Serum neurofilament light chain (NfL): new biomarker in multiple sclerosis

Serum neurofilament light chain (NfL) is emerging as an important biomarker in multiple sclerosis (MS).

In a new study (Sci Rep. 2020 Jun 25;10(1):10381) the authors evaluated the prognostic value of serum NfL levels obtained close to the time of MS onset with long-term clinical outcomes.

In this prospective cohort study, they identified patients with serum collected within 5 years of first MS symptom onset (baseline) with more than 15 years of routine clinical follow-up.

Levels of serum NfL were quantified in patients and matched controls using digital immunoassay (SiMoA HD-1 Analyzer, Quanterix).

Sixty-seven patients had a median follow-up of 18.9 years (range 15.0-27.0).

The median serum NfL level in patient baseline samples was 10.1 pg/mL, 38.5% higher than median levels in 37 controls (7.26 pg/mL, p = 0.004). Baseline NfL level was most helpful as a sensitive predictive marker to rule out progression; patients with levels less 7.62 pg/mL were 4.3 times less likely to develop an EDSS score of ≥ 4 (p = 0.001) and 7.1 times less likely to develop progressive MS (p = 0.054). Patients with the highest NfL levels (3rd-tertile, > 13.2 pg/mL) progressed most rapidly with an EDSS annual rate of 0.16 (p = 0.004), remaining significant after adjustment for sex, age, and disease-modifying treatment (p = 0.022). This study demonstrates that baseline sNfL is associated with long term clinical disease progression. sNfL may be a sensitive marker of subsequent poor clinical outcomes.