Influences of smoking and aging on allergic airway inflammation in asthma

Asthma exacerbations and airway redox imbalance under type 2 inflammatory conditions

Asthma is a chronic inflammatory airway disease characterized by bronchial hyperresponsiveness and reversibility. Despite considerable advances in asthma treatment based on our understanding of its pathophysiology, asthma exacerbations remain challenging. To reduce asthma exacerbations, it is essential to identify triggers, patients' risk factors, and underlying mechanisms. While exposure to viruses and environmental stimuli are known common triggers for asthma exacerbations, the key factors involved in asthma exacerbations have been identified as type 2 inflammation. Type 2 inflammatory biomarkers have been demonstrated to be useful in predicting individuals at risk of exacerbations. Furthermore, recent clinical trials of targeted biological therapy, which blocks the type 2 pathway, have supported the critical role of type 2 inflammation in asthma exacerbations. Although the specific mechanisms linking type 2 inflammation to asthma exacerbations have not yet been fully elucidated, increasing evidence shows that reduction/oxidation (redox) imbalance likely plays an important role in this association. Under type 2 inflammatory conditions, human airway epithelial cells activate 15-lipoxygenase-1 in complex with phosphatidylethanolamine binding protein-1, leading to the generation of electrophilic hydroperoxyl-phospholipids. When the accumulation of reactive lipid peroxidation surpasses a specific glutathione-dependent activity, these electrophilic compounds are not neutralized, leading to programmed cell death, ferroptosis. Reduced glutathione levels, caused by type 2 inflammation, may impair its ability to neutralize reactive lipid peroxidation. The accumulation of lipid peroxidation with intracellular redox imbalance may contribute to asthma exacerbations in individuals with type 2 inflammation. Inhibiting the ferroptotic pathway holds promise as a therapeutic strategy to alleviate asthma exacerbations.

Association between systemic immune-inflammation index and metabolic syndrome and its components: results from the National Health and Nutrition Examination Survey 2011-2016

BACKGROUND

Metabolic syndrome (MetS), a worldwide public health problem, affects human health and quality of life in a dramatic manner. A growing evidence base suggests that MetS is strongly associated with levels of systemic immune inflammation. The present study aimed to investigate the possible relationship between the systemic immune-inflammation index (SII), a novel inflammatory marker, and MetS to provide data support for effective MetS prevention by reducing the systemic inflammatory response.

METHODS

We included adult participants with complete SII and MetS information from the 2011-2016 National Health and Nutrition Examination Survey (NHANES). MetS was defined as using the criteria developed by the Adult Treatment Program III of the National Cholesterol Education Program. The formula for SII was as follows: SII = platelet counts × neutrophil counts/ lymphocyte counts. Weighted linear regression was used to assess differences in variables across SII quartile groups after the SII score was divided into 4 quartiles. The independent interaction between SII and MetS was investigated using weighted multivariate logistic regression analysis and subgroup analysis, and the relationship between SII levels and 5 particular MetS items was further explored in depth.

RESULTS

A total of 12,402 participants, 3,489 of whom were diagnosed with MetS, were included in this study. After correcting for covariates, the results of a logistic regression of multistage weighted complex sampling data revealed that participants with higher SII scores had a higher chance of developing MetS (odds ratio (OR) = 1.33, 95% confidence interval (CI): 1.14-1.55) and that SII levels could be used as an independent risk factor to predict that likelihood of MetS onset. In the Q1-Q4 SII quartile group, the risk of developing MetS was 1.33 times higher in the Q4 group, which had the highest level of systemic immune inflammation than in the Q1 group. After adjusting for all confounding factors, SII scores were found to have a negative correlation with high-density lipoprotein cholesterol (OR = 1.29; 95% CI, 0.99-1.67, P = 0.056) and a significant positive correlation with waist circumference (OR = 2.17; 95% CI, 1.65-2.87, P < 0.001) and blood pressure (BP) (OR = 1.65; 95% CI, 1.20-2.27, P = 0.003). Gender, age, and smoking status were shown to alter the positive association between SII and MetS in subgroup analyses and interaction tests (p for interaction < 0.05). Additionally, we demonstrated a nonlinear correlation between SII and MetS. The findings of the restricted cubic spline indicated that there was an inverted U-shaped association between SII and MetS.

CONCLUSIONS

Our findings imply that increased SII levels are related to MetS, and SII may be a simple and cost-effective method to identify individuals with MetS. Therefore, protective measures such as early investigation and anti-inflammatory interventions are necessary to reduce the overall incidence of MetS.

