interleukin-8 and Pneumonia--Ventilator-Associated

Ventilator-acquired pneumonia (VAP) is a common reason for antimicrobial therapy in the intensive care unit (ICU). Biomarker-based diagnostics could improve antimicrobial stewardship through rapid exclusion of VAP. Bronchoalveloar lavage (BAL) fluid biomarkers have previously been shown to allow the exclusion of VAP with high confidence.. This is a prospective, multi-centre, randomised, controlled trial to determine whether a rapid biomarker-based exclusion of VAP results in fewer antibiotics and improved antimicrobial management. Patients with clinically suspected VAP undergo BAL, and VAP is confirmed by growth of a potential pathogen at [≥] 10(4) colony-forming units per millilitre (CFU/ml). Patients are randomised 1:1, to either a 'biomarker-guided recommendation on antibiotics' in which BAL fluid is tested for IL-1β and IL-8 in addition to routine microbiology testing, or to 'routine use of antibiotics' in which BAL undergoes routine microbiology testing only. Clinical teams are blinded to intervention until 6 hours after randomisation, when biomarker results are reported to the clinician. The primary outcome is a change in the frequency distribution of antibiotic-free days (AFD) in the 7 days following BAL. Secondary outcome measures include antibiotic use at 14 and 28 days; ventilator-free days; 28-day mortality and ICU mortality; sequential organ failure assessment (SOFA) at days 3, 7 and 14; duration of stay in critical care and the hospital; antibiotic-associated infections; and antibiotic-resistant pathogen cultures up to hospital discharge, death or 56 days. A healthcare-resource-utilisation analysis will be calculated from the duration of critical care and hospital stay. In addition, safety data will be collected with respect to performing BAL. A sample size of 210 will be required to detect a clinically significant shift in the distribution of AFD towards more patients having fewer antibiotics and therefore more AFD.. This trial will test whether a rapid biomarker-based exclusion of VAP results in rapid discontinuation of antibiotics and therefore improves antibiotic management in patients with suspected VAP.. ISRCTN65937227 . Registered on 22 August 2013. ClinicalTrials.gov, NCT01972425 . Registered on 24 October 2013.

Topics: Anti-Bacterial Agents; Antimicrobial Stewardship; Bacteria; Biomarkers; Bronchoalveolar Lavage Fluid; Clinical Protocols; Colony Count, Microbial; Hospital Mortality; Humans; Interleukin-1beta; Interleukin-8; Length of Stay; Organ Dysfunction Scores; Patient Selection; Pneumonia, Bacterial; Pneumonia, Ventilator-Associated; Predictive Value of Tests; Prospective Studies; Research Design; Respiration, Artificial; Time Factors; United Kingdom; Unnecessary Procedures

The aim of this study was to identify the association polymorphism (rs11536889) in the 3'-untranslated region (3'-UTR) of Toll-like receptors 4 (TLR4) and the risk for ventilator-associated pneumonia (VAP). miRNA database online and luciferase assays were used to validate TLR4 as the target gene of miR-1236. Enzyme-linked immunosorbent assay analysis and western blot were used to analyze the level of TLR4 in different genotype groups. In the present study, miR-1236 was predicted to bind to the rs11536889 G allele rather than the rs11536889 C allele, which was further confirmed by the luciferase activity suppressed by a fragment of 3'-UTR containing the rs11536889 G allele induced by lipopolysaccharide (LPS) and interleukin-6 (IL-6). Bronchial epithelial cells isolated from participants genotyped as GG, GC, and CC, with no remarkable difference in TLR4 messenger RNA (mRNA) levels were observed among these genotype groups. After stimulating by LPS, a TLR4 ligand, the CC-genotyped cells expressed higher levels of IL-8, IL-6, and tumor necrosis factor alpha (TNF-α) on their surfaces than cells with the other genotypes. Finally, the western blot analysis results showed that the expression level of IL-8, IL-6, and TNF-α protein was much higher in the CC group than the GC and GG groups subsequent to stimulation by LPS, and the IL-8, IL-6, and TNF-α protein levels in the GC were grouped much lower compared with the GG group. These findings indicated the regulatory association of miR-1236 with TLR4 and the abnormal expression of TLR4 caused by the presence of rs11536889 in the 3'-UTR of mRNA, which interfere with its interaction with the miR-1236, contributing to the risk of VAP.

