Smoking in asthma is associated with elevated levels of corticosteroid resistant sputum cytokines-an exploratory study

Inadequate therapeutic responses to glucocorticoid treatment in bronchial asthma

Bronchial asthma (BA) is a heterogeneous disease. Some patients benefit greatly from glucocorticoid (GC) treatment, whereas others are non-responders. This could be attributable to differences in pathobiology. Thus, predicting the responses to GC treatment in patients with BA is necessary to increase the success rates of GC therapy and avoid adverse effects. The sustained inflammation in BA decreases glucocorticoid receptor (GR, NR3C1) function. Meanwhile, GRβ overexpression might contribute to GC resistance. Important factors in decreased GR function include p38 mitogen-activated protein kinase-dependent GR phosphorylated at Ser226, reduced expression of histone deacetylase 2 following activation of the phosphatidylinositol 3-kinase-δ signaling pathway, and increased nuclear factor-kappa B activity. MicroRNAs, which are involved in GC sensitivity, are considered biomarkers of the response to inhaled GCs. Some studies revealed that inflammatory phenotypes and disease-related modifiable factors, including infections, the airway microbiome, mental stress, smoking, and obesity, regulate individual sensitivity to GCs. Therefore, future investigations are warranted to improve treatment outcomes.

T2-Low Asthma: A Discussed but Still Orphan Disease

Asthma affects 10% of the worldwide population; about 5% of cases are severe with the need for target therapies such as biologics. All the biologics approved for asthma hit the T2 pathway of inflammation. T2-high asthma is classified as allergic and non-allergic, whereas T2-low asthma can be further defined as paucigranulocytic asthma, Type 1 and Type-17 inflammation and the neutrophilic form that accounts for 20-30% of all patients with asthma. Neutrophilic asthma's prevalence is even higher in patients with severe or refractory asthma. We searched Medline and PubMed archives from the past ten years for articles with the subsequent titles: "neutrophilic asthma", "non-type 2 asthma" and "paucigranulocytic asthma". We identified 177 articles; 49 were considered relevant by the title and 33 by the reading of the abstract. Most of these articles are reviews (n = 19); only 6 are clinical trials. No study identified an effective treatment. We used the literature reported by these articles to search for further biologic treatments that target pathways different from T2. We identified 177 articles, 93 of which were considered relevant for the review and included in the present article. In conclusion, T2-low asthma remains poorly investigated in terms of biomarkers, especially as a therapeutic orphan disease.

Corticosteroid resistance in asthma: Cellular and molecular mechanisms

Inhaled glucocorticoids (GCs) are drugs widely used as treatment for asthma patients. They prevent the recruitment and activation of lung immune and inflammatory cells and, moreover, have profound effects on airway structural cells to reverse the effects of disease on airway inflammation. GCs bind to a specific receptor, the glucocorticoid receptor (GR), which is a member of the nuclear receptor superfamily and modulates pro- and anti-inflammatory gene transcription through a number of distinct and complementary mechanisms. Targets genes include many pro-inflammatory mediators such as chemokines, cytokines, growth factors and their receptors. Inhaled GCs are very effective for most asthma patients with little, if any, systemic side effects depending upon the dose. However, some patients show poor asthma control even after the administration of high doses of topical or even systemic GCs. Several mechanisms relating to inflammation have been considered to be responsible for the onset of the relative GC resistance observed in these patients. In these patients, the side-effect profile of GCs prevent continued use of high doses and new drugs are needed. Targeting the defective pathways associated with GC function in these patients may also reactivate GC responsiveness.

Prevalence of asthma—chronic obstructive pulmonary disease overlap in patients with airflow limitation

Background

Asthma-COPD overlap (ACO) according to GINA and GOLD is not a single disease and is described by persistent airflow limitation with several features usually associated with asthma and several features usually associated with COPD. Some different protocols were proposed to diagnose ACO, besides those reported in GINA and GOLD guidelines. Despite the discrepancy between all the proposed diagnostic protocols, the diagnosis of ACO is still worthy as it may lead to a more appropriate treatment plan. In Egypt, prevalence of ACO is hardly estimated due to lack of database of patients. Our aim of work was to detect the prevalence of ACO in patients diagnosed as having a chronic airflow limiting disease.

