3 December 2010

A form of spinal arthritis is genetically linked to Inflammatory Bowel Disease, researchers at The University of Queensland Diamantina Institute in Brisbane, Australia, have found.

Their study was published this week in the open-access journal PLoS Genetics.

Ankylosing Spondylitis (AS) is a common form of arthritis involving chronic inflammation particularly of the spinal and pelvic joints.

The syndrome, which causes pain, stiffness, and often disability, is almost entirely genetically determined and affects up to 0.5 per cent of the population.

Curiously, AS patients appear to be highly susceptible to Inflammatory Bowel Disease (IBD), including Crohn's disease. Similarly, the development of AS is common in IBD patients.

Professor Matt Brown and his colleagues wanted to determine if this was more than a coincidence.

"It seemed likely that common pathogenic pathways may be acting in the development of both diseases," Professor Brown said.

In order to test whether genes associated with Crohn’s disease are also associated with AS, researchers looked for known genetic markers of Crohn’s disease in the genomes of more than 2700 AS patients, working with colleagues from England, North America and Canada.

The results revealed that both AS and Crohn's disease share several similar genetic variations, and identified seven genes affecting both conditions.

When the researchers took a closer look at the function of the genes they had identified, they found that four of the genes are known to influence the activation of a recently discovered class of helper T-cells called Th17 cells.

Identifying the involvement of these immune cells greatly increases what is known about how AS develops, and points to potential new therapies for this form of arthritis.

Professor Brown said the study highlighted the value of looking into individual genes that might be implicated in related diseases.

Contact: Dr Fiona McMillan, science writer/educator, The University of Queensland Diamantina Institute, ph +61 7 3176-5944