Re-Tysabri....Question about JC virus blood test

Hi everyone, just a quick question about the JC virus blood test.

I started on Tysabri in August and today I’ve had the blood test to see if I have the JC virus.

This may be a daft question, but is it a simple Positive or Negative result or are there different degrees of being positive? Thus more risks if you have a higher positive result?

I believe that I shall continue on the Tysabri even if I do prove positive, as the improvement I have had is worth the risk, but just wondered? I never thought of the question when I saw my consultant.

All the best to you all - Equus

Hi Equus , I was told BEFORE my 1st Tysabri fix that the JC virus is a simple “you have it or you don’t” result and even tho’ I had a positive result I was told by

the wonderful MS specialist nurses at the RVI “have Tysabri , the risks are worth it” I cant remember the figures but increases our chances of PML from 1 in

50,000 to 1 in30,00 but only if there if an infection that triggers it of ( or some thing like that ! ) My advice would be to stop worrying , go get your infusion , enjoy

life , get a tattoo ! ! Do you have good MS specialist nurses ? Surely they should have and could tell you all about the JC virus etc etc etc

Anyway that ramble was probaly of no use at all to you ! Sorry !

Take care and keep the faith

Pete x

Either your positive or negative

I have been on tysabri since Feb and when I had my neuro visit last month he said he wanted me to have the JC virus test - it wasn’t available at my hospital when I started the treatment.

I have an appointment to see the MS nurse before Xmas so she can take some blood and send it off to Denmark, she said I will be tested annually as even if I’m negative I could still pick the virus up somewhere.

Not sure I want to know the result - if it’s neagtive I will celebrate but if it’s positive will it make me worry more?

I know I don’t want to give up tysabri as it has helped me since starting…


Hi Equus

I just had my 40th infusion this morning I’ve never been tested for the JC virus to be honest I really dont care the benefits I’ve had are worth any risk for me, Before I started Tysabri I was in a wheelchair relapsing every 4 or 5 week now I’m walking have a life and never had a relapse since I started Tysabri in August 2008,

I’ve had MRI’s done before starting Tysabri and everyone showed my MS getting worse and more and more lesions but The MRI’s I’ve had done evey year since starting Tysabri has showed my MS to be stable with no new lesion’s infact the neuro said there’s a marked improvement with less lesion’s now then before I started Tysabri

I know Tysabri can get bad press but for me its been amazing and worth any risk.

If you where to get your hands on Septembers Issue of in Focus Tysabri magazine there’s a really good story but the JC virus the risks and what they are.

If you cant get it if you like PM me your email and I’ll email you that part of the magazine


Just wanted to say thank you to everyone who replied to my post. Pretty much knew the facts that you’ve all given - was just reasuring myself that I had understood the information I had been given.

Thanks again - Equus x

hello, I too am on tysabri (two years now) had he test done and am possitive for the JC virus… from what I understand many have it,and problems arise with supressed imunity… which in turn leaves the slight risk of the dormant virus entering the brain … this added to the fact tysabri is also connected to the blood brain barrier is where all the risks asociated from … That all said… I had no worries at all signing my consent form to carry on with tysabri… for me life one big gamble… and its another i willing to take… spose i cld have stopped but then yet another gamble that all the relapses i was having could return and MS take hold totaly!.. yeap for me Tysabri given me my life back … Last yearly brain scan showed no changes since last one… we are monitored all the time and for me really is a risk worth taking.

Be happy with what ever choice are good for you…best wishes Sarah XXX