Carla Romanello

Age-Related Renal Parenchymal Lesions in Children With First Febrile Urinary Tract Infections

OBJECTIVE: The aim of this study was to define the association between age and the occurrence of acute pyelonephritis and renal scars. METHODS: Between 1999 and 2002, all children 0 to 14 years of age consecutively seen with a first febrile urinary tract infection were enrolled in the study. 99mTc-Dimercaptosuccinic acid renal scintigraphy was performed within 5 days after admission for the detection of renal parenchymal involvement. The presence of vesicoureteral reflux was assessed by using cystography performed 1 month after the infection. If the acute scan results were abnormal, then follow-up 99mTc-dimercaptosuccinic acid scanning was performed after 6 months, to assess the frequency of scars. RESULTS: A total of 316 children were enrolled in the study (190 children <1 year, 99 children 1–4 years, and 27 children 5–14 years of age). 99mTc-Dimercaptosuccinic acid scintigraphy revealed that 59% of the children had renal involvement in the acute phase of infection. The frequency of kidney involvement in infants <1 year of age (49%) was significantly lower than that in children 1 to 4 years of age (73%) and >5 years of age (81%). Of the 187 children with positive acute 99mTc-dimercaptosuccinic acid scan results, 123 underwent repeat scintigraphy after 6 months. Renal scars were found for 28% of children <1 year, 37% of children 1 to 4 years, and 53% of children 5 to 14 years of age. No significant differences in the frequency of scars and the presence or absence of vesicoureteral reflux were noted. CONCLUSIONS: Our findings confirm that acute pyelonephritis and subsequent renal scarring occur only in some children with first febrile urinary tract infections. Children <1 year of age with febrile urinary tract infections have a lower risk of parenchymal localization of infection and renal scarring.

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.

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 and pyelonephritis in children.

Purpose of review In the past few years, procalcitonin has been proposed as a sensitive and specific inflammatory marker in various fields of medicine, especially in infectivology, where it has been used to discriminate between bacterial infections, viral infections and inflammation processes. Recently, different studies have emerged in the literature on the use of this marker to identify renal involvement in febrile urinary tract infections. Recent findings Procalcitonin seems to be a valid biological marker, with an acceptable sensitivity and specificity, which predicts a renal involvement of the infection (pyelonephritis), in comparison with the low specificity of C-reactive protein. Procalcitonin also seems to be correlated with the degree of the involvement at the moment of diagnosis of febrile urinary tract infections and with scarring. Summary Renal involvement has always been the main diagnostic objective in children with febrile urinary tract infections. If more studies confirm the correlation between procalcitonin, renal involvement during urinary infections and scar formation, we will finally have a noninvasive tool that can identify children at risk of complications and in need of a close follow-up as early as their first episode of febrile urinary tract infection.

Prediction of moderate and high grade vesicoureteral reflux after a first febrile urinary tract infection in children: construction and internal validation of a clinical decision rule.

PURPOSE Urinary tract infection leads to a diagnosis of moderate or high grade (III or higher) vesicoureteral reflux in approximately 15% of children. Predicting reflux grade III or higher would make it possible to restrict cystography to high risk cases. We aimed to derive a clinical decision rule to predict vesicoureteral reflux grade III or higher in children with a first febrile urinary tract infection. MATERIALS AND METHODS We conducted a secondary analysis of prospective series including all children with a first febrile urinary tract infection from the 8 European participating university hospitals. RESULTS A total of 494 patients (197 boys, reflux grade III or higher in 11%) were included. Procalcitonin and ureteral dilatation on ultrasound were significantly associated with reflux grade III or higher and then combined into a prediction model with an ROC AUC of 0.75 (95% CI 0.69-0.81). Given the prespecified constraint of achieving at least 85% sensitivity, our model led to the clinical decision rule, for children with a first febrile urinary tract infection cystography should be performed in cases with ureteral dilatation and serum procalcitonin level 0.17 ng/ml or higher, or without ureteral dilatation (ie ureter not visible) when serum procalcitonin level is 0.63 ng/ml or higher. The rule had 86% sensitivity (95% CI 74-93) with 47% specificity (95% CI 42-51). Internal cross-validation produced 86% sensitivity (95% CI 79-93) and 43% specificity (95% CI 39-47). CONCLUSIONS A clinical decision rule was derived to enable a selective approach to cystography in children with urinary tract infection. The rule predicts high grade vesicoureteral reflux with approximately 85% sensitivity and avoids half of the cystograms that do not find reflux grade III or higher. Further validation is needed before its widespread use.