The clinical and genetic features of COPD-asthma overlap syndrome

Concurrent physician-diagnosed asthma and chronic obstructive pulmonary disease: A population study of prevalence, incidence and mortality

OBJECTIVE

We conducted a population-based cohort study to estimate trends in prevalence, incidence, and mortality of concurrent physician-diagnosed asthma and chronic obstructive pulmonary disease (COPD).

STUDY DESIGN AND SETTING

Two validated health administrative case definitions were used to identify asthma and COPD among all individuals aged 35 years and older living in Ontario, Canada. Annual asthma, COPD, and concurrent asthma and COPD prevalence, incidence, and mortality, standardized for age and sex, were estimated, and compared from 2002 to 2012, using generalized linear models.

RESULTS

Standardized prevalence of concurrent asthma and COPD increased by 10.5%, from 2.9% in 2002 to 3.2% in 2012 overall, but more prominently in women compared to men. Overall, standardized incidence decreased by16%, from 2.5 to 2.1 per 1000 individuals, but increased significantly in young adults. All-cause mortality among patients with concurrent asthma and COPD decreased by 11.2%, from 2.6% to 2.2%. Being diagnosed with both diseases was significantly associated with higher all-cause mortality compared to asthma (OR = 1.56, 95% CI: 1.50-1.58), but not compared to COPD (OR = 0.97, 0.96-0.98), except in young adults aged 35 to 49 years where people with asthma and COPD had higher mortality (OR = 1.21, 1.15-1.27).

CONCLUSIONS

In a large North American population, the burden of concurrent physician-diagnosed asthma and COPD is increasing, particularly in women and young adults.

Sagittal-lung CT measurements in the evaluation of asthma-COPD overlap syndrome: a distinctive phenotype from COPD alone

OBJECTIVES

This study aimed at investigating the capability of sagittal-lung computed tomography (CT) measurements in differentiating chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap syndrome (ACOS).

METHODS

Clinical and high-resolution CT of 229 patients including 123 pure COPD patients and 106 ACOS patients were included. Sagittal-lung CT measurements in terms of bilateral lung height (LH), anterior-posterior lung diameter (APLD), diaphragm height (DH), and anterior sterno-diaphragmatic angle (ASDA), as well as inter-pulmonary septum length (IPSL) on axial images were measured both before and after bronchodilator (BD) administration. Comparisons of clinical characteristics and CT measurements between patient groups were performed.

RESULTS

All pre-BD quantitative sagittal features measuring diaphragm flattening and hyperinflation were not significantly different between patients with COPD and patients with ACOS (P values all >0.05). Following BD administration, the ACOS patients exhibited lower left LH, bilateral APLD, and bilateral ASDA, but higher right DH, compared to pure COPD patients (P values all <0.05). Right LH, left DH and IPSL were not significantly different between patient groups. Besides, variations of all sagittal-lung CT measurements were significantly larger in patients with ACOS than in patients with pure COPD (P values all <0.001) and showed high performance in differentiating these two kinds of patient, with diagnostic sensitivities ranging from 76.4 to 97.2%, specificities ranging from 86.2 to 100.0%, and accuracies ranging from 80.9 to 90.7%.

CONCLUSIONS

Sagittal-lung CT measurements allow for differentiating patients with ACOS from those with pure COPD. The ACOS patients had larger post-BD variations of sagittal-lung CT measurements than patients with pure COPD.

A genetic association study of CSMD1 and CSMD2 with cognitive function

The complement cascade plays a role in synaptic pruning and synaptic plasticity, which seem to be involved in cognitive functions and psychiatric disorders. Genetic variants in the closely related CSMD1 and CSMD2 genes, which are implicated in complement regulation, are associated with schizophrenia. Since patients with schizophrenia often show cognitive impairments, we tested whether variants in CSMD1 and CSMD2 are also associated with cognitive functions per se. We took a discovery-replication approach, using well-characterized Scandinavian cohorts. A total of 1637 SNPs in CSMD1 and 206 SNPs in CSMD2 were tested for association with cognitive functions in the NCNG sample (Norwegian Cognitive NeuroGenetics; n=670). Replication testing of SNPs with p-value<0.001 (7 in CSMD1 and 3 in CSMD2) was carried out in the TOP sample (Thematically Organized Psychosis; n=1025) and the BETULA sample (Betula Longitudinal Study on aging, memory and dementia; n=1742). Finally, we conducted a meta-analysis of these SNPs using all three samples. The previously identified schizophrenia marker in CSMD1 (SNP rs10503253) was also included. The strongest association was observed between the CSMD1 SNP rs2740931 and performance in immediate episodic memory (p-value=5×10^-6, minor allele A, MAF 0.48-0.49, negative direction of effect). This association reached the study-wide significance level (p⩽1.2×10^-5). SNP rs10503253 was not significantly associated with cognitive functions in our samples. In conclusion, we studied n=3437 individuals and found evidence that a variant in CSMD1 is associated with cognitive function. Additional studies of larger samples with cognitive phenotypes will be needed to further clarify the role of CSMD1 in cognitive phenotypes in health and disease.

Genetic loci associated with chronic obstructive pulmonary disease overlap with loci for lung function and pulmonary fibrosis

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality worldwide. We performed a genetic association study in 15,256 cases and 47,936 controls, with replication of select top results (P < 5 × 10-6) in 9,498 cases and 9,748 controls. In the combined meta-analysis, we identified 22 loci associated at genome-wide significance, including 13 new associations with COPD. Nine of these 13 loci have been associated with lung function in general population samples, while 4 (EEFSEC, DSP, MTCL1, and SFTPD) are new. We noted two loci shared with pulmonary fibrosis (FAM13A and DSP) but that had opposite risk alleles for COPD. None of our loci overlapped with genome-wide associations for asthma, although one locus has been implicated in joint susceptibility to asthma and obesity. We also identified genetic correlation between COPD and asthma. Our findings highlight new loci associated with COPD, demonstrate the importance of specific loci associated with lung function to COPD, and identify potential regions of genetic overlap between COPD and other respiratory diseases.

Heterogeneity of asthma-COPD overlap syndrome

Many patients suffering from asthma or COPD have overlapping features of both diseases. However, a phenotypical approach for evaluating asthma-COPD overlap syndrome (ACOS) has not been established. In this report, we examined the phenotypes in patients with ACOS. Patients diagnosed with ACOS between 2011 and 2015 were identified and classified into four phenotype groups. Group A was composed of patients who smoked <10 pack years and had blood eosinophil counts ≥300. Group B was composed of patients who smoked <10 pack years and had blood eosinophil counts <300. Group C was composed of patients who smoked ≥10 pack years and had blood eosinophil counts ≥300. Group D was composed of patients who smoked <10 pack years and had blood eosinophil counts <300. Clinical characteristics were analyzed and compared among groups. Comparisons were made among 103 ACOS patients. Patients in group D were oldest, while patients in group A were youngest. There were relatively more female patients in groups A and B; the majority of patients in groups C and D were male. The degree of airflow obstruction was most severe in group C. The rate of being free of severe exacerbation was significantly lower in group C than in the other groups. In this study, each ACOS phenotype showed different characteristics. The proportion of patients free of severe exacerbation differed significantly among groups. At this time, further studies on the phenotypes of ACOS are required.

Incidence and long-term outcome of severe asthma-COPD overlap compared to asthma and COPD alone: a 35-year prospective study of 57,053 middle-aged adults

Background

Incidence and prognosis for severe asthma–COPD overlap is poorly characterized. We investigated incidence and long-term outcome for patients with asthma–COPD overlap compared to asthma and COPD alone.

