MRI finds PML in some natalizumab-treated patients despite negative CSF, no symptoms
FROM JAMA NEUROLOGY
Dr. Wijburg and his coinvestigators reviewed data from Dutch and Belgian patients considered to have natalizumab (Tysabri)-associated PML during January 2007 and December 2014.
Patients were required to meet one of the following criteria:
• Definite or probable PML, based a positive PCR and MRI findings suggestive of PML, with or without PML symptoms.
• In the absence of a positive PCR, the presence of all four of the following features: high risk of PML development, such as positive anti-JCV serostatus and natalizumab treatment duration greater than 12 months; no MS disease activity prior to PML suspicion; MRI lesions highly suggestive of PML, with lesion characteristics as previously reported and absence of lesion characteristics suggestive of other diseases, as judged by an experienced neuroradiologist; and a lesion evolution on follow-up MRI scans suggestive of PML, including development of immune reconstitution inflammatory syndrome.
