News, Analysis, Trends, Management Innovations for
Clinical Laboratories and Pathology Groups

Hosted by Robert Michel

News, Analysis, Trends, Management Innovations for
Clinical Laboratories and Pathology Groups

Hosted by Robert Michel
Sign In

University of Utah Study Points to Genetic Link for High Risk of Stillbirth

Researchers at the university suggested their findings could lead to new genetic tests that could be offered by medical laboratories

New research conducted at the University of Utah suggests that clinical laboratories may someday be able to deploy genetic tests to indicate whether a couple has a higher-than-average risk of stillbirth.

This is yet another example of how researchers are cracking DNA’s code to understand how certain gene variants may affect the healthcare of offspring. The knowledge produced by this research, as confirmed by additional studies, may lead to genetic markers that medical laboratories can use to diagnose the risk of stillbirth using the parent’s DNA.

The researchers published their study in the British Journal of Obstetrics and Gynaecology (BJOG), titled “Familial Aggregation of Stillbirth: A Pedigree Analysis of a Matched Case–Control Study.”

Jessica Page, MD

“Stillbirth is one of those problems that is so tragic and life-changing,” said study co-author Jessica Page, MD (above). “It is especially frustrating when you don’t have a good answer for why it happens. This knowledge may give us the opportunity to change how we risk stratify people and reduce their risk through prevention.” Should this research be validated, clinical laboratories may soon have new genetics tests to help doctors identify risk for stillbirth. (Photo copyright: Intermountain Healthcare.)

Can Stillbirth be Prevented?

Jessica Page, MD, an assistant professor in the Department of Obstetrics and Gynecology at the University of Utah School of Medical and co-author of the 2022 study, was lead author of a 2018 study that estimated nearly one-fourth of stillbirths are preventable.

“Stillbirth rate reduction has been slow in the US and we think many stillbirths may be potentially preventable,” she said in a university press release. “This is motivating us to look for those genetic factors so we can achieve more dramatic rate reduction.”

According to the press release, the University of Utah researchers found that stillbirth “can be inherited and tends to be passed down through male members of the family. That risk preferentially comes from the mother’s or father’s male relatives—their brothers, fathers, grandfathers, uncles, or male cousins. But the odds of a couple losing a baby to stillbirth are even greater when the condition comes from the father’s side of the family.”

The researchers made this discovery by analyzing data from the Utah Population Database (UPDB), which contains information on eight million people who were born in the state or have other connections there. The database is maintained by the Huntsman Cancer Institute at the University of Utah. It includes genealogical information and health records that allowed the researchers to trace incidence of stillbirths across multiple generations of families.

The researchers examined 9,404 stillbirth cases between 1978 and 2019, along with 18,808 live births that served as controls. They identified 390 multi-generational families with high numbers of stillbirths. Within that group, they looked at incidence of stillbirth among first-, second-, and third-degree relatives of stillborn babies. They then compared those numbers with data from unaffected families.

“We were able to evaluate multigenerational trends in fetal death as well as maternal and paternal lineages to increase our ability to detect a familial aggregation of stillbirth,” said genetic epidemiologist Tsegaselassie Workalemahu, PhD, lead author of the study. “Not many studies have examined inherited genetic risk for stillbirth because of a lack of data. The Utah Population Database allows for a more rigorous evaluation than has been possible in the past.”

Workalemahu described the research as “an important step toward identifying specific genes that increase the risk of stillbirth, which could one day lead to better diagnosis and prevention,” according to the university press release.

One caveat, the press release notes, is that Utah’s population is disproportionately of northern European descent. “Future studies will need to determine whether the trends hold true among people of different races and ethnicities,” it stated.

Call for More Testing

The University of Utah study is part of a larger effort to gain a greater understanding of the causes of stillbirths.

“Researchers and national obstetric groups, including the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine, have called on doctors and hospitals to offer a stillbirth evaluation, a systematic assessment that includes placental exams, genetic testing, and autopsies,” states a recent story from ProPublica.

The story notes that “more than 20,000 pregnancies in the US end in stillbirth,” and in one in three of those cases, the cause is not determined.

Drucilla Roberts, MD, an obstetric and perinatal pathologist at Massachusetts General Hospital (MGH), told ProPublica that at a minimum, “the placenta should definitely be evaluated in every stillbirth.” But citing CDC data, the story notes that this is done in only 65% of stillbirths, and autopsies are performed in less than 20%.

