Interleukin-17 Gene Expression and Serum Levels in Children with Severe Asthma

Background: IL-17 is a major cytokine player in T cell mediated leukocyte associated inflammation. IL-17 is also recognized to participate in the pathophysiology of asthma. Objective: To determine the role of IL-17 in predicting severe asthma. Methods: We obtained serum samples from asthmatic children under the age of 5-year in three different groups of mild (n=33), moderate (n=28) and severe (n=32) persistent asthma. IL-17 serum concentrations and mRNA expression were determined by ELISA and real time PCR assays, respectively. Results: Serum IL-17 concentrations were significantly higher in patients with severe asthma than the other two groups of children with mild and moderate disease (p=0.00). Mean serum IL-17 values were 142.04 pg/ml in mild group, 180.4 pg/ml in moderate group and 251.25 pg/ml in severe group. IL-17 mRNA levels were also significantly elevated in severe asthmatic patients compared to mild and moderate asthmatic children (p=0.00). Conclusion: Our data reveal an increase in the serum IL-17 concentrations and IL-17 mRNA expressions in children with severe asthma compared to those with mild and moderate forms of the disease.