Which in vitro test measures specific IgE levels against an allergen?

Which in vitro test measures specific IgE levels against an allergen?

• A. Histamine release assay
• B. Radioimmunosorbent test (RIST)
• C. Fluorescent allergosorbent test (FAST)
• D. Precipitin radioimmunosorbent test (PRIST)

Answer: (C)

The fluorescent allergosorbent test (FAST) is designed to measure specific IgE antibodies in the serum that are directed against particular allergens. This test operates by using fluorescently labeled allergens bound to a solid phase. When a sample containing specific IgE is introduced, the IgE will bind to the allergen. After washing away non-bound components, a secondary antibody that is also labeled with a fluorescent marker is added. The fluorescence emitted is then measured, allowing for the quantification of the specific IgE levels. FAST provides a highly sensitive method for identifying allergic sensitivities, making it a favored approach in clinical immunology for diagnosing IgE-mediated allergies. In contrast, other options such as the histamine release assay generally assess mast cell activation rather than the quantification of IgE levels, while RIST measures total IgE but not specific IgE for allergens. PRIST also quantifies total IgE. Thus, for the determination of specific IgE levels to allergens, FAST is the most suitable test.

The fluorescent allergosorbent test (FAST) is designed to measure specific IgE antibodies in the serum that are directed against particular allergens. This test operates by using fluorescently labeled allergens bound to a solid phase. When a sample containing specific IgE is introduced, the IgE will bind to the allergen. After washing away non-bound components, a secondary antibody that is also labeled with a fluorescent marker is added. The fluorescence emitted is then measured, allowing for the quantification of the specific IgE levels.

FAST provides a highly sensitive method for identifying allergic sensitivities, making it a favored approach in clinical immunology for diagnosing IgE-mediated allergies.

In contrast, other options such as the histamine release assay generally assess mast cell activation rather than the quantification of IgE levels, while RIST measures total IgE but not specific IgE for allergens. PRIST also quantifies total IgE. Thus, for the determination of specific IgE levels to allergens, FAST is the most suitable test.