Celiac disease frustratingly restrictive, the only real medical intervention for sufferers being to avoid gluten altogether. What's more, diagnosis is arduous and involves consuming gluten to stimulate the painful autoimmune condition. But it may soon be much simpler and pain-free, thanks to a new blood test that can detect the biomarkers of celiac disease even when someone is on a gluten-free diet.
Scientists from the Walter and Eliza Hall Institute (WEHI) of Medical Research, in collaboration with Australia's Novoviah Pharmaceuticals, have developed a landmark blood test – the first of its kind in the world – that can identify gluten-specific immune cells, or T cells, even when they're not actively fighting inflammation.
“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,” said gastroenterologist Jason Tye-Din, an associate professor who heads WEHI's celiac laboratory. “This new test promises to simplify and speed up accurate diagnosis, while also avoiding the suffering that comes with eating gluten for extended periods to reactivate coeliac disease."
If you or someone you know has been diagnosed with celiac disease, you'll know how brutal the path to finding out is. Generally, it involves exposure to gluten for several weeks, before a series of tests – sometimes biopsies and gastroscopy in addition to bloods – which can be extremely debilitating.
Despite the science world's best efforts, there hasn't been a whole lot of advancement in the identification – or treatment – of the disease.
This new test can also identify asymptomatic celiac disease, which current diagnostic methods miss. This is a big deal, because "silent" celiac disease can still cause injury, damaging the villi that line the small intestine, which impacts how nutrients are absorbed and can lead to further long-term health issues.
One in around 141 Americans have celiac disease, according to experts, with a higher prevalence in people of European background or those who have other conditions such as type 1 diabetes or irritable bowel syndrome. There's no medical intervention for the disease besides adhering to a strict diet that avoids any gluten foods containing ingredients like wheat and barley. Aside from the damage that celiac disease causes to the small intestine, many of the symptoms are incredibly unpleasant – cramping, diarrhea, intense pain and joint aches are just a few of them.
“By eliminating the need for a gluten challenge, we’re addressing one of the biggest deterrents in current diagnostic practices," Tye-Din added. “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.”
Building on findings from a 2019 study that identified over-activity of the immune marker interleukin 2 (IL-2) as a celiac disease fingerprint, the team took blood samples from 181 participants – 75 people managing their disease with a gluten-free diet, 13 with an active and untreated condition, 32 with non-coeliac gluten sensitivity and 61 healthy recruits.
Their bloods were combined with gluten for a day and then tested to identify the IL-2 marker. And the results were reliable: 90% sensitivity and 97% specificity. Sensitivity tests for positive results, specificity for negative – essentially meaning that the blood screening is accurate and with a very low rate of false positives.
And celiac disease was also easily identified in the samples from participants on a strict, long-term gluten-free diet.
“This breakthrough is deeply personal as it could spare others from the grueling diagnostic process I had to endure," said Olivia Moscatello, a WEHI researcher who was diagnosed with celiac disease at the age of 18. "Knowing I’ve played a role in this achievement is a powerful, full-circle moment."
As of now, the "exposure therapy" way of diagnosing celiac disease has discouraged many people from seeking out testing. This new screening means only a blood sample is exposed to gluten. And they found that people with more extreme celiac symptoms had the most IL-2 activity. which gives both patient and medical professional clear information about their situation.
“This represents a promising new tool to support diagnosis, especially for people who can’t be diagnosed with the currently available methods," said Moscatelli. “We also found the strength of the IL-2 signal correlated with the severity of a patient’s symptoms, allowing us to predict how severely a person with coeliac disease might react to gluten, without them actually having to eat it.
“The test’s performance in individuals with other autoimmune conditions in addition to coeliac disease, such as type 1 diabetes or Hashimoto’s thyroiditis, is also unmatched," she added. “Some diagnostic tests give false positives in the presence of other autoimmune diseases, but this was not an issue for this test. This is largely because the technology we use is highly sensitive and can detect the IL-2 signal at exceptionally low levels. It’s like the equivalent of being able to detect a single grain of sand in a swimming pool.”
The team, along with the drug company, will now test the diagnostic tool on a more diverse population.
The study was published in the journal Gastroenterology.
