Differences between asthma-COPD overlap syndrome and adult-onset asthma

Trends in polypharmacy among U.S. adults with asthma, 2001-2020

OBJECTIVE

This study aimed to evaluate trends in polypharmacy prevalence among adults with asthma in the United States.

METHODS

Data from the 2001-2020 National Health and Nutrition Examination Survey were used to estimate the weighted prevalence of polypharmacy. Joinpoint regression analysis was conducted to evaluate trends in polypharmacy. Trends were first evaluated overall and then stratified by asthma severity and asthma control. A multivariable logistic regression model was used to identify factors associated with polypharmacy.

RESULTS

From 2001 to 2020, a stable trend in polypharmacy among U.S. adults with asthma was observed (average annual percent change [AAPC]=1.02, p=0.71). Trends across different asthma severity were stable (mild asthma: AAPC=2.93, p=0.20; moderate asthma: AAPC=-2.22, p=0.35; severe asthma: AAPC=0.45, p=0.82). Trends in adults with good asthma control and those with poor control stayed constant (good control: AAPC=0.82, p=0.68; poor control: AAPC=-1.22, p=0.82). Several factors, including older age, females, Non-Hispanic Black, health insurance coverage, family income, number of healthcare visits, former smokers, multi-morbidities, asthma severity, and asthma control, were associated with polypharmacy.

CONCLUSIONS

Polypharmacy prevalence has remained constant among U.S. adults with asthma over the past two decades. Despite a stable overall trend, disparities in polypharmacy prevalence persist across different asthma severity and control status, underscoring the need for tailored medication management to improve asthma care.

Differences in the Quantitative HRCT Characteristics of Patients with Asthma, COPD and Asthma-COPD Overlap and Their Relationships with Pulmonary Function

Purpose

We compared pulmonary function indices and quantitative CT parameters of airway remodeling, air trapping, and emphysema in asthmatic patients and patients with COPD and asthma-COPD overlap (ACO) and explored their relationships with airflow limitation.

Patients and Methods

Patients with asthma (n=48), COPD (n=52), and ACO (n=30) and controls (n=54) who completed pulmonary function tests and HRCT scans were retrospectively enrolled in our study. Quantitative CT analysis software was used to assess emphysema (LAA%), airway wall dimensions (wall area (WA), luminal area (LA), and wall area percentage (WA%)), and air trapping ((relative volume change of -860 HU to -950 HU (RVC-860 to-950) and the expiration-to-inspiration ratio of the mean lung density (MLDE/I))). Differences in pulmonary function and HRCT parameters were compared among the groups. Spearman correlation analysis and regression analysis were utilized to explore structure‒function relationships.

Results

The LAA% in COPD and ACO patients was significantly greater than that in asthmatic patients and controls. The WA% and WA in COPD and ACO patients were greater than those in controls, whereas the WA% and LA between asthmatic patients and controls reached statistical significance. The RVC-860 to -950 levels decreased in the following order: ACO, COPD, and asthma. RVC-860 to -950 independently predicted FEV1% in asthmatic patients; LAA% and MLDE/I in COPD patients; and LAA%, WA% and RVC-860 to -950 in ACO patients.

Conclusion

Comparable emphysema was observed in patients with COPD and ACO but not in asthmatic patients. All patients exhibited proximal airway remodeling. The bronchi were thickened outward in COPD and ACO patients but are thickened inward in asthmatic patients. Furthermore, air trapping in ACO patients was the most severe among all the groups. Indirect lung densitometry measurements might be more predictive of the degree of airflow limitation than direct airway measurements in obstructive airway diseases.

Exhaled volatile organic compounds associated with risk factors for obstructive pulmonary diseases: a systematic review

Background

Asthma and COPD are among the most common respiratory diseases. To improve the early detection of exacerbations and the clinical course of asthma and COPD new biomarkers are needed. The development of noninvasive metabolomics of exhaled air into a point-of-care tool is an appealing option. However, risk factors for obstructive pulmonary diseases can potentially introduce confounding markers due to altered volatile organic compound (VOC) patterns being linked to these risk factors instead of the disease. We conducted a systematic review and presented a comprehensive list of VOCs associated with these risk factors.

Methods

A PRISMA-oriented systematic search was conducted across PubMed, Embase and Cochrane Libraries between 2000 and 2022. Full-length studies evaluating VOCs in exhaled breath were included. A narrative synthesis of the data was conducted, and the Newcastle-Ottawa Scale was used to assess the quality of included studies.

Results

The search yielded 2209 records and, based on the inclusion/exclusion criteria, 24 articles were included in the qualitative synthesis. In total, 232 individual VOCs associated with risk factors for obstructive pulmonary diseases were found; 58 compounds were reported more than once and 12 were reported as potential markers of asthma and/or COPD in other studies. Critical appraisal found that the identified studies were methodologically heterogeneous and had a variable risk of bias.

Conclusion

We identified a series of exhaled VOCs associated with risk factors for asthma and/or COPD. Identification of these VOCs is necessary for the further development of exhaled metabolites-based point-of-care tests in these obstructive pulmonary diseases.

Aging-Related Mechanisms Contribute to Corticosteroid Insensitivity in Elderly Asthma

Asthma in elderly populations is an increasing health problem that is accompanied by diminished lung function and frequent exacerbations. As potent anti-inflammatory drugs, corticosteroids are commonly used to reduce lung inflammation, improve lung function, and manage disease symptoms in asthma. Although effective for most individuals, older patients are more insensitive to corticosteroids, making it difficult to manage asthma in this population. With the number of individuals older than 65 continuing to increase, it is important to understand the distinct mechanisms that promote corticosteroid insensitivity in the aging lung. In this review, we discuss corticosteroid insensitivity in asthma with an emphasis on mechanisms that contribute to persistent inflammation and diminished lung function in older individuals.

Asthma Care in the Elderly: Practical Guidance and Challenges for Clinical Management - A Framework of 5 "Ps"

Uncontrolled asthma in the elderly is a public health issue recognized in developed countries such as the United States and among the European Union, both from patient safety and economic perspectives. Variations in the cutoff, which defines elderly age, contribute to epidemiological study difficulties. Nonetheless, the relevance of elderly asthma from a socioeconomic perspective is inarguable. The projected growth of the enlarging geriatric population in the United States portends an impending national health burden that may or may not be preventable with pharmacologic and non-pharmacologic treatments. Asthma in the elderly might be a consequence of uncontrolled disease that is carried throughout a lifetime. Or elderly asthmatics could suffer from uncontrolled asthma, which overlaps with other ailments common with advancing ages that merit consideration, eg, COPD, heart disease, OSA, diabetes mellitus, and other comorbidities. Because of the heterogeneity of asthma phenotypes and other conditions that could mimic the symptoms of elderly asthma, further cohort studies are needed to elucidate the elderly asthmatic pathophysiology and management. More studies to characterize elderly asthma can help address these patients' unmet need for evidence-based guidelines. We introduce the 5 "Ps" (phenotypes, partnership, pharmacology, practice in acute exacerbations, and problems or barriers for the elderly asthmatics) that establish a framework approach for clinical practice.

Heterogeneity of asthma-chronic obstructive pulmonary disease (COPD) overlap from a cohort of patients with severe asthma and COPD

BACKGROUND

A considerable proportion of patients have features of both asthma and chronic obstructive pulmonary disease (COPD) simultaneously, called asthma-COPD overlap (ACO).

OBJECTIVES

The aim of this study was to identify heterogeneity of ACO from a cohort of patients with severe asthma and COPD using the same diagnostic criteria.

