Alzheimer’s disease is a brain disorder that destroys people’s memories and thinking skills. It’s believed to affect more than 50 million people worldwide, a number that continues to increase every year. Until now, the only solutions to diagnose this disease were expensive, ineffective, or both. Medical professionals dreamt for a day where Alzheimer’s could be diagnosed rapidly and effectively, but that day always seemed far away, until now.
Researchers at the Alzheimer’s Association International Conference (AAIC), which was held virtually this year, presented a new way of diagnosing Alzheimer’s that is both inexpensive and accurate: a blood test. In a study on JAMA Network, scientists measured a protein that could be used to diagnose the disease 20 years before any of its effects take place. This could save millions of lives and allow patients to take preventative measures that successfully inhibit the disease. Let’s see how it works.
What is Alzheimer’s Disease?
Before we can talk about how the blood test works, we must first understand Alzheimer’s disease and what it does to people. Alzheimer’s is a progressive neurological disorder that gradually destroys people’s memories, thinking skills, and even their ability to perform basic tasks. This disease is caused by an abnormal build-up of amyloid plaques, which are deformed proteins, and tau tangles, which are aggregates of tau proteins, in the brain. These proteins destroy many neurons, the cells that transmit electrical signals between our body and our brain to tell us what to do, which results in the loss of many neural connections.
By destroying connections in the brain, we will lose our ability to perform certain tasks and respond to certain stimuli. This damage usually occurs in the regions of the brain that are involved in memory and social behavior, but after a long time, it can spread to other areas of the brain and lead to death.
What’s Wrong With Current Diagnostic Methods?
Alzheimer’s affects millions of people, but many of these people are not wealthy and cannot access the best diagnostic methods. Currently, the primary methods of diagnosing Alzheimer’s are spinal taps, where doctors collect fluid from your spine for testing, and PET scans, where doctors use radioactive substances to check if your brain is functioning properly.
Unfortunately, these methods have three problems: they’re expensive, they are inaccessible for most, and they only detect amyloid plaque build-up, not tau tangles. Mario Carrillo, chief science officer at the Alzheimer’s Association, stated,
“Just saying you have amyloid in the brain through a PET scan today does not tell you they have tau, and that’s why it is not a diagnostic for Alzheimer’s.”
Because of the cost and inaccessibility of these diagnostic methods, most doctors must simply test a patient’s memory or thinking skills and interview their family and friends to get a feel for their behavior recently. This method is not accurate and cannot differentiate between Alzheimer’s and other brain disorders. Scientists estimate that by 2050, around 100 million people will have Alzheimer’s, so if we want to make sure most, if not all of these people live, we need a better diagnostic method. That is where these new blood tests come in.
How Does This Blood Test Work?
Tau tangles that are found in the brains of people with Alzheimer’s consist of deformed versions of regular tau proteins called p-tau217 (short for phospho-tau217). According to Dr. Oskar Hansson, a professor of clinical memory research at Lund University in Sweden and a major contributor to the research of the blood test, Alzheimer’s patients have seven times more of this protein than people with other or no neurological disorders. Because this protein makes it easy to distinguish Alzheimer’s from other disorders, the blood test works to detect this protein and amyloid plaques to specifically diagnose Alzheimer’s.
Before a medical innovation can be used in hospitals, it must be tested, and luckily, this blood test met experimental success. In the Arizona Brain Donation Cohort, it diagnosed brains with many amyloid plaques but not many tau proteins with an 89% accuracy, and diagnosed brains with high amounts of both amyloid plaques and tau tangles with a whopping 98% accuracy! The potential for this blood test is sky-high, and the number of deaths prevented could potentially be in the millions.
What Does This Mean For The Future?
The future is bright for this blood test, as diagnosing a disease like Alzheimer’s with such high accuracy is no easy feat. If this diagnostic method is perfected and deemed safe by medical professionals, it could be distributed to hospitals, where people could quickly be diagnosed up to 20 years before any effects take place! Expensive PET scans and spinal taps, which are not usually covered by health insurance, and inaccurate skill tests will no longer be needed. More people will be able to take measures to suppress the effects of Alzheimer’s and in the end, more deaths will be prevented.
Although this blood test will be able to specifically pinpoint Alzheimer’s disease, many people may contemplate to even do the test. I mean, not everyone would want to take a blood test to figure out if they have a disease that has no apparent cure.
Other than this caveat, the blood test brings mostly benefits, and I am sure many people, especially medical professionals and patients with lower incomes, will love having this test available.
The Alzheimer’s blood test presented by researchers at AAIC and in a study on JAMA shows great potential, but it’ll be at least five years until it’s ready for distribution. According to Clive Ballard, a professor of age-related disease at the University of Exeter Medical School,
“Although this research looks extremely promising, further validation in people from more routine clinical settings are still needed, and a lot of work will be needed to achieve standardisation of the test across laboratories.”
Want to learn more about these Alzheimer’s blood tests? Check out these websites: