Prevalence and characteristics of three clinical phenotypes of chronic obstructive pulmonary disease (COPD)

Respiratory Oscillometry and Functional Performance in Different COPD Phenotypes

Purpose

Chronic obstructive pulmonary disease (COPD) phenotypes may introduce different characteristics that need to be known to improve treatment. Respiratory oscillometry provides a detailed analysis and may offer insight into the pathophysiology of COPD. In this paper, we used this method to evaluate the differences in respiratory mechanics of COPD phenotypes.

Patients and Methods

This study investigated a sample of 83 volunteers, being divided into control group (CG = 20), emphysema (n = 23), CB (n = 20) and asthma-COPD overlap syndrome (ACOS, n = 20). These analyses were performed before and after bronchodilator (BD) use. Functional capacity was evaluated using the Glittre‑ADL test, handgrip strength and respiratory pressures.

Results

Initially it was observed that oscillometry provided a detailed description of the COPD phenotypes, which was consistent with the involved pathophysiology. A correlation between oscillometry and functional capacity was observed (r=-0.541; p = 0.0001), particularly in the emphysema phenotype (r = -0.496, p = 0.031). BD response was different among the studied phenotypes. This resulted in an accurate discrimination of ACOS from CB [area under the receiver operating curve (AUC) = 0.84] and emphysema (AUC = 0.82).

Conclusion

These results offer evidence that oscillatory indices may enhance the comprehension and identification of COPD phenotypes, thereby potentially improving the support provided to these patients.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

Machine learning reveals sex differences in clinical features of acute exacerbation of chronic obstructive pulmonary disease: A multicenter cross-sectional study

Introduction

Intrinsically, chronic obstructive pulmonary disease (COPD) is a highly heterogonous disease. Several sex differences in COPD, such as risk factors and prevalence, were identified. However, sex differences in clinical features of acute exacerbation chronic obstructive pulmonary disease (AECOPD) were not well explored. Machine learning showed a promising role in medical practice, including diagnosis prediction and classification. Then, sex differences in clinical manifestations of AECOPD were explored by machine learning approaches in this study.

Methods

In this cross-sectional study, 278 male patients and 81 female patients hospitalized with AECOPD were included. Baseline characteristics, clinical symptoms, and laboratory parameters were analyzed. The K-prototype algorithm was used to explore the degree of sex differences. Binary logistic regression, random forest, and XGBoost models were performed to identify sex-associated clinical manifestations in AECOPD. Nomogram and its associated curves were established to visualize and validate binary logistic regression.

Results

The predictive accuracy of sex was 83.930% using the k-prototype algorithm. Binary logistic regression revealed that eight variables were independently associated with sex in AECOPD, which was visualized by using a nomogram. The AUC of the ROC curve was 0.945. The DCA curve showed that the nomogram had more clinical benefits, with thresholds from 0.02 to 0.99. The top 15 sex-associated important variables were identified by random forest and XGBoost, respectively. Subsequently, seven clinical features, including smoking, biomass fuel exposure, GOLD stages, PaO2, serum potassium, serum calcium, and blood urea nitrogen (BUN), were concurrently identified by three models. However, CAD was not identified by machine learning models.

Conclusions

Overall, our results support that the clinical features differ markedly by sex in AECOPD. Male patients presented worse lung function and oxygenation, less biomass fuel exposure, more smoking, renal dysfunction, and hyperkalemia than female patients with AECOPD. Furthermore, our results also suggest that machine learning is a promising and powerful tool in clinical decision-making.

Lung Function Impairment, Associating Hyperinflation with Impaired Diffusion Capacity and Transfer Coefficient, Is a Risk Factor for Hip Osteoporosis in Patients with Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a risk factor for osteoporosis. Our objective is to determine if functional indices associated with emphysema on pulmonary function tests (DLCO—diffusion capacity of the lung for CO-; DLCO/AV—DLCO corrected for alveolar volume- and TLC—total lung capacity), considered alone or together, can identify COPD patients with osteoporosis. Methods: 90 COPD patients underwent dual-energy X-ray absorptiometry (DEXA) and pulmonary function tests. Results: 26% of the COPD patients were osteoporotic. In univariate analysis, each functional parameter associated with emphysema, analyzed separately, was not associated with osteoporosis. In contrast, patients with hyperinflation associated with impaired diffusion capacity and transfer coefficient, defined by the association of the three functional indices (DLCO < 70%, DLCO/AV < 80% and CPT > 115%), had significantly more osteoporosis at the total hip (OR: 5.9, CI: 1.5–23.8, p = 0.013). In multivariate analysis, this phenotype was confirmed as an independent factor associated with hip osteoporosis. In contrast, COPD airway obstruction severity, based on FEV1 (%), was not associated with osteoporosis. A lower BMI, female gender and age were also identified as osteoporosis risk factors. Conclusions: COPD patients with hyperinflation associated with impaired diffusion capacity and transfer coefficient are at higher risk for osteoporosis. Pulmonary function tests associated with emphysema detection can help to identify COPD patients with osteoporosis, in addition to the classical risk factors.

COPD: Providing the right treatment for the right patient at the right time

Chronic Obstructive Pulmonary Disease (COPD) is a common disease associated with significant morbidity and mortality that is both preventable and treatable. However, a major challenge in recognizing, preventing, and treating COPD is understanding its complexity. While COPD has historically been characterized as a disease defined by airflow limitation, we now understand it as a multi-component disease with many clinical phenotypes, systemic manifestations, and associated co-morbidities. Evidence is rapidly emerging in our understanding of the many factors that contribute to the pathogenesis of COPD and the identification of "early" or "pre-COPD" which should provide exciting opportunities for early treatment and disease modification. In addition to breakthroughs in our understanding of the origins of COPD, we are optimizing treatment strategies and delivery of care that are showing impressive benefits in patient-centered outcomes and healthcare utilization. This special issue of Respiratory Medicine, "COPD: Providing the Right Treatment for the Right Patient at the Right Time" is a summary of the proceedings of a conference held in Stresa, Italy in April 2022 that brought together international experts to discuss emerging evidence in COPD and Pulmonary Rehabilitation in honor of a distinguished friend and colleague, Claudio Ferdinando Donor (1948-2021). Claudio was a true pioneer in the field of pulmonary rehabilitation and the comprehensive care of individuals with COPD. He held numerous leadership roles in in the field, provide editorial stewardship of several respiratory journals, authored numerous papers, statement and guidelines in COPD and Pulmonary Rehabilitation, and provided mentorship to many in our field. Claudio's most impressive talent was his ability to organize spectacular conferences and symposia that highlighted cutting edge science and clinical medicine. It is in this spirit that this conference was conceived and planned. These proceedings are divided into 4 sections which highlight crucial areas in the field of COPD: (1) New concepts in COPD pathogenesis; (2) Enhancing outcomes in COPD; (3) Non-pharmacologic management of COPD; and (4) Optimizing delivery of care for COPD. These presentations summarize the newest evidence in the field and capture lively discussion on the exciting future of treating this prevalent and impactful disease. We thank each of the authors for their participation and applaud their efforts toward pushing the envelope in our understanding of COPD and optimizing care for these patients. We believe that this edition is a most fitting tribute to a dear colleague and friend and will prove useful to students, clinicians, and researchers as they continually strive to provide the right treatment for the right patient at the right time. It has been our pleasure and a distinct honor to serve as editors and oversee such wonderful scholarly work.