Results

In asthma group (75 patients), 53.3% (40 patients) were diagnosed as ACO with 3 statistically significant favoring diagnostic criteria; post-BDR test FEV1/FVC < 70%, longer disease duration, and sputum neutrophilia ≥ 57%. While in COPD group (75 patients), 42.7% (32 patients) were diagnosed as ACO with four statistically significant favoring diagnostic criteria; higher BDR, presence of personal history of either asthma or atopy and sputum eosinophils > 1%.

Conclusions

ACO has an underestimated prevalence among those diagnosed with either asthma or COPD. More consensus guidelines are needed to focus on the more effective and the more practical criteria to diagnose such hidden disease.

The effects of oral corticosteroids on lung function, type-2 biomarkers and patient-reported outcomes in stable asthma: A systematic review and meta-analysis

BACKGROUND

Several studies have investigated the physiological effect of OCS in stable asthma, however these have included heterogeneous populations and outcomes. This paper is the first to combine their results.

METHODS

We searched Medline, Embase and Web of Science databases for studies reporting the impact of OCS on FEV₁, FVC, blood eosinophils, fractional exhaled nitric oxide (FeNO), Asthma Control Questionnaire (ACQ) score or Asthma Quality Of Life Questionnaire (AQLQ) score in stable asthma. We extracted data on the correlates of OCS response.

RESULTS

61 studies, comprising 1608 patients, were included. FEV₁ was improved by 9% (95% CI: 7, 11). There were stronger increases in FEV₁ among those with a mean baseline FEV₁<60% predicted (19%, 95% CI: 13, 24). Despite these improvements, substantial residual impairment remained after treatment. Blood eosinophils were reduced by 76% (95% CI: 63, 88) with larger decreases in studies of corticosteroid-naïve patients (93%, 95% CI: 73,100). Sputum eosinophils were reduced by 89% (95% CI: 79, 98) while FeNO was decreased by 35% (95% CI: 28, 41). ACQ scores were reduced by 20% (95% CI: 11, 29). Patients with higher baseline lung function impairment, sputum eosinophils, blood eosinophils and FeNO had improved OCS response.

INTERPRETATION

OCS consistently improves lung function, reduces markers of type-2 inflammation, and alleviates asthma symptoms. However, substantial residual impairment remained following treatment and mean improvements were below the minimally important clinically difference. Patients with increased markers of type-2 inflammation are more responsive to treatment, suggesting these should be used to better target OCS use.

New insights in neutrophilic asthma

PURPOSE OF REVIEW

Recent advances in both murine models and clinical research of neutrophilic asthma are improving our understanding on the etiology and pathophysiology of this enigmatic endotype of asthma. We here aim at providing an overview of our current and latest insights on the pathophysiology and treatment of neutrophilic asthma.

RECENT FINDINGS

Activation of the NLRP3 inflammasome pathway with increased IL-1β has been demonstrated in various studies involving patients with asthma. It has been suggested that type 3 innate lymphoid cells are implicated in the inflammatory cascade leading to neutrophilic inflammation. The role of neutrophil extracellular traps is only at the start of being understood and might be an attractive novel therapeutic target. A diverse panel of nonallergic stimuli, such as cigarette smoke, intensive exercise, cold air or saturated fatty acids, have been linked with neutrophilic airway inflammation. Azithromycin treatment could reduce asthma exacerbations and quality of life in patients with persistent asthma.

SUMMARY

Research of the last few years has accelerated our insights in mechanisms underlying neutrophilic asthma. This is in stark contrast with the lack of efficacy of different therapies targeting neutrophil chemotaxis and/or signalling cascade, such as IL-17A or CXCR2. Macrolide therapy might be a useful add-on therapy for patients with persistent 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.

Epithelial growth factor receptor tyrosine kinase inhibitors alleviate house dust mite allergen Der p2-induced IL-6 and IL-8