Materials and methods

A total of 57,053 adults (aged 50–64 years) enrolled in the Danish Diet, Cancer, and Health cohort (1993–1997) were followed in the National Patients Registry for admissions for asthma (DJ45–46) and COPD (DJ40–44) and vital status. Asthma–COPD overlap was defined as at least one hospital admission for asthma and one for COPD (different time points), and incident asthma–COPD overlap as at least one of the diagnoses occurring after enrollment into the Diet, Cancer, and Health cohort.

Results

A total of 1,845 (3.2%) and 4,037 (7.1%) participants had admissions for asthma and COPD, respectively, with 662 (1.2%) participants with asthma–COPD overlap. Incidence rate of asthma–COPD overlap per 1,000 person-years was higher in women (0.73) than in men (0.54) (P<0.02). Mortality rate was higher in asthma–COPD overlap (25.9 per 1,000 person-years) compared with COPD (23.1, P<0.05) and asthma (7.9, P<0.001) alone. Compared to COPD alone, mortality was higher in women with asthma–COPD overlap (19.6 and 25.5, respectively; P<0.01), and the excess mortality rate for asthma–COPD overlap patients was most prominent for younger age groups (12.9 compared to 7.2 and 4.6 for COPD and asthma alone, respectively; P<0.01).

Conclusion

This large population-based study revealed a higher incidence of severe asthma–COPD overlap in women compared to men, and furthermore that all-cause mortality is higher in women and younger subjects with asthma–COPD overlap compared with those with asthma or COPD alone.

Asthma-COPD overlap syndrome in the US: a prospective population-based analysis of patient-reported outcomes and health care utilization

Background

Prior work suggests that asthma–COPD overlap syndrome (ACOS) has a greater health burden than asthma alone or COPD alone. In the current study, we have further evaluated the health burden of ACOS in a nationally representative sample of the US population, focusing on patient-reported outcomes and health care utilization and on comparisons with asthma alone and COPD alone. Patient-reported outcomes are especially meaningful, as these include functional activities that are highly valued by patients and are the basis for patient-centered care.

Methods

Using data from the Medical Expenditure Panel Survey (MEPS), we evaluated patient-reported outcomes and health care utilization among participants who were aged 40–85 years and had self-reported, physician-diagnosed asthma or COPD. MEPS administered five rounds of interviews, at baseline and approximately every 6 months over 2.5 years. Patient-reported outcomes included activities of daily living (ADLs), mobility, social/recreational activities, disability days in bed, and health status (Short Form 12, Version 2). Health care utilization included outpatient and emergency department (ED) visits, and hospitalization.

Results

Of 3,486 participants with asthma or COPD, 1,585 (45.4%) had asthma alone, 1,294 (37.1%) had COPD alone, and 607 (17.4%) had ACOS. Relative to asthma alone, ACOS was significantly associated with higher odds of prevalent disability in ADLs and limitations in mobility and social/recreational activities (adjusted odds ratios [adjORs]: 1.91–3.98), as well as with higher odds of incident limitations in mobility and social/recreational activities, disability days in bed, and respiratory-based outpatient and ED visits, and hospitalization (adjORs: 1.86–2.35). In addition, ACOS had significantly worse physical and mental health scores than asthma alone (P-values <0.0001). Relative to COPD alone, ACOS was significantly associated with higher odds of prevalent limitations in mobility and social/recreational activities (adjORs: 1.68–2.06), as well as with higher odds of incident disability days in bed and respiratory-based outpatient and ED visits (adjORs: 1.48–1.74). In addition, ACOS had a significantly worse physical health score, but similar mental health score, as compared with COPD alone (P-values 0.0025 and 0.1578, respectively).

Conclusion

In the US, ACOS is associated with a greater health burden, including patient-reported outcomes and health care utilization, relative to asthma alone and COPD alone.

Disease Burden of Patients with Asthma/COPD Overlap in a US Claims Database: Impact of ICD-9 Coding-based Definitions

The inclusion of an asthma/chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) population in the 2015 Global Initiative for Chronic Obstructive Lung Disease strategic documents has raised questions about the profile of these patients in clinical practice, as they are mostly excluded from asthma and COPD clinical trials. We estimated the disease burden, co-morbidities, and respiratory treatments of patients with asthma/COPD overlap, utilizing the Truven MarketScan commercial and Medicare databases. Patients with ≥1 COPD or chronic obstructive asthma diagnostic code were identified between January 1, 2008, and December 31, 2011. The asthma/COPD overlap group was defined and stratified based upon type and frequency of asthma diagnostic code (chronic obstructive asthma only, COPD and chronic obstructive asthma, and COPD and ≥1 asthma code). 1,488,613 patients were identified; of these, 1,171,626 were diagnosed with COPD alone and 316,987 with asthma/COPD overlap. Patients with asthma and COPD had higher disease burden indicators and inhaled corticosteroid/long-acting beta-agonist use compared with COPD alone. This trend was consistent for all definitions of asthma/COPD overlap. Patients with obstructive asthma and COPD tended to be older, with greater disease burden compared with other definitions; this population may represent a more severe form of asthma/COPD overlap. Disease burden and treatment also varied based on the codes defining asthma/COPD overlap, indicating possible phenotypic differences. More clinical insight and detailed phenotyping is needed to determine the reasons for coding variation in asthma/COPD overlap, with implications for further research to address unmet needs.

Asthma-chronic obstructive pulmonary disease overlap syndrome - Literature review and contributions towards a Portuguese consensus

INTRODUCTION

Phenotypic overlap between the two main chronic airway pulmonary diseases, asthma and chronic obstructive pulmonary disease (COPD), has been the subject of debate for decades, and recently the nomenclature of asthma-COPD overlap syndrome (ACOS) was adopted for this condition. The definition of this entity in the literature is, however, very heterogeneous, it is therefore important to define how it applies to Portugal.

METHODS

A literature review of ACOS was made in a first phase resulting in the drawing up of a document that was later submitted for discussion among a panel of chronic lung diseases experts, resulting in reflexions about diagnosis, treatment and clinical guidance for ACOS patients.

RESULTS

There was a consensus among the experts that the diagnosis of ACOS should be considered in the concomitant presence of: clinical manifestations characteristic of both asthma and COPD, persistent airway obstruction (post-bronchodilator FEV₁/FVC<0.7), positive response to bronchodilator test (increase in FEV₁ of ≥200mL and ≥12% from baseline) and current or past history of smoking or biomass exposure. In reaching diagnosis, the presence of peripheral eosinophilia (>300eosinophils/μL or >5% of leukocytes) and previous history of atopy should also be considered. The recommended first line pharmacological treatment in these patients is the ICS/LABA association; if symptomatic control is not achieved or in case of clinical severity, triple therapy with ICS/LABA/LAMA may be used. An effective control of the exposure to risk factors, vaccination, respiratory rehabilitation and treatment of comorbidities is also important.

CONCLUSIONS

The creation of initial guidelines on ACOS, which can be applied in the Portuguese context, has an important role in the generation of a broad nationwide consensus. This will give, in the near future, a far better clinical, functional and epidemiological characterization of ACOS patients, with the ultimate goal of achieving better therapeutic guidance.

