In the IgA- and/or IgG total gluten test (blood sample), circulating antibodies are measured against alpha-gliadin, a component of wheat gluten, and prolamines from rye, barley (hordein) and oats. The test is quantified by comparing the serum with sera from positive and negative patients, which are determined in one test.
At values below 0.500 it is assumed that gluten in the food from wheat, barley, rye and / or oats will not cause any symptoms.
The study of antibodies of type G (IgG) against gluten in the patient’s blood is a more sensitive but less specific method than research on antibodies of type A (IgA). IgG antibodies are also important in selective IgA deficiency, which often occurs in patients with gluten-sensitive enteropathy. This method selects patients at risk and / or patients suspected of celiac disease with IgA and / or IgG antibodies in the blood against gluten.
When patients keep to the gluten-free diet, compliance can best be determined by measuring only IgA total gluten.