Prediction of response to anti-PD-1 therapy in patients with non-small-cell lung cancer by electronic nose analysis of exhaled breath.

BACKGROUND: Immune checkpoint inhibitors have improved survival outcome of advanced non-small-cell lung cancer (NSCLC). However, most patients do not benefit. Therefore, biomarkers are needed that accurately predict response. We hypothesized that molecular profiling of exhaled air may capture the inflammatory milieu related to the individual responsiveness to anti-programmed death ligand 1 (PD-1) therapy. This study aimed to determine the accuracy of exhaled breath analysis at baseline for assessing nonresponders versus responders to anti-PD-1 therapy in NSCLC patients. METHODS: This was a prospective observational study in patients receiving checkpoint inhibitor therapy using both a training and validation set of NSCLC patients. At baseline, breath profiles were collected in duplicate by a metal oxide semiconductor electronic nose (eNose) positioned at the rear end of a pneumotachograph. Patients received nivolumab or pembrolizumab of which the efficacy was assessed by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 at 3-month follow-up. Data analysis involved advanced signal-processing and statistics based on independent t-tests followed by linear discriminant and receiver operating characteristic (ROC) analysis. RESULTS: Exhaled breath data of 143 NSCLC patients (training: 92, validation: 51) were available at baseline. ENose sensors contributed significantly (P < 0.05) at baseline in differentiating between patients with different responses at 3 months of anti-PD-1 treatment. The eNose sensors were combined into a single biomarker with an ROC-area under the curve (AUC) of 0.89 [confidence interval (CI) 0.82-0.96]. This AUC was confirmed in the validation set: 0.85 (CI 0.75-0.96). CONCLUSION: ENose assessment was effective in the noninvasive prediction of individual patient responses to immunotherapy. The predictive accuracy and efficacy of the eNose for discrimination of immunotherapy responder types were replicated in an independent validation set op patients. This finding can potentially avoid application of ineffective treatment in identified probable nonresponders.

Exhaled Breath Profiles Before, During and After Exacerbation of COPD: A Prospective Follow-Up Study.

Many patients with chronic obstructive lung disease (COPD) experience exacerbations. The diagnosis of an exacerbation is solely based on symptoms. We hypothesized that exhaled breath profiles, measured by Gas Chromatography-Mass Spectrometry (GC-MS) or electronic nose (eNose), are different between stable disease and exacerbations and may have the potential to serve as biomarkers for COPD exacerbations. In this prospective follow-up study, breath samples were taken during stable COPD, during a subsequent exacerbation and after recovery. Samples were analyzed by GC-MS and eNose. CCQ symptom scores were associated with univariate outcomes of GC-MS and eNose using analysis of covariance (ANCOVA). After multivariate modeling by Principal Component Analysis (PCA), paired student t-tests were performed. Sixty-eight patients were included, 31 had an exacerbation and 16 patients had breath sampled at all three time points. Significant differences were found in breathprints taken during exacerbation as compared to baseline and recovery for both GC-MS and eNose. Breath profiles obtained by GC-MS as well as by eNose showed a correct classification of 71% (10/14) for baseline vs exacerbation and of 78% (11/14) for exacerbation vs recovery. These results provide proof of principle that exhaled breath can serve as a noninvasive biomarker for the diagnosis of COPD exacerbations.

Profiling of volatile organic compounds produced by clinical Aspergillus isolates using gas chromatography-mass spectrometry.

Volatile organic compounds (VOCs) in exhaled breath may identify the presence of invasive pulmonary aspergillosis. We aimed to detect VOC profiles emitted by in vitro cultured, clinical Aspergillus isolates using gas chromatography-mass spectrometry (GC-MS). Three clinical Aspergillus isolates and a reference strain were cultured while conidiation was prevented. Headspace samples were analyzed using a standardized method. Breath samples of patients from which the cultures were obtained were checked for the presence of the VOCs found in vitro. Each Aspergillus isolate produced a distinct VOC profile. These profiles could not be confirmed in exhaled breath in vivo.

Exhaled breath profiles in the monitoring of loss of control and clinical recovery in asthma.