Identifying possible asthma-COPD overlap syndrome in patients with a new diagnosis of COPD in primary care

The asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) remains poorly characterised. Our aim was to describe an algorithm for identifying possible ACOS in adults with newly diagnosed COPD in primary care. General practitioners (n=241) consecutively recruited subjects ⩾35 years, with tobacco exposure, at least one respiratory symptom and no previous diagnosis of obstructive lung disease. Possible ACOS was defined as chronic airflow obstruction, i.e., post-bronchodilator (BD) forced expiratory volume 1/forced vital capacity (FEV₁/FVC) ratio<0.70, combined with wheeze (ACOS wheeze) and/or significant BD reversibility (ACOS BD reversibility). Of 3,875 (50% females, mean age 57 years) subjects screened, 700 (18.1%) were diagnosed with COPD, i.e., symptom(s), tobacco exposure and chronic airflow obstruction. Indications for ACOS were found in 264 (38%) of the COPD patients. The prevalence of ACOS wheeze and ACOS BD reversibility was 27% (n=190) and 16% (n=113), respectively (P<0.001), and only 6% (n=39) of the COPD patients fulfilled both criteria for ACOS. Patients with any ACOS were younger (P=0.04), had more dyspnoea (P<0.001), lower FEV₁%pred (67% vs. 74%; P<0.001) and lower FEV₁/FVC ratio (P=0.001) compared with COPD-only patients. Comparing subjects fulfilling both criteria for ACOS with those fulfilling criteria for ACOS wheeze only (n=151) and those fulfilling criteria for ACOS BD reversibility only (n=74) revealed no significant differences. Irrespective of the applied ACOS definition, no significant difference in life-time tobacco exposure was found between ACOS- and COPD-only patients. In subjects with a new diagnosis of COPD, the prevalence of ACOS is high. When screening for COPD in general practice among patients with no previous diagnosis of obstructive lung disease, patients with possible ACOS may be identified by self-reported wheeze and/or BD reversibility.

Asthma-COPD overlap syndrome (ACOS) vs 'pure' COPD: a distinct phenotype?

BACKGROUND

Some studies suggest that asthma-COPD overlap syndrome (ACOS) is associated with worse outcomes than chronic obstructive pulmonary disease (COPD). The goal of this study was to further explore the clinical characteristics and survival of patients with ACOS identified in a real-life cohort of patients with COPD.

METHODS

Data from the French COPD cohort 'INITIATIVES BronchoPneumopathie Chronique Obstructive' (n = 998 patients) were analyzed to assess the frequency of ACOS defined as a physician diagnosis of asthma before the age of 40 years and to analyze its impact. Univariate analyses were performed to assess the relationship between ACOS and sociodemographic characteristics, risk factors (smoking, occupational exposure, atopic diseases), symptoms (chronic bronchitis, dyspnea-modified Medical Research Council scale and baseline dyspnea index), quality of life (QoL), mood disorders, exacerbations, comorbidities, lung function, prescribed treatment, and survival.

RESULTS

ACOS was diagnosed in 129 patients (13%). In multivariate analyses, ACOS was associated negatively with cumulative smoking (odds ratio [OR]: 0.992; 95% CI 0.984-1.000 per pack-year) and positively with obesity: OR: 1.97 [1.22-3.16], history of atopic disease (hay fever: OR: 5.50 [3.42-9.00] and atopic dermatitis: OR 3.76 [2.14-6.61]), and drug use (LABA + ICS: 1.86 [1.27-2.74], antileukotrienes 4.83 [1.63-14.34], theophylline: 2.46 [1.23-4.91], and oral corticosteroids: [2.99;.1.26-7.08]). No independent association was found with dyspnea, QoL, exacerbations, and mortality.

CONCLUSIONS

Compared to 'pure' COPD patients, patients with ACOS exhibit lower cumulative smoking, suffer more from obesity and atopic diseases, and use more asthma treatments. Disease severity (dyspnea, QoL, exacerbations, comorbidities) and prognosis (mortality) are not different from 'pure' COPD patients.

Asthma-COPD Overlap Syndrome: What We Know and What We Don't

Approximately one in four patients with chronic obstructive pulmonary disease (COPD) have asthmatic features consisting of wheezing, airway hyper-responsiveness or atopy. The Global initiative for Asthma/Globalinitiative for chronic Obstructive Lung Disease committee recently labelled these patients as having asthma-COPD overlap syndrome or ACOS. ACOS also encompasses patients with asthma, ≥40 years of age, who have been cigarette smokers (more than 5–10 pack years) or have had significant biomass exposure, and demonstrate persistent airflow limitation defined as a post-bronchodilator forced expiratory volume in 1 second (FEV₁)/forced vital capacity of <70%. Data over the past 30 years indicate that patients with ACOS have greater burden of symptoms including dyspnea and cough and show higher risk of COPD exacerbations and hospitalizations than those with pure COPD or pure asthma. Patients with ACOS also have increased risk of rapid FEV₁ decline and COPD mortality. Paradoxically, experimental evidence to support therapeutic decisions in ACOS patients is lacking because traditionally, patients with ACOS have been systematically excluded from therapeutic COPD and asthma trials to maintain homogeneity of the study population. In this study, we summarize the current understanding of ACOS, focusing on definitions, epidemiology and patient prognosis.

Comprehensive Diagnostic Assessment of Health Status of Patients with Asthma or COPD: A Delphi Panel Study among Dutch Experts

A comprehensive diagnostic assessment is needed to improve understanding of the health status of patients with chronic obstructive pulmonary disease (COPD) or asthma. Therefore, this study investigated which components and subsequent instruments should be part of a holistic assessment in secondary care. We also explored which data need to be exchanged for an adequate transfer of patients between primary and secondary care, and vice versa. A cross-sectional Web-based survey was conducted among Dutch healthcare professionals using a Delphi-like procedure; these included professionals working in primary or secondary care, medical advisors of health insurance companies and patients' representatives. The national guidelines were used as a starting point, resulting in a questionnaire addressing 55 components related to a comprehensive diagnostic assessment, covering the domains physiological impairments, symptoms, functional limitations and quality of life. Of the 151 experts and stakeholders invited, 92 (60.9%) completed the first round and 79 (52.3%) the second round; most respondents were pulmonologists. There was a high level of agreement between respondents from primary versus secondary care regarding which components should be measured during a comprehensive assessment of patients with asthma or COPD in secondary care and the instruments to measure these components. Regarding the exchange of information, upon referral, pulmonologists required little information from the general practitioners, whereas general practitioners required more extensive information after referral. An overview is provided of what should be part of a holistic assessment of health status in asthma and COPD. This information can be used as input for integrated care pathways.

Genetics and Genomics of Longitudinal Lung Function Patterns in Individuals with Asthma

RATIONALE

Patterns of longitudinal lung function growth and decline in childhood asthma have been shown to be important in determining risk for future respiratory ailments including chronic airway obstruction and chronic obstructive pulmonary disease.

OBJECTIVES

To determine the genetic underpinnings of lung function patterns in subjects with childhood asthma.

METHODS

We performed a genome-wide association study of 581 non-Hispanic white individuals with asthma that were previously classified by patterns of lung function growth and decline (normal growth, normal growth with early decline, reduced growth, and reduced growth with early decline). The strongest association was also measured in two additional cohorts: a small asthma cohort and a large chronic obstructive pulmonary disease metaanalysis cohort. Interaction between the genomic region encompassing the most strongly associated single-nucleotide polymorphism and nearby genes was assessed by two chromosome conformation capture assays.

MEASUREMENTS AND MAIN RESULTS

An intergenic single-nucleotide polymorphism (rs4445257) on chromosome 8 was strongly associated with the normal growth with early decline pattern compared with all other pattern groups (P = 6.7 × 10-9; odds ratio, 2.8; 95% confidence interval, 2.0-4.0); replication analysis suggested this variant had opposite effects in normal growth with early decline and reduced growth with early decline pattern groups. Chromosome conformation capture experiments indicated a chromatin interaction between rs4445257 and the promoter of the distal CSMD3 gene.