Steroid-insensitive asthma-related airway inflammation is associated with the expression of epidermal growth factor receptor (EGFR) tyrosine kinase in asthmatic bronchial epithelium. Proinflammatory cytokines IL-6 and IL-8 are related to steroid-insensitive asthma. It is currently unknown how EGFR-tyrosine kinase inhibitors (EGFR-TKIs) affects house dust mite (HDM)-induced asthma in terms of inflammatory cytokines related to steroid-resistant asthma and further signaling pathway. Cytokine expressions and EGFR signaling pathway were performed by ELISA, reverse transcriptase PCR, real-time PCR, and Western blot in cell-line models. AMP-activated protein kinase (AMPK) pathway-related inhibitors were applied to confirm the association between EGFR-TKI and AMPK pathway. HDM induced IL-6 and IL-8 in a dose-dependent manner. Both Erlotinib (Tarceva) and Osimertinib (AZD-9291) reduced the levels of HDM-stimulated IL-6 and IL-8 levels in BEAS-2B cells. AZD-9291 was more effective than Erlotinib in inhibiting phospho-EGFR, and downstream phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) and phopho-signal transducer and activator of transcription 3 (p-STAT3) pathway signaling. In addition, AMPK pathway-related inhibitor, Calcium-/calmodulin-dependent protein kinase kinase β (CaMKKβ) inhibitor, down-regulated IL-8, but EGFR-TKI had no effect on AMPK pathway. Our findings highlight EGFR-TKIs, Tarceva, and AZD-9291, attenuate HDM-induced inflammatory IL-6 and IL-8 cytokines via EGFR signaling axis pathway, but not AMPK signaling pathway.

Challenges in the management of asthma associated with smoking-induced airway diseases

INTRODUCTION

Smoking-induced airway diseases such as chronic bronchitis, emphysema, and small airway dysfunction contribute to the chronic respiratory symptoms experienced by adults with asthma, including those with spirometric chronic obstructive pulmonary disease (COPD), termed asthma-COPD overlap (ACO). Drug treatment of symptomatic smokers with asthma or ACO is uncertain due to their exclusion from most clinical trials.

AREAS COVERED

This review summarizes evidence for the efficacy of small molecule drugs used in the clinic to treat current and former smokers with a diagnostic label of asthma or ACO. Other therapeutic interventions are reviewed, including smoking cessation and biologics.

EXPERT OPINION

Clinical trials and observational studies suggest that smoking cessation and approved drugs used to treat non-smokers with asthma produce clinical benefits in smokers with asthma or ACO, although the overall quality of evidence is low. The efficacy of some treatments for asthma is altered in current smokers, including reduced responsiveness to short-term inhaled corticosteroids and possibly improved responsiveness to leukotriene receptor antagonists. Preliminary findings suggest that low-dose theophylline, statins, and biologics, such as omalizumab, mepolizumab, and dupilumab, may improve clinical outcomes in smokers with asthma or ACO. Improved phenotyping and endotyping of asthma and smoking-induced airway diseases should lead to better targeted therapies.

Air pollution and resistance to inhaled glucocorticoids: Evidence, mechanisms and gaps to fill

Substantial evidence indicates that cigarette smoke exposure induces resistance to glucocorticoids, the primary maintenance medication in asthma treatment. Modest evidence also suggests that air pollution may reduce the effectiveness of these critical medications. Cigarette smoke, which has clear parallels with air pollution, has been shown to induce glucocorticoid resistance in asthma and it has been speculated that air pollution may have similar effects. However, the literature on an association of air pollution with glucocorticoid resistance is modest to date. In this review, we detail the evidence for, and against, the effects of air pollution on glucocorticoid effectiveness, focusing on results from epidemiology and controlled human exposure studies. Epidemiological studies indicate a correlation between increased air pollution exposure and worse asthma symptoms. But these studies also show a mix of beneficial and harmful effects of glucocorticoids on spirometry and asthma symptoms, perhaps due to confounding influences, or the induction of glucocorticoid resistance. We describe mechanisms that may contribute to reductions in glucocorticoid responsiveness following air pollution exposure, including changes to phosphorylation or oxidation of the glucocorticoid receptor, repression by cytokines, or inflammatory pathways, and epigenetic effects. Possible interactions between air pollution and respiratory infections are also briefly discussed. Finally, we detail a number of therapies that may boost glucocorticoid effectiveness or reverse resistance in the presence of air pollution, and comment on the beneficial effects of engineering controls, such as air filtration and asthma action plans. We also call attention to the benefits of improved clean air policy on asthma. This review highlights numerous gaps in our knowledge of the interactions between air pollution and glucocorticoids to encourage further research in this area with a view to reducing the harm caused to those with airways disease.

Extrafine compared to non-extrafine particle inhaled corticosteroids in smokers and ex-smokers with asthma

BACKGROUND

Smoking is as prevalent in asthmatics as in the general population. Asthmatic smokers benefit less from inhaled corticosteroids (ICS) than non-smoking asthmatics, possibly due to more smoking-induced small airways disease. Thus targeting small airways may be important in treating asthmatic (ex-)smokers. We hypothesized that extrafine particle ICS improve small airways function more than non-extrafine particle ICS in asthmatic (ex-)smokers.

