Mon Oct 7, 7:07 PM ET
By Ed Edelson
The statin drugs that help prevent heart attack and stroke by lowering blood cholesterol levels have another property that makes them candidates for treatment of multiple sclerosis, an Austrian study finds.
Indeed, laboratory results in test tubes and animals have been so good that one trial to see whether statins can slow the progression of MS has begun, with another in the works, an American expert says.
In multiple sclerosis, the immune system mounts an attack against the myelin tissue that is the protective cover of nerve cells, causing symptoms that range from numbness and tingling to paralysis. The Austrian study, reported in tomorrow?s issue of Neurology, says several statins can block activity of the T and B immune cells that attack myelin and can reduce the inflammation that also causes damage in MS.
It's not known exactly why statins have those effects, says study author Dr. Juan José Archelos, a professor of neurology at Karl-Franzens University in Graz.
"One common theory is that in the metabolism of cholesterol, some intermediate substances are formed that modulate immune responses," he says. "Statins may also influence directly genes involved in the immune function."
Whatever the reason, when four different statins were tested against blood samples drawn from MS patients, they had activity in the same range as interferon, an established treatment for MS, Archelos says. The effect was even greater when statins were combined with interferon.
"I have a paper coming out of my laboratory shortly that reports similar results," says Dr. Scott S. Zamvil, an assistant professor of neurology at the University of California, San Francisco, and co-author of an accompanying editorial.
"The data from animal models have been very provocative," Zamvil says. "They show upregulation of molecules involved in preventing central nervous system damage." Specifically, statins promote production of immune system T cells that prevent an immune attack on friendly tissue, he says.
A small-scale human trial to see whether one drug in the statin family, simvastatin, can slow the progression of MS has begun at the Medical University of South Carolina, with the participation of the University of Colorado and Yale University, says Dr. Nick LaRocco, director of health-care development at the National Multiple Sclerosis Society. Results could be available some time next year.
Zamvil says he is involved in the proposal for a larger multi-center trial of statin therapy in patients newly diagnosed with MS. Plans for that trial are "in the evaluation stage," he says.
MS might not be the only autoimmune disease against which statins can be used, Zamvil says. The same basic destructive process, in which inflammatory toxins are produced by the immune system, is also seen in rheumatoid arthritis, he notes.
There might be some pitfalls ahead, LaRocco notes. A lot is known about
statins because of their use in cardiology, but "the immunological effects
of statins are complex. They have pro-inflammatory as well as anti-inflammatory
effects, so studies must proceed with caution."
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