[Significance of the radioallergosorbent test (RAST) in the specific diagnosis of atopic bronchial asthma (author's transl)].

Abstract

The radioallergosorbent test (RAST) is a recently developed radioimmunological in-vitro method for determining IgE-specific serum antibodies in reaginic allergy. There was 63.4% overall correspondence between RAST and bronchial provocation test in 423 tests with a total of eight perennial allergens on adults with asthma. Where there was disagreement, combination of postiive inhalation test and a negative RAST was much more frequent (33.6%) than in the obverse (3%). Agreement between RAST and provocation tests was 79% for the house dust mite Dermatophagoides pteronyssinus, 71.5% for cat and dog epithelium, 70% for the Penicillium mould, 63% for Alternaria, 55% for Hormodendron and Aspergillus and only 53% for house dust. In asthmatics a positive RAST usually indicates clinically relevant sensitization (positive case history or positive provacation test), while negative results (especially in cases of mould or house dust allergy) do not rule out possible significant sensitization. On the other hand, skin tests with moulds and house dust are frequently "false" positive. First test in the specific diagnosis of bronchial asthma remains a thorough case history combined with careful skin testing. When the two disagree, RAST is helpful together with as a "secondary" allergy test.