Biomarkers. You might not be familiar with the term, but it’s likely you know something about them. Blood pressure. Cholesterol level. Body temperature. Mammogram results. All are biomarkers.
“Biomarkers can identify risk, predict the likelihood of developing a disease, give us a clue as to whether a disease is progressing and help us determine your response to medications,” says Alireza Atri, MD, PhD, director, Banner Sun Health Research Institute. “In the case of Alzheimer’s research, biomarkers are ‘friends’ that are going to help us prevent and defeat this disease.”
Biomarkers are taking center stage to help researchers identify people with a higher risk for developing disease or who are progressing to show signs of dementia; and to assist medical professionals in diagnosing individuals with less common symptoms. Much like your cholesterol numbers may indicate the need for medication to prevent heart disease, the day may come when a blood test may correlate to a similar need for medication to stave off Alzheimer’s.
For Alzheimer’s disease there are two important biomarkers – amyloid and tau – toxic proteins that clump and tangle in the brain. Ultimately, they cause the destruction of brain connections and cells, but this process can start 10 to 20 years or more before individuals show symptoms. Currently, in the research setting, these proteins are frequently measured by taking a sample of cerebrospinal fluid (spinal tap) or through a brain PET scan. Currently, dementia specialists typically reserve using these advanced, and expensive, diagnostic tools in patients with atypical or rapidly progressive dementias after a comprehensive evaluation of clinical symptoms, neuropsychological testing, lab tests and other imaging methods, such as MRI results, suggest Alzheimer’s, but with some doubt.
“In 1901 German physician, Alois Alzheimer, followed a young, 51 year-old, woman battling a strange constellation of symptoms including paranoia, agitation, and memory disturbance. Later, Professor Alzheimer identified, from autopsy, abnormal clumps between- and irregular tangles within- her brain cells. This was the notation of amyloid plaques and tau tangles that defined what later came to be called Alzheimer’s disease. Alzheimer’s disease was finally recognized in the 1970s and 80s as the main culprit for dementia in older individuals, not just young individuals,” says Dr. Atri. “Today, we don’t need to wait for an autopsy to see evidence of Alzheimer’s disease-related changes in the brain. We can use biomarkers, when needed, to get very high accuracy. What we don’t have yet is a minimally invasive and low-cost- biomarker; however, we are getting there. You need to crawl before you walk and that’s where we’re at now. But once you’re walking, it’s not long before you’re running.”
While research continues to focus on demonstrating the value and cost-effectiveness of amyloid PET scans for the clinical diagnosis and treatment of the disease, and to find less invasive and less expensive biomarkers; there are major efforts afoot to improve the timely and accurate diagnosis of Alzheimer’s and other dementias by medical providers. In July 2018, the Alzheimer’s Association announced a new set of best clinical practice guidelines for primary and specialty care providers that includes a patient- and care partner-centered and multi-tiered approach to the evaluation and disclosure process, including the selection of tailored assessments and tests, including a variety of biomarkers...
Dr. Atri, who co-chaired the Alzheimer’s Association workgroup, says these guidelines can lead us to evaluating and diagnosing patients sooner rather than later.
“Ultimately, that may mean we can find, treat and, one day even prevent, the disease before its debilitating symptoms take hold or before there is irreversible damage,” he says. “That’s where we’re headed – looking to find the right intervention, at the right time, with the right dose, in the right patient.”
In the meantime, Dr. Atri urges people to engage in Alzheimer’s research in any way they can.
“Every day brings us closer to the day when we figuratively ‘vacuum’ the brain of amyloid and tau before they set in to create damage,” he says. “We’re getting closer, but to get there we’re going to need volunteers to participate in research, and lots of them.”
Learn more about research studies in your area by visiting www.endalznow.org/find-a-study.