults and children. AKI(+) patients were younger and were more likely to present with vomiting. AKI(+) patients did not have higher rates of obstruction or UTI, and 51% of AKI(+) received NSAIDs.

BACKGROUND: The occurrence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the associated coronavirus disease 2019 (COVID-19) have profoundly affected adult kidney disease patients. In contrast, pediatric solid organ transplant recipients, including pediatric kidney transplant (KT) recipients, do not seem to be at particularly higher risk for SARS-CoV-2 infection or for severe COVID-19 disease. This patient population might be protected by certain mechanisms, such as the immunosuppressive medications with their anti-inflammatory properties or simply being well-versed in self-protection techniques. Assessing SARS-CoV-2 antibody serologies could potentially help understand why this patient population is apparently spared from severe SARS-CoV-2 clinical courses. OBJECTIVE: To examine SARS-CoV-2 serologic status in a cohort of pediatric KT recipients. METHODS: SARS-CoV-2 anti-spike IgG and IgM antibodies were measured by three different methods in pediatric KT recipients coming for routine clinic visits immediately post-confinement in May-June of 2020. The patients were considered seroconverted if SARS-CoV-2 antibodies were positive by 2/3 methods and weak positive/indeterminate if positive by 1/3. RESULTS: Thirty-one patients were evaluated (about 1/3 of our institution's pediatric KT population). One patient seroconverted, while three were considered weak positive/indeterminate. None were symptomatic and none had nasopharyngeal PCR confirmed SARS-CoV-2 disease. CONCLUSIONS: Seroconversion to SARS-CoV-2 was rare in this population and likely reflects the social distancing practiced by these patients. The results will serve as a foundation for a future longitudinal study to evaluate the long-term emergence and persistence of antibodies in this population and may inform studies of response to a future vaccine.

Dyspnea is the second leading cause of US emergency department (ED) visits and an independent predictor of morbidity and mortality1 in older adult patients aged ≥65 years. Unfortunately, the diagnosis of the cause of dyspnea presents diagnostic challenges to emergency physicians2-4 that disproportionately affects older adults.5 One in 5 dyspneic older adults experience missed diagnosis in the ED2 and 21% are treated for ≥1 pneumonia, acute exacerbation of chronic obstructive pulmonary disease [COPD], and acute exacerbation of heart failure [HF].5 Importantly, some may have multiple causes of their dyspnea but accurate diagnosis remains critical.

Coronavirus disease 2019 (COVID‐19) is a highly infectious disease caused by the severe acute respiratory syndrome coronavirus 2 virus (SARS‐CoV‐2). While children appear to experience less severe disease than adults, those with underlying conditions such as kidney disease may be more susceptible to infection. Limited data are present for children with kidney disease, and there are limited prior reports of pediatric hemodialysis patients with COVID‐19. This report describes the mild clinical disease course of COVID‐19 in two pediatric patients with chronic kidney disease, one on hemodialysis and both on chronic immunosuppression. We review treatment in these patients, as well as our measures to reduce transmission among our hemodialysis patients and staff.

Background Acute kidney injury (AKI) is increasingly recognized as a consequential clinical complication in children with severe malaria. However, approaches to estimate baseline creatinine (bSCr) are not standardized in this unique patient population. Prior to wide-spread utilization, bSCr estimation methods need to be evaluated in many populations, particularly in children from low-income countries. Methods We evaluated six methods to estimate bSCr in Ugandan children aged 6 months to 12 years of age in two cohorts of children with severe malaria (n = 1078) and healthy community children (n = 289). Using isotope dilution mass spectrometry (IDMS)-traceable creatinine measures from community children, we evaluated the bias, accuracy and precision of estimating bSCr using height-dependent and height-independent estimated glomerular filtration (eGFR) equations to back-calculate bSCr or estimating bSCr directly using published or population-specific norms. Results We compared methods to estimate bSCr in healthy community children against the IDMS-traceable SCr measure. The Pottel-age based equation, assuming a normal GFR of 120 mL/min per 1.73m2, was the more accurate method with minimal bias when compared to the Schwartz height-based equation. Using the different bSCr estimates, we demonstrated the prevalence of KDIGO-defined AKI in children with severe malaria ranged from 15.6–43.4%. The lowest estimate was derived using population upper levels of normal and the highest estimate was derived using the mean GFR of the community children (137 mL/min per 1.73m2) to back-calculate the bSCr. Irrespective of approach, AKI was strongly associated with mortality with a step-wise increase in mortality across AKI stages (p Conclusions We recommend using height-independent age-based approaches to estimate bSCr in hospitalized children in sub-Saharan Africa due to challenges in accurate height measurements and undernutrition which may impact bSCr estimates. In this population the Pottel-age based GFR estimating equation obtained comparable bSCr estimates to population-based estimates in healthy children.

