Distinguishing adult-onset asthma from COPD: a review and a new approach

"Air That Once Was Breath" Part 2: Wildfire Smoke and Airway Disease - "Climate Change, Allergy and Immunology" Special IAAI Article Collection: Collegium Internationale Allergologicum Update 2023

BACKGROUND

Population growth and climate change have led to more frequent and larger wildfires, increasing the exposure of individuals to wildfire smoke. Notably, asthma exacerbations and allergic airway sensitization are prominent outcomes of such exposure.

SUMMARY

Key research questions relate to determining the precise impact on individuals with asthma, including the severity, duration, and long-term consequences of exacerbations. Identifying specific risk factors contributing to vulnerability, such as age, genetics, comorbidities, or environmental factors, is crucial. Additionally, reliable biomarkers for predicting severe exacerbations need exploration. Understanding the long-term health effects of repeated wildfire smoke exposures in individuals with asthma and addressing healthcare disparities are important research areas.

KEY MESSAGES

This review discusses the need for comprehensive research efforts to better grasp wildfire smoke-induced respiratory health, particularly in vulnerable populations such as farmworkers, firefighters, pregnant women, children, the elderly, and marginalized communities. Effective mitigation would require addressing the current limitations we face by supporting research aimed at a better understanding of wildfire smoke-induced airway disease.

Impact of Mepolizumab on Exacerbations in the US Medicare Population

BACKGROUND

Asthma is a common chronic respiratory disorder associated with significant disease and economic burden. Mepolizumab is an anti-IL-5 mAb approved for use as an add-on treatment in patients with severe eosinophilic asthma.

OBJECTIVE

To assess the impact of mepolizumab initiation on asthma exacerbation frequency, oral corticosteroid (OCS) use, and asthma exacerbation-related costs in a US Medicare population.

METHODS

This was a retrospective cohort study of mepolizumab claims from patients with asthma in the Centers for Medicare and Medicaid Services Medicare database carried out between January 2016 and December 2018. The index date (first claim for mepolizumab) was required to occur between January and December 2017. The baseline and follow-up periods were the 12 months before and 12 months after the index, respectively. Outcomes included changes in the proportion of patients experiencing exacerbations (primary), OCS use (secondary), and asthma exacerbation-related costs during the baseline and follow-up periods.

RESULTS

The study identified 1,278 patients (mean age, 67.9 years; 65% female) with one or more prescription or administration claim for mepolizumab who were eligible for study inclusion. There was a significant relative reduction in the proportion of patients with an asthma exacerbation (27%; P < .0001) in the follow-up versus baseline period. Similarly, a lower proportion of patients received OCS for asthma (16% relative reduction; P < .0001), fewer patients were chronic OCS users (5 mg/day or more; 48% relative reduction; P < .0001), and there was a significant decrease in asthma exacerbation-related costs (total reduction, $888; P = .0002) during the follow-up versus the baseline period.

CONCLUSION

Mepolizumab reduced exacerbations, OCS use, and exacerbation-related healthcare costs in a US Medicare population, confirming its benefits in this specific population with severe asthma.

Artificial intelligence to differentiate asthma from COPD in medico-administrative databases

INTRODUCTION

Discriminating asthma from chronic obstructive pulmonary disease (COPD) using medico-administrative databases is challenging but necessary for medico-economic analyses focusing on respiratory diseases. Artificial intelligence (AI) may improve dedicated algorithms.

OBJECTIVES

To assess performance of different AI-based approaches to distinguish asthmatics from COPD patients in medico-administrative databases where the clinical diagnosis is absent. An "Asthma COPD Overlap" category was defined to further test whether AI can detect complexity.

METHODS

This study included 178,962 patients treated by two "R03" treatment prescriptions at least from January 2016 to December 2018 and managed by either a general practitioner and/or a pulmonologist participating in a permanent longitudinal observatory of prescription in ambulatory medicine (LPD). Clinical diagnoses are available in this database and were used as gold standards to develop diagnostic rules. Three types of AI approaches were explored using data restricted to demographics and treatment dispensations: multinomial regression, gradient boosting and recurrent neural networks (RNN). The best performing model (based on metric properties) was then applied to estimate the size of asthma and COPD populations based on a database (LRx) of treatment dispensations between July, 2018 and June, 2019.

RESULTS

The best models were obtained with the boosting approach and RNN, with an overall accuracy of 68%. Performance metrics were better for asthma than COPD. Based on LRx data, the extrapolated numbers of patients treated for asthma and COPD in France were 3.7 and 1.2 million, respectively. Asthma patients were younger than COPD patients (mean, 49.9 vs. 72.1 years); COPD occurred mostly in men (68%) compared to asthma (33%).

CONCLUSION

AI can provide models with acceptable accuracy to distinguish between asthma, ACO and COPD in medico-administrative databases where the clinical diagnosis is absent. Deep learning and machine learning (RNN) had similar performances in this regard.

Switching Treatment from Mepolizumab to Benralizumab for Elderly Patients with Severe Eosinophilic Asthma: A Retrospective Observational Study

Objective Switching from mepolizumab to benralizumab has been reported to significantly improve both asthma control and the lung function. However, the data on its efficacy in elderly patients with severe eosinophilic asthma are limited. This study aimed to assess whether elderly patients with severe eosinophilic asthma could experience an improved asthma control and lung function when switching directly from mepolizumab to benralizumab. Methods In this single-center, retrospective study conducted between February 2017 and September 2018, we assessed the effect of switching the treatment directly from mepolizumab to benralizumab on eosinophil levels, exacerbation rates, and lung function. We compared the treatment responses between the two groups using either Fisher's exact test or Mann-Whitney U-test, as appropriate. Patients We enrolled 12 elderly patients (age ≥65 years) with severe eosinophilic asthma treated with mepolizumab at Hiroshima Prefectural Hospital (Hiroshima, Japan) during the study period. Six patients were switched from mepolizumab to benralizumab, and six continued with the mepolizumab treatment. Results The switch from mepolizumab to benralizumab caused a near-complete reduction in the eosinophil count (p=0.008). The annual rate of clinically relevant exacerbations and hospitalizations diminished as well, albeit with no statistical significance. We found no improvement in the lung function after switching treatment and no difference in the treatment response between the groups. Conclusion Although this study is based on a small sample of participants, the results indicate that both mepolizumab treatment and switching from mepolizumab to benralizumab treatment without a washout period have clinically relevant asthma control benefits for elderly patients with severe eosinophilic asthma.

Mmp12 Is Upregulated by in utero Second-Hand Smoke Exposures and Is a Key Factor Contributing to Aggravated Lung Responses in Adult Emphysema, Asthma, and Lung Cancer Mouse Models

Matrix metalloproteinase-12 (Mmp12) is upregulated by cigarette smoke (CS) and plays a critical role in extracellular matrix remodeling, a key mechanism involved in physiological repair processes, and in the pathogenesis of emphysema, asthma, and lung cancer. While cigarette smoking is associated with the development of chronic obstructive pulmonary diseases (COPD) and lung cancer, in utero exposures to CS and second-hand smoke (SHS) are associated with asthma development in the offspring. SHS is an indoor air pollutant that causes known adverse health effects; however, the mechanisms by which in utero SHS exposures predispose to adult lung diseases, including COPD, asthma, and lung cancer, are poorly understood. In this study, we tested the hypothesis that in utero SHS exposure aggravates adult-induced emphysema, asthma, and lung cancer.

