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

NUM-score: A clinical-analytical model for personalised imaging after urinary tract infections

AIM

To identify predictive variables and construct a predictive model along with a decision algorithm to identify nephrourological malformations (NUM) in children with febrile urinary tract infections (fUTI), enhancing the efficiency of imaging diagnostics.

METHODS

We performed a retrospective study of patients aged <16 years with fUTI at the Emergency Department with subsequent microbiological confirmation between 2014 and 2020. The follow-up period was at least 2 years. Patients were categorised into two groups: 'NUM' with previously known nephrourological anomalies or those diagnosed during the follow-up and 'Non-NUM' group.

RESULTS

Out of 836 eligible patients, 26.8% had underlying NUMs. The study identified six key risk factors: recurrent UTIs, non-Escherichia coli infection, moderate acute kidney injury, procalcitonin levels >2 μg/L, age <3 months at the first UTI and fUTIs beyond 24 months. These risk factors were used to develop a predictive model with an 80.7% accuracy rate and elaborate a NUM-score classifying patients into low, moderate and high-risk groups, with a 10%, 35% and 93% prevalence of NUM. We propose an algorithm for approaching imaging tests following a fUTI.

CONCLUSION

Our predictive score may help physicians decide about imaging tests. However, prospective validation of the model will be necessary before its application in daily clinical practice.

Pediatric voiding cystourethrography: An essential examination for urologists but a terrible experience for children

Voiding cystourethrography is the most important fluoroscopic examination in pediatric urology for the investigation of lower urogenital tract diseases, such as vesicoureteral reflux or urethral stricture. However, this invasive procedure imposes a significant burden on children and their parents, and recently there has been a paradigm shift in the diagnosis and treatment of vesicoureteral reflux. In the 2011 revision, the American Academy of Pediatrics guidelines on urinary tract infection recommended abandoning routine voiding cystourethrography after the first febrile urinary tract infection. In 2014, the randomized intervention for children with vesicoureteral reflux study recommended discontinuation of routine continuous antibiotic prophylaxis for vesicoureteral reflux. The time is now ripe to radically reconsider indications for voiding cystourethrography and the procedure itself.

D-dimer as a marker of acute pyelonephritis in infants younger than 24 months with urinary tract infection

BACKGROUND

D-dimer, as well as other biomarkers related to coagulation, is significantly increased during severe bacterial infection and sepsis. The aim of this study was to evaluate the usefulness of serum D-dimer as a biological marker in diagnosing acute pyelonephritis (APN) and in predicting vesicoureteric reflux (VUR) in infants with urinary tract infection (UTI).

METHODS

We retrospectively analyzed the data of 177 young infants (<2 years) with febrile UTI between 2005 and 2014, grouped as APN and lower UTI groups. Conventional inflammatory markers (white blood cell count (WBC), erythrocyte sedimentation rates (ESR), C-reactive protein (CRP)), and D-dimer were measured.

RESULTS

The WBC counts (P = 0.002), ESR (P < 0.0001), CRP (P < 0.0001), D-dimer levels (P = 0.006) and the presence of VUR (P < 0.0001) were significantly higher in the APN group than in the lower UTI group. Multiple logistic regression analyses showed that D-dimer (odds ratio [OR]:1.003, 95% CI: 1.001-1.006, P = 0.002) was an independent predictive factor for VUR in young children with UTI. The area under the curve (AUC) value from the receiver operating characteristic (ROC) curve of D-dimer (0.621, P = 0.046, 95% CI: 0.499-0.743) for prediction of VUR was higher than other inflammatory markers, but was inferior to CRP in predicting APN.

CONCLUSIONS

Our results demonstrate that D-dimer can be used as an inflammatory marker in infants with febrile UTI in addition to other inflammatory markers.

Detection of PCT and urinary β2 -MG enhances the accuracy for localization diagnosing pediatric urinary tract infection

OBJECTIVE

The purpose of this article was to investigate whether the combination of urinary beta 2 microglobulin (urinary β₂ -MG) and procalcitonin (PCT) diagnosis could enhance the localization diagnostic precision of pediatric urinary tract infection comparing with single diagnosis.

