Multiplex Specific IgE Profile: ALEX 295-Allergen Test

Allergy is a condition in which the body reacts abnormally to substances known as allergens. These substances may enter the body through inhalation, skin contact, or ingestion. Allergies may result from several factors, including genetics, an abnormal immune response to foreign substances, and environmental influences.

In IgE-mediated allergic reactions, exposure to an allergen triggers mast cells and basophils to release histamine and other inflammatory mediators. This may lead to symptoms such as:

๐ Allergic rhinitis and conjunctivitis
๐ Asthma
๐ Atopic eczema
๐ Gastrointestinal symptoms
๐ Severe systemic reactions, including anaphylaxis

Blood testing for allergen-specific IgE can help identify substances that may trigger allergic reactions, allowing patients to avoid relevant allergens and receive appropriate medical advice.

Allergy Testing Methods

The two commonly used methods for identifying IgE-mediated allergies are:

๐ Allergen-specific IgE blood testing
๐ Skin-prick testing

The ALEX Multiplex Specific IgE Profile can test for up to 295 allergens in a single blood sample. The test covers allergen extracts and molecular allergens from several major groups, including:

๐ Inhalant allergens
๐ Food allergens
๐ Insect venoms
๐ Latex
๐ Individual molecular allergen components

What Makes the ALEX Test Unique?

The ALEX 295-allergen test can detect specific IgE antibodies against multiple allergen extracts and molecular components in a single test order. It provides a detailed overview of the patient’s sensitisation profile using macroarray-based ELISA technology.

The test reports allergen-specific IgE quantitatively and total IgE semi-quantitatively. Molecular components are highly purified proteins isolated from specific allergen sources, allowing more detailed and differentiated allergy assessment.

This information may help doctors:

๐ Identify the specific substances responsible for allergic sensitisation
๐ Distinguish genuine sensitisation from cross-reactions
๐ Assess the likelihood and potential severity of allergic reactions
๐ Develop personalised allergen-avoidance recommendations
๐ Make treatment and immunotherapy decisions

Example: Peanut and Cow’s Milk Sensitisation

A patient may test positive for sensitisation to peanuts and cow’s milk, with specific reactions to molecular components such as:

๐ Peanut storage proteins: Ara h 1, Ara h 2, and Ara h 6
๐ Cow’s milk proteins: Bos d 4, Bos d 5, and Bos d 8

Peanut Allergy

Symptoms associated with peanut allergy can range from oral allergy syndrome to severe anaphylactic reactions.

The peanut storage proteins Ara h 1, Ara h 2, Ara h 3, and Ara h 6 are associated with clinical reactions that may include severe anaphylaxis. These proteins are generally stable when exposed to heat and digestion.

Cross-reactivity between peanut storage proteins and proteins found in legumes, nuts, and seeds may range from low to moderate. In highly sensitive individuals, even small traces of peanuts may trigger a serious reaction.

Cow’s Milk Allergy

Cow’s milk allergy may cause:

๐ Severe allergic or anaphylactic reactions
๐ Gastrointestinal symptoms
๐ Atopic dermatitis

Bos d 4 and Bos d 5 are relatively sensitive to heat. Some sensitised patients may therefore tolerate milk that has been thoroughly cooked or baked.

Bos d 8, also known as casein, is more stable when exposed to heat and digestion. Patients sensitised to this protein may require strict avoidance of milk and milk-containing products.

Patients at risk of severe allergic reactions should receive personalised avoidance instructions and may be prescribed an emergency kit containing an adrenaline auto-injector.