Clinical outcomes and inflammatory biomarkers in current smokers and exsmokers with severe asthma

Longitudinal association of exclusive and dual use of cigarettes and cigars with asthma exacerbation among US adults: a cohort study

BACKGROUND

Cigar use among adults in the United States has remained relatively stable in the past decade and occupies a growing part of the tobacco marketplace as cigarette use has declined. While studies have established the detrimental respiratory health effects of cigarette use, the effects of cigar use need further characterization. In this study, we evaluate the prospective association between cigar use, with or without cigarettes, and asthma exacerbation.

METHODS

We used data from Waves 1-5 (2013-2019) of the Population Assessment of Tobacco and Health Study to run generalized estimating equation models examining the association between time-varying, one-wave-lagged cigarette and cigar use and self-reported asthma exacerbation among US adults (18+). We defined our exposure as non-established (reference), former, exclusive cigarette, exclusive cigar, and dual use. We defined an asthma exacerbation event as a reported asthma attack in the past 12 months necessitating oral or injected steroid medication or asthma symptoms disrupting sleep at least once a week in the past 30 days. We adjusted for age, sex, race and ethnicity, household income, health insurance, established electronic nicotine delivery systems use, cigarette pack-years, secondhand smoke exposure, obesity, and baseline asthma exacerbation.

RESULTS

Exclusive cigarette use (incidence rate ratio (IRR): 1.26, 95% confidence interval (CI): 1.03-1.54) and dual use (IRR: 1.41, 95% CI: 1.08-1.85) were associated with a higher rate of asthma exacerbation compared to non-established use, while former use (IRR: 1.01, 95% CI: 0.80-1.28) and exclusive cigar use (IRR: 0.70, 95% CI: 0.42-1.17) were not.

CONCLUSION

We found no association between exclusive cigar use and self-reported asthma exacerbation. However, exclusive cigarette use and dual cigarette and cigar use were associated with higher incidence rates of self-reported asthma exacerbation compared to non-established use. Studies should evaluate strategies to improve cigarette and cigar smoking cessation among adults with asthma who continue to smoke.

Asthma Inflammatory Phenotypes: How Can We Distinguish Them?

BACKGROUND AND OBJECTIVES

induced sputum is used to assess different inflammatory phenotypes in asthma, but is not used routinely. We aimed to determine the proportion of inflammatory asthma phenotypes based on induced sputum, to find biomarkers that can discriminate between phenotypes, and to evaluate biomarkers in patients with and without biological therapy in different inflammatory asthma phenotypes.

MATERIALS AND METHODS

this cross-sectional study investigated clinical characteristics, asthma control tests, skin prick test, impulse oscillometry (IOS), spirometry, induced sputum, biomarkers (IgE, eosinophils, fractional exhaled nitric oxide (FeNO), serum periostin, IL-5, IL-6, IL-8, IL-17A, IL-33) in 80 asthmatics. A total of 17/80 patients were treated with biologics (10 with omalizumab, 7 with benralizumab).

RESULTS

a total of 31% of patients had eosinophilic asthma (EA), 30% had mixed granulocytic asthma (MGA), 24% had paucigranulocytic asthma (PGA), and 15% had neutrophilic asthma (NA). The difference was found in blood eosinophils (p = 0.002), the highest observed in EA. The cut-off ≥ 240/μL eosinophils, with 64% sensitivity and 72.7% specificity, identified EA (AUC = 0.743, p = 0.001). A higher IL-8 level was associated with NA (p = 0.025). In 63 non-biologic asthma group, eosinophils were higher in EA than in NA, MGA, and PGA (p = 0.012, p = 0.028, and p = 0.049, respectively). A higher IL-17A was associated with EA without biologics (p = 0.004). A significantly higher IL-5 was found in EA treated with biologics, in comparison with EA without biologics (p = 0.043). The number of leucocytes and neutrophils was higher in MGA without biologics (p = 0.049, p = 0.019), while IL-5, IL-6, and IL-8 levels were higher in MGA treated with biologics (p = 0.012, p = 0.032, p = 0.038, respectively).

CONCLUSIONS

EA and MGA were the most prevalent asthma phenotypes. Blood eosinophils can identify EA, both in patients with and without biologics. Apart from the clinical profile, a broad spectrum of biomarkers for assessing inflammatory phenotypes is necessary for an adequate therapy approach to patients with asthma.

Tobacco Exposure and Efficacy of Biologic Therapy in Patients With Severe Asthma: A Nationwide Study From the Danish Severe Asthma Register

BACKGROUND

Randomized trials of biologics in severe, uncontrolled asthma have excluded patients with a cumulative tobacco exposure of more than 10 pack-years. Therefore, our knowledge of the impact of smoking exposure on the clinical effects of biologics in severe asthma remains incomplete. However, because many patients with asthma are current or former smokers, investigating the potential impacts of tobacco exposure on the effects of biologic treatment is clinically important.

OBJECTIVE

To investigate the impact of smoking history and tobacco exposure on the effectiveness of biologic therapy in real-life patients with severe asthma.

METHODS

We used data from a complete nationwide cohort of patients with severe asthma who were receiving biologics, the Danish Severe Asthma Register. We divided patients according to smoking history and cumulative tobacco exposure and analyzed data at baseline and after 12 months of biologic treatment.

RESULTS

A total of 724 bio-naive patients were identified in the Danish Severe Asthma Register, 398 of whom had never been smokers (55%), 316 were previous smokers (44%), and 10 were current smokers (1%). Within the group of current and former smokers, 37% had 1 to 9 pack-years of tobacco exposure, 26% had 10 to 19 pack-years, and 37% had 20 or more pack-years of tobacco exposure. Patients with tobacco exposure had similar reductions in the number of exacerbations, reductions in maintenance oral corticosteroid use, and improvements in asthma symptoms compared with patients with 0 pack-years.

CONCLUSION

Former smoking history and lifetime tobacco exposure do not have an impact on the efficacy of biologics in patients with severe asthma.

Antioxidant Intake and Biomarkers of Asthma in Relation to Smoking Status-A Review

Asthma is considered a chronic inflammatory disorder associated with airway hyperresponsiveness (AHR). Increased oxidative stress (OS) is a clinical feature of asthma, which promotes the inflammatory responses in bronchial/airway epithelial cells. Smokers and nonsmokers with asthma have been shown to have increases in several OS and inflammatory biomarkers. However, studies suggest significant differences in OS and inflammation biomarkers between smokers and nonsmokers. A few studies suggest associations between antioxidant intake from diet/supplements and asthma in patients with different smoking status. Evidence is lacking on the protective role of antioxidant vitamin and/or mineral consumption against asthma by smoking status with respect to inflammation and OS biomarkers. Therefore, the aim of this review is to highlight current knowledge regarding the relations between antioxidant intake, asthma, and its associated biomarkers, according to smoking status. This paper can be used to guide future research directions towards the health consequences of antioxidant intake in smoking and nonsmoking asthmatics.

How does cigarette smoking affect airway remodeling in asthmatics?

Asthma is a prevalent chronic airway inflammatory disease involving multiple cells, and the prolonged course of the disease can cause airway remodeling, resulting in irreversible or partial irreversible airflow limitation and persistent airway hyperresponsiveness (AHR) in asthmatics. Therefore, we must ascertain the factors that affect the occurrence and development of airway remodeling in asthmatics. Smokers are not uncommon in asthmatics. However, there is no systematic description of how smoking promotes airway remodeling in asthmatics. This narrative review summarizes the effects of smoking on airway remodeling in asthmatics, and the progress of the methods for evaluating airway remodeling.

Relevance of Smoking Habit in Severe Asthma Patients: Evidence from the Severe Asthma Network in Italy (SANI) Registry

Smoking habit is still fairly common among asthmatics. So far, the impact of smoke on severe asthma burden has not been specifically investigated. We aimed to estimate the frequency of smoking habit among severe asthma patients, their clinical features, and the impact of smoke on asthma outcomes. The Severe Asthma Network in Italy (SANI) registry was analyzed. Demographic, clinical, and functional features of smokers, never and former smokers were compared. Data from 1194 patients were explored. Smokers were younger, with a lower asthma onset age. Atopy, BMI and respiratory/systemic comorbidities were equally distributed. In former smokers pre- and post-FEV1/FVC was significantly lower; no other significant differences were detected. Similar findings were confirmed when stratifying the former smokers by pack-years and length of smoking cessation. Among former smokers, lymphocytes and neutrophils were higher in the <15 years of smoking cessation group. Blood eosinophils were comparable in never and former smokers. When clustering the population by blood eosinophils, no significant differences in pulmonary function and exacerbations were observed. Our data suggest that a personal smoking history has a relatively low impact on disease burden. It remarks the importance of smoking cessation as a main intervention, particularly in severe asthma.

