Diagnostic test incorporates artificial intelligence and could shorten the time clinical laboratories need to determine patients’ risk for antimicrobial resistance
Sepsis continues to be a major killer in hospitals worldwide. Defeating it requires early diagnosis, including antimicrobial susceptibility testing (AST), and timely administration of antibiotics. Now, in a pilot study, scientists at Seoul National University in South Korea have developed a new clinical laboratory test that uses artificial intelligence (AI) to pinpoint the condition sooner, enabling faster treatment of the deadly bacterial infection.
Sepsis, also known as septicemia or blood poisoning, is a serious medical condition that occurs when the body overreacts to an infection or injury. This often takes place in hospitals through blood-line infections and exposure to deadly bacteria. The dangerous reaction causes extensive inflammation throughout the body. If not treated early, sepsis can lead to organ failure, tissue damage, and even death.
Research teams around the world are creating new technologies and approaches to slash time to answer from when blood specimen is collected to a report of whether the patient is or is not positive for sepsis. The Seoul National University scientists’ new approach is yet another sign for microbiologists and clinical laboratory managers of the priority test developers are giving to solving the problem of diagnosing sepsis faster than using blood culture methodology, which requires several days of incubation.
“Sepsis strikes over 40 million people worldwide each year, with a mortality rate ranging from 20% to 50%,” said Sunghoon Kwon, PhD (above), professor of electrical and computer engineering at Seoul National University and senior author of the study, in an interview with The Times in the UK. “This high mortality rate leads to over 10 million deaths annually. Thus, accurate and prompt antibiotic prescription is essential for treatment,” he added. Clinical laboratories play a critical role in the testing and diagnosis of sepsis. (Photo copyright: Seoul National University.)
Reducing Time to Diagnosis
Seoul National University’s approach begins with drawing a sample of the patient’s blood. The researchers then attach special peptide molecules to magnetic nanoparticles and add those nanoparticles to the blood sample. The particles bind to the harmful pathogens in the blood.
The harmful bacteria are then collected using magnets. Their DNA is extracted, amplified, and analyzed to establish the type of microbes that are present in the sample.
The pathogens are exposed to antibiotics and an AI algorithm evaluates their growth patterns to forecast what treatments would be most beneficial to the patient. This last step is known as antimicrobial susceptibility testing or AST.
“The principle is simple,” said Sunghoon Kwon, PhD, professor of electrical and computer engineering at Seoul National University and senior author of the study, in a Nature podcast. “We have a magnetic nanoparticle. The surface of the magnetic nanoparticle we coat in a peptide that can capture the bacteria.”
Kwon is the CEO of Quantamatrix, the developer of the test.
The complete process can be performed on one machine and results are available in about 12 hours, which reduces typical AST time by 30 to 40 hours when compared to traditional processes.
“Sepsis progresses very quickly, with the survival rate dropping with each passing hour,” Kwon told The Times UK. “Every minute is crucial.”
Preventing Antimicrobial Resistance
The team assessed the performance of their test on 190 hospital patients who had a suspected sepsis infection. The test achieved a 100% match in the identification of a bacterial species. The test also achieved an efficiency of 96.2% for capturing Escherichia coli (E. coli) and 91.5% for capturing Staphylococcus aureus.
“Treatment assessment and patient outcome for sepsis depend predominantly on the timely administration of appropriate antibiotics,” the authors wrote in Nature.
“However,” they added, “the clinical protocols used to stratify and select patient-specific optimal therapy are extremely slow,” due to existing blood culture procedures that may take two or three days to complete.
“The microbial load in patient blood is extremely low, ranging between 1 and 100 colony-forming units (CFU) ml−1 and is vastly outnumbered by blood cells,” the study authors explained. “Due to this disparity, prior steps—including blood culture (BC) to amplify the number of pathogens followed by pure culture to subculture purified colonies of isolates—have been essential for subsequent pathogen species identification (ID) and AST.”
Further research, studies and regulatory approval are needed before this technique becomes available, but the South Korean scientists believe it could be ready for use within two to three years. They also state their test can help prevent antimicrobial resistance (AMR) and bolster the strength of existing antibiotics.
Previous Studies
The Seoul National University study is just the latest effort by scientists to develop faster methods for clinical laboratory testing and diagnosing of sepsis.
In September, Dark Daily reported on a similar test that uses digital imaging and AI to determine sepsis risk for emergency room patients.
According to the Centers for Disease Control and Prevention (CDC), at least 1.7 million adults develop sepsis annually in the US, and that at least 350,000 die as a result of the condition. CDC also lists sepsis as one of the main reasons people are readmitted to hospitals.
Microbiologists and clinical laboratory managers should be aware that scientists are prioritizing the creation of new testing methods for faster detection of sepsis. Various research teams around the world are devising technologies and approaches to reduce the time needed to diagnose sepsis to improve patient outcomes and save lives.
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.
Use of such precision diagnostics offer ‘early detection, localization, and the opportunity to monitor response to therapy,’ say the MIT scientists
Oncologists and medical laboratory scientists know that most clinical laboratory tests currently used to diagnose cancer are either based on medical imaging technologies—such as CT scans and mammography—or on molecular diagnostics that detect cancer molecules in the body’s urine or blood.
