Radio-Allergo-Sorbent Test
The Radio-Allergo-Sorbent-Test ( RAST ) is a diagnostic procedure that is used, for example, in the clarification of an allergy , to detect specific antibodies of class E against the allergen being tested (e.g. certain pollen, house dust mite excrement, animal allergen etc.) are directed. For this purpose, in the classic RAST process, the antigens are bound as a solid phase to a paper disk or in the further developed CAP-RAST (CAP stands for Carrier-Polymer-System ) on a cellulose sponge. Thereafter, the patient's blood serum is applied. If there are suitable antibodies in the serum, they bind with the associated antigen to form an antibody-antigen complex. In the next step, a radioactively marked tracer is applied, which in turn combines with these AG-AK complexes and can then be detected.
Classification
With the classic RAST, the classification ranges from 0 (no specific immunoglobulin E against the tested allergen detectable) to 4 (strong concentration of specific immunoglobulin E against the tested allergen detectable). With the CAP-RAST, on the other hand, the gradation ranges from 0 to 6.
| Allergen-specific IgE
[kUA / L] |
classification | |
|---|---|---|
| Rest 0 | <0.35 | negative result |
| Rest 1 | 0.35-0.70 | weak positive result |
| Rest 2 | 0.70-3.50 | moderately high result |
| Rest 3 | 3.50-17.5 | high result |
| Rest 4 | 17.5-50.0 | very high result |
It is important to know that there is not necessarily a connection between the clinical symptoms (an allergy) and the graduation obtained at the RAST.
See also
credentials
- ↑ a b c d e Gerhard Weigl (Gesundheit Österreich GmbH; Stubenring 6; 1010 Vienna): Immunoglobulin-E allergen-specific | Health portal. Federal Ministry for Health and Women; Radetzkystraße 2; 1030 Vienna, July 7, 2017, accessed on October 8, 2017 (Austrian German).
- ↑ Practical Pneumology in Pediatrics - Diagnostics (Rational Differential Diagnostics) (Thomas Nicolai, Matthias Griese), 1st edition (2010)