July 9, 2003 -- A potential blood test may help to better identify early multiple sclerosis, scientists say.
Researchers from Austria's University of Innsbruck report that the presence of two specific antibodies was highly predictive of early disease progression in a group of patients with symptoms and clinical evaluations suggesting multiple sclerosis (MS).
Multiple sclerosis is a chronic disease of the nervous system. If a person experiences an event that suggests multiple sclerosis, doctors can only diagnose the disease when a second event happens, which may be years later.
Though a significant percentage of patients in the study who had one or both of the antibodies experienced progression of their disease within a year of their first MS event, almost none of the patients with neither of the antibodies had progressed after three years. The findings are published in the July 10 issue of The New England Journal of Medicine.
Study author Thomas Berger, MD, tells WebMD that if the research team's findings are confirmed, the test could help doctors counsel their patients with symptoms that may indicate multiple sclerosis.
"Patients often ask me what their prognosis is, and in most cases I have to confess to them that I don't know," Berger tells WebMD. "We can't really tell most patients how quickly their disease will progress. Something that could help us predict this would be of enormous value."
Multiple sclerosis is characterized by intermittent, recurrent damage to the insulation that surrounds the nerves in the brain and spine, known as myelin. Symptomatic events often occur years apart, but each episode causes more hardening and scarring of the myelin, which interferes with transmission of nerve signals.
The Austrian study included 103 patients who had experienced a first event suggestive of multiple sclerosis and who had magnetic resonance imaging (MRI) and spinal fluid tests consistent with the disease. All patients were also tested for the presence of two antibodies in the blood.
Almost all of the patients who had both antibodies were confirmed to have multiple sclerosis within roughly five years, compared with about one-fourth of patients who had neither antibody.
Neurologist Jack P. Antel, MD, who wrote an editorial accompanying the study, says the promise of this potential marker is that it may help doctors better differentiate between people who experience an isolated episode of myelin damage vs. those with actual multiple sclerosis.
Last year, the interferon treatment Avonex became the first drug approved for treatment of multiple sclerosis prior to the second symptomatic event. Studies suggest that early treatment can dramatically slow disease progression. But there are significant side effects to taking interferon, including flu-like symptoms and fatigue, and Antel says some patients may chose to delay treatment if they know they are at low risk for having another episode.
"We know that somewhere around half of the patients with positive MRI will relapse within a year or two of their first event, but there are some patients who don't," he tells WebMD. "This test, if validated, could help us determine who will relapse and who will not."
But National Multiple Sclerosis Society spokesman Stephen Reingold, PhD, says patients with a positive MRI and spinal fluid tests should be treated as early as possible.
"We know that these people are almost certainly going to get MS later on," he says. "And the earlier you treat this disease, the better off you are. I don't see any reason to withhold treatment based on this research."