By Victoria Allen

Hope of a treatment is on the horizon for people with progressive multiple sclerosis (MS) from a stem cell injection into the brain.

More than 130,000 people in the UK are estimated to have MS, with nearly 7,000 diagnosed every year.

The vast majority of people have relapsing-remitting MS, causing occasional attacks of new or worsening symptoms, which can then go away for years at a time.

But about two-thirds of these people eventually develop secondary progressive MS, where their symptoms gradually worsen over time, often leading to muscle weakness, severe fatigue, vision problems and wheelchair use.

Now scientists have found a safe treatment which could press pause on the devastating illness and protect the brain from further damage in the long-term.

It is an injection of stem cells from the brain, which appears to counteract the immune system's attack on the brain and spinal cord - the cause of MS.

These stem cells were injected directly into the brains of 15 people with secondary MS recruited from two hospitals in Italy.

All these people had a high level of disability, with most needing a wheelchair, but over a full year after receiving the injection, none became more disabled or saw any increase or flare-up of symptoms.

Secondary progressive MS can cause problems with thinking, learning and planning, but such thinking problems did not worsen for people in the year after the injection, based on a battery of tests including remembering lists of words.

Professor Stefano Pluchino from the University of Cambridge, who co-led the study, added: 'We desperately need to develop new treatments for secondary progressive MS, and I am cautiously very excited about our findings, which are a step towards developing a cell therapy for treating MS.'

Dr Luca Peruzzotti-Jametti, a co-author also from the University of Cambridge, said: 'This was a small study to determine whether this treatment is safe.

'But people with secondary progressive MS see their independence slip away from them day by day, with only one drug, which is not available to everyone, and can only help alleviate symptoms.

'Hopes of a treatment which could stop the condition getting worse would be really important, so we will next trial this on many more people, including hopefully patients in the UK.'

In MS, the immune system attacks the protective layer of protein and fatty acids - called the myelin sheath - which protects the nerves which carry signals from the brain.

The myelin sheath becomes damaged and scarred, so brain signals, like those to the muscles which are needed to walk, are disrupted.

However stem cells, which have the ability to become almost any type of cell in the body, can block immune cells from causing this harmful damage.

They also produce natural chemicals which prevent scarring in the myelin sheath and help it to regenerate.

Adults do not have a good supply of these stem cells in their brain, as they have already been used up and turned into normal brain cells.

But unborn babies, whose brains have not yet fully developed, have many of the precious stem cells.

The stem cells used in the study were donated by the family of an unborn baby following a miscarriage.

They were injected directly into the cerebrospinal fluid which bathes the brain, through brain surgery under anaesthetic.

The MS patients in the study had no serious adverse side effects, and there were no deaths, although a patient had a seizure as a result of the brain surgery.

Also steroids and immunosuppressant drugs needed alongside the stem cells did lead to temporary psychosis in one patient and short-lived infections in several others.

However the researchers hope to overcome this in the future by using people's own stem cells for their treatment - reprogramming their skin cells to become brain stem cells using a special lab-based technique.

MRI scans provided further evidence the stem cells had stopped MS in its tracks, as suggested by people not getting any worse over a full year.

Those given higher doses of stem cells showed an apparent reduction in swelling within the brain - likely due to anti-inflammatory molecules released by the cells, which counteract the damage being done by the immune system.

Volunteers given higher doses of stem cells also had a higher level of fatty acids in their spinal fluid which suggested their brain was functioning more effectively.

Because the volunteers were so disabled, more evidence is needed to ensure MS really is prevented from getting worse using stem cells.

Researchers also want to understand if stem cells can help to regenerate a brain damaged by MS.

But the research, was described as 'really exciting' by Caitlin Astbury, from the MS Society, who said: 'These results show that special stem cells injected into the brain were safe and well-tolerated by people with secondary progressive MS.

'They also suggest this treatment approach might even stabilise disability progression.'

Dr Aravinthan Varatharaj, a clinical lecturer in neurology at the University of Southampton, said: 'Whilst this study showed that patients did not experience significant disease progression after treatment, there are other possible explanations for this, and this was not a controlled trial.'