I've taken 39 infusions of Tysabri and just tested positive for JCV antibodies. My neurologist removed me from Tysabri and the MRI taken a few days later showed no signs of PML, am I still at risk for PML and if so, for how long do I have to worry?
PML risk lasts at least 6 months after Tysabri discontinuation. The larger risk is regarding rebound MS disease activity (based on results of the RESTORE study). Transition to an appropriate therapy is important to minimize this risk (discussed elsewhere on this site).
A. Scott Nielsen MD MMSc
Neurologist and MS Specialist at Kaiser Permanente