Individuals concerned about their susceptibility to Alzheimer's disease can now conveniently access an online platform to purchase a blood test and obtain their confidential results within the comfort of their own residences. Although this may initially appear desirable, the introduction of this innovation has provoked strong opposition from Alzheimer's researchers and healthcare professionals.
The AD-Detect blood test by Quest Diagnostics is designed to detect elevated levels of amyloid-beta proteins, which are a key indicator of Alzheimer's disease. This test, launched in late July, is primarily aimed at individuals aged 50 and above who suspect they may be experiencing memory and cognitive impairment, as well as those with a family history of Alzheimer's or genetic predisposition to the disease.
Considering that Alzheimer's, along with cancer, is one of the most dreaded medical conditions, there is a potentially significant market for this test. In the United States alone, nearly 7 million older adults are affected by Alzheimer's, and this number is projected to double by 2060 if there are no breakthroughs in medical treatments.
But the validity of the Quest test is questioned by Alzheimer's researchers and clinicians. They express concerns about the potential for false-positive results as well as the limited understanding older adults may have regarding the implications of their results. Their recommendation is for the test to be taken only under the supervision of a physician, if taken at all. In addition, it is worth noting that the test originally had a price tag of $399 (recently discounted to $299) and is not covered by insurance, making it a relatively expensive option.
FILE PHOTO: Eli Lilly logo is shown on one of the company's offices in San Diego, California, U.S., September 17, 2020. REUTERS/Mike Blake/File Photo
Mike Blake/Reuters
Experimental Alzheimer's drug shows promising results in a significant trial, according to Eli Lilly, the pharmaceutical company. Despite the growing popularity of blood tests for Alzheimer's in the future, the Alzheimers Association advises against directly providing such tests to consumers at this stage.
Quest, which also offers direct-to-consumer tests for sexually transmitted diseases and other conditions, believes that older adults are capable of responding responsibly to AD-Detect results. It is important to note that the test is not intended to diagnose Alzheimer's, but rather to help assess an individual's risk of developing the condition. However, according to a new proposed biological definition of Alzheimer's, an excessive amount of amyloid could automatically indicate a diagnosis of "preclinical" Alzheimer's.
Dr. Michael Racke, the medical director of neurology at Quest, mentioned that those who test positive may be motivated to discuss cognitive symptoms with their doctors and seek comprehensive evaluations from dementia specialists. Others may simply wish to adopt brain-healthy behaviors like regular exercise and maintaining healthy blood pressure, blood sugar, and cholesterol levels.
"People conducting consumer-initiated testing are highly motivated to determine steps they can take to mitigate disease risk," he stated.
To obtain the test, individuals must initially visit the website for AD-Detect tests and provide information about experiencing mild cognitive decline and having at least one additional risk factor. (It should be noted that self-reported complaints of this nature are frequently deemed unreliable by experts.) The order is subsequently forwarded to a doctor affiliated with Quest, who will arrange for a blood test to be conducted at a Quest laboratory.
The results classifying a person's risk level as low, medium, or high will be accessible on a secure patient portal. Post-test counseling is optional, but individuals can choose to speak to a physician provided by Quest for a fee of $13. A recent poll conducted by the University of Michigan reveals that older adults are likely to take the results seriously. Ninety-seven percent of seniors stated that they would take action to enhance brain health upon receiving a positive blood test result, while 77% expressed willingness to consider adjustments to financial or end-of-life plans.
However, concerns arise among research scientists and clinicians regarding the lack of peer-reviewed studies from Quest that validate the accuracy of their tests. Suzanne Schindler, an associate professor of neurology at Washington University School of Medicine in St. Louis, highlights that the preliminary data presented by the company at the 2022 Alzheimers Association International Conference in San Diego indicates a relatively high probability of false-positive results.
This issue holds substantial implications since informing individuals of biological changes linked to Alzheimers disease is a significant matter that requires maximum precision, as noted by Schindler.
