I am JCV positive.
For most people, that doesn't mean anything. But people on Tysabri, or those who know people taking Tysabri, will probably understand why I know or care about JCV.
Let me backtrack by explaining a few terms....
Tysabri - It's an MS drug administered every 4 weeks by IV infusion. Unlike the earlier disease-modifying drugs, Tysabri is not self-administered, so no more shots at home. You go to an infusion center every 4 weeks and sit in a comfy chair with an IV in your arm. Then you stick around for another hour so the nurses can make sure you don't show any allergic reactions to the drug. That's it. You don't have to think about medicine for another 4 weeks. No more Sharps containers, no more alcohol wipes, no more psyching yourself up at home to stick a needle into your own body on a regular basis. During clinical trials, patients showed a significant reduction in relapses when taking Tysabri, and the drug was hailed as a huge positive step in the treatment of MS.
PML - PML stands for progressive multifocal leukoencephalopathy, a rare brain disorder that can kill or cause serious disability. Unfortunately, one of the risks of taking Tysabri is an increased risk of developing PML. That's a big reason why Tysabri is not usually the first drug of choice for MS patients and is usually recommended only after other disease-modifying drugs don't produce satisfying results. This risk is why Tysabri is one of those drugs with a black box warning detailing the potential dangers of taking the drug. It's also why patients on Tysabri are closely monitored and can only have their infusions in IV centers participating in the TOUCH program which oversees the administration of the drug.
JCV - JCV is the virus that causes PML, and it's a virus to which a large percentage of the population (I've seen numbers ranging from 50-90%) have been exposed. People taking Tysabri will be tested to see if they have the virus in their systems. If not, then they don't have to worry about developing PML. If they do, then they are at risk for developing PML. The risk increases further the longer you take Tysabri and whether you took certain immune-suppressing drugs before taking MS medications.
Given the high percentage of the population that has been exposed to JCV, I was not surprised when my blood test showed that I had been exposed to the virus. My neurologist and I talked about it during my last appointment, and I'm sure it won't be the last discussion we have on the subject. Typically, JCV-positive patients are at greater risk after taking Tysabri for 2 years, and I've only been taking it for 7 months. We agreed that for now, it's OK for me to still be getting the infusions, but that I need to speak up IMMEDIATELY if I notice any new or worsening symptoms. It used to be thought that there was no cure or treatment for PML, but when symptoms are detected early, stopping the Tysabri and doing a plasma exchange to flush out any remaining drug.
My neurologist also told me that brain MRIs can assist in the early detection of PML, so it was back in the tube for me. Since I'm claustrophobic, I wish I could avoid MRI machines, but when it comes to MS, neurologists get so much information about the disease and its progression that I have to just suck it up, take my IV valium, stick my tongue out at the MRI machine before going in, and begrudgingly accept the value that the MRIs have on my continued treatment. I can't let my fear get in the way of my treatment.