BACKGROUND: Asthma is a chronic inflammatory airway disease, associated with episodes of exacerbations. Therapy with inhaled corticosteroids (ICS) targets airway inflammation, which aims to maintain and restore asthma control. Clinical features are only modestly associated with airways inflammation. Therefore, we hypothesized that exhaled volatile metabolites identify longitudinal changes between clinically stable episodes and loss of asthma control. OBJECTIVES: To determine whether exhaled volatile organic compounds (VOCs) as measured by gas-chromatography/mass-spectrometry (GC/MS) and electronic nose (eNose) technology discriminate between clinically stable and unstable episodes of asthma. METHODS: Twenty-three patients with (partly) controlled mild to moderate persistent asthma using ICS were included in this prospective steroid withdrawal study. Exhaled metabolites were measured at baseline, during loss of control and after recovery. Standardized sampling of exhaled air was performed, after which samples were analysed by GC/MS and eNose. Univariate analysis of covariance (ANCOVA), followed by multivariate principal component analysis (PCA) was used to reduce data dimensionality. Next paired t tests were utilized to analyse within-subject breath profile differences at the different time-points. Finally, associations between exhaled metabolites and sputum inflammation markers were examined. RESULTS: Breath profiles by eNose showed 95% (21/22) correct classification for baseline vs loss of control and 86% (19/22) for loss of control vs recovery. Breath profiles using GC/MS showed accuracies of 68% (14/22) and 77% (17/22) for baseline vs loss of control and loss of control vs recovery, respectively. Significant associations between exhaled metabolites captured by GC/MS and sputum eosinophils were found (Pearson r≥.46, P<.01). CONCLUSIONS & CLINICAL RELEVANCE: Loss of asthma control can be discriminated from clinically stable episodes by longitudinal monitoring of exhaled metabolites measured by GC/MS and particularly eNose. Part of the uncovered biomarkers was associated with sputum eosinophils. These findings provide proof of principle for monitoring and identification of loss of asthma control by breathomics.

An early innate response underlies severe influenza-induced exacerbations of asthma in a novel steroid-insensitive and anti-IL-5-responsive mouse model.

BACKGROUND: Acute worsening of asthma symptoms (exacerbation) is predominantly triggered by respiratory viruses, with influenza causing the most severe exacerbations. The lack of an adequate animal model hampers mechanistic insight and the development of new therapeutics. AIM: We developed and characterized a robust, consistent, and reproducible mouse model of severe exacerbation of chronic allergic asthma. METHODS: Chronic allergic airway inflammation was induced following a house dust mite (HDM) sensitization protocol. HDM-sensitized mice and controls were infected with influenza virus A/X31 H3N2 and either or not treated with inhaled fluticasone propionate (FP), systemic corticosteroids (Pred), or anti-IL-5. Mice were killed at different time points after infection: Cellular accumulation and cytokines levels in the airways, PenH as a measure of airway hyper-responsiveness (AHR), and lung histology and viral replication were assessed. RESULTS: Infection with low-dose A/X31 H3N2 led to prolonged deterioration of lung function, aggravated mucus production, peri-vascular, peri-bronchial, and allergic inflammation that was unresponsive to inhaled corticosteroids, but responsive to systemic corticosteroids. The exacerbation was preceded at 14 h after virus exposure by a marked innate, but no Th2 and Th1 response subsequently followed by enhanced numbers of eosinophils, neutrophils, dendritic, and T cells into the lung lumen, parenchyma, and draining lymph nodes in HDM-sensitized mice. Anti-IL-5 treatment attenuated eosinophils and prevented the X31-induced exacerbation. CONCLUSIONS: Together, these findings indicate that an early innate response that involves eosinophils underlies the exacerbation. This model recapitulates all major features of severe asthma exacerbations and can serve to discern driving mechanisms and promote the development of novel therapeutics.

Long-term future risk of severe exacerbations: Distinct 5-year trajectories of problematic asthma.

