What makes Alzheimer's disease such a terrifying prospect is the inevitability of it all. We have no vaccines or preventive measures, so you either get Alzheimer’s or you don’t. Once you have it, there’s little hope of recovery, because we have no treatment or cure.
But what if we could detect the disease years before its symptoms start to appear, to not only give patients the chance to slow the progression, but also give researchers better insight into how it develops?
A 'proof of concept' trial of a new blood test has just been completed, and the team behind has reported "unparalleled accuracy" in detecting the early stages of Alzheimer’s.
"It is now generally believed that Alzheimer's-related changes begin in the brain at least a decade before the emergence of telltale symptoms," says one of the team, Robert Nagele from the Rowan University School of Osteopathic Medicine and Durin Technologies, Inc.
"To the best of our knowledge, this is the first blood test using autoantibody biomarkers that can accurately detect Alzheimer's at an early point in the course of the disease when treatments are more likely to be beneficial - that is, before too much brain devastation has occurred."
The test is designed to detect an early stage of Alzheimer's disease called mild cognitive impairment (MCI), and distinguish it from similar cases of mental decline that are caused by other factors such as vascular issues, chronic depression, alcohol abuse, and the side effects of certain drugs.
For the trial, Nagele and his team took blood samples from 236 participants, including 50 who had been diagnosed with MCI, 50 with mild-moderate Alzheimer's disease, 50 healthy controls, and the remainder had been diagnosed with mild-moderate Parkinson's disease, early-stage Parkinson's, multiple sclerosis, or breast cancer.
The MCI patients had been diagnosed based on having low levels of amyloid-beta 42 peptide in their cerebrospinal fluid, which has been identified as a predictor of rapid Alzheimer’s progression.
To analyse the blood, the test uses a number of human protein microarrays - catalogues of 9,486 unique human proteins - to send out proteins to attract autoantibodies in the blood that could be linked to the disease.
Autoantibodies are a particular type of antibody produced by the immune system to target certain proteins in the body. This can sometimes go horribly wrong, and end up as an autoimmune disease, but the way they respond to different types of diseases has made them a very promising new candidate for detection and diagnosis.
The researchers identified the 50 best autoantibody biomarkers for MCI and the other diseases diagnosed in their participants, and when they used these to analyse the blood samples, they found them to be 100 percent accurate in overall accuracy, sensitivity and specificity rate in detecting the blood samples from participants with MCI.
Using this biomarker method, the test was also successful in detecting mild-moderate Alzheimer's (98.7 percent), early-stage Parkinson's disease (98.0 percent), multiple sclerosis (100 percent) and breast cancer (100 percent).
The team says that while these results are exciting, they need to test the method on a much larger and more diverse sample, to see if that 100 percent average wavers with additional data.
While at this stage, knowing that you have Alzheimer’s earlier rather than later won’t prevent it from developing altogether, but it could give patients the opportunity to sign up for clinical trials for new drugs and treatments, plan out future medical care, and even explore ways to help delay its progression, the team reports in the journal Alzheimer’s & Dementia.
With the disease affecting approximately 5.3 million people in the US, including almost half of the population at 85 years and older, we need tests like this. And who knows? Maybe if we get to know Alzheimer's better in its early stages, we might just be able to figure out how it begins, and how to prevent it.