IL-8 gene expression and bronchial asthma phenotypes in children

Asthma is a common chronic illness among school children, where different cytokines, including IL-8 play a role in its pathogenesis. IL-8 induces chemotaxis and migration of immune cells, especially neutrophils to the site of inflammation. IL-8 level was significantly increased in sputum of severely asthmatic patients, but can it be linked to some asthma phenotypes. Our aim of the study was to detect the IL 8 gene expression in different asthma phenotypes and to determine its relation to asthma severity. This case control study included 320 subjects (160 asthmatic and 160 matched controls) aged from 5 to 16 years old in Beni-Suef governorate. IL-8 gene expression was assessed by a real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and studied regarding its level in cases versus controls and its relations to severity, phenotype and other laboratory parameters. IL-8 gene expression was statistically higher in asthmatic cases (P<0.001) and was significantly correlated to the phenotype (presence of other allergy as urticaria and drug eruption) and degree of asthma symptoms (r=0.869, P<0.001), FEV1(r=0.757, P<0.001) and serum IgE level (r=0.789, P<0.001). IL-8 gene expression level is increased with the degree of severity in asthmatic children and can be looked for in certain asthma phenotypes especially in presence of other atopic manifestation.