Serum and urine levels of interleukin-6 and interleukin-8 in children with acute pyelonephritis

Bacterial control of host gene expression through RNA polymerase II

The normal flora furnishes the host with ecological barriers that prevent pathogen attack while maintaining tissue homeostasis. Urinary tract infections (UTIs) constitute a highly relevant model of microbial adaptation in which some patients infected with Escherichia coli develop acute pyelonephritis, while other patients with bacteriuria exhibit an asymptomatic carrier state similar to bacterial commensalism. It remains unclear if the lack of destructive inflammation merely reflects low virulence or if carrier strains actively inhibit disease-associated responses in the host. Here, we identify a new mechanism of bacterial adaptation through broad suppression of RNA polymerase II–dependent (Pol II–dependent) host gene expression. Over 60% of all genes were suppressed 24 hours after human inoculation with the prototype asymptomatic bacteriuria (ABU) strain E. coli 83972, and inhibition was verified by infection of human cells. Specific repressors and activators of Pol II–dependent transcription were modified, Pol II phosphorylation was inhibited, and pathogen-specific signaling was suppressed in cell lines and inoculated patients. An increased frequency of strains inhibiting Pol II was epidemiologically verified in ABU and fecal strains compared with acute pyelonephritis, and a Pol II antagonist suppressed the disease-associated host response. These results suggest that by manipulating host gene expression, ABU strains promote tissue integrity while inhibiting pathology. Such bacterial modulation of host gene expression may be essential to sustain asymptomatic bacterial carriage by ensuring that potentially destructive immune activation will not occur.

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.

Serum levels of interleukin-6 and interleukin-8 as diagnostic markers of acute pyelonephritis in children

Purpose

Early diagnosis and treatment of acute pyelonephritis in children is of special importance in order to prevent serious complications. This study was conducted to determine the diagnostic value of serum interleukin (IL)-6 and IL-8 in children with acute pyelonephritis.

Methods

Eighty-seven patients between 1 month to 12 years old with urinary tract infection (UTI) were divided into 2 groups based on the result of 99m-technetium dimercapto-succinic acid renal scan: acute pyelonephritis (n=37) and lower UTI (n=50) groups. White blood cell (WBC) count, neutrophil (Neutl) count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) concentration, platelet count, and serum IL-6 and IL-8 concentrations of both groups were measured and compared.

Results

There was a significant difference between two groups regarding WBC count, Neutl count, ESR, and CRP concentration (P<0.05). In addition, the difference between the two groups regarding serum IL-6 and IL-8 concentrations was not significant (IL-6, 60 and 35.4 pg/mL and IL-8, 404 and 617 pg/mL, respectively). The sensitivity and specificity of serum IL-6 and IL-8 for diagnosis of acute pyelonephritis were 73%, 42% and 78%, 32%, respectively. Sensitivity, specificity, negative and positive predictive values of serum IL-6 and IL-8 were less than those of acute phase serum reactants such as CRP.

Conclusion

This study showed that there was no significant difference between acute pyelonephritis and lower UTI groups regarding serum IL-6 and IL-8 levels. Therefore, despite confirming results of previous studies, it seems that IL-6 and IL-8 are not suitable markers for differentiating between acute pyelonephritis and lower UTI.

Mortality after urinary tract infections in patients with advanced cirrhosis - Relevance of acute kidney injury and comorbidities

BACKGROUND

Bacterial infections increase mortality four-fold in patients with decompensated cirrhosis. However, specific mortality associated with urinary tract infections (UTI) in cirrhosis is not known.

METHODS

Retrospective single-centre analysis of all hospitalized patients with cirrhosis and ascites who underwent first paracentesis between 2006 and 2011 to determine 90-day mortality associated with UTI defined as pyuria with significant bacteriuria using Cox proportional hazard models.

