Allergy To Ferret

S U N D A Y 354 Characterization Of The Allergenic Activity Of Tropomyosin From Aedes Aegypti Mr. Jose F. Cantillo, Prof. Leonardo Puerta, Dr. Enrique FernandezCaldas, Dr. Sylvie Lafosse-Marin; Complutense University of Madrid, Spain; Inmunotek S.L., Alcal a de Henares, Spain, Institute for Immunological Research/University of Cartagena, Cartagena, Colombia, Inmunotek, S.L, Spain, Cabinet de Inmunoallergology, Fort de France, Martinique. RATIONALE: Mosquito bites are an important cause of skin lesions in allergic and non-allergic individuals worldwide. The inhalation of mosquito allergens may also be a cause of allergic respiratory diseases. It has been suggested that there may be cross-reactivity among mosquitoes and other arthropods such as mites, Chironomidae and shrimps. We hypothesized that the panallergen tropomyosin may be involved in this process. METHODS: Tropomyosin was purified from a whole body A. aegypti extract by size exclusion and anionic exchange chromatography. Specific IgE binding to the purified tropomyosin was evaluated by immunoblot and ELISA in allergic patients with positive ELISA to A. aegypti allergenic extract and control individuals. Cross-reactivitywas evaluated by immunoblotting and ELISA inhibitions using tropomyosin derived from the giant tiger prawn Penaeus monodon (nPen m 1) and from the whiteleg shrimp Litopenaeus vannamei (rLit v 1). RESULTS: A purified fraction from the allergenic A. aegypti extract showed four bands of several molecular weights with reactivity to antiPen m 1 rabbit serum, which showed also IgE reactivity to positive sera to mosquito extract. The IgE reactivity to these bands disappears when the sera where adsorbed with shrimps tropomyosin (nPen m 1 and rLit v 1). 25% of the mosquito allergic individuals had detectable specific IgE levels to this fraction. Inhibition of IgE reactivity higher than 90 % was demonstrated in a sera pool adsorded with nPen m 1 and rLit v 1. CONCLUSIONS: We have demonstrated the presence of tropomyosin in A. aegypti extract, which cross-react with shrimp tropomyosins.