Doença celíaca

Principais recomendações do NICE sobre diagnóstico

Coeliac disease can present with a wide range of clinical features. Be aware that some people initially experience few or no symptoms.

Offer serological testing for coeliac disease to first-degree relatives of people with coeliac disease, and to people with any of the following:

• Persistent unexplained abdominal or gastrointestinal symptoms

• Faltering growth, or unexplained weight loss

• Prolonged fatigue

• Severe or persistent mouth ulcers

• Unexplained iron, vitamin B12 or folate deficiency

• Irritable bowel syndrome (in adults)

• Type 1 diabetes or autoimmune thyroid disease (these people should be offered serological testing at diagnosis, as they are at a higher risk of coeliac disease).

Consider serological testing for coeliac disease in people with any of the following:

• Metabolic bone disorder (reduced bone mineral density or osteomalacia)

• Unexplained neurological symptoms (particularly peripheral neuropathy or ataxia)

• Unexplained subfertility or recurrent miscarriage

• Persistently raised liver enzymes with unknown cause

• Dental enamel defects

• Down’s syndrome or Turner syndrome.

Do not offer serological testing in infants before gluten has been introduced into the diet.

Explain to people thought to be at risk of coeliac disease that undiagnosed coeliac disease, or delayed diagnosis, can result in continuing ill health and serious long-term complications.

Advise people undergoing investigations for coeliac disease to eat some gluten in more than 1 meal every day for at least 6 weeks before testing (as any test is accurate only if a gluten-containing diet is eaten during the diagnostic process).

• Advise the person not to start a gluten-free diet until the diagnosis is confirmed by a specialist, even if serological test results are positive.

• Refer to a gastrointestinal specialist if the person has restricted/excluded dietary gluten and is reluctant/unable to re-introduce it before testing. Explain this may make it difficult to confirm the diagnosis by intestinal biopsy. In specialist settings, human leukocyte antigen (HLA) genetic testing may be considered in diagnosis of these people.

First-choice serological tests for suspected coeliac disease are total immunoglobulin A (IgA) and IgA tissue transglutaminase (tTG).

• In young people and adults (but not in children), IgA endomysial antibodies (EMA) should be tested if IgA tTG is weakly positive.

  • A positive serological test result in young people and adults is defined as unambiguously positive IgA tTG alone, or weakly positive IgA tTG and a positive IgA EMA test.

• If IgA is deficient (defined in the NICE guideline as total IgA <0.07 g per litre), IgG EMA, IgG deamidated gliadin peptide, or IgG tTG testing should be considered.

  • A positive result can be derived from any one of these IgG antibody tests.

Do not use HLA genetic testing for initial diagnosis in non-specialist settings.

If serological testing is positive, refer:

• Young people and adults to a gastrointestinal specialist for endoscopic intestinal biopsy to confirm or exclude coeliac disease

• Children to a paediatric specialist in gastroenterology for further investigation (e.g., IgA EMA to confirm serological positivity, HLA genetic testing, endoscopic biopsy).

If serological testing is negative:

• Refer to a gastrointestinal specialist for further assessment if coeliac disease is still clinically suspected

• Advise people (particularly first-degree relatives and people with type 1 diabetes) of the symptoms of coeliac disease and to return if any of these arise/persist

  • Have a low threshold for re-testing people if they develop any symptoms.