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Rationale: Severe asthma and chronic obstructive pulmonary disease (COPD) share common pathophysiological traits such as relative corticosteroid insensitivity. We recently published three transcriptome-associated clusters (TACs) using hierarchical analysis of the sputum transcriptome in asthmatics from the Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) cohort comprising one Th2-high inflammatory signature (TAC1) and two Th2-low signatures (TAC2 and TAC3)., Objective: We examined whether gene expression signatures obtained in asthma can be used to identify the subgroup of patients with COPD with steroid sensitivity., Methods: Using gene set variation analysis, we examined the distribution and enrichment scores (ES) of the 3 TACs in the transcriptome of bronchial biopsies from 46 patients who participated in the Groningen Leiden Universities Corticosteroids in Obstructive Lung Disease COPD study that received 30 months of treatment with inhaled corticosteroids (ICS) with and without an added long-acting β-agonist (LABA). The identified signatures were then associated with longitudinal clinical variables after treatment. Differential gene expression and cellular convolution were used to define key regulated genes and cell types., Measurements and Main Results: Bronchial biopsies in patients with COPD at baseline showed a wide range of expression of the 3 TAC signatures. After ICS±LABA treatment, the ES of TAC1 was significantly reduced at 30 months, but those of TAC2 and TAC3 were unaffected. A corticosteroid-sensitive TAC1 signature was developed from the TAC1 ICS-responsive genes. This signature consisted of mast cell-specific genes identified by single-cell RNA-sequencing and positively correlated with bronchial biopsy mast cell numbers following ICS±LABA. Baseline levels of gene transcription correlated with the change in RV/TLC %predicted following 30-month ICS±LABA., Conclusion: Sputum-derived transcriptomic signatures from an asthma cohort can be recapitulated in bronchial biopsies of patients with COPD and identified a signature of airway mast cells as a predictor of corticosteroid responsiveness., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Chronic exposure to environmental pollutants is a major contributor to the development and progression of obstructive airway diseases, including asthma and COPD. Understanding the mechanisms underlying the development of obstructive lung diseases upon exposure to inhaled pollutants will lead to novel insights into the pathogenesis, prevention and treatment of these diseases. The respiratory epithelial lining forms a robust physicochemical barrier protecting the body from inhaled toxic particles and pathogens. Inhalation of airborne particles and gases may impair airway epithelial barrier function and subsequently lead to exaggerated inflammatory responses and airway remodelling, which are key features of asthma and COPD. In addition, air pollutant-induced airway epithelial barrier dysfunction may increase susceptibility to respiratory infections, thereby increasing the risk of exacerbations and thus triggering further inflammation. In this review, we discuss the molecular and immunological mechanisms involved in physical barrier disruption induced by major airborne pollutants and outline their implications in the pathogenesis of asthma and COPD. We further discuss the link between these pollutants and changes in the lung microbiome as a potential factor for aggravating airway diseases. Understanding these mechanisms may lead to identification of novel targets for therapeutic intervention to restore airway epithelial integrity in asthma and COPD., Competing Interests: Conflict of interest: M. Aghapour reports personal fees from Kommission zur Förderung des wissenschaftlichen Nachwuchses, Medical Faculty, Otto-von-Guericke University, Magdeburg, non-financial support from German Research Foundation, funded by grant 361210922/RTG 2408, outside the submitted work. Conflict of interest: N.D. Ubags has nothing to disclose. Conflict of interest: D. Bruder reports grants from German Research Foundation, grant number 361210922/RTG 2408, outside the submitted work. Conflict of interest: P.S. Hiemstra reports grants from Boehringer Ingelheim, outside the submitted work. Conflict of interest: V. Sidhaye has nothing to disclose. Conflict of interest: F. Rezaee has nothing to disclose. Conflict of interest: I.H. Heijink has nothing to disclose., (Copyright ©The authors 2022.)

Vitamin D plays an active role in the modulation of innate and adaptive immune responses as well as in the protection against respiratory pathogens. Evidence for this immunomodulatory and protective role is derived from observational studies showing an association between vitamin D deficiency, chronic airway diseases and respiratory infections, and is supported by a range of experimental studies using cell culture and animal models. Furthermore, recent intervention studies have now shown that vitamin D supplementation reduces exacerbation rates in vitamin D-deficient patients with chronic obstructive pulmonary disease (COPD) or asthma and decreases the incidence of acute respiratory tract infections. The active vitamin D metabolite, 1,25-dihydroxy-vitamin D (1,25(OH) 2 D), is known to contribute to the integrity of the mucosal barrier, promote killing of pathogens (via the induction of antimicrobial peptides), and to modulate inflammation and immune responses. These mechanisms may partly explain its protective role against infections and exacerbations in COPD and asthma patients. The respiratory mucosa is an important site of local 1,25(OH) 2 D synthesis, degradation and signaling, a process that can be affected by exposure to inflammatory mediators. As a consequence, mucosal inflammation and other disease-associated factors, as observed in e.g., COPD and asthma, may modulate the protective actions of 1,25(OH) 2 D. Here, we discuss the potential consequences of various disease-associated processes such as inflammation and exposure to pathogens and inhaled toxicants on vitamin D metabolism and local responses to 1,25(OH) 2 D in both immune- and epithelial cells. We furthermore discuss potential consequences of disturbed local levels of 25(OH)D and 1,25(OH) 2 D for chronic lung diseases. Additional insight into the relationship between disease-associated mechanisms and local effects of 1,25(OH) 2 D is expected to contribute to the design of future strategies aimed at improving local levels of 1,25(OH) 2 D and signaling in chronic inflammatory lung diseases., (Copyright © 2020 Schrumpf, van der Does and Hiemstra.)

Objective: To determine the short-term and long-term effects of a high intensity pulmonary rehabilitation programme on asthma control, body composition, lung function and exercise capacity in obese asthma patients., Methods: Patients with obesity (body mass index (BMI)≥30 kg·m -2 ) and suboptimal controlled asthma (Asthma Control Questionnaire (ACQ)≥0.75) were randomly assigned to a 3-month pulmonary rehabilitation programme (PR only), pulmonary rehabilitation programme with the use of an internet based self-management support programme (PR+SMS) or usual care. The pulmonary rehabilitation programme included high-intensity interval training, nutritional intervention and psychological group sessions. Patients in the usual care group were advised to lose weight and to exercise. The primary outcome was the difference of change of ACQ between PR only and PR+SMS after 3 months. Total follow-up was 12 months., Results: 34 patients were included in the study (14 PR only, nine PR+SMS, 11 control). Compared with patients in usual care, patients in the PR only group had a significant reduction in BMI and significant improvements in asthma control, exercise capacity and aerobic capacity after 3 months. These improvements persisted during 12 months of follow-up. No difference in ACQ between PR+SMS and PR only groups was observed. However, users of the SMS programme had a significantly lower BMI after 12 months compared with subjects in the PR only group., Conclusion: A high-intensity pulmonary rehabilitation programme provides sustained improvements in asthma control, body composition and exercise capacity in obese asthmatics that are not optimally controlled and, therefore, should be considered in the treatment of these patients., Competing Interests: Conflict of interest: Y. Türk reports grants from GSK, TEVA, Novartis and Chiesi, during the conduct of the study. Conflict of interest: W. Theel has nothing to disclose Conflict of interest: A. van Huisstede has nothing to disclose. Conflict of interest: G-J.M. van de Geijn reports personal fees for lectures and non-financial support (travel and accommodation reimbursement, reagents and equipment for research) from Beckman Coulter, outside the submitted work. Conflict of interest: E. Birnie has nothing to disclose. Conflict of interest: P.S. Hiemstra has nothing to disclose. Conflict of interest: J.K. Sont has nothing to disclose. Conflict of interest: C. Taube has nothing to disclose. Conflict of interest: G-J. Braunstahl reports grants from GSK, Teva, Novartis and Chiesi, during the conduct of the study; personal fees from ALK Abello, GSK, AstraZeneca, Sanofi, Chiesi and Novartis, outside the submitted work., (Copyright ©ERS 2020.)

