Biomarker: F237-IgE Apricot

Overview

F237-IgE Apricot measures serum immunoglobulin E (IgE) antibodies directed against apricot (Prunus armeniaca) proteins. Apricot allergens include Pru ar 1, a Bet v 1-related protein, and Pru ar 3, a lipid transfer protein that has been identified as a major allergen in human studies. A detectable result indicates sensitization to apricot but does not, by itself, confirm clinical food allergy or predict reaction severity. The test is clinically useful as part of an allergy evaluation when interpreted with exposure history, symptoms, and other diagnostic findings.

Clinical Use Cases

Evaluation of suspected immediate hypersensitivity reactions after eating apricot.
Assessment of symptoms such as oral itching, urticaria, angioedema, gastrointestinal symptoms, wheezing, or anaphylaxis occurring after apricot exposure.
Investigation of possible cross-reactivity among Rosaceae fruits, including peach, plum, cherry, apple, and almond.
Supportive testing when skin-prick testing is unsuitable, unavailable, or influenced by medications or skin disease.
Assessment of sensitization to apricot in patients with suspected pollen-food allergy syndrome or lipid-transfer-protein allergy.
Selection of patients who may require additional evaluation, such as supervised oral food challenge. A positive specific-IgE result alone should not be used to impose broad dietary restrictions.

Specimen Types

Venous whole blood, with the laboratory typically analyzing separated serum.
Plasma may be accepted by some validated assay systems, depending on the laboratory protocol.

Measurement Methods

Allergen-specific IgE immunoassay using an apricot extract, commonly reported in kUA/L or an equivalent unit.
Fluorescence enzyme immunoassay or comparable solid-phase immunoassay for quantitative serum-specific IgE measurement.
Skin-prick testing with fresh apricot or standardized extract may be used as a complementary, rather than equivalent, assessment.
Immunoblotting and inhibition assays are primarily research techniques used to characterize apricot allergens such as Pru ar 3, not routine F237 testing.

Test Preparation and Influencing Factors

Fasting is generally not required for an allergy blood test.
Patients should report all medications and supplements. Antihistamines may affect some allergy tests, but medications should not be stopped unless instructed by a healthcare professional.
Blood collection timing is generally not restricted to a particular time of day.
Results may reflect sensitization without clinical allergy; interpretation requires correlation with symptoms after exposure.
The specific-IgE concentration does not reliably establish the severity of a future reaction.
Cross-reactive IgE antibodies to related plant allergens may produce a positive result without consistent clinical reactions to apricot.
Assay thresholds and reporting classes vary by laboratory, so results should be interpreted using the reporting laboratory’s reference framework.
Oral food challenges, when needed, should be performed only under appropriate medical supervision.

Synonyms

F237-IgE
Apricot-specific IgE
Apricot allergen-specific IgE
Apricot serum-specific IgE
Prunus armeniaca-specific IgE
Apricot fruit IgE
Apricot allergen code F237
Pru ar 3 sensitization, when referring specifically to the apricot lipid-transfer-protein component