MS linked to toxin found in sheep
EXPOSURE to a toxin primarily found in sheep could trigger multiple sclerosis, a study has suggested.
More than 100,000 people in Britain have MS, which occurs when the immune system attacks the protective coating surrounding nerve cells in the brain and spinal cord.
The condition leads to inflammation, pain, disability and in severe cases, early death, but experts still do not know the underlying cause. Now researchers at the University of Exeter have discovered that nearly half of the people with MS that they studied had been infected at some time in their lives by epsilon toxin.
The toxin is produced in the gut of sheep by the clostridium perfringens bacterium and can also be found in soil. The researchers say people could become infected with the toxin from being near sheep, and the bacteria can produce spores that can travel long distances in the air. It is unlikely to be caught through eating lamb as cooking kills the toxin.
Researchers looked at 250 people, half of whom had MS, and found 43 per cent of MS patients were carrying antibodies to epsilon toxin, proving it had been in the body long enough for the immune system to produce a response.
In comparison just 16 per cent of people without MS had been exposed.
“Our research suggests that there is a link between epsilon toxin and MS,” said Professor Rick Titball, of the
University of Exeter. “The causes of MS are still not fully understood and, while it’s possible that this toxin plays a role, it’s too early to say for certain.”
MS was first recognised in the 1860s and it has long been established that it is more common in northern, less sunny climates, giving rise to theories that the condition could be triggered by a lack of Vitamin D. But MS is also more common in latitudes and countries where sheep populations are high.
The university embarked on the study with MS Sciences Ltd, a life sciences company, after hearing that some MS patients in the US had tested positive for epsilon toxin antibodies.
Experts have suggested that the immune system may overreact to the toxin, or fail to turn off, leading it to begin attacking healthy cells in the body.
Trials in the US have shown it is possible to effectively cure some people of the condition by rebooting the immune system using chemotherapy drugs.
But if it can be proven that the condi- tion is caused by a bacterial toxin then a vaccine could be created to inoculate people against ever getting MS.
Simon Slater, the director of MS Sciences Ltd, said the company was confident the study could help researchers get closer to “an answer for the elusive triggers of MS”. Dr Sorrel Bickley, head of biomedical research at the MS Society, said: “Research into environmental and genetic factors is important, and this study gives us some new clues, but it’s only a small part of the story. More research will be needed before we can truly know why people develop MS.” The research will be published in the Multiple Sclerosis Journal.