An assay using mass spectrometry could go to clinical trial within two years
Dark Daily has regularly observed that humans generate a variety of volatile substances—particularly in breath—which can be used for diagnostic purposes. But what if people, like certain trained animals, could smell the presence of disease before the onset of symptoms? What types of clinical laboratory testing biomarkers could be developed based on human-generated volatile organic compounds?
Researchers at the University of Manchester (UM) in the United Kingdom (UK) say their “breakthrough” test to diagnose Parkinson’s disease “can diagnose disease from skin swabs in three minutes,” according to a university press release.
Perdita Barran, PhD (right), head of the University of Manchester research team that developed the mass spectrometry Parkinson’s test, is shown above with Joy Milne (left), the retired nurse from Scotland who inspired Barran’s team to develop a new Parkinson’s biomarker and method for identifying it. “We are tremendously excited by these results which take us closer to making a diagnostic test for Parkinson’s Disease that could be used in clinic,” she said in a press release. A viable clinical laboratory test for Parkinson’s disease is greatly needed, as more than 10 million people worldwide currently live with the neurodegenerative disorder. (Photo copyright: University of Manchester.)
Using Mass Spectrometry to Analyze Sebum
The UM scientists hypothesized that the smell could be due to sebum, a light oily substance on skin that was going through a chemical change due to the Parkinson’s disease, Hull Daily Mail explained.
Increased sebum, which is produced by the sebaceous glands, is a hallmark of Parkinson’s, the researchers noted.
Their new method involves analysis of sebum using mass spectrometry, according to the JACS AU paper. The method, the researchers claim, makes it possible to diagnose Parkinson’s disease from skin swabs in three minutes.
“There are no cures for Parkinson’s, but a confirmatory diagnosis would allow [Parkinson’s patients] to get the right treatment and get the drugs that will help to alleviate their symptoms,” Perdita Barran, PhD, told the Hull Daily Mail. Barran is Chair of Mass Spectrometry in the Department of Chemistry and Director of the Michael Barber Centre for Collaborative Mass Spectrometry at UM’s Manchester Institute of Biotechnology. “What we are now doing is seeing if (hospital laboratories) can do what we’ve done in a research lab in a hospital lab,” she added.
Sebum Analyzed with Mass Spectrometry
Parkinson’s disease—the world’s fastest growing neurodegenerative disorder—needs “robust biomarkers” that could advance detection and head off onset of motor symptoms such as tremor, rigidity, and postural instability, the researchers note in their paper.
Their recent study builds on earlier 2019 findings they published in ACS Central Science about volatile compounds in sebum possibly being used as Parkinson’s biomarkers.
“Sebum is an underexplored biofluid, which is readily obtained from non-invasive skin swabs, which primarily consists of a mixture of triglycerides, cholesterol, free fatty acids, waxy esters, and squalene,” the researchers explained in their JACS AU paper.
The scientists sought, “to develop a method to analyze sebum in its native state to facilitate rapid assessment of the Parkinson’s disease status. Paper spray ionization mass spectrometry, which allows the direct analysis of compounds from paper, has previously been demonstrated to detect small molecules from unprocessed biofluids, such as blood and urine, but not to date with sebum,” they wrote.
The UM researchers used mass spectrometry to analyze sebum collected on cotton swabs from the backs of 79 people with Parkinson’s and 71 healthy individuals, BBC Scotland News reported.
Depanjan Sarkar, PhD, Research Associate, University of Manchester, further explained the technique in the UM news release:
Sebum is taken from the swab to filter paper cut in a triangle.
Using a solvent and voltage, sebum compounds transfer into the mass spectrometer.
“When we did this, we found more than 4,000 unique compounds of which 500 are different between people with Parkinson’s compared to the control participants,” Sarkar said.
Fatty Acids Make Assay Possible
Could fatty acids pave the way to an assay? The UM researchers believe so.
“We have identified two classes of lipids, namely [triglycerides] and diglycerides, as components of human sebum that are significantly differentially expressed in PD,” the researchers wrote in JACS AU. “Non-invasive sampling followed by PS-IM-MS [paper spray-ion mobility–mass spectrometry] analysis targeting these compounds could provide an inexpensive assay to support clinical phenotyping for the confirmatory diagnosis of Parkinson’s disease.”
