Cross-allergenicity of the house dust mites Euroglyphus maynei and Blomia tropicalis.

Background: The domestic mites Euroglyphus maynei and Blomia tropicalis frequently co-inhabit homes in subtropical/tropical regions around the world. Both species are the source of substances that cause allergic reactions in patients.
Objective: The purpose of this study was to examine the immunologic cross-reactivity between E. maynei and B. tropicalis.
Methods: Sera of 19 mite-sensitive patients who were skin test positive to B. tropicalis and/or RAST positive to E. maynei were used to probe immunoblots or crossed radioimmunoelectrophoresis (CRIE) gels.
Results: Western blotting showed that individual sera had IgE that bound to 0 to 17 and 2 to 15 proteins in E. maynei and B. tropicalis extracts, respectively. Corresponding IgE-binding proteins of 105, 75, 57, 18, and 14 kD were detected in both E. maynei and B. tropicalis extracts. 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 reciprocal reaction, 10 of the 12 proteins of B. tropicalis that were precipitated by anti-E. maynei serum bound IgE with individual sera binding to 0 to 5 proteins.
Conclusion: This study indicated that E. maynei and B. tropicalis are the source of both species-specific and cross-reactive allergens, but most allergens in each extract were species-specific.