With asthma affecting over 300 million individuals world-wide and estimated to affect 400 million by 2025, developing effective, long-lasting therapeutics is essential. Allergic asthma, where Th2-type immunity plays a central role, represents 90% of child and 50% of adult asthma cases. Research based largely on animal models of allergic disease have led to the generation of a novel class of drugs, so-called biologicals, that target essential components of Th2-type inflammation. Although highly efficient in subclasses of patients, these biologicals and other existing medication only target the symptomatic stage of asthma and when therapy is ceased, a flare-up of the disease is often observed. Therefore, it is suggested to target earlier stages in the inflammatory cascade underlying allergic airway inflammation and to focus on changing and redirecting the initiation of type 2 inflammatory responses against allergens and certain viral agents. This focus on upstream aspects of innate immunity that drive development of Th2-type immunity is expected to have longer-lasting and disease-modifying effects, and may potentially lead to a cure for asthma. This review highlights the current understanding of the contribution of local innate immune elements in the development and maintenance of inflammatory airway responses and discusses available leads for successful targeting of those pathways for future therapeutics.

Background: Whether the clinical or pathophysiologic significance of the "treatable trait" high blood eosinophil count in COPD is the same as for asthma remains controversial. We sought to determine the relationship between the blood eosinophil count, clinical characteristics and gene expression from bronchial brushings in COPD and asthma., Methods: Subjects were recruited into a COPD (emphysema versus airway disease [EvA]) or asthma cohort (Unbiased BIOmarkers in PREDiction of respiratory disease outcomes, U-BIOPRED). We determined gene expression using RNAseq in EvA (n = 283) and Affymetrix microarrays in U-BIOPRED (n = 85). We ran linear regression analysis of the bronchial brushings transcriptional signal versus blood eosinophil counts as well as differential expression using a blood eosinophil > 200 cells/μL as a cut-off. The false discovery rate was controlled at 1% (with continuous values) and 5% (with dichotomized values)., Results: There were no differences in age, gender, lung function, exercise capacity and quantitative computed tomography between eosinophilic versus noneosinophilic COPD cases. Total serum IgE was increased in eosinophilic asthma and COPD. In EvA, there were 12 genes with a statistically significant positive association with the linear blood eosinophil count, whereas in U-BIOPRED, 1197 genes showed significant associations (266 positive and 931 negative). The transcriptome showed little overlap between genes and pathways associated with blood eosinophil counts in asthma versus COPD. Only CST1 was common to eosinophilic asthma and COPD and was replicated in independent cohorts., Conclusion: Despite shared "treatable traits" between asthma and COPD, the molecular mechanisms underlying these clinical entities are predominately different., (© 2019 The Authors. Allergy published by John Wiley & Sons Ltd.)

Background: Exacerbation in asthma is associated with decreased expression of specific host defence peptides (HDPs) in the lungs. We examined the effects of a synthetic derivative of HDP, innate defence regulator (IDR) peptide IDR-1002, in house dust mite (HDM)-challenged murine model of asthma, in interleukin (IL)-33-challenged mice and in human primary bronchial epithelial cells (PBECs)., Methods: IDR-1002 (6 mg/kg per mouse) was administered (subcutaneously) in HDM-challenged and/or IL-33-challenged BALB/c mice. Lung function analysis was performed with increasing dose of methacholine by flexi Vent small animal ventilator, cell differentials in bronchoalveolar lavage performed by modified Wright-Giemsa staining, and cytokines monitored by MesoScale Discovery assay and ELISA. PBECs stimulated with tumour necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ), with or without IDR-1002, were analysed by western blots., Results: IDR-1002 blunted HDM challenge-induced airway hyper-responsiveness (AHR), and lung leucocyte accumulation including that of eosinophils and neutrophils, in HDM-challenged mice. Concomitantly, IDR-1002 suppressed HDM-induced IL-33 in the lungs. IFN-γ/TNF-α-induced IL-33 production was abrogated by IDR-1002 in PBECs. Administration of IL-33 in HDM-challenged mice, or challenge with IL-33 alone, mitigated the ability of IDR-1002 to control leucocyte accumulation in the lungs, suggesting that the suppression of IL-33 is essential for the anti-inflammatory activity of IDR-1002. In contrast, the peptide significantly reduced either HDM, IL-33 or HDM+IL-33 co-challenge-induced AHR in vivo., Conclusion: This study demonstrates that an immunomodulatory IDR peptide controls the pathophysiology of asthma in a murine model. As IL-33 is implicated in steroid-refractory severe asthma, our findings on the effects of IDR-1002 may contribute to the development of novel therapies for steroid-refractory severe asthma., Competing Interests: Competing interests: NM and HP are inventors on a patent application filed with Canadian Intellectual Property Office (WO2015077888) that incorporates aspects of the findings described in this manuscript. Other authors have no competing interest to declare., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Epidemiological and experimental studies have shown that exposure to the gastric bacterium Helicobacter pylori , especially in early life, prevents the development of asthma. Recent mouse studies have shown that this protective effect does not require live bacteria and that treatment with an extract of H. pylori in neonates prevents the development of airway inflammation and goblet cell metaplasia. In the current study, the effect of administration of an extract of H. pylori was assessed in a therapeutic study design with application of the extract just prior to allergen challenge. C57BL/6 mice were sensitized and challenged with OVA or house dust mite. Treatment with H. pylori extract just prior to the challenge significantly reduced airway inflammation, as assessed in bronchoalveolar lavage fluid and lung tissue, and reduced airway remodeling, as assessed by goblet cell quantification. These effects were apparent in the OVA model and in the house dust mite model. Injection of H. pylori extract reduced the processing of allergen by dendritic cells in the lungs and mediastinal lymph node. Bone marrow-derived dendritic cells exposed to H. pylori extract were affected with regard to their ability to process Ag. These data show that application of H. pylori extract after sensitization effectively inhibits allergic airway disease., (Copyright © 2018 by The American Association of Immunologists, Inc.)

Background: Obesity is a risk factor for the development of asthma. In patients with obesity the diagnosis of asthma is often based on symptoms, but without objective measurements. Nevertheless, obesity-associated asthma is recognized as a distinct asthma phenotype. Therefore, this study explores lung function and symptoms in asthma patients with and without obesity., Methods: The Netherlands Epidemiology of Obesity (NEO) study is a population-based cohort study with 6671 participants (aged 45-65 years) of whom 472 had asthma. Of this latter group, linear regression analysis was used to examine differences in lung function and symptoms between asthma patients with (n = 248) and without obesity (n = 224), and between asthma patients with and without increased Fe NO . Analyses were adjusted for confounders., Results: Asthma patients with obesity had lower predicted FEV 1 and FVC values than patients without obesity [adjusted mean difference (MD) -3.3% predicted, 95% CI -6.5, -0.2; adjusted MD -5.0% predicted, 95% CI -7.8, -2.1]. The prevalence of symptoms was higher in patients with obesity. Asthma patients with obesity and with increased Fe NO had lower FEV 1 and FEV 1 /FVC values compared with those with low Fe NO (adjusted MD -6.9% predicted, 95% CI -11.7, -2.0; -2.4%, 95% CI -4.6, -0.2)., Conclusion: Asthma patients with obesity had lower FEV 1 and FVC values than patients without obesity. This suggests that patients with obesity have restrictive lung function changes, rather than obstructive changes. Asthma patients with obesity and increased Fe NO showed more obstructive changes. Fe NO might help to identify patients with eosinophilic inflammation-driven asthma, whereas patients with low Fe NO might have an obesity-associated asthma phenotype in which symptoms are partly caused by the obesity.

