The eosinophil and airway remodelling in asthma

Eosinophils are common findings cells in allergic asthma as is sub-base membrane thickening of the airways. The objective of this review was to summarise some recent findings linking the activities of eosinophils to airways remodelling.

The study used a review of current literature with emphasis on our own recent findings.

Eosinophils are found at increased numbers in asthma and more so in allergic as compared with non-allergic asthma. A link has been found in several clinical studies on allergic asthmatics, but not in studies on non-allergic asthma, between the presence of eosinophils and signs of airways remodelling. The eosinophil contains and secretes several pro-fibrogenic molecules such as eosinophil cationic protein (ECP) and transforming growth factor beta (TGF-beta). Genetic studies on subjects developing liver fibrosis as a consequence of Schistosoma mansoni infection show close relationships to ECP genotypes.

Several clinical and experimental studies indicate that eosinophils contribute to airways remodelling not only through their secretion of cationic proteins such as ECP and cytokines such as TGF-beta1, but also through interactions with mast cells and epithelial cells.