🌾 Coeliac Screen (tTG-IgA)

A key blood test to check for gluten intolerance and diagnose coeliac disease.

🔍 What is it?

The Coeliac Screen, typically based on the tissue transglutaminase antibody (tTG-IgA) test, is used to detect coeliac disease — an autoimmune condition where the body reacts to gluten, a protein found in wheat, barley, and rye.

In people with coeliac disease, gluten triggers the immune system to attack the lining of the small intestine, leading to nutrient malabsorption, gut symptoms, and systemic issues.

🧪 What does it measure?

• tTG-IgA (Tissue Transglutaminase Immunoglobulin A)
  • A highly sensitive and specific antibody marker for coeliac disease
  • Elevated levels suggest an immune response triggered by gluten
    
     

• Sometimes paired with:
  
  Total IgA – to rule out IgA deficiency, which could lead to a false negative

  EMA (Endomysial Antibody) – used as a confirmatory test in some cases
  
   

🔎 Note: To ensure accuracy, you should be eating gluten regularly before the test.

❓ Why might I need it?

You may be advised to get this test if you experience:

• 🤰 Persistent bloating, diarrhoea, or abdominal discomfort
• ⚖️ Unexplained weight loss
• 💤 Fatigue, 🤯 brain fog, or 😠 irritability
• 🧴 Skin rash (dermatitis herpetiformis)
• 🩸 Nutrient deficiencies – especially iron, B12, or folate
• 👨‍👩‍👧 Family history of coeliac disease or other autoimmune conditions
   

🧬 Conditions it can help detect:

• Coeliac disease
• Possible non-coeliac gluten sensitivity (if symptoms are present but tests are negative)
• Monitoring effectiveness of a gluten-free diet
  
   

Diagnosis is usually confirmed by follow-up tests, such as an endoscopy and small bowel biopsy.

🩺 How is it done?

• A blood sample is taken from a vein in your arm
• Results are typically available within 2–3 working days
• A gluten-containing diet must be maintained before testing for reliable results

💷 Typical Private Cost in the UK:

• £45–£90 for a coeliac screen panel
  
   
• May be included in digestive health panels or fatigue investigations
   

✅ Commonly Combined With:

• Full Blood Count (FBC) – to check for anaemia
• Iron, B12, Folate levels – to assess nutrient deficiencies
• Vitamin D test – malabsorption may reduce levels
• Stool tests – to rule out other causes of GI symptoms
  
   

📚 References:

1. NHS – Coeliac Disease Overview
2. Coeliac UK – Testing and Diagnosis
3. National Institute for Health and Care Excellence (NICE) – Coeliac disease diagnosis and management