People with diabetes mellitus have increased infection risk. With diabetes, urinary tract infection (UTI) is more common and has worse outcomes. Here, we investigate how diabetes and insulin resistance impact the kidney’s innate defenses and urine sterility. We report that type 2 diabetic mice have increased UTI risk. Moreover, insulin-resistant prediabetic mice have increased UTI susceptibility, independent of hyperglycemia or glucosuria. To identify how insulin resistance affects renal antimicrobial defenses, we genetically deleted the insulin receptor in the kidney’s collecting tubules and intercalated cells. Intercalated cells, located within collecting tubules, contribute to epithelial defenses by acidifying the urine and secreting antimicrobial peptides (AMPs) into the urinary stream. Collecting duct and intercalated cell–specific insulin receptor deletion did not impact urine acidification, suppressed downstream insulin-mediated targets and AMP expression, and increased UTI susceptibility. Specifically, insulin receptor–mediated signaling regulates AMPs, including lipocalin 2 and ribonuclease 4, via phosphatidylinositol-3-kinase signaling. These data suggest that insulin signaling plays a critical role in renal antibacterial defenses.

Urinary stone disease (USD) is affecting a greater number of children and low bone mineral density (BMD) and increased skeletal fractures have been demonstrated in stone patients; however, the mechanism(s) driving bone disease remain unclear. This pilot study was undertaken to assess an adolescent kidney stone cohort’s BMD and evaluate for an inverse correlation between BMD and urine concentration of lithogenic minerals and/or inflammatory levels. Prospective case–control study was carried out at a large pediatric center. 15 participants with USD (12–18 years of age, 8 female) were matched by age, sex, and body mass index to 15 controls. Lumbar and total body BMD z-score did not differ between groups. When stone formers were separated by sex, there was a significant difference between male stone formers vs. controls total body BMD z-score (Fig. 1). BMD z-score did not significantly correlate with urine calcium, oxalate, citrate or magnesium. Higher urine IL-13 did significantly correlate with higher total body BMD z-score (r = 0.677, p = 0.018). Total body BMD z-score did significantly correlate with body mass index (BMI) as expected for the control group (r = 0.6321, p = 0.0133). However, this relationship was not present in the USD group (r = − 0.1629, p = 0.5619). This is a small but hypothesis-generating study which demonstrates novel evidence of male-specific low BMD in adolescent stone formers. Furthermore, we demonstrated a positive association between urine IL-13 and total body BMD z-score USD patients as well as a lack of a positive BMD and BMI correlations in stone formers.

Urinary stone disease (USD) is increasing in adult and pediatric populations. Adult and pediatric studies have demonstrated decreased bone mineral density and increased fracture rates. USD has also been independently linked to increased rates of myocardial infarction and cerebral vascular accidents. Although USD is a multisystem disorder involving the kidneys, bone, and vasculature, the molecular mechanisms linking these three organs remain unknown. Calcium oxalate nephropathy was induced in C57BL/6J mice with intra-peritoneal (ip) injection of sodium glyoxolate. Half of each kidney underwent Pizzalato staining and half was snap frozen for RNA extraction. RT2 Profiler Mouse Atherosclerosis, Osteoporosis, and Calcium Signaling PCR Arrays (Qiagen) were performed. Only results that passed quality checks in PCR array reproducibility and genomic DNA contamination were included. Genes had to show at least fourfold differential expression and P 10-fold increase. All 10 have P ≤ 0.003. The calcium signaling array showed significant fourfold upregulation of 10 genes, four of which were ≥10-fold. All 10 have P ≤ 0.03. We have demonstrated that calcium oxalate nephropathy can induce upregulation of atherosclerotic, metabolic bone, and calcium homeostasis genes in a murine model. This may be and initial step in identifying the molecular mechanisms linking stone, bone, and cardiovascular disease. J. Cell. Biochem. 118: 2744–2751, 2017. © 2017 Wiley Periodicals, Inc.

Kidney stones are increasing in the pediatric and adult populations; similarly osteoporosis is increasingly recognized in children. While kidney stone formers are known to suffer from low bone density, metabolic bone patients have not been considered a high risk population for kidney stones. Retrospective chart review of Nationwide Children’s Hospital Metabolic Bone Clinic patients from October 2009–2013. Patients were identified by ICD 9 codes for osteoporosis, osteopenia, low bone density and kidney stones. Only patients with radiologic evidence of both diseases were included.Twenty-six of 889 patients met criteria; this is equivalent to an incidence of 30 per 100,000 patients. Osteoporosis was the most frequent bone diagnosis. Males were the majority (68%). Most common secondary diagnoses: seizure (52%) and cerebral palsy (44%). Treatment: calcium (48%), vitamin D (40%), bisphosphonates (48%). The majority (75%) were non-ambulatory. Most frequent lithogenic medications: Topiramate (42%) and corticosteroids (27%). This is one of the first studies to consider metabolic bone patients as high risk for urinary stone disease. We found a higher rate of kidney stones in pediatric metabolic bone patients compared to data available for the general pediatric kidney stone population. The most common risk factor for bone and stone disease was nonambulatory status. Males were more frequently affected than females; this is the reverse of general adolescent kidney stone population. The predominance of cerebral palsy and seizure patients can be attributed to their frequency of non-ambulatory status and lithogenic medications such as Topiramate.

