A lot of friends have been asking me about the whole process of getting tested for celiac disease. Enough by now that I’m figuring I ought to do a full write-up instead of typing up a new answer each time. So, without further ado:
The Tests Themselves
There are three: antibody, genetic, and biopsy.
- The antibody test, aka screening test, looks for anti-gluten antibodies and anti-self antibodies. IgG & IgA are the antibodies the body produces against gluten. EMA and tTG look for anti-self antibodies (this is the bit where your body attacks itself, specifically the intestines). This is usually the first celiac test you’ll take. While it’s pretty good, it’s not 100% accurate. It is possible to get a false result. You must be eating gluten for this test to be accurate. I’d been off gluten for a year before getting tested, and we all know what a disaster that led to.
- The genetic test looks for either of two markers, DQ2 and DQ8. Having those does not mean you have an active case of celiac disease. It just means that you’re a carrier. It may never become active. However, if you don’t have either of those, you probably can’t have celiac disease.(I have DQ8). You don’t need to be eating gluten for this one.
- The biopsy is the gold standard for celiac diagnosis. Most doctors won’t diagnose you without this test, and insurance usually won’t cover all of the other tests a celiac should get on a regular basis (like bone density scans) without an official diagnosis. The procedure is called endoscopy, and a GI will put a tube down your throat (you’ll be partially knocked out, so you won’t remember much) take pictures of anything interesting he sees on the way down, and then take samples from your small intestine. You do need to be eating gluten for this one.
You’ll probably have to get all of these tests for an official diagnosis. If you test positive for the genetic component, but not the other two tests, you’ll still want to get antibody tests every few years.
You can still have problems with gluten without being a celiac. Crohns, IBS, and I’m sure other diseases I’m not familiar with can all make you react to gluten (and that’s another reason to get the biopsy done – to rule out those other possible diseases).
I can’t predict how any individual doctor will react to you asking for a celiac disease test. The blood tests are fairly simple, so I see no good reason for a doctor to refuse. However, there are still plenty of doctors who don’t know much about celiac disease. You may run into one who thinks it only happens in children or that it’s just a fad of the rich and famous.
I’ve noticed that doctors tend to tune out when you get emotional, so… Logic. It’s hard to ignore someone who’s calmly talking about symptoms and tests. It’s easy to stop listening to someone who gets angry or upset. Bringing related medical records helps. Don’t bring reams of articles or talk about researching on the web. Doctors get that all the time and it’s usually a sign that the patient is too freaked out to be logical.
You could go through all this, convincing the doctor and getting all the tests, and still get a false result. With all the tests, it’s unlikely. But it’s possible. If you feel better on a gluten free diet, do it anyway. Just wait until after you’ve done the tests.