News, Analysis, Trends, Management Innovations for
Clinical Laboratories and Pathology Groups

Hosted by Robert Michel

News, Analysis, Trends, Management Innovations for
Clinical Laboratories and Pathology Groups

Hosted by Robert Michel
Sign In

100-Biomarker Lab Test for Alzheimer’s Disease Developed by Team at University of Pittsburgh

New clinical laboratory test could replace conventional spinal tap for diagnosing neurodegenerative disease

In a proof-of-concept study, University of Pittsburgh (Pitt) scientists validated a clinical laboratory test that measures more than 100 different genetic sequences associated with Alzheimer’s disease. The Pitt researchers believe the new diagnostic platform could help clinicians “capture the multifaceted nature of Alzheimer’s pathology and streamline early disease diagnostics,” according to a news release.

Clinical laboratory blood tests that detect biomarkers such as phosphorylated tau protein (pTau) have emerged in studies as diagnostic possibilities for Alzheimer’s disease, which is traditionally diagnosed using a lumbar puncture (spinal tap) procedure.

The Pitt scientists published the findings of their study titled, “Multi-Analyte Proteomic Analysis Identifies Blood-based Neuroinflammation, Cerebrovascular, and Synaptic Biomarkers in Preclinical Alzheimer’s Disease,” in the journal Molecular Neurodegeneration.

In their paper, neuroscientist Thomas Karikari, PhD, Assistant Professor of Psychiatry at  University of Pittsburgh, lead author of the study, and his research team acknowledged that progress has been made in detecting Alzheimer’s disease with blood-based biomarkers. However, they note that “two key obstacles remain: the lack of methods for multi-analyte assessments and the need for biomarkers for related pathophysiological processes like neuroinflammation, vascular, and synaptic dysfunction.”

The Pitt scientists believe the focus on so-called “classical Alzheimer’s blood biomarkers” limits exploration of neurodegenerative disease.

“Alzheimer’s disease should not be looked at through one single lens. Capturing aspects of Alzheimer’s pathology in a panel of clinically validated biomarkers would increase the likelihood of stopping the disease before any cognitive symptoms emerge,” said neuroscientist Thomas Karikari, PhD (above), Assistant Professor of Psychiatry, University of Pittsburgh, and lead author of the study in a news release. Should further studies prove Pitt’s research sound, clinical laboratories may have a replacement test for diagnosing neurodegenerative disease. (Photo copyright: University of Pittsburgh.)

120 Proteins Analyzed Simultaneously

To conduct their research, the Pitt scientists performed a proof-of-concept study on 176 blood samples from 113 adults in Pennsylvania (average age of 76.7). They analyzed the blood using the NULISAseq CNS (central nervous system) Disease Panel 120 by Alamar Biosciences of Freemont, California.

On its website, Alamar Biosciences explains that the disease panel offers neurological researchers:

  • “Multiplexed analysis of 120 neuro-specific and inflammatory proteins from 10 µl of plasma or CSF (cerebrospinal fluid).
  • Detection of “critical biomarkers—including pTau-217, GFAP (glial fibrillary acidic protein), NEFL (neurofilament light polypeptide) and alpha-synuclein.”

The NULISAseq test works with “a proprietary sequential immunocomplex capture and release mechanism and the latest advances in next-generation sequencing,” according to the company.

Inside Precision Medicine noted that the Alamar Biosciences assay enabled Pitt scientists to detect:

  • Biomarkers (usually found in CSF) “correlating with patients’ amyloid positivity status and changes in amyloid burden over time,” and,
  • Biomarkers including “neuroinflammation, synaptic function, and vascular health, which had not previously been validated in blood samples.”

“The performance of the NULISA platform was independently validated against conventional assays for classic Alzheimer’s biomarkers for each sample. Biomarker profiles over two years were also compared with imaging-based measures of amyloid, tau, and neurodegeneration,” LabMedica reported.

Opportunity to Track Alzheimer’s

Karikari sees the diagnostic platform being used to track individuals’ blood biomarker changes over time. 

