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.
Painless technology could one day replace some phlebotomy blood draws as the go-to specimen-collection method for clinical laboratory testing and health monitoring
Clinical laboratories have long sought a non-invasive way to do useful medical laboratory testing without the need for either a venipuncture or a needle stick. Now engineers at the McKelvey School of Engineering at Washington University in St. Louis in Missouri have developed a disposable microneedle patch that one day could be a painless alternative to some blood draws for diagnostics tests and health monitoring.
The technology uses an easy-to-administer low-cost patch that can be applied to the skin like an adhesive bandage. The patch is virtually painless because the microneedles are too small to reach nerve receptors. Another unique aspect to this innovative approach to collecting a specimen for diagnostic testing is that the Washington University in St. Louis (WashU) research team designed the microneedle patch to include plasmonic-fluor. These are ultrabright gold nanolabels that light up target protein biomarkers and can make the biomarkers up to 1,400 times brighter at low concentrations, compared to traditional fluorescent labels.
The patch, states a WashU news release, “… can be applied to the skin, capture a biomarker of interest and, thanks to its unprecedented sensitivity, allow clinicians to detect its presence.”
The technology is low cost, easy for clinicians or patients themselves to use, and could eliminate the need for a trip to patient service center where a phlebotomist would draw blood for clinical laboratory testing, the news release states.
“We have created a platform technology that anyone can use. And they can use it to find their own biomarker of interest,” study leader Srikanth Singamaneni, PhD (above), Lilyan and E. Lisle Hughes Professor in the Department of Mechanical Engineering and Materials Sciences at Washington University in St. Louis, said in the WashU news release. Singamaneni and his colleagues are developing a new specimen collection method that might someday be widely used by clinical laboratories. (Photo copyright: Washington University in St. Louis.)
“We used the microneedle patch in mice for minimally invasive evaluation of the efficiency of a cocaine vaccine, for longitudinal monitoring of the levels of inflammatory biomarkers, and for efficient sampling of the calvarial periosteum [a skull membrane]—a challenging site for biomarker detection—and the quantification of its levels of the matricellular protein periostin, which cannot be accurately inferred from blood or other systemic biofluids,” the researchers wrote. “Microneedle patches for the minimally invasive collection and analysis of biomarkers in interstitial fluid might facilitate point-of-care diagnostics and longitudinal monitoring.”
Mark Prausnitz, PhD, Regents’ Professor, J. Erskine Love Jr. Chair in Chemical and Biomolecular Engineering, and Director of the Center for Drug Design, Development, and Delivery at Georgia Tech, told WIRED, “Blood is a tiny fraction of the fluid in our body. Other fluids should have something useful—it’s just hard to get those fluids.”
“Previously, concentrations of a biomarker had to be on the order of a few micrograms per milliliter of fluid,” said Zheyu (Ryan) Wang, a PhD candidate in Srikanth Singamaneni’s lab at McKelvey School of Engineering and a lead author of the paper, in the WashU news release. By using plasmonic-fluor, researchers were able to detect biomarkers on the order of picograms per milliliter—one millionth of the concentration.
“That’s orders of magnitude more sensitive,” Wang said.
Unlike blood, dermal interstitial fluid often does not contain high enough concentrations of biomarkers to be easily detectable. To overcome this hurdle, the Washington University in St. Louis research team developed a microneedle patch with plasmonic-fluor—ultrabright gold nanolabels (above)—which lit up target protein biomarkers, making them roughly 1,400 times brighter at low concentrations than when using traditional fluorescent labels commonly used in many medical laboratory tests. (Photo copyright: Washington University in St. Louis.)
Can Microneedles Be Used as a Diagnostic Tool?
As reported in WIRED, the polystyrene patch developed by Srikanth Singamaneni’s lab at McKelvey School of Engineering removes interstitial fluid from the skin and turns the needles into “biomarker traps” by coating them with antibodies known to bind to specific proteins, such as Interleukin 6 (IL-6). Once the microneedles are mixed with plasmonic-fluor, the patch will glow if the IL-6 biomarkers are present.
The development of such a highly sensitive biomarker-detection method means skin becomes a potential pathway for using microneedles to diagnose conditions, such as myocardial infarction or to measure COVID-19 antibodies in vaccinated persons.
“Now we can actually use this tool to understand what’s going on with interstitial fluid, and how we’re going to be able to use it to answer healthcare-related or medical problems,” Maral Mousavi, PhD, Assistant Professor of Biomedical Engineering, Viterbi School of Engineering at the University of Southern California, told WIRED. “I think it has the potential to be that kind of a game changer.”
Because the WashU study is a proof-of-concept in mice, it may be many years before this technology finds its way to clinical application. Many skin biomarkers will need to be verified for direct links to disease before microneedle patches will be of practical use to clinicians for diagnostics. However, microneedle patch technology has already proven viable for the collection of blood.
In 2017, Massachusetts-based Seventh Sense Biosystems (7SBio) received 510(k) clearance for a new microneedle blood collection device. Called TAP, the device is placed on the upper arm and blood collection starts with a press of a button. The process takes two to three minutes.
Initially, the FDA clearance permitted only healthcare workers to use the device “to collect capillary blood for hemoglobin A1c (HbA1c) testing, which is routinely used to monitor blood sugar levels in diabetic or pre-diabetic patients,” a Flagship Pioneering news release noted.
Then, in 2019, the FDA extended its authorization “to include blood collection by laypersons. Regulators are also allowing the device to be used ‘at-home’ for wellness testing,” a 7SBio news release stated. This opened the door for a microneedle device to be used for home care blood collection.
“No one likes getting blood drawn, but blood is the single-most important source of medical information in healthcare today, with about 90% of all diagnostic information coming from blood and its components,” Howard Weisman, former CEO of 7SBio and current CEO of PaxMedica, a clinical-stage biopharmaceutical company, said in the Flagship Pioneering news release. “TAP has the potential to transform blood collection from an inconvenient, stressful, and painful experience to one people can do themselves anywhere, making health monitoring much easier for both healthcare professionals and patients.”
As microneedle technology continues to evolve, clinical laboratories should expect patches to be used in a growing number of drug delivery systems and diagnostic tests. But further research will be needed to determine whether interstitial fluid can provide an alternate pathway for diagnosing disease.
It took UCSF physicians just 48 hours to identify the bacteria in cerebrospinal fluid that was causing fourteen-year-old Joshua Osborn’s hydrocephalus and status epilepticus
There’s rich irony in the FDA’s recent announcement that it would move forward with plans to regulate “laboratory-developed tests ” (LDTs) just weeks after the national media published stories about how innovative use of an LDT helped physicians make an accurate diagnosis that saved the life of seriously-ill 14-year old boy.
Pathologists and clinical laboratory managers may be aware of the case of Joshua Osborn. It was a laboratory-developed test that used next-generation gene sequencing in a unique approach that gave his care team the diagnostic information they needed to select the right therapies for his condition. (more…)
