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

PPARγ attenuates cellular senescence of alveolar macrophages in asthma-COPD overlap

BACKGROUND

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) represents a complex condition characterized by shared clinical and pathophysiological features of asthma and COPD in older individuals. However, the pathophysiology of ACO remains unexplored. We aimed to identify the major inflammatory cells in ACO, examine senescence within these cells, and elucidate the genes responsible for regulating senescence.

METHODS

Bioinformatic analyses were performed to investigate major cell types and cellular senescence signatures in a public single-cell RNA sequencing (scRNA-Seq) dataset derived from the lung tissues of patients with ACO. Similar analyses were carried out in an independent cohort study Immune Mechanisms Severe Asthma (IMSA), which included bulk RNA-Seq and CyTOF data from bronchoalveolar lavage fluid (BALF) samples.

RESULTS

The analysis of the scRNA-Seq data revealed that monocytes/ macrophages were the predominant cell type in the lung tissues of ACO patients, constituting more than 50% of the cells analyzed. Lung monocytes/macrophages from patients with ACO exhibited a lower prevalence of senescence as defined by lower enrichment scores of SenMayo and expression levels of cellular senescence markers. Intriguingly, analysis of the IMSA dataset showed similar results in patients with severe asthma. They also exhibited a lower prevalence of senescence, particularly in airway CD206 + macrophages, along with increased cytokine expression (e.g., IL-4, IL-13, and IL-22). Further exploration identified alveolar macrophages as a major subtype of monocytes/macrophages driving cellular senescence in ACO. Differentially expressed genes related to oxidation-reduction, cytokines, and growth factors were implicated in regulating senescence in alveolar macrophages. PPARγ (Peroxisome Proliferator-Activated Receptor Gamma) emerged as one of the predominant regulators modulating the senescent signature of alveolar macrophages in ACO.

CONCLUSION

The findings suggest that senescence in macrophages, particularly alveolar macrophages, plays a crucial role in the pathophysiology of ACO. Furthermore, PPARγ may represent a potential therapeutic target for interventions aimed at modulating senescence-associated processes in ACO.Key words ACO, Asthma, COPD, Macrophages, Senescence, PPARγ.

Sex differences in comorbidities and mortality risk among patients with chronic obstructive pulmonary disease: a study based on NHANES data

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) commonly have coexisting comorbidities that contribute to higher exacerbation frequency, poorer health status, and increased all-cause mortality; however, there are only a few studies available on the sex discrepancy in the comorbidity distribution and outcomes among COPD patients, and there is limited information about the discrepancy in all-cause mortality between men and women.

METHODS

Based on data from the U.S. National Health and Nutrition Examination Survey conducted between 2007 and 2012, we compared participants aged 40-79 years with spirometry-defined COPD to compare the prevalence of comorbidities between men and women. The survival of the subjects was documented, and the sex discrepancy was determined using Kaplan-Meier analysis. Comorbidities and all-cause mortality were analyzed by using a Cox proportional hazards model to determine their strength of association in different sex groups.

RESULTS

Compared to men, women had a significantly higher prevalence of asthma (OR 1.93, 95% CI 1.46 to 2.57, p < 0.001) and arthritis (OR 1.77, 95% CI 1.39 to 2.24, p < 0.001). Women had a significantly lower prevalence of coronary heart disease (OR 0.48, 95% CI 0.27 to 0.87, p = 0.015) and gout (OR 0.42, 95% CI 0.25 to 0.67, p = 0.001). Kaplan-Meier analysis revealed that compared with that of the female group, the survival rate of the male group was significantly lower (p < 0.001). Among men, the presence of anemia (HR 2.38, [95% CI 1.52-3.73], p < 0.001), gout (HR 1.55, [95% CI 1.04-2.30], p = 0.029) and congestive heart failure comorbidities (HR 1.85, [95% CI 1.12-3.04] p = 0.016) was associated with a higher risk of mortality; among women, the presence of anemia (HR 2.21, [95% CI 1.17-4.20], p = 0.015) and stroke (HR 2.04, [95% CI 1.07-3.88], p = 0.031) comorbidities was associated with a higher risk of mortality after adjusting for age, race/Hispanic status, BMI, smoking status, FEV1% predicted and prevalent comorbidities.

CONCLUSIONS

COPD-related comorbidities and all-cause mortality were discrepant between men and women, and men had poorer survival than women in the nationally representative data that were analyzed.

Mortality of asthma, COPD, and asthma-COPD overlap during an 18-year follow up

BACKGROUND

We studied asthma, COPD, and asthma-COPD overlap (ACO) to predict mortality in a cohort of Finnish adults with an 18-year follow up.

