Development and comparative evaluation of a multiple-antigen RAST as a screening test for inhalant allergy.

We have developed a modified in vitro test for IgE antibodies, the multi-RAST, to detect antibodies of different allergen specificities simultaneously in a single tube. The multi-RAST is as sensitive for detecting low concentrations of individual IgE antibodies as the discrete RAST. We also evaluated the multi-RAST as a screening test for respiratory allergy to inhalant allergens in children by comparing the results of the multi-RAST performed by use of a mixture of SRP, TGP, and DF allergen-immunosorbents with the results of skin tests, discrete RAST tests for the same allergens, serum total IgE concentrations, and nasal smears for eosinophils in 100 children referred for allergic-disease evaluation. The results of the multi-RAST were more sensitive, specific, and efficient than the results of tests for serum IgE concentration and nasal eosinophils in establishing the diagnosis of inhalant allergy; the multi-RAST was the only diagnostic test that yielded results that were significantly associated with the clinician's impression of allergy. We conclude that the multi-RAST is a useful and cost-effective screening test for inhalant allergy in children.