amyloid plaques Archives

FDA Grants First-Ever Clearance of Clinical Laboratory Blood Test for Alzheimer’s Detection

Jun 23, 2025 | Laboratory Instruments & Laboratory Equipment, Laboratory News, Laboratory Pathology, Laboratory Resources, Laboratory Testing, Precision Medicine

Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio test measures blood biomarkers associated with the disease

Clinical laboratories could soon find themselves playing a significant role in Alzheimer’s care as the US Food and Drug Administration (FDA) announced its first-ever clearance of a blood test to assist in diagnosing the cognitive disease.

The agency issued a 510(k) clearance for the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio test from Fujirebio Diagnostics, Inc. The test is intended for “the early detection of amyloid plaques associated with Alzheimer’s disease in adult patients, aged 55 years and older, exhibiting signs and symptoms of the disease,” according to an FDA press release.

“Nearly seven million Americans are living with Alzheimer’s disease, and this number is projected to rise to nearly 13 million,” said FDA Center for Devices and Radiological Health Director Michelle Tarver, MD, PhD, in the press release. “Today’s clearance is an important step for Alzheimer’s disease diagnosis, making it easier and potentially more accessible for US patients earlier in the disease.”

“Alzheimer’s disease impacts too many people, more than breast cancer and prostate cancer combined,” said FDA Commissioner Martin A. Makary, MD, MPH, in the FDA press release.

“Knowing that 10% of people aged 65 and older have Alzheimer’s, and that by 2050 that number is expected to double, I am hopeful that new medical products such as this one will help patients,” said FDA Commissioner Martin A. Makary, MD, MPH, in the FDA press release. (Photo copyright: Johns Hopkins University.)

Blood Protein Test Details

Fujirebio’s test calculates the ratio of two blood proteins, pTau217 and β-amyloid 1-42. “This ratio is correlated to the presence or absence of amyloid plaques in the patient’s brain, reducing the need for a PET scan,” the press release states.

The FDA said it has already authorized or cleared similar tests that use cerebrospinal fluid (CSF) samples obtained through an invasive spinal tap. “This new Lumipulse test only requires a simple blood draw, making it less invasive and much easier for patients to access,” the FDA said.

In granting the clearance, the agency looked at data from a clinical study of 499 adults displaying signs of cognitive impairment. Close to 92% of participants with positive test results had amyloid plaques as determined by amyloid PET scan or CSF test results. Approximately 97% with negative results from the Lumipulse test were also shown to be negative in the PET scan or CSF test. Fewer than 20% of the patients received indeterminate results, which would require additional testing.

The primary risks of the test are false positive or false negative results, the federal agency noted.

“Importantly, the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio is not intended as a screening or stand-alone diagnostic test and other clinical evaluations or additional tests should be used for determining treatment options,” the FDA said.

‘Wild West’ Marketplace

In their reporting of this story,MedPage Today and the Associated Press both noted that some laboratory-developed tests can already measure plasma biomarkers associated with Alzheimer’s.

“But those tests aren’t reviewed by the FDA and generally aren’t covered by insurance,” the AP reported. “Doctors have also had little data to judge which tests are reliable and accurate, leading to an unregulated marketplace that some have called a ‘wild west.’”

Neurologist Richard S. Isaacson, MD, told CNN that he’s already using the test for research purposes. “It can provide better clarity into whether a person experiencing memory loss may have Alzheimer’s disease,” he said.

However, he cautioned that more research is needed to allow doctors to make best use of the test.

“I think the next step as a field is, we need to advance education about what these tests mean and what they don’t and who they should be used for,” he told CNN. “Because they mean different things in different people depending on their risk factors and whether they have symptoms. So, we’re still early.”

“The results must be interpreted in conjunction with other patient clinical information,” the FDA acknowledged in their press release.

Other Alzheimer’s Tests

The FDA said it reviewed the Lumipulse test through the 510(k) premarket notification pathway, in which the federal agency determines if a device is “substantially equivalent to a legally marketed predicate device.”

