Elevated neurofilament light chain in plasma is associated with reduced right hippocampal and amygdala volume in Alzheimer's patients

Background Plasma neurofilament light (NfL) levels have been considered as an especially promising biomarker for dementia, however, the mechanism of NfL regulating cognition is not very clear. Methods 43 amnesic mild cognitive impairment(aMCI), 35 Alzheimer’s disease (AD) and 30 cognitively normal subjects were recruited. Plasma NfL levels were examined by the Single Molecule array (Simoa) technique; the volumes of the hippocampus and amygdala were calculated and compared by T1-weighted MRI; and cognitive function was assessed by the Beijing version of the Montreal Cognitive Assessment (MoCA) Results Our results showed significantly increased plasma NfL levels in AD group (29.42 pg/ml) compared to aMCI(15.92 pg/ml) group and normal (12.85 pg/ml) group (both p < 0.001), while there was no statistical difference (p>0.05) between aMCI group and normal group. And the results of partial correlation analysis showed that plasma NfL levels were negatively correlated (p<0.05)with MoCA total score (r=-0.415, p=0.013), right hippocampal volume(r=-0.335,p=0.036) and right amygdala volume(r=-0.337, p=0.048). Conclusions NfL in plasma of AD patients is significantly increased, and the protein is related to atrophy of right hippocampus and right amygdala.