See which screening tests aid in diagnosis
Both genetic and antibody testing are available
Screening for celiac disease is done with both genetic and antibody tests. The genetic test shows if the genes necessary to develop the disease are present. This test is particularly good for ruling out the disease when no such genes are found. The antibody blood test shows if the body is responding negatively to gluten. In either case, a positive result requires further action for diagnosis. Diagnosis occurs only with an endoscopic biopsy.
For most people, the serum anti-tissue transglutaminase (tTG-IgA) is the best antibody blood test for screening for celiac disease; however, it is important to also get a total serum IgA. Having this total serum test will help bolster the reliability of the tTG test. The reason for this is that while the tTG test is very reliable, its reliability is dependent on the premise that the person being tested adequately produces IgA. If the individual does not produce sufficient amounts of IgA and is instead IgA deficient, then tTG-IgG should be tested instead.
There is also a newer version of the old screening test that checked the levels of anti-gliadin antibodies, called DPG (for deamidated gliadin peptides). While evidence shows these tests to be as reliable as the tTG, they are not necessarily better than the tTG.
NOTE: Dermatitis herpetiformis (also known as DH, the skin version of celiac disease) is best diagnosed with a skin biopsy that is sufficient for diagnosis. Patients with DH may, in fact, have normal serum tTG and occasionally even normal intestinal biopsy, yet they invariably need a strict gluten-free diet, just like every other celiac patient.
Annual free screening day
The University of Chicago Celiac Disease Center will hold its next annual free blood screening on Saturday, October 13, 2012. Be sure to direct appropriate patients to the Free Screening section of this Web site for more information.