Abstract
An expert panel of radiologists specialized in MRI monitoring of patients with multiple sclerosis proposes a safety protocol for monitoring of patients with increased risk of progressive multifocal leukoencephalopathy (PML). Patients administered natalizumab for longer than two years in whom anti JC virus antibodies have been detected have a higher risk of developing PML.
PML is a rare opportunistic infection that occurs in immunocompromised patients. Over the last decade, PML was reported to be associated with administration of monoclonal antibodies.
The disease has high lethality and severe clinical course. There is currently no effective treatment.
Early diagnosis, followed by treatment interruption and natalizumab elimination, is the only factor that influences patient prognosis. Regular monitoring with magnetic resonance imaging enables detection of the subclinical stage of the disease, thereby significantly improving patient prognosis.
This paper proposes essential MRI safety monitoring (protocol testing, monitoring frequency) and emphasises close cooperation between radiologists and neurologists. It also shows the characteristic MRI features of the disease and discusses published literature summarising early stage findings.
The paper seeks to highlight the imaging characteristics that help to distinguish PML from an MS relapse, i.e. the most common differential diagnostic problem.