METHODS

We performed an open-label, randomized, three-way cross-over study comparing extrafine beclomethasone (HFA-QVAR) to non-extrafine beclomethasone (HFA-Clenil) and fluticasone (HFA-Flixotide) in 22 smokers and 21 ex-smokers with asthma (?5 packyears).

RESULTS

Improvement from baseline in PD₂₀ adenosine after using QVAR, Clenil or Flixotide was 1.04 ± 1.71, 1.09 ± 2.12 and 0.94 ± 1.97 doubling doses, mean ± standard deviation (SD), respectively. The change from baseline in R₅-R₂₀ at PD₂₀ adenosine after using QVAR, Clenil or Flixotide was ?0.02 ± 0.27, 0.02 ± 0.21, and ?0.02 ± 0.31 kPa sL^?1, mean ± SD, respectively. The change in PD₂₀ adenosine and R₅-R₂₀ at PD₂₀ adenosine were neither statistically significant different between QVAR and Clenil (p = 0.86 and p = 0.82) nor between QVAR and Flixotide (p = 0.50 and p = 0.96).

CONCLUSION

Similar effectiveness in improving small airways function was found for extrafine and non-extrafine particle ICS treatment for asthmatic smokers and ex-smokers.

Cigarette smoking increases bronchial mucosal IL-17A expression in asthmatics, which acts in concert with environmental aeroallergens to engender neutrophilic inflammation

BACKGROUND

Mild asthmatics who smoke cigarettes may develop unstable disease and neutrophilic infiltration of the airways, features more usually associated with severe asthmatic disease. The mechanisms giving rise to this response remain unclear.

OBJECTIVE

To address the hypothesis that smoking increases bronchial mucosal production of IL-17A which acts on bronchial epithelial cells directly and in concert with other environmental stimuli to induce the production of IL-6 and neutrophil chemotaxins.

METHODS

IL-17A, IL-8, IL-6, neutrophils and eosinophils were detected and quantified by immunohistochemistry in endobronchial biopsy sections from smoking and non-smoking asthmatics. Human tracheal epithelial cells (HTEpC) were cultured with IL-17A in the presence/absence of cigarette smoke extract (CSE) and aeroallergens lacking intrinsic protease activity, and IL-6 and IL-8 production measured in vitro.

RESULTS

Expression of IL-17A, IL-6 and IL-8 and neutrophil numbers was significantly elevated in the bronchial mucosa of the asthmatic smokers compared to the non-smokers. Expression of IL-17A correlated with that of IL-8 and neutrophil numbers. In the smoking asthmatics, eosinophil numbers also correlated with expression of IL-8 and IL-17A. Exposure of HTEpC cells to both CSE and IL-17A increased expression of IL-6 and IL-8 in a concentration-dependent and synergistic manner. Co-stimulation with CSE, IL-17A and aeroallergens further increased IL-6 and IL-8 production synergistically.

CONCLUSIONS

The data support the hypothesis that asthmatic smokers develop neutrophilic inflammation of the airways propagated at least partly by smoke-induced production of IL-17A which together with smoke and other environmental stimuli acts on airways epithelial cells to induce neutrophil chemotaxins.

Elevated expression of placental growth factor is associated with airway-wall vascular remodelling and thickening in smokers with asthma

The increased expression of placental growth factor (PlGF) in chronic obstructive pulmonary disease and allergy-related asthma suggests its role in the pathogenesis of these diseases. In asthmatic smokers, airway remodelling is accompanied by an accelerated decline in lung function. However, whether PlGF contributes to the persistent airflow obstruction and vascular remodelling typically seen in asthmatic smokers is unknown. In this study we measured lung function, airway-wall thickening, and PlGF levels in serum and induced sputum in 74 asthmatic and 42 healthy smokers and never-smokers. Using human lung microvascular endothelial cells (HLMECs), we evaluated the in vitro effects of PlGF on each step of vascular remodelling, including proliferation, migration, stress-fibre expression, and tubule formation. Our data showed significantly higher serum and sputum PlGF levels in asthma patients, especially asthmatic smokers, than in healthy controls. Serum and sputum PlGF levels correlated negatively with post-bronchodilator forced expiratory volume in 1 s (FEV₁) and the FEV₁/forced vital capacity, but positively with airway-wall thickening. Stimulation of HLMECs with rhPlGF promoted all of the steps of airway-microvascular remodelling. These findings provide insights into the influence of cigarette smoking on the structural changes in the airways of asthmatics and the important pathogenic role played by PlGF.

