Exacerbation Of Airways Disease Research Articles

Pulmonary Immune-Related Adverse Events of PD-1 Versus PD-L1 Checkpoint Inhibitors: A Retrospective Review of Pharmacovigilance.

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapeutics. However, immune-related adverse events (irAEs) increase morbidity and mortality and thereby limit therapeutic utility. The real-world incidence of the entire spectrum of pulmonary irAEs has not been systematically described. The objective of this study is to assess the risk of developing pulmonary irAEs (pneumonitis, pleural events [i.e., effusion and pleurisy], exacerbations of airway disease [i.e., bronchitis and bronchiectasis], and sarcoidosis) with exposure to five commonly used ICIs: nivolumab, pembrolizumab, durvalumab, avelumab, and atezolizumab. We conducted a retrospective review of the Food and Drug Administration Adverse Events Reporting System (FAERS) pharmacovigilance database. We collected data from 2012 to 2021 to assess the risk of pulmonary irAEs and performed a disproportionality analysis using Open-Vigil, a software package used for analysis of pharmacovigilance data, to calculate reporting odds ratios (RORs). We used 95% CIs to evaluate the precision of RORs. An ROR greater than 1 and the upper limit of the 95% CI indicated statistical significance. A total of 17,273,403 events were reported in FAERS between 2012 and 2021. Of these, 88,099 (0.5%) were attributed to the PD-1 (programmed cell death protein 1) inhibitors and 21,905 (0.1%) to PD-L1 (programmed death ligand 1) inhibitors of interest. The most common indication for using the ICIs of interest was lung cancer: a total of 2832 (46.70%) for the PD-1 inhibitors and 1311 (70.9%) for the PD-L1 inhibitors. In the anti-PD-1 group, 2342 (38.6%) patients were hospitalized, and 1962 (32.4%) patients died from the lung adverse event. In the PD-L1 group, 744 (40.3%) patients were hospitalized, and 520 (28.1%) patients died from the event. Nivolumab resulted in the highest statistically significant risk (ROR, 10.5; 95% CI, 10.1-10.9) for pneumonitis. Avelumab had a lesser risk for pneumonitis (ROR, 0.2; 95% CI, 0.2-0.3). The risk for pleural events was highest with nivolumab (ROR, 3.6; 95% CI, 3.4-3.9), followed by pembrolizumab (ROR, 1.8; 95% CI; 1.6-2.0) (p < 0.001), with the lowest risks from durvalumab, atezolizumab, and avelumab. For ICI-related sarcoidosis, the risk was most significant with pembrolizumab (ROR, 3.6; 95% CI, 2.8-4.7), followed by nivolumab (ROR, 2.5; 95% CI, 1.9-3.5) (p < 0.001). The RORs for all five ICIs were less than 1 for exacerbations of airway diseases as compared with other drugs. Using a pharmacovigilance database, we found an increased risk of multiple pulmonary irAEs after ICI therapy, particularly with PD-1 inhibitors. Further work is needed to investigate the incidence of pulmonary irAEs other than pneumonitis.

Autophagy of mucin granules contributes to resolution of airway mucous metaplasia

Exacerbations of muco-obstructive airway diseases such as COPD and asthma are associated with epithelial changes termed mucous metaplasia (MM). Many molecular pathways triggering MM have been identified; however, the factors that regulate resolution are less well understood. We hypothesized that the autophagy pathway is required for resolution of MM by eliminating excess non-secreted intracellular mucin granules. We found increased intracellular levels of mucins Muc5ac and Muc5b in mice deficient in autophagy regulatory protein, Atg16L1, and that this difference was not due to defects in the known baseline or stimulated mucin secretion pathways. Instead, we found that, in mucous secretory cells, Lc3/Lamp1 vesicles colocalized with mucin granules particularly adjacent to the nucleus, suggesting that some granules were being eliminated in the autophagy pathway rather than secreted. Using a mouse model of MM resolution, we found increased lysosomal proteolytic activity that peaked in the days after mucin production began to decline. In purified lysosomal fractions, Atg16L1-deficient mice had reduced proteolytic degradation of Lc3 and Sqstm1 and persistent accumulation of mucin granules associated with impaired resolution of mucous metaplasia. In normal and COPD derived human airway epithelial cells (AECs), activation of autophagy by mTOR inhibition led to a reduction of intracellular mucin granules in AECs. Our findings indicate that during peak and resolution phases of MM, autophagy activity rather than secretion is required for elimination of some remaining mucin granules. Manipulation of autophagy activation offers a therapeutic target to speed resolution of MM in airway disease exacerbations.

