Procalcitonin to reduce the number of unnecessary cystographies in children with a urinary tract infection: a European validation study

Cases of Pediatric Pyelonephritis: A Single-Center Retrospective Study from an Extended-Spectrum β-Lactamase-Producing Escherichia coli Endemic Area in Japan

Background

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has been increasingly recognized as the cause of upper urinary tract infection (UTI) in children. We have been using flomoxef at our department since 2017 as the first-line empiric therapy for children diagnosed with UTIs, and we avoid using carbapenems, which are considered the first-line treatment for ESBL-producing E. coli. However, reports on the use of flomoxef for UTIs are limited, especially for pediatric patients. The presence of vesicoureteral reflux at the onset of pyelonephritis is a concern. Severe vesicoureteral reflux can lead to repeated UTI and future deterioration of renal function, but the indication for voiding urethrography, which closely examines the presence of vesicoureteral reflux complications, is controversial.

Methods

We retrospectively reviewed the laboratory findings, treatment, and clinical course of 96 pyelonephritis cases experienced at our department over a 7-year period from April 2014 to March 2021.

Results

ESBL-producing E. coli were identified as the cause of pyelonephritis in 51% of cases, and this value was significantly higher (88%) in 2017. No significant differences were found in the febrile period or recurrence rate between the flomoxef-initiated group and other antibiotics groups. We also examined clinical indicators to predict vesicoureteral reflux and found no significant differences in ultrasonographic findings of hydronephrosis.

Conclusion

In the present series, 51% of all pyelonephritis cases were found to be caused by ESBL-producing E. coli, with a significant increase in recent years. Flomoxef may be a useful alternative to carbapenem for ESBL-producing E. coli and the initial antibiotic of choice for upper UTIs in children. The indication for voiding cystourethrography should be carefully determined.

Urinary Tract Infection in Children

BACKGROUND

Urinary Tract Infection (UTI) is a common infection in children. Prompt diagnosis and appropriate treatment are very important to reduce the morbidity associated with this condition.

OBJECTIVE

To provide an update on the evaluation, diagnosis, and treatment of urinary tract infection in children.

METHODS

A PubMed search was completed in clinical queries using the key terms "urinary tract infection", "pyelonephritis" OR "cystitis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature and the pediatric age group. Patents were searched using the key terms "urinary tract infection" "pyelonephritis" OR "cystitis" from www.google.com/patents, http://espacenet.com, and www.freepatentsonline.com.

RESULTS

Escherichia coli accounts for 80 to 90% of UTI in children. The symptoms and signs are nonspecific throughout infancy. Unexplained fever is the most common symptom of UTI during the first two years of life. After the second year of life, symptoms and signs of pyelonephritis include fever, chills, rigor, flank pain, and costovertebral angle tenderness. Lower tract symptoms and signs include suprapubic pain, dysuria, urinary frequency, urgency, cloudy urine, malodorous urine, and suprapubic tenderness. A urinalysis and urine culture should be performed when UTI is suspected. In the work-up of children with UTI, physicians must judiciously utilize imaging studies to minimize exposure of children to radiation. While waiting for the culture results, prompt antibiotic therapy is indicated for symptomatic UTI based on clinical findings and positive urinalysis to eradicate the infection and improve clinical outcome. The choice of antibiotics should take into consideration local data on antibiotic resistance patterns. Recent patents related to the management of UTI are discussed.

CONCLUSION

Currently, a second or third generation cephalosporin and amoxicillin-clavulanate are drugs of choice in the treatment of acute uncomplicated UTI. Parenteral antibiotic therapy is recommended for infants ≤ 2 months and any child who is toxic-looking, hemodynamically unstable, immunocompromised, unable to tolerate oral medication, or not responding to oral medication. A combination of intravenous ampicillin and intravenous/intramuscular gentamycin or a third-generation cephalosporin can be used in those situations. Routine antimicrobial prophylaxis is rarely justified, but continuous antimicrobial prophylaxis should be considered for children with frequent febrile UTI.

