The diagnostic value of interleukin-6 and interleukin-8 for early prediction of bacteremia and sepsis in children with febrile neutropenia and cancer

Febrile illness in high-risk children: a prospective, international observational study

To assess and describe the aetiology and management of febrile illness in children with primary or acquired immunodeficiency at high risk of serious bacterial infection, as seen in emergency departments in tertiary hospitals. Prospective data on demographics, presenting features, investigations, microbiology, management, and outcome of patients within the 'Biomarker Validation in HR patients' database in PERFORM, were analysed. Immunocompromised children (< 18 years old) presented to fifteen European hospitals in nine countries, and one Gambian hospital, with fever or suspected infection and clinical indication for blood investigations. Febrile episodes were assigned clinical phenotypes using the validated PERFORM algorithm. Logistic regression was used to assess the effect size of predictive features of proven/presumed bacterial or viral infection. A total of 599 episodes in 482 children were analysed. Seventy-eight episodes (13.0%) were definite bacterial, 67 episodes probable bacterial (11.2%), and 29 bacterial syndrome (4.8%). Fifty-five were definite viral (9.2%), 49 probable viral (8.2%), and 23 viral syndrome (3.8%). One hundred ninety were unknown bacterial or viral infections (31.7%), and 108 had inflammatory or other non-infectious causes of fever (18.1%). Predictive features of proven/presumed bacterial infection were ill appearance (OR 3.1 (95% CI 2.1-4.6)) and HIV (OR 10.4 (95% CI 2.0-54.4)). Ill appearance reduced the odds of having a proven/presumed viral infection (OR 0.5 (95% CI 0.3-0.9)). A total of 82.1% had new empirical antibiotics started on admission (N = 492); 94.3% proven/presumed bacterial (N = 164), 66.1% proven/presumed viral (N = 84), and 93.2% unknown bacterial or viral infections (N = 177). Mortality was 1.9% (N = 11) and 87.1% made full recovery (N = 522).   Conclusion: The aetiology of febrile illness in immunocompromised children is diverse. In one-third of cases, no cause for the fever will be identified. Justification for standard intravenous antibiotic treatment for every febrile immunocompromised child is debatable, yet effective. Better clinical decision-making tools and new biomarkers are needed for this population. What is Known: • Immunosuppressed children are at high risk for morbidity and mortality of serious bacterial and viral infection, but often present with fever as only clinical symptom. • Current diagnostic measures in this group are not specific to rule out bacterial infection, and positivity rates of microbiological cultures are low. What is New: • Febrile illness and infectious complications remain a significant cause of mortality and morbidity in HR children, yet management is effective. • The aetiology of febrile illness in immunocompromised children is diverse, and development of pathways for early discharge or cessation of intravenous antibiotics is debatable, and requires better clinical decision-making tools and biomarkers.

Biomarkers for Diagnosing Febrile Illness in Immunocompromised Children: A Systematic Review of the Literature

OBJECTIVE

This study aims to assess the performance of biomarkers used for the prediction of bacterial, viral, and fungal infection in immunocompromised children upon presentation with fever.

METHODS

We performed a literature search using PubMed and MEDLINE and In-Process & Other Non-indexed Citations databases. Cohort and case-control studies assessing biomarkers for the prediction of bacterial, viral, or fungal infection in immunocompromised children vs. conventional microbiological investigations were eligible. Studies including adult patients were eligible if pediatric data were separately assessable. Data on definitions used for infections, fever, and neutropenia and predictive values were collected. Risk of bias was assessed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

Fifty-two studies involving 13,939 febrile episodes in 7,059 children were included. In total, 92.2% were in cancer patients (n = 48), and 15.7% also included hematopoietic stem cell transplantation patients (n = 8). Forty-three biomarkers were investigated, of which 6 (CRP, PCT, IL-8, IL-6, IL-10, and TNFα) were significantly associated with bacterial infection at admission, studied in multiple studies, and provided predictive data. Literature on the prediction of viral and fungal infection was too limited. Eight studies compared C-reactive protein (CRP) and procalcitonin (PCT), with PCT demonstrating superiority in 5. IL-6, IL-8, and IL-10 were compared with CRP in six, four, and one study, respectively, with mixed results on diagnostic superiority. No clear superior biomarker comparing PCT vs. IL-6, IL-8, or IL-10 was identified.

