Tau protein, beta-amyloid1–42 and clusterin CSF levels in the differential diagnosis of Parkinsonian syndrome with dementia

Abstract

BackgroundParkinson's disease (PD), PD with dementia (PDD) and Lewy body dementia (DLB) are synucleinopathies. PDD and DLB are sometimes considered a transition between PD and Alzheimer dementia (AD). Finding in vivo markers or their combination could help in the differential diagnosis of these neurodegenerative (ND) diseases. ObjectiveThe aim of this study was to assess cerebrospinal fluid (CSF) levels of tau protein, betaamyloid1–42 and clusterin and to compare these levels among patients with probable PD, PDD, DLB and AD. MethodsCSF levels of ND markers were assessed in 96 patients (27 patients with PD, 14 with PDD, 14 with DLB, 17 with AD and 24 subjects as a control group). ResultsIn all of the groups of patients, beta-amyloid1–42 levels were decreasing in the order PD>PDD>DLB>AD, whereas tau protein and the tau protein/beta-amyloid1–42 index were increasing in the same order (PD<PDD<AD), except for DLB. In paired group comparisons, higher levels of clusterin in PD patients (p=0.005) and PDD patients (p=0.052) compared to the CG were found. ConclusionThe results of the present study support the role of clusterin in PD pathogenesis. The decreasing CSF beta-amyloid1–42 levels in the order PDD, DLB and AD may relate to the increasing presence of AD pathology in these disorders.