New markers of urinary tract infection

Urinary tract infection (UTI) is the most common bacterial infection independent of age. It is also one of the most common causes of hospitalizations for infections among elderly people and the most common indication for antibiotic prescriptions in primary care. Both diagnostics and management of lower and upper urinary tract infections provide challenges in clinical practice due to their high prevalence and recurrence, and worldwide increase of antibiotic resistance. The clinical symptoms of UTI are often uncharacteristic or asymptomatic. The accurate diagnosis and early treatment are crucial due to risk of septicaemia and long-term consequences. Currently the diagnosis of urinary tract infection is based on the presence of clinical symptoms in combination with the results of nitrite strip test indicating the presence of bacteria in urine and semi-quantitative measurement of white blood cells count in urine. Although urine culture is the gold standard in UTI diagnostics it is both time-consuming and costly. Searching for novel biomarkers of UTI has attracted much attention in recent years. The article reviews several promising serum and urine biomarkers of UTI such as leukocyte esterase, C-reactive protein, procalcitonin, interleukins, elastase alpha (1)-proteinase inhibitor, lactofferin, secretory immunoglobulin A, heparin-binding protein, xanthine oxidase, myeloperoxidase, soluble triggering receptor expressed on myeloid cells-1, α-1 microglobulin (α1Mg) and tetrazolium nitroblue test (TNB).

Escherichia coli virulence patterns may help to predict vesicoureteral reflux in paediatric urinary tract infections

AIM

Ultrasound and biological tools are used to predict high-grade vesicoureteral reflux, but other markers are needed to better select patients who need voiding cystography. Our aim was to determine whether studying Escherichia coli virulence factors would help to predict vesicoureteral reflux in patients with their first acute pyelonephritis.

METHODS

We included children presenting with E. coli-related acute pyelonephritis or cystitis. Vesicoureteral reflux was assessed by voiding cystography. Virulence factors were identified by multiplex polymerase chain reaction. Statistical analysis was performed using logistic regression and the mean c-statistic test.

RESULTS

We included 198 patients: 30 with cystitis and 168 with acute pyelonephritis, including 46 with vesicoureteral reflux. High-grade reflux was associated with acute pyelonephritis caused by the E. coli lacking virulence factors papGII (82% versus 47%, p < 0.001) or papC (85% versus 53%, p < 0.001) or belonging to phylogenetic group A or B1. When we added genetic data (lack of papGII, fyuA and phylogenetic groups) to classical predictors of vesicoureteral reflux (ultrasound examination, gender, age), the ability to predict high-grade reflux increased, with the c-statistic rising from 0.88 to 0.93.

CONCLUSION

Bacterial virulence factors and clinical factors helped to predict high-grade reflux and may help to avoid unnecessary voiding cystographies.

Antibiotic prophylaxis and reflux: critical review and assessment

The use of continuous antibiotic prophylaxis (CAP) was critical in the evolution of vesicoureteral reflux (VUR) from a condition in which surgery was the standard of treatment to its becoming a medically managed condition. The efficacy of antibiotic prophylaxis in the management of VUR has been challenged in recent years, and significant confusion exists as to its clinical value. This review summarizes the critical factors in the history, use, and investigation of antibiotic prophylaxis in VUR. This review provides suggestions for assessing the potential clinical utility of prophylaxis.

Predictive risk factors in childhood urinary tract infection, vesicoureteral reflux, and renal scarring management

Approaches to the management of children with urinary tract infection (UTI), vesicoureteral reflux (VUR), and renal scars have been challenged and have become controversial over the past decade. It is difficult to determine when, how, and which patients will benefit from the diagnosis and management of this condition. Therefore, the issues of diagnostic imaging, observation, follow-up, and intervention tend to be decided more on a case-by-case basis, rather than by using an algorithm. Over the past few years, there have been advances in the identification of risk factors that predispose patients with UTI to present with VUR, to develop recurrent UTIs and renal scars, to have deteriorating renal function, to show VUR improvement and/or spontaneous resolution, and to be candidates for and benefit from early surgical intervention.

Procalcitonin to predict bacterial coinfection in infants with acute bronchiolitis: a preliminary analysis

OBJECTIVE

The aim of this study was to conduct a preliminary analysis of serum procalcitonin (PCT) to predict bacterial coinfection in infants with acute bronchiolitis.

