Role of amphiregulin in acute childhood asthma exacerbations and after remission of acute attacks

Background: Bronchial asthma is one of the commonest diseases in children and its prevalence is increasing in developing world. The prevalence of asthma and wheezing conditions among children has been rising globally. Amphiregulin (one of the cytokines that may influence the development and expression of asthma) is believed to play an essential role in airway inflammation and remodeling processes that occur in asthmatic patients.Objectives: The aim of this study was to assess amphiregulin level in acute and chronic childhood bronchial asthma and to clarify relationship between broncho-alveolar concentration and severity of bronchial asthma.Patients and methods: This is a cross-sectional case-control association study on 80 asthmatic infants and young children aged 8 months to 8 years (3.3 ± 0.98 years) and 20 bronchiolitis cases and 20 age- and sex/matched normal children as controls. All candidates were subjected to clinical evaluation and laboratory investigations through measurement of their peripheral eosinophil count, total serum IgE, sputum amphiregulin level by Enzyme-Linked Immunosorbent Assay (ELISA) and measurement of PEFR. The asthmatic children were divided according to 2008 GINA Guidelines into 4 subgroups: mild intermittent, mild persistent, moderate persistent and severe persistent.Results: In the present study, there was a statistically significant difference considering absolute eosinophilic count (p < 0.001), total serum IgE (p < 0.001) and sputum level of amphiregulin (p < 0.001) between cases and controls and bronchiolitis cases. PEFR is lowered in relation to asthma severity. Amphiregulin was increased in acute and chronic cases with statistically difference as amphiregulin is increased in acute cases (400 ± 200) in comparison to chronic cases (280 ± 160) with F value of 31.8 and p value of 0.001. This indicated that amphiregulin decreased after control of acute attack, but still little high in chronic cases to induced remodeling of chronicity of bronchial asthma. In comparison to IgE in all groups, IgE is increased in acute cases and chronic cases, but with highly significant increase in acute cases (mean ± SD = 118.8 ± 60) in comparison to chronic cases (mean ± SD = 100.7 ± 40) with F value of 31.6 and p value of 0.001. This indicated that IgE so increased in acute cases with statistical difference in comparison to chronic cases, but still high in chronic cases. In comparison to amphiregulin, there is statistically significant different increase in level between acute (400 ± 200) and chronic (280 ± 16) cases.Conclusion: Amphiregulin is a pleotropic cytokine that has pro-inflammatory effects in some settings and anti-inflammatory effects in others. It is believed to play an essential role in airway inflammation and remodeling processes that occur in asthmatic patients. Functional polymorphisms in the amphiregulin gene that affect its expression may modulate asthma occurrence. In the present study, we have demonstrated that there was a statistically significant difference considering sputum level of amphiregulin, total serum IgE and absolute eosinophilic count between cases and controls. This study concluded that amphiregulin may play a role in regulation of disease activity and the level of amphiregulin-induced sputum may be a marker of asthma.