In their Molecular Neurodegeneration paper, the Pitt researchers wrote, “These (results) were not limited to markers such as pTau217, p-Tau231, p-Tau181, and GFAP, the elevation of which have consistently shown strong associations with brain Aβ [amyloid beta] and/or tau load, but included novel protein targets that inform about the disease state of the individual in different pathological stages across the biological Alzheimer’s disease continuum.”

About seven million Americans are affected by Alzheimer’s disease, according to the Alzheimer’s Association, which estimated that figure will grow to 13 billion by 2050.

Further studies by Karikari may include larger samples and greater diversity among the people studied, Inside Precision Medicine noted.

“[Karikari’s] lab is developing a predictive model that correlates biomarker changes detected using NULISAseq with brain autopsy data and cognitive assessments collected over the course of several years. Their goal is to identify blood biomarkers that can help stage the disease and predict its progression, both for decision-making around clinical management and treatment plans,” the Pitt news release states.

His research was supported by the National Institute on Aging.

The Pitt scientists have developed a multiplex test that works with 100 different genetic sequences associated with Alzheimer’s. Such advances in the understanding of the human genome are giving scientists the opportunity to combine newly identified gene sequences that have a role in specific disease states.

In turn, as further studies validate the value of these biomarkers for diagnosing disease and guiding treatment decisions, clinical laboratories will have new assays that deliver more value to referring physicians and their patients.

—Donna Marie Pocius

Related Information:

Pitt Scientists Validated a New Panel for Blood Biomarkers of Alzheimer’s

Multi-Analyte Proteomic Analysis Identifies Blood-based Neuroinflammation, Cerebrovascular, and Synaptic Biomarkers in Preclinical Alzheimer’s Disease

Innovative Blood Test Validated for Comprehensive Early Alzheimer’s Diagnosis

New Blood Test Platform Simultaneously Measures Over 100 Biomarkers of Alzheimer’s Disease

Cerebrospinal Fluid and Plasma Tau as a Biomarker for Brain Tauopathy

UC San Francisco Scientists Discover Antibodies That Appear in Multiple Sclerosis Patients Years before Symptoms Occur

Findings may lead to new clinical laboratory biomarkers for predicting risk of developing MS and other autoimmune diseases

Scientists continue to find new clinical laboratory biomarkers to detect—and even predict risk of developing—specific chronic diseases. Now, in a recent study conducted at the University of California San Francisco (UCSF), researchers identified antibodies that develop in about 10% of Multiple Sclerosis (MS) patients’ years before the onset of symptoms. The researchers reported that of those who have these antibodies, 100% develop MS. Thus, this discovery could lead to new blood tests for screening MS patients and new ways to treat it and other autoimmune diseases as well.

The UCSF researchers determined that, “in about 10% [of] cases of multiple sclerosis, the body begins producing a distinctive set of antibodies against its own proteins years before symptoms emerge,” Yahoo Life reported, adding that “when [the patients] are tested at the time of their first disease flare, the antibodies show up in both their blood and cerebrospinal fluid.”

That MS is so challenging to diagnose in the first place makes this discovery even more profound. And knowing that 100% of a subset of MS patients who have these antibodies will develop MS makes the UCSF study findings quite important.

“This could be a useful tool to help triage and diagnose patients with otherwise nonspecific neurological symptoms and prioritize them for closer surveillance and possible treatment,” Colin Zamecnik, PhD, scientist and research fellow at UCSF, told Yahoo Life.

The researchers published their findings in the journal Nature Medicine titled, “An Autoantibody Signature Predictive for Multiple Sclerosis.”

“From the largest cohort of blood samples on Earth, we obtained blood samples from MS patients years before their symptoms began and profiled antibodies against self-autoantibodies that are associated with multiple sclerosis diagnosis,” Colin Zamecnik, PhD (above), scientist and research fellow at UCSF, told Yahoo Life. “We found the first molecular marker of MS that appears up to five years before diagnosis in their blood.” These findings could lead to new clinical laboratory tests that determine risk for developing MS and other autoimmune diseases. (Photo copyright: LinkedIn.)

UCSF Study Details

According to the MS International Foundation Atlas of MS, there are currently about 2.9 million people living with MS worldwide, with about one million of them in the US. The disease is typically diagnosed in individuals 20 to 50 years old, mostly targeting those of Northern European descent, Yahoo Life reported.