METHODS

Retrospective cohort chart review of 40 infants admitted with acute bronchiolitis to the pediatric intensive care unit. Logistic regression models were used to determine the association of PCT and white blood count with presence of bacterial coinfection defined by either positive culture or chest radiograph result.

RESULTS

Fifteen (38%) of 40 patients had a diagnosis of bacterial coinfection by positive culture (9/15) or chest radiograph (6/15). Procalcitonin (P < 0.0001) was significantly associated with bacterial coinfection. A cutoff value of 1.5 ng/mL had sensitivity of 0.80, specificity of 1.00, and area under the operating curve of 0.88. White blood count (P = 0.06) was borderline significant with sensitivity of 0.33, specificity of 0.96, and area under the operating curve of 0.67. Three of 15 patients were later found to have bacterial coinfection with initial PCT of less than 1.5 ng/mL. None had follow-up PCT measurements taken. Thirty-five of 40 were prescribed empiric antibiotic therapy, including 20 of 25 patients without evidence of bacterial coinfection. None had a PCT of greater than 1.5 ng/mL. If a PCT cutoff of greater than 1.5 ng/mL had been used, 57% fewer patients would have received antibiotics with a 45% reduction in antimicrobial charges.

CONCLUSIONS

An elevated PCT may assist clinicians in determining presence of bacterial coinfection at admission in infants with acute bronchiolitis. Implementation of a PCT cutoff of 1.5 ng/mL at admission may prevent unnecessary antibiotic use with associated cost savings. Serial PCT levels may increase sensitivity. Further validation is warranted.

Current medical diagnosis and management of vesicoureteral reflux in children

Vesico-ureteral reflux (VUR) is presented in approximately %1 of children and is associated with an increased risk of pyelonephritis and renal scarring. Despite its prevalence and morbidity, many aspects of VUR diagnosis and treatment are controversial. We objectively assessed the published data; the data base for many current diagnoses and treatment patterns of VUR is limited. Recent studies have focused on developed determination of VUR-related renal morbidity, improved stratification tools that children would benefit most from which VUR treatment option, and improved reporting of the long-term outcomes of VUR treatments in children who are at risk for VUR. In this review, the advances in the diagnosis and treatment of VUR will be accompanied by the current guidelines.

Role of procalcitonin in predicting dilating vesicoureteral reflux in young children hospitalized with a first febrile urinary tract infection

OBJECTIVE

The aim of this article was to assess the usefulness of procalcitonin (PCT) as a marker for predicting dilating (grades III-V) vesicoureteral reflux (VUR) in young children with a first febrile urinary tract infection.

METHODS

Children ≤2 years of age with a first febrile urinary tract infection were prospectively evaluated. Serum samples were tested for PCT at the time of admission to a tertiary hospital. All children underwent renal ultrasonography (US), Tc-dimercaptosuccinic acid renal scan, and voiding cystourethrography. The diagnostic characteristics of PCT test for acute pyelonephritis and dilating VUR were calculated.

RESULTS

Of 272 children analyzed (168 boys and 104 girls; median age, 5 months), 169 (62.1%) had acute pyelonephritis. There was VUR demonstrated in 97 (35.7%), including 70 (25.7%) with dilating VUR. The median PCT value was significantly higher in children with VUR than in those without (P < 0.001). Using a PCT cutoff value of ≥1.0 ng/mL, the sensitivity and negative predictive value for predicting dilating VUR were 94.3% and 95.4%, respectively, for PCT, and 97.1% and 97.8%, respectively, for the combined PCT and US studies, whereas the positive and negative likelihood ratios were 2.03 and 0.107, respectively, for PCT, and 1.72 and 0.067, respectively, for the combined studies. By multivariate analysis, high PCT values and abnormalities on US were independent predictors of dilating VUR.

CONCLUSIONS

PCT is useful for diagnosing acute pyelonephritis and predicting dilating VUR in young children with a first febrile urinary tract infection. A voiding cystourethrography is indicated only in children with high PCT values (≥1.0 ng/mL) and/or abnormalities found on a US.