Methods: Pregnant BALB/c mice were exposed from gestational days 6–19 to either 3 or 10mg/m³ of SHS or filtered air. At 10, 11, 16, or 17weeks of age, female offspring were treated with either saline for controls, elastase to induce emphysema, house-dust mite (HDM) to initiate asthma, or urethane to promote lung cancer. At sacrifice, specific disease-related lung responses including lung function, inflammation, gene, and protein expression were assessed.

Results: In the elastase-induced emphysema model, in utero SHS-exposed mice had significantly enlarged airspaces and up-regulated expression of Mmp12 (10.3-fold compared to air-elastase controls). In the HDM-induced asthma model, in utero exposures to SHS produced eosinophilic lung inflammation and potentiated Mmp12 gene expression (5.7-fold compared to air-HDM controls). In the lung cancer model, in utero exposures to SHS significantly increased the number of intrapulmonary metastases at 58weeks of age and up-regulated Mmp12 (9.3-fold compared to air-urethane controls). In all lung disease models, Mmp12 upregulation was supported at the protein level.

Conclusion: Our findings revealed that in utero SHS exposures exacerbate lung responses to adult-induced emphysema, asthma, and lung cancer. Our data show that MMP12 is up-regulated at the gene and protein levels in three distinct adult lung disease models following in utero SHS exposures, suggesting that MMP12 is central to in utero SHS-aggravated lung responses.

Adult-Onset Asthma Associated With E-Cigarette Use

Electronic cigarettes (e-cigarettes) are being increasingly used as a "safer" alternative to regular cigarettes as a method of de-addiction or a bridge to nicotine cessation. However, a multitude of pulmonary pathologies have been described associated with its use and have been clubbed under the category of e-cigarette or vaping use-associated lung injury (EVALI). This case describes a patient who started e-cigarette smoking in order to quit combustible cigarette smoking and developed adult-onset severe asthma. The clinical effect was initially reversible but later developed into persistent symptoms requiring inhaled and systemic therapy.

Dynamic Urinary Proteome Changes in Ovalbumin-Induced Asthma Mouse Model Using Data-Independent Acquisition Proteomics

Background

In this work, we aim to investigate dynamic urinary proteome changes during asthma development and to identify potential urinary protein biomarkers for the diagnosis of asthma.

Methods

An ovalbumin (OVA)-induced mouse model was used to mimic asthma. The urinary proteome from asthma and control mice was determined using data-independent acquisition combined with high-resolution tandem mass spectrometry.

Results

Overall, 331 proteins were identified, among which 53 were differentially expressed (26, 24, 14 and 20 on days 2, 8, 15 and 18, respectively; 1.5-fold change, adjust P<0.05). Gene Ontology annotation of the differential proteins showed that the acute-phase response, innate immune response, B cell receptor signaling pathway, and complement activation were significantly enriched. Protein–protein interaction network revealed that these differential proteins were partially biologically connected in OVA-induced asthma, as a group. On days 2 and 8, after two episodes of OVA sensitization, six differential proteins (CRAMP, ECP, HP, F2, AGP1, and CFB) were also reported to be closely associated with asthma. These proteins may hold the potential for the early screening of asthma. On days 15 and 18, after challenged with 1% OVA by inhalation, seven differential proteins (VDBP, HP, CTSE, PIGR, AAT, TRFE, and HPX) were also reported to be closely associated with asthma. Thus, these proteins hold the potential to be biomarkers for the diagnosis of asthma attack.

Conclusion

Our results indicate that the urinary proteome could reflect dynamic pathophysiological changes in asthma progression.

Biologic Treatments for Asthma and Chronic Obstructive Pulmonary Disorder

The global COVID-19 pandemic has brought respiratory disease to the forefront of public health, but asthma prevalence has been rising globally for decades. Asthma is mediated by errant immune activation and airway remodeling, but the influences of environment, nutrition, and comorbidities (e.g., asthma-chronic obstructive pulmonary disorder-overlap [ACO]) are still poorly understood. Even as a new generation of biologic-based treatments offer better airway control and reductions in mortality, a lack of prophylactic treatments and mechanistic understanding complicates efforts to prevent pathogenesis. This review will explicate and synthesize current knowledge on the effect of ACO and biologics (omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab) on pathogenesis, treatment, and prognosis.

Difference in Local Lung Movement During Tidal Breathing Between COPD Patients and Asthma Patients Assessed by Four-dimensional Dynamic-ventilation CT Scan

Background

The validity of four-dimensional dynamic-ventilation CT scan for distinguishing COPD from asthma has not been established.

Purpose

To assess whether four-dimensional dynamic-ventilation CT scan can aid in the diagnosis of COPD by comparing local lung movement during tidal breathing between COPD and asthma.

Patients and Methods

Thirty-three COPD patients (30 males and three females; median age 74; range 44-89 years) and 11 asthma patients (five males and six females; median age 55; range: 32-75 years) underwent whole-lung dynamic-ventilation CT scan. CT data were reconstructed, one respiratory cycle to 10 phases, and in addtion we reconstructed threefold new phase data sets. We then analyzed local lung movement during tidal breathing using unpaired t-tests and chi-squared tests.

Results

The local lung movement in COPD patients was significantly smaller than in asthma patients, especially in the ventral part of the lung. This was so even in patients who had mild emphysema (Goddard score <8).

Conclusion

Quantitative evaluation using four-dimensional dynamic-ventilation CT scan demonstrated that local lung movement during tidal breathing, particularly in the ventral lung, was smaller in COPD than in asthma patients, which may help distinguish COPD from asthma.

Exercise and Asthma

Asthma is a chronic lower respiratory disease that is very common worldwide, and its incidence is increasing year by year. Since the 1970s, asthma has become widespread, with approximately 300 million people affected worldwide and about 250,000 people have lost their lives. Asthma seriously affects people's physical and mental health, resulting in reduced learning efficiency, limited physical activities, and decreased quality of life. Therefore, raising awareness of the risk of asthma and how to effectively treat asthma have become important targets for the prevention and management of asthma in recent years. For patients with asthma, exercise training is a widely accepted adjunct to drug-based and non-pharmacological treatment. It has been recommended abroad that exercise prescriptions are an important part of asthma management.

Risk of respiratory hospital admission associated with modelled concentrations of Aspergillus fumigatus from composting facilities in England

Bioaerosols have been associated with adverse respiratory-related health effects and are emitted in elevated concentrations from composting facilities. We used modelled Aspergillus fumigatus concentrations, a good indicator for bioaerosol emissions, to assess associations with respiratory-related hospital admissions. Mean daily Aspergillus fumigatus concentrations were estimated for each composting site for first full year of permit issue from 2005 onwards to 2014 for Census Output Areas (COAs) within 4 km of 76 composting facilities in England, as previously described (Williams et al., 2019). We fitted a hierarchical generalized mixed model to examine the risk of hospital admission with a primary diagnosis of (i) any respiratory condition, (ii) respiratory infections, (iii) asthma, (iv) COPD, (v) diseases due to organic dust, and (vi) Cystic Fibrosis, in relation to quartiles of Aspergillus fumigatus concentrations. Models included a random intercept for each COA to account for over-dispersion, nested within composting facility, on which a random intercept was fitted to account for clustering of the data, with adjustments for age, sex, ethnicity, deprivation, tobacco sales (smoking proxy) and traffic load (as a proxy for traffic-related air pollution). We included 249,748 respiratory-related and 3163 Cystic Fibrosis hospital admissions in 9606 COAs with a population-weighted centroid within 4 km of the 76 included composting facilities. After adjustment for confounders, no statistically significant effect was observed for any respiratory-related (Relative Risk (RR) = 0.99; 95% Confidence Interval (CI) 0.96-1.01) or for Cystic Fibrosis (RR = 1.01; 95% CI 0.56-1.83) hospital admissions for COAs in the highest quartile of exposure. Similar results were observed across all respiratory disease sub-groups. This study does not provide evidence for increased risks of respiratory-related hospitalisations for those living near composting facilities. However, given the limitations in the dispersion modelling, risks cannot be completely ruled out. Hospital admissions represent severe respiratory episodes, so further study would be needed to investigate whether bioaerosols emitted from composting facilities have impacts on less severe episodes or respiratory symptoms.