DESIGN

We used the International Severe Asthma Registry (ISAR) and the Korean COPD Subgroup Study (KOCOSS) to evaluate clinical characteristics of ACO from each cohort.

METHODS

We classified subjects into four groups: (1) pure severe asthma, (2) ACO from the severe asthma cohort, (3) ACO from the COPD cohort, and (4) pure COPD. ACO was defined by satisfying extreme bronchodilator response (BDR) >15% and 400 ml and/or blood eosinophil count ⩾300 /µL in patients aged 40 years or older and post-BD forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ratio <0.7.

RESULTS

The ACO group had 25 (23%) of 111 in the ISAR cohort and 403 (23%) of 1781 in the KOCOSS cohort. The ACO from the COPD cohort was older with more males and more smokers, but had similar degree of airflow limitation compared with the ACO from the severe asthma cohort. ICS-containing inhaler treatment was prescribed for all severe asthma subjects, but only for 43.9% of ACO subjects from the COPD cohort. Compared with patients having pure severe asthma, the risk for exacerbation was comparable in ACO either from severe asthma or COPD cohort [adjusted odds ratio (aOR): 1.54, 95% CI: 0.22-10.95 or aOR: 2.15, 95% CI: 0.59-7.85].

CONCLUSION

The prevalence of ACO was similar in severe asthma and COPD cohorts applying identical diagnostic criteria. ACO from the severe asthma cohort was similar to ACO from the COPD cohort in terms of lung function and exacerbation risk.

Mortality Associated With Occupational Exposure in Helsinki, Finland-A 24-Year Follow-up

OBJECTIVES

Our objective was to study mortality related to different obstructive lung diseases, occupational exposure, and their potential joint effect in a large, randomized population-based cohort.

METHODS

We divided the participants based on the answers to asthma and chronic obstructive pulmonary disease (COPD) diagnoses and occupational exposure and used a combined effects model and compared the results to no asthma or COPD with no occupational exposure.

RESULTS

High exposure had a hazards ratio (HR) of 1.34 (1.11-1.62) and asthma and COPD coexistence of 1.58 (1.10-2.27). The combined effects of intermediate exposure and coexistence had an HR of 2.20 (1.18-4.09), high exposure with coexistence of 1.94 (1.10-3.42) for overall mortality, and sub-HR for respiratory-related mortality of 3.21 (1.87-5.50).

CONCLUSIONS

High occupational exposure increased overall but not respiratory-related mortality hazards, while coexisting asthma and COPD overall and respiratory-related hazards of mortality.

Sex-specific characteristics for the coexistence of asthma and COPD in the Canadian population: a cross-sectional analysis of CLSA data

Objective: The coexistence of asthma and COPD (asthma + COPD) is a condition found among patients who present with clinical features of both asthma and COPD. Epidemiological evidence points to an increasingly disproportionate burden of asthma + COPD and COPD in females. The objective of this cross-sectional study is to identify female and male-specific epidemiological and clinical characteristics associated with asthma + COPD.Methods: Baseline data from the comprehensive cohort of Canadian Longitudinal Study on Aging (CLSA) were used in this cross-sectional study which included 30,097 subjects between the ages of 45- and 85-years Participants were categorized into four mutually exclusive groups: asthma + COPD, COPD-only, asthma-only and neither asthma nor COPD.Results: The prevalence was significantly greater in females than males for asthma + COPD (2.71% vs. 1.41%; p < 0.001), COPD-only (3.22% vs. 2.87%; p < 0.001) and asthma-only (13.31% vs. 10.11%; p < 0.001). The association between smoking and asthma + COPD was modified by age in females. Osteoporosis and underactive thyroid disease were significantly more prevalent in females than in males in asthma + COPD, COPD-only and asthma-only groups. In asthma + COPD group, a greater proportion of respiratory symptoms associated with asthma was observed in females whereas a greater proportion of respiratory symptoms associated with COPD was observed in males. Severity of airway obstruction determined by spirometry measurements was greater in males than females.Conclusions: In the Canadian adult population, several epidemiological and clinical characteristics in asthma + COPD varied between females and males. The findings in this study will help healthcare professional in the recognition and management of coexisting asthma and COPD in females and males.

Defining Asthma-Chronic Obstructive Pulmonary Disease Overlap

Much interest has been given to the asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) in the past 2 decades, but the condition is still ill-defined. There is general agreement that a patient with longstanding asthma who develops fixed airflow obstruction after years of smoking has ACO although defining asthma in the face of COPD can be challenging. Many features of asthma are also found in patients with COPD without indicating an overlap and no consensus exists on which characteristics should be included in the definition of ACO. Nevertheless, some guidance has been issued to help clinicians and researchers to make a diagnosis of ACO and these will be reviewed here.

Airway and parenchymal transcriptomics in a novel model of asthma and COPD overlap

BACKGROUND

Asthma and chronic obstructive pulmonary disease (COPD) are common chronic respiratory diseases, and some patients have overlapping disease features, termed asthma-COPD overlap (ACO). Patients characterized with ACO have increased disease severity; however, the mechanisms driving this have not been widely studied.

OBJECTIVES

This study sought to characterize the phenotypic and transcriptomic features of experimental ACO in mice induced by chronic house dust mite antigen and cigarette smoke exposure.

METHODS

Female BALB/c mice were chronically exposed to house dust mite antigen for 11 weeks to induce experimental asthma, cigarette smoke for 8 weeks to induce experimental COPD, or both concurrently to induce experimental ACO. Lung inflammation, structural changes, and lung function were assessed. RNA-sequencing was performed on separated airway and parenchyma lung tissues to assess transcriptional changes. Validation of a novel upstream driver SPI1 in experimental ACO was assessed using the pharmacological SPI1 inhibitor, DB2313.

RESULTS

Experimental ACO recapitulated features of both asthma and COPD, with mixed pulmonary eosinophilic/neutrophilic inflammation, small airway collagen deposition, and increased airway hyperresponsiveness. Transcriptomic analysis identified common and distinct dysregulated gene clusters in airway and parenchyma samples in experimental asthma, COPD, and ACO. Upstream driver analysis revealed increased expression of the transcription factor Spi1. Pharmacological inhibition of SPI1 using DB2313, reduced airway remodeling and airway hyperresponsiveness in experimental ACO.

CONCLUSIONS

A new experimental model of ACO featuring chronic dual exposures to house dust mite and cigarette smoke mimics key disease features observed in patients with ACO and revealed novel disease mechanisms, including upregulation of SPI1, that are amenable to therapy.

Chronic obstructive pulmonary disease in never-smokers: risk factors, pathogenesis, and implications for prevention and treatment

Chronic obstructive pulmonary disease (COPD) was traditionally thought to be caused by tobacco smoking. However, recognition of the importance of non-smoking-related risk factors for COPD has increased over the past decade, with evidence on the burden, risk factors, and clinical presentations of COPD in never-smokers. About half of all COPD cases worldwide are due to non-tobacco-related risk factors, which vary by geographical region. These factors include air pollution, occupational exposures, poorly controlled asthma, environmental tobacco smoke, infectious diseases, and low socioeconomic status. Impaired lung growth during childhood, caused by a range of early-life exposures, is associated with an increased risk of COPD. Potential mechanisms for the pathogenesis of COPD in never-smokers include inflammation, oxidative stress, airway remodelling, and accelerated lung ageing. Compared with smokers who develop COPD, never-smokers with COPD have relatively mild chronic respiratory symptoms, little or no emphysema, milder airflow limitation, and fewer comorbidities; however, exacerbations can still be frequent. Further research-including epidemiological, translational, clinical, and implementation studies-is needed to address gaps in understanding and to advance potential solutions to reduce the burden of COPD in never-smokers.

