Transient pyelonephritic changes on 99mTechnetium-dimercaptosuccinic acid scan for at least five months after infection

Investigation of the Effects of N-acetylcysteine and Selenium on Vesicoureteral Reflux Nephropathy: An Experimental Study

INTRODUCTION

This study aimed to investigate the effects of N-acetylcysteine (NAC) and selenium (Se) on vesicoureteral reflux (VUR) nephropathy.

METHODS

A total of 44 rabbits in 7 groups, namely group 1 (Control), group 2 (VUR + sterile urine), group 3 (VUR + sterile urine + NAC), group 4 (VUR + sterile urine + Se), group 5 (VUR + infected urine), group 6 (VUR + infected urine + NAC) and group 7 (VUR + infected urine + Se), were used. 99mTc Dimercaptosuccinic acid renal scan (DMSA), cystogram and urine culture were performed both at the beginning and end of the study. Left VUR was created surgically, and E. coli was inoculated in infected urine groups. NAC and Se were administered daily for 21 days. Malondialdehyde (MDA) measurement, inflammatory response scores (IRSs), and cicatrization response scores (CRSs) in renal tissues were evaluated.

RESULTS

VUR did not reduce left renal uptake values in neither group 2 nor group 5. MDA levels of the left kidney were significantly higher in group 5 compared to group 1 (p = 0.001). There was no significant difference in MDA levels between group 5 and group 6, and between group 5 and group 7. Left kidney IRSs were found to be higher in all other groups except group 2 compared to the control group (p < 0.001). Left kidney CRSs were significantly higher in group 5 compared to group 2 (p = 0.026), group 6 (p < 0.001) and group 7 (p = 0.006).

CONCLUSION

A decrease in renal functions was not observed in VUR, even if there was infection. When CRSs were evaluated, NAC and Se had protective effects in terms of scar formation in VUR nephropathy.

TYPE OF STUDY

Experimental animal study.

LEVELS OF EVIDENCE

N/A.

Urinary Tract Infections in Children

Despite the American Academy of Pediatrics guidelines for the evaluation, treatment, and management of urinary tract infections (UTIs), UTI diagnosis and management remains challenging for clinicians. Challenges with acute UTI management stem from vague presenting signs and symptoms, diagnostic uncertainty, limitations in laboratory testing, and selecting appropriate antibiotic therapy in an era with increasing rates of antibiotic-resistant uropathogens. Recurrent UTI management remains difficult due to an incomplete understanding of the factors contributing to UTI, when to assess a child with repeated infections for kidney and urinary tract anomalies, and limited prevention strategies. To help reduce these uncertainties, this review provides a comprehensive overview of UTI epidemiology, risk factors, diagnosis, treatment, and prevention strategies that may help pediatricians overcome the challenges associated with acute and recurrent UTI management.

Renal scars in children with febrile urinary tract infection - Looking for associated factors

INTRODUCTION

Febrile urinary tract infection (UTI) is a common childhood infection related to renal scarring and potentially long-term complications like chronic kidney disease. It would be of great benefit to find a correlation between easy-accessible factors in the acute phase of a febrile UTI and the development of renal scar formation and/or decreased renal function in order to identify children at risk of future complications.

OBJECTIVE

The aim of this study was to identify factors associated with the development of decreased split renal function (DSRF) and/or permanent renal scar formation in children with febrile UTI.

STUDY DESIGN

The medical records of 212 Children aged 0 months to 15 years with febrile UTI admitted to The Pediatric Department of Lillebaelt Hospital, Kolding from January 2011 to September 2014 were systematically reviewed. We analyzed clinical, laboratory, and radiologic findings. Statistical analysis was performed to identify factors associated with renal scar formation and DSRF on nuclear imaging at 6 months follow-up.

RESULTS

A total of 113 medical records were eligible for further analysis, 99 girls and 14 boys, 34 patients younger than 12 months. In total 30 patients (26.5%) had an abnormal follow-up imaging (DSRF less than 45% and/or renal scarring). Nine patients (8%) had renal scarring. Four patients (3.5%) had renal scarring only, 21 patients (18.6%) had DSRF only, and five patients (4.4%) had both renal scarring and DSRF. Patients with renal scar formation on follow-up imaging had significantly higher C-reactive protein (CRP) than patients with no scarring (p < 0.01). CRP and absolute neutrophil count (ANC) was significantly higher in patients with abnormal follow-up imaging (p < 0.01 and p = 0.010), and these patients more often had positive nitrite in urine dipstick compared to patients with normal kidneys on follow-up (p = 0.048). Temperature above 38.5 °C and CRP >50 mg/L in combination were also associated with a higher risk of abnormal follow-up imaging (p = 0.016).

DISCUSSION

This study contributes with further knowledge to the ongoing debate regarding renal scarring but also reveals the possibility of associated factors for the development of DSRF following a febrile UTI in children. However, due to the retrospective design as well as the small number of events in our study definite conclusions on whether the above-mentioned factors are indeed prognostic for the development of renal scarring or DSRF following a febrile UTI can not be drawn.

The Influence of Non-E. Coli or Extended-Spectrum β-Lactamase-Producing Bacterial Growth on the Follow-Up Procedure of Infants with the First Febrile Urinary Tract Infection

OBJECTIVE

To evaluate the effects of non-E. coli or extended-spectrum β-lactamase-positive (ESBL-positive) microorganism growth in the first febrile urinary tract infection (UTI) of infants on laboratory findings or renal parenchymal damage presenting the severity of inflammation, anatomic abnormalities defined by imaging studies, and recurrent UTIs in the follow-up period.

METHODS

The data of patients aged between 2 and 24 mo and followed up for at least 6 mo with febrile UTI guideline of the authors' pediatric-nephrology clinic, were retrospectively analyzed. Ultrasonography was performed in all the cases at the time of UTI and dimercaptosuccinic-acid (DMSA) at least 4 mo after the infection. Voiding cystourethrography (VCUG) was performed only if ultrasonography findings were abnormal, the uptake deformity was detected in DMSA scan, or the patients experienced recurrent UTIs. The patients were grouped concerning E. coli or non-E. coli and ESBL-PB or non-ESBL-BP growth in the urine cultures.

RESULTS

There were 277 infants followed up for 28.55 ± 15.24 (6-86) mo. The causative microorganisms were non-E. coli in 73 (26.4%) and ESBL-PB in 58 (20.9%) cases. CRP values, pyuria, and leukocyte-esterase positivity were significantly higher in UTIs caused by E. coli compared to non-E. coli bacteria. All clinical and laboratory findings were similar between the ESBL-PB and non-ESBL groups, but abnormal ultrasonography findings were more common in non-E. coli group.

CONCLUSION

E. coli causes more severe inflammation, but non-E. coli infections are more frequently associated with ultrasound abnormalities. However, ESBL production did not affect either laboratory or radiological findings in the present cohort.

SNMMI procedure standard/EANM practice guideline on pediatric [99mTc]Tc-DMSA renal cortical scintigraphy: an update

The Society of Nuclear Medicine and Molecular Imaging (SNMMI), founded in 1954, is an international scientific and professional organization with a purpose to promote the science, technology, and practical application of nuclear medicine. The European Association of Nuclear Medicine (EANM), founded in 1985, is a nonprofit professional medical association with a purpose to facilitate international communication among individuals in nuclear medicine pursuing clinical and academic excellence. Members of the SNMMI and EANM are physicians, technologists, and scientists who specialize in the research and practice of nuclear medicine. The SNMMI and EANM will periodically publish new guidelines for nuclear medicine practice to further advance the science of nuclear medicine and improve patient care. Existing standards/guidelines will be reviewed for revision or renewal, as appropriate. Each standard/guideline, representing a policy statement by the SNMMI/EANM, has undergone a thorough review, and represents an expert consensus. The SNMMI and EANM recognize that the safe and effective use of diagnostic nuclear medicine imaging requires specific training and skills, as described in each document. These standards/guidelines are educational resources designed to assist practitioners in providing appropriate nuclear medicine care for patients. They are consensus documents, and are not mandatory provisions or requirements of practice. They are not intended, nor should they be used, to establish a legal standard of care. For these reasons and those set forth below, the SNMMI and the EANM cautions against the use of these standards/guidelines in litigation procedures that call into question the clinical decisions of a practitioner. The ultimate judgment regarding the appropriateness and propriety of any specific procedure or course of action must be made by medical professionals, taking into account the unique context of each case. Thus, there is no implication that action differing from what is detailed in these standards/guidelines, on its own, is below the standard of care. On the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set forth in the standards/guidelines when, based on the reasonable judgment of the practitioner, such course of action is warranted based on the condition of the patient, limitations of available resources, or advances in knowledge or technology subsequent to publication of the standards/guidelines. Practicing medicine involves not only the science, but also the art of dealing with the prevention, detection, diagnosis, and treatment of disease. The variety and complexity of human conditions make it impossible for general guidelines to consistently allow for an accurate diagnosis to be reached or a specific treatment response to be predicted. Therefore, it should be recognized that adhering to these standards/guidelines does not ensure a successful outcome. All that should be expected is that a practitioner follows a reasonable course of action based on their level of training, the current landscape of knowledge, the resources at their disposal, and the needs/context of the particular patient being treated. The purpose of this document is to provide nuclear medicine physicians, radiologists, and other clinicians with guidelines for the recommendation, performance and interpretation of 99mTc-dimercaptosuccinic acid renal cortical scintigraphy ([99mTc] Tc-DMSA scintigraphy) in pediatric patients. These recommendations represent the expert opinions of experienced leaders in this field, and these recommendations are not all supported by a high level of evidence. Further studies are required to have evidence-based recommendations for the application of [99mTc] Tc-DMSA renal cortical scintigraphy in pediatrics. This guideline summarizes the views of the SNMMI Renal Cortical Scintigraphy in Children Working Group and the EANM Pediatrics Committee. It reflects recommendations for which the SNMMI and EANM cannot be held responsible. The recommendations should be taken into context of good practice of nuclear medicine and do not substitute for national and international legal or regulatory provisions.

