Coeliac Disease Blood Test

Screens for coeliac disease by measuring tissue transglutaminase (tTG) antibodies — the primary blood marker for this autoimmune condition triggered by gluten. Coeliac disease affects approximately 1 in 70 Australians, with an estimated 80% remaining undiagnosed. Symptoms extend far beyond digestive complaints to include fatigue, iron deficiency, brain fog, skin rashes, joint pain, and unexplained weight loss.

Coeliac disease is an autoimmune condition where gluten triggers the immune system to attack the small intestinal lining, destroying the villi that absorb nutrients. The tissue transglutaminase antibody test (tTG-IgA) is the recommended first-line screening test, with sensitivity and specificity both above 95% in people consuming a normal gluten-containing diet. The condition affects approximately 1 in 70 Australians, but because symptoms are diverse and often attributed to other causes, an estimated 4 in 5 cases remain undiagnosed. Beyond classic digestive symptoms (bloating, diarrhoea, abdominal pain), coeliac disease commonly presents with iron deficiency anaemia that does not respond to supplementation, unexplained fatigue, osteoporosis at a young age, recurrent mouth ulcers, and dermatitis herpetiformis — a characteristic itchy skin rash. Critically, you must be consuming gluten regularly (at least 4 slices of bread equivalent daily for 6 weeks) before testing for accurate results. If you have already started a gluten-free diet, antibody levels may have normalised even if the underlying condition is present. ClearLabs delivers results through their secure dashboard. A positive result should be followed up with a gastroenterologist for confirmatory small bowel biopsy before committing to lifelong dietary changes.