Loss of Pleckstrin homology like domain, family A, member 1 promotes type Ⅱ alveolar epithelial cell apoptosis in chronic obstructive pulmonary disease emphysematous phenotype via interaction with tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein epsilon

Emphysematous phenotype is the most important phenotypic component of chronic obstructive pulmonary disease and is associated with substantial morbidity and mortality. The current pharmaceutical treatments and therapeutic procedures do not reduce pulmonary damage in patients with emphysematous phenotype. Therefore, it is important to identify effector molecules that can be used as interfering targets in such patients. Apoptosis of type II alveolar epithelial cells plays a key role in the phenotypic formation. This study aimed to further explore the molecular mechanisms involved in this process. The number of type II alveolar epithelial cells was significantly reduced due to increased apoptosis in patients with emphysematous phenotype compared to those with non-emphysematous phenotype. Pleckstrin homology like domain, family A, member 1 (PHLDA1) was mainly distributed in type II alveolar epithelial cells in both groups but was markedly reduced in patients with emphysematous phenotype. Overexpression of PHLDA1 prevented cigarette smoke extract-stimulated apoptosis of type II alveolar epithelial cells, whereas its knockdown worsened the apoptosis. PHLDA1 binding ability to tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein epsilon (YWHAE) was weakened after exposure to cigarette smoke extract, with decreased PHLDA1 level lowering the abundance of YWHAE and attenuating the binding ability of YWHAE to p-Bad. These results demonstrate that considerable apoptosis of type II alveolar epithelial cells occurs in patients with emphysematous phenotype, and PHLDA1 may act as an effective antiapoptotic factor via YWHAE. Moreover, PHLDA1 may serve as a potential interfering target, providing insights into therapeutic strategies for emphysematous phenotype.

A novel computed tomography radiomic nomogram for early evaluation of small airway dysfunction development

The common respiratory abnormality, small airway dysfunction (fSAD), is easily neglected. Its prognostic factors, prevalence, and risk factors are unclear. This study aimed to explore the early detection of fSAD using radiomic analysis of computed tomography (CT) images to predict fSAD progress. The patients were divided into fSAD and non-fSAD groups and divided randomly into a training group (n = 190) and a validation group (n = 82) at a 7:3 ratio. Lung kit software was used for automatic delineation of regions of interest (ROI) on chest CT images. The most valuable imaging features were selected and a radiomic score was established for risk assessment. Multivariate logistic regression analysis showed that age, radiomic score, smoking, and history of asthma were significant predictors of fSAD (P < 0.05). Results suggested that the radiomic nomogram model provides clinicians with useful data and could represent a reliable reference to form fSAD clinical treatment strategies.

Epidemiology of Asthma-Chronic Obstructive Pulmonary Disease Overlap

Asthma COPD Overlap has consistently reported to be associated with an increase burden of disease but the impact on lung function decline and mortality varies by study. The prevalence increases with age but the relationship with gender also varies with the study population. The variability in the prevalence and clinical characteristics of ACO is linked to differences in how chronic obstructive pulmonary disease (COPD) and asthma are defined, including diagnostic criteria (spirometry-based vs. clinical or symptom-based diagnoses vs. claims data), the population studied, the geographic region and environment and a consensus approach to the diagnosis of ACO is needed to allow meaningful and consistent epidemiologic information to be generated about this condition.

Real-life burden of hospitalizations due to COPD exacerbations in Spain

Patients with chronic obstructive pulmonary disease (COPD) often suffer episodes of exacerbation of symptoms (ECOPD) that may eventually require hospitalization due to several, often overlapping, causes. We aimed to analyse the characteristics of patients hospitalized because of ECOPD in a real-life setting using a big-data approach. The study population included all patients older than 40 years with a diagnosis of COPD (n=69.359; prevalence 3.72%) registered since January 1st, 2011, until March 1, 2020, in the database of the public healthcare service (SESCAM) of Castilla-La Mancha (Spain) (n=1.863.759 subjects). We used natural language processing (Savana Manager v3.0) to identify those who were hospitalized during this period for any cause, including ECOPD. During the study 26.453 COPD patients (38.1%) were hospitalized (at least once). Main diagnoses at discharge were respiratory infection (51%), heart failure (38%) or pneumonia (19%). ECOPD was the main diagnosis at discharge (or hospital death) in 8.331 of them (12.0% of the entire COPD population and 31.5% of those hospitalized). In-hospital ECOPD-related mortality rate was 3.1%. These patients were hospitalized 2.36 times per patient, with a mean hospital stay of 6.1 days. Heart failure (HF) was the most frequent comorbidity in patients hospitalized because of ECOPD (52.6%). This analysis shows that, in a real-life setting, ECOPD hospitalizations are prevalent, complex (particularly in relation to HF), repetitive and associated with significant in-hospital mortality.

CD19 and POU2AF1 are Potential Immune-Related Biomarkers Involved in the Emphysema of COPD: On Multiple Microarray Analysis

Purpose

Emphysema is the main cause of the progression of chronic obstructive pulmonary disease (COPD). This study aimed to identify the key genes involved in COPD-related emphysema.

Patients and Methods

GSE76925 was downloaded from Gene Expression Omnibus database. Protein–protein interaction networks of differentially expressed genes (DEGs) between control and COPD groups were constructed to identify hub genes using Cytoscape. Diagnostic performance of hub genes was evaluated using receiver operating characteristic analysis. Correlation analysis was performed to identify the key genes by analyzing the relationship between the hub genes and lung function and computed tomography (CT) indexes of emphysema. COPD patients were then divided into two groups based on the median expression of key genes and DEGs between these two groups were identified. Enrichment analysis of DEGs and correlation analysis between key genes and the infiltration of the immune cells were also analyzed. Finally, the role of key genes was evaluated in a lung tissues dataset (GSE47460) and a blood dataset (GSE76705). Additionally, the expression of key genes was validated by quantitative real-time polymerase chain reaction and immunohistochemistry.

