What is coeliac disease?
- It’s an immune response to gluten, a protein found in wheat, rye, barley and oats
- It causes damage to the small bowel, leading to a reduced surface area for nutrient absorption
- Only 1 in 30 people with a genetic susceptibility to coeliac will develop the disease
- 80 per cent of Australians with coeliac disease remain undiagnosed
- Coeliac disease cannot be cured, but people can manage the condition through a gluten-free diet
Could a seemingly harmless virus you had as a baby be behind coeliac disease?
New research suggests an infection with a strain of reovirus, often symptomless, could be the reason why some people’s immune systems react to gluten like a dangerous pathogen instead of harmless food protein. The research, published today in Science, found mice engineered to be genetically susceptible to gluten intolerance who were infected with the reovirus strain T1L went on to have an immune response against gluten.
The virus is usually harmless however if the first exposure to a food with gluten occurs during a reovirus infection, the virus turns the immune system against the food protein, Professor Dermody and his colleagues found.
In people with coeliac disease, the protein gluten is treated like a harmful pathogen. Immune system damages the small intestine lining causing symptoms like bloody diarrhea.
Dr Jason Tye-Din, head of coeliac research at the Walter and Eliza Hall Institute of Medical Research in Melbourne, did not work on the study but said the research was a “big leap” in understanding how coeliac disease can develop. “The significance of this work is that it provides a mechanism for how virus infection might actually trigger the disease,” Dr Tye-Din said. “Epidemiologic studies show infection could be a trigger, but no-one’s ever really shown how that would happen.”
Dr Tye-Din said about half the Australian population were genetically susceptible to coeliac disease, but that environmental factors — which are still not understood in detail — were involved in activating the disease.
This research was a step in the direction of understanding how these environmental triggers worked, he said.
Anti-coeliac vaccine:
Professor Dermody said he does not think that the T1L reovirus, which was used in the study, is the only virus that can stimulate coeliac disease. Future research will analyze the potential of other viruses and determine whether T1L was a true trigger of the disease in humans.
If it is, then a reovirus vaccine could be developed for at-risk children, which could potentially block the development of the disease, “and that would be pretty amazing”, Professor Dermody said.
“[The research] raises a possibility that infections such as this might be underlying a range of abnormal immune responses to other food proteins or even triggering other autoimmune diseases,” he said.
“What its saying is, here’s a mechanism for how what otherwise might seem to be harmless virus might confuse the immune system into thinking something’s a harmful protein.”