Differential role of mucus plugs in asthma: Effects of smoking and association with airway inflammation

BACKGROUND

The physiological importance of mucus plugs in computed tomography (CT) imaging is being increasingly recognized. However, whether airway inflammation and smoking affect the association between mucus plugs and clinical-physiological outcomes in asthma remains to be elucidated. The objective of this study is to examine how airway inflammation and/or smoking affect the correlation of CT-based mucus plug scores with exacerbation frequency and airflow limitation indices in asthma.

METHODS

A total of 168 patients with asthma who underwent chest CT and sputum evaluation were enrolled and classified in eosinophilic asthma (EA; n = 103) and non-eosinophilic asthma (NEA; n = 65) groups based on sputum eosinophil percentage (cut-off: 3%). The mucus plug score was defined as the number of lung segments with mucus plugs seen on CT.

RESULTS

More mucus plugs were detected on CT scans in the EA group than in the NEA group, regardless of smoking status. Mucus plug score and exacerbation frequency during one year after enrollment were significantly associated in the EA group but not in the NEA group after adjusting for demographics, blood eosinophil count, and fractional exhaled nitric oxide. Mucus plug score was associated with percentage of predicted forced expiratory volume in 1 s in non-smoking individuals in the EA and NEA group and in smoking individuals in the EA group but not in the NEA group after adjusting for demographics.

CONCLUSIONS

The association of mucus plug score with exacerbation frequency and reduced lung function may vary due to airway inflammatory profile and smoking status in asthma.

Multiple Tobacco Product Use among Adolescents with Asthma in Korea

Few studies have examined the use of multiple tobacco products among adolescents with asthma. The purpose of this study was to examine multiple tobacco product use and smoking behaviors. In this study, data from the Korea Youth Risk Behavior Web-based Survey (KYRBWS) were used, and 57,303 samples from 400 middle schools and 400 high schools in Korea were classified as study participants. Statistical analysis was performed with a complex sample design, using frequency analysis, chi-square test, and multiple logistic regression analysis. Adolescents with asthma had a higher current smoking rate for combustible cigarettes (CC), e-cigarettes (EC), and heated tobacco products (HTPs) than those without asthma (p < 0.001). The rates of dual use (using two types of tobacco; CC + EC or CC + HTPs or EC + HTPs; OR = 2.62, 95% CI: 1.626−4.240, R2 = 26.8%) and triple use (using three types of tobacco; CC + EC + HTPs; OR = 2.61, 95% CI: 1.678−4.065, R2 = 34.9%) were higher in adolescents with asthma than those without asthma, after adjusting for confounders. The smoking rate of new types of tobacco among adolescents with asthma is on the rise. Therefore, the calculation of basic data related to new tobacco smoking among adolescents is essential for establishing a continuous monitoring system to alleviate the burden of disease on national health.

Early Features of Chronic Obstructive Pulmonary Disease in Patients with Asthma: Is there ACO before ACO?

The diagnosis of asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) is considered when a patient presents features of both asthma and COPD, usually including a component of irreversible airway obstruction (IRAO). However, some patients with asthma, particularly smokers, may have various features typical of COPD in the absence of such component of IRAO. Features of early COPD can be found at a young age in such patients even with normal spirometry. More longitudinal studies should be conducted to determine steps needed to improve clinical outcomes of these patients including the early recognition of these changes and the application of preventative/therapeutic interventions.

Cigarette Smoking and Asthma

Globally, around half the adult asthma population are current or former cigarette smokers. Cigarette smoking and asthma interact to induce an "asthma-smoking phenotype(s)," which has important implications for diagnosis, pathogenic mechanisms, and management. The lack of progress in understanding the effects of smoking on adults with asthma is due in part to their exclusion from most investigative studies and large clinical trials. In this review, we summarize the adverse clinical outcomes associated with cigarette smoking in asthma, highlight challenges in diagnosing asthma among cigarette smokers with chronic respiratory symptoms, particularly in older individuals with a long-standing smoking history, and review pathogenic mechanisms involving smoking- and asthma-related airway inflammation, tissue remodeling, corticosteroid insensitivity, and low-grade systemic inflammation. We discuss the key components of management including the importance of smoking cessation strategies, evidence for the effectiveness of the Global Initiative for Asthma recommendations on treatment in cigarette smokers, and the role of treatable traits such as type 2 eosinophilic airway inflammation. Lastly, we provide an algorithm to aid clinicians to manage current and former smokers with asthma. In the future, controlled and pragmatic trials in real-world populations should include cigarette smokers with asthma to provide an evidence base for treatment recommendations.

Magnesium isoglycyrrhizinate alleviate airway inflammatory responses in ovalbumin-induced mouse model of allergic asthma

OBJECTIVE

Asthma is a common chronic airway inflammatory disease, lacking effective therapeutic approaches. Magnesium isoglycyrrhizinate (MgIG) is an anti-inflammatory drug for treating chronic inflammation. However, it is still ambiguous whether MgIG can function in allergy induced asthma. In this study, we investigated the anti-inflammation effect of MgIG in mice with allergy induced asthma and explored the underlying mechanisms.

METHODS

Mouse asthma model was established with ovalbumin (OVA) sensitization and challenge. Subsequently, mice sensitized with OVA were randomly assigned into fourgroups: asthma model group (MDL), dexamethasone group (DXM), MgIG group (MgIG), and normal mice were used as normal control (CON). The mice in MgIG, MDL were given 0.2 mg/ml MgIG solution by atomization inhalation for 30 min before 1% (w/v) OVA challenge. At the completion of model establishment and drug treatment, cells in bronchoalveolar lavage fluid were classified, inflammatory factors in serum were determined, histopathological analysis was performed by H&E staining, and expression of MUC5AC, NLRP3, and cleaved caspase-1 in the lung tissue was also determined by immunohistochemistry and western blotting, respectively.

KEY FINDINGS

In comparison to MDL group, MgIG treatment could significantly inhibit the recruitment of white blood cells, neutrophils, and eosinophils in BALF, reduced the production of IL-6, TNF-α, and IgE in serum, and reduced mucus secretion and the infiltration of inflammatory cells. Also, an increase of NLRP3 and Caspase-1 protein levels were suppressed by MgIG treatment.

CONCLUSION

Our study findings support that nebulizer inhalation of MgIG as an effective therapy in treating the allergy induced asthma.

Smoking behavior might affect allergic rhinitis and vasomotor rhinitis differently: A mendelian randomization appraisal

Background

Allergic rhinitis and vasomotor rhinitis are harassing numerous patients and their risk factors have not been well investigated. Here, we try to identify their risk factors and distinguish these 2 diseases.

Methods

A two-sample Mendelian randomization (MR) study was implemented to discover the risk factors of allergic and vasomotor rhinitis. Based on previous studies, we selected 15 potential risk factors and the genome-wide summary statistics were extracted from the non-FinnGen consortium. The genome-wide summary statistics of rhinitis were obtained from the FinnGen consortium. Both univariable MR and multivariable MR analyses were performed to identify the causal risk factors. The Cochrane's Q value was calculated to appraise the heterogeneity. MR-Egger intercept and MR-RPESSO were utilized to appraise the pleiotropy.

Results

In the univariable model, the number of cigarettes per day can decrease the risk of allergic rhinitis (IVW OR = 0.29[0.18, 0.47], p-value = 2.70 × 10⁻⁷) while increasing the risk of vasomotor rhinitis (IVW OR = 1.30[1.04, 1.62], p-value = 0.022). Besides, no other risk factors could affect the risk of either allergic or vasomotor rhinitis. After adjusting for age of smoking initiation and alcohol intake, the cigarettes per day could still decrease the risk of allergic rhinitis (IVW OR = 4.66 × 10⁻³ [1.99 × 10⁻⁴, 0.11], p-value = 0.003) while not affecting the risk of vasomotor rhinitis (IVW OR = 0.92[0.44, 1.96], p-value = 0.834).

