Studies presented at the Alzheimer’s Association International Conference point to the p-tau217 protein as an especially useful biomarker
Researchers disclosed a potentially useful biomarker for Alzheimer’s Disease at a major conference this summer. The good news for clinical laboratories is that the biomarker is found in blood. If further research confirms these early findings, medical laboratories could one day have a diagnostic test for this condition.
That possibility emerged from the Alzheimer’s Association International Conference (AAIC), which was held online July 27-31. Researchers presented findings from multiple studies that suggested blood/plasma levels of a protein known as phospho-tau217 (p-tau217) can indicate brain anomalies associated with Alzheimer’s.“Changes in brain proteins amyloid and tau, and their formation into clumps known as plaques and tangles, respectively, are defining physical features of Alzheimer’s disease in the brain,” states an AAIC press release. “Buildup of tau tangles is thought to correlate closely with cognitive decline. In these newly reported results, blood/plasma levels of p-tau217, one of the forms of tau found in tangles, also seem to correlate closely with buildup of amyloid.”
At present, “there is no single diagnostic test that can determine if a person has Alzheimer’s disease,” the association states on its website. Clinicians will typically review a patient’s medical history and conduct tests to evaluate memory and other everyday thinking skills. That may help determine that an individual has dementia, but not necessarily that Alzheimer’s is the cause.
“Currently, the brain changes that occur before Alzheimer’s dementia symptoms appear can only be reliably assessed by positron-emission tomography (PET) scans, and from measuring amyloid and tau proteins in [cerebrospinal] fluid (CSF),” the association states. “These methods are expensive and invasive. And, too often, they are unavailable because they are not covered by insurance or difficult to access, or both.”
In the AAIC press release, Alzheimer’s Association Chief Science Officer Maria C. Carrillo, PhD, said that a clinical laboratory blood test “would fill an urgent need for simple, inexpensive, non-invasive and easily available diagnostic tools for Alzheimer’s.
“New testing technologies could also support drug development in many ways,” she added. “For example, by helping identify the right people for clinical trials, and by tracking the impact of therapies being tested. The possibility of early detection and being able to intervene with a treatment before significant damage to the brain from Alzheimer’s disease would be game changing for individuals, families, and our healthcare system.”
However, she cautioned, “these are early results, and we do not yet know how long it will be until these tests are available for clinical use. They need to be tested in long-term, large-scale studies, such as Alzheimer’s clinical trials.”
The study, led by Oskar Hansson, MD, of Lund University in Sweden, included 1,402 participants. About half of these were enrolled in BioFINDER-2, an ongoing dementia study in Sweden. In this group, researchers were most interested in the test’s ability to distinguish Alzheimer’s from other neurodegenerative disorders that cause dementia.
Diagnostic accuracy was between 89% and 98%, the researchers reported, which was similar to the performance of PET imaging and CSF tests. P-tau217 was more accurate than magnetic resonance imaging (MRI) as well as other biomarkers, such as p-tau181.
“Today the majority of individuals with Alzheimer’s disease around the world do not get a timely diagnosis, which results in suboptimal symptomatic treatment and care,” Oskar Hansson, MD, said in an Eli Lilly news release. “With rising prevalence of Alzheimer’s disease, more patients will be evaluated in primary care and other clinics where CSF and PET biomarkers are not available. Blood-based biomarkers, like plasma p-tau217, together with digital tools for checking memory performance, such as smartphone-based apps, can considerably improve the diagnostic work-up of Alzheimer’s disease patients in such clinics.” (Photo copyright: Alzheimer’s Fund.)
Another cohort consisted of 81 participants in the Brain and Body Donation Program at Banner Sun Health Research Institute in Sun City, Ariz. In this program, elderly volunteers submit to periodic clinical assessments and agree to donate their organs and tissue for study after they die.
Here, the researchers’ primary goal was to determine the test’s ability to distinguish between individuals with and without Alzheimer’s. Researchers ran the p-tau217 test on plasma samples collected within 2.9 years of death and compared the results to postmortem examinations of the brain tissue. Accuracy was 89% in individuals with amyloid plaques and tangles, and 98% in individuals with plaques and more extensive tangles.
