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.
The NIH’s Researching COVID to Enhance Recovery (RECOVER) Initiative used a cohort study of more than 10,000 individuals with and without previous COVID-19 diagnoses and compared samples using 25 common laboratory tests in hopes a useful biomarker could be identified. They were unsuccessful.
Long COVID—or PASC—is an umbrella term for those with persistent post-COVID infection symptoms that negatively impact quality of life. Though it affects millions worldwide and has been called a major public health burden, the NIH/Langone study scientists noted one glaring problem: PASC is defined differently in the major tests they studied. This makes consistent diagnoses difficult.
The study brought to light possible roadblocks that prevented biomarker identification.
“This study is an important step toward defining long COVID beyond any one individual symptom,” said study author Leora Horwitz, MD (above), director of the Center for Healthcare Innovation and Delivery Science and co-principal investigator for the RECOVER CSC at NYU Langone, in a Langone Health news release. “This definition—which may evolve over time—will serve as a critical foundation for scientific discovery and treatment design.” In the future, clinical laboratories may be tasked with finding combinations of routine and reference tests that, together, enable a more precise and earlier diagnosis of long COVID. (Photo copyright: Yale School of Medicine.)
NIH/Langone Study Details
“The study … examined 25 routinely used and standardized laboratory tests chosen based on availability across institutions, prior literature, and clinical experience. These tests were conducted prospectively in laboratories that are certified by the Clinical Laboratory Improvement Amendments (CLIA). The samples were collected from 10,094 RECOVER-Adult participants, representing a diverse cohort from all over the US,” Inside Precision Medicine reported.
However, the scientists found no clinical laboratory “value” among the 25 tests examined that “reliably indicate previous infection, PASC, or the particular cluster type of PASC,” Inside Precision Medicine noted, adding that “Although some minor differences in the results of specific laboratory tests attempted to differentiate between individuals with and without a history of infection, these findings were generally clinically meaningless.”
“In a cohort study of more than 10,000 participants with and without prior SARS-CoV-2 infection, we found no evidence that any of 25 routine clinical laboratory values provide a reliable biomarker of prior infection, PASC, or the specific type of PASC cluster. … Overall, no evidence was found that any of the 25 routine clinical laboratory values assessed in this study could serve as a clinically useful biomarker of PASC,” the study authors wrote in Annals of Internal Medicine.
In addition to a vague definition of PASC, the NIH/Langone researchers noted a few other potential problems identifying a biomarker from the research.
“Use of only selected biomarkers, choice of comparison groups, if any (people who have recovered from PASC or healthy control participants); duration of symptoms; types of symptoms or phenotypes; and patient population features, such as sex, age, race, vaccination status, comorbidities, and severity of initial infection,” could be a cause for ambiguous results, the scientists wrote.
Future Research
“Understanding the basic biological underpinnings of persistent symptoms after SARS-CoV-2 infection will likely require a rigorous focus on investigations beyond routine clinical laboratory studies (for example, transcriptomics, proteomics, metabolomics) to identify novel biomarkers,” the study authors wrote in Annals of Internal Medicine.
“Our challenge is to discover biomarkers that can help us quickly and accurately diagnose long COVID to ensure people struggling with this disease receive the most appropriate care as soon as possible,” said David Goff, MD, PhD, director of the division of cardiovascular sciences at the NIH’s National Heart, Lung, and Blood Institute, in an NHLBI news release. “Long COVID symptoms can prevent someone from returning to work or school, and may even make everyday tasks a burden, so the ability for rapid diagnosis is key.”
“Approximately one in 20 US adults reported persisting symptoms after COVID-19 in June 2024, with 1.4% reporting significant limitations,” the NIH/Langone scientists wrote in their published study.
Astute clinical laboratory scientists will recognize this as possible future diagnostic testing. There is no shortage of need.
Discovery could lead to new treatments for cancer and tumors, but probably not to any new diagnostic assays for clinical laboratories
Researchers at the University of Texas Southwestern (UTSW) Medical Center have reported discovery of “acid walls” that appear to protect various types of cancer tumors from attack by the body’s immune system cells. Though the discovery is not directly related to a biomarker for a clinical laboratory diagnostic test, the basic research will help scientists develop ways to address the tumor’s acid wall strategy for defeating the immune system.
The UT scientists made their discovery using an internally developed imaging technique that employs nanoparticle probes to detect levels of acidity in cells. The research, they suggest, “could pave the way for new cancer treatment approaches that alter the acidic environment around tumors,” according to a UTSW press release.