METHODS

A national health examination survey representing Finnish adults aged ≥30 years was performed in 2000-2001. The study cohort included 5922 participants (73.8% of the sample) with all relevant data, including a comprehensive clinical examination and spirometry. These participants were followed continuously from baseline until end of 2018 for total, cardiovascular, cancer, and respiratory mortality through a record linkage. Asthma, COPD, and ACO were defined based on the survey data, including spirometry and register data. There were three separate groups of obstructive subjects (one definition excluding the others).

RESULTS

Asthma and COPD were significantly associated with higher total mortality in Cox's model adjusted for sex, age, smoking, education level, BMI, leisure time physical activity, cardiovascular disease, diabetes, and hypertension. Hazard ratios (HR) (95% confidence interval [CI]) for asthma, COPD, and ACO were 1.29 (1.05-1.58), 1.50 (1.20-1.88), and 1.26 (0.97-1.65), respectively. Additionally, asthma (HR 1.47, 95% CI 1.09-1.97) and COPD (HR 1.53, 95% CI 1.08-2.16) were associated with cardiovascular mortality. Although ACO did not predict mortality in the whole cohort, there was a significant association with mortality risk among those with hs-CRP 1-2.99 mg/l.

CONCLUSIONS

Asthma or COPD predicts higher total mortality and premature death from cardiovascular diseases.

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.

Concurrent asthma and chronic obstructive pulmonary disease in adult ED patients: A national perspective

OBJECTIVES

Emergency department (ED) visits for Asthma and Chronic Obstructive Pulmonary Disease (COPD) are common. The designation of Asthma-COPD overlap (ACO) has been used to describe patients with features of both diseases. Studies show that ACO patients may be at increased risk of poor outcomes relative to patients with either disease alone. We sought to characterize ED visits and ED-related outcomes of patients with ACO compared to patients with Asthma or COPD alone.

METHODS

We conducted a secondary analysis of the National Hospital Ambulatory Medical Care Survey (NHAMCS, 2005-2018) characterizing ED visits in patients ≥35 years of age with Asthma Only, COPD Only or ACO. We performed univariable and multivariable analyses adjusting for demographics to assess relevant ED outcome variables.

RESULTS

From 2005 to 2018, there were an estimated 8.15, 17.78 and 0.56 million ED visits for Asthma Only, COPD Only and ACO, respectively. ACO patients were younger than COPD Only patients (mean age 50.18 versus 61.79; p < 0.001). ACO patients differed in terms of sex, race and ethnicity from patients with either disease alone. When triaged, Asthma Only (adjusted odds ratio (aOR) = 11.45; 95% confidence interval (CI), 1.20-109.38) patients were more likely to require immediate care than ACO patients. Although admission rates were comparable between groups, ACO patients had a decreased mean length of ED visit compared to both Asthma Only (p < 0.001) and COPD Only (p < 0.05) patients. COPD Only patients were less likely than ACO patients to be seen in the ED in the last 72 h (aOR = 0.22; 95% CI, 0.056-0.89), receive nebulizer therapy (aOR = 0.55; 95% CI, 0.31-0.97), bronchodilators (aOR = 0.24; 95% CI, 0.12-0.48) and systemic corticosteroids (aOR = 0.18; 95% CI, 0.091-0.35). Asthma Only patients were less likely than ACO patients to undergo any imaging (aOR = 0.55; 95% CI, 0.31-0.96) and receive antibiotics (aOR = 0.46; 95% CI, 0.23-0.93).

CONCLUSIONS

ACO patients appear to differ demographically from patients with either disease alone in the ED. After adjustment for these demographic differences, ACO patients appear to differ with respect to several ED variables, notably respiratory therapies; however, clinical outcomes including admission and mortality rates appear to be comparable between groups.

The prevalence and clinical features of chronic obstructive pulmonary disease patients with traits of asthma in Taiwan

BACKGROUND/PURPOSE

The application of the checkbox for identifying patients with traits of both chronic obstructive pulmonary disease (COPD) and asthma proposed by the 2015 Global Initiative for Asthma (GINA)/Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommendations has not been well studied although such identification is important in clinical practice. Thus, we aimed to investigate the prevalence and features of COPD coexistent with asthma traits diagnosed based on the 2015 GINA/GOLD strategies, and explore the gap between guidelines and routine practice in the diagnosis and pharmacological management of such condition in a COPD cohort.

METHODS

COPD subjects were enrolled retrospectively throughout Taiwan. A patient record form was completed for each participant and the data were analyzed.

