Case Report: Neurofilament light chain in the follow up of progressive multifocal leukoencephalopathy in a patient with multiple sclerosis treated with ocrelizumab

TL;DR

This case report explores the potential of neurofilament light chain as a biomarker for early detection of PML in MS patients treated with ocrelizumab.

Contribution

The study suggests that serum neurofilament light chain levels may aid in the early diagnosis of PML in MS patients.

Findings

Serum neurofilament light chain levels were elevated at the time of PML diagnosis.

sNFL levels progressively increased during the patient's follow-up.

Monitoring sNFL may help detect PML early in MS patients.

Abstract

Progressive multifocal leukoencephalopathy (PML) results from the reactivation of John Cunningham virus JC virus and is a rare complication of anti-CD20 drug therapy. Neurofilament light chains increasingly serve as a marker of neuroaxonal damage in the follow-up of patients with multiple sclerosis (MS), but its role in the monitoring and detection of processes such as PML is yet to be defined. We report the case of a patient with MS who was treated with ocrelizumab and developed PML. Results: Serum neurofilament light chain (sNFL) levels were elevated at the diagnosis and progressively increased over his follow-up. Our results suggest that the monitoring of sNFL levels may be useful for the early diagnosis of PML in patients with MS.

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