Alzheimer's disease can be diagnosed before symptoms appear

A large study led by Lund University in Sweden has shown that Alzheimer's patients can now be identified before any symptoms appear
.
It is also now possible to predict who will deteriorate
in the coming years.
The study, published in the journal Nature Medicine, is very timely compared to the newly developed new drugs to treat Alzheimer's
disease.

It has long been known that there are two proteins associated with Alzheimer's disease, β-amyloid, which forms plaques in the brain, and tau, which accumulates
in brain cells later in life.
Elevated levels of these proteins, combined with cognitive impairment, were previously the basis for
diagnosing Alzheimer's disease.

"The brain changes 10 to 20 years before the patient develops any noticeable symptoms, and only when the tau protein begins to spread, the nerve cells die, and the patient develops the first cognitive problems
.
" This is why Alzheimer's disease is difficult to diagnose in its early stages," explains
Oscar Hansen, Senior Doctor of Neurology at Sköne University Hospital and Professor at Lund University.

He now leads a large international study involving 1325 participants from Sweden, the United States, the Netherlands and Australia
.
At the start of the study, the participants did not have any cognitive impairment
.
Through the PET scan, the presence of
tau and amyloid in the participants' brains was visible.

At follow-up after a few years, people who found these two proteins had a 20-40 times
higher risk of developing the disease than those without biological changes.

"When both β amyloid and tau are present in the brain, it's no longer seen as a risk factor, but as a diagnosis
.
A pathologist examining such a brain sample immediately diagnoses the patient with Alzheimer's disease," said
Rick Osenkopeli, lead author of the study and senior researcher at Lund University and University Medical Center Amsterdam.

He explained that Alzheimer's researchers belong to two schools of thought — on the one hand, those who believe that Alzheimer's disease can only be diagnosed when cognitive impairment
begins.
There's also a group to which he and his colleagues belong, who believe that diagnoses can be based purely on biology and what
you see in the brain.

"For example, you can compare
our results to prostate cancer.
If you do a biopsy and find cancer cells, then the diagnosis is cancer, even if the patient is not yet symptomatic," Rik Ossenkoppele said
.

Recently, positive results have been seen in clinical trials of Lecanemab, a new drug for the treatment of Alzheimer's disease, which has been evaluated
in Alzheimer's patients.
Based on this, the Lund University study is particularly interesting, the researchers said:

"If we can diagnose the disease before cognitive challenges arise, we may finally be able to use this drug to slow the disease
at a very early stage.
" Combined with physical activity and good nutrition, a person has a greater chance of preventing or slowing down future cognitive impairment
.
However, more research is needed before treatment can be recommended for people who have not yet experienced memory loss
.
”

Courtesy of Lund University