Results

CD19 and POU2AF1 had diagnostic efficacy for COPD and were significantly correlated with lung function and CT indexes of emphysema. Enrichment and immune analyses revealed that CD19 and POU2AF1 were correlated with the B cells in COPD. These results were consistent in GSE47460. The expression of CD19 and POU2AF1 in blood was the opposite of that in lung tissues, and CD19 and POU2AF1 were both significantly upregulated in COPD lung tissues at both the mRNA and protein levels.

Conclusion

CD19 and POU2AF1 may serve as key regulators of emphysema and contribute to the progression of COPD by regulating the B-cell immunology. Targeting B cells may be a promising strategy for treating COPD.

Current Knowledge of Asthma-COPD Overlap (ACO) Genetic Risk Factors, Characteristics, and Prognosis

Asthma-COPD overlap (ACO) is a newly identified phenotype of chronic obstructive airway diseases with shared asthma and COPD features. Patients with ACO are poorly defined, and some evidence suggests that they have worse health outcomes and greater disease burden than patients with COPD or asthma. Generally, there is no evidence-based and universal definition for ACO; several consensus documents have provided various descriptions of the phenotype. In addition, the mechanisms underlying the development of ACO are not fully understood. Whether ACO is a distinct clinical entity with its particular discrete genetic determinant different from asthma and COPD alone or an intermediate phenotype with overlapping genetic markers within asthma and COPD spectrum of obstructive airway disease remains unproven. This review summarizes the current knowledge of the genetic risk factors, characteristics, and prognosis of ACO.

Lung Cancer Risk Among Patients with Asthma-Chronic Obstructive Pulmonary Disease Overlap

RATIONALE

Chronic obstructive pulmonary disease (COPD) is a well-established independent risk factor for lung cancer, while the literature on the association between asthma and lung cancer is mixed. Whether Asthma COPD Overlap (ACO) is associated with lung cancer has not been studied.

OBJECTIVES

We aimed to compare lung cancer risk among patients with ACO vs. COPD and other conditions associated with airway obstruction.

METHODS

We studied 13,939 smokers from the National Lung Cancer Screening Trial who had baseline spirometry, and utilized spirometric indices and history of childhood asthma to categorize participants into 5 specific airway disease subgroups. We used Poisson regression to compare unadjusted and adjusted lung cancer risk.

RESULTS

The incidence rate of lung cancer per 1,000 person-years was: ACO, 13.2 (95% confidence interval [CI]: 8.1-21.5); COPD, 11.7 (95% CI: 10.5-13.1); asthmatic smokers, 1.8 (95% CI: 0.6-5.4); Global Initiative for Chronic Obstructive Lung Disease-Unclassified, 7.7 (95% CI: 6.4-9.2); and normal-spirometry smokers, 4.1 (95% CI: 3.5-4.8). ACO patients had increased adjusted risk of lung cancer compared to patients with asthma (incidence rate ratio [IRR]: 4.5, 95% CI: 1.3-15.8) and normal spirometry smokers (IRR: 2.3, 95% CI: 1.3-4.2) in models adjusting for other risk factors. Adjusted lung cancer incidence in patients with ACO and COPD were not found to be different (IRR: 1.2, 95% CI 0.7 - 2.1).

CONCLUSIONS

Risk of lung cancer among patients with ACO is similar to those with COPD and higher than other groups of smokers. These results provide further evidence that COPD, with or without a history of childhood asthma, is an independent risk factor for lung cancer.

Imbalance Between Injury and Defense in the COPD Emphysematous Phenotype

The chronic obstructive pulmonary disease (COPD) emphysematous phenotype is characterized by destruction of lung tissue structure. Patients with this phenotype usually present with typical emphysema-like changes on chest computed Tomography CT, experience higher mortality and poorer prognosis, and are insensitive to routine pharmacological COPD therapy. However, the pathogenesis for the COPD emphysematous phenotype remains unclear, resulting in diagnostic and therapeutic challenges. The imbalance between injury and defense mechanisms is essential in the progression of many pulmonary diseases. Thus, in this review, we focus on the pathogenesis of the COPD emphysematous phenotype and discuss the pathophysiological processes involved in disease progression, from the perspective of injury and defense imbalance.

Defining the Heterogeneity of Sleep Apnea Syndrome: A Cluster Analysis With Implications for Patient Management

INTRODUCTION

Obstructive sleep apnea (OSA) is a complex pathology with heterogeneity that has not been fully characterized to date. Our objective is to identify groups of patients with common clinical characteristics through cluster analysis that could predict patient prognosis, the impact of comorbidities and/or the response to a common treatment.

METHODS

Cluster analysis was performed using the hierarchical cluster method in 2025 patients in the apnea-HUGU cohort. The variables used for building the clusters included general data, comorbidity, sleep symptoms, anthropometric data, physical exam and sleep study results.

RESULTS

Four clusters were identified: (1) young male without comorbidity with moderate apnea and otorhinolaryngological malformations; (2) middle-aged male with very severe OSA with comorbidity without cardiovascular disease; (3) female with mood disorder; and (4) symptomatic male with established cardiovascular disease and severe OSA.

CONCLUSIONS

The characterization of these four clusters in OSA can be decisive when identifying groups of patients who share a special risk or common therapeutic strategies, orienting us toward personalized medicine and facilitating the design of future clinical trials.

Molecular Imaging of Inflammatory Disease

Inflammatory diseases include a wide variety of highly prevalent conditions with high mortality rates in severe cases ranging from cardiovascular disease, to rheumatoid arthritis, to chronic obstructive pulmonary disease, to graft vs. host disease, to a number of gastrointestinal disorders. Many diseases that are not considered inflammatory per se are associated with varying levels of inflammation. Imaging of the immune system and inflammatory response is of interest as it can give insight into disease progression and severity. Clinical imaging technologies such as computed tomography (CT) and magnetic resonance imaging (MRI) are traditionally limited to the visualization of anatomical information; then, the presence or absence of an inflammatory state must be inferred from the structural abnormalities. Improvement in available contrast agents has made it possible to obtain functional information as well as anatomical. In vivo imaging of inflammation ultimately facilitates an improved accuracy of diagnostics and monitoring of patients to allow for better patient care. Highly specific molecular imaging of inflammatory biomarkers allows for earlier diagnosis to prevent irreversible damage. Advancements in imaging instruments, targeted tracers, and contrast agents represent a rapidly growing area of preclinical research with the hopes of quick translation to the clinic.

Asthma and Chronic Obstructive Pulmonary Disease Overlap According to the Japanese Respiratory Society Diagnostic Criteria: The Prospective, Observational ACO Japan Cohort Study

INTRODUCTION

Patients with asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) present with chronic respiratory symptoms with features of both asthma and COPD. New ACO diagnostic criteria (2018) were suggested by the Japanese Respiratory Society (JRS). This prospective, multicenter, observational cohort study was conducted to investigate the proportion of patients who meet the JRS ACO diagnostic criteria among COPD patients in clinical practice.