BACKGROUND: Assessing future risk of exacerbations is an important component of asthma management. Existing studies have investigated short- but not long-term risk. Problematic asthma patients with unfavorable long-term disease trajectory and persistently frequent severe exacerbations need to be identified early to guide treatment. AIM: To identify distinct trajectories of severe exacerbation rates among "problematic asthma" patients and develop a risk score to predict the most unfavorable trajectory. METHODS: Severe exacerbation rates over five years for 177 "problematic asthma" patients presenting to a specialist asthma clinic were tracked. Distinct trajectories of severe exacerbation rates were identified using group-based trajectory modeling. Baseline predictors of trajectory were identified and used to develop a clinical risk score for predicting the most unfavorable trajectory. RESULTS: Three distinct trajectories were found: 58.5% had rare intermittent severe exacerbations ("infrequent"), 32.0% had frequent severe exacerbations at baseline but improved subsequently ("nonpersistently frequent"), and 9.5% exhibited persistently frequent severe exacerbations, with the highest incidence of near-fatal asthma ("persistently frequent"). A clinical risk score composed of ≥2 severe exacerbations in the past year (+2 points), history of near-fatal asthma (+1 point), body mass index ≥25kg/m2 (+1 point), obstructive sleep apnea (+1 point), gastroesophageal reflux (+1 point), and depression (+1 point) was predictive of the "persistently frequent" trajectory (area under the receiver operating characteristic curve: 0.84, sensitivity 72.2%, specificity 81.1% using cutoff ≥3 points). The trajectories and clinical risk score had excellent performance in an independent validation cohort. CONCLUSIONS: Patients with problematic asthma follow distinct illness trajectories over a period of five years. We have derived and validated a clinical risk score that accurately identifies patients who will have persistently frequent severe exacerbations in the future.

Detection of Airway Colonization by Aspergillus fumigatus by Use of Electronic Nose Technology in Patients with Cystic Fibrosis.

Currently, there is no noninvasive test that can reliably diagnose early invasive pulmonary aspergillosis (IA). An electronic nose (eNose) can discriminate various lung diseases through an analysis of exhaled volatile organic compounds. We recently published a proof-of-principle study showing that patients with prolonged chemotherapy-induced neutropenia and IA have a distinct exhaled breath profile (or breathprint) that can be discriminated with an eNose. An eNose is cheap and noninvasive, and it yields results within minutes. We determined whether Aspergillus fumigatus colonization may also be detected with an eNose in cystic fibrosis (CF) patients. Exhaled breath samples of 27 CF patients were analyzed with a Cyranose 320. Culture of sputum samples defined the A. fumigatus colonization status. eNose data were classified using canonical discriminant analysis after principal component reduction. Our primary outcome was cross-validated accuracy, defined as the percentage of correctly classified subjects using the leave-one-out method. The P value was calculated by the generation of 100,000 random alternative classifications. Nine of the 27 subjects were colonized by A. fumigatus. In total, 3 subjects were misclassified, resulting in a cross-validated accuracy of the Cyranose detecting IA of 89% (P = 0.004; sensitivity, 78%; specificity, 94%). Receiver operating characteristic (ROC) curve analysis showed an area under the curve (AUC) of 0.89. The results indicate that A. fumigatus colonization leads to a distinctive breathprint in CF patients. The present proof-of-concept data merit external validation and monitoring studies.

Genetic variation in uncontrolled childhood asthma despite ICS treatment.

Genetic variation may partly explain asthma treatment response heterogeneity. We aimed to identify common and rare genetic variants associated with asthma that was not well controlled despite inhaled corticosteroid (ICS) treatment. Data of 110 children was collected in the Children Asthma Therapy Optimal trial. Associations of genetic variation with measures of lung function (FEV1%pred), airway hyperresponsiveness (AHR) to methacholine (Mch PD20) and treatment response outcomes were analyzed using the exome chip. The 17q12-21 locus (containing ORMDL3 and GSMDB) previously associated with childhood asthma was investigated separately. Single-nucleotide polymorphisms (SNPs) in the 17q12-21 locus were found nominally associated with the outcomes. The strongest association in this region was found for rs72821893 in KRT25 with FEV1%pred (P=3.75*10(-5)), Mch PD20 (P=0.00095) and Mch PD20-based treatment outcome (P=0.006). No novel single SNPs or burden tests were significantly associated with the outcomes. The 17q12-21 region was associated with FEV1%pred and AHR, and additionally with ICS treatment response.