COPD, airflow limitation and chronic bronchitis in farmers: a systematic review and meta-analysis

Introduction

The current definition of chronic obstructive pulmonary disease (COPD) associates persistent airflow limitation and chronic respiratory symptoms. Agricultural work has been associated with an increased risk of developing COPD, but the prevalence and definition of the disease vary greatly between studies. This meta-analysis aimed to assess the association between agricultural work and COPD using the most widely used definitions of the disease.

Methods

Inclusion criteria were: (1) design: cross-sectional or longitudinal, (2) groups: at least one group of farmers and a control group of non-farmers, (3) outcome: prevalence or unadjusted OR of COPD, airflow limitation and/or chronic bronchitis, (4) study subjects: groups of exposed subjects comprising ≥30 individuals and with a mean age ≥40 years and (5) language: English and French language, full-length, original publications in peer-reviewed journals.

Results

In total, 22 manuscripts were included in the meta-analysis. Eight studies assessed only the prevalence of airflow limitation, nine assessed only the prevalence of chronic bronchitis and four assessed the prevalence of both these parameters. Only one assessed the prevalence of COPD according to its current definition, and this study also provided the prevalence of airflow limitation. Ten studies showed a positive association between farming exposure and airflow limitation or chronic bronchitis, and 12 showed no association (OR (95% CI)=1.77 (1.50 to 2.08), p<0.001). Cattle, swine, poultry and crop farming were associated with either airflow limitation or chronic bronchitis.

Conclusion

Although some features of COPD are associated with some agricultural work, well-designed studies with appropriate diagnostic criteria should be conducted to draw strong conclusions about the relationship between COPD and farming.

Genetic risk factors for the development of pulmonary disease identified by genome-wide association

Chronic respiratory diseases are a major cause of morbidity and mortality. Asthma and chronic obstructive pulmonary disease (COPD) combined affect over 500 million people worldwide. While environmental factors are important in disease progression, asthma and COPD have long been known to be heritable with genetic components playing an important role in the risk of developing disease. Identification of genetic variation contributing to disease progression is important for a number of reasons including identification of risk alleles, understanding underlying disease mechanisms and development of novel therapies. Genome-wide association studies (GWAS) have been successful in identifying many loci associated with lung function, COPD and asthma. In recent years, meta-analyses and improved imputation have facilitated the growth of GWAS in terms of numbers of subjects and the number of single nucleotide polymorphisms (SNP) that can be interrogated. As a consequence, there has been a significant increase in the number of signals associated with asthma, COPD and lung function. SNP that have shown association with lung function reassuringly show a significant overlap with SNP associated with COPD giving a glimpse at pathways that may be involved in COPD mechanisms including genes in, for example, developmental pathways. In asthma, association signals are often in or near genes involved in both adaptive and innate immune response pathways, epithelial cell homeostasis and airway structural changes. The challenges now are translating these genetic signals into a new understanding of lung biology, understanding how variants impact health and disease and how they may provide opportunities for therapeutic intervention.

Epidemiology and risk factors of asthma-chronic obstructive pulmonary disease overlap in low- and middle-income countries

BACKGROUND

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) represents the confluence of bronchial airway hyperreactivity and chronic airflow limitation and has been described as leading to worse lung function and quality of life than found with either singular disease process.

OBJECTIVE

We aimed to describe the prevalence and risk factors for ACO among adults across 6 low- and middle-income countries (LMICs).

METHODS

We compiled cross-sectional data for 11,923 participants aged 35 to 92 years from 4 population-based studies in 12 settings. We defined COPD as postbronchodilator FEV₁/forced vital capacity ratio below the lower limit of normal, asthma as wheeze or medication use in 12 months or self-reported physician diagnosis, and ACO as having both.

RESULTS

The prevalence of ACO was 3.8% (0% in rural Puno, Peru, to 7.8% in Matlab, Bangladesh). The odds of having ACO were higher with household exposure to biomass fuel smoke (odds ratio [OR], 1.48; 95% CI, 0.98-2.23), smoking tobacco (OR, 1.28 per 10 pack-years; 95% CI, 1.22-1.34), and having primary or less education (OR, 1.35; 95% CI, 1.07-1.70) as compared to nonobstructed nonasthma individuals. ACO was associated with severe obstruction (FEV₁ %, <50; 31.6% of ACO vs 10.9% of COPD alone) and severe spirometric deficits compared with participants with asthma (-1.61 z scores FEV₁; 95% CI, -1.48 to -1.75) or COPD alone (-0.94 z scores; 95% CI, -0.78 to -1.10).

CONCLUSIONS

ACO may be as prevalent and more severe in LMICs than has been reported in high-income settings. Exposure to biomass fuel smoke may be an overlooked risk factor, and we favor diagnostic criteria for ACO that include environmental exposures common to LMICs.

Repetitive TLR3 activation in the lung induces skeletal muscle adaptations and cachexia

Due to immunosenescence, older adults are particularly susceptible to lung-based viral infections, with increased severity of symptoms in those with underlying chronic lung disease. Repeated respiratory viral infections produce lung maladaptations, accelerating pulmonary dysfunction. Toll like 3 receptor (TLR3) is a membrane protein that senses exogenous double-stranded RNA to activate the innate immune response to a viral infection. Polyinosinic-polycytidylic acid [poly(I:C)] mimics double stranded RNA and has been shown to activate TLR3. Utilizing an established mouse viral exacerbation model produced by repetitive intranasal poly(I:C) administration, we sought to determine whether repetitive poly(I:C) treatment induced negative muscle adaptations (i.e. atrophy, weakness, and loss of function). We determined skeletal muscle morphological properties (e.g. fiber-type, fiber cross-sectional area, muscle wet mass, etc.) from a treated group ((poly(I:C), n = 9) and a sham-treated control group (PBS, n = 9); age approximately 5 months. In a subset (n = 4 for both groups), we determined in vivo physical function (using grip test for strength, rotarod for overall motor function, and treadmill for endurance) and muscle contractile properties with in vitro physiology (in the EDL, soleus and diaphragm). Our findings demonstrate that poly(I:C)-treated mice exhibit both muscle morphological and functional deficits. Changes of note when comparing poly(I:C)-treated mice to PBS-treated controls include reductions in fiber cross-sectional area (-27% gastrocnemius, -25% soleus, -16% diaphragm), contractile dysfunction (soleus peak tetanic force, -26%), muscle mass (gastrocnemius -19%, soleus -23%), physical function (grip test -34%), body mass (-20%), and altered oxidative capacity (140% increase in succinate dehydrogenase activity in the diaphragm, but 66% lower in the gastrocnemius). Our data is supportive of a new model of cachexia/sarcopenia that has potential for future research into the mechanisms underlying muscle wasting.

