SPECIFIC IGE-DEPENDENT SENSITIZATION, ATOPY, AND BRONCHIAL HYPERRESPONSIVENESS IN APPRENTICES STARTING EXPOSURE TO PROTEIN-DERIVED AGENTS

Atopy, specific IgE sensitization, and bronchial hyperresponsiveness ( BHR) were examined in a cohort of 769 apprentices starting career prog rams in animal health or veterinary medicine (Group 1), pastry making (Group 2), and dental hygiene (Group 3). The hypothesis were that: (1) a proportion of subjects can be ''sensitized'' although no significan t specific occupational exposure has occurred; and (2) there is a rela tionship between baseline specific sensitization to work-related antig ens and host characteristics. Skin tests were administered using 11 co mmon inhalants and specific allergens, including six laboratory animal extracts, three cereal antigens, alpha-amylase, and latex. Methacholi ne challenge tests were performed. The prevalence of atopy was 54.4% i n Group 1, 58.1% in Group 2, and 52.5% in Group 3. Skin reactivity to work-specific proteins was as follows: laboratory animal proteins, 13. 8% in Group 1, 14.0% in Group 2, and 15.6% in Group 3. No subject was sensitized to alpha-amylase, whereas 1.2% in Group 1, 5% in Group 2, a nd 4.1% in Group 3 were sensitized to flour. Five subjects reacted to latex. BHR (PC20 less than or equal to 8 mg/ml) was present in 17.6%, 21.2%, and 14.8% of subjects in Groups 1, 2, and 3, respectively. Spec ific sensitization was associated with positive skin reactions to comm on allergens, work-related symptoms, and BHR. These results suggest th at students starting career programs with exposure to high-molecular-w eight allergens have a low but substantial frequency of specific sensi tization to work-related allergens that is related to atopy and BHR.