Topics: 3' Untranslated Regions; Alleles; Alveolar Epithelial Cells; Cells, Cultured; Female; Genetic Predisposition to Disease; Genotype; Humans; Interleukin-6; Interleukin-8; Lipopolysaccharides; Male; MicroRNAs; Middle Aged; Pneumonia, Ventilator-Associated; Polymorphism, Single Nucleotide; Pulmonary Disease, Chronic Obstructive; Respiration, Artificial; RNA, Messenger; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha

Clinical investigations lack predictive value when diagnosing pneumonia, especially when patients are ventilated and develop ventilator associated pneumonia (VAP). New tools to aid diagnosis are important to improve outcomes. This pilot study examines the potential for a panel of inflammatory mediators to aid in the diagnosis. Forty-four ventilated patients, 17 with pneumonia and 27 with brain injuries, eight of whom developed VAP, were recruited. 51 inflammatory mediators, including cytokines and oxylipins, were measured in patients' serum using flow cytometry and mass spectrometry. The mediators could separate patients admitted to ICU with pneumonia compared to brain injury with an area under the receiver operating characteristic curve (AUROC) 0.75 (0.61-0.90). Changes in inflammatory mediators were similar in both groups over the course of ICU stay with 5,6-dihydroxyeicosatrienoic and 8,9-dihydroxyeicosatrienoic acids increasing over time and interleukin-6 decreasing. However, brain injured patients who developed VAP maintained inflammatory profiles similar to those at admission. A multivariate model containing 5,6-dihydroxyeicosatrienoic acid, 8,9-dihydroxyeicosatrienoic acid, intercellular adhesion molecule-1, interleukin-6, and interleukin-8, could differentiate patients with VAP from brain injured patients without infection (AUROC 0.94 (0.80-1.00)). The use of a selected group of markers showed promise to aid the diagnosis of VAP especially when combined with clinical data.

Topics: Biomarkers; Brain Injuries; Critical Care; Female; Flow Cytometry; Humans; Inflammation; Intensive Care Units; Interleukin-6; Interleukin-8; Male; Mass Spectrometry; Middle Aged; Pneumonia, Ventilator-Associated; ROC Curve

Ventilator-associated pneumonia (VAP) is a serious complication of mechanical ventilation leading to high morbidity and mortality among intubated neonates in neonatal intensive care units (NICUs). Endotracheal tube (ETT) biofilm flora were considered to be responsible for the occurrence of VAP as a reservoir of pathogens. However, regarding neonates with VAP, little is known about the complex microbial signatures in ETT biofilms. In the present study, a culture-independent approach based on next generation sequencing was performed as an initial survey to investigate the microbial communities in ETT biofilms of 49 intubated neonates with and without VAP. Our results revealed a far more complex microflora in ETT biofilms from intubated neonates compared to a previous culture-based study. The abundance of Streptococci in ETT biofilms was significantly related to the onset of VAP. By isolating Streptococci in ETT biofilms, we found that Streptococci enhanced biofilm formation of the common nosocomial pathogen Pseudomonas aeruginosa PAO1 and decreased IL-8 expression of airway epithelia cells exposed to the biofilm conditioned medium of PAO1. This study provides new insight into the pathogenesis of VAP among intubated neonates. More studies focusing on intubated neonates are warranted to develop strategies to address this important nosocomial disease in NICUs.