ObjectiveCurrent urinary tract infection (UTI) diagnostic strategies that rely on leukocyte esterase have limited accuracy. We performed an aptamer-based proteomics pilot study to identify urine protein levels that could differentiate a culture proven UTI from culture negative samples, regardless of pyuria status.MethodsWe analyzed urine from 16 children with UTIs, 8 children with culture negative pyuria and 8 children with negative urine culture and no pyuria. The urine levels of 1,310 proteins were quantified using the Somascan™ platform and normalized to urine creatinine. Machine learning with support vector machine (SVM)-based feature selection was performed to determine the combination of urine biomarkers that optimized diagnostic accuracy.ResultsEight candidate urine protein biomarkers met filtering criteria. B-cell lymphoma protein, C-X-C motif chemokine 6, C-X-C motif chemokine 13, cathepsin S, heat shock 70kDA protein 1A, mitogen activated protein kinase, protein E7 HPV18 and transgelin. AUCs ranged from 0.91 to 0.95. The best prediction was achieved by the SVMs with radial basis function kernel.ConclusionsBiomarkers panel can be identified by the emerging technologies of aptamer-based proteomics and machine learning that offer the potential to increase UTI diagnostic accuracy, thereby limiting unneeded antibiotics.

Autoantibodies targeting host antigens contribute to autoimmune disorders, frequently occur during and after infections and have been proposed to contribute to malaria-induced anemia. We measured anti-phosphatidylserine (PS) and anti-DNA antibody levels in 382 Ugandan children prospectively recruited in a study of severe malaria (SM). High antibody levels were defined as antibody levels greater than the mean plus 3 standard deviations of community children (CC). We observed increases in median levels of anti-PS and anti-DNA antibodies in children with SM compared to CC (p

Vesicoureteral reflux (VUR) is a complex, heritable disorder. Genome-wide linkage analyses of families affected by VUR have revealed multiple genomic loci linked to VUR. These loci normally harbor a number of genes whose biologically functional variant is yet to be identified. DNA copy number variations (CNVs) have not been extensively studied at high resolution in VUR patients. In this study, we performed array comparative genomic hybridization (aCGH) on a cohort of patients with a history of both VUR and urinary tract infection (UTI) with the objective of identifying genetic variations responsible for VUR and/or UTI susceptibility. UTI/VUR-associated CNVs were identified by aCGH results from the 192 Randomized Intervention for Children With Vesicoureteral Reflux (RIVUR) patients compared to 683 controls. Rare, large CNVs that are likely pathogenic and lead to VUR development were identified using stringent analysis criteria. Because UTI is a common affliction with multiple risk factors, we utilized standard analysis to identify potential disease-modifying CNVs that can contribute to UTI risk. Gene ontology analysis identified that CNVs in innate immunity and development genes were enriched in RIVUR patients. CNVs affecting innate immune genes may contribute to UTI susceptibility in VUR patients and may provide the first step in assisting clinical medicine in determining adverse outcome risk in children with VUR.

Background: Urinary stones are affecting more children, and pediatric stone formers have unique pathophysiology compared to adults. While adult stone formers are most frequently male, children have an age dependent sex prevalence. Under 10 years, a majority of stone formers are boys; adolescent stone formers are mostly female. Previous adult studies have shown that stone composition is influenced by the sex and age of the stone former. Thus, we hypothesize that female and male stone forming children will also have sex and age specific stone phenotypes.Methods: Retrospective chart review of a large pediatric center's stone forming children 6/1/2009 to 6/1/2016. Patients were identified by ICD 9 codes: N20, N20.1, and N20.9. Charts were reviewed for radiographic evidence of stones or documented visualized stone passage.Results: One hundred and thirty six subjects: 54 males and 82 females. Females were older, median age 14 years [interquartile range (IQR): 11, 15] vs. males' median age 12 years (IQR: 11, 14) (p < 0.01). Females had lower height z-scores, median 0.2 (IQR: −0.8, 0.8) vs. males' median 0.8 (IQR: −0.2, 1.8) (p < 0.01). Presenting symptoms were similar except flank pain affecting 39% of females vs. 22% of males (p = 0.04). Leukocyte esterase was positive in more females than males (33 vs. 4%) (p < 0.001). Males had a higher BUN/Cr ratio, mean ± standard deviation of 19.8 ± 6.3 vs. 16.6 ± 6.5 in females (p = 0.01). Glomerular hyperfiltration was present in 9% of patients while 35% of patients had estimated glomerular filtration rate (eGFR) < 90 ml/min/1.73 m2. Treatment strategies and clinical course were similar except females were told to increase dietary citrate more frequently than males (21 vs. 4%) (p < 0.01).Conclusion: We have provided a novel analysis and demonstrated that low height z-score and pyuria are more common in female stone formers. We have also shown that 9% of pediatric stone formers have labs consistent with hyperfiltration. Whether high protein intake and/or chronic dehydration are associated with hyperfiltration and long-term renal function in children with kidney stones will be an area for future research.

Expanding epidemiologic and physiologic data suggest that urinary stone disease is best conceptualized as a chronic metabolic condition punctuated by symptomatic, preventable stone events. These acute events herald substantial future chronic morbidity, including decreased bone mineral density, cardiovascular disease, and CKD. Urinary stone disease imposes a large and growing public health burden. In the United States, 1 in 11 individuals will experience a urinary stone in their lifetime. Given this high incidence and prevalence, urinary stone disease is one of the most expensive urologic conditions, with health care charges exceeding $10 billion annually. Patient care focuses on management of symptomatic stones rather than prevention; after three decades of innovation, procedural interventions are almost exclusively minimally invasive or noninvasive, and mortality is rare. Despite these advances, the prevalence of stone disease has nearly doubled over the past 15 years, likely secondary to dietary and health trends. The NIDDK recently convened a symposium to assess knowledge and treatment gaps to inform future urinary stone disease research. Reducing the public health burden of urinary stone disease will require key advances in understanding environmental, genetic, and other individual disease determinants; improving secondary prevention; and optimal population health strategies in an increasingly cost–conscious care environment.