“This study revealed a previously unrecognized polarized extracellular acidity that is prevalent around cancer cells,” said lead study author Jinming Gao, PhD (above), Professor in the Harold C. Simmons Comprehensive Cancer Center and head of the Gao Lab at UT Southwestern Medical Center, in a press release. Gao believes the study “will lead to several new lines of research, such as studies to better understand how cancer cells polarize their acid excretion, how those cells can withstand the acidity level that kills CD8+ T cells, and how to inhibit acid excretion to allow T cells to better kill cancer cells,” the press release notes. (Photo copyright: University of Texas.)
Developing Acid Walls
As explained in the press release, scientists have long known that cancer cells are slightly more acidic than most healthy tissue. Gao and his team designed a nanoparticle known as pegsitacianine—a pH-sensitive fluorescent nanoprobe for image-guided cancer surgery—that disassembles and lights up when exposed to the acidic conditions in tumors.
However, “it was unclear why these nanoparticles fluoresced since a tumor’s acidity was thought to be too mild to trigger their activation,” the press release note.
To learn more, they used nanoparticle probes to illuminate a variety of individual cancer cells sampled from humans and mice, including lung, breast, melanoma, and glioblastoma, as well as tumor tissue. They discovered that the cancer cells secreted lactic acid—a waste product of digested glucose—at higher levels than previously known. The cells “pumped” the acid away from their malignant neighbors to form a protective “acid wall” around the tumor, the researchers noted in Nature Biomedical Engineering.
“Samples from human tumors showed that this acid wall was practically devoid of CD8+ T cells within the tumors, an immune cell type known to fight cancer,” the press release states. “When the researchers grew cancer cells and CD8+ T cells together in petri dishes that had been acidified to a 5.3 pH, the cancer cells were spared while the CD8+ T cells perished within three hours, suggesting that this severe acidity might thwart immune cell attack without harming the cancer cells.”
Gao’s team previously discovered that sodium lactate, the “conjugate base of lactic acid” as they describe it, increases the longevity of T cells and thus enhances their cancer-fighting capabilities. The researchers described the two molecules—lactate and lactic acid—as “Dr. Jekyll and Mr. Hyde,” and suggested that future therapies could seek to convert lactic acid to lactate.
“Gao noted that this discovery will lead to several new lines of research, such as studies to better understand how cancer cells polarize their acid excretion, how those cells can withstand the acidity level that kills CD8+ T cells, and how to inhibit acid excretion to allow T cells to better kill cancer cells,” the press release states.
Commercializing the Technology
Pegsitacianine was designed to aid cancer surgeons by illuminating the edges of solid metastatic tumors in real time during surgery, a 2023 UTSW Medical Center press release explains. About 24 hours prior to surgery, nanoprobes are delivered via IV. Then, the surgeon uses a near-infrared camera to visualize the cells.
UTSW has licensed pegsitacianine to OncoNano Medicine, a Dallas-area biotech startup launched to commercialize technologies from Gao Lab. Gao and his colleague Baran Sumer, MD, Professor and Chief of the Division of Head and Neck Oncology in UT Southwestern Medical Center’s Department of Otolaryngology and co-author on the study, both sit on OncoNano’s advisory board.
In January 2023, OncoNano announced that pegsitacianine had received Breakthrough Therapy Designation for Real-Time Surgical Imaging from the US Food and Drug Administration (FDA), which will fast-track the technology for development and regulatory review.
In a Phase II clinical trial published in the Annals of Surgical Oncology, the researchers tested the technology as part of cytoreductive surgery in patients with peritoneal metastases. However, a November 2023 UTSW press release noted that the technology is “tumor-agnostic and could potentially be used in other forms of cancer.” It is currently ready for Phase 3 trials, according to the OncoNano website.
More research and studies are needed to better understand this dynamic of cancer cells. Collectively, this research into cancer by different scientific teams is adding new insights into the way tumors originate and spread. At this time, these insights are not expected to lead to any new diagnostics tests that pathologists and clinical laboratories could use to detect cancer.
Proof-of-concept study may eventually lead to new clinical laboratory urine tests for fast, non-invasive detection of cancer
Here is the latest example of researchers finding useful biomarkers in urine for diagnosing certain cancers. The discovery comes from the University of Michigan Health Rogel Cancer Center, where, in a proof-of-concept study, scientists developed a urine-based test that screens for circulating free DNA (cfDNA) fragments (aka, cell-free DNA) released by tumors in the head and neck. If they confirm these findings, it’s possible the technology could be adapted into a non-invasive clinical laboratory test for selected cancers.
