LP test before starting Ty

[kosmicmisfit]

Hi

I have MS and have been offered a lumber puncture prior to commencing treatment for Ty.

How effective is this test in determining the chances of getting PML? Or is that a silly questions?

I am more confused then before. Help please!

S

[HCB]

hi welcome to MS World--I have been on TY for 3 years this month and thank heavens I'm doing great on it. According to everything I have read there has only been 1 case of PML for anyone that has been on TY for less than a year--the worry is for those who have been on it for 24 months or longer. I have never heard of getting an LP before starting TY. There is a blood test out that can test to see if you test positive for the JV virus which can make one more suscepectible(sp?) to getting PML. you may look into getting that then facing a LP. Good luck with TY

[LL60]

Welcome-
I would talk to your doctor more about the LP test, I think you misunderstood him. An LP CAN confirm MS, and you certainly would want to be sure before starting Tysabri, but it isn't a definitly type test either. (did that make sense?)

Even the JC virus test they have is still being studied.

Read all the threads here, lots of people have had a variety of experiences with it. There are those just starting and those who have been on it since the very begining. Think someone has had 54 infusions! I have had 15 myself and I also have had a very very good response to it. I will continue on it.

Let us know how you are doing okay?

[0485c10]

Interesting thought. As the two replies above, no one here has gotten an LP before starting TY. It would not prove a risk of PML at all...but it could as LL60 said confirm MS.

In the original trial for Tysabri, one person who died from PML, it was determined on autopsy she did not have MS.

So it was the drug treating a disease she did not have that killed her. So I could see your doc being extra careful to confirm your MS status.

Her name was Anita Smith, she died from PML & on autopsy it was found she did not have MS.

Since the early days it was thought that doing an LP to get spinal fluid to test for JCV DNA when PML was suspected was the confirmation. But the NMS wrote an update report that it is possible to have PML without JCV DNA in the spinal fluid.

"Likewise, the absence of JC virus DNA in the spinal fluid does not exclude PML".

http://www.nationalmssociety.org/new....aspx?nid=2308

Your best bet to determine the PML risk is the JCV antibody test which is in trial, as said above.

They do not yet know what having the JCV antibody means, but they believe if someone doesn't have the JCV antibody, they were never exposed to the JCV virus so they would not be at risk for PML.

But those with JCV antibodies were exposed to the JCV virus and could have a risk of PML with Tysabri use; An unknown risk. So the JCV antibody test is to identify a sub-group of people with no risk.

Its still in trial, they hope that those without JCV antibodies have no risk.

If your interested in finding out a risk of PML the best bet right now is that JCV antibody test. The Stratify 2 trail. There are links to it in replies in this forum.

The JCV virus is tough to detect.

Because it can lie dormant in bones, kidneys, spleen,or throat(? may be more organs). Then for some reason it will go mobile(active ) in the blood and mutate to a virus that will cross the blood brain barrier, get into the brain and cause PML....for people on Tysabri their immune system can't get into the brain to fight the virus and PML occurs.

Since the JCV virus can lie dormant in so many organs, I don't think spinal fluid would give any indication of PML risk.

When JCV is dormant it is totally harmless to a person. It might not be in the spinal fluid, it probably isn't yet, it might be in the kidneys? So LP wouldn't give a PML risk, it may more clearly define you have MS .

The antibody test (now in trial)will tell if a person has been exposed to JCV in the past, regardless of where it is presently laying dormant.

So that's the best hope for something that will finally predict a person's risk of PML with tysabri use--or identify those people who are not at risk of PML with tysabri use..

Its in trial, so they are not certain yet if it will do that.

We might not know for a few more years if it does predict PML risk or lack of risk....until they collect all the data from the ongoing trial and the data is evaluated. Many docs believe there is strong evidence that it will define those not at risk--because everyone who got PML had JCV antibodies.

[kosmicmisfit]

Hi

Thanks for the replies.

I live in the London, UK. I was dx with MS Sept 2008. (It just struck me that its nearly 2 years, times does fly even when you have MS!!)

The MS was confirmed by MRI and LP (painful or what!) I still am an in denial about the MS and do not believe that I have it!

I was on Beta Interferon and then on Copaxone.

My MS nurse suggested/offered that the LP would be used to test for JC Virus. The hosiptal where I go to has the 2nd largest number of people taking Ty. The largest I hear is being Milan.

I have read the threads and posted as I could not find someone who has had the LP to test for JC Virus.

still confused

[0485c10]

Hi kosmicmisfit,

Ouch the trial I so strongly recommended and explained the theory behind, is being done in the US. The need is strong in europe too but it may take a while to get there, by that time at least it will be known if there is validity in the anti body test.
I'm in the US, but I'm not in the trial so I too will have to wait until the results are in

Perhaps in europe they are collecting spinal fluid information to find a pattern. PML is a multi international effort. PML happened in the US but was first survived in europe..so that knowledge is shared. When a prediction for PML risk happens it will also be shared, whichever side of the pond it comes from. We are excited about this anti body trial on this side now..The answer might come from spinal fluids on the other side of the pond. This side its a less painful blood test, I rather hope its the one that works.