RESULTS

Of 340 participants, the prevalence of COPD coexistent with traits of asthma was 39.4% and 30.3% based on guidelines and physician's judgment, respectively. Coexistent patients were characterized by blood eosinophilia, higher total immunoglobulin E (IgE) levels, preserved lung function, and the presence of gastro-esophageal reflux disease and atopic disease while total IgE level > 100 kU/L and the presence of atopic disease were predictors for coexistent patients. Gaps existed in the diagnosis (a weak agreement with kappa = 0.53) and treatment (non-adherence to the preferred therapy in 18.4% of physician-judged coexistent patients) in COPD patients with asthma traits. The exacerbation history was similar between coexistent and non-coexistent patients.

CONCLUSION

We found that measuring circulatory eosinophil and total IgE levels may raise clinicians' awareness of the presence of traits of asthma in the management of COPD.

Asthma-COPD overlap in World Trade Center Health Registry enrollees, 2015-2016

INTRODUCTION

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) is a newly redefined form of chronic airway disease and has not been well studied among 9/11-exposed populations with increased prevalence of asthma. We assessed the prevalence and risk factors associated with ACO in an exposure cohort of World Trade Center Health Registry (WTCHR) enrollees.

METHODS

This is a longitudinal study, including enrollees with complete data on 9/11/01 exposure at enrollment (2003-2004, Wave 1), asthma and COPD diagnoses and at least 25 years of age at the time of the 2015-2016 (Wave 4) WTCHR survey. Probable ACO was defined as self-reported post-9/11 physician-diagnosed asthma and either emphysema, chronic bronchitis, or COPD. We evaluated whether probable ACO was associated with World Trade Center (WTC)-related exposures, using multivariable logistic regression.

RESULTS

Of 36,864 Wave 4 participants, 29,911 were eligible for this analysis, and 1,495 (5.0%) had self-reported post-9/11 probable ACO. After adjusting for demographics and smoking status, we found 38% increased odds of having ACO in enrollees with exposure to the dust cloud, and up to 3.39 times the odds in those with ≥3 injuries sustained on 9/11. Among rescue/recovery workers, ever working on the pile, on the pile on 9/11 or 9/12/01, or working on the WTC site for >7 days showed increased odds ratios of having ACO.

CONCLUSION

Probable ACO is associated with WTC exposures. Further study of ACO is needed to understand the development of this and other environmentally or occupationally-related airway diseases, and how to prevent these in disasters like 9/11.

The many faces of asthma-chronic obstructive pulmonary disease overlap

PURPOSE OF REVIEW

Asthma and chronic obstructive pulmonary disease (COPD) are common diseases that often overlap. The term asthma-COPD overlap (ACO) has been used to define this entity but there remain several speculations on its exact definition, impact, pathophysiology, clinical features, and management. We reviewed recent publications on ACO to obtain more insight of current knowledge and outline future needs.

RECENT FINDINGS

Criteria for ACO vary from one publication to another and the many variable features of these patients underline the need to reconsider the evaluation and approach of patients with overlapping features based on clinical traits and underlying biological mechanisms. Epidemiological studies reveal that ACO patients have generally an increased burden of illness and healthcare use in addition to poorer quality of life (QoL) compared with asthma and higher or equal to COPD. However, their long-term outcome seems better than patients with COPD alone. Various methods have been proposed to evaluate these patients but their usefulness compared to 'classical' investigation of obstructive lung diseases remains speculative and needs further evaluation. Furthermore, there are no formal studies that examined and compared the different treatment strategies of well-characterized patients with ACO as such patients are usually excluded from clinical trials.

SUMMARY

ACO is a common condition with variable features and a high burden of disease. There is no consensus on its definition, diagnostic, and clinical features and more research should be done on its optimal management and long-term outcomes.

Future research trends in understanding the mechanisms underlying allergic diseases for improved patient care

The specialties of allergy and clinical immunology have entered the era of precision medicine with the stratification of diseases into distinct disease subsets, specific diagnoses, and targeted treatment options, including biologicals and small molecules. This article reviews recent developments in research and patient care and future trends in the discipline. The section on basic mechanisms of allergic diseases summarizes the current status and defines research needs in structural biology, type 2 inflammation, immune tolerance, neuroimmune mechanisms, role of the microbiome and diet, environmental factors, and respiratory viral infections. In the section on diagnostic challenges, clinical trials, precision medicine and immune monitoring of allergic diseases, asthma, allergic and nonallergic rhinitis, and new approaches to the diagnosis and treatment of drug hypersensitivity reactions are discussed in further detail. In the third section, unmet needs and future research areas for the treatment of allergic diseases are highlighted with topics on food allergy, biologics, small molecules, and novel therapeutic concepts in allergen‐specific immunotherapy for airway disease. Unknowns and future research needs are discussed at the end of each subsection.