“Experts blame the low rates on several factors,” the story states. “Because an autopsy often is performed in the days following a stillbirth, doctors and nurses have to ask families soon after they receive news of the death if they would like one. Many families can’t process the loss, let alone imagine their baby’s body being cut open. What’s more, many doctors aren’t trained in the advantages of an autopsy, or in communicating with parents about the exam.”

One consequence, ProPublica notes, is that clinicians are ill-equipped to advise patients on how to reduce risk in future pregnancies. The story describes the case of Karen Gibbins, MD, a maternal-fetal medicine specialist and an assistant professor of obstetrics and gynecology at the Oregon Health and Science University (OHSU) in Portland.

An Opportunity for Pathologists

Gibbins’ son was stillborn in 2018. She asked for an autopsy and learned that her son “had a rare disease caused by her antibodies attacking the cells in his liver,” the story states. When she became pregnant again, her doctor prescribed antibody infusions and she later gave birth to a healthy son. “If we had not had that autopsy, my third child would have died as well,” she told ProPublica.

This parent’s comment about the value of the autopsy done after her son’s stillbirth identifies an opportunity for the pathology profession. For several decades, health plans have become ever more reluctant to pay for autopsies. Yet, pathologists know the value that autopsies can provide.

The immediate value comes from revealing useful insights about all the health conditions of the deceased. The long-term value comes from the ability to gather the findings across a large number of autopsies that can contribute to new knowledge about health conditions that physicians use to improve the diagnoses of different health conditions.

Thus, with the publication of this peer-reviewed study about the connection between genetic variations and stillbirth, there is the opportunity for some of the nation’s pathology societies to advocate for funding a pilot program to fund more autopsies of stillborn babies, specifically to add more knowledge about the role of gene mutations as a causative factor in stillbirths.

Stephen Beale

Related Information:

Increased Risk for Stillbirth Passed Down Through Fathers, Male Relatives

Familial Aggregation of Stillbirth: A Pedigree Analysis of a Matched Case–Control Study

Potentially Preventable Stillbirth in a Diverse U.S. Cohort

Raising the Bar on Stillbirth Research

Study Finds Genes Might Play Major Factor in Stillbirths

Risk of Stillbirth Linked to Father’s Family History, Study Suggests

After a Stillbirth, an Autopsy Can Provide Answers. Too Few of Them Are Being Performed

Her Child Was Stillborn at 39 Weeks. She Blames a System That Doesn’t Always Listen to Mothers

New Case of Polio Diagnosed in New York, Poliovirus Found in Wastewater in Two Counties

Experts say it is time ‘to restore our confidence in vaccines’ as many medical laboratories take steps to support testing for the polio virus

Clinical laboratories and microbiologists in the state of New York will want to know that, in July, a man in New York was diagnosed with polio and subsequently the virus was detected in the wastewater of two New York counties.

The area, Rockland County, N.Y., just north of New York City, was also at the forefront of a measles outbreak that occurred in 2018 and 2019. The outbreak was attributed to low vaccination rates within the community.

The unidentified, immunocompetent young man was admitted to a New York hospital after experiencing a low-grade fever, neck stiffness, back and abdominal pain, constipation, and lower extremity weakness. He eventually developed paralysis from the disease, which is irreversible. 

Poliomyelitis, commonly known as polio, is a disabling and life-threatening disease that is caused by the poliovirus. Though it rarely surfaces in the United States, there is now confirmation of the first US case since 2013.

Mary T. Bassett, MD

“The polio vaccine is safe and effective, protecting against this potentially debilitating disease, and it has been part of the backbone of required, routine childhood immunizations recommended by health officials and public health agencies nationwide,” said Mary T. Bassett, MD (left), Health Commissioner at the New York Department of Health, in a press release. Clinical laboratories and microbiologists in New York may want to prepare for an increase in vaccination requests. (Photo copyright: Time.)

Is Polio Back in America? Clinical Laboratories Will Want to Be Prepared

“I think it’s concerning because it can spread,” epidemiologist Walter Orenstein, MD, Professor, Department of Medicine, Division of Infectious Diseases at Emory University School of Medicine told STAT. “If there are unvaccinated communities, it can cause a polio outbreak.”

