Profiling Plasma Biomarkers, Particularly pTau217 and pTau217/Aβ42, and Their Relation to Cognition in Memory Clinic Patients.

Alzheimer's disease (AD) is characterized by brain protein depositions, impaired synaptic transmission, and progressive cognitive decline. This clinical study, conducted at the tertiary memory clinic of Karolinska University Hospital in Stockholm, evaluates plasma pTau217 (in comparison to other plasma biomarkers) as a non-invasive marker for predicting brain amyloid load and cognitive impairment. Uniquely, it integrates plasma biomarkers with cognitive profiling and amyloid PET to assess diagnostic utility across disease stages in a real-world memory clinic setting.

Early microglial and astrocyte reactivity in preclinical Alzheimer's disease.

Introduction: The role of neuroinflammation in preclinical Alzheimer's disease (AD) remains unclear.

Methods: We assessed changes in microglial and astrocytic biomarkers in a well-characterized cohort of 211 cognitively unimpaired individuals. Structural equation modeling was used to simultaneously assess all relationships among microglial and astrocytic responses and AD pathological events.

Biomarker discovery in Alzheimer's and neurodegenerative diseases using Nucleic Acid Linked Immuno-Sandwich Assay.

Introduction: Recent advancements in immunological methods accurately quantify biofluid biomarkers for Alzheimer's disease (AD) pathology. Despite progress, more biomarkers, ideally in blood, are needed for effective disease monitoring for AD and other neurodegenerative proteinopathies.

Methods: We used the Nucleic Acid Linked Immuno-Sandwich Assay (NULISA) central nervous system panel for biomarker quantification in plasma, serum, and cerebrospinal fluid of patients with AD, mild cognitive impairment, Lewy body dementia, progranulin (GRN) mutation carriers.

Biofluid-based staging of Alzheimer's disease.

Recently, conceptual systems for the in vivo staging of Alzheimer's disease (AD) using fluid biomarkers have been suggested. Thus, it is important to assess whether available fluid biomarkers can successfully stage AD into clinically and biologically relevant categories. In the TRIAD cohort, we explored whether p-tau217, p-tau205 and NTA-tau (biomarkers of early, intermediate and late AD pathology, respectively) have potential for biofluid-based staging in cerebrospinal fluid (CSF; n = 219) and plasma (n = 150), and compared them in a paired CSF and plasma subset (n = 76).

Inflammation biomarkers and Alzheimer's disease: A pilot study using NULISAseq.

Introduction: Increasing evidence links amyloid beta (Aβ) aggregation with inflammation. This pilot study investigated the use of an immunoassay panel to map biomarker changes in patients with Alzheimer's disease (AD). Furthermore, we evaluated the stability of protein quantification after multiple freeze-thaw cycles (FTCs).

Identify biological Alzheimer's disease using a novel nucleic acid-linked protein immunoassay.

Blood-based biomarkers have been revolutionizing the detection, diagnosis and screening of Alzheimer's disease. Specifically, phosphorylated-tau variants (p-tau, p-tau and p-tau) are promising biomarkers for identifying Alzheimer's disease pathology. Antibody-based assays such as single molecule arrays immunoassays are powerful tools to investigate pathological changes indicated by blood-based biomarkers and have been studied extensively in the Alzheimer's disease research field.

Disentangling relationships between Alzheimer's disease plasma biomarkers and established biomarkers in patients of tertiary memory clinics.

Background: Several plasma biomarkers for Alzheimer's disease (AD) have demonstrated diagnostic and analytical robustness. Yet, contradictory results have been obtained regarding their association with standard diagnostic markers of AD. This study aims to investigate the specific relationship between the AD biomarkers currently used in clinical practice and the plasma biomarkers.

Plasma pTau181 and pTau217 predict asymptomatic amyloid accumulation equally well as amyloid PET.

The dynamic phase of preclinical Alzheimer's disease, as characterized by accumulating cortical amyloid-β, is a window of opportunity for amyloid-β-lowering therapies to have greater efficacy. Biomarkers that accurately predict amyloid-β accumulation may be of critical importance for participant inclusion in secondary prevention trials and thus enhance development of early Alzheimer's disease therapies. We compared the abilities of baseline plasma pTau181, pTau217 and amyloid-β PET load to predict future amyloid-β accumulation in asymptomatic elderly.

Longitudinal plasma phosphorylated-tau217 and other related biomarkers in a non-demented Alzheimer's risk-enhanced sample.

