Allergenic cross-reactivity between Blomia tropicalis and Blomia kulagini (Acari: Echymiopodidae) extracts from optimized mite cultures.

BACKGROUND At present, data about the cross-reactivity of Blomia spp. comes from studies made among different genera of mites, and no results have been published involving different species of the genus Blomia. OBJECTIVE The aim of this study was to find out the level of cross-reactivity between the two main species of Blomia causing allergy, and its implication in the diagnosis of Blomia sensitization. METHODS Using extracts from optimal growth phases of Blomia kulagini (Zakhvatkin, 1936) and Blomia tropicalis (van Bronswijk, Cock and Oshima, 1973) as allergenic material, the allergenic cross-reactivity between both house dust mites was evaluated by means of cutaneous tests, specific IgE values, ImmunoCAP-inhibition and SDS-PAGE-IgE-immunoblotting-inhibition. RESULTS The results demonstrated that IgE-binding components belonging to both species are very similar from the immunological point of view, showing high correlations between both species when using cutaneous tests (R2=0.915) or specific IgE (R2=0.980). ImmunoCAP-inhibition and SDS-PAGE-IgE-Immunoblotting-inhibition probed with human sera, showed a total inhibition of specific IgE reactions by the heterologous antigens. CONCLUSION The results obtained strongly suggest the great resemblance between the allergenic composition of both species.