Coeliac disease
Autoimmune intestinal disease triggered by gluten. Highly under-diagnosed; presents with iron deficiency, vitamin malabsorption, GI symptoms — or often nothing obvious.
What it is
Coeliac disease is an autoimmune enteropathy triggered, in genetically susceptible people (HLA-DQ2 / DQ8), by gluten — the storage protein of wheat, rye and barley. The immune response flattens the small-bowel villi, impairing absorption of iron, B12, folate, calcium, vitamin D and fat-soluble vitamins. About 1% of the global population has it; an estimated 70% are still undiagnosed because the presentation is so variable — from classic chronic diarrhoea to silent iron-deficiency anaemia, infertility, neuropathy or persistently raised liver enzymes. The only treatment is lifelong strict gluten avoidance.
Key lab markers
- Anti-tissue transglutaminase IgA (tTG-IgA) — first-line screen; total IgA must be checked simultaneously to exclude IgA deficiency.
- Iron / ferritin — iron-deficiency anaemia is the commonest extra-intestinal finding.
- Vitamin B12, folate, vitamin D, calcium — malabsorption pattern.
- Albumin — falls in severe enteropathy.
- Liver enzymes (ALT, AST) — modest elevation in ~10% of patients, often the only sign.
- Duodenal biopsy — gold-standard confirmation; do NOT start a gluten-free diet before testing.
Symptoms
Can be silent. Classic presentation:
- Chronic diarrhoea, bloating, abdominal pain
- Weight loss, malnutrition
- Iron-deficiency anaemia unexplained by other cause
- Fatigue
- Dermatitis herpetiformis (itchy blistering rash)
- Recurrent mouth ulcers
- Tooth-enamel defects
- Infertility, recurrent miscarriage
- Neuropathy
When to discuss with a doctor
Any unexplained iron-deficiency anaemia in an adult, persistent GI symptoms, family history of coeliac disease, or autoimmune comorbidity (type 1 diabetes, autoimmune thyroid) warrants screening with tTG-IgA. Critically, do NOT remove gluten from the diet before testing — it can render serology and biopsy falsely negative. Mediora.AI surfaces the iron + B12 + folate pattern that often precedes a coeliac diagnosis; the diagnosis itself is gastroenterology territory.