Plackett-Burman and face-centered composite designs for development and optimization of chromatographic method for the simultaneous determination of glycopyrronium, indacaterol and mometasone in their fixed dose combination inhaler - Green profile assessment

A novel simple, specific, sensitive, accurate and precise reversed phase high performance liquid chromatographic method (RP-HPLC/UV) was developed and validated for the simultaneous estimation of Glycopyrronium bromide (GLY), Indacaterol acetate (IND) and Mometasone furoate (MOF) in pure form, in laboratory prepared mixtures and in pharmaceutical dosage form. Experimental design methodology was applied by using Plackett-Burman and face-centered composite designs to achieve the best resolution with minimum experimental trials. The designed model was statistically analyzed, graphically presented by surface plots and the relationships between coefficients of the derived polynomial equations were interpreted. Chromatographic separation was achieved on Inertsil ODS C18 column (250 ×4.6 mm, 5 µm) at ambient temperature using a mobile phase composed of methanol: 0.1% glacial acetic acid (pH4) in a gradient elution at a flow rate 1 mL /min. UV detection was carried out at 233 nm. Response was found to be linear in the concentration range of 20-120 µg /mL with regression coefficient (r2 = 0.999) for GLY, 50-300 µg /mL with regression coefficient (r2 = 0.9995) for IND and 50-300 µg /mL with regression coefficient (r2 = 0.9998) for MOF. The method was validated as per ICH guidelines and satisfactory results were achieved. The method was successfully applied for the analysis of the cited drugs in their fixed dose combination (FDC) pharmaceutical formulation. Statistical comparison between the results obtained by the proposed method and the reference methods for GLY, IND and MOF showed no significant difference. The developed method could be implemented in quality control aspects of the cited drugs. Four green metrics were used to evaluate the new RP-HPLC/UV method's greenness and compare it to other published techniques.

Clinical, functional, and inflammatory characteristics of asthma among adults aged over 60 years old: a case-control study

ObjectiveThis observational case-control study analyzed the clinical, functional, inflammatory profile, and treatment data of a cohort of patients with asthma who were followed up at the outpatient clinic of a teaching hospital.MethodsPatients who visited the clinic between January 2008 and February 2020 and diagnosed with asthma according to the Global Initiative for Asthma (GINA) criteria were included in the study. Patients were broadly classified into two groups: age <60 or age ≥60 years. The patients were evaluated for asthma control and severity, medications used, comorbidities, smoking status, occurrence of exacerbation, spirometry at the first and last visits, sputum cytology, allergic prick test, and inflammatory cytokine levels.ResultsPatients over 60 years of age had lower asthma control test (ACT) scores, required higher doses of inhaled corticosteroids to achieve asthma control and had worse lung function with fixed airway obstruction, higher number of comorbidities, greater exposure to tobacco, and longer outpatient follow-up than younger patients with asthma. Furthermore, older patients presented with neutrophilia and higher levels of TNFα in the induced sputum as compared to younger patients.ConclusionsThese findings suggest that patients aged ≥60 years of age had a more severe asthma profile and poorer lung function than younger patients with asthma. Furthermore, aging, long-term asthma, comorbidities, and tobacco exposure contributed to an accelerated decline in lung function.

Association of air pollution, genetic risk, and lifestyle with incident adult-onset asthma: A prospective cohort study

BACKGROUND

Numerous studies have explored the association of air pollution with asthma but have yielded conflicting results. The exact role of air pollution in the incidence of adult-onset asthma and whether this effect is modified by genetic risk, lifestyle, or their interaction remain uncertain.

METHODS

We conducted a prospective cohort study on 298,738 participants (aged 37-73 years) registered in the UK Biobank. Cox proportional hazard models were used to evaluate the association of air pollution, including particulate matter (PM_2.5, PM_coarse, and PM₁₀), nitrogen dioxide (NO₂), and nitrogen oxides (NO_x), with asthma incidence. We constructed genetic risk and lifestyle scores, assessed whether the impact of air pollution on adult-onset asthma risk was modified by genetic susceptibility or lifestyle factors, and evaluated the identified interactions.

RESULTS

We found that each interquartile range increase in annual concentrations of PM_2.5, NO₂, and NO_x was related to 1.04 (95% confidence interval [CI]: 1.01, 1.08), 1.04 (95% CI: 1.00, 1.08), and 1.03 (95% CI: 1.00, 1.06) times the risk of adult-onset asthma, respectively. The size of the effect of air pollution was greater among subpopulations with low genetic risk or unfavorable lifestyles. We also identified an additive interaction effect of air pollution with lifestyle factors, but not with genetic risk, on the risk of adult-onset asthma.

CONCLUSION

Our analyses show that air pollution increases the risk of adult-onset asthma, but that the size of the effect is modified by lifestyle and genetic risk. These findings emphasize the need for integrated interventions for environmental pollution by the government as well as adherence to healthy lifestyles to prevent adult-onset asthma.

