Biomarker: F235-IgE Lentil

Overview

F235-IgE Lentil measures serum immunoglobulin E (IgE) antibodies directed against lentil allergens, usually from Lens culinaris. Specific IgE reflects immune sensitization to lentil proteins, but sensitization alone does not establish a clinically relevant food allergy. Higher results may increase the likelihood of an IgE-mediated reaction when consistent with the patient’s history, while low or undetectable results reduce but do not completely eliminate the possibility of allergy. The test is clinically useful as an adjunct to an allergy-focused history and, when appropriate, skin-prick testing or a medically supervised oral food challenge.

Clinical Use Cases

Supports evaluation of suspected immediate, IgE-mediated reactions after lentil ingestion.
Helps identify lentil sensitization in patients with suspected legume allergy.
Provides complementary evidence when skin-prick testing is impractical, contraindicated, or difficult to interpret.
Supports evaluation of possible reactions to multiple legumes, including lentil, chickpea, pea, and peanut.
May be used with clinical history and other testing when assessing whether a patient may have developed tolerance to lentil.
May contribute to research on lentil allergens and component-specific responses, including Len c 1 and Len c 3.

Specimen Types

Serum, typically collected from venous blood.
Plasma may be accepted by some laboratory platforms, but requirements vary by laboratory.

Measurement Methods

Quantitative allergen-specific IgE immunoassay, commonly using an ImmunoCAP-based platform.
Other validated solid-phase immunoassays may be used by individual laboratories.
Research methods include ELISA, immunoblotting, and microarray immunoassays for characterization of lentil-specific or component-specific IgE.

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 assessments, but medications should not be stopped unless instructed by a clinician.
Results must be interpreted with the timing, reproducibility, and nature of symptoms after lentil exposure.
A positive result indicates sensitization and does not by itself prove clinical allergy or predict reaction severity.
The quantitative IgE concentration does not reliably predict how severe a future reaction will be.
Total IgE concentration, age, atopic disease, and the assay platform may influence interpretation.
Different laboratories and platforms may use different reporting scales and reference classifications.
Lentil extract composition and processing can affect IgE binding. Studies have reported differences between crude and boiled lentil extracts, so results may not fully predict reactions to every form of lentil.
Oral food challenges should be performed only under appropriate medical supervision when the diagnosis remains uncertain.