Fungal bronchitis is a distinct clinical entity which is responsive to antifungal therapy.

Chronic productive cough in the context of exacerbations of airway disease can be associated with positive sputum cultures for fungi, in particular Aspergillus fumigatus and Candida spp., suggesting fungal bronchitis, a condition not widely recognised, as a possible cause for the exacerbation. Our objective was to determine the response to antifungal therapy in patients with suspected fungal bronchitis. Retrospective analysis of data extracted from case records of patients under secondary care respiratory clinics who had been treated with triazole therapy for suspected fungal bronchitis between 2010–2017. Primary outcome was lung function response after 1 month of treatment. Nineteen patients with fungal bronchitis due to A. fumigatus and 12 patients due to Candida spp., were included in the study. Most of the patients, particularly in the Aspergillus group, had allergic fungal airway disease on a background of asthma. All but one of the patients in each group were recorded as showing clinical improvement with antifungal therapy. In the majority of patients this was reflected in an improvement in lung function. Aspergillus group: FEV1 (1.44 ± 0.8 L vs 1.6 ± 0.8 L: p < 0.02), FVC (2.49 ± 1.08 L vs 2.8 ± 1.1 L: p = 0.01), and PEF (260 ± 150L/min vs 297 ± 194ml/min: p < 0.02). Candida group: FEV1 (1.6 ± 0.76 L vs 2.0 ± 0.72 L: p < 0.004), FVC (2.69 ± 0.91 L vs 3.13 ± 0.7 L: p = 0.05), and PEF (271± 139L/min vs 333 ± 156 L/min: p = 0.01). Side effects of treatment were common, but resolved on stopping treatment. This service improvement project supports the idea that fungal bronchitis is a distinct clinical entity which is responsive to treatment. Controlled clinical trials to confirm the clinical impression that this is relatively common and treatable complication of complex airway disease are required.

Rhinovirus-16 increases ATP release in A549 cells without concomitant increase in production.

Human rhinovirus (RV) is the most common cause of upper respiratory tract infection (URTI) and chronic airway disease exacerbation. Cough is present in 50–80% of URTI cases, accompanied by heightened airway hypersensitivity, yet no effective treatment currently exists for this infectious cough. The mechanism by which RV causes cough and airway hypersensitivity in URTI is still unknown despite recent advances in potential therapies for chronic cough.The effect of RV-16 infection (MOI 1) on intracellular ATP stores and ATP release in A549 alveolar epithelial cells was measured.RV-16 infection was found to significantly increase (by 50% from basal at 24 h) followed by decrease (by 50% from basal at 48 and 72 h) intracellular ATP concentrations, while increasing ATP release (from 72 h) independently of secondary stimulation. This effect was mimicked by intercellular adhesion molecule 1 receptor binding alone through ultraviolet-inactivated sham control. In addition, RV-16-infected cells became more sensitive to secondary stimulation with both hypotonic and isotonic solutions, suggestive of a hypersensitive response. These responses were not mediated via increased TRPV4 or pannexin-1 whole-cell expression as determined by Western blotting. Interestingly, the increased ATP release seen was not a result of increased mitochondrial ATP production.Thus, this is the first report demonstrating that RV-16 infection of airway epithelial cells causes hypersensitivity by increasing ATP release. These finding provide a novel insight into the process by which viruses may cause cough and identify a potential target for treatment of viral and post-viral cough.

Airway cholinergic history modifies mucus secretion properties to subsequent cholinergic challenge in diminished chloride and bicarbonate conditions.