Asthma-COPD Overlap Syndrome: Recent Insights and Unanswered Questions

The term asthma-COPD overlap (ACO) has been used to identify a heterogeneous condition in which patients present with airflow limitation that is not completely reversible and clinical and inflammatory features of both asthma and chronic obstructive pulmonary disease (COPD). ACO diagnosis may be difficult in clinical practice, while controversy still exists regarding its definition, pathophysiology, and impact. Patients with ACO experience a greater disease burden compared to patients with asthma or COPD alone, but in contrast they show better response to inhaled corticosteroid treatment than other COPD phenotypes. Current management recommendations focus on defining specific and measurable treatable clinical traits, according to disease phenotypes and underlying biological mechanisms for every single patient. In this publication, we review the current knowledge on definition, pathophysiology, clinical characteristics, and management options of ACO.

Self-Reported Physician Diagnosed Asthma with COPD is Associated with Higher Mortality than Self-Reported Asthma or COPD Alone - A Prospective 24-Year Study in the Population of Helsinki, Finland

Asthma and COPD are common chronic obstructive respiratory diseases. COPD is associated with increased mortality, but for asthma the results are varying. Their combination has been less investigated, and the results are contradictory. The aim of this prospective study was to observe the overall mortality in obstructive pulmonary diseases and how mortality was related to specific causes using postal questionnaire data. This study included data from 6,062 participants in the FinEsS Helsinki Study (1996) linked to mortality data during a 24-year follow-up. According to self-reported physician diagnosed asthma, COPD, or smoking status, the population was divided into five categories: combined asthma and COPD, COPD alone and asthma alone, ever-smokers without asthma or COPD and never-smokers without asthma or COPD (reference group). For the specific causes of death both the underlying and contributing causes of death were used. Participants with asthma and COPD had the highest hazard of mortality 2.4 (95% CI 1.7-3.5). Ever-smokers without asthma or COPD had a 9.5 (3.7-24.2) subhazard ratio (sHR) related to lower respiratory tract disease specific causes. For asthma, COPD and combined, the corresponding figures were 10.8 (3.4-34.1), 25.0 (8.1-77.4), and 56.1 (19.6-160), respectively. Ever-smokers without asthma or COPD sHR 1.7 (95% CI 1.3-2.5), and participants with combined asthma and COPD 3.5 (1.9-6.3) also featured mortality in association with coronary artery disease. Subjects with combined diseases had the highest hazard of overall mortality and combined diseases also showed the highest hazard of mortality associated with lower respiratory tract causes or coronary artery causes.Abbreviations: CigCigaretteCOPDChronic obstructive pulmonary diseaseCVDCardiovascular diseaseFEV₁Forced Expiratory Volume in one secondFVCForced Vital CapacityFinEsSFinland, Estonia, and Sweden study on chronic obstructive pulmonary diseasesHRHazard RatiosHRSubhazard RatioICD-10International Statistical Classifications of Diseases and Related Health Problems (Version 10).

Clinical value of bronchodilator response for diagnosing asthma in steroid-naïve adults

Spirometry and testing for bronchodilator response have been recommended to detect asthma, and a bronchodilator response (BDR) of ≥12% and ≥200 mL has been suggested to confirm asthma. However, the clinical value of bronchodilation tests in newly diagnosed steroid-naïve adult patients with asthma remains unknown. We evaluated the sensitivity of BDR in forced expiratory volume in 1 s (FEV₁) as a diagnostic test for asthma in a real-life cohort of participants in the Seinäjoki Adult Asthma Study. In the diagnostic phase, 369 spirometry tests with bronchodilation were performed for 219 steroid-naïve patients. The fulfilment of each test threshold was assessed. According to the algorithm of the National Institute for Health and Care Excellence, we divided the patients into obstructive (FEV₁/forced vital capacity (FVC) <0.70) and non-obstructive (FEV₁/FVC ≥0.70) groups. Of the overall cohort, 35.6% fulfilled ΔFEV₁ ≥12% and ≥200 mL for the initial FEV₁, 18.3% fulfilled ΔFEV₁ ≥15% and ≥400 mL for the initial FEV₁, and 36.1% fulfilled ΔFEV₁ ≥9% of predicted FEV₁ at least once. One-third (31%) of these steroid-naïve patients was obstructive (pre-bronchodilator FEV₁/FVC <0.7). Of the obstructive patients, 55.9%, 26.5% and 48.5%, respectively, met the same thresholds. In multivariate logistic regression analysis, different thresholds recognised different kinds of asthma patients. In steroid-naïve adult patients, the current BDR threshold (ΔFEV₁ ≥12% and ≥200 mL) has low diagnostic sensitivity (36%) for asthma. In obstructive patients, sensitivity is somewhat higher (56%) but far from optimal. If the first spirometry test with bronchodilation is not diagnostic but asthma is suspected, spirometry should be repeated, and other lung function tests should be used to confirm the diagnosis.

Small Airways Response to Bronchodilators in Adults with Asthma or COPD: A Systematic Review

BACKGROUND

Bronchodilator responsiveness (BDR) is commonly used in the diagnosis of lung disease. Although small airways dysfunction is a feature of asthma and COPD, physiological tests of small airways are not included in guidelines for BDR testing. This systematic review assessed the current evidence of BDR using small airways function in asthma and COPD.

METHODS

The systematic review used standard methodology with the protocol prospectively registered on PROSPERO (CRD42020164140). Electronic medical databases (EMBASE and Medline) were searched using related keywords. Abstracts and full texts were screened independently by two reviewers. Studies that reported the change of physiological small airways function and FEV₁ were included in the review. The revised Cochrane risk of bias tool for RCT and NIH quality assessment tool for cohort and cross-sectional studies were used to evaluate the studies.

RESULTS

A total of 934 articles were identified, with 12 meeting the inclusion criteria. Ten studies included asthma patients, 1 study included COPD patients and 1 study included both asthma and COPD. A total of 1104 participants were included, of whom 941 were asthmatic, 64 had COPD and 109 were healthy controls. Studies were heterogeneous in design including the device, dose and time intervals for BDR assessment. A small airway BDR was seen for most tests in asthma and COPD, including oscillometry (R5-20, reactance (X5), area of reactance (AX) and resonant frequency (Fres)) and Maximal Mid Expiratory Flow.

CONCLUSION

There is a measurable BDR in the small airways. However, with no consensus on how to assess BDR, studies were heterogeneous. Further research is needed to inform how BDR should be assessed, its clinical impact and place in routine clinical practice.

The Value of Impulse Oscillometric Parameters and Quantitative HRCT Parameters in Differentiating Asthma-COPD Overlap from COPD

Purpose

To evaluate the value of impulse oscillometry (IOS) and quantitative HRCT parameters for differentiating asthma-COPD overlap (ACO) in COPD patients.

Patients and Methods

We enrolled 44 controls and 66 COPD patients, divided into the pure COPD group (n=40) and the ACO group (n=26). Spearman correlation analysis was utilized to assess the relationship between the quantitative HRCT and IOS parameters. A binary logistic regression analysis was performed to analyze the associations between the different variables and the risk of ACO. Receiver operating characteristic (ROC) curves were employed to identify the optimal cutoff and assess the diagnostic value of relative volume change -856 HU to -950 HU (RVC_{-856 to -950}), decrease in the resistance from 5 Hz to 20 Hz (R5-R20) and their combination in predicting ACO. Bootstrapping validation was used to evaluate the internal validation. The concordance index (C-index) and calibration plot were calculated to assess the discrimination and calibration of the prediction model.