Association between Serum 25-Hydroxy Vitamin D Levels and the Prevalence of Adult-Onset Asthma

The major circulating metabolite of vitamin D (25(OH)D) has been implicated in the pathogenesis for atopic dermatitis, asthma and other allergic diseases due to downstream immunomodulatory effects. However, a consistent association between 25(OH)D and asthma during adulthood has yet to be found in observational studies. We aimed to test the association between 25(OH)D and asthma during adulthood and hypothesised that this association would be stronger in non-atopic participants. Using information collected on the participants of the 1958 birth cohort, we developed a novel measure of atopic status using total and specific IgE values and reported history of eczema and allergic rhinitis. We designed a nested case-control analysis, stratified by atopic status, and using logistic regression models investigated the association between 25(OH)D measured at age 46 years with the prevalence of asthma and wheezy bronchitis at age 50 years, excluding participants who reported ever having asthma or wheezy bronchitis before the age of 42. In the fully adjusted models, a 10 nmol/L increase in serum 25(OH)D prevalence had a significant association with asthma (aOR 0.94; 95% CI 0.88–1.00). There was some evidence of an atopic dependent trend in the association between 25(OH)D levels and asthma. Further analytical work on the operationalisation of atopy status would prove useful to uncover whether there is a role for 25(OH)D and other risk factors for asthma.

Design of a Clinical Decision Support System for Fracture Prediction Using Imbalanced Dataset

More than 1 billion people suffer from chronic respiratory diseases worldwide, accounting for more than 4 million deaths annually. Inhaled corticosteroid is a popular medication for treating chronic respiratory diseases. Its side effects include decreased bone mineral density and osteoporosis. The aims of this study are to investigate the association of inhaled corticosteroids and fracture and to design a clinical support system for fracture prediction. The data of patients aged 20 years and older, who had visited healthcare centers and been prescribed with inhaled corticosteroids within 2002-2010, were retrieved from the National Health Insurance Research Database (NHIRD). After excluding patients diagnosed with hip fracture or vertebrate fractures before using inhaled corticosteroid, a total of 11645 patients receiving inhaled corticosteroid therapy were included for this study. Among them, 1134 (9.7%) were diagnosed with hip fracture or vertebrate fracture. The statistical results showed that demographic information, chronic respiratory diseases and comorbidities, and corticosteroid-related variables (cumulative dose, mean exposed daily dose, follow-up duration, and exposed duration) were significantly different between fracture and nonfracture patients. The clinical decision support systems (CDSSs) were designed with integrated genetic algorithm (GA) and support vector machine (SVM) by training and validating the models with balanced training sets obtained by random and cluster-based undersampling methods and testing with the imbalanced NHIRD dataset. Two different objective functions were adopted for obtaining optimal models with best predictive performance. The predictive performance of the CDSSs exhibits a sensitivity of 69.84-77.00% and an AUC of 0.7495-0.7590. It was concluded that long-term use of inhaled corticosteroids may induce osteoporosis and exhibit higher incidence of hip or vertebrate fractures. The accumulated dose of ICS and OCS therapies should be continuously monitored, especially for patients with older age and women after menopause, to prevent from exceeding the maximum dosage.

Bronchodilator effects of Lignosus rhinocerotis extract on rat isolated airways is linked to the blockage of calcium entry

BACKGROUND

Lignosus rhinocerotis (Cooke) Ryvarden is a popular medicinal mushroom used for centuries in Southeast Asia to treat asthma and chronic cough. The present study aimed to investigate the effect of this mushroom on airways patency.

MATERIALS AND METHODS

The composition of L. rhinocerotis TM02 cultivar was analyzed. Organ bath experiment was employed to study the bronchodilator effect of Lignosus rhinocerotis cold water extract (CWE) on rat isolated airways. Trachea and bronchus were removed from male Sprague-Dawley rats, cut into rings of 2 mm, pre-contracted with carbachol before adding CWE into the bath in increasing concentrations. To investigate the influence of incubation time, tissues were exposed to intervals of 5, 15 and 30 min between CWE concentrations after pre-contraction with carbachol in subsequent protocol. Next, tissues were pre-incubated with CWE before the addition of different contractile agents, carbachol and 5-hydroxytrptamine (5-HT). The bronchodilator effect of CWE was compared with salmeterol and ipratropium. In order to uncover the mechanism of action of CWE, the role of beta-adrenoceptor, potassium and calcium channels was investigated.

RESULTS

Composition analysis of TM02 cultivar revealed the presence of β-glucans and derivatives of adenosine. The extract fully relaxed the trachea at 3.75 mg/ml (p < 0.0001) and bronchus at 2.5 mg/ml (p < 0.0001). It was observed that lower concentrations of CWE were able to fully relax both trachea and bronchus but at a longer incubation interval between concentrations. CWE pre-incubation significantly reduced the maximum responses of carbachol-induced contractions (in both trachea, p = 0.0012 and bronchus, p = 0.001), and 5-HT-induced contractions (in trachea, p = 0.0048 and bronchus, p = 0.0014). Ipratropium has demonstrated a significant relaxation effect in both trachea (p = 0.0004) and bronchus (p = 0.0031), whereas salmeterol has only affected the bronchus (p = 0.0104). The involvement of β₂-adrenoceptor and potassium channel in CWE-mediated airway relaxation is ruled out, but the bronchodilator effect was unequivocally affected by influx of calcium.

CONCLUSIONS

The bronchodilator effect of L. rhinocerotis on airways is mediated by calcium signalling pathway downstream of G_αq-coupled protein receptors. The airway relaxation effect is both concentration- and incubation time-dependent. Our findings provide unequivocal evidence to support its traditional use to relieve asthma and cough.

Factors associated with Chronic Obstructive Pulmonary Disease among the elderly

This study aimed to identify factors associated with Chronic Obstructive Pulmonary Disease (COPD) among non-institutionalized elderly people. It involved a cross-sectional study conducted on the basis of a household survey, followed by spirometry. People diagnosed with COPD were compared with those with normal spirometry, through bivariate analysis, followed by multivariate regression analysis. We identified 53 elderly people were identified with COPD. After multivariate analysis, the following factors associated with COPD were identified: past or current smoking (OR: 3.74; 95% CI: 1.65-8.46), presence of chronic sputum (OR: 4.92; 95% CI: 2.03-11.95), pulse oximetry at rest ≤ 90% (OR: 8.74; 95%CI: 1.27-60.07), self-reported asthma (OR: 3.41; 95% CI: 1.01-11.57). The results reveal associated factors that highlight the need to review the selection criteria for patients at risk of COPD among the elderly.

The Prevalence and Symptom Profile of Asthma-COPD Overlap: The HUNT Study

The concept of asthma and COPD as separate conditions has been questioned, and the term asthma-COPD overlap syndrome has been introduced. We assessed the prevalence, symptoms, and lifestyle factors of asthma-COPD overlap (ACO) in a large Norwegian population-based study. From 2006 to 2008, a total of 50,777 residents of Nord-Trøndelag participated in the Nord-Trøndelag Health Study, Norway. They completed questionnaires regarding respiratory symptoms, disease status, and medication use. We estimated the prevalence and 95% confidence intervals of ACO. Additionally, spirometry was used to estimate the prevalence of ACO in a subgroup. The prevalence of self-reported ACO was 1.9%, and in age groups <40, 40-60 and ≥60 years it was 0.7%, 1.4%, and 3.2%, respectively. Among those reporting COPD, the proportion of ACO was 0.56. In the spirometry subgroup when ACO was defined as doctor diagnosed asthma ever and FEV₁/FVC < 0.70, the prevalence of ACO was 2.0%. All respiratory symptoms, separately or in combination, as well as medication use were reported most frequently in those with ACO compared to the other groups. Strikingly, we observed a two-fold higher proportion of allergic rhinitis in ACO compared to COPD only. In this Norwegian population, the prevalence of self-reported ACO was 1.9%, and the corresponding proportion of ACO among those with COPD was 0.56. Participants with ACO generally had the highest proportions of respiratory symptoms compared to asthma or COPD.