What is the central question of this study? What is the impact of airway cholinergic history on the properties of airway mucus secretion in a cystic fibrosis-like environment? What is the main finding and its importance? Prior cholinergic challenge slightly modifies the characteristics of mucus secretion in response to a second cholinergic challenge in a diminished bicarbonate and chloride transport environment. Such modifications might lead to retention of mucus on the airway surface, thereby potentiating exacerbations of airway disease. Viral infections precipitate exacerbations in many airway diseases, including asthma and cystic fibrosis. Although viral infections increase cholinergic transmission, few studies have examined how cholinergic history modifies subsequent cholinergic responses in the airway. In our previous work, we found that airway resistance in response to a second cholinergic challenge was increased in young pigs with a history of airway cholinergic stimulation. Given that mucus secretion is regulated by the cholinergic nervous system and that abnormal airway mucus contributes to exacerbations of airway disease, we hypothesized that prior cholinergic challenge would also modify subsequent mucus responses to a secondary cholinergic challenge. Using our established cholinergic challenge-rechallenge model in pigs, we atomized the cholinergic agonist bethanechol or saline control to pig airways. Forty-eight hours later, we removed tracheas and measured mucus secretion properties in response to a second cholinergic stimulation. The second cholinergic stimulation was conducted in conditions of diminished chloride and bicarbonate transport to mimic a cystic fibrosis-like environment. In pigs previously challenged with bethanechol, a second cholinergic stimulation produced a mild increase in sheet-like mucus films; these films were scarcely observed in animals originally challenged with saline control. The subtle increase in mucus films was not associated with changes in mucociliary transport. These data suggest that prior cholinergic history might modify mucus secretion characteristics with subsequent stimulation in certain environmental conditions or disease states. Such modifications and/or more repetitive stimulation might lead to retention of mucus on the airway surface, thereby potentiating exacerbations of airway disease.

2796. The Impact of Syndromic Molecular Point-of-Care Testing for Respiratory Viruses on Antibiotic Use in Adults Presenting to Hospital with Exacerbation of Airways Disease: Further Analysis From a Randomized Controlled Trial

BackgroundThe ResPOC study demonstrated that syndromic molecular point-of-care testing (POCT) for respiratory viruses was associated with earlier discontinuation of unnecessary antibiotics. Subgroup analysis suggests this occurs predominantly in patients with exacerbation of airways disease. Molecular POCT use is becoming widespread but there is a lack of evidence to inform the choice between multiplex syndromic panels vs. uniplex tests for influenza.MethodsWe evaluated patients with exacerbation of asthma or COPD who were treated with antibiotics. The duration of antibiotics and proportion with early discontinuation were compared between patients testing positive for viruses by POCT (FilmArray Respiratory Panel) those testing negative by POCT and controls. Patients testing positive for viruses by POCT were compared according to virus types detected. Survival curves were generated for duration of antibiotics and compared using the log-rank test.ResultsThere were 118 patient with exacerbation of airways disease in the POCT group who received antibiotics and 111 in the controls. In the POCT group 49/118 (42%) patients tested positive for viruses. Of those testing positive for viruses by POCT 17/49 (35%) had early discontinuation of antibiotics vs. 9/81 (13%) in those testing negative and 7/111 (6%) in controls, P < 0.0001. Survival curve analysis showed a reduced time to antibiotic discontinuation in those testing positive for viruses, P = 0.034. Of those positive for viruses by POCT 20% were positive for influenza, 43% for rhinovirus and 37% for other viruses combined. The proportion with early discontinuation of antibiotics was not different between the virus types, P = 0.53.ConclusionSyndromic molecular POCT for viruses in adults with exacerbation of airways disease leads to early discontinuation in those positive for viruses. As most viruses detected were non-influenza viruses and there was no difference in antibiotic use between virus types, syndromic molecular POCT for respiratory viruses should be favored over uniplex POCT for influenza. Disclosures All authors: No reported disclosures.

729. Comparing Length of Stay and Clinical Outcomes for Hospitalized Patients at Bridgeport Hospital who Received Baloxavir Marboxil (BM) or Oseltamivir Phosphate (OP) During the 2018–2019 Influenza Season