[Diagnostics and therapy of urinary tract infections]

In infants and young children, urinary tract infections (UTI) often present with unspecific symptoms. Appropriate techniques of urine sampling play an important role for accurate microbiological diagnosis. In infants urine sampling by bladder puncture or transurethral catheter is recommended. In young infants with suspected pyelonephritis, calculated antibiotic treatment should be initiated parenterally with a combination of a third generation cephalosporin or an aminoglycoside with ampicillin. After the age of 3-6 months group 3 oral cephalosporins can be used in uncomplicated pyelonephritis. With the first febrile UTI early sonography is recommended to provide information about renal parenchymal involvement and to exclude malformations of the kidneys and urinary tract. Strategies for the recognition of vesicoureteral reflux and renal damage are under discussion. Recently published guidelines by the American Academy of Pediatrics for the diagnosis and management of UTI in febrile children and infants aged 2-24 months will most likely influence the still pending German guidelines.

Procalcitonin in pediatrics

Over the past two decades, the body of literature on the clinical usefulness of procalcitonin (PCT) in adults has grown rapidly. Although this approach has led to increased insight, it has also prompted debate regarding its potential use in diagnosis and management of severe infection. Clinicians, however, are less familiar with the use of PCT in pediatric populations. In this review, we examine PCT as a marker of severe clinical pediatric conditions including its role in systemic inflammation, infection, and sepsis.

[Procalcitonin, a useful biomarker in pediatric urinary tract infection]

Urinary tract infections (UTIs) are one of the most common sources of bacterial infections among young febrile children. Accurate diagnosis of acute pyelonephritis (APN) and vesico-ureteral reflux (VUR) are important because of their association with renal scarring, sometimes leading to long-term complications. However, the gold standard examinations are either a DMSA scan for APN and scarring, or cystography for VUR, but both present limitations (feasibility, pain, cost, etc.). Procalcitonin, a reliable marker of bacterial infections, was demonstrated to be a good predictor of renal parenchymal involvement in the acute phase and in late renal scars, as well as of high-grade VUR. These findings need further broad validations and impact studies before being implemented into daily practice. However, procalcitonin may play a role in the complex and still debated picture of which examination should be performed after UTI in children.

Evaluation and management of urinary tract infections in the neonate

PURPOSE OF REVIEW

The prevalence of urinary tract infections (UTIs) among full-term neonates has been reported to be up to 1.1%, increasing up to 7% among those with fever. UTI in neonates may be the first indicator of underlying abnormalities of kidneys and the urinary tract.

RECENT FINDINGS

Early recognition and therapy of UTI and detection of risk factors offer chances for applying strategies to avoid renal damage and recurrences. However, established diagnostic strategies and prophylactic concepts today are under debate. Currently, the main focus has been on renal changes as indicators for underlying risk factors like vesicoureteral reflux, attaching much importance to dimercaptosuccinyl acid scans. Serum and urine markers will probably allow more restrictive diagnostic imaging. Prenatal and postnatal ultrasound screenings provide additional opportunities for prophylactic measures.

SUMMARY

Main objectives in the management of neonatal UTIs are the prevention of acute infection-related complications and renal damage. Neonates and very young infants with suspicious pyelonephritis should obligatorily be treated with a combination of parenterally administered antibiotics. As far as possible, diagnostic imaging should be risk-oriented and restricted to noninvasive, nonstressful procedures. The strategies of antibacterial prophylaxis for the prevention of recurrent UTIs are changing. In infants at risk, its benefits have not yet been proven by evident data.

Prediction of high-grade vesicoureteral reflux after pediatric urinary tract infection: external validation study of procalcitonin-based decision rule

BACKGROUND

Predicting vesico-ureteral reflux (VUR) ≥3 at the time of the first urinary tract infection (UTI) would make it possible to restrict cystography to high-risk children. We previously derived the following clinical decision rule for that purpose: cystography should be performed in cases with ureteral dilation and a serum procalcitonin level ≥0.17 ng/mL, or without ureteral dilatation when the serum procalcitonin level ≥0.63 ng/mL. The rule yielded a 86% sensitivity with a 46% specificity. We aimed to test its reproducibility.

STUDY DESIGN

A secondary analysis of prospective series of children with a first UTI. The rule was applied, and predictive ability was calculated.