RESULTS

A total of 108 patients with at least one episode of UTI and 291 with exclusion of UTI were identified. Bacterial infections other than UTI were diagnosed in 136 (34%) of patients at the time of urine analysis. Female gender, Child-Pugh stage C, higher grade of ascites and systemic inflammatory response syndrome were associated with UTI. After adjustment for liver function and co-morbidity, the hazard ratios (HR) of death within 90 days after urine analysis were 2.08 (95% CI 1.28-3.38) in patients with UTI, 2.93 (1.90-4.52) in patients with other bacterial infections and 3.39 (2.03-5.65) in patients with UTI and concomitant infection. Independent predictors of death after UTI were renal dysfunction at presentation (HR 2.52; 95% CI 2.52), subsequent acute kidney injury within 48 h after diagnosis (4.57; 2.54-8.24), concomitant bacterial infection (1.77; 1.04-3.00) and malignant comorbidity (1.85; 1.03-3.30). The combination of these factors was more accurate in predicting 90-day mortality than the MELD score or C-reactive protein.

CONCLUSIONS

The presence of UTI indicates an increased risk of 90-day mortality in patients with advanced cirrhosis. Renal dysfunction and comorbidities are predictors of death in these patients.

Genome-wide mapping of cystitis due to Streptococcus agalactiae and Escherichia coli in mice identifies a unique bladder transcriptome that signifies pathogen-specific antimicrobial defense against urinary tract infection

The most common causes of urinary tract infections (UTIs) are Gram-negative pathogens such as Escherichia coli; however, Gram-positive organisms, including Streptococcus agalactiae, or group B streptococcus (GBS), also cause UTI. In GBS infection, UTI progresses to cystitis once the bacteria colonize the bladder, but the host responses triggered in the bladder immediately following infection are largely unknown. Here, we used genome-wide expression profiling to map the bladder transcriptome of GBS UTI in mice infected transurethrally with uropathogenic GBS that was cultured from a 35-year-old women with cystitis. RNA from bladders was applied to Affymetrix Gene-1.0ST microarrays; quantitative reverse transcriptase PCR (qRT-PCR) was used to analyze selected gene responses identified in array data sets. A surprisingly small significant-gene list of 172 genes was identified at 24 h; this compared to 2,507 genes identified in a side-by-side comparison with uropathogenic E. coli (UPEC). No genes exhibited significantly altered expression at 2 h in GBS-infected mice according to arrays despite high bladder bacterial loads at this early time point. The absence of a marked early host response to GBS juxtaposed with broad-based bladder responses activated by UPEC at 2 h. Bioinformatics analyses, including integrative system-level network mapping, revealed multiple activated biological pathways in the GBS bladder transcriptome that regulate leukocyte activation, inflammation, apoptosis, and cytokine-chemokine biosynthesis. These findings define a novel, minimalistic type of bladder host response triggered by GBS UTI, which comprises collective antimicrobial pathways that differ dramatically from those activated by UPEC. Overall, this study emphasizes the unique nature of bladder immune activation mechanisms triggered by distinct uropathogens.

Relationship among bacterial virulence, bladder dysfunction, vesicoureteral reflux and patterns of urinary tract infection in children

PURPOSE

We hypothesized that virulence levels of Escherichia coli isolates causing pediatric urinary tract infections differ according to severity of infection and also among various uropathies known to contribute to pediatric urinary tract infections. We evaluated these relationships using in vitro cytokine interleukin-6 elicitation.

MATERIALS AND METHODS

E. coli isolates were cultured from children presenting with urinary tract infections. In vitro cytokine (interleukin-6) elicitation was quantified for each isolate and the bacteria were grouped according to type of infection and underlying uropathy (neurogenic bladder, nonneurogenic bowel and bladder dysfunction, primary vesicoureteral reflux, no underlying etiology).

RESULTS

A total of 40 E. coli isolates were collected from children with a mean age of 61.5 months (range 1 to 204). Mean level of in vitro cytokine elicitation from febrile urinary tract infection producing E. coli was significantly lower than for nonfebrile strains (p = 0.01). The interleukin-6 response to E. coli in the neurogenic bladder group was also significantly higher than in the vesicoureteral reflux (p = 0.01) and no underlying etiology groups (p = 0.02).

