Officials also worry about diminishing smallpox vaccinations, which offered people protection against the infectious disease
Monkeypox challenges from the current outbreak have dogged public health agencies even though the disease was first identified more than 50 years ago. That is because the virus has found new avenues of infection. These developments will be relevant for the nation’s clinical laboratories, which are often the first healthcare providers to confirm a suspected case is positive for monkeypox and notify a public health laboratory about the positive test result.
The latest monkeypox numbers from the federal Centers for Disease Control and Prevention (CDC) indicate that, as of September 6, the US has identified 19,962 cases in the 2022 outbreak, while worldwide the case number is 52,037.
In “When It Comes to Monkeypox Testing, Clinical Laboratories Should Be Aware of Five Significant Developments,” Dark Daily wrote about steps being taken to identify and control infections in America as well as trends in medical laboratory testing for monkeypox. This included reports of phlebotomists refusing to draw monkeypox blood samples and how social stigma surrounding the disease can affect who gets a medical laboratory test.
Workers at clinical laboratories and anatomic pathology groups will gain from understanding why monkeypox has spread beyond its traditional geography.
“Monkeypox symptoms include swollen lymph nodes, fever, and body aches that result in red bumps on hands, feet, mouth, and genitals,” Bodhraj Acharya, PhD (above), of the Laboratory Alliance of Central New York, told Dark Daily. “It spreads by close contact, respiratory droplets, lesions, and bodily fluids.” Clinical laboratories engaged in testing for monkeypox will want to stay alert to patients presenting with such symptoms. (Photo copyright: Laboratory Alliance of Central New York.)
African Public Health Officials Saw New Monkeypox Challenges Coming
Researchers and public health experts have been perplexed about how and why the latest monkeypox outbreak has occurred so aggressively beyond its origin in rural Central Africa.
“Monkeypox is caused by the pox virus, with a close resemblance to smallpox,” said Bodhraj Acharya, PhD, Manager of Chemistry and Referral Testing at the Laboratory Alliance of Central New York, in a conversation with Dark Daily. “Unlike COVID-19, this is an old enemy which has roots in the 1970s from Congo, when the disease was erratically endemic in Africa.”
According to the World Health Organization (WHO), most monkeypox cases since 1970 have been reported from rural rainforest regions in Central and Western Africa.
Thus, a monkeypox outbreak occurring in Europe and the United States in 2022 has puzzled virologists and microbiologists because it does not follow the historical pattern of the virus’ spread. For example, the first monkeypox case in the US arrived in May from a Massachusetts patient who had traveled to Canada, a state press release noted.
Before the Nigerian outbreak, the virus rose from rural areas where hunters came in close contact with animals. The illness resulted in lesions on the face, hands, and feet, Nature wrote of Yinka-Ogunleye’s recollections.
However, after 2017, she and other epidemiologists warned peers that the virus was spreading in new ways and in urban settings. For example, infected people sometimes had genital lesions, suggesting that the virus might spread through human sexual contact.
Now, in 2022, “the world is paying the price for not having responded adequately” in 2017, Yinka-Ogunleye told Nature.
Lack of Smallpox Vaccination Increases Monkeypox Challenges
The waning effects of smallpox vaccinations, which ended in 1980 after smallpox was basically eradicated from the world, may have opened the door for monkeypox to spread earlier this year. Smallpox vaccines provided some protection against monkeypox, but by now three generations of people have not received smallpox inoculations.
“Eyebrows were raised when multiple cases of monkeypox were reported from various non-endemic countries starting in May of 2022,” Acharya said. “Due to genetic similarity, smallpox vaccination provided some cross-protection, but the termination of smallpox vaccination could have provided ground for the recent insurgence and spread of monkeypox.”
Trying to jumpstart a new monkeypox vaccination campaign on the heels of COVID-19 shots may be met with resistance from a virus-weary public. But other options at preventing the current spread of monkeypox may present challenges as well, such as trying to curtail sexual activity among affected population, the BBC reported.
“The easiest way to prevent it is to close down all highly active sexual networks for a couple of months until it goes away, but I don’t think that will ever happen. Do you?” Paul Hunter, PhD, Professor of Medicine at the University of East Anglia in Norwich, England, told the BBC.
