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.
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.)
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.
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.
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.
“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 proteomeseroreactivity 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.
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.
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.”
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
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.
“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.
With further study, this research may provide clinical laboratories with a new proteomic biomarker for dementia screenings that identifies risk more than 10 years before symptoms appear
Researchers at the University of Warwick in the UK and Fudan University in Shanghai, China, identified four protein biomarkers in blood that they say can predict dementia up to 15 years before diagnosis. They say these biomarkers may lead to clinical laboratory blood tests that offer alternatives to costly brain scans and lumbar punctures for diagnosis of dementia.
The scientists “used the largest cohort of blood proteomics and dementia to date,” according to a University of Warwick news release. This included taking blood from 52,645 “healthy” people without dementia who participated in the UK Biobank—a population-based study cohort, the new release noted.
“The proteomic biomarkers are [easy] to access and non-invasive, and they can substantially facilitate the application of large-scale population screening,” said neurovegetative disease specialist Jin-tai Yu, MD, PhD, a professor at Fudan University and co-author of the study, in the news release.
“The advent of proteomics offers an unprecedented opportunity to predict dementia onset,” the researchers wrote.
“This is a well-conducted study that adds to what we know about changes in blood that occur very early in diseases that cause dementia, which will be important for early diagnosis in the future,” said Tara Spires-Jones, PhD, in a post from the Science Media Center in the UK. “However,” she added, “it is important to note that these are still scientific research studies and that there are currently no blood tests available for routine use that can diagnose dementia with certainty.
“Based on this study, it does seem likely that blood tests will be developed that can predict risk for developing dementia over the next 10 years, although individuals at higher risk often have difficulty knowing how to respond,” Suzanne Schindler, MD, PhD (above), told Reuters. Schindler, an Associate Professor of Neurology at Washington University in St. Louis, was not involved in the research. Clinical laboratories may soon have a new blood test for dementia. (Photo copyright: VJDementia.)
Predicting Onset of Dementia with 90% Accuracy
The researchers analyzed 52,645 blood samples from the UK Biobank (UKBB). The samples were collected between 2006 and 2010 from healthy individuals who at that time were without dementia.
By March 2023, 1,417 of the study participants had developed Alzheimer’s disease or some other form of dementia. The researchers looked at 1,463 proteins and identified four that were present in high levels among those people:
“Individuals with higher GFAP levels were 2.32 times more likely to develop dementia,” the researchers wrote in Nature Aging. “Notably, GFAP and LTBP2 were highly specific for dementia prediction. GFAP and NEFL began to change at least 10 years before dementia diagnosis.”
When adding known risk factors such as age, sex, and genetics, the researchers said they could predict onset of dementia with 90% accuracy, according to the University of Warwick news release.
“Our findings strongly highlight GFAP as an optimal biomarker for dementia prediction, even more than 10 years before the diagnosis, with implications for screening people at high risk for dementia and for early intervention,” the researchers wrote.
The news release also noted that smaller studies had already identified some of the proteins as potential biomarkers, “but this new research was much larger and conducted over several years.”
Further Validation Needed
Amanda Heslegrave, PhD, of the UK Dementia Research Institute, University College London described the UKBB as “an excellent resource” in the Science Media Center (SMC) post. However, she noted, it’s “a highly curated biobank and may not capture all populations that we need to know the risk for. The new biomarkers identified will need further validation before being used as screening tools.”
Another expert raised additional questions about the University of Warwick/Fudan University study in the SMC post.
“These results may help researchers understand the biological systems involved in the development of dementia,” said David Curtis, MD, PhD, of the UCL Genetics Institute at University College London. “However in my view the strengths of the reported associations are not really strong enough to say that these would form a useful test for predicting who will get dementia in the future.”
Conversely, Curtis pointed to other studies suggesting that phosphorylated tau (p-tau) proteins are better candidates for developing a simple blood test.
P-tau “provides a very good indicator of whether the pathological processes leading to Alzheimer’s disease are present in the brain,” he said. “When effective treatments for Alzheimer’s disease are developed it will be very helpful indeed to have simple blood tests—such as measuring phosphorylated tau—available in order to identify who could benefit.”
At least two blood tests based on the p-tau217 variant—from ALZpath and C2N—are currently available to US clinicians as laboratory developed tests (LDT).
The UK Biobank continues to be used by researchers both in the UK and abroad because of the full sets of data on large numbers of patients over many years. There are few other sources of such data elsewhere in the world. The UK Biobank is a large-scale biomedical database and research resource. It contains de-identified genetic, lifestyle and health information, and biological samples from 500,000 UK participants.
On its website, the UK Biobank states, “It is the most comprehensive and widely-used dataset of its kind and is globally accessible to approved researchers who are undertaking health-related research that is in the public interest, whether they are from academic, commercial, government or charitable settings.”
