Alzheimer’s Disease Blood Tests Show Promise for Early Detection
Alzheimer’s researchers at Washington University in St. Louis have released a new study showing promise in a blood test’s ability to detect the disease earlier than traditional methods. The study of 150 adults was published in Neurology this past August. Importantly, it found that a blood test can measure the level of amyloid-beta in the bloodstream indicating whether the protein has accumulated in the brain, as an early indicator of disease.
The new study seems to indicate a potential breakthrough in early Alzheimer’s disease detection. Do you believe it has merit?
“There have been several new potential biomarkers for Alzheimer’s disease detected in spinal fluid or serum (plasma) markers,” Conner says. “The potentially promising news here is if biomarker testing shows a positive result, there is a higher likelihood of developing Alzheimer’s than traditional tests.”
Conner also notes that biomarker tests are more sensitive if the patient already has the disease, in which the tests are highly likely to show a positive result.
Knowing this, does early detection and earlier treatment have benefits for the patient?
While Conner notes that early detection and therefore earlier treatment can slow progression for the patient, as of right now, that benefit appears to wear off at the second-year mark.
Does it change prescribing patterns for the patient?
“Yes, if you have a marker that supports your diagnosis, you are more likely to treat the patient earlier,” Conner explains. “Earlier treatment may allow any new or old medications to be more effective or might provide an opportunity to help protect the brain’s neurons from damage. New biomarkers may allow novel potential targets for future treatments. Further, biomarkers may allow us to classify dementias better and define subsets of the disease to a greater degree.”
Conner adds that there may be a potential downside. While negative results from a biomarker test may reassure the patient, a positive result, when done in a routine screen for another purpose, may cause unnecessary anxiety.
How might the blood test be an improvement over currently used PET brain scans?
“Biomarker tests, such as the blood test in the study, could have several advantages over a PET scan,” Conner says. “First, PET scans look for amyloid deposition in the brain, but it’s worth noting there may be bias built into how the scan is interpreted. As such, not all patients with amyloid deposition develop Alzheimer’s disease. In such cases, the result is a false positive causing the patient unnecessary fear and anxiety.”
Accessibility to a PET scan facility is another issue because not every community has one, especially in rural communities. On the flip side, a biomarker test could be conducted in most clinical facilities and shipped to a central lab to read the results.
Some believe Alzheimer’s research has lagged behind that for other diseases. Do you believe that is the case? If so, why do you believe that is?
“Honestly, Alzheimer’s disease research and treatment progress has been disappointing, and there have been no new medications available in the last decade,” Conner says. “The brain remains medicine’s big black box, and the complexities of memory and how disease processes affect it is unknown to us. Reliable animal models important in disease research don’t exist in this case.
“Further, the disease process progresses over years, making research difficult and costly. I also wonder if there is a certain bias against Alzheimer’s since it’s the elderly who are primarily affected. It may not tug at the heartstrings as much as other diseases, so perhaps all of these factors contribute to a lack of progress.”
What advice do you share with patients and caregivers regarding lifestyle changes that may help stave off the advancement of Alzheimer’s?
A large retrospective study looking at almost 200,000 individuals with a high genetic risk for Alzheimer’s found that changing from an unfavorable to a favorable lifestyle would prevent one case of dementia for every 121 individuals in 10 years.
“The researchers defined a favorable lifestyle as not smoking, eating a healthy diet that maximizes fruits and vegetables, limiting alcohol intake, getting plenty of sleep, and staying socially engaged, among other factors,” Conner explains.
What signs should a family member or caregiver look for that may indicate the potential for Alzheimer’s?
Families need to be on the lookout for short-term memory decline, repeating themselves, making financial errors, misplacing objects, getting lost, personality changes and becoming socially isolated.
As you look to the future, what thoughts do you have about the prospect of finding a cure and/or improvement in current treatment for patients with Alzheimer’s?
“I think we are seeing a new direction in Alzheimer’s research where it is focusing less on amyloid and more on inflammation and cell processes that have gone awry,” Conner says. “With our aging population, there is more of a recognized emergent need.”
If you’re concerned about a loved one’s recent memory changes or to learn more about the neuroscience program at a hospital near you, visit TexasHealth.org/neurosciences or call 1-877-THR-WELL.