UW scientists believe their at-home test could help more people on anticoagulants monitor their clotting levels and avoid blood clots
In a proof-of-concept study,researchers at the University of Washington (UW) are developing a new smartphone-based technology/application designed to enable people on anticoagulants such as warfarin to monitor their clotting levels from the comfort of their homes. Should this new test methodology prove successful, clinical laboratories may have yet one more source of competition from this at-home PT/INR test solution.
PT/INR (prothrombin time with an international normalized ratio) is one of the most frequently performed clinical laboratory blood tests. This well-proven assay helps physicians monitor clotting in patients taking certain anticoagulation medications.
However, the process can be onerous for those on anticoagulation drugs. Users of this type of medication must have their blood tested regularly—typically by a clinical laboratory—to ensure the medication is working effectively. When not, a doctor visit is required to adjust the amount of the medication in the bloodstream.
Alternatively, where a state’s scope of practice law permits, pharmacists can perform a point-of-care test for the patient, thus allowing the pharmacist to appropriately adjust the patient’s prescription.
Though in the early stages of its development, were the UW’s new smartphone-based blood clotting test to be cleared by the federal Food and Drug Administration (FDA), then users would only need to see a doctor when their readings went and stayed out of range, according to Clinical Lab Products (CLP).
Enabling Patients to Test Their Blood More Frequently
More than eight million Americans with mechanical heart valves or other cardiac conditions take anticoagulants, and 55% of people taking those medication say they fear experiencing life-threatening bleeding, according to the National Blood Clot Alliance.
They have reason to be worried. Even when taking an anticoagulation drug, its level may not stay within therapeutic range due to the effects of food and other medications, experts say.
“In the US, most people are only in what we call the ‘desirable range’ of PT/INR levels about 64% of the time. This number is even lower—only about 40% of the time—in countries such as India or Uganda, where there is less frequent testing. We need to make it easier for people to test more frequently,” said anesthesiologist and co-author of the study Kelly Michaelsen, MD, PhD, UW Assistant Professor of Anesthesiology and Pain Medicine, in a UW news release.
“Back in the day, doctors used to manually rock tubes of blood back and forth to monitor how long it took a clot to form. This, however, requires a lot of blood, making it infeasible to use in home settings,” said senior study author Shyam Gollakota, PhD (above), professor and head of the Networks and Mobile Systems Lab at UW’s Paul G. Allen School of Computer Science and Engineering, in the UW news release. “The creative leap we make here is that we’re showing that by using the vibration motor on a smartphone, our algorithms can do the same thing, except with a single drop of blood. And we get accuracy similar to the best commercially available techniques [used by clinical laboratories].” (Photo copyright: University of Washington.)
How UW’s Smartphone-based Blood Clotting Test Works
The UW researchers were motived by the success of home continuous glucose monitors, which enable diabetics to continually track their blood glucose levels.
According to the Nature Communications paper, here’s how UW’s “smartphone-based micro-mechanical clot detection system” works:
Samples of blood plasma and whole blood are placed into a thimble-size plastic cup.
The cup includes a small copper particle and thromboplastin activator.
When the smartphone is turned on and vibrating, the cup (which is mounted on an attachment) moves beneath the phone’s camera.
Video analytic algorithms running on the smartphone track the motion of the copper particle.
If blood clots, the “viscous mixture” slows and stops.
PT/INR values can be determined in less than a minute.
“Our system visually tracks the micro-mechanical movements of a small copper particle in a cup with either a single drop of whole blood or plasma and the addition of activators,” the researchers wrote in Nature Communications. “As the blood clots, it forms a network that tightens. And in that process, the particle goes from happily bouncing around to no longer moving,” Michaelsen explained.
The system produced these results:
140 de-identified plasma samples: PT/INR with inter-class correlation coefficients of 0.963 and 0.966.
79 de-identified whole blood samples: 0.974 for both PT/INR.
Another At-home Test That Could Impact Clinical Laboratories
The UW scientists intend to test the system with patients in their homes, and in areas and countries with limited testing resources, Medical Device Network reported.
Should UW’s smartphone-based blood-clotting test be cleared by the FDA, there could be a ready market for it. But it will need to be offered it at a price competitive with current clinical laboratory assays for blood clotting, as well as with the current point-of-care tests in use today.