DISCUSSION

There is great heterogeneity in the biomarkers studied and cutoff values and definitions used, thus complicating the analysis. Literature for immunocompromised children with non-malignant disease and for non-bacterial infection is sparse. Literature on novel diagnostics was not available. We illustrated the challenges of diagnosing fever adequately in this study population and the need for improved biomarkers and clinical decision-making tools.

Serum biomarkers to differentiate Gram-negative, Gram-positive and fungal infection in febrile patients

Introduction. Contamination of specimens and overuse of broad spectrum antibiotics contribute to false positives and false negatives, respectively. Therefore, useful and applicable biomarkers of bacteremia are still required.Hypothesis/Gap Statement. IL-6 can be used as a serum biomarker to discriminate among bacterial infections and fungal infections in febrile patients with a bloodstream infection.Aim. We aimed to evaluate the diagnostic efficiency of neutrophil/lymphocyte ratio (NLR), procalcitonin (PCT) and interleukin-6 (IL-6) in discriminating Gram-negative (G^-) bacteria from Gram-positive (G⁺) bacteria and fungi in febrile patients.Methodology. A total of 567 patients with fever were evaluated. Serum levels of IL-6, PCT, NLR and CRP were compared among a G^- group (n=188), a G⁺ group (n=168), a fungal group (n=38) and a culture negative group (n=173). Sensitivity, specificity, Yuden's index and area under the Receiver operating characteristic (ROC) curve (AUC) were obtained to analyse the diagnostic abilities of these biomarkers in discriminating bloodstream infection caused by different pathogens.Results. Serum IL-6 and PCT in the G^- group increased significantly when compared with both the G⁺ group and fungal group (P <0.05). AUC of IL-6 (0.767, 95 % CI:0.725-0.805) is higher than AUC of PCT (0.751, 95 % CI:0.708-0.796) in discriminating the G^- group from G⁺ group. When discriminating the G^- group from fungal group, the AUC of IL-6 (0.695, 95 % CI:0.651-0.747) with a cut-off value of 464.3 pg ml^-1 was also higher than the AUC of PCT (0.630, 95 % CI:0.585-0.688) with a cut-off value of 0.68 ng ml^-1. Additionally, AUC of NLR (0.685, 95 % CI:0.646-0.727) in discriminating the fungal group from G⁺ group at the cut-off value of 9.03, was higher than AUC of IL-6, PCT and CRP.Conclusion. This study suggests that IL-6 could be used as a serum biomarker to discriminate among bacterial infections and fungal infections in febrile patients with a bloodstream infection. In addition, NLR is valuable to discriminate fungal infections from Gram-positive infections in febrile patients with a bloodstream infection.

Development of Prediction Models for New Integrated Models and a Bioscore System to Identify Bacterial Infections in Systemic Lupus Erythematosus

Objectives

Distinguishing flares from bacterial infections in systemic lupus erythematosus (SLE) patients remains a challenge. This study aimed to build a model, using multiple blood cells and plasma indicators, to improve the identification of bacterial infections in SLE.

Design

Building PLS-DA/OPLS-DA models and a bioscore system to distinguish bacterial infections from lupus flares in SLE.

Setting

Department of Rheumatology of the Second Hospital of Shanxi Medical University.

Participants

SLE patients with flares (n = 142) or bacterial infections (n = 106) were recruited in this retrospective study.

Outcome

The peripheral blood of these patients was collected by the experimenter to measure the levels of routine examination indicators, immune cells, and cytokines. PLS-DA/OPLS-DA models and a bioscore system were established.

Results

Both PLS-DA (R2Y = 0.953, Q2 = 0.931) and OPLS-DA (R2Y = 0.953, Q2 = 0.942) models could clearly identify bacterial infections in SLE. The white blood cell (WBC), neutrophile granulocyte (NEUT), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), procalcitonin (PCT), interleukin-6 (IL-6), IL-10, interferon-γ (IFN-γ), and tumor necrosis factor α (TNF-α) levels were significantly higher in bacteria-infected patients, while regulatory T (Treg) cells obviously decreased. A multivariate analysis using the above 10 dichotomized indicators, based on the cut-off value of their respective ROC curve, was established to screen out the independent predictors and calculate their weights to build a bioscore system, which exhibited a strong diagnosis ability (AUC = 0.842, 95% CI 0.794–0.891). The bioscore system showed that 0 and 100% of SLE patients with scores of 0 and 8–10, respectively, were infected with bacteria. The higher the score, the greater the likelihood of bacterial infections in SLE.

