Diagnosing Alzheimer's disease can be a bit tricky. Traditional tests to confirm a person has Alzheimer's include an invasive spinal tap, a special PET scan which is quite expensive, and looking into a person's symptoms, then using cognitive exams to diagnose whether Alzheimer's could be the cause for their memory problems.
Now, a new Swedish study suggests that a certain form of blood testing may be more accurate than current methods. It's based on the idea that there are certain "biomarkers" which lead to the slow degeneration of a person's cognitive functioning.
In traditional tests, beta-amyloid was the primary biomarker being measured to confirm Alzheimer's. When this sticky protein builds up and forms plaques in the brain, it may block cell-to-cell signaling at synapses and even activate immune system cells that trigger inflammation and devour disabled cells.
Generally, it takes a period of about 20 years before the first signs and symptoms of Alzheimer's appear, however, that means several plaques have already accumulated and may have done considerable damage to the nerve cells in the brain.
Current medication to mitigate the progression of the disease is usually most effective when taken in the earlier stages of Alzheimer's, but it requires an early diagnosis as well, which, due to the incredible difficulty in identifying whether a person has already developed Alzheimer's, would also take time before a person is verified or cleared for the drug.
Since the diagnosis of Alzheimer's in patients is in a murky state, researchers have been trying to find new methods to detect Alzheimer's at the earliest possible moment. That's how this new Swedish study using blood tests came about.
The researchers looked at 1,200 patients who consulted a primary care doctor or a specialist for their memory problems, received an initial diagnosis, had blood tests taken, and then proceeded to get a spinal tap or PET scan for confirmation. In comparing the accuracy between the primary care doctors' initial diagnosis, the specialists' assessment, and the blood tests' results, the researchers from Lund University found that primary care doctors had a 61% accuracy rate, specialists had 73%, and the blood tests were 91% accurate.
Digging deeper into the gaps in accuracy between the three, one of the reasons why blood tests had higher accuracy in diagnosing for Alzheimer's was the fact that they measured another biomarker which was correlated with the development of Alzheimer's, called tau protein.
The benchmark measure being used in those blood tests is p-tau217, which, according to Dr. John Hsiao of the National Institute on Aging, and Maria Carrillo, the chief science officer of the Alzheimer's Association, was correlated with the amount of plaque buildup in a person's brain. If the blood test shows a high level of p-tau217, then there is a high probability that a person's memory problem is being caused by Alzheimer's. Otherwise, there may be other reasons.
At the moment, the companies offering p-tau217 tests include ALZpath Inc., Roche, Eli Lilly, and C2N Diagnostics. However, these tests can only be availed by the order of a doctor from the labs, since there are still no guidelines from the Alzheimer's Association regarding its use, neither is there FDA approval for the procedure as of yet.
Despite stressing the importance of getting an early diagnosis for Alzheimer's, these blood tests cannot yet be used for people who may be susceptible to Alzheimer's, due to their family's medical history, but have not yet shown any signs or symptoms of it. However, studies are being conducted on possible therapies for these people who are at high risk of getting Alzheimer's in the future.
For now, the only way to lower the chance of getting Alzheimer's or perhaps, preventing it completely, is to eat a healthy diet, exercise, and get enough rest and sleep. I would like to add to those pieces of advice engaging in activities that exercise the mind so as to keep it sharp and active, and staying away from stressful environments or anything that may cause stress.
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