Toronto, June 10 (IANS): Researchers have developed a risky stem cell therapy that has the potential to halt and even reverse some of the symptoms of multiple sclerosis (MS) in the long-term.

MS is among the most common chronic inflammatory diseases of the central nervous system, with around two million people affected worldwide, the researchers said. 

It is caused when the immune system attacks the body, known as autoimmunity. 

The findings showed that chemotherapy followed by autologous haematopoietic stem cell transplantation (aHSCT) can fully halt clinical relapses in patients with MS.

For the study, published in The Lancet, the team enrolled 24 patients aged 18-50 from three Canadian hospitals who had all previously undergone standard immunosuppressive therapy, which did not control the MS.

All patients had poor prognosis and their disability ranged from moderate to requiring a walking aid to walk 100m.

The therapy proved to be beneficial in 23 of 24 patients with MS as no relapses occurred during the follow up period (between four and 13 years). 

Also, eight of the 23 patients had a sustained improvement in their disability 7.5 years after treatment.

“This treatment is similar to that used in other trials, except our protocol uses stronger chemotherapy and removes immune cells from the stem cell graft product," said Harold L. Atkins from the University of Ottawa, in Canada.

Progressive brain deterioration that is typical of MS also slowed to a rate associated with normal ageing in nine patients. 

“The chemotherapy we use is very effective at crossing the blood-brain barrier and this could help eliminate the damaging immune cells from the central nervous system,” Atkins added. 

However, the therapy has a poor safety profile, especially with regards to treatment-related mortality, the researchers warned, as it also lead to death of one patient from liver failure. 

"These results are impressive and seem to outbalance any other available treatment for multiple sclerosis. This trial is the first to show complete suppression of any inflammatory disease activity in every patient for a long period," commented Jan Dorr from Charite-Universitatsmedizin in Germany, in a linked article.

"Since this is an aggressive treatment it should only be offered in specialist centres experienced both in MS treatments and stem cell therapy," Atkins suggested.