For medical laboratory workers and others who may find themselves testing for the disease in the future, the biggest lessons from current monkeypox challenges are twofold: The virus has invaded new geography, and discontinued smallpox vaccination campaigns may have left younger people exposed to monkeypox.
The federal agency shipped tests to five commercial clinical laboratory companies, augmenting efforts by public health labs
Medical laboratories in the US are ramping up their efforts to respond to an outbreak of monkeypox that has been spreading around the globe. Microbiologists and clinical laboratory scientists will be interested to learn that this infectious agent—which is new to the US—may be establishing itself in the wild rodent population in this country. If proved to be true, it means Americans would be at risk of infection from contact with rodents as well as other people.
The Centers for Disease Control and Prevention (CDC) announced on May 18 that it had identified the infection in a Massachusetts resident who had recently traveled to Canada. As of August 3, the federal agency was reporting 6,617 confirmed cases in the US.
“Because there are no other non-variola orthopoxviruses circulating in the US, a positive test result is presumed to be monkeypox,” states the APHL press release.
“As we focus on the US response, we keep a close watch on the global outbreak. Infectious diseases don’t respect borders, as we know,” said Chris Mangal (above), director of public health preparedness and response, APHL, in a press release. “I am proud of how LRN member laboratories have rapidly and effectively responded to this emergency. This is precisely what the LRN was intended to do. Should this outbreak continue to grow, preparing for expanded testing and increasing capacity beyond LRN laboratories is important to ensuring we are ready for a surge in testing.” (Photo copyright: Association of Public Health Laboratories.)
Commercial Labs Get Involved
Seeking to bolster testing capacity, the federal Department of Health and Human Services (HHS) announced on June 22 that the CDC had begun shipping OrthopoxvirusPCR tests to five commercial lab companies. They include:
“By dramatically expanding the number of testing locations throughout the country, we are making it possible for anyone who needs to be tested to do so,” said HHS Secretary Xavier Becerra in an HHS press release.
Labcorp was first out of the gate, announcing on July 6 that it was offering the CDC-developed test for its customers, as well as accepting overflow from public labs. “We will initially perform all monkeypox testing in our main North Carolina lab and have the capacity to expand to other locations nationwide should the need arise,” said Labcorp chief medical officer and president Brian Caveney, MD, in a press release.
Mayo Clinic Laboratories followed suit on July 11, announcing that the clinic’s Department of Laboratory Medicine and Pathology would perform the testing at its main facility in Rochester, Minnesota.
“Patients can access testing through Mayo Clinic healthcare professionals and will soon be able to access testing through healthcare professionals who use Mayo Clinic Laboratories as their reference laboratory,” Mayo stated in a press release.
Then, Quest Diagnostics announced on July 13 that it was testing for the virus with an internally developed PCR test, with plans to offer the CDC test in the first half of August.
The lab-developed test “was validated under CLIA federal regulations and is now performed at the company’s advanced laboratory in San Juan Capistrano, Calif.,” Quest stated in a press release.
Public Health Emergency?
Meanwhile, the CDC announced on June 28 that it had established an Emergency Operations Center to respond to the outbreak. A few weeks later, on July 23, World Health Organization (WHO) Secretary-General Tedros Adhanom Ghebreyesus, PhD, declared that the outbreak represented “a public health emergency of international concern.”
He noted that international health regulations required him to consider five elements to make such a declaration.
“WHO’s assessment is that the risk of monkeypox is moderate globally and in all regions, except in the European region where we assess the risk as high,” he said in a WHO news release. “There is also a clear risk of further international spread, although the risk of interference with international traffic remains low for the moment. So, in short, we have an outbreak that has spread around the world rapidly, through new modes of transmission, about which we understand too little, and which meets the criteria in the International Health Regulations.”
Still, public health authorities have made it clear that this is not a repeat of the COVID-19 outbreak.
“Monkeypox virus is a completely different virus than the viruses that cause COVID-19 or measles,” the CDC stated in a June 9 advisory. “It is not known to linger in the air and is not transmitted during short periods of shared airspace. Monkeypox spreads through direct contact with body fluids or sores on the body of someone who has monkeypox, or with direct contact with materials that have touched body fluids or sores, such as clothing or linens. It may also spread through respiratory secretions when people have close, face-to-face contact.”