Febrile urinary tract infection in children: changes in epidemiology, etiology, and antibiotic resistance patterns over a decade

BACKGROUND

Understanding the epidemiology and prevalence of febrile urinary tract infection (fUTI) in children is important for risk stratification and selecting appropriate urine sample collection candidates to aid in its diagnosis and treatment.

PURPOSE

This study aimed to analyze the epidemiology, etiology, and changes in antibiotic susceptibility patterns of the first fUTI in children.

METHODS

This retrospective observational cohort study included children younger than 19 years of age who were diagnosed and treated for their first fUTI in 2006-2016. Electronic medical records were analyzed and radiologic images were evaluated.

RESULTS

A total of 359 patients (median age, 5.1 months; interquartile range, 3.0-10.5 months) fit the inclusion criteria; of them, 78.0% (n=280) were younger than 12 months old. The male to female ratio was 5.3:1 for patients aged 0-2 months, 2.1:1 for those 3-5 months, and 1.6:1 for those 6-11 months. Beyond 12 months of age, there was a female predominance. Escherichia coli was the leading cause (83.8%), followed by Enterococcus species (6.7%), and Klebsiella pneumoniae (3.6%). Significant yearly increases in the proportions of multidrug-resistant strains (P<0.001) and extended-spectrum beta-lactamase (ESBL) producers (P<0.001) were observed. In patients with vesicoureteral reflux (VUR), the overall recurrence rate was 53.6% (n=15). A significantly higher recurrence rate was observed when the fUTI was caused by an ESBL versus non-ESBL producer (75.0% vs. 30.0%, P=0.03).

CONCLUSION

fUTI was most prevalent in children younger than 12 months of age and showed a female predominance in patients older than 12 months of age. The proportion of ESBL producers causing fUTI is increasing. Carbapenems, rather than noncarbapenems, should be considered for treating fUTI caused by ESBL-producing enteric gram-negative rods to reduce short-term recurrence rates in children with VUR.

Impact of Antibiotic Prescribing Patterns on Susceptibilities of Uropathogens in Children below 24 Months Old

Monitoring regional antibiotic resistance patterns of uropathogens are important for deciding suitable empirical antibiotics for urinary tract infections (UTIs) in children. This study aimed to investigate regional differences in antimicrobial susceptibility patterns of E. coli and Klebsiella spp. in children below 24 months old, diagnosed with their first episode of UTI, and to find factors associated with an increased risk for UTI caused by extended-spectrum β-lactamase (ESBL)-producing uropathogens. This was a retrospective cohort study of children diagnosed between 2011 and 2017 in four different hospitals located in four different regions of South Korea; regions A, B, C, and D. The government’s big data repository was used to acquire data on regional antibiotic prescriptions. The pooled antimicrobial susceptibilities of E. coli and Klebsiella spp. (n = 2044) were as follows: ampicillin–sulbactam (61.0%), 3rd generation cephalosporin (3C) (82.8%), and trimethoprim–sulfamethoxazole (72.0%). Multivariate analysis showed that children diagnosed at hospital A (OR, 1.8; 95% confidence interval [CI], 1.2–2.6; P = 0.002) and every year that increased in the study period (OR, 1.1; 95% CI, 1.1–1.2; P < 0.001) were factors associated with an increased risk for UTIs with ESBL-producers. Regions A and B had significantly higher amounts of oral 3Cs prescribed compared to regions C and D (P = 0.009), which correlate with hospitals in the regions that had higher proportions of UTIs with ESBL-producing uropathogens (A and B vs. C and D, P < 0.001). Therefore, children in certain regions are at a higher risk for UTIs caused by ESBL-producers compared to other regions, which correlate with regions that had higher amounts of oral 3Cs prescribed.

Procalcitonin, C-reactive protein, and erythrocyte sedimentation rate for the diagnosis of acute pyelonephritis in children

BACKGROUND

In children with urinary tract infection (UTI), only those with pyelonephritis (and not cystitis) are at risk for developing long-term renal sequelae. If non-invasive biomarkers could accurately differentiate children with cystitis from children with pyelonephritis, treatment and follow-up could potentially be individualized. This is an update of a review first published in 2015.

OBJECTIVES

The objectives of this review were to 1) determine whether procalcitonin (PCT), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) can replace the acute DMSA scan in the diagnostic evaluation of children with UTI; 2) assess the influence of patient and study characteristics on the diagnostic accuracy of these tests, and 3) compare the performance of the three tests to each other.

SEARCH METHODS

We searched MEDLINE, EMBASE, DARE, Web of Science, and BIOSIS Previews through to 17th December 2019 for this review. The reference lists of all included articles and relevant systematic reviews were searched to identify additional studies not found through the electronic search.

SELECTION CRITERIA

We only considered published studies that evaluated the results of an index test (PCT, CRP, ESR) against the results of an acute-phase ⁹⁹Tc-dimercaptosuccinic acid (DMSA) scan (conducted within 30 days of the UTI) in children aged 0 to 18 years with a culture-confirmed episode of UTI. The following cut-off values were used for the primary analysis: 0.5 ng/mL for procalcitonin, 20 mg/L for CRP and 30 mm/hour for ESR.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the selection criteria to all citations and independently abstracted data. We used the bivariate model to calculate pooled random-effects pooled sensitivity and specificity values.

MAIN RESULTS

A total of 36 studies met our inclusion criteria. Twenty-five studies provided data for the primary analysis: 12 studies (1000 children) included data on PCT, 16 studies (1895 children) included data on CRP, and eight studies (1910 children) included data on ESR (some studies had data on more than one test). The summary sensitivity estimates (95% CI) for the PCT, CRP, ESR tests at the aforementioned cut-offs were 0.81 (0.67 to 0.90), 0.93 (0.86 to 0.96), and 0.83 (0.71 to 0.91), respectively. The summary specificity values for PCT, CRP, and ESR tests at these cut-offs were 0.76 (0.66 to 0.84), 0.37 (0.24 to 0.53), and 0.57 (0.41 to 0.72), respectively.

AUTHORS' CONCLUSIONS

The ESR test does not appear to be sufficiently accurate to be helpful in differentiating children with cystitis from children with pyelonephritis. A low CRP value (< 20 mg/L) appears to be somewhat useful in ruling out pyelonephritis (decreasing the probability of pyelonephritis to < 20%), but unexplained heterogeneity in the data prevents us from making recommendations at this time. The procalcitonin test seems better suited for ruling in pyelonephritis, but the limited number of studies and the marked heterogeneity between studies prevents us from reaching definitive conclusions. Thus, at present, we do not find any compelling evidence to recommend the routine use of any of these tests in clinical practice.

Urine flow cytometry is an adequate screening tool for urinary tract infections in children

Diagnosing a urinary tract infection in children is often difficult due to non-specific symptoms and requires invasive and time-consuming procedures. Flow cytometry is a new and rapid method of analyzing urine to confirm or exclude UTIs. We have investigated the sensitivity and specificity of urine flow cytometry (Sysmex UF1000i) compared to conventional diagnostic techniques in a prospective study from January 1, 2014 until January 1, 2015. All children under 13 years of age with a suspicion of urinary tract infection were screened using both urine flow cytometry and urine culture. A urinary tract infection was defined as the combination of leukocyturia (≥ 25 leukocytes per μl) and a positive urine culture in the presence of clinical symptoms. A total number of 412 urine samples were collected, of which 63 cases (15.3%) were positive for a urinary tract infection. Receiver operating characteristic analysis showed an area under the curve of 0.97 (95% confidence interval h0.93-1.00) for the bacterial count. When using a cut-off value of 250 bacteria/μl in the presence of leukocyturia, the sensitivity for urinary tract infection is 0.97 with a negative predictive value of 97%, and the specificity is 0.91 with a positive predictive value of 90%.Conclusion: Flow cytometry-based bacterial and leukocyte count analysis is a time-efficient method of diagnosing or ruling out urinary tract infection in children, with a higher sensitivity and specificity than dipstick and microscopic analysis. What is known • Screening for urinary tract infections in children is difficult due to invasive and time-consuming procedures. • There is both over- and under-treatment of urinary tract infections due to the delays in accurate diagnosing. What is new • Flow cytometry is a rapid and accurate method to provide useful information in the diagnosis of urinary tract infection in children. When negative, flow cytometry can exclude urinary tract infection in children with a high degree of confidence. When flow cytometry is positive, the possibility of a urinary tract infection in children is increased.