Conclusions

The PLS-DA/OPLS-DA models, including the above biomarkers, showed a strong predictive ability for bacterial infections in SLE. Combining WBC, NEUT, CRP, PCT, IL-6, and IFN-γ in a bioscore system may result in faster prediction of bacterial infections in SLE and may guide toward a more appropriate, timely treatment for SLE.

Cytokines in Febrile Diseases

The human body has a perfect thermoregulatory system to meet the needs of normal life activities. The central regulation of body temperature is mainly explained by the theory of "setting point (setpoint, SP)". Fever is a positive but nonspecific response of the body to infections and other pyrogens, which causes immune cells to release cytokines, leading to a brain protein-mediated rise in body temperature. Cytokines can be roughly divided into 2 categories: proinflammatory cytokines and anti-inflammatory cytokines. IL-1, TNF-α, and IL-6 are proinflammatory cytokines, whereas IL-4 and IL-10 are anti-inflammatory cytokines. IL-2 is a cytokine that can both activate and inhibit immunity. IL-8 is a neutrophil chemotactic factor, and IFN is a cytokine that plays a key role in the proper induction and maintenance of innate and acquired immunity. This article reviews the pathophysiological characteristics of fever and the cytokines related to fever (IL-2, 4, 6, 8, 10, IFN, TNF, etc.).

Biomarkers in pediatric sepsis: a review of recent literature

Sepsis remains the leading cause of death in infants and children worldwide. Prompt diagnosis and monitoring of infection is pivotal to guide therapy and optimize outcomes. No single biomarker has so far been identified to accurately diagnose sepsis, monitor response and predict severity. We aimed to assess existing evidence of available sepsis biomarkers, and their utility in pediatric population. C-reactive protein and procalcitonin remain the most extensively evaluated and used biomarkers. However, biomarkers related to endothelial damage, vasodilation, oxidative stress, cytokines/chemokines and cell bioproducts have also been identified, often with regard to the site of infection and etiologic pathogen; still, with controversial utility. A multi-biomarker model driven by genomic tools could establish a personalized approach in future disease management.

Pro-inflammatory cytokine ratios determine the clinical course of febrile neutropenia in children receiving chemotherapy

Background

Febrile neutropenia is a common and serious complication during treatment of childhood cancer. Empirical broad-spectrum antibiotics are usually administered until neutrophil cell count recovery. It was the aim of this study to investigate cytokine profiles as potential biomarkers using in-vitro sepsis models to differentiate between distinct clinical courses of febrile neutropenia (FN).

Methods

We conducted an observational study in FN episodes of pediatric oncology patients. Courses of neutropenia were defined as severe in case of proven blood stream infection or clinical evidence of complicated infection. We collected blood samples at various time points from the onset of FN and stimulated ex vivo with lipopolysaccharide (LPS) and Staphylococcus epidermidis (SE) for 24 h. Twenty-seven cytokine levels were measured in the whole blood culture supernatants by a multiplex immunoassay system.

Results

Forty-seven FN episodes from 33 children were investigated. IL-8, IL-1β, and MCP-1 expression increased significantly over time. IL-8, MIP-1α, MIP-1β, MCP-1, and TNF-α showed significantly lower concentration in patients with a clinically severe course of the FN.

Conclusions

Distinct patterns of cytokine profiles seem to be able to determine infectious FN and to predict the severity of its clinical course. If these data can be verified in a multi-centre setting, this may finally lead to an individualized treatment strategy facilitating antibiotic stewardship in these patients.

Immune response against Chlamydia trachomatis via toll-like receptors is negatively regulated by SIGIRR