The New York Times reported that some experts disagreed with the CDC’s assessment that the virus “is not known to linger in the air.” But Professor of Environmental Health Donald Milton, MD, DrPH, of the University of Maryland, told The Times it is still “not nearly as contagious as the coronavirus.”
The Massachusetts resident who tested positive in May was not the first known case of monkeypox in the US, however, previous cases involved travel from countries where the disease is more common. Two cases in 2021—one in Texas and one in Maryland—involved US residents who had recently returned from Nigeria, the CDC reported. And a 2003 outbreak in the Midwest was linked to rodents and other small mammals imported to Texas from Ghana in West Africa.
“Labcorp and Quest don’t dispute that in many cases, their phlebotomists are not taking blood from possible monkeypox patients,” according to CNN. “What remains unclear, after company statements and follow-ups from CNN, is whether the phlebotomists are refusing on their own to take blood or if it is the company policy that prevents them. The two testing giants say they’re reviewing their safety policies and procedures for their employees.”
One symptom of monkeypox, the CDC states, is a rash resembling pimples or blisters. Clinicians are advised that two swabs should be collected from each skin lesion, though “procedures and materials used for collecting specimens may vary depending on the phase of the rash.”
“Effective communication and precautionary measures between specimen collection teams and laboratory staff are essential to maximizing safety when manipulating specimens suspected to contain monkeypox virus,” the CDC notes. “This is especially relevant in hospital settings, where laboratories routinely process specimens from patients with a variety of infectious and/or noninfectious conditions.”
Perhaps the negative reaction to the CDC’s initial response to the COVID-19 outbreak in the US is driving the federal agency’s swift response to this new viral threat. Regardless, clinical laboratories and pathology groups will play a key role in the government’s plan to combat monkeypox in America.
In fact, the UB study suggests traditional anatomical methods for determining the evolutionary relationships between species may not be as accurate as once thought, an article in SciTechDaily reported.
Nevertheless, the UB’s research into convergent evolution is unlocking new insights into how genes evolve over time and this new knowledge may help researchers develop genetic tests that more accurately identify different diseases and health conditions.
Additionally, studies that bring a better understanding of how beneficial genetic mutations work their way into a species’ genome might also aid researchers in developing personalized clinical laboratory testing and therapies based on manipulating a patient’s genetic sequences in ways that would be beneficial.
Gene Sequencing More Accurate at Determining Evolutionary Relationships
The UB study suggests that existing evolutionary (phylogenetic) trees may need to be reconsidered. To put a finer point on the findings, a UB news release on the study states, “determining evolutionary trees of organisms by comparing anatomy rather than gene sequences is misleading.”
The UB scientists used genetic sequencing to quickly—and more cost effectively—determine evolutionary relationships as compared to traditional morphology (anatomy and structure), according to the news release.
They found genetic data that revealed surprising relationships about where the sequenced species originated, and which differed with prior conclusions that were drawn based on the species’ appearance. The findings suggest there may be need to “overturn centuries of scientific work in classifying relation of species by physical traits,” the UB scientists said.
“For over a hundred years, we’ve been classifying organisms according to how they look and are put together anatomically, but molecular data often tells us a rather different story,” said Matthew Wills, PhD (above), Professor of Evolutionary Paleobiology, Milner Center for Education at the University of Bath, in the news release. “Our study proves statistically that if you build an evolutionary tree of animals based on their molecular data, it often fits much better with their geographical distribution.” This new use of genetic sequencing could lead to improved precision medicine treatments and clinical laboratory testing. (Photo copyright: University of Bath.)
Molecular Data Leads to New Insights into Convergent Evolution
The UB study’s use of genetic sequencing led the researchers to a greater understanding of convergent evolution, defined by “a characteristic evolving separately in two genetically unrelated groups of organisms,” according to UB.
For example, wings are a widely developed characteristic. But they are not necessarily a sign of relatedness when it comes to birds, bats, and insects.
“Now with molecular data, we can see that convergent evolution happens all the time—things we thought were closely related often turn out to be far apart on the tree of life,” Wills said, adding, “Individuals within a family don’t always look similar; it’s the same with evolutionary trees, too.”
Family Trees: Morphology Versus Molecular
In their paper, the UB researchers acknowledged the importance of phylogenies (evolutionary history of species) in areas of biology, including medicine. They aimed to study a better way to produce accurate phylogenetic trees.