METHODS

This 2-year ongoing study enrolled consecutive outpatients aged ≥ 40 years with COPD who visited one of 27 Japanese centers at which the medical examinations/tests required for ACO diagnosis were routinely conducted. At registration, the proportion of ACO or non-ACO patients was determined using the JRS diagnostic criteria, and the characteristics of the two groups were compared using analysis of variance and chi-square test.

RESULTS

Of 708 COPD patients analyzed at registration, 396 (55.9%) had the data necessary for ACO diagnosis to be conducted, and 312 (44.1%) were lacking these data. Of the 396 patients who had the data necessary for ACO diagnosis, 101 (25.5%) met the diagnostic criteria for ACO, and 295 (74.5%) did not (non-ACO patients). ACO patients were younger, had a greater rate of asthma based on a physician's diagnosis, and used more medications, including inhaled corticosteroids (p < 0.05), compared with non-ACO patients.

CONCLUSIONS

We have determined the proportion of patients with the data necessary to diagnose ACO using the JRS criteria, and the proportion of these who met the ACO criteria among the COPD population at the time of registration. Patients, including those lacking necessary examination/test data at registration, will continue to undergo follow-up to explore changes in their testing and ACO diagnostic status over time. Analyses of study data over 2 years will provide relevant information on the ACO symptoms, clinical course, and real-world treatment patterns.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03577795.

Identification of hub genes and key pathways in the emphysema phenotype of COPD

Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition associated with high morbidity and mortality. This study aimed to use weighted gene co-expression network analysis (WGCNA) to explore the molecular pathogenesis of the emphysema phenotype of COPD. After obtaining lung mRNA expression profiles from ten patients with the emphysema phenotype of COPD and eight controls, emphysema-associated gene modules were identified with WGCNA. Among 13 distinct modules, the green-yellow and brown modules showed the strongest correlations with emphysema severity and lung function and were thus selected as hub modules. On gene ontology analysis, these two modules were mainly enriched in immune response, B cell receptor (BCR) signaling pathway, extracellular matrix (ECM) organization, and collagen fibril organization. Pathway analysis primarily showed enrichment in BCR signaling pathways, ECM receptor interaction, and NF-κB and TGF-β signaling pathways for the two hub modules. Several genes, including FCRLA, MS4A1, CD19, FKBP10, C1S and HTRA1, among others, were identified as hub genes. Our results shed light on the potential genetic mechanisms underlying the pathogenesis of the emphysema phenotype of COPD. However, further research will be needed to confirm the involvement of the identified genes and to determine their therapeutic relevance.

What Is Asthma Chronic Obstructive Pulmonary Disease Overlap?

The term asthma chronic obstructive pulmonary disease (COPD) overlap (ACO) has been popularized to describe people who simultaneously have features of both diseases. Analysis of the basis of disease classification and comparison of the clinical, pathophysiological, and therapeutic features of asthma and COPD concludes that it is not useful to use the term ACO. Rather, it is important to make the individual diagnoses, recognizing that both diseases may coexist. If a concurrent diagnosis of COPD is suspected in people with asthma, pharmacotherapy should primarily follow asthma guidelines, but pharmacologic and nonpharmacologic approaches also may be needed for COPD.

Small airway immunoglobulin A profile in emphysema-predominant chronic obstructive pulmonary disease

BACKGROUND

Due to airway remodeling and emphysematous destruction in the lung, the two classical clinical phenotypes of chronic obstructive pulmonary disease (COPD) are emphysema and bronchiolitis. The present study was designed to investigate the levels of small airway immunoglobulin A (IgA) in COPD with "emphysema phenotype." The study also evaluated the associations between the small airway IgA levels and the severity of disease by the extent of emphysema versus airflow limitation.

METHODS

Thirty patients (20 with COPD and ten healthy smokers) undergoing lung resection surgery for a solitary peripheral nodule were included. The study was conducted from January 2015 to December 2018 in the Shanxi Dayi Hospital. The presence of small airway IgA expression was determined in the lung by immunohistochemistry. In vivo, Wistar rats were exposed to silica by intratracheal instillation. Rats were sacrificed at 15 and 30 days after exposure of silica (n = 10 for each group). We also evaluated airway IgA from rats.

RESULTS

Small airway secretory IgA (sIgA), dimeric IgA (dIgA), and dIgA/sIgA of Global Initiative for Chronic Obstructive Lung Disease grade 1-2 COPD patients showed no difference compared with smoking control subjects (5.15 ± 1.53 vs. 6.03 ± 0.85; 1.94 ± 0.66 vs. 1.67 ± 0.04; 41.69 ± 21.02 vs. 28.44 ± 9.45, all P > 0.05). dIgA/sIgA level in the lung of COPD patients with emphysema showed higher levels than that of COPD patients without emphysema (51.89 ± 24.81 vs. 31.49 ± 9.28, P = 0.03). The percentage of low-attenuation area below 950 Hounsfield units was positively correlated with dIgA/sIgA levels (r = 0.45, P = 0.047), but not associated with the severity of disease by spirometric measurements (forced expiratory volume in the first second %pred, P > 0.05). Likewise, in the rat study, significant differences in sIgA, dIgA, dIgA/sIgA, mean linear intercept, mean alveoli number, and mean airway thickness of bronchioles (VV airway, all P < 0.01) were only observed between control rats and those exposed for 30 days. However, in the group exposed for 15 days, although the VV airway was higher than that in normal rats (27.61 ± 2.26 vs. 20.39 ± 1.99, P < 0.01), there were no significant differences in IgA and emphysema parameters between the two groups (all P > 0.05).

CONCLUSION

Airway IgA concentrations in mild and moderate COPD patients are directly associated with the severity of COPD with "emphysema phenotype" preceding severe airway limitation. This finding suggests that small airway IgA might play an important role in the pathophysiology of COPD, especially emphysema phenotype.

Gene expression profiling of bronchial brushes is associated with the level of emphysema measured by computed tomography-based parametric response mapping

Parametric response mapping (PRM) is a computed tomography (CT)-based method to phenotype patients with chronic obstructive pulmonary disease (COPD). It is capable of differentiating emphysema-related air trapping with nonemphysematous air trapping (small airway disease), which helps to identify the extent and localization of the disease. Most studies evaluating the gene expression in smokers and COPD patients related this to spirometric measurements, but none have investigated the relationship with CT-based measurements of lung structure. The current study aimed to examine gene expression profiles of brushed bronchial epithelial cells in association with the PRM-defined CT-based measurements of emphysema (PRM^Emph) and small airway disease (PRM^fSAD). Using the Top Institute Pharma (TIP) study cohort (COPD = 12 and asymptomatic smokers = 32), we identified a gene expression signature of bronchial brushings, which was associated with PRM^Emph in the lungs. One hundred thirty-three genes were identified to be associated with PRM^Emph. Among the most significantly associated genes, CXCL11 is a potent chemokine involved with CD8⁺ T cell activation during inflammation in COPD, indicating that it may play an essential role in the development of emphysema. The PRM^Emph signature was then replicated in two independent data sets. Pathway analysis showed that the PRM^Emph signature is associated with proinflammatory and notch signaling pathways. Together these findings indicate that airway epithelium may play a role in the development of emphysema and/or may act as a biomarker for the presence of emphysema. In contrast, its role in relation to functional small airways disease is less clear.

