Diagnosis of Alzheimer's by blood
A blood test for Alzheimer's disease has become available for clinical use in the United States
Marina Astvatsaturyan, Echo of Moscow
The first test for detecting Alzheimer's disease by blood was developed by C2N Diagnostics to help doctors. Currently, there are already two tests for changes in the brain associated with Alzheimer's disease: one, based on the determination of biomarkers in the cerebrospinal fluid, requires a puncture, and the other, which is a scan on a tomograph to identify amyloid plaques – distinctive signs of the disease – requires the introduction of a radioactive indicator, which costs thousands of dollars and is carried out only in specialized centers.
The new method will significantly expand the range of test subjects. A blood test for Alzheimer's disease costs $ 1,250, but for patients with sponsorship, the price can be reduced and range from $ 25 to $ 400, The Scientist reports, citing Joel Braunstein, executive director of C2N. Insurance companies currently do not pay for Alzheimer's disease testing.
"If you had asked me five or ten years ago whether a blood test for Alzheimer's disease would ever be created, I would have answered very skeptically, primarily because of the blood-brain barrier," says Howard Fillit, scientific director of the Alzheimer's Drug Research Foundation (Alzheimer's Drug Discovery Foundation), invested in the development of the test by C2N. But modern analytical methods make it possible to capture negligible amounts of biomarkers entering the peripheral blood from the brain.
The C2N test is based on the determination of two parameters: the ratio of two isoforms of beta-amyloid protein, Aß42 and Aß40, aggregating with the formation of amyloid plaques in the brain, and the presence of isoforms of apolipoprotein E (ApoE), indicating that the patient has a genetic variant associated with an increased risk of developing Alzheimer's disease. The results are translated into points indicating the probability of detecting amyloid plaques with appropriate tomography.
Doctors can attach the test results to other information about the patient who is to be diagnosed. According to the company, in a study of 686 patients with cognitive impairments, it was found that with scores above a certain limit, a positive response during subsequent amyloid tomography was noted in 92% of cases, with scores below this limit, the probability of negative results of tomographic scanning was 77%.
Since there are no drugs for Alzheimer's disease yet, the ability to distinguish it from other causes of cognitive impairment is certainly very valuable, Fillit notes.
Portal "Eternal youth" http://vechnayamolodost.ru