Evaluation of the Radio-Allergo-Sorbent-Test (RAST) with respect to misinterpretations of the results.
Two hundred and twenty two single allergens were assayed in 36 outpatients, using a commercial RAST kit. It was found that a significant proportion of the patients were evaluated incorrectly as having elevated levels of allergen-specific IgE. This was due to an as yet unconsidered parameter of the RAST, i.e. unspecific binding of the radioactive tracer to the wall of the test tubes, resulting in values that did not correlate with the total IgE concentrations of individual sera. The unspecific binding amounted in some cases to 89% of the total radioactivity (counts/min) when the instruction manual of the manufacturer was followed. This resulted in either false positive results and/or RAST classifications that were 1 to 2 classes too high. The results can be corrected by a slight modification of the assay.
Czuppon
A B
AB
Berufsgenossenschaftliches Forschungsinstitut für Arbeitsmedizin, Ruhr-Universität Bochum, Germany.
Baur
X
X
D000485:Allergens; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis* / Q000276:immunology; D007073:Immunoglobulin E / Q000032:analysis*; D011786:Quality Control; D011852:Radioallergosorbent Test / Q000379:methods*; D011933:Reagent Kits, Diagnostic
D000485:Allergens; D011933:Reagent Kits, Diagnostic; D007073:Immunoglobulin E