Feb 23, 2004
Findings from an autopsy study by Australian researchers question the theory of multiple sclerosis (MS) that holds that an autoimmune attack on myelin is the inciting event for the disease.
Instead, it appears that myelin-producing cells die first and then immune cells show up to clear out these dead cells and their myelin, lead author Dr. John W. Prineas, from the University of Sydney, said in a statement.
The results, which are reported in the February 23rd online issue of the Annals of Neurology, are based on the clinical and pathologic findings noted in 12 patients with relapsing and remitting MS who died during or soon after a relapse episode.
In seven of the cases, the researchers observed pathologic changes that had not previously been observed in newly formed MS lesions. Specifically, the lesions showed extensive oligodendrocyte apoptosis and microglial activation, but little or no lymphocytes or myelin phagocytes.
The authors believe that the current findings could have a profound impact on MS research, which is largely focused on determining why the immune system attacks myelin.
"The important point, at this stage of our investigation, seems to be that we have no laboratory model for this sort of pathology," Dr. Prineas said.
Ann Neurol 2004;55
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