Quest Launches Alzheimer’s Beta-Amyloid Blood Test for Consumers

Pictured: Quest Diagnostics headquarters in New Jersey/iStock, JHVEPhoto

Pictured: Quest Diagnostics headquarters in New Jersey/iStock, JHVEPhoto

Monday, Quest Diagnostics launched the AD-Detect Test, a direct-to-consumer blood test designed to catch abnormal levels of the beta-amyloid protein to assess a patient’s risk of developing Alzheimer’s disease.

According to Quest, AD-Detect is the first direct-to-consumer blood-based biomarker test for Alzheimer’s disease, though the company is quick to point out that it is not a diagnostic test. “Only a physician or healthcare professional can provide an Alzheimer’s disease diagnosis,” the company said in its announcement.

“The risk of having Alzheimer's disease as the underlying cause for mild cognitive impairment (MCI) or dementia should be considered in conjunction with the findings from medical and family history, physicals, nutritional deficiency biomarkers, neurological and neuropsychological examinations, and neuroimaging,” according to Quest.

AD-Detect works by measuring two types of beta-amyloid biomarkers in the blood and determining the beta-amyloid 42/40 ratio, a validated tool used to assess a patient’s risk of developing Alzheimer’s risk. As a rule of thumb, lower ratio values are indicative of a higher disease risk.

The company has given AD-Detect a $399 price tag on its website, plus a $13 physician service fee. The tests are overseen by an independent doctor network, and consumers can also opt to talk to a licensed physician regarding their results. The company specifically recommends AD-Detect for people with a family predisposition for Alzheimer’s disease, are 65 years and above and have suffered brain or head trauma in the past.

AD-Detect’s launch comes amid the biopharma industry’s revitalized interest in Alzheimer’s disease. In January 2023, Biogen and Eisai won the FDA’s accelerated approval for Leqembi (lecanemab), a therapeutic antibody designed to target beta-amyloid plaques.

In July 2023, the FDA gave Leqembi full approval, making it the first-ever Alzheimer’s disease antibody to be granted the regulator’s traditional approval. This decision follows an advisory committee meeting in June that saw unanimous panel support for Leqembi’s full approval.

Following the full approval, the Centers for Medicare and Medicaid Services broadened its coverage for Leqembi to also allow reimbursement for patients not enrolled in clinical trials. Still, only those with mild cognitive impairment or mild Alzheimer’s disease dementia with evidence of beta-amyloid deposits in the brain will be eligible.

CMS has also proposed to ease the limits on its coverage of PET scans for detecting amyloid plaques in the brain, a typical diagnostic test for Alzheimer’s disease patients.

Tristan Manalac is an independent science writer based in metro Manila, Philippines. He can be reached at or

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