BackgroundBM has been approved for the management of acute uncomplicated influenza in otherwise healthy individuals between age 12 and 64, and found to have a greater reduction in viremia. The original trial excluded hospitalized patients and those with co-morbidities.MethodsThis is a single-center, retrospective analysis of hospitalized patients diagnosed with influenza between October 1, 2018 and March 31, 2019. This study excluded those diagnosed before the addition of BM to the hospital formulary; those who were not treated with antivirals, treated before admission, or treated with both antivirals; those younger than 12 years old; and those who remain hospitalized. The relationship between length of stay and antiviral used was ascertained using t-test and multivariate linear regression. Due to heterogeneity in reasons for hospitalization, analysis was stratified by the main reasons for hospitalization. T-test and Wilcoxon’s rank-sum test were used for continuous variables, and Pearson’s chi-squared test was used for categorical variables. The significance level was 0.05.ResultsThe study population (n = 145) has a mean age of 66.5 years; of whom, 43% are male. In terms of patient characteristics, those treated with BM (n = 105) vs. OP (n = 40) were older, less frequently admitted to ICU and of differing ethnic composition. The length of stay was similar in those treated with BM vs. OP in both univariate and multivariate linear regression (5.5 (5.3) vs. 8.2 (11.4) days, P = 0.33). In addition, the length of stay was similar in those treated with BM vs. OP when stratified by reasons for hospitalization: pneumonia/bronchitis (6.6 (7.1) vs. 8.2 (9.2) days, P = 0.43), obstructive airway disease exacerbation (5.5 (4.8) vs. 4.8 (8.0) days, P = 0.56), elderly with multiple co-morbidities (5.0 (4.0) vs. 3.4 (6.8) days, P = 0.63), reactive airway disease (4.1 (4.8) vs. 7.4 (1.5) days, P = 0.27) or congestive heart failure exacerbation (9.8 (9.0) vs. 5.6 (5.0) days, P = 0.43).ConclusionIn hospitalized patients with co-morbidities diagnosed with influenza, there was no difference in length of stay in those who received BM vs. OP. This highlights the need to clarify the role of BM in this population, particularly given its comparable symptom reduction, greater cost, and the emergence of PA138T viral mutant.Disclosures All authors: No reported disclosures.

Sputum microbiomic clustering in asthma and chronic obstructive pulmonary disease reveals a Haemophilus-predominant subgroup.

BackgroundAirway ecology is altered in asthma and chronic obstructive pulmonary disease (COPD). Anti‐microbial interventions might have benefit in subgroups of airway disease. Differences in sputum microbial profiles at acute exacerbation of airways disease are reflected by the γProteobacteria:Firmicutes (γP:F) ratio. We hypothesized that sputum microbiomic clusters exist in stable airways disease, which can be differentiated by the sputum γP:F ratio.MethodsSputum samples were collected from 63 subjects with severe asthma and 78 subjects with moderate‐to‐severe COPD in a prospective single centre trial. Microbial profiles were obtained through 16S rRNA gene sequencing. Topological data analysis was used to visualize the data set and cluster analysis performed at genus level. Clinical characteristics and sputum inflammatory mediators were compared across the clusters.ResultsTwo ecological clusters were identified across the combined airways disease population. The smaller cluster was predominantly COPD and was characterized by dominance of Haemophilus at genus level (n = 20), high γP:F ratio, increased H influenzae, low diversity measures and increased pro‐inflammatory mediators when compared to the larger Haemophilus‐low cluster (n = 121), in which Streptococcus demonstrated the highest relative abundance at the genus level. Similar clusters were identified within disease groups individually and the γP:F ratio consistently differentiated between clusters.ConclusionCluster analysis by airway ecology of asthma and COPD in stable state identified two subgroups differentiated according to dominance of Haemophilus. The γP:F ratio was able to distinguish the Haemophilus‐high versus Haemophilus‐low subgroups, whether the Haemophilus‐high group might benefit from treatment strategies to modulate the airway ecology warrants further investigation.

Prognostic significance of chronic respiratory symptoms in individuals with normal spirometry.

Normal spirometry is often used to preclude airway disease in individuals with unspecific respiratory symptoms. We tested the hypothesis that chronic respiratory symptoms are associated with respiratory hospitalisations and death in individuals with normal spirometry without known airway disease.We included 108 246 randomly chosen individuals aged 20-100 years from a Danish population-based cohort study. Normal spirometry was defined as a pre-bronchodilator forced expiratory volume in 1 s/forced vital capacity ratio ≥0.70. Chronic respiratory symptoms included dyspnoea, chronic mucus hypersecretion, wheezing and cough. Individuals with known airway disease, i.e. chronic obstructive pulmonary disease and/or asthma, were excluded (n=10 291). We assessed risk of hospitalisations due to exacerbations of airway disease and pneumonia, and respiratory and all-cause mortality, from 2003 through 2018.52 999 individuals had normal spirometry without chronic respiratory symptoms and 30 890 individuals had normal spirometry with chronic respiratory symptoms. During follow-up, we observed 1037 hospitalisations with exacerbation of airway disease, 5743 hospitalisations with pneumonia and 8750 deaths, of which 463 were due to respiratory disease. Compared with individuals with normal spirometry without chronic respiratory symptoms, multivariable adjusted hazard ratios for individuals with normal spirometry with chronic respiratory symptoms were 1.62 (95% CI 1.20-2.18) for exacerbation hospitalisations, 1.26 (95% CI 1.17-1.37) for pneumonia hospitalisations, 1.59 (95% CI 1.22-2.06) for respiratory mortality and 1.19 (95% CI 1.13-1.25) for all-cause mortality. There was a positive dose-response relationship between number of symptoms and risk of outcomes. Results were similar after 2 years of follow-up, for never-smokers alone, and for each symptom separately.Chronic respiratory symptoms are associated with respiratory hospitalisations and death in individuals with normal spirometry without known airway disease.