In this case, the agency found that the test is substantially equivalent to Fujirebio’s Lumipulse G β-amyloid Ratio (1-42/1-40), which measures the same proteins in CSF samples. The FDA authorized that device in 2022, according to a Fujirebio press release. That test uses Fujirebio’s automated Lumipulse G1200 instrument system.

Other companies including Roche, Eli Lilly, and C2N Diagnostics are also developing Alzheimer’s tests they intend to submit for FDA review, the AP reported.

—Stephen Beale

New Research Challenges Long-Held Theory about Causes of Alzheimer’s Disease, Creating the Possibility of Useful New Biomarkers for Clinical Laboratory Tests

Dec 7, 2022 | Digital Pathology, International Laboratory News, Laboratory Pathology, Laboratory Resources, Laboratory Testing, Precision Medicine

University of Cincinnati researchers hypothesize that low levels of amyloid-beta protein, not amyloid plaques, are to blame

New research from the University of Cincinnati (UC) and Karolinska Institute in Sweden challenges the prevailing theory about the causes of Alzheimer’s disease, suggesting the possibility of new avenues for the development of effective clinical laboratory assays, as well as effective therapies for treating patients diagnosed with Alzheimer’s.

Scientists have long theorized that the disease is caused by a buildup of amyloid plaques in the brain. These plaques are hardened forms of the amyloid-beta protein, according to a UC news story.

However, in their findings published in the Journal of Alzheimer’s Disease, titled “High Soluble Amyloid-β42 Predicts Normal Cognition in Amyloid-Positive Individuals with Alzheimer’s Disease-Causing Mutations,” the researchers advanced an alternative hypothesis—that Alzheimer’s is instead caused by “depletion” of a soluble form of that same amyloid-beta protein.

“The paradox is that so many of us accrue plaques in our brains as we age, and yet so few of us with plaques go on to develop dementia,” said Alberto Espay, MD, one of the lead researchers of the study, in another UC news story. Espay is Professor of Neurology at the UC College of Medicine and Director and Endowed Chair of the Gardner Center for Parkinson’s Disease and Movement Disorders.

“Yet the plaques remain the center of our attention as it relates to biomarker development and therapeutic strategies,” he added.

“It’s only too logical, if you are detached from the biases that we’ve created for too long, that a neurodegenerative process is caused by something we lose, amyloid-beta, rather than something we gain, amyloid plaques,” said Alberto Espay, MD (above), in a University of Cincinnati news story. “Degeneration is a process of loss, and what we lose turns out to be much more important.” The UC study could lead to new clinical laboratory diagnostics, as well as treatments for Alzheimer’s and Parkinson’s diseases. (Photo copyright: University of Cincinnati.)

High Levels of Aβ42 Associated with Lower Dementia Risk

In their retrospective longitudinal study, the UC researchers looked at clinical assessments of individuals participating in the Dominantly Inherited Alzheimer Network (DIAN) cohort study. DIAN is an ongoing effort, sponsored by the Washington University School of Medicine in St. Louis, to identify biomarkers associated with Alzheimer’s among people who carry Alzheimer’s mutations.

The researchers found that study participants with high levels of a soluble amyloid-beta protein, Aβ42, were less likely to develop dementia than those with lower levels of the protein, regardless of the levels of amyloid plaques in their brains or the amount of tau protein—either as phosphorylated tau (p-tau) or total tau (t-tau)—in their cerebral spinal fluid. P-tau and t-tau are proteins that form “tau tangles” in the brain that are also associated with Alzheimer’s.

One limitation of the study was that the researchers were unable to include Aβ40, another amyloid-beta protein, in their analysis. But they noted that this “did not limit the testing of our hypothesis since Aβ40 exhibits lower fibrillogenicity and lesser depletion than Aβ42, and is therefore less relevant to the process of protein aggregation than Aβ42.” Fibrillogenicity, in this context, refers to the process by which the amyloid-beta protein hardens into plaque.

