Testing for Celiac Disease and Gluten Sensitivity

Who should be tested for celiac disease?
People with symptoms of celiac disease should ask their doctor about being tested.

In addition, people with any of the following associated conditions should ask about testing for celiac disease:

• Addison’s Disease
• AIDS
• Asthma
• Attention deficit disorder in children (ADD)
• Autism
• Autoimmune liver disease
• Autoimmune thyroid disease
• Chronic diarrhea of unknown origin
• Dermatitis herpetiformis
• Diabetes mellitus, type 1
• Down’s syndrome
• Gastroesophageal reflux disease (GERD)
• Hepatitis C
• Idiopathic pulmonary fibrosis
• Inflammatory bowel disease (IBD)
• Irritable bowel syndrome (IBS)
• Iron deficiency
• Lupus
• Microscopic colitis
• Osteopenia
• Osteoporosis
• Peripheral neuropathy
• Miscarriages (persistent) or infertility, or any woman with children that have neural tube defects
• Rheumatoid arthritis
• Seizure disorders
• Short stature in children
• Sjogren’s syndrome
• Any other autoimmune syndrome

Relatives of celiacs or gluten-sensitive individuals should also be tested, and individuals with celiac disease should be re-tested one year after following a gluten-free diet.

What are the tests for celiac disease?
Your doctor will do a blood test first. The celiac panel antibody blood test should include:

• Anti-Tissue Transglutaminase (tTG) – if positive, celiac disease is likely. This test can produce false negatives.
• Anti-Endomysial (EMA) – if positive, celiac disease is likely. This test can produce false negatives. The EMA test is subject to operator interpretation, making the results more subjective than those for tTG.
• Deamidated gliadin peptide antibody (DGP) – this is the newest test for celiac disease, and is meant to be used in conjuction with the tTG to help make a diagnosis of celiac disease without needing a biopsy.
• Total Serum IgA – this tests a person’s ability to make immunoglobin IgA. If someone is IgA deficient, they will test negative for the above tests even if they have celiac disease. This test must be done in conjunction with above antibody testing.
• Anti-Gliadin (AGA) IgA and Anti-Gliadin (AGA) IgG – these tests are considered outdated to detect celiac disease, but may be useful in follow-up testing to make sure that people are following a gluten-free diet, and have been considered useful in detecting gluten sensitivity. They may also be useful for screening children younger than 18 months old in whom tTG and EMA tests may yield false negative results.

What if I test positive on the celiac blood tests?
If you test positive on the tTg or EMA, then your doctor will most likely order a biopsy to check for flattening of the villi in your small intestine. If positive for damage, a diagnosis of celiac disease is usually made.

What if I test negative on the celiac blood tests?
The blood tests for celiac disease are not 100% accurate. Therefore, if you test negative on the blood tests, this does not mean that celiac disease should be ruled out. Some people have positive biopsies despite having a negative blood test. It is possible to have latent celiac disease, which means the signs of celiac haven’t shown up yet in your life, but still could.

Also, it is possible that you have Non-Celiac Gluten Sensitivity (NCGS), or gluten intolerance. You may respond positively to a gluten-free diet even though you have not met the strict criteria for a diagnosis of celiac disease.

Are there any other testing options?

Gene testing is a way to tell if a person is predisposed to developing celiac disease. If someone has the genes HLA DQ-2 or DQ-8, he may develop celiac disease. If he does not have these particular genes, it is unlikely that he will develop celiac disease, but this does not rule out gluten sensitivity.

If the tests for celiac disease are negative, but reactions to gluten persist, another testing option is a stool test for gluten sensitivity, offered by Enterolab. There are also new tests being offered by Cyrex Labs.

Ultimately, the treatment for celiac disease and gluten intolerance are the same — a gluten-free diet. If you feel better on a gluten-free diet, then stick with it! You could always do a gluten challenge and see if your symptoms return (though I personally don’t recommend this for someone who knows they react to gluten and will get very ill if they intentionally eat it).

Please consult a doctor and dietitian regarding any testing, diagnosis and diet.