Drugs used to treat HIV could potentially be used to treat multiple sclerosis (MS) in the future, experts have said after new research showed that people with the virus have a lower risk of MS.
Researchers found that people with an HIV infection have a significantly lower risk of developing the debilitating condition.
They said that chronic dampening down of the immune system as a result of HIV or the powerful antiretroviral drugs that are used to treat it could be the reason behind the lowered risk.
Charity the MS Society said that while much more research is needed into the subject, the study shows that antiretrovirals could be a potential future option for the treatment of MS.
Researchers from Queen Mary University of London, the University of Oxford and the Prince of Wales Hospital in Sydney, Australia, examined more than 21,000 HIV-positive patients treated in hospitals in England between 1999 and 2011 and compared them to more than five million control subjects.
Their study, published in the Journal of Neurology, Neurosurgery and Psychiatry, found that those with HIV were 62pc less likely to develop MS than the controls.
The authors wrote: "HIV infection is associated with a significantly decreased risk of developing MS.
"Mechanisms of this observed possibly protective association may include immunosuppression induced by chronic HIV infection and antiretroviral medications."
Commenting on the study, Dr Emma Gray, research communications manager at the MS Society, said: "This is a valuable and intriguing new study, and the first to show a significant link between HIV and a reduced risk of MS.
"Much more research is needed to definitively prove whether having HIV or being treated for HIV with antiretrovirals, or even a combination of the two, reduces the risk of someone developing MS.
"We know that people with MS want new, effective treatments and this study provides some encouragement.
"Clinical trials are the only way to determine this, and the good news is there is a London-based trial ongoing."