Both exhaled nitric oxide and blood eosinophil count were associated with mild allergic asthma only in non-smokers

BACKGROUND

The fractional exhaled nitric oxide (FENO) and the blood eosinophil count (B-eos) are markers of eosinophilic inflammation used in the diagnosis and management of asthma. The relationships between smoking cigarette and both FENO and B-eos are complex and raise questions about the association between these markers and asthma in smokers.

OBJECTIVE

To determine the relationships between both FENO and B-eos on one hand and asthma and atopy on the other, according to smoking status.

METHODS

FENO and B-eos were measured in, respectively, 1579 and 1496 of the 1607 middle-aged adults randomly selected from the general population in the cross-sectional ELISABET survey. Allergic asthma was defined as asthma (a self-report of physician-diagnosed asthma, and wheezing in the previous 12 months or the use of asthma medications) with atopy (allergic rhinitis or hayfever in the previous 12 months, or a previous positive prick test or allergen desensitization therapy). Non-allergic asthma was defined as asthma without atopy.

RESULTS

The analysis included 812 (51.4%) never, 473 (30%) former and 294 (18.6%) current smokers. A total of 490 (32%) participants were atopic, 80 (5.1%) had allergic asthma, and 31 (2%) had non-allergic asthma. Only 16.2% (18/111) of asthmatics were treated with glucocorticoid inhalants, suggesting that among them a majority of participants had mild asthma. A positive interaction between smoking status and allergic asthma was observed in multivariate models explaining FENO (P = 0.003) and B-eos (P = 0.001). Thus, compared to those without allergic asthma, participants with allergic asthma had higher FENO values (+ 63.4%, 95% CI = [39; 92]) and higher B-eos (+ 63.2% [38.2; 92.7]) in never and former smokers, but not in current smokers. Lastly, an analysis of receiver-operating characteristic curves showed that each of the two markers was able to discriminate moderately allergic asthma but only in non-smokers.

CONCLUSIONS & CLINICAL RELEVANCE

FENO and B-eos were associated with the presence of mild allergic asthma only in non-smokers, not in current smokers. These findings raise questions about the clinical value of FENO and B-eos in smokers.

Distinct Phenotypes of Cigarette Smokers Identified by Cluster Analysis of Patients with 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 cigarette smokers.

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. Twelve 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.

MEASUREMENTS AND MAIN RESULTS

Five clinical clusters were identified, including two characterized by high pack-year exposure to cigarette smoking and low FEV1/FVC. There were marked differences between the two clusters of cigarette smokers. One had high levels of circulating eosinophils, high IgE levels, and a high sinus disease score. The other was characterized by low levels of the same parameters. Sputum analysis revealed increased levels of IL-5 in the former cluster and increased levels of IL-6 and osteopontin in the latter. 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 1 year later.

CONCLUSIONS

This study reveals two distinct phenotypes of severe asthma in current and former cigarette smokers with potentially different biological pathways contributing to fixed airflow limitation. Clinical trial registered with www.umin.ac.jp (000003254).

Current and future biomarkers in allergic asthma

Diagnosis early in life, sensitization, asthma endotypes, monitoring of disease and treatment progression are key motivations for the exploration of biomarkers for allergic rhinitis and allergic asthma. The number of genes related to allergic rhinitis and allergic asthma increases steadily; however, prognostic genes have not yet entered clinical application. We hypothesize that the combination of multiple genes may generate biomarkers with prognostic potential. The current review attempts to group more than 161 different potential biomarkers involved in respiratory inflammation to pave the way for future classifiers. The potential biomarkers are categorized into either epithelial or infiltrate-derived or mixed origin, epithelial biomarkers. Furthermore, surface markers were grouped into cell-type-specific categories. The current literature provides multiple biomarkers for potential asthma endotypes that are related to T-cell phenotypes such as Th1, Th2, Th9, Th17, Th22 and Tregs and their lead cytokines. Eosinophilic and neutrophilic asthma endotypes are also classified by epithelium-derived CCL-26 and osteopontin, respectively. There are currently about 20 epithelium-derived biomarkers exclusively derived from epithelium, which are likely to innovate biomarker panels as they are easy to sample. This article systematically reviews and categorizes genes and collects current evidence that may promote these biomarkers to become part of allergic rhinitis or allergic asthma classifiers with high prognostic value.

