Allergens causing bird fancier's asthma.

The study investigates to what extent bird feathers contain relevant allergens/antigens involved in bird fancier's asthma. The study group consisted of two budgerigar fanciers, two parrot fanciers and one canary fancier. All subjects complained of asthmatic symptoms, caused by contact with their birds, and they showed a significant bronchial hyperreactivity to acetylcholine. Positive IgE antibody reactions to bird sera as well as to extracts of feathers were observed in RAST. Well-defined major allergenic bands could be detected and identified in the IgE immunoblots with feather extracts as well as with serum proteins of budgerigar, parrot, pigeon, canary, and hen (mol. mass 20-30 kDa and 67 kDa). The most pronounced bands appeared with the extracts of species to which an exposure had taken place. Weaker IgG-binding patterns were also observed. Our results show that inhalable feather dust contains several allergenic components which cross-react with serum allergens/antigens of the same as well as of other bird species. This emphasizes the significance of bird feathers for immediate-type allergic reactions.