Serum neurofilament light for detecting disease activity in individual patients in multiple sclerosis: A 48-week prospective single-center study

Steps toward the implementation of neurofilaments in multiple sclerosis: patient profiles to be prioritized in clinical practice

Multiple sclerosis (MS) is a chronic central nervous system disease characterized by neurodegeneration and inflammation. Neurofilament light chain (NfL), a protein released during axonal injury, has gained recognition as a potential biomarker for monitoring MS progression and treatment response. Evidence indicates that blood NfL (bNfL) offers a minimally invasive, cost-effective tool for tracking neuroaxonal damage. Regular bNfL assessments can identify subclinical disease activity, guide treatment intensification, and support individualized care. However, bNfL level evaluation is currently not optimized in Italian clinical practice. This work examines the utility of bNfL monitoring in clinical practice, focusing on optimizing its use within specific patient profiles, especially in resource-limited settings. bNfL testing, particularly in targeted MS patient profiles, including stable patients exhibiting subclinical signs of disease activity, such as fatigue, and patients off-treatment, represents a promising adjunct for personalized disease management. Its integration into clinical practice, alongside MRI and clinical assessments, can enhance decision-making and improve care efficiency, especially in settings with limited MRI resources. Further research is needed to standardize testing protocols and establish disease-specific cutoffs.

Impact of serum neurofilament light on clinical decisions in a tertiary multiple sclerosis clinic

BACKGROUND AND OBJECTIVES

Serum neurofilament light (sNfL) is a biomarker for neuro-axonal damage in multiple sclerosis (MS). Clinical implementation remains limited. We investigated the impact of implementation on clinical decisions using questionnaires at the MS Center Amsterdam, a tertiary outpatient clinic.

METHODS

sNfL assessments were added to routine clinical practice (August 2021-December 2022). Before and after the results, clinicians filled in questionnaires on context of testing, clinical decisions, certainty herein, expectation of magnetic resonance imaging (MRI) activity, urgency, and motivation to receive the sNfL result and perceived value of sNfL.

RESULTS

sNfL was assessed in 166 cases (age 41 ± 12 years, 68% female, 64% disease-modifying therapy (DMT) use) for the following contexts: "DMT monitoring" (55%), "new symptoms" (18%), "differential diagnosis" (17%), and "DMT baseline" (11%). Clinical decisions changed in 19.3% of cases post-disclosure, particularly in context "new symptoms" (38%) and with higher sNfL levels (β = 0.03, p = 0.04). Certainty increased (p = 0.004), while expectation of MRI activity decreased with disclosure of low sNfL levels (p = 0.01). Motivation was highest in context "differential diagnosis" (p < 0.001); perceived value and urgency were highest in context "new symptoms" (p = 0.02).

CONCLUSION

In this study, sNfL implementation had considerable impact on clinical decision-making and certainty herein. Standard implementation may complement patient care but warrants caution and more exploration in diverse clinical settings.