According to the federal Centers for Disease Control and Prevention (CDC), public health experts are working diligently to discover how and where the infected individual contracted polio. The CDC website states that the risk for people who have received the polio vaccine is very low, but there is concern for those who have not received the recommended doses of the vaccine.

“Most of the US population has protection against polio because they were vaccinated during childhood, but in some communities with low vaccine coverage, there are unvaccinated people at risk,” the CDC noted. “Polio and its neurologic effects cannot be cured but can be prevented through vaccination.”

The US uses an injectable polio vaccine for the poliovirus which contains killed viruses. The vaccine “instructs” the immune system to recognize and combat the virus. This inactivated polio vaccine (IPV) is administered to children as a shot in the arm or leg and is typically given in four separate doses.

“The inactivated polio vaccine we have is very effective and very safe and could have prevented this,” Orenstein told STAT. “We need to restore our confidence in vaccines.”

“Based on what we know about this case, and polio in general, the (New York) Department of Health strongly recommends that unvaccinated individuals get vaccinated or boosted with the FDA-approved IPV polio vaccine as soon as possible,” said Mary T. Bassett, MD, Health Commissioner at the New York Department of Health in a press release.

Poliovirus Found in Wastewater via Use of Gene Sequencing

Poliovirus is very contagious and is transmitted through person-to-person contact. The virus lives in an infected person’s throat and intestines and can contaminate food and water in unsanitary conditions. According to the CDC, typical symptoms of the illness include flu-like symptoms such as:

  • Sore throat
  • Fever
  • Tiredness
  • Nausea
  • Headache
  • Stomach pain

Most of these symptoms will disappear within five days, but polio can invade the nervous system and cause more serious complications, such as meningitis, paralysis, and even death.

After confirmation of the new case of polio, wastewater surveillance detected the presence of the poliovirus in Rockland and Orange counties, New York.

Wastewater analysis can uncover pathogens within a community and has been used in the fight against other infectious diseases, including:

“In some regards, wastewater is a public health dream scenario,” said Mark Siedner, MD, an infectious disease doctor at Massachusetts General Hospital and associate professor at Harvard Medical School, in an interview with Fortune. “Everyone poops, and most people poop every day. It provides real-time data on infection rates. In that regard, it’s an extremely powerful tool, particularly good at detecting early warning signs. Before people get sick, we might get a signal.”

Wastewater analysis can provide insights regarding the types of viruses that people within a community are shedding and if the volume of those viruses are increasing. This information can provide scientists with an early marker for an outbreak of an illness that is on the verge of spreading.

Microbiologists and clinical laboratories should be aware of the specific types of infectious agents public health authorities are detecting in wastewater, even as they perform screening and diagnostic tests on their patients for similar infectious diseases.

Polio is Appearing Worldwide

The Global Polio Eradication Initiative (GPEI) has announced that new cases of polio have been reported in Israel and the United Kingdom. These are countries where polio cases are extremely rare. 

This indicates that microbiologists and clinical laboratories managers will want to be on constant alert for uncommon infectious diseases that may appear suddenly, even if those illnesses are rare. Accurate and immediate diagnoses of such infectious diseases could play a major role in triggering a public health response to control potential outbreaks while they are in their earlier stages.

JP Schlingman

Related Information:

N.Y. State Detects Polio Case, First in the U.S. Since 2013

US Polio Case Tied to Viruses Detected in UK, Israel, Suggesting Silent Spread

New York Adult Diagnosed with Polio, First US Case in Nearly a Decade

New York State Department of Health and Rockland County Department of Health Alert the Public to a Case of Polio in the County

Public Health Response to a Case of Paralytic Poliomyelitis in an Unvaccinated Person and Detection of Poliovirus in Wastewater—New York, June—August 2022

Polio Found in New York Wastewater as State Urges Vaccinations

Polio is Found in the UK For the First Time in Nearly 40 years. Here’s What It Means

Poliovirus Detected in Sewage from North and East London

Can’t Help Falling in Love with a Vaccine: How Polio Campaign Beat Vaccine Hesitancy

Vaccine-derived Polio Is on the Rise. A New Vaccine Aims to Stop the Spread

Statement of the Thirty-first Polio IHR Emergency Committee

What is Polio?

