MRI finds PML in some natalizumab-treated patients despite negative CSF, no symptoms

March 20, 2018|Clinical Neurology News

MRI not yet ready for bigger role in PML detection

FROM JAMA NEUROLOGY

Some multiple sclerosis patients who are treated with natalizumab can have small progressive multifocal leukoencephalopathy (PML) lesions seen on MRI yet have undetectable JC virus DNA in their cerebrospinal fluid, a cross-sectional, retrospective study has revealed.

The findings show that for some people with MS, PML diagnosis could be delayed if cerebrospinal fluid (CSF) sampling is negative and patients are asymptomatic, potentially resulting in worse functional outcomes and survival rates, according to the authors, led by Martijn T. Wijburg, MD, of the MS Center at VU University Medical Center in Amsterdam.

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The study also described a potential correlation between PML lesion volume and John Cunningham virus (JCV) copy numbers. “To our knowledge, this is the first study that shows an association between total PML lesion volume measured by brain MRI and CSF JCV PCR [polymerase chain reaction] results in patients with [natalizumab-associated PML]. This may have considerable implications for patient care,” the research team wrote in JAMA Neurology.

PML, a lytic infection of glial and neuronal cells by the JCV, can be diagnosed when a patient exhibits clinical symptoms, JC virus DNA is detected in CSF by PCR, and specific brain lesions are seen on MRI, according to a consensus statement from the Neuroinfectious Disease section of the American Academy of Neurology.