The third cohort consisted of 622 members of a large extended family in Colombia whose members share a genetic mutation that makes them susceptible to early-onset Alzheimer’s, The New York Times reported. Among the members, 365 were carriers of the mutation. In this group, levels of plasma p-tau217 increased by age, and “a significant difference from noncarriers was seen at age 24.9 years,” the researchers wrote in Jama Network. That’s about 20 years before the median age when mild cognitive impairment typically begins to appear in carriers.
Other Alzheimer Biomarker Studies Presented at AAIC
Suzanne Schindler, MD, PhD, a neurologist and instructor in the Department of Neurology at the Washington University School of Medicine (WUSM) in St. Louis, presented results of an Alzheimer’s Disease (AD) study that used mass spectrometry to analyze amyloid and p-tau variants in blood samples collected from participants. The researchers compared these with CSF and PET results and found that some of the of p-tau isoforms, especially p-tau217, had a strong concordance.
“These findings indicate that blood plasma Aβ and p-tau measures are highly precise biomarkers of brain amyloidosis, tauopathy, and can identify stages of clinical and preclinical AD,” stated an AAIC press release on the studies.
The WUSM researches launched the effort to develop and validate Alzheimer’s blood biomarkers called the Study to Evaluate Amyloid in Blood and Imaging Related to Dementia (SEABIRD) in April 2019. It runs through August 2023 and will seek to enroll more than 1,100 participants in the St. Louis area.
Another study presented at the conference compared the performance of p-tau217 and p-tau181 in distinguishing between Alzheimer’s and Frontotemporal Lobar Degeneration (FTLD), another condition that causes dementia. Study author Elisabeth Thijssen, MSc, of the UC San Francisco Memory and Aging Center reported that both biomarkers could be useful in differential diagnosis, but that p-tau217 was “potentially superior” for predicting a tau positive PET scan result.
For decades, physicians have wanted a diagnostic test for Alzheimer’s Disease that could identify this condition early in its development. This would allow the patient and the family to make important decisions before the onset of severe symptoms. Such a clinical laboratory test would be ordered frequently and thus would be a new source of revenue for medical laboratories.
Abbott sends the SARS-CoV-2 test results directly to patients’ smartphones, which can be displayed to gain entrance into areas requiring proof of COVID-19 testing
There is no greater example that COVID-19 is a major force for change in the clinical laboratory industry than the fact that—though the US federal government pays 50% of the nation’s total annual healthcare spend of $3.5 trillion—it recently spent $760 million to purchase 150 million COVID-19 tests from Abbott Laboratories (NYSE:ABT), an American multinational medical devices and healthcare company headquartered in Abbott Park, Ill., “to expand strategic, evidence-based testing in the United States,” according to the company’s website.
In August, the federal Food and Drug Administration (FDA) granted an emergency use authorization (EUA) to Abbott for its BinaxNOW portable rapid-response COVID-19 antigen (Ag) test. The credit-card sized test costs $5 and can return clinical laboratory test results in minutes, rather than hours, days, or in some cases, weeks, the Wall Street Journal (WSJ) reported.
The test includes a free smartphone app called NAVICA, which enables those tested to receive their test results directly on their mobile devices—bypassing the patient’s primary care physicians.
According to Abbott’s website, the app “allows people who test negative to get an encrypted temporary digital NAVICA Pass, similar to an airline boarding pass. NAVICA-enabled organizations will be able to verify an individual’s negative COVID-19 test results by scanning the individual’s digital NAVICA Pass to facilitate entry into facilities.”
This feature of Abbott’s new COVID-19 test is a good example of how quickly innovation in the medical laboratory testing profession is bringing new features and new capabilities to the marketplace. By marrying the SARS-CoV-2 test with the NAVICA Pass feature, Abbott hopes to deliver increased value—not just to physicians and their patients—but also to employers with employee screening programs and federal government programs designed to screen federal employees, as well as being used for screening travelers at airports and other transportation hubs.
Abbott appears to be banking that in the future such identification will be required to “enter organizations and other places where people gather,” as the company’s website states.
Testing Limited to CLIA-Certified Clinical Laboratories
An HHS news release announcing the government’s planned distribution of the BinaxNOW tests stated that “Testing will be potentially deployed to schools and to assist with serving other special needs populations.”
In the news release, Alex Azar, HHS Secretary, said, “By strategically distributing 150 million of these tests to where they’re needed most, we can track the virus like never before and protect millions of Americans at risk in especially vulnerable situations.”