Conclusion

Smoking can affect the risk of allergic and vasomotor rhinitis differently where it decreases the risk of allergic rhinitis and increases the risk of vasomotor rhinitis.

Blood eosinophil counts in the general population and airways disease: a comprehensive review and meta-analysis

BACKGROUND

The clinical context for using blood eosinophil (EOS) counts as treatment-response biomarkers in asthma and COPD requires better understanding of EOS distributions and ranges. We describe EOS distributions and ranges published in asthma, COPD, control (non-asthma/COPD) and general populations.

METHODS

We conducted a comprehensive literature review and meta-analysis of observational studies (January 2008 to November 2018) that included EOS counts in asthma, severe asthma, COPD, control and general populations. Excluded studies had total sample sizes <200, EOS as inclusion criterion, hospitalised population only and exclusively paediatric participants.

RESULTS

Overall, 91 eligible studies were identified, most had total-population-level data available: asthma (39 studies), severe asthma (12 studies), COPD (23 studies), control (seven studies) and general populations (14 studies); some articles reported data for multiple populations. Reported EOS distributions were right-skewed (seven studies). Reported median EOS counts ranged from 157-280 cells·µL-1 (asthma, 22 studies); 200-400 cells·µL-1 (severe asthma, eight studies); 150-183 cells·µL-1 (COPD, six studies); and 100-160 cells·µL-1 (controls, three studies); and 100-200 cells·µL-1 (general populations, six studies). The meta-analysis showed that observed variability was mostly between studies rather than within studies. Factors reportedly associated with higher blood EOS counts included current smoking, positive skin-prick test, elevated total IgE, comorbid allergic rhinitis, age ≤18 years, male sex, spirometric asthma/COPD diagnosis, metabolic syndrome and adiposity.

CONCLUSION

EOS distribution and range varied by study population, and were affected by clinical factors including age, smoking history and comorbidities, which, regardless of severity, should be considered during treatment decision-making.

Plasma proteins elevated in severe asthma despite oral steroid use and unrelated to Type-2 inflammation

Rationale

Asthma phenotyping requires novel biomarker discovery.

Objectives

To identify plasma biomarkers associated with asthma phenotypes by application of a new proteomic panel to samples from two well-characterised cohorts of severe (SA) and mild-to-moderate (MMA) asthmatics, COPD subjects and healthy controls (HCs).

Methods

An antibody-based array targeting 177 proteins predominantly involved in pathways relevant to inflammation, lipid metabolism, signal transduction and extracellular matrix was applied to plasma from 525 asthmatics and HCs in the U-BIOPRED cohort, and 142 subjects with asthma and COPD from the validation cohort BIOAIR. Effects of oral corticosteroids (OCS) were determined by a 2-week, placebo-controlled OCS trial in BIOAIR, and confirmed by relation to objective OCS measures in U-BIOPRED.

Results

In U-BIOPRED, 110 proteins were significantly different, mostly elevated, in SA compared to MMA and HCs. 10 proteins were elevated in SA versus MMA in both U-BIOPRED and BIOAIR (alpha-1-antichymotrypsin, apolipoprotein-E, complement component 9, complement factor I, macrophage inflammatory protein-3, interleukin-6, sphingomyelin phosphodiesterase 3, TNF receptor superfamily member 11a, transforming growth factor-β and glutathione S-transferase). OCS treatment decreased most proteins, yet differences between SA and MMA remained following correction for OCS use. Consensus clustering of U-BIOPRED protein data yielded six clusters associated with asthma control, quality of life, blood neutrophils, high-sensitivity C-reactive protein and body mass index, but not Type-2 inflammatory biomarkers. The mast cell specific enzyme carboxypeptidase A3 was one major contributor to cluster differentiation.

Conclusions

The plasma proteomic panel revealed previously unexplored yet potentially useful Type-2-independent biomarkers and validated several proteins with established involvement in the pathophysiology of SA.

Application of new proteomic panel in two established European asthma cohorts identifies plasma proteins associated with disease severity independently of Type-2 inflammation, suggesting potentially useful novel biomarkers and therapeutic targets.https://bit.ly/3jtTq5m

Inhaled corticosteroid response in smoker versus non-smoker asthmatic patients: a cross-sectional study

Background

Asthmatic smokers are a distinct phenotype of asthma. There is a lack of specific information about the treatment of asthma in smokers. The purpose of this study was to compare the effects of inhaled corticosteroid (ICS) on asthmatic smokers and non-smokers.

Results

The present observational, cross-sectional study was conducted at the Chest Department in Assiut University Hospital, during the period from August 2018 to January 2020. Hundred and seventeen asthmatic patients (42 smokers, 30 ex-smokers, and 45 non-smokers) were assessed using an asthma control questionnaire (ACQ), spirometry, sputum cytology, and serum periostin and eotaxin-2 to compare between a patient on inhaled corticosteroid for at least 3 months and patients who do not receive any form of corticosteroid. Asthmatic smokers had poor response to ICS and had insignificant improvement as regard all parameters. However, asthmatic ex-smokers had a partial response to ICS. They had higher post-bronchodilator FEV1 in comparison to those who did not receive ICS. Asthmatic non-smokers on ICS showed the best response as they were well controlled as regard ACQ. Moreover, they had higher post-bronchodilator FEV1/FVC, post-bronchodilator FEV1, and post-bronchodilator FEF25-75, and lower sputum eosinophils and neutrophils.

Conclusion

Smoking adversely affects the course and response to ICS therapy in asthma.

Trial registration

Interrelation between bronchial asthma and smoking: ClinicalTrials.gov ID: NCT03207620. Registered 27 June 2017.

Inhaled corticosteroids' effects on biomarkers in exhaled breath condensate and blood in patients newly diagnosed with asthma who smoke

OBJECTIVE

Exposure to cigarette smoke complicates the treatment and management of asthma through a variety of inflammatory effects. This study aimed to investigate the differences between newly diagnosed cases of asthma in smokers and nonsmokers in terms of localized and systemic biomarkers following treatment with inhaled corticosteroids (ICS) or ICS in combination with a long-acting β2 agonist (LABA).

METHODS

Specimens of exhaled breath condensate (EBC) from newly diagnosed patients with asthma were used to quantify inflammation in the airways, while blood samples were used to assess systemic inflammation. In both samples, the levels of IL-6, LTB4, LTD4, and 8-isoprostane were measured and these were repeated after 3 months of treatment with ICS or ICS + LABA.

RESULTS

Of the 20 patients, 10 (50%) were nonsmokers with asthma (NSA) and 10 (50%) smokers with asthma (SA). There was no statistically significant difference in the blood or EBC levels of IL-6, LTB4, LTD4, or 8-isoprostane between the groups prior to treatment. Only the decrease in 8-isoprostane level in the EBC samples was found to be significantly greater in the NSA group after treatment (for smokers, the change was 2.91 ± 23.22, while for nonsmokers it was -22.72 ± 33.12, p = 0.022). Post-treatment asthma control was significantly better in the NSA group (p = 0.033).

CONCLUSION

Monitoring the alterations in 8-isoprostane levels in EBC in patients with asthma who smoke may be helpful in deciding on therapeutic management and switching treatments. Asthma control was better in nonsmokers than in smokers.

Asthma and COVID-19: a dangerous liaison?

The coronavirus disease 2019 (COVID-19) pandemic, caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), provoked the most striking international public health crisis of our time. COVID-19 can cause a range of breathing problems, from mild to critical, with potential evolution to respiratory failure and acute respiratory distress syndrome. Elderly adults and those affected with chronic cardiovascular, metabolic, and respiratory conditions carry a higher risk of severe COVID-19. Given the global burden of asthma, there are well-founded concerns that the relationship between COVID-19 and asthma could represent a "dangerous liaison".Here we aim to review the latest evidence on the links between asthma and COVID-19 and provide reasoned answers to current concerns, such as the risk of developing SARS-CoV-2 infection and/or severe COVID-19 stratified by asthmatic patients, the contribution of type-2 vs. non-type-2 asthma and asthma-COPD overlap to the risk of COVID-19 development. We also address the potential role of both standard anti-inflammatory asthma therapies and new biological agents for severe asthma, such as mepolizumab, reslizumab, and benralizumab, on the susceptibility to SARS-CoV-2 infection and severe COVID-19 outcomes.