Topics: Biofilms; Female; Humans; Infant, Newborn; Interleukin-8; Male; Microbiota; Pneumonia, Ventilator-Associated; Pseudomonas aeruginosa; Respiratory Mucosa; Streptococcus; Ventilators, Mechanical

Ventilator-associated pneumonia (VAP) is common during mechanical ventilation (MV). Beside obvious deleterious effects on muco-ciliary clearance, MV could adversely shift the host immune response towards a pro-inflammatory pattern through toll-like receptor (TLRs) up-regulation. We tested this hypothesis in a rabbit model of Staphylococcus aureus VAP. Pneumonia was caused by airway challenge with S. aureus, in either spontaneously breathing (SB) or MV rabbits (n = 13 and 17, respectively). Pneumonia assessment regarding pulmonary and systemic bacterial burden, as well as inflammatory response was done 8 and 24 hours after S. aureus challenge. In addition, ex vivo stimulations of whole blood taken from SB or MV rabbits (n = 7 and 5, respectively) with TLR2 agonist or heat-killed S. aureus were performed. Data were expressed as mean±standard deviation. After 8 hours of infection, lung injury was more severe in MV animals (1.40±0.33 versus [vs] 2.40±0.55, p = 0.007), along with greater bacterial concentrations (6.13±0.63 vs. 4.96±1.31 colony forming units/gram, p = 0.002). Interleukin (IL)-8 and tumor necrosis factor (TNF)-αserum concentrations reached higher levels in MV animals (p = 0.010). Whole blood obtained from MV animals released larger amounts of cytokines if stimulated with TLR2 agonist or heat-killed S. aureus (e.g., TNF-α: 1656±166 vs. 1005±89; p = 0.014). Moreover, MV induced TLR2 overexpression in both lung and spleen tissue. MV hastened tissue injury, impaired lung bacterial clearance, and promoted a systemic inflammatory response, maybe through TLR2 overexpression.

Topics: Animals; Interleukin-8; Pneumonia, Staphylococcal; Pneumonia, Ventilator-Associated; Rabbits; Respiration, Artificial; Staphylococcus aureus; Toll-Like Receptor 2; Tumor Necrosis Factor-alpha

Currently, no clinical or animal studies have been performed to establish the relationship between airway humidification and mechanical ventilation-induced lung inflammatory responses. Therefore, an animal model was established to better define this relationship.. Rabbits (n = 40) were randomly divided into 6 groups: control animals, sacrificed immediately after anesthesia (n = 2); dry gas group animals, subjected to mechanical ventilation for 8 h without humidification (n = 6); and experimental animals, subjected to mechanical ventilation for 8 h under humidification at 30, 35, 40, and 45°C, respectively (n = 8). Inflammatory cytokines in the bronchi alveolar lavage fluid (BALF) were measured. The integrity of the airway cilia and the tracheal epithelium was examined by scanning and transmission electron microscopy, respectively. Peripheral blood white blood cell counts and the wet to dry ratio and lung pathology were determined.. Dry gas group animals showed increased tumor necrosis factor alpha levels in BALF compared with control animals (P < .05). The tumor necrosis factor alpha and interleukin-8 levels in the BALF reached baseline levels when the humidification temperature was increased to 40°C. Scanning and transmission electron microscopy analysis revealed that cilia integrity was maintained in the 40°C groups. Peripheral white blood cell counts were not different among those groups. Compared with control animals, the wet to dry ratio was significantly elevated in the dry gas group (P < .05). Moreover, humidification at 40°C resulted in reduced pathologic injury compared with the other groups based on the histologic score.. Pathology and reduced inflammation observed in animals treated at 40°C was similar to that observed in the control animals, suggesting that appropriate humidification reduced inflammatory responses elicited as a consequence of mechanical ventilation, in addition to reducing damage to the cilia and reducing water loss in the airway.

Topics: Animals; Bronchoalveolar Lavage Fluid; Humidity; Interleukin-8; Leukocyte Count; Lung; Male; Pneumonia, Ventilator-Associated; Rabbits; Random Allocation; Respiration, Artificial; Temperature; Tumor Necrosis Factor-alpha; Ventilator-Induced Lung Injury

