This is one of the major challenges in treating Alzheimer’s disease: diagnose this pathology long before the first symptoms appear. because recent studies have shown that brain changes sometimes take place two decades before the onset of cognitive decline, memory problems etc.
In a large international study published in the JAMA, researchers report having obtained good results for a blood test aimed precisely at diagnosing Alzheimer’s disease as early as possible. The study was also presented at the Alzheimer’s Association annual conference.
Concretely, the blood test in question measures the concentration of Tau protein in the blood (specifically for this test phospho-tau217, or p-tau217), the abnormal accumulation of which is partly involved in Alzheimer’s disease and other forms of dementia.
Scientists then discovered that “the diagnostic accuracy of blood p-tau217 was as high as established diagnostic methods, including positron emission tomography (PET) imaging and cerebrospinal fluid biomarkers, which are invasive, expensive and less available”. This analysis of p-tau217 in the blood also made it possible to differentiate people with Alzheimer’s disease from those with other neurodegenerative diseases with a diagnostic accuracy of between 89 and 98%.
The study showed blood levels of p-tau217 increased seven-fold in Alzheimer’s disease compared to other dementias. In addition, in people with a gene predisposing to Alzheimer’s disease, the blood levels of p-tau217 started to rise 20 years before the onset of cognitive impairment.
“This test, once verified and confirmed, opens up the possibility of an early diagnosis of Alzheimer’s disease before the dementia stage, which is very important for clinical trials evaluating new therapies that may stop or slow down. the disease process”, Commented Dr. Oskar Hansson, co-author of the study.
While further studies and clinical trials will need to be conducted before this test is available in hospitals and clinics, this type of diagnostic approach for Alzheimer’s disease could revolutionize its prognosis and management.