Now, in a study being conducted at the Massachusetts Institute of Technology (MIT), researchers have developed diagnostic nanoparticles that can not only detect cancer cells in bodily fluids but also image the cancer’s location. This is the latest example of how scientists are combining technologies in new ways in their efforts to develop more sensitive diagnostic tests that clinical laboratories and other providers can use to detect cancer and other health conditions.
Precision diagnostics such as molecular, imaging, and analytics technologies are key tools in the pursuit of precision medicine.
“Therapeutic outcomes in oncology may be aided by precision diagnostics that offer early detection, localization, and the opportunity to monitor response to therapy,” the authors wrote, adding, “Through tailored target specificities, this modular platform has the capacity to be engineered as a pan-cancer test that may guide treatment decisions for numerous tumor type.”
Development of Multimodal Diagnostics
The MIT scientists are developing a “multimodal” diagnostic that uses molecular screening combined with imaging techniques to locate where a cancer began in the body and any metastases that are present.
“In principle, this diagnostic could be used to detect cancer anywhere in the body, including tumors that have metastasized from their original locations,” an MIT new release noted.
“This is a really broad sensor intended to respond to both primary tumors and their metastases,” said biological engineer Sangeeta Bhatia, MD, PhD (above), in the news release. Bhatia is the John and Dorothy Wilson Professor of Health Sciences and Technology and Electrical Engineering and Computer Science at MIT and senior author of the study.
“It can trigger a urinary signal and also allow us to visualize where the tumors are,” she added. Bhatia previously worked on the development of cancer diagnostics that can produce synthetic biomarkers which are detectable in urine samples.
“The vision is that you could use this in a screening paradigm—alone or in conjunction with other tests—and we could collectively reach patients that do not have access to costly screening infrastructure today,” said Sangeeta Bhatia, MD, PhD (above), in the MIT news release. “Every year you could get a urine test as part of a general check-up. You would do an imaging study only if the urine test turns positive to then find out where the signal is coming from. We have a lot more work to do on the science to get there, but that’s where we would like to go in the long run.” (Photo copyright: NBC News.)
Precision Diagnostic Assists Assessment of Response to Cancer Therapy
For their research, the scientists added a radioactive tracer known as copper-64 to the nanoparticles. This enabled the particles to be used for positron emission tomography (PET) imaging. The particles were coated with a peptide that induced them to accumulate at tumor sites and insert themselves into cell membranes, producing a strong imaging signal for tumor detection.
The researchers tested their diagnostic nanoparticles in mouse models of metastatic colon cancer where tumor cells had traversed to the liver or the lungs. After treating the cancer cells with a chemotherapy regimen, the team successfully used both urine and imaging to determine how the tumors were responding to the treatment.
Bhatia is hopeful that this type of diagnostic could be utilized in assessing how patients are responding to treatment therapies and the monitoring of tumor recurrence or metastasis, especially for colon cancer.
What is unique about the approach used by Bhatia’s team is that one application of the copper-64 tracer can be used in vivo, in combination with imaging technology. The other application of the copper-64 tracer is in vitro in a urine specimen that can be tested by clinical laboratories.
“Those patients could be monitored with the urinary version of the test every six months, for instance. If the urine test is positive, they could follow up with a radioactive version of the same agent for an imaging study that could indicate where the disease had spread,” Bhatia said in the news release. “We also believe the regulatory path may be accelerated with both modes of testing leveraging a single formulation.”
The graphic above, taken from the MIT news release, shows how “multimodal nanosensors (1) are engineered to target and respond to hallmarks in the tumor microenvironment. The nanosensors provide both a noninvasive urinary monitoring tool (2) and an on-demand medical imaging agent (3) to localize tumor metastasis and assess response to therapy,” the news release states. (Photo and caption copyright: Massachusetts Institute of Technology.)
Precision Medicine Cancer Screening Using Nano Technologies
Bhatia hopes that the nanoparticle technology may be used as a screening tool in the future to detect any type of cancer.
Her previous research with nanoparticle technology determined that a simple urine test could diagnose bacterial pneumonia and indicate if antibiotics could successfully treat that illness, the news release noted.
Nanoparticle-based technology might be adapted in the future to be part of a screening assay that determines if cancer cells are present in a patient. In such a scenario, clinical laboratories would be performing tests on urine samples while imaging techniques are simultaneously being used to diagnose and monitor cancers.
Surgical pathologists may also want to monitor the progress of this research, as it has the potential to be an effective tool for monitoring cancer patients following surgery, chemotherapy, or radiation therapy.
This research could lead to a useful liquid biopsy test that would be a powerful new tool for clinical laboratories and anatomic pathologists
Cancer researchers have long sought the Holy Grail of
diagnostics—a single biomarker that can quickly detect cancer from blood or
biopsied tissue. Now, researchers in Australia may have found that treasure. And
the preliminary diagnostic test they have developed reportedly can return
results in just 10 minutes with 90% accuracy.
