New clue to MS relapses.

In the healthy human body, immune cells enlisted to fight an infection will "self-destruct" once the bacteria or viruses have been eliminated. But a new study has shown that a protein found in abundance in people with MS may help destructive immune cells survive to continue or repeat their attack against brain and spinal cord tissues.

The study, conducted by Dr. Lawrence Steinman and researchers at Stanford University, was funded by the National MS Society, the National Institutes of Health, and others. Nature Immunology published the results in an early, online edition.

Previous studies had shown that the protein--called osteopontin--was elevated in damaged areas of the nervous system in people with MS and that there were increased levels of it in blood plasma just before a person experienced an MS relapse. Osteopontin has been linked to other immune diseases, including rheumatoid arthritis and lupus.

The Stanford researchers carried out the study on mice with different MS-like diseases. Some of the mice had been engineered to lack osteopontin. In a series of experiments, the investigators found that the mice with osteopontin had repeated relapses, they were less likely to recover from symptoms, and their disease progressed more severely.

"These findings may lead to new therapeutic approaches that target osteopontin," John Richert, MD, the National MS Society's executive vice president of Research and Clinical Programs, told InsideMS. "But osteopontin has many functions, including the maintenance of bones. We need more research in order to find ways to stop its influence on immune attacks without keeping it from doing its other jobs."