The role of serum and urine interleukin-8 on acute pyelonephritis and subsequent renal scarring in children

Role of dexamethasone in controlling the proinflammatory cytokine cascade in the first episode of paediatric acute pyelonephritis

AIM

Febrile urinary tract infection is a common bacterial infection in childhood. The kidney damage after acute pyelonephritis (APN) could be related to the stimulation of the proinflammatory response. We aimed to investigate the role of inflammatory cytokines and the effect of dexamethasone after a first episode of APN.

METHODS

Subanalysis of the DEXCAR RCT in which children with confirmed APN (1 month-14 years) were randomly assigned to receive a 3 days course of either intravenous dexamethasone or placebo. Urinary cytokine levels at diagnosis and after 72 h of treatment were measured.

RESULTS

Ninety-two patients were recruited. Younger patients, males and those with abnormalities in the ultrasound study or vesicoureteral reflux showed higher values of urinary cytokines. Patients with severe APN had higher Tumour Necrosis Factor (TNF)α levels (81.0 ± 75.8 vs. 33.6 ± 48.5 pg/mg creatinine, p = 0.015). Both intervention groups showed similar basal clinical characteristics, including urinary cytokine levels. Treatment reduced urinary cytokine levels irrespective of dexamethasone administration. Neither the intervention group nor the urinary cytokine levels modulated the development of kidney scars.

CONCLUSION

Basal urinary cytokines were associated with age, abnormal ultrasound and vesicoureteral reflux. Patients with severe APN had higher TNFa urinary levels. Administration of dexamethasone in children with APN does not improve the control of the proinflammatory cytokine cascade.

Is technetium-99m dimercaptosuccinic acid renal scintigraphy available for predicting vesicoureteral reflux in children with first febrile urinary tract infection under the age of 24 months?

OBJECTIVE

Vesicoureteral reflux (VUR) is a common complication after urinary tract infection (UTI) and can lead to irreversible renal scar. Voiding cystourethrogram is the most reliable technology to detect VUR and its severity, but it is restricted in children's examinations for various shortcomings. This study aimed to evaluate and compare the efficiency of Tc-99m DMSA renal scintigraphy and conventional ultrasonography (USG) in predicting VUR with the gold standard of cystourethrogram results.

METHODS

This retrospective study consisted of 285 first febrile UTI children under the age of 24 months who completed inflammatory indicator examinations, USG, Tc-99m DMSA renal scintigraphy and underwent cystourethrography after controlling infection with prophylactic antibiotics. The efficiency of Tc-99m DMSA renal scintigraphy and USG in predicting VUR was calculated and compared.

RESULTS

Abnormal USG (40.23% vs. 21.72%, P = 0.001) and Tc-99m DMSA renal scintigraphy results (87.36% vs. 71.72%, P = 0.004) were more common in VUR children. The sensitivity of USG in predicting VUR was only 40.23%, whereas the sensitivity and negative predictive value of Tc-99m DMSA renal scintigraphy reached 87.63 and 83.58%, respectively. Tc-99m DMSA renal scintigraphy had a higher efficacy than USG in predicting high-grade reflux kidneys (73.87% vs. 33.33%; P < 0.001), but there was no significant difference in predicting low-grade reflux kidneys ( P = 0.703).

CONCLUSION

Tc-99m DMSA renal scintigraphy had a significant higher efficiency in predicting VUR (a common cause of renal scarring, detected on DMSA) in first febrile urinary tract infection children under the age of 24 months as compared with USG, especially in high-grade reflux.

Anti-inflammatory effects of lavender and eucalyptus essential oils on the in vitro cell culture model of bladder pain syndrome using T24 cells

BACKGROUND

Interstitial cystitis (IC) has a chronic chemical irritation and inflammation of non-bacterial origin in the bladder wall leading to various severe symptoms. There is evidence that chronic inflammation is significantly associated with abnormal urothelial barrier function, epithelial dysfunction. This is the underlying cause of urothelial apoptosis and sterile inflammation.

METHOD

The anti-inflammatory effects of lavender and eucalyptus essential oils (EOs) and their main components (linalool and eucalyptol) were investigated in the T24 human bladder epithelial cell line on TNFα stimulated inflammation, at 3 types of treatment schedule. The mRNA of pro-inflammatory cytokines (IL-1β, IL-6, IL-8) were measured by Real Time PCR. Human IL-8 ELISA measurement was performed as well at 3 types of treatment schedule. The effects of lavender and eucalyptus EOs and their main components were compared to the response to NFκB inhibitor ACHP (2-amino-6-[2-(cyclopropylmethoxy)-6-hydroxyphenyl]-4-(4-piperidinyl)-3-pyridinecarbonitrile).

