RAST in the diagnostic of dog dander allergy. A comparison between three allergen preparations using two variants of RAST.

The results of the skin, bronchial or conjunctival provocation tests and of the radioallergosorbent test (RAST) with dog dander and hair extract preparations from two different producers were compared. 202 asthmatic children were included in the study. The clinical tests, Al-RAST and paper RAST, were performed using only one allergen preparation (Hu073), while two allergen preparations (e2 and e5) 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. Al-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 Al-RAST methods, classes 0-1 can be regarded as negative, class 2 as doubtful and classes 3-4 as clinically positive results.