Comparison of CSF levels of tau and β-amyloid peptide1-42 between patients with Alzheimer's disease and those with Parkinson's dementia

Objective To investigate the levels and clinical significance of β-amyloid peptide1-42(Aβ1-42) in cerebrospinal fluid(CSF) of patients with Alzheimer's disease(AD) and Parkinson's dementia(PDD).Methods The subjects were 22 patients with AD,20 patients with PDD and 21 controls(NC).The CSF levels of tau and Aβ1-42 of each subject were measured by enzyme linked immunosorbent assay(ELISA).Results The mean CSF level(ng/L) of tau of AD group was significantly higher than that of NC group,but there was no significant difference between AD and PDD groups.The mean CSF level(ng/L) of Aβ1-42 of AD group was significantly lower than that of NC group(P0.05).However,no significant difference was observed between PDD group and NC group(P0.05). Conclusions The CSF levels of tau and Aβ1-42 of patients with AD could be the indexes for diagnosing AD early and differential diagnosis from PDD.