Ricerc@Sapienza

The biomarker neurofilament light chain (NfL) is used for assessment of neuronal damage and is normally measured in cerebrospinal fluid (CSF) obtained through a lumbar puncture, a sometimes-harmful procedure for the patient. During recent years, novel methods have given the possibility to measure NfL in plasma instead, which could be a convenient tool to estimate severity of disease and prognosis in neurological disorders. The novel ultra-sensitive method, a digital enzyme-linked immunosorbent assay (ELISA), has been shown to be a both reliable and compelling alternative for analysis of plasma NfL in patients with central nervous system (CNS) disease, such as multiple sclerosis (MS).
Despite its proved efficacy for patients with highly active relapsing-remitting MS, the use of natalizumab (anti-¿4 integrin) is limited due to the increased risk of progressive multifocal leukoencephalopathy (PML) caused by the polyomavirus JC (JCV). In addition to existing PML risk stratification algorithms based on natalizumab treatment duration, previous immunosuppressive therapies, and JC virus index, other biomarkers may certainly contribute to estimate the risk of PML at an individual level. Yet, the usefulness of measuring plasma NfL levels in patients with PML is scarcely elucidated. Here, we propose to investigate the correlation of serum and CSF NFL in MS patients with PML treated with natalizumab, assessing the potential useful for serum NFL levels to predict the risk of PML and to discriminate PML from MS relapses.