A new blood test to detect Alzheimer’s disease

The United States Food and Drug Administration (FDA) recently approved a new blood test to detect Alzheimer’s disease. The test, called Elecsys pTau181was developed by the pharmaceutical companies Roche and Eli Lilly. It is based on measuring the level of Tau proteins which is related to phosphorus in the blood. Tau is one of two proteins that are produced naturally in the brain and the accumulation of an abnormal form of which is associated with the development of Alzheimer’s disease.

dictation Originally published on the Davidson Institute for Science Education website

Alzheimer’s is a degenerative disease that is characterized by a gradual deterioration in the patient’s memory and thinking and information processing skills, due to severe damage to the nerve cells in the brain and their mass death. The new test is not a diagnostic test, which means it does not make it possible to determine with certainty whether a person has Alzheimer’s disease. Its purpose is the opposite: according to the publications of the Roche company, its great advantage lies in its ability rule out the disease with an accuracy of almost 98 percent, and to do it with a simple blood test given by the family doctor. From this it follows that the vast majority of people who suffer from a decline in memory and thinking but are not Alzheimer’s patients, will be able to get a quick answer without the need for complicated and expensive tests.​

Only recently was another test approved for use for Alzheimer’s disease, named Lumipulse G pTau217/ß-Amyloid 1-42developed by Fujirebio Diagnostics, which specializes in medical diagnostics. The test measures the ratio between a form of tau protein bound to phosphorus called pTau217, similar to the protein measured in the new test, and the amyloid-beta protein – another protein deposit whose accumulation is identified with the development of the disease. That is, the test allows not just rule outbut also to identify signs of the existence of Alzheimer’s disease in those who suffer from it. However, the two blood tests will often not give an unequivocal answer, and in order to get a definite diagnosis, additional operations are required, such as a PET scan of the brain or a lumbar puncture to draw cerebrospinal fluid.

Data collected in the United States indicate Underdiagnosis of Alzheimer’s disease – that is, many of the patients are diagnosed very late. Diagnosis of the disease made based on combination of several types of tests, including a conversation with the patient and his family, observation of his function, tests that test memory functions, understanding, fulfilling instructions and similar functions, and sometimes also brain imaging tests and blood tests.

In the past they were done Attempts to develop methods to diagnose Alzheimer’s patients Already in the early stages of the disease. There is currently no medicine that can cure the disease or stop it, however There are remedies that help slow down the rate of disease progression. A diagnosis can also help to provide the patient with an enveloping environment that will make it easier for him and his family to deal with the difficulties. The new developments promise to allow a faster, simpler and more accessible diagnosis of the disease. However, the current developments mainly emphasize negation – that is, they are designed to reduce the concerns of people who suffer from memory loss that is probably not related to Alzheimer’s disease, and to refer them to further investigation of their condition, in order to match them with the most appropriate treatment.