Chlamydia trachomatis is the most common bacterial sexually-transmitted infection and the major cause of preventable blindness worldwide. The asymptomatic nature of many infections along with uncontrolled inflammation leads to irreversible damage in the upper genital tract and the tarsal conjunctivae, with the major complications of infertility and chronic pelvic pain, and blindness, respectively. Inflammation must, therefore, be tightly regulated to avoid an unrestrained immune response. The genetic factors that regulate inflammation through Toll-like receptor (TLR) signaling pathways during C. trachomatis infection have not been fully characterized. SIGIRR (also known as IL-1R8 or TIR8) can regulate inflammation in response to various pathogens and diseases. However, nothing is known about its role during C. trachomatis infection. Expression of the pro-inflammatory chemokine, IL-8, was measured in epithelial cells infected with C. trachomatis. The effect of SIGIRR was determined by depleting SIGIRR or over-expressing SIGIRR in the epithelial cells before infection. Our results indicate that, in the absence of SIGIRR, epithelial cells induce higher levels of the pro-inflammatory chemokine, IL-8, in response to C. trachomatis infection. In addition, SIGIRR associates with MyD88 in both infected and uninfected infected cells. Collectively, our data demonstrate that SIGIRR functions as a negative regulator of the immune response to C. trachomatis infection. This finding provides insights into the immuno-pathogenesis of C. trachomatis that can be used to treat and identify individuals at risk of uncontrolled inflammation during infection.

Updated systematic review and meta-analysis of the predictive value of serum biomarkers in the assessment and management of fever during neutropenia in children with cancer

Routinely measurable biomarkers as predictors for adverse outcomes in febrile neutropenia could improve management through risk stratification. This systematic review assesses the predictive role of biomarkers in identifying events such as bacteraemia, clinically documented infections, microbiologically documented infection, severe sepsis requiring intensive care or high dependency care and death. This review collates 8319 episodes from 4843 patients. C-reactive protein (CRP), interleukin (IL)-6, IL-8 and procalcitonin (PCT) consistently predict bacteraemia and severe sepsis; other outcomes have highly heterogeneous results. Performance of the biomarkers at admission using different thresholds demonstrates that PCT > 0.5 ng/mL offers the best compromise between sensitivity and specificity: sensitivity 0.67 (confidence interval [CI] 0.53-0.79) specificity 0.73 (CI 0.66-0.77). Seventeen studies describe the use of serial biomarkers, with PCT having the greatest discriminatory role. Biomarkers, potentially with serial measurements, may predict adverse outcomes in paediatric febrile neutropenia and their role in risk stratification is promising.

Carboplatin-induced hematotoxicity among patients with non-small cell lung cancer: Analysis on clinical adverse events and drug-gene interactions

In order to clarify the risk of hematotoxicity of carboplatin, we inspected 19901 case reports of non-small cell lung cancer patients that were submitted to the FDA Adverse Event Reporting System (FAERS) between January 2004 and December 2015. These comprised 3907 cases which were treated with carboplatin and 15994 cases which were treated with other therapies in the absence of carboplatin. By comparison, carboplatin cases were significantly more likely to report anemia (OR = 2.27, 95% CI 1.85-2.78, P = 5.04×10⁻¹⁵), neutropenia (OR = 2.27, 95% CI 1.76-2.92, P = 2.39×10⁻¹⁰), and thrombocytopenia (OR = 2.38, 95% CI 1.84-3.08, P = 5.60×10⁻¹¹). We further explored published evidences and found 205 human genes interacting with carboplatin. Functional analysis corroborated that these genes were significantly enriched in the biochemical pathway of hematopoietic cell lineage (adjusted P = 6.02×10⁻¹¹). This indicated that carboplatin could profoundly affect the development of blood cells. Given the early awareness of the hematologic risks, great caution should be exercised in prescribing carboplatin to non-small cell lung cancer patients. And functional enrichment analysis on carboplatin-related genes warranted subsequent research with regard to the underlying toxicological mechanisms.

Diagnostic Accuracy of Interleukin-6, Interleukin-8, and Interleukin-10 for Predicting Bacteremia in Children with Febrile Neutropenia

Despite improvements in diagnosis and treatment, infections are still a major cause of morbidity and mortality in children with febrile neutropenia. In the majority of febrile episodes, the source of infection cannot be defined. In this study, we aimed to identify the earlier predictors of bacteremia/fungemia and a useful cytokine to identify the source of infection and to discriminate the patients with culture-confirmed bacterial/fungal infection. The most sensitive cytokine was interleukin (IL)-10 and the most specific was IL-8 in predicting culture-confirmed cases. IL-8 had greater sensitivity and specificity in determination of gram-negative bacterial infections with a higher negative predictive value; therefore, IL-8 can be used particularly to rule out gram-negative bacterial infections. IL-6, IL-8, and IL-10 circulating levels were shown to be higher in cases of infection. Further studies are needed to recommend a routine practice for predicting culture-confirmed bacterial infections.

