
Common Questions About the FDA-Approved Alzheimer’s Blood Test
Alzheimer’s disease is a devastating condition that affects more than , according to the Alzheimer’s Association. As the Baby Boomer generation ages, this number is estimated to grow to 13 million by 2050.
However, the has cleared the use of the Lumipulse Plasma Ratio, the first FDA-approved blood test that can help diagnose Alzheimer’s.
“The blood test is an easy and non-invasive way to add supporting diagnostic information to a workup for cognitive disorders,” says Michelle Sorweid, DO, MPH, a geriatric physician and cognitive disorder specialist at Ƶ of Utah Ƶ. “In addition, results come back within a couple of weeks or sooner compared to taking months to obtain other diagnostic tests due to scheduling wait times.”
It’s important to understand what the availability of this test means for patients, their families, and folks who have a higher risk of developing Alzheimer’s. However, it’s equally important to understand what this DZ’t mean.
How Does the Test Work?
Alzheimer’s is a brain disorder that primarily affects adults aged 65 and older. It’s the most common cause of dementia and leads to the gradual decline of memory and thinking skills. It’s progressive, meaning the symptoms worsen over time. Early symptoms include memory loss and other cognitive issues that would typically be evaluated with a mental status test.
If the mental status evaluation determines that cognitive impairment is present, the next steps in the diagnostic process have traditionally been:
- Brain imaging tests
- Cerebrospinal fluid tests
While these tests may still be performed to rule out other conditions such as stroke or a brain mass, the Lumipusle test is a simple blood draw which looks for two specific proteins that build up in the brains of people with Alzheimer’s: beta-amyloid and phosphorylated tau proteins. The detection of these proteins correlates with the presence of amyloid plaques in a person’s brain, which causes the decline of healthy brain cells and is a key sign of Alzheimer’s.
If your eyes glazed over while reading that, bear with us.
Imagine your brain as busy interconnected roads and highways. In a healthy brain, the vehicles run smoothly on those roads, successfully carrying information, memories, thoughts, and emotions. In a brain with Alzheimer’s, debris (beta-amyloid) begins to build up on the road, causing impassable traffic jams (amyloid plaques), making it difficult for information to successfully travel through the brain. Simultaneously, the actual infrastructure of the roads (tau proteins) begins to collapse and becomes tangled into a mess.
Think of the blood test as a GPS system alerting you to major traffic jams on your route.
, the Ƶ of Utah’s blood bank and laboratory partner, has , though it has not been cleared by the FDA yet. Like the Lumipulse test, this is a simple blood draw that can identify phosphorylated tau proteins, which correlates with the presence of amyloid plaques and therefore the potential for Alzheimer’s. In other words, the support beams (tau proteins) of a highway become so damaged (phosphorylation) that they collapse, pile up, and cause major traffic jams (amyloid plaques).
Why Is a Blood Test a Significant Development?
According to the Alzheimer’s Association, say they would want to know if they have Alzheimer’s before their symptoms interfered with daily activities, or before having any symptoms at all. While the test is currently only for older adults who have already begun having symptoms, a blood draw is an easy, non-invasive, and cheaper way to gather supporting diagnostic information so the patient can begin their care journey.
“Blood tests are an added tool to the diagnostic process, not necessarily a substitute for other testing methods,” Sorweid says. “But they are just as good at detecting disease as a spinal tap or amyloid PET scan.”
While the Lumipulse test is the first of its kind to receive FDA approval, several other promising blood tests for Alzheimer’s are in line for consideration by the FDA. Some of these tests have shown similar or better performance in disease prediction.
Who Is a Candidate for the Test?
Adults older than 55 who have already started exhibiting symptoms of cognitive decline are eligible for this test.
“Good candidates are individuals who are identified as having cognitive impairment distinct from normal aging via abnormal cognitive screening,” Sorweid says. “These tests should not be used in individuals without symptoms, as they cannot be interpreted well in those individuals. Referral based on cognitive screening assessments is the first step to determine whether these blood tests are appropriate.”
While research of Alzheimer’s care is ever-evolving, a simple blood test being cleared by the FDA is a significant step toward more accessible diagnostics.
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