A routine blood test instead of a spinal fluid test may become the future for detecting Alzheimer's.
Researchers at Lund University have tested the method in regular healthcare, with promising results.
In an earlier study, researchers showed that their method, which measures a specific variant of the tau protein, was as good as today's spinal fluid test in identifying Alzheimer's disease. Since blood tests are simpler and more cost-effective, it could mean benefits for both patients and healthcare.
Now, the researchers have published another study where they investigated how well the blood test, developed by researchers at Lund University and a company in the USA, performed in a regular care environment.
Tested with blood tests
A total of 1,200 people who sought care for memory impairment, which can be a sign of early Alzheimer's, participated in the study. The group included both patients who were investigated in primary care and those who were investigated at a specialized memory clinic. All were tested with both the new blood test and the spinal fluid test. The average age among the participants was 74 years.
About half of the patients had markers in the test that indicated Alzheimer's changes in the brain. According to the results, published in the scientific journal Jama, the blood test can with 90% accuracy determine whether a person with memory difficulties has Alzheimer's or not.
Preventive treatment is lacking
The accuracy of primary care physicians in identifying Alzheimer's disease before they saw the test results was 61%, while specialist physicians had it right in 73% of the cases.
"An early diagnosis becomes increasingly important as new disease-slowing treatments are developed," says Oskar Hansson, professor of neurology at Lund University, in a press release.
Today, there is no preventive medication that has an effect on healthy individuals who have abnormal blood test values. As recently as Friday, the much-publicized drug candidate Lecanemab received a no from the European Medicines Agency because the effect was not considered sufficient in relation to the side effects.
Alzheimer's disease is the most common dementia disease. More than half of all those who have a dementia disease have Alzheimer's disease.
The symptoms develop slowly. In the disease, nerve cells in the temporal and parietal lobes are primarily destroyed. Plaques form in brain cells that consist of the protein beta-amyloid, a substance that also occurs in healthy brains.
When nerve cells are destroyed, memory and how one perceives information from one's senses are affected.
In Sweden, over 100,000 people have Alzheimer's disease. The most important risk factors are high age and heredity. The disease can also occur early, between 35 and 65 years of age, but is most common after 65 years.
Sources: 1177, Alzheimer's Foundation