The most common acute glomerulonephritis in children is poststreptococcal glomerulonephritis (PSGN) usually occurring between 3 and 12 years old. Hypertension and gross hematuria are common presenting symptoms. Most PSGN patients do not experience complications, but rapidly progressive glomerulonephritis and hypertensive encephalopathy have been reported. This paper reports 17 patients seen in 1 year for PSGN including 4 with atypical PSGN, at a pediatric tertiary care center. Seventeen children (11 males), mean age of 8 years, were analyzed. Ninety-four percent had elevated serum BUN levels and decreased GFR. Four of the hospitalized patients had complex presentations that included AKI along with positive ANA or ANCAs. Three patients required renal replacement therapy and two were thrombocytopenic. PSGN usually does not occur as a severe nephritis. Over the 12-month study period, 17 cases associated with low serum albumin in 53%, acute kidney injury in 94%, and thrombocytopenia in 18% were treated. The presentation of PSGN may be severe and in a small subset have associations similar to SLE nephritis findings including AKI, positive ANA, and hematological anomalies.

This case series describes subclinical development of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in some patients and health care workers in a pediatric dialysis unit after contact with a seropositive patient.

BACKGROUND: Urinary stone are increasing in children, primarily during adolescence. Although urinary stones are often viewed in the context of intermittent stone events, increasing evidence indicates that stones are a metabolic process associated with chronic kidney disease and low bone mass. These aforementioned stone associated conditions may have pediatric origins. OBJECTIVE: To compare urine inflammatory markers in otherwise healthy stone forming children versus matched controls. METHODS: Urine samples were collected from 12 adolescents with urinary stones along with 15 controls. The levels of 30 urine cytokines were measured using a Mesoscale 30-Plex Human Cytokine panel and normalized to urine creatinine levels. RESULTS: Macrophage inflammatory protein 1β and Interleukin 13 levels were significantly elevated in the urine of the stone forming adolescents compared to controls. Interleukin 17A was elevated in the urine of controls. CONCLUSIONS: This study indicates that urine levels of cytokines involved in chronic inflammation and fibrosis are elevated urinary stone formers as early as adolescence. Because stone formers are at risk for chronic kidney disease, Macrophage inflammatory protein 1β and Interleukin 13 represent investigative targets.

Objectives: Low hydration has a deleterious effect on many conditions. In the absence of a urine concentrating defect, urine concentration is a marker of hydration status. However, markers to evaluate hydration status have not been well studied in children. The objectives of this paper are to compare measures of thirst and urine concentration in children and to develop a novel mobile technology application to measure urine concentration.Study Design: Children age 12–17 years were selected (n = 21) for this pilot study. Thirst perception, specific gravity (automated dipstick analysis and refractometer), and urine color scale results were correlated to urine osmolality. The technology department developed a mobile technology camera application to measure light penetrance into urine which was tested on 25 random anonymized urine samples.Results: The patients' thirst perception and color scale as well as two researchers color scale did not significantly correlate with osmolality. Correlation between osmolality and hydration markers resulted in the following Pearson coefficients: SG automated dipstick, 0.61 (P 0.003); SG refractometer, 0.98 (P < 0.0001); urine color scale (patient), 0.37 (P 0.10), and light penetrance, −0.77 (P < 0.0001). The correlation of light penetrance with osmolality was stronger than all measures except SG by refractometer and osmolality.Conclusion: The mobile technology application may be a more accurate tool for urine concentration measurement than specific gravity by automated dipstick, subjective thirst, and urine color scale, but lags behind specific gravity measured by refractometer. The mobile technology application is a step toward patient oriented hydration strategies.

OBJECTIVES The aim of this study was to examine computed tomography (CT) and ultrasound (US) utilization trends in incident and prevalent pediatric emergency department (ED) urolithiasis patients before and after imaging guideline release. METHODS We reviewed imaging modalities for children with 2 or more ED encounters between January 1, 2006, and September 1, 2013, for urolithiasis using the Pediatric Health Information System database. Z scores compared the proportion of patient encounters receiving CT and US before (January 1, 2006, to December 31, 2010) and after (January 1, 2011, to September 1, 2013) the release of imaging guidelines. McNemar test for paired proportions compared the percentage of US and CT use between initial versus subsequent visits. Piecewise logistic regression was used to determine the probability of US use and CT use over time before and after the implementation of imaging guidance. RESULTS Analysis was completed on 2041 patients with 4930 unique encounters for urolithiasis. During 1758 encounters (35.7%), CT was performed initially. Ultrasound was performed 1585 times (32.2%). Fourteen percent fewer CT procedures were performed during first urolithiasis visits after guideline release (P < 0.01), whereas US use increased by 15% (P < 0.01). Fewer CT procedures were performed at later visits compared with the first (P < 0.05), and US was used more during second or later visits than the first (P < 0.05). CONCLUSIONS Medical providers at large academic pediatric EDs have decreased use of CT and increased use of US over the study time frame to diagnose urolithiasis and are now similar during initial visits (US 36.4% vs CT 36.2%, P = 0.94). Physicians are still more likely to use US as the initial urolithiasis imaging modality during second and later encounters.

