Sensitization to the fungus Hemileia vastatrix (coffee leaf rust).

BACKGROUND: The aim of the present study was to determine the existence of sensitization to the fungus Hemileia vastatrix (coffee leaf rust) in a sample of the Brazilian population. This fungus attacks coffee plantations, and in some regions of Brazil the concentration of its spores in the air can be very high. METHODS: A total of 378 individuals underwent skin tests (prick and intradermal tests) with H. vastatrix extract. The subjects were divided into four groups according to the occurrence of atopy and the region where they lived (coffee-growing or non-coffee-growing regions), and another group (V) consisted of 50 rural workers employed on coffee plantations. The presence of specific IgE against the fungus H. vastatrix in sensitized individuals was demonstrated in vitro by immunoblotting. RESULTS: There was no statistical difference in comparing the results with intradermal or prick tests. The incidence of positive tests was significantly higher among atopic individuals residing in coffee-growing regions (14.7%). Among rural workers, 10% showed positive tests. Immunoblotting revealed specific IgE against 20 protein bands of H. vastatrix. CONCLUSION: The fungus H. vastatrix may be an important allergen in coffee-producing countries. The sensitization is more frequent among atopic individuals residing in coffee-growing regions.