A Putative Role of Apolipoprotein L1 Polymorphism in Renal Parenchymal Scarring Following Febrile Urinary Tract Infection in Nigerian Under-Five Children: Proposal for a Case-Control Association Study

Background

Although urinary tract infection (UTI) resolves with prompt treatment in a majority of children, some children, especially those aged less than 5 years, also develop renal parenchymal scarring (RPS). RPS causes high blood pressure that may lead to severe chronic kidney disease and end-stage renal disease (ESRD). Although the risk of UTI is higher in white children than in black children, it is unknown whether RPS is more common in white children than in black children as data are scarce in this regard. A common genetic predisposition to kidney disease in African Americans and the sub-Saharan African blacks is the possession of apolipoprotein L1 (APOL1). APOL1 risk variants regulate the production of APOL1. APOL1 circulates in the blood, and it is also found in the kidney tissue. While circulating, APOL1 kills the trypanosome parasites; an increased APOL1 in kidney tissues, under the right environmental conditions, can also result in the death of kidney tissue (vascular endothelium, the podocytes, proximal tubules, and arterial cells), which, ultimately, is replaced by fibrous tissue. APOL1 may influence the development of RPS, as evidence affirms that its expression is increased in kidney tissue following UTI caused by bacteria. Thus, UTI may be a putative environmental risk factor responsible for APOL1-induced kidney injury.

Objective

The aim of this proposal was to outline a study that seeks to determine if the possession of two copies of either G1 or G2 APOL1 variant increases the risk of having RPS, 6 months following a febrile UTI among Nigerian under-five children.

Methods

This case-control association study seeks to determine whether the risk of RPS from febrile UTI is conditional on having 2 APOL1 risk alleles (either G1 or G2). Cases will be children with a confirmed RPS following a febrile UTI. Controls will be age-, gender-, and ethnic-matched children with a febrile UTI but without RPS. Children with vesicoureteral reflux and other congenital anomalies of the urinary tract are to be excluded. Association between predictor variables (ethnicity, APOL1 G1 or G2, and others) and RPS will be tested at bivariate logistic regression analyses. Predictors that attained significance at a P value of ˂.05 will be considered for multiple logistic regressions. Likelihood-based tests will be used for hypothesis testing. Estimation will be done for the effect size for each of the APOL1 haplotypes using a generalized linear model.

Results

The study is expected to last for 3 years.

Conclusions

The study is contingent on having a platform for undergoing a research-based PhD program in any willing university in Europe or elsewhere. The findings of this study will be used to improve the care of African children who may develop RPS following febrile UTI.

Registered Report Identifier

RR1-10.2196/9514

Imaging of the Pediatric Urinary System

Recent advances in pediatric urinary tract imaging include development of alternative imaging methods without use of ionizing radiation; evolving understanding of the relationship of urinary tract infection, vesicoureteral reflux, and renal scarring, including the important role of dysfunctional voiding; development of a consensus nomenclature and risk-based classification for fetal and antenatal urinary tract dilation; advances in the understanding of sporadic and inherited renal cystic disease; and a proposed modification of the Bosniak criteria for distinguishing complex renal cysts from cystic renal tumors in children.

Urinary tract infection in small children: the evolution of renal damage over time

BACKGROUND

Our objective was to analyze the evolution of kidney damage over time in small children with urinary tract infection (UTI) and factors associated with progression of renal damage.

METHODS

From a cohort of 1003 children <2 years of age with first-time UTI, a retrospective analysis of 103 children was done. Children were selected because of renal damage at index ^99mTc-dimercaptosuccinic acid (DMSA) scintigraphy at least 3 months after UTI, and a late DMSA scan was performed after at least 2 years. Damage was classified as progression when there was a decline in differential renal function (DRF) by ≥4%, as regression when there was complete or partial resolution of uptake defects.

RESULTS

Of 103 children, 20 showed progression, 20 regression, and 63 remained unchanged. There were no differences between groups regarding gender or age. In the progression group, 16/20 (80%) children had vesicoureteral reflux (VUR) grade III-V and 13 (65%) had recurrent UTI. In multivariable regression analysis, both VUR grade III-V and recurrent UTI were associated with progression. In the regression group, 16/20 (80%) had no VUR or grade I-II, and two (10%) had recurrent UTI.

CONCLUSIONS

Most small children with febrile UTI do not develop renal damage and if they do the majority remain unchanged or regress over time. However, up to one-fifth of children with renal damage diagnosed after UTI are at risk of renal deterioration. These children are characterized by the presence of VUR grades III-V and recurrent febrile UTI and may benefit from follow-up.

Dimercaptosuccinic acid scan or ultrasound in screening for vesicoureteral reflux among children with urinary tract infections

BACKGROUND

There is considerable interest in detecting vesicoureteral reflux (VUR) because its presence, especially when severe, has been linked to an increased risk of urinary tract infections and renal scarring. Voiding cystourethrography (VCUG), also known as micturating cystourethrography, is the gold standard for the diagnosis of VUR, and the grading of its severity. Because VCUG requires bladder catheterisation and exposes children to radiation, there has been a growing interest in other screening strategies that could identify at-risk children without the risks and discomfort associated with VCUG.

OBJECTIVES

The objective of this review is to evaluate the accuracy of two alternative imaging tests - the dimercaptosuccinic acid renal scan (DMSA) and renal-bladder ultrasound (RBUS) - in diagnosing VUR and high-grade VUR (Grade III-V VUR).

SEARCH METHODS

We searched MEDLINE, EMBASE, BIOSIS, and the Cochrane Register of Diagnostic Test Accuracy Studies from 1985 to 31 March 2016. The reference lists of relevant review articles were searched to identify additional studies not found through the electronic search.

SELECTION CRITERIA

We considered published cross-sectional or cohort studies that compared the results of the index tests (DMSA scan or RBUS) with the results of radiographic VCUG in children less than 19 years of age with a culture-confirmed urinary tract infection.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the selection criteria to all citations and independently abstracted data. We used the bivariate model to calculate summary sensitivity and specificity values.

MAIN RESULTS

A total of 42 studies met our inclusion criteria. Twenty studies reported data on the test performance of RBUS in detecting VUR; the summary sensitivity and specificity estimates were 0.44 (95% CI 0.34 to 0.54) and 0.78 (95% CI 0.68 to 0.86), respectively. A total of 11 studies reported data on the test performance of RBUS in detecting high-grade VUR; the summary sensitivity and specificity estimates were 0.59 (95% CI 0.45 to 0.72) and 0.79 (95% CI 0.65 to 0.87), respectively. A total of 19 studies reported data on the test performance of DMSA in detecting VUR; the summary sensitivity and specificity estimates were 0.75 (95% CI 0.67 to 0.81) and 0.48 (95% CI 0.38 to 0.57), respectively. A total of 10 studies reported data on the accuracy of DMSA in detecting high-grade VUR. The summary sensitivity and specificity estimates were 0.93 (95% CI 0.77 to 0.98) and 0.44 (95% CI 0.33 to 0.56), respectively.

AUTHORS' CONCLUSIONS

Neither the renal ultrasound nor the DMSA scan is accurate enough to detect VUR (of all grades). Although a child with a negative DMSA test has an < 1% probability of having high-grade VUR, performing a screening DMSA will result in a large number of children falsely labelled as being at risk for high-grade VUR. Accordingly, the usefulness of the DMSA as a screening test for high-grade VUR should be questioned.

Renal ultrasound and DMSA screening for high-grade vesicoureteral reflux

BACKGROUND

Selection of the appropriate radiologic investigation in a child after first febrile urinary tract infection (UTI) remains a contentious issue. This report investigated the effectiveness of renal bladder ultrasound (RBUS) and late 6 month dimercaptosuccinic acid (DMSA) renal scan in the detection of high-grade vesicoureteral reflux (VUR) after first febrile UTI in infants aged <1 year.

