JC Positive and Tysabri

Hi,I have read many posts but this is my first message… Wondering if anyone can share their thoughts or experience? I have tested positive to JC Virus and though I know the ‘possible’ side effects are not trivial! I have decided to continue with the Tysabri and have just had my 3rd infusion. Naturally feeling quite anxious maybe even admit to feeling scared but trying to keep in prospective the positive benefits possible from being on Tysabri rather than the ‘what if’ negatives. BUT could you please share your personal opinion wether positive or negative to help me build a picture in my own mind. Thanks x


I too am JC+ and I have been on Tysabri around 14/15 months now. I didnt have the test for the JC virus until I was about 3 infusions in. I have to say I didnt really take the virus into consideration as my thoughts were that if I were negative I could turn positive at any point and the possible benefits of being on Tysabri far out weighed the possible effects of anything nasty happening because of being JC+. I go to Southampton General for mine and I feel really reassured that we always have the same nurses (give or take 1 who could be on leave or in clinic) and they do keep a really close eye on me (and others). I have an MRI annually, in fact just had my first one since starting Tysabri and there was very little change to my previous one. Being on Tysabri has changed everything for me - ofcourse MS is so unpredictable that you dont know what could happen and when - but literally nothing has happened since I started. For the first 6 infusions I felt quite tired and a bit sick, but from then on it couldnt be better - I know they say it doesnt improve anything it just tried to slow things down. But I feel completely different on this treatment, about 10 days after I have an infusion I feel fantastic - in a way I hadnt felt for years.

I think the docs will review me after 2 years on Ty because of being JC+ but I will seriously kick up merry hell if they try to take me off it!!

I cant speak for anyone else, but I have my infusions with 2 other ladies who are both JC+ and have been on it a lot longer than me and after spending time with them over the last 14 months I would say there thoughts pretty much mirror mine.

Its natural to feel worried and scared about it - do you have a family/partner? I was told its important for them to be aware of the dreaded PML so they can pick up on any changes in you that you may not notice.

I realise I have rambled a bit…I hope it helps a little. Bottom line is I think Ty rocks!!

Good Luck and take care



I recently relapsed quite badly while taking Rebif injections so they decided to escalate my DMDs. My neurologist and MS Specialist Nurse gave me the option of Tysabri or Gilenya. They explained everything to me but my head was spinning so I went away and researched it for a while. I ended up opting for Gilenya because the risk of PML seemed too great, although most of the stuff I’ve read has been good even when positive for the JC virus. I don’t know yet if I’m positive or not but the the Gilenya seemed to be the less risky option, however, the benefits of Tysabri are greater. It was a tough one!

Having said all that, the risks with Gilenya are still significant. A suppressed immune system means a higher risk of minor infections becoming serious (or even cancer) and there is still the risk of PML (although not as high as with Tysabri). I’ve been assured that they will monitor me closely and I’m sure they will do that for you as well. I’m trying to stay positive about it all but I have to admit it’s scary.

Best of luck and I’m sure it will be fine.


Not a personal opinion, but the Barts & London posted a useful update on risk yesterday. Go to slide 18 for the breakdown.


I wrote a huge reply to this earlier this morning but its gone! So here I go again.

I am about 14 infusions in on Tysabri and I am JC+ although I didnt know that until my third or forth infusion. After being on REBIF and it not working well for me at all - I was really keen to get on Ty ASAP, as I had heard all the wonderful stories and none of the bad ones. Reading up about PML is terrifying but the risk is so small I decided to ignore it as best I could. I dont know where you get your infusions but I have mine in Southampton and more often than not we have the same nurses every infusion so they know us well and the really keep a close eye on everyone but more so the JC+ people. I have an annual MRI, just had my latest one and it showed very little change since my pre Tysabri one. Now I am over a year in on this treatment - it has changed everything. They said it wouldnt improve anything just try to slow it down - but since maybe my 7th or 8th infusion I have felt fantastic and dare I say it (everyone touch wood) my walking has really really improved.

When I started and I got the “Welcome Pack” (not sure what else to call it) I was told it was important to make my husband and immediate family aware of it. Apparently with things like PML it is family/people who know you best that pick up on the very early signs which helps in early diagnosis. I think - although this is not fact that there hasnt been any PML cases linked to Ty in the UK.

It really is personal choice, but I just felt like I was so bad pre-Ty I would of tried anything. But now I am on it I wouldnt ever want to come off - I know I will reassesed after 2 years on it. I am a very much “ignore it until it slaps you in the face” kinda gal - so PML rarely crosses my mind now. I think as well (please dont think this is patronising) but at 3 infusions in - its all still really new and daunting and scary and horrid. But you dont want to go on forever feeling scared and anxious but I do believe it will ease up for you. It almost becomes part of life. My only problem now is they can never EVER find a vein!!

Good Luck H xxxxxx

This site provides a clear breakdown of risk on slide no.18.

Thanks JakeZander for your comments it is always good to hear other peoples thoughts and decision making process’s hoping the Gelenya works its magic for you.

Hi haley894, I really appreciate your informative reply, it is REALLY good to know your thoughts at 3 and 14 infusion…this is exactly what I was hoping to hear. When I found out I was JC+, I asked the infusion nurse what she had come accross in her experience she said someone else had refused to go on T, but then other people didnt want to know their JC results because they were going to go on T regardless - this is how my Neuro put it accross to me…so heaing about your improvements from 7 onwards sound great -watch this space and THANKS!