“Phylogenetic relationships are inferred principally from two classes of data: morphological and molecular,” they wrote, adding, “The superiority of molecular trees has rarely been assessed empirically.”
So, they set out to compare the two approaches to building evolutionary trees:
Traditional morphology analysis, and
Phylogenetic trees developed using molecular data.
Using 48 pairs of morphological and molecular trees, they mapped data geographically.
“We show that, on average, molecular trees provide a better fit to biogeographic data than their morphological counterparts, and that biogeographic congruence increases over research time,” the researchers wrote.
Biogeography a Better Gauge of Relatedness than Anatomy
The study also found animals on molecular trees lived geographically closer as compared to groups on morphological trees.
For example, molecular studies put aardvarks, elephants, golden moles, swimming manatees, and elephant shews in an Afrotheria group, named for Africa, which is where they came from. Therefore, the biogeography matches, however the appearances of these mammals clearly do not, the UB scientists point out.
“What’s most exciting is that we find strong statistical proof of molecular trees fitting better not just in groups like Afrotheria, but across the tree of life in birds, reptiles, insects, and plants,” said Jack Oyston PhD, UB Department of Biology and Biochemistry Research Associate and first author of the study, in the news release.
The researchers believe their findings support the accuracy of genetic-themed trees.
“It being such a widespread pattern makes it much more potentially useful as a general test of different evolutionary trees. But it also shows just how pervasive convergent evolution has been when it comes to misleading us,” Oyston added.
Advantages of Molecular Data
In their Nature Communications Biology paper, the UB scientists wrote that molecular data offer up these advantages over morphology:
Widely available in vast quantity.
Opportunity exists to “search, repurpose, and reanalyze sequenced data alongside novel sequences.”
Less subjectivity in researchers’ analysis.
Well-developed data at the ready and “still in their infancy.”
The University of Bath’s study of convergent evolution, phylogenetic trees, and comparison of molecular data versus morphology, has implications for medical laboratories. Should their research lead to new insights into how genes evolve over time, diagnostics professionals may have new information to identity diseases and work with others to precisely treat patients.
It’s the latest example of how genetic technologies have advanced to the point where DNA can be extracted and sequenced from human remains that are thousands of years old, often generating new insights that can benefit clinical laboratory testing
How might an individual in Pompeii who died in the famous Mount Vesuvius volcanic eruption of 79 AD help medical science today? The answer is that sequencing this individual’s DNA may yield insights into health conditions and infectious diseases of that era that could help scientists better understand disease today in ways that improve diagnosis and clinical laboratory testing.
Additionally, researchers studying genetic sequencing are discovering the technology has many more capabilities that previously thought. One such example involves scientists from the University of Copenhagen, the University of Salento, and victims of the eruption. This research team has determined that even severely damaged biological samples may contain viable DNA.
When Mount Vesuvius erupted, volcanic ash and pumice buried many residents of the town of Pompeii in southern Italy. The ash was estimated to have been about 500 degrees Fahrenheit, which should have been hot enough to cause significant damage to DNA. However, it appears the pyroclastic materials released during the eruption may instead have preserved some of the victims’ DNA.
“One of the main drivers of DNA degradation is oxygen (the other being water),” Gabriele Scorrano, PhD, Assistant Professor, University of Copenhagen and lead author of the study told CNN. “Temperature works more as a catalyst, speeding up the process. Therefore, if low oxygen is present, there is a limit of how much DNA degradation can take place.”
The scientists succeeded in performing completed genetic sequencing on one of the victims of the violent eruption. This has genetic researchers rethinking how DNA could be recovered from damaged biological materials.
“In the future, many more genomes from Pompeii can be studied,” anthropologist Serena Viva, PhD (above), a postdoctoral researcher at the University of Salento in Italy and one of the authors of the study told the Guardian. “The victims of Pompeii experienced a natural catastrophe, a thermal shock, and it was not known that you could preserve their genetic material. This study provides this confirmation, and that new technology on genetic analysis allows us to sequence genomes also on damaged material.” What new clinical laboratory testing may come out of this study is not known. But it shows that there is still much to learn about genetic sequencing. (Photo copyright: University of Salento.)