• Renal anomalies are identified in 0.5% of pregnancies and account for 20% of all identified prenatal anomalies. • Hydronephrosis (abnormal increase in the fetal renal pelvic diameter) is the most common identified renal anomaly. • Oligohydramnios should prompt an evaluation for severe, bilateral, poorly functioning, or absent kidneys. • Fetal magnetic resonance imaging may be useful as a complementary imaging modality when ultrasound results are inconclusive. • Prenatal intervention strategies that improve long-term kidney and urinary tract outcomes remain in need of ongoing research. • Monogenic gene disorders account for a significant number of structural and/or glomerular kidney disorders identified in infants. • Palpable abdominal masses in neonates most often originate from the urinary tract and are commonly cystic or obstructive. • Absolute/corrected glomerular filtration rate is much lower in newborns than in older children and adults.

Alport syndrome is a rare hereditary disorder caused by rare variants in 1 of 3 genes encoding for type IV collagen. Rare variants in COL4A5 on chromosome Xq22 cause X-linked Alport syndrome, which accounts for ∼80% of the cases. Alport syndrome has a variable clinical presentation, including progressive kidney failure, hearing loss, and ocular defects. Exome sequencing performed in 2 affected related males with an undefined X-linked glomerulopathy characterized by global and segmental glomerulosclerosis, mesangial hypercellularity, and vague basement membrane immune complex deposition revealed a COL4A5 sequence variant, a substitution of a thymine by a guanine at nucleotide 665 (c.T665G; rs281874761) of the coding DNA predicted to lead to a cysteine to phenylalanine substitution at amino acid 222, which was not seen in databases cataloguing natural human genetic variation, including dbSNP138, 1000 Genomes Project release version 01-11-2004, Exome Sequencing Project 21-06-2014, or ExAC 01-11-2014. Review of the literature identified 2 additional families with the same COL4A5 variant leading to similar atypical histopathologic features, suggesting a unique pathologic mechanism initiated by this specific rare variant. Homology modeling suggests that the substitution alters the structural and dynamic properties of the type IV collagen trimer. Genetic analysis comparing members of the 3 families indicated a distant relationship with a shared haplotype, implying a founder effect.

Background Baclofen (para-chlorophenyl-gamma-aminobutyric acid) is widely used for its therapeutic effect of providing muscle relaxation from the persistent muscle spasms and posturing often related to spinal and central nervous system injuries. However, baclofen is also a potent neuronal depressant which is most evident in cases of toxicity. In severe toxicity, respiratory failure and obtundation may occur. Case-diagnosis/treatment We present the case of a neurologically devastated 16-year-old on chronic baclofen therapy for bilateral spastic cerebral palsy (Gross Motor Function Classification System level V) who presented with fever, leukocytosis, and hypotension. Initial management with fluid resuscitation and antimicrobials for presumed infection did initially improve the patient's mental status; however, he subsequently became comatose later during the same hospitalization. Comprehensive diagnostic studies and infectious work-up did not reveal an etiology. Upon further examination of history, acute kidney injury from chronic nonsteroidal use and complicated by vancomycin toxicity was suspected to cause acute baclofen toxicity. The patient underwent a single run of hemodialysis with resultant neurologic improvement and later laboratory-confirmed toxic baclofen levels. Conclusion Clinicians should consider possible acute baclofen toxicity in patients with impaired renal function who present with neurologic depression. Respiratory failure and mechanical ventilation, with its associated intensive care costs and complications, may be avoided with prompt treatment using hemodialysis.

Objectives Urinary tract infection (UTI) often represents a diagnostic challenge in the emergency department (ED) where urine culture results are generally not available and other tests demonstrate limited sensitivity and specificity. Antimicrobial peptides (AMPs) are components of the innate immune system that have demonstrated increased urinary levels in response to infection both in children and in adults with chronic UTI. The objective of this study was to determine the relationship between urinary AMP levels and positive urine cultures in adult ED patients with suspected UTI. Methods This was a prospective, observational study of adult ED patients with suspected UTI. Enzyme-linked immunosorbent assays were performed to measure urine levels of AMPs: human neutrophil peptides 1–3 (HNP1–3), human α-defensin 5 (HD5), human beta defensin 2 (hBD-2), and cathelicidin (LL-37). Comparisons between positive and negative cultures were performed using Wilcoxon rank sum tests and receiver operating characteristic curves, with calculation of area under the curve (AUC). Data were also analyzed for the older adult subgroup. Results Of 40 patients enrolled, 23 (58%) were ≥ 65 years, 25 were female (64%), and seven (17%) were nonwhite. Cultures were positive in 13 (32%), including seven in those ≥ 65 years old. HNP1–3, HD5, and hBD-2 levels were significantly higher in those with positive than negative urine cultures. Median HNP1–3 was 5.39 ng/mg (interquartile range [IQR] = 2.74 to 11.09) in positive vs. 0.81 ng/mg (IQR = 0.06 to 3.87) in negative cultures. Median HD5 was 4.75 pg/mg (IQR = 1.6 to 22.7) in positive versus 0.00 pg/mg (IQR = 0 to 2.60) in negative cultures, and median hBD-2 was 0.13 pg/mg (IQR = 0.08 to 0.17) in positive versus 0.02 pg/mg (IQR = 0 to 0.04) in negative cultures (p < 0.05 for all). Findings were similar for adults ≥ 65 years. The AUC was ≥ 0.75 for all three AMPs, both overall and in the older adult subgroup. LL-37 was not significantly higher in patients with positive urine culture. However, LL-37 expression is vitamin D dependent, and inadequate serum levels (< 30 ng/mL) were present in 72% of those tested. Conclusions Urinary levels of HNP1–3, HD5, and hBD-2 are significantly greater in the presence of positive urine cultures in ED patients with suspected UTI. These findings are maintained in the high-risk subgroup of older adults.