Bradykinin B2 receptor expression in the bronchial mucosa of allergic asthmatics: the role of NF-kB.

BACKGROUND: Bradykinin (BK) mediates acute allergic asthma and airway remodelling. Nuclear factor-kappa B (NF-kB) is potentially involved in BK B2 receptor (B2R) regulation. OBJECTIVE: In this observational cross-sectional study, B2R and NF-kB expression was evaluated in bronchial biopsies from mild asthmatics (after diluent/allergen challenge) and healthy controls, examining the role of NF-kB in B2R expression in primary human fibroblasts from normal and asthmatic subjects (HNBFb and HABFb). METHODS: B2R and NF-kB (total and nuclear) expression was analysed by immunohistochemistry in biopsies from 10 mild intermittent asthmatics (48 h after diluent/allergen challenge) and 10 controls undergoing bronchoscopy. B2R co-localization in 5B5(+) and αSMA(+) mesenchymal cells was studied by immunofluorescence/confocal microscopy, and B2R expression in HABFb/HNBFb incubated with interleukin (IL)-4/IL-13 with/without BK, and after NF-kB inhibitor, by Western blotting. RESULTS: Bronchial mucosa B2R and nuclear NF-kB expression was higher in asthmatics after diluent (B2R only) and allergen challenge than in controls (P < 0.05), while B2R and NF-kB (total and nuclear) increased after allergen compared with after diluent (P < 0.05). Allergen exposure increased B2R expression in 5B5(+) and αSMA(+) cells. Constitutive B2R protein expression was higher in HABFb than in HNBFb (P < 0.05) and increased in both cell types after IL-13 or IL-4/IL-13 and BK treatment. This increase was suppressed by a NF-kB inhibitor (P < 0.05). CONCLUSIONS & CLINICAL RELEVANCE: Bronchial B2R expression is constitutively elevated in allergic asthma and is further increased after allergen exposure together with NF-kB expression. NF-kB inhibitor blocked IL-4/IL-13-induced increase in B2R expression in cultured fibroblasts, suggesting a role as potential anti-asthma drug.

Loss of asthma control and activation of coagulation and fibrinolysis.

BACKGROUND: Epidemiologic studies have shown that patients with severe asthma have increased risk of pulmonary embolism, in particular patients with frequent asthma exacerbations. Therefore, we hypothesized that asthma exacerbations are associated with increased haemostatic activity. OBJECTIVE: To investigate whether induced loss of asthma control is associated with changes in coagulation and fibrinolytic parameters in peripheral blood. METHODS: We performed a prospective, inhaled steroid withdrawal study in 23 patients with moderate to moderately severe asthma, consisting of a baseline visit and a visit after loss of asthma control. During the visits, we measured asthma control questionnaire (ACQ), atopy, lung function, inflammatory markers (eosinophils and neutrophils), and haemostatic parameters in plasma. RESULTS: Complete cessation of inhaled corticosteroids led to a loss of asthma control in 22 of 23 patients. We found increased asthma symptoms (ACQ 0.9 vs. 2.9, P < 0.01), significantly reduced lung function (forced expiratory volume in 1 s (FEV1) 3.51L vs. 3.13L, P < 0.01) and increased levels of eosinophils in plasma (0.26 × 10(E9)/L vs. 0.16 × 10(E9)/L, P = 0.03) in patients after loss of asthma control. However, we observed no significant changes in the coagulation and fibrinolysis parameters. CONCLUSION: Loss of asthma control after cessation of inhaled corticosteroids does not lead to increased haemostatic activation in patients with moderate to moderately severe asthma. This suggests that more severe inflammation or additional risk factors are required for activation of coagulation or reduction of fibrinolysis in asthma.

How to achieve safe, high-quality clinical studies with non-Medicinal Investigational Products? A practical guideline by using intra-bronchial carbon nanoparticles as case study.