RESULTS

The study included 413 patients (157 boys, VUR ≥3 in 11%) from eight centers in five countries. The rule offered a 46% specificity (95% CI, 41-52), not different from the one in the derivation study. However, the sensitivity significantly decreased to 64% (95%CI, 50-76), leading to a difference of 20% (95%CI, 17-36). In all, 16 (34%) patients among the 47 with VUR ≥3 were misdiagnosed by the rule. This lack of reproducibility might result primarily from a difference between derivation and validation populations regarding inflammatory parameters (CRP, PCT); the validation set samples may have been collected earlier than for the derivation one.

CONCLUSIONS

The rule built to predict VUR ≥3 had a stable specificity (ie. 46%), but a decreased sensitivity (ie. 64%) because of the time variability of PCT measurement. Some refinement may be warranted.

Procalcitonin is a predictor for high-grade vesicoureteral reflux in children: meta-analysis of individual patient data

OBJECTIVE

To assess the predictive value of procalcitonin, a serum inflammatory marker, in the identification of children with first urinary tract infection (UTI) who might have high-grade (≥3) vesicoureteral reflux (VUR).

STUDY DESIGN

We conducted a meta-analysis of individual data, including all series of children aged 1 month to 4 years with a first UTI, a procalcitonin (PCT) level measurement, cystograms, and an early dimercaptosuccinic acid scan.

RESULTS

Of the 152 relevant identified articles, 12 studies representing 526 patients (10% with VUR ≥3) were included. PCT level was associated with VUR ≥3 as a continuous (P = .001), and as a binary variable, with a 0.5 ng/mL preferred threshold (adjusted OR, 2.5; 95% CI, 1.1 to 5.4). The sensitivity of PCT ≥0.5 ng/mL was 83% (95% CI, 71 to 91) with 43% specificity rate (95% CI, 38 to 47). In the subgroup of children with a positive results on dimercaptosuccinic acid scan, PCT ≥0.5 ng/mL was also associated with high-grade VUR (adjusted OR, 4.8; 95% CI, 1.3 to 17.6).

CONCLUSIONS

We confirmed that PCT is a sensitive and validated predictor strongly associated with VUR ≥3, regardless of the presence of early renal parenchymal involvement in children with a first UTI.

[Comparison of two protocols of febrile urinary tract infection management in children]

PURPOSE

To compare two first febrile urinary tract infection (UTI) management protocols with regards to the diagnosis of high-grade vesicoureteral reflux (VUR) and cost.

METHODS

This study compared two cohorts of children under 16 years of age, admitted for a first episode of febrile UTI. The first group (in 2005) was managed according to previous recommendations (IV treatment and cystography performed for all children under 3 years of age). The second group (in 2006) was managed according to age and procalcitonin level. High-grade VUR frequency, UTI recurrence, hospitalization rate, and cost were compared between the two cohorts.

RESULTS

A total of 225 children were included in 2005 and 116 in 2006. High-grade VUR was found in 6.2 and 9.5% of the patients in 2005 and 2006, respectively (P=0.274). There was no statistically significant difference in the UTI recurrence rate between the two cohorts (5.3% in 2005 and 8.6% in 2006; P=0.237). The mean cost of an episode of febrile UTI was not significantly different in 2005 and 2006 (€2235 in 2005, €2256 in 2006; P=0.902), but was lower for children older than 6 months in 2006 (€1292 versus €1882 in 2005; P=0.0042).

CONCLUSION

Our management protocol for a first febrile UTI episode in children based on procalcitonin levels seems to be suitable for the diagnosis of high-grade VUR. The hospitalization rate and the mean cost of management for children older than 6 months of age was significantly reduced in 2006. The management guidelines for a first occurrence of febrile UTI in children should be reconsidered.

Procalcitonin: a key marker in children with urinary tract infection

Urinary tract infections (UTIs) are the most common source of bacterial infections among young febrile children. Accurate diagnosis of acute pyelonephritis (APN) and vesicoureteral reflux (VUR) is important because of their association with renal scarring, leading in the cases to long-term complications. However, the gold standard examinations for both are either DMSA scan (for APN and scar) or cystography (for VUR) and present limitations (feasibility, pain, cost, etc.). Procalcitonin, a reliable marker of bacterial infections, was demonstrated to be a good predictor of both renal parenchymal involvement in the acute phase and late renal scars. Furthermore, it was also found to be associated with high-grade VUR and was the key tool of a clinical decision rule to predict high-grade VUR in children with a first UTI. Therefore, procalcitonin may certainly be found playing a role in the complex and still debated picture of which examination should be performed after UTI in children.

