Food Sensitivities and related diseases can cause a wide variety of illnesses ranging from skin rashes and headaches/migraines to chronic intestinal diseases.

Unbalanced or inadequate diets, enzyme deficiencies, stress, genetic predisposition, infections and inflammation, chemicals, medication/drugs, environmental pollutants and toxins are all possible contributing factors in the development of food sensitivities.

The Relevance of IgG + C3d

An IgG antibody reaction to a food is a delayed reaction (anywhere from several hours to days). Research has indicated that IgG antibodies produced in the blood against particular foods may promote certain inflammatory reactions within the body.

Testing for Complement (C3d) is a direct measure of systemic inflammation. The activation of Complement alongside the high production of IgG antibodies establishes the exact foods that need to be eliminated from your diet. Avoiding excessive food elimination programs.

Link Between Complement (C3d) and Inflammation

Any food antigen entering the bloodstream can produce symptoms associated with food sensitivities. Most food antigens enter the bloodstream through the intestinal epithelium and stimulate the production of IgG antibodies. IgG antibodies bind to food antigens that are free in the blood or that have deposited in tissues and form immune complexes (IC).

These immune complexes activate complement C3 which becomes covalently linked to the IgG forming IC-C3b; the C3b on the IC is cleaved forming IC-C3d. During this process, C3a (anaphylatoxin) is released which causes smooth muscle contraction and has a potent vascular effect.

Under normal circumstances, circulating IC-C3b bind to the CR1 receptors on red blood cells and are cleared from the circulation via the liver and spleen. The continued production of antibodies and the formation of IC may result in the accumulation of IC within our body tissues, subsequently, resulting in the activation of the terminal complement pathway C5-9 on the surface of these tissue causing cell lysis and inflammation.

Measuring both IgG and IC-C3d simultaneously generates twice the signal which enhances the tests sensitivity and specificity.