This pilot study was performed to investigate the feasibility of pre-surgical pulmonary rehabilitation (PR) in morbidly obese patients with uncontrolled asthma, undergoing bariatric surgery. Four morbidly obese female patients with asthma participated in a 12-week PR program (exercise, diet, and psychological intervention) before undergoing bariatric surgery, and the outcomes were compared to a matched group of seven female controls (bariatric surgery only). In patients who participated in PR, asthma control and asthma quality of life improved dramatically after 3 months of PR. Besides, asthma control was better at the moment of surgery. The results of this pilot study show that PR is feasible in morbidly obese asthmatics and should be considered for a selected group of patients with uncontrolled asthma before undergoing bariatric surgery.

Asthma and chronic obstructive pulmonary disease (COPD) are considered as two distinct obstructive diseases. Both chronic diseases share a component of airway epithelial dysfunction. The airway epithelium is localized to deal with inhaled substances, and functions as a barrier preventing penetration of such substances into the body. In addition, the epithelium is involved in the regulation of both innate and adaptive immune responses following inhalation of particles, allergens and pathogens. Through triggering and inducing immune responses, airway epithelial cells contribute to the pathogenesis of both asthma and COPD. Various in vitro research models have been described to study airway epithelial cell dysfunction in asthma and COPD. However, various considerations and cautions have to be taken into account when designing such in vitro experiments. Epithelial features of asthma and COPD can be modelled by using a variety of disease-related invoking substances either alone or in combination, and by the use of primary cells isolated from patients. Differentiation is a hallmark of airway epithelial cells, and therefore models should include the ability of cells to differentiate, as can be achieved in air-liquid interface models. More recently developed in vitro models, including precision cut lung slices, lung-on-a-chip, organoids and human induced pluripotent stem cells derived cultures, provide novel state-of-the-art alternatives to the conventional in vitro models. Furthermore, advanced models in which cells are exposed to respiratory pathogens, aerosolized medications and inhaled toxic substances such as cigarette smoke and air pollution are increasingly used to model e.g. acute exacerbations. These exposure models are relevant to study how epithelial features of asthma and COPD are affected and provide a useful tool to study the effect of drugs used in treatment of asthma and COPD. These new developments are expected to contribute to a better understanding of the complex gene-environment interactions that contribute to development and progression of asthma and COPD., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

One of the major goals of asthma therapy is to maintain asthma control and prevent acute exacerbations. Long-acting bronchodilators are regularly used for the treatment of asthma patients and in clinical studies the anti-cholinergic tiotropium has recently been shown to reduce exacerbations in patients with asthma. So far it is unclear how tiotropium exerts this effect. For this purpose, we designed an allergen-driven rechallenge model of allergic airway inflammation in mice, to assess the effectiveness of tiotropium and the long-acting β-2 adrenoceptor agonist olodaterol on allergen-induced exacerbations of airway disease. Female C57BL/6J mice were sensitized intranasally (i.n.) with 1 μg of house dust mite (HDM) extract followed by a challenge regime (5 consecutive days 10 μg HDM extract i.n.) after one week. Mice were exposed to a secondary challenge five weeks after sensitization and were treated i.n. with different concentrations of tiotropium or olodaterol (1, 10 and 100 μg/kg) or a combination thereof (10 μg/kg each) prior to and during the secondary challenge period. Three days after the last challenge, bronchoalveolar lavage (BAL) fluid and lung tissue were collected for flow cytometry and histologic analysis, respectively. Secondary challenge with HDM extract strongly induced allergic airway disease reflected by inflammatory cell infiltration and goblet cell metaplasia. Treatment with tiotropium, but not with olodaterol reduced tissue inflammation and goblet cell metaplasia in a dose-dependent manner. The combination of tiotropium and olodaterol was more effective in significantly reducing tissue inflammation compared to tiotropium treatment alone, and also led to a decrease in BAL cell counts. These data suggest that in a model of relapsing allergic airway disease tiotropium directly prevents exacerbations by reducing inflammation and mucus production in the airways. In addition, the combination of tiotropium and olodaterol exerts synergistic effects., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Purpose: To compare the effects of an outpatient pulmonary rehabilitation (PR) program on exercise tolerance and asthma control in obese and nonobese patients with asthma., Methods: Nonobese (body mass index [BMI] <30 kg/m) and obese (BMI ≥ 30 kg/m) patients with asthma who participated in a local multidisciplinary 12-week PR program were analyzed retrospectively. Effects of PR were assessed by changes in 6-minute walking distance (6MWD) and Asthma Control Questionnaire (ACQ)., Results: A total of 138 asthma patients were included: 53 (38.4%) obese and 85 (61.6%) nonobese. At baseline, obese patients with asthma had a lower level of exercise tolerance reflected by a lower 6MWD (525 m vs 621 m; P < .001). After PR, the 6MWD improved significantly in both groups (≥50 m in nonobese vs ≥45 m in obese; P < .001 in both groups). The improvement in 6MWD was clinically relevant in 71% of the nonobese and 60% of the obese patients. These patients had lower 6MWD (P = .024), higher usage of long-acting β-agonist (P = .034) and oral corticosteroids (P = .033). Asthma control also improved in both groups (ΔACQ -0.3 in nonobese vs ΔACQ -0.4 in obese; P = .021 and P = .019, respectively). Clinically relevant improvement was achieved by 46.5% of nonobese and 51.9% of obese patients with asthma. The improvements between the groups were not statistically different., Conclusions: A standardized PR program is feasible in obese patients with asthma and they benefit as much as nonobese patients with asthma. However, there are still a large number of patients who show no clinically significant improvement. Patients with more severe asthma seem to benefit the most from PR.

Asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) seems an important clinical phenotype, but multiple definitions have been proposed. This study's objectives were to assess the effect of different ACOS definitions on prevalence, patient characteristics and exacerbations.5675 individuals aged 45-65 years, with 846 asthma/COPD patients, were included in the Netherlands Epidemiology of Obesity study between 2008 and 2012, and followed-up for a median of 1.8 years. ACOS was defined by recent consensus criteria and five other definitions, based on registry, questionnaires and lung function.Prevalence of ACOS in the asthma/COPD population ranged between 4.4% and 38.3%, depending on the definition used. Agreement between registry-based and self-reported ACOS was 0.04 and 0.41 when lung function (forced expiratory volume in 1 s (FEV 1 )/forced vital capacity (FVC) <0.7) was added. With registry or self-report defined ACOS, only 51% and 33% had FEV 1 /FVC <0.7. Patient characteristics were similar, but asthma duration was longer with self-reported compared with registry-based ACOS (mean difference 22 years (95% CI 12-33)). Exacerbation risk was highest with registry-based ACOS compared with asthma (adjusted incidence rate ratio 1.6 (95% CI 1.2-2.1)).This study adds important knowledge about agreement between ACOS definitions and their relation with exacerbations. Given the low agreement, differences in prevalence, patient characteristics and risk of exacerbations, consensus about ACOS definition in different care settings is urgently needed., Competing Interests: Conflict of interest: None declared., (Copyright ©ERS 2017.)

