Last month, Food and drug addiction has approved a new blood test to aid in the diagnosis of Alzheimer’s disease. Produced by Roche, Elecsys PTau181 measures the availability of a specific molecule – the phosphorylated form of tau protein – in the blood. Tau is one of two proteins, the other being amyloid, that accumulates in the brains of patients with certain types of dementia. It is believed that the production of these proteins interferes with the communication of brain cells, which leads to these symptoms of patients.
The test was already receiving approval in July for marketing in Europe and therefore it is the start of the first program to test Alzheimer’s Use in primary care markets allowed in two markets of the Planet. It is open to what must be a crowded field, because there are several other tests in the advanced stages of evaluation and admission.
How do such tests work?
Elecsys PTAU181 looks in blood plasma to detect the form of tau with a phosphate group attached, which is often found in high amounts in Alzheimer’s patients. This molecule is an indirect marker of amyloid plaques and neurofibrillary tangles of Tau seen in patients with this disease.
Other tests are also approved, although not pre-acceleration. This examines other biomarkers related to these two proteins. One test, called Lumipulse and made by the Japanese company Fujirebio, looks at the ratio between another type of phosphorylated Tau (PTAU217) and a key piece of Pretein
The bottom line is that these tests give indications of the possible presence of Amyloidosis in the brain, which requires that it be found to be tested more, looking at the rurebrospinal cleaning area) Analysis of living punlology in living patients. Even this, however, comes with a degree of uncertainty; The real verification of the truth can be a post-psychological attack.
Why Allow These Tests Now?
In the past, confirming the diagnosis of alzheimer was not very important, as there were no drugs or treatments that could change the course of the disease. But with the adoption of the New Monoclonal antibody’s treatment, the situation has changed in the last few years.
To use these drugs, you need a way to determine which patients will benefit. And since these drugs produce the best results when used early in the progression of the disease, cheap and inexpensive and non-invasive tests are very helpful. Using all elderly people with suspected symptoms the mental decline of domestic animals and the sampling of cerebrospinal fluid is not possible, so this is where the blood test for Alzheimer’s comes in.
How is this useful?
Elecsys PTAU181 is the first exam to be approved for use as a public assessment tool. The idea is that it should be managed at the level of primary care—so, by a primary care physician or a general practitioner. The test has been shown to have a good “negative predictive value”—that is, it’s effective at accurately identifying who it doesn’t become amyloid disease. In settings where the increase in total amyloid is low, a negative result from this test is 97.9 percent reliable. This makes it useful in choosing which patients to prioritize for further evaluation.
The results are similar to those of other tests that have already been approved in recent months, such as Lumipulse from Fujirebio of Japan, which tests showed a negative predictive value of 97 percent.
However, there are important limitations to be aware of: In all blood tests for Alzheimer’s, it is often a large part of patients (15-30 percent is a common estimate) that enters the gray area of uncertainty, where the levels of identified biomarkers do not allow any answer.
