I was on it briefly, but had no specific tests beforehand. I was on Rebif previous to that, so I had blood tests regularly for testing my liver, I believe. It is usually OK. But no other tests specific to Tysabri, at least for me. But call up the Advances Solutions (people who sell Tysabri) line and speak to a nurse. You should be able to speak to a nurse and ask questions all during the week.

Watch out for allergic reaction. At least I had a bad reaction within a few minutes of the infusion and had to be taken off. So that is why I can't go on that drug and just as well. Anyway, good luck.

The JCV antibody blood test is part of a world wide trial that includes about 10,000 people taking Tysabri.

I believe you may be too late to get into that trial. I've had 26 infusions so far and though I asked my doc if I could get in the trial, she said no. The doc's at my clinic are not participating in it. She said not until more is known about what the JCV antibody test results mean?

She said right now a negative might give a person a false sense of security and cause them to ignore early PML symptoms and a positive test would give someone unnecessary anxiety because the docs would not change the use of Tysabri until they have more proof a positive JCV antibody test places a person at a higher risk for PML. They have more trust in the Touch monitoring program than the blood test at this time.

Early press releases on The Strata trials(JCVanti body test):

-from this trial they are finding about 50-60% of tysabri users have jcv anti bodies..

-JCV anti bodies do not increase with Usage of Ty.

-They hope to have a report on the results of JCV antibody trial out by January and get the test released to market in January, so all Tysabri users can get the test.

-The test has about a 2% false negative result & about 2.5% of the people who tested negative spontaneously test positive in the future. This means that Tysabri users will need to have periodic JCV antibody blood test while using Tysabi.

-Biogen is working with the FDA to get this JCV anti body test included on the label. They are finding increased cases of PML in people who have tested positive for JCV antibodies, compared to people who have tested negative.--so the blood test does seem to have relevance to tysabri & PML. risk.

Another person speculated and I agree, after all I have read on it....the label will be updated to say something like.."with periodic negative tests for the JCV antibody a person has a 1 in 1,000 risk of PML but with a positive JCV antibody test the person has a greater than 1 in 1,000 risk of PML"

Just my guess, and I have been following this fairly closely since i heard of the trial, so my guess is a good one but we won't know until the report comes out in January and the FDA updates the label to include this JCV antibody test.


As far as your decision....ABSOLUTELY NO PERSON HAS GOTTEN PML IN THE FIRST 12 INFUSIONS WHEN TYSABRI HAS BEEN USED FOR THE TREATMENT OF MS.

The PML RISK breaks down like this for the treatment of MS...

0-12 infusions: 0 in 1,000 (0% risk--no risk)
13-24 infusions: 0.38 per 1,000 ( very low risk)
25-36 infusions: 1.44 per 1,000 (took a big jump in risk)
all greater than 24 infusions: 1.87 per 1,000 (doesn't seem to have an upper limit in this range, but not many people have had this many infusions yet)


The blood test should be available before you reach 12 infusion and any PML risk starts. Maybe continue through the very low risk 13-24 infusions. Start Tysabri now, knowing you will make a decision on continued use after 12 or 24 infusions at that time.

Most of us pre-JCV anti body test tysabri users are pretty comfortable up to 24 infusion. After 24 we are a little more skitish & wait anxiously for the JCV antibody test to be release to market.

Let me know if this information has helped you make a decision? I believe I can find the early unofficial results that have been reported to back up what I have said/believe to be true. its a little bit of work I don't have time to do right now or in the next few days.

I have a friend who recently started Tysabri and her neurologist gave her the test for the JVC antibody before deciding to start her on Tysabri. The neurologist is affiliated with the University of Utah however and has access to the test which is not yet widely available.

Thanks for the replies. It explains why the nurse was not quite getting what I was asking. Although she could have told me information you all gave. She just said they would do a liver function test. Or maybe that was if I wanted to try Gilenya, which I don't. Maybe I could handle the Tysabri for a year. The only thing is they don't know what long term effects it might have 5-10 or more yrs down the road, And I'd like to think 5-10 yrs at least is in my future. Anyone have information on that? Thanks so much. It is a really difficult decision.