Establishing the relationship of inhaler satisfaction, treatment adherence, and patient outcomes: a prospective, real-world, cross-sectional survey of US adult asthma patients and physicians

Background

Inhaled asthma medications are the mainstay of treatment for chronic asthma. However, nonadherence rates for long-term inhaler therapy among adults are estimated to exceed 50 %. Nonadherence is associated with unfavorable clinical outcomes and diminished quality of life. Research suggests that adherence is associated with patients’ satisfaction with their treatment regimen and other factors, such as concomitant allergic rhinitis and tobacco use.

Methods

This prospective, cross-sectional survey of physicians and their patients evaluated the relationship between patient satisfaction with attributes of inhaler devices, treatment adherence, and clinical outcomes. Primary care and specialist physicians completed a physician-reported patient record form for patients with a confirmed asthma diagnosis. Patients for whom a physician-reported form was completed were invited to complete a patient-reported form. Both surveys collected information about demographics, symptoms, exacerbation history, treatment, smoking status, comorbidities, type of inhaler device, and treatment adherence. Patients also indicated the degree to which they were satisfied with attributes of their currently prescribed inhaler device(s). Partial least squares path modeling quantified relationships between latent variables and clinical outcomes.

Results

A total of 243 patients were included in our analysis and 41 % had poorly controlled asthma. More favorable clinical outcomes were significantly associated with greater patient satisfaction with drug delivery (P = 0.002), higher medication adherence (P = 0.049), no history of tobacco use (P < 0.001), and absence of comorbid allergic rhinitis (P = 0.005). Attributes associated with device satisfaction included patient perceptions of consistency in the amount of drug delivery to the lungs, ease of use, and feedback about the number of remaining doses.

Conclusions

Higher patient satisfaction with their asthma drug delivery inhaler device is a significant predictor of more favorable clinical outcomes while allergic rhinitis and smoking history were negatively associated with optimal control of asthma. These findings provide clinicians with opportunities to improve patients’ clinical outcomes by tailoring choice of inhaler device therapy and providing education about the correct way to use the device to ensure optimal outcomes. Patients will likely benefit from medical therapy to manage comorbid allergic rhinitis and smoking cessation interventions. Patients unable to stop smoking may require alternative medical therapies to improve their clinical outcomes.

Increased Acquired Cholesteatoma Risk in Patients with Osteoporosis: A Retrospective Cohort Study

Objective

Clinically, we found the increased incidence of acquired colesteatoma in the patients with osteoporosis. In this study, we used a retrospective cohort to examine this association and to investigate the possible mechanism.

Methods

We conducted a population-based retrospective cohort study by using the National Health Insurance Research Database (NHIRD). We identified an osteoporosis cohort comprising 37 124 patients newly diagnosed with osteoporosis aged 20 years or older. Patients in the comparison cohort had no history of osteoporosis and were frequency matched with the patients in the osteoporosis cohort according to sex, age, and index year.

Results

The acquired cholesteatoma incidence rates for the osteoporosis and comparison cohorts were 1.12 and 0.83 per 1000 person-years, respectively. After we adjusted for confounding factors, the osteoporosis cohort exhibited a 1.32-fold increased acquired cholesteatoma risk relative to the comparison cohort (hazard ratio [HR] = 1.32, 95% confidence interval [CI] = 1.11–1.57). In addition, patients with no history of otitis media (HR = 1.33, 95% CI = 1.11–1.59), cancer (HR = 1.34, 95% CI = 1.12–1.60), or COPD (HR = 1.26, 95% CI = 1.05–1.52) in the osteoporosis cohort exhibited an increased risk of subsequent acquired cholesteatoma relative to those in the comparison cohort.

Conclusions

Our cohort study indicated that patients with osteoporosis had a 1.31-fold increased acquired cholesteatoma risk relative to the comparison cohort. This risk was further increased in patients with comorbid otitis media. Hence, we recommend that otolaryngologists evaluate the condition of the middle ear of patients with osteoporosis.