CONCLUSIONS

In vitro interleukin-6 elicitation, an established marker to determine bacterial virulence, correlates inversely with clinical urinary tract infection severity. Less virulent, high cytokine producing E. coli were more likely to cause cystitis and were more commonly found in patients with neurogenic bladder and nonneurogenic bowel and bladder dysfunction, whereas higher virulence isolates were more likely to produce febrile urinary tract infections and to affect children with primary vesicoureteral reflux and no underlying etiology. These findings suggest that bacteria of different virulence levels may be responsible for differences in severity of pediatric urinary tract infections and may vary among different underlying uropathies.

Intrauterine growth restriction is a direct consequence of localized maternal uropathogenic Escherichia coli cystitis

Despite the continually increasing rates of adverse perinatal outcomes across the globe, the molecular mechanisms that underlie adverse perinatal outcomes are not completely understood. Clinical studies report that 10% of pregnant women will experience a urinary tract infection (UTI) and there is an association of UTIs with adverse perinatal outcomes. We introduced bacterial cystitis into successfully outbred female mice at gestational day 14 to follow pregnancy outcomes and immunological responses to determine the mechanisms that underlie UTI-mediated adverse outcomes. Outbred fetuses from mothers experiencing localized cystitis displayed intrauterine growth restriction (20–80%) as early as 48 hours post-infection and throughout the remainder of normal gestation. Robust infiltration of cellular innate immune effectors was observed in the uteroplacental tissue following introduction of UTI despite absence of viable bacteria. The magnitude of serum proinflammatory cytokines is elevated in the maternal serum during UTI. This study demonstrates that a localized infection can dramatically impact the immunological status as well as the function of non-infected distal organs and tissues. This model can be used as a platform to determine the mechanism(s) by which proinflammatory changes occur between non-contiguous genitourinary organs

Innate transcriptional networks activated in bladder in response to uropathogenic Escherichia coli drive diverse biological pathways and rapid synthesis of IL-10 for defense against bacterial urinary tract infection

Early transcriptional activation events that occur in bladder immediately following bacterial urinary tract infection (UTI) are not well defined. In this study, we describe the whole bladder transcriptome of uropathogenic Escherichia coli (UPEC) cystitis in mice using genome-wide expression profiling to define the transcriptome of innate immune activation stemming from UPEC colonization of the bladder. Bladder RNA from female C57BL/6 mice, analyzed using 1.0 ST-Affymetrix microarrays, revealed extensive activation of diverse sets of innate immune response genes, including those that encode multiple IL-family members, receptors, metabolic regulators, MAPK activators, and lymphocyte signaling molecules. These were among 1564 genes differentially regulated at 2 h postinfection, highlighting a rapid and broad innate immune response to bladder colonization. Integrative systems-level analyses using InnateDB (http://www.innatedb.com) bioinformatics and ingenuity pathway analysis identified multiple distinct biological pathways in the bladder transcriptome with extensive involvement of lymphocyte signaling, cell cycle alterations, cytoskeletal, and metabolic changes. A key regulator of IL activity identified in the transcriptome was IL-10, which was analyzed functionally to reveal marked exacerbation of cystitis in IL-10-deficient mice. Studies of clinical UTI revealed significantly elevated urinary IL-10 in patients with UPEC cystitis, indicating a role for IL-10 in the innate response to human UTI. The whole bladder transcriptome presented in this work provides new insight into the diversity of innate factors that determine UTI on a genome-wide scale and will be valuable for further data mining. Identification of protective roles for other elements in the transcriptome will provide critical new insight into the complex cascade of events that underpin UTI.