Land cover and air pollution are associated with asthma hospitalisations: A cross-sectional study

BACKGROUND

There is increasing policy interest in the potential for vegetation in urban areas to mitigate harmful effects of air pollution on respiratory health. We aimed to quantify relationships between tree and green space density and asthma-related hospitalisations, and explore how these varied with exposure to background air pollution concentrations.

METHODS

Population standardised asthma hospitalisation rates (1997-2012) for 26,455 urban residential areas of England were merged with area-level data on vegetation and background air pollutant concentrations. We fitted negative binomial regression models using maximum likelihood estimation to obtain estimates of asthma-vegetation relationships at different levels of pollutant exposure.

RESULTS

Green space and gardens were associated with reductions in asthma hospitalisation when pollutant exposures were lower but had no significant association when pollutant exposures were higher. In contrast, tree density was associated with reduced asthma hospitalisation when pollutant exposures were higher but had no significant association when pollutant exposures were lower.

CONCLUSIONS

We found differential effects of natural environments at high and low background pollutant concentrations. These findings can provide evidence for urban planning decisions which aim to leverage health co-benefits from environmental improvements.

Asthma, other atopic conditions and risk of infections in 105 519 general population never and ever smokers

BACKGROUND

Individuals with atopic conditions may have increased susceptibility to infections outside the organs directly affected by their atopic condition.

OBJECTIVE

We tested the hypothesis that atopic conditions overall, and stratified by smoking history, are associated with increased risk of hospitalization for infections.

METHODS

We collected information on smoking history and self-reported atopic conditions from 105 519 individuals from the general population and followed them for up to 23 years for infectious disease hospitalizations and deaths. For asthma, we focused on never smokers with asthma diagnosed before age 50 (early asthma) to minimize confounding by chronic obstructive pulmonary disease.

RESULTS

During follow-up, 11 160 individuals had infections. Never smokers with early asthma versus no atopic conditions had significantly increased risks of any infection (hazard ratio 1.65; 95% confidence interval 1.40-1.94), pneumonia (2.44; 1.92-3.11) and any non-respiratory tract infection (1.36; 1.11-1.67); results were similar in ever smokers. Never smokers with any asthma had significantly increased risks of any infection (1.44; 1.24-1.66) and pneumonia (1.99; 1.62-2.44). Neither atopic dermatitis (1.00; 0.91-1.10) nor hay fever (1.00; 0.93-1.07) was associated with risk of any infection. In never smokers, risk estimates for any infection were comparable between asthma and diabetes, as were the population attributable fractions of 2.2% for any asthma and 2.9% for diabetes.

CONCLUSION

Early asthma was associated with significantly increased risks of any infection, pneumonia and any non-respiratory tract infection in never and ever smokers. In never smokers, risk estimates as well as population attributable fractions for any infection were comparable between asthma and diabetes, suggesting that asthma may be a substantial risk factor for infections in the general population.

Leukotriene Receptor Antagonists for the Treatment of Asthma in Elderly Patients

Elderly asthma (EA) is regarded as a distinct phenotype of asthma and is associated with age-related changes in airway structure and alterations in lung function and immune responses. EA is difficult to diagnose because of aging and co-morbidities, and overlaps with fixed airway obstructive disease. Novel modalities to differentiate between EA and chronic obstructive pulmonary disease (COPD) are necessary. A multifaceted approach, including clinical history, smoking habits, atopy, and measurement of lung function, is mandatory to differentiate asthma from COPD. There are a variety of co-morbidities with EA, of which COPD, upper airway diseases, depression, obesity, and hypertension are the most common, and these co-morbidities can affect the control status of EA. However, leukotriene receptor antagonists (LTRAs) can facilitate the management of EA, and thus addition of an LTRA to inhaled corticosteroid (ICS) monotherapy or ICS plus long-acting β₂-agonist therapy improves symptoms in EA patients. LTRA treatment is safe and beneficial in patients who are unable to use inhalation devices properly or who have co-morbid diseases. Therefore, clinical studies targeting a specific population of EA patients are warranted to help achieve a better therapeutic strategy in EA patients.

Chronic Obstructive Pulmonary Disease in Farmers: A Systematic Review

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a significant public health problem but it is unclear whether agricultural work causes an increased risk of disease. The aim of this review was to study COPD risk among farmers and analyze occupational exposures in agricultural workplaces.

METHODS

A systematic literature search was conducted to identify epidemiological studies investigating COPD prevalence in farmers.

RESULTS

In the 14 studies reviewed, COPD prevalence ranged from 3% to 68% due to different characteristics of study population, working activities, case definition/diagnosis. Livestock farmers were at higher risk and significant associations were observed for exposure to organic dusts, endotoxins, mites, ammonia, and hydrogen sulfide.

CONCLUSIONS

Farming work was associated with greater risk of developing COPD. However, considering the several variables that may influence the disease prevalence in farmers, we suggest the adoption of a standardized research strategy.

[The effects of inhaled steroids withdrawal in COPD]

The key pathophysiological feature of chronic obstructive pulmonary disease (COPD) is an abnormal inflammatory bronchial reaction after inhalation of toxic substances. The priority is the avoidance of such toxic inhalations, but the use of anti-inflammatory drugs also seems appropriate, especially corticosteroids that are the sole anti-inflammatory drug available for this purpose in France. The risks associated with the prolonged use of these parenteral drugs are well known. Inhalation is therefore the optimal route, but inhaled drugs may also lead to adverse consequences. In COPD, there is an inhaled corticosteroids overuse, and a non-satisfactory respect of the guidelines. Consequently, their withdrawal should be considered. We reviewed seven clinical studies dealing with inhaled corticosteroids withdrawal in patients with COPD and found that included populations were heterogenous with different concomitant treatments. In non-frequent exacerbators receiving inhaled corticosteroids outside the recommendations, withdrawal appears to be safe under a well-managed bronchodilator treatment. In patients with severe COPD and frequent exacerbations, the risk of acute respiratory event is low when they receive concomitant optimal inhaled bronchodilators. However, other risks may be observed (declining lung function, quality of life) and a discussion of each case should be performed, especially in case of COPD and asthma overlap.

Tight junctions in pulmonary epithelia during lung inflammation

Inflammatory lung diseases like asthma bronchiale, chronic obstructive pulmonary disease and allergic airway inflammation are widespread public diseases that constitute an enormous burden to the health systems. Mainly classified as inflammatory diseases, the treatment focuses on strategies interfering with local inflammatory responses by the immune system. Inflammatory lung diseases predispose patients to severe lung failures like alveolar oedema, respiratory distress syndrome and acute lung injury. These life-threatening syndromes are caused by increased permeability of the alveolar and airway epithelium and exudate formation. However, the mechanism underlying epithelium barrier breakdown in the lung during inflammation is elusive. This review emphasises the role of the tight junction of the airway epithelium as the predominating structure conferring epithelial tightness and preventing exudate formation and the impact of inflammatory perturbations on their function.

Computer quantification of "angle of collapse" on maximum expiratory flow volume curve for diagnosing asthma-COPD overlap syndrome

Background

In a previous study, we demonstrated that asthma patients with signs of emphysema on quantitative computed tomography (CT) fulfill the diagnosis of asthma-COPD overlap syndrome (ACOS). However, quantitative CT measurements of emphysema are not routinely available for patients with chronic airway disease, which limits their application. Spirometry was a widely used examination tool in clinical settings and shows emphysema as a sharp angle in the maximum expiratory flow volume (MEFV) curve, called the “angle of collapse (AC)”. The aim of this study was to investigate the value of the AC in the diagnosis of emphysema and ACOS.