Serum periostin in smokers and never smokers with asthma

BACKGROUND

Elevated serum periostin is associated with airway eosinophilia and may predict response to therapies targeting Th2 inflammation. Smoking in asthma is generally associated with non-eosinophilic airway inflammation and corticosteroid insensitivity. We determined the effect of smoking status on serum periostin in asthma.

METHODS

Serum periostin (ELISA; Aviscera Bioscience) was measured in 107 patients with stable asthma of different disease severity and 45 healthy controls. The effects on serum periostin of clinical indices including smoking status and of inflammatory biomarkers including sputum eosinophil count were analysed. Serum periostin was measured before and after two weeks of oral corticosteroids in a separate group of 33 non-smokers and smokers with stable asthma.

RESULTS

Serum periostin (median [IQR], ng/mL) was reduced in smokers with asthma compared to never smokers with asthma; 9 (9, 307) versus 233 (34, 1108) respectively, p = 0.017. Periostin was not influenced by disease severity (p = 0.786) or atopic status (p = 0.144). There was a weak correlation between serum periostin and sputum eosinophil count in smokers with asthma (r = 0.315, p = 0.020). The proportion of patients with an elevated serum periostin concentration was greater in never smokers with asthma compared to smokers with asthma [65% versus 39% respectively, p = 0.003]. Oral steroid treatment reduced serum periostin (p = 0.030) in non-smokers with asthma.

CONCLUSION

Despite lower median serum periostin concentrations in smokers with asthma compared to never smokers with asthma, approximately forty percent of this group had a high level. The potential value of a raised serum periostin concentration in predicting a beneficial response to therapies targeting Th2 inflammation in smokers with asthma requires to be investigated.

Montelukast in paediatric asthma: where we are now and what still needs to be done?

Leukotriene receptor antagonists were introduced as an entirely new concept in asthma therapy, which indeed they are. However, although an intellectually new concept, they have largely disappointed in clinical practice. A small minority of school age asthmatics may respond better to these medications as against inhaled corticosteroids as prophylactic therapy. In children not responding to low dose inhaled corticosteroids, the best add-on therapy is salmeterol, but a small number respond better to Montelukast. In pre-school wheeze, intermittent Montelukast may be an effective strategy in some children who wheeze just with viral colds, but the clinical trial data are controversial. Pre-schoolers with multiple trigger wheeze are probably best treated with inhaled corticosteroids. What is clear is that clinically, a higher proportion of children are prescribed Montelukast than would be predicted from the lterature to respond to the medication. No biomarker to predict response to Montelukast has reached clinical practice, so N of 1 clinical trials should be performed. It is important not to leave children on Montelukast if there is no convincing response to this treatment.

Atorvastatin in combination with inhaled beclometasone modulates inflammatory sputum mediators in smokers with asthma

BACKGROUND

Statins have pleiotropic immunomodulatory effects that may be beneficial in the treatment of asthma. We previously reported that treatment with atorvastatin improved asthma symptoms in smokers with asthma in the absence of a change in the concentration of a selection of sputum inflammatory mediators.

OBJECTIVE

To determine the effects of atorvastatin alone and in combination with inhaled corticosteroid on a range of sputum cytokines, chemokines and growth factors implicated in the pathogenesis of asthma, and their association with asthma control questionnaire (ACQ) and/or asthma quality of life questionnaire (AQLQ) scores.

METHODS

Sputum samples were analysed from a sub-group of 39 smokers with mild to moderate asthma recruited to a randomised controlled trial comparing atorvastatin (40 mg/day) versus placebo for four weeks, followed by inhaled beclometasone (400 μg/day) for a further four weeks. Induced sputum supernatant fluid was analysed (Luminex or biochemical analyses) for concentrations of 35 mediators.

RESULTS

Sputum mediator concentrations were not reduced by inhaled beclometasone alone. Atorvastatin significantly reduced sputum concentrations of CCL7, IL-12p70, sCD40L, FGF-2, CCL4, TGF-α and MMP-8 compared with placebo and, when combined with inhaled beclometasone, reduced sputum concentrations of MMP-8, IL-1β, IL-10, MMP-9, sCD40L, FGF-2, IL-7, G-CSF and CCL7 compared to ICS alone. Improvements in ACQ and/or AQLQ scores with atorvastatin and ICS were associated with decreases in G-CSF, IL-7, CCL2 and CXCL8.

