Reduction of β‐amyloid peptide42 in the cerebrospinal fluid of patients with Alzheimer's disease

Abstract

In this clinical study, the cerebrospinal fluid (CSF) level of a Novemberel form of the β‐amyloid peptide (Aβ) extending to position 42 (Aβ₄₂) was determined in patients with Alzheimer's disease (AD) as well as controls. In addition to measurement of CSF Aβ₄₂ levels, total Aβ peptides, microtubule‐associated protein τ, and apolipoprotein E (ApoE) genotype were also assessed. It is interesting that CSF Aβ₄₂ levels were found to be significantly lower in AD patients relative to controls, whereas total Aβ levels were not. Aβ₄₂ has recently been shown to preferentially deposit in the brain tissue of patients with AD, suggesting that diminished clearance may account for its reduction in CSF. As previously reported, τ levels were increased in AD patients; however, neither Aβ₄₂ nor τ levels were apparently influenced by the ApoE genotype.