Biomarker: T022-IgE Pecan, Hickory

Overview

T022-IgE measures circulating immunoglobulin E (IgE) antibodies directed against pecan and hickory pollen allergens, primarily from Carya species. IgE is involved in immediate hypersensitivity reactions by binding to immune cells that release mediators after allergen exposure. A detectable or elevated result indicates sensitization, which may be associated with seasonal allergic rhinitis, conjunctivitis, or asthma, but it does not by itself establish clinical allergy or predict reaction severity. The test is clinically useful when interpreted with exposure history, symptoms, physical findings, and other allergy testing.

Clinical Use Cases

Evaluation of suspected seasonal allergic rhinitis, allergic conjunctivitis, or pollen-triggered asthma.
Identification of sensitization to pecan or hickory pollen when symptoms occur during relevant pollen seasons.
Assessment of possible cross-sensitization among related tree pollens, including Carya and Juglans species.
Supporting selection of allergens for environmental control measures or allergen immunotherapy evaluation.
Evaluation when skin-prick testing is unsuitable because of extensive eczema, dermatographism, or medications that interfere with skin testing.

Specimen Types

Venous blood serum.
Plasma may be accepted by some validated immunoassay platforms.

Measurement Methods

Allergen-specific serum IgE immunoassay using an immobilized pecan or hickory pollen extract.
Fluorescence enzyme immunoassay.
Chemiluminescent immunoassay.
Enzyme-linked immunosorbent assay.
Older radioallergosorbent test methods are historical and are generally replaced by newer automated immunoassays.

Test Preparation and Influencing Factors

Fasting is generally not required for a serum specific-IgE test.
Patients should report all medications and supplements. Antihistamines generally do not suppress serum specific-IgE results, but medication instructions may differ if skin testing is also planned.
Do not stop prescribed medication unless directed by a healthcare professional.
Collection timing should be considered in relation to symptom patterns and seasonal exposure, although serum specific IgE can be measured outside the pollen season.
Results may reflect sensitization without clinically important symptoms and should be interpreted with the patient’s exposure history.
Cross-reactive antibodies may contribute to positive results involving related tree pollens, including hickory, pecan, and walnut.
Total IgE concentration, assay characteristics, allergen extract composition, and analytical cutoffs can affect interpretation.
A positive result does not determine the severity of a future reaction, and a negative result does not completely exclude allergy when the clinical history is strongly suggestive.