Background: The impact of airway hyperreactivity (AHR) on respiratory mortality and systemic inflammation among patients with chronic obstructive pulmonary disease (COPD) is largely unknown. We used data from 2 large studies to determine the relationship between AHR and FEV 1 decline, respiratory mortality, and systemic inflammation., Objectives: We sought to determine the relationship of AHR with FEV 1 decline, respiratory mortality, and systemic inflammatory burden in patients with COPD in the Lung Health Study (LHS) and the Groningen Leiden Universities Corticosteroids in Obstructive Lung Disease (GLUCOLD) study., Methods: The LHS enrolled current smokers with mild-to-moderate COPD (n = 5887), and the GLUCOLD study enrolled former and current smokers with moderate-to-severe COPD (n = 51). For the primary analysis, we defined AHR by a methacholine provocation concentration of 4 mg/mL or less, which led to a 20% reduction in FEV 1 (PC 20 )., Results: The primary outcomes were FEV 1 decline, respiratory mortality, and biomarkers of systemic inflammation. Approximately 24% of LHS participants had AHR. Compared with patients without AHR, patients with AHR had a 2-fold increased risk of respiratory mortality (hazard ratio, 2.38; 95% CI, 1.38-4.11; P = .002) and experienced an accelerated FEV 1 decline by 13.2 mL/y in the LHS (P = .007) and by 12.4 mL/y in the much smaller GLUCOLD study (P = .079). Patients with AHR had generally reduced burden of systemic inflammatory biomarkers than did those without AHR., Conclusions: AHR is common in patients with mild-to-moderate COPD, affecting 1 in 4 patients and identifies a distinct subset of patients who have increased risk of disease progression and mortality. AHR may represent a spectrum of the asthma-COPD overlap phenotype that urgently requires disease modification., (Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

While certain bacteria and respiratory viruses promote local inflammation and disease onset, a more diverse colonization of the different species in the (gut) microbiome may be linked to more regulatory responses and protection against asthma and allergies. These processes are also influenced in part by food intake, both targeting the composition of the gut microbiome and influencing the immune system via metabolites. Early life environmental microbial exposure also contributes to protection against asthma and allergy and is linked with an early activation of the innate immune system and the development of regulatory immune responses. Although greater mechanistic insight is needed, it is tempting to speculate that part of the environmental effect can be explained by modulation of the microbiome composition at mucosal surfaces, epithelial barrier function and/or local immunity. A review of the latest studies is provided., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Which inflammatory markers in the bronchial mucosa of asthma patients are associated with decline of lung function during 14 years of prospective follow-up?To address this question, 19 mild-to-moderate, atopic asthmatic patients underwent spirometry and bronchoscopy at baseline and after 14 years of follow-up (t=14). Baseline bronchial biopsies were analysed for reticular layer thickness, eosinophil cationic protein (EG2), mast cell tryptase (AA1), CD3, CD4 and CD8. Follow-up biopsies were stained for EG2, AA1, neutrophil elastase, CD3, CD4, CD8, CD20, granzyme B, CD68, DC-SIGN, Ki67 and mucins.Decline in forced expiratory volume in 1 s (FEV1) % predicted was highest in patients with high CD8 (p=0.01, both pre- and post-bronchodilator) or high CD4 counts at baseline (p=0.04 pre-bronchodilator, p=0.03 post-bronchodilator). Patients with high CD8, CD3 or granzyme B counts at t=14 also exhibited faster decline in FEV1 (p=0.00 CD8 pre-bronchodilator, p=0.04 CD8 post-bronchodilator, p=0.01 granzyme B pre-bronchodilator, and p<0.01 CD3 pre-bronchodilator).Long-term lung function decline in asthma is associated with elevation of bronchial CD8 and CD4 at baseline, and CD8, CD3 and granzyme B at follow-up. This suggests that high-risk groups can be identified on the basis of inflammatory phenotypes., (Copyright ©ERS 2016.)

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., (© 2015 John Wiley & Sons Ltd.)

The worldwide incidence and prevalence of asthma continues to increase. Asthma is now understood as an umbrella term for different phenotypes or endotypes, which arise through different pathophysiologic pathways. Understanding the many factors contributing to development of the disease is important for the identification of novel therapeutic targets for the treatment of certain asthma phenotypes. The hygiene hypothesis has been formulated to explain the increasing prevalence of allergic disease, including asthma. This hypothesis postulates that decreased exposure at a young age to certain infectious agents as a result of improved hygiene, increased antibiotic use and vaccination, and changes in lifestyle and dietary habits is associated with changes in the immune system, which predispose subjects to allergy. Many microbes, during their coevolution with human subjects, developed mechanisms to manipulate the human immune system and to increase their chances of survival. Improving models of asthma, as well as choosing adequate end points in clinical trials, will lead to a more complete understanding of the underlying mechanisms, thus providing an opportunity to devise primary and secondary interventions at the same time as identifying new molecular targets for treatment. This article reports the discussion and conclusion of a workshop under the auspices of the Netherlands Lung Foundation to extend our understanding of how modulation of the immune system by bacterial, parasitic, and viral infections might affect the development of asthma and to map out future lines of investigation., (Copyright © 2016 American Academy of Allergy, Asthma & Immunology. All rights reserved.)

Background: Allergy is often accompanied by infections and lower levels of antimicrobial peptides (AMPs). Vitamin D has been shown to increase expression of selected AMPs. In this study we investigated whether antimicrobial peptide levels in nasal secretions of allergic asthma patients are lower than in healthy controls, and whether administration of the active form of vitamin D (1,25(OH)2D3) affects these antimicrobial peptide levels., Methods: The levels of antimicrobial peptides in nasal secretions were compared between 19 allergic asthma patients and 23 healthy controls. The effect of seven days daily oral treatment with 2 μg 1,25(OH)2D3 on antimicrobial peptides in nasal secretions was assessed in a placebo-controlled cross-over clinical study., Results: Levels of neutrophil α-defensins (human neutrophil peptides 1-3; HNP1-3) and lipocalin 2 (LCN2; also known as NGAL) were significantly lower in asthmatics, but no differences in LL-37 and SLPI were detected. Treatment with a short-term 1,25(OH)2D3 caused a small increase in HNP1-3, but not when the asthma and control groups were analyzed separately. LL-37, LCN2 and SLPI did not change after treatment with 1,25(OH)2D3., Conclusion: Levels of the antimicrobial peptides HNP1-3 and LCN2 are lower in nasal secretions in asthmatics and are not substantially affected by a short-term treatment with active vitamin D.

