Oct 16, 2002
By Anthony J. Brown, MD
An antibody against a component of myelin, known as myelin oligodendrocyte glycoprotein (MOG), is present in virtually all patients with progressive multiple sclerosis (MS), researchers from the University of California, San Francisco, report.
Although the antibody can be found in healthy subjects and in patients with relapsing and remitting MS, it could still be a useful marker for disease progression, Dr. Claude Genain told Reuters Health. Furthermore, in combination with other tests, such as MRI, anti-MOG testing could clarify the pathogenesis of MS and lead to new treatments, he added.
Findings from animal studies have shown that anti-MOG is capable of destroying myelin. Still, because the antibody has been found in healthy subjects, its role in MS has been unclear.
In the current study, Dr. Genain and colleagues analyzed blood samples from 27 patients with relapsing/remitting MS, 49 with progressive MS, and 18 healthy control subjects for the presence of several anti-myelin antibodies, including anti-MOG.
Approximately one third of control subjects and patients with relapsing/remitting MS tested positive for anti-MOG, according to the findings, presented Tuesday at the 127th Annual Meeting of the American Neurological Association. In contrast, anti-MOG was found in the serum of nearly all patients with progressive MS. Other anti-myelin antibodies were equally common among the three groups.
"For MS, there are few markers for disease progression," Dr. Genain noted. "Now, we have a blood test that may provide an indication of disease progression," he said. "Larger studies are needed to confirm the current findings, but still it's a very exciting prospect."
At this point, it is unclear if anti-MOG causes progressive forms of MS or if it is just a marker of other destructive processes, Dr. Genain said. "If it turns out that anti-MOG is directly responsible, we already have chemotherapeutic agents that can suppress antibody secretion by B cells," he added.
"We do not know why the antibody is also present in some healthy subjects," Dr. Genain noted.
"One possibility is that a certain antibody level has to be reached before MS occurs," Dr. Genain said. "In our study, we only tested for the presence of anti-MOG," he noted. Studies are now being conducted to determine the exact antibody levels.
"A second possibility is that the anti-MOG in MS patients is actually different from that in healthy subjects," Dr. Genain stated. "With currently available assays, we are unable to determine if the antibodies are different."
Finally, it may be that "other factors are present in MS patients but
not in healthy subjects that allow anti-MOG into the central nervous system,"
Dr. Genain speculated.
© 2002 Reuters Ltd