Impact of point-of-care testing for respiratory viruses on antibiotic use in adults with exacerbation of airways disease

The ResPOC study demonstrated that syndromic molecular point-of-care testing (POCT) for respiratory viruses was associated with early discontinuation of unnecessary antibiotics compared to routine clinical care. Subgroup analysis suggests these changes occur predominantly in patients with exacerbation of airways disease. Use of molecular POCT for respiratory viruses is becoming widespread but there is a lack of evidence to inform the choice between multiplex syndromic panels versus POCT for influenza only. We evaluated patients from the ResPOC study with exacerbation of asthma or COPD who were treated with antibiotics. The duration of antibiotics and proportion with early discontinuation were compared between patients testing positive and negative for viruses by POCT, and controls. Patients testing positive for viruses by POCT were compared according to virus types. 118 patient with exacerbation of airways disease received antibiotics in the POCT group and 111 in the control group. In the POCT group 49/118 (42%) patients tested positive for viruses. Of those testing positive for viruses 17/49 (35%) had early discontinuation of antibiotics versus 9/69 (13%) testing negative and 7/111 (6%) of controls, p<0.0001. Of those positive for viruses by POCT 10/49 (20%) were positive for influenza, 21/49 (43%) for rhinovirus and 18/49 (37%) for other viruses. The proportion with early discontinuation of antibiotics was not different between the virus types (p = 0.34). This data suggests that syndromic molecular POCT for respiratory viruses should be favoured over POCT for influenza alone in adults with exacerbation of airways disease.

A bronchoprotective role for Rgs2 in a murine model of lipopolysaccharide-induced airways inflammation

BackgroundAsthma exacerbations are associated with the recruitment of neutrophils to the lungs. These cells release proteases and mediators, many of which act at G protein-coupled receptors (GPCRs) that couple via Gq to promote bronchoconstriction and inflammation. Common asthma therapeutics up-regulate expression of the regulator of G protein signalling (RGS), RGS2. As RGS2 reduces signaling from Gq-coupled GPCRs, we have defined role(s) for this GTPase-activating protein in an acute neutrophilic model of lung inflammation.MethodsWild type and Rgs2−/− C57Bl6 mice were exposed to nebulized lipopolysaccharide (LPS). Lung function (respiratory system resistance and compliance) was measured using a SCIREQ flexivent small animal ventilator. Lung inflammation was assessed by histochemistry, cell counting and by cytokine and chemokine expression in bronchoalveolar lavage (BAL) fluid.ResultsLipopolysaccharide inhalation induced transient airways hyperreactivity (AHR) and neutrophilic lung inflammation. While AHR and inflammation was greatest 3 h post-LPS exposure, BAL neutrophils persisted for 24 h. At 3 h post-LPS inhalation, multiple inflammatory cytokines (CSF2, CSF3, IL6, TNF) and chemokines (CCL3, CCL4, CXCL1, CXCL2) were highly expressed in the BAL fluid, prior to declining by 24 h. Compared to wild type counterparts, Rgs2−/− mice developed significantly greater airflow resistance in response to inhaled methacholine (MCh) at 3 h post-LPS exposure. At 24 h post-LPS exposure, when lung function was recovering in the wild type animals, MCh-induced resistance was increased, and compliance decreased, in Rgs2−/− mice. Thus, Rgs2−/− mice show AHR and stiffer lungs 24 h post-LPS exposure. Histological markers of inflammation, total and differential cell counts, and major cytokine and chemokine expression in BAL fluid were similar between wild type and Rgs2−/− mice. However, 3 and 24 h post-LPS exposure, IL12B expression was significantly elevated in BAL fluid from Rgs2−/− mice compared to wild type animals.ConclusionsWhile Rgs2 is bronchoprotective in acute neutrophilic inflammation, no clear anti-inflammatory effect was apparent. Nevertheless, elevated IL12B expression in Rgs2−/− animals raises the possibility that RGS2 could dampen Th1 responses. These findings indicate that up-regulation of RGS2, as occurs in response to inhaled corticosteroids and long-acting β2-adrenoceptor agonists, may be beneficial in acute neutrophilic exacerbations of airway disease, including asthma.