Background: The pathogenesis of asthma in obese subjects is poorly understood and has been described as a specific phenotype in these patients. Weight loss improves asthma control and lung function. Whether this improvement is the result of better mechanical properties of the airways or decreased systemic and bronchial inflammation remains unclear., Methods: A longitudinal study in obese patients with asthma (bariatric surgery and asthma group (BS+A), n=27) and obese control (bariatric surgery without asthma group (BS-A), n=39) subjects undergoing bariatric surgery, and obese patients with asthma without intervention (no bariatric surgery and asthma group (NBS+A), n=12). Lung function, asthma control, cellular infiltrates in bronchial biopsies and circulating markers of systemic inflammation were measured during follow up at 3, 6 and 12 months., Results: Bariatric surgery resulted in a profound weight loss at 12 months. In the BS+A group as well as the BS-A group FEV1, functional residual capacity, total lung capacity improved, whereas FEV1/FVC only improved in the BS-A group. In addition, Asthma Control Questionnaire (ACQ), Asthma Quality of Life Questionnaire, inhaled corticosteroid use and PD20 improved in BS+A, whereas in the NBS+A group only ACQ improved. Small airway function R5-R20 improved in both surgery groups, however the change in the BS+A group was greater, resulting in a comparable R5-R20 between BS+A and BS-A at 12-month follow-up. Besides improvement of systemic inflammation (high sensitivity C-reactive protein, adiponectin and leptin) after BS, only a decrease in mast cell numbers was detectable in the BS+A group., Conclusions: Bariatric surgery improved small airway function, decreased systemic inflammation and number of mast cells in the airways. These effects could explain the improvement of asthma control, quality of life and lung function. Therefore bariatric surgery, in addition to all other positive effects, also improves asthma in subjects with morbid obesity., Trial Registration Number: 3204., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Rationale: Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease and likely includes a subgroup that is biologically comparable to asthma. Studying asthma-associated gene expression changes in COPD could add insight into COPD pathogenesis and reveal biomarkers that predict a favorable response to corticosteroids., Objectives: To determine whether asthma-associated gene signatures are increased in COPD and associated with asthma-related features., Methods: We compared disease-associated airway epithelial gene expression alterations in an asthma cohort (n = 105) and two COPD cohorts (n = 237, 171). The T helper type 2 (Th2) signature (T2S) score, a gene expression metric induced in Th2-high asthma, was evaluated in these COPD cohorts. The T2S score was correlated with asthma-related features and response to corticosteroids in COPD in a randomized, placebo-controlled trial, the Groningen and Leiden Universities study of Corticosteroids in Obstructive Lung Disease (GLUCOLD; n = 89)., Measurements and Main Results: The 200 genes most differentially expressed in asthma versus healthy control subjects were enriched among genes associated with more severe airflow obstruction in these COPD cohorts (P < 0.001), suggesting significant gene expression overlap. A higher T2S score was associated with decreased lung function (P < 0.001), but not asthma history, in both COPD cohorts. Higher T2S scores correlated with increased airway wall eosinophil counts (P = 0.003), blood eosinophil percentage (P = 0.03), bronchodilator reversibility (P = 0.01), and improvement in hyperinflation after corticosteroid treatment (P = 0.019) in GLUCOLD., Conclusions: These data identify airway gene expression alterations that can co-occur in asthma and COPD. The association of the T2S score with increased severity and "asthma-like" features (including a favorable corticosteroid response) in COPD suggests that Th2 inflammation is important in a COPD subset that cannot be identified by clinical history of asthma.

The airway epithelium is now considered to be central to the orchestration of pulmonary inflammatory and immune responses, and is also key to tissue remodelling. It acts as the first barrier in the defence against a wide range of inhaled challenges, and is critically involved in the regulation of both innate and adaptive immune responses to these challenges. Recent progress in our understanding of the developmental regulation of this tissue, the differentiation pathways, recognition of pathogens and antimicrobial responses is now exploited to help understand how epithelial cell function and dysfunction contributes to the pathogenesis of a variety of inflammatory lung diseases. Herein, advances in our knowledge of the biology of airway epithelium, as well as its role and (dys)function in asthma, chronic obstructive pulmonary fibrosis and cystic fibrosis will be discussed., (Copyright ©ERS 2015.)

Background: Low levels of vitamin D are associated with asthma severity, airway remodeling, and exacerbation rate increase, especially in nonatopic asthma. Reduced steroid responsiveness or impaired antimicrobial defense might be underlying mechanisms., Objective: We sought to evaluate the effect of vitamin D supplementation on eosinophilic and neutrophilic airway inflammation in patients with nonatopic asthma., Methods: In a double-blind, randomized, placebo-controlled trial, we investigated the effect of long-acting vitamin D3 (400,000 IU) on sputum neutrophils and eosinophils in 44 patients with nonatopic asthma with neutrophilic (≥53%) and/or eosinophilic (≥3%) airway inflammation. Sputum induction was performed at baseline and after 9 weeks. Other measurements included questionnaires, blood samples, and pulmonary function., Results: Treatment with vitamin D did not significantly affect sputum neutrophils or eosinophils compared with treatment with placebo in the total group. Regarding sputum eosinophils, the effect of vitamin D appeared to be dependent on baseline sputum eosinophil levels (interaction P = .015). In patients with eosinophil levels of 26.2% or more (median in patients with sputum eosinophilia, >3%), eosinophils decreased from a median of 41.0% to 11.8% after vitamin D treatment as compared with an increase from 51.8% to 63.3% in patients receiving placebo (P = .034). Vitamin D treatment also resulted in slightly better Asthma Control Questionnaire scores (P = .08)., Conclusions: Vitamin D supplementation reduced eosinophilic airway inflammation in patients with nonatopic asthma with severe eosinophilic airway inflammation, but did not affect sputum neutrophils. Also, a small effect on asthma control was observed. These findings suggest that vitamin D might have potential as an add-on treatment option in eosinophilic asthma., (Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Regulatory B cells have been identified that strongly reduce allergic and auto-immune inflammation in experimental models by producing IL-10. Recently, several human regulatory B-cell subsets with an impaired function in auto-immunity have been described, but there is no information on regulatory B cells in allergic asthma., Objective: In this study, the frequency and function of IL-10 producing B-cell subsets in allergic asthma were investigated., Methods: Isolated peripheral blood B cells from 13 patients with allergic asthma and matched healthy controls were analyzed for the expression of different regulatory B-cell markers. Next, the B cells were activated by lipopolysaccharide (LPS), CpG or through the B-cell receptor, followed by co-culture with endogenous memory CD4(+) T cells and house dust mite allergen DerP1., Results: Lower number of IL-10 producing B cells were found in patients in response to LPS, however, this was not the case when B cells were activated through the B-cell receptor or by CpG. Further dissection showed that only the CD24(hi)CD27(+) B-cell subset was reduced in number and IL-10 production to LPS. In response to DerP1, CD4(+) T cells from patients co-cultured with LPS-primed total B cells produced less IL-10 compared to similar cultures from controls. These results are in line with the finding that sorted CD24(hi)CD27(+) B cells are responsible for the induction of IL-10(+) CD4(+) T cells., Conclusions: Taken together, these data indicate that CD24(hi)CD27(+) B cells from allergic asthma patients produce less IL-10 in response to LPS leading to a weaker IL-10 induction in T cells in response to DerP1, which may play a role in allergic asthma., (© 2013 John Wiley & Sons Ltd.)