Findings Suggest High Levels of Genetic Diversity
“There was the expectation that the high temperatures would make our effort in DNA sequencing in Pompeii fruitless,” Scorrano stated. “Cremated bodies, for example, show no sign of DNA preservation according to multiple studies.”
The scientists examined the skeletal remains of two victims found in a building known as Casa del Fabbro or House of the Craftsman to determine if any DNA was present. One skeleton was that of a man in his 30’s who was about five feet four inches in height and the other skeleton was of a woman who appeared to be at least 50 years of age and around five feet tall.
Although the researchers did obtain genetic material from both skeletons, they were only able to sequence the entire genome from the remains of the male skeleton.
The researchers compared his DNA with that of 1,030 other ancient and 471 modern western Eurasian people. The results suggest that the DNA from the male Pompeii skeleton shares the most similarities with people who currently live or lived in central Italy in the past.
Further analysis of the man’s DNA identified groups of genes that are commonly found in people from the island of Sardinia, but not in other people who lived in Italy during the Roman Imperial age. This suggested to the researchers that there may have been high levels of genetic diversity across Italy in 79 AD when Mount Vesuvius erupted.
Additional testing also identified sequences that are commonly found in a group of bacteria known to cause tuberculosis of the spine (Pott disease), a common ailment at that time. This implies the man had the illness when he perished.
The photo above shows the two skeletons (one man and one woman) found in Pompeii’s Casa del Fabbro. Though the University scientists tried to extract full sequences from both skeletons, they only succeeded with the male. (Photo copyright: Notizie degli Scavi di Antichità, 1934, p. 286, fig. 10.)
First Pompeiian Genetic Sequence
Scientists had attempted to sequence DNA from Pompeiian victims before, but previous endeavors to analyze more than small DNA strands failed.
“To our knowledge, our results represent the first successfully sequenced Pompeiian human genome,” they wrote in Nature Scientific Reports. “Our initial findings provide a foundation to promote an intensive and extensive paleogenetic analysis in order to reconstruct the genetic history of population from Pompeii, a unique archaeological site.”
It is unclear how equivalent studies could fare in the future, but the researchers involved in this study hope to use their sequencing techniques on other remains. It is possible that DNA from this Roman man who died in Pompeii in 79 AD may be used to determine if he has any descendants living today.
After months of research and the charting of Cheddar Man’s DNA, the scientists visited a school in Cheddar to extract DNA samples from schoolchildren and look for DNA matches. About 20 samples were taken in total including one from a teacher named Adrian Targett.
“They wanted to take DNA samples from some of the students whose families had lived longest in the area,” Targett told the Los Angeles Times. “I gave a [cheek swab] sample too, just to encourage the children and to make up the numbers.”
Although none of the children were a genetic match to the Cheddar Man, Targett was identified as a direct descendant of the skeleton.
“It’s a bit frightening to think that there are all those links across all those generations,” Targett said. “But the nice thing is that there are links that are so strong. We are all descended from an ancestor like Cheddar Man. Who knows how many people we are related to and don’t know about?”
The Pompeii DNA research is the latest example of how the ongoing reduction in the cost, faster throughput, and increased accuracy of genetic sequencing is allowing scientists to gain new knowledge from ancient artifacts. In turn, some of these new insights may lead to improving how certain health conditions are diagnosed, possibly using novel clinical laboratory tests developed as a result of this research.
Should their research result in new ways to identify and diagnose disease, doctors and clinical laboratories would do confirmatory testing and then initiate a precision medicine plan.
Dan Roden, MD, Senior Vice President for Personalized Medicine at VUMC and Senior Author of the Circulation study, said in a VUMC news release that the findings support the growing use of genetic information in clinical care.
“The questions we asked were: How many people who had no previous indication for cardiac genetic testing had pathogenic or likely pathogenic variants, and how many of those people actually had a phenotype in the electronic health records?” he explained.
Arrhythmia More Common than Previously Thought
The VUMC researchers drew data for their reports from the eMERGE Phase III study, which investigated the feasibility of population genomic screening by sequencing 109 genes across the spectrum of Mendelian diseases—genetic diseases that are caused by a mutation in a single gene—in more than 20,000 individuals. The scientists returned variant results to the participants and used EHR and follow-up clinical data to ascertain patient phenotypes, according to a Northwestern University Feinberg School of Medicine news release.