The EUA adds that “Testing of nasal swab specimens using [BinaxNOW] … is limited to laboratories certified under CLIA that meet the requirements to perform high, moderate, or waived complexity tests. This test is authorized for use at the [point of care], i.e., in patient care settings operating under a CLIA Certificate of Waiver, Certificate of Compliance, or Certificate of Accreditation.”
The FDA’s EUA describes the BinaxNOW portable rapid-response COVID-19 antigen test (above) as “a lateral flow immunoassay intended for the qualitative detection of nucleocapsid protein antigen from SARS-CoV-2 in direct nasal swabs from individuals suspected of COVID-19 by their healthcare provider within the first seven days of symptom onset.” The test costs $5 and Abbott sends results directly to the patient’s smartphone using the free NAVICA app included with the test. (Photo copyright: Abbott Laboratories.)
IVD Companies See Boom in COVID-19 Test Sales
Demand for COVID-19 testing has created opportunities for in vitro diagnostics (IVD) companies that can develop and bring tests to market quickly.
Recent issues of Dark Daily’s sister print publication—The Dark Report (TDR)—covered IVD companies’ second quarter (Q2) boom in sales of COVID-19 instruments and tests, while also noting a fall-off in routine clinical laboratory testing during the COVID-19 pandemic.
Abbott Laboratories saw molecular diagnostics sales increase 241% in Q2 driven by $283 million in sales of COVID-19 testing, while rapid diagnostic COVID-19 testing rose 11% on $180 million in sales in Q2, TDR reported, based on Abbott data.
“There is huge economic incentive for diagnostic companies to develop technologies that can be used to create rapid tests that are cheap to perform,” said Robert Michel, Publisher and Editor-in-Chief of TDR and Dark Daily. “In this sense, COVID is a major force for change.”
“This new COVID-19 antigen test is an important addition to available tests because the results can be read in minutes, right off the testing card,” said Jeff Shuren, MD, JD (above), Director of the FDA’s Center for Devices and Radiological Health (CDRH), in an FDA news release announcing the federal government’s $760 million purchase of 150 million Abbott BinaxNOW rapid-response antigen COVID-19 tests. “This means people will know if they have the virus in almost real-time. Due to its simpler design and the large number of tests the company anticipates making in the coming months, this new antigen test is an important advancement in our fight against the pandemic.” (Photo copyright: The New York Times.)
Thus, Abbott is determined to ensure this product launch is successful and that the test works as promised. According to a news release, “In data submitted to the FDA from a clinical study conducted by Abbott with several leading US research universities, the BinaxNOW COVID-19 Ag Card demonstrated sensitivity of 97.1% (positive percent agreement) and specificity of 98.5% (negative percent agreement) in patients suspected of COVID-19 by their healthcare provider within the first seven days of symptom onset.”
“The massive scale of this test and app will allow tens of millions of people to have access to rapid and reliable testing,” said Joseph Petrosino, PhD, professor and chairman, Molecular Virology and Microbiology, Baylor College of Medicine, in the Abbott news release. “With lab-based tests, you get excellent sensitivity but might have to wait days or longer to get the results. With a rapid antigen test, you get a result right away, getting infectious people off the streets and into quarantine so they don’t spread the virus.”
Abbott has invested hundreds of millions of dollars in two manufacturing facilities where the tests will be made, John Hackett Jr, PhD, an immunologist and Abbott’s Divisional Vice President Applied Research and Technology, and lead scientist on the BinaxNOW project, told The Atlantic.
“Our nation’s frontline healthcare workers and clinical laboratory personnel have been under siege since the onset of this pandemic,” said Charles Chiu, MD, PhD, professor of Laboratory Medicine at University of California, San Francisco, in the Abbott news release. “The availability of rapid testing for COVID-19 will help support overburdened laboratories, accelerate turnaround times, and greatly expand access to people who need it.”
However, other experts are not so sure. In the Atlantic article, Michael Mina MD, PhD, Assistant Professor Epidemiology at Harvard’s T.H. Chan School of Public Health, voiced the need to test both asymptomatic and pre-symptomatic people. “This is the type of [COVID-19] test we have been waiting for—but may not be the test.”
Nevertheless, the federal government’s investment is significant. Abbott plans to start shipping tens of millions of tests in September and produce 50 million tests per month starting in October, Forbes reported.
Shifting Clinical Laboratory Paradigms
BinaxNOW will be performed without doctors’ orders, in a variety of locations, and results go directly to patients’ smartphone—without a pathologist’s interpretation and medical laboratory report. This is new ground and the impact on non-CLIA labs, and on healthcare in general, is yet to be seen.