Prediction of first acute exacerbation using COPD subtypes identified by cluster analysis

Purpose

In patients with COPD, acute exacerbation (AE) is not only an important determinant of prognosis, but also an important factor in choosing therapeutic agents. In this study, we evaluated the usefulness of COPD subtypes identified through cluster analysis to predict the first AE.

Patients and methods

Among COPD patients in the Korea COPD Subgroup Study (KOCOSS) cohort, 1,195 who had follow-up data for AE were included in our study. We selected seven variables for cluster analysis – age, body mass index, smoking status, history of asthma, COPD assessment test (CAT) score, post-bronchodilator (BD) FEV₁ % predicted, and diffusing capacity of carbon monoxide % predicted.

Results

K-means clustering identified four clusters for COPD that we named putative asthma-COPD overlap (ACO), mild COPD, moderate COPD, and severe COPD subtypes. The ACO group (n=196) showed the second-best post-BD FEV₁ (75.5% vs 80.9% [mild COPD, n=313] vs 52.4% [moderate COPD, n=345] vs 46.7% [severe COPD, n=341] predicted), the longest 6-min walking distance (424 m vs 405 m vs 389  m vs 365 m), and the lowest CAT score (12.2 vs 13.7 vs 15.6 vs 17.5) among the four groups. ACO group had greater risk for first AE compared to the mild COPD group (HR, 1.683; 95% CI, 1.175–2.410). The moderate COPD and severe COPD group HR values were 1.587 (95% CI, 1.145–2.200) and 1.664 (95% CI, 1.203–2.302), respectively. In addition, St. George’s Respiratory Questionnaire score (HR: 1.019; 95% CI, 1.014–1.024) and gastroesophageal reflux disease were independent factors associated with the first AE (HR: 1.535; 95% CI, 1.116–2.112).

Conclusion

Our cluster analysis revealed an exacerbator subtype of COPD independent of FEV₁. Since these patients are susceptible to AE, a more aggressive treatment strategy is needed in these patients.

Asthma-COPD Overlap-A Discordance Between Patient Populations Defined by Different Diagnostic Criteria

BACKGROUND

The concordance between asthma-chronic obstructive pulmonary disease overlap (ACO) defined according to Global Inititative for Asthma (GINA)/Global Initiative for Chronic Obstructive Lung Disease (GOLD) and other diagnostic criteria is unknown.

OBJECTIVE

To assess the concordance between different ACO definitions and to estimate the definition-based ACO prevalence and characteristics.

METHODS

A prospective, real-life study based on a 32-item data set was performed in a mixed population of patients with asthma and chronic obstructive pulmonary disease (COPD). Five different definitions of ACO, including the GINA/GOLD criteria, were analyzed.

RESULTS

A total of 1609 patients were included in the final analysis. Application of Venn diagram for ACO populations resulted in 31 ACO subpopulations, which were further reduced to 6 separate populations by introducing a rank order for the analyzed definitions to classify patients from intersecting groups. Overall, the level of agreement between different ACO definitions was poor. Cohen kappa coefficient for the agreement between ACO GINA/GOLD definition and other ACO definitions varied from 0.06 to 0.21. Only 2 patients (0.12%) met all the ACO definitions. Definition-based ACO prevalence ranged between 3.8% (Spanish criteria) and 18.4% (clinician's diagnosis). A total of 573 (33.4%) patients met the criteria from at least 1 ACO definition. Patients who could not be classified as suffering from "pure" asthma, "pure" COPD, or ACO accounted for as much as 27.5% of the whole investigated group. The most severe symptoms were observed in patients with ACO defined as COPD and asthma diagnosed at age less than 40 years.

CONCLUSIONS

The current ACO definitions identify distinct populations that share only a small number of common features and present with different disease phenotypes. ACO prevalence is highly variable, depending on the definition applied.

Longitudinal comparison of outcomes in patients with smoking-related asthma-COPD overlap and in non-smoking asthmatics with incomplete reversibility of airway obstruction

Background

There is a need to characterize the impact of the smoking status on the clinical course of asthmatics with incomplete reversibility of airway obstruction (IRAO).

Objective

To compare longitudinal health care use, symptom control, and medication needs between smoking and non-smoking asthmatics with IRAO.

