RAST in the Diagnosis of Dog Dander Allergy.

Abstract

The results of skin, bronchial or conjunctival provocation tests and of the radioallergosorbent test (RAST) with dog dander and hair extract preparations from 2 different producers were compared in a study of 202 asthmatic children. The clinical tests, A1-RAST [RAST using A1(OH)3 coupled to the allergen] and paper RAST, were performed using only 1 allergen preparation (Hu 073), while 2 allergen preparations (e2 [dog epithelium] and e5 [dog dandruff]) were used in Phadebas RAST. A good correlation was generally found between the results of the clinical diagnostic tests, the clinical history and the results of RAST. Phadebas RAST e2 was the most specific but the least sensitive: it gave a class 0 result in 18% and class 3-4 in 34.5% of the subjects with a positive provocation test. The corresponding numbers for e5 RAST were 6.0% and 70.2%, respectively. A1-RAST was equally sensitive, but had lower specificity than Phadebas RAST e5. The correlation between Phadebas RAST e5 and paper RAST Hu 073 was excellent, which indicates a remarkable similarity between these allergen extracts. Using sensitive, immunochemically standardized Phadebas RAST e5 or A1-RAST methods, classes 0-1 can be regarded as negative, class as doubtful and classes 3-4 as clinically positive results.