Gluten Sensitivity Test: Everything You Need to Know About Screening for Celiac Disease
Diagnosing celiac disease is not always a simple process. It begins with a review of symptoms and a physical exam, often including blood tests to check for certain antibodies in the blood. From there, an endoscopy may be required to confirm the diagnosis.
If you’re suffering from any of the 200+ symptoms related to celiac disease, talk to your doctor about administering a gluten sensitivity test. Screening measures do exist, and receiving an accurate diagnosis is the first step in your path to recovery and living a healthy life.
Keep reading to learn more…
How Does Celiac Disease Affect the Body?
Celiac disease is also known as celiac sprue or gluten-sensitive enteropathy. Though you may not have heard these names before, you’re probably already familiar with the effects of the disease on the body.
In short, celiac disease is an immune reaction to eating gluten – a protein found in certain grains, including wheat, barley, and rye. When someone with celiac disease eats gluten, it triggers an immune response in the small intestine which, over time, damages the delicate lining of the intestines and prevents the body from absorbing nutrients properly. The damage may also lead to a number of digestive symptoms like diarrhea, bloating, and flatulence as well as anemia, fatigue, and weight loss.
Celiac disease affects different people in different ways. Some celiac sufferers experience digestive symptoms, while a small percentage experience skin problems. The diversity of symptoms is what makes the condition so hard to properly diagnose, but there are certain things to look for, which indicate a strong possibility and a need for screening.
Who Should Be Screened for Celiac Disease?
If you start experiencing digestive symptoms that last for more than a few days, it could be a sign of an underlying issue. The best thing to do is write down the symptoms you’ve been experiencing, when they began, and how often you have them. This will give your doctor a place to start. Celiac disease symptoms are highly variable, but any sort of chronic digestive issue is worth a closer look.
In addition to people with celiac symptoms, the following people should be screened for celiac disease:
- Anyone with a first-degree relative with celiac disease. People with parents, children, or siblings with celiac disease have a 1-in-10 risk compared to a 1-in-100 risk of developing it.
- Anyone who has a related autoimmune disorder, including type 1 diabetes, thyroid disease, Down syndrome, Turner syndrome, Williams syndrome, and selective IgA deficiency.
- Females with chronic digestive symptoms. Research shows that 60% to 70% of celiac disease sufferers are women.
Screening for celiac disease in young children can be tricky. Most doctors recommend that children at risk for celiac disease be screened at age 2 or 3 unless symptoms manifest earlier. The child must be eating wheat- or barley-based cereals for about a year before you can expect to see an autoimmune response to gluten in testing. Failure to focus, ADHD symptoms, and constant digestive issues (such as persistent diarrhea and bloating) are the most common symptoms in children that indicate a need for celiac disease screening.
Step-by-Step Screening for Celiac Disease
Now that you have a better understanding of how celiac disease affects the body and who should be tested, you may be wondering how the testing process actually works. Below is a quick overview of the steps involved in screening for celiac disease.
- Tissue Transglutaminase IgA antibody test (tTG-IgA test)
- IgA Endomysial antibody (EMA) test
- Total serum IgA test
- Deaminated gliadin peptide (DGP IgA and IgG) test
The first of these tests, the tTG-IgA test, is the best way to screen for celiac disease in most adults and children. This test shows up positive in about 98% of patients with celiac disease as long as at the time of the test they are following a gluten-containing diet. There is some risk for a false-positive result and, though rare, it is possible for people with celiac disease to return a negative test result.
If the results of the tTG-IgA test are inconclusive, or if you want to double-check, there are some other tests your doctor may determine necessary. An EMA test is less sensitive than the tTG-IgA test, but it has a specificity of almost 100%. About 5% to 10% of people with celiac disease return a negative result, however, and it is very expensive by comparison. The total serum IgA test checks for an IgA deficiency, a condition that can cause a false negative result. Deaminated gliadin peptide tests are used to screen for celiac disease in people with IgA deficiency and people who test negative for tTG or EMA antibodies.
Another method of screening for celiac disease is genetic testing. People who have celiac disease carry one or both of the DQ8 and HLA DQ2 genes, but so does up to 30% of the general population. If you have one or both of these genes, your risk of developing celiac disease is 3% versus 1% for the general population. The test is great for people who have first-degree relatives with celiac disease because a negative result rules out the possibility of later developing the disease. However, it is not a conclusive positive result.
Genetic testing is recommended in the following cases:
- When other diagnostic tests for celiac disease return unclear results
- When antibody testing results are ambiguous (particularly in children under 3)
- When there is a discrepancy between antibody or biopsy findings in family members of people with celiac disease
A negative result indicates a 99% probability that patients who have first-degree relatives with celiac disease will NOT develop it. A positive result indicates that the patients should follow up with celiac disease screening every 2 to 3 years or if symptoms develop.
Confirming a Diagnosis of Celiac Disease
The tests discussed in the previous section cannot officially diagnose celiac disease on their own. A positive result on a tTG-IgA test or other tests indicates a strong likelihood that the patient has celiac disease, but other measures are required to confirm the diagnosis.
The only way to fully confirm a diagnosis of celiac disease is to have an intestinal biopsy. Also known as a duodenal biopsy, an intestinal biopsy will tell you if you have celiac disease, if your symptoms improve on a gluten-free diet due to the placebo effect, or if you have another digestive disorder or sensitivity that responds to dietary changes.
There are two ways to perform an endoscopy – by inserting a long tube with a tiny camera through the mouth into the intestine or by swallowing a capsule containing a tiny camera. The benefit of a traditional endoscopy is that the doctor can also use the tube to take a small tissue sample to examine more closely while a capsule endoscopy can only take pictures.
In cases of celiac disease where the patient shows symptoms of dermatitis herpetiformis or gluten rash, a skin biopsy may be necessary as well. This biopsy is generally sufficient for diagnosing both celiac disease and the dermatitis herpetiformis.
Tips for Managing Celiac Disease
Unfortunately, as of right now, celiac disease is an incurable condition. However, it is very manageable with a gluten free diet. Removing gluten from your diet is the only way to prevent the autoimmune reaction that damages the intestines and causes symptoms.
Here are some additional tips for managing celiac disease:
- Work together with your doctor and dietician to make sure you thoroughly understand the gluten free diet and how to transition onto it properly.
- Find a support or advocacy group online or in person to connect with other celiac sufferers.
- Ask your doctor about getting additional bloodwork done to test for nutritional deficiencies and take supplements as needed.
- Take the time to learn how to read food labels, paying particular attention to the allergen warning, and learn how to identify hidden sources of gluten in food.
- Experiment with gluten-free baking alternatives like nut flours to create gluten free versions of your favorite recipes.
- Be patient and really stick to the diet – it may take time to see true results, but the more you adhere to the diet, the sooner you’ll start to feel better.
Being diagnosed with a chronic illness is never easy, but celiac disease is relatively easy to manage. It is important to obtain an accurate diagnosis at the start and to follow your doctor’s advice for making changes to your diet and lifestyle to speed your recovery and provide lasting results.