Practice guidelines for imaging studies in children after the first urinary tract infection

PURPOSE

Urinary tract infection is common in children and may be associated with significant urinary tract pathology. Many children are investigated for vesicoureteral reflux after the first urinary tract infection but less than a quarter have reflux. Imaging with voiding cystourethrogram is not without risk. An approach was proposed to predict reflux in children with a urinary tract infection. We sought to validate a preestablished clinical decision rule to target voiding cystourethrogram more efficiently in children after the first urinary tract infection.

MATERIALS AND METHODS

We tested the usefulness of a clinical decision rule to predict vesicoureteral reflux in 406 consecutive children younger than 5 years who were treated or referred for consultation due to an acute urinary tract infection. Symptoms and signs of urinary tract infection and imaging findings were analyzed.

RESULTS

Vesicoureteral reflux was found in 120 children (35%), including 69 (20%) with grade III-V reflux. An abnormal ultrasound finding was seen in 71 cases (18%) but was not associated with reflux. The clinical decision rule appeared to have poor sensitivity of only 24% to identify grade III-V reflux. We found it impractical to predict vesicoureteral reflux in children with a urinary tract infection.

CONCLUSIONS

Results show that it is not possible to predict grade III-V vesicoureteral reflux reliably using the clinical decision rule. The recent guidelines recommending a search for reflux after a urinary tract infection in children cannot be revised using this decision rule.

Predicting severe bacterial infections in well-appearing febrile neonates: laboratory markers accuracy and duration of fever

OBJECTIVES

To assess the diagnostic accuracy of white blood cell count (WBC), absolute neutrophil count (ANC), and C-reactive protein (CRP) in detecting severe bacterial infections (SBI) in well-appearing neonates with early onset fever without source (FWS) and in relation to fever duration.

METHODS

An observational study was conducted on previously healthy neonates 7 to 28 days of age, consecutively hospitalized for FWS from less than 12 hours to a tertiary care Pediatric Emergency Department, over a 4-year period. Laboratory markers were obtained upon admission in all patients and repeated 6 to 12 hours from admission in those with normal values on initial determination. Sensitivity, specificity, positive and negative likelihood ratios, and receiver operating characteristic analysis were carried out for primary and repeated laboratory examinations.

RESULTS

Ninety-nine patients were finally studied. SBI was documented in 25 (25.3%) neonates. Areas under receiver operating characteristic curves were 0.78 (95% CI, 0.69-0.86) for CRP, 0.77 (95% CI, 0.67-0.85) for ANC and 0.59 (95% CI, 0.49-0.69) for WBC. Sixty-two patients presented normal laboratory markers on initial determination. Of these, 58 successfully underwent repeated blood examination at >12 hours from fever onset. Five of them had an SBI. The area under curve calculated for repeated laboratory tests showed better values, respectively of 0.99 (95% CI, 0.92-1) for CRP, 0.85 (95% CI, 0.73-0.93) for ANC and 0.79 (95% CI, 0.66-0.88) for WBC.

CONCLUSIONS

In well-appearing neonates with early onset FWS, laboratory markers are more accurate and reliable predictors of SBI when performed after >12 hours of fever duration. ANC and especially CRP resulted better markers than the traditionally recommended WBC.

Serum procalcitonin for prediction of renal parenchymal involvement in children with urinary tract infections: a meta-analysis of prospective clinical studies

OBJECTIVE

To determine by meta-analysis whether serum procalcitonin (PCT) is a useful marker of acute renal parenchymal involvement (RPI) in children with culture-proven urinary tract infection (UTI), as diagnosed by acute-phase DMSA (Tc-99m dimercaptosuccinic acid) renal scintigraphy.

STUDY DESIGN

We searched PubMed and the Cochrane Central Register of Controlled Trials for prospective studies involving children with culture-proven UTIs. Additional eligibility criteria were measurement of serum PCT at presentation and performance of DMSA scintigraphy within 14 days.

