Tissue Transglutaminase IgA (Coeliac)
This blood test detects tissue transglutaminase IgA antibodies associated with coeliac disease. It is the primary screening test for gluten-related autoimmune intestinal damage.
Turnaround time
2 days
Biomarkers count
1
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Details about Tissue Transglutaminase IgA (Coeliac)
What is the Tissue Transglutaminase IgA test?
The Tissue Transglutaminase IgA (tTG IgA) test measures IgA antibodies produced by the immune system in response to tissue transglutaminase, an enzyme involved in intestinal tissue repair. In coeliac disease, ingestion of gluten triggers an autoimmune reaction that damages the lining of the small intestine.
Elevated tTG IgA antibodies are strongly associated with coeliac disease and reflect active immune-mediated intestinal inflammation. This test is widely recommended as the first-line blood test for coeliac screening.
For accurate results, the test should be performed while gluten is still included in the diet.
Why do I need a Tissue Transglutaminase IgA test?
Coeliac disease can present with a wide range of digestive and non-digestive symptoms, and some individuals have minimal or no gastrointestinal complaints.
You may need this test if you experience:
- Chronic diarrhoea or constipation
- Bloating, gas, or abdominal discomfort
- Unexplained weight loss
- Fatigue or low energy
- Iron deficiency or anaemia
- Vitamin or mineral deficiencies
- Skin rashes (such as dermatitis herpetiformis)
- Family history of coeliac disease
- Other autoimmune conditions
Identifying coeliac disease early helps prevent long-term complications such as malabsorption and nutritional deficiencies.
Benefits of the test
- Primary screening test for coeliac disease
Most sensitive and specific blood test for coeliac screening. - Detects autoimmune intestinal damage
Identifies immune response triggered by gluten. - Explains non-specific symptoms
Useful when symptoms are vague or extra-intestinal. - Guides further investigation
Positive results support referral for confirmatory testing. - Simple blood-based testing
Requires only a blood sample. - Useful in adults and children
Widely used across age groups. - Supports early diagnosis
Early detection helps prevent long-term complications. - Reduces diagnostic delay
Helps avoid prolonged unexplained symptoms.
Step-by-step: How we offer testing
Clinic-based testing (UK-wide)
- Choose your nearest UK clinic
- Attend your appointment
- A clinician draws a blood sample
- Sample is sent to the laboratory
- Results are issued once analysis is complete
Home or hotel visit (+£60, UK-wide)
- Book a mobile phlebotomist
- Blood sample taken at your home or hotel
- No need to attend a clinic
- Sample securely transported to the laboratory
Your results explained
Negative (unlikely coeliac disease)
- tTG IgA within reference range
- UK standard (typical): <7 U/mL
- Suggests no evidence of active coeliac disease
Borderline or mildly positive
- tTG IgA slightly above reference range
- UK standard: 7–10 U/mL
- May suggest early or mild disease
Positive (suggestive of coeliac disease)
- Significantly elevated tTG IgA
- UK standard: >10 U/mL
- Strongly supportive of coeliac disease
Total IgA levels may be checked separately if IgA deficiency is suspected.
How It Works
Simple steps to get your results
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Visit or Test at Home
Attend one of our UK or London clinics, arrange a home nurse visit, or use a finger-prick kit where available.
Get Your Results
Your sample is analysed by accredited UK laboratories, with secure results delivered directly to you.
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WhatsApp UsHow to Prepare for Your Test
Follow these guidelines for accurate results
Sample Timing
Where possible, attend your blood test between 7am and 12pm. Please wait until any short-term illness or infection has fully resolved before testing. Avoid intense exercise for 24–48 hours beforehand, as this can affect certain markers.
Fasting & Hydration
Fasting is not always required, but some tests may recommend it. If fasting is advised, avoid food for 8–12 hours before your appointment and drink water only. Stay well hydrated, as this helps with sample collection and accuracy.
Medications & Supplements
Continue prescribed medications unless advised otherwise by your clinician. Avoid vitamin, mineral, or biotin supplements for at least 24–48 hours before your test, as these can interfere with results. If you are unsure about any medication or supplement, please let us know before your appointment.
Hormones & Menstrual Cycle
For hormone-related tests, timing within your menstrual cycle may be important. If relevant, follow any specific guidance provided on your test page.
If you have any questions or special circumstances, our team is happy to advise before your appointment.