Survey of IgE Reactivity to Nonbiting Midges in Korea and Identification of IgE-Binding Protein

Chironomids (nonbiting midges) are widely and abundantly distributed near ponds, rivers, and artificially dammed pools used for irrigation. Chironomids contain allergens and cause airway allergy in humans. In this study, we aimed to examine the allergic potential of chironomids in inhabitants living near artificially dammed pools. We examined immunoglobulin E (IgE) reactivity to chironomid extracts in the sera of residents living around installed dams and assessed the correlations of IgE responses between chironomids ( , , ) and house dust mites ( ). In addition, we identified potential IgE binding proteins specific for adult C. bicinctus, a popular species in Korea. Specific IgE antibodies in sera collected from the participants against the extracts were tested using enzyme-linked immunosorbent assay (ELISA). The average IgE-positive rates were 10.4%, 8.1%, and 8.2% in , , and , respectively. The IgE-positive rate and IgE titer of antigen were higher in residents living around installed dams than in those who lived other places ( = 0.013). Western blotting using sera having high IgE titers to in ELISA showed the presence of a protein of approximately 42 kDa that was homologous to the actin protein isoform in extracts as demonstrated using mass spectrometry. Our results showed that people living near installed dams were more sensitized to and that the 42 kDa IgE-binding protein could be useful for further studies on chironomid allergic disease and clinical applications.