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Sick Kids researchers look at viral triggers for multiple sclerosis in children

Researchers at The Hospital for Sick Children (Sick Kids) have shown an association between paediatric multiple sclerosis (MS) and the Epstein-Barr virus (EBV), indicating that exposure to the virus at a certain time in childhood may be an important environmental trigger for the development of MS. This research is reported in the April 21, 2004 issue of JAMA (The Journal of the American Medical Association).

"Earlier studies suggested a relationship between childhood exposure to Epstein-Barr virus and the risk of developing MS. This is virtually impossible to quantify in adult MS patients, as nearly 90 per cent of the healthy adult population in Western countries has been exposed to EBV. In the paediatric patients, we can study viral exposures more easily, as children have fewer viral exposures due to their young age," said Dr. Brenda Banwell, the study's principal investigator, a Sick Kids neurologist and associate scientist, and an assistant professor in the Department of Paediatrics at the University of Toronto.

The research team found that 83 per cent of the paediatric MS patients showed evidence of a past EBV infection, compared with 42 per cent for the healthy control group. The paediatric MS patients also were less likely than the control subjects to have been exposed to herpes simplex virus. Epstein-Barr virus is very common and transmissible virus in the herpes family that causes infectious mononucleosis.

"We think the Epstein-Barr virus plays an important role in the development of MS, as the genetic code of the virus contains sequences that are identical to genetic sequences in the myelin basic protein, which is expressed in the brain, and destroyed in MS. It is conceivable that the immune system mounts a response to that genetic sequence in EBV, then sees it in myelin and targets it as well," added Dr. Banwell.

More here.

April 21, 2004 in research | Permalink