BACKGROUND: Clinical studies investigating medicinal products need to comply with laws concerning good clinical practice (GCP) and good manufacturing practice (GMP) to guarantee the quality and safety of the product, to protect the health of the participating individual and to assure proper performance of the study. However, there are no specific regulations or guidelines for non-Medicinal Investigational Products (non-MIPs) such as allergens, enriched food supplements, and air pollution components. As a consequence, investigators will avoid clinical research and prefer preclinical models or in vitro testing for e.g. toxicology studies. THE AIM OF THIS ARTICLE IS TO: 1) briefly review the current guidelines and regulations for Investigational Medicinal Products; 2) present a standardised approach to ensure the quality and safety of non-MIPs in human in vivo research; and 3) discuss some lessons we have learned. METHODS AND RESULTS: We propose a practical line of approach to compose a clarifying product dossier (PD), comprising the description of the production process, the analysis of the raw and final product, toxicological studies, and a thorough risk-benefit-analysis. This is illustrated by an example from a human in vivo research model to study exposure to air pollutants, by challenging volunteers with a suspension of carbon nanoparticles (the component of ink cartridges for laser printers). CONCLUSION: With this novel risk-based approach, the members of competent authorities are provided with standardised information on the quality of the product in relation to the safety of the participants, and the scientific goal of the study.

Relationship between atrial septal defects and asthma-like dyspnoea: the impact of transcatheter closure.

BACKGROUND: Patients with atrial septal defects (ASD) are often misdiagnosed as asthma patients and accordingly receive erroneous bronchodilator treatment. In order to characterise their symptoms of dyspnoea to explain this clinical observation, we investigated the prevalence of asthma-like symptoms in patients with secundum ASD who then underwent successful percutaneous closure. METHODS: A total of 80 ASD patients (74 % female, mean age 46.7 ± 16.8 years, median follow-up 3.0 [2.0-5.0] years) retrospectively completed dyspnoea questionnaires determining the presence and extent of cough, wheezing, chest tightness, effort dyspnoea and bronchodilator use on a 7-point scale (0 = none, 6 = maximum) before and after ASD closure. The Mini Asthma Quality of Life (Mini-AQLQ) and Asthma Control Questionnaire with bronchodilator use (ACQ6) were administered. RESULTS: A total of 48 (60 %) patients reported cough, 27 (34 %) wheezing, 26 (33 %) chest tightness and 62 (78 %) effort dyspnoea. Symptom resolution or reduction was found in 64 (80 %) patients after ASD closure. Asthma symptom scores decreased significantly on the Mini-AQLQ and ACQ6 (both p < 0.001). The number of patients using bronchodilators decreased from 16 (20 %) to 8 (10 %) patients after ASD closure (p = 0.039) with less frequent use of bronchodilators (p = 0.015). CONCLUSIONS: A high prevalence of asthma-like symptoms and bronchodilator use is present in ASD patients, which exceeds the low prevalence of bronchial asthma in this study population. Future prospective research is required to confirm this phenomenon. The presence of an ASD should be considered in the differential diagnosis of patients with asthma-like symptoms, after which significant symptom relief can be achieved by ASD closure.

DNA hypermethylation analysis in sputum for the diagnosis of lung cancer: training validation set approach.

BACKGROUND: Lung cancer has the highest mortality of all cancers. The aim of this study was to examine DNA hypermethylation in sputum and validate its diagnostic accuracy for lung cancer. METHODS: DNA hypermethylation of RASSF1A, APC, cytoglobin, 3OST2, PRDM14, FAM19A4 and PHACTR3 was analysed in sputum samples from symptomatic lung cancer patients and controls (learning set: 73 cases, 86 controls; validation set: 159 cases, 154 controls) by quantitative methylation-specific PCR. Three statistical models were used: (i) cutoff based on Youden's J index, (ii) cutoff based on fixed specificity per marker of 96% and (iii) risk classification of post-test probabilities. RESULTS: In the learning set, approach (i) showed that RASSF1A was best able to distinguish cases from controls (sensitivity 42.5%, specificity 96.5%). RASSF1A, 3OST2 and PRDM14 combined demonstrated a sensitivity of 82.2% with a specificity of 66.3%. Approach (ii) yielded a combination rule of RASSF1A, 3OST2 and PHACTR3 (sensitivity 67.1%, specificity 89.5%). The risk model (approach iii) distributed the cases over all risk categories. All methods displayed similar and consistent results in the validation set. CONCLUSIONS: Our findings underscore the impact of DNA methylation markers in symptomatic lung cancer diagnosis. RASSF1A is validated as diagnostic marker in lung cancer.