Background: The prevalence of obesity and asthma has increased concurrently over the last decades, suggesting a link between obesity and asthma. However, asthma might not be adequately diagnosed in this population., Aim: To investigate whether not only overdiagnosis but also underdiagnosis of asthma is present in an obese population., Methods: Morbidly obese subjects with or without physician-diagnosed asthma were recruited from a pre-operative screening programme for bariatric surgery, and were characterized using an extensive diagnostic algorithm., Results: 473 subjects were screened; 220 met inclusion criteria, and 86 agreed to participate. Among the 32 participating subjects who had a physician diagnosis of asthma, reversible airway obstruction and/or bronchial hyperresponsiveness could only be detected in 19 patients (59%, 95% CI [0.41-0.76]), whereas in 13 patients (41%, 95% CI [0.24-0.50]) the diagnosis of asthma could not be confirmed (overdiagnosis). In contrast, in the remaining 54 patients, 17 (31%, 95% CI [0.20-0.46]) were newly diagnosed with asthma (underdiagnosis)., Conclusion: Besides overdiagnosis, there is also substantial underdiagnosis of asthma in the morbidly obese. Symptoms could be incorrectly ascribed to either obesity or asthma, and therefore also in the morbidly obese the diagnosis of asthma should also be based on pulmonary function testing., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Smoking in asthma occurs frequently and is associated with increased symptom severity, an impaired response to corticosteroids, and accelerated lung function decline. Airway pathology in smoking asthmatics is characterized by neutrophilia and epithelial changes such as goblet cell hyperplasia and increased proliferation. Bronchial CD8(+) T cells are implicated in lung function decline in asthma and COPD. We hypothesized that smoking modifies airway inflammation in asthma by increasing the number of CD8(+) T cells at an early stage., Objectives & Methods: To study effects of smoking on airway pathology in bronchial biopsies from atopic patients with controlled intermittent or mild persistent asthma (12 smokers, 9.7 py and 11 never-smokers, 0.0 py; 20-50 yrs; FEV1 > 70% predicted; PC20MCh < 8 mg/mL, no ICS) using immunohistochemistry., Results: Smoking asthmatics showed higher numbers of bronchial CD8(+) T cells (55.8 vs 23.9 cells/0.1 mm(2); p = 0.001) and CD68(+) macrophages (7.5 vs 4.6 cells/0.1 mm(2), p = 0.012), and a lower CD4(+)/CD8(+) cell ratio (0.16 vs 0.40; p = 0.007) compared with non-smoking asthmatics, but no difference in neutrophils. Furthermore, the % intact epithelium was higher in smoking asthmatics (49.3 vs 23.3, p = 0.001)., Conclusion: Smoking asthmatics with a limited smoking history show a distinct pattern of airway pathology characterized by a bronchial infiltrate of CD8(+) T cells and CD68(+) macrophages, and epithelial remodelling resembling COPD-like features. This raises the hypothesis that early presence of CD8(+) T cells contributes to disease progression in smoking asthmatics., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Bradykinin drives normal lung fibroblasts into myofibroblasts, induces fibroblast proliferation and activates mitogen activated protein kinase pathways (MAPK) but its effects on bronchial fibroblasts from asthmatics (HBAFb) have not been yet studied. We studied bradykinin-induced fibroblast proliferation and differentiation and the related intracellular mechanisms in HBAFb compared to normal bronchial fibroblasts (HNBFb). Bradykinin-stimulated HBAFb and HNBFb were used to assess: bradykinin B2 receptor expression by Western blot analysis; cell proliferation by [(3)H] thymidine incorporation; α-smooth muscle actin (SMA) expression/polymerization by Western blot and immunofluorescence; epidermal growth factor (EGF) receptor, extracellular-regulated kinase (ERK) 1/2 and p38 MAPK activation by immunoprecipitation and Western blot, respectively. Constitutive bradykinin B2 receptor and α-SMA expression was higher in HBAFb as compared to HNBFb. Bradykinin increased bradykinin B2 receptor expression in HBAFb. Bradykinin, via bradykinin B2 receptor, significantly increased fibroblast proliferation at lower concentration (10(-11)M) and α-SMA expression/polymerization at higher concentration (10(-6)M) in both cells. Bradykinin increased ERK1/2 and p38 phosphorylation via bradykinin B2 receptor; EGF receptor inhibitor AG1478 and panmetalloproteinase inhibitor GM6001 blocked bradykinin-induced ERK1/2 activation but not p38 phosphorylation. Bradykinin, via bradykinin B2 receptor, induced EGF receptor phosphorylation that was suppressed by AG1478. In HBAFb AG1478, GM6001, the ERK1/2-inhibitor U0126 and the p38 inhibitor SB203580 suppressed bradykinin-induced cell proliferation, but only SB203580 reduced myofibroblast differentiation. These data indicate that bradykinin is actively involved in asthmatic bronchial fibroblast proliferation and differentiation, through MAPK pathways and EGF receptor transactivation, by which bradykinin may contribute to airway remodeling in asthma, opening new horizons for potential therapeutic implications in asthmatic patients., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Exhaled nitric oxide (FeNO) has been associated with bronchial eosinophilia and with airway hyperresponsiveness (AHR) in mild stable asthma. We previously demonstrated in a large project that allergen exposure is able to raise FeNO and to worsen AHR to bradykinin. We postulated that allergen-induced increase in FeNO could be related to heightened mucosal eosinophils and AHR to bradykinin in atopic asthma. We performed a new immunohistochemical analysis on bronchial biopsy specimens, previously obtained from the same large project, in order to assess the number of mucosal eosinophils (EG-2+ cell) and other inflammatory cells at 48 hours after diluent and allergen exposures. Inflammatory cell counts were related to FeNO and AHR to BK (expressed as logPD20 bradykinin). In 10 atopic mild asthmatics, we found that the numbers of EG-2+ and CD4+ cells in bronchial submucosa were significantly increased after allergen compared to the respective counts after diluent (p &#x003C; 0.01). EG-2+ cells in the bronchial submucosa were negatively correlated with logPD20 bradykinin only after allergen challenge (rho = -0.709, p = 0.027). We also found a positive strong correlation between EG-2+ cells and FeNO values in atopic asthmatics at 48 hours after both diluent (rho = 0.746, p = 0.017) and allergen (rho = 0.644, p = 0.049) challenge. FeNO values negatively correlated with responsiveness to bradykinin only after allergen challenge (rho = -0.675, p = 0.039). This study indicates that after allergen exposure heightened level of exhaled NO may reflect augmented airway eosinophilic inflammation and airway responsiveness to bradykinin indicating loss of asthma control.

Background: IgE and its high-affinity receptor FcɛRI play an important role in allergy and asthma. The distribution of FcɛRI expression in the airways and within the airway wall, however, is largely unknown., Objective: In this study, we aimed to map the distribution of FcɛRI in different layers of large airways (LA) and small airways (SA) in lung tissue from non-smoking and smoking patients who died of asthma [fatal asthma (FA)] and non-smoking controls (CTR)., Methods: Postmortem lung tissue from 24 cases of non-smoking FA, 13 smoking FA patients and from 19 subjects who died of non-pulmonary causes (CTR) was immunohistochemically stained for FcɛRI and AA1 (mast cell tryptase marker). The expression of these markers was analysed in inner, muscle, and outer layers of both LA and SA by image analysis., Results: FcɛRI expression was higher in non-smoking and smoking FA compared with CTR in the inner and outer layer of SA. In the outer layer of LA, FcɛRI expression was higher in non-smoking FA compared with CTR. AA1 was higher in non-smoking FA compared with smoking FA and CTR in the outer layer of the SA, which was correlated with FcɛRI in this layer., Conclusion: Our results show that the expression of FcɛRI is higher in both LA and SA in FA compared with CTR. These differences are predominantly found in the outer layer where they can be attributed in part to the increased mast cell numbers. These results indicate an increased capacity to mount IgE-mediated reactions in FA, both in LA and SA., (© 2010 Blackwell Publishing Ltd.)

Background: Analysis of exhaled breath condensate (EBC) is a non-invasive method for studying the acidity (pH) of airway secretions in patients with inflammatory lung diseases., Aim: To assess the reproducibility of EBC pH for two commercially available devices (portable RTube and non-portable ECoScreen) in healthy controls, patients with asthma or COPD, and subjects suffering from an acute cold with lower-airway symptoms. In addition, we assessed the repeatability in healthy controls., Methods: EBC was collected from 40 subjects (n = 10 in each of the above groups) using RTube and ECoScreen. EBC was collected from controls on two separate occasions within 5 days. pH in EBC was assessed after degasification with argon for 20 min., Results: In controls, pH-measurements in EBC collected by RTube or ECoScreen showed no significant difference between devices (p = 0.754) or between days (repeatability coefficient RTube: 0.47; ECoScreen: 0.42) of collection. A comparison between EBC pH collected by the two devices in asthma, COPD and cold patients also showed good reproducibility. No differences in pH values were observed between controls (mean pH 8.27; RTube) and patients with COPD (pH 7.97) or asthma (pH 8.20), but lower values were found using both devices in patients with a cold (pH 7.56; RTube, p < 0.01; ECoScreen, p < 0.05)., Conclusion: We conclude that pH measurements in EBC collected by RTube and ECoScreen are repeatable and reproducible in healthy controls, and are reproducible and comparable in healthy controls, COPD and asthma patients, and subjects with a common cold.