RESULT

There is no significant difference statistically, but measurements show that lavender EOs are more effective than eucalyptus EO. Long time treatment (24 h) of both lavender EO and linalool showed higher effect in decreasing pro-inflammatory cytokine mRNA expression than ACHP inhibitor following TNFα pre-treatment. Moreover, both lavender EOs were found to be significantly more effective in decreasing IL-8 secretion of T24 cells after TNFα pre-treatment compared to the ACHP NFκB-inhibitor.

CONCLUSION

The lavender EOs may be suitable for use as an adjunct to intravesical therapy of IC. Their anti-inflammatory effect could well complement glycosaminoglycan-regenerative therapy in the urinary bladder after appropriate pharmaceutical formulation.

The value of interleukin levels in the diagnosis of febrile urinary tract infections in children and adolescents; a systematic review and meta-analysis

INTRODUCTION

In recent years, researchers have been looking for tools and biomarkers to identify urinary tract infections (UTI) in children. Since there exists no systematic reviews and meta-analyses on the matter, the present study intends to determine the diagnostic value of serum and urinary levels of interleukins (IL) in the diagnosis of febrile UTI in children and adolescents.

METHODS

Medline, Embase, Scopus, and Web of Science were searched until the end of 2020, using keywords related to UTI and serum and urinary ILs. Two independent researchers included relevant studies and summarized the data. Analyzed data were reported as standardized mean difference (SMD) with 95% confidence interval (CI).

RESULTS

Data from 23 articles were included in the present study. Analyses showed that IL-6, IL-8, IL 1 beta and IL-1 alpha urinary levels are significantly higher in children with UTI than that of other children. Moreover, serum levels of IL-6 and IL-8 in children with UTI were significantly higher than that of healthy children. However, IL-6 and IL-8 serum levels were not significantly different between children with UTI and non-UTI febrile group. Finally, the area under the curve of urinary IL-6 and IL-8 and serum IL-8 levels in the diagnosis of pediatric UTIs were 0.89 (95% CI: 0.86, 0.92), 0.95 (95% CI: 0.92, 0.96) and 0.80 (95% CI: 0.77, 0.84), respectively.

CONCLUSION

The findings of the present study showed that the diagnostic utility of ILs 8 and 6 urinary levels is most desirable in the detection of febrile UTIs from other febrile conditions in children and adolescents, in comparison with the diagnostic utility of other ILs' urinary and serum levels in the detection of febrile UTI. However, even after nearly 3 decades of research on these biomarkers, their optimal cut-off points in diagnosing pediatric UTIs are still to be determined in further studies.

Serum and Urine Interleukin-6 and Interleukin-8 Levels Do Not Differentiate Acute Pyelonephritis from Lower Urinary Tract Infections in Children

Background

Urinary tract infection (UTI) is common in pediatrics. Infection of the upper urinary tract may cause renal scarring, and subsequently renal failure and hypertension. Permanent renal damage has been suggested to be caused by the host inflammatory response. Therefore, it is crucial to understand the host defense mechanisms against such infection in order to make timely diagnosis. The aim of this study was to evaluate interleukin-6 (IL-6) and IL-8 as potential biomarkers in differentiating acute pyelonephritis (AP) from cystitis (Cys) in children.

Methods

Forty-three children (21 with AP and 22 with Cys) were included. Serum and urinary IL-6 and IL-8 were measured during the acute phase (within 12 hours of presentation) and the convalescent phase (8 weeks post-infection). Thirty-eight healthy children were included as controls.

Results

During the acute phase, the mean urinary IL-6 level in the Cys group was significantly higher than that in the controls (17.8 pg/mL vs 14.8 pg/mL, P=0.03), while the serum levels were significantly higher in both the Cys and AP groups than in the controls (19.5 pg/mL, 19.4 pg/mL, 15 pg/mL, P=0.005 and 0.02, respectively). During the convalescent phase, serum and urinary IL-6 levels were higher in patients than in controls. Urinary IL-8 levels were significantly higher in both the AP and Cys groups compared to controls (206.5 pg/mL, 291.8 pg/mL, 89.4 pg/mL, P=0.05 and 0.02, respectively) during the acute phase. Serum IL-8 was not significantly different between the 3 groups. Nonetheless, no significant differences were found between the AP and Cys groups, in urinary or serum levels of IL-6 or IL-8, during both phases.

