IgG antibodies in relation to exposure to laboratory-animal allergens

An ELISA technique has been used to measure levels of specific IgG in individuals exposed to laboratory animals in comparison to levels in unexposed individuals. The technique was to determine whether these levels could be useful as a monitor of exposure. Both symptomatic (with and without specific IgE) and nonsymptomatic individuals were studied. Several antigenic source materials were investigated for each animal. The IgG response was extremely complex and elicited a varied pattern of response between animals (mouse, rat, and rabbit). No evidence was found for raised IgG levels being directly related to the degree of exposure, more to the presence of clinical symptoms and specific IgE. Long-term heavy exposure to rats in nonsymptomatic individuals appeared to produce a suppression of the IgG response in relation to control levels. These findings suggest that IgG is not an indicator of exposure but demonstrate a varied response related to the presence of specific allergy to an animal, the particle size on which antigens are carried, and the physiologic state of the mucosa onto which the particles impact.