Methods

This study included 716 participants: 151 asthma patients, 173 COPD patients, and 392 normal control subjects. All the participants underwent pulmonary function tests. COPD and asthma patients also underwent quantitative CT measurements of emphysema. The AC was measured using computer models based on Matlab software. The value of the AC in the diagnosis of emphysema and ACOS was evaluated using receiver-operating characteristic (ROC) curve analysis.

Results

The AC of COPD patients was significantly lower than that of asthma patients and control subjects. The AC was significantly negatively correlated with emphysema index (EI; r=−0.666, P<0.001), and patients with high EI had a lower AC than those with low EI. The ROC curve analysis showed that the AC had higher diagnostic efficiency for high EI (area under the curve =0.876) than did other spirometry parameters. In asthma patients, using the AC ≤137° as a surrogate criterion for the diagnosis of ACOS, the sensitivity and specificity were 62.5% and 89.1%, respectively.

Conclusion

The AC on the MEFV curve quantified by computer models correlates with the extent of emphysema. The AC may become a surrogate marker for the diagnosis of emphysema and help to diagnose ACOS.

Results from a pragmatic prospective cohort study: Shared decision making improves outcomes for children with asthma

OBJECTIVE

Patient/provider shared decision making (SDM) improves asthma control in a pragmatic clinical trial setting. This study evaluated the impact of an evidence-based SDM toolkit on outcomes for patients with asthma implemented by providers in a real world setting. We hypothesized that these patients with asthma would demonstrate improved outcomes such as reduced emergency department (ED) visits, hospitalizations, and oral steroid use in the 12 months following a SDM visit compared to those who did not receive the intervention.

METHODS

Patients with asthma were identified within six primary care practices that serve vulnerable populations in Charlotte, NC (746 children; 718 adult patients). Propensity scores were used to match 200 children and 206 adults for analysis. The primary outcome variable was asthma exacerbation defined as an ED visit or hospitalization for asthma or outpatient prescription of an oral steroid. Patients were monitored at 3, 6, and 12 months after the intervention date. The outcome variables of ED visits, hospitalizations, and oral steroids were compared between intervention and matched control patients.

RESULTS

The proportion of pediatric patients with one or more exacerbations was significantly lower in the SDM intervention group compared to controls during 12 months after exposure to the intervention (33% vs. 47%, p = 0.023). For adults, there was not a strong association between use of the SDM intervention and outcomes improvement.

CONCLUSIONS

The evidence-based SDM intervention implemented in this study was associated with improved asthma outcomes for pediatric patients but not adult patients in a real world clinical setting.

Can computed tomography and carbon monoxide transfer coefficient diagnose an asthma-like phenotype in COPD?

BACKGROUND AND OBJECTIVE

Post-mortem and computed tomography (CT) studies indicated that emphysema is a feature of COPD even in the 'blue bloater/chronic bronchitis' type. We aim to test the hypothesis that the non-emphysematous patients are distinct from the main body of COPD and are more akin to asthmatic patients.

METHODS

We studied 54 patients with COPD. Emphysema was measured by Goddard's visual scoring of CT scan and the carbon monoxide transfer coefficient (KCO). Bronchial biopsy was offered for thickness of basement membrane (BM) (≥7 µm) as a marker of remodelling in irreversible asthma. Spirometry was repeated after therapy with Budesonide/Formoterol for 1 year.

RESULTS

The non-emphysematous phenotype were 24 of 54 patients (44%) by CT scan and 23 of 54 patients (43%) by KCO, showing agreement in 53 out of 54 patients. The non-emphysematous patients were younger, had higher forced expiratory volume in 1 s (FEV₁ ) (median 61% vs 49.7%), greater prevalence of hypertrophy of nasal turbinates and higher serum IgE. The emphysematous phenotype had lower BMI and greater dyspnoea score. The BM was thickened in 11 of 14 and 0 of 10 patients in the non-emphysematous and emphysematous groups, respectively. Three patients without emphysema and a normal BM normalized their FEV₁ upon receiving inhaled corticosteroid (ICS)/long-acting β2 agonist (LABA). All the non-emphysematous improved their FEV₁ after ICS/LABA (median = 215 mL). The median decline in the emphysematous was -65 mL.

CONCLUSION

The non-emphysematous phenotype of COPD displays important features of asthma: clinical picture, histology and response to ICS. CT and KCO can predict spirometric response to ICS/LABA.

Klf10 deficiency in mice exacerbates pulmonary inflammation by increasing expression of the proinflammatory molecule NPRA

KLF10 is a transforming growth factor (TGF)-β/Smad downstream regulated gene. KLF10 binds to the promoter of target genes and mimics the effects of TGF-β as a transcriptional factor. In our laboratory, we noted that Klf10 deficiency in mice is associated with significant inflammation of the lungs. However, the precise mechanism of this association remains unknown. We previously identified NPRA as a target gene potentially regulated by KLF10 through direct binding; NPRA knockout have known that prevented lung inflammation in a mouse model of allergic asthma. Here, we further explored the regulatory association between KLF10 and NPRA on the basis of the aforementioned findings. Our results demonstrated that KLF10 acts as a transcriptional repressor of NPRA and that KLF10 binding reduces NPRA expression in vitro. Compared with wild-type mice, Klf10-deficient mice were more sensitive to lipopolysaccharide or ovalbumin challenge and showed more severe inflammatory histological changes in the lungs. Moreover, Klf10-deficient mice showed pulmonary neutrophil accumulation. These findings collectively reveal the precise site where KLF10 signaling affects pulmonary inflammation by attenuating NPRA expression. They also verify the importance of KLF10 and atrial natriuretic peptide/NPRA in exerting influences on chronic pulmonary disease pathogenesis.

Occupational exposure and risk of chronic obstructive pulmonary disease: a systematic review and meta-analysis

INTRODUCTION

Due to contradictory literature we have performed a systematic review and meta-analyse of population-based studies that have used Job Exposure Matrices to assess occupational exposure and risk of Chronic Obstructive Pulmonary Disease (COPD).

AREAS COVERED

Two researchers independently searched databases for published articles using predefined inclusion criteria. Study quality was assessed, and results pooled for COPD and chronic bronchitis for exposure to biological dust, mineral dust, and gases/fumes using a fixed and random effect model. Five studies met predetermined inclusion criteria. The meta-analysis showed low exposure to mineral dust, and high exposure to gases/fumes were associated with an increased risk of COPD. We also found significantly increased the risk of chronic bronchitis for low and high exposure to biological dust and mineral dust. Expert commentary: The relationship between occupational exposure assessed by the JEM and the risk of COPD and chronic bronchitis shows significant association with occupational exposure. However, the heterogeneity of the meta-analyses suggests more wide population-based studies with older age groups and longitudinal phenotype assessment of COPD to clarify the role of occupational exposure to COPD risk.

Gene-based analysis identified the gene ZNF248 is associated with late-onset asthma in African Americans

BACKGROUND

Late-onset asthma (LOA) has distinct characteristics and its pathogenesis might rely on unique pathways. Although current studies are focused primarily on childhood asthma, more research is needed to show the mechanisms underlying LOA.

OBJECTIVE

To conduct genomewide association analysis and gene-based analysis to identify single-nucleotide polymorphisms and genes associated with LOA.