Background: Anti-IgE, omalizumab, inhibits the allergen response in patients with asthma. This has not been directly related to changes in inflammatory conditions. We hypothesized that anti-IgE exerts its effects by reducing airway inflammation. To that end, the effect of anti-IgE on allergen-induced inflammation in bronchial biopsies in 25 patients with asthma was investigated in a randomized, double-blind, placebo-controlled study., Methods: Allergen challenge followed by a bronchoscopy at 24 h was performed at baseline and after 12 weeks of treatment with anti-IgE or placebo. Provocative concentration that causes a 20% fall in forced expiratory volume in 1 s (PC(20)) methacholine and induced sputum was performed at baseline, 8 and 12 weeks of treatment. Changes in the early and late responses to allergen, PC(20), inflammatory cells in biopsies and sputum were assessed., Results: Both the early and late asthmatic responses were suppressed to 15.3% and 4.7% following anti-IgE treatment as compared with placebo (P < 0.002). This was paralleled by a decrease in eosinophil counts in sputum (4-0.5%) and postallergen biopsies (15-2 cells/0.1 mm(2)) (P < 0.03). Furthermore, biopsy IgE+ cells were significantly reduced between both the groups, whereas high-affinity IgE receptor and CD4+ cells were decreased within the anti-IgE group. There were no significant differences for PC(20) methacholine., Conclusion: The response to inhaled allergen in asthma is diminished by anti-IgE, which in bronchial mucosa is paralleled by a reduction in eosinophils and a decline in IgE-bearing cells postallergen without changing PC(20) methacholine. This suggests that the benefits of anti-IgE in asthma may be explained by a decrease in eosinophilic inflammation and IgE-bearing cells.

Background: Smooth muscle content is increased within the airway wall in patients with asthma and is likely to play a role in airway hyperresponsiveness. However, smooth muscle cells express several contractile and structural proteins, and each of these proteins may influence airway function distinctly., Objective: We examined the expression of contractile and structural proteins of smooth muscle cells, as well as extracellular matrix proteins, in bronchial biopsies of patients with asthma, and related these to lung function, airway hyperresponsiveness, and responses to deep inspiration., Methods: Thirteen patients with asthma (mild persistent, atopic, nonsmoking) participated in this cross-sectional study. FEV(1)% predicted, PC(20) methacholine, and resistance of the respiratory system by the forced oscillation technique during tidal breathing and deep breath were measured. Within 1 week, a bronchoscopy was performed to obtain 6 bronchial biopsies that were immunohistochemically stained for alpha-SM-actin, desmin, myosin light chain kinase (MLCK), myosin, calponin, vimentin, elastin, type III collagen, and fibronectin. The level of expression was determined by automated densitometry., Results: PC(20) methacholine was inversely related to the expression of alpha-smooth muscle actin (r = -0.62), desmin (r = -0.56), and elastin (r = -0.78). In addition, FEV(1)% predicted was positively related and deep inspiration-induced bronchodilation inversely related to desmin (r = -0.60), MLCK (r = -0.60), and calponin (r = -0.54) expression., Conclusion: Airway hyperresponsiveness, FEV(1)% predicted, and airway responses to deep inspiration are associated with selective expression of airway smooth muscle proteins and components of the extracellular matrix.

Rationale: Deep inspirations provide physiologic protection against airway narrowing in healthy subjects, which is impaired in asthma and chronic obstructive pulmonary disease (COPD). Airway inflammation has been suggested to alter airway mechanics during deep inspiration., Objectives: We tested the hypothesis that the number of bronchial inflammatory cells is related to deep inspiration-induced bronchodilation in asthma and COPD., Methods: In a cross-sectional study, three modified methacholine challenges were performed in 13 patients with mild, persistent asthma, 12 patients with mild to moderate COPD, and 12 healthy control subjects., Measurements and Main Results: After a 20-minute period of deep inspiration avoidance, inhalation of methacholine was followed by either one or five deep inspirations, or preceded by five deep inspirations. The response to deep inspiration was measured by forced oscillation technique. Inflammatory cells were counted within the lamina propria and airway smooth muscle area in bronchial biopsies of patients with asthma and COPD. The reduction in expiratory resistance by one and five deep inspirations was significantly less in asthma (mean change+/-SD: -0.5+/-0.8 and -0.9+/-1.0 cm H2O/L/s, respectively) and COPD (+0.2+/-1.1 and +0.4+/-1.0 cm H2O/L/s, respectively) as compared with healthy subjects (-1.5+/-1.3 and -2.0+/-1.2 cm H2O/L/s, respectively; p=0.05 and p=0.001, respectively). In asthma, this was related to an increase in mast cell numbers within the airway smooth muscle area (r=0.73; p=0.03), and in CD4+ lymphocytes in the lamina propria (r=0.61; p=0.04)., Conclusions: Inflammation in the airway smooth muscle bundles and submucosa of bronchial biopsies is positively associated with impaired airway mechanics during deep inspiration in asthma, but not in COPD. Clinical trial registered with www.clinicaltrials.gov (NCT OO279136).

Unlabelled: The aim of this study was to investigate the relationship between urinary eosinophil protein X (uEPX) and asthma symptoms, lung function, and other markers of eosinophilic airway inflammation in asthmatic school children., Methods: A cross-sectional study was performed in 180 steroid dependent atopic children with stable moderately severe asthma, who were stable on 200 or 500 microg of fluticasone per day. uEPX was measured in a single sample of urine and was normalized for creatinine concentration (uEPX/c). Symptom scores were kept on a diary card. FEV1 and PD20 methacholine were measured. Sputum induction was performed in 49 and FE(NO) levels measured in 24 children., Results: We found an inverse correlation between uEPX/c and FEV1 (r = -.20, P = .01) and a borderline significant correlation between uEPX/c and PD20 methacholine (r = -.15, P = .06). Symptom score, %eosinophils and ECP in induced sputum and FE(NO) levels did not correlate with uEPX/c., Conclusion: uEPX/c levels did not correlate with established markers of asthma severity and eosinophilic airway inflammation in atopic asthmatic children.

Adhesion molecule very late antigen-4 (VLA-4) is implicated in the recruitment and activation of inflammatory cells in asthma, including eosinophils, T cells and mast cells. VLA-4 antagonists have been proposed as a new anti-inflammatory treatment modality for asthma. Therefore, we investigated whether a single inhaled dose of VLA-4 antagonist GW559090X could protect against allergen-induced changes in airway responses and airway inflammation in patients with asthma. We performed a randomized, double-blind, three-way crossover study with single inhaled doses of 3 mg of GW559090X, 500 microg of fluticasone propionate (FP) or placebo in 15 patients with mild intermittent asthma, controlled with short-acting beta(2)-agonists only. All patients developed a late asthmatic response (LAR) after allergen inhalation during screening. Study medication was administered 30 min prior to allergen challenge. Pre-dose and 24 h post-dose PC20 methacholine and levels of exhaled nitric oxide (eNO) were determined. At the given dose, VLA-4 antagonist GW559090X did not attenuate the early asthmatic response (EAR) when compared with placebo: mean AUC0-2 h(+/-SEM) (%fall h): 27.2+/-3.7 and 21.9+/-3.0 respectively (P=0.33); nor the LAR: mean AUC3-8 h(+/-SEM) (%fall h): 98.8+/-12.9 and 94.8+/-6.8 respectively (P=0.84). However, pretreatment with FP did attenuate both EAR and LAR when compared with placebo: mean AUC0-2 h11.6+/-3.3 (P=0.024) and mean AUC3-8 h 6.3+/-7.6 (P<0.001). None of these treatments had an effect on allergen-induced changes in airway hyper-responsiveness or eNO levels. These findings suggest that VLA-4 may not play a major role in allergen-induced airway responses and inflammation in asthma.

