Biomarker: E001-IgE Cat Dander
Overview
E001-IgE Cat Dander measures immunoglobulin E (IgE) antibodies specific to cat dander and associated cat allergens in blood. Cat allergens are present primarily in skin flakes, saliva, and other secretions; Fel d 1 is the major recognized cat allergen. A high result indicates sensitization to cat allergens, but it does not by itself confirm symptomatic allergy or predict reaction severity. The test is clinically useful when interpreted with exposure history and symptoms such as allergic rhinitis, conjunctivitis, dermatitis, wheezing, or asthma.
Clinical Use Cases
- Support evaluation of suspected cat allergy in patients with symptoms associated with cat exposure.
- Identify sensitization to cat allergens in patients with allergic rhinitis, conjunctivitis, eczema, or asthma.
- Help assess potential environmental triggers of asthma or respiratory symptoms.
- Supplement or provide an alternative to skin-prick testing when skin testing is unsuitable, unavailable, or affected by medications or skin disease.
- Support allergen avoidance counseling and broader evaluation of environmental allergen sensitization.
- Provide a basis for additional component-resolved testing, such as testing for Fel d 1, when clinically indicated.
Specimen Types
- Venous whole blood, from which serum or plasma is analyzed.
- Serum is the most commonly reported specimen for allergen-specific IgE measurement.
Measurement Methods
- Quantitative serum allergen-specific IgE immunoassay.
- Fluorescence enzyme immunoassay, including ImmunoCAP-type assays.
- Enzyme-linked immunosorbent assay or other enzyme immunoassay formats.
- Older radioallergosorbent test, or RAST-type, methods are historical predecessors to current nonradioactive immunoassays.
- Skin-prick testing measures tissue reactivity rather than circulating IgE and may be used as a complementary method.
Test Preparation and Influencing Factors
- No fasting or other special preparation is usually required for an allergy blood test.
- Patients should report all medications and supplements to their healthcare professional.
- Antihistamines generally do not interfere with serum-specific IgE testing, although they may affect skin-prick testing. Medication instructions should be provided by the healthcare professional.
- Medications should not be stopped unless specifically instructed by a healthcare professional.
- Recent or ongoing exposure to cats does not generally require a particular collection time.
- Results may be influenced by assay characteristics, laboratory reference ranges, and the analytical cutoff used.
- A positive result indicates immunologic sensitization, which is not synonymous with clinically relevant allergy. Interpretation should incorporate symptoms, exposure history, and other clinical findings.
- The concentration of cat-specific IgE does not reliably predict the severity of an allergic reaction.
Synonyms
- Cat dander-specific IgE
- Cat allergen-specific IgE
- Cat epithelium-specific IgE
- Cat serum-specific IgE
- Cat-specific immunoglobulin E
- Cat dander IgE
- Cat allergen IgE
- E1 cat dander IgE
- Felis domesticus-specific IgE
- Fel d 1-specific IgE, when testing the major molecular cat allergen rather than the whole cat-dander extract
This information is provided for general educational purposes and is not medical advice. Biomarker information may describe testing methods, measurements, or interpretations that vary by laboratory or specific test. For details about a particular lab test, including biomarkers measured, specimen type, collection requirements, preparation, and turnaround time, please refer to the individual test description. Talk with a licensed health care provider about your results.
