Why carry out this study?

Multiple studies have demonstrated that serum neurofilament light chain (sNfL) levels are on average abnormally increased in untreated multiple sclerosis (MS) patients compared to controls, mainly driven by focal inflammatory central nervous system activity, and are reduced by effective therapies. However, insights are lacking into the kinetics of sNfL abnormalities in relation to newly developing disease activity, the potential use of sNfL to capture sub-clinical disease activity, and how sNfL measurements may complement magnetic resonance imaging (MRI) scans in clinical practice in order to monitor disease activity

The present study explored both the temporal association between sNfL and development of subclinical disease activity as assessed by MRI at the group level and evaluated the potential of sNfL as a biomarker for capturing newly developing subclinical disease activity in individual relapsing MS (RMS) patients

What was learned from the study?

Our findings indicate that sNfL may have utility in monitoring newly developing subclinical disease activity in RMS patients as shown by its temporal association with new gadolinium-enhancing (Gd +) T1 lesion activity, its overall comparable prognostic value to baseline MRI, and its added value over MRI in prognostic value of on-study Gd + T1 lesion formation in patients free of brain MRI disease activity at baseline

Overall, our results suggest that when frequent MRI scans are not feasible, serial sNfL measurements may provide an attractive alternative to MRI monitoring if a standardized test becomes available to physicians