Combinational approach using in situ hybridization targeting 23S ribosomal RNA genes and blood cultures for bacterial identification in patients with neutropenia and fever

BACKGROUND

A new 23S ribosomal RNA genes-targeted in situ hybridization (ISH) probe to detect global bacterial genomic DNA (59 species from 35 genera; referred to as the GB probe) phagocytized in leukocytes was recently developed. This method provided early and direct evidence of bacterial infection with high sensitivity and specificity in spontaneous bacterial peritonitis ascites. However, the utility of this method in febrile neutropenia (FN) is unknown.

METHODS

We prospectively evaluated the utility of the ISH approach using the GB probe and previously reported probes in patients with neutropenia and fever undergoing chemotherapy at our institution between June 2011 and July 2013. Blood samples for culture analysis and ISH tests were collected simultaneously at the onset of fever; the latter were performed repeatedly.

RESULTS

Fifty febrile episodes were evaluated. In 24 episodes of fever of unknown origin and 15 episodes of local infection (all negative for blood cultures), ISH tests identified causal bacteria in 21% and 13% of cases, respectively, at the onset of fever. In seven sepsis cases (all positive for blood culture), positive ISH test results at fever onset were achieved in 71%; for two patients with neutrophil counts of 0/μl and 171/μl, respectively, negative results were obtained.

CONCLUSIONS

This new ISH approach could prove useful for early detection of bacteria in patients with neutropenia and blood culture-negative, with fever of unknown etiology after chemotherapy. Using this method in combination with blood culture, even in cases with extremely low neutrophil counts, might contribute to better management of FN.

Diagnostic value of levels of presepsin (soluble CD14-subtype) in febrile neutropenia in patients with hematological disorders

BACKGROUND

Whether presepsin (soluble CD14-subtype) is better than other markers including procalcitonin (PCT), has not been adequately investigated in febrile neutropenia (FN).

METHODS

We prospectively examined the utility of presepsin in FN in Cohort 1 (C1) and 2 (C2), between November 2010 and February 2012, and between November 2013 and January 2014, respectively. The purpose of this study was to investigate 1) the relative value of serum presepsin over serum PCT in C1, and 2) the relative value of plasma presepsin as compared with serum PCT, C-reactive protein, interleukin-6 and interleukin-8 with frequent, repeated sampling in C2.

RESULTS

Seventy-nine FN episodes (C1, 75; C2, 4) were evaluable. In C1, when compared with control values, presepsin was significantly higher at onset of FN (P = 0.004), while PCT was not significantly higher (P = 0.54). The median value of serum presepsin within 72 h of onset of FN in subjects with fever of unknown origin, local infection, bacteremia and septic shock was 680 (reference 314) pg/ml, 763, 782 and 1359, respectively. In C2, the mean levels of plasma presepsin from onset of FN to 72 h were classified as negative in the two patients with no suspected site of infection, and those of the remaining two patients with clinically probable infections were positive (175, 131, 346 and 329 pg/ml, respectively). In contrast, the other markers did not discriminate between this two groups.

CONCLUSIONS

In FN, presepsin may be an earlier and more sensitive indicator of bacterial infection than PCT.

Host response biomarkers in the diagnosis of sepsis: a general overview

Critically ill patients who display a systemic inflammatory response syndrome (SIRS) are prone to develop nosocomial infections. The challenge remains to distinguish as early as possible among SIRS patients those who are developing sepsis. Following a sterile insult, damage-associated molecular patterns (DAMPs) released by damaged tissues and necrotic cells initiate an inflammatory response close to that observed during sepsis. During sepsis, pathogen-associated molecular patterns (PAMPs) trigger the release of host mediators involved in innate immunity and inflammation through identical receptors as DAMPs. In both clinical settings, a compensatory anti-inflammatory response syndrome (CARS) is concomitantly initiated. The exacerbated production of pro- or anti-inflammatory mediators allows their detection in biological fluids and particularly within the bloodstream. Some of these mediators can be used as biomarkers to decipher among the patients those who developed sepsis, and eventually they can be used as prognosis markers. In addition to plasma biomarkers, the analysis of some surface markers on circulating leukocytes or the study of mRNA and miRNA can be helpful. While there is no magic marker, a combination of few biomarkers might offer a high accuracy for diagnosis.