Transcriptomic profiles of age-related genes in female trachea and bronchus

Background: Studies demonstrated that age-related cellular and functional changes of airway significantly contribute to the pathogenesis of many airway diseases. However, our understanding on the age-related molecular alterations of human airway remains inadequate.

Methods: Airway (trachea and bronchus) brushing specimens were collected from 14 healthy, female non-smokers with ages ranging from 20 to 60 years. Bulk RNA sequencing was performed on all the specimens (n = 28). Airway cell types and their relative proportions were estimated using CIBERSORTx. The cell type proportions were compared between the younger (age 20–40) and elder group (age 40–60) in the trachea and bronchus respectively. The linear association between cell type proportion and age was assessed using the Pearson correlation coefficient. Differentially expressed genes (DEGs) between the two age groups were identified using DESeq2. Three kinds of enrichment analysis of the age-related DEGs were performed, including Gene ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, and disease enrichment analysis.

Results: Sixteen and thirteen cell types were separately identified in tracheal and bronchial brushings, with the airway epithelial cells (including suprabasal, submucosal gland (SMG) goblet, serous, secretory, multiciliated, cycling.basal, basal cells) accounting for 85.1% in the trachea and 92.5% in the bronchus. The lymphatic cell and NK cells had a higher abundance ratio in the trachea, compared with the bronchus. The proportion of basal cells was negatively related to age both in the trachea and bronchus. Thirty-one and fifty-two age-related DEGs (p &lt; 0.1) were identified in the trachea and bronchus, respectively. Among them, five common DEGs (CXCL2, CXCL8, TCIM, P4HA3, AQP10) were identified. Pathway enrichment analysis showed both tracheal and bronchial age-related DEGs were primarily involved in immune regulatory signaling pathways (TNF, NF-kappa B, IL-17 et al.). Disease enrichment analysis suggested that tracheal age-related DEGs significantly related to asthmatic pulmonary eosinophilia, and chronic airflow obstruction et al., and that bronchial age-related DEGs were enriched in airflow obstruction, bronchiectasis, pulmonary emphysema, and low respiratory tract infection et al.

Conclusion: We found the proportion of basal cells decreased with age in both the trachea and bronchus, suggesting a weakening of their self-renew ability with age. We identified transcriptomic signature genes associated with the early aging process of the human trachea and bronchus, and provided evidence to support that changes in their immune regulatory function may play critical roles in age-related airway diseases.

Association of genetic risk and lifestyle with incident adult-onset asthma in the UK Biobank cohort

Background

Both genetic and lifestyle factors contribute to the development of asthma, but whether unfavourable lifestyle is associated with similar increases in risk of developing asthma among individuals with varying genetic risk levels remains unknown.

Methods

A healthy lifestyle score was constructed using body mass index, smoking status, physical activities and dietary pattern to further categorise into ideal, intermediate and poor groups. Genetic risk of asthma was also categorised as three groups based on the tertiles of polygenic risk score established using 212 reported and verified single-nucleotide polymorphisms of European ancestry in the UK Biobank study. We examined the risk of incident asthma related with each lifestyle level in each genetic risk group by Cox regression models.

Results

Finally, 327 124 participants without baseline asthma were included, and 157 320 (48.1%) were male. During follow-up, 6238 participants (1.9%) developed asthma. Compared to ideal lifestyle in a low genetic risk group, poor lifestyle was associated with a hazard ratio of up to 3.87 (95% CI, 2.98-5.02) for developing asthma in a high genetic risk group. There was interaction between genetic risk and lifestyle, and the population-attributable fraction of lifestyle and genetic risk were 30.2% and 30.0% respectively.

Conclusion

In this large contemporary population, lifestyle and genetic factors jointly play critical roles in the development of asthma, and the effect values of lifestyle on incident adult-onset asthma were greater than that of genetic risk. Our findings highlighted the necessity of a comprehensive intervention for the prevention of asthma despite the genetic risk.

Characterization and cluster analyses of elderly asthma in comparison with nonelderly patients with asthma in Japan

BACKGROUND

Asthma is a heterogeneous disease with multiple phenotypes that are useful in precision medicine. As the population ages, the elderly asthma (EA, aged ≥ 65 years) population is growing, and EA is now a major health problem worldwide.

OBJECTIVE

To characterize EA and identify its phenotypes.

METHODS

In adult patients with asthma (aged ≥ 18 years) who had been diagnosed with having asthma at least 1 year before study enrollment, 1925 were included in the NHOM-Asthma (registered in UMIN-CTR; UMIN000027776), and the data were used for this study, JFGE-Asthma (registered in UMIN-CTR; UMIN000036912). Data from EA and non-EA (NEA) groups were compared, and Ward's minimum-variance hierarchical clustering method and principal component analysis were performed.