Ventilator-associated pneumonia (VAP) increases mortality in critical illness. However, clinical diagnostic uncertainty persists. We hypothesised that measuring cell-surface and soluble inflammatory markers, incorporating Triggering Receptor Expressed by Myeloid cells (TREM)-1, would improve diagnostic accuracy.. A single centre prospective observational study, set in a University Hospital medical-surgical intensive Care unit, recruited 91 patients into 3 groups: 27 patients with VAP, 33 ventilated controls without evidence of pulmonary sepsis (non-VAP), and 31 non-ventilated controls (NVC), without clinical infection, attending for bronchoscopy. Paired samples of Bronchiolo-alveolar lavage fluid (BALF) and blood from each subject were analysed for putative biomarkers of infection: Cellular (TREM-1, CD11b and CD62L) and soluble (IL-1β, IL-6, IL-8, sTREM-1, Procalcitonin). Expression of cellular markers on monocytes and neutrophils were measured by flow cytometry. Soluble inflammatory markers were determined by ELISA. A biomarker panel ('Bioscore'), was constructed, tested and validated, using Fisher's discriminant function analysis, to assess its value in distinguishing VAP from non VAP.. The expression of TREM-1 on monocytes (mTREM-1) and neutrophils (nTREM-1) and concentrations of IL-1β, IL-8, and sTREM-1 in BALF were significantly higher in VAP compared with non-VAP and NVC (p<0.001). The BALF/blood mTREM-1 was significantly higher in VAP patients compared to non-VAP and NVC (0.8 v 0.4 v 0.3 p<0.001). A seven marker Bioscore (BALF/blood ratio mTREM-1 and mCD11b, BALF sTREM-1, IL-8 and IL-1β, and serum CRP and IL-6) correctly identified 88.9% of VAP cases and 100% of non-VAP cases.. A 7-marker bioscore, incorporating cellular and soluble TREM-1, accurately discriminates VAP from non-pulmonary infection.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers; Bronchoalveolar Lavage Fluid; Calcitonin; Calcitonin Gene-Related Peptide; Case-Control Studies; CD11b Antigen; Female; Gene Expression; Humans; Intensive Care Units; Interleukin-1beta; Interleukin-6; Interleukin-8; L-Selectin; Male; Membrane Glycoproteins; Middle Aged; Monocytes; Neutrophils; Pneumonia, Ventilator-Associated; Predictive Value of Tests; Prospective Studies; Protein Precursors; Receptors, Immunologic; Triggering Receptor Expressed on Myeloid Cells-1

To assess the efficacy of linezolid compared with vancomycin in an experimental model of pneumonia induced by methicillin-resistant Staphylococcus aureus (MRSA) in ventilated pigs.. Forty pigs (30 kg) were intubated and challenged via bronchoscopy with a suspension of 106 colony forming units of MRSA into every lobe. Afterwards, pigs were ventilated up to 96 hours. Twelve hours after bacterial inoculation, the animals were randomized into 4 groups of treatment: group 1, control; group 2, vancomycin twice daily; group 3, continuous infusion of vancomycin; and group 4, linezolid. Clinical and laboratory parameters were monitored throughout the study. Bacterial cultures of bronchoalveolar lavage fluid and lung tissue samples were performed at the end of the study. Measurements of histopathology derangements of lung samples and studies of intrapulmonary drug penetration were performed.. A total of 34 animals completed the study. No differences in clinical and laboratory parameters were observed. The percentage of bronchoalveolar lavage fluid and lung tissue samples with positive cultures for MRSA in controls and groups 2, 3, and 4 was respectively 75%, 11%, 11%, and 0% (p < .01); 52%, 9%, 24%, and 2.5% (p < .01). Histopathology studies demonstrated signs of pneumonia in 95%, 69%, 58%, and 57% and signs of severe pneumonia in 48%, 29%, 22%, and 0% of controls and groups 2, 3, and 4, respectively (p < .01). In addition, pharmacokinetics/pharmacodynamics profile in serum and lung tissue showed better results for linezolid compared with both vancomycin treatments.. In this animal model of MRSA pneumonia, linezolid showed a better efficacy than vancomycin showed because of a better pharmacokinetics/pharmacodynamics index.