External validation of blood eosinophils, FE(NO) and serum periostin as surrogates for sputum eosinophils in asthma.

BACKGROUND: Monitoring sputum eosinophils in asthma predicts exacerbations and improves management of asthma. Thus far, blood eosinophils and FE(NO) show contradictory results in predicting eosinophilic airway inflammation. More recently, serum periostin was proposed as a novel biomarker for eosinophilic inflammation. OBJECTIVES: Quantifying the mutual relationships of blood eosinophils, FE(NO), and serum periostin with sputum eosinophils by external validation in two independent cohorts across various severities of asthma. METHODS: The first cohort consisted of 110 patients with mild to moderate asthma (external validation cohort). The replication cohort consisted of 37 patients with moderate to severe asthma. Both cohorts were evaluated cross-sectionally. Sputum was induced for the assessment of eosinophils. In parallel, blood eosinophil counts, serum periostin concentrations and FENO were assessed. The diagnostic accuracy of these markers to identify eosinophilic asthma (sputum eosinophils ≥3%) was calculated using receiver operating characteristics area under the curve (ROC AUC). RESULTS: In the external validation cohort, ROC AUC for blood eosinophils was 89% (p<0.001) and for FE(NO) level 78% (p<0.001) to detect sputum eosinophilia ≥3%. Serum periostin was not able to distinguish eosinophilic from non-eosinophilic airway inflammation (ROC AUC=55%, p=0.44). When combining these three variables, no improvement was seen. The diagnostic value of blood eosinophils was confirmed in the replication cohort (ROC AUC 85%, p<0.001). CONCLUSIONS: In patients with mild to moderate asthma, as well as patients with more severe asthma, blood eosinophils had the highest accuracy in the identification of sputum eosinophilia in asthma. The use of blood eosinophils can facilitate individualised treatment and management of asthma. TRIAL REGISTRATION: NTR1846 and NTR2364.

Regulation of YKL-40 expression by corticosteroids: effect on pro-inflammatory macrophages in vitro and its modulation in COPD in vivo.

BACKGROUND: Macrophages constitute a heterogeneous cell population with pro- (MΦ1) and anti-inflammatory (MΦ2) cells. The soluble chitinase-like-protein YKL-40 is expressed in macrophages and various other cell types, and has been linked to a variety of inflammatory diseases, including COPD. Dexamethasone strongly reduces YKL-40 expression in peripheral blood mononuclear cells (PBMC) in vitro. We hypothesized that: a) YKL-40 is differentially expressed by MΦ1 and MΦ2, b) is decreased by corticosteroids and c) that long-term treatment with inhaled corticosteroids (ICS) affects YKL-40 levels in serum and sputum of COPD patients. METHODS: Monocytes of healthy subjects were cultured in vitro for 7 days with either GM-CSF or M-CSF (for MΦ1 and MΦ2, respectively) and stimulated for 24 h with LPS, TNFα, or oncostatin M (OSM). MΦ1 and MΦ2 differentiation was assessed by measuring secretion of IL-12p40 and IL-10, respectively. YKL-40 expression in macrophages was measured by quantitative RT-PCR (qPCR) and ELISA; serum and sputum YKL-40 levels were analyzed by ELISA. RESULTS: Pro-inflammatory MΦ1 cells secreted significantly more YKL-40 than MΦ2, which was independent of stimulation with LPS, TNFα or OSM (p < 0.001) and confirmed by qPCR. Dexamethasone dose-dependently and significantly inhibited YKL-40 protein and mRNA levels in MΦ1. Serum YKL-40 levels of COPD patients were significantly higher than sputum YKL-40 levels but were not significantly changed by ICS treatment. CONCLUSIONS: YKL-40 secretion from MΦ1 cells is higher than from MΦ2 cells and is unaffected by further stimulation with pro-inflammatory agents. Furthermore, YKL-40 release from cultured monocyte-derived macrophages is inhibited by dexamethasone especially in MΦ1, but ICS treatment did not change YKL-40 serum and sputum levels in COPD. These results indicate that YKL-40 expression could be used as a marker for MΦ1 macrophages in vitro, but not for monitoring the effect of ICS in COPD. TRIAL REGISTRATION: ClinicalTrials.gov, registration number: NCT00158847.

