Unknown link between common viral infections and autoimmune disease found

A previously unknown link between common viral infections and autoimmune disease has been discovered by WA scientists.

A study undertaken by the University of WA and the Lions Eye Institute that focused on Sjogren’s syndrome found chronic viral infections can lead to autoimmune disease.

Sjogren’s is the second most common autoimmune disease, which causes ‘dry eye’ and affects up to 3 per cent of the population, mainly women.

The research found that chronic cytomegalovirus infection (CMV) – which is part of the herpes family – could lead to Sjogren’s syndrome.

In healthy people, CMV causes mild flu-like symptoms, but in those with compromised immune systems, it can lead to serious illness.

Up to 80 per cent of the population in developed countries are infected with CMV, which can trigger autoimmunity.

UWA and Lions Eye Institute professor Mariapia Degli-Esposti said it was hoped the results could be extrapolated to other conditions such as diabetes and rheumatoid arthritis.

“In fact, this might be a more general concept and we hope that some of the mechanistic pathways we’ve identified might be similar in different auto-immune conditions,” she said.

She said the research was extremely important because in identifying a cause of Sjogren’s, it had also discovered a previously-unknown function of an immune cell population.

“What we’ve discovered is that a common viral infection can actually elicit autoimmune disease,” she said.

“We are hoping that this actually going to be important for autoimmunity in general.”

Genetics play vital role: Professor

Professor Degli-Esposti said genetic predisposition played a crucial role.

“One of the things that is important to understand is that a common viral infection in most people can be completely innocuous [but] given the appropriate genetic background, these viruses can actually become triggers for autoimmunity,” she said.

“The genetic background is essential in the development of autoimmunity and a key component of the disease.”

She said severe forms of autoimmune diseases were usually treated with immunosuppressant drugs, but it was hoped the research breakthrough would lead to the development of more targeted treatments.

“We hope to move away from that broad approach to a more targeted approach using molecules or cell therapies that target key pathways,” she said.

Pattie Leonard has had Sjogren’s for 20 years.

“It’s like sandpaper on sandpaper and sometimes it’s like you blink and you blink and you blink and you blink just trying to force a tiny bit of moisture [into the eye] and there’s none,” she said.

It is hoped the discovery will lead to new treatments for Sjogren’s as well as other forms of autoimmune disease

The findings have been published in the journal Immunity.

 

This article was first published at http://www.abc.net.au/news/2014-10-17/wa-scientists-in-medical-breakthrough-linking-common-viral-infe/5820536