Blood-Based Biomarkers Detectable by Simple Blood Test Could Simplify Diagnosis of Alzheimer's
Posted on 06 Apr 2023
Currently, the diagnosis of Alzheimer's disease relies on expensive and invasive techniques like positron emission tomography (PET) and tau-PET biomarkers, or less accurate methods such as measuring brain atrophy by MRI, or invasive procedures like lumbar punctures to collect cerebrospinal fluid and p-tau. Now, a new study has demonstrated that blood-based biomarkers for amyloid and tau are highly correlated with the established biomarkers used for Alzheimer's diagnosis. These blood-based biomarkers have also shown great diagnostic accuracy in distinguishing between normal and non-normal levels of amyloid and tau biomarkers.
For the study, an international research team led by the HUG (Geneva, Switzerland) and the UNIGE (Geneva, Switzerland) used a high-precision machine that employs an immunofluorescence assay technique to detect abnormal protein concentrations linked to Alzheimer's disease. This method is more sensitive than standard assays and can more accurately identify individuals at high risk of developing the disease. The study involved 200 patients, including 82 with no cognitive disorders, 99 with mild cognitive impairment, and 19 with dementia. Within a 12-month period, the researchers collected plasma biomarkers and at least one traditional biomarker from each patient.
The researchers found that blood-based biomarkers offer significant advantages over traditional biomarkers for diagnosing Alzheimer's disease. They are less invasive, more affordable, and could potentially reduce the number of necessary tests by up to 49%. Blood testing allows for the simultaneous assessment of multiple biomarkers and is more accessible, making large-scale screening possible. Early detection and monitoring of disease progression could also be improved. Furthermore, blood testing could help identify patients who need neuroimaging or lumbar puncture and enable regular monitoring of disease progression.
Blood-based biomarkers can be easily detected through a routine blood test in medical settings such as hospitals, doctor's offices, or laboratories, and can be integrated with other markers as a part of standard health screening. Currently, they are primarily used for research purposes, and their clinical application is subject to the establishment of technical standards, including normality/abnormality thresholds and laboratory protocols. However, with the possibility of these standards being established soon, attending physicians could be involved in the early stages of diagnosis and the costs could be covered by health insurance companies.
“The use of blood-based biomarkers in the general practitioner’s office, for example, would considerably reduce the number of diagnostic examinations, generate significant savings and improve outcomes,” said Prof. Giovanni Frisoni, head of the study, director of the HUG Memory Centre and full professor in the Department of Rehabilitation and Geriatrics at the UNIGE Faculty of Medicine.