One such cancer is human papillomavirus (HPV) which, though “widely recognized for causing cervical cancer” is “increasingly found to cause cancers in the mouth, throat, and other head and neck regions,” according to a U-M Medical School press release.
The U-M study findings could lead to an early, non-invasive test for the detection of cancer, as compared to traditional urine or blood-based liquid biopsy testing.
“In this study, we provide evidence to support the hypothesis that conventional assays do not detect ultrashort fragments found in urine since they are designed to support longer DNA fragments. Our team used an unconventional approach to develop a urine test for HPV-positive head and neck cancer ctDNA detection,” said Chandan Bhambhani, PhD (above), Research Lab Specialist Intermediate at University of Michigan and co-first author of the study, in a news release. Clinical laboratories may soon have a new urine-based test for detecting cancer. (Photo copyright: LinkedIn.)
According to the researchers, benefits of urine testing include:
Testing with urine is convenient for people who may be unable to access healthcare and phlebotomy services.
Urine has low biohazard risk and may be easily collected in large amounts, compared with blood.
Ongoing collection of urine could make way for TR-ctDNA “kinetics to be used as a high time-resolution biomarker” to monitor patients’ response to treatment.
However, urine, the researchers cautioned, must be analyzed in a different manner if it is to be comparable in efficiency to blood-based ctDNA testing.
“There have been mixed reports on the efficiency of TR-ctDNA detection compared with that of blood ctDNA. A potentially crucial factor for the analysis of TR-ctDNA is knowing the length of TR-ctDNA fragments present in urine, because this affects assay design for optimal sensitivity in TR-ctDNA detection,” the researchers explained.
New Assay Detects Ultrashort DNA Fragments
To complete their study, the U-M researchers developed an ultrashort HPV droplet digital PCR (polymerase chain reaction) assay that enabled detection of TR-ctDNA from HPV-associated oropharyngeal squamous cell carcinoma (HPV OPSCC), BioTechniques reported.
The assay was made to target the HPV16 E6 (Human papillomavirus 16) gene and to measure TR-ctDNA in patients with HPV OPSCC, the JCI Insight paper noted.
“The HPV16 E6 gene represents a highly recurrent ctDNA target in the population of patients with HPV OPSCC,” the researchers wrote in JCI Insight, adding:
Targeting ultrashort fragments was essential “for robust TR-ctDNA detection.”
Results in urine with patients with HPV OPSCC was consistent with results from plasma ctDNA.
The test, still in the discovery phase, was mailed to patients who were being treated for the disease and who reside within 100 miles of Ann Arbor, Mich. They returned urine samples for testing at the U-M lab and to get insights into possible post-treatment needs.
“Using longitudinal urine samples from a small case series, we showed proof of concept for early detection of cancer recurrence. Thus, our results indicate that by targeting ultrashort DNA fragments, TR-ctDNA becomes a viable approach for HPV OPSCC detection and potentially for cancer recurrence monitoring after treatment,” the authors wrote.
Further Studies, Possible Test Expansion
HPV infection—and especially HPV type 16—is a growing risk factor for oropharyngeal cancers, according to the National Cancer Institute.
The U-M Rogel Cancer Center scientists plan more studies to leverage the information urine may carry about an individual’s health. The researchers intend to expand the scope of their new test to other cancers including breast cancer and acute myeloid leukemia.
“The test that has been developed has detected cancer far earlier than would typically happen based on clinical imaging. As such, these promising results have given us the confidence to broaden the scope of this study, seeking to expanding distribution even further,” said J. Chad Brenner, PhD, Associate Professor of Otolaryngology-Head and Neck Surgery, U-M Medicine, and co-senior author of the study, in the news release.
The University of Michigan Health study exemplifies scientists’ commitment to new categories of biomarkers that can be used for medical laboratory tests and prescription drugs. And by focusing on urine, the researchers made it possible for patients to collect specimens themselves and send them to the medical laboratory for analysis and reporting.
