Celiac Disease Antibodies
Celiac disease is a problem that happens when gluten in food causes your immune system to attack the lining of your small intestine.
As part of this mistaken attack, your immune system creates certain proteins called antibodies. If your doctor thinks you may have celiac disease, he or she will order a simple blood test that looks for these antibodies.
Why It Is Done
A celiac disease antibodies test is done to:
- Help diagnose celiac disease.
- Check how well a gluten-free diet is working as a treatment for celiac disease.
- Look for celiac disease in people who don't have symptoms but who do have close family members with the disease.
How To Prepare
If the test is being used to help diagnose your symptoms, it must be done while you are still eating foods that contain gluten. So if you have started a gluten-free diet, your doctor will have you go back to eating gluten foods several weeks ahead of the test.
You won't have to do anything else to prepare for the test.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form( What is a PDF document? ).
How It Is Done
The health professional taking a sample of your blood will:
- Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
- Clean the needle site with alcohol.
- Put the needle into the vein. More than one needle stick may be needed.
- Attach a tube to the needle to fill it with blood.
- Remove the band from your arm when enough blood is collected.
- Put a gauze pad or cotton ball over the needle site as the needle is removed.
- Put pressure on the site and then put on a bandage.
How It Feels
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
There is very little chance of a problem from having a blood sample taken from a vein.
- You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
- In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. A warm compress can be used several times a day to treat this.
Celiac disease antibody tests measure the amount of these antibodies in your blood.
There are several types of celiac disease antibodies that can be measured. The most common are:
- Tissue transglutaminase antibodies, or anti-tTG.
- Deamidated gliadin peptide antibodies, or anti-DGP.
- Anti-endomysial antibodies, or anti-EMA.
Celiac disease antibodies are not found in your blood. It's not likely that you have the disease.
Celiac disease antibodies are found. It's likely that you have the disease.
What Affects the Test
You may not be able to have the test, or the results may not be helpful, if:
- You have been on a gluten-free diet for several weeks before the test.
What To Think About
- You can have problems with gluten and not have celiac disease. If that's the case, your antibody tests will be negative.
- A positive test result doesn't always mean that you have celiac disease. But it's strong evidence that you need to have a biopsy. In a biopsy, the doctor takes a small sample of tissue from your small intestine. The tissue is then tested in a lab. A biopsy is the only way to confirm that you have celiac disease. The biopsy is done using upper GI endoscopy.
- Close relatives of people with celiac disease sometimes have this test. This is because you're more likely to get celiac disease if a close family member has it.