New insights into laboratory animal exposures and allergic responses

Abstract

To update the epidemiology of laboratory animal allergy, identify new exposures in the laboratory animal workplace, discuss complexities in the exposure-response relationship, and review the immunology of symptomatic and allergic responses. Laboratory animal allergy remains a common occupational hazard of research scientists, technicians and animal handlers. The epidemiology is typical of a stable workforce: incidence is low, although prevalence is high. Risk factors of atopy, current exposures, and sensitization to cats or dogs incompletely predict disease. Exposures include a complex, potent mixture of allergens, biological adjuvants such as endotoxin and irritants. The dose-response relationship between laboratory animal exposure, sensitization and symptoms is hard to define: cross-sectional studies identify most sensitized workers in moderate laboratory animal exposure, not in the highest exposure. Exposure assessments based on workday averages underestimate exposure peaks that may be significant for symptoms and disease. Although we have assumed that workers without symptoms are not sensitized to laboratory animal allergens, recent data demonstrate that many asymptomatic workers do make laboratory animal-specific immune responses that may be necessary to prevent symptomatic disease. Understanding laboratory animal exposures and disease must include exposures other than allergen, and responses other than allergic disease.