Two new tests for Alzheimer’s: Would they help you or a loved one?
Medical advances regarding Alzheimer’s disease have been slow in coming, but two new blood tests are on the horizon that may help diagnose the disease at an earlier stage.
The first test, which is available now for people age 60 or older who are showing signs of cognitive disfunction, must be ordered by a doctor. The test measures two types of amyloid particles plus various types of a protein that reveals whether someone has the gene that raises their risk of Alzheimer’s.
The second blood test is even more promising, according to studies unveiled at the 2020 Alzheimer’s Association International Conference. The studies focused on a blood test that measures for abnormal versions of the p-tau217 protein. This protein is one of the most specific forms of tau and it is one of the earliest ones to show changes. It also closely correlates to a buildup of amyloid proteins. Amyloid and tau proteins are responsible for the “plaques and tangles” that are a hallmark of Alzheimer’s disease.
While the new tests hold promise for earlier and better diagnosis of the disease, treatment is still a challenge, said Neurologist Sean Horrigan, DO, of Neurologists of Cape Cod.
“It’s exciting that we have another way in which to screen for Alzheimer’s disease, but the ultimate question is what do you do with the information once you have it?” he said. “Even if the test is positive there is no therapy available at this time to treat Alzheimer’s.”
(Editor’s Note: On June 7, 2021 the federal Food and Drug Administration approved the drug aducanumab as a treatment for patients with Alzheimer’s. The drug was profiled in a Feb. 11, 2020 Cape Cod Health News story.)
Dr. Horrigan does not automatically recommend testing for patients over the age of 65 who have obvious symptoms of some type of cognitive impairment. Instead, he recommends going to a neurologist for a clinical workup.
“Statistically speaking neurologists are pretty good at diagnosing dementia on a clinical basis alone,” he said. “We usually get the diagnosis right 85 percent of the time without any extra testing. So, we’re pretty good detectives in that regard, just based on examining a patient and hearing the story alone.”
It is tempting for a person in their 40s or 50s who has a parent with Alzheimer’s disease to want to be tested to see if the markers are present, and it is a really personal decision whether you want that information, Dr. Horrigan said. He has seen patients get expensive tests and then regret the decision because a positive result changes their outlook on their life.
Help for a Cure
There is one very important application for these blood tests, according to Dr. Horrigan: research. The new tests could be crucial in helping scientists develop new treatments.
“As a neurologist, what I’m excited about with a blood test marker for Alzheimer’s is really the implications for clinical research and drug trials because the real hardship is that we only have four drugs for Alzheimer’s and they’re not excellent for treating symptoms or for changing the progression of the illness, and we haven’t had a new drug on the market for over 20 years,” he said.
It hasn’t been for lack of trying. There have been numerous drug trials for new medications, but they have all failed so far. Dr. Horrigan believes one of the reasons they are failing is that the medications are being utilized too late in the illness. If someone has been living with Alzheimer’s for years, the damage to their brain just might be too great to correct.
“Maybe these drugs are in fact effective, it’s just that we’re using them way too late in the stage of the illness to make an impact,” he said. “But if you have someone that would enroll for a clinical trial, maybe with a family history of Alzheimer’s, and they do a blood test and, sure enough, the markers are elevated and they’re at a higher risk for Alzheimer’s disease, maybe they would also be a prime candidate for an experimental drug that tries to halt the disease from ever developing.”
Another advantage of knowing that Alzheimer’s might be in your future is that it might inspire you to take better care of your health. But Dr. Horrigan reminds patients that we have to assume that we are all at high risk for dementia, so we should be taking good care of ourselves regardless of heredity or getting a positive test result.
That includes the following lifestyle choices, he said:
- Keep mentally sharp.
- Stay socially engaged.
- Avoid alcohol.
- Don’t smoke.
- Drink lots of water.
- Exercise regularly.
- Keep medical conditions like hypertension, cholesterol and diabetes under firm control.
- Regularly follow up with your doctor.
“We do know for a fact that men and women who maintain excellent physical and cognitive health, even if they develop Alzheimer’s, the disease may not develop until a later point in their lives or they may have milder symptoms for a longer period of time,” Dr. Horrigan said.