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The AD-Detect™ Test for Alzheimer’s disease, a blood-based biomarker test, is now available for purchase by consumers in the United States. Image credit: Jasmin Merdan/Getty Images.
  • Quest Diagnostics has introduced the AD-Detect™ Test for Alzheimer’s disease, a blood-based biomarker test available for purchase by consumers.
  • The new test allows individuals to gauge their risk of developing Alzheimer’s disease by measuring beta-amyloid protein, a key indicator of the condition.
  • With the potential to reshape early detection strategies, this new test aligns with the changing landscape of Alzheimer’s care, helping individuals to proactively manage their cognitive health.

Blood tests have the potential to enhance the accuracy and convenience of diagnosing and tracking Alzheimer’s disease.

With more than 6 million Americans currently affected by the disease, a number projected to rise to almost 13 million by 2050, early detection and intervention are crucial.

Current diagnostic methods, such as MRI scans, cognitive tests, and physical examinations have limitations due to their need for specialized clinics and trained staff.

By improving the accessibility of Alzheimer’s testing, medical professionals could identify the disease earlier and provide interventions to potentially slow progression.

By allowing consumers to take control of their cognitive health assessment, Quest Diagnostics claims to facilitate a proactive approach to Alzheimer’s risk identification.

Traditionally, Alzheimer’s disease detection has relied on symptom screening followed by invasive and costly tests.

However, Quest’s AD-Detect™ Test brings a more accessible alternative, particularly beneficial for those experiencing cognitive decline, exhibiting mild cognitive impairment symptoms, or with a family history of Alzheimer’s.

A company spokesperson from Quest Diagnostics spoke to Medical News Today, saying that “the AD-Detect Test for Alzheimer’s disease on questhealth.com is a starting point for evaluating [the] risk of Alzheimer’s disease.”

“This new consumer-initiated test utilizes the same expertise and technology as Quest Diagnostics’ clinical AD-Detect Amyloid Beta 42/40 Ratio test, an analytically validated blood test that aids in assessing the risk of Alzheimer’s disease, which we launched for physician ordering in early 2022,” they added.

“Specifically, it [the test] measures two peptides of the amyloid-beta protein — A-beta 42 and A-beta 40 — to arrive at a ratio score. A lower ratio of A-beta 42 to A-beta 40 in the brain is associated with a greater risk of developing Alzheimer’s disease. Our test uses tandem mass spectrometry, a highly sensitive method.”

– Quest Diagnostics spokesperson

The AD-Detect Test for Alzheimer’s disease is not a direct-to-consumer test. It is a test that consumers can initiate but it must be ordered and overseen by a physician.

A network of independent physicians manages the test ordering and result delivery process.

After purchasing the test online, individuals need to schedule an appointment at a Quest Diagnostics patient service center for a blood draw. According to the company website, the test itself is priced at $399, to which a $13 physician service fee is added.

Test results are accessible through a secure patient portal and are presented in a clear, easily understandable report.

Individuals can discuss their results with a licensed physician to gain insight into their implications and plan for ongoing care.

This may involve follow-up with their regular physician or a specialist. The option to share results with their personal physician is available.

Additionally, individuals with results indicating a potential Alzheimer’s disease risk will be contacted by a physician from the independent network.

“We explain on questhealth.com that the test is for individuals who meet certain criteria, including family [Alzheimer’s] history, evidence of mild cognitive impairment, or prior brain trauma or head injury,” the Quest Diagnostics spokesperson told MNT.

“In addition, prior to purchase of the service online, a pop-up box appears that an individual must check on digitally to acknowledge they meet one of several specified risk factors. If they don’t click on this box, they can’t purchase the test,” the spokesperson further noted.

While the test is a starting point for evaluating the risk of Alzheimer’s, it is not a definitive diagnostic tool, and Quest Diagnostics encourages individuals who are concerned about their risk to confer with their healthcare provider.

“Early detection can help encourage the necessary discussions with a healthcare provider about steps to minimize risk. In addition to emerging therapies, growing science indicates that behavioral and other changes can influence risk (i.e., exercise, not smoking, socializing). We encourage anyone who receives a result suggestive of [Alzheimer’s disease] risk to confer with a physician to discuss next steps.”

– Quest Diagnostics spokesperson

Dr. Raymond J. Tesi, CEO and CMO of INmune Bio, a biotechnology company that aims to use elements of the immune system to fight cancer and Alzheimer’s disease, spoke to MNT about the pros and cons of a blood test focusing on detecting beta-amyloid.

He noted that “almost half of people with normal cognition die with amyloid in their brains” and “[a]ll patients with [Alzheimer’s disease] have amyloid in their brains.”

“This disconnect means that many people with positive blood tests will not have [Alzheimer’s disease],” Dr. Tesi cautioned.

“That is, the sensitivity of the test is the ability of the test to prove you have amyloid. It does not [prove] you have [Alzheimer’s disease],” he said. Still, “I consider this issue a headache more than a problem,” he added.

As for why this newly commercially available blood test could be an important step forward, Dr. Tesi commented:

“Most people won’t get the test unless they have problems with memory. If the result is a positive test and it ‘inspires’ them to be evaluated by a clinical team that can formalize the diagnosis to allow for early treatment […] it is a big, big win for the patient, the family, and the payors.”

Dr. Tesi concluded: “[L]ike the anti-amyloid drugs that are an important but imperfect first step in the war against [Alzheimer’s], this is a first but imperfect step in simplifying the diagnosis of [Alzheimer’s disease]. There need to be additional blood biomarkers added, […] like GFAP, and there need to be easy and reliable tests of cognitive function (web-based) to improve the precision of the diagnosis, but it is the first step in a long journey.”