Researchers from Kyoto Prefectural University of Medicine in Japan have developed a new method that can diagnose Alzheimer’s disease directly from the blood. In a new paper published on the journal Molecular Neurodegeneration, the team described a potential method that can detect with high accuracy the levels of phosphorylated tau, a protein that builds up in the brain of Alzheimer’s patients and has been attributed to cause Alzheimer’s disease.
Because phosphorylated tau exists in the Cerebrospinal Fluid (CSF), current detection methods involve inserting a needle into the body to gain a sample of the fluid. This invasive procedure puts a heavy physical burden on patients.
With the hope of finding alternatives to this invasive procedure, the researchers developed an ultrasensitive test that can detect Alzheimer’s biomarker directly from the blood. Instead of using the biomarker that is obtained from the cerebrospinal fluid (CSF), the researchers chose another subset of Tau protein called p-tau181. They explained:
“The CSF biomarkers have serious limitations because of their invasiveness and the considerable care and skill needed to collect CSF samples, and so these markers have not found their way into routine clinical use.” ~ Harutsugu et al (Molecular Neurodegeneration)
According to the researchers, the biomarker p-tau181, which is found in the plasma of the blood, originates from the brain. The new method is incredibly sensitive that it can detect p-tau181 in just 0.2 milliliter of blood. That’s 1,000 times more sensitive than using a previous assay developed by the U.S. company Quanterix. In fact, the new method is a modified version of the same assay with an improved sensitivity.
The team used the technique to analyze blood samples from 20 Alzheimer’s disease patients aging between 60 and 89 years old and discovered larger amounts of phosphorylated tau (p-tau181) than in the blood samples of healthy people. Researchers hope to further optimize the technique and test the method in more patients to confirm its usefulness.
“We report for the first time quantitative data on the plasma levels of p-tau181 in controls and patients with AD and DS, and these data suggest that the plasma p-tau181 is a promising blood biomarker for brain AD pathology. This exploratory pilot study warrants further large-scale and well-controlled studies to validate the usefulness of plasma p-tau181 as an urgently needed surrogate marker for the diagnosis and disease progression of AD.” ~ Harutsugu et al (Molecular Neurodegeneration)