While the presence of plaques may be correlated with Alzheimer’s, “Espay and his colleagues hypothesized that plaques are simply a consequence of the levels of soluble amyloid-beta in the brain decreasing,” UC news stated. “These levels decrease because the normal protein, under situations of biological, metabolic, or infectious stress, transform into the abnormal amyloid plaques.”

The UC News story also noted that many attempts to develop therapeutics for Alzheimer’s have focused on reducing amyloid plaques, but “in some clinical trials that reduced the levels of soluble amyloid-beta, patients showed worsening in clinical outcomes.”

New Therapeutics for Multiple Neurodegenerative Diseases

Eisai, a Japanese pharmaceutical company, recently announced phase three clinical trial results of lecanemab, an experimental drug jointly developed by Eisai and Biogen, claiming that the experimental Alzheimer’s drug modestly reduced cognitive decline in early-stage patients, according to NBC News.

Espay noted that lecanemab “does something that most other anti-amyloid treatments don’t do in addition to reducing amyloid: it increases the levels of the soluble amyloid-beta.” That may slow the process of soluble proteins hardening into plaques.

Beyond their findings about Alzheimer’s, the researchers believe similar mechanisms could be at work in other neurodegenerative diseases such as Parkinson’s disease, where the soluble alpha-synuclein protein also hardens into deposits.

“We’re advocating that what may be more meaningful across all degenerative diseases is the loss of normal proteins rather than the measurable fraction of abnormal proteins,” Espay said. “The net effect is a loss not a gain of proteins as the brain continues to shrink as these diseases progress.”

Espay foresees two approaches to treating these diseases: Rescue medicine, perhaps based on increasing levels of important proteins, and precision medicine, which “entails going deeper to understand what is causing levels of soluble amyloid-beta to decrease in the first place, whether it is a virus, a toxin, a nanoparticle, or a biological or genetic process,” according to UC News. “If the root cause is addressed, the levels of the protein wouldn’t need to be boosted because there would be no transformation from soluble, normal proteins to amyloid plaques.”

Clinical Laboratory Impact

What does this mean for clinical laboratories engaged in treatment of both Alzheimer’s and Parkinson’s patients? A new understanding of the disease would create “the opportunity to identify new biomarkers and create new clinical laboratory tests that may help diagnose Alzheimer’s earlier in the disease progression, along with tests that help with the patient’s prognosis and monitoring his or her progression,” said Robert Michel, Editor-in-Chief of Dark Daily and its sister publication The Dark Report.

Given the incidence of Alzheimer’s disease in the population, any clinical laboratory test cleared by the FDA would be a frequently-ordered assay, Michel noted. It also would create the opportunity for pathologists and clinical laboratories to provide valuable interpretation about the test results to the ordering physicians.

—Stephen Beale

Related Information:

High Soluble Amyloid-β42 Predicts Normal Cognition in Amyloid-Positive Individuals with Alzheimer’s Disease-Causing Mutations

UC Study: Decreased Proteins, Not Amyloid Plaques, Tied to Alzheimer’s Disease

US News: Scientists Propose New Mechanism Driving Alzheimer’s

Scientists Propose New Mechanism Driving Alzheimer’s Disease

Alzheimer’s: Lack of Beta-Amyloid, Not Plaque Buildup, May Be the Culprit

Better Cognitive Predictor in People at High Risk of Alzheimer’s Disease

UC Study: Researchers Question Prevailing Alzheimer’s Theory with New Discovery

ABPP Amyloid Plaques’ Role in Onset of Alzheimer’s Questioned by Cincinnati University: GlobalData Reveals That ABPP Targeted by a Tenth of All Alzheimer’s Drugs

Blots on a Field? A Neuroscience Image Sleuth Finds Signs of Fabrication in Scores of Alzheimer’s Articles, Threatening a Reigning Theory of the Disease

WVXU: Does a Key Alzheimer’s Study Contain Fabricated Images?