Background: Inflammatory and structural changes of the airway mucosa are chronic features of asthma. The mechanisms underlying these changes and their modulation by steroid prophylaxis have not been clarified., Objective: We postulated that asymptomatic ongoing allergen exposure could drive airway inflammation as well as changes in the extracellular matrix (ECM), and that inhaled steroids could prevent this., Methods: Therefore, we exposed patients with mild asthma to 2 weeks of repeated low-dose allergen, with concomitant inhaled steroid or placebo treatment. Bronchial biopsies, which were taken before and after this exposure, were stained and digitally analysed. The ECM proteins in asthmatics were also compared with a normal control group., Results: Low-dose allergen exposure alone resulted in a significant increase of bronchial epithelial macrophages. Despite ongoing allergen exposure, inhaled steroids reduced the numbers of mucosal eosinophils, neutrophils and T lymphocytes. At baseline, the mean density of the proteoglycans (PGS) biglycan and decorin were, respectively, higher and lower in the bronchial mucosa of asthmatics as compared with normal controls. Steroid treatment, during allergen exposure, increased the mean density of the PGS biglycan and versican., Conclusion: We conclude that chronic allergen exposure induces inflammatory changes in the bronchial mucosa. Despite ongoing allergen exposure, steroid treatment decreases mucosal inflammatory cells while altering PG density. The latter observation highlights the need to examine steroid-induced changes closely in the airway structure in patients with asthma.

Rationale: Patients with asthma have an accelerated decline in lung function, which can lead to irreversible airway obstruction. It is generally assumed that this is related to specific aspects of airway inflammation and/or remodeling., Objective: We investigated the prognostic significance of bronchial eosinophil and CD8+ cell counts and subepithelial reticular layer thickness for the subsequent decline in lung function in patients with asthma after 7.5 years of follow-up., Methods: In a prospective study, pre- and post-bronchodilator lung function (FEV1) was measured at baseline, and after 2 years and 7.5 years in 32 patients with asthma. Annual decline in lung function after 7.5 years of follow-up was related to type and severity of airway inflammation and remodeling in bronchial biopsies, which were taken at baseline and at Year 2., Results: Annual decline in post-bronchodilator FEV1 (mean [SD], 46.6 [53.4] ml/year) was significantly larger than the decline in prebronchodilator FEV1 (mean [SD], 27.5 [62.5] ml/year), indicating loss in reversibility. Although annual fall in post-bronchodilator FEV1 was not related to thickness of the reticular layer or to eosinophil counts in bronchial biopsies, there was a significant correlation with CD8+ T cells (r=-0.39, p=0.032). Analyzing the biopsies taken at Year 2, the significant association between annual fall in post-bronchodilator FEV1 and CD8 cells could independently be confirmed (r=-0.39, p=0.036)., Conclusion: The outcome of asthma, as determined by the annual decline in FEV1, can be predicted by the bronchial CD8+ cell infiltrate. This suggests that the inflammatory phenotype in asthma has prognostic relevance, which may require phenotype-specific therapeutic strategies.

Background: Several studies suggest that the periphery of the lung is the major site of inflammation in asthma. Fractional exhaled nitric oxide (Feno) and 8-isoprostane have been proposed as biomarkers of inflammation and oxidative stress. We therefore hypothesised that small airway dysfunction in asthma is of inflammatory origin that can be detected by molecular markers in exhaled air. To test this hypothesis, we examined the relationship of Feno and 8-isoprostane in exhaled air with small airways function as assessed by the single breath nitrogen test., Methods: Sixteen patients (14 women) with mild atopic asthma (forced expiratory volume in 1 second >80% predicted) of mean (SD) age 23.0 (5.5) years participated in a cross sectional study. Feno was recorded by chemiluminescence and 8-isoprostane was measured by ELISA in concentrated exhaled breath condensate. The slope of phase III (deltaN2) and the closing volume (CV) were assessed from the single breath washout curve., Results: The median Feno level was 30.4 ppb (range 10.1-82.8), the median 8-isoprostane concentration in exhaled breath condensate was 2.2 pg/ml (range 1.6-2.7), and the mean (SD) deltaN2 value was 1.1 (0.4)% N2/l. Feno was positively associated with deltaN2 (r(s) = 0.54, p = 0.032) while 8-isoprostane was inversely correlated with FEV1% predicted (rs= -0.58; p = 0.017) and CV as a percentage of vital capacity (rs= 0.58; p = 0.019)., Conclusions: Feno and 8-isoprostane in exhaled air are associated with small airways function in mild asthma. This suggests that these markers reflect small airway inflammation and favours a role for them as disease markers that is complementary to spirometry in the monitoring of patients with asthma.

Background: The mechanisms leading to death from asthma are not completely understood. Recent studies suggest the involvement of the anaphylatoxins C3a and C5a, generated during complement activation, and their receptors C3aR and C5aR in the pathogenesis of asthma., Objective: The aim of our study was to investigate the expression of C3aR and C5aR in fatal asthma., Methods: We analyzed lung tissue from 14 subjects who died of asthma (fatal asthma; FA) and 14 subjects who died of nonpulmonary causes (controls) and bronchial biopsy specimens from 16 subjects with mild intermittent asthma (MIA). C3aR and C5aR expression was evaluated by immunohistochemistry, and a semiquantitative analysis of the intensity of staining was performed according to a visual analogue scale (score, 0-3)., Results: C3aR was expressed on airway epithelium, smooth muscle, submucosal, and parenchymal vessels. C5aR was expressed on myeloid cells infiltrating the submucosa and on airway epithelium. Statistical analysis demonstrated higher expression of C3aR on submucosal vessels in FA compared with controls and MIA (median [minimum-maximum], controls, 0.24 [0-1.48]; MIA, 0.0 [0-1.00]; FA, 1.56 [0.13-3]; P = .002). C3aR was also increased on parenchymal vessels in FA (controls, 0.56 [0-2.00]; FA, 1.81 [0.5-3]; P = .0004). C5aR expression on airway epithelium was increased in FA compared with controls and MIA (controls, 1.25 [0.25-3]; MIA, 1.00 [0-2.00]; FA, 3.00 [1.13-3.00]; P = .001)., Conclusion: The results of our study suggest a role of complement in FA.

Background: Eotaxin-1, eotaxin-2, and eotaxin-3 are chemokines involved in the activation and recruitment of eosinophils through activation of their main receptor, CC chemokine receptor 3. The differential roles of these chemokines still remain to be established. It has been suggested that eotaxin-1 is an important mediator in the early phase of allergen-induced recruitment of eosinophils into the airways. Eotaxin-2 and eotaxin-3 might play a role in the subsequent persistence of allergen-induced bronchial eosinophilia., Objective: The aim of this study was to determine the expression of eotaxins and eosinophil counts in the bronchial mucosa of subjects with mild asthma after resolution of the late-phase asthmatic response (LAR)., Methods: The expression of eotaxins and eosinophil counts were determined in bronchial biopsy specimens obtained from 10 subjects with mild asthma 48 hours after diluent and allergen challenge by using immunohistochemistry. Positively stained cells were counted in a 125-mum-deep zone of the lamina propria., Results: Eotaxin-2 and eotaxin-3 expression in bronchial mucosa was significantly increased 48 hours after allergen challenge ( P = .001 and P = .013, respectively). At this time point, when marked tissue eosinophilia was still present, these increases were positively correlated with the magnitude of the LAR ( r = 0.72, P = .019 and r = 0.64, P = .046, respectively). Furthermore, eotaxin-2 expression was associated with the number of eosinophils after allergen challenge ( r = 0.72, P = .018)., Conclusion: Our findings suggest that eotaxin-2 and eotaxin-3 might account for the persistence of bronchial eosinophilia after resolution of the LAR.