Allergenic differences between the domestic mites Blomia tropicalis and Dermatophagoides pteronyssinus
Source: Clinical & Experimental Allergy, Volume 29, Number 7, July 1999 , pp. 982-988(7)
Abstract:Background House dust mite allergens are the most important indoor allergens associated with asthma and rhinitis in Singapore and the tropics. Recent data to suggest that besides the Dermatophagoides spp., the domestic mite Blomia tropicalis (Bt) is also an important source of allergens in these regions. Objective To evaluate the degree of allergenic cross-reactivity between Bt and D. pteronyssinus (Dp). Methods Cross-reactivity between extracts of Bt and Dp was evaluated by fluorescent allergosorbent (FAST) inhibition studies and cross enzyme immunoelectrophoresis. Additionally, the major Dp allergens — Der p 1, Der p 2 and Der p 5, were also compared with the Bt extract by dot blot inhibition. Skin prick and intradermal end-point titration were then carried out to compare the homologous allergens of the mite species, Blo t 5 and Der p 5. Results FAST inhibition studies showed low to moderate cross-reactivity between the two dust mite extracts (maximum cross-inhibition, 60%). Native allergens studied by cross enzyme immunoelectrophoresis using mite allergic sera also showed similar results but with at least four cross-reactive IgE binding antigens. Dot blot inhibition studies using allergens of Dp, Der p 1, Der p 2, and Der p 5, showed little cross-reactivity between these allergens with components of the crude Bt extracts. Further, evaluation of a recombinant allergen of Bt, Blo t 5, showed low levels of cross-reactivity even with its homologous Dp counterpart, Der p 5. Conclusion These results provide evidence that Bt allergens are distinct and have relatively low to moderate cross-reactivity with Dermatophagoides spp. allergens. Bt allergens should therefore be included in the diagnostic panel for the evaluation of allergic disorders in the tropics, and the development of new diagnostic and therapeutic strategies should include allergens of Bt.
Document Type: Research article
Affiliations: 1: Department of Paediatrics, National University of Singapore, Republic of Singapore, 2: CBF Leti, SA, Madrid, Spain, 3: School of Medicine of Ribeirão Preto, Sao Paulo, Brazil, 4: Asthma and Allergic Disease Center, Department of Internal Medicine, University of Virginia Health Science Center, Charlottesville VA, USA
Publication date: 1999-07-01