Amyloid pathology influences aβ1-42 cerebrospinal fluid levels in dementia with lewy bodies.

A significant proportion of patients with dementia with Lewy bodies (DLB) showAlzheimer's disease (AD) pathology like senile plaques and neurofibrillary tangles. Biomarkers in cerebrospinal fluid (CSF), such as amyloid-beta(1-42) (A beta(1-42)), total tau (T-tau), and hyperphosphorylated tau (P-tau(181P)), are linked to the different pathological hallmarks of AD. We set up a study to investigate the influence of AD co-pathology on CSF biomarker concentrations and profiles in autopsy-confirmed DLB. DLB patients with senile plaques showed significantly lower CSF A beta(1-42) concentrations than DLB patients without senile plaques, but not compared to the AD patients. There were no significant differences in CSF T-tau or P-tau181P concentrations between DLB patients with and without neurofibrillary tangles. A correlation was found between the number of APOE epsilon 4 alleles and A beta(1-42) CSF levels in DLB patients with senile plaques. Although the CSF biomarkers A beta(1-42), T-tau, and P-tau181P have an added diagnostic value for the differential dementia diagnosis, concomitant amyloid pathology in DLB limits the use of CSF A beta(1-42) for the differential diagnosis of AD versus DLB.