RESULTS

Overall, 10 studies eligible for inclusion, involving a total of 627 children, were identified. Half of these studies evaluated children with a first episode of UTI; 8 involved children with febrile UTIs. Using a cutoff value of 0.5 to 0.6 ng/mL, the pooled diagnostic odds ratio of serum PCT for UTI with RPI was 14.25 (95% confidence interval, 4.70 to 43.23). High statistical between-study heterogeneity that could mainly be attributed to 2 studies was observed. The remaining 8 studies uniformly favored PCT use.

CONCLUSIONS

In children with culture-proven UTI, a serum PCT value >0.5 ng/mL predicts reasonably well the presence of RPI, as evidenced by DMSA scintigraphy. PCT may aid in the identification of children with UTI, necessitating more intense evaluation and management.

Controversies in the management of vesicoureteral reflux: the rationale for the RIVUR study

The current management of vesicoureteral reflux (VUR) focuses on the prevention of urinary tract infections (UTI), with curative surgery being limited to those children that fail conservative measures. This is based on the assumption that UTIs are preventable with the use of prophylatic antibiotics, leading to reduction of renal scarring, and the possibility that VUR in children can resolve spontaneously.

METHODS

Review of the recent literature has demonstrated a growing concern that antibiotic prophylaxis may not lead to prevention of UTIs. Additionally, data indicate that renal scarring may not be preventable with antibiotic prophylaxis or even surgical correction of VUR. An overview of all of the current controversies is presented in this paper.

RESULTS

Does antibiotic prophylaxis lead to reduction in UTIs in children with VUR? To address this question, the National Institutes of Health have developed a randomized placebo-controlled study of children with VUR (the RIVUR Study), identified following the development of a UTI.

CONCLUSIONS

There are far reaching consequences of the results of the RIVUR Study. If antibiotic prophylaxis does not prevent UTI in children with VUR, or lead to reduction in renal scarring, does identification of VUR provide any benefits? Perhaps appropriate treatment of UTI may be all that is necessary for preserving renal function. Final answers will have to wait until the completion of this study.

Novel biomarkers for the diagnosis of urinary tract infection-a systematic review

Urinary tract infections (UTIs) are associated with significant morbidity. We rely on clinical presentation, urinalysis, and urine culture to diagnose UTI. To differentiate between lower UTI and pyelonephritis, we depend on the clinical presentation. In the extremes of age and in immunocompromised individuals, clinical presentation is often atypical posing a challenge to diagnosis. In the elderly, the high prevalence of asymptomatic bacteriuria is another confounder. We conducted a search of publications to find novel biomarkers to diagnose UTI and to ascertain its severity. We searched PUBMED, MEDLINE and SCOPUS databases for studies pertaining to novel biomarkers and UTI. Two reviewers independently evaluated the methodology of the studies using the STARD (Standards for Reporting of Diagnostic Accuracy) criteria. We have identified procalcitonin as a biomarker to differentiate lower UTI from pyelonephritis in the pediatric age group. Elevated serum procalcitonin levels can result in early and aggressive treatment at the time of presentation. Interleukin 6 has also shown some promise in differentiating between lower UTI and pyelonephritis but needs further validation. Lastly, given the paucity of data in certain subgroups like diabetics, kidney transplant recipients, and individuals with spinal cord injury, further studies should be conducted in these populations to improve diagnostic criteria that will inform clinical management decisions.