The research team looked specifically at the 120 consortium participants that had disease-associated pathogenic or likely pathogenic (P/LP) variants in the arrhythmia-associated genes. An analysis of the EHR data showed that 0.6% of the studied population had a variant that increases risk for potentially life-threatening arrhythmia, and that there was overrepresentation of arrhythmia phenotypes among patients, the VUMC news release noted.
The research team returned results to 54 participants and, with clinical follow-up, made 19 diagnoses (primarily long-QT syndrome) of inherited arrhythmia syndromes. Twelve of those 19 diagnoses were made only after variant results were returned, the study’s authors wrote.
Carlos G. Vanoye, PhD, Research Associate Professor of Pharmacology at Northwestern University (NU), said the study suggests arrhythmia genes may be more common than previously thought.
“A person can carry a disease-causing gene variant but exhibit no obvious signs or symptoms of the disease,” he said in the NU news release. “Because the genes we studied are associated with sudden death, which may have no warning signs, discovery of a potentially life-threatening arrhythmia gene variant can prompt additional clinical work-up to determine risks and guide preventive therapies.”
“The take-home message is that 3% of people will carry a pathogenic or likely pathogenic variant in a disease-causing gene and many others will carry variants of uncertain significance,” said Dan Roden, MD (above), Senior Vice President for Personalized Medicine at VUMC and Senior Author of the Circulation study in the VUMC news release. “We can use genetic testing, electronic health record phenotypes, and in vitro technologies to evaluate and find people who have unrecognized genetic disease and save lives by making earlier diagnoses.” Clinical laboratories will play a key role in making those early diagnoses and in managing personalized medical treatment plans. (Photo copyright: Vanderbilt University.)
Variants of Uncertain Significance
According to the NU news release, the scientists determined the functional consequences of the variants of uncertain significance they found and used that data to refine the assessment of pathogenicity. In the end, they reclassified 11 of the variants: three that were likely benign and eight that were likely pathogenic.
In the JAMA Oncology study, the VUMC scientists and other researchers conducted a phenome-wide association study to find EHR phenotypes associated with variants in 23 hereditary cancer genes. According to the VUMC news release, they identified 19 new associations:
The VUMC study findings could improve disease diagnosis and management for cancer patients and help identify high-risk individuals, the researchers noted in their published report.
In an editorial published in Circulation, titled, “First Steps of Population Genomic Medicine in the Arrhythmia World: Pros and Cons,” the professors noted that using genomic information in the case of potentially lethal inherited arrhythmia syndromes could be “lifesaving,” but questioned the benefits of reporting such secondary findings when patients are undergoing genome sequencing for other indications such as cancer.
“The likelihood that these ‘genetic diagnoses’ are translated into clinical diagnoses have not been completely evaluated,” they wrote. “In addition to the challenge of accurately identifying disease-causing genetic variants, defining the penetrance of such variants is critical to this process, i.e., what proportion of individuals in the general population with apparently pathogenic variants will develop the associated phenotype? If penetrance is low for particular gene/phenotype combinations, the costs associated with clinical screening and the psychological effects on individuals informed that they have potentially life-threatening variants may outweigh the benefits of the few new clinical diagnoses.”
These latest studies provide further evidence of the value of big data in healthcare and offer another lesson to clinical laboratories and pathologist about the future role data streaming from clinical laboratories and pathology assays may have in the growth of personalized medicine.
Two studies show the accuracy of perception-based systems in detecting disease biomarkers without needing molecular recognition elements, such as antibodies
Researchers from multiple academic and research institutions have collaborated to develop a non-conventional machine learning-based technology for identifying and measuring biomarkers to detect ovarian cancer without the need for molecular identification elements, such as antibodies.
Traditional clinical laboratory methods for detecting biomarkers of specific diseases require a “molecular recognition molecule,” such as an antibody, to match with each disease’s biomarker. However, according to a Lehigh University news release, for ovarian cancer “there’s not a single biomarker—or analyte—that indicates the presence of cancer.
“When multiple analytes need to be measured in a given sample, which can increase the accuracy of a test, more antibodies are required, which increases the cost of the test and the turnaround time,” the news release noted.
