US Approves First Blood Test to Detect Alzheimer’s

The United States has approved the first blood test for Alzheimer’s disease, marking a major step toward earlier and more accessible diagnosis of the condition.

The test, developed by Fujirebio Diagnostics, measures the ratio of two specific proteins in the blood. This ratio is linked to amyloid plaques in the brain—one of the key indicators of Alzheimer’s. Until now, such plaques could only be detected through brain scans or spinal fluid tests.

Alzheimer’s currently affects around 10 percent of people aged 65 and older, and that number is expected to double by 2050. Health officials expressed hope that new tools like this test will help patients receive treatment sooner, when it may be more effective.

Two Alzheimer’s treatments are currently approved in the US—lecanemab and donanemab. These antibody-based drugs target amyloid plaques and have shown some ability to slow the disease’s progression, especially when started early.

The new blood test has shown results that closely align with more invasive diagnostic methods in clinical studies. It is approved for use in patients showing signs of cognitive decline, and results must be considered alongside other clinical assessments.

Experts say the test could make Alzheimer’s diagnosis more accessible and less costly, helping patients begin treatment and care planning sooner.

Alzheimer’s is the most common form of dementia, gradually eroding memory, reasoning, and independence over time.