Results

Binary logistic regression analysis indicated that RVC_{-856 to -950} and the IOS parameters (R5-R20, R5, X5) were independently correlated with a higher risk of developing ACO after adjusting for age, sex, body mass index (BMI), history of smoking, exacerbation and atopy or allergic rhinitis. A correlation analysis showed a good correlation between the pulmonary function parameters and RVC_{-856 to -950}, with a weaker correlation with the % area of low attenuation (LAA%) in ACO patients. Combining RVC_{-856 to -950} and R5-R20 to predict ACO, the AUC was 0.909, and the optimal cutoff value was >-0.62 for RVC_{-856 to -950} and >0.09 for R5-R20. Good calibration and favorable discrimination were displayed with a higher C-index.

Conclusion

More serious small airway impairment exists in ACO patients. The combination of RVC_{-856 to -950} and R5-R20 could be applied to differentiate ACO from COPD patients.

Association between Physical Activity and Comorbidities in Spanish People with Asthma-COPD Overlap

Asthma and chronic obstructive pulmonary disease (COPD) are important conditions which often coexist. Higher rates of comorbidities among people with asthma-COPD overlap (ACO) may complicate clinical management. The aim of this study was to determine the prevalence of 30 different comorbidities and to analyze associations between these comorbidities and physical activity (PA) in Spanish people with ACO. Cross-sectional data from the Spanish National Health Survey 2017 were analyzed. A total of 198 Spanish people with ACO aged 15–69 years (60.6% women) were included in this study. PA was measured with the International Physical Activity Questionnaire (IPAQ) short form. Diagnosis of chronic conditions were self-reported. Associations between PA and comorbidities were analyzed using multivariable logistic regression models. The most prevalent comorbidities were chronic allergy (58.1%), chronic lumbar pain (42.4%), chronic cervical pain (38.4%), hypertension (33.3%) and arthrosis (31.8%). A PA level lower than 600 MET·min/week was significantly associated with urinary incontinence (OR = 3.499, 95% CI = 1.369–8.944) and osteoporosis (OR = 3.056, 95% CI = 1.094–8.538) in the final adjusted model. Therefore, the potential influence of PA on reducing the risk of these conditions among people with ACO should be considered, not only because of the health benefits, but also because PA can contribute to a more sustainable world.

Update on Asthma-COPD Overlap (ACO): A Narrative Review

Although chronic obstructive pulmonary disease (COPD) and asthma are well-characterized diseases, they can coexist in a given patient. The term asthma-COPD overlap (ACO) was introduced to describe patients that have clinical features of both diseases and may represent around 25% of COPD patients and around 20% of asthma patients. Despite the increasing interest in ACO, there are still substantial controversies regarding its definition and its position within clinical guidelines for patients with obstructive lung disease. In general, most definitions indicate that ACO patients must present with non-reversible airflow limitation, significant exposure to smoking or other noxious particles or gases, together with features of asthma. In patients with a primary diagnosis of COPD, the identification of ACO has therapeutic implication because the asthmatic component should be treated with inhaled corticosteroids and some studies suggest that the most severe patients may respond to biological agents indicated for severe asthma. This manuscript aims to summarize the current state-of-the-art of ACO. The definitions, prevalence, and clinical manifestations will be reviewed and some innovative aspects, such as genetics, epigenetics, and biomarkers will be addressed. Lastly, the management and prognosis will be outlined as well as the position of ACO in the COPD and asthma guidelines.

Level of education and asthma control in adult-onset asthma

OBJECTIVE

Education in itself and as a proxy for socioeconomic status, may influence asthma control, but remains poorly studied in adult-onset asthma. Our aim was to study the association between the level of education and asthma control in adult-onset asthma.

METHODS

Subjects with current asthma with onset >15 years were examined within the Obstructive Lung Disease in Northern Sweden study (OLIN, n = 593), Seinäjoki Adult Asthma Study (SAAS, n = 200), and West Sweden Asthma Study (WSAS, n = 301) in 2009-2014 in a cross-sectional setting. Educational level was classified as primary, secondary and tertiary. Uncontrolled asthma was defined as Asthma Control Test (ACT) score ≤19. Altogether, 896 subjects with complete data on ACT and education were included (OLIN n = 511, SAAS n = 200 and WSAS n = 185).

RESULTS

In each cohort and in pooled data of all cohorts, median ACT score was lower among those with primary education than in those with secondary and tertiary education. Uncontrolled asthma was most common among those with primary education, especially among daily ICS users (42.6% primary, 28.6% secondary and 24.2% tertiary; p = 0.001). In adjusted analysis, primary education was associated with uncontrolled asthma in daily ICS users (OR 1.92, 95% CI 1.15-3.20). When stratified by atopy, the association between primary education and uncontrolled asthma was seen in non-atopic (OR 3.42, 95% CI 1.30-8.96) but not in atopic subjects.

CONCLUSIONS

In high-income Nordic countries, lower educational level was a risk factor for uncontrolled asthma in subjects with adult-onset asthma. Educational level should be considered in the management of adult-onset asthma.

Physical activity behavior in people with asthma and COPD overlap residing in Spain: a cross-sectional analysis

OBJECTIVES

To identify levels of physical activity (PA) among the Spanish population with asthma and chronic obstructive pulmonary disease overlap (ACO). A further aim was to analyze differences in PA levels by sex, age, education, marital status, cohabiting, smoking habits, alcohol consumption and body mass index (BMI).

METHODS

In this cross sectional study, data from the Spanish National Health Survey 2017 were analyzed. A total of 198 people with ACO aged 15-69 years were included in the analyses. The short version of the international physical activity questionnaire (IPAQ) was used to measure total PA (MET·min/week). PA was further classified as low, moderate and high, and analyzed according to sample characteristics. Data were analyzed using the Mann-Whitney U test, Kruskal-Wallis H test and chi squared test. Statistical significance was set at p < 0.05.

RESULTS

People with ACO engaged in a mean volume of 2038.1 MET·min/week. Those aged 30-60 years and those with normal weight were significantly more active than those aged ≥60 and those with obesity. When classifying PA level in low, moderate and high, results showed no significant differences between sample characteristics. Overall, moderate and high levels of PA were the most and least frequent levels (48.0% and 16.2%, respectively).

CONCLUSIONS

More than three out of ten Spanish adults with ACO do not achieve PA recommendations. Therefore, it is recommended to implement programs that promote the importance and benefits of PA among the Spanish population with ACO, and such programs should focus on older adults and those who are obese.

Asthma Remission by Age at Diagnosis and Gender in a Population-Based Study

BACKGROUND

Child-onset asthma is known to remit with high probability, but remission in adult-onset asthma is seemingly less frequent. Reports of the association between remission and asthma age of onset up to late adulthood are scarce.

OBJECTIVE

To evaluate the association between asthma remission, age at diagnosis and gender, and assess risk factors of nonremission.

METHODS

In 2016, a random sample of 16,000 subjects aged 20 to 69 years from Helsinki and Western Finland were sent a FinEsS questionnaire. Physician-diagnosed asthma was categorized by age at diagnosis to early- (0-11 years), intermediate- (12-39 years), and late-diagnosed (40-69 years) asthma. Asthma remission was defined by not having had asthma symptoms and not having used asthma medication in the past 12 months.