Did I Get the Polio Vaccine? How to Know If You Are Protected Against the Virus

Polio Detected in New York City Sewage Suggesting Local Circulation of Virus, Health Officials Say

Wastewater Is Trying to Tell Us Something about the Future of COVID, Polio, Monkeypox, and the Next Epidemic to Come

‘Silent’ Spread of Polio in New York Drives CDC to Consider Additional Vaccinations for Some People

Updated Statement on Report of Polio Detection in United States

Researchers at Harvard’s Massachusetts General Hospital Develop a Non-Invasive Liquid Biopsy Blood Test to Detect and Monitor Common Brain Tumors in Adults

Breakthrough assay a ‘tenfold improvement over any prior assay for TERT mutations in the blood for brain tumors,’ MGH says in an affirmation of a diagnostic technology clinical labs might soon use

In recent years, investors have poured tens of millions of dollars into companies that promised to create non-invasive cancer tests which use liquid biopsy technology. Medical laboratory scientists even watched some of these companies hype their particular liquid biopsy tests before clinical studies generated data demonstrating that these tests produced accurate, reliable, and reproducible results.

For diagnosing cancer, a liquid biopsy test typically uses a blood sample with the goal of finding and identifying circulating tumor cells. Harvard Medical School researchers at Massachusetts General Hospital (MGH) believe they have developed just such a blood test. Their assay utilizes an enhanced form of liquid biopsy to detect and monitor one of the more prevalent types of brain tumor in adults—a glioma—and, according to a Harvard news release, can detect the presence of glioma at a significantly higher “overall sensitivity” than other similar liquid-biopsy tests.

Gliomas start in glia cells contained in the brain or spine. They account for about 30% of all brain and central nervous system tumors and 80% of all malignant brain tumors.

During their study, MGH researchers compared blood samples and tumor biopsy tissues from patients diagnosed with a glioma. They discovered that an assay they developed—a droplet digital polymerase chain reaction (ddPCR) blood test—could detect and monitor two types of telomerase reverse transcriptase (TERT) promoter gene mutations—C228T and C250T. These two gene mutations promote cancer growth and are present in more than 60% of all gliomas. The mutations are also present in 80% of all high-grade gliomas, which are the most aggressive and life-threatening types of the cancer.  

In the press release, instructor in Neurosurgery at MGH and one of the study’s authors, Leonora Balaj, PhD, said, “By ‘supercharging’ our ddPCR assay with novel technical improvements, we showed for the first time that the most prevalent mutation in malignant gliomas can be detected in blood, opening a new landscape for detection and monitoring of the tumors.”

The MGH researchers released their findings in Clinical Cancer Research, a peer-reviewed medical journal devoted to the field of oncology published by the American Association of Cancer Research (AACR). 

Bob Carter, MD, PhD
Bob Carter, MD, PhD (above), is neurosurgical oncologist and Chief of Neurosurgery at MGH, a Professor of Neurosurgery at Harvard Medical School, and one of the study’s authors. In the MGH press release he said, “We envision the future integration of tests like this one into the clinical care of our patients with brain tumors. For example, if a patient has a suspected mass on MRI scanning, we can take a blood sample before the surgery and assess the presence of the tumor signature in the blood and then use this signature as a baseline to monitor as the patient later receives treatment, both to gauge response to the treatment and gain early insight into any potential recurrence.” What Carter describes is precision medicine and could open new diagnostic opportunities for anatomic pathology groups and clinical laboratories. (Photo copyright: Massachusetts General Hospital.)

MGH’s Ten-Fold Improvement over Previous ddPCR Assays

A liquid biopsy is the sampling and analysis of non-solid tissue in the body—primarily blood. MGH’s liquid-biopsy method detects cancer by examining fragments of tumor DNA circulating in the bloodstream. Since the technique is mostly non-invasive, tests can be performed more frequently to track tumors and mutations and monitor treatment progression. Prior to this new method, brain tumors had been difficult to detect using liquid biopsies.

“Liquid biopsy is particularly challenging in brain tumors because mutant DNA is shed into the bloodstream at a much lower level than any other types of tumors,” Balaj said in the press release.

However, MGH’s new ddPCR assay has an overall sensitivity rate of 62.5% and a specificity of 90%, which represents a tenfold improvement over prior assays for TERT mutations in the blood.

