Serum Neurofilament Light Chain Levels and Myelin Oligodendrocyte Glycoprotein Antibodies in Pediatric Acquired Demyelinating Syndromes.

The relationship between serum neurofilament light chain (sNfL) and myelin oligodendrocyte glycoprotein antibody (MOG-Ab) status has not been yet investigated in children with the acquired demyelinating syndrome (ADS). The sNfL levels and MOG-Abs were measured by ultrasensitive single-molecule array and cell-based assay in a cohort of 37 children with ADS and negativity for serum anti-aquaporin 4 (AQP4) antibodies. The sNfL levels were compared in MOG-Ab+/MOG-Ab- and in two subgroups MOG-Ab+ with/without encephalopathy. About 40% ADS resulted in MOG-Ab+. MOG-Ab+ were younger at sampling (median = 9.8; range = 2.17-17.5 vs. 14.7/9-17; = 0.002) with lower frequency of cerebrospinal fluid oligoclonal bands positivity (27% vs. 70%; = 0.013) compared to MOG-Ab-. About 53% of MOG-Ab+ presented encephalopathy at onset, 1/22 of MOG-Ab- ( = 0.0006). Higher sNfL levels ( = 0.0001) were found in MOG-Ab+ (median/range = 11.11/6.8-1,129) and MOG-Ab- (median/range = 11.6/4.3-788) compared to age-matched controls (median/range = 2.98/1-4.53), without significant difference. MOG-Ab+ with encephalopathy resulted significantly younger at sampling (median/range: 4.5/2.17-11.17 vs. 14.16/9.8-17.5; = 0.004), had higher sNfL levels (median/range:75.24/9.1-1,129 vs. 10.22/6.83-50.53; = 0.04), and showed a trend for higher MOG-Ab titer (0.28/0.04-0.69 vs. 0.05/0.04-0.28; = 0.1) in comparison to those without encephalopathy. We confirmed high sNfL levels in pediatric ADS independently from the MOG-Ab status. Encephalopathy at onset is associated more frequently with MOG Ab+ children with higher sNfL levels and MOG titer. These findings suggest a role of acute demyelination in association with axonal damage in the pathogenesis of encephalopathy in pediatric ADS.