RESULTS

Totally, 8199 (51.5%) responded, and 879 reported physician-diagnosed asthma. Remission was most common in early-diagnosed (30.2%), followed by intermediate-diagnosed (17.9%), and least common in late-diagnosed asthma (5.0%) (P < .001), and the median times from diagnosis were 27, 18.5, and 10 years, respectively. In males, the corresponding remission rates were 36.7%, 20.0%, and 3.4%, and in females, 20.4%, 16.6%, and 5.9% (gender difference P < .001). In multivariable binary logistic regression analysis, significant risk factors of asthma nonremission were intermediate (odds ratio [OR] = 2.15, 95% confidence interval: 1.37-3.36) and late diagnosis (OR = 11.06, 4.82-25.37) compared with early diagnosis, chronic obstructive pulmonary disease (COPD) (OR = 5.56, 1.26-24.49), allergic rhinitis (OR = 2.28, 1.50-3.46), and family history of asthma (OR = 1.86, 1.22-2.85). Results were similar after excluding COPD.

CONCLUSION

Remission was rare in adults diagnosed with asthma after age 40 years in both genders. Late-diagnosed asthma was the most significant independent risk factor for nonremission.

Asthma-chronic obstructive pulmonary disease overlap syndrome

Overlap of asthma and chronic obstructive lung disease (ACO) in patients with obstructive lung disease is growing in recognition, though there is no consistent agreement on the diagnostic criteria for the disease process. Patients with ACO have distinct clinical characteristics and trajectories, which are representative of a heterogenous, multifactorial, and incompletely understood inflammatory pathophysiology. Current treatment strategies are focused on titration of inhaled therapies such as long-acting bronchodilators, with increasing interest in the use of targeted biologic therapies aimed at the underlying inflammatory mechanisms. Future directions for research will focus on elucidating the varied inflammatory signatures leading to ACO, the development of consistent diagnostic criteria and biomarkers of disease, and improving the clinical management with an eye toward targeted therapies.

Prevalence of COPD among workers with work-related asthma

Objective: Concurrent asthma and chronic obstructive pulmonary disease (COPD) diagnoses occur in 15%-20% of patients, and have been associated with worse health outcomes than asthma or COPD alone. Work-related asthma (WRA), asthma that is caused or made worse by exposures in the workplace, is characterized by poorly controlled asthma. The objective of this study was to assess the proportion of ever-employed adults (≥18 years) with current asthma who have been diagnosed with COPD, by WRA status.Methods: Data from 23 137 respondents to the 2012-2014 Behavioral Risk Factor Surveillance System Asthma Call-back Survey from 31 states and the District of Columbia were examined. Logistic regression was used to calculate adjusted prevalence ratios (PRs), examining six disjoint categories of WRA-COPD overlap with non-WRA/no COPD as the referent category.Results: An estimated 51.9% of adults with WRA and 25.6% of adults with non-WRA had ever been diagnosed with COPD. Adults with WRA/COPD were more likely than those with non-WRA/no COPD to have an asthma attack (PR = 1.77), urgent treatment for worsening asthma (PR = 2.85), an asthma-related emergency room visit (PR = 4.21), overnight stay in a hospital because of asthma (PR = 6.57), an activity limitation on 1-13 days (PR = 2.01) or ≥14 days (PR = 5.02), and very poorly controlled asthma (PR = 3.22).Conclusions: COPD was more frequently diagnosed among adults with WRA than those with non-WRA, and adults diagnosed with both WRA and COPD appear to have more severe adverse asthma outcomes than those with non-WRA and no COPD.

Therapeutic efficacy of IL-17A neutralization with corticosteroid treatment in a model of antigen-driven mixed-granulocytic asthma

Many mouse models of allergic asthma exhibit eosinophil-predominant cellularity rather than the mixed-granulocytic cytology in steroid-unresponsive severe disease. Therefore, we sought to implement a novel mouse model of antigen-driven, mixed-granulocytic, severe allergic asthma to determine biomarkers of the disease process and potential therapeutic targets. C57BL/6J wild-type, interleukin-6 knockout (IL-6-/-), and IL-6 receptor knockout (IL-6R-/-), mice were injected with an emulsion of complete Freund's adjuvant and house dust mite antigen (CFA/HDM) on day 1. Dexamethasone, a lymphocyte-depleting biological, or anti-IL-17A was administered during the intranasal HDM challenge on days 19-22. On day 23, the CFA/HDM model elicited mixed bronchoalveolar lavage (BAL) cellularity (typically 80% neutrophils and 10% eosinophils), airway hyperresponsiveness (AHR) to methacholine, diffusion impairment, lung damage, body weight loss, corticosteroid resistance, and elevated levels of serum amyloid A (SAA), pro-inflammatory cytokines, and T helper type 1/ T helper type 17 (Th1/Th17) cytokines compared with eosinophilic models of HDM-driven allergic airway disease. BAL cells in IL-6- or IL-6R-deficient mice were predominantly eosinophilic and associated with elevated T helper type 2 (Th2) and reduced Th1/Th17 cytokine production, along with an absence of SAA. Nevertheless, AHR remained in IL-6-deficient mice even when dexamethasone was administered. However, combined administration of anti-IL-17A and systemic corticosteroid significantly attenuated both overall and neutrophilic airway inflammation and also reduced AHR and body weight loss. Inhibition of IL-17A combined with systemic corticosteroid treatment during antigen-driven exacerbations may provide a novel therapeutic approach to prevent the pathological pulmonary and constitutional changes that greatly impact patients with the mixed-granulocytic endotype of severe asthma.

Relationship between age and bronchodilator response at diagnosis in adult-onset asthma

BACKGROUND

Possible variation in bronchodilator response (BDR) according to age at the diagnosis of adult-onset asthma is unknown. Our aim was to assess if BDR in FEV1 is related to age at diagnosis of adult-onset asthma and how many subjects fulfill the 400 mL criterion of BDR, the suggested cut-off for asthma-like reversibility in asthma-COPD overlap (ACO).

METHODS

A total of 1030 patients with adult-onset asthma were included; 245 from SAAS (Seinäjoki Adult Asthma Study, Finland) and 785 from COREA (Cohort for Reality and Evolution of Adult Asthma in Korea) cohorts. BDR in FEV1 at the diagnosis of asthma was assessed. Patients were divided into groups based on age at asthma diagnosis: < 40, 40-59.9, and ≥ 60 years. The cohorts were analyzed separately.

RESULTS

BDR % in FEV1 did not differ between the groups of different age at asthma diagnosis and no correlation between BDR and age was found. Of patients aged ≥40 years, only 18% (SAAS-cohort) and 5% (COREA-cohort) reached the 400 mL BDR in FEV1. After exclusion of possible ACO patients, the results remained similar.

CONCLUSION

By using two large cohorts of steroid-naive patients with asthma, we have shown that BDR at diagnosis of asthma is constant over large age span range, and the limit of 400 mL in BDR in FEV1 is rarely reached.

TRIAL REGISTRATION

Seinäjoki Adult Asthma Study is registered at ClinicalTrials.gov with identifier number NCT02733016 .

Bringing asthma care into the twenty-first century

Despite access to diagnostic tests and effective therapies, asthma often remains misdiagnosed and/or poorly controlled or uncontrolled. In this review, we address the key issues of asthma diagnosis and management, recent evidence for levels of asthma control, the consequences of poor control and, in line with that, explore the potential reasons for poor asthma control and acute exacerbations. Based on recent evidence and current guidelines, we also aim to provide practical answers to the key questions of how to improve asthma management, with the best possible prevention of exacerbations, addressing the basics-adherence, inhaler misuse, obesity and smoking-and how to facilitate a new era of asthma care in the twenty-first century. We hope this review will be useful to busy primary care clinicians in their future interactions with their patients with both suspected and proven asthma.