The Impact of Tobacco Smoking on Adult Asthma Outcomes

Background: Tobacco smoking is associated with more severe asthma symptoms, an accelerated decline in lung function, and reduced responses to corticosteroids. Our objective was to compare asthma outcomes in terms of disease control, exacerbation rates, and lung function in a population of asthmatic patients according to their smoking status. Methods: We compared patients’ demographics, disease characteristics, and lung-function parameters in current-smokers (CS, n = 48), former-smokers (FS, n = 38), and never-smokers (NS, n = 90), and identified predictive factors for asthma control. Results: CS had a higher prevalence of family asthma/atopy, a lower rate of controlled asthma, impaired perception of dyspnea, an increased number of exacerbations, and poorer lung function compared to NS. The mean asthma control questionnaire’s (ACQ) score was higher in CS vs. NS and FS (1.9 vs. 1.2, p = 0.02). Compared to CS, FS had a lower rate of exacerbations, a better ACQ score (similar to NS), a higher prevalence of dyspnea, and greater lung-diffusion capacity. Non-smoking status, the absence of dyspnea and exacerbations, and a forced expiratory volume in one second ≥80% of predicted were associated with controlled asthma. Conclusions: CS with asthma exhibit worse clinical and functional respiratory outcomes compared to NS and FS, supporting the importance of smoking cessation in this population.

Heterogeneity of Paucigranulocytic Asthma: A Prospective Cohort Study with Hierarchical Cluster Analysis

BACKGROUND

Asthma, a heterogeneous disease, can be divided into 4 inflammatory phenotypes using induced sputum cell counts-eosinophilic asthma (EA), neutrophilic asthma (NA), mixed granulocytic asthma, and paucigranulocytic asthma (PGA). Although research has focused on EA and NA, there is little known about PGA.

OBJECTIVE

To study the heterogeneity of PGA and identify possible PGA clusters to guide clinical treatment.

METHODS

Patients with PGA were grouped by hierarchical cluster analysis and enrolled into a prospective cohort study to validate the clusters, relative to future risk of asthma exacerbations in a real-world setting. Clusters were validated by tree analysis in a separate population. Finally, we explored PGA stability.

RESULTS

Cluster analysis of 145 patients with PGA identified 3 clusters: cluster 1 (n = 110, 75.9%) was "mild PGA," cluster 2 (n = 20, 13.8%) was "PGA with psychological dysfunction and rhinoconjunctivitis and other allergic diseases," and cluster 3 (n = 15, 10.3%) was "smoking-associated PGA." Cluster 3 had significantly increased risk of severe exacerbation (relative risk [RR] = 6.43, P = .01), emergency visit (RR = 8.61, P = .03), and hospitalization (RR = 12.94, P < .01). Results of the cluster analysis were successfully validated in an independent PGA population classified using decision tree analysis. Although PGA can transform into or develop from other phenotypes, 70% were stable over time.

CONCLUSIONS

Among 3 identified PGA clusters, cluster 3 had a higher risk of severe exacerbation. PGA heterogeneity indicates the requirement of novel targeted interventions.

[Smoking cessation in asthmatic patients and its impact]

INTRODUCTION

The prevalence of smoking in asthmatic patients is similar to, or even higher than in the general population.

OBJECTIVES

This systematic review addresses (1) the effects of smoking on asthma, (2) smoking cessation strategies in asthmatic patients, and (3) the consequences of smoking cessation for people with asthma.

RESULTS

Active or passive smoking can promote the development of asthma. The few studies on smoking cessation in asthma confirm the efficacy of validated smoking cessation strategies in these patients (nicotine replacement therapy, varenicline, bupropion, cognitive and behavioural therapies). Smoking cessation in parents with asthmatic children is essential and is based on the same strategies. Electronic cigarettes may be a useful help to quit smoking in some patients. Smoking cessation is beneficial in asthmatic smokers and associated with (1) a reduction of asthma symptoms, acute exacerbations, bronchial hyperresponsiveness, and bronchial inflammation, (2) decreased use of rescue medications and in doses of inhaled corticosteroids, (3) improved asthma control, quality of life, and lung function.

CONCLUSION

In asthmatic patients, it is essential to assess smoking status and health professionals must assist them to quit smoking.

Characterisation of patients with severe asthma in the UK Severe Asthma Registry in the biologic era

Background

The UK Severe Asthma Registry (UKSAR) is the world’s largest national severe asthma registry collecting standardised data on referrals to UK specialist services. Novel biologic therapies have transformed the management of type 2(T2)-high severe asthma but have highlighted unmet need in patients with persisting symptoms despite suppression of T2-cytokine pathways with corticosteroids.

Methods

Demographic, clinical and treatments characteristics for patients meeting European Respiratory Society / American Thoracic Society severe asthma criteria were examined for 2225 patients attending 15 specialist severe asthma centres. We assessed differences in biomarker low patients (fractional exhaled nitric oxide (FeNO) <25 ppb, blood eosinophils <150/μL) compared with a biomarker high population (FeNO ≥25 ppb, blood eosinophils ≥150/µL).

Results

Age (mean 49.6 (14.3) y), age of asthma onset (24.2 (19.1) y) and female predominance (62.4%) were consistent with prior severe asthma cohorts. Poor symptom control (Asthma Control Questionnaire-6: 2.9 (1.4)) with high exacerbation rate (4 (IQR: 2, 7)) were common despite high-dose treatment (51.7% on maintenance oral corticosteroids (mOCS)). 68.9% were prescribed biologic therapies including mepolizumab (50.3%), benralizumab (26.1%) and omalizumab (22.6%). T2-low patients had higher body mass index (32.1 vs 30.2, p<0.001), depression/anxiety prevalence (12.3% vs 7.6%, p=0.04) and mOCS use (57.9% vs 42.1%, p<0.001). Many T2-low asthmatics had evidence of a historically elevated blood eosinophil count (0.35 (0.13, 0.60)).

Conclusions

The UKSAR describes the characteristics of a large cohort of asthmatics referred to UK specialist severe asthma services. It offers the prospect of providing novel insights across a range of research areas and highlights substantial unmet need with poor asthma control, impaired lung function and high exacerbation rates. T2-high phenotypes predominate with significant differences apparent from T2-low patients. However, T2-low patients frequently have prior blood eosinophilia consistent with possible excessive corticosteroid exposure.

Asthma with Irreversible Airway Obstruction in Smokers and Nonsmokers: Links between Airway Inflammation and Structural Changes

BACKGROUND

The development of irreversible airway obstruction (IRAO) in asthma is related to lung/airway inflammatory and structural changes whose characteristics are likely influenced by exposure to tobacco smoke.

OBJECTIVE

To investigate the interplay between airway and lung structural changes, airway inflammation, and smoking exposure in asthmatics with IRAO.

METHODS

We studied asthmatics with IRAO who were further classified according to their smoking history, those with ≥20 pack-years of tobacco exposure (asthmatics with smoking-related IRAO [AwS-IRAO]) and those with <5 pack-years of tobacco exposure (asthmatics with nonsmoking-related IRAO [AwNS-IRAO]). In addition to recording baseline clinical and lung function features, all patients had a chest computed tomography (CT) from which airway wall thickness was measured and quantitative and qualitative assessment of emphysema was performed. The airway inflammatory profile was documented from differential inflammatory cell counts on induced sputum.

RESULTS

Ninety patients were recruited (57 AwS-IRAO and 33 AwNS-IRAO). There were no statistically significant differences in the extent of emphysema and gas trapping between groups on quantitative chest CT analysis, although Pi10, a marker of airway wall thickness, was significantly higher in AwS-IRAO (p = 0.0242). Visual analysis showed a higher prevalence of emphysema (p = 0.0001) and higher emphysema score (p < 0.0001) in AwS-IRAO compared to AwNS-IRAO and distribution of emphysema was different between groups. Correlations between radiological features and lung function were stronger in AwS-IRAO. In a subgroup analysis, we found a correlation between airway neutrophilia and emphysematous features in AwS-IRAO and between eosinophilia and both airway wall thickness and emphysematous changes in AwNS-IRAO.

