Diagnosis

Diagnosis of coeliac disease should not be made by symptomatic response to gluten withdrawal or challenge.

Currently coeliac disease is diagnosed on the basis of positive coeliac serology followed by a confirmatory duodenal biopsy (presence of villous atrophy and increased intraepithelial lymphocytes) (1)

An isolated increase in intraepithelial lymphocyte in the absence of villous atrophy should be interpreted in the context of coeliac serology, symptoms and HLA typing.

Symptomatic patients with positive serology (EMA or TTG antibody) may be treated with a gluten-free diet. If there remains diagnostic doubt, then a repeat biopsy after a gluten-free diet should be performed to look for improvement.

A second (post-treatment) biopsy is reserved for patients in whom the first biopsy and serologic test are inconclusive (e.g. - seronegative enteropathy or the biopsy shows show evidence of increased intraepithelial lymphocytes without villous atrophy) or for patients who are receiving a strict gluten-free diet but fail to respond.

A gluten challenge test (the offending agent is reintroduced while the patient is on a restrictive diet) is reserved for patients who are receiving treatment but have a doubtful diagnosis (2)

Patients with suspected coeliac disease in whom histological or serological (or both) results are not diagnostic should be referred to a gastroenterologist with an interest in coeliac disease (1)

Reference:

• (1) Mooney PD, Hadjivassiliou M, Sanders DS. Coeliac disease. BMJ. 2014;348:g1561
• (2) World Gastroenterology Organisation (2012). Global Guidelines. Celiac disease.