RESULTS

EA was characterized by older asthma onset, longer asthma duration and smoking history, more comorbidities, lower pulmonary function, less atopic, lower adherence, and more hospital admissions because of asthma. In contrast, the number of eosinophils, total immunoglobulin E level, oral corticosteroid use, and asthma control questionnaire scores were equivalent between EA and NEA. There were 3 distinct phenotypes in EA, which are as follows: EA1: youngest, late onset, short duration, mild; EA2: early onset, long duration, atopic, low lung function, moderate; and EA3: oldest, eosinophilic, overweight, low lung function, most severe. The classification factors of the EA phenotypes included the age of onset and asthma control questionnaire-6. Similarities were observed between EA and NEA phenotypes after principal component analysis.

CONCLUSION

The EA in Japan may be unique because of the population's high longevity. Characterization of EA phenotypes from the present cohort indicated the need for distinct precision medicine for EA.

TRIAL REGISTRATION

JFGE-Asthma registered in UMIN-CTR (https://www.umin.ac.jp/ctr/); UMIN000036912.

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.

Revisiting differences between atopic and non-atopic asthmatics: When age is shaping airway inflammatory profile

Background

Atopic asthma is one of the most common asthma phenotypes and is generally opposed to the non-atopic counterpart. There have been very few large-scale studies comparing atopic and non-atopic asthmatics in terms of systemic and airway inflammation across the age spectrum.

Methods

Here, we have undertaken a retrospective study investigating 1626 patients (924 atopic and 702 non-atopic asthmatics) recruited from our university asthma clinic who underwent extensive clinical investigations including induced sputum. Atopy was defined by any positive specific IgE to common aeroallergens (>0,35 kU/L). We performed direct comparisons between the groups and sought to appreciate the influence of age on the airway and systemic inflammatory components. The study was approved by the ethics committee of the University Hospital of Liege (Ref. 2016/276). Informed consents were obtained from healthy subjects.

Results

Atopic asthmatics were younger (P < .001), had a higher male/female ratio (P < .001), an earlier disease onset (P < .001) and a greater proportion of treated rhinitis (P < .001) while non-atopic asthmatics had greater smoke exposure (P < .001), lower FEV₁/FVC ratio (P = .01) and diffusing capacity (P < .001). There was no difference between the 2 groups regarding FEV₁ (% predicted), asthma control, asthma quality of life and exacerbations in the previous 12 months. Regarding inflammation, atopic patients had higher FeNO levels (median = 28 ppb, P < .001), were more eosinophilic both in blood (median = 2.8%, P < .001) and in sputum (median = 2.2%, P < .001) while non-atopic patients displayed greater blood (median = 57%, P = .01) and sputum (median = 58.8%, P = .01) neutrophilic inflammation. However, stratifying patients by age showed that non-atopic asthmatics above 50 years old became equally eosinophilic in the sputum (P = .07), but not in the blood, as compared to atopic patients. Likewise, FeNO rose in non-atopic patients after 50 years old but remained, however, lower than in atopic patients.

Conclusions

We conclude that, while sharing many features, atopic group still differentiates from non-atopic asthmatics by demographics, functional and inflammatory profiles. When atopic asthmatics showed a constant eosinophilic pattern across the age spectrum, non-atopic asthmatics were found to be neutrophilic before the age of 50 but eosinophilic above 50 years old.

Indacaterol, glycopyrronium, and mometasone: pharmacological interaction and anti-inflammatory profile in hyperresponsive airways

LABA/ICS and LABA/LAMA/ICS combinations elicit beneficial effects in asthma. Specific evidence concerning the impact of combining indacaterol acetate (IND), glycopyrronium bromide (GLY), and mometasone furoate (MF) on human airway hyperresponsiveness (AHR) and airway inflammation is still missing. The aim of this study was to characterize the synergy of IND/MF and IND/GLY/MF combinations, both once-daily treatments for asthma, in hyperresponsive airways. Passively sensitized human medium and small airways were stimulated by histamine and treated with IND/MF (molar ratio: 100/45, 100/90) and IND/GLY/MF (molar ratio: 100/37/45, 100/37/90). The effect on contractility and airway inflammation was tested. Drug interaction was assessed by Bliss Independence equation and Unified Theory. IND/MF 100/90 elicited middle-to-very strong synergistic relaxation in medium and small airways (+≈20-30% vs. additive effect, P<0.05), for IND/MF 100/45 the synergy was middle-to-very strong in small airways (+≈20% vs. additive effect, P<0.05), and additive in medium bronchi (P>0.05 vs. additive effect). IND/GLY/MF 100/37/45 and 100/37/90 induced very strong synergistic relaxation in medium and small airways (+≈30-50% vs. additive effect, P<0.05). Synergy was related with significant (P<0.05) reduction in IL-4, IL-5, IL-6, IL-9, IL-13, TNF-α, TSLP, NKA, SP, and non-neuronal ACh, and enhancement in cAMP. IND/MF and IND/GLY/MF combinations synergistically interact in hyperresponsive medium and small airways and modulate the levels of cytokines, neurokinins, ACh, and intracellular cAMP. The concentrations of MF in the combinations modulate the effects in the target tissue.