To complete their study, the UCSF scientists used the Department of Defense Serum Repository (DoDSR), which is comprised of more than 10 million individuals, the researchers noted in their Nature Medicine paper.

From that group, the scientists identified 250 individuals who developed MS, spanning a period of five years prior to showing symptoms through one year after their symptoms first appeared, Medical News Today reported. These people were compared to 250 other individuals in the DoDSR who have no MS diagnosis but who all had similar serum collection dates, ages, race and ethnicities, and sex.

“The researchers validated the serum results against serum and cerebrospinal fluid results from an incident MS cohort at the University of California, San Francisco (ORIGINS) that enrolled patients at clinical onset. They used data from 103 patients from the UCSF ORIGINS study,” according to Medical News Today. “They carried out molecular profiling of autoantibodies and neuronal damage in samples from the 500 participants, measuring serum neurofilament light chain measurement (sNfL) to detect damage to nerve cells.

“The researchers tested the antibody patterns of both MS and control participants using whole-human proteome seroreactivity which can detect autoimmune reactions in the serum and CSF,” Medical News Today noted.

Many who developed MS had an immunogenicity cluster (IC) of antibodies that “remained stable over time” and was not found in the control samples. The higher levels of sNfL in those with MS were discovered years prior to the first flare up, “indicating that damage to nerve cells begins a long time before symptom onset,” Medical News Today added.

“This signature is a starting point for further immunological characterization of this MS patient subset and may be clinically useful as an antigen-specific biomarker for high-risk patients with clinically or radiologically isolated neuroinflammatory syndromes,” the UCSF scientists wrote in Nature Medicine.

“We believe it’s possible that these patients are exhibiting cross reactive response to a prior infection, which agrees with much current work in the literature around multiple sclerosis disease progression,” Zamecnik told Yahoo Life.

It “validates and adds to prior evidence of neuro-axonal injury occurring in patients during the MS preclinical phase,” the researchers told Medical News Today.

Implications of UCSF’s Study

UCSF’s discovery is a prime example of technology that could soon work its way into clinical use once additional studies and research are done to support the findings.

The researchers believe their research could lead to a simple blood test for detecting MS years in advance and discussed how this could “give birth to new treatments and disease management opportunities,” Neuroscience News reported.

Current MS diagnosis requires a battery of tests, such as lumbar punctures for testing cerebrospinal fluid, magnetic resonance imaging (MRI) scans of the spinal cord and brain, and “tests to measure speed and accuracy of nervous system responses,” Medical News Today noted.

“Given its specificity for MS both before and after diagnosis, an autoantibody serology test against the MS1c peptides could be implemented in a surveillance setting for patients with high probability of developing MS, or crucially at a first clinically isolated neurologic episode,” the UCSF researchers told Medical News Today.

“It would also be interesting to see whether these antibodies could be a marker of disease severity and explain some of the MS course heterogeneity,” epidemiologist Marianna Cortese, MD, PhD, senior research scientist at Harvard T.H. Chan School of Public Health, told Medical News Today.

The UCSF discovery is another example of nascent technology that could work its way into clinical use after more research and studies. Microbiologists, clinical laboratories, and physicians tasked with diagnosing MS and other autoimmune diseases should find the novel biomarkers the researchers identified most interesting, as well as what changed with science and technology that enabled researchers to identify these biomarkers for development.

—Kristin Althea O’Connor

Related Information:

An Autoantibody Signature Predictive for Multiple Sclerosis

Signs of Multiple Sclerosis Can Be Detected in Blood 5 Years before Symptoms Appear, New Study Finds. Here’s Why This Breakthrough Is Important.

Signs of MS May Be Visible in Blood Years Before First Flare-Up of Symptoms

Blood Test Predicts Multiple Sclerosis Years Before Symptoms Appear

In Vitro Diagnostics Companies Race to Develop Blood-based Tests for Alzheimer’s Disease, Data Suggest a Worldwide Growing Market

As new diagnostic assays are cleared by regulators, clinical laboratories will play a key role in identifying appropriate patients for new less-invasive Alzheimer’s tests

With multiple companies racing to develop a blood-based test for Alzheimer’s disease (AD), clinical laboratories may soon have new less-invasive diagnostic assays for AD on their menus.