Clinical laboratory managers will want to monitor the rise of rapid-response tests that can be easily accessed, conducted, and reported on without physician input.
Amazon’s app-based employee healthcare service could be first step toward retailer becoming a disruptive force in healthcare; federal VA develops its own mHealth apps
More consumers are using smartphone applications (apps) to manage different aspects of their healthcare. That fact should put clinical laboratories and anatomic pathology groups on the alert, because a passive “wait and see” strategy for making relevant services and lab test information available via mobile apps could cause patients to choose other labs that do offer such services.
Patient use of apps to manage healthcare is an important trend. In January, Dark Daily covered online retail giant Amazon’s move to position itself as a leader in smartphone app-based healthcare with its launch of Amazon Care, a virtual medical clinic and homecare services program. At that time, the program was being piloted for Seattle-based employees and their families only. Since then, it has been expanded to include eligible Amazon employees throughout Washington State.
Mobile health (mHealth) apps are giving healthcare providers rapid access to patient information. And healthcare consumers are increasingly turning to their mobile devices for 24/7 access to medical records, clinical laboratory test results, management of chronic conditions, and quick appointment scheduling and prescription refills.
Thus, hearing ‘There’s an app for that’ has become part of patients’ expectations for access to quality, affordable healthcare.
For clinical laboratory managers, this steady shift toward mHealth-based care means accommodating patients who want to use mobile apps to access lab test results and on-demand lab data to monitor their health or gain advice from providers about symptoms and health issues.
Amazon, VA, and EMS Develop Their Own mHealth Apps
The Amazon Care app can be freely downloaded from Apple’s App Store and Google Play. With it, eligible employees and family members can:
Communicate with an advice nurse;
Launch an in-app video visit with a doctor or nurse practitioner for advice, diagnoses, treatment, or referrals;
Request a mobile care nurse for in-home or in-office visits;
Receive prescriptions through courier delivery.
The combination telehealth, in-person care program, mobile medical service includes dispatching nurses to homes or workplaces who can provide “physical assessments, vaccines or common [clinical laboratory] tests.”
“Amazon is a company that is experimenting a lot with a variety of opportunities in healthcare,” Glen Tullman (above), Executive Chairman of Livongo, a healthcare company specializing in treating diabetes, and an Amazon partner company, told CNBC. “It’s one to watch.” (Photo copyright: CNBC.)
However, the US federal Department of Veterans Affairs (VA) also is becoming a major player in the mHealth space with the development of its own mobile app—VA Launchpad—which serves as a portal to a range of medical services.
Veterans can access five categories of apps that allow them to manage their health, communicate with their healthcare team, share health information, and use mental health and personal improvement tools.
“The VA was an early adopter of digital health tools and remains a leader within US healthcare in leveraging technology to enhance patient engagement,” Neil C. Evans, MD (above), Chief Officer in the VA Office of Connected Care, told Healthcare IT News. “These digital tools are allowing veterans to more actively understand their health data, to better communicate with VA clinical teams, and to engage more productively as they navigate their individual health journeys,” Evans added. (Photo copyright: Department of Veterans’ Affairs.)
mHealthIntelligence reported that mobile health tools also are enabling first responders to improve emergency patient care. At King’s Daughters Medical Center in Brookhaven, Miss., emergency medical technicians (EMTs) are using a group of mHealth apps from DrFirst called Backline to gain real-time access to patients’ HIPAA-compliant medication histories, share clinical data, and gain critical information about patients prior to arriving on the scene.
Using Backline, EMTs can scan the barcode on a patient’s driver’s license to access six months’ worth of medication history.
“In the past, we could only get information from [patients] who are awake or are willing to give us that information,” Lee Robbins, Director of Emergency Medical Services at King’s Daughters Medical Center in Brookhaven, Miss., told mHealthIntelligence. “Knowing this information gives us a much better chance at a good outcome.”
Smartphone App Detects Opioid Overdose
The opioid crisis remains one of the US’ greatest health challenges. The federal Centers for Disease Control and Prevention (CDC) reported 47,600 opioid-related deaths in 2017, and the problem has only gotten worse since then.
To curtail these tragic deaths, University of Washington (UW) researchers developed a smartphone app called Second Chance, that they believe can save lives by quickly diagnosing when an opioid overdose has occurred.
