The Comparison of CSF Levels of β-Amyloid Peptide_(1-42) between Patients with Alzheimer's Disease and Those with Vascular Dementia

Objective:To investigate the cerebrospinal fluid (CSF) levels of β-amyloid peptide 1-42 (Aβ 1-42 ) in patients with Alzheimer's disease (AD) and their diagnostic value for AD.Methods:The subjects were 22 patients with AD and 41 controls, including 20 patients with vascular dementia (VD) and 21 normal controls (NC). The CSF levels of Aβ 1-42 of each subject were measured by enzyme-linked immunosorbent assay (ELISA). Subjects in the groups of both AD and VD were assessed for parameters with MMSE, CDR and Hachinski rating scales. Results:(1)The mean CSF levels( pg/ml ) of Aβ 1-42 of AD group was 343.94±165.87, VD 466.65±222.46,and NC 480.40±217.16. The CSF levels of Aβ 1-42 of AD group were significantly lower than that of NC ( P 0.05). However, no significant difference was observed between other two groups ( P 0.05).(2)In AD group, there were significant correlations between the CSF levels of Aβ 1-42 and the MMSE or CDR scores ( P 0.05). Conclusions: The CSF levels of Aβ 1-42 of patients with AD are significantly lower than that in NC group. Decreased CSF levels of Aβ 1-42 may be a marker for AD,which is helpful in diagnosing AD.