METHODS

A total of 387 infants aged <1 year with first febrile UTI who completed diagnostic follow up consisting of RBUS, voiding cystourethrogram (VCUG) and late 6 month DMSA scan were enrolled in the study. The effectiveness of RBUS and DMSA scan in the detection of high-grade VUR, including cost and benefit were assessed.

RESULTS

Abnormal RBUS was identified in 95 infants (24.5%). VUR was identified on VCUG in 79 (20.4%), of whom eight (2.1%) had high-grade VUR (grade IV-V). Abnormal renal parenchyma was identified on late 6 month DMSA scan in 22 infants (5.7%). The sensitivity of abnormal RBUS and of late 6 month DMSA scan in the prediction of high-grade VUR was 50% and 87.5%, and the proportion of infants who avoided unnecessary VCUG was 75.5% and 94.3%, respectively.

CONCLUSIONS

Fifty percent of high-grade VUR was not identified on RBUS screening after first febrile UTI. Although late 6 month DMSA scan had higher sensitivity in the detection of high-grade VUR, with the added benefit of detection of renal scars, the practical application of this method was limited due to its high cost, radiation exposure and the associated delay in decision making.

Update on the approach of urinary tract infection in childhood

OBJECTIVE

Urinary tract infection (UTI) is the most common bacterial infection in childhood. UTI may be the sentinel event for underlying renal abnormality. There are still many controversies regarding proper management of UTI. In this review article, the authors discuss recent recommendations for the diagnosis, treatment, prophylaxis, and imaging of UTI in childhood based on evidence, and when this is lacking, based on expert consensus.

SOURCES

Data were obtained after a review of the literature and a search of Pubmed, Embase, Scopus, and Scielo.

SUMMARY OF THE FINDINGS

In the first year of life, UTIs are more common in boys (3.7%) than in girls (2%). Signs and symptoms of UTI are very nonspecific, especially in neonates and during childhood; in many cases, fever is the only symptom.

CONCLUSIONS

Clinical history and physical examination may suggest UTI, but confirmation should be made by urine culture, which must be performed before any antimicrobial agent is given. During childhood, the proper collection of urine is essential to avoid false-positive results. Prompt diagnosis and initiation of treatment is important to prevent long-term renal scarring. Febrile infants with UTIs should undergo renal and bladder ultrasonography. Intravenous antibacterial agents are recommended for neonates and young infants. The authors also advise exclusion of obstructive uropathies as soon as possible and later vesicoureteral reflux, if indicated. Prophylaxis should be considered for cases of high susceptibility to UTI and high risk of renal damage.

Procalcitonin, C-reactive protein, and erythrocyte sedimentation rate for the diagnosis of acute pyelonephritis in children

BACKGROUND

In children with urinary tract infection (UTI), only those with pyelonephritis (and not cystitis) are at risk for developing long-term renal sequelae. If non-invasive biomarkers could accurately differentiate children with cystitis from children with pyelonephritis, treatment and follow-up could potentially be individualized.

OBJECTIVES

The objectives of this review were to 1) determine whether procalcitonin, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) can replace the acute DMSA scan in the diagnostic evaluation of children with UTI; 2) assess the influence of patient and study characteristics on the diagnostic accuracy of these tests, and 3) compare the performance of the three tests to each other.

SEARCH METHODS

We searched MEDLINE, EMBASE, DARE, Web of Science, and BIOSIS Previews for this review. The reference lists of all included articles and relevant systematic reviews were searched to identify additional studies not found through the electronic search.

SELECTION CRITERIA

We only considered published studies that evaluated the results of an index test (procalcitonin, CRP, ESR) against the results of an acute-phase DMSA scan (conducted within 30 days of the UTI) in children aged 0 to 18 years with a culture-confirmed episode of UTI. The following cutoff values were used for the primary analysis: 0.5 ng/mL for procalcitonin, 20 mg/L for CRP and 30 mm/h for ESR.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the selection criteria to all citations and independently abstracted data. We used the bivariate model to calculate pooled random-effects pooled sensitivity and specificity values.

MAIN RESULTS

A total of 24 studies met our inclusion criteria. Seventeen studies provided data for the primary analysis: six studies (434 children) included data on procalcitonin, 13 studies (1638 children) included data on CRP, and six studies (1737 children) included data on ESR (some studies had data on more than one test). The summary sensitivity estimates (95% CI) for the procalcitonin, CRP, ESR tests at the aforementioned cutoffs were 0.86 (0.72 to 0.93), 0.94 (0.85 to 0.97), and 0.87 (0.77 to 0.93), respectively. The summary specificity values for procalcitonin, CRP, and ESR tests at these cutoffs were 0.74 (0.55 to 0.87), 0.39 (0.23 to 0.58), and 0.48 (0.33 to 0.64), respectively.

AUTHORS' CONCLUSIONS

The ESR test does not appear to be sufficiently accurate to be helpful in differentiating children with cystitis from children with pyelonephritis. A low CRP value (< 20 mg/L) appears to be somewhat useful in ruling out pyelonephritis (decreasing the probability of pyelonephritis to < 20%), but unexplained heterogeneity in the data prevents us from making recommendations at this time. The procalcitonin test seems better suited for ruling in pyelonephritis, but the limited number of studies and the marked heterogeneity between studies prevents us from reaching definitive conclusions. Thus, at present, we do not find any compelling evidence to recommend the routine use of any of these tests in clinical practice.

Urinary tract infections in children: EAU/ESPU guidelines

CONTEXT

In 30% of children with urinary tract anomalies, urinary tract infection (UTI) can be the first sign. Failure to identify patients at risk can result in damage to the upper urinary tract.

OBJECTIVE

To provide recommendations for the diagnosis, treatment, and imaging of children presenting with UTI.

EVIDENCE ACQUISITION

The recommendations were developed after a review of the literature and a search of PubMed and Embase. A consensus decision was adopted when evidence was low.

EVIDENCE SYNTHESIS

UTIs are classified according to site, episode, symptoms, and complicating factors. For acute treatment, site and severity are the most important. Urine sampling by suprapubic aspiration or catheterisation has a low contamination rate and confirms UTI. Using a plastic bag to collect urine, a UTI can only be excluded if the dipstick is negative for both leukocyte esterase and nitrite or microscopic analysis is negative for both pyuria and bacteriuria. A clean voided midstream urine sample after cleaning the external genitalia has good diagnostic accuracy in toilet-trained children. In children with febrile UTI, antibiotic treatment should be initiated as soon as possible to eradicate infection, prevent bacteraemia, improve outcome, and reduce the likelihood of renal involvement. Ultrasound of the urinary tract is advised to exclude obstructive uropathy. Depending on sex, age, and clinical presentation, vesicoureteral reflux should be excluded. Antibacterial prophylaxis is beneficial. In toilet-trained children, bladder and bowel dysfunction needs to be excluded.

CONCLUSIONS

The level of evidence is high for the diagnosis of UTI and treatment in children but not for imaging to identify patients at risk for upper urinary tract damage.

PATIENT SUMMARY

In these guidelines, we looked at the diagnosis, treatment, and imaging of children with urinary tract infection. There are strong recommendations on diagnosis and treatment; we also advise exclusion of obstructive uropathy within 24h and later vesicoureteral reflux, if indicated.

Update on urinary tract infections in the emergency department

PURPOSE OF REVIEW

To review recent changes in the diagnostic and therapeutic approach to pediatric urinary tract infection in the emergency department.

RECENT FINDINGS

Updated guidelines from the American Academy of Pediatrics have significantly changed the approach to UTI, risk-stratifying patients according to their likelihood of UTI, and re-defining criteria for diagnosis of UTI. New studies have delineated important risk factors for concomitant bacteremia and adverse events. Procalcitonin has emerged as the inflammatory marker most predictive of upper versus lower urinary tract infection and renal scarring. Delays in empiric antibiotic therapy are associated with increased rates of renal scarring. Corticosteroids are a potential adjunctive therapy to antibiotics.

SUMMARY

Timely diagnosis and therapy of UTI are essential. New guidelines may alter the traditional approach to evaluation and management. Future studies will likely focus on the impact of the new guidelines, further delineate the role of procalcitonin in predicting UTI, and explore the role of corticosteroids as an adjunct to antibiotic therapy.

