IgE and IgG4 antibodies in specific human allergies.

In 90 sera from patients with specific allergies (i. e. to guinea pig dander, cat dander, horse dander, dog dander, human dander or ipecac) and with positive skin tests to the allergenic preparations, the presence of IgE and IgG4 antibodies was determined by radioallergosorbent test (RAST). A correlation between IgE RAST scores and IgG4 RAST scores to the individual allergens was established. In patients allergic to guinea pig dander, a high incidence of negative IgE RAST scores but positive IgG4 RAST scores was found. This was less often the case in the group with cat dander allergy. IgG RAST scores determined in 51 sera proved to have some predictive value with respect to IgG4 or other IgG subclasses involved in the allergic reactions. Because a high incidence of negative IgE RAST scores was found, IgE RAST inhibition does not seem to be the method of choice for the standardization of allergenic preparations in general.