Why a race? Because a less-invasive clinical laboratory test that uses a venous blood draw (as opposed to a spinal tap)—and which has increased sensitivity/specificity—has a potentially large market given the substantial numbers of elderly predicted to develop Alzheimer’s over the next decade. It has the potential to be a high volume, high dollar diagnostic test.

In fact, Mordor Intelligence estimates that the market for Alzheimer’s disease therapeutics will grow from $7.7 billion in 2024 to $10.10 billion by 2029.

Alzheimers.gov, an official website of the US government, says, “Researchers have made significant progress in developing, testing, and validating biomarkers that detect signs of the disease process. For example, in addition to PET scans that detect abnormal beta-amyloid plaques and tau tangles [abnormal forms of tau protein] in the brain, NIH-supported scientists have developed the first commercial blood test for Alzheimer’s. This test and others in development can not only help support diagnosis but also be used to screen volunteers for research studies.”

Several test developers presented their research at a recent Alzheimer’s Association   International Conference. They shared data about blood-based assay accuracy in diagnosis of Alzheimer’s as compared to current practices that involve a lumbar puncture (spinal tap) to collect cerebrospinal fluid (CSF).

Additionally, the US Food and Drug Administration (FDA) is clearing new Alzheimer’s drugs for clinical use. The pharma companies behind these drugs need clinical laboratory tests that accurately diagnosis the disease and confirm that it would be appropriate for the patient to receive the new therapeutic drugs, a key element of precision medicine.

“The big promise for blood tests is that they will eventually be accessible, hopefully, cost-effective, and noninvasive,” Rebecca Edelmayer, PhD (above), Vice President, Scientific Engagement, Alzheimer’s Association, told USA Today. “The field is really moving forward with use of these types of tests,” she added. Clinical laboratories may soon have these new assays on their test menus. (Photo copyright: Alzheimer’s Association.)

Companies in the Race to Develop Blood-based Alzheimer’s Tests

One advancing test is the PrecivityAD2 from in vitro test developer C2N Diagnostics, St. Louis, Mo., which Dark Daily reported on in “C2N Diagnostics Releases PrecivityAD, the First Clinical Laboratory Blood Test for Alzheimer’s Disease.”

Researchers found that C2N’s blood test can detect brain amyloid status with “sensitivity, specificity, positive and negative predictive values that approximate those of amyloid positron emission tomography (PET) imaging,” according to a news release.

“The PrecivityAD2 blood test is intended for use in patients aged 55 and older with signs or symptoms of mild cognitive impairment or dementia who are undergoing evaluation of Alzheimer’s disease or dementia. Only a healthcare provider can order the PrecivityAD2 test,” the news release noted.

A study published in Alzheimer’s and Dementia, a journal of the Alzheimer’s Association, used “mass spectrometry-based assays to measure %p-tau217 and amyloid beta 42/40 ratio in blood samples from 583 individuals with suspected AD.”

“The PrecivityAD2 blood test showed strong clinical validity with excellent agreement with brain amyloidosis by PET,” the researchers wrote.

The PrecivityAD2 test, which is mailed directly by C2N to doctors and researchers, is performed at the company’s CLIA-certified lab, according to USA Today, which added that the cost of $1,450 is generally not covered by insurance plans.

Expanding Test Access with IVD Companies

ALZpath, Inc. has a different approach to the Alzheimer’s disease test market. The Carlsbad, Calif.-based company, set up an agreement with in vitro diagnostics (IVD) company Roche Diagnostics for use of its phosphorylated tau (pTau)217 antibody “to develop and commercialize an Alzheimer’s disease diagnostic blood test that will be offered on the Roche Elecsys platform,” according to a news release.

Roche received FDA breakthrough device designation on the Elecsys pTau217 test earlier this year and will work with pharmaceutical company Eli Lilly to commercialize the test.

Estimates show 75% of dementia cases go undetected—a number which could grow to 140 million by 2050, according to data shared by Roche with Fierce Biotech.