Coronary heart disease and heart failure in asthma, COPD and asthma-COPD overlap

INTRODUCTION

We investigated risk of coronary heart disease and heart failure in phenotypes of obstructive airway disease.

METHODS

Among 91 692 participants in the Copenhagen General Population Study, 42 058 individuals were classified with no respiratory disease, and 11 988 individuals had different phenotypes of obstructive airways disease: asthma with early onset or late-onset, chronic obstructive pulmonary disease (COPD) with forced expiratory volume in one second (FEV₁) above or below 50% of predicted value (%p) or asthma-COPD overlap (ACO).

RESULTS

During a mean follow-up of 5.7 years we registered 3584 admissions for coronary heart disease and 1590 admissions for heart failure. Multivariable Cox regression analyses of time to first admission were used with a two-sided p value of 0.05 as significance level. Compared with no respiratory disease the highest risks of coronary heart disease and heart failure were observed in ACO with late-onset asthma and FEV₁ <50% p, HR=2.2 (95% CI 1.6 to 3.0), and HR=2.9 (95% CI 2.0 to 4.3), respectively. In COPD with FEV₁ above 50% p the HRs were 1.3 (95% CI 1.2 to 1.5) for coronary heart disease and 1.9 (95% CI 1.6 to 2.3) for heart failure. Asthma associated with increased risks of coronary heart disease and heart failure, however, in asthma without allergy the HR was 1.1 (95% CI 0.7 to 1.6) for coronary heart disease while individuals with allergy had an HR of 1.4 (95% CI 1.1 to 1.6).

CONCLUSIONS

Risks of coronary heart disease and heart failure were increased in asthma, COPD and ACO. In asthma, the risk of coronary heart disease depended on presence of allergy. We suggest that cardiovascular risk factors should be assessed systematically in individuals with obstructive airway disease with the potential to facilitate targeted treatments.

Clinical Impact of Multidisciplinary Outpatient Care on Outcomes of Patients with COPD

Purpose

Heterogeneous nature of Chronic Obstructive Pulmonary Disease (COPD) must be comprehensively addressed. It is unclear if integrative multidisciplinary disease management (IMDM) can optimize clinical outcomes of patients with COPD.

Methods

A single-center, retrospective cohort observational study with a historical intervention was conducted in a clinic specialized for COPD care. Patients with a confirmed diagnosis of COPD were administered IMDM with measurement of BODE score on initial and follow-up visits. Primary outcomes were dynamic changes in BODE quartiles after receiving IMDM.

Results

Of 124 patients, 21% were misdiagnosed with COPD. Patients with a confirmed diagnosis of COPD were 50% female, median age 64 years (IQR 57-70), 43% actively smoking and initial visit median BODE quartile 2 (IQR 1-3). Three subgroups were identified based on the changes in BODE quartiles: worsened (21%), unchanged (55%) and improved (24%). At baseline, mMRC (median [IQR]) was higher in improved subgroup vs worsened and unchanged subgroup (3 [3, 4] vs 2 [1, 2] vs 2 [1, 3], p value 0.002) respectively. Drop in all components of BODE score was noted in worsened group, but significant improvement in mMRC with preservation of spirometry values was noted in the improved group. The incidence of smoking cigarettes changed from 39% to 26% during follow-up.

Conclusion

Our study demonstrates that IMDM can be potentially effective in a subgroup of COPD patients. In others precipitous drop in lung function, activity tolerance, and subjective symptoms seems inevitable with worsening BODE quartiles.

Analysis of high-resolution computed tomography phenotypes and pulmonary function in chronic obstructive pulmonary disease

Objective

To explore the correlation between high-resolution computed tomography (HRCT) phenotype and pulmonary function in patients with chronic obstructive pulmonary disease (COPD).

Methods

Fifty-six patients with COPD were retrospectively evaluated using pulmonary function tests (PFTs) and HRCT, and phenotypic pulmonary function parameters were analyzed.

Results

Thirty-one patients were classified as having imaging phenotype A, 11 were phenotype E, and 14 were phenotype M. The total lung capacity (TLC)% of phenotype E was significantly higher than that of phenotypes A and M. The residual volume (RV) to TLC ratio (RV/TLC) in phenotype A was significantly lower than that in phenotypes E and M. The forced expiratory volume in one second percentage (FEV1%) and FEV1/forced vital capacity (FVC) of phenotype A was significantly higher than that of phenotypes E and M.

Conclusion

FEV1/FVC and FEV1% were higher and RV/TLC was lower, indicating less severe emphysema, in patients with phenotype A compared with patients with phenotypes E and M. TLC% of patients with phenotype E was significantly higher than that of patients with phenotypes A and M. The degree of airflow limitation was most severe in patients with phenotype M.

Clinical Characteristics Of Patients With Asthma COPD Overlap (ACO) In Australian Primary Care

Purpose

Many older adults with a history of smoking and asthma develop clinical features of both asthma and COPD, an entity sometimes called asthma-COPD overlap (ACO). Patients with ACO may be at higher risk of poor health outcomes than those with asthma or COPD alone. However, understanding of ACO is limited in the primary care setting and more information is needed to better inform patient management. We aimed to compare the characteristics of patients with ACO or COPD in Australian general practices.

Patients and methods

Data were from the RADICALS (Review of Airway Dysfunction and Interdisciplinary Community-based care of Adult Long-term Smokers) trial, an intervention study of an interdisciplinary community-based model of care. Baseline demographic and clinical characteristics, pre- and post-bronchodilator spirometry, dyspnoea and St. George’s Respiratory Questionnaire scores were compared between 60 ACO patients and 212 with COPD alone.

Results

Pre-bronchodilator Forced Expiratory Volume in 1 second (mean±SD 58.4±14.3 vs 67.5±20.1% predicted) and Forced Vital Capacity (mean 82.1±16.9 v 91.9±17.2% predicted) were significantly lower in the ACO group (p<0.001), but no difference was found in post-bronchodilator spirometry. Demographic and clinical characteristics, dyspnoea, quality of life, comorbidities and treatment prescribed did not differ significantly between groups.

