Upper and lower airway remodelling mechanisms in asthma, allergic rhinitis and chronic rhinosinusitis: The one airway concept revisited

Abstract

Allergic rhinitis (AR), chronic rhinosinusitis (CRS) and asthma often co-exist. The one airway model proposes that disease mechanisms occurring in the upper airway may mirror lower airway events. Airway remodelling is the term used to describe tissue structural changes that occur in a disease setting and reflect the dynamic process of tissue restructuring during wound repair. Remodelling has been long identified in the lower airways in asthma and is characterized by epithelial shedding, goblet cell hyperplasia, basement membrane thickening, subepithelial fibrosis, airway smooth muscle hyperplasia and increased angiogenesis. The concept of upper airway remodelling has only recently been introduced, and data so far are limited and often conflicting, an indication that more detailed studies are needed. Whilst remodelling changes in AR are limited, CRS phenotypes demonstrate epithelial hyperplasia, increased matrix deposition and degradation along with accumulation of plasma proteins. Despite extensive research over the past years, the precise cellular and molecular mechanisms involved in airway remodelling remain incompletely defined. This review describes our current rather limited understanding of airway remodelling processes in AR, CRS and asthma and presents mechanisms both shared and distinct between the upper and lower airways. Delineation of shared and disease-specific pathogenic mechanisms of remodelling between the sinonasal system and the lung may guide the rational design of more effective therapeutic strategies targeting upper and lower airways concomitantly and improving the health of individuals with inflammatory airway diseases.

Distinct Type 2-high Inflammation Associated Molecular Signatures of Chronic Rhinosinusitis with Nasal Polyps with Comorbid Asthma

“…The united airway concept suggests that the upper and lower airway in ammation share common pathogenic mechanisms and in uence each other [9,10]. There is evidence that several features of in ammatory pattern, disrupted epithelial barrier and airway remodelling are similar in CRSwNP and asthma [11][12][13]. Thus, understanding the molecular relationship between CRSwNP and comorbid asthma may help to reveal the mechanisms that underlie airway chronic in ammation.…”

Effect of Cellulose Powder on Human Nasal Epithelial Cell Activity and Ciliary Beat Frequency

“…Therefore, medications that directly act on the nasal mucosa might affect epithelial barrier function and alter the mucociliary clearance. This is particularly important in the milieu of the significant remodeling of nasal mucosa in patients with AR [18, 19], which indicates an impaired epithelial proliferation capacity and mucociliary clearance. A previous study showed that cellular activities such as DNA replication may depend on oxygen concentration, so hypoxia might result in a decrease in the rate of cell proliferation [20].…”

Recent developments and highlights in allergic rhinitis

“…The etiology of allergic disease is poorly understood, and its potential biologic mechanisms are still unclear . As other allergic inflammatory diseases, AR is considered to have complex associations with genetic and environment factors in etiology.…”