The app uses sonar to monitor an opioid user’s breathing rate and, according to a UW press release, can detect overdose-related symptoms about 90% of the time from up to three feet away. The app then contacts the user’s healthcare provider or emergency services.
The UW researchers are applying for US Food and Drug Administration (FDA) clearance. They published their findings in the journal Science Translational Medicine.
While Demand for mHealth Apps Grows, Concern over Privacy and Security also Increases
According to mobile data and analytics company App Annie, global downloads of medical apps grew to more than 400 million in 2018, up 15% from two years earlier.
“As with mobile banking, consumers are showing they trust mobile apps with their most sensitive information and are willing to leverage them to replace tasks traditionally fulfilled in-person, such as going into a bank branch or, in the case of medical apps, to a doctor’s office,” App Annie’s website states.
However, the proliferation of mHealth apps has raised privacy and safety concerns as well. While the FDA does regulate some mobile health software functions, it does not ensure an mHealth app’s accuracy or reliability.
Fierce Healthcarereported that federal lawmakers are worried veterans who use the VA’s 47 mHealth apps could find their sensitive healthcare information shared or sold by third-party companies. In fiscal year 2018, veterans participated in more than one million video telehealth visits, a VA press release reported.
US Rep. Susie Lee, D-Nevada, Chairperson of the House Veterans’ Affairs Subcommittee on Technology Modernization, told Fierce Healthcare, “As we assess the data landscape at the VA and the larger health IT space, we need to look at where protections exist or don’t exist and whether we need more guardrails.”
What does all this mean for clinical laboratories? Well, lab managers will want to keep an eye on the growing demand from consumers who want direct access to laboratory test data and appointment scheduling through mHealth apps. And, also be aware of HIPAA regulations concerning the sharing of that information.
Ability to produce unbroken DNA sequencing could eventually be used by medical laboratories to identify gene sequences that play significant roles in a variety of diseases and health conditions
While near 24/7 coronavirus coverage occupies much of the media, it is refreshing to report on important breakthroughs in clinical laboratory medicine and diagnostics that are unrelated to the COVID-19 pandemic. It wasn’t long ago that the top stories in advanced medicine revolved around whole-genome sequencing, so it’s nice to return to the topic, if just for a little while.
Using nanopore sequencing technology from multiple companies, researchers at the University of California Santa Cruz Genomics Institute (UCSC Genomics Institute) have produced what they say is the first telomere-to-telomere or end-to-end map of the human X chromosome. This could prove to be a major milestone for genomics research and help scientists gain a better understanding of certain genetic conditions.
The completely gapless DNA sequencing was produced by using new sequencing technologies that enable much longer reads of strings of DNA base pairs. In the past, most sequencing technologies produced relatively short reads of each sequence, which then had to be painstakingly pieced together to assemble the complete genome.
“With nanopore sequencing we get ultra-long reads of hundreds of thousands of base pairs that can span an entire repeat region, so that bypasses some of the challenges,” said Karen Miga, PhD, a post-doctoral research scientist at the UCSC Genomics Institute and lead author of the study, in a UCSC news release.
UCSC Researchers Find ‘Rich’ Information in the ‘Gaps’ in Reference Sequences
Nanopore sequencing technology from Oxford Nanopore Technologies was combined with sequencing technologies from Pacific Biosciences (PacBio) and Illumina, as well as with optical maps from Bionano, to produce the results of the research. The combination of these technologies allowed the UCSC team to produce a whole-genome sequence assembly with no gaps and with a previously unforeseen level of accuracy.
“These repeat-rich sequences were once deemed intractable, but now we’ve made leaps and bounds in sequencing technology,” Miga said.
According to the Oxford Nanopore Technologies website, “Nanopore sequencing is a unique, scalable technology that enables direct, real-time analysis of long DNA or RNA fragments. It works by monitoring changes to an electrical current as nucleic acids are passed through a protein nanopore. The resulting signal is decoded to provide the specific DNA or RNA sequence.”
By filling in gaps in the human genome, the UCSC researchers opened up new possibilities to finding clues and answers regarding important questions about our genes and how they may contribute to illnesses.
“We’re starting to find that some of these regions where there were gaps in the reference sequence are actually among the richest for variation in human populations, so we’ve been missing a lot of information that could be important to understanding human biology and disease,” said Karen Miga, PhD (above), post-doctoral researcher at the UCSC Genomics Institute and lead author of the study, in the UCSC news release. (Photo copyright: UCSC Genomics Institute.)