Conclusion

IL-6 and IL-8 levels are elevated in patients with UTI. However, the levels did not differentiate between AP and cystitis. Further studies are warranted to evaluate their roles as indicators of the site of UTIs.

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.

Biomarkers in vesicoureteral reflux: an overview

Aim: This article aimed to review the role of cytokines, chemokines, growth factors and cellular adhesion molecules as biomarkers for vesicoureteral reflux (VUR) and reflux nephropathy (RN). Methods: We reviewed articles from 1979 onward by searching PubMed and Scopus utilizing the combination of words: 'VUR' or 'RN' and each one of the biomarkers. Results: Genetic, inflammatory, fibrogenic, environmental and epigenetic factors responsible for renal scarring need to be better understood. TGF-β, IL-10, IL-6, IL-8 and TNF seem to exert a role in VUR particularly in RN based on the current literature. Serum levels of procalcitonin have been also associated with high-grade VUR and RN. These molecules should be more intensively evaluated as potential biomarkers for renal scarring in VUR. Conclusion: Further studies are necessary to define which molecules will really be of utility in clinical decisions and as therapeutic targets for VUR and RN.

Impact of cytokine genetic polymorphisms on the risk of renal parenchymal infection in children

BACKGROUND

Acute pyelonephritis is associated with renal scarring in up to 30% of patients. Renal scarring may cause significant long-term morbidity. The pathogenesis of acute pyelonephritis remains unclear, although it involves interaction among uroepithelium, the immune system cells, and the locally produced cytokines. That some UTI-prone children develop acute pyelonephritis, and eventually renal parenchymal scarring, suggests a genetic role. Interleukin-6, interleukin-8, chemokine receptor-1 (CXCR1), and tumor necrosis factor-alpha (TNFα), the key regulators of the host immune responses, are proteins whose secretion is controlled by genes. We postulated that functional polymorphic variants of their genes might have a role in APN susceptibility.

OBJECTIVES

We sought to investigate a possible association of the common functional polymorphisms in genes encoding IL-6, IL-8, CXCR1, and TNFα with the risk of APN in children.

METHODS

Urine culture was used to diagnose 300 children with UTI, of mean age of 51.31 ± 37.4 months (2-180 months). 99Tc-DMSA scans diagnosed 86 children with APN. Follow-up scans identified new renal scars in 18 children. Six functional single-nucleotide polymorphisms (SNPs) in genes encoding IL-6, IL-8, CXCR1, and TNFα were genotyped in all subjects (IL-6 rs1800795 (-174G/C), IL-6 rs1800796 (-572G/C), IL-8 rs2227306 (781C/T), IL8 rs4073 (-251A/T), CXCR1 rs2234671 (2607G/C), and TNFα rs1800629 (-308G/A)).

RESULTS

TT genotype of IL-8 -251A/T polymorphism was significantly higher in APN patients (26.7%) than those with lower UTI (11.7%, p = 0.01) and control individuals (12.2%, p = 0.002). T allele was significantly more common in APN than in lower UTI (p = 0.025) and was significantly more common in APN (46%) than in the controls (p = 0.001). Similarly, TT genotype of IL-8 781C/T polymorphism was significantly more common in APN patients (31.4%) than those with lower UTI (17.3%, p = 0.003) and the controls (14.3%, p = 0.001). T allele was significantly more common in APN (55%) than lower UTI (40%, p = 0.005) and controls (37%, p = 0.001). However, IL-8 -251A/T and +781C/T SNPs did not qualify as an independent risk for parenchymal infection (OR 1.9, 95% CI 0.68-2.6, p = 0.13 and OR 2.3, 95% CI 0.89-3.7, p = 0.091, respectively). Lower UTI did not differ from the controls. The frequency of the genotypes and alleles of IL-6, CXCR1, and TNFα SNPs did not differ significantly among the different groups of the study.

CONCLUSION

IL-8 -251A/T and +781C/T SNPs are associated with susceptibility to renal parenchymal infection in children and could be implicated in APN risk. However, none of these variants could clearly and independently predict this risk.

The urinary and serum levels of IL-32 in children with febrile urinary tract infections

Aim

We assessed the urinary and serum levels of IL-32 in pediatric patients with acute pyelonephritis (APN) with and without renal scarring.

Results

We enrolled children aged 2 months to 16 years with APN. Dimercaptosuccinic acid scans and ultrasonography studies were ordered for all patients, and a voiding. A total of 86 children (aged 57 ± 39 months, 74 [86%] female) were enrolled in this study. Group 1 was composed of 19 (16 female) patients, group 2 of 38 (35 female) patients and group 3 of 29 (23 female) patients. There were no significant differences in the serum and absolute urinary levels of IL-32 (UIL-32) between groups, but the urinary IL-32/creatinine ratio (UIL-32/Cr) was significantly higher in children with pyelonephritis than controls.