A clinical trial for their test, which costs about $20, may be done within two years in Manchester area, the Daily Mail reported.
When Dark Daily reported in 2020 on Joy Milne’s unique ability to smell her husband’s Parkinson’s disease before it was formally diagnosed, we predicted a diagnostic test for Parkinson’s may be years away. And here it is, albeit with regulatory clearance needed following clinical trials.
It may in fact be possible to leverage sebum analysis to detect other diseases, the UM researchers noted.
For diagnostics developers, this story of Joy Milne and her husband Les Milne is a useful example of how, in tracking the life of a specific patient with a specific disease and close family members, researchers were able to identify a new class of biomarkers that could be used in a diagnostic assay.
It will be interesting to follow the University of Manchester researchers in their quest for a diagnostic mass spectrometry clinical laboratory test for Parkinson’s disease. According to Parkinson’s Foundation statistics, about 10 million people worldwide live with the neurodegenerative disorder. Such a new diagnostic test could be vitally important to medical laboratory care, and to patients and their families.
Decision is part of UK effort to diagnose 75% of all cancers at stage I or stage II by 2028 and demonstrates to pathologists that the technology used in liquid biopsy tests is improving at a fast pace
Pathologists and medical laboratory scientists know that when it comes to liquid biopsy tests to detect cancer, there is plenty of both hope and hype. Nevertheless, following a successful pilot study at the Christie NHS Foundation Trust in Manchester, England, which ran from 2015-2021, the UK’s National Health Service (NHS) is pushing forward with the use of liquid biopsy tests for certain cancer patients, The Guardian reported.
NHS’ decision to roll out the widespread use of liquid biopsies—a screening tool used to search for cancer cells or pieces of DNA from tumor cells in a blood sample—across the UK is a hopeful sign that ongoing improvements in this diagnostic technology are reaching a point where it may be consistently reliable when used in clinical settings.
The national program provides personalized drug therapies based on the genetic markers found in the blood tests of cancer patients who have solid tumors and are otherwise out of treatment options. The liquid biopsy creates, in essence, a match-making service for patients and clinical trials.
Liquid Biopsy Genetic Testing for Cancer Patients
“The learnings from our original ‘Target’ study in Manchester were that genetic testing needs to be done on a large scale to identify rare genetic mutations and that broader access to medicines through clinical trials being undertaken across the country rather than just one site are required,” Matthew Krebs, PhD, Clinical Senior Lecturer in Experimental Cancer Medicine at the University of Manchester, told The Guardian.
Krebs, an honorary consultant in medical oncology at the Christie NHS Foundation Trust, led the Target National pilot study.
“This study will allow thousands of cancer patients in the UK to access genetic testing via a liquid biopsy. This will enable us to identify rare genetic mutations that in some patients could mean access to life-changing experimental medicines that can provide great treatment responses, where there are otherwise limited or no other treatment options available.”
Detecting cancers at earlier stages of disease—when treatment is more likely to result in improved survival—has become a strategic cancer planning priority in the UK, theBMJ noted.
“The NHS is committed to diagnosing 75% of all cancers at stage I or II by 2028, from around 50% currently,” the BMJ wrote. “Achieving such progress in less than a decade would be highly ambitious, even without disruption caused by the COVID-19 pandemic. In this context, considerable hope has been expressed that blood tests for circulating free DNA—sometimes known as liquid biopsy—could help achieve earlier detection of cancers.”
The Guardian noted that the UK’s initiative will use a liquid biopsy test made by Swiss-healthcare giant Roche.
“We can’t guarantee that we will find a fault in the genetic code of every cancer patient we recruit, or that if we do, there will be a suitable drug trial for them,” Matthew Krebs, PhD (above), lead scientist of the NHS’ Target National pilot study, told The Guardian. “However, as we learn more about the genetics of cancer in this study, it will help doctors and scientists develop new treatments to help people in the future. Ultimately, we hope liquid biopsy testing will be adopted into routine NHS care, but we need studies such as this to show the benefit of the test on a large scale and provide the evidence that patients can benefit from being matched to targeted medicines on the basis of the blood test.” (Photo copyright: Cancer Research UK Manchester Centre.)
