Gene Expression Profile and Inflammation Profile of Classic Asthma, Cough Variant Asthma and Eosinophilic Bronchitis

Asthma is a common and heterogeneous respiratory disorder affecting millions of people, posing a considerable burden on health care systems globally. The disease is characterized by inflammation of the airways with eosinophils, neutrophils, mast cells, lymphocytes, airway epithelial cells, smooth muscle cells and other cells, by airflow obstruction and by bronchial hyperresponsiveness. The disease is triggered by multiple gene-environment interactions. Asthma heterogeneity is recognized in terms of clinical phenotypes of asthma whereby classic asthma (CA) and cough variant asthma (CVA) are identified. classic asthma is a common phenotype of asthma that presents episodic dyspnoea and wheezing with or without cough. Cough variant asthma is a phenotype of asthma that presents solely cause of chronic cough. Eosinophilic bronchitis (EB) is a common cause of chronic cough, which like eosinophils asthma is characterized by airway eosinophilic inflammation, but unlike asthma there is no airway hyperresponsiveness or variable airflow obstruction. Improvement of disease diagnosis and management require a better understanding of disease heterogeneity. A useful biomarker for phenotype recognition will represent underlying pathologic mechanisms of disease, marking heterogeneity and guiding personalized treatment approaches. Our hypothesis was that the different clinical manifestos in patients with eosinophilic bronchitis, classic asthma, and cough-variant asthma could be caused by differential gene expression profiles of peripheral blood mononuclear cells (PBMC) and differential inflammation profiles and other aspects.