Usefulness of analytical parameters in the management of paediatric patients with suspicion of acute pyelonephritis. Is procalcitonin reliable?

OBJECTIVE

To investigate the usefulness of procalcitonin (PCT) and other analytical parameters (white blood cell count [WBC], C-reactive protein [CRP]) as markers of acute renal damage in children after a first febrile or afebrile urinary tract infection (UTI).

METHODS

A retrospective study was conducted on children with a first episode of UTI admitted between January 2009 to December 2011, and in whom serum PCT, CRP and white blood cell count were measured, as well as assessing the acute renal damage with renal scintigraphy with ^99mTc-DMSA (DMSA) within the first 72h after referral. A descriptive study was performed and ROC curves were plotted, with optimal cut-off points calculated for each parameter.

RESULTS

The 101 enrolled patients were divided into two groups according to DMSA scintigraphy results, with 64 patients being classified with acute pyelonephritis (APN), and 37 with UTI. The mean WBC, CRP and PCT values were significantly higher in patients with APN with respect to normal acute DMSA. The area under the ROC curve was 0.862 for PCR, 0.774 for WBC, and 0.731 for PCT. The optimum statistical cut-off value for PCT was 0.285ng/ml (sensitivity 71.4% and specificity 75%).

CONCLUSION

Although the mean levels of fever, WBC, CRP, and PCT were significantly increased in patients with APN than in those who had UTI, the sensitivity and specificity of these analytical parameters are unable to predict the existence of acute renal damage, making the contribution by renal DMSA scintigraphy essential.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Urinary concentration of cytokines in children with acute pyelonephritis

Urinary tract infection (UTI) is a common bacterial infection among infants and children. Predicting which children with upper UTI will develop long-term sequelae remains difficult. We aimed at evaluating the predictive value of urine concentrations of interleukin-6 (UIL-6) and interleukin-8 (UIL-8) in subsequent renal scarring. In the current observational prospective study, urine samples for UIL-6 and UIL-8 were obtained from two groups: 31 children with first episode of febrile UTI and 22 febrile children of other origin. UIL-6 and UIL-8 were increased in children with febrile UTI, compared to children with fever of other origin [median and range (picograms per milliliter): (1) UIL-6, 74.46 (0-168) vs. 10.51 (0-47.50), respectively, p = 0.0001; (2) UIL-8, 2,660.38 (0-13,801) vs. 0, respectively, p = 0.0001]. Renal scarring was found in 5/31 (16 %) children with acute pyelonephritis. Initial median UIL-8 values were significantly higher in children with later renal scarring than in those without renal scarring [median and range (picograms per milliliter): 6,163 (2,021-13,801) vs. 1,490.5 (0-5,737), respectively, p = 0.018]. In conclusion, UIL-8 might serve as a predictive biomarker for renal scarring after an acute episode of pyelonephritis. Since UIL-8 emerges as a renal-specific diagnostic and prognostic marker, it may be suitable as a selective screening tool for children with febrile UTI.

Cytokines in chronic kidney disease: potential link of MCP-1 and dyslipidemia in glomerular diseases

BACKGROUND

Many studies have indicated a role for cytokines in chronic kidney disease (CKD). The aim of this study was to evaluate plasma and urinary levels of monocyte chemoattractant protein-1 (MCP-1/CCL2), transforming growth factor-beta1 (TGF-β1), and interleukin-8 (IL-8/CXCL8) in pediatric patients with CKD stages 2-4.

METHODS

Cytokines were measured in 37 healthy controls and in 42 CKD patients by enzyme-linked immunoassay. Patients were divided into groups according to CKD etiology: glomerular disease (group 1, n = 11) and congenital anomalies of the kidney and urinary tract (group 2, n = 31). Urinary cytokine measurements were standardized for creatinine.

RESULTS

Plasma and urinary levels of MCP-1/CCL2 were significantly higher in both CKD groups compared to the control group. Between the two CKD groups, only urinary MCP-1/CCL2 levels were significantly different, with MCP-1/CCL2 levels higher in group 1 patients. Plasma and urinary levels of IL-8/CXCL8 and TGF-β1 were undetectable in the control group but comparable between the two CKD groups. In group 1 patients, urinary MCP-1/CCL2 levels were negatively correlated to serum albumin levels and positively correlated to the levels of total cholesterol and triglycerides. In group 2 patients, urinary levels of IL-8/CXCL8 were negatively correlated with the estimated glomerular filtration rate and positively correlated with body mass index.

