Biomarker: M001-IgE Penicillium chrysogen

Overview

M001-IgE measures serum allergen-specific immunoglobulin E (IgE) antibodies directed against Penicillium chrysogen, an airborne indoor mold also known as Penicillium notatum. IgE participates in immediate hypersensitivity reactions, and sensitization to Penicillium may be relevant to allergic rhinitis, asthma, or other mold-associated respiratory symptoms. A detectable or elevated result indicates immunologic sensitization, but does not by itself prove that exposure causes symptoms or establish allergy severity. The test is clinically useful as part of an evaluation of suspected mold allergy, particularly when skin testing is unsuitable or cannot be performed.

Clinical Use Cases

Evaluating suspected sensitization to Penicillium chrysogen in patients with allergic rhinitis, asthma, or other mold-associated respiratory symptoms.
Identifying a specific mold allergen that may contribute to symptoms when the clinical history suggests mold exposure.
Supporting differential evaluation of respiratory symptoms when mold allergy is suspected.
Complementing skin-prick testing or mold-mixture specific IgE testing in the assessment of fungal sensitization.
Supporting allergen avoidance counseling and consideration of allergy-directed management when results are consistent with the patient’s history.
Evaluating patients who cannot undergo skin testing because of extensive skin disease, inability to discontinue interfering medications, or other clinical considerations.

Specimen Types

Serum from venous blood is the typical specimen.
Plasma may be accepted by some laboratories, depending on the assay and laboratory protocol.

Measurement Methods

Quantitative allergen-specific IgE immunoassay.
Fluorescence enzyme immunoassay, including ImmunoCAP-type methods.
Other validated solid-phase immunoassays may be used by individual laboratories.
Research methods have included immunoblotting for IgE reactivity to individual P. chrysogen allergens, such as Pen ch 13, but these are not the usual routine clinical method.

Test Preparation and Influencing Factors

Fasting is generally not required for an allergy-specific IgE blood test.
Patients should provide a complete list of prescription medicines, over-the-counter medicines, and supplements.
Antihistamines generally do not invalidate serum specific IgE testing, but they may affect skin-prick testing. Follow the ordering clinician’s instructions before stopping any medication.
Do not discontinue prescribed medicines without medical advice.
Results must be interpreted with the clinical history because a positive result indicates sensitization and does not independently confirm symptomatic allergy.
Reported concentrations and positive thresholds may vary by assay and laboratory. A commonly used threshold for aeroallergen sensitization is approximately (0.35\ \text{kU/L}), although clinical interpretation should follow the laboratory’s reference range.
Total IgE concentration, age, atopic conditions, and the patient’s pattern of environmental exposure may influence interpretation, but total IgE does not substitute for allergen-specific IgE testing.
Recent exposure to Penicillium is not usually required before blood collection.