Aim To find the trend in patient’s visits to our centers for vesicoureteral reflux (VUR). We hypothesize that VUR diagnosis and hence possible nephropathy recognition may be diminishing because of changing practice patterns. Methods Data were extracted from electronic medical records for new and follow-up patients aged 0–18 years with ICD-9/10 codes to correspond with VUR, VUR unilateral, VUR bilateral, and VUR with reflux nephropathy, as well as new patients with diagnoses of urinary tract infections (UTI) and pyelonephritis at two major pediatric centers from 2012 to 2015. Figures and statistics to reflect absolute clinic visits and annual trends were created with SPSS 2010. Linear regression was applied. Results Annually, Le Bonheur Children’s Hospital and Nationwide Children’s Hospital experienced an average decrease of 13 and 17% in total VUR visits, and an average decrease of 22 and 27% in VUR nephropathy visits, respectively, for each institution. Patient visits for UTIs were reduced an average of 16% annually in both centers. Linear regression demonstrated that number of patients (patients/year ± SE) decreased annually 69 ± 19 (P = 0.02), 7 ± 2 (P = 0.02), and 67 ± 25 (P = 0.04) for VUR, VUR nephropathy, and UTI, respectively. Conclusion We conclude that the decreased number of VUR and VUR nephropathy cases identified in subspecialty clinics (Nephrology/Urology) at two major children’s hospitals reflect a possible decreased identification of VUR. This trend may also be due to decreased referral of low grade cases of VUR. We cannot conclude that “undifferentiated UTI” referrals increased concomitantly to account for the decreased VUR as our data reflects a decreased trend in those visits as well. We suggest that clinicians following the American Academy of Pediatrics guidelines ensure that all UTI are accounted for and surveillance is appropriately escalated for recurrent UTI or abnormal imaging results.

To review the recent publications describing the link between pediatric nephrolithiasis and bone metabolism.Nephrolithiasis incidence is increasing in children and is associated with low bone mineral density (BMD). Affected children are conceptually at risk for fractures and osteoporosis. In addition to abnormal calcium metabolism, inflammation, genetic makeup and dietary habits are being recognized as important factors in the pathophysiology of nephrolithiasis and low bone density. Findings from retrospective reviews suggest that low BMD in children may be improved with citrate or thiazide treatment.The healthcare burden from low BMD with subsequent osteoporosis and fracture risk is immense with potential far-reaching effects in patient quality of life and healthcare expense. Bone mass is acquired in the pediatric age range, thus it is important to identify and treat at-risk children. Retrospective reviews in pediatric patients indicate that citrate or thiazide diuretic treatment may improve BMD. We now understand that a relationship exists between nephrolithiasis and low BMD. To improve healthcare for our current patients as well as protect their future health it is important to identify low BMD and initiate strategies to improve BMD in 'at-risk' children.

Despite its proximity to the fecal flora, the urinary tract is considered sterile. The precise mechanisms by which the urinary tract maintains sterility are not well understood. Host immune responses are critically important in the antimicrobial defense of the urinary tract. During recent years, considerable advances have been made in our understanding of the mechanisms underlying immune homeostasis of the kidney and urinary tract. Dysfunctions in these immune mechanisms may result in acute disease, tissue destruction and overwhelming infection. The objective of this review is to provide an overview of the innate immune response in the urinary tract in response to microbial assault. In doing so, we focus on the role of antimicrobial peptides – a ubiquitous component of the innate immune response.

Objective To characterize the clinical course after cutaneous vesicostomy (CV) in megabladder ( mgb −/− ) mice with functional urinary bladder obstruction. Materials and Methods A total of 45 mgb −/− male mice underwent CV at a median age of 25 days. The 34 mice that survived >3 days after CV were evaluated by serial observation and renal ultrasonography. The moribund mice were killed. The urinary bladders and kidneys were analyzed by histopathologic analysis, and urine biochemical studies were performed. Results At a median duration of 11 weeks after CV, 35% of mgb −/− male mice (12 of 34) had become moribund with pelvic masses, which were identified as bladder stones at necropsy. The urine pH was alkaline, and microscopic examination demonstrated struvite crystals. The urine samples contained Gram-positive cocci, and the urine cultures were polymicrobial. The stone composition was chiefly struvite (88%-94%) admixed with calcium phosphate. In 40% of cases (2 of 5), retained intravesical polypropylene suture was identified as the presumed nidus. No stones were detected in >100 male mice before CV or in 25 cases when CV was performed using polydioxanone suture. The kidneys from 33% of the mice (4/12) with bladder stones contained staghorn calculi. The histopathologic findings from the mice with struvite stones demonstrated active cystitis, pyelitis, and chronic pyelonephritis. Conclusion These findings attest to the importance of the nidus in lithogenesis and provide a novel murine model for struvite urolithiasis and chronic infection of the diverted urinary tract.

