Apport du dosage de la procalcitonine pour le diagnostic de pyélonéphrite aiguë de l'enfant

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.

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.

Association of procalcitonin with acute pyelonephritis and renal scars in pediatric UTI

BACKGROUND AND OBJECTIVE

Urinary tract infections (UTIs) are common childhood bacterial infections that may involve renal parenchymal infection (acute pyelonephritis [APN]) followed by late scarring. Prompt, high-quality diagnosis of APN and later identification of children with scarring are important for preventing future complications. Examination via dimercaptosuccinic acid scanning is the current clinical gold standard but is not routinely performed. A more accessible assay could therefore prove useful. Our goal was to study procalcitonin as a predictor for both APN and scarring in children with UTI.

METHODS

A systematic review and meta-analysis of individual patient data were performed; all data were gathered from children with UTIs who had undergone both procalcitonin measurement and dimercaptosuccinic acid scanning.

RESULTS

A total of 1011 patients (APN in 60.6%, late scarring in 25.7%) were included from 18 studies. Procalcitonin as a continuous, class, and binary variable was associated with APN and scarring (P < .001) and demonstrated a significantly higher (P < .05) area under the receiver operating characteristic curve than either C-reactive protein or white blood cell count for both pathologies. Procalcitonin ≥0.5 ng/mL yielded an adjusted odds ratio of 7.9 (95% confidence interval [CI]: 5.8-10.9) with 71% sensitivity (95% CI: 67-74) and 72% specificity (95% CI: 67-76) for APN. Procalcitonin ≥0.5 ng/mL was significantly associated with late scarring (adjusted odds ratio: 3.4 [95% CI: 2.1-5.7]) with 79% sensitivity (95% CI: 71-85) and 50% specificity (95% CI: 45-54).

CONCLUSIONS

Procalcitonin was a more robust predictor compared with C-reactive protein or white blood cell count for selectively identifying children who had APN during the early stages of UTI, as well as those with late scarring.

[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.

[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.

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.

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.

Usefulness of procalcitonin rapid test for the diagnosis of acute pyelonephritis in children in the emergency department

BACKGROUND

Urinary tract infection (UTI) is a common problem in children. The aim of this study was to determine the usefulness of the procalcitonin (PCT) rapid test in the diagnosis of renal involvement in children with urinary tract infection.

METHODS

Through a case series study, PCT and C-reactive protein rapid tests were measured in children with proven UTI at the Tehran Children's Medical Center, Iran. One-hundred patients aged 1 month-14 years old (19 boys and 81 girls) with documented UTI were enrolled in the study.

RESULTS

Of 100 children, 62 patients (62%) had renal involvement on the basis of abnormal Tc-dimercaptosuccinic acid scintigraphy and 38 patients (38%) had infection restricted to the lower urinary tract. There were no differences related to age or gender among the groups. The sensitivity and specificity of PCT were 77% and 89%, respectively, in prediction of renal involvement, whereas C-reactive protein had a sensitivity of 80% and a specificity of 65%.

CONCLUSION

We concluded that a rapid determination of PCT concentration could be useful for the management of children with febrile UTI in the emergency room.

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.

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.

Comparative efficacies of procalcitonin and conventional inflammatory markers for prediction of renal parenchymal inflammation in pediatric first urinary tract infection

OBJECTIVES

To compare the reliability of procalcitonin (PCT) with conventional laboratory parameters in predicting for renal parenchymal inflammation (RPI).

METHODS

The study cohort consisted of 57 children who were admitted for a first-episode urinary tract infection. All patients underwent measurement of the leukocyte count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum PCT. RPI was evaluated by technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy within 7 days of admission. If the first DMSA findings were abnormal, another analysis was performed 6 months later. The cutoff points for ESR, CRP, and PCT were established by comparing the areas under their receiver operating characteristic curves. Statistical analysis was performed using 1-way analysis of variance.

RESULTS

Of the 57 children, 27 were diagnosed with RPI on the basis of positive DMSA results. The ESR, CRP, and PCT levels were significantly greater (P < .001) in the patients with RPI than in those without RPI. In contrast, the leukocyte count was the same in both groups (P > .05). PCT was a more sensitive and specific marker for differentiating upper and lower urinary tract infection than ESR and CRP. Persistent lesions at the site of previous RPI were found in 12 patients in the follow-up DMSA analysis, with total regression evident in the remaining 15. The PCT levels were significantly greater in those with persistent renal lesions than in those with total regression (P = .005).

CONCLUSIONS

Serum PCT is a more reliable biologic marker than the ESR, CRP, or leukocyte count for the early prediction of RPI in children with a first episode of urinary tract infection. In addition, the greater the elevation of PCT at admission, the more positive the correlation for subsequent permanent renal damage.

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.

Procalcitonin for the early prediction of renal parenchymal involvement in children with UTI: preliminary results

In order to establish the most reliable marker for distinguishing urinary tract infections (UTI) with and without renal parenchymal involvement (RPI), we recorded the clinical features and admission leukocyte count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum procalcitonin (PCT) in 57 children (including 43 girls) aged 2-108 months admitted with a first episode of UTI. RPI was evaluated by Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy within 7 days of admission. To establish cut-off points for ESR, CRP, and PCT, we used receiver operating characteristics curves and compared the area under the curve for ESR, CRP, and PCT. Twenty-seven children were diagnosed as having RPI based on positive renal scintigraphy. A body temperature of >38 degrees C, a history of diarrhea, and poor oral intake were more common in patients with RPI. ESR, CRP, and PCT, but not leukocyte count, were significantly higher in patients with RPI (P < 0.001). PCT was more sensitive and specific for the diagnosis of upper versus lower UTI than ESR and CRP. Using a cut-off value of 0.85 ng/ml, PCT had the best performance, with sensitivity, specificity, and positive and negative predictive values of 89%, 97%, 96%, and 91% respectively. Serum PCT is a better marker than ESR, CRP, and leukocyte count for the early prediction of RPI in children with a first episode of UTI.

Diagnostic significance of clinical and laboratory findings to localize site of urinary infection

The aim of this study was to define in children younger than 2 years of age the diagnostic significance of clinical and laboratory findings to localize site of febrile urinary tract infection. We reviewed the records of 185 children younger than 2 years of age admitted to hospital with febrile urinary tract infection. Patients were divided into having either acute pyelonephritis or acute cystitis according to the presence or absence of acute lesions on dimercaptosuccinic acid (DMSA) renal scintigraphy. Clinical and laboratory [white blood cell count (WBC), urinalysis, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP)] findings were compared between the two groups using Student's t test, chi-square test, and multivariate analysis. Patients with pyelonephritis had statistically significant higher age, WBC, ESR, and CRP than those with cystitis. Although the sensitivity of the tests was 80-100%, their specificity was <28%. On multivariate analysis, 33% of patients with cystitis were diagnosed as having pyelonephritis, whereas 22% of those with pyelonephritis were considered to have cystitis. Given the low specificity of clinical findings and available laboratory tests to define the site of urine infection in this age group, we recommend DMSA renal scintigram as the test of choice to make the diagnosis of acute pyelonephritis in these patients.