New Study Questions Safety of Spinal Cord Injury Treatment
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NR-08-04 (sent 4/9/04) For more information, please call Dawn McCoy at 202-462-6688.
NEW STUDY QUESTIONS SAFETY OF SPINAL CORD INJURY TREATMENT
WASHINGTON, DC April 9 — New research contradicts earlier findings suggesting that amplifying the body's natural immune response following spinal cord injury can boost healing.
Spinal cord injury interrupts the flow of electrical information between the brain and the body, often leaving an individual without sensation or unable to move below the level of the injury. In some individuals, cells in the spinal cord continue to die for weeks after the injury, creating so-called "secondary injury."
Previous work had suggested that vaccinations that increased autoimmune responses could improve recovery, but in the new study, rats vaccinated with myelin basic protein to increase their autoimmune response following spinal cord injury did not recover the ability to walk as well as nonvaccinated rats. Moreover, vaccination increased the amount of inflammation in the spinal cords of the rats and increased secondary injury. The study was conducted by Phillip Popovich, PhD, and his colleagues at Ohio State University and supported by the National Institutes of Health.
Earlier work by Michal Schwartz, PhD, and her colleagues at the Weizmann Institute of Science in Rehovot, Israel, showed that trauma to the central nervous system in rats and mice evoked a protective immune response that reduced loss of neurons from secondary injury. The findings seemed to challenge accepted dogma that an autoimmune response in the central nervous system is harmful and suggested the possibility of a vaccine that could amplify the autoimmune response in treating spinal cord injury. The Popovich study, which appears in the April 14 issue of The Journal of Neuroscience, raises important questions about this conclusion.
"Using a model of rat spinal cord injury that resembles a majority of human injuries, we show that when T-cell autoimmune responses are increased by vaccination, rats did not fare as well in their recoveries as nonvaccinated rats," says Popovich.
The study could have important implications in the development of treatments for spinal cord injury. Clinical trials are under way to boost the regenerative potential of macrophages after spinal cord injury. Trials based on boosting autoreactive T cell responses are not yet under way for spinal cord injury.
"Premature translation of findings from animals to human clinical trials might not only lead to ineffective therapies, but harmful ones," says Mark Tuszinski, MD, PhD, of the University of California at San Diego. "This is a time both of great promise and substantial risk in the field of spinal cord injury research, and the basic medical tenet of 'first do no harm' may be an apt reminder."
Popovich's co-authors include T. Bucky Jones, Daniel P. Ankeny, Zhen Guan, Violeta McGaughy, Lesley C. Fisher, and D. Michele Basso. Popovich is a member of the Society for Neuroscience, an organization of more than 34,000 basic scientists and clinicians who study the brain and nervous system. The Society publishes The Journal of Neuroscience. Popovich can be reached at firstname.lastname@example.org.