In her article “The Promise of Liquid Biopsies for Cancer Diagnosis,” published in the American Journal of Managed Care (AJMC) Evidence-based Oncology, serial healthcare entrepreneur and faculty lecturer at Harvard Medical School Liz Kwo, MD, detailed the optimism surrounding the “revolutionary screening tool,” including its potential for:
identifying mechanisms of resistance to therapies,
measuring remaining disease after treatment,
assessing cancer relapse or resistance to treatment, and
eliminating risk surrounding traditional biopsies.
The AJMC article estimated the liquid biopsy market will be valued at $6 billion by 2030. However, Kwo also noted that clinical adoption of liquid biopsies in the US continues to face challenges.
Welch compared the investor hype surrounding liquid biopsies to that of the now-defunct blood testing company Theranos, which lured high-profile investors to pour millions into its unproven diagnostic technology.
“Effective cancer screening requires more than early detection. It also requires that starting therapy earlier helps people live to older ages than they would if they started treatment later,” he wrote. “If that doesn’t happen, liquid biopsies will only lead to people living longer with the knowledge they have a potentially incurable disease without extending their lives. These people would be subjected to cancer therapies and their toxicities earlier, but at a time when they would otherwise be experiencing no cancer-related signs or symptoms.”
And so, while there’s much excitement about the possibility of a minimally invasive way to detect cancer, anatomic pathology groups and clinical laboratories will have to wait and see if the hype and hope surrounding liquid biopsies is substantiated by further research.
Researchers find declining antibody levels in SARS-CoV-2 patients are offset by T cells and B cells that remain behind to fight off reinfection
Questions remain regarding how long antibodies produced by a COVID-19 vaccine or natural infection will provide ongoing protection against SARS-CoV-2. However, a new study showing COVID-19 immunity may be “robust” and “long lasting” may signal important news for clinical laboratories and in vitro diagnostics companies developing serological tests for the coronavirus disease.
The LJI research team analyzed blood samples from 188 COVID-19 patients, 7% of whom had been hospitalized. They measured not only virus-specific antibodies in the blood stream, but also memory B cell infections, T helper cells, and cytotoxic (killer) T cells.
While antibodies eventually disappear from the blood stream, T cells and B cells appear to remain to fight future reinfection.
“As far as we know, this is the largest study ever for any acute infection that has measured all four of those components of immune memory,” Crotty said in a La Jolla Institute news release.
The LJI researchers found that virus-specific antibodies remained in the blood stream months after infection while spike-specific memory B cells—which could trigger an accelerated and robust antibody-mediated immune response in the event of reinfection—actually increased in the body after six months. In addition, COVID-19 survivors had an army of T cells ready to halt reinfection.
“Our data show immune memory in at least three immunological compartments was measurable in ~95% of subjects five to eight months post symptom onset, indicating that durable immunity against secondary COVID-19 disease is a possibility in most individuals,” the study concludes. The small percentage of the population found not to have long-lasting immunity following COVID-19 infection could be vaccinated in an effort to stop reinfection from occurring on the way to achieving herd immunity, the LJI researchers maintained.
Do COVID-19 Vaccines Create Equal Immunity Against Reinfection?
Whether COVID-19 vaccinations will provide the same immune response as an active infection has yet to be determined, but indications are protection may be equally strong.
“It is possible that immune memory will be similarly long lasting similar following vaccination, but we will have to wait until the data come in to be able to tell for sure,”
LJI Research Professor Daniela Weiskopf, PhD, said in the LJI statement. “Several months ago, our studies showed that natural infection induced a strong response, and this study now shows that the response lasts. The vaccine studies are at the initial stages, and so far, have been associated with strong protection. We are hopeful that a similar pattern of responses lasting over time will also emerge for the vaccine-induced responses.”
The study’s authors cautioned that people previously diagnosed with COVID-19 should not assume they have protective immunity from reinfection, the Washington Post noted. In fact, according to the LJI news release, researchers saw a “100-fold range in the magnitude of immune memory.”