The value of small airway function parameters and fractional exhaled nitric oxide for predicting positive methacholine challenge test in asthmatics of different ages with FEV1 ≥ 80% predicted

Background

Small airway function parameters (SAFPs) combined with fractional exhaled nitric oxide (FeNO) can predict a positive methacholine challenge test (MCT) for asthma diagnosis. However, their predictive utility in patients with forced expiratory volume in one second (FEV₁) ≥80% predicted within different age ranges remains unclear. This study aimed to assess the utility of SAFPs, alone or combined with FeNO, to predict a positive MCT in patients in two age groups (<55 and ≥55 years) with asthma‐suggestive symptoms and FEV₁ ≥80% predicted.

Methods

We enrolled 846 Chinese patients with suspected asthma and standard spirometry, FeNO, and MCT findings. Using the area under the curves (AUCs), the utility of SAFPs, alone or combined with FeNO, for predicting a positive MCT was analyzed in a discovery (n = 534) and validation cohort (n = 312) in both age groups with FEV₁ ≥80% predicted.

Results

In the discovery cohort, the optimal cut‐off values for predicting a positive MCT in patients aged <55 years (74.2% and 74.9% for forced expiratory flow (FEF)_50% and FEF_25%–75%, respectively) were higher than those in patients aged ≥55 years (65.0% and 62.9% for FEF_50%, FEF_25%–75%, respectively). However, the optimal FeNO value in patients aged <55 years (43 ppb) was lower than that in patients aged ≥55 years (48 ppb). FeNO combined with SAFPs (FEF_50%, FEF_25%–75%) significantly increased the AUCs in both groups (≥55 years [0.851 for FEF_50% and 0.844 for FEF_25%–75%]; <55 years [0.865 for FEF_50% and 0.883 for FEF_25%–75%]) compared with a single parameter (p < 0.05). These findings were confirmed in the validation cohort. Compared with patients ≥55 years, those aged <55 years had higher and lower optimal cut‐off values for SAFPs and FeNO, respectively. The AUCs of FeNO combined with SAFPs for predicting a positive MCT for asthma diagnosis were significantly higher than those of the individual parameters (p < 0.05) in both age groups.

Conclusions

There were age‐group differences in the utility of SAFPs combined with FeNO for predicting a positive MCT. Patients with an asthma‐suggestive history and a normal FEV₁ should be stratified by age when using SAFPs combined with FeNO to predict a positive MCT.

The Prevalence of Allergic Rhinitis and Associated Risk Factors Among University Students in Anatolia

INTRODUCTION

Allergic rhinitis is a common disease in Turkey. However, there are not enough studies on its prevalence. Survey-based studies conducted by experienced and qualified researchers to large populations provide information about the prevalence of allergic rhinitis and risk factors associated with it.

AIM

The aim of this study was to determine the prevalence of allergic rhinitis and related factors in university students in Anatolia.

METHODS

An extended and modified form of "The European Community Respiratory Health Survey" was conducted to university students in Turkey. The data were obtained through a face-to-face interview method. R version 4.0.2 was used for statistical analysis. Data were presented as frequency and percentage. Chi-squared test of independence was used to analyze the relationship between allergic rhinitis diagnosis and other variables. Statistically significant variables were further analyzed with multivariate logistic regression test.

RESULTS

Data was collected from a total of 2020 participants, but 1714 participants were eligible for multivariate analysis. The mean age of the participants was 20.71 ± 3.12 years; 42.88 (n= 735) were male, and 57.12% (n= 979) were female. While the rate of those who thought that they had nasal allergies was 23.862% (n = 409), the rate of those diagnosed by a doctor was 15.986% (n = 274). The most common allergic symptom in the participants was sneezing, and the most common triggering factor was house dust.

CONCLUSION

We found a high prevalence of 15.986% doctor diagnosed allergic rhinitis among university students in Anatolia. Genetic, environmental and economic factors were associated with high prevalence of allergic rhinitis.

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.

