Biomarker: F244-IgE Cucumber

Overview

F244-IgE Cucumber measures immunoglobulin E (IgE) antibodies in blood that recognize cucumber (Cucumis sativus) allergens. IgE is involved in immediate-type allergic reactions, including oral itching, hives, gastrointestinal symptoms, respiratory symptoms, and, rarely, anaphylaxis. A detectable or elevated result indicates sensitization to cucumber but does not by itself confirm clinical allergy or predict reaction severity. The test is clinically useful as part of an allergy-focused evaluation, particularly when symptoms occur after cucumber exposure or when skin testing is unsuitable.

Clinical Use Cases

Evaluate suspected IgE-mediated cucumber allergy.
Investigate symptoms occurring after eating cucumber, including oral allergy symptoms, urticaria, vomiting, wheezing, or anaphylaxis.
Assess possible cross-reactive food sensitization in patients with pollen or latex sensitization.
Support evaluation when skin-prick testing is contraindicated, unsuitable, or affected by medications.
Monitor cucumber sensitization in clinical research or specialist allergy assessment.
Contribute to a diagnostic assessment alongside clinical history, skin-prick testing, and, when necessary, a medically supervised oral food challenge.

Specimen Types

Serum from venous blood.
Plasma from venous or capillary blood, depending on the assay.
Capillary blood-derived serum in laboratories validated for that specimen type.

Measurement Methods

Fluorescence enzyme immunoassay, commonly using a solid-phase allergen platform such as ImmunoCAP.
Enzyme-linked immunosorbent assay or comparable solid-phase immunoassays.
Immunoblotting, primarily for research or specialized investigation of cucumber allergen proteins.
Skin-prick testing and oral food challenge may complement serum-specific IgE measurement but do not measure F244-IgE directly.

Test Preparation and Influencing Factors

Fasting is generally not required for an allergy blood test.
Patients should report all medications, particularly antihistamines and other treatments that may affect allergy evaluation. Medications should not be stopped without medical instruction.
Results should be interpreted with the exposure history, timing of symptoms, symptom pattern, and other allergy-test findings.
A positive result indicates sensitization and does not establish that eating cucumber will cause symptoms or indicate reaction severity.
False-positive results may occur, including because of cross-reactive IgE antibodies.
A negative cucumber-specific IgE result does not completely exclude clinical allergy. In a published human case, cucumber-specific serum IgE was negative despite an IgE-mediated cucumber reaction, while skin-prick testing was positive.
Serum or plasma should be collected, processed, and stored according to the requirements of the performing laboratory and assay manufacturer.