Why Do We Test IgG4 Over Total IgG Or IgG1?
Food allergies, intolerances and sensitivities are becoming more topical in a variety of sectors in the healthcare industry. It is a constant talking point for both health professionals and their patients. Nutrition as a topic and, more specifically allergies, intolerances and sensitivities, are getting more coverage than ever in the media. This is helping spread awareness about potential symptoms and the benefits of testing.
IgG1 and IgG4
In order to test for immune-mediated intolerances specifically, testing for IgG antibodies is required. Within the IgG class there are four IgG subclasses. There are a range of IgG tests, which are available to health professionals all over the world, some testing all subclasses and others testing one subclass but there are on-going discussions about which is the most effective. Of the four subclasses the 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. The main difference between IgG1 and IgG4 is how they respond to food antigens. IgG1 antibodies are like ‘first responders’ and are produced in response to new food antigens whereas IgG4 antibodies are produced when the body is continually exposed to an antigen. If you’d like to understand the deeper science behind the production of IgG1 and IgG4 antibodies click here.
Therefore testing for IgG4 over IgG1 or total IgG is an advantage, as it leads to a reduced number of false-positives and allows for much more targeted, relevant results. It reduces the incidence of patients removing too many foods and doing so unnecessarily, therefore improving patient compliance and outcome. Basically, you are able to learn and understand the food items your body can tolerate, or, no longer tolerate and take steps to make changes with confidence.