Proteomic identification of moesin upon exposure to acrolein

BackgroundAcrolein (allyl Aldehyde) as one of smoke irritant exacerbates chronic airway diseases and increased in sputum of patients with asthma and chronic obstructive lung disease. But underlying mechanism remains unresolved. The aim of study was to identify protein expression in human lung microvascular endothelial cells (HMVEC-L) exposed to acrolein.MethodsA proteomic approach was used to determine the different expression of proteins at 8 h and 24 h after treatment of acrolein 30 nM and 300 nM to HMVEC-L. Treatment of HMVEC-L with acrolein 30 nM and 300 nM altered 21 protein spots on the two-dimensional gel, and these were then analyzed by MALDI-TOF MS.ResultsThese proteins included antioxidant, signal transduction, cytoskeleton, protein transduction, catalytic reduction. The proteins were classified into four groups according to the time course of their expression patterns such as continually increasing, transient increasing, transient decreasing, and continually decreasing. For validation immunohistochemical staining and Western blotting was performed on lung tissues from acrolein exposed mice. Moesin was expressed in endothelium, epithelium, and inflammatory cells and increased in lung tissues of acrolein exposed mice compared with sham treated mice.ConclusionsThese results indicate that some of proteins may be an important role for airway disease exacerbation caused by acrolein exposure.

Sputum plug selection under inverted microscopy improves microbial identification during exacerbations of airway diseases.

Salivary contamination decreases the yield of identifying potential airway bacterial and fungal pathogens in routine cultures of spontaneous or induced sputum during exacerbations of airway diseases. We investigated the utility of selecting out the squamous cells from sputum using inverted microscopy. Sputum was obtained from fifty subjects, then divided to facilitate parallel processing of paired samples for gram-stain and semi-quantitative cultures, and quantitative cytometry. Selective processing under inverted microscopy allowed for fewer sample rejections (2% vs. 24%) and greater culture positivity (58% vs. 24%) compared with routine practices, with significant yield of fungal organisms. While known pathogens were associated with intense sputum neutrophilia, organisms that were not routinely considered as airway pathogens were also associated with modest neutrophilia indicating that they are capable of inducing a clinically relevant cellular response. Sputum selection under inverted microscopy improves the detection of bacterial pathogens during infective exacerbations. The methods to assign pathogenicity to microbes in the airway needs to be re-visited by assessing the cellular responses that they evoke in the airways.

The nasopharyngeal microbiome.

Human microbiomes have received increasing attention over the last 10 years, leading to a pervasiveness of hypotheses relating dysbiosis to health and disease. The respiratory tract has received much less attention in this respect than that of, for example, the human gut. Nevertheless, progress has been made in elucidating the immunological, ecological and environmental drivers that govern these microbial consortia and the potential consequences of aberrant microbiomes. In this review, we consider the microbiome of the nasopharynx, a specific niche of the upper respiratory tract. The nasopharynx is an important site, anatomically with respect to its gateway position between upper and lower airways, and for pathogenic bacterial colonisation. The dynamics of the latter are important for long-term respiratory morbidity, acute infections of both invasive and non-invasive disease and associations with chronic airway disease exacerbations. Here, we review the development of the nasopharyngeal (NP) microbiome over the life course, examining it from the early establishment of resilient profiles in neonates through to perturbations associated with pneumonia risk in the elderly. We focus specifically on the commensal, opportunistically pathogenic members of the NP microbiome that includes Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae and Moraxella catarrhalis. In addition, we consider the role of relatively harmless genera such as Dolosigranulum and Corynebacterium. Understanding that the NP microbiome plays such a key, beneficial role in maintaining equilibrium of commensal species, prevention of pathogen outgrowth and host immunity enables future research to be directed appropriately.

