Blood tests for Alzheimer’s are nearing availability in doctors' offices. These tests could transform diagnosis accuracy and speed up research and treatment. This was shared at the Alzheimer’s Association International Conference® (AAIC®) 2024 in Philadelphia and online.
Dementia is often underdiagnosed, and many people remain unaware of their diagnosis. According to the 2024 Alzheimer’s Disease Facts and Figures report, new blood tests could greatly improve diagnostic accuracy. They offer better access and enhance communication.
The most promising blood tests find Alzheimer’s-related brain changes by measuring phosphorylated tau (p-tau) protein. This marker can build up before symptoms appear. Specifically, the p-tau217 marker increases with worsening memory and brain shrinkage. It also predicts the presence of amyloid plaques, another key Alzheimer’s marker.
"Blood tests, once proven over 90% accurate and widely available, could improve clinical trial recruitment and diagnosis processes," said Maria C. Carrillo, Ph.D., Alzheimer’s Association chief science officer. She added that doctors should currently use a mix of memory and biomarker testing for diagnosis. Blood tests could enhance early diagnosis and treatment access.
Researchers at AAIC 2024 shared a study of the PrecivityAD2 test (APS2), which combines p-tau217 and amyloid ratios. Among 1,213 patients, APS2 was 90% accurate. It outperformed memory clinic specialists, who were 73% accurate, and primary care doctors, who were 63% accurate.
Lead author Sebastian Palmqvist, M.D., Ph.D., emphasized APS2's accuracy even in patients with other medical conditions. Senior author Oskar Hansson, M.D., Ph.D., called this a major step toward global clinical use. The next step involves setting guidelines for using these tests in practice.