March 21, 2011 -- Replacing bone marrow with the body’s own stem cells may help patients with aggressive forms of multiple sclerosis (MS) go for years without seeing their disease progress, a new study shows.

Researchers in Greece are following a group of 35 patients who received experimental stem cell transplants for multiple sclerosis.

By purposefully wiping out the immune cells in a patient’s bone marrow with chemotherapy and then repopulating it with healthy stem cells, researchers hope the body’s immune system will stop attacking its own nerves, which eventually become so damaged from MS that they can’t properly transmit signals.

That damage can lead to wide-ranging troubles, including problems with vision, speech, weakness, coordination of movement, numbness, and pain.

According to the National Multiple Sclerosis Society, 400,000 Americans and 2.1 million people worldwide have MS.