CONCLUSIONS

Early decline in lung function after normal growth is associated with a genetic polymorphism that may also protect against early decline in reduced growth groups. Clinical trial registered with www.clinicaltrials.gov (NCT00000575).

Combination therapy of inhaled steroids and long-acting beta2-agonists in asthma-COPD overlap syndrome

BACKGROUND

The efficacy of inhaled corticosteroids (ICSs)/long-acting beta2-agonist (LABA) treatment in patients with asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) compared to patients with COPD alone has rarely been examined. This study aimed to evaluate the clinical efficacy for the improvement of lung function after ICS/LABA treatment in patients with ACOS compared to COPD alone patients.

METHODS

Patients with stable COPD were selected from the Korean Obstructive Lung Disease (KOLD) cohort. Subjects began a 3-month ICS/LABA treatment after a washout period. ACOS was defined when the patients had 1) a personal history of asthma, irrespective of age, and wheezing in the last 12 months in a self-reported survey and 2) a positive bronchodilator response.

RESULTS

Among 152 eligible COPD patients, 45 (29.6%) fulfilled the criteria for ACOS. After a 3-month treatment with ICS/LABA, the increase in forced expiratory volume in 1 second (FEV₁) was significantly greater in ACOS patients than in those with COPD alone (240.2±33.5 vs 124.6±19.8 mL, P=0.002). This increase in FEV₁ persisted even after adjustment for confounding factors (adjusted P=0.002). According to severity of baseline FEV₁, the ACOS group showed a significantly greater increase in FEV₁ than the COPD-alone group in patients with mild-to-moderate airflow limitation (223.2±42.9 vs 84.6±25.3 mL, P=0.005), whereas there was no statistically significant difference in patients with severe to very severe airflow limitation.

CONCLUSION

This study provides clinical evidence that ACOS patients with mild-to-moderate airflow limitation showed a greater response in lung function after 3 months of ICS/LABA combination treatment.

Treatment Patterns in Asthma- Chronic Obstructive Pulmonary Disease Overlap Syndrome

BACKGROUND

Asthma and chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) is a complex disease entity with limited guidance surrounding medication therapy.

OBJECTIVE

To evaluate a patient population with possible ACOS and their medication regimen based on the Global Initiative for Asthma and Global Initiative for COPD joint statement for ACOS.

METHODS

This was a retrospective study based at a large clinical practice within a school of medicine. The sample included adults 40 to 85 years old who had an active concurrent diagnosis of asthma and COPD. Patients were considered to have likely inconsistent therapy (only preventive, no rescue medication), inconsistent therapy (neither preventive nor rescue medication), and likely consistent therapy (both preventive and rescue medication or rescue medication alone).

RESULTS

A total of 513 patients were included the study. The majority of the sample were female (75%) and white (87.1%), with an average age of 61 years. About 7% of patients had likely inconsistent therapy, whereas 7.7% had inconsistent therapy to control their airway disease. Never smokers were more likely than former smokers to have inconsistent therapy (adjusted odds ratio [OR] = 4.54; CI = 1.86-11.04). Adults 65 years and older were more likely than those aged 40 to 49 years to be in the likely inconsistent therapy group (adjusted OR = 4.01; CI = 1.04-15.34). Patients without any comorbid conditions were more likely than those with 2 or more comorbid conditions to be in the likely inconsistent group (adjusted OR = 3.50; CI = 1.39-8.77).

CONCLUSION

As the disease definition and treatment recommendations evolve, future studies should continue to monitor ACOS treatment patterns and outcomes.

Omalizumab Treatment Response in a Population With Severe Allergic Asthma and Overlapping COPD

BACKGROUND

Asthma and COPD are common airway diseases. Individuals with overlapping asthma and COPD experience increased health impairment and severe disease exacerbations. Efficacious treatment options are required for this population. Omalizumab (anti-IgE) therapy is effective in patients with severe persistent asthma, but limited data are available on efficacy in populations with overlapping asthma and COPD.

METHODS

Data from the Australian Xolair Registry were used to compare treatment responses in individuals with asthma-COPD overlap with responses in patients with severe asthma alone. Participants were assessed at baseline and after 6 months of omalizumab treatment. We used several different definitions of asthma-COPD overlap. First, we compared participants with a previous physician diagnosis of COPD to participants with no COPD diagnosis. We then made comparisons based on baseline lung function, comparing participants with an FEV₁ < 80% predicted to those with an FEV₁ > 80% predicted after bronchodilator use. In the population with an FEV₁< 80%, analysis was further stratified based on smoking history.

RESULTS

Omalizumab treatment markedly improved asthma control and health-related quality of life in all populations assessed based on the Asthma Control Questionnaire and Asthma Quality of Life Questionnaire scores. Omalizumab treatment did not improve lung function (FEV₁, FVC, or FEV₁/FVC ratio) in populations that were enriched for asthma-COPD overlap (diagnosis of COPD or FEV₁ < 80%/ever smokers).

CONCLUSIONS

Our study suggests that omalizumab improves asthma control and health-related quality of life in individuals with severe allergic asthma and overlapping COPD. These findings provide real-world efficacy data for this patient population and suggest that omalizumab is useful in the management of severe asthma with COPD overlap.

Fifteen-year mortality of patients with asthma-COPD overlap syndrome

BACKGROUND

The coexistence of asthma and chronic obstructive pulmonary disease (asthma-COPD overlap syndrome: ACOS) is increasingly recognized but data about its prevalence and long-term mortality are needed.

METHODS

Prevalence of ACOS and 15-year mortality rates were assessed in 1065 subjects aged >65years, enrolled in the SA.R.A. study, with complete clinical, lung functional and follow-up data. Physical performance, disease-related disability, and health-related quality of life (HRQL) were also evaluated.

RESULTS

ACOS was found in 11.1% of subjects (29.4% of those previously diagnosed with COPD and 19.7% of those with asthma). ACOS was positively associated with impaired physical performance, functional ability, and HRQL. Individuals with ACOS had higher mortality rates than controls (7.17 per 100 person-years; mortality rate ratio: 1.83). After adjustment for the main confounders, the risk of all-cause mortality remained significantly increased in subjects with ACOS (HR: 1.82), COPD (HR: 2.12), and restriction (HR: 2.41), but not asthma.

CONCLUSIONS

Long-term prognosis of ACOS was similar to COPD, and worse than asthma and healthy controls. ACOS had a significant impact on physical performance, functional ability, and HRQL.

Advances in understanding COPD

In recent years, thousands of publications on chronic obstructive pulmonary disease (COPD) and its related biology have entered the world literature, reflecting the increasing scientific and medical interest in this devastating condition. This article is a selective review of several important emerging themes that offer the hope of creating new classes of COPD medicines. Whereas basic science is parsing molecular pathways in COPD, its comorbidities, and asthma COPD overlap syndrome (ACOS) with unprecedented sophistication, clinical translation is disappointingly slow. The article therefore also considers solutions to current difficulties that are impeding progress in translating insights from basic science into clinically useful treatments.

Fractional exhaled nitric oxide levels in asthma-COPD overlap syndrome: analysis of the National Health and Nutrition Examination Survey, 2007-2012

Purpose

Recent studies propose T_H2-mediated inflammation in patients with asthma–chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS). However, little is known about whether fractional exhaled nitric oxide (FeNO) differs between patients with ACOS and those with COPD alone. To address this knowledge gap, a nationally representative sample was analyzed to determine the difference in FeNO levels between patients with ACOS and those with COPD alone in the US population.

Patients and methods

This is a cross-sectional analysis of the National Health and Nutrition Examination Survey from 2007 through 2012. All subjects aged ≥40 years with COPD were identified. ACOS was defined as self-reported wheezing in past 12 months plus bronchodilator response (forced expiratory volume increase of >200 mL and >12%) or self-reported physician diagnosis of asthma.