CONCLUSIONS

Although bronchial structural changes were relatively similar in smoking and nonsmoking patients with asthma and IRAO, emphysematous changes were more predominant in smokers. However, neutrophils in AwS-IRAO and eosinophils in AwNS-IRAO were associated with lung and airway structural changes.

Targeting neutrophils in asthma: A therapeutic opportunity?

Suppression of airway inflammation with inhaled corticosteroids has been the key therapeutic approach for asthma for many years. Identification of inflammatory phenotypes in asthma has moreover led to important breakthroughs, e.g. with specific targeting of the IL-5 pathway as add-on treatment in difficult-to-treat eosinophilic asthma. However, the impact of interfering with the neutrophilic component in asthma is less documented and understood. This review provides an overview of established and recent insights with regard to the role of neutrophils in asthma, focusing on research in humans. We will describe the main drivers of neutrophilic responses in asthma, the heterogeneity in neutrophils and how they could contribute to asthma pathogenesis. Moreover we will describe findings from clinical trials, in which neutrophilic inflammation was targeted. It is clear that neutrophils are important actors in asthma development and play a role in exacerbations. However, more research is required to fully understand how modulation of neutrophil activity could lead to a significant benefit in asthma patients with airway neutrophilia.

Multidimensional Assessment of Asthma Identifies Clinically Relevant Phenotype Overlap: A Cross-Sectional Study

BACKGROUND

Asthma is a heterogeneous disease with multiple phenotypes; however, the relevance of phenotype overlap remains largely unexplored.

OBJECTIVE

To examine the relationship between phenotype overlap and clinical and inflammatory profiles of asthma.

METHODS

In this cross-sectional study, adult participants with stable asthma (n = 522) underwent multidimensional assessments. The 10 most common phenotypes of asthma were defined and then classified into those commonly associated with Type (T) 2 or non-T2 inflammation. Furthermore, phenotype overlap scores (POS), representing the cumulative concomitant phenotypes, were used to analyze its association with clinical and inflammatory asthmatic profiles.

RESULTS

Among the 522 participants, 73.4% (n = 383) had phenotype overlap, and mixed T2 and non-T2 inflammation coexisted in 47.5% (n = 248). T2 POS was positively associated with eosinophils, IgE, and fractional exhaled nitric oxide (FeNO), and negatively with Asthma Quality of Life Questionnaire (AQLQ), sputum neutrophils, IL-17A, IL-8, and TNF-α. Non-T2 POS was positively associated with Asthma Control Questionnaire, neutrophils and sputum IL-8, and negatively with AQLQ, forced expiratory volume in 1 s, blood eosinophils, IgE, and FeNO (all P < .05). Patients with phenotypes that are associated with mixed T2 and non-T2 inflammation had elevated T2 inflammation biomarkers but worse asthma control. Both T2 (adjusted β = -0.191, P = .035) and non-T2 (adjusted β = 0.310, P < .001) POS were significantly associated with severe exacerbations.

CONCLUSIONS

Phenotype overlap is extremely common in asthmatic patients and significantly associated with clinical and inflammatory profiles. Patients with phenotypes associated with mixed T2 and non-T2 inflammation might be unresponsive to medications owing to increased non-T2 inflammation. Multidimensional asthma assessment identifies clinically relevant phenotype overlap.

The influence of smoking on asthma in the real-life

BACKGROUND

Asthmatic smokers have reduced quality of life and need frequent specialist visits/hospitalization. Smoking habit represents for asthmatics a higher risk for comorbidities and lung function impairment. The impact of cigarette smoking on asthmatics should be addressed to evaluate the related risk factors.

METHODS

This real-life observational study evaluated demographic, clinical/functional, and biological parameters of 521 asthmatic patients stratified as never (0 PY), light (1-10 PY), and heavy smokers (>10PY).

RESULTS

The heavy smokers with asthma were more frequently older, male, overweight, and non-allergic than other asthmatics. Although similar ICS dose and severity among groups, heavy smokers had more significant airflow limitation (FEV₁/FVC = 0.65 ± 0.10, p < 0.01; FEV₁%pred = 79.20 ± 21.20, p < 0.01), air trapping (RV %pred. = 135.6 ± 44.8, p < 0.05; RV/TLC = 0.48 ± 0.12, p < 0.05), and fixed airflow obstruction (post-bronchodilation FEV₁/FVC = 0.66 ± 0.10; p = 0.01) than never and light smokers with asthma. Heavy smokers also demonstrated reduced blood eosinophils (p < 0.05) and FeNO (p < 0.01), increased frequency of type-2 low inflammation and LABA/LAMA use but had less frequently persistent rhinitis and chronic rhinosinusitis with nasal polyposis. Heavy smokers showed higher prevalence of paraseptal/bullous emphysema and arterial hypertension. Considering the risk analysis, heavy smokers showed less chance to have allergy (OR = 0.5), persistent rhinitis (OR = 0.6), chronic rhinosinusitis with nasal polyposis (OR = 0.3), or high FeNO (OR = 0.4), but they were prone to develop fixed airflow obstruction (post-bronchodilation FEV1%pred<80%, OR = 2.0, and post-bronchodilation FEV1/FVC≤0.70, OR = 2.0).

CONCLUSIONS

Heavy smokers had more severe obstructive impairments than light and never smokers with similar ICS dose, showing a steroid insensitivity, but displayed less allergy with low FeNO and blood eosinophil count, thus being a definite phenotype.

Azithromycin is the answer in paediatric respiratory medicine, but what was the question?

The first clinical indication of non-antibiotic benefits of macrolides was in the Far East, in adults with diffuse panbronchiolitis. This condition is characterised by chronic airway infection, often with Pseudomonas aeruginosa, airway inflammation, bronchiectasis and a high mortality. Low dose erythromycin, and subsequently other macrolides, led in many cases to complete remission of the condition, and abrogated the neutrophilic airway inflammation characteristic of the disease. This dramatic finding sparked a flurry of interest in the many hundreds of macrolides in nature, especially their anti-inflammatory and immunomodulatory effects. The biggest subsequent trials of azithromycin were in cystic fibrosis, which has obvious similarities to diffuse panbronchiolitis. There were unquestionable improvements in lung function and pulmonary exacerbations, but compared to diffuse panbronchiolitis, the results were disappointing. Case reports, case series and some randomised controlled trials followed in other conditions. Three trials of azithromycin in preschool wheeze gave contradictory results; a trial in pauci-inflammatory adult asthma, and a trial in non-cystic fibrosis bronchiectasis both showed a significant reduction in exacerbations, but none matched the dramatic results in diffuse panbronchiolitis. There is clearly a huge risk of antibacterial resistance if macrolides are used widely and uncritically in the community. In summary, Azithromycin is not the answer to anything in paediatric respiratory medicine; the paediatric respiratory community needs to refocus on the dramatic benefits of macrolides in diffuse panbronchiolitis, use modern - omics technologies to determine the endotypes of inflammatory diseases and discover in nature or synthesise designer macrolides to replicate the diffuse panbronchiolitis results. We must now find out how to do better!

Quitting smoking reverses nasal mucosal changes

BACKGROUND

Smoking, whether active or passive, has proven deleterious effects on the nasal mucosa. There is also a link between smoking and development and/or maintenance of chronic rhinosinusitis (CRS). Reversal of smoking-induced mucosal changes after quitting smoking is still unconfirmed and controversial. The present study investigated the possibility of reversal of smoking-related nasal mucosal changes back to normal after completely quitting smoking.

METHODS

The study was performed on 32 smokers whose nasal mucosa was previously biopsied for electron microscopic examination and then they completely quit smoking. Smoking history of the participants and duration of cessation of smoking were recorded. A tiny 1-mm3 biopsy was taken from the inferior turbinate 1 cm behind its anterior end and processed for electron microscopy. The specimens were processed for electron microscopy and the sections were examined by a pathologist who was blinded to the identity and smoking status of the participant. The results of electron microscopic examination of the nasal mucosa before and after quitting smoking were compared.