METHODS

The Women's Health Initiative (WHI) observational cohort and the Multi-Ethnic Study of Atherosclerosis (MESA) were used to identify subjects with LOA. The association between LOA and body mass index and smoking was evaluated. In the discovery stage of the genetic analysis, 1,218 African American subjects from WHI with genotype data (271 cases and 947 controls) were used for single-nucleotide polymorphism and gene-based association analyses. Significant or suggestive results were subsequently investigated in an independent African American population from MESA (38 cases and 806 controls).

RESULTS

In WHI, the relative odds for LOA in obese vs normal-weight subjects was 2.55 (95% confidence interval 1.74-3.76). Ever smokers also had greater odds for LOA compared with never smokers (odds ratio 1.59, 95% confidence interval 1.21-2.09). The same trends were observed in MESA. In WHI, 6 single-nucleotide polymorphisms were associated with LOA at a genomewide-suggestive significance level (P < 1.0 × 10(-5)). The gene ZNF248 was associated with LOA and reached genomewide significance (P = 4.0 × 10(-7)). In MESA, the association between ZNF248 and LOA was successfully replicated (P = .015).

CONCLUSION

Smoking and obesity are risk factors for LOA. ZNF248 confers increased susceptibility to LOA in African Americans.

Chronic obstructive pulmonary disease: an overview

As chronic obstructive pulmonary disease (COPD) is one of the major causes of worldwide mortality, it is important to prevent, diagnose and manage it. COPD creates a huge burden on the NHS and has a significant impact on patients. This is a problem with the increase in morbidity and mortality rates. In primary care there is a lack of knowledge, under-use of quality-assured spirometry and under-diagnosis in about half of all cases. To be able to effectively diagnose, assess and manage COPD, health professionals must understand the physiology and aetiology of the disease. COPD is similar to asthma in its presentation and physiology but management of the condition can differ. The authors therefore looked at the similarities between the two conditions and what tests one can use to make a diagnosis of COPD.

Asthma: definitions and pathophysiology

BACKGROUND

Asthma is a common condition due to chronic inflammation of the lower respiratory tract. Chronic lower airway inflammation is known to be more common in individuals that also have inflammatory disorders of the upper airway. The scientific understanding of asthma continues to improve and it is important for providers who treat upper or lower airway inflammation to be familiar with asthma's definition and pathophysiology.

METHODS

Articles were selected based on literature reviews through PubMed and personal knowledge of the author. The search selection was not standardized.

RESULTS

Asthma is a heterogenic condition that is underdiagnosed and undertreated despite that the skills needed to diagnose it are readily attainable and effective treatments are available. Providers need a working understanding of asthma in order to be proficient at managing their patients with chronic nasal or sinus inflammation. This article provides a primer focusing on the current conception asthma in terms of definition, possible etiologies, inflammatory profile, pathophysiology, subtypes, and overlapping conditions.

CONCLUSION

Asthma is a chronic inflammatory disorder arising from not fully understood heterogenic gene-environment interactions. It features variable airway obstruction and bronchial hyperresponsiveness. Clinically, asthmatics exhibit recurrent episodes of wheeze, cough, chest tightness, and shortness of breath.

GP utilisation by education level among adults with COPD or asthma: a cross-sectional register-based study

There is a marked socioeconomic gradient in the prevalence of chronic obstructive pulmonary disease (COPD) and asthma, but a large proportion of patients remain undiagnosed. It is a challenge for general practitioners (GPs) to both identify patients and contribute to equity and high quality in services delivered. The aim of this study was to identify patients with COPD and asthma diagnoses recorded by GPs and explore their utilisation of GP services by education level. This was a cross-sectional, national, register-based study from Norwegian general practice in the period 2009–2011. Based on claims from GPs, the number of patients aged ⩾40 years with a diagnosis of COPD or asthma and their GP services utilisation were estimated and linked to the national education database. Multivariate Poisson and logistic regression models were used to explore the variations in GP utilisation. In the population aged ⩾40 years, 2.8% had COPD and 3.8% had asthma according to GPs’ diagnoses. COPD was four times more prevalent in patients with basic education than higher education; this increase was ⩽80% for asthma. Consultation rates were 12% higher (P<0.001) for COPD and 25% higher (P<0.001) for asthma in patients with low versus high education in the age group of 40–59 years after adjusting for comorbidity, and patient and GP characteristics. Approximately 25% of COPD patients and 20% of asthma patients had ⩾1 spirometry test in general practice in 2011, with no significant education differences in adjusted models. The higher consultation rate in lower-education groups indicates that GPs contribute to fair distribution of healthcare.

Quantitative computed tomography measurements of emphysema for diagnosing asthma-chronic obstructive pulmonary disease overlap syndrome

Background

The diagnostic criteria of asthma–COPD overlap syndrome (ACOS) are controversial. Emphysema is characteristic of COPD and usually does not exist in typical asthma patients. Emphysema in patients with asthma suggests the coexistence of COPD. Quantitative computed tomography (CT) allows repeated evaluation of emphysema noninvasively. We investigated the value of quantitative CT measurements of emphysema in the diagnosis of ACOS.

Methods

This study included 404 participants; 151 asthma patients, 125 COPD patients, and 128 normal control subjects. All the participants underwent pulmonary function tests and a high-resolution CT scan. Emphysema measurements were taken with an Airway Inspector software. The asthma patients were divided into high and low emphysema index (EI) groups based on the percentage of low attenuation areas less than −950 Hounsfield units. The characteristics of asthma patients with high EI were compared with those having low EI or COPD.

Results

The normal value of percentage of low attenuation areas less than −950 Hounsfield units in Chinese aged >40 years was 2.79%±2.37%. COPD patients indicated more severe emphysema and more upper-zone-predominant distribution of emphysema than asthma patients or controls. Thirty-two (21.2%) of the 151 asthma patients had high EI. Compared with asthma patients with low EI, those with high EI were significantly older, more likely to be male, had more pack-years of smoking, had more upper-zone-predominant distribution of emphysema, and had greater airflow limitation. There were no significant differences in sex ratios, pack-years of smoking, airflow limitation, or emphysema distribution between asthma patients with high EI and COPD patients. A greater number of acute exacerbations were seen in asthma patients with high EI compared with those with low EI or COPD.

Conclusion

Asthma patients with high EI fulfill the features of ACOS, as described in the Global Initiative for Asthma and Global Initiative for Chronic Obstructive Lung Disease guidelines. Quantitative CT measurements of emphysema may help in diagnosing ACOS.

Characterization and redox mechanism of asthma in the elderly

Asthma is a chronic disease characterized by reversible airflow limitation, coughing, bronchial constriction, and an inflammatory immune response. While asthma has frequently been categorized as emerging in childhood, evidence has begun to reveal that the elderly population is certainly susceptible to late-onset, or even long-standing asthma. Non-atopic asthma, most commonly found in elderly patients is associated with elevated levels of serum and sputum neutrophils and may be more detrimental than atopic asthma. The mortality of asthma is high in the elderly since these patients often possess more severe symptoms than younger populations. The redox mechanisms that mediate inflammatory reactions during asthma have not been thoroughly interpreted in the context of aging. Thus, we review the asthmatic symptoms related to reactive oxygen species (ROS) and reactive nitrogen species (RNS) in seniors. Moreover, immune status in the elderly is weakened in part by immunosenescence, which is broadly defined as the decline in functionality of the immune system that corresponds with increasing age. The effects of immunosenescence on the expression of biomarkers potentially utilized in the clinical diagnosis of asthma remain unclear. It has also been shown that existing asthma treatments are less effective in the elderly. Thus, it is necessary that clinicians approach the diagnosis and treatment of asthmatic senior patients using innovative methods. Asthma in the elderly demands more intentional diagnostic and therapeutic research since it is potentially one of the few causes of mortality and morbidity in the elderly that is largely reversible.

