Comparative safety and effectiveness of inhaled bronchodilators and corticosteroids for treating asthma-COPD overlap: a systematic review and meta-analysis

Pharmacologic Management Strategies of Asthma-Chronic Obstructive Pulmonary Disease Overlap

The best therapeutic approach to patients with asthma-chronic obstructive pulmonary disease overlap (ACO) is unknown. Current treatment recommendations rely on expert opinions, roundtable discussions, and strategy documents, because patients with ACO have been excluded from most clinical studies in asthma and COPD. Because of the underlying asthma initial therapy, early use of inhaled corticosteroids along with a long-acting bronchodilator is recommended. If maintenance inhaler therapy is not effective, advanced therapies based on phenotyping and identification of treatable traits may be considered.

Unraveling the Pathogenesis of Asthma and Chronic Obstructive Pulmonary Disease Overlap: Focusing on Epigenetic Mechanisms

Asthma and COPD overlap (ACO) is characterized by patients presenting with persistent airflow limitation and features of both asthma and COPD. It is associated with a higher frequency and severity of exacerbations, a faster lung function decline, and a higher healthcare cost. Systemic inflammation in COPD and asthma is driven by type 1 T helper (Th1) and Th2 immune responses, respectively, both of which may contribute to airway remodeling in ACO. ACO-related biomarkers can be classified into four categories: neutrophil-mediated inflammation, Th2 cell responses, arachidonic acid-eicosanoids pathway, and metabolites. Gene–environment interactions are key contributors to the complexity of ACO and are regulated by epigenetic mechanisms, including DNA methylation, histone modifications, and non-coding RNAs. Thus, this review focuses on the link between epigenetics and ACO, and outlines the following: (I) inheriting epigenotypes without change with environmental stimuli, or epigenetic changes in response to long-term exposure to inhaled particles plus intermittent exposure to specific allergens; (II) epigenetic markers distinguishing ACO from COPD and asthma; (III) potential epigenetic drugs that can reverse oxidative stress, glucocorticoid insensitivity, and cell injury. Improved understanding of the epigenetic regulations holds great value to give deeper insight into the mechanisms, and clarify their implications for biomedical research in ACO.

Polystichum braunii ameliorates airway inflammation by attenuation of inflammatory and oxidative stress biomarkers, and pulmonary edema by elevation of aquaporins in ovalbumin-induced allergic asthmatic mice

Asthma is a chronic inflammation of pulmonary airways associated with bronchial hyper-responsiveness. The study was aimed to validate the folkloric use of Polystichum braunii (PB) against ovalbumin (OVA)-induced asthmatic and chemical characterization OF both extracts. Allergic asthma was developed by intraperitoneal sensitization with an OVA on days 1 and 14 followed by intranasal challenge. Mice were treated with PB methanolic (PBME) and aqueous extract (PBAE) orally at 600, 300, and 150 mg/kg and using dexamethasone (2 mg/kg) as standard from day 15 to 26. High performance liquid chromatography-diode array detector analysis revealed the presence of various bioactive compounds such as catechin, vanillic acid, and quercetin. The PBME and PBAE profoundly (p < 0.0001-0.05) declined immunoglobulin E level, lungs wet/dry weight ratio, and total and differential leukocyte count in blood and bronchial alveolar lavage fluid of treated mice in contrast to disease control. Histopathological examination showed profoundly decreased inflammatory cell infiltration and goblet cell hyperplasia in treated groups. Both extracts caused significant (p < 0.0001-0.05) diminution of IL-4, IL-5, IL-13, IL-6, IL-1β, TNF-α, and NF-κB and upregulation of aquaporins (1 and 5), which have led to the amelioration of pulmonary inflammation and attenuation of lung edema in treated mice. Both extracts profoundly (p < 0.0001-0.05) restored the activities of SOD, CAT, GSH and reduced the level of MDA dose dependently. Both extracts possessed significant anti-asthmatic action mainly PBME 600 mg/kg might be due to phenols and flavonoids and could be used as a potential therapeutic option in the management of allergic asthma.