The TH2-polarizing function of atopic interleukin 17 receptor B–positive dendritic cells up-regulated by lipopolysaccharide

BackgroundRecent studies suggest that epithelial cell (EC)-derived cytokines contribute to allergic airway disease exacerbation. ObjectiveTo confirm our hypothesis that atopic dendritic cells (DCs) are activated to up-regulate the receptors of cytokines that mainly derived from ECs and enhance TH2 responses. MethodsThe expressions of interleukin 17 receptor B (IL-17RB) (IL-25 receptor), membrane-bound ST2 (IL-33 receptor), thymic stromal lymphopoietin receptor (TSLPR), granulocyte-macrophage colony-stimulating factor receptor (GM-CSFR), and several functional markers on CD1c+ monocyte-derived DCs (mo-DCs) were detected by flow cytometry. Lipopolysaccharide (LPS)-activated mo-DCs were cocultured with autologous CD4+ T cells, and cytokine production by these T cells was determined by intracellular flow cytometry. ResultsLPS activated both nonatopic and atopic mo-DCs to express a higher level of GM-CSFR but only activated atopic mo-DCs to express increased IL-17RB, which was subsequently activated by IL-25 involved with signal transducer and activator of transcription 5 phosphorylation. In addition, LPS increased the expression of the OX40 ligand (OX40L) but decreased inducible costimulator ligand on atopic CD86+ mo-DCs. More importantly, IL-25 further up-regulated OX40L on atopic CD86+ mo-DCs. After coculturing with LPS-activated mo-DCs from atopic individuals, CD4+ T cells had enhanced inflammatory responses by increased production of IL-4, IL-5, IL-13, and interferon γ (IFN-γ). In contrast, further addition of IL-25 led CD4+ T cells to produce higher level of IL-4 but lower level of IFN-γ. ConclusionAtopic IL-17RB+ DCs can be up-regulated by LPS and promote a TH2-type response, implying that the IL-25/IL-17RB pathway may represent a potential molecular mechanism underlying the regulation of ECs on DCs in allergic airway disease.

Enterovirus D68 Infections Associated with Severe Respiratory Illness in Elderly Patients and Emergence of a Novel Clade in Hong Kong.

Despite the recent emergence of enterovirus D68 (EV-D68), its clinical impact on adult population is less well defined. To better define the epidemiology of EV-D68, 6,800 nasopharyngeal aspirates (NPAs) from 2010–2014 were subject to EV-D68 detection by RT-PCR and sequencing of 5′UTR and partial VP1. EV-D68 was detected in 30 (0.44%) NPAs from 22 children and 8 adults/elderlies. Sixteen patients (including five elderly) (53%) had pneumonia and 13 (43%) patients were complicated by small airway disease exacerbation. Phylogenetic analysis of VP1, 2C and 3D regions showed four distinct lineages of EV-D68, clade A1, A2, B1 and B3, with adults/elderlies exclusively infected by clade A2. The potentially new clade, B3, has emerged in 2014, while strains closely related to recently emerged B1 strains in the United States were also detected as early as 2011 in Hong Kong. The four lineages possessed distinct aa sequence patterns in BC and DE loops. Amino acid residues 97 and 140, within BC and DE-surface loops of VP1 respectively, were under potential positive selection. EV-D68 infections in Hong Kong usually peak in spring/summer, though with a delayed autumn/winter peak in 2011. This report suggests that EV-D68 may cause severe respiratory illness in adults/elderlies with underlying co-morbidities.

Innate lymphoid cells contribute to allergic airway disease exacerbation by obesity

Epidemiologic and clinical observations identify obesity as an important risk factor for asthma exacerbation, but the underlying mechanisms remain poorly understood. Type 2 innate lymphoid cells (ILC2s) and type 3 innate lymphoid cells (ILC3s) have been implicated, respectively, in asthma and adipose tissue homeostasis and in obesity-associated airway hyperresponsiveness (AHR). We sought to determine the potential involvement of innate lymphoid cells (ILCs) in allergic airway disease exacerbation caused by high-fat diet (HFD)-induced obesity. Obesity was induced by means of HFD feeding, and allergic airway inflammation was subsequently induced by means of intranasal administration of house dust mite (HDM) extract. AHR, lung and visceral adipose tissue inflammation, humoral response, cytokines, and innate and adaptive lymphoid populations were analyzed in the presence or absence of ILCs. HFD feeding exacerbated allergic airway disease features, including humoral response, airway and tissue eosinophilia, AHR, and TH2 and TH17 pulmonary profiles. Notably, nonsensitized obese mice already exhibited increased lung ILC counts and tissue eosinophil infiltration compared with values in lean mice in the absence of AHR. The numbers of total and cytokine-expressing lung ILC2s and ILC3s further increased in HDM-challenged obese mice compared with those in HDM-challenged lean mice, and this was accompanied by high IL-33 and IL-1β levels and decreased ILC markers in visceral adipose tissue. Furthermore, depletion of ILCs with an anti-CD90 antibody, followed by T-cell reconstitution, led to a profound decrease in allergic airway inflammatory features in obese mice, including TH2 and TH17 infiltration. These results indicate that HFD-induced obesity might exacerbate allergic airway inflammation through mechanisms involving ILC2s and ILC3s.