Obstructive Lung Disease and Obstructive Sleep Apnea (OLDOSA) cohort study: 10-year assessment

STUDY OBJECTIVES

Asthma, chronic obstructive pulmonary disease (COPD), and obstructive sleep apnea (OSA) are very prevalent disorders. Their coexistence in the same individual has an unclear effect on natural history and long-term outcomes.

METHODS

The OLDOSA (Obstructive Lung Disease and Obstructive Sleep Apnea) cohort enrolled 4,980 veterans with an acute hospitalization and in whom asthma, COPD, OSA, overlapping conditions, or none of these disorders at baseline had been diagnosed. Pulmonary function, polysomnography, positive airway pressure (PAP) recommendations and adherence, and vital status were collected and analyzed. Various proportional hazards models were built for patients with OSA to test the effect of PAP therapy on survival.

RESULTS

Ten-year all-cause cumulative mortality rate was 52.8%; median time to death was 2.7 years. In nonoverlapping asthma, OSA and COPD, mortality rates were 54.2%, 60.4%, and 63.0%, respectively. The overlap syndromes had the following mortality: COPD-OSA 53.2%, asthma-COPD 62.1%, asthma-OSA 63.5%, and triple overlap asthma-COPD-OSA 67.8%. In patients with OSA not on PAP therapy, after adjustment for age, comorbidities, and lung function, risk of death was 1.34 (1.05-1.71) times higher than those undergoing treatment. Similarly, in patients with OSA nonadherent to PAP therapy the adjusted risk of death was 1.78 (1.13-2.82) times higher versus those using it at least 70% of nights and more than 4 hours nightly.

CONCLUSIONS

In this large longitudinal cohort of hospitalized veterans with high comorbid burden, asthma, COPD, OSA and their overlap syndromes had very high long-term mortality. In patients with OSA, PAP initiation and superior therapeutic adherence were associated with significantly better survival.

Evolving phenotypes to endotypes: is precision medicine achievable in asthma?

Introduction: The development of biologic molecules led to a drastic change in the therapeutic approach to asthma. With the prospect of acting on different pathophysiological mechanisms of the disease, the idea of precision medicine was developed, in which a single molecule is able to modify a specific triggering mechanism. Thus, it seemed limiting to stop at the distinction of patients phenotypes and the concept of endotypes became more relevant in the therapeutic approach.Areas covered: This review deepened the topic of precision medicine through the transition from phenotyping to endotyping. We performed a review of the literature, preferring articles quoted in Medline and published in journals with an impact factor. Results showed that it is fundamental to take into consideration the role of biomarkers and the related therapies currently available for precision medicine.Expert opinion: The possible overlap of patients in different phenotypes requires a more precise classification, which considers endotypization. With the development of biological drugs able to modify and modulate some pathophysiological mechanisms of the disease, the theoretical concept of endotyping becomes practical, allowing the clinician to choose the specific mechanism to 'attack' in order to control the disease.

Effect of asthma control on general health-related quality of life in patients diagnosed with adult-onset asthma

Health-related quality of life (HRQoL) is a well-established aspect of health that can be measured by both disease-specific and general instruments. The effect of uncontrolled asthma on generic HRQoL has not been shown in patients with clinically confirmed adult-onset asthma and with asthma control defined according to the Global Initiative for Asthma, so the aim of this study was to determine this. In the 12-year follow-up cohort of the Seinäjoki Adult Asthma Study (n = 203), patients with uncontrolled and partially controlled asthma had lower generic HRQoL as determined by 15D compared to the controlled group. On 10 out of 15 dimensions of 15D, the mean scores were significantly lower in patients with uncontrolled asthma compared with those with controlled asthma. The affected dimensions were mobility, breathing, sleeping, usual activities, mental function, discomfort and symptoms, depression, distress, vitality and sexual activity. In the Tobit regression analysis, a poorer 15D score was associated with uncontrolled asthma, lower postbronchodilator FEV₁, female sex, depression, treated dyspepsia and poorer 15D score at diagnosis. Our results show that uncontrolled asthma affects everyday life in several aspects, including previously unknown components such as sexual activity and vitality.

Global prevalence of asthma-COPD overlap (ACO) in the general population: a systematic review and meta-analysis

Background

Asthma-COPD overlap (ACO) is a term that encompasses patients with features of both asthma and COPD. To date, the global prevalence of ACO in the general population remains unknown. The objective of this study was to estimate the prevalence of ACO in the general population using a systematic review and meta-analysis.

Methods

A systematic search of ISI Web of Knowledge, MEDLINE/PubMed, and Scopus was performed up to May 2019 to identify studies reporting the prevalence of ACO. Reference lists from identified studies and relevant review articles were also searched. Eligibility criteria were studies reporting the prevalence of ACO, performed in general population, and published in English language. Pooled prevalence of ACO with 95% confidence interval (CI) was calculated using random effects Meta-analysis.

Results

A total of 27 studies were included in this meta-analysis. The Cochran Q test and I² statistics revealed substantial heterogeneity among studies. Based on the random-effects model, the pooled prevalence of ACO was 2.0% (95% CI: 1.4–2.6%) in the general population, 26.5% (95% CI: 19.5–33.6%) among patients with asthma, and 29.6% (95% CI: 19.3–39.9%) among patients with COPD. In addition, for included studies, the global prevalence of asthma-only was 6.2% (95% CI: 5.0–7.4%) and COPD-only was 4.9% (95% CI: 4.3–5.5%).

Conclusion

We estimated the global prevalence of ACO based on population-based studies and found that 2.0% of the general population is affected. However, the prevalence of ACO depends on its diagnostic criteria. Therefore, there is a vital need to better define the ACO diagnostic criteria, management and treatment. It is worth noting that the limitations of the present study include lack of studies in some region of the world and small number of studies included in the subgroup analyses.

Occupational exposures and asthma-COPD overlap in a clinical cohort of adult-onset asthma

Occupational exposure to vapours, gases, dusts or fumes (VGDF) increases the prevalence of asthma-COPD overlap (ACO) in adult-onset asthma. VGDF exposure is independently associated with ACO and an additive effect with smoking is proposed. http://bit.ly/2LiMiXW.

Effects of short-term smoking on lung function and airway hyper-responsiveness in young patients with untreated intermittent adult-onset asthma: retrospective cross-sectional study at a primary-tertiary care hospital in Japan

OBJECTIVE

In daily clinical practice, smokers with asthma and with intermittent disease severity are frequently encountered. The effects of short-term smoking on lung function or disease presentation in younger patients with intermittent adult-onset asthma remain unclear. We sought to clarify the effects of short-term smoking (<10 pack-years) on lung function and airway hyper-responsiveness (AHR) in young patients with untreated intermittent adult-onset asthma.

DESIGN

Retrospective, cross-sectional study.

SETTING

A single primary-tertiary medical centre in Japan.

PARTICIPANTS

From patients who underwent bronchodilator reversibility tests between January 2004 and March 2011 (n=7291), 262 consecutive patients (age, 20-34 years) with untreated intermittent adult-onset asthma, including 157 never smokers and 105 current smokers within 10 pack-years, were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the association of the daily smoking frequency (number of cigarettes per day), smoking duration (years) and cumulative smoking history (pack-years) with postbronchodilator lung function. The secondary outcome was the association of the former three smoking parameters with AHR.

RESULTS

The daily smoking frequency, smoking duration and cumulative smoking history were significantly associated with decreased postbronchodilator lung function. Daily smoking of ≥11 cigarettes per day was also associated with marked AHR (OR 2.23; 95% CI 1.03 to 4.80), even after adjustment for age, sex, disease duration and body mass index.

