by Katelynn Fleming
Nearly everyone has known someone or heard of someone who has Alzheimer’s Disease. According to Science News, a new blood test may be able to detect Alzheimer’s Disease early by testing proteins in the blood, but it is unknown whether it will help us to better understand the disease.
A neurodegenerative disorder characterized by dementia, patients of Alzheimer’s experience memory loss to the point that they have difficulty with attention, planning, abstract thinking and remembering words, according to Khan Academy. Later in the course of the disease, they experience emotional instability and lose control of their bodily functions. Most heart wrenching is that they often lose the ability to recognize close friends and family members.
Despite the widespread nature of the disease, scientists know very little about why it happens. According to Khan Academy, researchers have observed that the disease is the result of severe damage to the neurons in the brain. Multiple strokes or other factors can cause the neurons to die off over time and the cerebral cortex as a whole to shrink. The loss of neurons and synapses is what causes the symptoms, but much is still unknown about why the damage happens on such a large scale in the first place. However, scientists have been able to link the disease progression to a buildup of amyloid plaques in the brain. Amyloid plaques are groups of proteins which are folded so that they stick together easily, building up between neurons in the brain. Although researchers cannot yet tell what role these proteins play in the progression of the disease, they can be used to track the disease.
Currently, the only ways to detect the amyloid plaques are PET scans or spinal taps, both of which are invasive and expensive, so a blood test would be a sizeable improvement, as long as it could be made affordable. In the past, blood tests have not been useful in detecting Alzheimer’s because the amounts of the detectable protein, amyloid-beta, or A-beta in the blood are too small to be discernibly different, and the total amount of the protein in the blood has not correlated strongly enough to the build up of the protein in the brain to predict the progression of the disease. However, in the new test, researchers put the blood sample through a mass spectrometer, which is able to measure the amount of A-beta with much higher precision than other blood tests. Then, instead of comparing the total amount of A-beta, as in previous attempted tests, they found the ratios between different types of A-beta in the bloodstream. In their study of 252 Australians and 171 Japanese people with varying neural conditions, using the ratios researchers were able to tell with 90% accuracy whether the subject had amyloid plaque buildup in the brain or not. These results mirror a smaller trial completed last year with a different group of subjects, and the consistency is encouraging.
While the results are promising, it remains to be shown whether this test can be made financially beneficial to patients with Alzheimer’s. Although there is currently no treatment to cure or slow the progression of Alzheimer’s Disease, this blood test may be able to identify potential subjects for clinical trials of early-intervention treatments, getting us just a little bit closer to the research we need to finally understand and cure this devastating disease.