Persistence of smoking induced non-small cell lung carcinogenesis by decreasing ERBB pathway-related microRNA expression

Background

Tobacco use is responsible for approximately 80–90% of non‐small cell lung cancer cases. A large evidence base has shown that the ERBB pathway is associated with the occurrence of lung cancer. However, the mechanisms of how smoking activates the ERBB pathway have yet to be explained. We hypothesized that microRNAs may induce ERBB pathway activity during the process of lung cancer carcinogenesis.

Methods

We analyzed microRNA array data from the Gene Expression Omnibus and the Kyoto Encyclopedia of Genes and Genomes to determine any associations between genes and smoking in three groups of patients with NSCLC: smokers, former smokers, and non‐smokers.

Results

The interaction network among miRNAs, including hsa‐mir‐185‐3p, hsa‐mir‐4295, hsa‐mir‐4288, and hsa‐mir‐613, promotes lung cancer development by affecting the ERBB pathway.

Conclusion

Our findings provide evidence to explain the mechanism of lung cancer development in smokers.

Sex-Specific Asthma Phenotypes, Inflammatory Patterns, and Asthma Control in a Cluster Analysis

BACKGROUND

Asthma is a heterogeneous disease with complex mechanisms and involves many risk factors and in vivo cellular molecules. It is notable that sex differences may have a potential effect on asthma phenotype.

OBJECTIVE

To identify sex-specific phenotypes and health outcomes of asthma.

METHODS

We conducted the Taiwanese Adult Asthma Cohorts study to enroll female (n = 421) and male (n = 299) adult patients with stable asthma. Eight variables were selected by a factor analysis. We further performed a 2-step sensitivity cluster analysis to classify asthma clusters. The risks of asthma-related outcomes among the clusters were assessed using simple logistic regressions.

RESULTS

Three different clusters were identified in males and females. In the female clusters, atopy/eosinophil-predominant (cluster 2), and obesity/neutrophil-predominant pattern (cluster 3) had more than a 2-fold risk of asthma exacerbations (odds ratio, 2.51; 95% CI, 1.12-5.59 and odds ratio, 2.22; 95% CI, 1.01-4.93). In the male clusters, current smoker/neutrophilic atopic cluster (cluster 5) and ex-smoker/eosinophil-predominant or mixed inflammatory pattern (cluster 6) also had a higher risk of asthma exacerbations.

CONCLUSIONS

This study identified heterogeneous characteristics between sexes. In females, the analysis showed atopy with eosinophil-predominant and obese with neutrophil-predominant inflammation. Two distinct asthma phenotypes were found in current and ex-smokers in males. Understanding asthma phenotypes and explaining the potentially biological pathways have become important.

The role of HDAC2 in cigarette smoke-induced airway inflammation in a murine model of asthma and the effect of intervention with roxithromycin

BACKGROUND

Cigarette smoke is well known to worsen asthma symptoms in asthmatic patients and to make them refractory to treatment, but the underling molecular mechanism is unclear. We hypothesized that cigarette smoke can reduce the expression of HDAC2 in asthma and the process was achieved by activating the PI3K-δ/Akt signaling pathway. We further hypothesized that roxithromycin (RXM) can alleviate the impacts by cigarette smoke.

METHODS

A murine model of asthma induced by ovalbumin (OVA) and cigarette smoke has been established. The infiltration of inflammatory cells and inflammatory factors was examined in this model. Finally, we evaluated the expression of HDAC2, Akt phosphorylation levels, and the effects of RXM treatment on the model described earlier.

RESULTS

Cigarette smoke exposure reduced HDAC2 protein expression by enhancing the phosphorylation of Akt in PI3K-δ/Akt signaling pathway. Furthermore, RMX reduced the airway inflammation and improved the level of expression of HDAC2 in the cigarette smoke-exposed asthma mice.

CONCLUSIONS

This study provides a novel insight into the mechanism of cigarette smoke exposure in asthma and the effects of RXM treatment on this condition. These results may be helpful for treating refractory asthma and emphasizing the need for a smoke-free environment for asthmatic patients.

Sensitization to Staphylococcus aureus enterotoxins in smokers with asthma

BACKGROUND

Sensitization to Staphylococcus aureus enterotoxins (SEs) augments eosinophilic inflammation in asthma. Recent epidemiologic studies demonstrate that sensitization to SEs is increased in healthy smokers; however, there is no evidence on the association between sensitization to SEs and eosinophilic inflammation in smokers with asthma.

OBJECTIVE

To clarify the role of SEs on clinical indexes, including eosinophilic inflammation and lung function in smokers with asthma.

METHODS

The frequency of atopic sensitization to SEs was examined in adult patients with asthma. In current or ex-smokers with asthma, the association of sensitization to SEs with eosinophilic inflammation, airflow limitation, or treatment steps was determined. Clinical indexes were examined at the first visit, and treatment steps were assessed 6 months after enrollment.