The use of fluorescence correlation spectroscopy (FCS) as an alternative biomarker detection technique: a preliminary study

Biomarkers are essential part of daily medical practice. Currently, biomarkers are being used both for diagnostic and prognostic purposes. There are many approaches e.g. ELISA by which biomarker levels are detected from patient samples. However, all these approaches are laborious, time consuming and expensive. There is therefore a general need for exploring new technique which can overcome these drawbacks. Here, we present a preliminary study for detection of serum biomarkers by fluorescence correlation spectroscopy (FCS) based diagnostic technique. FCS is a technique basically used for spatial and temporal analysis of molecular interactions of extremely low-concentration biomolecules in solution. FCS is able to measure diffusion time of the fluorescent molecules passing through the open detection volume and it can also measure the average number of fluorescent molecules passing through the detection volume. Because diffusion speed is correlated with shape and molecular mass of the fluorescent molecule, this property makes it possible to study the complex formation between a small fluorescently labelled and a large unlabelled molecule. In this preliminary study, we utilize this FCS property for detection of serum biomarker. Further studies on various pathological serum samples are warranted to explore further aspects of this technique.

Novel management of urinary tract infections

PURPOSE OF REVIEW

To highlight observations that have suggested the need for changing the conventional approach to the evaluation and management of urinary tract infections (UTIs) and vesicoureteral reflux in children and examine new alternative approaches to prevention of UTI and renal scarring based on research into host-pathogen interaction.

RECENT FINDINGS

Recent studies have questioned the traditional approach of using prophylactic antibiotics to prevent recurrence of UTI and development of renal scarring in children with vesicoureteral reflux. Ongoing research on host-pathogen interactions reveals a promising capability to analyze virulence factors in bacteria causing UTIs in children, identify highly virulent bacteria capable of causing pyelonephritis and renal injury, and to selectively target the gastrointestinal reservoirs of these bacteria for elimination using probiotics.

SUMMARY

Promising experimental studies correlating bacterial virulence with pattern of UTI and identification and characterization of a newly available probiotic capable of eradicating uropathogenic bacteria make targeted probiotic prevention of renal injury-inducing UTIs a potential therapeutic reality.

Experimental Gonococcal Infection in Male Volunteers: Cumulative Experience with Neisseria gonorrhoeae Strains FA1090 and MS11mkC

Experimental infection of male volunteers with Neisseria gonorrhoeae is safe and reproduces the clinical features of naturally acquired gonococcal urethritis. Human inoculation studies have helped define the natural history of experimental infection with two well-characterized strains of N. gonorrhoeae, FA1090 and MS11mkC. The human model has proved useful for testing the importance of putative gonococcal virulence factors for urethral infection in men. Studies with isogenic mutants have improved our understanding of the requirements for gonococcal LOS structures, pili, opacity proteins, IgA1 protease, and the ability of infecting organisms to obtain iron from human transferrin and lactoferrin during uncomplicated urethritis. The model also presents opportunities to examine innate host immune responses that may be exploited or improved in development and testing of gonococcal vaccines. Here we review results to date with human experimental gonorrhea.

Diagnostic Criteria of Urinary Tract Infection in Male Patients With Spinal Cord Injury

Background. The current diagnostic criteria of urinary tract infection (UTI) in male patients with spinal cord injury (SCI) are not clear. Methods. The authors studied 381 episodes of “symptomatic” UTI (209 participants) and 277 episodes of “asymptomatic” UTI (205 participants) in male SCI patients using intermittent catheterization. UTI was defined as a bacterial count ≥102 colony-forming units (cfu)/mL (American Paraplegia Society criterion). Univariate analysis and receiver operating characteristic (ROC) curve analysis were used to determine optimal cfu and white blood cell (WBC) thresholds. Results. The most prevalent clinical signs, alone or in combination, were cloudy and/or malodorous urine (51.4%), onset of urinary incontinence (51.2%), fatigue (41.7%), fever (30.7%), and increased spasticity (30.2%). Urine cfu and WBC levels in patients with only one sign, including fever, were not significantly higher than those in asymptomatic controls. WBC, but not cfu, levels increased significantly with the number of signs ( P = .026). Univariate analysis and ROC curve analysis failed to identify cfu, WBC, or a combination of cfu and WBC count thresholds, allowing discrimination between the symptomatic and asymptomatic UTI groups. Conclusions. Clinical signs of UTI correlate poorly with the urine cfu and WBC levels in SCI patients, except for a positive relationship between WBC counts and the number of signs. Fever alone has no higher diagnostic value. There are no satisfactory cfu and WBC thresholds: thresholds more restrictive than the current American Paraplegia Society criteria provide higher specificity values but with equivalent loss of sensitivity.