RESULTS

The mean duration of quitting smoking was 30.75 months (± 8.26). Examination of the electron microscopic sections before quitting smoking showed variable degrees of loss of cilia and columnar cells, edema between the epithelial cells, few goblet cells, hyperplasia of seromucinous acini, and vascular congestion. The pathologic changes correlated positively with the smoking index of the participant. On the other hand, the sections after quitting smoking showed variable degrees of regeneration of the ciliated cells and decreased vascular congestion. Numerous goblet cells and seromucinous acini were seen. Less pathologic changes were observed with longer durations of cessation of smoking.

CONCLUSIONS

The present study showed an association between smoking and the nasal mucosa. Smoking has several injurious effects on the nasal mucosa. However, the nasal mucosa has excellent regeneration potentials and quitting smoking for sufficient periods of time may reverse these deleterious changes. Considering the established link between smoking and CRS, quitting smoking may help smokers to overcome their recalcitrant disease. This should be further investigated.

Cytokines at the Interplay Between Asthma and Atherosclerosis?

Cardiovascular disease (CVD) is an important comorbidity in a number of chronic inflammatory diseases. However, evidence in highly prevalent respiratory disease such as asthma are still limited. Epidemiological and clinical data are not univocal in supporting the hypothesis that asthma and CVD are linked and the mechanisms of this relationship remain poorly defined. In this review, we explore the relationship between asthma and cardiovascular disease, with a specific focus on cytokine contribution to vascular dysfunction and atherosclerosis. This is important in the context of recent evidence linking broad inflammatory signaling to cardiovascular events. However inflammatory regulation in asthma is different to the one typically observed in atherosclerosis. We focus on the contribution of cytokine networks encompassing IL-4, IL-6, IL-9, IL-17A, IL-33 but also IFN-γ and TNF-α to vascular dysfunction in atherosclerosis. In doing so we highlight areas of unmet need and possible therapeutic implications.

Airway inflammation and remodeling of cigarette smoking exposure ovalbumin-induced asthma is alleviated by CpG oligodeoxynucleotides via affecting dendritic cell-mediated Th17 polarization

Cigarette smoking (CS) is common in asthma, aggravating inflammatory reactions. However, the current treatment strategies for asthma are still not effective enough, and novel therapeutic approaches are required for CS-induced asthmatic disorders. We here investigated the ability of CpG oligodeoxynucleotides (CpG-ODNs) to inhibit airway inflammation and remodeling in ovalbumin (OVA)-associated asthma in mice exposed to chronic CS, revealing potential mechanistic insights. Lung tissue specimens were histologically analyzed. Th1/Th2/Th17 associated cytokines in serum, bronchoalveolar lavage fluid (BALF), and lung specimens were quantitated by ELISA, qRT-PCR and immunoblot. Parameters of bone marrow-derived dendritic cells (BMDCs) functions were evaluated as well. The results showed that BALB/c mice after CS and OVA treatments developed an asthmatic phenotype with airway inflammation involving both eosinophils and neutrophils, goblet cell metaplasia, airway remodeling, and elevated OVA-specific serum IgE, serum IL-17A, and BALF Th17/Th2 associated cytokines. CpG-ODNs and budesonide were found to synergistically inhibit inflammatory cell recruitment in the lung, airway remodeling, IgE synthesis, and Th17/Th2 associated cytokines. Mechanistically, CpG-ODNs and budesonide acted synergistically on BMDCs via downregulation of TSLP receptor (TSLPR) and IL-23 production, and subsequently contributed to dampen Th17/Th2 polarization in CS-associated asthma. In conclusion, combined administration of CpG-ODNs and budesonide, in a synergistic manner, inhibits airway inflammation, and tissue remodeling mediated by BMDCs by regulating IL-23 secretion and blocking TSLP signaling, which subsequently contribute to alleviate Th17/Th2 imbalance in CS-associated asthma.

Body mass index, asthma, and respiratory symptoms: a population-based study

Objective:

To estimate the prevalence of respiratory symptoms and asthma, according to body mass index (BMI), as well as to evaluate factors associated with physician-diagnosed asthma, in individuals ≥ 40 years of age.

Methods:

This was a population-based cross-sectional study conducted in Florianópolis, Brazil, with probability sampling. Data were collected during home visits. Demographic data were collected, as were reports of physician-diagnosed asthma, respiratory symptoms, medications in use, and comorbidities. Anthropometric measurements were taken. Individuals also underwent spirometry before and after bronchodilator administration. Individuals were categorized as being of normal weight (BMI < 25 kg/m²), overweight (25 kg/m² ≥ BMI < 30 kg/m²), or obese (BMI ≥ 30 kg/m²).

Results:

A total of 1,026 individuals were evaluated, 274 (26.7%) were of normal weight, 436 (42.5%) were overweight, and 316 (30.8%) were obese. The prevalence of physician-diagnosed asthma was 11.0%. The prevalence of obesity was higher in women (p = 0.03), as it was in respondents with ≤ 4 years of schooling (p < 0.001) or a family income of 3-10 times the national minimum wage. Physician-diagnosed asthma was more common among obese individuals than among those who were overweight and those of normal weight (16.1%, 9.9%, and 8.0%, respectively; p = 0.04), as were dyspnea (35.5%, 22.5%, and 17.9%, respectively; p < 0.001) and wheezing in the last year (25.6%, 11.9%, and 14.6%, respectively; p < 0.001). These results were independent of patient smoking status. In addition, obese individuals were three times more likely to report physician-diagnosed asthma than were those of normal weight (p = 0.005).

Conclusions:

A report of physician-diagnosed asthma showed a significant association with being ≥ 40 years of age and with having a BMI ≥ 30 kg/m². Being obese tripled the chance of physician-diagnosed asthma.

The Effect of Flavored E-cigarettes on Murine Allergic Airways Disease

Flavored e-cigarettes are preferred by the majority of users yet their potential toxicity is unknown. Therefore our aim was to determine the effect of selected flavored e-cigarettes, with or without nicotine, on allergic airways disease in mice. Balb/c mice were challenged with PBS or house dust mite (HDM) (Days 0, 7, 14-18) and exposed to room air or e-cigarette aerosol for 30 min twice daily, 6 days/week from Days 0-18 (n = 8-12/group). Mice were exposed to Room Air, vehicle control (50%VG/%50PG), Black Licorice, Kola, Banana Pudding or Cinnacide without or with 12 mg/mL nicotine. Mice were assessed at 72 hours after the final HDM challenge. Compared to mice challenged with HDM and exposed to Room Air, nicotine-free Cinnacide reduced airway inflammation (p = 0.045) and increased peripheral airway hyperresponsiveness (p = 0.02), nicotine-free Banana Pudding increased soluble lung collagen (p = 0.049), with a trend towards increased airway inflammation with nicotine-free Black Licorice exposure (p = 0.089). In contrast, all e-cigarettes containing nicotine suppressed airway inflammation (p < 0.001 for all) but did not alter airway hyperresponsiveness or airway remodeling. Flavored e-cigarettes without nicotine had significant but heterogeneous effects on features of allergic airways disease. This suggests that some flavored e-cigarettes may alter asthma pathophysiology even when used without nicotine.

ERICA: smoking is associated with more severe asthma in Brazilian adolescents

OBJECTIVE

To investigate the association between smoking and asthma, and possible associated factors in Brazilian adolescents.

METHODS

A cross-sectional, national, school-based study with adolescents aged 12-17 years, participants in the Study of Cardiovascular Risks in Adolescents (Estudo de Riscos Cardiovasculares em Adolescentes - ERICA). A total of 66,394 participants answered a self-administered questionnaire with questions about asthma, smoking, lifestyle and sociodemographic variables. Bivariate analysis between Current Asthma (CA) and Severe Asthma (SA) and the other study variables were performed using Chi-squared. Then, the crude and adjusted Prevalence Ratios (PR), and respective 95% Confidence Intervals (95% CI) of current asthma/severe asthma and smoking variables, corrected for sociodemographic and lifestyle variables, were estimated using generalized linear models with Poisson regression, logit link, and robust variance.

