New scientific insights from these studies represent progress in the effort to develop a clinical laboratory test that would enable physicians to diagnose Alzheimer’s Disease earlier and with greater accuracy
Most medical laboratory professionals are aware that, for more than 30 years, in vitro diagnostic (IVD) developers and pharmaceutical researchers have sought the Holy Grail of clinical laboratory testing—an accurate test for Alzheimer’s disease that is minimally-invasive and produces information that is actionable by clinicians at a reasonable cost. Such a test could spark a revolution in the diagnosis and treatment of this debilitating disease and would improve the lives of tens of thousands of people each year.
Now, two different research studies being conducted in Germany and Japan may have developed such tests that use blood samples. The tests detect specific biomarkers found in Alzheimer’s patients and one day could enable physicians to diagnose the disease in its preclinical stages.
German Test Identifies Amyloid-Beta Biomarker
The test under development at Ruhr University in Bochum, Germany, detects the presence of amyloid-beta, a component of amyloid plaque (AKA, amyloid-β plaques), which has consistently been found in Alzheimer’s patents, according to United Press International (UPI).
A healthy brain has amyloid-beta plaques, too. However, in a person with Alzheimer’s disease, the amyloid-beta is misfolded, formed like a sheet, and toxic to nerve cells, the researchers explained in a press release.
The test works with small amounts of blood plasma and employs an immuno-infrared-sensor, also developed at Ruhr University. The sensor measures the amounts of both pathological (the misfolded kind) and healthy amyloid-beta in the blood.
Amyloid plaques can start to form decades prior to the onset of Alzheimer’s symptoms, making them identifiable biomarkers that can be used as a “preselection funnel in two‐step diagnostics,” the researchers noted.
“The use of the immuno‐infrared‐sensor as an initial screening funnel to identify people who should undergo further diagnostics and eventually take part in clinical trials on therapeutics targeting Aβ misfolding might already be an important step forward because subjects with early AD stages are hard to identify,” the researchers note. “To our knowledge, there is today no other plasma test available, which has been tested both in an AD research cohort and in the general population.”
Another Blood Test Finds Amyloid-Beta
Interestingly, just a few months ahead of the German researchers’ paper, scientists at the Center for Development of Advanced Medicine for Dementia (CAMD) in Obu City, Japan, published their own paper on a similar blood test they developed that also identifies high levels of amyloid-beta in patients with Alzheimer’s.
The study, which was published in Nature, involved 373 people: 121 Japanese in the discovery cohort set and 252 Australians in the validation data set. The test found amyloid-beta levels in the brain with 90% accuracy, The Scientist reported.
“These results demonstrate the potential clinical utility of plasma biomarkers in predicting brain amyloid-β burden at an individual level. These plasma biomarkers also have cost-benefit and scalability advantages over current techniques, potentially enabling broader clinical access and efficient population screening,” the researchers wrote in their paper.
Previous Alzheimer’s Research
These studies are not the first to seek biomarkers that could detect the early-onset of Alzheimer’s disease. In 2016, Dark Daily reported on two other studies: one conducted at Rowan University School of Osteopathic Medicine (RowanSOM) and another by IVD company Randox Laboratories. (See Dark Daily, “Two Different Research Teams Announce Tests for Alzheimer’s Disease That Could Be Useful for Clinical Laboratories after Clearance by the FDA,” November 30, 2016.)
Nevertheless, as of 2018, Alzheimer’s disease has impacted the lives of approximately 5.7 million Americans of all ages, according to the Alzheimer’s Association. And yet, doctors currently only have expensive positron emission tomography (PET) brain scans and invasive cerebrospinal fluid (CSF) analysis to identify the disease, generally in the latter stages of its development.
Thus, a less invasive, inexpensive test that accurately identifies biomarkers found in the majority of people during the early stages of the disease would be a boon to physicians who treat chronic neurodegenerative disease, medical laboratories that perform the tests, and, of course, the thousands of people each year who are diagnosed and suffer with this debilitating condition.
—Donna Marie Pocius