Current state-of-art of the application of serum neurofilaments in multiple sclerosis diagnosis and monitoring

INTRODUCTION: Neurodegenerative processes occur from the beginning of multiple sclerosis, contribute to irreversible clinical disability and are only partially addressed by current disease-modifying therapies. Reliable quantification of neuro-axonal damage may contribute to improve the assessment of disease activity and progression, the definition of patients' prognosis and treatment monitoring. Neurofilaments are neuron-specific cytoskeletal components that are released after neuro-axonal damage. Among them, neurofilament light chains represent a promising biomarker of neuro-axonal damage in multiple sclerosis. AREAS COVERED: This review summarizes the current state-of-art of neurofilament light chain quantification in multiple sclerosis, starting from their quantification in the cerebrospinal fluid to the most recent and sensitive techniques for their assessment in the blood. Their associations with clinical activity, disability, and MRI measures and their prognostic role during the different phases of the diseases are also discussed. Finally, their promise as biomarker of treatment effect and response is also examined. EXPERT OPINION: Serum neurofilaments light chain quantification is technically feasible and is likely to provide relevant pieces of information to understand MS pathophysiology, and identify patients at higher risk to develop multiple sclerosis and more severe disability. A future role in monitoring treatment effects and response and drug-related side-effects is envisaged.