The comparison of cerebrospinal fluid levels of tau protein and β-amyloid peptide1-42 in the patients with Alzheimer's disease and those with vascular dementia

Objective To investigate the cerebrospinal fluid (CSF) levels of tau protein and β-amyloid peptide1-42( Aβ1-42 ) in the 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 tau protein and Aβ1-42 were measured with enzyme-linked immunosorbent assay. Results The mean CSF levels of tau were (318±249) ng/L in AD patients, (219±190) ng/L in VD, and (119±65) ng/L in NC, respectively, and the difference between AD and NC was statistically significant (P 0. 05). The mean CSF levels of Aβ1-42 were (344±166) ng/L in AD, (467±223) ng/L in VD, and (480±217) ng/L in NC, and the difference between AD and NC was statistically significant ( P 0. 05 ). In discriminant analysis of combining the CSF levels of tau and Aβ1-42, only 44% of subjects were correctly classified. Conclusions Both the elevated CSF levels of tau protein and the decreased CSF levels of Aβ1-42 may be biomarkers for AD patients, which have potential utility in clinical diagnosing AD.