CONCLUSION

Short-term treatment with atorvastatin alone or in combination with inhaled beclometasone reduces several sputum cytokines, chemokines and growth factors concentrations unresponsive to inhaled corticosteroids alone, in smokers with asthma.

Emerging molecular phenotypes of asthma

Although asthma has long been considered a heterogeneous disease, attempts to define subgroups of asthma have been limited. In recent years, both clinical and statistical approaches have been utilized to better merge clinical characteristics, biology, and genetics. These combined characteristics have been used to define phenotypes of asthma, the observable characteristics of a patient determined by the interaction of genes and environment. Identification of consistent clinical phenotypes has now been reported across studies. Now the addition of various 'omics and identification of specific molecular pathways have moved the concept of clinical phenotypes toward the concept of molecular phenotypes. The importance of these molecular phenotypes is being confirmed through the integration of molecularly targeted biological therapies. Thus the global term asthma is poised to become obsolete, being replaced by terms that more specifically identify the pathology associated with the disease.

Increased sputum endotoxin levels are associated with an impaired lung function response to oral steroids in asthmatic patients

BACKGROUND

Airway endotoxin might contribute to corticosteroid insensitivity in asthmatic patients.

OBJECTIVE

Because cigarette smoke contains endotoxin, we tested the hypothesis that sputum endotoxin concentrations are increased in cigarette smokers and that endotoxin concentrations are associated with corticosteroid insensitivity in asthmatic patients.

METHODS

Sixty-nine asthmatic patients (never smokers, smokers, and exsmokers) and 20 healthy subjects (never smokers and smokers) were recruited. Fifty-three asthmatic patients received a 2-week course of oral dexamethasone. Serum and induced sputum endotoxin and cytokine concentrations were quantified by using an enzyme immunoassay.

RESULTS

Median (interquartile range [IQR]) sputum endotoxin concentration were not significantly different between asthmatic never smokers (184 endotoxin units [EU]/mL; IQR, 91-310 EU/mL), exsmokers (123 EU/mL; IQR, 39-207 EU/mL), and smokers (177 EU/mL; IQR, 41-772 EU/mL; P = .703) and healthy subjects (164 EU/mL; IQR, 106-373 EU/mL). The lung function response to oral corticosteroids decreased with increasing sputum endotoxin concentrations in the never smokers (linear regression α = .05, Spearman r = -0.503, P = .009) but not in smokers (α = .587, r = -0.282, P = .257), as confirmed by using multiple regression analysis. Asthmatic smokers had higher concentrations of serum endotoxin than asthmatic nonsmokers (0.25 EU/mL [IQR, 0.09-0.39 EU/mL] vs 0.08 EU/mL [IQR, 0.05-0.19 EU/mL], P = .042) unrelated to steroid insensitivity or serum cytokine concentrations. In the asthmatic group sputum endotoxin concentrations correlated with sputum IL-1 receptor antagonist concentrations (r = 0.510, P < .001), and serum endotoxin concentrations significantly correlated with sputum IL-6, IL-8, and chemokine motif ligand 2 concentrations.

CONCLUSION

Asthmatic smokers have similar sputum endotoxin concentrations compared with those of asthmatic never smokers. The association between higher sputum endotoxin levels and an impaired lung function response to oral corticosteroids, particularly in asthmatic never smokers, suggests that airway endotoxin might contribute to corticosteroid insensitivity in asthmatic patients.

Regulatory tone and mucosal immunity in asthma

The lung is constantly exposed to a variety of inhaled foreign antigens, many of which are harmless to the body. Therefore, the mucosal immune system must not only have the capacity to distinguish self from non-self, but also harmless versus dangerous non-self. To address this, mucosal immune cells establish an anti-inflammatory steady state in the lung that must be overcome by inflammatory signals in order to mount an effector immune response. In the case of inhaled allergens, the false detection of dangerous non-self results in inappropriate immune activation and eventual allergic asthma. Both basic and clinical studies suggest that the balance between tolerogenic and inflammatory immune responses is a key feature in the outcome of health or disease. This review is focused on what we term 'regulatory tone': the immunosuppressive environment in the lung that must be overcome to induce inflammatory responses. We will summarize the current literature on this topic, with a particular focus on the role of regulatory T cells in preventing allergic disease of the lung. We propose that inter-individual differences in regulatory tone have the potential to not only establish the threshold for immune activation in the lung, but also shape the quality of resulting effector responses following tolerance breakdown.