Materials and methods

This was a 12-month follow-up of a cross-sectional study comparing asthmatics with IRAO according to their tobacco exposure. One group had a tobacco exposure ≥20 pack-years and was considered to have asthma-COPD overlap (ACO) and the second with a past tobacco exposure <5 pack-years was considered as non-smokers with IRAO (NS-IRAO). Study participants were contacted by telephone every 3 months to document exacerbation events and symptom control.

Results

A total of 111 patients completed all follow-up telephone calls: 71 ACO and 40 NS-IRAO. The number of exacerbations per patient over the 12-month follow-up was similar in both groups. However, ACO reported worse symptom control throughout the follow-up as compared to NS-IRAO, although no significant variations within a group were observed over the study period.

Conclusion

Although asthma control scores were poorer in ACO patients over 1 year compared to NS-IRAO, exacerbation rate was similar and low in both groups of asthmatics. These observations suggest that poorer asthma control in ACO was not driven by the number of exacerbations but may reflect the influence of chronic airway changes related to the COPD component.

[Personalised COPD care: Where are we going?]

The concept of personalised medicine is recent but the underlying notions are not new: knowing how to adapt care to patients' characteristics is one of the components of the "art of medicine". The advances of science allow to refine considerably the applications of the concept in many fields of medicine including COPD: research has identified phenotypes, endotypes and treatable traits. Personalisation can be applied to all components of care. For instance, the decision to perform screening spirometry relies not only on risk factors (age, smoking, other exposures) but also on symptoms. Assessment of comorbidities often associated with COPD is based on risk factors and their combinations, variable between individuals. Rehabilitation and its components are in essence highly individualised, which a major condition for their success. Last but not least, personalisation of pharmacological therapy, which has long been rather poor, could not benefit from biomarkers of interest (predictive of response), such as blood eosinophil count. Practical strategies using these still need to be established, and new biomarkers may usefully enrich the collection!

Clinical Approach to the Therapy of Asthma-COPD Overlap

Over the last few years, there has been a renewed interest in patients with characteristics of both asthma and COPD. Although the precise definition of asthma-COPD overlap (ACO) is still controversial, patients with overlapping features are frequently encountered in clinical practice, and may indeed have worse clinical outcomes and increased health-care utilization than those with asthma or COPD. Therefore, there is a critical need to set a framework for the therapeutic approach of such patients. There are key distinctions in the therapy between asthma and COPD, particularly regarding the initial choice of therapy. However, there is considerable overlap in the use of existing medications for both diseases. Furthermore, novel therapies approved for asthma, such as monoclonal antibodies, may have a role in patients with COPD and ACO. The use of biomarkers, such as peripheral blood eosinophils, exhaled nitric oxide, and serum IgE, may help in selecting appropriate therapies for ACO. In this review, we provide an overview of available treatments for both asthma and COPD and explore their potential role in the treatment of patients with ACO.

Asthma versus chronic obstructive pulmonary disease, the Dutch versus British hypothesis, and role of interleukin-5

PURPOSE OF REVIEW

Asthma and COPD represent heterogeneous disorders with broad ranging impact on patients and health systems. This review focuses on evidence for early attempts at understanding their pathogenesis by the British and Dutch hypotheses. It also addresses the role of eosinophils, IL-5, and biologics targeting these pathways in asthma and COPD.

RECENT FINDINGS

Among asthma and COPD patients, clusters exist based on phenotypic and biologic markers allowing for further understanding of endotypes. Recent studies suggest the role of eosinophils and optimal therapies for each condition may be different.

SUMMARY

Although patients with ACOS or overlap symptoms may be an exception, overall there appears to be more evidence supporting that asthma and COPD are distinct processes. Targeting eosinophils with anti-IL-5 therapy appears to be an exciting pathway in the properly selected patient with asthma and recent data also supports its use in COPD.

Psychosocial risk factors and asthma among adults in Puerto Rico

OBJECTIVE

Asthma and psychosocial stressors are common among Puerto Rican adults living in the United States. We estimated the prevalence of current asthma, and examined potential psychosocial risk factors and current asthma, among adults in Puerto Rico.

METHODS

Cross-sectional study of 3,049 Puerto Ricans aged 18-64 years living in Puerto Rico between May 2014 and June 2016. A structured interview was conducted to obtain information on demographics, lifestyle, mental disorders, and respiratory health. Current asthma was defined as self-reported physician-diagnosed asthma and still having asthma. Multivariable logistic regression was used to examine psychosocial risk factors and current asthma.