The IL-6 -174G/C polymorphism and renal scarring in children with first acute pyelonephritis

Urinary tract infections (UTI) are common in infants and children and may result in serious complications, such as renal scarring, hypertension, and renal failure. Identification of the new markers in relation to acute pyelonephritis (APN) and its treatment is essential for designing interventions that would minimize tissue damage. This prospective study investigated the first UTI infection in 71 children (age range: 1-24 months) in respect to interleukin-6 (IL-6) -174G/C polymorphism and renal scarring. The patients were divided into an APN group and a lower UTI group according to dimercaptosuccinic acid (DMSA). The IL-6 -174G/C genotypes were determined by tetra-primer ARMSPCR. Serum IL-6 was significantly higher in the APN group than in the group with lower UTI (p<0.05). In both groups, the -174G/C genotype and allele frequencies did not differ significantly from the control group. The highest white blood cell (WBC) count was observed in the CC genotype (p<0.05). A non-significant trend toward higher serum IL-6 was observed in children with CC genotype. On follow-up DMSA imaging performed 6 months later, renal scarring was detected in 36.9% of APN children. We did not find the significant association of IL-6 -174G/C polymorphism with APN and/or postinfectious renal scarring. These results indicate that serum IL-6 concentrations were significantly higher in children with APN than in patients with lower UTI.

Interleukin 8 (IL-8) - a universal biomarker?

Many clinical conditions including various types of cancers are complex and generally require invasive, laborious, expensive and time-consuming investigations for their diagnosis, treatment and follow-up. There is therefore a general need for exploring non-invasive markers in clinical medicine. Interleukin 8 (IL-8) is currently being applied in various subspecialties of medicine either for the purpose of rapid diagnosis or as a predictor of prognosis. Nevertheless, there is need for large-scale studies to substantiate accuracy and outcome. This article will summarize current evidence suggesting that Interleukin 8 (IL-8) may serve as a useful biomarker.

Urinary levels of interleukin-6 and interleukin-8 in patients with vesicoureteral reflux and renal parenchymal scar

The objective of this study was to assess the urine levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) as noninvasive markers of vesicoureteral reflux (VUR) and renal parenchymal scarring (RPS) in children in the absence of a recent urinary tract infection (UTI) episode. Urine concentrations of IL-6 and IL-8 in 114 children aged 1 month to 16 years were evaluated. The children were divided into four groups: group 1, 26 children with VUR and RPS; group 2, 27 children with VUR without RPS; group 3, 34 children with RPS without VUR, group 4, 27 children without VUR and RPS, as the control group. After the first assessment, the children were divided into four larger groups for comparison purposes: group A (groups 1+2), 53 children with VUR; group B (groups 3+4), 61 children without VUR; group C (groups 1+3), 60 children with RPS; group D (groups 2+4), 54 children without RPS. Urinary IL-6 and IL-8 concentrations were determined. To avoid dilution effects and to the standardize samples, urinary levels of IL-6 and IL-8 were expressed as the ratio of cytokine to urinary creatinine (pg/mg). The median urine IL-6/creatinine was significantly higher in patients with VUR than in those without VUR (5.72 vs. 3.73). In patients with VUR, there was a significant but rather weak correlation between IL-6/creatinine concentrations and there flux grade (p<0.05, R=0.305). The median urine IL-8/creatinine was significantly higher in patients with RPS than in those without RPS (43.12 vs. 16.36). In patients with RPS, there was a significant but rather weak correlation between IL-8/creatinine concentrations and the renal scar grade (p<0.05, R=0.251). The results of this study provide preliminary evidence that children with VUR have a high urine IL-6 concentration, whereas children with RPS have a high urine IL-8 concentration.

