Asthma Therapy and Its Effect on Airway Remodelling

Abstract

Asthma remains a major health problem with significant morbidity, mortality and economic costs. In asthma, airway remodelling, which refers to all the microscopic structural changes seen in the airway tissue, has been recognised for many decades and remains one of the defining characteristics of the disease; however, it is still poorly understood. The detrimental pathophysiological consequences of some features of remodelling, like increased airway smooth muscle mass and subepithelial fibrosis, are well documented. However, whether targeting these by therapy would be beneficial is unknown. Although the prevailing thinking is that remodelling is an abnormal response to persistent airway inflammation, recent evidence, especially from studies of remodelling in asthmatic children, suggests that the two processes occur in parallel. The effects of asthma therapy on airway remodelling have not been studied extensively due to the challenges of obtaining airway tissue in the context of clinical trials. Corticosteroids remain the cornerstone of asthma therapy, and their effects on remodelling have been better studied than other drugs. Bronchial thermoplasty is the only asthma therapy to primarily target remodelling, although how it results in the apparent clinical benefits seen is not exactly clear. In this article we discuss the mechanisms of airway remodelling in asthma and review the effects of conventional and novel asthma therapies on the process.

Associations in asthma between quantitative computed tomography and bronchial biopsy-derived airway remodelling

“…As reported here airway smooth muscle mass is typically (4, 5), but not always (22), a major determinant of lung function impairment. Increased airway smooth muscle mass is a feature of severe childhood asthma (7) and is described in both the large and small airways in studies of asthma deaths (8, 9).…”

“…In addition to symptoms, asthma is characterized by variable airflow obstruction, airway inflammation and remodelling (2, 3). Airway remodelling is a collective term for the structural changes in the airway wall including epithelial thickness and integrity, airway smooth muscle mass, neoangiogenesis and subepithelial fibrosis (2–4) and is related to persistent airflow limitation and airflow obstruction (4–6). It is a feature even in childhood disease (7) demonstrating that it can occur early in disease and post-mortem studies of asthma deaths demonstrate airway remodelling in the large and small airways (8, 9).…”

Racial and ethnic disparities in meeting MTM eligibility criteria among patients with asthma

“…1 In 2010, a total of 25.7 million people had asthma, and the prevalence of asthma increased from 7.3% in 2001 to 8.4% in 2010. 2 Asthma has a substantial impact on patients’ quality of life and health care utilization and costs.…”

Chinese consensus statement on standard procedure and perioperative management of bronchial thermoplasty

“…BT, as a supplement to the medical treatment of asthma, is a new choice for the individualized treatment for severe asthma (8,(10)(11)(12)(13)(14)(15)(16)(17). BT can reduce the mass and function of airway smooth muscles to improve asthma control, reduce drug use, improve patients' quality of life, and reduce economic burdens.…”