And when testing the performance of the ddPCR assay in tumor tissue, the MGH researchers discovered their results were the same as results from a previous independently-performed clinical laboratory assessment of TERT mutations within collected tumor specimens. They also found that their assay could detect TERT mutations when looking at blood plasma samples collected at other facilities.

The researchers believe that their test could be performed in most clinical laboratories and can be utilized to follow the course of disease in cancer patients. The MGH researcher’s goal is to expand and adapt the blood test to diagnose, differentiate, and monitor other types of brain tumors in addition to gliomas.

Of course, more research will be needed before MGH’s new assay can become a vital tool in the fight against disease. However, this type of genetic analysis may soon provide pathologists with new techniques to more accurately diagnose and monitor cancers, and to provide healthcare providers with valuable data regarding which therapies would be the most beneficial for individual patients, a key element of precision medicine. 

—JP Schlingman

Related Information:

Breakthrough Blood Test Developed for Brain Tumors

TERT Promoter Mutation Analysis for Blood-based Diagnosis and Monitoring of Gliomas

New Understanding of CRISPR-Cas9-Guided Base Editors Could Trigger Development of Gene-Editing Tools Targeting Diseases and New Types of Clinical Laboratory Tests

Being able to study the 3D-structure of a CRISPR base editor could help refine the entire CRISPR system, says lead study author Jennifer Doudna, PhD

Molecular biology laboratories engaged in CRISPR gene editing will be interested to note that researchers at the University of California Berkeley (UC Berkeley) have created for the first time a three-dimensional (3D) view of the molecular structure of a base editor for CRISPR-Cas9. This breakthrough may lead to new, more accurate gene-editing tools for biomedical research and gene therapy.

Clinical laboratories involved in genetic testing may find this welcomed news, after a pair of studies conducted in 2019 raised concerns about CRISPR base editing. The researchers of those studies observed that it “causes a high number of unpredictable mutations in mouse embryos and rice,” Chemical and Engineering News (C&EN) reported, adding, “Other groups have raised concerns about off-target mutations caused when the traditional CRISPR-Cas9 form of gene editing cuts DNA at a location that it wasn’t supposed to touch. The results of the new studies are surprising, however, because scientists have lauded base editors as one of the most precise forms of gene editing yet.”

Dark Daily covered similar study findings by Massachusetts General Hospital (MGH) in “Researchers at Massachusetts General Hospital Identify Ways That CRISPR DNA Base Editors Sometimes Unintentionally Alter RNA,” May 31, 2019.

Nevertheless, UC Berkeley’s latest breakthrough is expected to drive development of new and more accurate CRISPR-Cas genome-editing tools, which consist of base editors as well as nucleases, transposases, recombinases, and prime editors.

The UC researchers published their findings in the journal Science, titled, “DNA Capture by a CRISPR-Cas9–Guided Adenine Base Editor.”

Understanding CRISPR Base Editors At a ‘Deeper Level’

Harvard University Chemistry and Chemical Biology Professor David Liu, PhD, who co-authored the study, explained the significance of this latest discovery.

“While base editors are now widely used to introduce precise changes in organisms ranging from bacteria to plants to primates, no one has previously observed the three-dimensional molecular structure of a base editor,” he said in a UC Berkeley news release. “This collaborative project reveals the beautiful molecular structure of a state-of-the-art highly-active base editor—ABE8e—caught in the act of engaging a target DNA site.”

UC Berkeley Professor Jennifer Doudna, PhD (above), who served as senior author of the study, says scientists may now have the information necessary to refine base editors and improve their precision and genome-targeting ability. “This structure helps us understand base editors at a much deeper level,” she said in the UC Berkeley statement. “Now that we can see what we’re working with, we can develop informed strategies to improve the system.” (Photo copyright: UC Berkeley.)

Jennifer Doudna, PhD, UC Berkeley Professor, Howard Hughes Medical Institute Investigator, and senior author of the study, has been a leading figure in the development of CRISPR-Cas9 gene editing. In 2012, Doudna and Emmanuelle Charpentier, PhD, Founding, Scientific and Managing Director at Max Planck Unit for the Science of Pathogens in Berlin, led a team of researchers who “determined how a bacterial immune system known as CRISPR-Cas9 is able to cut DNA, and then engineered CRISPR-Cas9 to be used as a powerful gene editing technology.” In a 2017 news release, UC Berkeley noted that the work has been described as the “scientific breakthrough of the century.”

