And success was limited.
But, for the new study, researchers tweaked the technique and moved it to relapse-remitting patients who were younger than in previous studies.
"This is a safer approach, and we do it earlier in the disease because people have less disability so it's safer again," Burt said.
The study involved 21 patients with the earlier stage of the disease who were not responding to treatment with interferon.
The procedure basically involves stripping the patient's body of its immune cells, and then repopulating the body with stem cells from the patient's bone marrow.
"You're trying to wipe out the immune system and then, with one's own cells, reconstitute it with the hope that the new cells will not target myelin. That's the theory, get rid of bad cells and reconstitute it with new cells from one's own body so hopefully they haven't been triggered yet to attach to myelin," O'Looney said.
Seventeen of the participants improved by at least one point on a scale used to measure disability. Five participants relapsed, then went into remission after more treatment.
After about three years, none of the patients' disease was progressing and 16 were no longer relapsing. And some experienced improvements, all without major side effects.
The findings were published online Jan. 30 in The Lancet Neurology and will appear in the March print issue of the journal.
Still, specialists are curbing their enthusiasm until further results are seen.
"We need to see a larger number of samples... and [we need to] know if the benefit they're seeing is due to the immune system being reset or because the immune system has been suppressed and will return as the way it was," O'Looney said.
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