What insight does the Food Sensitivity C3d and IgG4 test provide?

Testing for C3d and IgG4 Food Sensitivities provides insight on pro-inflammatory, complement system-activating, and autoimmune potential of sensitive foods. IgG4 subclass antibodies are connected to a protective response in the Complement (C3d) pathway of the innate immune system. IgG4 accounts for ~4-6% of total IgG. IgG4 subclass antibodies are created in response to an antigen that the body wants to prevent a subsequent inflammatory response to. Formation of antigen specific IgG4 antibodies often follows repeated and long term exposure to an antigen. Additionally, the rise in food-specific IgG4 may be an initial response to attenuate IgE-mediated disease but which, ultimately, results in a pro-inflammatory process in susceptible hosts. Overall, the role of allergen specific IgG antibodies and IgG4 subclass is still the subject of intensive research and debate in the scientific community. For more information, see the attached Food Sensitivity IgG4-C3d One Pager.