Cerebrospinal fluid α synuclein concentrations in patients with positive AD biomarkers and extrapyramidal symptoms.

Extrapyramidal symptoms (EP) are not uncommon in Alzheimer's Disease (AD); when present, they negatively influence the course of the disorder. A large proportion of AD patients shows concomitant Lewy bodies' pathology post mortem. Total α Synuclein (αSyn) concentrations are frequently increased in the cerebrospinal fluid (CSF) of AD patients, but are decreased in Parkinson's Disease (PD) and Dementia with Lewy Bodies (DLB).

Searching for novel cerebrospinal fluid biomarkers of tau pathology in frontotemporal dementia: an elusive quest.

Background: Frontotemporal dementia (FTD) is a pathologically heterogeneous neurodegenerative disorder associated usually with tau or TDP-43 pathology, although some phenotypes such as logopenic variant primary progressive aphasia are more commonly associated with Alzheimer's disease pathology. Currently, there are no biomarkers able to diagnose the underlying pathology during life. In this study, we aimed to investigate the potential of novel tau species within cerebrospinal fluid (CSF) as biomarkers for tau pathology in FTD.

Interlaboratory proficiency processing scheme in CSF aliquoting: implementation and assessment based on biomarkers of Alzheimer's disease.

Background: In this study, we tested to which extent possible between-center differences in standardized operating procedures (SOPs) for biobanking of cerebrospinal fluid (CSF) samples influence the homogeneity of the resulting aliquots and, consequently, the concentrations of the centrally analyzed selected Alzheimer's disease biomarkers.

Methods: Proficiency processing samples (PPSs), prepared by pooling of four individual CSF samples, were sent to 10 participating centers, which were asked to perform aliquoting of the PPSs into two secondary aliquots (SAs) under their local SOPs. The resulting SAs were shipped to the central laboratory, where the concentrations of amyloid beta (Aβ) 1-42, pTau181, and albumin were measured in one run with validated routine analytical methods.

Plasma neurofilament light as a potential biomarker of neurodegeneration in Alzheimer's disease.

Background: A growing body of evidence suggests that the plasma concentration of the neurofilament light chain (NfL) might be considered a plasma biomarker for the screening of neurodegeneration in Alzheimer's disease (AD).

Methods: With a single molecule array method (Simoa, Quanterix), plasma NfL concentrations were measured in 99 subjects with AD at the stage of mild cognitive impairment (MCI-AD; n = 25) or at the stage of early dementia (ADD; n = 33), and in nondemented controls (n = 41); in all patients, the clinical diagnoses were in accordance with the results of the four core cerebrospinal fluid (CSF) biomarkers (amyloid β (Aβ)1-42, Aβ42/40, Tau, and pTau181), interpreted according to the Erlangen Score algorithm. The influence of preanalytical storage procedures on the NfL in plasma was tested on samples exposed to six different conditions.

CSF nonphosphorylated Tau as a biomarker for the discrimination of AD from CJD.

Creutzfeldt-Jakob disease and Alzheimer's disease are characterized by the presence of elevated total-Tau cerebrospinal fluid concentrations while the presence of hyperphosphorylated Tau forms in the cerebrospinal fluid is rather a hallmark of Alzheimer's disease. Here we aimed to investigate potential contribution of nonphospho-Tau epitopes (non-P-Tau) in the discrimination between both diseases. Non-P-Tau cerebrospinal fluid concentration was highly increased in Creutzfeldt-Jakob disease ( = 57, 3683 ± 3599 pg/mL) compared to Alzheimer's disease ( = 41, 148 ± 219 pg/mL) and neurological controls ( = 56, 62 ± 40 pg/mL), and significantly improved the proportion of correctly classified patients (99%) compared to that achieved by total-Tau (90%), P-Tau (62%) and 14-3-3 (91%).

A Specific Reduction in Aβ vs. a Universal Loss of Aβ Peptides in CSF Differentiates Alzheimer's Disease From Meningitis and Multiple Sclerosis.

A reduced concentration of Aβ in CSF is one of the established biomarkers of Alzheimer's disease. Reduced CSF concentrations of Aβ have also been shown in multiple sclerosis, viral encephalitis and bacterial meningitis. As neuroinflammation is one of the neuropathological hallmarks of Alzheimer's disease, an infectious origin of the disease has been proposed.