Congenital obstructive uropathy (COU) is a leading cause of pediatric chronic kidney disease (CKD). Urinary tract infections (UTIs) pose a risk for ascending infections and CKD in patients with COU. We evaluated the impact of comorbid UTIs on hospital charges and length of stay (LOS) for pediatric COU discharges.The study sample (n = 2832) was drawn from the 2003 and 2006 US Healthcare Cost and Utilization Project Kids' Inpatient Database. Data were analyzed using logistic and linear regression.Comorbid UTIs complicated 6.7% of COU discharges, and were most common in patients with posterior urethral valves (15.7% of discharges). Comorbid UTIs increased mean charges by $7910 (95% confidence interval (CI) $4770-$11,040; p 0.001) and prolonged mean LOS by 2.66 days (95% CI 2.03-3.29; p 0.001) compared to COU discharges without UTI. After controlling for LOS, charges for COU with a secondary diagnosis of UTI were no longer significantly higher. Mean charges in inflation-adjusted dollars increased by $2710, a 15.8% increase unexplained by covariate diagnoses and procedures.Comorbid UTIs contribute significantly to inpatient charges for COU, by prolonging LOS.

Calcium nephrolithiasis in children is increasing in prevalence and tends to be recurrent. Although children have a lower incidence of nephrolithiasis than adults, its etiology in children is less well understood; hence treatments targeted for adults may not be optimal in children. To better understand metabolic abnormalities in stone forming children, we compared chemical measurements and the crystallization properties of 24-hour urine collections from 129 stone formers matched to 105 non-stone forming siblings and 183 normal, healthy children with no family history of stones; all aged 6 to 17 years. The principal risk factor for calcium stone formation was hypercalciuria. Stone formers have strikingly higher calcium excretion along with high supersaturation for calcium oxalate and calcium phosphate, and a reduced distance between the upper limit of metastability and supersaturation for calcium phosphate, indicating increased risk of calcium phosphate crystallization. Other differences in urine chemistry that exist between adult stone formers and normal individuals such as hyperoxaluria, hypocitraturia, abnormal urine pH and low urine volume were not found in these children. Hence, hypercalciuria and a reduction in the gap between calcium phosphate upper limit of metastability and supersaturation are crucial determinants of stone risk. This highlights the importance of managing hypercalciuria in children with calcium stones.

In the last 10 years, the incidence of kidney stones has increased in the pediatric population, and this rise has been paralleled by a significant increase in pediatric obesity rates in the USA. The purpose of this study was to evaluate percentage body fat (%BF) measured by dual energy X-ray absorptiometry (DXA) in hypercalciuric children with and without kidney stones. A retrospective chart review was performed on children with idiopathic hypercalciuria based on a 24-h urine calcium excretion of4 mg/kg/day or200 mg/day who had undergone DXA scanning. Patients were then classified by sex and by %BF (3 categories; normal:27% girls,21% boys; at risk for obesity: 27-36% girls, 21-30% boys; obese:36% girls,30% boys). The 2003-2004 NHANES data were used as a control. Fifty patients (24 males) were analyzed, of whom 26% were assessed as having a normal %BF, 44% as being at risk for obesity, and 30% as being obese. Children with an increased %BF had a significantly higher occurrence of kidney stones (p = 0.03) than those with a normal %BF. No significant differences were noted in 24-h urine chemistries between the groups. In conclusion, an increased %BF was associated with an increased occurrence of kidney stones in children with idiopathic hypercalciuria.

Prune belly syndrome (PBS) is a congenital anomaly characterized by the clinical triad of lax abdominal musculature, bilateral cryptorchidism, and abnormalities of the kidney and urinary tract. Previous reports of malignancy in patients with PBS have been limited to germ cell tumors. Hepatoblastoma (HBL) is the most common hepatic malignancy of childhood, affecting approximately 100 children each year in the USA. We describe a set of 4 pediatric patients with PBS and HBL. All individuals were born after 2002. These subjects lacked genetic, natal, or environmental factors known to confer risk of HBL. The occurrence of PBS and HBL in these patients constitutes a novel potential association.

This study evaluates the impact of pediatric uninary tract infection (UTI)s on the economy and inpatient healthcare utilization in the USA. A retrospective analysis of patient demographics and hospital economics was performed on children less than 18 years of age admitted with a UTI between 2000 and 2006 using the Healthcare Cost and Utilization Project Kids’ Inpatient Database. Our results were stratified as follows. Hospital admissions—nearly 50,000 children/year were admitted with a UTI. Pediatric UTIs represented 1.8% of all pediatric hospitalizations. Seventy-three percent of patients were female and 40% were under 1 year of age. Payer information—from 2000 to 2006, pediatric insurance coverage shifted from the private sector to the public sector. Hospital cost—in 2000, estimated hospital costs for UTIs were $2,858 per hospitalization and rose to $3,838 by 2006. Mean hospital charges increased from $6,279 to $10,489 per stay. By 2006, aggregate hospital charges exceeded $520 million. Our results indicate that UTIs are among the most common pediatric admission diagnoses. Hospitalization is more common in females and younger children. Since 2000, hospital charges for UTIs increased disproportionately to hospital costs. Over time, more children hospitalized with a UTI depend on public agencies to cover healthcare expense. More efforts are needed to evaluate cost-effective strategies for evaluation and treatment of UTIs.