Prevalência de pielonefrite aguda e incidência de cicatriz renal em crianças menores de dois anos de idade com infecção do trato urinário avaliadas por cintilografia renal com 99mTc-DMSA: a experiência de um hospital universitário

OBJETIVO: Calcular as frequências de pielonefrite aguda e cicatriz renal em pacientes menores de dois anos com cintilografia renal com 99mTc-DMSA com primeiro quadro de infecção do trato urinário em hospital universitário brasileiro, comparando com dados da literatura internacional. MATERIAIS E MÉTODOS: Foram revisados laudos cintilográficos de crianças menores de dois anos de idade que realizaram cintilografia renal com 99mTc-DMSA em um hospital universitário no Rio Grande do Sul, entre 2006 e 2009, para pesquisa de pielonefrite aguda/cicatriz renal. Revisaram-se a presença de refluxo vesicoureteral, o uso precoce de antibiótico, e a presença de comorbidades que constassem nos prontuários eletrônicos. Calculou-se a amostra com base num estudo de revisão sistemática e obteve-se um mínimo de 147 pacientes. Excluíram-se pacientes sem registro eletrônico. RESULTADOS: Cento e cinquenta e sete crianças preencheram critérios de inclusão do estudo, 48 tiveram pielonefrite aguda e 8 destas apresentaram cicatriz renal. Nem a idade nem o gênero dos pacientes apresentaram associação significativa com pielonefrite aguda (p = 0,405 e p = 0,124, respectivamente). Não houve diferença estatística nas associações de refluxo vesicoureteral e pielonefrite aguda (p = 1,0) e outras comorbidades (p = 0,470) e em relação ao uso precoce de antibiótico com pielonefrite aguda (p = 0,130) e cicatriz renal (p = 0,720). CONCLUSÃO: As frequências de pielonefrite aguda e cicatriz renal obtidas concordam com os resultados da maioria dos estudos publicados.

Adjunctive oral methylprednisolone in pediatric acute pyelonephritis alleviates renal scarring

OBJECTIVE

To determine if glucocorticoids can prevent renal scar formation after acute pyelonephritis in pediatric patients.

METHODS

Patients younger than 16 years diagnosed with their first episode of acute pyelonephritis with a high risk of renal scar formation (ie, inflammatory volume ≥ 4.6 mL on technetium-99m-labeled dimercaptosuccinic acid scan [DMSA] or abnormal renal ultrasonography results) were randomly assigned to receive either antibiotics plus methylprednisolone sodium phosphate (1.6 mg/kg per day for 3 days [MPD group]) or antibiotics plus placebo (placebo group) every 6 hours for 3 days. Patients were reassessed by using DMSA 6 months after treatment. The primary outcome was the development of renal scars.

RESULTS

A total of 84 patients were enrolled: 19 in the MPD group and 65 in the placebo group. Patient characteristics were similar between the 2 groups, including the acute inflammatory parameters and the initial DMSA result. Renal scarring was found in 33.3% of children treated with MPD and in 60.0% of those who received placebo (P < .05). The median cortical defect volumes on follow-up DMSA were 0.0 mL (range: 0-4.5 mL) and 1.5 mL (range: 0-14.8 mL) for the MPD and placebo groups, respectively (P < .01). Patients in the MPD group experienced faster defervescence after treatment than the placebo group.

CONCLUSIONS

Adjunctive oral MPD therapy reduced the occurrence and/or severity of renal scarring after acute pyelonephritis in these hospitalized children who had a high risk of renal scar formation.

Risk of renal scarring in children with a first urinary tract infection: a systematic review

BACKGROUND

To our knowledge, the risk of renal scarring in children with a urinary tract infection (UTI) has not been systematically studied.

OBJECTIVE

To review the prevalence of acute and chronic renal imaging abnormalities in children after an initial UTI.

METHODS

We searched Medline and Embase for English-, French-, and Spanish-language articles using the following terms: "Technetium (99m)Tc dimercaptosuccinic acid (DMSA)," "DMSA," "dimercaptosuccinic," "scintigra*," "pyelonephritis," and "urinary tract infection." We included articles if they reported data on the prevalence of abnormalities on acute-phase (≤15 days) or follow-up (>5 months) DMSA renal scans in children aged 0 to 18 years after an initial UTI. Two evaluators independently reviewed data from each article.

RESULTS

Of 1533 articles found by the search strategy, 325 full-text articles were reviewed; 33 studies met all inclusion criteria. Among children with an initial episode of UTI, 57% (95% confidence interval [CI]: 50-64) had changes consistent with acute pyelonephritis on the acute-phase DMSA renal scan and 15% (95% CI: 11-18) had evidence of renal scarring on the follow-up DMSA scan. Children with vesicoureteral reflux (VUR) were significantly more likely to develop pyelonephritis (relative risk [RR]: 1.5 [95% CI: 1.1-1.9]) and renal scarring (RR: 2.6 [95% CI: 1.7-3.9]) compared with children with no VUR. Children with VUR grades III or higher were more likely to develop scarring than children with lower grades of VUR (RR: 2.1 [95% CI: 1.4-3.2]).

CONCLUSIONS

The pooled prevalence values provided from this study provide a basis for an evidence-based approach to the management of children with this frequently occurring condition.

Vesicoureteral reflux associated renal damage: congenital reflux nephropathy and acquired renal scarring

PURPOSE

The pathophysiology, evaluation, description and clinical implications of renal damage associated with vesicoureteral reflux remain controversial. We summarized the current understanding of this important aspect of clinical vesicoureteral reflux.

MATERIALS AND METHODS

We performed a detailed review of the literature on clinical, pathological and experimental data related to congenital vesicoureteral reflux and bladder dynamics. We also reviewed the clinical context and imaging evaluation with underlying experimental data related to post-infectious reflux nephropathy.

RESULTS

Congenital reflux nephropathy is a pattern of impaired renal function and development with renal dysplasia as the most severe but not the only form. Mechanisms of developmental disruption are potentially related to vesicoureteral reflux dynamics during gestation and associated bladder dynamics, which may continue into postnatal life. Acquired renal injury associated with infection is related to particular bacterial and host factors that determine infection virulence, host inflammatory response and tissue recovery. As best seen on dimercapto-succinic acid scan, acute changes may resolve but may also persist as permanent renal scarring. Specific risk factors for acute pyelonephritis and renal scarring in patients with vesicoureteral reflux include higher reflux grade, dysfunctional voiding/elimination, recurrent pyelonephritic episodes and delayed initiation of antibiotic therapy. Low pressure sterile reflux is not a cause of reflux nephropathy.

CONCLUSIONS

Renal damage associated with vesicoureteral reflux may be congenital or acquired and the respective pathophysiological mechanisms are likely different. Congenital damage is often dysplasia, which may be a result of disordered renal development secondary to significant alterations in bladder dynamics. These processes may continue into the newborn period while kidney maturation continues. Recognizing the clinical potential for ongoing effects on renal function and the role of bladder development are important for clinical care. Post-pyelonephritic acquired damage is the result of a complex interaction of host and bacterial factors that leads to acute alterations in renal function, and may lead to permanent renal scarring. Strategies for timely intervention as well as prevention are essential to limit the risk of permanent renal injury, which may predispose to hypertension and renal insufficiency in some patients.

Ultrasonography as predictor of permanent renal damage in infants with urinary tract infection

AIM

To evaluate the ability of ultrasound (US) in infants (<1 year) with acute urinary tract infection (UTI), to identify those with permanent renal damage (PRD) at scintigraphy 1 year later.

METHODS

US, dimercaptosuccinic acid scintigraphy and voiding cystourethrography were performed in 191 infants.

RESULTS

US was abnormal in 46 infants (24%). PRD was found in 46 infants (24%); 19 of these had abnormal US (sensitivity 41%). In 145 infants without PRD, 27 had abnormal US (specificity 81%). Dilating reflux or verified obstruction occurred in 21 (11%) infants, of whom 18 (86%) had PRD while 28 of 170 (16%) without such diagnoses had PRD. Of 16 infants with dilating reflux, 9 (sensitivity 56%) had abnormal US and 14 (88%) PRD. Dilatation at US was seen in 27 children; 7 of these had dilating reflux and 5 verified obstruction.

CONCLUSION

US performed in association with acute UTI had limited ability to identify children with PRD at (99m)Tc-dimercaptosuccinic acid (DMSA) 1 year later, although abnormal renal size was a strong indicator of renal damage. The ability of US to identify children with dilating reflux was also limited. However, once detected at US, dilatation of the urinary tract was associated with dilating reflux or obstruction in half of the cases. Our study confirms that dilating reflux and obstruction are strong indicators of PRD but only half of those who developed PRD had such diagnoses.

Vesicoureteral reflux and urinary tract infection: evolving practices and current controversies in pediatric imaging

OBJECTIVE

Pediatric patients with urinary tract infection (UTI) undergo imaging tests to detect vesicoureteral reflux (VUR) in the belief that VUR correlates to risk of renal scarring. This article describes recent evolution and controversies in the management of UTI and VUR.

CONCLUSION

Multitechnique imaging of UTI and VUR is complex and controversial. Evolution in practice patterns is motivated by the desire to rationally minimize unnecessary interventions and radiation exposure. Ongoing evidence-based research is needed to further improve practice guidelines.