RESULTS

The prevalence of current asthma and severe asthma were significantly higher in adolescents who were exposed to: experimentation (current asthma: PR=1.78, 95% CI: 1.51-2.09; severe asthma: PR=2.01; 95% CI: 1.35-2.98); current smoking (current asthma: PR=2.08, 95% CI: 1.65-2.64; severe asthma: PR=2.29; 95% CI: 1.38-3.82); regular smoking (current asthma: PR=2.25, 95% CI: 1.64-3.07; severe asthma: PR: 2.41; 95% CI: 1.23-4.73); and passive smoking (current asthma: PR=1.47, 95% CI: 1.27-1.67; severe asthma: PR=1.66; 95% CI: 1.19-2.32); these associations remained significant after adjustment.

CONCLUSIONS

Asthma and smoking were significantly associated in Brazilian adolescents, regardless of the sociodemographic and lifestyle factors, notably in those with more severe disease.

Bronchial thermoplasty increases airway volume measured by functional respiratory imaging

BACKGROUND

The purpose of this study was to use CT scanning with computational fluid dynamics to evaluate the mechanisms by which Bronchial Thermoplasty (BT) improves asthmatic symptoms.

METHODS

The study was conducted in a university teaching hospital, experienced in performing BT. Imaging studies were performed before, and after, BT of the left lung, and prior to treatment of the right lung, which therefore acted as a control. On each occasion, two high-resolution CT scans were performed, one at full inspiration (TLC) and the other at Functional Residual Capacity (FRC). The study protocol was offered to 10 patients, all of whom met the definition of severe asthma, despite high dose inhaled corticosteroids and dual long acting bronchodilators.

RESULTS

Significant increases in airway luminal volume were observed on the treated side, compared with control, at both full inspiration (by 27%) and at FRC (by 17%). The ratio of distal airway volume to lung volume significantly increased on the treated side. The change in airway volume with inspiration from FRC increased by 48% on the treated side compared to 5% in the control lung, suggesting treatment increased airway distensibility. No effect was observed on airway wall thickness, nor air trapping. There was a trend towards correlation between the improvement in airway volume at TLC and improvement in symptoms.

CONCLUSION

This study demonstrates that BT increases the luminal airway volume on the treated side compared to the control lung. We suggest that this is an important link between the airway smooth muscle atrophy demonstrated pathologically, and the improvement in symptoms observed clinically.

Serum levels of IL-5, IL-6, IL-8, IL-13 and IL-17A in pre-defined groups of adult patients with moderate and severe bronchial asthma

BACKGROUND

Bronchial asthma (BA) is a complex disease characterised by persistent inflammation. Exhaled nitric oxide (FeNO) and blood eosinophil count (b-Eos) are biomarkers for type 2 endotype of BA.

OBJECTIVE

To analyse a panel of serum interleukins and total IgE in predefined by FeNO and b-Eos groups of moderate and severe BA patients.

METHODS

Serum levels of IL-5, IL-6, IL-8, IL-13 and IL-17A (ELISA) were measured in 30 healthy controls (HC) and 80 adult BA patients. BA patients were split into 4 groups. Group 1:Low FeNO/Low b-Eos (n = 23; 28.8%); Group 2:Low FeNO/High b-Eos (n = 17; 21.3%); Group 3:High FeNO/Low b-Eos (n = 15; 18.8%); Group 4:High FeNO/High b-Eos (n = 25; 31.3%).

RESULTS

All interleukins and total IgE were significantly higher in patients with BA as compared with HC. IL-5 levels were highest in Group 2 (p < 0.05). IL-6, IL-13 and IL-17A levels were elevated in Groups 2, 3 and 4 as compared with HC (p < 0.05). Higher IL-8 levels were associated with a pattern of current smokers. Highest IL-17A levels were found in type 2 high groups with frequent exacerbations, mostly uncontrolled and severe BA. We have found a distinct pattern for each group based on demographic, clinical, functional, immunological and inflammatory characteristics.

CONCLUSION

FeNO and b-Eos are useful in the identification of severe type 2 BA subgroups with frequent exacerbations. IL-5, IL-6, IL-13 and IL-17A are involved in the persistent type 2 immune response in moderate and severe BA. We have identified a pattern of refractory, severe type 2/IL-17A high BA in the real clinical practice.

Basic characteristics and clinical value of FeNO in smoking asthmatics-a systematic review

Fractional exhaled nitric oxide (FeNO) reflects eosinophilic airway inflammation and it can be used to diagnose and phenotype asthma and predict treatment responses. However, smoking decreases FeNO and it is not clear if FeNO has clinical value in smoking subjects with asthma. We conducted a systematic review focusing on four basic characteristics and five clinical questions on using FeNO in smokers with asthma. At least two authors independently screened search results, extracted data and assessed the quality of the included studies. Data were synthesised mainly by qualitative methods. Twenty-two studies were included. FeNO is lower in smoking than in non-smoking asthmatics, but importantly FeNO is higher in untreated smoking asthmatics than in healthy smokers. Information was incomplete but there is some indication that FeNO might be useful in detecting eosinophilic airway inflammation and in diagnosing asthma in smoking subjects. There was no data available to four of the five clinical questions. In conclusion, at the moment there is insufficient data to give specific guidelines on using FeNO in smoking subjects, but although smoking decreases FeNO it does not seem to make FeNO measurement redundant. FeNO is also associated with asthma in smokers and current results encourage conducting clinical trials on FeNO in smokers with asthma.

Distinct Phenotypes of Smokers with Fixed Airflow Limitation Identified by Cluster Analysis of Severe Asthma

RATIONALE

Smoking may have multifactorial effects on asthma phenotypes, particularly in severe asthma. Cluster analysis has been applied to explore novel phenotypes, which are not based on any a priori hypotheses.

OBJECTIVES

To explore novel severe asthma phenotypes by cluster analysis when including smoking patients with asthma.

METHODS

We recruited a total of 127 subjects with severe asthma, including 59 current or ex-smokers, from our university hospital and its 29 affiliated hospitals/pulmonary clinics. Clinical variables obtained during a 2-day hospital stay were used for cluster analysis. After clustering using clinical variables, the sputum levels of 14 molecules were measured to biologically characterize the clinical clusters.

RESULTS

Five clinical clusters, including two characterized by low forced expiratory volume in 1 second/forced vital capacity, were identified. When characteristics of smoking subjects in these two clusters were compared, there were marked differences between the two groups: one had high levels of circulating eosinophils, high immunoglobulin E levels, and a high sinus score, and the other was characterized by low levels of the same parameters. Sputum analysis revealed intriguing differences of cytokine/chemokine pattern in these two groups. The other three clusters were similar to those previously reported: young onset/atopic, nonsmoker/less eosinophilic, and female/obese. Key clinical variables were confirmed to be stable and consistent 3 years later.

CONCLUSIONS

This study reveals two distinct phenotypes with potentially different biological pathways contributing to fixed airflow limitation in cigarette smokers with severe asthma.

Severe Occupational Asthma: Insights From a Multicenter European Cohort

BACKGROUND

Although sensitizer-induced occupational asthma (OA) accounts for an appreciable fraction of adult asthma, the severity of OA has received little attention.

OBJECTIVE

The aim of this study was to characterize the burden and determinants of severe OA in a large multicenter cohort of subjects with OA.

METHODS

This retrospective study included 997 subjects with OA ascertained by a positive specific inhalation challenge completed in 20 tertiary centers in 11 European countries during the period 2006 to 2015. Severe asthma was defined by a high level of treatment and any 1 of the following criteria: (1) daily need for a reliever medication, (2) 2 or more severe exacerbations in the previous year, or (3) airflow obstruction.

RESULTS

Overall, 162 (16.2%; 95% CI, 14.0%-18.7%) subjects were classified as having severe OA. Multivariable logistic regression analysis revealed that severe OA was associated with persistent (vs reduced) exposure to the causal agent at work (odds ratio [OR], 2.78; 95% CI, 1.50-5.60); a longer duration of the disease (OR, 1.04; 95% CI, 1.00-1.07); a low level of education (OR, 2.69; 95% CI, 1.73-4.18); childhood asthma (OR, 2.92; 95% CI, 1.13-7.36); and sputum production (OR, 2.86; 95% CI, 1.87-4.38). In subjects removed from exposure, severe OA was associated only with sputum production (OR, 3.68; 95% CI, 1.87-7.40); a low education level (OR, 3.41; 95% CI, 1.72-6.80); and obesity (OR, 1.98; 95% CI, 0.97-3.97).

