RESUMO
OBJECTIVE: To determine the IgE reactivity against recombinant protein Blo t 1 from the dust mite Blomia tropicalis (Bt) using serum from patients with positive skin test to this mite and to investigate the cross-reactivity between Bt and Dermatophagoides pteronyssinus. BACKGROUND: Dust mites have an important role as inducers of allergic asthma and rhinitis. Particularly, Bt is an important mite specie in the tropic and subtropical regions of the world. Therefore, recombinant allergens of this organism could be an important feature for development of effective diagnostic and therapeutic measures. MATERIALS AND METHODS: Purified recombinant Blot t 1 was produced in Escherichia coli and tested against sera from 54 allergic individuals by the dot blot technique. RESULTS: IgE response to Blot 1 was 72% for sera from patients with positive skin test to Bt. Cross-reactivity with Dermatophagoides pteronyssinus was not detected. Statistical analyses of the dot blot test results show 71.74% of sensitivity and 100% of specificity. CONCLUSION: By using a panel of allergic sera and an in vitro assay, the allergen rBlo t 1 exhibits no IgE cross-reactivity with Dermathophagoides pteronyssinus allergens. This finding suggests that specific clinical reagents are necessary for precise diagnosis and treatment of sensitization to Bt.