Celiac & Gluten Sensitivity Test

Description

What this test will show

This comprehensive test uses widely accepted immunological biomarkers to aid in the diagnosis of celiac disease and gluten sensitivity. Analytes tested include total IgA, anti-tissue transglutaminase IgA (tTG IgA), anti-deamidated gliadin IgA (DGP IgA), and reflex anti-endomysial IgA (EMA IgA). Gluten sensitivity is assessed with anti-gliadin IgA and anti-gliadin IgG.

Who is this test for

For those who suspect they are reacting to gluten.

Celiac disease is an autoimmune condition of the small intestine, caused by exposure to dietary gluten in genetically susceptible individuals. The inflammatory response in the upper part of the small intestine can eventually interfere with nutrient absorption and may lead to deficiencies. Symptoms associated with celiac disease include bloating, IBS, diarrhea, weight loss, post prandial abdominal pain, infertility, conditions associated with the liver and other automimmune conditions.

Non-celiac gluten sensitivity (NCGS) is triggered by eating gluten, but on testing there are no celiac specific antibodies present. Symptoms of gluten sensitivity include abdominal pain, bloating, diarrhea, constipation, alternating bowel habits, IBS, nausea, brain fog, fatigue, inability to concentrate, headache, anxiety, joint pain, skin rash.

A wheat allergy (see the IgE Food antibody test) and celiac disease should be eliminated first before diagnosing NCGS.

Sample type: Blood – you will need to arrange to attend one of our phlebotomy clinics to get a blood draw; click here to find your nearest clinic, surgery or hospital offering this service.

Turnaround time: 12 days

Before taking this test: The patient must continue to include gluten in the diet whilst performing this test because antibodies will only be present if the patient has consumed gluten prior to testing. According to the American College of Gastroenterology, a proposed gluten challenge after being gluten-free involves eating 3 grams of gluten daily for 8 weeks prior to testing. However, diagnostic changes are seen in most celiac disease patients after as little as 2 weeks of gluten ingestion.¹

Rubio-Tapia A, et. al. ACG Clinical Guidelines: Diagnosis and Management of Celiac Disease. American Journal of Gastroenterology. 2013;108:656-676.

If the patient is already on a gluten-free diet, genetic testing of the HLA DQ2/DQ8 genes may be helpful. We are not currently able to offer this test.

Conditions which may influence test results: Antibody testing may be inaccurate if the patient has liver disease, severe kidney disease, protein-losing enteropathy from gastrointestinal tract damage, HIV infection, or other immunodeficiencies. Results may be skewed in patients with rheumatological pathologies associated with the production of heterophilic antibodies, such as rheumatoid factor (RF).

Viruses such as Epstein-Barr virus (EBV), rubella, and cytomegalovirus (CMV) can be associated with lower antibody levels.

Diseases associated with a false positive tissue transglutaminase (tTG) IgA antibody on the celiac test may include type 1 diabetes, autoimmune liver disease, primary biliary cirrhosis, inflammatory bowel disease, connective tissue diseases, and HIV infection. Genetic testing of the HLA DQ2/DQ8 genes may be helpful in these patients.

Medications which may influence test results: glucocorticoids including oral prednisone, steroid metered-dose inhaler, cortisone cream; chemotherapy; other immunosuppressive agents (eg humira, rituxan); NSAIDS (ibuprofen, naproxen, aspirin); anticonvulsants (carbamazepine, valproate); omalizumab, which is a monoclonal antibody designed to bind to free serum IgE. Heparin interferes with the measurement of tissue transglutaminase (tTG) antibodies on the celiac panel.

Whilst stopping these medications will produce a more accurate result, we do not recommend stopping any prescription or over the counter medications without first consulting with your healthcare provider.