METHODS

A study was conducted in the Nephrology Department of Wuhan women and children's health care centre. This study incorporated 85 participants, including 35 children who were diagnosed as upper urinary tract infection (UUTI) with the symptom of fever and 50 children who conducted lower urinary tract infection (LUTI). Levels of PCT and urinary β₂ -MG in both UUTI and LUTI patients were measured and compared.

RESULTS

The level of PCT and β₂ -MG were both significantly higher in UUTI group compared with in LUTI group. AUC of urinary β₂ -MG ROC (sensitivity of 71.4%, specificity of 90.0%) was significantly smaller than that of PCT ROC (sensitivity of 77.1%, specificity of 96.0%) in the single diagnosis. Although in the combined diagnosis, the sensitivity and specificity increased to 88.6% and 98%, respectively.

CONCLUSIONS

Both PCT and β₂ -MG could be used to localize the UTI. Introducing urinary β₂ -MG into PCT diagnosis could increase the sensitivity and specificity of UTI lesion diagnosis in clinical practice.

Discrepancies between plasma procalcitonin and C-reactive protein levels are common in acute illness

AIM

Procalcitonin (PCT) and C-reactive protein (CRP) are biomarkers of bacterial infection with distinct clinical qualities. This study aimed to determine the occurrence and significance of discrepancies in plasma PCT and CRP levels in hospitalised children.

METHODS

This was a single centre, retrospective analysis of simultaneous PCT and CRP measurements. Clinical characteristics, microbiological findings and diagnoses were compared between cases in which only PCT or CRP levels were elevated.

RESULTS

We studied 635 pairs of PCT and CRP measurements and found discrepancies in 29% of these. In the group with increased PCT and low CRP, there were more children with hypoxia or haemodynamic stress (14 versus 0, p < 0.001) and more bacteraemic patients (eight versus zero, p = 0.001) than in the group with low PCT and increased CRP. The latter group was associated with focal bacterial infections (three versus 18, p = 0.009), inflammatory conditions (one versus 12, p = 0.016) and postoperative setting (one versus 19, p = 0.001). Diabetic ketoacidosis was associated with a marked elevation of PCT.

CONCLUSION

Discrepancies in plasma PCT and CRP levels occurred in 29% of acutely ill children. Both biomarkers can increase in the absence of bacterial infection, but PCT may offer an advantage over CRP in the diagnosis of bacteraemia.

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.

Low urinary bacterial counts: do they count?

In their article which appears in this issue of Pediatric Nephrology, Dr. S. Swerkersson and co-workers claim that as many as one in every five infants with a true episode of urinary tract infection (UTI) will be missed with the commonly used cut-off level of ≥10(5) colony forming units (CFU)/mL. This controversial finding is supported by the results of seven previous studies including a total of 1587 children. Dr. E.H. Kass, who in the 1950s suggested the presently used cut-off level, knew at the time that it excluded a number of patients with a true infection. Later studies in adult patients also showed that up to 46–49% of women with a likely diagnosis of cystitis had low bacterial counts. These findings can, if true, improve our understanding of cases of unexplained postinfectious renal scarring. Children with low bacterial counts during an acute infectious episode have a significant risk of receiving delayed or even no antimicrobial treatment. The results of scientific studies are also confounded if 20 % of the subjects with a true infection are wrongly included in a control group diagnosed as having no UTI due to low bacterial counts. This problem cannot be easily solved by lowering the cut-off level and generally accepting that any bacterial count signifies a Btrue^ infection as this approach will drastically reduce the specificity of the culture result. Instead, as many as possible urine samples for culture should be collected from babies, infants and small children with a suprapubic bladder puncture, or a catheterised sample. In such samples bacterial counts as low as 103 CFU/mL are generally regarded as significant. In many cases, however, the only possibility is a Bclean catch^ or bag sample. In these situations, the treating physician needs to take all relevant clinical and laboratory parameters into account and if clinically important data support the diagnosis of a UTI not disregard this diagnosis based only on low bacterial counts. C-reactive protein or procalcitonin can, in a febrile child, help the physician differentiate between a febrile bacterial UTI and a viral infection. A positive nitrite test provides, albeit with a low sensitivity, strong support for a UTI diagnosis.

