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

Abstract

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 Ae. vexans bites. Twenty-two of the 29 also reacted to Ae. aegypti bites. Mean serum mosquito–IgE levels to each of the three species were significantly higher in the reactive subjects than in the nonreactive subjects. Significant intercorrelations were 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. (J Allergy Clin Immunol 1997;100:192-8.)