Febrile neutropenia in children treated for malignancy

Febrile neutropenia (FN) in children treated for malignancy is a common and direct sequela of chemotherapy. Episodes of FN can be life-threatening, and demand prompt recognition, assessment and treatment with broad spectrum antibiotics. While in the majority of episodes no causal infection is identified, 10-20% are secondary to a bloodstream infection (BSI). A reduction in episodes of BSI could be achieved through robust infection prevention strategies, such as CVL care bundles. Alongside good antimicrobial stewardship, these strategies could reduce the risk of emergent, multi-drug resistant (MDR) infections. Emerging bacterial pathogens in BSI include Viridans Group Streptococci (VGS) and Enterobacteriaceae such as Klebsiella spp. which are known for their ability to carry MDR genes. There is also increased recognition of the role of invasive fungal infection (IFI) in FN, in particular with Aspergillus spp. Novel diagnostics, including multiplex blood and respiratory polymerase chain reaction assays can identify infections early in FN, facilitating targeted therapy, and reducing unnecessary antimicrobial exposure. Given appropriate, and sensitive rapid diagnostics, potential also exists to safely inform the risk assessment of patients with FN, identifying those at low risk of complication, who could be treated in the out-patient setting. Several clinical decision rules (CDR) have now been developed and validated in defined populations, for the risk assessment of children being treated for cancer. Future research is needed to develop a universal CDR to improve the management of children with FN.

IL-6, A1 and A2aR: a crosstalk that modulates BDNF and induces neuroprotection

Several diseases are related to retinal ganglion cell death, such as glaucoma, diabetes and other retinopathies. Many studies have attempted to identify factors that could increase neuroprotection after axotomy of these cells. Interleukin-6 has been shown to be able to increase the survival and regeneration of retinal ganglion cells (RGC) in mixed culture as well as in vivo. In this work we show that the trophic effect of IL-6 is mediated by adenosine receptor (A2aR) activation and also by the presence of extracellular BDNF. We also show that there is a complex cross-talk between IL-6, BDNF, the Adenosine A1 and A2a receptors that results in neuroprotection of retinal ganglion cells.

Laboratory detection of sepsis: biomarkers and molecular approaches

Sepsis, severe sepsis, and septic shock cause significant morbidity and mortality worldwide. Rapid diagnosis and therapeutic interventions are desirable to improve the overall mortality in patients with sepsis. However, gold standard laboratory diagnostic methods for sepsis, pose a significant challenge to rapid diagnosis of sepsis by physicians and laboratories. This article discusses the usefulness and potential of biomarkers and molecular test methods for a more rapid clinical and laboratory diagnosis of sepsis. Because new technologies are quickly emerging, physicians and laboratories must appreciate the key factors and characteristics that affect the clinical usefulness and diagnostic accuracy of these test methodologies.

Prospective validation of a risk prediction model for severe sepsis in children with cancer and high-risk febrile neutropenia

BACKGROUND

We previously created a risk prediction model for severe sepsis not clinically apparent during the first 24 hours of hospitalization in children with high-risk febrile neutropenia (HRFN), which identified 3 variables, age ≥ 12 years, serum C-reactive protein (CRP) ≥ 90 mg/L and interleukin-8 ≥ 300 pg/mL, evaluated at the time of admission and at 24 hours of hospitalization. The combination of these 3 variables identified a risk for severe sepsis ranging from 8% to 73% with a relative risk of 3.15 (95% confidence interval: 1.1-9.06). The aim of this study was to validate prospectively our risk prediction model for severe sepsis in a new cohort of children with cancer and HRFN.

METHODS

Predictors of severe sepsis identified in our previous model (age, CRP and interleukin-8) were evaluated at admission and at 24 hours of hospitalization in a new cohort of children with HRFN between April 2009 and July 2011. Diagnosis of severe sepsis, not clinically apparent during the first 24 hours of hospitalization, was made after discharge by a blind evaluator.

RESULTS

A total of 447 HRFN episodes were studied, of which 76 (17%) had a diagnosis of severe sepsis. The combination of age ≥ 12 years, CRP ≥ 90 mg/L and interleukin-8 ≥ 300 pg/mL at admission and/or at 24 hours in the new cohort identified a risk for severe sepsis ranging from 7% to 46% with an RR of 6.7 (95% CI: 2.3-19.5).

CONCLUSIONS

We validated a risk prediction model for severe sepsis applicable to children with HRFN episodes within the first 24 hours of admission. We propose to incorporate this model in the initial patient assessment to offer a more selective management for children at risk for severe sepsis.

