Biomarker: F214-IgE Spinach

Overview

F214-IgE Spinach measures immunoglobulin E (IgE) antibodies in blood that recognize proteins from spinach (Spinacia oleracea). IgE is involved in immediate hypersensitivity reactions, including symptoms such as oral itching, hives, swelling, wheezing, vomiting, or anaphylaxis. A detectable result indicates sensitization to spinach but does not by itself establish a clinical spinach allergy; a low or undetectable result reduces, but does not completely eliminate, the likelihood of an IgE-mediated reaction. The test is clinically useful when interpreted with the patient’s reaction history and, when appropriate, skin testing or a medically supervised oral food challenge.

Clinical Use Cases

Supports evaluation of suspected IgE-mediated reactions after eating spinach.
Helps assess possible oral allergy syndrome associated with spinach exposure.
May assist in evaluating occupational or inhalational reactions to spinach dust in relevant exposure settings.
Helps identify spinach sensitization when skin testing is impractical, contraindicated, or affected by medications.
Supports, but does not replace, clinical history, physical examination, and medically supervised food-challenge assessment.

Specimen Types

Venous blood serum.
Capillary blood-derived serum may be acceptable for some assay systems.
Plasma may be accepted by selected assay platforms, according to laboratory-specific requirements.

Measurement Methods

Fluorescence enzyme immunoassay, commonly using an allergen-coated solid phase such as an ImmunoCAP-type system.
Enzyme-linked immunosorbent assay or other solid-phase immunoassays.
Results are generally reported as allergen-specific IgE concentration in kUA/L or as an assay-specific class or grade.

Test Preparation and Influencing Factors

Fasting is generally not required.
Patients should report all medications and supplements. Antihistamines usually do not affect serum-specific IgE testing, but medication instructions should be confirmed with the ordering clinician.
Medications should not be stopped unless specifically directed by a healthcare professional.
Results should be interpreted with the timing, amount, preparation, and reproducibility of spinach exposure and the symptoms that followed.
A positive result indicates sensitization, not necessarily symptomatic allergy. Positive tests can occur without clinical reactions.
Test performance and reference categories vary by assay and laboratory; results should not be compared directly across different platforms.
Total IgE elevation, atopic dermatitis, and other allergic conditions may complicate interpretation of allergen-specific IgE results.
Testing should be targeted to foods suspected from the clinical history rather than performed as an indiscriminate food panel.