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Tests

Most coeliac disease testing involves the detection of specific autoantibodies. It is performed to diagnose and monitor coeliac disease, primarily in symptomatic people. Testing may include:

  • Anti-tissue Transglutaminase (anti-tTG) Antibodies, IgA: This is the most sensitive and specific blood test for coeliac disease and is typically the initial test performed.
  • Anti-tTG, IgG: The test for the IgG class of anti-tTG is less sensitive and specific than the IgA class but is not affected by IgA deficiency, which is more common in those with coeliac disease.
  • Deamidated Gliadin Peptide (DGP) Antibodies, IgA: a relatively new test that may be positive in some people with coeliac disease who are anti-tTG negative; DGP IgG testing along with anti- tTG IgA is recommended in Australia.
  • Anti-Gliadin Antibodies (AGA), IgG and IgA: an autoantibody against the gliadin portion of gluten; guidelines by the American College of Gastroenterology published in 2013 do not recommend this test for the primary detection of coeliac disease due to concerns with its accuracy.
  • Anti-Endomysial Antibodies (EMA), IgA: less common, provides essentially the same information as anti-tTG.
  • Anti-Reticulin Antibodies (ARA), IgA: less common; not as specific or sensitive as other tests.
  • Anti-Actin IgA (F-actin): less common; may indicate increased intestinal damage.

To confirm a diagnosis of coeliac disease, a biopsy of the small intestine is examined to detect damage to the intestinal villi.

Genetic tests that look for the markers that are strongly associated with coeliac disease are available but not routinely ordered. These tests include the Human Leukocyte Antigen (HLA) markers DQ2 and DQ8. A positive result does not diagnose coeliac disease since greater than 40% of the Australian population also carry these markers but do not have the disease. A negative result, however, can essentially rule out coeliac disease in those individuals for whom results of other tests, including biopsy, are unclear. These tests are most useful for family members of individuals with the disease who fall into a high risk category and for those with other diagnostic test results that are inconclusive.

Other tests may be ordered to evaluate the severity of the disease and the extent of a person's malnutrition, malabsorption, and organ involvement. These may include:

 

Non-laboratory testing: X-rays of the intestines after barium ingestion may show characteristic findings that indicate intestinal damage.


Last Review Date: June 4, 2017