Allergen Profile, Horse, IgE With Component Reflex

Clinical Use

Use

The diagnostic assessment of allergy starts with the patient’s clinical history and examination and is followed by an extract-based analysis to confirm the presence of specific IgE (sIgE) antibody.1 sIgE is necessary but not sufficient for eliciting an allergic response and thus generating a definitive diagnosis of allergic disease. Testing utilizing allergenic extracts does not lend itself to the differentiation of primary sensitization from a cross-reactivity-driven response because of the complexity of the extracts. Extracts contain most of the extractable allergenic components from the suspected sensitizer. However it is often not possible to predict the relative risk of having a systemic allergic reaction using an extract-based diagnostic test. Component Resolved Diagnostics (CRD) refers to the use of purified or recombinant allergens in the serologic assessment of individuals who suffer reproducible hypersensitivity reactions with exposures to an allergen at a dose tolerated by non-allergic individuals.1,2 This approach offers advantages over the use of a complete extract, especially in polysensitized individuals, given its usefulness for distinguishing between sensitizations specific to singular species and sensitizations due to cross-reactivity.3

Special Instructions

Not provided.

Limitations

Allergen-specific IgE assays do not demonstrate absolute positive and negative predictive values for allergic disease. Clinical history must be incorporated into the diagnostic determination. The use of component resolved IgE testing may enhance the evaluation of potentially allergic individuals over the use of whole extracts alone, but it cannot yet replace clinical history and oral food challenge in most cases.

Test Details