Topics: Acetamides; Animals; Anti-Bacterial Agents; Bronchoalveolar Lavage Fluid; Disease Models, Animal; Interleukin-6; Interleukin-8; Linezolid; Lung; Methicillin-Resistant Staphylococcus aureus; Oxazolidinones; Pneumonia, Staphylococcal; Pneumonia, Ventilator-Associated; Respiration, Artificial; Swine; Tumor Necrosis Factor-alpha; Vancomycin

A major unanswered question in ventilator-associated pneumonia (VAP) management relates to patient response to therapy. We investigated the use of pulmonary cytokines as biomarkers for response to antibiotic therapy for VAP.. Prospective, observational pilot study of 12 critically ill trauma patients with VAP using a bronchoscopic bronchoalveolar lavage (BAL) (> or =100,000 colony-forming units [cfu]/mL). All patients underwent repeat BAL after three days of adequate antibiotic therapy. Changes in pulmonary effluent interleukin (IL)-8 and tumor necrosis factor (TNF)-alpha concentrations measured on diagnostic and repeat BAL were evaluated on the basis of the presence of a microbiologic response (<10,000 cfu/mL on repeat BAL).. Six post-therapy BAL samples showed a microbiologic response. In responders, IL-8 and TNF-alpha concentrations decreased significantly (1,303 +/- 1,150 ng/mL in diagnostic BAL sample vs. 309 +/- 448 ng/mL after response; p = 0.08 and 9.9 +/- 18.4 ng/mL in diagnostic vs. 0.1 +/- 0.1 ng/mL in post-treatment sample; p = 0.06, respectively). In non-responders, IL-8 (449 +/- 426 ng/mL vs. 326 +/- 319 ng/mL; p = 0.59) and TNF-alpha (1.2 +/- 1.9 ng/mL vs. 0.3 +/- 0.3 ng/mL; p = 0.31) did not change significantly. Clinical response measures did not change or increased in responders, whereas these parameters did not change or decreased paradoxically in non-responders.. This pilot study indicates pulmonary concentrations of IL-8 and TNF-alpha decrease in microbiologic responders with VAP. Conversely, clinical response parameters were discordant with the microbiologic response. The utility of pulmonary cytokine behavior in evaluating the effectiveness of antibiotic therapy for VAP should be studied further.

Topics: Adult; Anti-Bacterial Agents; Bacteria; Bronchoalveolar Lavage Fluid; Colony Count, Microbial; Drug Monitoring; Female; Humans; Interleukin-8; Lung; Male; Middle Aged; Pilot Projects; Pneumonia, Ventilator-Associated; Tumor Necrosis Factor-alpha; Young Adult

Ventilator-associated pneumonia (VAP) is the most commonly fatal nosocomial infection. Clinical diagnosis of VAP remains notoriously inaccurate. The hypothesis was tested that significantly augmented inflammatory markers distinguish VAP from conditions closely mimicking VAP.. A prospective, observational cohort study was carried out in two university hospital intensive care units recruiting 73 patients with clinically suspected VAP, and a semi-urban primary care practice recruiting a reference group of 21 age- and sex-matched volunteers. Growth of pathogens at >10(4) colony-forming units (cfu)/ml of bronchoalveolar lavage fluid (BALF) distinguished VAP from "non-VAP". Inflammatory mediators were quantified in BALF and serum. Mediators showing significant differences between patients with and without VAP were analysed for diagnostic utility by receiver operator characteristic (ROC) curves.. Seventy-two patients had recoverable lavage-24% had VAP. BALF interleukin-1beta (IL-1beta), IL-8, granulocyte colony-stimulating factor and macrophage inflammatory protein-1alpha were significantly higher in the VAP group (all p<0.005). Using a cut-off of 10 pg/ml, BALF IL-1beta generated negative likelihood ratios for VAP of 0.09. In patients with BALF IL-1beta <10 pg/ml the post-test probability of VAP was 2.8%. Using a cut-off value for IL-8 of 2 ng/ml, the positive likelihood ratio was 5.03. There was no difference in cytokine levels between patients with sterile BALF and those with growth of <10(4) cfu/ml.. BALF IL-1beta and IL-8 are amongst the strongest markers yet identified for accurately demarcating VAP within the larger population of patients with suspected VAP. These findings have potential implications for reduction in unnecessary antibiotic use but require further validation in larger populations.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Bronchoalveolar Lavage Fluid; Epidemiologic Methods; Female; Humans; Inflammation Mediators; Interleukin-1beta; Interleukin-8; Male; Middle Aged; Pneumonia, Ventilator-Associated; Young Adult