CONCLUSION

Short-term active smoking in early adulthood may be associated with decreased lung function and AHR, even in patients with intermittent adult-onset asthma. Our findings suggest a benefit of never smoking, even for young patients with intermittent adult-onset asthma.

Nitrosative stress in patients with asthma-chronic obstructive pulmonary disease overlap

BACKGROUND

Asthma-chronic obstructive pulmonary disease overlap (ACO) has frequent exacerbations and a poor quality of life and prognosis compared with those of chronic obstructive pulmonary disease alone. However, the pathogenesis of ACO has not been fully elucidated yet.

OBJECTIVES

The aim of this study was to investigate nitrosative stress, which causes a redox imbalance and tissue inflammation in the airways of patients with ACO, and to evaluate the relationship between nitrosative stress and the clinical course in study subjects.

METHODS

Thirty healthy subjects and 56 asthmatic patients participated in this study. The asthmatic patients were divided into 33 asthmatic patients and 23 patients with ACO. The study subjects had been followed prospectively for 2 years to evaluate the clinical course. Nitrosative stress was evaluated based on the production of 3-nitrotyrosine (3-NT) in sputum cells.

RESULTS

Production of 3-NT was significantly enhanced in patients with ACO compared with that in asthmatic patients. Amounts of reactive persulfides and polysulfides, newly identified powerful antioxidants, were significantly decreased in the ACO group. Baseline levels of 3-NT were significantly correlated with the frequency of exacerbations and decrease in FEV₁ adjusted by age, smoking history, and blood eosinophil count. The 3-NT-positive cells were also significantly correlated with amounts of proinflammatory chemokines and cytokines.

CONCLUSIONS

These findings suggested that greater nitrosative stress occurred in the airways of patients with ACO, and the degree of nitrosative stress was correlated with an impairment in the clinical course. Nitrosative stress might be related to the pathogenesis of ACO.

Practical Guide to the Identification and Diagnosis of Asthma-COPD Overlap (ACO)

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of mortality around the world. COPD is characterised by a heterogeneous clinical presentation and prognosis which may vary according to the clinical phenotype. One of the phenotypes of COPD most frequently studied is the asthma-COPD overlap (ACO), however, there are no universally accepted diagnostic criteria for ACO. It is recognised that the term ACO includes patients with clinical features of both asthma and COPD, such as more intense eosinophilic bronchial inflammation, more severe respiratory symptoms and more frequent exacerbations, but in contrast, it is associated with a better prognosis compared to COPD. More importantly, ACO patients show better response to inhaled corticosteroid treatment than other COPD phenotypes. The diagnosis of ACO can be difficult in clinical practice, and the identification of these patients can be a challenge for non-specialized physicians. We describe how to recognise and diagnose ACO based on a recently proposed Spanish algorithm and by the analysis of three clinical cases of patients with COPD. The diagnosis of ACO is based on the diagnosis of COPD (chronic airflow obstruction in an adult with significant smoking exposure), in addition to a current diagnosis of asthma and/or signficant eosinophilia.

The Prevalence of Asthma-COPD Overlap (ACO) Among Patients with Asthma

OBJECTIVES

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) is defined as a persistent airflow limitation with features of both asthma and COPD. However, in Turkey, there are limited data about ACO. The aims of the present study were to determine the prevalence of ACO among patients with asthma, to compare the clinical characteristics of patients with ACO and asthma, and to determine the threshold values for the diagnosis of ACO.

MATERIALS AND METHODS

The study group comprised 338 patients admitted to the outpatient clinics between 2010 and 2017 and who had undergone at least three pulmonary function tests within the last 2 years. Patients aged >40 years with a smoking history of >10 pack-years or biomass exposure, with at least three features of both diseases, and with reversible and persistent airflow limitation were diagnosed with ACO. The study is a retrospective study so we did not get informed concent.

RESULTS

Asthma-chronic obstructive pulmonary disease overlap was diagnosed in 40 (11.8%) patients. Patients with ACO had fewer allergic comorbidities, worse spirometric parameters, and required higher doses of inhaled corticosteroids than patients with asthma only (p<0.05). No significant differences were observed between the groups regarding survival or number of hospitalizations and attacks (p>0.05). Threshold values were determined as age ≥57.5 years, smoking history ≥14 pack-years, and diagnosis at age ≥40.5 years.

CONCLUSION

The frequency of ACO was observed to be very high in patients with asthma. In patients >57.5 years old, with a smoking history of >14.5 pack-years, and diagnosed with asthma at >40.5 years old, the probability of ACO diagnosis increases.

Biomarkers in asthma: state of the art

Asthma is a heterogenous disease characterized by multiple phenotypes driven by different mechanisms. The implementation of precision medicine in the management of asthma requires the identification of phenotype-specific markers measurable in biological fluids. To become useful, these biomarkers need to be quantifiable by reliable systems, reproducible in the clinical setting, easy to obtain and cost-effective. Using biomarkers to predict asthma outcomes and therapeutic response to targeted therapies has a great clinical significance, particularly in severe asthma. In the last years, significant research has been realized in the identification of valid biomarkers for asthma. This review focuses on the existent and emerging biomarkers with clinical higher applicability in the management of asthma.

Recent developments and highlights in biomarkers in allergic diseases and asthma

The potential of precision medicine in allergy and asthma has only started to be explored. A significant clarification in the pathophysiology of rhinitis, chronic rhinosinusitis, asthma, food allergy and drug hypersensitivity was made in the last decade. This improved understanding led to a better classification of the distinct phenotypes and to the discovery of new drugs such as biologicals, targeting phenotype-specific mechanisms. Nevertheless, many conditions remain poorly understood such as non-eosinophilic airway diseases or non-IgE-mediated food allergy. Moreover, there is a need to predict the response to specific therapies and the outcome of drug and food provocations. The identification of patients at risk of progression towards severity is also an unmet need in order to establish adequate preventive or therapeutic measures. The implementation of precision medicine in the clinical practice requires the identification of phenotype-specific markers measurable in biological matrices. To become useful, these biomarkers need to be quantifiable by reliable systems, and in samples obtained in an easy, rapid and cost-efficient way. In the last years, significant research resources have been put in the identification of valid biomarkers for asthma and allergic diseases. This review summarizes these recent advances with focus on the biomarkers with higher clinical applicability.

Daily physical activity and lung function decline in adult-onset asthma: a 12-year follow-up study

Background: There is a lack of knowledge on the association between daily physical activity and lung function in patients with asthma.

Objective: This study aims to examine the association between daily physical activity and asthma control, lung function, and lung function decline in patients with adult-onset asthma.

Design: This study is part of Seinäjoki Adult Asthma Study (SAAS), where 201 patients were followed for 12 years after asthma diagnosis. Daily physical activity was assessed at follow-up by a structured questionnaire and used to classify the population into subgroups of low (≤240 min) or high (>240 min) physical activity. Three spirometry evaluation points were used: 1. diagnosis, 2. the maximum lung function during the first 2.5 years after diagnosis (Max_0-2.5), 3. follow-up at 12 years.

Results: High physical activity group had slower annual FEV₁ (p<0.001) and FVC (p<0.018) decline. Additionally, the high physical activity group had higher FEV₁ values at follow-up, and higher FEV₁/FVC ratios at follow-up and diagnosis. There was no difference in BMI, smoking, medication, or frequency of physical exercise between high and low physical activity groups. Differences remained significant after adjustments for possible confounding factors.

Conclusion: This is the first demonstration of an association between long-term FEV₁ decline and daily physical activity in clinical asthma. Low physical activity is independently associated with faster decline in lung function. Daily physical activity should be recommended in treatment guidelines in asthma.

