Defining the allergen responsible for eliciting signs and symptoms
Identifying allergens responsible for allergic disease and/or anaphylactic episode
Confirming sensitization prior to beginning immunotherapy
Investigating the specificity of allergic reactions to insect venom allergens, drugs, or chemical allergens
Specimen Type
Serum
Specimen Requirements
Preferred: Red Top
Acceptable: Serum Gel
Minimum Sample Volume
For 1 allergen: 0.3 mL
For more than 1 allergen: (0.05 mL x number of allergens) + 0.25 mL deadspace
Stability
Refrigerated (preferred): 14 days
Frozen: 90 days
Limitations
Testing for IgE antibodies is not useful in patients previously treated with immunotherapy to determine if residual clinical sensitivity exists, or in patients in whom the medical management does not depend upon identification of allergen specificity
Some individuals with clinically insignificant sensitivity to allergens may have measurable levels of IgE antibodies in serum, and results must be interpreted in the clinical context
False-positive results for IgE antibodies may occur in patients with markedly elevated serum IgE (>2,500 kU/L) due to nonspecific binding to allergen solid phases.