CONCLUSIONS

This study indicates that a substantial proportion of subjects with OA experience severe asthma and identifies potentially modifiable risk factors for severe OA that should be targeted to reduce the adverse impacts of the disease.

Longitudinal comparison of outcomes in patients with smoking-related asthma-COPD overlap and in non-smoking asthmatics with incomplete reversibility of airway obstruction

Background

There is a need to characterize the impact of the smoking status on the clinical course of asthmatics with incomplete reversibility of airway obstruction (IRAO).

Objective

To compare longitudinal health care use, symptom control, and medication needs between smoking and non-smoking asthmatics with IRAO.

Materials and methods

This was a 12-month follow-up of a cross-sectional study comparing asthmatics with IRAO according to their tobacco exposure. One group had a tobacco exposure ≥20 pack-years and was considered to have asthma-COPD overlap (ACO) and the second with a past tobacco exposure <5 pack-years was considered as non-smokers with IRAO (NS-IRAO). Study participants were contacted by telephone every 3 months to document exacerbation events and symptom control.

Results

A total of 111 patients completed all follow-up telephone calls: 71 ACO and 40 NS-IRAO. The number of exacerbations per patient over the 12-month follow-up was similar in both groups. However, ACO reported worse symptom control throughout the follow-up as compared to NS-IRAO, although no significant variations within a group were observed over the study period.

Conclusion

Although asthma control scores were poorer in ACO patients over 1 year compared to NS-IRAO, exacerbation rate was similar and low in both groups of asthmatics. These observations suggest that poorer asthma control in ACO was not driven by the number of exacerbations but may reflect the influence of chronic airway changes related to the COPD component.

NETopathic Inflammation in Chronic Obstructive Pulmonary Disease and Severe Asthma

Neutrophils play a central role in innate immunity, inflammation, and resolution. Unresolving neutrophilia features as a disrupted inflammatory process in the airways of patients with chronic obstructive pulmonary disease (COPD) and severe asthma. The extent to which this may be linked to disease pathobiology remains obscure and could be further confounded by indication of glucocorticoids or concomitant respiratory infections. The formation of neutrophil extracellular traps (NETs) represents a specialized host defense mechanism that entrap and eliminate invading microbes. NETs are web-like scaffolds of extracellular DNA in complex with histones and neutrophil granular proteins, such as myeloperoxidase and neutrophil elastase. Distinct from apoptosis, NET formation is an active form of cell death that could be triggered by various microbial, inflammatory, and endogenous or exogenous stimuli. NETs are reportedly enriched in neutrophil-dominant refractory lung diseases, such as COPD and severe asthma. Evidence for a pathogenic role for respiratory viruses (e.g., Rhinovirus), bacteria (e.g., Staphylococcus aureus) and fungi (e.g., Aspergillus fumigatus) in NET induction is emerging. Dysregulation of this process may exert localized NET burden and contribute to NETopathic lung inflammation. Disentangling the role of NETs in human health and disease offer unique opportunities for therapeutic modulation. The chemokine CXCR2 receptor regulates neutrophil activation and migration, and small molecule CXCR2 antagonists (e.g., AZD5069, danirixin) have been developed to selectively block neutrophilic inflammatory pathways. NET-stabilizing agents using CXCR2 antagonists are being investigated in proof-of-concept studies in patients with COPD to provide mechanistic insights. Clinical validation of this type could lead to novel therapeutics for multiple CXCR2-related NETopathologies. In this Review, we discuss the emerging role of NETs in the clinicopathobiology of COPD and severe asthma and provide an outlook on how novel NET-stabilizing therapies via CXCR2 blockade could be leveraged to disrupt NETopathic inflammation in disease-specific phenotypes.

European Respiratory Society International Congress 2018: Allied Respiratory Professionals' report of highlighted sessions

This article provides an overview of outstanding sessions that were supported by Assembly 9 during the recent European Respiratory Society International Congress in Paris, France. Session content was mainly targeted at allied health professionals such as respiratory physiologists, respiratory physiotherapists and respiratory nurses. Recent developments and novel findings related to pulmonary function testing, respiratory muscle function assessments and treatment, and multidimensional and multidisciplinary approaches to the assessment and management of dyspnoea were the focus of these sessions and are summarised here.

Randomised controlled trials in severe asthma: selection by phenotype or stereotype

Previous publications have highlighted the disparity between research trial populations and those in clinical practice, but it has not been established how this relates to randomised controlled trials (RCTs) of phenotype-targeted biological therapies in severe asthma.Detailed characterisation data for 342 severe asthma patients within the Wessex Severe Asthma Cohort (WSAC) was compared against comprehensive trial eligibility criteria for published phase IIB and phase III RCTs evaluating biological therapies in severe asthma since 2000.37 RCTs evaluating 20 biological therapies were identified. Only a median of 9.8% (range 3.5-17.5%) of severe asthma patients were found to be eligible for enrolment in the phase III trials. Stipulations for airflow obstruction, bronchodilator reversibility and smoking history excluded significant numbers of patients. A median of 78.9% (range 73.2-86.6%) of patients with severe eosinophilic asthma would have been excluded from participation in the phase III licensing trials of interleukin (IL)-5/IL-5R targeted therapies.Despite including only well characterised and optimally treated severe asthmatics under specialist care within the WSAC study, the vast majority were excluded from trial participation by criteria designed to re-confirm diagnostic labels rather than by biomarker criteria that predict the characteristic addressed by the treatment.

Sulforaphane ameliorates steroid insensitivity through an Nrf2-dependent pathway in cigarette smoke-exposed asthmatic mice

Oxidative stress induced by cigarette smoke and other environmental pollutants contributes to refractory asthma. To better understand the role of smoking in asthma, we investigated the effects of cigarette smoke on allergic airway responses in mice and examined expression of nuclear factor-E2-related factor-2 (Nrf2) and its downstream factors, because Nrf2 is known to play a pivotal role in antioxidant responses. OVA-sensitized and challenged BALB/c mice were exposed to cigarette smoke and then treated with dexamethasone, sulforaphane (an activator of Nrf2), or their combination. Upon exposure to cigarette smoke, Nrf2 and associated transcripts were upregulated in response to oxidative stress, and asthmatic responses were steroid resistant. In OVA-sensitized and challenged mice exposed to cigarette smoke and treated with sulforaphane, Nrf2-mediated antioxidant responses were upregulated to a greater extent, and steroid sensitivity of asthmatic responses was restored. Moreover, the expression and activity of histone deacetylase 2 (HDAC2), a key regulator of steroid responsiveness, was reduced in mice exposed to cigarette smoke, but restored by sulforaphane treatment. No effects of sulforaphane were observed in Nrf2-deficient mice. These findings indicate that cigarette smoke induces steroid unresponsiveness in asthmatic airways, and that sulforaphane restores steroid sensitivity via upregulation of Nrf2 and enhancement of HDAC2 expression and activity. Thus, Nrf2 may serve as a potential molecular target for cigarette smoke-related refractory asthma resistant to steroid therapy.

The Portuguese Severe Asthma Registry: Development, Features, and Data Sharing Policies

The Portuguese Severe Asthma Registry (Registo de Asma Grave Portugal, RAG) was developed by an open collaborative network of asthma specialists. RAG collects data from adults and pediatric severe asthma patients that despite treatment optimization and adequate management of comorbidities require step 4/5 treatment according to GINA recommendations. In this paper, we describe the development and implementation of RAG, its features, and data sharing policies. The contents and structure of RAG were defined in a multistep consensus process. A pilot version was pretested and iteratively improved. The selection of data elements for RAG considered other severe asthma registries, aiming at characterizing the patient's clinical status whilst avoiding overloading the standard workflow of the clinical appointment. Features of RAG include automatic assessment of eligibility, easy data input, and exportable data in natural language that can be pasted directly in patients' electronic health record and security features to enable data sharing (among researchers and with other international databases) without compromising patients' confidentiality. RAG is a national web-based disease registry of severe asthma patients, available at asmagrave.pt. It allows prospective clinical data collection, promotes standardized care and collaborative clinical research, and may contribute to inform evidence-based healthcare policies for severe asthma.