Cerebrospinal fluid Alzheimer biomarkers can be useful for discriminating dementia with Lewy bodies from Alzheimer's disease at the prodromal stage

Background Differential diagnosis between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) is not straightforward, especially in the early stages of disease. We compared AD biomarkers (phospho-Tau 181, total-Tau, A beta 42 and A beta 40) in cerebrospinal fluid (CSF) of patients with DLB and AD, focusing especially on the prodromal stage. Methods A total of 1221 CSF were collected in different memory centres (ePLM network) in France and analysed retrospectively. Samples were obtained from patients with prodromal DLB (pro-DLB; n= 57), DLB dementia (DLB-d; n= 154), prodromal AD (pro-AD; n= 132) and AD dementia (n= 783), and control subjects (CS; n= 95). These centres use the same diagnostic procedure and criteria to evaluate the patients. Results In patients with pro-DLB, CSF A beta 42 levels appeared much less disrupted than in patients at the demented stage (DLB-d) (P<0.05 CS>pro-DLB; P<0.001 CS>DLB-d). On average, A beta 40 levels in patients with DLB (pro-DLB and DLB-d) were much below those in patients with pro-AD (P< 0.001 DLB groups