During the 1960s, scientific research into the cause of MS came to focus on two main lines of inquiry that are still being explored today.

The first emerged from a finding about the immune system. White blood cells that react against myelin, specifically against a component called myelin basic protein, were discovered in both EAE and human MS. This led scientists to consider the possibility that MS involves a direct immune-system attack on myelin.

The second idea came from studies that showed that people with MS have altered antibodies against viruses. This revived the older thinking that MS could be caused by a virus. But rather than a viral infection directly damaging the central nervous system, viruses involved in MS were now thought to alter the immune system and trigger it to damage myelin.

These two ideas remain closely mingled today: MS may combine features of both an infectious and an autoimmune disease.

Reference

Written by Loren A. Rolak, MD. Reproduced by permission from the National Multiple Sclerosis Society, USA. © NMSS, 2003