Antibody May Trigger MS

Simple Blood Test Could Help Diagnose Severe Forms of MS

From the WebMD Archives

Oct. 16, 2002 -- Researchers have identified a potential key player in multiple sclerosis. People with advanced disease show significantly elevated levels of an antibody called anti-MOG.

Researchers don't know yet whether this antibody is a cause or a byproduct of nerve damage. But the finding should open entirely new areas for investigation and potential therapy.

In fact, blood tests to measure anti-MOG antibodies could help diagnose the more severe forms of MS, says researcher Claude Genain, MD, from the University of California, San Francisco.

He presented his paper at the American Neurological Association's annual meeting held in New York City this week.

"This appears to be the first simple, reliable, and inexpensive blood test that correlates so strongly with [MS]," says Genain in a news release. "[It would] significantly enhance our understanding of what causes the different forms of MS and how they should be treated."

Multiple sclerosis is a disorder of the nerve fibers of the brain and spinal cord. In people with MS, scarring, or sclerosis, replaces myelin -- the substance that normally insulates the nerves and speeds electrical impulses through the fibers.

Weakness, clumsiness, numbness, visual disturbances, even emotional and intellectual changes are all characteristic of MS -- depending on which nerve fibers are affected.

While doctors don't know what causes MS, most evidence suggests that it is an autoimmune disorder. The immune system's defense mechanisms identify the myelin as a foreign object, triggering its destruction.

Genain and colleagues have been searching for molecules, like antibodies, that help identify the targets of the immune system.

Anti-MOG is an antibody to a component of myelin. It's already known to play a role in destroying myelin in mice with MS, reports Genain, but how it works in people is less clear.

To better understand the significance of the anti-MOG antibodies, Genain applied tests to different groups of MS patients.

One group of 27 patients had "relapsing and remitting" disease, 49 had a progressive form that can lead to severe debilitation, and another group of 18 healthy people served as controls.

As in previous studies, anti-MOG antibodies were found in about one-third of controls and patients with relapsing/remitting MS. However, almost all the patients with progressive MS tested positive for anti-MOG.

This pattern has not been seen with other antibodies and means that anti-MOG antibodies are either causing the disease process or are at least a strong marker of tissue destruction, says Genain.

"It's use in combination with other disease markers such as MRI would significantly enhance our understanding of what causes the different forms of MS and how they should be treated," he says. "We can envision that therapies against antibodies or [cells that make antibodies] will be useful to treat this disease." -->