CONCLUSIONS

Differences in cytokine profiles may be related to CKD etiology and other disease-associated alterations.

Urinary cytokine levels in apparently healthy cats and cats with chronic kidney disease

Chronic kidney disease (CKD) is a common cause of illness and death in cats. The hallmark of CKD in cats is chronic tubulointerstitial nephritis, and inflammation contributes to the progression of renal fibrosis. However, at present, it is difficult to assess directly the degree of intra-renal inflammation without renal biopsy. Measurement of inflammatory cytokine levels in urine may provide a non-invasive means of assessing intra-renal inflammation. Urine cytokine levels (urine cytokine/urine creatinine ratio) were measured in 18 healthy cats and 26 cats with CKD. When urine cytokine levels in healthy and CKD cats were compared, we found significantly higher levels of IL-8 and transforming growth factor-β1 (TGF-β1) in urine of CKD cats, along with significantly lower vascular endothelial growth factor (VEGF) levels. A significant positive correlation between serum creatinine and TGF-β1 levels was found in CKD cats. Urinary cytokine measurement may, potentially, be a useful means of assessing intra-renal inflammation, fibrosis and vascular health in cats with CKD.

Urine IL-8 concentrations in infectious and non-infectious urinary tract conditions

Urine IL-8 concentrations are known to be elevated in urinary tract infection (UTI), as well as in vesicoureteral reflux (VUR) even in the absence of infection. In this study we further investigated urine IL-8 in infants with congenital anomalies of the kidneys and urinary tract and with antenatally diagnosed isolated pelvic dilatation. Urine IL-8 was measured in 159 infants aged 1 month to 1 year with acute UTI (group A, n = 26), resolved UTI (group B, n = 16), VUR without recent UTI (group C, n = 44), non-VUR congenital urinary anomalies without recent UTI (group D, n = 30), isolated antenatal pelvic dilatation (group E, n = 14) and in infants without known urinary tract condition (control group F, n = 29). Median values of urine IL-8/creatinine levels were 61.5, 4.64, 15.5, 14.3, 1.06 and 4.19 pg/μmol in groups A, B, C, D, E and F respectively. Compared with the control group, urine IL-8 was elevated in infants with acute UTI, VUR without acute UTI and congenital anomalies without acute UTI (p < 0.0001; p < 0.005; and p = 0.027 respectively), but not in infants with resolved UTI or with antenatal pelvic dilatation. Urine IL-8 levels are elevated in a variety of infectious and non-infectious urinary tract conditions, and hence may serve as a sensitive but not specific screening biomarker of urinary tract diseases.

The role of procalcitonin for acute pyelonephritis and subsequent renal scarring in infants and young children

PURPOSE

We assessed the usefulness of procalcitonin as a biological marker in diagnosing acute pyelonephritis and for predicting subsequent renal scarring in young children with a first febrile urinary tract infection.

MATERIALS AND METHODS

Children 2 years old or younger with a first febrile urinary tract infection were prospectively studied. Renal parenchymal involvement was assessed by (99m)Tc-dimercaptosuccinic acid scan within 5 days of admission and after 6 months. Serum samples from all patients were tested for procalcitonin, C-reactive protein and white blood cell count measurements.

RESULTS

The 112 enrolled patients (age range 24 days to 24 months old) were divided into acute pyelonephritis (76) and lower urinary tract infection (36) groups according to the results of (99m)Tc-dimercaptosuccinic acid scans. Median values of procalcitonin, C-reactive protein and white blood cell count at hospitalization were significantly higher in patients with acute pyelonephritis than in those with lower urinary tract infection. The area under receiver operating characteristic curves showed that procalcitonin was superior to C-reactive protein and white blood cell count as a marker for diagnosing acute pyelonephritis. Initial and post-antibiotic treatment procalcitonin values were significantly higher in children with renal scarring than in those without scarring (p <0.001). Procalcitonin values at hospitalization and after treatment were independent predictors of later renal scarring on logistic regression analysis.

CONCLUSIONS

Our results indicate the superior diagnostic accuracy of procalcitonin for predicting acute pyelonephritis in children 2 years old or younger. Higher initial and posttreatment procalcitonin values are independent risk factors for later renal scarring.

Adjunctive oral methylprednisolone in pediatric acute pyelonephritis alleviates renal scarring

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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