Viewing the Base Editor’s 3D Shape

CRISPR-Cas9 gene editing allows scientists to permanently edit the genetic information of any organism, including human cells, and has been used in agriculture as well as medicine. A base editor is a tool that manipulates a gene by binding to DNA and replacing one nucleotide with another.

According to the recent UC Berkeley news release, the research team used a “high-powered imaging technique called cryo-electron microscopy” to reveal the base editor’s 3D shape.

Genetic Engineering and Biotechnology News notes that, “The high-resolution structure is of ABE8e bound to DNA, in which the target adenine is replaced with an analog designed to trap the catalytic conformation. The structure, together with kinetic data comparing ABE8e to earlier ABEs [adenine base editors], explains how ABE8e edits DNA bases and could inform future base-editor design.”

The graphic above, taken from the UC Berkeley news release, shows the “3D structure of a base editor, comprised of the Cas9 protein (white and gray), which binds to a DNA target (teal and blue helix) complementary to the RNA guide (purple), and the deaminase proteins (red and pink), which switch out one nucleotide for another.” (Image and caption copyright: UC Berkeley.)

Knowing the Cas9 fusion protein’s 3D structure may help eliminate unintended off-target effects on RNA, extending beyond the targeted DNA. However, until now, scientists have been hampered by their inability to understand the base editor’s structure.

“If you really want to design truly specific fusion protein, you have to find a way to make the catalytic domain more a part of Cas9, so that it would sense when Cas9 is on the correct target and only then get activated, instead of being active all the time,” study co-first author Audrone Lapinaite, PhD, said in the news release. At the time of the study, Lapinaite was a postdoctoral fellow at UC Berkeley. She is now an assistant professor at Arizona State University.

“As a structural biologist, I really want to look at a molecule and think about ways to rationally improve it. This structure and accompanying biochemistry really give us that power,” added UC Berkeley postdoctoral fellow Gavin Knott, PhD, another study co-author. “We can now make rational predications for how this system will behave in a cell, because we can see it and predict how it’s going to break or predict ways to make it better.”

Clinical laboratory leaders and pathologists will want to monitor these new advances in CRISPR technology. Each breakthrough has the power to fuel development of cost-effective, rapid point-of-care diagnostics.

—Andrea Downing Peck

Related Information:

New Understanding of Crispr-Cas9 Tool Could Improve Gene Editing

DNA Capture by a CRISPR-Cas9-Guided Adenine Base Editor

CRISPR Base Editors Cause Unexpected Mutations

How CRISPR Works

Cryo-EM Captures CRISPR-Cas9 Base Editor in Action

Researchers at Massachusetts General Hospital Identify Ways That CRISPR DNA Base Editors Sometimes Unintentionally Alter RNA

King’s College London Study Identifies Six Distinct ‘Types’ of COVID-19 Illness, Each with a Distinct ‘Cluster’ of Symptoms

The KCL researchers’ new models for predicting which patients will need hospitalization and breathing support may be useful for pathologists and clinical laboratory scientists

One more window into understanding the SARS-CoV-2 coronavirus may have just opened. A British study identified six distinct “clusters” of symptoms that the research scientists believe may help predict which patients diagnosed with COVID-19 will require hospitalization and respiratory support. If further research confirms these early findings, pathologists and medical laboratory managers may gain new tools to diagnose infections faster and more accurately.

Researchers from King’s College London (KCL) analyzed data gathered from the COVID Symptom Study App, a mobile-device application developed by health science company ZOE in collaboration with scientists and physicians at KCL and Massachusetts General Hospital, as well as:

Launched in March in the United Kingdom and extended to the United States and Sweden, the app has attracted more than four million users who track their health and potential COVID symptoms on a daily basis.

Increased Accuracy in Predicting COVID-19 Hospitalizations

On July 17, 2020, the Centers for Disease Control and Prevention (CDC) published “Symptom Profiles of a Convenience Sample of Patients with COVID-19—United States, January–April 2020,” which identifies cough, fever, and shortness of breath as the most typical symptoms of COVID-19. However, the KCL study takes those findings a step further.