Pathogenesis of Viral Infection in Exacerbations of Airway Disease.

Chronic airway diseases are a significant cause of morbidity and mortality worldwide, and their prevalence is predicted to increase in the future. Respiratory viruses are the most common cause of acute pulmonary infection, and there is clear evidence of their role in acute exacerbations of inflammatory airway diseases such as asthma and chronic obstructive pulmonary disease. Studies have reported impaired host responses to virus infection in these diseases, and a better understanding of the mechanisms of these abnormal immune responses has the potential to lead to the development of novel therapeutic targets for virus-induced exacerbations. The aim of this article is to review the current knowledge regarding the role of viruses and immune modulation in acute exacerbations of chronic pulmonary diseases and to discuss exciting areas for future research and novel treatments.

Interleukin-17A and Toll-Like Receptor 3 Ligand Poly(I:C) Synergistically Induced Neutrophil Chemoattractant Production by Bronchial Epithelial Cells.

Chronic inflammatory airway diseases, such as bronchial asthma and chronic obstructive pulmonary disease, are common respiratory disorders worldwide. Exacerbations of these diseases are frequent and worsen patients’ respiratory condition and overall health. However, the mechanisms of exacerbation have not been fully elucidated. Recently, it was reported that interleukin (IL)-17A might play an important role in neutrophilic inflammation, which is characteristic of such exacerbations, through increased production of neutrophil chemoattractants. Therefore, we hypothesized that IL-17A was involved in the pathogenesis of acute exacerbation, due to viral infection in chronic inflammatory airway diseases. In this study, we assessed chemokine production by bronchial epithelial cells and investigated the underlying mechanisms. Comprehensive chemokine analysis showed that, compared with poly(I:C) alone, co-stimulation of BEAS-2B cells with IL-17A and poly(I:C) strongly induced production of such neutrophil chemoattractants as CXC chemokine ligand (CXCL)8, growth-related oncogene (GRO), and CXCL1. Co-stimulation synergistically induced CXCL8 and CXCL1 mRNA and protein production by BEAS-2B cells and normal human bronchial epithelial cells. Poly(I:C) induced chemokine expression by BEAS-2B cells mainly via Toll-like receptor 3/TIR-domain-containing adapter-inducing interferon-β–mediated signals. The co-stimulation with IL-17A and poly(I:C) markedly activated the p38 and extracellular-signal-regulated kinase 1/2 pathway, compared with poly(I:C), although there was little change in nuclear factor-κB translocation into the nucleus or the transcriptional activities of nuclear factor-κB and activator protein 1. IL-17A promoted stabilization of CXCL8 mRNA in BEAS-2B cells treated with poly(I:C). In conclusion, IL-17A appears to be involved in the pathogenesis of chronic inflammatory airway disease exacerbation, due to viral infection by promoting release of neutrophil chemoattractants from bronchial epithelial cells.

Pulmonary Rehabilitation for Patients with Chronic Airways Obstruction

Pulmonary rehabilitation is a patient-centered and interdisciplinary intervention with major components of exercise training and self-management education. Although having no direct effect on lung function, this intervention often results in substantial improvements in respiratory symptoms, functional status, and health status. It probably also reduces subsequent health care utilization, especially when provided after a hospitalization for an exacerbation of airways disease. The beneficial effects of pulmonary rehabilitation reflect its ability to reduce the impact of systemic consequences of chronic respiratory disease and to improve patients' self-efficacy through promoting collaborative self-management. Pulmonary rehabilitation is indicated for patients with respiratory diseases (regardless of specific diagnosis) who have persistent symptoms or functional or health status limitation despite otherwise optimal medical therapy. Those patients with severe asthma (particularly those with airways remodeling) or asthma-chronic obstructive pulmonary disease overlap who have daily symptoms and substantial functional/health status limitation despite controller and bronchodilator therapy would be appropriate candidates for pulmonary rehabilitation.