When it comes to understanding and diagnosing coeliac (celiac) disease, it’s easy to feel overwhelmed by all the terminology you may not be familiar with. However, getting the right diagnosis is crucial for your health and wellbeing. This guide will walk you through the steps involved in diagnosing coeliac disease and explain the meaning of terms you might hear like coeliac serology and bloodwork.
What is Coeliac Disease?
Coeliac disease is an autoimmune disease where the immune system mistakenly attacks the lining of the small intestine when dietary gluten is consumed. Gluten, a protein found in wheat, barley, and rye, triggers this response, leading to inflammation and damage to the digestive tract. This can cause a range of gastrointestinal symptoms, including abdominal pain, diarrhoea, bloating, and nausea, as well as non-digestive issues like fatigue, joint pain, and skin conditions such as dermatitis herpetiformis.
The diagnosis of coeliac disease typically involves a combination of a physical exam, blood tests (including those for IgA deficiency), and an upper endoscopy, where a thin tube with a camera is used to examine the small intestine and take a biopsy. In some cases, a skin biopsy may be performed to confirm dermatitis herpetiformis. Coeliac disease can sometimes be misdiagnosed as irritable bowel syndrome, making it essential for medical professionals and health care professionals to assess symptoms thoroughly.
Risk factors for developing coeliac disease include a family history of the condition, other autoimmune diseases, and certain genetic markers. While it affects about 1% of the general population, many cases remain undiagnosed. If left untreated, coeliac disease can lead to severe complications, including malnutrition, osteoporosis, infertility, and even an increased risk of certain cancers.
Managing coeliac disease requires strict avoidance of dietary gluten. Those diagnosed should work closely with a pediatric gastroenterologist (for children) or a specialist to receive the latest medical information and ensure proper management of the condition.
Coeliac Serology: The First Step in Diagnosis
One of the primary methods used to diagnose coeliac disease is through coeliac serology. This involves a series of blood tests that look for specific antibodies in your blood. When you have coeliac disease and consume gluten, your body produces higher levels of certain antibodies, such as tissue transglutaminase (tTG).
Your doctor will typically order these blood tests if you’re experiencing symptoms of coeliac disease, such as abdominal pain, diarrhoea, fatigue, and weight loss. It’s important to note that for these tests to be accurate, you need to be on a gluten-containing diet. If you’ve already eliminated gluten from your diet, the antibody levels might not be elevated, leading to a false-negative result.
If you’ve been gluten-free for more than about 6 weeks, you’ll need to start eating it again before testing to make sure your results are accurate. This process is known as a ‘gluten challenge.’ It might sound a bit daunting, but it’s an important step to get a clear and accurate diagnosis.
Blood Tests for Coeliac Disease: What to Expect
When you go for bloodwork to test for coeliac disease, your healthcare provider will likely order a panel of tests. The most common ones include:
- tTG-IgA Test: This is the most sensitive and specific test for coeliac disease. High levels of tTG-IgA antibodies strongly suggest coeliac disease.
- EMA Test: The endomysial antibody (EMA) test is another highly specific test. A positive result almost always indicates coeliac disease, although it’s less commonly used due to being more expensive.
- Total IgA: Since some people with coeliac disease have an IgA deficiency, doctors will often check your total IgA levels to ensure the accuracy of the tTG-IgA test.
- Deamidated Gliadin Peptide (DGP) Test: This test may be used, particularly in young children, as it can sometimes detect cases that the tTG-IgA test might miss.
If your coeliac antibody levels are high, it could indicate coeliac disease, but these blood tests alone aren’t enough for a definite diagnosis. Even with a positive result, don’t start a gluten-free diet yet. You’ll need to see a gastroenterologist to confirm the diagnosis.
Small Bowel Biopsy – Gold Standard for Diagnosis
If your bloodwork suggests coeliac disease, your gastroenterologist will likely recommend a gastroscopy (also called an endoscopy) to collect tiny samples (biopsies) of the small bowel. During this procedure, a small camera is inserted through your mouth and into your small intestine to take tissue samples. These samples are then examined under a microscope to check for damage to the villi—tiny hair-like structures in the small intestine that help with nutrient absorption. Damage to these villi is a hallmark of coeliac disease.
In some cases, genetic testing may also be recommended. While not definitive on its own, genetic testing can identify if you carry the HLA-DQ2 or HLA-DQ8 genes, which are necessary for coeliac disease to develop. However, having these genes alone doesn’t mean you will definitely develop the condition.
When to Talk to Your Doctor
If you’re experiencing symptoms that you suspect might be related to coeliac disease, it’s essential to talk to your doctor. Early diagnosis and treatment can prevent long-term complications and help you feel better sooner. Remember, it’s crucial to keep eating gluten until all tests are completed, as going gluten-free beforehand can skew your results.
Getting a diagnosis of coeliac disease can feel daunting, but understanding the testing process can empower you to take charge of your health. Coeliac serology and bloodwork are the first steps in identifying the condition, followed by an gastroscopy to confirm the diagnosis. With the right medical guidance and a strict gluten-free diet, those with coeliac disease can live healthy, fulfilling lives.
If you have any questions or concerns about coeliac disease, don’t hesitate to reach out to your healthcare provider. They’re there to help guide you through the process and ensure you get the support you need. For meal ideas to help you navigate your gluten-free life, head over to our recipe index for lots of delicious inspo.