Serum interleukin -8 is not a reliable marker for prediction of vesicoureteral reflux in children with febrile urinary tract infection

OBJECTIVE

In view of the side effects of voiding cystourethrography (VCUG), identification of noninvasive markers predicting the presence of vesicoureteral reflux (VUR) is important. This study was conducted to determine the predictive value of serum interleukin-8 (IL-8) in diagnosis of VUR in children with first febrile urinary tract infection (UTI).

MATERIALS AND METHODS

Eighty children with first febrile UTI were divided into two groups, with and without VUR, based on the results of VCUG .The sensitivity, specificity, positive and negative predictive value positive and negative likelihood ratio, and accuracy of IL-8 for prediction of VUR were investigated.

RESULTS

Of the 80 children with febrile UTI, 30 (37.5%) had VUR. There was no significant difference between the children with and without VUR and also between low and high-grade VUR groups in terms of serum concentration of IL-8 (P>0.05). Based on ROC curve, the sensitivity, specificity, likelihood ratio positive, and accuracy of serum IL-8 was lower than those of erythrocyte sedimentation rate and C-reactive protein. Multivariate logistic regression analysis showed significant positive correlation only between erythrocyte sedimentation rate and VUR.

CONCLUSIONS

This study showed no significant difference between the children with and without VUR in terms of the serum concentration of IL-8. Therefore, it seems that serum IL-8 is not a reliable marker for prediction of VUR.

Urinary tract infections in children: knowledge updates and a salute to the future

1. Evaluating and treating bladder and bowel dysfunction are critical in reducing the risk of urinary tract infections (UTIs). 2. The pathogenesis of Escherichia coli infections reveals that quiescent intracellular reservoirs may be antibiotic-protected sources of recurrent infections.

OBJECTIVES

1. Review the documentation of UTI and the importance of the urine culture. 2. Understand the controversy over imaging and management of febrile UTIs in children. 3. Recognize the risk factors for recurrent UTIs and strategies for intervention. 4. Update information on the pathogenesis of E coli UTIs.

Vesicoureteric reflux in children

Vesicoureteric reflux is defined as the retrograde passage of urine from the bladder into one or both ureters and often up to the kidneys, and mainly affects babies and infants. In severe cases dilatation of the ureter, renal pelvis, and calyces might be seen. Traditionally it was thought that only a low percentage of children have vesicoureteric reflux, but studies have suggested as many as 25-40% are affected. Guidelines recommend that the number of investigations for vesicoureteric reflux in children who have had a febrile urinary tract infection be reduced, but this approach is controversial. The recommendations also suggest that prophylactic antibiotics and surgery should be avoided in children with non-severe vesicoureteric reflux. In this Seminar I present data on the management of children with vesicoureteric reflux and give suggestions on how to navigate this difficult area.

Procalcitonin: potential role in diagnosis and management of sepsis

Sepsis is an important cause of worldwide morbidity and mortality. Early recognition and diagnosis are keys to achieving improved outcomes. Procalcitonin has been widely investigated as a potential biomarker for sepsis. Furthermore, management of sepsis and other infectious disease is becoming increasingly complicated by the emergence of antibiotic resistant strains of pathogens. Good antibiotic governance is important in reducing the risk of the development of further antibiotic resistance. We reviewed the current literature on the use of procalcitonin in sepsis to determine whether it should be recommended for use in either of these roles. Procalcitonin should not be used as a stand-alone diagnostic test to rule-in or rule-out sepsis or bacterial infection, or for prognostication, in the absence of clinical judgment. Used as part of a clinical algorithm, however, it has been shown to reduce antibiotic prescribing in critical care environments and for respiratory tract infections.

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.

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.

Systematic review of methods for individual patient data meta- analysis with binary outcomes

Background

Meta-analyses (MA) based on individual patient data (IPD) are regarded as the gold standard for meta-analyses and are becoming increasingly common, having several advantages over meta-analyses of summary statistics. These analyses are being undertaken in an increasing diversity of settings, often having a binary outcome. In a previous systematic review of articles published between 1999–2001, the statistical approach was seldom reported in sufficient detail, and the outcome was binary in 32% of the studies considered. Here, we explore statistical methods used for IPD-MA of binary outcomes only, a decade later.