KCL researchers identified six distinct “types” of COVID-19, each distinguished by a particular cluster of symptoms. They include headaches, muscle pains, fatigue, diarrhea, confusion, loss of appetite, shortness of breath, and more. The researchers also found that COVID-19 disease progression and outcome also vary significantly between people, ranging from mild flu-like symptoms or a simple rash to severe or fatal conditions.

Using app data logged by 1,600 users in March and April, the researchers developed an algorithm that combined information on age, gender, body mass index (BMI), and pre-existing conditions with recorded symptoms from the onset of the illness through the first five days. The researchers then tested the algorithm using a second independent dataset of 1,000 users, logged in May.

In a news release, the KCL researchers identified the six clusters of symptoms as:

  • Flu-like with No Fever: Headache, loss of smell, muscle pains, cough, sore throat, chest pain, no fever.
  • Flu-like with Fever: Headache, loss of smell, cough, sore throat, hoarseness, fever, loss of appetite.
  • Gastrointestinal: Headache, loss of smell, loss of appetite, diarrhea, sore throat, chest pain, no cough.
  • Severe Level One, Fatigue: Headache, loss of smell, cough, fever, hoarseness, chest pain, fatigue.
  • Severe Level Two, Confusion: Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain.
  • Severe Level Three, Abdominal and Respiratory: Headache, loss of smell, loss of appetite, cough, fever, hoarseness, sore throat, chest pain, fatigue, confusion, muscle pain, shortness of breath, diarrhea, abdominal pain.

Using the data, the researchers were able to more accurately predict—78.8% versus 69.5%—which of the six symptom clusters placed patients at higher risk of requiring hospitalization and breathing support (ventilation or additional oxygen) than with prediction models based on personal characteristics alone. For example, nearly 50% of the patients in cluster six (Severe Level Three, Abdominal and Respiratory) ended up in the hospital, compared with 16% of those in cluster one (Flu-like with No Fever).

Claire Steves, MD, PhD a Clinical Senior Lecturer at King’s College London
“These findings have important implications for care and monitoring of people who are most vulnerable to severe COVID-19,” Claire Steves, MD, PhD (above left), Clinical Senior Lecturer at King’s College London, said in the KCL news release. “If you can predict who these people are at day five, you have time to give them support and early interventions, such as monitoring blood oxygen and sugar levels, and ensuring they are properly hydrated—simple care that could be given at home, preventing hospitalizations and saving lives.” (Photo copyright: King’s College London.)

According to the Zoe website, the ongoing research is led by:

The researchers published their study findings at medRxiv, titled, “Symptom Clusters in COVID-19: A Potential Clinical Prediction Tool from the COVID Symptom Study App.” The study has not yet undergone peer review.

Encouraging Everyone to Use the COVID-Symptom Study App

The study points out that—broadly speaking—people with cluster four, five, or six COVID-19 symptoms tended to be older and frailer and were more likely to be overweight and have pre-existing conditions, such as diabetes or lung disease, than those with cluster one, two, or three symptoms.

Carole Sudre, PhD a research fellow at King's College London
“Our study illustrates the importance of monitoring symptoms over time to make our predictions about individual risk and outcomes more sophisticated and accurate,” said lead researcher Carole Sudre, PhD (above), a Research Fellow at King’s College London and the study’s lead researcher, in the KCL news release. “This approach is helping us to understand the unfolding story of this disease in each patient so they can get the best care.” (Photo copyright: University College London.)

Tim Spector, FMedSci, Head of the Department of Twin Research and Genetic Epidemiology, and Professor of Genetic Epidemiology at King’s College London, encourages everyone to download the COVID Symptom Study app and help increase the data available to researchers.

“Data is our most powerful tool in the fight against COVID-19,” Spector said in the KCL news release. “We urge everyone to get in the habit of using the app daily to log their health over the coming months, helping us to stay ahead of any local hotspots or a second wave of infections.”

As the body of knowledge surrounding COVID-19 grows, clinical laboratory professionals would be well advised to remain informed on further research regarding not only the potential for COVID-19 variants to exist, but also the evolving guidance on infection prevention and testing.

—Andrea Downing Peck

Related Information:

Six Distinct ‘Types’ of COVID-19 Identified

Symptom Clusters in COVID19: A Potential Clinical Prediction Tool from the COVID Symptom Study App

Symptom Profile of a Convenience Sample of Patients with COVID-19–United States, January-April 2020

;