Conclusion

This is the first study describing the clinical characteristics of ACO patients in Australian general practices. Our finding of lower pre-bronchodilator lung function in the ACO group compared to those with COPD reinforces the importance of spirometry in primary care to inform management.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12614001155684.

Differential coexpression networks in bronchiolitis and emphysema phenotypes reveal heterogeneous mechanisms of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease with multiple molecular mechanisms. To investigate and contrast the molecular processes differing between bronchiolitis and emphysema phenotypes of COPD, we downloaded the GSE69818 microarray data set from the Gene Expression Omnibus (GEO), which based on lung tissues from 38 patients with emphysema and 32 patients with bronchiolitis. Then, weighted gene coexpression network analysis (WGCNA) and differential coexpression (DiffCoEx) analysis were performed, followed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes enrichment analysis (KEGG) analysis. Modules and hub genes for bronchiolitis and emphysema were identified, and we found that genes in modules linked to neutrophil degranulation, Rho protein signal transduction and B cell receptor signalling were coexpressed in emphysema. DiffCoEx analysis showed that four hub genes (IFT88, CCDC103, MMP10 and Bik) were consistently expressed in emphysema patients; these hub genes were enriched, respectively, for functions of cilium assembly and movement, proteolysis and apoptotic mitochondrial changes. In our re‐analysis of GSE69818, gene expression networks in relation to emphysema deepen insights into the molecular mechanism of COPD and also identify some promising therapeutic targets.

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.

Role of medical and molecular imaging in COPD

Chronic obstructive pulmonary disease (COPD) is expected to climb on the podium of the leading causes of mortality worldwide in the upcoming decade. Clinical diagnosis of COPD has classically relied upon detecting irreversible airflow obstruction on pulmonary function testing as a global assessment of pulmonary physiology. However, the outcome is still not favorable to decrease mortality due to COPD. Progress made in both medical and molecular imaging fields are beginning to offer additional tools to address this clinical problem. This review aims to describe medical and molecular imaging modalities used to diagnose COPD and to select patients for appropriate treatments and to monitor response to therapy.

Overlap of Asthma and Chronic Obstructive Pulmonary Disease in Patients in the United States: Analysis of Prevalence, Features, and Subtypes

Background

Although asthma and chronic obstructive pulmonary disease (COPD) are clinically distinct diseases, they represent biologically diverse and overlapping clinical entities and it has been observed that they often co-occur. Some research and theorizing suggest there is a common comorbid condition termed asthma-chronic obstructive pulmonary disease overlap (ACO). However, the existence of ACO is controversial.

Objective

The objective of this study is to describe patient characteristics and estimate prevalence, health care utilization, and costs of ACO using claims-based diagnoses confirmed with medical record information.

Methods

Eligible patients were commercial US health plan enrollees; ≥40 years; had asthma, COPD, or ACO; ≥3 prescription fills for asthma/COPD medications; and ≥2 spirometry tests. Records for a random sample of 5000 patients with ACO were reviewed to validate claims-based diagnoses.

Results

The estimated ACO prevalence was 6% (estimated 10,250/183,521) among 183,521 full study patients. In the claims-based cohorts, the comorbidity burden for ACO was greater versus asthma but similar to COPD cohorts. Medication utilization was higher in ACO versus asthma and COPD. Mean total health care costs were significantly higher for ACO versus asthma but similar to COPD. In confirmed diagnoses cohorts, mean total health care costs (medical plus pharmacy) were lower for ACO versus COPD but similar to asthma (US $20,035; P=.56). Among confirmed cases, where there was medical record evidence, smoking history was higher in ACO (300/343, 87.5%) versus asthma cohorts (100/181, 55.2%) but similar to COPD (68/84, 81%).

Conclusions

ACO had more comorbidities, medication utilization, and costs than patients with asthma or COPD but differences were not seen after confirmation with medical records.

Chronic obstructive pulmonary disease subpopulations and phenotyping

The diagnosis and treatment of chronic obstructive pulmonary disease (COPD) has been based largely on a one-size-fits-all approach. Diagnosis of COPD is based on meeting the physiologic criteria of fixed obstruction in forced expiratory flows and treatment focus on symptomatic relief, with limited effect on overall prognosis. However, patients with COPD have distinct features that determine very different evolutions of the disease. In this review we highlight distinct subgroups of COPD characterized by unique pathophysiologic derangements, response to treatment, and disease progression. It is likely that identification of subgroups of COPD will lead to discovery of much needed disease-modifying therapeutic approaches. We argue that a precision approach that integrates multiple dimensions (clinical, physiologic, imaging, and endotyping) is needed to move the field forward in the treatment of this disease.

Epidemiology of asthma-chronic obstructive pulmonary disease overlap (ACO)

The term "asthma-COPD overlap" (ACO) has been applied to the condition in which a person has persistent airflow limitation with clinical features of both asthma and COPD. The certain definition and diagnostic criteria for ACO have not yet been established, and ACO prevalence has varied widely in studies: from 0.9% to 11.1% in the general population, from 11.1% to 61.0% in asthma patients, and from 4.2% to 66.0% in COPD patients. Furthermore, the frequency of exacerbations and prognosis in ACO patients have not been clearly demonstrated. Although ACO consists with several subgroups of patients with distinct clinical and pathophysiological features, it would be important to propose a standardized definition of and/or diagnostic criteria for ACO based on biomarkers and objective measures, even if it is tentative. It may lead cohort studies with large population or clinical trials around the world.

Prevalence and features of asthma-chronic obstructive pulmonary disease overlap in Northern Italy general population

OBJECTIVE

There is controversy about the diagnostic criteria, prevalence, symptoms, and spirometry characteristics of asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO). Recent data indicate that the fixed method for diagnosing airway obstruction (AO) may overestimate ACO prevalence in the elderly, and a variable method may be more accurate. We aimed at estimating ACO prevalence in a general population sample and comparing patient and clinical features in subjects with ACO, COPD, and asthma.

METHODS

We analyzed data from a cross-sectional study estimating COPD prevalence in randomly selected adults aged 20-79 years in Verona, Italy, and estimated prevalence and analyzed characteristics of asthma, COPD, and ACO. ACO was defined as AO (Forced Expiratory Volume in one second-FEV₁/ Forced Vital Capacity-FVC < Lower Limit of Normal-LLN), highly positive bronchodilator test (≥15% increase in FEV₁ and FVC ≥400 mL), and personal self-reported history of physician diagnosed asthma and atopy.

RESULTS

One thousand two hundred and thirty-six patients were included; 207 (16.7%) had asthma, COPD, or ACO (mean ages: 61.2, 59.7, and 57.2 years, respectively). The 3 groups had similar clinical and demographic variables; however, spirometry revealed differences between ACO and COPD patients, particularly post-bronchodilator FEV₁ reversibility, which was detected in ACO and asthma patients but not in those with COPD.

