What's IgG4 and why do we use it?
Immunoglobulin G (IgG) is a type of antibody found in human blood. The antibody has four subclasses (1-4) and make up an important part of the body’s immune response.
We test for raised IgG4 levels when identifying immune-mediated intolerances. There are a range of IgG tests available to health professionals all over the world, some testing all subclasses and others testing one subclass but there is still debate about which is the most effective.
The subclasses most commonly tested are IgG1 and IgG4, as these are produced in response to food antigens and therefore can be used to identify intolerances. IgG2 and IgG3 are not generally produced in response to food antigens and therefore produce a high rate of false positives.
The results provided by testing of these antibodies are commonly used to adapt an individual’s diet through elimination or optimisation.