Quest launches blood test for Alzheimer's disease aimed at general consumers

Advances in drug treatments for Alzheimer’s disease have opened doors for diagnostics, and Quest is the latest to walk through. 

The clinical testing giant has put forward a blood test designed to help gauge a person’s levels of beta amyloid—one of the hallmarks of the neurodegenerative condition—and it’s now making it available directly to consumers.

Listed for sale on the company’s website, the AD-Detect test retails for $399 plus a $13 physician fee. Quest Diagnostics says the blood test, though not an official diagnostic, is designed for anyone “who has a family history of Alzheimer’s disease, is experiencing memory loss, or is experiencing early cognitive decline.”

The AD-Detect test measures the ratio between two types of beta amyloid proteins in plasma and was previously offered to biopharma companies to help screen participants in clinical trials for Alzheimer’s disease, dementia and mild cognitive impairment. 

The push to use blood samples has required the development of super-sensitive assays to detect beta amyloid proteins, which are much less common in plasma compared to cerebrospinal fluid and the brain. In the past, a definitive diagnosis of Alzheimer’s has required PET/CT scans, spinal tap procedures or an autopsy.

Though blood tests for Alzheimer’s have begun to show promise in recent years, milestones in pharmaceutical treatments have accelerated the drive for more diagnostics into something of a gold rush—starting with the full FDA approval granted earlier this month to Eisai and Biogen’s Leqembi antibody for reducing amyloid beta plaques. Meanwhile, Eli Lilly is looking to secure approval of its competing antibody donanemab by the end of this year. 

Since then, multiple testmakers have been quick to remind the public of their diagnostic research in the field. Quanterix launched a prescription test earlier this month, while Danaher’s Beckman Coulter division linked up with Japanese developer Fujirebio to develop an Alzheimer’s blood test for the U.S. market. 

“We are seeing much attention on emerging therapies for Alzheimer's disease, but with new treatment options will come the need to make screening and diagnosis more widely available,” Quest’s medical director for neurology, Michael Racke, M.D., said in the company’s announcement. “We're also seeing a push from consumers who have a desire to take more control of their health, including within more advanced areas like Alzheimer's disease risk assessment.”

According to Quest, many people want to be evaluated for dementia and the early signs of Alzheimer’s almost 10 years before the ages used in current medical practice. The company also projects the number of people in the U.S. with Alzheimer’s to grow to 14 million by 2060.