Results

A total of 197 subjects with COPD were identified in the National Health and Nutrition Examination Survey. Of these, 23% met the criteria of ACOS. The FeNO level was higher in subjects with ACOS compared with those with COPD alone in both unadjusted (mean 21.2 ppb vs 13.0 ppb; difference, 8.2 [95% CI, 0.2 to 16.2]; P=0.045) and adjusted (difference, 8.2 [95% CI, 0.9 to 15.5]; P=0.03) analyses. Although there was no significant difference among current smokers, the FeNO level was significantly higher in non-current smokers with ACOS than nonsmokers with COPD alone (mean 31.9 ppb vs 20.3 ppb; adjusted difference, 20.5 [95% CI, 4.4 to 36.6]; P=0.02). In a sensitivity analysis using an alternative definition of ACOS, the results did not change materially. The diagnostic value of FeNO to discriminate ACOS from COPD alone was not sufficient, with the area under the curve of 0.63 (95% CI, 0.54 to 0.72).

Conclusion

By using nationally representative US data, it was found that 23% of COPD subjects met the ACOS criteria and also that the FeNO level was higher in subjects with ACOS compared with those with COPD alone, particularly in non-current smokers.

Analysis of Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome Defined on the Basis of Bronchodilator Response and Degree of Emphysema

RATIONALE

Despite the increasing recognition of asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) as a clinical entity, it remains poorly characterized due to a lack of agreement on its definition and diagnostic criteria.

OBJECTIVES

The aim of this study was to use spirometry and computed tomography (CT) to help better define ACOS as well as to classify subjects with ACOS based on Global Initiative for Chronic Obstructive Lung Disease (GOLD) letter grade.

METHODS

We analyzed 10,192 subjects enrolled in the COPDGene Study. Subjects were non-Hispanic white or African American current or former smokers aged 45-80 years with at least a 10-pack-year smoking history. Subjects were categorized as having either ACOS with a bronchodilator response or chronic obstructive pulmonary disease with emphysema on the basis of spirometry, high-resolution CT, and a history of asthma or hay fever.

MEASUREMENTS AND MAIN RESULTS

Subjects with ACOS were younger (60.6 vs. 65.9 years old; P < 0.0001), more likely to be African American (26.8% vs. 14.4%; P < 0.0001), had a higher body mass index (29.6 vs. 25.1 kg/m(2); P < 0.0001), and were more likely to be current smokers (50.9% vs. 20.7%; P < 0.0001). The majority of subjects with ACOS were categorized as GOLD grade B. Despite less severe spirometry and CT findings in subjects with ACOS, there was no significant difference in severe or frequent exacerbations.

CONCLUSIONS

Bronchodilator responsiveness and degree of emphysema can help define ACOS. When defined on the basis of bronchodilator responsiveness and degree of emphysema, patients with ACOS represent a unique and high-risk group with distinct clinical features.

Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome: Nothing New Under the Sun

The debate about whether asthma and chronic obstructive pulmonary disease (COPD) are distinct clinical syndromes is not new; there is heightened interest in understanding the group of individuals with obstructive lung disease who seem to have elements of both conditions because recent studies have demonstrated increased risk for respiratory events and exacerbations. We describe the clinical characteristics of this subtype of disease and suggest 4 working definitions of individuals who would fall into the asthma-COPD overlap category. Understanding the mechanisms underlying these subtypes will hopefully lead into a better understanding of therapeutic strategies that can target specific pathobiologic pathways.

Understanding the pathophysiology of the asthma-chronic obstructive pulmonary disease overlap syndrome

PURPOSE OF REVIEW

The review will provide an update on the pathophysiology and studies of inflammation associated with the asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) and the mechanism(s) responsible for persistent expiratory airflow limitation in never-smoked asthma patients who develop loss of lung elastic recoil consistent with an asthma-COPD clinical phenotype (ACOS in nonsmokers).

RECENT FINDINGS

Patients with a clinical diagnosis of ACOS have more frequent respiratory exacerbations and hospitalizations than COPD patients without ACOS. ACOS patients should be treated with inhaled corticosteroids, short and long-acting β2-agonist, and long-acting muscarinic receptor antagonist. Biomarker work suggests that a molecular phenotype of ACOS (e.g., elevated markers of eosinophilic or type 2 inflammation) incompletely corresponds to clinical phenotypes. Recently, we reported sentinel observation of unsuspected mild diffuse centrilobular emphysema in never-smoked asthma patients at autopsy, despite mild changes in lung computed tomography and normal diffusing capacity.

SUMMARY

Recent studies have shown that subgroups of COPD and asthma patients may have overlapping immune responses. Never-smoked asthma patients may have persistent expiratory airflow limitation because of loss of lung elastic recoil. This may be because of unsuspected centrilobular emphysema detected at autopsy, and not easily diagnosed on lung computed tomography and diffusing capacity.

Clinical phenotypes of obstructive airway diseases in an outpatient population

BACKGROUND AND OBJECTIVES

Historically, obstructive airway diseases such as asthma and COPD are classified as different diseases. Although the definitions are clearly described, classification of patients into these traditional, clinical disease entity can be difficult. Recent evidence that there are complex, overlapping phenotypes of obstructive lung disease. Our aim was to capture clinical phenotypes of obstructive diseases through the use of cluster analysis in a representative patient population at a common Dutch pulmonary outpatient clinic. Clinical physiological and cellular/ molecular markers were used in the analysis.

METHODS

To carry out the cluster analysis, an imputed dataset was created from a random sample of 191 adult patients chosen from a pulmonary outpatient clinic. The selection criteria from the sample included patients with a doctor's diagnosis for asthma or COPD. Detailed assessment of patient pulmonary function, blood eosinophil counts, allergic sensitisation and smoking history was collected.

RESULTS

We observed four distinct clusters with different clinical characteristics of obstructive lung diseases. Cluster 1: patients with a history of extensive cigarette smoking, airway obstruction without signs of emphysema; cluster 2: patients with features of the emphysematous type of COPD; cluster 3: patients with characteristics of allergic asthma; cluster 4: patients with features suggesting an overlap syndrome of atopic asthma and COPD.

CONCLUSION

Four phenotypes of obstructive lung disease were identified amongst patients clinically labelled as asthma or COPD. These findings emphasize the concept that there are different phenotypes of obstructive lung diseases, including overlapping and complementary disease entities. These phenotypes of chronic airways disease can serve to tailor disease management.

What is asthma-COPD overlap syndrome? Towards a consensus definition from a round table discussion

Patients with asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) have been largely excluded from pivotal therapeutic trials and, as a result, its treatment remains poorly defined and lacking firm evidence. To date, there is no universally accepted definition of ACOS, which has made it difficult to understand its epidemiology or pathophysiology. Despite many uncertainties, there is emerging agreement that some of the key features of ACOS include persistent airflow limitation in symptomatic individuals 40 years of age and older, a well-documented history of asthma in childhood or early adulthood and a significant exposure history to cigarette or biomass smoke. In this perspective, we propose a case definition of ACOS that incorporates these key features in a parsimonious algorithm that may enable clinicians to better diagnose patients with ACOS and most importantly enable researchers to design therapeutic and clinical studies to elucidate its epidemiology and pathophysiology and to ascertain its optimal management strategies.

The asthma-COPD overlap syndrome: do we really need another syndrome in the already complex matrix of airway disease?

