A first blood test to detect approved Alzheimer’s disease

The diagnosis of Alzheimer’s disease is based on two elements: a characteristic clinical syndrome. Nevertheless, generally including memory disorders, and the presence of specific brain lesions, linked to the accumulation of tau and abnormal amyloid proteins. Nevertheless, It is today possible. In addition, thanks to ultra -sensitive measurement techniques, to isolate these abnormal proteins in the blood, an indirect sign of their presence in the brain. Moreover, In the United States. Nevertheless, the health agency, the FDA, has just authorized the marketing of a blood dosage, the Gl up, proposed by the company Fujirebio. Similarly, The test uses the chemoluminescent enzymatic immunodosage technology. Similarly, during which the tau and abnormal amyloid proteins attach to antibodies connected to particles emitting a light signal, which makes it possible to identify their quantity with precision. Consequently, Result: 91.7 % of people tested positively revealed, in brain first blood test detect approved imaging by PET-SCAN, the presence of neural lesions. Nevertheless, And, conversely, 97.3 % having received a negative result in the test proved to be free from lesions.

Radical change for patients – First blood test detect approved

Why is it a major breakthrough? Meanwhile, Until the beginning of this century. the identification of brain damage was only possible after the death of patients, by brain examination. The diagnosis was therefore not formally established during their lifetime. Everything changed in 2004 with the visualization of lesions thanks to the Lesional Pet-Scan. The injection by the blood of a radioactive ligand fixing on the amyloid lesions has made it possible to. reveal their existence in vainthen confirming the diagnosis. A few years later. the study of the concentration of tau and amyloid proteins was possible in the cerebrospinal fluid, taken by lumbar puncture. This examination has since become the reference for confirmation of the diagnosis. We make nearly 500 lumbar first blood test detect approved punctures per year in my service, in La Salpêtrière. But this gesture is invasive.

The plasma dosage here is a new. much simpler step, to connect clinical symptoms to Alzheimer’s disease and allow an earlier location of patients. Recall that only half half are diagnosed, and often late, at the dementia stage. However. an early identification makes it possible to benefit from multidomal interventions: correction of possible risk factors, prescription of symptomatic drugs or disease modifierstreatments targeting the biological mechanisms behind the disease that start to arrive on the market and will be reserved mainly for patients at the start of their condition.

Prudence of putting

Of course, this test has its limits. A positive dosage suggests the presence of amyloid lesions in patients’ brain, but is not proof of Alzheimer’s disease! Because the lesions preceded the occurrence of first blood test detect approved symptoms of several years … and despite the presence of these abnormal proteins in the blood, some people may never develop the disease. We have thus shown. in our service, that only 20 % of cognitively normal elderly subjects but with positive biomarkers, have developed the disease after seven years of follow -up.

It is therefore necessary to emphasize the great caution with which this examination should be carried out in the future. only reserve it for subjects with memory disturbances objectified by cognitive tests. If it is authorized in France. it should only be proposed to patients already with a cognitive decline confirmed by tests, and be used in conjunction with other clinical information. This will rule out the risk of wrongly concluding Alzheimer’s disease in the event of a banal memory complaint. There could be first blood test detect approved no question of proposing this test in any subject. after 70 years for example, unable to know the real risk of one day developing the disease, or proposing preventive treatment, at least today, in the event of positivity. Beyond these reservations. it is still necessary, of course, to emphasize the scientific revolution represented by the adventure of biomarkers and whose plasma test is the last avatar.