Biomarkers Identified for Differentiating Alzheimer’s Disease

Specific biomarkers in a cerebrospinal fluid (CSF) sample can distinguish patients with Alzheimer’s (AD) disease from those with other types of dementia.

A method has been developed to differentiate patients with Alzheimer's disease or Parkinson disease (PD) and other diseases by analyzing a panel of proteins in cerebrospinal fluid samples.

Scientists at the University of Gothenburg (Sweden) carried out a cross-sectional, clinic-based study among 450 patients at Skåne University Hospital (Malmo, Sweden) and Sahlgrenska University Hospital (Gothenburg, Sweden). The study involved measuring the level of five proteins that serve as biomarkers for the two diseases. The investigators analyzed 453 CSF samples that were obtained from healthy individuals serving as controls and from patients with AD, PD, PD with dementia (PDD), dementia with Lewy bodies (DLB), progressive supranuclear palsy (PSP), multiple system atrophy (MSA), or corticobasal degeneration (CBD).

Levels of α-synuclein in CSF samples were decreased in patients with PD, PDD, DLB, and MSA, but increased in patients with AD. Levels of β-amyloid 1-42 in CSF samples were decreased in DLB and even further decreased in AD. Levels of total tau and hyperphosphorylated tau were increased in AD patient’s CSF. Analysis revealed that these biomarkers could accurately differentiate AD from DLB and PDD, with α-synuclein and total tau contributing most to the model. The biomarkers can also differentiate patients with PD from those with typical Parkinsonian disorders.

Annika Öhrfelt, PhD, a senior author of the study, said, “This study has found that the inclusion of a new protein can differentiate patients with Alzheimer's disease from those with Lewy body dementia, Parkinson disease dementia and other types of dementia." Additional studies are needed before the biomarkers can be used in clinical practice during the early stages of disease, but these results represent an important step along the way.” The study was published in the November 2012 issue of the Archives of Neurology.

Related Links:
University of Gothenburg
Skåne University Hospital
Sahlgrenska University Hospital