New diagnostic test for coeliac disease

Promising results from a small study on a new diagnostic test for coeliac disease may simplify the detection of this condition.

The collaborative research, involving researchers from the Walter and Eliza Hall Institute and The Royal Melbourne Hospital in Melbourne and biotechnology company ImmusanT in Boston, US, showed that the test rapidly and accurately diagnoses coeliac disease without the need for prolonged gluten exposure.

Coeliac disease is caused by an abnormal immune (T cell) reaction to gluten in the diet, leading to damage to the small intestine. It can cause digestive symptoms such as nausea, vomiting, bloating and diarrhoea, as well as lethargy, anaemia, headaches and weight loss.

As many as one in 60 women and one in 80 men in Australia have coeliac disease, but four out of five remain undiagnosed.

“Current diagnosis of coeliac disease is limited by the need for intestinal biopsies and patients to be eating gluten,” said Dr Jason Tye-Din, head of coeliac research at the Walter and Eliza Hall Institute and gastroenterologist at The Royal Melbourne Hospital.

“For the many people who follow gluten-free diets without a formal diagnosis, reliable testing for coeliac disease requires them to consume gluten again, which is often unpleasant and difficult.”

In the initial study, which involved 48 participants, the new diagnostic test produced a result within 24 hours and accurately detected coeliac disease. Larger studies will be conducted to confirm the test’s role as a tool for diagnosing coeliac disease.

“Our findings reveal this novel blood test is accurate after only three days of gluten consumption, not the several weeks or months traditionally required to make a diagnosis using intestinal biopsies,” Dr Tye-Din said.

The test involves a ‘cytokine release’ test that measures the T cell response to gluten after three days of consumption. A positive response is highly predictive of coeliac disease.

“With this test, we were able to detect a T cell response in the majority of study participants known to have coeliac disease; and importantly, the test was negative in all of the patients who did not have coeliac disease, even though they followed a gluten-free diet and thought gluten was the cause of their symptoms,” said Dr Tye-Din.

Dr Tye-Din predicts that the simpler test will improve disease detection because many ‘gluten sensitive’ people found it distressing to reintroduce gluten into their diet in order to be tested properly for coeliac disease.

“People are fearful about experiencing unpleasant symptoms and end up stopping prematurely or avoiding testing altogether,” he said.

“This new diagnostic approach is encouraging and we hope that larger studies can validate these findings and establish its role in the diagnosis of coeliac disease, with the possibility of avoiding intestinal biopsies for diagnosis altogether.”

Dr Bob Anderson, chief scientific officer at ImmusanT, said that the blood test could also assist in the monitoring of a therapeutic vaccine for coeliac disease.

“This is an important step toward a tool that could monitor changes in the small population of circulating T cells responsible for coeliac disease when using treatments intended to restore tolerance to gluten, such as Nexvax2, the compound currently being developed by ImmusanT,” Dr Anderson said.

The results of the study were published in the journal Clinical & Experimental Immunology.