Diagnosis of allergic sensitization in patients with allergic rhinitis and asthma in a tropical environment

Abstract

Background: Few studies in tropical developing countries have utilized molecular diagnosis to characterize allergen-specific responses to aeroallergens. Objective: To investigate the in vivo and in vitro responses of IgE antibodies to inhalant allergens in allergic patients with rhinitis and/or asthma. Methods: A prospective study in which patients with allergic rhinitis and/or asthma were included. Skin prick tests with 16 inhalant extracts of allergens were carried out and total and specific IgE levels for allergens and their molecular components in the serum were determined. Results: In a total of 189 patients, 73.5% showed high levels of total IgE in the serum. The prick tests were positive for the following allergens: Dust mite extracts; more than 60 %, cat; 29.6 %, dog; 23.4 %, and Periplaneta Americana; 21.6 %. Specific IgE for Dermatophagoides farinae and Pteronyssinus was present in 66.6 % of the patients; for Blomia tropicalis; in 45.0 %, for Ascaris lumbricoides; in 24.7 %, for cat; in 17.3 %, for parrot feathers; in 14.8 %, and for Penicillium notatum; in 12.3 %. IgE antibodies to mite allergens of group 1 and 2 were present in 59.0 % and 70.1 % of the sera; 39.1 % contained IgE to rBlo t5, 30.4 %contained rBla g4, 19.9 % contained rFel d1, 11.8 % contained rArt v3, 11.2 % contained Der p10, 9.9 % contained rBla g2, 9.3 % contained rPer a7, 9.3 % contained nFel d2, and 8.7 % contained rCan f1. Conclusions: This study confirms that mites are the main sensitizing agents in patients with respiratory allergic diseases in a tropical environment. There was a good correlation between the results of the skin tests and the results of the in vitro tests.

Keywords

• allergic rhinitis
• asthma
• molecular diagnosis
• mites