Traditional biomarkers and clinical hallmarks in the frame of epithelial driven airways inflammation

IntroductionThe airway epithelium is composed of different cell types and acts as a physical barrier preventing pathogens, allergens, and microbes from entering the lungs. The recent investigations on epithelial barrier dysfunction-related mechanisms have provided a new perspective to look at asthma pathobiology.Areas coveredIn this review, we aim to describe the evidence related to epithelial barrier dysfunction and the 'traditional' asthma biomarkers: eosinophils, FeNO, IgE, cytokines, and epithelial barrier dysfunction in order to explore potential connections, inflammatory pathways, potential new therapeutic targets and to identify novel clinical profiles of asthma patients expressing an epithelial-driven disease.Expert opinionAlthough the existence of an 'epithelial-driven' profile in asthma is supported by pathobiological evidence, its identification on a clinical ground is still challenging and lacks specific biomarkers. However, by integrating the traditional hallmarks of type 2 inflammation with the clinical evidence of an impaired environment-host interaction, the relevance of epithelial barrier dysfunction as a predominant driver of airway immunity reshaping can be suspected. It has an important impact on treatment selection and overall management in the light of a precision medicine approach.