Objective: Viral infections and sensitization to aeroallergens are major factors in the exacerbation of asthma and its development during early childhood. However, the cytokine profiles and eosinophil activation status linked to the association between viral infections and sensitization to aeroallergens are incompletely understood. Here we investigated respiratory viruses, serum eosinophil cationic protein (ECP), and various cytokines/chemokines in acute exacerbation of childhood asthma.
Methods: We analyzed peripheral eosinophil counts, serum ECP, and 27 cytokines/chemokines in 76 virus-induced acute asthma cases with or without aeroallergen sensitization. Asthma due to sensitization was defined by a positive reaction to at least one aeroallergen in serum specific IgE antibody tests. Virus detection was performed using antigen detection kits and/or RT-PCR, followed by direct DNA sequencing analysis. Serum cytokines/chemokines were measured using a multi-cytokine detection system.
Results: Peripheral eosinophil counts and serum ECP and IL-5 levels were significantly elevated in sensitized cases compared with nonsensitized cases. Conversely, IP-10 values were significantly higher in nonsensitized cases. An inverse correlation between IP-10 and IL-5 production was identified in virus-induced acute exacerbations of asthma but not in controls.
Conclusions: Cytokine profiles and eosinophil activation status might be different between sensitized and nonsensitized cases of virus-induced acute exacerbations of asthma.