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.
An average of 11 years after their transplants, 25% of the patients in Greece have not seen their disease progress, the researchers report.
Among patients with active lesions on MRI scans before their transplants, indicating that they were in an inflammatory phase of the disease, 44% have not progressed.
Only 10% of patients who went into the study without evidence of ongoing inflammation were able to remain disease free.
Two patients died from transplant-related complications.
“Keeping that in mind, our feeling is that stem cell transplants may benefit people with rapidly progressive MS,” says study researcher Vasilios Kimiskidis, MD, of Aristotle University of Thessaloniki Medical School, Greece, in a news release.
“This is not a therapy for the general population of people with MS but should be reserved for aggressive cases that are still in the inflammatory phase of the disease,” he says.
The study is published in journal Neurology.
“This is the first long-term paper that’s being published on this,” says Richard Nash, MD, an oncologist and member of the Fred Hutchinson Cancer Research Center in Seattle.
Nash is part of a National Institutes of Health trial of stem cell transplants for MS, but he was not involved in the Greek study.
“When we’re transplanting patients with autoimmune diseases and especially for something like progressive MS, secondary or primary progressive MS, or even relapsing-remitting MS, we’re really interested in what’s happening over the longer term,” Nash says.
Because patients with MS sometimes go through periods where their disease appears to be dormant before it becomes active again, it can be difficult for researchers to tell if an improvement would have happened naturally or if it is the result of treatment, he explains.
“The progression-free survivals at three, four, and five years in this group were 80%. So they were very high, and people were very hopeful,” Nash says.
Based on this report, however, it now appears that at least some of that early benefit may not have been related to treatment, he says.
But he says the study has helped to better define which patients may respond to stem cells.