The relationship between inflammatory markers and spirometric parameters in ACOS, Asthma, and COPD

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.

Asthma-COPD overlap: The NP's role in diagnosis and management

ABSTRACT

Asthma-COPD overlap (ACO) presents in persons, especially adults, with persistent airflow limitation along with clinical symptoms reflective of both asthma and chronic obstructive pulmonary disease (COPD). It includes multiple clinical phenotypes with different underlying pathophysiology. Patients with ACO typically have a worse clinical course than those with asthma or COPD alone. This article provides an overview of diagnosis and management of this underrecognized condition.

Concepts of advanced therapeutic delivery systems for the management of remodeling and inflammation in airway diseases

Chronic respiratory disorders affect millions of people worldwide. Pathophysiological changes to the normal airway wall structure, including changes in the composition and organization of its cellular and molecular constituents, are referred to as airway remodeling. The inadequacy of effective treatment strategies and scarcity of novel therapies available for the treatment and management of chronic respiratory diseases have given rise to a serious impediment in the clinical management of such diseases. The progress made in advanced drug delivery, has offered additional advantages to fight against the emerging complications of airway remodeling. This review aims to address the gaps in current knowledge about airway remodeling, the relationships between remodeling, inflammation, clinical phenotypes and the significance of using novel drug delivery methods.

Modern understanding of bronchial asthma with fixed airflow obstruction

The review provides data on one of the phenotypes of severe bronchial asthma it is asthma with fixed airway obstruction. According to data published today, there is no single pathway for the formation of fixed airway obstruction in patients with severe asthma. Increasing knowledge of the pathophysiology of fixed airway obstruction, as well as identifying the most significant risk factors, is essential for the successful treatment of such patients. In addition, the development of fixed obstruction is associated with a worse and sometimes fatal prognosis. Expanding the existing views is also necessary to overcome the difficulties of differential diagnosis between bronchial asthma with fixed airway obstruction and bronchial asthma in combination with COPD. All this will optimize the approach to the management of patients with bronchial asthma to prevent the formation of fixed airway obstruction.

The pharmacological management of asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS)

Introduction: Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is a disease phenotype that shares T helper lymphocyte cell Th1/neutrophilic/non-Type-2 Inflammation pathways thought to be key in COPD and Th2/eosinophilic/Type-2 inflammatory pathways of asthma. The pharmacology of treating ACOS is challenging in severe circumstances.Areas covered: This review evaluates the stepwise treatment of ACOS using pharmacological treatments used in both COPD and asthma. The most common medications involve the same inhalers used to treat COPD and asthma patients. Advanced stepwise therapies for ACOS patients are based on patient characteristics and biomarkers. Very few clinical trials exist that focus specifically on ACOS patients.Expert opinion: After inhalers, advanced therapies including phosphodiesterase inhibitors, macrolides, N-acetylcysteine and statin therapy for those ACOS patients with a COPD appearance and exacerbations are available. In atopic ACOS patients with exacerbations, advanced asthma therapies (leukotriene receptor antagonists and synthesis blocking agents.) are used. ACOS patients with elevated blood eosinophil/IgE levels are considered for immunotherapy or therapeutic monoclonal antibodies blocking specific Th2/Type-2 interleukins or IgE. Symptom control, stabilization/improvement in pulmonary function and reduced exacerbations are the metrics of success. More pharmacological trials of ACOS patients are needed to better understand which patients benefit from specific treatments.Abbreviations: 5-LOi: 5-lipoxygenase inhibitor; ACOS: asthma - COPD overlap syndrome; B₂AR: Beta₂ adrenergic receptors; cAMP: cyclic adenosine monophosphate; cGMP: cyclic guanosine monophosphate; CI: confidence interval; COPD: chronic obstructive pulmonary disease; CRS : chronic rhinosinusitis; cys-LT: cysteinyl leukotrienes; DPI: dry powder inhaler; EMA: European Medicines Agency; FDA: US Food and Drug Administration; FDC: fixed-dose combination; FeNO: exhaled nitric oxide; FEV₁: forced expiratory volume in one second; FVC: forced vital capacity; GM-CSF: granulocyte-macrophage colony-stimulating factor; ICS : inhaled corticosteroids; IL: interleukin; ILC2: Type 2 innate lymphoid cells; IP₃: Inositol triphosphate; IRR: incidence rate ratio; KOLD: Korean Obstructive Lung Disease; LABA: long-acting B₂ adrenergic receptor agonist; LAMA: long-acting muscarinic receptor antagonist; LRA: leukotriene receptor antagonist; LT: leukotrienes; MDI: metered-dose inhalers; M_N: M-subtype muscarinic receptors; MRA: muscarinic receptor antagonist; NAC: N-acetylcysteine; NEB: nebulization; OR: odds ratio; PDE: phosphodiesterase; PEFR: peak expiratory flow rate; PGD2: prostaglandin D2; PRN: as needed; RR: risk ratio; SABA: short-acting B₂ adrenergic receptor agonist; SAMA: short-acting muscarinic receptor antagonist; SDMI: spring-driven mist inhaler; Th1: T helper cell 1 lymphocyte; Th2: T helper cell 2 lymphocytes; TNF-α: tumor necrosis factor alpha; US : United States.

Immunological biomarkers in severe asthma

Severe asthma is heterogeneous in its clinical presentation, underlying pathophysiology, course and response to therapy. Clinical and physiological assessment of severe asthma is often inadequate in predicting underlying disease mechanisms and or response to medications. With the emergence of novel targeted therapies in severe asthma, the need for reproducible, easily measured biomarkers became obvious but only few are currently available for clinical use. These biomarkers along with the clinical presentation of the patient play an important role in identifying phenotypes and endotypes, predicting the clinical course and prognosis and improving the precision therapeutic approach to asthma.