New Blood Test May Predict Alzheimer's Years Before Symptoms Appear: Study Shows - Video

Researchers have identified a blood marker that reflects the amount of Alzheimer's pathology in the brain. This discovery may play a key role in determining who is most likely to benefit from the new Alzheimer's drugs.

Key points from the study:

The blood-based marker (P-tau217) may start to change several years before the onset of Alzheimer's symptoms. The marker can be measured using a simpler and cheaper analytical method.

Compared with a highly specialised analytical method, the fully automated method demonstrated a high level of accuracy.

The accuracy was over 90 percent regardless of age, gender, co-morbidity or whether the test is done in a specialist or primary care setting.

A multicentre study has now evaluated a simpler method of analysis for alzheimer’s disease. In total, 1,767 people with cognitive symptoms were included in the study.

The researchers used two cut-offs as the main method to determine whether the blood sample should be interpreted as positive or negative. If a test result is above the upper cut-off, it is classified as positive, i.e. the presence of Alzheimer's disease pathology. If it is below the lower cut-off, it is classified as negative. Values between these cut-offs fall into a grey area and are not assessed in the analysis.

The results were slightly less reliable (83-87%) for the oldest group included in the study if only one cut-off was used.

The simpler method of analysis means that a blood test for Alzheimer's disease can be introduced even in small hospitals.

"When the method was tested in patient groups, the accuracy was between 92 and 94 per cent," says Noëlle Warmenhoven, researcher and doctoral student in clinical memory research at Lund University, and first co-author. "This is very promising as this method is likely to become one of the more widely used methods in clinical practice worldwide, including Sweden."

Reference: https://www.lunduniversity.lu.se/article/more-opportunities-test-alzheimers-using-new-analytical-method