A blood test for detecting pTau181 biomarker of Alzheimer’s disease shows promising results
A research team funded by the National Institutes of Health have made advancements in the development of a blood test able to detect biomarkers associated with Alzheimer’s disease (AD).
As explained in the findings released in the peer-reviewed journal Nature Medicine, a such approach could simplify the current process of conducting brain imaging scans and examining spinal fluid for indications of progressive neurodegeneration.
The approach involves identifying biomarkers, like abnormal accumulations of tau protein, known to be correlated with cognitive decline exhibited by patients with Alzheimer’s. Using this type of approach, a blood test would quickly screen a large number of participants interested in recruitment for clinical studies.
To attain a blood test efficient at detecting indications of dementia, researchers measured the plasma concentration of phosphorylated tau 181 (pTau181) in the samples of more than 400 participants exhibiting symptoms of cognitive decline.
“A blood-based test for AD would be a less invasive and less expensive screening tool than the currently approved cerebrospinal fluid or amyloid β positron emission tomography (PET) diagnostic tests,” the findings state.
“We examined whether plasma tau phosphorylated at residue 181 (pTau181) could differentiate between clinically diagnosed or autopsy-confirmed AD and frontotemporal lobar degeneration. Plasma pTau181 concentrations were increased by 3.5-fold in AD compared to controls and differentiated AD from both clinically diagnosed and autopsy-confirmed frontotemporal lobar degeneration.”
From their analysis of samples, the presence of pTau181 in plasma could distinguish healthy participants from those demonstrating Alzheimer’s pathology and others with frontotemporal lobar degeneration (FTLD). Even years later, follow-up assessments determined that high levels of plasma pTau181 could be an indicator for predicting Alzheimer’s later on in life.
Researchers also found that “plasma pTau181 identified individuals who were amyloid β-PET-positive regardless of clinical diagnosis and correlated with cortical tau protein deposition measured by 18F-flortaucipir PET.”
“Plasma pTau181 may be useful to screen for tau pathology associated with AD,” the findings concluded.
All-in-all, the research team were able to distinguish Alzheimer’s pathology from other neurodegenerative diseases similar to spinal fluid pTau181 and PET brain imaging tests. If capable for dementia patients, such blood tests would replace complex and time-consuming approaches currently being used.