Serum neurofilament light is a sensitive biomarker that reflects grey matter volume in Japanese patients with...

To evaluate the degree of neuroaxonal injury in Japanese multiple sclerosis (MS) patients using serum neurofilament light (sNfL) and to investigate the relationship of sNFL with the degree of brain volume.

sNfL levels in 82 consecutive Japanese MS patients in remission were cross-sectionally evaluated using a single molecule array assay. Within this sample, cross-sectional volumetric brain MRI data was evaluated in 80 patients, and longitudinal data was evaluated in 63 patients.

MS patients (female/male = 61/21), including those with relapsing-remitting MS (82%), secondary progressive MS (17%), and primary progressive MS (1%), were studied. The mean age of the patients was 41.2 ± 8.7 years, and 77 of the MS patients (94%) were treated with disease-modifying therapy (DMT). Their median sNfL level was 7.985 (IQR, 5.959-10.9), and their sNfL levels were significantly correlated with their grey matter volume and their age. A standard least squares regression model revealed that approximately 57% of the variation in grey matter volume could be explained by a regression equation using three explanatory variables: sNfL concentration, age, and sex. Moreover, the sNfL level multiplied by disease duration was significantly correlated with the Expanded Disability Status Scale (EDSS) scores and whole and grey matter volumes.

Although neuroaxonal injury appeared to be mild in our Japanese MS patients, their sNfL levels significantly reflected grey matter volume. Moreover, when multiplied by the disease duration, sNfL can reflect disability and brain volume.