CSF biomarker profile and diagnostic value in vascular dementia

The differential diagnosis between vascular dementia (VD) and Alzheimer's disease (AD) or mixed dementia (MD) is not always easy in clinical practice. The purpose of the present study was to evaluate the cerebrospinal fluid (CSF) biomarkers tau protein in its total (tau(T)) or hyperphosphorylated at threonin-181(tau(P-181)) form and beta amyloid peptide 1-42 (A beta 42) alone and their combinations to investigate their diagnostic value in the discrimination between VD and AD or MD.

The above CSF biomarkers were determined in duplicate and blind to the clinical diagnosis by double sandwich, enzyme-linked immunosorbent assay (ELISA) commercial kits (Innogenetics, Gent, Belgium) in 92 AD patients, 23 VD patients, 17 patients with MD and 68 controls.

Alzheimer's disease and MD showed increased levels of tau(T), tau(P) and reduced levels of A beta 42 as compared with the controls. The best discrimination between VD and AD or MD was achieved by the combination of all three biomarkers, correctly classifying >or=85% of patients, either in the form of a discriminant function or in the form of the tau(T) x tau(P-181)/A beta 42 formula.

Cerebrospinal fluid biomarkers may be a useful adjunct for the discrimination between AD/ MD and VD in every day clinical practice.