RESULTS

Overall, 23 current smokers, 40 ex-smokers, and 118 never smokers with asthma were enrolled. The frequency of sensitization to SEs, but not to other aeroallergens, was significantly higher in current, ex-, and never smokers, in decreasing order. In current or ex-smokers with asthma, patients with sensitization to SEs exhibited higher serum levels of total and specific IgE to aeroallergens, higher blood eosinophil counts, greater airflow limitation, and more severe disease 6 months later than those without sensitization to SE. A longer smoking abstinence period was associated with serum specific IgE levels to SEs, and 3 years was the best cutoff of abstinence period to predict the absence of sensitization to SEs.

CONCLUSION

Sensitization to SEs is increased in smokers with asthma, and it may be a marker of eosinophilic inflammation and severe asthma in smokers with asthma.

TRIAL REGISTRATION

umin.ac.jp Identifier: UMIN000007818.

Prevalence trends in the characteristics of patients with allergic asthma in Beijing, 1994 to 2014

This study aimed to determine the clinical profiles and prevalence trends during 1994 to 2014 among patients with allergic asthma (AA), which is a clinical phenotype of asthma.We retrospectively analyzed the characteristics of 319 patients who were diagnosed with AA between March 1, 1994 and February 28, 2014 at 3 Beijing centers.The patients included 155 males and 164 females, and the mean age was 50.86 ± 15.27 years (range 13-86 years). The proportions of asthma attacks in summer and autumn were 60.7% (1994-1999), 61.8% (1999-2004), 56.4% (2004-2009), and 33.1% (2009-2014). The most frequently used medication at home was theophylline (27.9%), which was followed by inhaled corticosteroids (20.38%), inhaled corticosteroids/long-acting beta-2-agonists (10.66%), and leukotriene receptor antagonists (9.4%). The elderly group had the highest rates of summer and autumn attacks, multiple hospitalizations, reduced pulmonary function, smoking history, and positive allergen tests. The middle-aged group had the lowest rates of summer and autumn attacks, and multiple hospitalizations. The youngest group had the lowest rates of reduced pulmonary function, smoking history, and positive allergen tests. The top 5 allergens were dust (9.1%), mites (8.8%), seafood (8.2%), pollen (6.3%), and animal fur (6%). Women were significantly more likely to have a positive allergen test (93 women vs 68 men).The present study revealed the characteristics of Chinese patients with AA, and allergen-specific differences in sex and age during 1994 to 2014. The use of therapeutic drugs at home remains insufficient.

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).

Effects of omalizumab in severe asthmatics across ages: A real life Italian experience

BACKGROUND

This retrospective study aimed at evaluating long-term effects of Omalizumab in elderly asthmatics in a real-life setting.

METHODS

105 consecutive severe asthmatics (GINA step 4-5; mean FEV₁% predicted:66 ± 15.7) treated with Omalizumab for at least 1 year (treatment mean duration 35.1 ± 21.7 months) were divided into 3 groups according to their age at Omalizumab treatment onset: 18-39, 40-64 and ≥ 65 years.

RESULTS

Comorbidities, number of overweight/obese subjects and patients with late-onset asthma were more frequent among older people. A similar reduction of inhaled corticosteroids dosage and SABA on-demand therapy was observed in all groups during Omalizumab treatment; a similar FEV₁ increased was also observed. Asthma Control Test (ACT) improved significantly (p < 0.001) in the three groups, increasing from 15 [IQR:12-18] to 24 [IQR:22-25] in younger subjects, from 14 [IQR:10-16] to 21 [IQR:20-23] in the 40-64-year-group and from 15 [IQR:12-16] to 20 [IQR:18-22] in elderly patients where improvement was lower (p = 0.039) compared to younger people. Asthma exacerbations decreased significantly after Omalizumab but the percentage of exacerbation-free patients was higher in younger people (76.9%) compared to middle aged patients (49.2%) and the elderly (29%) (p = 0.049). After Omalizumab treatment, the risk for exacerbations was lower in subjects aged 40-64 (OR = 0.284 [CI95% = 0.098-0.826], p = 0.021) and 18-39 (OR = 0.133 [CI95% = 0.026-0.678], p = 0.015), compared to elderly asthmatics. Also, a significantly reduced ACT improvement (β = -1.070; p = 0.046) passing from each age class was observed.

CONCLUSION

Omalizumab improves all asthma outcomes independently of age, although the magnitude of the effects observed in the elderly seems to be lower than in the other age groups.

Effects of conventional tobacco smoke and nicotine-free cigarette smoke on airway inflammation, airway remodelling and lung function in a triple allergen model of severe asthma

BACKGROUND

Patients with asthma who smoke have reduced lung function, increased exacerbation rates and increased steroid resistance compared to non-smoking asthmatics. In mice, cigarette smoke has been reported to have both pro- and anti-Th2 response effects.