Thus, clinical laboratory managers and pathologists can expect a continuing stream of published studies that identify biomarkers associated with different health conditions and to see where the data used in these analyses came from the UK’s biobank.
New non-invasive test could replace traditional painful spinal taps and clinical laboratory fluid analysis for diagnosis of Parkinson’s disease
Scientists at AXIM Biotechnologies of San Diego have added another specimen that can be collected non-invasively for rapid, point-of-care clinical laboratory testing. This time it is tears, and the diagnostic test is for Parkinson’s disease (PD).
The new assay measures abnormal alpha-synuclein (a-synuclein), a protein that is a biomarker for Parkinson’s, according to an AXIM news release which also said the test is the first rapid test for PD.
“The revolutionary nature of AXIM’s new test is that it is non-invasive, inexpensive, and it can be performed at a point of care. It does not require a lumbar puncture, freezing, or sending samples to a lab. AXIM’s assay uses a tiny tear drop versus a spinal tap to collect the fluid sample and the test can be run at a doctor’s office with quantitative results delivered from a reader in less than 10 minutes,” the news release notes.
“Furthermore, emerging evidence shows that a-synuclein assays have the potential to differentiate people with PD from healthy controls, enabling the potential for early identification of at-risk groups,” the news release continues. “These findings suggest a crucial role for a-synuclein in therapeutic development, both in identifying pathologically defined subgroups of people with Parkinson’s disease and establishing biomarker-defined at-risk cohorts.”
This is just the latest example of a disease biomarker that can be collected noninvasively. Other such biomarkers Dark Daily has covered include:
“With this new assay, AXIM has immediately become a stakeholder in the Parkinson’s disease community, and through this breakthrough, we are making possible new paradigms for better clinical care, including earlier screening and diagnosis, targeted treatments, and faster, cheaper drug development,” said John Huemoeller, CEO, AXIM (above), in a news release. Patients benefit from non-invasive clinical laboratory testing. (Photo copyright: AXIM Biotechnologies.)
Fast POC Test versus Schirmer Strip
AXIM said it moved forward with its novel a-synuclein test propelled by earlier tear-related research that found “a-synuclein in its aggregated form can be detected in tears,” Inside Precision Medicine reported.
But that research used what AXIM called the “outdated” Schirmer Strip method to collect tears. The technique involves freezing tear samples at -80 degrees Celsius (-112 Fahrenheit), then sending them to a clinical laboratory for centrifugation for 30 minutes; quantifying tear protein content with a bicinchoninic acid assay, and detecting a-synuclein using a plate reader, AXIM explained.
Alternatively, AXIM says its new test may be performed in doctors’ offices and offers “quantitative results delivered from a reader in less than 10 minutes.”
“Our proven expertise in developing tear-based diagnostic tests has led to the development of this test in record speed, and I’m extremely proud of our scientific team for their ability to expand our science to focus on such an important focus area as Parkinson’s,” said John Huemoeller, CEO, AXIM in the news release.
“This is just the beginning for AXIM in this arena,” he added. “But I am convinced when pharmaceutical companies, foundations, and neurologists see how our solution can better help diagnose Parkinson’s disease in such an expedited and affordable way, we will be at the forefront of PD research, enabling both researchers and clinicians a brand-new tool in the fight against PD.”
One of those tests was “a lateral flow diagnostic for point-of-care use that measures the level of lactoferrin proteins in tear fluid, which work to protect the surface of the eye. … Axim said that low lactoferrin levels have also been linked to Parkinson’s disease and that the assay can be used alongside its alpha-synuclein test,” Fierce Biotech noted.
“It made sense to try and look at the proteinaceous [consisting of or containing protein] constituents of tear fluid,” Lew told Neurology Live. “Tear fluid is easy to collect. It’s noninvasive, inexpensive. It’s not like when you do a lumbar puncture, which is a much more involved ordeal. There’s risk of contamination with blood (saliva is dirty) issues with blood and collection. [Tear fluid analysis] is much safer and less expensive to do.”
In Biomarkers in Medicine, Lew et al noted why tears make good biomarkers for Parkinson’s disease, including “the interconnections between the ocular [eye] surface system and neurons affected in Parkinson’s disease.”
The researchers also highlighted “recent data on the identification of tear biomarkers including oligomeric α-synuclein, associated with neuronal degeneration in PD, in tears of PD patients” and discussed “possible sources for its release into tears.”
Future Clinical Laboratory Testing for Parkinson’s
Parkinson’s disease is the second most common neurodegenerative disorder after Alzheimer’s. It affects nearly one million people in the US. About 1.2 million people may have it by 2030, according to the Parkinson’s Foundation.
Thus, an accurate, inexpensive, non-invasive diagnostic test that can be performed at the point of care, and which returns clinical laboratory test results in less than 10 minutes, will be a boon to physicians who treat PD patients worldwide.
Clinical laboratory managers and pathologists may want to follow AXIM’s future research to see when the diagnostic test may become available for clinical use.
