So I am entering into my fourth year of being on Tysabri as my treatment and it is really helping me, but from what I remember my doctor telling me I will eventually have to probably be put on another treatment, because eventually I will go from JC negative to positive and I wont be able to be on Tysabri anymore, because it woulld bring on PML which after reading about that disease is scary. So I was wondering if anyone of you guys has went from JC negative to positive and how long did it take, because I really like the treatment I am on, but I do not want PML. :)
First of all - I am not a doctor but I've had MS for 17 years. So I'm going to give you some advice about Tysabri. I've been on Tysabri for 8 years. I'm right on the edge of being JC positive - my number is 3.19 - anything over 4.0 is considered positive. I've also been just over 4.0 but the numbers can fluctuate each time you take the blood test which is probably only once or twice a year, right? But to answer your question, it took me about 6 years before I came anywhere close to a positive reading.
Doctors get in an uproar if you test positive and want to take you off Tysabri right away. I talked with my neuro (who only works with MS patients) and we decided I should stay on the Tysabri because I'm doing very well on it and that we would do 2 MRI's and 2 bloodtests for JC virus a year. Did you know that they can see PMI on an MRI if that's what they are looking for instead of lesions.
The point is stay on the Tysabri as long as you can and as long as it is working for you. All of the newer oral drugs have awful side effects including PML.
Good luck to you,
Thanks for posting this- the JC piece is pretty complicated it seems. The rough part is, any of us can be exposed any day. That's just the way it works- so there's absolutely no way to predict if you'll ever become exposed, or if it could happen in a few days (for example). I wish I had a better answer, he's a little more information:
JC Virus Testing