Biomarker: W014-IgE Pigweed, Common

Overview

W014-IgE Pigweed, Common measures serum IgE antibodies specific to common pigweed pollen, generally associated with Amaranthus retroflexus. Specific IgE indicates immune sensitization to the tested pollen, which may contribute to allergic rhinitis, conjunctivitis, or asthma when exposure causes compatible symptoms. A high result supports sensitization but does not establish clinical allergy or predict symptom severity. The test is clinically useful for identifying suspected pollen triggers when interpreted together with exposure history, seasonal symptoms, and physical examination.

Clinical Use Cases

Evaluate suspected pollen-related allergic rhinitis, allergic conjunctivitis, or asthma.
Identify common pigweed as a possible seasonal aeroallergen trigger.
Support allergen selection for avoidance counseling or allergen immunotherapy evaluation.
Assess patients who cannot undergo skin testing because of extensive skin disease, medication interference, or safety concerns.
Contribute to an aeroallergen sensitization profile in patients with seasonal respiratory symptoms.
Support research on sensitization patterns to Amaranthus pollen and its characterized allergens, including Ama r 1 and Ama r 2.

Specimen Types

Venous blood.
Serum separated from venous blood.
Plasma may be accepted by some assay platforms, according to the performing laboratory’s validated requirements.

Measurement Methods

In vitro allergen-specific IgE immunoassay using an extract of common pigweed pollen.
Fluorescence enzyme immunoassay or other automated solid-phase immunoassays.
Enzyme-linked immunosorbent assay methods in research settings.
Component-resolved testing for selected pigweed allergen molecules, such as Ama r 1 or Ama r 2, when clinically available. These component tests are distinct from whole-pollen extract-specific IgE testing.
Skin-prick testing with pigweed pollen extract is an alternative clinical assessment, but it does not measure serum IgE and is not the same as the W014 blood test.

Test Preparation and Influencing Factors

Fasting is generally not required for an allergy blood test.
Tell the clinician about all medications and supplements. Do not stop prescribed medicines unless specifically instructed.
Antihistamines and some other medications may interfere more with skin testing than with blood-based specific IgE testing; the ordering clinician should determine whether any medication changes are needed.
Results should be interpreted in relation to symptoms, timing of exposure, geographic pollen exposure, and physical examination.
A positive result indicates sensitization and does not by itself prove that common pigweed causes symptoms.
The concentration of specific IgE does not reliably predict the severity of an allergic reaction.
Different assay platforms and allergen extracts may produce results that are not directly interchangeable; interpretation should use the reporting laboratory’s reference ranges.
Total IgE elevation, cross-reactive pollen proteins, and polysensitization may complicate interpretation of an individual positive result.