The term asthma–COPD overlap syndrome (ACOS) is one of multiple terms used to describe patients with characteristics of both COPD and asthma, representing ~20% of patients with obstructive airway diseases. The recognition of both sets of morbidities in patients is important to guide practical treatment decisions. It is widely recognized that patients with COPD and coexisting asthma present with a higher disease burden, despite the conceptual expectation that the “reversible” or “treatable” component of asthma would allow for more effective management and better outcomes. However, subcategorization into terms such as ACOS is complicated by the vast spectrum of heterogeneity that is encapsulated by asthma and COPD, resulting in different clinical clusters. In this review, we discuss the possibility that these different clusters are suboptimally described by the umbrella term “ACOS”, as this additional categorization may lead to clinical confusion and potential inappropriate use of resources. We suggest that a more clinically relevant approach would be to recognize the extreme variability and the numerous phenotypes encompassed within obstructive airway diseases, with various degrees of overlapping in individual patients. In addition, we discuss some of the evidence to be considered when making practical decisions on the treatment of patients with overlapping characteristics between COPD and asthma, as well as the potential options for phenotype and biomarker-driven management of airway disease with the aim of providing more personalized treatment for patients. Finally, we highlight the need for more evidence in patients with overlapping disease characteristics and to facilitate better characterization of potential treatment responders.

Do we really need asthma-chronic obstructive pulmonary disease overlap syndrome?

The association of asthma and chronic obstructive pulmonary disease (COPD) in the same patient, which is designated as mixed asthma-COPD phenotype or overlap syndrome (ACOS), remains a controversial issue. This is primarily because many conflicting aspects in the definition of ACOS remain, and it is extremely difficult to summarize the distinctive features of this syndrome. Furthermore, we are realizing that asthma, COPD, and ACOS are not single diseases but rather syndromes consisting of several endotypes and phenotypes and, consequently, comprising a spectrum of diseases. The umbrella term ACOS blurs the lines between asthma and COPD and allows an approach that simplifies therapy. However, this approach contradicts the modern concept according to which we must move toward more targeted and personalized therapies to treat patients with these diseases. Therefore we argue that the term ACOS must be abandoned and ultimately replaced when new phenotypes and underlying endotypes are identified and a new taxonomy of airway diseases is generated.

Health Issues in Hispanic/Latino Youth

This review focuses on obesity, asthma and mental health functioning as salient health issues affecting Hispanic youth. Burden of these conditions and consequences for adult health are also discussed. Hispanic youth are affected by obesity at an early age; the prevalence of obesity among Hispanic children 6-11 years old is twice as high as the prevalence for non-Hispanic White children of the same age, but among 2-5 years old is 4 times higher. Asthma disproportionally affects certain Hispanic groups, notably children of Puerto Rican ancestry, and the comorbidity of asthma and obesity is an emerging health issue. Another area of concern is the scant data on mental health functioning among Hispanic youth. Research on Hispanic youth mental health have reported high rates of depressive symptomatology and high rates of alcohol use among Hispanic adolescents but despite these findings, they have inadequate access to mental health services. This review highlights the need for better data to gain a better understanding of the health status of Hispanic youth and help develop preventive programs that addresses the need of this population. Improving access to health services, in particular mental health services, is also a crucial aspect.

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.

Gender and asthma-chronic obstructive pulmonary disease overlap syndrome

OBJECTIVE

To assess relationships between obstructive lung diseases, respiratory symptoms, and comorbidities by gender.

METHODS

Data from 12 594 adult respondents to the 2012 South Carolina Behavioral Risk Factor Surveillance System telephone survey were used. Five categories of chronic obstructive airway disease (OAD) were defined: former asthma only, current asthma only, chronic obstructive pulmonary disease (COPD) only, asthma-COPD overlap syndrome (ACOS), and none. Associations of these categories with respiratory symptoms (frequent productive cough, shortness of breath, and impaired physical activities due to breathing problems), overall health, and comorbidities were assessed using multivariable logistic regression for men and women.

RESULTS

Overall, 16.2% of men and 18.7% of women reported a physician diagnosis of COPD and/or asthma. Former asthma only was higher among men than women (4.9% vs. 3.2%, t-test p = 0.008). Current asthma only was more prevalent among women than men (7.2% vs. 4.7%, p < 0.001), as was ACOS (4.0% vs. 2.2%, p < 0.001). Having COPD only did not differ between women (4.3%) and men (4.4%). Adults with ACOS were most likely to report the 3 respiratory symptoms. COPD only and ACOS were associated with higher likelihoods of poor health and most comorbidities for men and women. Current asthma only was also associated with these outcomes among women, but not among men.

CONCLUSIONS

In this large population-based sample, women were more likely than men to report ACOS and current asthma, but not COPD alone. Gender differences were evident between the OAD groups in sociodemographic characteristics, respiratory symptoms, and comorbidities, as well as overall health.

Smoking asthma phenotype: diagnostic and management challenges

PURPOSE OF REVIEW

The prevalence of active smoking in adults with asthma is similar to the general population. Smoking asthma is associated with poorer disease control, impaired response to corticosteroid therapy, accelerated decline in lung function, and increased rate of healthcare utilization. Current asthma guidelines do not provide specific treatment advice for smoking asthmatic patients. There is an urgent need for better understanding of the underlying mechanisms and effective treatment for smoking asthmatic patients.

RECENT FINDINGS

An association between both active and passive smoking and adult-onset asthma is supported by many studies.The asthma-COPD overlap syndrome (ACOS) has recently gained particular interest and smoking asthmatic patients should be evaluated for ACOS.Treatment regimens for smoking asthma include higher doses of inhaled corticosteroids (ICS), extrafine particle ICS formulations, antileukotrienes, and combinations of these options.Asthma is associated with increased risk of cardiovascular comorbidities whereas smoking is an additional strong independent risk factor for pulmonary and cardiovascular diseases. Tobacco smoking and not asthma per se seems to be the reason of poor prognosis, especially with regard to lung cancer, cardiovascular diseases, and mortality in asthmatic patients.

SUMMARY

Smoking asthma represents a common challenge to the clinician both in terms of diagnosis and management. These aspects have not been thoroughly evaluated and deserve further investigation.

COPD assessment test and severity of airflow limitation in patients with asthma, COPD, and asthma-COPD overlap syndrome

OBJECTIVE

The COPD assessment test (CAT) consists of eight nonspecific scores of quality of life. The aim of this study was to compare the health-related quality of life and severity of airflow limitation in patients with asthma, COPD, and asthma-COPD overlap syndrome (ACOS) using the CAT.

METHODS

We examined CAT and lung functions in 138 patients with asthma, 99 patients with COPD, 51 patients with ACOS, and 44 patients with chronic cough as a control. The CAT score was recorded in all subjects, and the asthma control test was also administered to patients with asthma and ACOS. The CAT scores were compared, and the relationships between the scores and lung function parameters were analyzed.

RESULTS

The total CAT scores and scores for cough, phlegm, and dyspnea were higher in patients with ACOS than in patients with asthma and COPD. The total CAT scores were correlated with the percent predicted forced expiratory volume in 1 second only in patients with COPD. The total CAT scores and dyspnea scores adjusted by the percent predicted forced expiratory volume in 1 second were higher in patients with ACOS than in patients with COPD and asthma. The CAT scores and asthma control test scores were more closely correlated in patients with ACOS than in patients with asthma.

CONCLUSION

Patients with ACOS have higher disease impacts and dyspnea sensation unproportional to the severity of airflow limitation.