CONCLUSION

ACO prevalence in Northern Italy was estimated at 2.1%, in the range of values reported by previous studies. Marked differences between ACO and COPD revealed by spirometry may have important clinical implications in terms of treatment for patients with ACO.

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

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

A proposal for the withdrawal of inhaled corticosteroids in the clinical practice of chronic obstructive pulmonary disease

According to the current clinical practice guidelines for chronic obstructive pulmonary disease (COPD), the addition of inhaled corticosteroids (ICS) to long-acting β2 agonist therapy is recommended in patients with moderate-to-severe disease and an increased risk of exacerbations. However, ICS are largely overprescribed in clinical practice, and most patients are unlikely to benefit from long-term ICS therapy.Evidence from recent randomized-controlled trials supports the hypothesis that ICS can be safely and effectively discontinued in patients with stable COPD and in whom ICS therapy may not be indicated, without detrimental effects on lung function, health status, or risk of exacerbations. This article summarizes the evidence supporting the discontinuation of ICS therapy, and proposes an algorithm for the implementation of ICS withdrawal in patients with COPD in clinical practice.Given the increased risk of potentially serious adverse effects and complications with ICS therapy (including pneumonia), the use of ICS should be limited to the minority of patients in whom the treatment effects outweigh the risks.

Identification and distribution of COPD phenotypes in clinical practice according to Spanish COPD Guidelines: the FENEPOC study

Background

The Spanish Guidelines for COPD (GesEPOC) describe four clinical phenotypes: non-exacerbator (NE), asthma-COPD overlap syndrome (ACO), frequent exacerbator with emphysema (EE), and exacerbator with chronic bronchitis (ECB). The objective of this study was to determine the frequency of COPD phenotypes, their clinical characteristics, and the availability of diagnostic tools to classify COPD phenotypes in clinical practice.

Materials and methods

This study was an epidemiological, cross-sectional, and multi-centered study. Patients ≥40 years old with a post-bronchodilator forced expiratory volume in 1 s (FEV₁)/forced vital capacity ratio of <0.7 and who were smokers or former smokers (with at least 10 pack-years) were included. The availability of diagnostic tools to classify COPD phenotypes was assessed by an ad hoc questionnaire.

Results

A total of 647 patients (294 primary care [PC], 353 pulmonology centers) were included. Most patients were male (80.8%), with a mean age (SD) of 68.2 (9.2) years, mean post-bronchodilator FEV₁ was 53.2% (18.9%) and they suffered a mean of 2.2 (2.1) exacerbations in the last year. NE was the most frequent phenotype (47.5%) found, followed by ECB (29.1%), EE (17.0%), and ACO (6.5%). Significant differences between the four phenotypes were found regarding age; sex; body mass index; FEV₁; body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE)/body mass index, airflow obstruction, dyspnea and exacerbations (BODEx) index; modified Medical Research Council dyspnea scale; respiratory symptoms; comorbidi-ties; hospitalizations; and exacerbations in the last year. Physicians considered that >80% of the diagnostic tools needed to classify COPD phenotypes were available, with the exception of computed tomography (26.9%) and carbon monoxide transfer test (13.5%) in PC, and sputum eosinophilia count in PC and pulmonology centers (40.4% and 49.4%, respectively).

Conclusion

In Spanish clinical practice, almost half of the patients with COPD presented with NE phenotype. The prevalence of ACO according to the Spanish consensus definition was very low. In general, physicians indicated that they had the necessary tools for diagnosing COPD phenotypes.

Epidemiology and impact of chronic bronchitis in chronic obstructive pulmonary disease

Research on the association between chronic bronchitis and chronic obstructive pulmonary disease (COPD) exacerbations has led to discordant results. Furthermore, the impact of chronic bronchitis on mortality in COPD subjects is unclear.Within the Rotterdam Study, a population-based cohort study of subjects aged ≥45 years, chronic bronchitis was defined as having a productive cough for ≥3 months per year for two consecutive years. Linear, logistic regression and Cox proportional hazard models were adjusted for age, sex and pack-years.Out of 972 included COPD subjects, 752 had no chronic phlegm production (CB-) and 220 had chronic phlegm production, of whom 172 met the definition of chronic bronchitis (CB+). CB+ subjects were older, more frequently current smokers and had more pack-years than CB- subjects. During a median 6.5 years of follow-up, CB+ subjects had greater decline in lung function (-38 mL·year-1, 95% CI -61.7--14.6; p=0.024). CB+ subjects had an increased risk of frequent exacerbations (OR 4.0, 95% CI 2.7-5.9; p<0.001). In females, survival was significantly worse in CB+ subjects compared to CB- subjects. Regarding cause-specific mortality, CB+ subjects had an increased risk of respiratory mortality (hazard ratio 2.16, 95% CI 1.12-4.17; p=0.002).COPD subjects with chronic bronchitis have an increased risk of exacerbations and respiratory mortality compared to COPD subjects without chronic phlegm production.

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.

The Reemergence of the Asthma-COPD Overlap Syndrome: Characterizing a Syndrome in the Precision Medicine Era

PURPOSE OF REVIEW

The asthma-COPD overlap syndrome (ACOS) has reemerged in the medical literature. This review addresses our current understanding of ACOS as a clinical and biological entity and how new and existing therapies may be targeted to this group.

RECENT FINDINGS

Many studies suggest that ACOS is common and associated with more morbidity than asthma and COPD in general. However, there is no consensus on an ACOS definition, likely due to the heterogeneity of the disease. Variable definitions have led to variable results in ACOS studies. Given this clinical variability, biomarkers (e.g., eosinophils and type 2 inflammatory markers) are increasingly being used to identify an ACOS molecular phenotype which appears to be more responsive to inhaled corticosteroids. Although ACOS has become a popular diagnosis, it is unclear whether identifying ACOS as a separate disease entity is clinically useful. Future studies should focus on identifying key clinical features and biomarkers that characterize vulnerable and treatment-responsive patients.

Active smoking and COPD phenotype: distribution and impact on prognostic factors

PURPOSE

Smoking can affect both the phenotypic expression of COPD and factors such as disease severity, quality of life, and comorbidities. Our objective was to evaluate if the impact of active smoking on these factors varies according to the disease phenotype.

PATIENTS AND METHODS

This was a Spanish, observational, cross-sectional, multicenter study of patients with a diagnosis of COPD. Smoking rates were described among four different phenotypes (non-exacerbators, asthma-COPD overlap syndrome [ACOS], exacerbators with emphysema, and exacerbators with chronic bronchitis), and correlated with disease severity (body mass index, obstruction, dyspnea and exacerbations [BODEx] index and dyspnea grade), quality of life according to the COPD assessment test (CAT), and presence of comorbidities, according to phenotypic expression.