Differences in airway structural changes assessed by 3-dimensional computed tomography in asthma and asthma-chronic obstructive pulmonary disease overlap

BACKGROUND

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) is a clinical phenotype sharing features of asthma and COPD. Multidetector row computed tomography (MDCT) can be used to evaluate the airway structure; however, differences between asthma and ACO seen on MDCT are poorly understood.

OBJECTIVE

To investigate the difference in airway structural between asthma and ACO, using MDCT in patients with clinical asthma.

METHODS

Sixty-four patients with asthma were allocated to an asthma group (never smokers and ex-smokers with a smoking history of < 10 pack-years) or an ACO group (patients with a ≥10-pack-year smoking history and forced expiratory volume in 1 second [FEV₁]/forced vital capacity [FVC] < 0.7). The asthma group was further divided into patients with airflow limitation (AL; FEV₁/FVC < 0.7) and those without AL. Wall thickness (WT) and airway inner luminal area in the third-generation to fifth-generation bronchi were evaluated using MDCT in both study groups and in 29 healthy controls.

RESULTS

Forty-three patients were included in the asthma group (20 with AL, 23 without AL) and 16 in the ACO group. Patients with asthma and ACO had significantly greater WT than the healthy controls. WT in the third-generation bronchi was significantly greater in the ACO group than in the asthma group. The ACO group and the asthma with AL group were matched for age, disease duration, and FEV₁/FVC. The WT in the third-generation bronchi was still greater in the ACO group than in the asthma with AL group.

CONCLUSION

Patients with ACO have a thicker airway wall than those with asthma, suggesting that airway remodeling is more prominent in ACO than in asthma. UMIN Clinical Trials Registry (UMIN-CTR) system (http://www.umin.ac.jp/ctr/UMIN000028913).

Asthma-COPD Overlap Phenotypes and Smoking :Comparative features of asthma in smoking or non-smoking patients with an incomplete reversibility of airway obstruction

The development of COPD features, such as an incomplete reversibility of airway obstruction (IRAO), in smoking or non-smoking asthmatic patients, a condition often named Asthma-COPD Overlap (ACO), has been recognized for decades. However, there is a need to know more about the sub-phenotypes of this condition according to smoking. This study aimed at comparing the clinical, physiological and inflammatory features of smoking and non-smoking asthmatic patients exhibiting IRAO. In this cross-sectional study, patients with an IRAO with (ACO, ≥20 pack-years) or without (NS-IRAO, <5 pack-years) significant smoking history completed questionnaires about asthma control (ACQ, score 0-6, 6 = better score) and quality of life (AQLQ, score 1-7, 1 = better score) and performed expiratory flows, lung volume and carbon monoxide diffusion capacity measurements. Blood sampling and induced sputum were obtained for systemic and lower airway inflammation assessment. A total of 115 asthmatic patients were included (75 ACO: age 61 ± 10 years, 60% women and 40 NS-IRAO: age 64 ± 9 years, 38% women). ACO patients had worse asthma control scores (1.8 ± 0.9 vs 1.4 ± 0.9, P = 0.02) and poorer asthma quality of life (5.3 ± 1.0 vs 5.9 ± 1.0, P = 0.003). In addition, ACO had higher residual volume (145 ± 45 vs 121 ± 29% predicted, P = 0.008) and a lower carbon monoxide diffusing capacity corrected for alveolar volume (90 ± 22 vs 108 ± 20% predicted, P = 0.0008). No significant differences were observed in systemic or lower airway inflammation. In conclusion, in smokers and non-smokers, the presence of IRAO in asthmatics is associated with different phenotypes that reflect the addition of smoking-induced changes to asthma physiopathology.

Chronic airway obstruction in a population-based adult asthma cohort: Prevalence, incidence and prognostic factors

BACKGROUND

Asthma and COPD may overlap (ACO) but information about incidence and risk factors are lacking. This study aimed to estimate prevalence, incidence and risk factors of chronic airway obstruction (CAO) in a population-based adult asthma cohort.

METHODS

During 1986-2001 a large population-based asthma cohort was identified (n = 2055, 19-72y). Subsamples have participated in clinical follow-ups during the subsequent years. The entire cohort was invited to a clinical follow-up including interview, spirometry, and blood sampling in 2012-2014 when n = 983 subjects performed adequate spirometry. CAO was defined as post-bronchodilator FEV₁/FVC<0.7.

RESULTS

At study entry, asthmatics with prevalent CAO (11.4%) reported more respiratory symptoms, asthma medication use, and ischemic heart disease than asthmatics without CAO (asthma only). Subjects who developed CAO during follow-up (17.6%; incidence rate of 16/1000/year) had a more rapid FEV₁ decline and higher levels of neutrophils than asthma only. Smoking, older age and male sex were independently associated with increased risk for both prevalent and incident CAO, while obesity had a protective effect.

CONCLUSIONS

In this prospective adult asthma cohort, the majority did not develop CAO. Smoking, older age and male sex were risk factors for prevalent and incident CAO, similar to risk factors described for COPD in the general population.

Nordic consensus statement on the systematic assessment and management of possible severe asthma in adults

Although a minority of asthma patients suffer from severe asthma, they represent a major clinical challenge in terms of poor symptom control despite high-dose treatment, risk of exacerbations, and side effects. Novel biological treatments may benefit patients with severe asthma, but are expensive, and are only effective in appropriately targeted patients. In some patients, symptoms are driven by other factors than asthma, and all patients with suspected severe asthma ('difficult asthma') should undergo systematic assessment, in order to differentiate between true severe asthma, and 'difficult-to-treat' patients, in whom poor control is related to factors such as poor adherence or co-morbidities. The Nordic Consensus Statement on severe asthma was developed by the Nordic Severe Asthma Network, consisting of members from Norway, Sweden, Finland, Denmark, Iceland and Estonia, including representatives from the respective national respiratory scientific societies with the aim to provide an overview and recommendations regarding the diagnosis, systematic assessment and management of severe asthma. Furthermore, the Consensus Statement proposes recommendations for the organization of severe asthma management in primary, secondary, and tertiary care.

Inhaled corticosteroids and asthma control in adult-onset asthma: 12-year follow-up study

BACKGROUND

Prescribed inhaled corticosteroid (ICS) doses in asthma have been studied in cross-sectional settings whereas long-term follow-up studies have not been carried out.

OBJECTIVE

To evaluate prescribed medication longitudinally by calculating cumulative ICS doses and dose changes in a cohort of new-onset adult asthma during 12 years and in different groups of asthma control.

METHODS

A total of 203 patients were followed for 12 years as part of Seinäjoki Adult Asthma Study (SAAS). All asthma-related visits and prescribed medication over the study period were collected from medical records.

RESULTS

Total cumulative ICS dose for the 12-year follow-up period was 3.4g (±SEM 0.1) per patient. Both respiratory specialists and GPs prescribed step-ups and step-downs in ICS treatment and in total 649 dose changes were noted during the follow-up (median 3(1-5) per patient). Patients with uncontrolled asthma received higher ICS doses throughout the follow-up period, and therefore, cumulative 12-year ICS dose (3.8g ± SEM 0.2) in this group was higher than that in those with partially controlled (3.4g ± SEM 0.2) or controlled disease (2.9g ± SEM 0.2) (p = 0.0001). Patients with uncontrolled asthma were also prescribed a higher number of ICS dose changes than patients with controlled disease.

CONCLUSION

Despite frequent dose changes and high ICS doses during the 12-year follow-up, the level of asthma control remained poor in patients with uncontrolled asthma. This suggests that high ICS doses may not be effective enough for management of disease in patients with uncontrolled adult-onset asthma and novel targeted treatments are required.