Expression of interleukin-35 and type 2 cytokines in children with acute allergic asthma

Allergic asthma is believed to be a T helper 2 cell (Th2) preponderant response caused by airway hyper-responsiveness. Interleukin-35 (IL-35) is a newly discovered anti-inflammatory cytokine.

To determine if the expression of IL-35 is associated with type-2 inflammation in children with asthma exacerbations.

Thirty children (6-12 years old) with acute allergic asthma and twenty healthy controls were enrolled. Sputum was induced from lower airways. IL-35 and type 2 cytokines expression from serum and induced sputum were measured at mRNA and protein level by real-time PCR and enzyme-linked immunosorbent assay (ELISA). The sampling and the test were repeated eight weeks after the asthma exacerbation.

At the time of exacerbation, IL-35 expression in induced sputum and serum decreased significantly than in the controls. The expression of IL-35 was negatively correlated with IL-4, IL-5 and IL-13 expression. The IL-35 from induced sputum increased significantly, whereas type-2 cytokines decreased significantly eight weeks after the exacerbation.

Our results showed that decreased IL-35 was associated with type-2 cytokines in asthma exacerbations in children, suggesting that IL-35 may be a potential future drug target for asthma exacerbations.