In May 2025, the US Food and Drug Administration cleared the first blood test used in evaluating Alzheimer's disease. The Lumipulse G pTau217/β-Amyloid 1-42 Plasma Ratio uses the relationship between two biomarkers measured in blood to estimate whether amyloid plaques may be present in the brain.
Who Is the Test For?
It is intended for adults 55 years and older who have signs or symptoms associated with Alzheimer's disease and are being assessed in a specialized-care setting. It is not a screening test for people without symptoms, and family history alone is not an indication for this test.
How Accurate Is It?
In a sample of 499 people, 91.7% of positive results were confirmed to have amyloid plaques by PET imaging or cerebrospinal fluid testing. Among negative results, 97.3% were confirmed not to have plaques; fewer than one in five results were indeterminate. These data are useful, but no percentage means perfect diagnosis for every patient.
Why Is It Important?
Amyloid PET imaging and cerebrospinal fluid testing are valuable, but cost, availability, or the need for an invasive procedure can limit access. When used appropriately, blood biomarkers could make part of the diagnostic pathway more accessible.
Is This the Same as a Genetic Test?
No. This test measures disease-associated protein biomarkers in blood; it does not sequence DNA or measure inherited risk. Genetic evaluation answers a different question and, when appropriate, should be planned with genetic counseling.