Pre-existing Pulmonary Diseases and Survival in Patients With Stage-dependent Lung Adenocarcinoma: A STROBE-compliant Article

Asthma, chronic obstructive pulmonary disease (COPD), and pulmonary tuberculosis (TB) are common lung diseases associated with lung cancer mortality. This study evaluated sex disparities in pre-existing pulmonary diseases and stage-dependent lung adenocarcinoma survival.Patients newly diagnosed with lung adenocarcinoma between 2003 and 2008 were identified using the National Health Insurance Research Database and Cancer Registry. Cases with lung adenocarcinoma were followed until the end of 2010. Survival curves were estimated by the Kaplan-Meier method. Cox proportional-hazard regression was used to calculate the hazard ratio (HR) of pre-existing asthma, COPD, and/or TB, and to estimate all-cause mortality risk in patients with different stages of lung adenocarcinoma.A total of 14,518 cases were identified with lung adenocarcinoma. Specifically, among men, the HRs for TB were 1.69 (95% confidence interval [CI], 1.10-2.58), 1.48 (95% CI, 1.14-1.93), and 1.27 (95% CI, 1.08-1.49) for individuals with stage I + II, III, and IV diseases, respectively. The HRs for asthma were 1.41 (95% CI, 1.00-1.99) in women with stage I + II and 1.14 (95% CI, 1.04-1.26) in men with stage IV disease. For pulmonary disease combinations in men, the HRs were 1.45 (95% CI, 1.12-1.89) for asthma + COPD + TB, 1.35 (95% CI, 1.12-1.63) for COPD + TB, 1.28 (95% CI, 1.01-1.63) for TB, and 1.15 (95%CI, 1.04-1.27) for asthma + COPD, respectively. For women with stage I + II disease, the HR was 6.94 (95% CI, 2.72-17.71) for asthma + COPD + TB.Coexistence of pre-existing pulmonary diseases increased mortality risk in men with adenocarcinoma. TB is at elevated risk of mortality among men with different stages of adenocarcinoma. Asthmatic women with early-stage adenocarcinoma had increased risk of mortality.

Risk factors for COPD exacerbations in inhaled medication users: the COPDGene study biannual longitudinal follow-up prospective cohort

Background

Despite inhaled medications that decrease exacerbation risk, some COPD patients experience frequent exacerbations. We determined prospective risk factors for exacerbations among subjects in the COPDGene Study taking inhaled medications.

Methods

2113 COPD subjects were categorized into four medication use patterns: triple therapy with tiotropium (TIO) plus long-acting beta-agonist/inhaled-corticosteroid (ICS ± LABA), tiotropium alone, ICS ± LABA, and short-acting bronchodilators. Self-reported exacerbations were recorded in telephone and web-based longitudinal follow-up surveys. Associations with exacerbations were determined within each medication group using four separate logistic regression models. A head-to-head analysis compared exacerbation risk among subjects using tiotropium vs. ICS ± LABA.

Results

In separate logistic regression models, the presence of gastroesophageal reflux, female gender, and higher scores on the St. George’s Respiratory Questionnaire were significant predictors of exacerbator status within multiple medication groups (reflux: OR 1.62–2.75; female gender: OR 1.53 - OR 1.90; SGRQ: OR 1.02–1.03). Subjects taking either ICS ± LABA or tiotropium had similar baseline characteristics, allowing comparison between these two groups. In the head-to-head comparison, tiotropium users showed a trend towards lower rates of exacerbations (OR = 0.69 [95 % CI 0.45, 1.06], p = 0.09) compared with ICS ± LABA users, especially in subjects without comorbid asthma (OR = 0.56 [95 % CI 0.31, 1.00], p = 0.05).

Conclusions

Each common COPD medication usage group showed unique risk factor patterns associated with increased risk of exacerbations, which may help clinicians identify subjects at risk. Compared to similar subjects using ICS ± LABA, those taking tiotropium showed a trend towards reduced exacerbation risk, especially in subjects without asthma.

Trial registration

ClinicalTrials.gov NCT00608764, first received 1/28/2008.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0191-7) contains supplementary material, which is available to authorized users.

The asthma-COPD overlap syndrome: how is it defined and what are its clinical implications?

It is increasingly recognized that both asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous diseases with a large inter-individual variability with respect to their clinical expression, disease progression, and responsiveness to the available treatments. The introduction of asthma–COPD overlap syndrome (ACOS) may lead to a better clinical characterization and improved treatment of patients with obstructive airways disease. However, it is still in its early phase and several improvements will have to be made. First, a clear definition of ACOS and preferably also its sub-phenotypes, eg, asthma–ACOS and COPD–ACOS, is urgently needed. That would also allow researchers to design clinical studies in well-defined patients. The latter is important since the interpretation of clinical studies performed so far is hampered by the use of many different definitions of ACOS. Second, future studies are needed to investigate the role of state-of-the-art techniques such as computed tomography, genetics, and genomics in the phenotyping of patients with obstructive airways disease, ie, asthma, COPD, and ACOS. Third, longitudinal studies are now needed to better define the clinical implications of ACOS with respect to the long-term outcome and treatment of ACOS and its sub-phenotypes compared to only asthma or COPD.

A review of national guidelines for management of COPD in Europe

The quality of care can be improved by the development and implementation of evidence-based treatment guidelines. Different national guidelines for chronic obstructive pulmonary disease (COPD) exist in Europe and relevant differences may exist among them.This was an evaluation of COPD treatment guidelines published in Europe and Russia in the past 7 years. Each guideline was reviewed in detail and information about the most important aspects of patient diagnosis, risk stratification and pharmacotherapy was extracted following a standardised process. Guidelines were available from the Czech Republic, England and Wales, Finland, France, Germany, Italy, Poland, Portugal, Russia, Spain and Sweden. The treatment goals, criteria for COPD diagnosis, consideration of comorbidities in treatment selection and support for use of long-acting bronchodilators, were similar across treatment guidelines. There were differences in measures used for stratification of disease severity, consideration of patient phenotypes, criteria for the use of inhaled corticosteroids and recommendations for other medications (e.g. theophylline and mucolytics) in addition to bronchodilators.There is generally good agreement on treatment goals, criteria for diagnosis of COPD and use of long-acting bronchodilators as the cornerstone of treatment among guidelines for COPD management in Europe and Russia. However, there are differences in the definitions of patient subgroups and other recommended treatments.

Asthma COPD Overlap Syndrome on CT Densitometry: A Distinct Phenotype from COPD

Patients with asthma COPD overlap syndrome (ACOS) are an important but poorly characterized group. This study sought to explore the distinct characteristics of ACOS on CT densitometry. The study population was randomly selected from communities via questionnaires. All participants underwent low-dose volumetric chest CT both before and after bronchodilator administration. Each CT scan was performed at full-inspiration and full-expiration for CT densitometry. Emphysema index (EI), air trapping (AT), mean lung density (MLD) and total lung volume (TLV) were measured and compared between the ACOS and COPD groups. The distributions of both EI and AT were compared between patients with ACOS and COPD. The variations between the pre- and post-BD measurements observed in patients with ACOS were compared with those in patients with COPD. A total of 71 patients completed the study, including 32 patients with COPD and 39 patients with ACOS. The patients with ACOS exhibited lower EI and more upper-zone-predominant EI distributions, compared with the patients with COPD. No significant differences were exhibited in AT and its distribution. Following bronchodilator administration, the variations in AT and expiratory MLD were greater in patients with ACOS than in patients with COPD. No differences were observed in the variations of EI and inspiratory MLD. Our results indicate that patients with ACOS have lower extent of emphysema and different emphysema distribution, as well as greater post-BD variations in air trapping, compared with patients with COPD. These findings suggest that CT densitometry characterizes ACOS as a distinct phenotype from COPD.