During their research, the team had to manually resolve several gaps in the sequence and identify variants within the repeat sequence to serve as markers. They were then able to align the long reads and connect them together to span the centromere of the X chromosome. The centromere is a difficult region of repetitive DNA that is found in every chromosome. It encompasses an area of very repetitive DNA that spans 3.1 million base pairs.
“For me, the idea that we can put together a 3-megabase-size [3-million base pairs] tandem repeat is just mind-blowing. We can now reach these repeat regions covering millions of bases that were previously thought intractable,” Miga said.
The researchers also had to employ a polishing strategy using data obtained from different sequencing technologies to ensure accuracy.
“We used an iterative process over three different sequencing platforms to polish the sequence and reach a high level of accuracy,” Miga explained. “The unique markers provide an anchoring system for the ultra-long reads, and once you anchor the reads, you can use multiple data sets to call each base.”
Linking Gene Variations to Specific Genetic Diseases
Besides the advantages of providing ultra-long reads, nanopore sequencing can also detect bases that have been modified by methylation, a biological process by which methyl groups are added to the DNA molecule. Methylation is an epigenetic change that can alter the activity of a DNA segment without changing the sequence, and can have important effects on the DNA structure and gene expression. When located in a gene promoter, DNA methylation typically acts to repress gene transcription.
The researchers were able to observe and map patterns of methylation on the X chromosome and found some interesting trends in methylation patterns within the centromere. By looking at this previously unmapped area of the genome, scientists may be able to search for potential links between these variations and genetic diseases.
“You could be turning a blind eye to some of the richest sequence diversity that exists in the human population, and some of that sequence diversity that you’re not looking at could be correlated with disease in a way we’ve never been able to study before,” Miga told OneZero.
The work performed by researchers at the UCSC Genomics Institute could provide genetic scientists with a road map for producing complete sequences in other human chromosomes. This may lead genomic researchers to identify gene sequences that play significant roles in a variety of diseases and health conditions. In turn, this would give clinical laboratories new biomarkers for diagnosing disease and other chronic conditions in patients.
Study scientists identified several currently available drugs that could inhibit growth of these “streaming filaments,” which infected cells use to go after non-infected cells
Like a scene from a bad horror movie, scientists have discovered that SARS-CoV-2, the coronavirus responsible for the COVID-19 pandemic, may be even more sinister and macabre than previously thought. The new research findings will interest those pathologists and clinical laboratory professionals who want to understand how the coronavirus spreads once it enters the body.
Headed by scientists from the University of San Francisco (UCSF), a team of international researchers discovered that “when the SARS-CoV-2 virus infects a human cell, it sets off a ghoulish transformation,” reported the Los Angeles Times (LA Times).
“Obeying instructions from the virus,” the LA Times continued, “the newly infected cell sprouts multi-pronged tentacles studded with viral particles. These disfigured zombie cells appear to be using those streaming filaments, or filopodia, to reach still-healthy neighboring cells. The protuberances appear to bore into the cells’ bodies and inject their viral venom directly into those cells’ genetic command centers—thus creating another zombie.”
As If the Coronavirus Weren’t Bad Enough!
“It’s just so sinister that the virus uses other mechanisms to infect other cells before it kills the cell,” Nevan Krogan, PhD, Professor, Department of Cellular Molecular Pharmacology at the UCSF School of Medicine, one of the study’s authors, told the LA Times.
The images above taken with an electron microscope show the streaming filaments—or as the researchers described in their published study, “filopodial protrusions possessing budding viral particles”—reaching out from cells infected with the SARS-CoV-2 coronavirus looking for other cells to infect. (Photos copyright: Los Angeles Times/Elizabeth Fischer, MA, Chief, RML Microscopy Unit, NIAID/NIH.)
SARS-CoV-2 Has Evolved, Study Suggests
Prior to this discovery, scientists believed that the coronavirus infected cells in a typical fashion by finding receptors on the surface of cells lining an individual’s mouth, nose, respiratory tract, lungs or blood vessels, and eventually replicating and invading larger cells. However, this new research may suggest that the virus has evolved and developed new ways to pass quickly and effectively from cell to cell.