Racke mentioned that at least three scientific studies on the AD-Detect test have been submitted to medical journals. These studies are expected to be published by the end of this year. However, experts raise concerns about the test's usefulness. They argue that a positive result, which indicates abnormal levels of amyloid in the blood, does not necessarily mean that an individual will definitely develop Alzheimer's disease. Amyloid accumulation in the brain occurs gradually over several decades, typically starting in middle age and becoming more prevalent as people age.
"This test provides a somewhat unclear response. The chances of developing dementia, the onset of symptoms, or the actual risk level for an individual are truly uncertain," medical director of the Senior Care clinic at Stanford Healthcare, Meera Sheffrin, stated.
According to the Alzheimer's Association, 14% of Hispanic people 65 and older have Alzheimer's dementia, compared to 10% of White older adults.
Jose Luis Pelaez Inc/Digital Vision/Getty Images
Research indicates that older Hispanic individuals are disproportionately at a higher risk of developing Alzheimer's compared to older White individuals.
Additionally, cognitive symptoms that lead individuals to undergo testing may be attributed to various other factors such as mini-strokes, sleep apnea, thyroid issues, vitamin B12 deficiency, or interactions with medications. Consequently, if an older adult becomes anxious, depressed, or hopeless upon discovering their increased susceptibility to Alzheimer's — which in itself is a cause for concern — they may opt against pursuing further evaluation and seeking the necessary care, as stated by Rebecca Edelmayer, senior director of scientific engagement at the Alzheimer's Association.
According to a poll by the University of Michigan, it has been revealed that there is a possibility of misunderstanding. Among seniors who received a positive result from a blood test, 74% believed that they were at a high risk of developing Alzheimer's, and 64% anticipated experiencing significant distress as a result.
Due to ongoing advancements in the science behind blood tests for Alzheimer's and the fact that patients may not fully grasp the uncertainty associated with test results, Edelmayer explained that the Alzheimer's Association does not support the utilization of the AD-Detect test by consumers.
Quests blood test is one of several advancements reshaping Alzheimer's care in the United States. In July, the FDA granted full approval to Leqembi, an anti-amyloid therapy that slightly decelerates cognitive decline in individuals with mild cognitive impairment and early-stage Alzheimer's. The availability of this disease-modifying medication has underscored the increased significance of early detection of cognitive symptoms and diagnosis of cognitive dysfunction.
Furthermore, in July, a task group comprised of representatives from the National Institute on Aging and the Alzheimer's Association proposed a novel definition for Alzheimer's disease to be implemented in clinical practice.
Previously, a diagnosis of Alzheimer's disease required both evidence of brain pathology (such as amyloid plaques and tau tangles) and cognitive symptoms (like memory loss, poor judgment, and disorientation), along with accompanying impairments (such as difficulty with managing finances or self-care). However, the new definition of Alzheimer's disease would be solely based on biological factors, specifically the presence of brain pathological changes like amyloid accumulation. This means that if these guidelines are adopted, individuals who are cognitively normal could receive a positive result on the Quest test and be diagnosed with Alzheimer's disease. Eric Widera, a professor of medicine at the University of California-San Francisco, warns about this potential outcome.
Demand for follow-up evaluations by dementia specialists is likely to be high and contribute to already-long waits for care, he suggested.
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There are additional concerns surrounding the test, particularly regarding the protection of privacy and the potential for discrimination. People who receive Alzheimer's biomarker results do not have federal laws to safeguard them against discriminatory practices, such as employment discrimination or the denial of life, disability, or long-term care insurance. The Genetic Information Nondiscrimination Act only applies to genetic tests. Furthermore, the usual laws that protect the privacy of health information do not extend to this particular field, as stated by Emily Largent, an assistant professor of medical ethics and health policy at the University of Pennsylvania's Perelman School of Medicine.
HIPAA, the Health Insurance Portability and Accountability Act, does not cover laboratory tests that are advertised directly to consumers.
In summary: Prior to undergoing a test, "older adults should question themselves as to why they desire this information, how they plan to utilize it, how they will respond, and what adjustments they would make in the future," advised C. Munro Cullum, a distinguished professor of clinical psychology and neuropsychologist at the University of Texas Southwestern Medical Center. "It is crucial to exercise extreme caution and careful consideration when using this test."
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