In a news release, University of Queensland researchers discussed identifying a “simple signature” that was common to all forms of cancer, but which would stand out among healthy cells. This development will be of interest to both surgical pathologists and clinical laboratory managers. Many researchers looking for cancer markers in blood are using the term “liquid biopsies” to describe assays they hope to develop which would be less invasive than a tissue biopsy.
“This unique nano-scaled DNA signature appeared in every type of breast cancer we examined, and in other forms of cancer including prostate, colorectal, and lymphoma,” said Abu Sina, PhD, Postdoctoral Research Fellow at the Australian Institute for Bioengineering and Nanotechnology (AIBN), University of Queensland (UQ), in the news release.
“We designed a simple test using gold nanoparticles that
instantly change color to determine if the three-dimensional nanostructures of cancer
DNA are present,’ said Matt
Trau, PhD, Professor of Chemistry at the University of Queensland, and
Deputy Director and Co-Founder of UQ’s AIBN, in the news release.
The team’s test is preliminary, and more research is needed before
it will be ready for Australia’s histopathology laboratories (anatomic
pathology labs in the US). Still, UQ’s research is the latest example of how
increased knowledge of DNA is making it possible for researchers to identify
new biomarkers for cancer and other diseases.
“We certainly don’t know yet whether it’s the holy grail for
all cancer diagnostics, but it looks really interesting as an incredibly simple
universal marker of cancer, and as an accessible and inexpensive technology
that doesn’t require complicated lab-based equipment like DNA sequencing,” Trau
added.
The UQ researchers published their study in the journal Nature Communications. In it, they noted that “Epigenetic reprogramming in cancer genomes creates a distinct methylation landscape encompassing clustered methylation at regulatory regions separated by large intergenic tracks of hypomethylated regions. This methylation landscape that we referred to as ‘Methylscape’ is displayed by most cancer types, thus may serve as a universal cancer biomarker.”
While methyl patterning is not new, the UQ researchers say they were the first to note the effects of methyl pattern in a particular solution—water. With the aid of transmission electron microscopy, the scientists saw DNA fragments in three-dimensional structures in the water. But they did not observe the signature in normal tissues in water.
“To date, most research has focused on the biological consequences of DNA Methylscape changes, whereas its impact on DNA physicochemical properties remains unexplored,” UQ scientists Matt Trau, PhD (left), Abu Sina, PhD (center), and Laura Carrascosa (right), wrote in their study. “We exploit these Methylscape differences to develop simple, highly sensitive, and selective electrochemical or colorimetric one-step assays for the detection of cancer.” (Photo copyright: University of Queensland.)
Their test averaged 90% accuracy during the testing of 200
human cancer samples. Furthermore, the researchers found the DNA structure to
be the same in breast, prostate, and bowel cancers, as well as lymphomas, noted
The Conversation.
“We find that DNA polymeric
behavior is strongly affected by differential patterning of methylcytosine
leading to fundamental differences in DNA solvation and DNA-gold affinity
between cancerous and normal genomes,” the researchers wrote in NatureCommunications.“We exploit
these methylscape differences to develop simple, highly sensitive, and
selective electrochemical or one-step assays for detection of cancer.”
Next Steps for the
“Gold Test”
“This approach represents an exciting step forward in
detecting tumor DNA in blood samples and opens up the possibility of a generalized
blood-based test to detect cancer, Ged Brady, PhD, Cancer Research UK
Manchester Institute, told The
Oxford Scientist. “Further clinical studies are required to evaluate
the full clinic potential of the method.”
Researchers said the next step is a larger clinical study to
explore just how fast cancer can be detected. They expressed interest in
finding different cancers in body fluids and at various stages. Another opportunity
they envision is to use the cancer assay with a mobile device.
DiCarlo told USA Today
that such a mobile test could be helpful to clinicians needing fast answers for
people in rural areas. However, he’s also concerned about false positives. “You
don’t expect all tumors to have the same methylation pattern because there’s so
many different ways that cancer can develop,” he told USA Today. “There
are some pieces that don’t exactly align logically.”
The UQ researchers have produced an intriguing study that differs
from other liquid biopsy papers covered by Dark Daily. While their test may need to be used in combination with other
diagnostic tests—MRI, mammography, etc.—it has the potential to one day be used
by clinical laboratories to quickly reveal diverse types of cancers.
Concept is for patients to take a pill containing nanoparticles programmed to detect cancers or other disease symptoms and a wearable gadget would report their findings
Google is using the same biomarker molecules as clinical laboratories in an attempt to enable in vitro monitoring of an individual’s health status. The device is under development and represents yet one more effort by Google (NASDAQ:GOOG) to penetrate the market for consumer health services.
This futuristic project is under development by the Google X Life Sciences team. The goal is create a device that would allow patients to noninvasively self-diagnose most diseases and health conditions.
The team is led by Andrew Conrad Ph.D.. The device under development is called the NanoParticle platform. It is a tool that continuously monitors an individual’s health status from the inside and reports what it finds through a wearable, watch-like device. (more…)