Scientists turned to metabolomics to find cause of biological aging and release index of 25 metabolites that predict healthy and rapid agers
Researchers at the University of Pittsburg Medical Center and the University of Pittsburgh School of Medicine have identified biomarkers in human blood which appear to affect biological aging (aka, senescence). Since biological aging is connected to a person’s overall condition, further research and studies confirming UPMC’s findings will likely lead to a new panel of tests clinical laboratories can run to support physicians’ assessment of their patients’ health.
UPMC’s research “points to pathways and compounds that may underlie biological age, shedding light on why people age differently and suggesting novel targets for interventions that could slow aging and promote health span, the length of time a person is healthy,” according to a UPMC news release.
“We decided to look at metabolites because they’re very dynamic,” Aditi Gurkar, PhD, the study’s senior author, told the Pittsburgh Post-Gazette. Gurkar is Assistant Professor of Medicine, Division of Geriatric Medicine, Aging Institute at the University of Pittsburg. “They can change because of the diet, they can change because of exercise, they can change because of lifestyle changes like smoking,” she added.
The scientists identified 25 metabolites that “showed clear differences” in the metabolomes of both healthy and rapid agers. Based on those findings, the researchers developed the Healthy Aging Metabolic (HAM) Index, a panel of metabolites that predicted healthy agers regardless of gender or race.
“Age is more than just a number,” said Aditi Gurkar, PhD (above), Assistant Professor of Geriatric Medicine at University of Pittsburg School of Medicine and the study’s senior author in a news release. “Imagine two people aged 65: One rides a bike to work and goes skiing on the weekends and the other can’t climb a flight of stairs. They have the same chronological age, but very different biological ages. Why do these two people age differently? This question drives my research.” Gurkar’s research may one day lead to new clinical laboratory tests physicians will order when evaluating their patients’ health. (Photo copyright: University of Pittsburg.)
Clear Differences in Metabolites
According to the National Cancer Institute, a metabolite is a “substance made or used when the body breaks down food, drugs, or chemicals, or its own tissue (for example, fat or muscle tissue). This process, called metabolism, makes energy and the materials needed for growth, reproduction, and maintaining health. It also helps get rid of toxic substances.”
The UPMC researchers used metabolomics—the study of chemical process in the body that involves metabolites, other processes, and biproducts of cell metabolism—to create a “molecular fingerprint” of blood drawn from individuals in two separate study groups.
They included:
People over age 75 able to walk a flight of stairs or walk for 15 minutes without a break, and
People, age 65 to 75, who needed to rest during stair climbing and walk challenges.
The researchers found “clear differences” in the metabolomes of healthy agers as compared to rapid agers, suggesting that “metabolites in the blood could reflect biological age,” according to the UPMC news release.
“Other studies have looked at genetics to measure biological aging, but genes are very static. The genes you’re born with are the genes you die with,” said Gurkar in the news release.
Past studies on aging have explored other markers of biological age such as low grade-inflammation, muscle mass, and physical strength. But those markers fell short in “representing complexity of biological aging,” the UPMC study authors wrote in Aging Cell.
“One potential advantage of metabolomics over other ‘omic’ approaches is that metabolites are the final downstream products, and changes are closely related to the immediate (path) physiologic state of an individual,” they added.
The researchers used an artificial intelligence (AI) model that could identify “potential drivers of biological traits” and found three metabolites “that were most likely to promote healthy aging or drive rapid aging. In future research, they plan to delve into how these metabolites, and the molecular pathways that produce them, contribute to biological aging and explore interventions that could slow this process,” the new release noted.
“While it’s great that we can predict biological aging in older adults, what would be even more exciting is a blood test that, for example, can tell someone who’s 35 that they have a biological age more like a 45-year-old,” Gurkar said. “That person could then think about changing aspects of their lifestyle early—whether that’s improving their sleep, diet or exercise regime—to hopefully reverse their biological age.”
Looking Ahead
The UPMC scientists plan more studies to explore metabolites that promote healthy aging and rapid aging, and interventions to slow disease progression.
It’s possible that the blood-based HAM Index may one day become a diagnostic tool physicians and clinical laboratories use to aid monitoring of chronic diseases. As a commonly ordered blood test, it could help people find out biological age and make necessary lifestyle changes to improve their health and longevity.
With the incidence of chronic disease a major problem in the US and other developed countries, a useful diagnostic and monitoring tool like HAM could become a commonly ordered diagnostic procedure. In turn, that would allow clinical laboratories to track the same patient over many years, with the ability to use multi-year lab test data to flag patients whose biomarkers are changing in the wrong direction—thus enabling physicians to be proactive in treating their patients.