While some other illnesses, including smallpox, human immunodeficiency virus (HIV), and some influenza viruses have been known to use filopodia to enhance their ability to infect cells, Krogan contends that those other viruses do not seem to have the prolific growth of the SARS-CoV-2 filopodia.
“By conducting a systematic analysis of the changes in phosphorylation when SARS-CoV-2 infects a cell, we identified several key factors that will inform not only the next areas of biological study, but also treatments that may be repurposed to treat patients with COVID-19,” he said, in a UCSF news release.
UCSF Study Identifies Drugs, Compounds That May Disrupt Growth of Filopodia
One key finding is that the coronavirus was utilizing a specific type of molecule from a family of cellular helpers known as Kinase to create the filopodia.
The researchers conducted a “quantitative mass spectrometry-based phosphoproteomics survey of SARS-CoV-2 infection in Vero E6 cells,” the study noted, which revealed a “dramatic rewiring of phosphorylation on host and viral proteins.
“SARS-CoV-2 infection promoted casein kinase 2 (CK2) and p38 MAPK activation, production of diverse cytokines, and shutdown of mitotic kinases, resulting in cell cycle arrest,” the study continued, adding, “Infection also stimulated a marked induction of CK2-containing filopodial protrusions possessing budding viral particles.
“Eighty-seven drugs and compounds were identified by mapping global phosphorylation profiles to dysregulated kinases and pathways. We found pharmacologic inhibition of the p38, CK2, CDK, AXL, and PIKFYVE kinases to possess antiviral efficacy, representing potential COVID-19 therapies,” the researchers concluded.
To determine if they might be helpful in combating COVID-19, the UCSF research team tested drugs and compounds that were either already cleared to market by the US federal Food and Drug Administration (FDA), in clinical trials, or under preclinical development.
After discovering the Kinase connection, the scientists focused on specialized drugs known as Kinase inhibitors.
“We narrowed in on about a dozen, and we highlighted about six or seven that look particularly potent in a laboratory setting,” Krogan told ABC News. “And we’re very excited now to try and take these into clinical trials.”
Among the drugs the study identified as potentially being able to disrupt the creation of filopodia and slow the spread of COVID-19 in the body are:
Silmitasertib: A drug that is currently in the clinical trial stages as a treatment for bile duct cancer and other cancers, including hematological and lymphoid malignancies;
“We are encouraged by our findings that drugs targeting differentially phosphorylated proteins inhibited SARS-CoV-2 infection in cell culture,” said Kevan Shokat, PhD, Professor of Cellular and Molecular Pharmacology at UCSF, and co-author of the study, in the UCSF news release. “We expect to build upon this work by testing many other kinase inhibitors, while concurrently conducting experiments with other technologies to identify underlying pathways and additional potential therapeutics that may intervene in COVID-19 effectively.”
Presently, the UCSF study provides no direct benefit to COVID-19 illness patients or clinical laboratories performing SARS-CoV-2 testing. However, that could change rapidly. Pathologists and medical laboratory managers will want to keep an eye on this research, because it may lead to new treatments for COVID-19 that would require increased clinical laboratory testing to identify people infected with the coronavirus.
Though the test initially drew ‘raves’ from Trump administration, the FDA now suggests negative results should be confirmed with an additional ‘high-sensitivity authorized SARS-CoV-2 molecular test’
This spring, as the United States attempted to jump-start a national response to the SARS-CoV-2 coronavirus pandemic, the Trump administration heralded Abbott Laboratories’ five-minute test for COVID-19 as a major breakthrough. But even as the federal Food and Drug Administration (FDA) issued dozens of Emergency Use Authorizations (EUAs) to quickly get COVID-19 diagnostic tests into clinical use, the accuracy of some of those tests came into question—including Abbott’s ID NOW COVID-19 rapid molecular test.
The continuing controversy over Abbott’s ID NOW COVID-19 test shows how the national spotlight can be a double-edged sword, bringing both widespread favorable attention to a breakthrough technology, followed by heightened public scrutiny if deficiencies emerge. At the same time, from the first news stories about the Abbott ID NOW COVID-19 test, pathologists and clinical laboratory managers understood that this test always had certain performance parameters, as is true of every diagnostic test.
“Everybody was raving about it,” a former administration official, speaking on the condition of anonymity to discuss internal deliberations, said of ID NOW in an interview with Kaiser Health News (KHN). “It’s an amazing test, but it has limitations which are now being better understood.”