“We plan to leverage our installed base of diagnostic systems, which is the largest in the world, to ensure we are able to create access to this test for those who need it the most,” Matt Sause, CEO, Roche Diagnostics, told Fierce Biotech.

Another IVD company, Beckman Coulter, recently signed an agreement to use ALZpath’s pTau217 antibody test in its DxI 9000 Immunoassay Analyzer. In a news release, Kathleen Orland, SVP and General Manager of the Clinical Chemistry Immunoassay Business Unit at Beckman Coulter, said that the test had “high performance in detecting amyloid pathology” and could “integrate into our advanced DxI 9000 platform to support broad-based testing.”

Clinical Laboratory Participation

The FDA is drafting new guidance titled, “Early Alzheimer’s Disease: Developing Drugs for Treatment” that is “intended to assist sponsors in the clinical development of drugs for the treatment of the stages of sporadic Alzheimer’s disease (AD) that occur before the onset of overt dementia.” 

Pharma companies intent on launching new drugs for Alzheimer’s will need medical laboratory tests that accurately diagnosis the disease to confirm the medications would be appropriate for specific patients.

Given development of the aforementioned pTau217 antibody tests, and others featuring different diagnostic technologies, it’s likely clinical laboratories will soon be performing new assays for diagnosing Alzheimer’s disease.

—Donna Marie Pocius

Related Information:

Alzheimer’s Diagnosis and Drugs Market

How New Blood Testing Technology Could Change Alzheimer’s Treatment Forever

New Research Shows the PrecivityAD2 Blood Test Has High Accuracy Compared to Amyloid PET Scans in Individuals with Cognitive Impairment

Clinical Validation of the PrecivityAD2 Blood Test: A Mass Spectrometry-Based Test with Algorithm Combing %p-tau217 and Aβ42/40 Ratio to Identify Presence of Brain Amyloid

ALZpath Announces Licensing Agreement with Roche for Use of ALZpath’s Proprietary

Alzheimer’s Blood Test from Roche, Eli Lilly Nabs FDA Breakthrough Tag

ALZpath Signs Licensing Agreement with Beckman Coulter Diagnostics to Provide Proprietary pTau217 Antibody to Develop a Diagnostic Test for Alzheimer’s Disease

Diagnostic Accuracy of a Plasma Phosphorylated Tau 217 Immunoassay for Alzheimer Disease Pathology

Groundbreaking Alzheimer’s Blood Test Proves Highly Effective in Primary Healthcare

Blood Biomarkers to Detect Alzheimer Disease in Primary Care and Secondary Care

C2N Diagnostics Releases PrecivityAD, the First Clinical Laboratory Blood Test for Alzheimer’s Disease

Artificial Intelligence in the Operating Room: Dutch Scientists Develop AI Application That Informs Surgical Decision Making during Cancer Surgery

Speedy DNA sequencing and on-the-spot digital imaging may change the future of anatomic pathology procedures during surgery

Researchers at the Center for Molecular Medicine (CMM) at UMC Utrecht, a leading international university medical center in the Netherlands, have paired artificial intelligence (AI) and machine learning with DNA sequencing to develop a diagnostic tool cancer surgeons can use during surgeries to determine in minutes—while the patient is still on the operating table—whether they have fully removed all the cancerous tissue.

The method, “involves a computer scanning segments of a tumor’s DNA and alighting on certain chemical modifications that can yield a detailed diagnosis of the type and even subtype of the brain tumor,” according to The New York Times, which added, “That diagnosis, generated during the early stages of an hours-long surgery, can help surgeons decide how aggressively to operate, … In the future, the method may also help steer doctors toward treatments tailored for a specific subtype of tumor.”

This technology has the potential to reduce the need for frozen sections, should additional development and studies confirm that it accurately and reliably shows surgeons that all cancerous cells were fully removed. Many anatomic pathologists would welcome such a development because of the time pressure and stress associated with this procedure. Pathologists know that the patient is still in surgery and the surgeons are waiting for the results of the frozen section. Most pathologists would consider fewer frozen sections—with better patient outcomes—to be an improvement in patient care.

