World.- Researchers from the United States and several European centers have developed a test capable of detecting in the blood the abnormal accumulation of a form of tau protein indicating changes in the brain due to the disease.
An international scientific team led by the University of California, San Francisco (UCSF) has created a method to detect Alzheimer’s disease in people who show signs of dementia with a simple blood test. This approach is less invasive and expensive than currently used brain and cerebrospinal fluid imaging. The results of the study have been published in the journal Nature Medicine.
They found that the accumulation of the pTau181 protein was 3.5 times higher in people with the disease compared to their healthy peers
As the authors explain, the new test detects in the blood the abnormal accumulation of a tau protein, known as phosphorylated-tau-181 (ptau181), which is a biomarker indicating changes in the brain due to Alzheimer’s. Blood samples from more than 400 ucSF Memory and Aging Center participants have been used in the study.
Researchers at the US university and several European institutions found that the presence of pTau181 was 3.5 times higher in people with the disease compared to their healthy peers. Conversely, in patients with frontotemporal dementia – a disease often misdiagnosed as Alzheimer’s – pTau181 was found to be within the same range as the control group.
It could be used in primary care
The research leader Adam Boxer stresses that «this test could be used in primary care with patients who show memory problems to identify which of them should be referred to specialized centers, or to participate in trials to be treated with new Alzheimer’s therapies, once they have been approved.»
«People in the early stages of Alzheimer’s are more likely to respond to new treatments that are being developed,» he says.
Methods used so far to diagnose Alzheimer’s include measuring amyloid deposits – another protein involved in dementia – from a positron emission tomography (PET) or lumbar puncture for quantify amyloid and tau in cerebrospinal fluid.
The new study is a continuation of another published last year that found that high levels of plasma amyloid were a predictor of Alzheimer’s. However, amyloid builds up in the brain many years before symptoms appear, if they do occur, Boxer notes.
They expect the new test to be available in medical offices within five years
A strong predictor
«On the contrary,» he adds, «the amount of tau that accumulates in the brain, which we can measure with the new blood test, «is closely related to the onset, severity and characteristic symptoms of the disease.»
A supplementary study, conducted by Oskar Hansson of Lund University in Sweden, published in the same issue of Nature Medicine, corroborates the results of the UCSF-led study. It concludes that pTau181 is a stronger predictor of the development of Alzheimer’s in healthy elderly people than amyloid.
The authors of the new paper, funded by the U.S. National Institutes of Health (NIH), expect the new blood test to be available in medical offices within five years.