Detection of IgE antibodies to a wide range of insect species in subjects with suspected inhalant allergies to insects.

Sera obtained from subjects diagnosed on the basis of case history and skin tests as having inhalant allergies to insects, were tested for the presence of IgE antibodies to antigens from the house fly Musca domestica, a blowfly Calliphora stygia, the common clothes moth Tineola bisselliella, warehouse moth Ephestia cautella, cockroach Blattella germanica, carpet beetle Anthrenus verbasci and silverfish Ctenolepisma longicaudata. Approximately one-third of the sera reacted with extracts from all seven species, over half the sera reacted with four of the extracts and only 3 sera proved negative to all of the extracts. Twenty-six of the sera also contained IgE antibodies that reacted with the house dust mite Dermatophagoides farinae. Tests with a further eleven species of flies from the order Diptera and with extracts of the grain borer Rhyzopertha dominica, locust Chortoicetes terminifera and Bogong moth Agrotis infusa revealed strong IgE antibody responses to all of the species. Electroblotting studies revealed up to 15 IgE-binding components in extracts from 11 different insect species including 6 species of flies. Some IgE-binding insect components with similar electrophoretic mobilities indicated the possible presence of common allergens in extracts from different species. In particular, blots of each of the fly extracts showed a dense IgE-binding component of MW approximately 37,000 daltons. 'Pan allergy' to insects may occur in subjects who have been sensitized to one or a few insects and allergenic similarities may extend to at least some other noninsect members of the phylum Arthropoda.