I haven't heard anything further about that specific test lately, but you can be sure that when they do develop a reliable test, they will be trumpeting it everywhere.

It's my doctor's policy that tests will be done on the CSF because it's a much better indicator than blood, so MRI, LP and decision. He also says ANY relapses are suspicious when on Tysabri and that if there is any indication that a patient is starting a relapse he would follow the same procedure.

I've read on other boards about people who were taken off Tysabri due to relapse, increased inflammation or other adverse indications, including blood work.
Some of them weren't happy and some had the attitude that it was better than PML.

I am not sure if socialized medicine would preclude MRIs. I think that any doctor even if overseas would get the MRI approved and done immediately, because of the history of the drug.