The way I've read it explained before (but it was in reference to how they thought PML was occurring with the use of Tysabri) . . . Tysabri's mechanisms are based on the belief that Multiple Sclerosis is caused when T-cells (which are the soldiers in the immune system), "mistakenly attack the lining of nerves in the brain. Without this lining, cells stop functioning and die. Tysabri works by preventing the T-cells from entering the brain. (But those same T-cells normally keep the virus that causes PML in check. If that virus, which is dormant in most people, is allowed to run rampant, it damages or destroys the brain)."

So, I see where you are coming from with the explanation on Tysabri managing new lesions/inflammation, etc. and how it could be effective for that purpose.

The part I'm still confused about though is how an infusion would seem to be CAUSING a fever for Natalie. While I can see how Tysabri might be controlling the inflammation from causing more inflammatory lesions (which is perhaps why she had so many fevers before Tysabri, and isn't now), I still don't understand why is it that every time she has an infusion she seems to get a fever for a few days?

Cherie