Biomarker: T015-IgE Ash, White

Overview

T015-IgE Ash, White measures immunoglobulin E (IgE) antibodies directed against white ash (Fraxinus americana) pollen. IgE is involved in immediate-type allergic responses, including activation of mast cells and release of inflammatory mediators. A detectable or elevated result indicates sensitization to the tested pollen, but does not by itself confirm symptomatic allergy or predict reaction severity. The test supports evaluation of seasonal allergic rhinitis, conjunctivitis, and asthma when interpreted with symptoms, exposure history, and other allergy findings.

Clinical Use Cases

Evaluation of suspected white ash pollen allergy and springtime respiratory symptoms.
Assessment of allergic rhinitis, conjunctivitis, or asthma associated with tree-pollen exposure.
Identification of sensitization when skin testing is unsuitable because of skin disease, medication use, or concern about systemic reactions.
Selection of relevant allergens for environmental counseling and consideration of allergen-specific immunotherapy.
Investigation of pollen sensitization patterns, including possible cross-reactivity within the Oleaceae family.
Research on the prevalence and clinical relevance of ash-pollen sensitization.

Specimen Types

Venous blood serum.
Plasma may be accepted by some validated assay systems, according to the performing laboratory’s requirements.

Measurement Methods

Allergen-specific immunoassay using an immobilized white ash pollen extract.
Fluorescence enzyme immunoassay, including ImmunoCAP-type methods.
Other validated enzyme-linked or chemiluminescent immunoassays.
Skin-prick testing and component testing may be used as complementary methods, but they do not measure T015-IgE directly.
Molecular assays may assess related Oleaceae allergens such as Ole e 1, which can correlate with ash-pollen sensitization, although this is not identical to measuring T015-specific IgE.

Test Preparation and Influencing Factors

Fasting is generally not required for an allergy-specific IgE blood test.
No special preparation is usually needed, but the patient should report all medications and supplements.
Antihistamines commonly affect skin-prick testing more than blood-specific IgE testing, but medication instructions should come from the treating clinician.
IgE results should be interpreted with the timing of symptoms, geographic exposure, seasonal pollen levels, and relevant clinical history.
A positive result indicates sensitization and does not establish that exposure causes symptoms or indicate their severity.
Cross-reactivity with other Oleaceae pollens, including olive pollen, may influence results or interpretation.
Differences between white ash and other ash species may affect measured sensitization; Fraxinus americana and Fraxinus excelsior are not interchangeable for all patients.
Assay platforms, allergen extracts, reporting units, and decision thresholds vary, so results should be interpreted using the reference range and method reported by the testing laboratory.
Smoking, parasitic infection, and other conditions can affect broader IgE interpretation, although they do not specifically establish white ash allergy.