Alzheimer's Blood Test Achieves 86% Accuracy

[alice]

Sunday, July 7
Experimental Alzheimer's Blood Test Achieves 86% Accuracy


NEWS: A new way to catch and predict Alzheimer's with a blood test is in advanced stages of trials. The test promises to delay dementia, as well as improve diagnosis and treatment. Find out about this step forward in the battle against Alzheimer's.

A new blood test is getting great grades at catching Alzheimer's plaque, called plasma Aβ. Achieving 86% accuracy, the test does a full computerized check of the blood, also known as a fully automated immunoassay. The report on the test was published in the respected journal JAMA Neurology, a leading resource on Alzheimer's disease (AD).

The test "accurately predicted cerebral [beta]-amyloid status in all stages of Alzheimer disease," according to lead researcher Dr. Oskar Hansson, Lund University, Sweden. He says, "[W]e are starting to approach a level of accuracy that is usable in routine clinical care around the world."

"We also need to test the technique in clinical settings, which we will do fairly soon in a major primary care study in Sweden. We hope that this will validate our results," said first author Dr. Sebastian Palmqvist

Alzheimer's Blood Test Should Improve Primary Care
Alzforum.com - Researchers led by Oskar Hansson, Lund University, Sweden, report how a fully automated immunoassay for plasma Aβ performed when they put it through its paces. Roche Diagnostic’s Elecsys system predicted Aβ-positive individuals with about 80 percent accuracy. That number improved by 5 percent when the researchers took ApoE genotype into consideration. Alzforum first reported on this data when Hansson presented it at AAIC in 2018 (Aug 2018 conference news). Since then, first author Sebastian Palmqvist and colleagues have tested samples in a validation cohort in Germany. Here the test was more accurate, at 86 percent. “I think we are not that far away from a blood-based biomarker that can be implemented in primary care to improve diagnostics of AD,” Hansson told Alzforum.

Fighting Misdiagnosis, Screening for Risk
The Elecsys system is one of a handful of plasma immunoassays that are vying with mass spectrometry-based methods for use as a blood test in the clinic. Each has its pros and cons. The immunoassays are easier to implement, though not quite as accurate as the mass-spec approaches. Being fully automated, the Elecsys system comes with the added advantage of cutting down on variability that can be introduced by manual steps that are part of mass spec, ELISA, and Simoa immunoassay approaches. It can be scaled up easily for use in primary-care settings, which makes it attractive to Hansson. “A lot of patients with Alzheimer’s disease are not diagnosed, or they get an incorrect diagnosis,” he noted. “A plasma assay could improve this situation and boost the number of people who get proper symptomatic treatments,” he said.