Among the many critical issues related to Alzheimer’s disease, one concerns the difficulty of diagnosing it in its early stages. Although research has not yet identified a viable therapeutic approach, diagnostically the situation may soon change with the development of a blood test that scientists say can Diagnose up to 94 percent of Alzheimer’s cases 20 years earlier That the symptoms of the disease occur. The researchers in question are from Washington University in St Louis and described the test in the journal Neurology.
The disease is characterized by the increase ofbeta-amyloid plaques in the brain, associated with the accumulation of tau protein tangles, and the test proposed by the U.S. researchers relies precisely on the measurement of beta-amyloid in the blood, which would correlate with that in the brain .
The idea is not new and is a refinement of a technique already presented two years ago; it uses mass spectrometry to measure beta-amyloid-or, more precisely, the ratio between two forms of the protein, called A-β 42 and A-β 40 – and associates its blood concentration with two fundamental risk factors for developing Alzheimer’s: advanced age and the presence of a genetic variant called APOE4.
In this way, the accuracy of the test outperforms that of previous blood tests.
The team recruited 158 adults over the age of 50; all but 10 were described as cognitively normal. Each participant underwent at least one blood test and one PET scan with amyloid tracers , which is the current gold standard, and each test was labeled as amyloid positive or amyloid negative depending on the results produced.
Among experts, there is a growing consensus that in order to manage or treat Alzheimer’s, it is important to intercept it as early as possible, before symptoms begin to appear and the brain is not too damaged.
More than for a cure, which is not currently available, the test could further research. Today, to conduct clinical trials, we check people with scans, which is time-consuming and expensive, whereas with a blood test we could easily examine a large number of subjects, which would help us find treatments more quickly, with a huge potential impact.
Source: Schindler SE, Bollinger JG, et al. High-precision plasma β-amyloid 42/40 predicts current and future brain amyloidosis. Neurology. 2019 Aug 1.
