CROSS-ALLERGENICITY OF THE HOUSE-DUST MITES EUROGLYPHUS-MAYNEI AND BLOMIA-TROPICALIS

Background: The domestic mites Euroglyphus maynei and Blomia tropicali s frequently co-inhabit homes in subtropical/tropical regions around t he world. Both species are the source of substances that cause allergi c reactions in patients.Objective: The purpose of this study was to ex amine the immunologic cross-reactivity between E. maynei and B. tropic alis. Methods: Sera of 19 mite-sensitive patients who were skin test p ositive to B. tropicalis and/or RAST positive to E. maynei were used t o probe immunoblots or crossed radioimmunoelectrophoresis (CRIE) gels. Results: Western blotting showed that individual sera had IgE that bo und to 0 to 17 and 2 to 15 proteins in E. maynei and B. tropicalis ext racts, respectively. Corresponding IgE-binding proteins of 105, 75, 57 , 18, and 14 kD were detected in both E. maynei and B. tropicalis extr acts. The majority of IgE-binding proteins did not show corresponding bands in both extracts. Heterologous CRIE showed IgE binding to six of the nine E. maynei antigens precipitated by anti-B. tropicalis serum with individual sera recognizing 0 to 4 of the six allergens. In the r eciprocal reaction, 10 of the 12 proteins of B. tropicalis that were p recipitated by anti-E. maynei serum bound IgE with individual sera bin ding to 0 to 5 proteins. Conclusion: This study indicated that E. mayn ei and B. tropicalis are the source of both species-specific and cross -reactive allergens, but most allergens in each extract were species-s pecific.