The aims of this study were to measure the levels of bile acids in patients with suspected ventilator-associated pneumonia (VAP) and provide a possible pathway for neutrophilic inflammation to explain its proinflammatory effect on the airway.. Bile acid levels were measured by spectrophotometric enzymatic assay, and liquid chromatography mass spectrometry was used to quantify the major bile acids. Alveolar cells were grown on modified air-liquid interface culture inserts, and bile acids were then employed to stimulate the cells. Reverse transcriptase polymerase chain reaction and Western blots were used to determine the involved gene expression and protein levels.. The mean (+/- SE) concentration of total bile acids in tracheal aspirates was 6.2 +/- 2.1 and 1.1 +/- 0.4 mumol/L/g sputum, respectively, for patients with and without VAP (p < 0.05). The interleukin (IL)-8 level was significantly higher in the VAP group (p < 0.05). The major bile acid, chenodeoxycholic acid, stimulated alveolar epithelial cells to increase IL-8 production at both the messenger RNA and protein level through p38 and c-Jun N-terminal kinase (JNK) activation. The selective p38 and JNK inhibitors, as well as dexamethasone, successfully inhibited IL-8 production.. These data suggest that early intervention to prevent bile acid aspiration may reduce the intensity of neutrophilic inflammation in intubated and mechanically ventilated patients in the ICU.

Topics: Aged; Aged, 80 and over; Cell Culture Techniques; Chenodeoxycholic Acid; Cholic Acids; Cohort Studies; Critical Care; Epithelial Cells; Female; Gastrointestinal Agents; Humans; Interleukin-8; Male; Mitogen-Activated Protein Kinases; Mucus; Pneumonia, Ventilator-Associated; Pulmonary Alveoli; Respiratory Aspiration; Respiratory Mucosa

Inflammatory markers have been assessed for the diagnosis and follow-up of ventilator-associated pneumonia (VAP), but their potential role in predicting the risk for VAP is unknown. We prospectively assessed the evolution of cytokines in mechanically ventilated patients and their predictive and diagnostic role for VAP.. Prospective observational study.. Medical intensive care unit.. Mechanically ventilated patients. Exclusion criteria were active infection at admission and subsequent extrapulmonary infection.. None.. Sequential measurements of interleukin (IL)-1, IL-6, IL-8, IL-10, and tumor necrosis factor-alpha were done in 44 ventilated patients. VAP was suspected in 20 cases and microbiologically confirmed in nine. At admission, demographics, severity scores, and clinical and standard laboratory values did not discriminate patients with and without VAP, but the median (interquartile range) serum levels of IL-6 were higher in patients who subsequently developed VAP, compared with those without VAP (235 [141-803] vs. 113 [60-170] pg/mL, p = 0.015). The sensitivity and specificity of IL-6 to predict VAP was 71% and 78%, respectively, using 198 pg/mL as optimal cutoff, with relative risk (95% confidence interval) 8.9 (1.4-56.3). When VAP was suspected, serum levels of IL-6 were higher in patients with confirmed compared with nonconfirmed VAP (1131 [496-1987] vs. 236 [115-357] pg/mL, p = 0.016). The sensitivity and specificity to discriminate between confirmed and nonconfirmed VAP was 71% and 89%, respectively, using 620 pg/mL as optimal cutoff, with relative risk (95% confidence interval) 15.0 (1.2-185.2).. IL-6 at admission is an early and accurate indicator of patients at increased risk for VAP. IL-6 is also accurate in discriminating patients with VAP from other causes of pulmonary infiltrates. Extrapolation of these results to the overall population of critically ill patients is limited by the small number of patients.

Topics: Aged; Cohort Studies; Critical Care; Critical Illness; Female; Hospital Mortality; Humans; Inflammation Mediators; Intensive Care Units; Interleukin-1; Interleukin-10; Interleukin-6; Interleukin-8; Male; Middle Aged; Pneumonia, Ventilator-Associated; Predictive Value of Tests; Probability; Prognosis; Prospective Studies; Respiration, Artificial; Respiratory Insufficiency; Risk Assessment; Sensitivity and Specificity; Statistics, Nonparametric; Survival Analysis; Systemic Inflammatory Response Syndrome