Asthma-COPD Overlap: What Are the Important Questions?

Asthma-COPD overlap (ACO) is a heterogeneous condition that describes patients who show persistent airflow limitation with clinical features that support both asthma and COPD. Although no single consensus definition exists to diagnose this entity, common major criteria include a strong bronchodilator reversibility or bronchial hyperreactivity, a physician diagnosis of asthma, and a ≥ 10-pack-year cigarette smoking history. The prevalence of ACO ranges from 0.9% to 11.1% in the general population, depending on the diagnostic definition used. Notably, patients with ACO experience greater symptom burden, worse quality of life, and more frequent and severe respiratory exacerbations than those with asthma or COPD. The underlying pathophysiologic features of ACO have been debated. Although emerging evidence supports the role of environmental and inhalational exposures in its pathogenesis among patients with a pre-existing airway disease, biomarker profiling and genetic analyses suggest that ACO may be a heterogeneous condition, but with definable characteristics. Early-life factors including childhood-onset asthma and cigarette smoking may interact to increase the risk of airflow obstruction later in life. For treatment options, the population with ACO historically has been excluded from therapeutic trials; therefore strong, evidence-based recommendations are lacking beyond first-line inhaler therapies. Advanced therapies in patients with ACO are selected according to disease phenotypes and are based on extrapolated data from asthma and COPD. Research focused on defining biomarkers and evidence-based treatment options for ACO is needed urgently.

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.

Gender Differences in Inhaled Pharmacotherapy Utilization in Patients with Obstructive Airway Diseases (OADs): A Population-Based Study

Purpose

Gender differences in the incidence, susceptibility and severity of many obstructive airway diseases (OADs) have been well recognized. However, gender differences in the inhaled pharmacotherapy profile are not well characterized.

Methods

We conducted a retrospective cohort study to investigate gender differences in new-users of inhaled corticosteroids (ICS), short-or long-acting beta₂-agonist (SABA or LABA), ICS/LABA, short-or long-acting muscarinic antagonist (SAMA or LAMA) among patients with asthma, COPD or asthma-COPD overlap (ACO). We used Clinical Practice Research Datalink to identify OAD patients, 18 years and older, who were new-users (1-year washout period) from 01-January-1998 to 31-July-2018. Multivariable logistic regression was used to examine gender differences in each of the inhaled pharmacotherapies after controlling for potential confounders.

Results

A total of 242,079 new-users (asthma: 84.93%; COPD: 10.19%; ACO: 4.88%) of inhaled pharmacotherapies were identified. The multivariable analyses showed that males with COPD were more likely to be a new user of a LABA (odds ratio [OR] 1.29; 95% confidence interval [CI], 1.12–1.49), LAMA (OR 1.21; 95% CI 1.10–1.33), SAMA (OR 1.11; 95% CI 1.01–1.21) and less likely to be a new user of a SABA (OR 0.84; 95% CI, 0.80–0.89) compared to females. Similar patterns were also observed for patients with ACO; males were more likely to be prescribed with LABA (OR 1.26; 95% CI 1.03–1.55), LAMA (OR 1.28; 95% CI 1.11–1.48), SAMA (OR 1.28; 95% CI 1.11–1.48), and less likely to be a new user of a SABA (OR 0.89; 95% CI, 0.82–0.96). Also, males with asthma were more likely to be a new-user of ICS/LABA (OR 1.15; 95% CI, 1.08–1.23) and less likely to start an ICS (OR 0.97; 95% CI, 0.95–0.99) in comparison with females.

Conclusion

Our study showed significant gender differences in new-users of inhaled pharmacotherapies among OAD patients. Adjusting for proxies of disease severity, calendar year, smoking and socioeconomic status did not change the association by gender.