In a White House ceremony on March 29, 2020, President Trump praised his administration’s role in speeding up development “on both testing and treatment that will help us win our war against the coronavirus.” Among the moves highlighted was the FDA’s approval two days earlier of Abbott’s ID-NOW COVID-19 rapid molecular test (above), which the President stated, “delivers lightning-fast results in as little as five minutes,” adding, “Normally, this approval process from the FDA would take 10 months, and even longer, but we did it in four weeks.” (Photo copyright: Washington Post.)
FDA Warns Public about Inaccurate Test Results
On May 14, the FDA issued a public warning about the point-of-care test’s accuracy after receiving 15 “adverse event reports” indicating some patients were receiving “false negative results.”
“Regardless of method of collection and sample type, Abbott ID NOW COVID-19 had negative results in a third of the samples that tested positive by Cepheid Xpert Xpress when using nasopharyngeal swabs in viral transport media and 45% when using dry nasal swabs,” the NYU study authors stated.
Abbott Rebuts Criticism
In a statement following the FDA’s warning, Abbott said, “We’re seeing studies being conducted to understand the role of ID NOW in ways that it was not designed to be used. In particular, the NYU study results are not consistent with other studies. While we’ve seen a few studies with sensitivity performance percentages in the 80s, we’ve also seen other studies with sensitivity at or above 90%, and one as high as 94%.
“While we understand no test is perfect, test outcomes depend on a number of factors including patient selection, specimen type, collection, handling, storage, transport and conformity to the way the test was designed to be run. ID NOW is intended to be used near the patient with a direct swab test method,” Abbott’s statement added, noting the company would be “further clarifying our product information to provide better guidance” and “reinforcing proper sample collection and handling instructions.”
Then, on May 21, Abbott issued another statement highlighting an interim analysis of an ongoing multisite clinical study demonstrating ID NOW COVID-19 test performance is ≥94.7% in positive agreement (sensitivity) and ≥98.6% negative agreement (specificity) when compared to two different lab-based molecular PCR reference methods.
“We’re pleased ID NOW is delivering on what it was designed to do—quickly detect the virus in people who need to know now if they’re infected,” said Philip Ginsburg, MD, SAIM, Senior Medical Director, Infectious Disease, Rapid Diagnostics at Abbott, in the statement. “This is great news for people who are experiencing symptoms and want to take action before they infect others, reducing the spread of infection in society.”
Nonetheless, KHN reported on June 22 that the FDA had “received a total of 106 reports of adverse events for the Abbott test, a staggering increase. The agency has not received a single adverse event report for any other point-of-care tests meant to diagnose COVID-19.”
Second Comparison Study Results for Abbott’s ID NOW
The Abbott ID NOW test correctly identified 74% of positive samples. In comparison, Cepheid’s Xpert Xpress SARS CoV-2 test correctly identified 99% of positives. Negative agreement was 100% and 92.0% for ID NOW and Xpert, respectively.
The FDA’s testing policy for clinical laboratories and commercial manufacturers recommends diagnostic tests correctly identify at least 95% of positive samples. However, KHN pointed out, a senior FDA official in late May said coronavirus tests that were administered outside lab settings would be considered useful in fighting the pandemic even if they miss 20% of positive cases.
“There’s no way I would be comfortable missing two out of 10 patients,” Whittier told KHN.
Abbott ID-NOW’s Role in the Global Fight to Stop COVID-19
Abbott’s ID NOW COVID-19 test is promoted as delivering positive test results in five minutes and negative results in about 13 minutes. On its website and in news releases, Abbott maintains its test “performs best in patients tested earlier post symptom onset.”
In a July 17 statement, Abbott said, “ We have shipped 5.3 million of our rapid ID NOW tests to all 50 states, Washington DC, Puerto Rico and the Pacific Islands. The majority of these tests have been sent to outbreak hotspots and we’ve asked that customers prioritize frontline healthcare workers and first responders.”
It is common for a new diagnostic instrument and a new clinical laboratory test to be continually improved after initial launch. Thus, the performance of such devices at the time they are given clearance from the FDA to be used in clinical care can be much improved several months or years later.
Given the importance of a reliable point-of-care SARS-CoV-2 test during the pandemic, it can be assumed that Abbott Laboratories is working closely with its medical laboratory customers specifically to improve the accuracy, reliability, and reproducibility of both the instrument and the test kit.