RESULTS

In total, 1,610 patients were recruited, of whom 46.70% were classified as non-exacerbators, 14.53% as ACOS, 16.37% as exacerbators with emphysema, and 22.40% as exacerbators with chronic bronchitis. Smokers were predominant in the latter 2 groups (58.91% and 57.67%, respectively, P=0.03). Active smoking was significantly associated with better quality of life and a higher dyspnea grade, although differences were observed depending on clinical phenotype.

CONCLUSION

Active smoking is more common among exacerbator phenotypes and appears to affect quality of life and dyspnea grade differently, depending on the clinical expression of the disease.

The variability of respiratory symptoms and associated factors in COPD

Few studies have investigated the variability of COPD-related symptoms or factors related to symptom variability. This observational, prospective, multicentre study was conducted to describe the number and intensity of morning and night-time respiratory symptoms and their variability over one week using the Night-time and Early Morning Symptoms of COPD Instruments (NiSCI and EMSCI) to evaluate stable COPD patients. Logistic regression analyses were performed to investigate factors associated with symptom variability. A total of 2669 patients were evaluated (mean age, 67.7 years; 80.9% men; mean FEV1 50.6%). Of these, 48% reported night-time symptoms and 71% reported morning symptoms. Of the 2293 patients who completed the NiSCI and EMSCI, 90% showed variability in either symptom number (89.6%) or symptom intensity (15.8%). More severe dyspnoea, more exacerbations during the previous year and the exacerbator or mixed COPD-asthma phenotypes were associated with variability in symptom number or intensity. Anxiety was significantly associated with variability in symptom number and intensity. Most COPD patients showed symptom variability over a weeklong period, especially in terms of symptom number. Several COPD-related factors, mainly factors related to more severe disease and more frequent exacerbations, were associated with increased symptom variability.

Consensus on the Asthma-COPD Overlap Syndrome (ACOS) Between the Spanish COPD Guidelines (GesEPOC) and the Spanish Guidelines on the Management of Asthma (GEMA)

Following a proposal by the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR), sponsor of the Spanish COPD Guidelines (GesEPOC) and the Spanish Guidelines on the Management of Asthma (GEMA), authors of both papers have unified the criteria for the diagnosis of asthma-COPD overlap syndrome (ACOS). This consensus defines ACOS as the presence in a given patient of three elements: significant smoking exposure, chronic airflow limitation and asthma. Diagnosis is confirmed when a patient (35years of age or older), smoker or ex-smoker of more than 10 pack-years, presents airflow limitation (post-bronchodilator FEV1/FVC<0.7) that persists after treatment with bronchodilators and inhaled corticosteroids (even after systemic corticosteroids in selected cases), and an objective current diagnosis of asthma (according to GEMA criteria). In cases in which the diagnosis of asthma cannot be demonstrated, marked positive results on a bronchodilator test (FEV₁≥15% and ≥400mL) or elevated blood eosinophil count (≥300eosinophils/μL) will also be diagnostic of ACOS. The opinion of another 33 experts who had not participated in the consensus was sought using a modified Delphi survey. Up to 80% of respondents gave a very positive opinion of the consensus, and declared that it was better than other previous proposals. The GesEPOC-GEMA consensus on ACOS provides a unique perspective of the diagnostic problem, using a simple proposal and a pragmatic diagnostic algorithm that can be applied at any healthcare level.

Defining asthma-COPD overlap syndrome: a population-based study

Asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) seems an important clinical phenotype, but multiple definitions have been proposed. This study's objectives were to assess the effect of different ACOS definitions on prevalence, patient characteristics and exacerbations.5675 individuals aged 45-65 years, with 846 asthma/COPD patients, were included in the Netherlands Epidemiology of Obesity study between 2008 and 2012, and followed-up for a median of 1.8 years. ACOS was defined by recent consensus criteria and five other definitions, based on registry, questionnaires and lung function.Prevalence of ACOS in the asthma/COPD population ranged between 4.4% and 38.3%, depending on the definition used. Agreement between registry-based and self-reported ACOS was 0.04 and 0.41 when lung function (forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) <0.7) was added. With registry or self-report defined ACOS, only 51% and 33% had FEV₁/FVC <0.7. Patient characteristics were similar, but asthma duration was longer with self-reported compared with registry-based ACOS (mean difference 22 years (95% CI 12-33)). Exacerbation risk was highest with registry-based ACOS compared with asthma (adjusted incidence rate ratio 1.6 (95% CI 1.2-2.1)).This study adds important knowledge about agreement between ACOS definitions and their relation with exacerbations. Given the low agreement, differences in prevalence, patient characteristics and risk of exacerbations, consensus about ACOS definition in different care settings is urgently needed.

Asthma-COPD overlap syndrome (ACOS) in primary care of four Latin America countries: the PUMA study

BACKGROUND

Asthma-COPD overlap syndrome (ACOS) prevalence varies depending on the studied population and definition criteria. The prevalence and clinical characteristics of ACOS in an at-risk COPD primary care population from Latin America was assessed.

METHODS

Patients ≥40 years, current/ex-smokers and/or exposed to biomass, attending routine primary care visits completed a questionnaire and performed spirometry. COPD was defined as post-bronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) < 0.70; asthma was defined as either prior asthma diagnosis or wheezing in the last 12 months plus reversibility (increase in post-bronchodilator FEV₁ or FVC ≥200 mL and ≥12%); ACOS was defined using a combination of COPD with the two asthma definitions. Exacerbations in the past year among the subgroups were evaluated.

RESULTS

One thousand seven hundred forty three individuals completed the questionnaire, 1540 performed acceptable spirometry, 309 had COPD, 231 had prior asthma diagnosis, and 78 asthma by wheezing + reversibility. ACOS prevalence in the total population (by post-bronchodilator FEV₁/FVC < 0.70 plus asthma diagnosis) was 5.3 and 2.3% by post-bronchodilator FEV₁/FVC < 0.70 plus wheezing + reversibility. In the obstructive population (asthma or COPD), prevalence rises to 17.9 and 9.9% by each definition, and to 26.5 and 11.3% in the COPD population. ACOS patients defined by post-bronchodilator FEV₁/FVC < 0.7 plus wheezing + reversibility had the lowest lung function measurements. Exacerbations for ACOS showed a prevalence ratio of 2.68 and 2.20 (crude and adjusted, p < 0.05, respectively) (reference COPD).

CONCLUSIONS

ACOS prevalence in primary care varied according to definition used. ACOS by post-bronchodilator FEV₁/FVC < 0.7 plus wheezing + reversibility represents a clinical phenotype with more frequent exacerbations, which is probably associated with a different management approach.

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.