Procalcitonin as a predictor of renal scarring in infants and young children

The aim of this study was to evaluate the usefulness of procalcitonin (PCT) as a marker of renal scars in infants and young children with a first episode of acute pyelonephritis. Children aged 7 days to 36 months admitted for first febrile urinary tract infection (UTI) to a pediatric emergency department were prospectively enrolled. The PCT concentration was determined at admission. Acute (99m)Tc-dimercaptosuccinic acid (DMSA) scintigraphy was performed within 7 days of admission and repeated 12 months later when abnormal findings were obtained on the first scan. Of the 72 children enrolled in the study, 52 showed signs of acute pyelonephritis (APN) on the first DMSA scan. A follow-up scintigraphy at the 12-month follow-up performed on 41 patients revealed that 14 (34%) patients had developed renal scars; these patients also presented significantly higher PCT values than those without permanent renal lesions [2.3 (interquartile range 1-11.6) vs. 0.5 (0.2-1.4) ng/mL; p = 0.007]. A comparison of the PCT concentration in patients with febrile UTI without renal involvement, with APN without scar development and with APN with subsequent renal scarring revealed a significant increasing trend (p = 0.006, Kruskal-Wallis test). The area under the ROC curve for scar prediction was 0.74 (95% confidence interval 0.61-0.85), with an optimum statistical cut-off value of 1 ng/mL (sensitivity 78.6%; specificity 63.8%). Based on these results, we suggest that serum PCT concentration at admission is a useful predictive tool of renal scarring in infants and young children with acute pyelonephritis.

Vesicoureteral reflux, a benign condition

The combination of urinary tract infection (UTI) and vesicoureteral reflux (VUR) is commonly thought to predispose the child to pyelonephritis, renal scarring and, later in life, to hypertension or end-stage renal disease (ESRD). This paradigm has led to the active search, follow-up and treatment of VUR, and also prevention of recurrent UTI in children. The causality of VUR and ESRD is controversial, however. According to recent meta-analyses it is uncertain whether we can prevent renal scarring or ESRD by treating VUR. Studies on VUR are abundant, but the findings and conclusions are confounding. Because of the lack of evidence of the role of VUR, reasonable doubt has recently been presented on the rationale of imaging all children with UTI and treating the children with VUR. The overall importance of VUR is confounded because of the natural tendency of VUR to resolve spontaneously, its dynamic nature, and its different grades in children. The historical studies showing that VUR is much more common, even among healthy children, than usually claimed, have been forgotten. Since it seems that we are referring too many healthy children to unpleasant and possibly unnecessary imaging tests for VUR, we are uncertain when and what kind of VUR-if any-we should treat, and whether our present rationale of addressing VUR truly makes any difference to renal scarring or ESRD in children, we should critically revisit the subject of VUR.

Is serum procalcitonin able to predict long-term kidney morbidity from urinary tract infections in children?

A new diagnostic strategy for children with febrile urinary tract infections could be the routine use of procalcitonin assessment to identify children requiring closer follow-up since being at risk for kidney damage. A total of 11 studies were published between 1998 and 2007. Children with very high procalcitonin levels during urinary tract infections are likely to be at risk of renal damage and vesico-ureteral reflux. Therefore, the prediction of long-term renal damage showed contradictory results. However, high procalcitonin values at diagnosis and positive scintigraphic scans may suggest the need to investigate for vesico-ureteral reflux. Consequently, procalcitonin levels should be included in follow-up protocols for urinary tract infections to aid in decision making concerning scintigraphic scans and voiding cystourethrograms.

Normal dimercaptosuccinic acid scintigraphy makes voiding cystourethrography unnecessary after urinary tract infection

OBJECTIVE

To test the hypothesis that infants with dilating vesicoureteral reflux (VUR) have abnormal acute dimercaptosuccinic acid (DMSA) scintigraphy results, as was suggested by an earlier retrospective study.

STUDY DESIGN

We conducted a prospective study of infants <1 year old with first diagnosed symptomatic urinary tract infection at the Children's Hospital of Göteborg, Sweden. Two hundred ninety consecutive children (161 boys and 129 girls) with complete records were examined. Renal ultrasound scanning and DMSA scintigraphy were performed within a few days from diagnosis, and VCU was performed within 2 months.

RESULTS

VUR was found in 52 children, of which 27 had dilating VUR (grade III-V). DMSA scintigraphy results were abnormal in 149 infants (51%), 105 of 238 (44%) without VUR, 18 of 25 (72%) with VUR grade I to II, and 26 of 27 (96%) with VUR grade III to V (P <.001).

CONCLUSION

DMSA scintigraphy results were abnormal in all 27 infants with dilating VUR except 1. This single false-negative finding should be compared with 140 unnecessary VCU investigations. This supports our hypothesis that DMSA scintigraphy results are abnormal when there is dilating VUR. Thus, a normal DMSA scan makes VCU unnecessary in the primary examination of infants with UTI.