- An infection can create proteins that cause the immune system to malfunction
- In patients with rheumatoid arthritis, this leads to inflammation and joint pain
- However, this process was also apparent in sample of patients with gum disease
Brushing your teeth could prevent arthritis, new research suggests.
Bugs known to cause gum infections also trigger the crippling condition that blights the lives of many around the world.
Experts say the findings add to the evidence that rheumatoid arthritis (RA) is linked to dental hygiene, a long-suspected theory.
An infection with A. actinomycetemcomitans – known to cause gum disease – sparks the production of proteins that cause the immune system to falter.
Citrullination – which regulates the production of proteins – is known to happen naturally in humans.
But in people with RA, the process becomes overactive and leads to inflammation and damaged tissue, researchers from Johns Hopkins University found.
However, in the new findings, they discovered this was also apparent in samples of patients with gum disease.
But the researchers warned that more than half of the participants who had RA had not been infected.
They say this may indicate other bacteria in the gut, lung or elsewhere could be responsible for the joint pain.
Professor Felipe Andrade, of Johns Hopkins University in the US, said: ‘This is like putting together the last few pieces of a complicated jigsaw puzzle that has been worked on for many years.
‘If we know more about the evolution of both combined, perhaps we could prevent rather than just intervene.’
The new findings, published in the journal Science Translational Medicine, have important implications for prevention and treatment of RA.
The condition is caused when the immune system malfunctions and attacks cells, making joints stiff and painful.
More than 700,000 people in Britain suffer from the destroyer of soft tissue, cartilage and bone. It affects mainly, but not exclusively, the elderly.
Study leader Dr Maximilian Konig, now at Massachusetts General Hospital, said: ‘This research may be the closest we have come to uncovering the root cause of RA.’