Are Asthma and COPD a Continuum of the Same Disease?

Asthma and chronic obstructive pulmonary disease (COPD) are common heterogeneous diseases with significant impact on morbidity, mortality, and health care costs. In most of the cases, the main features and pathophysiology differ substantially between both asthma and COPD, which allows differentiating both entities and providing appropriate treatment. The recognition of a subgroup of patients who present clinically with features of both conditions, asthma chronic obstructive pulmonary disease overlap syndrome, has reignited the question of whether asthma and COPD are different manifestations of the same disease or unique processes, the so-called Dutch hypothesis versus British hypothesis controversy. There is enough heterogeneity in the clinical and mechanistic profiles of these 3 diseases, and subsets of these 3 diseases, to suggest that a new approach relying on the concept of endotypes of obstructive airways disease may be more useful. This characterization has provided the basis for opening new areas of research that may eventually lead to the development of new targeted drugs. This review focuses on the current knowledge of asthma, COPD, and asthma chronic obstructive pulmonary disease overlap syndrome phenotypes with emphasis on mechanisms of disease and how these may define endotypes, providing a more rational approach to research and clinical care.

Asthma-COPD overlap syndrome (ACOS): A diagnostic challenge

Asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) is characterized by persistent airflow limitation with several features usually associated with asthma and several features usually associated with COPD. ACOS may be a special phenotype of a spectrum of chronic obstructive airway diseases, in which asthma and COPD are at the two opposite ends. The prevalence of ACOS varies considerably due to differing criteria being applied for diagnosis. Patients with ACOS utilize a large proportion of medical resources. They are associated with more frequent adverse outcomes than those with asthma or COPD alone. ACOS is currently a diagnostic challenge for physicians because there are no specific biomarkers to differentiate ACOS from asthma or COPD. The approach to diagnosing ACOS depends on the population from which the patient originated. The management of ACOS should be individualized to ensure the most effective treatment with minimal side effects. In this paper, we review the diagnostic criteria of ACOS used in previous studies, propose practical approaches to diagnosing and managing ACOS and raise some research questions related to ACOS.

Management of the patient with eosinophilic asthma: a new era begins

Now that it is generally accepted that asthma is a heterogeneous condition, phenotyping of asthma patients has become a mandatory part of the diagnostic workup of all patients who do not respond satisfactorily to standard therapy with inhaled corticosteroids. Late-onset eosinophilic asthma is currently one of the most well-defined asthma phenotypes and seems to have a different underlying pathobiology to classical childhood-onset, allergic asthma. Patients with this phenotype can be identified in the clinic by typical symptoms (few allergies and dyspnoea on exertion), typical lung function abnormalities (“fixed” airflow obstruction, reduced forced vital capacity and increased residual volume), typical comorbidities (nasal polyposis) and a good response to systemic corticosteroids. The definitive diagnosis is based on evidence of eosinophilia in bronchial biopsies or induced sputum, which can be estimated with reasonable accuracy by eosinophilia in peripheral blood. Until recently, patients with eosinophilic asthma had a very poor quality of life and many suffered from frequent severe exacerbations or were dependent on oral corticosteroids. Now, for the first time, novel biologicals targeting the eosinophil have become available that have been shown to be able to provide full control of this type of refractory asthma, and to become a safe and efficacious substitute for oral corticosteroids.

Late-onset eosinophilic asthma has a distinct clinical and functional profile with treatment implicationshttp://ow.ly/MH7AH

Age-of-asthma onset as a determinant of different asthma phenotypes in adults: a systematic review and meta-analysis of the literature

Age-of-asthma onset is often used to distinguish different adult asthma phenotypes; however, similarities and differences between early- and late-onset adult asthma have not been summarized to date. Of the 2921 records found, we identified 12 studies comparing early- and late-onset current asthma in adults. Age 12 was most commonly used to delineate the two age-of-onset phenotypes. Adults with early-onset current asthma were more likely to be atopic and had a higher frequency of asthma attacks, whereas adults with late-onset disease were more likely to be female, smokers and had greater levels of spirometrically defined fixed airflow obstruction. The prevalence of severe asthma was similar in both groups, and, in general, there were few phenotypic differences between severe asthmatics regardless of age of onset. Findings for several key characteristics, including lung function, were inconsistent between studies. Overall, there appears to be distinctive phenotypic differences with age of asthma onset. Although early-onset adult asthma is likely more attributable to atopy and potentially genetic factors, late-onset adult asthma appears to be more related to environmental risk factors, and so may be better targeted by preventive strategies. More detailed research is required to better characterize these phenotypes and to clarify potential clinical implications.

Asthma in the older adult: presentation, considerations and clinical management

Asthma affects older adults to the same extent as children and adolescents. However, one is led to imagine that asthma prevalence decreases with aging and becomes a rare entity in the elderly. From a clinical perspective, this misconception has nontrivial consequences in that the recognition of the disease is delayed and the treatment postponed. The overall management of asthma in the elderly population is also complicated by specific features that the disease develops in the most advanced ages, and by the difficulties that the physician encounters when approaching the older asthmatic subjects. The current review article aims at describing the specific clinical presentations of asthma in the elderly and highlights the gaps and pitfalls in the diagnostic and therapeutic approaches. Relevant issues with regard to the clinical management of asthma in the elderly are also discussed.

Comorbidity in chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary diseases (COPD) often experience comorbid conditions. The most common comorbidities that have been associated with COPD include cardiovascular diseases, lung cancer, metabolic disorder, osteoporosis, anxiety and depression, skeletal muscle dysfunction, cachexia, gastrointestinal diseases, and other respiratory conditions. Not only are comorbidities common but they also considerably influence disease prognosis and patients׳ health status, and are associated with poor clinical outcomes. However, perusal of literature indicates that little has been done so far to effectively assess, manage, and treat comorbidities in patients with COPD. The aim of this review is to comprehensively narrate the comorbid conditions that often coexist with COPD, along with their reported prevalence and their significant impacts in the disease management of COPD. A perspective on integrated disease management approaches for COPD is also discussed.

Lung transplantation in chronic obstructive pulmonary disease: long-term survival, freedom from bronchiolitis obliterans syndrome, and factors influencing outcome

OBJECTIVES

Lung transplantation (LTx) remains the definitive treatment for end-stage lung failure, whereas chronic obstructive pulmonary disease (COPD) represents one of the main diagnoses leading to the indication for a transplant. We sought to assess long-term outcomes after LTx in patients diagnosed with COPD and analyze factors influencing outcome in this frequent patient cohort.

METHODS

Between January 2007 and November 2013, a total of 88 LTx were performed in patients with COPD in our institution. Patients with emphysema associated with alpha1-antitrypsin deficiency were excluded from this observation. The study design was a retrospective review of the prospectively collected data. A large number of pre-, intra-, and postoperative variables were analyzed including long-term survival and freedom from bronchiolitis obliterans syndrome (BOS). Furthermore, impact of different variables on survival was analyzed.

RESULTS

Preoperative donor data indicated a large proportion of marginal donors. While the overall cumulative survival after six yr was 57.4%, the results in terms of BOS-free survival in long-term follow-up were 39.7% after six yr. Patients with COPD were also associated with a low incidence (2.3%) of the need for postoperative extracorporeal life support (ECLS).

CONCLUSIONS

Long-term results after LTx in patients with COPD are acceptable with excellent survival, freedom from BOS, and low use of ECLS postoperatively despite permanently increasing proportion of marginal organs used.