[Diagnostic value of RAST-classes in various allergens]

Abstract

Specific IgE-fractions can be determined in the blood serum by Radio-Allergo-Sorbent-Test (RAST). The positive tests are arranged into four groups, the so called RAST-classes, of which class 1 represents the lowest, class 4 the highest content of specific IgE. The diagnostical value of equal RAST-classes among the groups of allergens is different. We examined 13 600 allergens in 700 patients by RAST and found 2441 positive reactions. It turned out that especially in weeds, house dust and mould allergy, the lower RAST-classes are predominant with more than 90 per cent. In grass pollen allergy, a comparable percentage of positive tests accumulates in the range of RAST-class 3. From this distribution of positive tests we concluded, that in house dust, mould and weeds pollen allergy RAST-class 1 has a real diagnostical value and can be the basis of therapeutical consequences. In patients with lower RAST-classes in mould, house dust and weed pollen allergy, in our experience, the average total IgE is already in a pathological range; in patients with grass pollen allergy total IgE is increased pathologically almost until RAST-class 4.