Features Partner Sites Information LinkXpress hp
Sign In
Advertise with Us
LGC Clinical Diagnostics

Download Mobile App




Blood Test Detects Alzheimer's Disease before Symptoms Appear

By LabMedica International staff writers
Posted on 27 Feb 2019
A blood-based assessment of preclinical disease would have huge potential in the enrichment of participants for Alzheimer’s disease (AD) therapeutic trials. Much effort has been dedicated to the discovery of single- and multianalyte protein markers to differentiate AD from age-matched cognitively unimpaired individuals.

Ultrasensitive immunoassay and immunoprecipitation mass spectrometry (MS) methods have recently reported plasma amyloid β (Aβ) ratios as being able to predict Aβ positron emission tomography (PET). However, there has been limited investigation using untargeted methods in the discovery of novel blood markers that could reflect Aβ burden.

A large international team of scientists led by the group from King’s College London (London, UK) started by measuring protein group levels in blood samples from 238 (cognitively unimpaired) people participating in two Australian-based biomarker and aging studies. All of the donors had previously undergone PET scans to determine their Aβ status. The team then built a computer model to classify proteins and then analyzed data from participants in one of the biomarker and aging study groups with a machine-learning algorithm designed to learn to identify markers indicating preclinical Alzheimer's disease. Then they tested the system on data from the second group of study participants.

Some of the methodology used by the scientist included immunodepletion, enzymatic digestion, and tandem mass tag peptide labeling. Albumin and immunoglobulin G immuno-depletion was achieved by a commercially available ProteoPrep immunoaffinity column. Peptide separation was achieved using the 3100 OFFGEL Fractionator with a 24-well setup. Liquid chromatography–tandem MS (LC-MS/MS) analysis, chromatographic separation and mass spectra acquisition was performed using the LTQ Orbitrap Velos Pro.

The team reported that preliminary testing showed the technique to be 90% accurate in matching results obtained from PET scan testing. They report also that their system found 10 protein features that together represent a biomarker, two of which had been identified as possibilities previously. The serine protease prothrombin (a precursor to thrombin) was the highest ranked feature in the cognitively unimpaired cohort. At the univariate level, prothrombin (or coagulation factor II) was shown to be decreased in Aβ+ individuals but had a modest effect size. Two protein groups were specifically associated with Aβ burden in cognitively unimpaired individuals (GPR115 and RPS6KA3). GPR115 was the second most important feature, after prothrombin, offering it as a potential marker of early Aβ deposition.

The authors concluded that using an unbiased MS approach, they found and replicated with high accuracy, specificity, and sensitivity a plasma protein classifier reflecting Aβ burden in a cognitively unimpaired cohort. These predictive panels highlighted novel and established markers for AD. The study was published on February 6, 2019, in the journal Science Advances.

Related Links:
King’s College London


Gold Member
Fully Automated Cell Density/Viability Analyzer
BioProfile FAST CDV
Verification Panels for Assay Development & QC
Seroconversion Panels
New
Immunoassays and Calibrators
QMS Tacrolimus Immunoassays
New
Piezoelectric Micropump
Disc Pump
Read the full article by registering today, it's FREE! It's Free!
Register now for FREE to LabMedica.com and get access to news and events that shape the world of Clinical Laboratory Medicine.
  • Free digital version edition of LabMedica International sent by email on regular basis
  • Free print version of LabMedica International magazine (available only outside USA and Canada).
  • Free and unlimited access to back issues of LabMedica International in digital format
  • Free LabMedica International Newsletter sent every week containing the latest news
  • Free breaking news sent via email
  • Free access to Events Calendar
  • Free access to LinkXpress new product services
  • REGISTRATION IS FREE AND EASY!
Click here to Register








Channels

Immunology

view channel
Image: The cancer stem cell test can accurately choose more effective treatments (Photo courtesy of University of Cincinnati)

Stem Cell Test Predicts Treatment Outcome for Patients with Platinum-Resistant Ovarian Cancer

Epithelial ovarian cancer frequently responds to chemotherapy initially, but eventually, the tumor develops resistance to the therapy, leading to regrowth. This resistance is partially due to the activation... Read more

Microbiology

view channel
Image: The lab-in-tube assay could improve TB diagnoses in rural or resource-limited areas (Photo courtesy of Kenny Lass/Tulane University)

Handheld Device Delivers Low-Cost TB Results in Less Than One Hour

Tuberculosis (TB) remains the deadliest infectious disease globally, affecting an estimated 10 million people annually. In 2021, about 4.2 million TB cases went undiagnosed or unreported, mainly due to... Read more

Pathology

view channel
Image: The ready-to-use DUB enzyme assay kits accelerate routine DUB activity assays without compromising data quality (Photo courtesy of Adobe Stock)

Sensitive and Specific DUB Enzyme Assay Kits Require Minimal Setup Without Substrate Preparation

Ubiquitination and deubiquitination are two important physiological processes in the ubiquitin-proteasome system, responsible for protein degradation in cells. Deubiquitinating (DUB) enzymes contain around... Read more

Technology

view channel
Image: The HIV-1 self-testing chip will be capable of selectively detecting HIV in whole blood samples (Photo courtesy of Shutterstock)

Disposable Microchip Technology Could Selectively Detect HIV in Whole Blood Samples

As of the end of 2023, approximately 40 million people globally were living with HIV, and around 630,000 individuals died from AIDS-related illnesses that same year. Despite a substantial decline in deaths... Read more

Industry

view channel
Image: The collaboration aims to leverage Oxford Nanopore\'s sequencing platform and Cepheid\'s GeneXpert system to advance the field of sequencing for infectious diseases (Photo courtesy of Cepheid)

Cepheid and Oxford Nanopore Technologies Partner on Advancing Automated Sequencing-Based Solutions

Cepheid (Sunnyvale, CA, USA), a leading molecular diagnostics company, and Oxford Nanopore Technologies (Oxford, UK), the company behind a new generation of sequencing-based molecular analysis technologies,... Read more
Copyright © 2000-2025 Globetech Media. All rights reserved.