Detection of workers sensitised to high molecular weight allergens: a diagnostic study in laboratory animal workers

Objectives: To determine whether results from questionnaires, exposure measurements, and laboratory tests, commonly used in occupational health practice, can predict the presence or absence of sensitisation in workers exposed to high molecular weight (HMW) allergens. The study aims to develop and validate a diagnostic rule to predict sensitisation in laboratory animal workers. The main reason for such research is efficiency. Methods: Baseline data from 551 laboratory animal workers participating in an ongoing cohort study, bridging a period of 3 years, were used for diagnostic research. Data from 472 workers participating in the study during the first period were used to develop a prediction rule; these workers represented the derivation set. Data from 79 workers, participating during the second period, were used to evaluate the rule's performance—the validation set. Serum samples were analysed for specific immunoglobulin E (IgE) antibodies against common and laboratory animal allergens. Questionnaire items, exposure determinants, IgE serology, skin prick tests (SPTs), and lung function tests were analysed, corresponding to diagnostic investigation, in a multiple logistic regression model. The accuracy of the model was evaluated by receiver operating characteristic (ROC) curve analysis, and by comparison of the predicted and observed prevalences. Results: Asthmatic symptoms, (work related) allergic symptoms, sex, occupational exposure to rats, and a positive SPT to common allergens, showed the best performance in discriminating workers at high or at low risk of being sensitised. Conclusion: High and low risk categories for work related sensitisation can be distinguished from simple questionnaire data and SPT results. The method can easily be applied in occupational medical practice and may markedly increase the efficiency of occupational health surveillance in laboratory animal workers as well as other workers exposed to HMW allergens