The UMC Utrecht scientist published their findings in the journal Nature titled, “Ultra-Fast Deep-Learned CNS Tumor Classification during Surgery.”

 “It’s imperative that the tumor subtype is known at the time of surgery,” Jeroen de Ridder, PhD (above), associate professor in the Center for Molecular Medicine at UMC Utrecht and one of the study leaders, told The New York Times. “What we have now uniquely enabled is to allow this very fine-grained, robust, detailed diagnosis to be performed already during the surgery. It can figure out itself what it’s looking at and make a robust classification,” he added. How this discovery affects the role of anatomic pathologists and pathology laboratories during cancer surgeries remains to be seen. (Photo copyright: UMC Utrecht.)

Rapid DNA Sequencing Impacts Brain Tumor Surgeries

The UMC Utrecht scientists employed Oxford Nanopore’s “real-time DNA sequencing technology to address the challenges posed by central nervous system (CNS) tumors, one of the most lethal type of tumor, especially among children,” according to an Oxford Nanopore news release.

The researchers called their new machine learning AI application the “Sturgeon.”

According to The New York Times, “The new method uses a faster genetic sequencing technique and applies it only to a small slice of the cellular genome, allowing it to return results before a surgeon has started operating on the edges of a tumor.”

Jeroen de Ridder, PhD, an associate professor in the Center for Molecular Medicine at UMC Utrecht, told The New York Times that Sturgeon is “powerful enough to deliver a diagnosis with sparse genetic data, akin to someone recognizing an image based on only 1% of its pixels, and from an unknown portion of the image.” Ridder is also a principal investigator at the Oncode Institute, an independent research center in the Netherlands.

The researchers tested Sturgeon during 25 live brain surgeries and compared the results to an anatomic pathologist’s standard method of microscope tissue examination. “The new approach delivered 18 correct diagnoses and failed to reach the needed confidence threshold in the other seven cases. It turned around its diagnoses in less than 90 minutes, the study reported—short enough for it to inform decisions during an operation,” The New York Times reported.

But there were issues. Where the minute samples contain healthy brain tissue, identifying an adequate number of tumor markers could become problematic. Under those conditions, surgeons can ask an anatomic pathologist to “flag the [tissue samples] with the most tumor for sequencing, said PhD candidate Marc Pagès-Gallego, a bioinformatician at UMC Utrecht and a co-author of the study,” The New York Times noted. 

“Implementation itself is less straightforward than often suggested,” Sebastian Brandner, MD, a professor of neuropathology at University College London, told The Times. “Sequencing and classifying tumor cells often still required significant expertise in bioinformatics as well as workers who are able to run, troubleshoot, and repair the technology,” he added. 

“Brain tumors are also the most well-suited to being classified by the chemical modifications that the new method analyzes; not all cancers can be diagnosed that way,” The Times pointed out.

Thus, the research continues. The new method is being applied to other surgical samples as well. The study authors said other facilities are utilizing the method on their own surgical tissue samples, “suggesting that it can work in other people’s hands.” But more work is needed, The Times reported.

UMC Utrecht Researchers Receive Hanarth Grant

To expand their research into the Sturgeon’s capabilities, the UMC Utrecht research team recently received funds from the Hanarth Fonds, which was founded in 2018 to “promote and enhance the use of artificial intelligence and machine learning to improve the diagnosis, treatment, and outcome of patients with cancer,” according to the organization’s website.

The researchers will investigate ways the Sturgeon AI algorithm can be used to identify tumors of the central nervous system during surgery, a UMC Utrecht news release states. These type of tumors, according to the researchers, are difficult to examine without surgery.

“This poses a challenge for neurosurgeons. They have to operate on a tumor without knowing what type of tumor it is. As a result, there is a chance that the patient will need another operation,” said de Ridder in the news release.

The Sturgeon application solves this problem. It identifies the “exact type of tumor during surgery. This allows the appropriate surgical strategy to be applied immediately,” the news release notes.

The Hanarth funds will enable Jeroen and his team to develop a variant of the Sturgeon that uses “cerebrospinal fluid instead of (part of) the tumor. This will allow the type of tumor to be determined already before surgery. The main challenge is that cerebrospinal fluid contains a mixture of tumor and normal DNA. AI models will be trained to take this into account.”

