Hi Sally,

Thanks for the link. You gotta remember though that those are only allegations made relating to a lawsuit, none of those things have been proven. Also the guy who claims it's not safe works for competing MS drug co's.

I would really like to see the scientific research about whether Avonex with Tysabri increases the bioavailability of Tysabri or whether use of immunosupressants affect Tysabri's effects on the body. Could people who use Avonex use LESS Tysabri then to get the same effect but without going over to increasing the risks of developing infections?

I am surprised the FDA allowed it back on the market before knowing this. Avonex is not really even considered an "immunosuppressant" so much as immuno-modulating. But given that MSer's often ARE given immunosuppressants which would seemingly have more effect at suppressing the immune system in conjunction with Tysabri, and given that the Crohn's patient had been OFF Azathioprine for a while yet still developed PML, I would think that we really need the answer to the question of what the risks are of developing PML having EVER used an immunosuppressant or immuno-modulator.

Maybe the risks are still not huge given that we can assume that probably a fair # of people in the MS or Crohn's trials had used some kind of immunosuppressants at some point in their illness and only a very few developed PML. But how long does one need to wait to make sure that there is no contraindication occurring? What parameters put one at risk for PML? Is it even related to use of immune suppressants at all.

I really wish we could know exactly WHAT puts someone at risk for PML.