Unveiled in two sequential studies, the new method for detecting ovarian cancer uses machine learning to examine spectral signatures of carbon nanotubes to detect and recognize the disease biomarkers in a very non-conventional fashion.
“Carbon nanotubes have interesting electronic properties,” said Daniel Heller, PhD (above), in the Lehigh University news release. “If you shoot light at them, they emit a different color of light, and that light’s color and intensity can change based on what’s sticking to the nanotube. We were able to harness the complexity of so many potential binding interactions by using a range of nanotubes with various wrappings. And that gave us a range of different sensors that could all detect slightly different things, and it turned out they responded differently to different proteins.” This method differs greatly from traditional clinical laboratory methods for identifying disease biomarkers. (Photo copyright: Memorial Sloan-Kettering Cancer Center.)
Perception-based Nanosensor Array for Detecting Disease
In the Science Advances paper, the researchers described their development of “a perception-based platform based on an optical nanosensor array that leverages machine learning algorithms to detect multiple protein biomarkers in biofluids.
“Perception-based machine learning (ML) platforms, modeled after the complex olfactory system, can isolate individual signals through an array of relatively nonspecific receptors. Each receptor captures certain features, and the overall ensemble response is analyzed by the neural network in our brain, resulting in perception,” the researchers wrote.
“This work demonstrates the potential of perception-based systems for the development of multiplexed sensors of disease biomarkers without the need for specific molecular recognition elements,” the researchers concluded.
In the Nature Biomedical Engineering paper, the researchers described a fined-tuned toolset that could accurately differentiate ovarian cancer biomarkers from biomarkers in individuals who are cancer-free.
“Here we show that a ‘disease fingerprint’—acquired via machine learning from the spectra of near-infrared fluorescence emissions of an array of carbon nanotubes functionalized with quantum defects—detects high-grade serous ovarian carcinoma in serum samples from symptomatic individuals with 87% sensitivity at 98% specificity (compared with 84% sensitivity at 98% specificity for the current best [clinical laboratory] screening test, which uses measurements of cancer antigen 125 and transvaginal ultrasonography,” the researchers wrote.
“We demonstrated that a perception-based nanosensor platform could detect ovarian cancer biomarkers using machine learning,” said Yoona Yang, PhD, a postdoctoral research associate in Lehigh’s Department of Chemical and Biomolecular Engineering and co-first author of the Science Advances article, in the news release.
How Perception-based Machine Learning Platforms Work
According to Yang, perception-based sensing functions like the human brain.
“The system consists of a sensing array that captures a certain feature of the analytes in a specific way, and then the ensemble response from the array is analyzed by the computational perceptive model. It can detect various analytes at once, which makes it much more efficient,” Yang said.
“SWCNTs have unique optical properties and sensitivity that make them valuable as sensor materials. SWCNTS emit near-infrared photoluminescence with distinct narrow emission bands that are exquisitely sensitive to the local environment,” the researchers wrote in Science Advances.
“Carbon nanotubes have interesting electronic properties,” said Daniel Heller, PhD, Head of the Cancer Nanotechnology Laboratory at Memorial Sloan Kettering Cancer Center and Associate Professor in the Department of Pharmacology at Weill Cornell Medicine of Cornell University, in the Lehigh University news release.
“If you shoot light at them, they emit a different color of light, and that light’s color and intensity can change based on what’s sticking to the nanotube. We were able to harness the complexity of so many potential binding interactions by using a range of nanotubes with various wrappings. And that gave us a range of different sensors that could all detect slightly different things, and it turned out they responded differently to different proteins,” he added.
The researchers put their technology to practical test in the second study. The wanted to learn if it could differentiate symptomatic patients with high-grade ovarian cancer from cancer-free individuals.
The research team used 269 serum samples. This time, nanotubes were bound with a specific molecule providing “an extra signal in terms of data and richer data from every nanotube-DNA combination,” said Anand Jagota PhD, Professor, Bioengineering and Chemical and Biomolecular Engineering, Lehigh University, in the news release.
This year, 19,880 women will be diagnosed with ovarian cancer and 12,810 will die from the disease, according to American Cancer Society data. While more research and clinical trials are needed, the above studies are compelling and suggest the possibility that one day clinical laboratories may detect ovarian cancer faster and more accurately than with current methods.