Predicting frequent asthma exacerbations using blood eosinophil count and other patient data routinely available in clinical practice

PURPOSE

Acute, severe asthma exacerbations can be difficult to predict and thus prevent. Patients who have frequent exacerbations are of particular concern. Practical exacerbation predictors are needed for these patients in the primary-care setting.

PATIENTS AND METHODS

Medical records of 130,547 asthma patients aged 12-80 years from the UK Optimum Patient Care Research Database and Clinical Practice Research Datalink, 1990-2013, were examined for 1 year before (baseline) and 1 year after (outcome) their most recent blood eosinophil count. Baseline variables predictive (P<0.05) of exacerbation in the outcome year were compared between patients who had two or more exacerbations and those who had no exacerbation or only one exacerbation, using uni- and multivariable logistic regression models. Exacerbation was defined as asthma-related hospital attendance/admission (emergency or inpatient) or acute oral corticosteroid (OCS) course.

RESULTS

Blood eosinophil count >400/µL (versus ≤400/µL) increased the likelihood of two or more exacerbations >1.4-fold (odds ratio [OR]: 1.48 (95% confidence interval [CI]: 1.39, 1.58); P<0.001). Variables that significantly increased the odds by up to 1.4-fold included increasing age (per year), female gender (versus male), being overweight or obese (versus normal body mass index), being a smoker (versus nonsmoker), having anxiety/depression, diabetes, eczema, gastroesophageal reflux disease, or rhinitis, and prescription for acetaminophen or nonsteroidal anti-inflammatory drugs. Compared with treatment at British Thoracic Society step 2 (daily controller ± reliever), treatment at step 0 (none) or 1 (as-needed reliever) increased the odds by 1.2- and 1.6-fold, respectively, and treatment at step 3, 4, or 5 increased the odds by 1.3-, 1.9-, or 3.1-fold, respectively (all P<0.05). Acute OCS use was the single best predictor of two or more exacerbations. Even one course increased the odds by more than threefold (OR: 3.75 [95% CI: 3.50, 4.01]; P<0.001), and three or more courses increased the odds by >25-fold (OR: 25.7 [95% CI: 23.9, 27.6]; P<0.001).

CONCLUSION

Blood eosinophil count and several other variables routinely available in patient records may be used to predict frequent asthma exacerbations.

Defining the Asthma-COPD Overlap Syndrome in a COPD Cohort

BACKGROUND

Asthma-COPD overlap syndrome (ACOS) has been recently described by international guidelines. A stepwise approach to diagnosis using usual features of both diseases is recommended although its clinical application is difficult.

METHODS

To identify patients with ACOS, a cohort of well-characterized patients with COPD and up to 1 year of follow-up was analyzed. We evaluated the presence of specific characteristics associated with asthma in this COPD cohort, divided into major criteria (bronchodilator test > 400 mL and 15% and past medical history of asthma) and minor criteria (blood eosinophils > 5%, IgE > 100 IU/mL, or two separate bronchodilator tests > 200 mL and 12%). We defined ACOS by the presence of one major criterion or two minor criteria. Baseline characteristics, health status (COPD Assessment Test [CAT]), BMI, airflow obstruction, dyspnea, and exercise capacity (BODE) index, rate of exacerbations, and mortality up to 1 year of follow-up were compared between patients with and without criteria for ACOS.

RESULTS

Of 831 patients with COPD included,125 (15%) fulfilled the criteria for ACOS, and 98.4% of them sustained these criteria after 1 year. Patients with ACOS were predominantly male (81.6%), with symptomatic mild to moderate disease (67%), who were receiving inhaled corticosteroids (63.2%). There were no significant differences in baseline characteristics, and only survival was worse in patients with non-ACOS COPD after 1 year of follow-up (P < .05).

CONCLUSIONS

The proposed ACOS criteria are present in 15% of a cohort of patients with COPD and these patients show better 1-year prognosis than clinically similar patients with COPD with no ACOS criteria.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01122758; URL: www.clinicaltrials.gov.

Revisiting the Dutch hypothesis

The Dutch hypothesis was first articulated in 1961, when many novel and advanced scientific techniques were not available, such as genomics techniques for pinpointing genes, gene expression, lipid and protein profiles, and the microbiome. In addition, computed tomographic scans and advanced analysis techniques to dissect (small) airways disease and emphysema were not available. At that time, the group of researchers under the visionary guidance of Professor N. G. M. Orie put forward that both genetic and environmental factors can determine whether one would have airway obstructive diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Moreover, they stipulated that the phenotype of obstructive airway disease could be affected by sex and changes with aging. Orie and colleagues' call to carefully phenotype patients with obstructive airways diseases has been adopted by many current researchers in an attempt to determine the heterogeneity of both asthma and COPD to better define these diseases and optimize their treatment. The founders of the Dutch hypothesis were far ahead of their time, and we can learn from their insights. We should fully characterize all patients in our clinical practice and not just state that they have asthma, COPD, or asthma and COPD overlap syndrome. This detailed phenotyping can help in understanding these obstructive airway diseases and provide guidance for disease management.

Asthma and chronic obstructive pulmonary disease overlap: asthmatic chronic obstructive pulmonary disease or chronic obstructive asthma?

Asthma and chronic obstructive pulmonary disease (COPD) are different disease entities. They are both clinical diagnoses, with diagnostic tools to discriminate between one another. However, especially in older patients (>55 years) it seems more difficult to differentiate between asthma and COPD. This has led to the definition of a new phenotype called asthma COPD overlap syndrome (ACOS). However, our understanding of ACOS is at a very preliminary stage, as most research has involved subjects with existing diagnoses of asthma or COPD from studies with different definitions for ACOS. This has led to different and sometimes opposing results between studies on several features of ACOS, also depending on the comparison with COPD alone, asthma alone or both, which are summarized in this review.We suggest not using the term ACOS for a patient with features of both asthma and COPD, but to describe a patient with chronic obstructive airway disease as completely as possible, with regard to characteristics that determine treatment response (e.g. eosinophilic inflammation) and prognosis (such as smoking status, exacerbation rate, fixed airflow limitation, hyperresponsiveness, comorbidities). This will provide a far more clinically relevant diagnosis, and would aid in research on treatment in more homogenous groups of patients with chronic airways obstruction. More research is certainly needed to develop more evidence-based definitions for this patient group and to evaluate biomarkers, which will help to further classify these patients, treat them more adequately and unravel the underlying pathophysiological mechanism.

Pentraxin 3 sputum levels differ in patients with chronic obstructive pulmonary disease vs asthma

BACKGROUND

Immune response has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD) and asthma. Pentraxin 3 (PTX3) is a multifunctional pattern recognition protein and an important component of the innate immune system that can be assessed in blood and induced sputum.

OBJECTIVE

To determine whether PTX3 measured in induced sputum could discriminate patients with COPD from patients with asthma.

METHODS

A cross-sectional study of 68 participants (27 with COPD, 25 with asthma, and 16 healthy controls) was performed. At study inclusion sputum was collected and total and differential cell numbers and PTX3 levels were determined.

RESULTS

Pentraxin 3 was detected in 89% of patients with COPD, 56% of patients with asthma, and 19% of controls (P = .001). It discriminated participants with COPD (24.6 ng/mL, 0-384 ng/mL) from controls (0 ng/mL, 0-36 ng/mL, P < .001) and from participants with asthma (1.2 ng/mL, 0-100 ng/mL, P = .01; area under the receiver operating curve 0.82 [0.71-0.94]). Regression analyses determined that sputum PTX3 and neutrophil counts were independently associated with COPD. In addition, PTX3 levels were independently associated with COPD severity.

CONCLUSION

Pentraxin 3 sputum levels are increased in patients with COPD and has good power to discriminate these patients from patients with asthma and healthy individuals.