Cross-reactivity of skin and serum specific IgE responses and allergen analysis for three mosquito species with worldwide distribution

Background: Allergic reactions to mosquito bites are a common problem worldwide. Cross-reactive immunologic responses have not been reported. Objective: For the three most common mosquito species, Aedes (Ae.) vexans, Ae. aegypti, and Culex (Cx.) quinquefaciatus, we investigated skin and serum specific IgE responses and analyzed salivary allergens. Methods: Locally, Ae. vexans is a major pest, but Ae. aegypti and Cx. quinquefaciatus are not found, We studied 41 subjects living in Manitoba, using (1) skin bite tests, (2) ELISA to measure serum mosquito saliva-or salivary gland-specific IgE, (3) ELISA inhibition tests, and (4) sodium dodecylsulfate-polyacrylamide gel electrophoresis and immunoblotting. Results: Twenty-nine of the 41 subjects had skin reactions to lie. vexans bites, Twenty-two of the 29 also reacted to Ae. aegvpti bites, Mean serum mosquito-IgE levels to each of the three species mere significantly higher in the reactive subjects than in the nonreactive subjects. Significant intercorrelations mere found among skin reactions and mosquito-specific IgE levels for the three species. The Ae. aegypti-IgE ELISA reaction could be inhibited by addition of each mosquito extract, The serum IgE and IgG from Manitobans reacted with the antigens of all three species. A 37 kd allergen in each of the three species was recognized by the antibody against a recombinant Ae. aegypti saliva protein. Conclusions: Strong cross-reactive skin and IgE responses and species-shared antigens exist among the three mosquito species studied.