A team of scientists in Sweden has developed a simple and reliable tool for diagnosing Alzheimer's disease in its early stages. The prototype analyzes the results of a single blood test and three cognitive tests, which take only ten minutes to complete.
With this little information, the new algorithm was able to predict with 90% certainty which patients would develop Alzheimer's within the next four years.
A big step forward in Alzheimer's disease diagnostics
Compared to current diagnostic methods, this is a nice improvement. Already the first tests of the prototype have achieved significantly greater results even than those of the most experienced neurologists.
The first phase
Doctors (who use a person's medical history and brain scans to diagnose Alzheimer's disease) were right 72 percent of the time.
The new algorithm, based only on blood tests, achieved a more flattering 83%
The key factors reviewed for diagnosing Alzheimer's disease
Blood plasma samples were used to look for a known risk gene for Alzheimer's disease and traces of tau protein in those already suffering from mild memory problems.
Recent studies suggest that tau proteins are present in the brain from the earliest stages of Alzheimer's disease, and last year scientists discovered that plasma P-tau217 (a product of the blood tau protein) is a good predictor of cognitive decline in people with mild cognitive impairment.
Attempts made in the past
The discovery that P-tau217 in CSF predicts Alzheimer's-specific cognitive decline was important, but spinal fluid tests were far more invasive and expensive than a simple blood test.
"The algorithm will allow us to recruit people with Alzheimer's disease at an early stage, when new drugs have a better chance of slowing the course of the disease," says the neuroscientist. Oskar Hansson of the University of Lund in Sweden.
The researchers hope that their test, after further improvements, will one day make a big difference in diagnosing Alzheimer's. And they target countries where expensive brain imaging technologies or CSF testing cannot be afforded.
"Our hope is that the algorithm will also be validated for use in primary health care. Especially in developing countries with limited resources," says the study's lead author. Sebastian Palmqvist, also from the University of Lund.