Food Antigen Testing

When does a food allergy occur?

Food reactions can be divided into 3 categories:

1. Allergies IgE

2. Sensitivities

3. Intolerances

Food Allergy

When someone is allergic to an ingested food, the immune system sees this as potentially dangerous and produces the antibody against it and is known as an ‘IgE antibody response’. When antigens then bind to IgE on the surface of intestinal mast cells, they can cause a relatively immediate hypersensitivity reaction - often expressed as a large amount of histamine released into the body’s tissues.

IgE (Immunoglobulin E)

The IgE antibody response is the most commonly known food allergy response. This response usually occurs immediately and can create severe symptoms such as fluid retention, rashes, skin conditions, respiratory challenges, and even anaphylaxis.

IgE reactions can be permanent or can be influenced by working on your intestinal barrier function. About 8 foods account for 95% of food allergies - these include: soy, dairy, peanuts, tree nuts, fish, shellfish, wheat, and eggs.

IgG Subtype 4

IgG4 is important in relation to IgE because it can act as a blocking agent for an IgE reaction, reducing anaphylaxis and the symptoms mediated by IgE.

When the IgG4 reaction is greater than the IgE reaction for a particular antigen, IgG4 can block the IgE antibodies from binding to the receptor sites that would encourage the release of histamine, thereby reducing severity of the symptoms associated with the IgE reaction. This is referred to as the ‘blocking potential’. So not all IgE reactions are severe.

Food Sensitivity

The symptoms of food sensitivities are often milder than IgE allergy symptoms and the reaction can be delayed up to several days later. Antibodies (IgG) are still produced and cause a milder release of histamine from mast cells to help fight the intruder. This time however, the histamine is released into the bloodstream instead of into the body’s tissues, causing less severe symptoms. The blood can then carry the histamine to any part of the body, causing symptoms to be more widespread, making the sensitivities more difficult to diagnose. IgG reactions create inflammation that makes many health challenges worse.

Consistent exposure to the offending foods can cause trouble in the eyes, sinuses, airways and skin, but may also lead to chronic inflammation, pain, tissue damage and digestive disturbances. Symptoms like a constant runny nose, poor appetite, frequent headaches, mood changes, dark circles under the eyes and eczema are highly suspect of being a result of one or several food sensitivities because they don’t come on suddenly and tend to linger.

C3d (Complement component 3)

A dietary antigen test (IgG with Complement) measures the ‘complement activation’ for multiple foods. Complement activation is well-defined in the research as not only a cause of inflammation but one of the strongest causes. Reaction to the specified food will worsen if C3d activation is present along with an IgG antibody response.

When C3d is activated in response to an antigen, the C3 portion attaches to the antigen. This activation, even though it is independent, will amplify the reaction that occurs with total IgG greatly increasing inflammation and symptoms of sensitivity.

Thus all of the measurements (IgE, IgG (Subtypes 1-4) and C3d) are an important part of ascertaining how your body is responding to foods. This test needs to be sent to the USA for analysis (with an average of 3 weeks turn around for results) and costs $515 for the detailed lab work. For further enquiries, please contact me directly.