Celiac.com 05/01/2020 - If you have celiac disease symptoms, for example chronic diarrhea, anemia, bloating, abdominal pain, anemia, etc, your doctor may order a blood test for celiac disease. Note that you must be eating gluten daily for at least 4-6 weeks to be accurately tested celiac disease, otherwise you may end up with false negative results.
For a celiac disease antibody test, a clinician collects a small amount of the patient's blood. The sample is then sent to a lab, where the blood cells are then removed, and the test is conducted.
Celiac Disease Blood Antibody Screening is ~98% Accurate When Done Using This Protocol
Testing begins with a test called Immunoglobulin A (IgA). If the results are normal, then a Tissue transglutaminase, antibody, IgA test is given. A weak positive should lead to the following tests:
- Endomysial antibodies (IgA) and;
- Gliadin (deamidated) antibody, IgA.
If the initial Immunoglobulin A (IgA) test is low, then these two tests should be done:
- Tissue transglutaminase antibodies, IgA and IgG profle.
- Gliadin (deamidated) antibodies evaluation, IgG and IgA.
If the initial Immunoglobulin A (IgA) test is deficient then these two tests should be done:
- Tissue transglutaminase (tTG) antibody, IgG.
- Gliadin (deamidated) antibody, IgG.
It sounds complicated, but it's pretty standard procedure now, and when blood screening is done this way the results for celiac disease are ~98% accurate.
Children Should Now be Diagnosed Using Only Blood Tests and No Biopsy
In most cases, it is no longer necessary to use biopsy to diagnose celiac disease in children.
Biopsy Still Standard in Adult Celiac Diagnosis
After positive blood tests some doctors still require a biopsy to confirm the diagnosis. However, this is changing, as new techniques allow doctors to accurately detect celiac disease in adults without a biopsy.
Remember, nearly all tests and screening for celiac disease require the patient to be eating a gluten-containing diet before testing, usually for at least 4-6 weeks before testing. Be sure to check with your doctor for the latest protocol.
Blood Tests for Follow Up Care
Blood tests may also be useful in follow up care in those with celiac disease to confirm that their diet is indeed free of gluten. Also, because of the lack of standardization, keep in mind that blood test results may not be directly comparable from one lab to the next.
More Celiac Disease Testing Resources
Blood Test Questions on the Celiac Disease and Gluten-Free Forum