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Hope for simplifying coeliac disease diagnosis
Early studies suggest a blood test could eliminate the need for a gluten challenge in a ‘major step towards faster, safer diagnosis’.
Current diagnostic tests for coeliac disease require patients to eat large amounts of gluten, with many discouraged from doing so to avoid the discomfort.
New Australian-led research hailed as a potential ‘game-changer’ may help to address limitations for diagnosing coeliac disease, as well as identify those at risk of severe gluten reactions and detect the condition in asymptomatic people.
Reliable diagnosis for coeliac disease is currently enabled when gluten is regularly consumed – the gluten challenge – and gastroscopy and biopsy performed.
But a simple blood test could change that.
Published in the Gastroenterology journal and led by specialists from the Walter and Eliza Hall Institute (WEHI), the research examined the potential of a blood test to aid diagnosis of a condition that impacts an estimated 350,000 Australians.
The study indicates that people would no longer need to eat large amounts of gluten for weeks to get an accurate result, a finding that promises to ‘take away the pain of diagnosis’.
Current diagnosis of coeliac disease is ‘inaccurate’ in patients following a gluten-free diet, according to the authors, who say that blood-based diagnostics targeting gluten-specific T cells are ‘highly sensitive and specific’ but impractical for clinical use.
Instead, they examined the potential of a simple whole-blood assay measuring interleukin-2 (IL-2) release for detecting gluten-specific T cells to aid diagnosis. The IL-2 assay demonstrated ‘high accuracy’ for coeliac disease diagnosis, including in patients following a strict gluten-free diet, with up to 90% sensitivity and 97% specificity.
From 181 participants aged 18–75, blood samples were taken from:
- 75 people with coeliac disease who had been on a gluten-free diet for at least a year
- 13 with active, untreated coeliac disease
- 32 with non-coeliac gluten sensitivity
- 61 controls who did not have coeliac disease or gluten sensitivity.
Co-lead author, gastroenterologist and head of WEHI’s Coeliac Research Laboratory, Associate Professor Jason Tye-Din, said the new test ‘promises to simplify and speed up’ accurate diagnosis.
‘[It also allows] avoiding the suffering that comes with eating gluten for extended periods to reactivate coeliac disease,’ he said.
‘By eliminating the need for a gluten challenge, we’re addressing one of the biggest deterrents in current diagnostic practices.
‘This test could be a game-changer, sparing thousands of people the emotional and physical toll of returning to gluten. It’s a major step towards faster, safer diagnosis.’
Associate Professor Jason Tye-Din
previously told newsGP that GPs play ‘the biggest role in the diagnosis of coeliac disease, as they decide when to test for it’.
In Australia, it is estimated that
one in 70 people have coeliac disease, but only 20% of them are diagnosed.
The study authors note that while early diagnosis is critical to minimising long-term complications, the majority of cases remain undiagnosed as many people are discouraged from seeking a definite diagnosis because they do not want to consume gluten and be sick.
‘There are likely millions of people around the world living with undiagnosed coeliac disease simply because the path to diagnosis is difficult, and at times, debilitating,’ Associate Professor Tye-Din said.
The breakthrough research comes following WEHI researchers’ 2019 discovery that the immune marker IL-2 spiked in the bloodstream of people with coeliac disease shortly after they ate gluten.
Now, they have determined that gluten-stimulated IL-2 secretion indicates the presence of pathogenic gluten-specific cells and is ‘a useful diagnostic’ for the disease.
However, they note the limitations of the study in the small sample size and that children and patients on immunosuppressants were not assessed.
Gastroenterologist at Western Sydney University’s School of Medicine, Associate Professor Vincent Ho, would like to see the results replicated in larger studies in other centres.
‘The test is very new, and needs to be validated across other laboratories and be cost-effective compared to current tests before it can be used in clinical practice,’
he told The Guardian.
‘In theory … coeliac disease could be diagnosed without the need for weeks of exposure to gluten.’
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blood test coeliac disease gastroenterology gluten challenge gluten-specific T cells interleukin-2 release
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