The "top-down" approach to the evaluation of children with febrile urinary tract infection

The evaluation of children presenting with urinary tract infection (UTI) has long entailed sonography and cystography to identify all urological abnormalities that might contribute to morbidity. The identification of vesicoureteral reflux (VUR) has been of primary concern since retrospective studies from the 1930s to 1960s established a strong association between VUR, recurrent UTI, and renal cortical scarring. It has been proposed that all VUR carries a risk for renal scarring and, therefore, all VUR should be identified and treated. We will not discuss the controversies surrounding VUR treatment in this review focusing instead on a new paradigm for the evaluation of the child with UTI that is predicated on identifying those at risk for scarring who are most deserving of further evaluation by cystography.

Renal power Doppler ultrasound does not predict renal scarring after urinary tract infection

OBJECTIVE

Young children may develop renal scarring following a urinary tract infection (UTI) especially after pyelonephritis which is difficult to diagnose. Permanent renal scars are diagnosed by dimercapto-succinic acid (DMSA) scan several months later. To decrease unnecessary exposure to radiation, we investigate the role of renal power Doppler (RPD) in predicting those who may not require a late DMSA scan.

METHODS

Children under four years of age with a first UTI underwent an RPD study soon after diagnosis, and a DMSA scintigraphy six months later. The predictive values of the early RPD to detect DMSA renal scarring were calculated.

RESULTS

Twenty three children (median age 30 months) were enrolled: 13 had a febrile presentation, two with bacteraemia. Permanent scarring occurred in three children (13%). In the 46 kidney units studied, initial RPD was abnormal in two and late DMSA abnormal in three units. Overall concordance between RPD and DMSA was 93.5%. The sensitivity of RPD for renal scar as per DMSA was 33.3%, specificity 97.7%; positive predictive value 50% and a negative predictive value of 95.4%.

CONCLUSIONS

RPD offered no advantage over ultrasound to predict renal scarring and cannot be recommended to predict renal scarring following UTI.

TGF-beta1 gene polymorphisms and primary vesicoureteral reflux in childhood

The aim of this study was to assess the association between the transforming growth factor-beta1 (TGF-beta1) gene polymorphisms rs1800469 (commonly known as T-509C) and rs1982073 (commonly known as Leu (10)-->Pro) and primary vesicoureteral reflux (VUR) and renal scarring. Using a case-control approach, we examined 121 children with primary VUR and 169 controls. Genotyping of the TGF-beta1 gene polymorphisms was performed by restriction fragment length polymorphism (RFLP) analysis. The (99m)Tc-DMSA- or (99m)Tc-unitiol-single photon emission computed tomography method was used to evaluate renal scars in 84 of 121 VUR children. Statistical analysis revealed differences in rs1800469 genotype frequencies between VUR patients and controls (p = 0.0021). Our data demonstrate that individuals homozygous for the TT genotype are at risk of primary VUR [odds ratio (95% confidence interval) = 2.7 (1.46-5.08)]. Distribution of the rs1982073 polymorphism was similar in VUR children and controls. In terms of renal scarring, patients were stratified into non-scar and scar subgroups, and no differences in the genotype frequencies of either polymorphism was found. Previous reports have shown that the TT genotype of the rs1800469 polymorphism is a risk factor for renal scarring in primary VUR, and the results of our study suggest that this same polymorphism is associated with susceptibility to this congenital uropathy.

Randomised trial of oral versus sequential intravenous/oral cephalosporins in children with pyelonephritis

The hypothesis was tested that oral antibiotic treatment in children with acute pyelonephritis and scintigraphy-documented lesions is equally as efficacious as sequential intravenous/oral therapy with respect to the incidence of renal scarring. A randomised multi-centre trial was conducted in 365 children aged 6 months to 16 years with bacterial growth in cultures from urine collected by catheter. The children were assigned to receive either oral ceftibuten (9 mg/kg once daily) for 14 days or intravenous ceftriaxone (50 mg/kg once daily) for 3 days followed by oral ceftibuten for 11 days. Only patients with lesions detected on acute-phase dimercaptosuccinic acid (DMSA) scintigraphy underwent follow-up scintigraphy. Efficacy was evaluated by the rate of renal scarring after 6 months on follow-up scintigraphy. Of 219 children with lesions on acute-phase scintigraphy, 152 completed the study; 80 (72 females, median age 2.2 years) were given ceftibuten and 72 (62 females, median age 1.6 years) were given ceftriaxone/ceftibuten. Patients in the intravenous/oral group had significantly higher C-reactive protein (CRP) concentrations at baseline and larger lesion(s) on acute-phase scintigraphy. Follow-up scintigraphy showed renal scarring in 21/80 children treated with ceftibuten and 33/72 with ceftriaxone/ceftibuten (p = 0.01). However, after adjustment for the confounding variables (CRP and size of acute-phase lesion), no significant difference was observed for renal scarring between the two groups (p = 0.2). Renal scarring correlated with the extent of the acute-phase lesion (r = 0.60, p < 0.0001) and the grade of vesico-ureteric reflux (r = 0.31, p = 0.03), and was more frequent in refluxing renal units (p = 0.04). The majority of patients, i.e. 44 in the oral group and 47 in the intravenous/oral group, were managed as out-patients. Side effects were not observed. From this study, we can conclude that once-daily oral ceftibuten for 14 days yielded comparable results to sequential ceftriaxone/ceftibuten treatment in children aged 6 months to 16 years with DMSA-documented acute pyelonephritis and it allowed out-patient management in the majority of these children.

Prospective, randomized trial comparing short and long intravenous antibiotic treatment of acute pyelonephritis in children: dimercaptosuccinic acid scintigraphic evaluation at 9 months

OBJECTIVE

We report a prospective, randomized, multicenter trial that compared the effect of 3 vs 8 days of intravenous ceftriaxone treatment on the incidence of renal scarring at 6 to 9 months of follow-up in 383 children with a first episode of acute pyelonephritis.

METHODS

After initial treatment with intravenous netilmicin and ceftriaxone, patients were randomly assigned to either 5 days of oral antibiotics (short intravenous treatment) or 5 days of intravenous ceftriaxone (long intravenous treatment). Inclusion criteria were age 3 months to 16 years and first acute pyelonephritis episode, defined by fever of >38.5 degrees C, C-reactive protein level of >20 mg/L, and bacteriuria at >10(5)/mL. All patients underwent 99m technetium-dimercaptosuccinic acid scintigraphy 6 to 9 months after inclusion. A total of 548 children were included, 48 of whom were secondarily excluded and 117 of whom were lost to follow-up or had incomplete data; therefore, 383 children were eligible, 205 of them in the short intravenous treatment group and 178 in the long intravenous treatment group.

RESULTS

At inclusion, median age was 15 months, median duration of fever was 43 hours, and median C-reactive protein level was 122 mg/L. A total of 37% (143 of 383) of patients had a vesicoureteral reflux grades 1 to 3. Patient characteristics at inclusion were similar in both groups, except for a significantly higher proportion of girls in the short intravenous treatment group. The frequency of renal scars at scintigraphy was similar in both groups. Multivariate analysis demonstrated that renal scars were significantly associated with increased renal height at initial ultrasound and with the presence of grade 3 vesicoureteric reflux.

CONCLUSIONS

The incidence of renal scars was similar in patients who received 3 days compared 8 days of intravenous ceftriaxone. Increased renal height at initial ultrasound examination and grade 3 vesicoureteric reflux were significant risk factors for renal scars.

Does early treatment of urinary tract infection prevent renal damage?

OBJECTIVE

Therapeutic delay has been suggested as the most important factor that is likely to have an effect on the development of scarring after acute pyelonephritis. However, this opinion has not been supported by prospective studies, so we tested it.

METHODS

In a prospective clinical study, we evaluated whether the time interval between the onset of the renal infection and the start of therapy correlates with the development of acute inflammatory changes and the subsequent development of renal scars, documented by dimercaptosuccinic acid scintigraphy. A total of 278 infants (153 male and 125 female) aged 0.5 to 12.0 months with their first urinary tract infection were enrolled in the study.

RESULTS

The median time between the onset of infection and the institution of therapy was 2 days (range: 1-8 days). Renal inflammatory changes were documented in 57% of the infants. Renal defects were recorded in 41% of the patients treated within the first 24 hours since the onset of fever versus 75% of those treated on day 4 and onward. Renal scarring was developed in 51% of the infants with an abnormal scan in the acute phase of infection. The frequency of scarring in infants treated early and in those whose treatment was delayed did not differ, suggesting that once acute pyelonephritis has occurred, ultimate renal scarring is independent of the timing of therapy. Acute inflammatory changes and subsequent scarring were more frequent in the presence of vesicoureteral reflux, especially that which is high grade. However, the difference was not significant, which suggests that renal damage may be independent of the presence of reflux.

CONCLUSIONS

Early and appropriate treatment of urinary tract infection, especially during the first 24 hours after the onset of symptoms, diminishes the likelihood of renal involvement during the acute phase of the infection but does not prevent scar formation.

