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OK. Have been on Tysabri for over 4 years, DX in 1998, Avonex before Tysabri.

After the first blood draw as a part of the "Stratify" study have been told that I have the antibodies for JCV. My neurologist wants to know what I want to do. Tysabri has been very effective for me. I have had perhaps one minor flare since begining treatment. I have some minor optical issues, some minor cognitive I think, but otherwise I am blessedly symptom free.

My last several MRIs have shown no active lesions in brain or spinal shots.

It goes without saying I don't WANT to come off Tysabri, and my DR is not providing any real advice.

Thoughts anyone? I mean perhaps 80% of people carry JCV...

Bodie wrote:OK. Have been on Tysabri for over 4 years, DX in 1998, Avonex before Tysabri.

After the first blood draw as a part of the "Stratify" study have been told that I have the antibodies for JCV. My neurologist wants to know what I want to do. Tysabri has been very effective for me. I have had perhaps one minor flare since begining treatment. I have some minor optical issues, some minor cognitive I think, but otherwise I am blessedly symptom free.

My last several MRIs have shown no active lesions in brain or spinal shots.

It goes without saying I don't WANT to come off Tysabri, and my DR is not providing any real advice.

You are facing a tough decision that many Tysabri patients have and there isn't a lot of solid information available for you to make an informed decision.

What is emerging is that the risk of PML to MS patients who use Tysabri increases the longer that they are on the drug. Initially, Biogen told us that the risk factor was 1/1000 and that has more or less remained at that level for the first year of use. But after 3 years, the risk rises to about 1/500 and that obviously is a cause for concern. There isn't much data available beyond the 3 year level at this time. Biogen is working on a test assay to try and determine how susceptible MS patients are to the JCV virus but that is still in the study phase.

Some neuros are suggesting their patients take a 6 month Tysabri holiday after 3 years but there is some evidence that this can trigger a severe exacerbation. Resuming the drug again returns the patient to previous disease activity level but I don't imagine a MS patient wants to suffer any kind of exacerbation.

What all this means is that trying to decide whether to remain on Tysabri is a VERY difficult decision especially if the drug appears to be helping the patient. Until the drug has been used by a lot of patients for a 5 year period, reliable data on PML is going to be hard to come by.

Whatever your decision, I hope it works out well for you.

Harry