Scientists have been searching for decades for a quick and effective way to diagnose Alzheimer’s that could replace expensive or invasive medical tests, such as brain scans or spinal taps, that are currently used to determine the presence and progression of this disease in the body. brain.
Now, researchers at the Washington University School of Medicine in St. Louis (USA) have confirmed that a blood test developed by them and capable of detecting early signs of this dementia is highly accurate in identifying people at risk for this disease, even in different countries where different protocols are followed to process blood samples.
This blood test lets you know if amyloid beta plaques have begun to accumulate in the brain based on the ratio of the levels of amyloid beta proteins Aβ42 and Aβ40 in the blood, and when combined with genetic risk factors, such as the presence of the APOE4 genetic variant, its accuracy in identifying individuals at risk of Alzheimer’s reaches 93%, as shown by a new study involving 465 patients from three continents.
“Our study shows that the blood test provides a robust measure of detecting amyloid plaques associated with Alzheimer’s disease, even among patients not yet experiencing cognitive decline,” said Randall J. Bateman, MD, Charles Distinguished Professor. F. and Joanne Knight of Neurology and lead author of the paper, which has been published in Neurology.
“The blood test provides a robust measure for detecting amyloid plaques associated with Alzheimer’s disease, even among patients who do not yet experience cognitive decline.”
“A blood test for Alzheimer’s disease provides a major boost for research and diagnosis of the disease, dramatically reducing the time and cost of identifying patients for clinical trials and spurring the development of new treatment options,” Bateman said. . “As new drugs become available, a blood test could determine who might benefit from treatment, including those in very early stages of the disease.”
Highly accurate results in individuals with and without cognitive impairment
The scientists wanted to see if small differences in sampling methods, such as whether the blood is drawn after fasting or the type of anticoagulant used when processing the blood, could influence the accuracy of the test, because the results are based on changes subtle changes in amyloid beta protein levels in the blood and an incorrect measurement could result in a false-negative or false-positive result.
To confirm the accuracy of the test, it was applied to blood samples from people who had enrolled in Alzheimer’s studies being conducted in the United States, Australia and Sweden, countries in which different protocols are used to process the samples. of blood and related brain imaging.
The research findings demonstrated that Aβ42/Aβ40 blood test results using a high-precision immunoprecipitation mass spectrometry technique developed at the University of Washington are highly accurate and consistent in individuals with cognitive impairment and without cognitive impairment. all three studies.
“A negative test result could also help doctors rule out Alzheimer’s disease in patients whose deficiencies may be related to some other health problem, disease, or medication.”
Combining amyloid blood levels with the presence of the APOE4 genetic variant, which is considered another important risk factor for developing Alzheimer’s, the accuracy of the blood test was 88% compared to brain imaging and 93% compared to brain imaging. comparison with lumbar puncture.
“These results suggest that the test may be useful in identifying able-bodied patients who may be at risk for dementia later in life, offering them the opportunity to enroll in clinical trials when early intervention has the potential to do the most good.” Batman said. “A negative test result could also help doctors rule out Alzheimer’s disease in patients whose deficiencies may be related to some other health problem, disease, or medication.”
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