Renal scarring sequelae in childhood Kawasaki disease

To assess renal inflammation and its sequelae in Kawasaki disease (KD) patients, we conducted a prospective study in a university medical center setting in Taiwan. From June 2002 to January 2005, 50 children with KD were enrolled, and after admission, all received technetium-99m dimercaptosuccinic acid scintigraphy single photon emission computed tomography (DMSA renal SPECT), the results of which were used as the reference standard for determining renal inflammation. Patients with renal inflammation underwent another DMSA renal SPECT more than 6 months later to evaluate the sequelae. We found that 26 of the 50 patients (52%) had renal inflammatory foci. There were no significant relationships between clinical or laboratory parameters and renal involvement in KD, except the presence of coronary artery lesions [P<0.01; odds ratio (OR) 5.18; 95% confidence interval (CI) 1.52-17.65]. Although all patients were free of clinical symptoms, the 6-month follow-up DMSA renal SPECT showed renal scarring in 11 of the 24 patients (46%). Patients with an initial abnormal renal ultrasound did predict a greatly increased risk of scarring (P<0.05; OR 16.2; 95% CI 1.27-206.20). In conclusion, this study demonstrated that the potential long-term clinical impact of KD is not limited to coronary artery lesion sequelae but also includes renal scar formation.

Resolution of cortical lesions on serial renal scans in children with acute pyelonephritis

BACKGROUND

The ideal time for distinguishing a renal scar from acute inflammatory lesions by renal DMSA scintigraphy remains controversial.

OBJECTIVE

To determine the time needed for resolution of lesions after acute pyelonephritis.

MATERIALS AND METHODS

A total of 105 children with acute pyelonephritis underwent renal sonography, voiding cystourethrography and baseline DMSA scintigraphy. Two subsequent scans were performed during the 6th and 12th months in patients with abnormal findings on the previous scan.

RESULTS

The baseline DMSA scintigraphy revealed cortical lesions in 37 patients. At 6 months, 13 patients (38.2%) were found to have cortical lesions. At 12 months, 6 patients (17.6%) were found to have persistent renal cortical lesions. The resolution rates for lesions detected on the first scan were 61.8% and 82.4% on the 6- and 12-month scans, respectively. Vesicoureteric reflux, and bilaterality or multifocality were not relevant for resolution of lesions. Female gender seemed to be associated with a higher persistence rate.

CONCLUSIONS

The renal cortical defects present at 6 months have a high rate of resolution later during follow-up. DMSA scintigraphy performed 12 months after the infection provides more reliable data regarding persistence of renal cortical lesions.

[Evaluation of renal lesions using 99mTc-DMSA in children with urinary tract infection and the relation with vesicoureteral reflux]

OBJECTIVE

Paediatric patients with urinary tract infection (UTI) have risk of developing renal scarrings. Although it is known that vesicoureteral reflux (VUR) predisposes to UTIs and it seems to have an important role in the development of renal lesions, some recent published studies question that relation. The aim of the study was to evaluate renal scarring by using renal scintigraphy 99mTc-DMSA and see the relation with or without the presence of VUR.

MATERIAL AND METHODS

We evaluated retrospectively a total of 230 patients (460 renal units), mean age: 11 months (range: 12d-5y), with UTI probed by urinoculture. All were studied with voiding cistourethrography (MCU) to evaluate the presence or absence of VUR. Patients were evaluated with 99mTc-DMSA scan 6 months after UTI to determine if UTI caused renal scarring.

RESULTS

Renal scans with 99mTc-DMSA 6 months post-infection were abnormal in 62 renal units, affecting 54 patients (23 %). From all patients studied, 110 were diagnosis of VUR being affected 161 renal units, 43 of them (27 %) presented renal scarrings. From the remaining 120 patients without VUR that is 240 renal units, 19 of them (8 %) presented parenchymatous damage.

CONCLUSION

Renal scarring resulting from UTI are in some cases related to VUR, but sometimes are caused by the infection itself. Not all patients with VUR develop renal lesions, and neither the presence of VUR always predispose children to renal lesions. MCU and direct isotopic cystography are useful for diagnosis of VUR but we shouldn't avoid 99mTc-DMSA scan in the management of children with UTI.

Vesicoureteral reflux increases the risk of renal scars: a study of unilateral reflux

The aim of this study was to assess the impact of vesicoureteral reflux (VUR) on renal scar following acute pyelonephritis by comparing the refluxing renal units with nonrefluxing renal units in children with unilateral primary VUR. Forty-eight children with unilateral primary VUR diagnosed after the first pyelonephritis were enrolled. Mean age of patients was 1.0+/-1.6 years (29 boys and 19 girls). All patients underwent renal ultrasonography and renal 99 m-technetium dimercaptosuccinic acid (DMSA) scan within three days following the diagnosis of pyelonephritis, and voiding cystourethrography (VCU) was performed soon after fever subsided and the infection was controlled. The DMSA scan was rechecked six months after the initial study when the first scan showed a renal defect. The first DMSA showed renal defects in 34 (70.8%) out of 48 of the refluxing renal units and in 13 (27.1%) out of 48 of the nonrefluxing renal units (P<0.01, OR: 6.54). At six months after the infection, 23 (47.9%) out of 48 refluxing renal units and seven (14.6%) out of 48 nonrefluxing renal units had renal scars on DMSA scan (P<0.01, OR: 5.39). The prevalence of renal scars did not vary significantly according to the grade of VUR. The CRP level on admission was significantly higher in patients with acute renal defect and scar. In conclusion, VUR increases the risk of post-pyelonephritic renal scars in children.

Ten-year results of randomized treatment of children with severe vesicoureteral reflux. Final report of the International Reflux Study in Children

For the comparison of long-term outcome of the management of medical or surgical treatment of children with severe vesicoureteral reflux (VUR), children aged <11 years with non-obstructive grade III/IV reflux, previous urinary tract infection (UTI) and glomerular filtration rate (GFR) >or=70 ml/min per 1.73 m2 body surface area were recruited, and 306 were randomly allocated to receive antimicrobial prophylaxis or ureteral reimplantation. Primary endpoints were new renal scars and renal growth. Follow up, originally planned for 5 years, was extended to 10 years for 252 children, 223 of whom had follow-up imaging. Up to 5 years, 40 new urographic scars (medical 19, surgical 21) were seen. Between 5 years and 10 years, only two further scars were observed. Renal growth and UTI recurrence rate were similar, except that medically treated patients had more febrile infections. There was no difference in somatic growth, radionuclide imaging or renal function. A GFR <70 ml/min per 1.73 m2 was found in only one patient. Three patients developed hypertension requiring treatment. We conclude that, with close supervision and prompt treatment of recurrences, children entering the study with GFR >or=70 ml/min per 1.73 m2 progressed remarkably well under either medical or surgical management, emphasizing the importance of continued supervision and the entry level of renal function.

Permanent renal parenchymal defects after febrile UTI are closely associated with vesicoureteric reflux

The finding of scintigraphic renal defects in children with febrile urinary tract infection (UTI) even in the absence of vesicoureteric reflux (VUR) has led to the conclusion that VUR is a weak predictor of renal defects in these patients. We used isotopic cystography (IC) for diagnosis of VUR in children with febrile UTI. Dimercaptosuccinic acid renal scintigraphy was performed 6 months after cure of the last UTI. Renal defects were defined by the finding of focal defects of radionuclide uptake and/or by a split renal function <43%. The study included 206 children with primary VUR and 77 without VUR. Among the subjects with and without VUR, respectively, renal defects were found in 40 and 6% (p=0.0001), focal uptake defects in 33 and 5% (p=0.0001) and split renal function <43% in 26 and 5% (p=0.0001). Permanent renal defects in children with febrile UTI are closely associated with VUR. The possibility that a child will have permanent renal defects can reasonably be ruled out on the basis of the absence of VUR by IC.

Clinical significance of primary vesicoureteral reflux and urinary antibiotic prophylaxis after acute pyelonephritis: a multicenter, randomized, controlled study

OBJECTIVES

To evaluate the role of primary vesicoureteral reflux (VUR) in increasing the frequency and severity of urinary tract infections (UTIs) and renal parenchymal damage among patients with acute pyelonephritis and to determine whether urinary antibiotic prophylaxis reduces the frequency and/or severity of UTIs and/or prevents renal parenchymal damage among patients with mild/moderate VUR.

METHODS

Patients 3 months to 18 years of age with acute pyelonephritis, with or without VUR, were assigned randomly to receive urinary antibiotic prophylaxis or not. Patients were monitored every 3 months for 1 year. Dimercaptosuccinic acid renal scans were repeated at 6 months or if there was a recurrence of febrile UTI. Urinalysis and urine culture were performed at each clinic visit. Renal ultrasound scans and voiding cystourethrograms were repeated at the end of 1 year of follow-up monitoring.