Lipopolysaccharide amplifies eosinophilic inflammation after segmental challenge with house dust mite in asthmatics.

BACKGROUND: House dust contains mite allergens as well as bacterial products such as lipopolysaccharide (LPS). Asthma exacerbations are associated with the level of exposure to allergens and LPS. LPS can potentiate allergen effects in steroid-naïve patients. Long-acting ß2-agonists (LABA) were shown to inhibit LPS-induced bronchial inflammation in healthy volunteers. The aim of this study was to assess the effect of LPS on the allergen-induced eosinophilic inflammation [primary endpoints: eosinophil counts and eosinophil cationic protein (ECP)] induced by bronchial instillation of house dust mite (HDM) in patients with asthma on maintenance treatment with inhaled corticosteroids (ICS). METHODS: Thirty-two nonsmoking asthmatics with HDM allergy were treated with run-in medication (fluticasone propionate 100 µg bid) during 2 weeks before the study day. All patients underwent bronchial challenge with HDM, and half of them were randomized to receive additional LPS. Both groups were randomized to receive pretreatment with a single inhalation of 100 µg salmeterol 30 min before bronchial segmental challenge. Six hours later, bronchoalveolar lavage (BAL) was collected for leukocyte cell count, differentials, and cellular activation markers. RESULTS: Challenge with HDM/LPS induced a significant increase in eosinophil cationic protein (P = 0.036) and a trend toward an increase in BALF eosinophils as compared to HDM challenge. CONCLUSION: Lipopolysaccharide promotes eosinophilic airway inflammation in patients with asthma despite being on maintenance treatment with ICS.

Changes in microbiota during experimental human Rhinovirus infection.

BACKGROUND: Human Rhinovirus (HRV) is responsible for the majority of common colds and is frequently accompanied by secondary bacterial infections through poorly understood mechanisms. We investigated the effects of experimental human HRV serotype 16 infection on the upper respiratory tract microbiota. METHODS: Six healthy volunteers were infected with HRV16. We performed 16S ribosomal RNA-targeted pyrosequencing on throat swabs taken prior, during and after infection. We compared overall community diversity, phylogenetic structure of the ecosystem and relative abundances of the different bacteria between time points. RESULTS: During acute infection strong trends towards increases in the relative abundances of Haemophilus parainfluenzae and Neisseria subflava were observed, as well as a weaker trend towards increases of Staphylococcus aureus. No major differences were observed between day-1 and day 60, whereas differences between subjects were very high. CONCLUSIONS: HRV16 infection is associated with the increase of three genera known to be associated with secondary infections following HRV infections. The observed changes of upper respiratory tract microbiota could help explain why HRV infection predisposes to bacterial otitis media, sinusitis and pneumonia.

Frequent exacerbators--a distinct phenotype of severe asthma.

BACKGROUND: Exacerbations represent a major source of morbidity and mortality in asthma and are a prominent feature of poorly controlled, difficult-to-treat disease. OBJECTIVE: The goal of our study was to provide a detailed characterization of the frequent exacerbator phenotype and to identify risk factors associated with frequent and seasonal exacerbations. METHODS: Ninety-three severe asthmatics (SA) and 76 mild-to-moderate patients (MA) were screened and prospectively followed up for 1 year (NCT00555607). Medical history, baseline clinical data and biomarkers were used to assess risk factors for frequent exacerbations. RESULTS: During the study, 104 exacerbations were recorded in the SA group and 18 in the MA. Frequent exacerbators were characterized by use of higher doses of inhaled (1700 vs. 800 µg) and oral (6.7 vs. 1.7 mg) glucocorticosteroids, worse asthma control (ACQ score 2.3 vs. 1.4), lower quality of life (SGRQ score 48.5 vs. 33.3), higher sputum eosinophils (25.7% vs. 8.2%) and a more rapid decline in FEV1 /FVC ratio (-0.07 vs. -0.01 ΔFEV1 /FVC, frequent vs. non-frequent, respectively, P < 0.05). Exhaled NO > 45 p.p.b. and a history of smoking were associated with an increased risk of frequent exacerbations (odds ratios: 4.32 and 2.90 respectively). CONCLUSION AND CLINICAL RELEVANCE: We were able to distinguish and characterize a subphenotype of asthma subjects--frequent exacerbators--who are significantly more prone to exacerbations. Patients with FeNO > 45 p.p.b. and a history of smoking are at increased risk of frequent exacerbations and require careful monitoring in clinical practice.

