Background:Asthma and COPD are characterized by airway dysfunction and inflammation. Neutrophilic airway inflammation is a common feature of COPD and is recognized in asthma, particularly in severe disease. The T helper (Th) 17 cytokines IL-17A and IL-17F have been implicated in the development of neutrophilic airway inflammation, but their expression in asthma and COPD is uncertain.Methods:We assessed IL-17A and IL-17F expression in the bronchial submucosa from 30 subjects with asthma, 10 ex-smokers with mild to moderate COPD, and 27 nonsmoking and 14 smoking control subjects. Sputum IL-17 concentration was measured in 165 subjects with asthma and 27 with COPD.Results:The median (interquartile range) IL-17A cells/mm2 submucosa was increased in mild to moderate asthma (2.1 [2.4]) compared with healthy control subjects (0.4 [2.8]) but not in severe asthma (P = .04). In COPD, IL-17A+ cells/mm2 submucosa were increased (0.5 [3.7]) compared with nonsmoking control subjects (0 [0]) but not compared with smoking control subjects (P = .046). IL-17F+ cells/mm2 submucosa were increased in severe asthma (2.7 [3.6]) and mild to moderate asthma (1.6 [1.0]) compared with healthy controls subjects (0.7 [1.4]) (P = .001) but was not increased in subjects with COPD. IL-17A and IL-17F were not associated with increased neutrophilic inflammation, but IL-17F was correlated with the submucosal eosinophil count (rs = 0.5, P = .005). The sputum IL-17 concentration in COPD was increased compared with asthma (2 [0-7] pg/mL vs 0 [0-2] pg/mL, P < .0001) and was correlated with post-bronchodilator FEV1% predicted (r = −0.5, P = .008) and FEV1/FVC (r = −0.4, P = .04).Conclusions:Our findings support a potential role for the Th17 cytokines IL-17A and IL-17F in asthma and COPD, but do not demonstrate a relationship with neutrophilic inflammation.

In response to infections and irritants, the respiratory epithelium releases the alarmin interleukin (IL)-33 to elicit a rapid immune response. However, little is known about the regulation of IL-33 following its release. Here we report that the biological activity of IL-33 at its receptor ST2 is rapidly terminated in the extracellular environment by the formation of two disulphide bridges, resulting in an extensive conformational change that disrupts the ST2 binding site. Both reduced (active) and disulphide bonded (inactive) forms of IL-33 can be detected in lung lavage samples from mice challenged with Alternaria extract and in sputum from patients with moderate–severe asthma. We propose that this mechanism for the rapid inactivation of secreted IL-33 constitutes a ‘molecular clock' that limits the range and duration of ST2-dependent immunological responses to airway stimuli. Other IL-1 family members are also susceptible to cysteine oxidation changes that could regulate their activity and systemic exposure through a similar mechanism.

No abstract

No abstract

Pre-clinical data demonstrate a pivotal role for interleukin (IL)-13 in the development and maintenance of asthma. This study assessed the effects of tralokinumab, an investigational human IL-13-neutralising immunoglobulin G4 monoclonal antibody, in adults with moderate-to-severe uncontrolled asthma despite controller therapies.194 subjects were randomised to receive tralokinumab (150, 300 or 600 mg) or placebo subcutaneously every 2 weeks. Primary end-point was change from baseline in mean Asthma Control Questionnaire score (ACQ-6; ACQ mean of six individual item scores) at week 13 comparing placebo and combined tralokinumab dose groups. Secondary end-points included pre-bronchodilator lung function, rescue β2-agonist use and safety. Numerical end-points are reported as mean±sd.At week 13, change from baseline in ACQ-6 was -0.76±1.04 for tralokinumab versus -0.61±0.90 for placebo (p=0.375). Increases from baseline in forced expiratory volume in 1 s (FEV1) were 0.21±0.38 L versus 0.06±0.48 L (p=0.072), with a dose-response observed across the tralokinumab doses tested. β2-agonist use (puffs per day) was decreased for tralokinumab -0.68±1.45 versus placebo -0.10±1.49 (p=0.020). The increase in FEV1 following tralokinumab treatment remained evident 12 weeks after the final dose. Safety profile was acceptable with no serious adverse events related to tralokinumab.No improvement in ACQ-6 was observed, although tralokinumab treatment was associated with improved lung function.

Background-The importance of IL-13 in the asthma paradigm is supported by increased expression in human subjects, particularly in patients with mild-to-moderate asthma. However, the role of IL-13 in severe asthma needs to be further defined.

Rationale:The relationship between airway inflammation and obesity in severe asthma is poorly understood. Objectives: We sought to determine the relationship between sputum mediator profiles and the distribution of eosinophilic inflammation and obesity in people with severe asthma. Methods: Clinical parameters and eight mediators in sputum were assessed in 131 subjects with severe asthma from a single center categorized into lean, overweight, and obese groups defined by their body mass index. In an independent group of people with severe asthma (n ¼ 45) and healthy control subjects (n ¼ 19) eosinophilic inflammation was enumerated in bronchial submucosa, blood, and sputum and related to their body mass index. Measurements and Main Results: Sputum IL-5 geometric mean (95% confidence interval) (pg/ml) was elevated in the obese (1.8 [1.2-2.6]) compared with overweight (1.1 [0.8-1.3]; P ¼ 0.025) and lean (0.9 [0.6-1.2]; P ¼ 0.018) subjects with asthma and was correlated with body mass index (r ¼ 0.29; P , 0.001). There was no relationship among body mass index, the sputum cell count, or other sputum mediators. In the bronchoscopy group the submucosal eosinophil number in the subjects with asthma was correlated with body mass index (Spearman rank correlation, r s ¼ 0.38; P ¼ 0.013) and the median (interquartile range) number of submucosal eosinophils was increased in obese (19.4 [11.8-31.2]) (cells per square millimeter) versus lean subjects (8.2 [5.4-14.6]) (P ¼ 0.006). There was no significant association between sputum or peripheral blood eosinophil counts and body mass index. Conclusions: Sputum IL-5 and submucosal eosinophils, but not sputum eosinophils, are elevated in obese people with severe asthma. Whether specific antieosinophilic therapy is beneficial, or improved diet and lifestyle in obese asthma has antiinflammatory effects beyond weight reduction, requires further study.Keywords: asthma; obesity; cytokines; phenotypes; eosinophil Asthma is a common, complex inflammatory disorder affecting about 5% of adults in the general population, of which approximately 5-10% suffer from severe disease (1, 2). Severe disease is often associated with comorbidities, such as obesity, and is particularly important because these patients suffer from substantial morbidity and consume a disproportionately high amount of the overall healthcare resources spent on asthma management (3-6). Asthma, and in particular severe asthma, is a heterogeneous disease as highlighted by the different phenotypes identified using cluster analysis of clinical data (7-10) and cytokine profiles of airway samples (11-13). The key benefit of dividing a multidimensional disease, such as asthma, into distinct phenotypes is expected to be more effective treatment targeting. This has been effectively shown with the success of eosinophilic airway inflammationdirected corticosteroid (14-16) and anti-IL-5 treatment (17-19) to prevent asthma exacerbations in eosinophilic subjects with asthma. The association of obesity and asthma has been evident Support...

AD is a heterogeneous disease both clinically and biologically. Four distinct clusters of patients with AD have been identified that could represent endotypes with unique biological mechanisms. Elucidation of these endotypes warrants further investigation and will require future intervention trials with specific agents, such as biologics.