Stability of CSF β-Amyloid_1–42 and Tau Levels by APOE Genotype in Alzheimer Patients

Abstract

Background: Cerebrospinal fluid (CSF) measures of β-amyloid_1–42and tau differ between patients with Alzheimer’s Disease (AD) and elderly normal controls. The effect of time and APOE genotype on these biomarkers continues to be elucidated. Methods: We assessed CSF β-amyloid_1–42 and tau in 20 mild-to-moderate AD patients, 11 APOE Ε4+ and 9 APOE Ε4–, over a mean time of 3.8 years (range 1–11.1 years). Results: Over the period measured, CSF β-amyloid_1–42 levels were lower in APOE Ε4+ compared to APOE Ε4– patients, and the levels decreased over time. Tau levels were stable over time and did not show an effect of APOE allele. Conclusions: While this is a limited clinical sample, the further decrease in CSF β-amyloid_1–42(i.e., more abnormal) combined with the CSF tau stability over a mean period of almost 4 years suggests that β-amyloid_1–42and tau maintain their potential usefulness as diagnostic biomarkers over time. These findings should be taken into account if CSF β-amyloid_1–42 and tau are used as measures of treatment response.

Slowing of EEG correlates with CSF biomarkers and reduced cognitive speed in elderly with normal cognition over 4 years

“…In addition, we required repeated normal range scores on general cognitive screening tests of those participating to assure stable cognition. The one-year time period between EEG testing and CSF analysis allows cross-sectional comparison, since longitudinal studies on CSF biomarkers have reported remarkably stable values over this time period [5,8,13], although a decrease in Aβ42 has been reported when followed 3-4 years [25,56]. Furthermore, only one earlier study has investigated the relation between CSF biomarkers and EEG frequencies [28].…”

Risk Factors for Disease Progression in Alzheimer's Disease

“…Furthermore this increment seemed to be associated with cognitive decline (Stomrud et al, 2010). Regarding Aβ1-42 levels, Huey and colleagues found these to slightly decrease while Tau staying stable observed over a period of 4 years (Huey et al, 2006).…”

Cerebrospinal fluid biomarkers of Alzheimer’s disease in cognitively healthy elderly

“…Studies that have not found relationships between t-tau and age are in the minority [70,89-91]. Smaller study groups [89,90] or the fact that AD patients were examined may explain their lack of positive findings [91]. Finally, even with larger groups [70], intrinsic differences between populations may result in dissimilar findings.…”