Biomarker: F040-IgE Tuna

Overview

F040-IgE Tuna measures immunoglobulin E (IgE) antibodies in blood that recognize tuna proteins, indicating sensitization to tuna. Tuna allergens include parvalbumin and other proteins such as enolase and aldolase, which may contribute to fish-specific or cross-reactive fish allergy. A detectable or elevated result may indicate an increased likelihood of tuna allergy, but it does not by itself establish clinical allergy, predict reaction severity, or prove that symptoms will occur. The test is clinically useful when interpreted with the patient’s reaction history, examination, and, when necessary, a supervised oral food challenge.

Clinical Use Cases

Assess suspected IgE-mediated reactions occurring after tuna exposure.
Identify tuna as a possible allergen in patients with suspected fish allergy.
Help evaluate whether a patient may be sensitized to tuna but clinically tolerant of it.
Support assessment of possible allergy to individual fish species rather than assuming allergy to all fish.
Contribute to decisions about supervised oral food challenge when the clinical history and test results are inconclusive.
Support research on fish-allergen sensitization and cross-reactivity.

Specimen Types

Serum collected from venous blood.
Plasma may be accepted by some assay systems, but specimen requirements vary by laboratory.

Measurement Methods

Allergen-specific immunoassay for tuna-specific IgE.
Fluorescence enzyme immunoassay, including solid-phase assays such as ImmunoCAP.
Other validated automated or enzyme-linked immunoassays may be used by individual laboratories.
Skin-prick testing with tuna extract is a complementary in-vivo method, but it does not measure circulating F040-IgE.

Test Preparation and Influencing Factors

Fasting is generally not required for serum-specific IgE testing.
Patients should follow the ordering laboratory’s collection and medication instructions.
Do not stop prescription or over-the-counter medicines unless instructed by a healthcare professional.
Results should be interpreted with the timing, reproducibility, and characteristics of symptoms after tuna exposure.
Age, geographic location, atopic dermatitis, other allergic diseases, and total IgE levels may influence interpretation of specific-IgE results.
Cross-reactivity among fish allergens may produce sensitization to tuna without clinically significant tuna allergy.
Different assay platforms and allergen extracts may produce results that are not directly comparable.
A negative result does not completely exclude tuna allergy when the clinical history is strongly suggestive.
A supervised oral food challenge is the reference method for confirming or excluding food allergy when history and testing do not provide sufficient certainty.