Alessandro Sette, Doctor of Biological Sciences (above), an Italian immunologist, Professor at the Center for Autoimmunity and Inflammation/Center for Infectious Disease and Vaccine Research at La Jolla Institute for Immunology, and co-author of the study, told the Washington Post that people should act responsibly. “If I had COVID, I would still not throw away my masks, I would not go to rave parties … It’s like driving a car where you know you have 90% probability that the brakes work.” (Photo copyright: La Jolla Institute for Immunology.)
Previous Studies Found Little Natural Immunity Against SARS-CoV-2 Reinfection
The Scientist reported that several widely publicized previous studies raised concerns that immunity from natural infection was fleeting, perhaps dwindling in weeks or months. And a United Kingdom study published in Nature Microbiology found that COVID-19 generated “only a transient neutralizing antibody response that rapidly wanes” in patients who exhibited milder infection.
Daniel M. Davis, PhD, Professor of Immunology at the University of Manchester, says more research is needed before scientists can know for certain how long COVID-19 immunity lasts after natural infection.
“Overall, these results are interesting and provocative, but more research is needed, following large numbers of people over time. Only then, will we clearly know how many people produce antibodies when infected with coronavirus, and for how long,” Davis told Newsweek.
While additional peer-reviewed studies on the body’s immune response to COVID-19 will be needed, this latest study from the La Jolla Institute for Immunity may help guide clinical laboratories and in vitro diagnostic companies that are developing serological antibody tests for COVID-19 and lead to more definitive answers as to how long antibodies confer protective immunity.
She worked with researchers at the University of Manchester in England to identify volatile biomarkers for Parkinson’s disease that may lead to first noninvasive screening
Clinical pathologists and medical laboratories are used to working with certain biological indicators that drive diagnostics and clinical laboratory testing. Mostly, those biomarkers are contained within various liquid samples, such as blood and urine. But what if a person’s odor could accurately predict risk for certain diseases as well?
Joy Milne, a retired nurse from Perth, Scotland, is the women whose heightened sense of smell enabled her to detect her husband’s Parkinson’s a decade before he was diagnosed with the disease.
Of course, Milne did not know at the time that what she was smelling was in fact a disease. She told NPR that she first noticed that her husband’s smell had changed from “his lovely male musk smell,” which she’d noticed when they first met, into “this overpowering sort of nasty yeast smell.”
Frequent washing did not remove the odor and as time went on the smell became stronger. When aspects of her husband’s personality and sleep habits also began to change, Joy convinced her husband, Les Milne, an anesthetist, to seek a diagnosis, thinking he had a brain tumor. Les was diagnosed with Parkinson’s disease.
It was 20 years later, when the Milnes attended a Parkinson’s disease support group, that Joy recognized the same distinctive smell she had noticed on Les on the other members of the group. That’s when the Milnes first realized Joy’s heightened sense of smell was something quite unique and possibly unprecedented.
Retired nurse Joy Milne (above) of Perth, Scotland, has an uncanny ability to diagnose Parkinson’s disease based on her highly sensitive sense of smell. Before her husband was diagnosed with the disease, she noticed a change in his smell. When she later recognized the same distinct odor among participants in a Parkinson’s support group, the Milnes asked scientists to investigate. (Photo copyright: NPR.)
Dogs Can Do It, Why Not Humans?
The concept that a disease gives off an aroma that can be detected by humans or animals is not far-fetched. As far back as 2013, Dark Daily was writing about such research. For example, in “C. diff-sniffing Beagle Dog Could Lead to Better Infection Control Outcomes in Hospitals and Nursing Homes,” we wrote about one hospital’s innovative approach to early detection of Clostridium difficile (C. diff) infection using a two-year-old beagle named Cliff that was faster at detecting certain infections than standard clinical laboratory tests used daily in hospitals throughout the world.
Thus, when the Milnes approached Dr. Kunath about Joy’s ability to “smell” Parkinson’s, they were on solid ground. However, he was not convinced.
“It just didn’t seem possible,” Kunath told NPR. “Why should Parkinson’s have an odor? You wouldn’t think neurodegenerative conditions such as Parkinson’s, or Alzheimer’s, would have an odor.”