Methods

We selected 56 articles, published in 2011 that presented results from an individual patient data meta-analysis. Of these, 26 considered a binary outcome. Here, we review 26 IPD-MA published during 2011 to consider: the goal of the study and reason for conducting an IPD-MA, whether they obtained all the data they sought, the approach used in their analysis, for instance, a two-stage or a one stage model, and the assumption of fixed or random effects. We also investigated how heterogeneity across studies was described and how studies investigated the effects of covariates.

Results

19 of the 26 IPD-MA used a one-stage approach. 9 IPD-MA used a one-stage random treatment-effect logistic regression model, allowing the treatment effect to vary across studies. Twelve IPD-MA presented some form of statistic to measure heterogeneity across studies, though these were usually calculated using two-stage approach. Subgroup analyses were undertaken in all IPD-MA that aimed to estimate a treatment effect or safety of a treatment,. Sixteen meta-analyses obtained 90% or more of the patients sought.

Conclusion

Evidence from this systematic review shows that the use of binary outcomes in assessing the effects of health care problems has increased, with random effects logistic regression the most common method of analysis. Methods are still often not reported in enough detail. Results also show that heterogeneity of treatment effects is discussed in most applications.

Increased serum procalcitonin levels in pregnant patients with asymptomatic bacteriuria

Background

Among the pregnancy urinary tract infections, asymptomatic bacteriuria (ASB) is the most common one. Untreated ASB can progress to pyelonephritis in 30-50% of the patients and can also result in prematurity in 27% of the pregnancy so it needs immediate diagnosis and treatment. In this study, we wanted to evaluate procalcitonin levels, compared to other inflammatory in pregnant women with ASB.

Methods

The study was designed between the period of January 2012 and February 2013 at Sakarya University School of Medicine, Department of Gynecology and Obstetrics. The study population included 30 pregnant patients with asymptomatic bacteriuria and 39 healthy pregnant controls.

Results

Mean age was 28 (SD, 5.5) of the study population; mean maternal weight was 70 (SD, 8) kilogram. There were no statically significant differences between the groups according to the routine biochemical parameters, but gestational age was significantly lower in the ASB group compared to the controls (20.4 vs 28.6, respectively; p < 0.001). Serum procalcitonin levels were negative in all of the controls. In ASB group, 9 (30%) patients had procalcitonin levels greater than >0.05 ng/ml and 21(70%) patients had negative procalcitonin levels (Chi-squrae, p < 0.001). The sensitivity and specificity of procalcitonin assay for ASB was calculated as 30% and 100%, respectively. The positive predictive value was 100% and the negative predictive value was 65%. The most frequent microorganisms in the urine culture were Escherichia coli (26 patients, 87%), Proteus mirabilis (3 patients, 10%) and Klebsiella (1 patient, 3%) in the ASB group. We experienced four (44%) recurrences among nine positive procalcitonin in ASB patients after completion of treatment of the first ASB diagnosis.

Discussion

Procalcitonin levels were significantly higher in ASB group than the control group and serum procalcitonin levels were higher in pregnant women with recurrent ASB. This finding is an important result revealed that high procalcitonin level can predict the further urinary tract infection risk. Finally, serum procalcitonin levels were normal in healthy pregnant women while other inflammatory markers such as WBC, ESR and CRP levels were higher.

Interleukin-18, CRP and procalcitonin levels in vesicoureteral reflux and reflux nephropathy

BACKGROUND

Some patients with vesicoureteral reflux (VUR) develop reflux nephropathy (RN) and a number of them progress to chronic kidney disease (CKD). However, it is unclear to predict which patient will develop RN and/or CKD. The aim of this study is to evaluate the role of Interleukin-18 (IL-18), C-reactive protein (CRP) and procalcitonin (PCT) as an indicator of RN in VUR.

METHODS

Ninety-three children aged 3.5-16 years with primary VUR were enrolled. Patients were divided into two groups according to the presence of renal scarring (RS). CRP, PCT, blood urea nitrogen (BUN), serum creatinine (Scr), urinary protein (Up), creatinine (Ucr) and microalbumin (Umalb), serum and urine IL-18 levels were determined during urinary tract infection (UTI) free episode.