RESULTS

The estimated prevalence of current asthma was 10.2%. In a multivariable analysis, exposure to violence (odds ratio [OR] for each 1-point increment in a validated scale = 1.14, 95% confidence interval [CI] = 1.07 to 1.21) and a lifetime history of at least one suicide attempt (OR = 3.01, 95% CI = 1.80 to 5.01) were significantly associated with current asthma, independently of major depressive disorder. Moreover, a lifetime history of at least one suicide attempt was associated with co-existing asthma and chronic obstructive pulmonary disease (i.e., asthma-COPD overlap syndrome or ACOS (OR = 9.05, 95% CI = 3.32-24.67).

CONCLUSIONS

Our findings suggest that asthma is a major health problem among adults in Puerto Rico, with psychosocial risk factors playing a significant role in asthma and ACOS. Addressing chronic stressors and mental illness should be part of comprehensive strategies to reduce asthma burden in this population.

Distribution and characteristics of COPD phenotypes - results from the Polish sub-cohort of the POPE study

Background

This study aimed to examine the distribution of predefined phenotypes, demographic data, clinical outcomes, and treatment of patients who were included in the Polish cohort of the Phenotypes of COPD in Central and Eastern Europe (POPE) study.

Patients and methods

This was a sub-analysis of the data from the Polish cohort of the POPE study, an international, multicenter, observational cross-sectional survey of COPD patients in Central and Eastern European countries. The study included patients aged >40 years, with a confirmed diagnosis of COPD, and absence of exacerbation for at least 4 weeks before study inclusion. A total of seven Polish centers participated in the study.

Results

Among the 430 Polish COPD patients enrolled in the study, 61.6% were non-exacerbators (NON-AE), 25.3% were frequent exacerbators with chronic bronchitis (AE CB), 7.9% were frequent exacerbators without chronic bronchitis (AE NON-CB), and 5.1% met the definition of asthma-COPD overlap syndrome (ACOS). There were statistically significant differences among these phenotypes in terms of symptom load, lung function, comorbidities, and treatment. Patients with the AE CB phenotype were most symptomatic with worse lung function, and more frequently reported anxiety and depression. Patients with the ACOS phenotype were significantly younger and were diagnosed with COPD earlier than those with other COPD phenotypes; those with the ACOS phenotype were also more often atopic and obese.

Conclusion

There is significant heterogeneity among COPD patients in the Polish population in terms of phenotype and clinical outcome. The non-exacerbator phenotype is observed most frequently in Poland, while the frequent exacerbator with chronic bronchitis phenotype is the most symptomatic.

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.

Heterogeneity of asthma and COPD overlap

Background

Asthma and COPD are heterogeneous diseases. Patients with both disease features (asthma-COPD overlap [ACO]) are common. However, clinical characteristics and socio-economic burden of ACO are still controversial. The aim of this study was to identify the heterogeneity of ACO and to find out the subtypes with clinical impact among ACO subtypes.

Methods

In the Korean National Health and Nutrition Examination Survey (KNHANES) conducted between 2007 and 2012, subjects who were ≥40 years and had prebronchodilator FEV₁/FVC <0.7 and FEV₁ ≥50% predicted were included. The presence or absence of self-reported wheezing was indicated by W+ or W- and used as an index of airway hyper-responsiveness. S+/S- was defined as subjects who were smokers/never smokers. The subjects were divided into the following four groups: W-S-, W-S+, W+S-, and W+S+. W+S- and W+S+ were asthma-predominant ACO and COPD-predominant ACO, respectively. KNHANES and linked National Health Insurance data were analyzed.

Results

The asthma-predominant ACO group showed the lowest socioeconomic status, FEV₁, FVC% predicted, and quality of life (QoL) levels. The COPD-predominant ACO group showed the highest hospitalization rate, outpatient medical cost, and total and outpatient health care utilization. COPD-predominant ACO was associated with exacerbations compared to the W-S- group (adjusted odds ratio [aOR], 1.79; 95% confidence interval [CI], 1.12-2.85; P=0.015) and W-S+ group (OR 2.11; 95% CI 1.43-3.10; P<0.001). COPD-predominant ACO was associated with increased medical cost.

Conclusion

Asthma-predominant ACO individuals displayed poorer socioeconomic status and QoL compared to the COPD-predominant ACO group. The COPD-predominant ACO group displayed more frequent exacerbations and greater medical costs. Considering the heterogeneity of ACO, it is desirable to identify subtypes of ACO patients and appropriately allocate limited medical resources.

Effect of the asthma-chronic obstructive pulmonary disease syndrome on the stroke, Parkinson's disease, and dementia: a national cohort study

Background

To evaluate the association of asthma–chronic obstructive pulmonary disease syndrome (ACOS) with neurodegenerative diseases (stroke, Parkinson's disease and dementia) and the role of the steroids in the neurodegenerative diseases among the ACOS cohort.