But Kunath reconsidered after learning of research presented during the Experimental Biology annual meeting in 2019, which showed canines can in fact effectively detect lung cancer biomarkers in blood serum.
He contacted Milne and devised an experiment in which a group of people who had Parkinson’s disease, and another group that did not, would take home t-shirts and wear them overnight. The next day the t-shirts were assigned randomized numbers and put in a box. Milne then smelled each of the 12 t-shirts and assigned each one a score.
Kunath told NPR that Milne was “incredibly accurate.” She had misidentified only one shirt worn by a person in the control group. She incorrectly diagnosed the person with Parkinson’s. However, three months later, that man was in fact diagnosed with Parkinson’s, meaning Joy’s accuracy was 12-for-12.
“She was telling us this individual had Parkinson’s before he knew, before anybody knew,” Kunath told the BBC Scotland.
In an ensuing study, “Discovery of Volatile Biomarkers of Parkinson’s Disease from Sebum,” published in 2019 in ACS Central Science, the researchers describes the “distinct volatiles-associated signature” of Parkinson’s disease, which includes “altered levels of perillic aldehyde and eicosane, the smell of which was then described as being highly similar to the scent of Parkinson’s disease by our ‘Super Smeller.’” Joy Milne co-authored the study.
The concept of the human body producing volatile chemicals that can serve as biomarkers for disease or illness is not new to clinical laboratory professionals. The urea breath test, for example, to detect the presence of active H. pylori bacteria in the stomach is a longstanding example of one such diagnostic test.
Barran led a larger Manchester University study which was published on ChemRxiv, titled, “Sebum: A Window into Dysregulation of Mitochondrial Metabolism in Parkinson’s Disease,” which was funded by a Michael J. Fox research grant (12921). Barran and her research team, which included Milne, “found 10 compounds linked to Parkinson’s by using mass spectrometry and other techniques” on skin sebum samples, reported NPR.
“We really want to know what is behind this and what are the molecules. And then, [determine if] the molecules [can] be used as some sort of diagnostic test,” Kunath told NPR.
A Definitive, Noninvasive Test for Parkinson’s?
The UK researchers discovered in the skin sebum volatile biomarkers of Parkinson’s disease that may lead to development of the first definitive test for the disease.
Katherine Crawford, Scotland Director of Parkinson’s UK, aka the Parkinson’s Disease Society of the United Kingdom, said a noninvasive diagnostic test for Parkinson’s would be game changing.
“We still effectively diagnose it today the way that Dr. James Parkinson diagnosed it in 1817, which is by observing people and their symptoms,” Crawford told BBC Scotland. “A diagnostic test like this could cut through so much of that, enable people to go in and see a consultant, have a simple swab test and come out with a clear diagnosis of Parkinson’s.”
“It wouldn’t have happened without Joy,” Barran told BBC Scotland. “For all the serendipity, it was Joy and Les who were absolutely convinced that what she could smell would be something that could be used in a clinical context, and so now we are beginning to do that.”
A viable, working diagnostic test based on these new biomarkers may be years away. Nevertheless, clinical laboratory leaders will want to follow the ongoing efforts toward development of a noninvasive swab test for Parkinson’s disease. Such a breakthrough would revolutionize Parkinson’s testing and might never have come to light without the persistence of a woman with an extremely sensitive sense of smell.
The VirScan test gives doctors insight into a patient’s lifetime exposure to viruses and thus may be developed into a useful medical laboratory test
Scientists and pathologists are learning that blood is like a time capsule, holding precious information about exposure to viruses over the years—chickenpox at five, mononucleosis at 18, flu at 40. You get the idea.
Now, researchers at Howard Hughes Medical Institute (HHMI) have found a way to tap that entire data stream, so to speak. An inexpensive blood test, they say, reveals every virus that has passed through the body over time.
New Discoveries Could Lead to a Useful Clinical Laboratory Test
The testing method, called VirScan by researchers, is an efficient alternative to current medical laboratory tests that test for specific viruses one at a time, according to an HHMI news statement about the new technology. (more…)