Procalcitonin as an early marker of bacterial infection in neutropenic febrile children with acute lymphoblastic leukemia

OBJECTIVE AND DESIGN

The aim of this study was to assess the value of procalcitonin (PCT), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-a), interleukin (IL)-1b, IL-8, and soluble TNF receptor II (sTNFRII) in early and rapid diagnosis of infection in neutropenic children with acute lymphoblastic leukemia (ALL) and to distinguish bacterial from viral infections.

PATIENTS

The study included five groups (A, B, C, D, and E) of children with ALL undergoing intensive chemotherapy. Groups A and B consisted of neutropenic children with bacterial and viral infection, respectively. Groups C and D consisted of nonneutropenic children with bacterial and viral infection, respectively. Group E consisted of children without neutropenia and without fever.

METHODS

In all groups, blood samples were collected upon admission and then for 7 days on a daily basis. Levels of CRP, PCT, TNF-a, IL-1b, IL-8, and sTNFRII were determined in all blood samples.

RESULTS

We found a highly significant difference in PCT levels between bacterial and nonbacterial episodes. Sensitivity and specificity of PCT were 94 and 96.5%, respectively.

CONCLUSIONS

Serial measurement of PCT levels on a daily basis seems to be helpful for early prediction of severe bacterial infections, monitoring febrile episodes regarding response to antibiotic therapy, and early detection of complications in the infectious process.

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

BACKGROUND

Interleukin (IL)-8 acts as a potent neutrophils chemoattractant responsible for the migration of neutrophils into the infected renal tissue to protect against invading pathogens. The aim of this study was to assess the role of IL-8 on acute-phase pyelonephritis and later renal scarring in children.

PATIENTS AND METHODS

A total of 124 children with a first-time febrile urinary tract infection (UTI) were studied. The diagnosis of acute pyelonephritis was confirmed by Tc-dimercaptosuccinic acid (DMSA) renal scan. Serum and urine samples were obtained from 124 children with UTI and 20 healthy children for IL-8 measurement.

RESULTS

The 124 children were divided into acute pyelonephritis (n = 70) and lower UTI (n = 54) groups according to the results of DMSA scans. The initial serum and urine IL-8 values of children with acute pyelonephritis were significantly higher when compared with lower UTI and healthy controls (all P < 0.001). Renal scarring was seen in 26 (38.8%) of these 67 children with acute pyelonephritis at follow-up DMSA scans. Both the initial serum and urine IL-8 concentrations were significantly higher in children with renal scarring than in those without (both P < 0.001). The mean age of children with renal scarring was also significantly lower than those without scarring (P = 0.004). Multivariate analysis showed that the highest initial IL-8 values, age <20 months and reflux grades > or =III all were independent predictors of renal scarring.

CONCLUSIONS

Those children younger than 2 years of age with the highest IL-8 concentrations during the acute phase of pyelonephritis as well as children with reflux grades of III or greater are at a high-risk for developing renal scarring in the future.

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

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

Relationship between serum and urine interleukin-6 elevations and renal scarring in children with acute pyelonephritis

OBJECTIVE

Acute pyelonephritis is a common infectious disease in children and can result in permanent renal damage. Interleukin-6 (IL-6) is an important mediator of inflammation in response to bacterial infection. This study investigated the potential relationship between acute-phase IL-6 and subsequent renal scarring in children with a first time febrile acute pyelonephritis.