RESULTS

Of the 236 patients enrolled in the study, 218 completed the 1-year follow-up monitoring. Groups were similar with respect to age, gender, and reflux grade distribution for those with VUR. No statistically significant differences were found among the groups with respect to rate of recurrent UTI, type of recurrence, rate of subsequent pyelonephritis, and development of renal parenchymal scars.

CONCLUSIONS

After 1 year of follow-up monitoring, mild/moderate VUR does not increase the incidence of UTI, pyelonephritis, or renal scarring after acute pyelonephritis. Moreover, a role for urinary antibiotic prophylaxis in preventing the recurrence of infection and the development of renal scars is not supported by this study.

Kidney length and scarring in children with urinary tract infection: importance of ultrasound scans

BACKGROUND

Many studies have demonstrated that dimercaptosuccinic acid (DMSA) scintigraphy is the most sensitive diagnostic method in the identification of irreversible renal lesions (scars) in children with previous episodes of acute pyelonephritis (APN). This study assessed the reliability of ultrasound in identifying reflux nephropathy in children with acute pyelonephritis with or without vesicoureteric reflux (VUR).

METHODS

Eighty children (45 female and 35 male, age range 5 months to 10 years, average age 2 years 1 month) with a positive history for at least one episode of APN participated in this study. All children underwent voiding cystourethrography, DMSA scintigraphy 4 to 8 months after the most recent episode of APN, and an ultrasound test evaluation less than 2 months after DMSA scintigraphy.

RESULTS

Voiding cystourethrograms showed VUR in 52 children (68%); 13 of these were bilateral, for a total of 65 refluxing kidney units of the 154 (42%) evaluated; DMSA scintigram was normal for 108 of 154 kidneys (70%). Of the 65 kidneys with VUR, DMSA scintigram displayed normal findings in 29 cases (45%) and pathologic findings in 36 (55%). In the 79 nonrefluxing kidneys, DMSA scintigram was normal in 69 cases (87%). The relative risk of scarring in VUR kidneys is 2.6. The ultrasound study recorded a maximum longitudinal diameter between the 5th and 95th percentiles in 80 of 89 (81%) kidneys without VUR and in 21 of 65 (32%) with VUR. A significant correlation was found between maximum longitudinal diameters and DMSA scintigraphic findings in kidneys with VUR and those without VUR, respectively.

CONCLUSION

This study establishes that ultrasound scans, by means of a simple and reproducible measurement technique, maximum longitudinal diameter, have a predictive value with regard to the presence of scars, with few exceptions. This finding, in our opinion, could lead to a decrease in the number of invasive procedures, in particular DMSA scan, in patients with APN.

Evaluation of acute pyelonephritis with DMSA scans in children presenting after the age of 5 years

It is generally believed that infants are more susceptible to development of renal scarring after pyelonephritis than children over 5 years old. This view has led to differences in investigations and treatment according to age. The aim of this prospective study was to assess the occurrence of renal parenchymal lesion in children over 5 years admitted with a first-time symptomatic urinary tract infection (UTI). Between October 2000 and April 2002, 52 children aged over 5 years who were admitted to our department with probable acute pyelonephritis (APN) and a positive urine culture were included in this study. All children received antibiotics for 14 days. During the acute phase of infection, scintigraphy with technetium-99m-labeled dimercaptosuccinic acid (DMSA) and ultrasonography (US) were done. Voiding cystourethrography (VCUG) was performed in all children early in the course of the illness, generally within 5-7 days of hospitalization. When scintigraphy showed renal parenchymal changes, repeat scintigraphy was done after at least 3 months to assess the progression of renal abnormalities. Of the 52 children with a first-time documented pyelonephritis, cortical scintigraphy showed renal lesion in 41 children (78.8%). US was normal in all children with normal renal scintigraphy, while it detected renal abnormalities in 16 of the 41 (39 %) with abnormal scintigraphy (p <0.0001). Topographic analysis of the 165 focal lesions showed that 42.4% were localized to the upper poles, 17.5% to the middle third, and 40% to the lower poles of the kidneys. Repeat scintigraphy showed persistent lesions corresponding to those on the initial scan in nine (28.2%) of the 32 children. Renal lesions had partly regressed in 23 (71.8%) of the patients who underwent repeat scintigraphy. Vesicoureteral reflux was observed in 13.4% of kidneys and renal parenchymal abnormalities were identified in 71.4% and 72.2% of renal units, respectively, with and without reflux ( p >0.05). In conclusion, our data did not confirm the conventional opinion that the risk of renal scarring after pyelonephritis is low in children over the age of 5 years. Our findings suggest that renal scintigraphy may be a more appropriate method of investigation than VCUG for evaluation of the children over 5 years with acute pyelonephritis. Additionally, the frequency of scintigraphic changes is high, and a strategy based exclusively on ultrasound findings would miss about 61% of the abnormal renal units. We recommend that all children, irrespective of age, will benefit from further investigations that might prevent or limit the development of scarring process and renal complications.

IMPACT OF VESICOURETERAL REFLUX ON THE SIZE OF RENAL LESIONS AFTER AN EPISODE OF ACUTE PYELONEPHRITIS

PURPOSE

We determined the impact of vesicoureteral reflux (VUR) on the size of renal lesions in children after an episode of acute pyelonephritis.

MATERIALS AND METHODS

A total of 161 children (mean age 2.44 years) with acute pyelonephritis were studied. All had renal lesions on dimercapto-succinic acid scintigraphy done at admission to the hospital. A second dimercapto-succinic acid scan was performed at 3 months. Voiding cystourethrography was done at 6 weeks and VUR was graded I to V. For each renal unit layouts of renal lesions were drawn, and the damage surface was calculated and reported for the total surface of the kidney.

RESULTS

Mean size of acute lesions and scars increased with severity of reflux (p <0.0001), with an important overlap of individual values. Mean size of renal scars in the group of renal units with acute lesions was 5.8% +/- 8.5% in patients without VUR, 9.9% +/- 7.3% in those with grade I reflux, 7.7% +/- 11.0% in those with grade II reflux, 17.7% +/- 14.7% in those with grade III reflux and 17.4% +/- 27.7% in those with grade IV reflux (p <0.001). The size of renal lesions decreased significantly with time. The rate of regression of lesions decreased with increasing reflux. When analyzed according to 3 age groups sizes of scars increased significantly with age.

CONCLUSIONS

VUR has an impact on the size of renal lesions after an episode of pyelonephritis. Children with a grade III or IV reflux are more likely to have larger renal scars. On the other hand, acute lesions of important size may develop even in the absence of VUR.

Acute pyelonephritis and sequelae of renal scar in pediatric first febrile urinary tract infection

To investigate the incidence of acute pyelonephritis (APN) and renal scarring in children with febrile urinary tract infection (UTI), 191 of 216 (88%) children with their first episode of UTI received (99m)Tc-dimercaptosuccinic acid renal single-photon emission computed tomography. They were investigated within 7 days of admission and were followed for 6 months. One hundred and six patients (49.1%) underwent a voiding cystourethrogram. The incidence of vesicoureteric reflux (VUR) in group I (</=1 year old) was 22%, group II (1-5 years old) 69%, and group III (5-17 years old) 44%. The overall incidence of APN in febrile UTI was 70% (male 66%, female 76%, P=0.110). Children had a higher incidence of APN than infants ( P<0.05 in group I vs. II and group I vs. III). Of patients with APN, 57% (35/61) showed renal scar formation. VUR was found in 31%(24/78) of children with APN and 58% (14/24) of children with renal scar. In addition, children with high-grade VUR were more susceptible to APN and scar formation than those with low-grade VUR ( P<0.05). Older children with a first febrile UTI had a higher incidence of APN than infants (</=1 year), and half of the children with APN developed a renal scar.

Early treatment of urinary infection prevents renal damage on cortical scintigraphy

Diagnosis of urinary infection in young children is often delayed, which may result in renal damage. However, it remains to be clarified how soon the treatment should be started to prevent renal changes. The present study prospectively enrolled young children with diagnosis of their first febrile urinary infection who underwent technetium-99m dimercaptosuccinate renal cortical scintigraphy within 120 h of initiation of treatment. Patients with abnormal renoscintigraphy received antibiotics for 2 weeks and scintigraphy was repeated 1 year later. Twenty-two children were enrolled from July 1995 through March 2000. Acute-phase renoscintigraphy identified focal defects in 0 of the 14 children who were treated within 24 h of the disease, 1 of the 3 treated in 24-48 h, and 2 of the 5 treated in 48-72 h. Repeat renoscintigraphy showed disappearance of the focal defects in all 3 children. The present study has shown that early treatment within 24 h of onset of the fever due to urinary infection should deter renal changes. Fever for more than 24 h prior to diagnosis indicates a high risk for renal changes and needs an immediate effective treatment to avoid renal damage.