Biomarker: M002-IgE Cladosporium herbarum

Overview

This biomarker measures allergen-specific immunoglobulin E (IgE) antibodies in blood directed against Cladosporium herbarum, an outdoor and indoor mold. IgE is involved in immediate hypersensitivity reactions and can contribute to allergic rhinitis, conjunctivitis, wheezing, and asthma symptoms in sensitized individuals. A high result indicates sensitization to the tested mold but does not by itself confirm symptomatic allergy or predict reaction severity; a low or negative result makes detectable sensitization less likely but does not completely exclude allergy. Testing is clinically useful when interpreted with exposure history, symptoms, physical findings, and, when appropriate, skin testing.

Clinical Use Cases

Assess suspected mold-related allergic rhinitis, conjunctivitis, or asthma.
Identify sensitization to C. herbarum in patients with respiratory symptoms associated with mold exposure.
Support evaluation when skin-prick testing is unsuitable, contraindicated, or difficult to perform.
Help identify potential aeroallergen triggers for exposure-reduction counseling.
Support clinical or epidemiologic research on fungal sensitization and allergic respiratory disease.
Distinguish IgE-mediated mold sensitization from non-IgE-mediated conditions, recognizing that the test does not diagnose infection, toxic mold exposure, or hypersensitivity pneumonitis.

Specimen Types

Venous blood.
Serum, typically separated from the collected blood sample.
Plasma may be accepted by some laboratory methods, depending on the assay protocol.

Measurement Methods

In-vitro serum allergen-specific IgE immunoassays.
Enzyme-linked immunosorbent assays.
Fluorescent or chemiluminescent immunoassays.
Older radioallergosorbent test methods, generally referred to as RAST.
Skin-prick or puncture testing with C. herbarum extracts as an alternative assessment of sensitization, although this is not a blood measurement.

Test Preparation and Influencing Factors

Fasting is generally not required for an allergen-specific IgE blood test.
Patients should report all medications, particularly antihistamines and drugs that may affect the choice or interpretation of complementary skin testing. Medications should not be stopped unless directed by a healthcare professional.
Results should be interpreted with the patient’s symptom pattern, timing of exposure, season, occupational or residential environment, and other allergy-test results.
A positive result indicates sensitization and does not establish that C. herbarum is causing current symptoms or indicate disease severity.
Cross-reactivity among fungal allergens can complicate interpretation.
Mold-specific IgE assays and allergen extracts have variable standardization, sensitivity, and specificity. Testing should not be used as a stand-alone assessment of environmental mold exposure.
Total IgE, smoking, parasitic infection, and other allergic conditions can influence overall IgE measurements, but they do not specifically identify C. herbarum sensitization.