MATERIAL AND METHODS

In total, 79 children (age range 1-120 months) with a first time febrile urinary tract infection (UTI) were included. The diagnosis of acute pyelonephritis was confirmed by (99m)Tc-dimercaptosuccinic acid (DMSA) renal scan. Serum and urine samples were collected for IL-6 measurement by enzyme-linked immunosorbent assay before antibiotic treatment for the infection.

RESULTS

The 79 children were divided into acute pyelonephritis (n=45) and lower UTI (n=34) groups according to the findings of DMSA scans. The initial serum and urine IL-6 levels of children with acute pyelonephritis were significantly higher compared with lower UTI (p < 0.001). Renal scarring was detected at the follow-up DMSA scans in 15 (34.1%) of the 44 children with acute pyelonephritis. Both serum and urine IL-6 levels during the acute phase of pyelonephritis were significantly higher in children with renal scarring than in those without (p=0.005 and p = 0.002). The median age of children with renal scarring was significantly lower than those without (p=0.034). Multiple regression analysis showed that higher initial serum and urine IL-6 levels and a younger age were associated with renal scarring.

CONCLUSION

These results demonstrate that in younger children with a first time febrile acute pyelonephritis, elevations of the acute-phase serum and urine IL-6 levels were correlated with an increased risk of subsequent renal scarring.

Cytokines in urine in elderly subjects with acute cystitis and asymptomatic bacteriuria

OBJECTIVE

Searching for useful diagnostic tools to discriminate between asymptomatic bacteriuria (ASB) and acute cystitis, this study compared urinary levels of cytokines/chemokines and leukocyte esterase in three groups of elderly subjects; those with acute cystitis, those with ASB, and those without bacteriuria.

DESIGN

Comparative laboratory.

SETTING

Primary care.

SUBJECTS

A total of 16 patients with acute cystitis, 24 subjects with ASB, and 20 controls without bacteriuria, all of whom were aged 80 or over.

MAIN OUTCOME MEASURES

Urinary levels of IL-1 beta, TNF-alpha, IL-12, IL-18, CXCL1 (GRO-alpha), CXCL8 (IL-8), CCL2 (MCP-1), IL-6, IL-10, and leukocyte esterase.

RESULTS

Urinary levels of CXCL1, CXCL8, and IL-6 were significantly higher in acute cystitis patients than in the ASB group. The sensitivities and specificities for CXCL8, IL-6, and leukocyte esterase to discriminate between acute cystitis and ASB were 63% (95% CI 36-84) and 96% (95% CI 77-100) (cut-off > 285 pg/mg creatinine), 81% (95% CI 54-95) and 96% (95% CI 77-100) (cut-off > 30 pg/mg creatinine), and 88% (95% CI 60-98) and 79% (95% CI 57-92) (cut-off > 2, on a scale of 0-4), respectively.

CONCLUSIONS

The results indicate that measurement of urinary cytokines, and also leukocyte esterase, when using a cut-off value > 2, could be useful in clinical practice to discriminate between symptomatic and asymptomatic urinary tract infections in the elderly. A combination of IL-6 and leukocyte esterase could be even more useful. This needs to be evaluated in prospective studies on the diagnosis and treatment of urinary tract infections in an elderly population.

Abnormal immunological profile and vaginal microbiota in women prone to urinary tract infections

