Characterization of relevant bovine dander allergen components

Abstract

Background: The diagnostics of allergic occupational diseases is highly dependent on the quality of the allergen extracts and specific IgE tests available. To enhance the diagnostics of bovine-related occupational rhinitis, asthma and urticaria, we produced an in-house cow dander extract, assessed its allergen profile and performance in clinical tests, and compared it to commercial bovine dander extracts. Methods: One hundred patients with a suspected bovine-related occupational disease underwent skin prick tests (SPTs) with in-house and one to two commercial bovine dander extracts. Nasal allergen provocation tests were performed on 31 patients with suspected occupational rhinitis. We used Western blot to study the specific IgE-protein reactions from the serums of the patients with positive provocation tests, and identified allergens from immunoblot bands using tandem mass spectrometry. Results: Odorant-binding protein Bos d OBP, bovine serum albumin Bos d 6, and lipocalin Bos d 2 were identified as the major allergens. We found altogether 24 bovine dander allergens, of which several were formerly unknown. The in-house extract sensitivity and specificity in SPTs were 100% and 94%, in 87 patients respectively and SPTs appeared negative in 20 healthy controls. Nasal allergen provocation tests with inhouse extract detected occupational rhinitis with 100% sensitivity in 21 patients. Five healthy controls remained negative in the provocation tests. Conclusions: Three major and several minor allergens were found from bovine dander as a cause of occupational rhinitis. A sufficient concentration and variety of tested allergens were essential in the diagnostics of bovine-related occupational diseases.