Introduction: Understanding longitudinal change in key plasma biomarkers will aid in detecting presymptomatic Alzheimer's disease (AD).

Methods: Serial plasma samples from 424 Wisconsin Registry for Alzheimer's Prevention participants were analyzed for phosphorylated-tau217 (p-tau217; ALZpath) and other AD biomarkers, to study longitudinal trajectories in relation to disease, health factors, and cognitive decline. Of the participants, 18.

Plasma concentrations of glial fibrillary acidic protein, neurofilament light, and tau in Alexander disease.

Introduction: Alexander disease (AxD) is a rare leukodystrophy caused by dominant gain-of-function mutations in the gene encoding the astrocyte intermediate filament, glial fibrillary acidic protein (GFAP). However, there is an urgent need for biomarkers to assist in monitoring not only the progression of disease but also the response to treatment. GFAP is the obvious candidate for such a biomarker, as it is measurable in body fluids that are readily accessible for biopsy, namely cerebrospinal fluid and blood.

Plasma Phosphorylated Tau 231 Increases at One-Year Intervals in Cognitively Unimpaired Subjects.

Background: Plasma biomarkers of Alzheimer's disease (AD) constitute a non-invasive tool for diagnosing and classifying subjects. They change even in preclinical stages, but it is necessary to understand their properties so they can be helpful in a clinical context.

Objective: With this work we want to study the evolution of p-tau231 plasma levels in the preclinical stages of AD and its relationship with both cognitive and imaging parameters.

Comparison of two plasma p-tau217 assays to detect and monitor Alzheimer's pathology.

Background: Blood-based biomarkers of Alzheimer's disease (AD) have become increasingly important as scalable tools for diagnosis and determining clinical trial eligibility. P-tau217 is the most promising due to its excellent sensitivity and specificity for AD-related pathological changes.

Methods: We compared the performance of two commercially available plasma p-tau217 assays (ALZpath p-tau217 and Janssen p-tau217+) in 294 individuals cross-sectionally.

Profiling of plasma biomarkers in the context of memory assessment in a tertiary memory clinic.

Plasma biomarkers have shown promising performance in research cohorts in discriminating between different stages of Alzheimer's disease (AD). Studies in clinical populations are necessary to provide insights on the clinical utility of plasma biomarkers before their implementation in real-world settings. Here we investigated plasma biomarkers (glial fibrillary acidic protein (GFAP), tau phosphorylated at 181 and 231 (pTau181, pTau231), amyloid β (Aβ) 42/40 ratio, neurofilament light) in 126 patients (age = 65 ± 8) who were admitted to the Clinic for Cognitive Disorders, at Karolinska University Hospital.

Levels of Alzheimer's disease blood biomarkers are altered after food intake-A pilot intervention study in healthy adults.

Introduction: Blood biomarkers accurately identify Alzheimer's disease (AD) pathophysiology and axonal injury. We investigated the influence of food intake on AD-related biomarkers in cognitively healthy, obese adults at high metabolic risk.

Methods: One-hundred eleven participants underwent repeated blood sampling during 3 h after a standardized meal (postprandial group, PG).

Blood β-synuclein is related to amyloid PET positivity in memory clinic patients.

Introduction: β-synuclein is an emerging blood biomarker to study synaptic degeneration in Alzheimer´s disease (AD), but its relation to amyloid-β (Αβ) pathology is unclear.

Methods: We investigated the association of plasma β-synuclein levels with flutemetamol positron emission tomography (PET) in patients with AD dementia (n = 51), mild cognitive impairment (MCI-Aβ+ n = 18, MCI- Aβ- n = 30), non-AD dementias (n = 22), and non-demented controls (n = 5).

Results: Plasma β-synuclein levels were higher in Aβ+ (AD dementia, MCI-Aβ+) than in Aβ- subjects (non-AD dementias, MCI-Aβ-) with good discrimination of Aβ+ from Aβ- subjects and prediction of Aβ status in MCI individuals.

Differential roles of Aβ42/40, p-tau231 and p-tau217 for Alzheimer's trial selection and disease monitoring.

Blood biomarkers indicative of Alzheimer's disease (AD) pathology are altered in both preclinical and symptomatic stages of the disease. Distinctive biomarkers may be optimal for the identification of AD pathology or monitoring of disease progression. Blood biomarkers that correlate with changes in cognition and atrophy during the course of the disease could be used in clinical trials to identify successful interventions and thereby accelerate the development of efficient therapies.