RESULTS

BUN, Scr, Up/Ucr and Umalb/Ucr concentrations were higher whereas calculated creatinine clearance (Ccr) values were lower in RS (+) group compared to RS (-) group. CRP, PCT, serum and urine IL-18 levels and mean urine IL-18/Cr concentrations were similar in both groups. Serum and urine IL-18 levels did not differ according to the grade of VUR. No significant correlation was found between CRP, PCT and IL-18.

CONCLUSIONS

Proteinuria and microalbuminuria are valuable hallmarks of RN. CRP and PCT seem not to be reliable indicators of RN in VUR patients. Moreover, serum and urine IL-18 might not predict RN.

[Comparative study of C-reactive protein and procalcitonin in the severity diagnosis of pyelonephritis in children]

OBJECTIVE

The aim of this study is to compare two biologic parameters; C-reactive protein (CRP) and procalcitonin (PCT) in the detection of acute renal lesions assessed by DMSA scintigraphy in the urinary tract infection in child.

DESIGN

In a prospective study, serum PCT, CRP and leukocyte counts were measured for children admitted, between January and December 2010, with a first episode of febrile urinary tract infection.

RESULTS

Seventy-five children were enrolled in the study. Thirty-three patients had renal lesions (group A) and 42 had a normal DMSA scintigraphy (group B). The mean PCT level was significantly higher in group A than in group B (8.81 ng/mL versus 1.7 ng/mL, P=0.01). In this study, using receiver operating characteristic (ROC) curve, we identified that the optimal cut-off value with ideal sensitivity and specificity for PCT in detection of renal lesions was 0.76 ng/mL and for CRP, it was 70 mg/L. The sensitivity, the negative predictive value and the indice of Youden of the cut-off value of PCT were significantly higher than CRP (82% versus 70%; 84% versus 70% and 0.58 versus 0.25).

CONCLUSIONS

This study confirmed that the serum PCT level was more sensitive and specific than the CRP in the detection of renal lesions in the first urinary tract infection in child.

Incidence of abnormal imaging and recurrent pyelonephritis after first febrile urinary tract infection in children 2 to 24 months old

PURPOSE

The AAP (American Academy of Pediatrics) no longer recommends voiding cystourethrogram in children 2 to 24 months old who present with a first urinary tract infection if renal-bladder ultrasound is normal. We identified factors associated with abnormal imaging and recurrent pyelonephritis in this population.

MATERIALS AND METHODS

We retrospectively evaluated children diagnosed with a first episode of pyelonephritis at age 2 to 24 months using de-identified electronic medical record data from an institutional database. Data included age at first urinary tract infection, gender, race/ethnicity, need for hospitalization, intravenous antibiotic use, history of abnormal prenatal ultrasound, renal-bladder ultrasound and voiding cystourethrogram results, urinary tract infection recurrence and surgical intervention. Risk factors for abnormal imaging and urinary tract infection recurrence were analyzed by univariate logistic regression, the chi-square test and survival analysis.

RESULTS

We identified 174 patients. Of the 154 renal-bladder ultrasounds performed 59 (38%) were abnormal. Abnormal prenatal ultrasound (p = 0.01) and the need for hospitalization (p = 0.02) predicted abnormal renal-bladder ultrasound. Of the 95 patients with normal renal-bladder ultrasound 84 underwent voiding cystourethrogram. Vesicoureteral reflux was more likely in patients who were white (p = 0.003), female (p = 0.02) and older (p = 0.04). Despite normal renal-bladder ultrasound, 23 of 84 patients (24%) had dilating vesicoureteral reflux. Of the 95 patients with normal renal-bladder ultrasound 14 (15%) had recurrent pyelonephritis and 7 (7%) went on to surgical intervention.

CONCLUSIONS

Despite normal renal-bladder ultrasound after a first pyelonephritis episode, a child may still have vesicoureteral reflux, recurrent pyelonephritis and the need for surgical intervention. If voiding cystourethrogram is deferred, parents should be counseled on these risks.

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.