Good question! Thanks for asking. So, for those who don't know, IgG is the most important tailor-made antibody in the immune system's defense against invaders - including allergens. It remains long after the initial cause has been suppressed and attempts to prevent another “attack.” When someone is allergic to gluten, for instance, the body recognizes proteins from gluten to be foreign. The body then sends out antibodies, including IgG, to protect the body. With this said, IgG measu...