Decreased β-Amyloid1-42and Increased Tau Levels in Cerebrospinal Fluid of Patients With Alzheimer Disease

Abstract

While the exact biological cascade associated with Alzheimer disease (AD) is only partially understood, many potential biomarkers of this disease process are known.¹ Two of the most obvious candidates are β-amyloid_1-42 and tau proteins, as they are intimately related to the pathognomonic features of amyloid plaques and neurofibrillary tangles in the AD brain.^2,3 Multiple previous studies have reported decreases in cerebrospinal fluid (CSF) measures of β-amyloid.^4-7 Similarly, CSF measures of tau have routinely showed considerable elevations of this peptide in AD cases worldwide.^7-12 Some authors have reported that these 2 measures alone can accurately differentiate clinically diagnosed AD cases from controls more than 85% of the time.^7,13