Gene expression profiling of laser microdissected airway smooth muscle tissue in asthma and atopy.

BACKGROUND: Asthma and atopy share common characteristics including type 2 helper-T-cell-mediated inflammation. However, only asthma is associated with variable airways obstruction. The complex cellular and molecular pathways distinguishing asthma and atopy can now be captured by transcriptomic analysis (RNA-Seq). We hypothesized that the transcriptomic profile of airway smooth muscle (ASM) distinguishes atopic asthma from atopic healthy controls. First, we compared the ASM transcriptomic profiles of endobronchial biopsies between glucocorticoid-free, atopic asthma patients, and atopic and nonatopic healthy controls. Second, we investigated the association between ASM transcriptomic profiles and airway function. METHODS: Twelve asthma patients and 12 control subjects (six atopic, six nonatopic) underwent bronchoscopy. RNA of laser-dissected ASM from 96 bronchial biopsy specimens was sequenced with Roche GS FLX. Gene networks were identified using Ingenuity Pathway Analysis. RNA-Seq reads were assumed to follow a negative binomial distribution. With the current sample size, the estimated false discovery rate was approximately 1%. RESULTS: One hundred and seventy four ASM genes were differentially expressed between asthma patients and atopic controls, 108 between asthma patients and nonatopic controls, and 135 between atopic and nonatopic controls. A set of eight genes discriminated asthma patients from nonasthmatic controls, irrespective of atopy. Four of these genes (RPTOR, VANGL1, FAM129A, LEPREL1) were associated with airway hyper-responsiveness (P < 0.05). CONCLUSION: Airway smooth muscle from asthma patients can be distinguished from that of atopic and nonatopic control subjects by a specific gene expression profile, which is associated with airway hyper-responsiveness.

Stability of phenotypes defined by physiological variables and biomarkers in adults with asthma.

BACKGROUND: Although asthma is characterized by variable airways obstruction, most studies of asthma phenotypes are cross-sectional. The stability of phenotypes defined either by biomarkers or by physiological variables was assessed by repeated measures over 1 year in the Pan-European BIOAIR cohort of adult asthmatics. METHODS: A total of 169 patients, 93 with severe asthma (SA) and 76 with mild-to-moderate asthma (MA), were examined at six or more visits during 1 year. Asthma phenotype clusters were defined by physiological variables (lung function, reversibility and age of onset of the disease) or by biomarkers (eosinophils and neutrophils in induced sputum). RESULTS: After 1 year of follow-up, the allocation to clusters was changed in 23.6% of all asthma patients when defined by physiological phenotypes and, remarkably, in 42.3% of the patients when stratified according to sputum cellularity (P = 0.034). In the SA cohort, 30% and 48.6% of the patients changed allocation according to physiological and biomarker clustering, respectively. Variability of phenotypes was not influenced by change in oral or inhaled corticosteroid dose, nor by the number of exacerbations. Lower stability of single and repeated measure was found for all evaluated biomarkers (eosinophils, neutrophils and FeNO) in contrast to good stability of physiological variables (FEV1 ), quality of life and asthma control. CONCLUSION: Phenotypes determined by biomarkers are less stable than those defined by physiological variables, especially in severe asthmatics. The data also imply that definition of asthma phenotypes is improved by repeated measures to account for fluctuations in lung function, biomarkers and asthma control.