Drebrin is a novel biomarker of cognitive deterioration in Alzheimer's disease.

BackgroundThe cerebrospinal fluid (CSF) and plasma amyloid-β (Aβ)40/42 ratio, p-217tau and p-181tau, and neurofilament light chain are biomarkers of Aβ proteinopathy, tau proteinopathy, and neuronal injury, respectively, in Alzheimer's disease (AD). However, direct biomarkers of cognitive function have yet to be identified.ObjectiveTherefore, the present study investigated the potential of CSF and plasma levels of drebrin, a postsynaptic protein, as biomarkers of synaptic activity and cognitive function in the human brain in clinical settings.MethodsWe developed a novel ELISA to measure CSF and plasma levels of drebrin and analyzed 68 CSF and 128 plasma samples from patients with AD and other neurological diseases.ResultsCSF drebrin levels were significantly reduced in samples of mild cognitive impairment due to AD, the dementia stages of AD, and idiopathic normal pressure hydrocephalus. Plasma drebrin levels were also significantly reduced in samples of MCI due to AD.ConclusionsCSF and plasma drebrin levels are specific biomarkers of cognitive decline in the MCI stage of AD.