Biomarker: F317-IgE Coriander/Cilantro

Overview

Coriander, also called cilantro when referring to the fresh leaves, is the herb and spice derived from Coriandrum sativum in the Apiaceae family. F317-IgE refers to allergen-specific IgE directed against coriander extract, typically evaluated in blood or serum. Coriander can rarely cause IgE-mediated reactions after ingestion or inhalation of airborne spice dust, including respiratory, skin, oral, and systemic symptoms. Evaluation may help investigate suspected reactions or occupational exposure, but a positive result indicates sensitization and does not by itself establish clinical allergy.

Clinical Use Cases

Evaluation of suspected IgE-mediated allergy: Measures coriander-specific IgE when a patient reports reproducible symptoms after eating coriander, cilantro, or foods containing coriander flavoring.
Investigation of exposure-related symptoms: May support evaluation of urticaria, angioedema, oral symptoms, rhinitis, bronchospasm, or anaphylaxis associated with ingestion or handling of coriander.
Occupational allergy assessment: May be useful for food-industry workers, spice grinders, and individuals exposed to airborne coriander dust who develop work-related respiratory or skin symptoms.
Serum-specific IgE assessment: Blood-based testing can identify IgE antibodies to coriander extract when skin testing is unsuitable, unavailable, or requires complementary evaluation.
Integrated clinical interpretation: Results should be assessed with the exposure history, timing and reproducibility of symptoms, examination, and other indicated allergy tests. An oral food challenge under medical supervision may be required when the diagnosis remains uncertain.
Cross-sensitization investigation: Testing may be considered alongside relevant pollen, celery, carrot, or other Apiaceae testing when cross-reactive sensitization is suspected.

Specimen Types

Serum: Commonly used for measurement of coriander-specific IgE.
Plasma: May be accepted by some validated laboratory immunoassays, depending on the laboratory method.

Measurement Methods

Allergen-specific IgE immunoassay: Measures circulating IgE antibodies that bind to coriander extract in a blood or serum sample. Results indicate immunologic sensitization and must be interpreted with clinical findings.
Extract-based testing: F317 testing uses an extract of Coriandrum sativum. Individual coriander allergenic proteins have not been fully characterized, limiting routine component-level interpretation.
Component-resolved diagnostics: No widely established, routinely used coriander-specific molecular component test is currently well documented for clinical practice. Reports of IgE-reactive coriander proteins in individual patients do not constitute a validated component-testing panel.
Additional clinical testing: Skin-prick testing or medically supervised exposure procedures may be used by allergy specialists when appropriate, but these approaches also assess sensitization or clinical reactivity in context rather than replacing clinical assessment.

Test Preparation and Influencing Factors

Blood-test preparation: Serum-specific IgE testing generally requires no fasting or other special preparation.
Medications: Patients should report all medications. Antihistamines can interfere with some skin tests, but they generally do not prevent serum-specific IgE measurement. Medications should not be stopped without clinical guidance.
Clinical history: Timing, reproducibility, amount and form of coriander exposure, and symptom pattern are essential for interpreting the result.
Sensitization versus allergy: Detectable coriander-specific IgE demonstrates sensitization, not necessarily symptomatic allergy or risk of a severe reaction.
Cross-reactive sensitization: IgE binding may reflect antibodies recognizing shared proteins in pollen, celery, carrot, or related spices rather than clinically important reactivity to coriander itself.
Total IgE and age: Total IgE concentration, age, and the patient’s broader atopic profile can affect interpretation of quantitative specific-IgE results. No coriander-specific decision threshold reliably confirms clinical allergy.
Timing after exposure: Testing does not require immediate collection after eating coriander. A negative result should nevertheless be interpreted in relation to the history and the assay’s performance if testing was performed soon after a suspected reaction or when clinical suspicion remains high.
Assay variation: Results and reporting categories can vary between assay platforms and laboratories; numerical values should be interpreted using the reporting system and reference information for the method used.

Cross-Reactivity

Apiaceae plants: Coriander belongs to the Apiaceae family. Reported sensitization patterns include associations with celery, carrot, fennel, anise, dill, and caraway, although shared IgE binding does not prove that every related food will cause symptoms.
Birch and mugwort pollen: Human clinical and inhibition studies have identified associations between spice sensitization and birch or mugwort pollen allergy. Cross-reactive plant proteins, including profilin and Bet v 1-related proteins, have been implicated in some patients.
Related spices: Coriander, anise, and dill have been reported to contain common IgE-binding structures. The clinical significance of this finding varies, and cross-reactivity between coriander and unrelated spices such as ginger, paprika, or fenugreek has not been consistently demonstrated.
Clinical relevance: Cross-reactive IgE may contribute to oral symptoms after raw plant-food exposure or may produce positive laboratory results without clinical reactions. Sensitization to pollen or another Apiaceae food should not be equated with confirmed coriander allergy.
Occupational exposure: In individual occupational cases, inhalation of coriander dust caused immediate IgE-mediated respiratory reactions, including asthma, and in one report coriander-associated anaphylaxis occurred after occupational sensitization.