Materials and Methods

Comparison of the ACOS cohort (N = 10,260) with the non-ACOS cohort (n = 20,513) based on the patients aged ≧40 years in the National Health Insurance Research Database from January 1, 2000 to December 31, 2010. These patients follow up to diagnosis of neurodegenerative diseases or the December 31, 2011; using multivariable Cox proportional hazards models.

Results

After adjustment for potential confounders, the [adjusted hazard ratio (aHR), 95% confidence interval (CI)] in the ACOS cohort were [1.39, 1.28–1.50] [1.56, 1.34–1.81] and [1.43, 1.29–1.59] for stroke, Parkinson's disease, dementia; respectively. The [aHR, 95% CI] for ACOS cohort with (inhaler corticosteroids ≧0.13 gram/ oral steroids ≧0.08gram) were with less risk (all aHR<1, p values <0.05) for these 3 neurodegenerative diseases except Parkinson's disease with inhaler corticosteroids >0.43 gram. The risk of stroke and dementia were the lower in patients with < 250 μg/d of a fluticasone equivalent inhaler corticosteroids (aHR = 0.53, 95% CI = 0.35–0.79; aHR = 0.53, 95% CI = 0.31–0.90, respectively).

Conclusions

The ACOS cohort had a higher risk of the neurodegenerative diseases. The lower dose of the inhaler corticosteroids with cumulative dose ≧0.13 gram have the less risk of stroke and dementia.

Clinical characteristics of chronic bronchitic, emphysematous and ACOS phenotypes in COPD patients with frequent exacerbations

Purpose

Chronic bronchitis (CB), emphysematous (EM) and asthma–chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) phenotypes in COPD are well recognized. This study aimed to investigate distinguishing characteristics of these phenotypes in COPD patients with frequent exacerbations (FE).

Patients and methods

A retrospective study was carried out. COPD patients with acute exacerbations were consecutively reviewed from November 2015 to October 2016. Patients were divided into FE and infrequent exacerbations (iFE) subgroups.

Results

A total of 142 eligible COPD subjects were reviewed. In the CB phenotype subgroup, age, body mass index, forced expiratory volume in 1 second (FEV₁) % predicted, COPD assessment test (CAT), modified Medical Research Council breathlessness measurement (mMRC) dyspnea scale, emphysema scores and arterial carbon dioxide pressure (PaCO₂) were significantly different in subjects with FE when compared to those in subjects with iFE of CB. In the EM phenotype subgroup, age, CAT, mMRC scores and history of COPD were different in subjects with FE when compared to those in CB subjects with iFE. Multivariate analysis indicated that FEV₁% predicted (odds ratio [OR] =0.90, P=0.04) and PaCO₂ (OR =1.22, P=0.02) were independent risk factors for FE in COPD with CB phenotype, and CAT (OR =2.601, P=0.001) was the independent risk factor for FE in COPD with EM phenotype. No significant differences in characteristics were observed in ACOS phenotype subgroups with FE or iFE.

Conclusion

In CB or EM phenotypes, COPD patients with FE present several differential clinical characteristics compared to patients with iFE, while the characteristics of ACOS phenotype in patients with FE need more investigation.

Relationship between blood eosinophils, clinical characteristics, and mortality in patients with COPD

In patients with COPD, there is controversy regarding the association of blood eosinophil (Eos) levels with 1) exacerbation frequency and 2) the effect of inhaled corticosteroids for prevention of exacerbations. To determine whether Eos define subgroups of patients exhibiting attributes of COPD clinical phenotypes, we compared clinical features and mortality rates in COPD patients from the Initiatives BPCO French cohort categorized using different thresholds of blood Eos levels. The following data were collected at inclusion: medical and smoking history, occupational exposures, dyspnea, cough and sputum production, exacerbations in the previous year, history of allergy and asthma, nasal symptoms, body mass index, St George Respiratory Questionnaire (SGRQ) total score, post-bronchodilator spirometry, comorbidities, and medications. Three-year survival between groups was compared using Kaplan–Meier analysis. Three sets of analyses were performed to compare patients with ≥2% versus <2%, ≥3% versus <3%, and ≥4% versus <4% Eos. Eos was available in 458 patients (mean age: 62 years, 72% male, mean forced expiratory volume in 1 second: 51% pred), including 235 patients with Eos ≥2% (49%), 149 with Eos ≥3% (33%), and 90 with Eos ≥4% (20%). For all cutoffs, there was no difference between Eos+ and Eos− groups in univariate analyses except for diabetes and SGRQ score (more frequent and more impaired, respectively, in lower Eos categories). In particular, there was no difference in exacerbation rate, history of asthma, or three-year survival. In conclusion, regardless of the cutoff, Eos+ COPD patients exhibited no specific characteristic in terms of symptoms, lung function, exacerbation rate, and prognosis. These findings suggest that the association of higher Eos with exacerbations reported in previous studies could be population specific, which does not support generalizing the use of Eos as a biomarker for COPD phenotyping.