Summary Purpose The metabolic evaluation of children with nephrolithiasis begins with a 24-h urine collection. For adults, the diagnostic yield increases with consecutive collections; however, little is known regarding the variability of multiple 24-h studies in the pediatric population. We sought to evaluate the variability of consecutive 24-h urine collection in children through a multi-institutional study hypothesizing that compared with a single collection, consecutive 24-h urine collections would reveal a greater degree of clinically useful information in the evaluation of children at risk for nephrolithiasis. Materials and methods Including data from six institutions, we identified children less than 18 years of age considered at risk for recurrent nephrolithiasis, undergoing metabolic evaluation. We evaluated a subset of patients performing two collections with urine creatinine varying by 10% or less during a 7-day period. Discordance between repeat collections based on normative urine chemistry values was evaluated. Results A total of 733 children met inclusion criteria, and in over a third both urine calcium and urine volume differed by 30% or more between samples. Urine oxalate demonstrated greater variation between collections in children p = 0.030) while variation in other parameters did not differ by age. Discordance between repeat samples based on normative values was most common for urine oxalate (22.5%) and the derived relative supersaturation ratios for both calcium phosphate (25.1%) and calcium oxalate (20.5%). The proportion of discordant samples, based on normative thresholds, as well as variability greater ≥30% and 50%, respectively, are shown in the table. Conclusions Our analysis indicates that stone risk in as many as one in four children may be misclassified if normative values of only a single 24-h urine are used. In light of these findings, repeat 24-h urine collections prior to targeted intervention to modify stone risk are advised to increase diagnostic yield in children at risk for nephrolithiasis. Table . Percent variability and discordant samples (based on normative thresholds) for urinary parameters in consecutive 24-h urine studies in children. Parameter Percent variability Discordant samples ≥30% ≥50% Calcium ( N , %) 219 (34.2) 102 (15.9) 88 (13.1) Oxalate ( N , %) 94 (23.3) 28 (6.9) 104 (22.5) Citrate ( N , %) 92 (16.6) 22 (4.0) 42 (8.2) SS CaOx ( N , %) N/A N/A 138 (20.5) SS CaPhos ( N , %) N/A N/A 169 (25.1) Volume 269 (36.8) 89 (12.2) N/A

Renal agenesis/adysplasia is the leading etiology of end stage renal disease in children. The etiology for renal agenesis/adysplasia has not been identified. The purpose of the present study was to determine if renal agenesis/adysplasia occur in a familial pattern. Twenty seven cases of bilateral renal agenesis/adysplasia were identified by review of autopsy records, and four were excluded. A male excess of 2.8:1 was noted with a mean gestation of 35 weeks. Prenatal and family histories were obtained on 11/23 families. Potential embryologic stressors were identified in 8/11 pregnancies. Thirty-four 1st and 2nd degree relatives from five families participated in a renal ultrasound exam. An increased prevalence of congenital renal anomalies was identified in the relatives of index patients with bilateral renal agenesis/adysplasia (14.7%) compared to controls (2.2%), with a recurrence risk of 6.2 for 1st degree relatives. The most frequently identified renal anomalies in the family members were solitary kidneys and duplicated collecting systems. The increased prevalence of a range of renal anomalies within affected families raises the possibility that isolated renal malformations result from unidentified gene-environment interactions.

Urinary tract infections (UTI) are a common condition in children. Vesicoureteral reflux (VUR) represents a common associated condition with childhood UTI. UTI susceptibility appears to have a genetic component based on family and UTI cohort studies. Targeted analysis of innate immune system genetic variations indicate that these variations are important in UTI susceptibility. In this overview, we discuss how current cohorts and genetic strategies can be implemented to discover new susceptibility loci in patients with UTI.

Urinary tract infections (UTIs), including pyelonephritis, are among the most common and serious infections encountered in nephrology practice. UTI risk is increased in selected patient populations with renal and urinary tract disorders. As the prevalence of antibiotic-resistant uropathogens increases, novel and alternative treatment options will be needed to reduce UTI-associated morbidity. Discoveries over the past decade demonstrate a fundamental role for the innate immune system in protecting the urothelium from bacterial challenge. Antimicrobial peptides, an integral component of this urothelial innate immune system, demonstrate potent bactericidal activity toward uropathogens and might represent a novel class of UTI therapeutics. The urothelium of the bladder and the renal epithelium secrete antimicrobial peptides into the urinary stream. In the kidney, intercalated cells--a cell-type involved in acid-base homeostasis--have been shown to be an important source of antimicrobial peptides. Intercalated cells have therefore become the focus of new investigations to explore their function during pyelonephritis and their role in maintaining urinary tract sterility. This Review provides an overview of UTI pathogenesis in the upper and lower urinary tract. We describe the role of intercalated cells and the innate immune response in preventing UTI, specifically highlighting the role of antimicrobial peptides in maintaining urinary tract sterility.