The host determinants of susceptibility to recurrent urinary tract infections (UTI) are poorly understood. We investigated whether the susceptibility is associated with abnormalities in the immunological defense and further explored the linkage to vaginal microbiota. For this purpose, we compared vaginal, urine, and blood samples collected during a disease-free period from 22 women with recurrent UTI and from 17 controls. In UTI-prone women, interleukin-12 (IL-12) production in peripheral monocytes and myeloid dendritic cells (DCs) was significantly (P < 0.05) enhanced whether measured in relative numbers of IL-12-producing cells or in mean IL-12 production per cell. In contrast, no T-cell polarization was observed. Interestingly, it seemed that the cytokine production of DCs and monocytes did not translate into T-cell activation in the UTI-prone group in a manner similar to that seen with the controls. In vaginal mucosa, UTI-prone women had a lower concentration of tissue repair-associated vascular endothelial growth factor (VEGF) (P = 0.006) and less often had detectable amounts of the chief monocyte and DC chemoattractant, monocyte chemotactic protein 1 (P = 0.005), than the controls. The microbiota of UTI-prone women was characterized by a diminished lactobacillus morphotype composition, with an abnormally high (>3) mean Nugent score of 4.6 compared to 1.7 for the controls (P = 0.003). Normal lactobacillus composition was associated with increased IL-17 and VEGF concentrations in vaginal mucosa. In conclusion, immunological defects and a persistently aberrant microbiota, a lack of lactobacilli in particular, may contribute to susceptibility to recurrent UTI. Further studies of antigen-presenting-cell function and T-cell activation in recurrent UTI are called for.

Serum and urine levels of interleukin-8 in patients with non-Hodgkin's lymphoma

Angiogenesis plays an important role in many types of cancer. Interleukin-8 (IL-8) is known to be a pro-inflammatory and pro-angiogenic cytokine, and IL-8 has been reported to be associated with tumor progression, prognosis and survival in several types of cancers. However, the role of IL-8 in non-Hodgkin's lymphoma (NHL) has not been fully determined. Here, we evaluated the usefulness of measuring serum and urine IL-8 levels in patients with NHL. We developed reference intervals for serum and urine IL-8 level in 131 control individuals. We measured serum IL-8 and urine IL-8 levels in patients with NHL, and we compared the concentrations with those of control individuals. The reference intervals for serum IL-8 and urine IL-8 corrected by creatinine (Cr) were 15.9-430.3 pg/mL and 0.0-28.4 pg/mg Cr, respectively. The concentrations of urine IL-8/Cr were significantly higher in patients than in controls (48.9+/-194.4 vs. 5.2+/-13.8 pg/mg Cr, P<0.001). However, there were no significant differences in serum IL-8 concentrations between NHL patients and controls (159.2+/-40.4 vs. 99.6+/-107.1 pg/mL; P=0.099). Receiver operating characteristic (ROC) analysis gave 0.83 and 0.43 ROC area values for urine IL-8/Cr and serum IL-8, respectively. There was no correlation between the serum and urine concentrations of IL-8 and clinical variables, the only exception being the international prognostic index (IPI), which showed a marginal correlation with urine IL-8/Cr levels (P=0.07). This study indicated that urine IL-8/Cr levels might be useful as a diagnostic marker of NHL.

Urinary interleukin-6 is useful in distinguishing between upper and lower urinary tract infections

This study was designed to determine whether the measurement of interleukin (IL)-6 in urine is useful for distinguishing between acute pyelonephritis and lower urinary tract infection. This observational study was carried out at León Hospital (Spain) on 35 patients (ten boys) aged between 0 and 14 years with urinary tract infection. Urinary levels of IL-6 were determined with enzyme-linked immunosorbent assay (ELISA) at diagnosis and after recovery. Renal dimercaptosuccinate acid (DMSA) scan was performed on all patients to discard or confirm acute pyelonephritis. The mean urinary concentration [x +/- standard deviation (SD)] of IL-6 at diagnosis was 20.3 +/- 23.3 and 5.3 +/- 9.7 pg/ml in patients with acute pyelonephritis and lower urinary infection, respectively [95% confidence interval (CI): 2.6-27.4; p < 0.01]. Specificity for a value of IL-6 >15 pg/ml, was 94.1% (95% CI: 91.1-97.1). Positive predictive value for IL-6 >15 pg/ml was 87.5% (95% CI: 81.1-93.8). IL-6 was undetectable in the urine of both groups of patients at the time of recovery. Urinary levels of IL-6 are useful in differentiating between upper and lower urinary tract infection in children. In this clinical setting, a value >15 pg/ml is a strong indicator of acute pyelonephritis.