Diagnosis in children

Children who are offered serological testing for coeliac disease should be including gluten in more than one meal per day for more than six weeks prior to testing to reduce the risk of a false negative. When requesting tests for children, laboratories should:

• test for total IgA and IgA tTG, as first choice test
• consider using IgG EMA, IgG DGP or IgG tTG in cases of IgA deficiency. 

For children, a biopsy may not be necessary in every case, but the diagnosis of coeliac disease should be made in secondary care. NICE recommends that children with a positive serological test are referred to a paediatric gastroenterologist or paediatrician with a special interest in gastroenterology for further investigation.

When can a no-biopsy diagnosis be considered in children?

Since 2012, ESPGHAN guidelines have had an algorithm for a no-biopsy strategy, in 2019 these guidelines were updated.

The latest guidelines state:

• Children whose blood tests show a high level of IgA tissue transglutaminase antibodies (>10 x upper limit of normal for the assay) may not need to undergo a biopsy to secure diagnosis.
• A positive endomysial antibody (EMA) blood test is required to confirm the diagnosis in a no-biopsy diagnosis. 
• For children with IgA deficiency, a no-biopsy approach should not be offered.
• Genetic testing to confirm the diagnosis was removed from the no-biopsy algorithm in the 2019 guideline.
• New to the 2019 guideline, a no-biopsy diagnosis can be offered for asymptomatic children. This decision should be approached using shared decision making with the parents/carers and child, where appropriate.

Following the publication of the ESPGHAN guidelines, the joint BSPGHAN and Coeliac UK guidelines will be updated. 

Children with a positive blood test and those with negative antibodies where coeliac disease is suspected should be referred to a paediatric gastroenterologist or paediatrician with a specialist interest in gastroenterology.

IgA deficiency

Total IgA should be measured when testing for coeliac disease. This is because IgA deficiency is more common in people with coeliac disease than the general population. People with IgA deficiency will have a false negative serological result when tested for IgA antibody, which may lead to a missed diagnosis of coeliac disease.

In individuals with IgA deficiency, IgG antibodies are recommended in place of IgA antibodies. For children with IgA deficiency, a biopsy is required to confirm the diagnosis.

Advice before testing 

It is important to inform parents/carers of children undergoing testing for coeliac disease that in order to get accurate test results, their child should continue to eat a gluten containing diet before and during the diagnosis process. NICE recommends including gluten in more than one meal a day for at least six weeks before testing. 

A gluten free diet should not be initiated until diagnosis is confirmed by a specialist, even if the results of a serological test are positive.

If gluten has already been restricted or excluded from the child's diet and they are unable to reintroduce gluten into their diet before testing, refer the patient to a paediatrician or paediatric gastroenterologist and explain that it may be difficult to confirm their diagnosis.