A multiplex cytokine score for the prediction of disease severity in pediatric hematology/oncology patients with septic shock

Although many inflammatory cytokines are prognostic in sepsis, the utility of cytokines in evaluating disease severity in pediatric hematology/oncology patients with septic shock was rarely studied. On the other hand, a single particular cytokine is far from ideal in guiding therapeutic intervention, but combination of multiple biomarkers improves the accuracy. In this prospective observational study, 111 episodes of septic shock in pediatric hematology/oncology patients were enrolled from 2006 through 2012. Blood samples were taken for inflammatory cytokine measurement by cytometric bead array (CBA) technology at the initial onset of septic shock. Interleukin (IL)-6 and IL-10 were significantly elevated in majority of patients, while tumor necrosis factor (TNF)-α and interferon (IFN)-γ were markedly increased in patients with high pediatric index of mortality 2 (PIM2) score and non-survivors. All the four cytokines paralleled the PIM2 score and differentially correlated with hemodynamic disorder and fatal outcomes. The pediatric multiplex cytokine score (PMCS), which integrated the four cytokines into one score system, was related to hemodynamic disorder and mortality as well, but showed more powerful prediction ability than each of the four cytokines. PMCS was an independent predictive factor for fatal outcome, presenting similar discriminative power with PIM2, with accuracy of 0.83 (95% CI, 0.71-0.94). In conclusion, this study develops a cytokine scoring system based on CBA technique, which performs well in disease severity and fatality prediction in pediatric hematology/oncology patients with septic shock.

Cytokines and chemokines as biomarkers of community-acquired bacterial infection

Routinely used biomarkers of bacterial etiology of infection, such as C-reactive protein and procalcitonin, have limited usefulness for evaluation of infections since their expression is enhanced by a number of different conditions. Therefore, several inflammatory cytokines and chemokines were analyzed with sera from patients hospitalized for moderate bacterial and viral infectious diseases. In total, 57 subjects were enrolled: 21 patients with community-acquired bacterial infections, 26 patients with viral infections, and 10 healthy subjects (control cohorts). The laboratory analyses were performed using Luminex technology, and the following molecules were examined: IL-1Ra, IL-2, IL-4, IL-6, IL-8, TNF-α, INF-γ, MIP-1β, and MCP-1. Bacterial etiology of infection was associated with significantly (P < 0.001) elevated serum concentrations of IL-1Ra, IL-2, IL-6, and TNF-α in comparison to levels observed in the sera of patients with viral infections. In the patients with bacterial infections, IL-1Ra and IL-8 demonstrated positive correlation with C-reactive protein, whereas, IL-1Ra, TNF-α, and MCP-1 correlated with procalcitonin. Furthermore, elevated levels of IL-1Ra, IL-6, and TNF-α decreased within 3 days of antibiotic therapy to levels observed in control subjects. The results show IL-1Ra as a potential useful biomarker of community-acquired bacterial infection.

IL-8 predicts pediatric oncology patients with febrile neutropenia at low risk for bacteremia

INTRODUCTION

Despite a low bacteremia rate, pediatric oncology patients are frequently admitted for febrile neutropenia. A pediatric risk prediction model with high sensitivity to identify patients at low risk for bacteremia is not available. We performed a single-institution prospective cohort study of pediatric oncology patients with febrile neutropenia to create a risk prediction model using clinical factors, respiratory viral infection, and cytokine expression.

MATERIALS AND METHODS

Pediatric oncology patients with febrile neutropenia were enrolled between March 30, 2010 and April 1, 2011 and managed per institutional protocol. Blood samples for C-reactive protein and cytokine expression and nasopharyngeal swabs for respiratory viral testing were obtained. Medical records were reviewed for clinical data. Statistical analysis utilized mixed multiple logistic regression modeling.

RESULTS

During the 12-month period, 195 febrile neutropenia episodes were enrolled. There were 24 (12%) episodes of bacteremia. Univariate analysis revealed several factors predictive for bacteremia, and interleukin (IL)-8 was the most predictive variable in the multivariate stepwise logistic regression. Low serum IL-8 predicted patients at low risk for bacteremia with a sensitivity of 0.9 and negative predictive value of 0.98.

CONCLUSIONS

IL-8 is a highly sensitive predictor for patients at low risk for bacteremia. IL-8 should be utilized in a multi-institution prospective trial to assign risk stratification to pediatric patients admitted with febrile neutropenia.