Biomarker: D002-IgE D farinae

Overview

D002-IgE measures serum immunoglobulin E (IgE) antibodies specific to Dermatophagoides farinae, a common house dust mite. IgE binds to mast cells and basophils and can trigger the release of histamine and other inflammatory mediators after exposure to mite allergens. A detectable or elevated result indicates sensitization and may support an allergy diagnosis when consistent with symptoms and exposure history, while a low or undetectable result makes sensitization less likely but does not independently exclude allergy. The test is clinically useful for evaluating suspected dust mite-associated allergic rhinitis, asthma, or other immediate hypersensitivity conditions and for identifying allergens before allergen immunotherapy.

Clinical Use Cases

Supporting evaluation of suspected house dust mite allergy.
Investigating allergic rhinitis, asthma, eczema, or other symptoms associated with indoor allergen exposure.
Identifying the allergen responsible for symptoms when the clinical history is unclear.
Supporting allergen selection before initiating immunotherapy.
Providing an alternative to skin testing when skin testing is unsuitable because of skin disease, medication use, age, or concern about a systemic reaction.
Assessing sensitization in clinical or epidemiologic research involving dust mite exposure and allergic disease.

Specimen Types

Serum collected from venous blood.
Plasma may be accepted by some assay systems, but specimen requirements vary by laboratory and method.

Measurement Methods

Allergen-specific immunoassays.
Fluorescence enzyme immunoassay (FEIA), including solid-phase assays such as ImmunoCAP.
Other platform-specific immunoassays, including enzyme-linked immunosorbent assays (ELISA) and chemiluminescent immunoassays.
Results may be reported in ( \text{kU/L} ), ( \text{kUA/L} ), or semiquantitative classes, depending on the laboratory.

Test Preparation and Influencing Factors

Fasting is generally not required for a specific IgE blood test.
Patients should report all medications, particularly antihistamines and other allergy treatments. Medications that interfere with skin testing may not affect blood testing in the same way, but medication decisions should be directed by a healthcare professional.
Results should be interpreted with symptoms, exposure history, physical findings, and other allergy testing because sensitization does not always indicate clinically significant allergy.
The measured concentration does not reliably predict the severity of a future allergic reaction.
Total IgE, smoking, parasitic infection, and other conditions may affect overall IgE concentrations and can complicate interpretation.
Markedly elevated total IgE may contribute to nonspecific binding and false-positive specific IgE results.
Results can vary between assay platforms and laboratories, so reference ranges and reporting classes should be interpreted according to the performing laboratory.
Testing after allergen immunotherapy is generally not useful for determining whether residual clinical sensitivity remains.