Understanding COPD-overlap syndromes

INTRODUCTION

Chronic obstructive pulmonary disease accounts for a large burden of lung disease. It can 'overlap' with other respiratory diseases including bronchiectasis, fibrosis and obstructive sleep apnea (OSA). While COPD alone confers morbidity and mortality, common features with contrasting clinical outcomes can occur in COPD 'overlap syndromes'. Areas covered: Given the large degree of heterogeneity in COPD, individual variation to treatment is adopted based on its observed phenotype, which in turn overlaps with features of other respiratory disease states such as asthma. This is coined asthma-COPD overlap syndrome ('ACOS'). Other examples of such overlapping clinical states include bronchiectasis-COPD ('BCOS'), fibrosis-COPD ('FCOS') and OSA-COPD ('OCOS'). The objective of this review is to highlight similarities and differences between the COPD-overlap syndromes in terms of risk factors, pathophysiology, diagnosis and potential treatment differences. Expert commentary: As a consequence of COPD overlap syndromes, a transition from the traditional 'one size fits all' treatment approach is necessary. Greater treatment stratification according to clinical phenotype using a precision medicine approach is now required. In this light, it is important to recognize and differentiate COPD overlap syndromes as distinct disease states compared to individual diseases such as asthma, COPD, fibrosis or bronchiectasis.

Asthma-COPD Overlap Shows Favorable Clinical Outcomes Compared to Pure COPD in a Korean COPD Cohort

Purpose

Comparisons of the characteristics of chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap syndrome (ACOS) have been the focus of several studies since the diseases were defined by the Global Initiative for Asthma and Global Initiative for Chronic Obstructive Lung Disease guidelines. However, no consensus is available yet. In this study, we aimed to compare the characteristics of asthma-COPD overlap (ACO) and COPD.

Methods

We retrospectively reviewed 1,504 patients with COPD in a Korean COPD Subtype Study cohort. The occurrence of ACO was defined as a positive response to a bronchodilator (an increase in forced expiratory volume in 1 second [FEV1] of 12% and 200 mL).

Results

Among 1,504 patients with COPD, 223 (14.8%) were diagnosed with ACO. Men (95.5%) and current smokers (32.9%) were more prevalent in the ACO group compared with the pure COPD group (90.5% and 25.3%, respectively; P=0.015 and P=0.026, respectively). Patients with ACO had a better quality of life (St. George's Respiratory Questionnaire for COPD score=31.0±18.0 [mean±standard deviation]) than those with pure COPD (35.3±19.1) (P=0.002). Although the prevalence of acute exacerbation was not different between the 2 groups, patients with severe exacerbation required hospital admission significantly more frequently in the pure COPD group than in the ACO group. Patients with ACO showed a higher likelihood of FEV1 recovery than those with pure COPD (P<0.001).

Conclusions

We suggest that ACO is characterized by less severe symptoms, and therefore it might lead to rare severe exacerbation and the possibility of lung function recovery.

Airflow obstruction: is it asthma or is it COPD?

Despite the availability of guideline recommendations, diagnostic confusion between COPD and asthma appears common, and often it is very difficult to decide whether the obstruction is caused by asthma or COPD in a patient with airway obstruction. However, there are well-defined features that help in differentiating asthma from COPD in the presence of fixed airflow obstruction. Nonetheless, the presentations of asthma and COPD can converge and mimic each other, making it difficult to give these patients a diagnosis of either condition. The association of asthma and COPD in the same patient has been designated mixed asthma–COPD phenotype or overlap syndrome. However, since the absence of a clear definition and the inclusion of patients with different characteristics under this umbrella term, it may not facilitate treatment decisions, especially in the absence of clinical trials addressing this heterogeneous population. We are realizing that neither asthma nor COPD are single diseases, but rather syndromes consisting of several endotypes and phenotypes, consequently comprising a spectrum of diseases that must be recognized and adequately treated with targeted therapy. Therefore, we must treat patients by personalizing therapy on the basis of those treatable traits present in each subject.