RESUMO
BACKGROUND/OBJECTIVE: This study aimed to evaluate serum neurofilament light chain (NF-L) levels in former professional contact sports athletes with multiple concussions (ExPro) as a potential biomarker of neurodegeneration and predictor of white-matter (WM) abnormality progression. METHODS: Concentrations of NF-L in the serum of fifty-two cognitively normal ExPro and twenty-one healthy controls (HC) with no history of concussions were measured using single molecule array (Simoa) technology. Both groups underwent neuroimaging at the time of serum collection. Eighteen of the participants in the ExPro underwent follow-up imaging after 2 years. RESULTS: Levels of serum NF-L were not significantly different between the ExPro and HC. However, in the ExPro group, NF-L levels were positively correlated with the mean diffusivity (MD) of corpus callosum (CC) and fornix, and total ventricular volume. Moreover, NF-L levels in the ExPro group at the first visit were positively correlated with the amount of increase in CC MD at the 2-year follow-up. CONCLUSIONS: NF-L levels reflect neuronal changes in the ExPro group and predict the extent of decrease in white matter integrity over time. Serum NF-L might be a biomarker of neurodegeneration and WM abnormality progression in ExPro.