OBJECTIVE

We hypothesized that combining tobacco cigarette smoke (tCS) with allergen exposure increases inflammation, airway remodelling and lung function in mice. To test this hypothesis, we combined a severe triple allergen model with tCS exposure and investigated whether effects were due to Toll-like receptor 4 signalling and/or nicotine and also observed when nicotine-free cigarettes were used.

METHODS

Mice were sensitized with ovalbumin, cockroach and house dust mite allergen in alum followed by intratracheal challenges with allergen twice a week for 6 weeks or additionally exposed to tCS during the allergen challenge period. Nicotine or nicotine-free herbal cigarette smoke was also applied to allergen challenged mice.

RESULTS

tCS significantly reduced eosinophil numbers, IL-4 and IL-5 concentrations in the lung, total and allergen-specific IgE in serum, improved lung function and reduced collagen I levels. With the exception of collagen I all parameters reduced by tobacco cigarette smoke were also reduced in Toll-like receptor 4-deficient mice. Nicotine-free cigarette smoke also had significant anti-inflammatory effects on eosinophils, IL-4 and IL-5 concentrations in the lung and reduced airway hyperreactivity, albeit weaker than tobacco smoke. Applying nicotine alone also reduced Th2 cytokine levels and eosinophil numbers in the airways.

CONCLUSION

Our experiments show that tCS exposure reduces allergen-induced Th2 response in the lung and associated collagen I production and development of airway hyperreactivity. With the exception on collagen I formation, these effects were not dependent on Toll-like receptor 4. The observed anti-Th2 effects of both nicotine and nicotine-free herbal cigarette smoke together suggests that tCS reduces the Th2 responses through nicotine and other products released by burning tobacco.

[Factors associated with a severe asthma in asthmatic patients followed at Pneumo-phthisiology National Hospital of Cotonou (Benin) in 2014]

Introduction

la présente étude vise à déterminer la fréquence de l'asthme sévère chez les patients asthmatiques suivis au Centre National Hospitalier de Pneumo-Phtisiologie (CNHPP) de Cotonou et identifier les facteurs de risque qui lui sont associés

Méthodes

l’étude transversale, descriptive et analytique a porté sur 213 patients asthmatiques de la file active 2013 du CNHPP. Les données ont été collectées par l'exploitation des dossiers et l'entretien individuel avec les patients. Elles ont été traitées et analysées à l'aide des logiciels EPIINFO7 et STATA11. Le test Chi2 de Pearson, la régression logistique uni variée et multi variée ont été utilisés au seuil de signification de 0,05

Résultats

au total, 154 patients asthmatiques soit 72,7% ont répondu au questionnaire. Parmi eux 20,8% (IC95%:(14,67; 28,05)) souffraient d'asthme sévère. L’âge des patients s’étendait de 10 à 76 ans avec une médiane de 41 ans; 51,3% étaient de sexe féminin, 79,9% avaient des antécédents d'allergie, 61,7% ont commencé leur asthme après l’âge de 12 ans et seuls 11% ont consommé ou consommaient du tabac. Les facteurs associés à la survenue de l'asthme sévère étaient: l’âge de 46 à 55 ans (p = 0,04); les troisième et quatrième quintiles du bien-être économique (p = 0,01) et le début de l'asthme après l’âge de 12 ans (p < 0,001)

Conclusion

l’étude a montré une fréquence élevée de l'asthme sévère au Bénin et permettra d'améliorer sa prise en charge au CNHPP.

Allergic disorders at a venerable age: a mini-review

This review focuses on 3 allergic disorders of persons coming up against venerable age: asthma, allergic rhinitis, and atopic dermatitis. The prevalence of allergic diseases in the elderly ranges from 5 to 10% and appears to be rising. A gradual decline in immune function, termed immunosenescence, and age-related changes in tissue structure influence the development of these disorders. Common complications are comorbidities, polypharmacy, and adverse effects of drugs. The elderly have difficulty mounting protective immune responses against newly encountered antigens. The integrity of epithelial barriers is compromised, leading to a chronic, subclinical inflammatory state and an enhanced Th2 (allergic) immune response. Undiagnosed asthma is frequent in elderly persons (about 8%) and still more commonplace in those with respiratory symptoms. Poorly controlled asthma in the elderly undermines their functional status and leads to a loss of autonomy and social isolation that may delay seeking medical services. Aggravation of allergic rhinitis coincides with exacerbation of asthma, whereas treatment of nasal inflammation improves control of the asthma. Atopic dermatitis is a chronically relapsing inflammatory skin disease often associated with respiratory allergy.