The UMC Utrecht scientists’ breakthrough is another example of how organizations and research groups are working to shorten time to answer, compared to standard anatomic pathology methods. They are combining developing technologies in ways that achieve these goals.

—Kristin Althea O’Connor

Related Information:

Ultra-fast Deep-Learned CNS Tumor Classification during Surgery

New AI Tool Diagnoses Brain Tumors on the Operating Table

Pediatric Brain Tumor Types Revealed Mid-Surgery with Nanopore Sequencing and AI

AI Speeds Up Identification Brain Tumor Type

Four New Cancer Research Projects at UMC Utrecht Receive Hanarth Grants

Rapid Nanopore Sequencing, Machine Learning Enable Tumor Classification during Surgery

University of Gothenburg Study Findings Affirm Accuracy of Clinical Laboratory Blood Test to Diagnose Alzheimer’s Disease

Already-existing clinical laboratory blood test may be new standard for detecting Alzheimer’s biomarkers

In Sweden, an independent study of an existing blood test for Alzheimer’s disease—called ALZpath—determined that this diagnostic assay appears to be “just as good as, if not surpass, lumbar punctures and expensive brain scans at detecting signs of Alzheimer’s in the brain,” according to a report published by The Guardian.

Alzheimer’s disease is one of the worst forms of dementia and it affects more than six million people annually according to the Alzheimer’s Association. Clinical laboratory testing to diagnose the illness traditionally involves painful, invasive spinal taps and brain scans. For that reason, researchers from the University of Gothenburg in Sweden wanted to evaluate the performance of the ALZpath test when compared to these other diagnostic procedures.

Motivated to seek a less costly, less painful, Alzheimer’s biomarker for clinical laboratory testing, neuroscientist Nicholas Ashton, PhD, Assistant Professor of Neurochemistry at the University of Gothenburg, led a team of scientists that looked at other common biomarkers used to identify changes in the brain of Alzheimer’s patients. That led them to tau protein-based blood tests and specifically to the ALZpath blood test for Alzheimer’s disease developed by ALZpath, Inc., of Carlsbad, Calif.

The researchers published their findings in the journal JAMA Neurology titled, “Diagnostic Accuracy of a Plasma Phosphorylated Tau 217 Immunoassay for Alzheimer Disease Pathology.”

In their JAMA article, they wrote, “the pTau217 immunoassay showed similar accuracies to cerebrospinal fluid biomarkers in identifying abnormal amyloid β (Aβ) and tau pathologies.”

In an earlier article published in medRxiv, Ashton et al wrote, “Phosphorylated tau (pTau) is a specific blood biomarker for Alzheimer’s disease (AD) pathology, with pTau217 considered to have the most utility. However, availability of pTau217 tests for research and clinical use has been limited.”

Thus, the discovery of an existing pTau217 assay (ALZpath) that is accessible and affordable is a boon to Alzheimer’s patients and to the doctors who treat them.

“The ALZpath pTau217 assay showed high diagnostic accuracy in identifying elevated amyloid (AUC, 0.92-0.96; 95%CI 0.89-0.99) and tau (AUC, 0.93-0.97; 95%CI 0.84-0.99) in the brain across all cohorts. These accuracies were significantly higher than other plasma biomarker combinations and equivalent to CSF [cerebrospinal fluid] biomarkers,” an ALZpath press release noted.

“This is an instrumental finding in blood-based biomarkers for Alzheimer’s, paving the way for the clinical use of the ALZpath pTau217 assay,” stated Henrik Zetterberg, MD, PhD (above), Professor of Neurochemistry at the University of Gothenburg and co-author of the study. “This robust assay is already used in multiple labs around the globe.” Clinical laboratories may soon be receiving doctors’ orders for pTau217 blood tests for Alzheimer’s patients. (Photo copyright: University of Gothenburg.)

Study Details

Ashton’s team conducted a cohort study that “examined data from three single-center observational cohorts.” The cohorts included:

“Participants included individuals with and without cognitive impairment grouped by amyloid and tau (AT) status using PET or CSF biomarkers. Data were analyzed from February to June 2023,” the researchers wrote. 

