The following is a summary of “Temporal Relationship Between Serum Neurofilament Light Chain and Radiologic Disease Activity in Patients With Multiple Sclerosis,” published in the April 2024 issue of Neurology by Fox et al.

While elevated serum neurofilament light chain (sNfL) levels are linked to disease activity in multiple sclerosis (MS), the specifics of this relationship remain unclear.

Researchers conducted a retrospective study in RESTORE to investigate the association between monthly sNfL levels and radiologic MS disease activity during the 24-week natalizumab treatment interruption.

They conducted the RESTORE trial involving participants with relapsing forms of MS who had been on natalizumab for at least 12 months. The trial randomly assigned them to either continue or discontinue natalizumab, monitoring them with MRI and blood tests every four weeks until week 28 and again at week 52. sNfL levels were measured and correlated with the development of gadolinium-enhancing (Gd+) lesions. The log-linear trend in sNfL levels from baseline to week 28 was longitudinally modeled using generalized estimating equations with a robust variance estimator.

The results showed 166 participants of RESTORE revealed that Gd+ lesions were younger (37.7 years vs. 43.1 years, P=0.001) and had lower baseline disability scores (2.7 vs. 3.4, P=0.017) than without Gd+ lesions. While sNfL levels increased in the Gd+ group (n=65) than the non-Gd+ group (n=101), with a mean change of 12.1 pg/mL vs. 3.2 pg/mL (P=0.003), a significant portion (71%) of the Gd+ group did not surpass the sNfL threshold of the non-Gd+ group. Interestingly, the initial rise in sNfL lagged behind the first detection of Gd+ lesions, with a peak increase occurring at a median of 8 weeks [interquartile range] after the initial Gd+ lesion appearance.

Investigators concluded that while sNfL correlated with Gd+lesions, many patients with lesions lacked sNfL elevation, limiting its utility as a sole MS activity biomarker.

Source: neurology.org/doi/10.1212/WNL.0000000000209357