These trials from the US, Canada, and Spain featured 786 participants and featured “either a lumbar puncture or an amyloid PET scan to identify signs of amyloid and tau proteins—hallmarks of Alzheimer’s disease,” The Guardian reported, adding that results of the University of Gothenburg’s study showed that the ALZpath pTau217 blood test “was superior to brain atrophy assessments, in identifying signs of Alzheimer’s.”

“80% of individuals could be definitively diagnosed on a blood test without any other investigation,” Ashton told The Guardian.

Diagnosis Needed to Receive Alzheimer’s Disease Treatments

“If you’re going to receive [the new drugs], you need to prove that you have amyloid in the brain,” Ashton told The Guardian. “It’s just impossible to do spinal taps and brain scans on everyone that would need it worldwide. So, this is where the blood test [has] a huge potential.”

Even countries where such drugs were not yet available (like the UK) would benefit, Ashton said, because the test, “Could potentially say that this is not Alzheimer’s disease and it could be another type of dementia, which would help to direct the patient’s management and treatment routine.”

However, Ashton himself noted the limitations of the new findings—specifically that there is no success shown yet in Alzheimer’s drugs being taken by symptom-free individuals.

“If you do have amyloid in the brain at 50 years of age, the blood test will be positive,” he said. “But what we recommend, and what the guidelines recommend with these blood tests, is that these are to help clinicians—so someone must have had some objective concern that they have Alzheimer’s disease, or [that] their memory is declining,” he told The Guardian.

Experts on the Study Findings

“Blood tests could be used to screen everyone over 50-years old every few years, in much the same way as they are now screened for high cholesterol,” David Curtis, MD, PhD, Honorary Professor in the Genetics, Evolution and Environment department at University College London, told The Guardian.

“Results from these tests could be clear enough to not require further follow-up investigations for some people living with Alzheimer’s disease, which could speed up the diagnosis pathway significantly in future,” Richard Oakley, PhD, Associate Director of Research and Innovation at the Alzheimer’s Society, UK, told The Guardian.

Though Oakley found the findings promising, he pointed out what should come next. “We still need to see more research across different communities to understand how effective these blood tests are across everyone who lives with Alzheimer’s disease,” he said.

“Expanding access to this highly accurate Alzheimer’s disease biomarker is crucial for wider evaluation and implementation of AD blood tests,” the researchers wrote in JAMA Neurology.

“ALZpath makers are in discussions with labs in the UK to launch it for clinical use this year, and one of the co-authors, Henrik Zetterberg, MD, PhD, Professor of Neurochemistry at the University of Gothenburg, is making the assay available for research use as part of the ‘biomarker factory’ at UCL,” The Guardian reported.

In the US, to be prescribed any of the available Alzheimer’s medications, a doctor must diagnose that the patient has amyloid in the brain. A pTau217 diagnostic blood test could be used to make such a diagnosis. Currently, however, the test is only available “for research studies through select partner labs,” Time reported.

“But later this month, doctors in the US will be able to order the test for use with patients. (Some laboratory-developed tests performed by certain certified labs don’t require clearance from the US Food and Drug Administration.),” Time added.

It may be that the University of Gothenburg study will encourage Alzheimer’s doctors in the UK and around the world to consider ordering pTau217 diagnostic blood tests from clinical laboratories, rather than prescribing spinal taps and brains scans for their Alzheimer’s patients.

—Kristin Althea O’Connor

Related Information:

New Study Published in JAMA Neurology Affirms High Diagnostic Accuracy of ALZpath’s pTau217 Test in Identifying Amyloid and Tau in the Brain

Blood Test Could Revolutionize Diagnosis of Alzheimer’s, Experts Say

Simple Blood Tests for Dementia to Be Trialed in NHS

A Blood Test for Alzheimer’s Disease Is Almost Here

Diagnostic Accuracy of a Plasma Phosphorylated Tau 217 Immunoassay for Alzheimer Disease Pathology

Alzheimer’s Disease Facts and Figures

Scientists Develop Blood Test for Alzheimer’s Disease

;