Nevertheless, UW’s work is the latest example of a self-testing methodology that could become a new competitor for clinical laboratories. This may motivate medical laboratories to keep PT/INR testing costs low, while also reporting quick and accurate results to physicians and patients on anticoagulants.
Alternatively, innovative clinical laboratories could develop a patient management service to oversee a patient’s self-testing at home and coordinate delivery of the results with the patient’s physician and pharmacist. This approach would enable the lab to add value for which it could be reimbursed.
New nanotechnology device is significantly faster than typical rapid detection clinical laboratory tests and can be manufactured to identify not just COVID-19 at point of care, but other viruses as well
Researchers at the University of Central Florida (UCF) announced the development of an optical sensor that uses nanotechnology to identify viruses in blood samples in seconds with an impressive 95% accuracy. This breakthrough underscores the value of continued research into technologies that create novel diagnostic tests which offer increased accuracy, faster speed to answer, and lower cost than currently available clinical laboratory testing methods.
The innovative UCF device uses nanoscale patterns of gold that reflect the signature of a virus from a blood sample. UCF researchers claim the device can determine if an individual has a specific virus with a 95% accuracy rate. Different viruses can be identified by using their DNA sequences to selectively target each virus.
According to a UCF Today article, the University of Central Florida research team’s device closely matches the accuracy of widely-used polymerase chain reaction (PCR) tests. Additionally, the UCF device provides nearly instantaneous results and has an accuracy rate that’s a marked improvement over typical rapid antigen detection tests (RADT).
Debashis Chanda, PhD (above), holds up the nanotechnology biosensor he and his team at the University of Central Florida developed that can detect viruses in a blood sample in seconds with 95% accuracy and without the need for pre-preparation of the blood sample. Chanda is professor of physics at the NanoScience Technology Center and the College of Optics and Photonics (CREOL) at UCF. Should this detection device prove effective at instantly detecting viruses at the point of care, clinical laboratories worldwide could have a major new tool in the fight against not just COVID-19, but all viral pathogens. (Photo copyright: University of Central Florida.)
Genetic Virus Detection on a Chip
“The sensitive optical sensor, along with the rapid fabrication approach used in this work, promises the translation of this promising technology to any virus detection, including COVID-19 and its mutations, with high degree of specificity and accuracy,” Debashis Chanda, PhD, told UCF Today. Chanda is professor of physics at the NanoScience Technology Center at UCF and one of the authors of the study. “Here, we demonstrated a credible technique which combines PCR-like genetic coding and optics on a chip for accurate virus detection directly from blood.”
The team tested their device using samples of the Dengue virus that causes Dengue fever, a tropical disease spread by mosquitoes. The device can detect viruses directly from blood samples without the need for sample preparation or purification. This feature enables the testing to be timely and precise, which is critical for early detection and treatment of viruses. The chip’s capability also can help reduce the spread of viruses.
No Pre-processing or Sample Preparation Needed for Multi-virus Testing
The scientists confirmed their device’s effectiveness with multiple tests using varying virus concentration levels and solution environments, including environments with the presence of non-target virus biomarkers.
“A vast majority of biosensors demonstrations in the literature utilize buffer solutions as the test matrix to contain the target analyte,” Chanda told UCF Today. “However, these approaches are not practical in real-life applications because complex biological fluids, such as blood, containing the target biomarkers are the main source for sensing and at the same time the main source of protein fouling leading to sensor failure.”
The researchers believe their device can be easily adapted to detect other viruses and are optimistic about the future of the technology.
“Although there have been previous optical biosensing demonstrations in human serum, they still require off-line complex and dedicated sample preparation performed by skilled personnel—a commodity not available in typical point-of-care applications,” said Abraham Vazquez-Guardado, PhD, a Postdoctoral Fellow at Northwestern University who worked on the study, in the UCS Today article. “This work demonstrated for the first time an integrated device which separated plasma from the blood and detects the target virus without any pre-processing with potential for near future practical usages.”
More research and additional studies are needed to develop the University of Central Florida scientists’ technology and prove its efficacy. However, should the new chip prove viable for point-of-care testing, it would give clinical laboratories and microbiologists an ability to test blood samples without any advanced preparation. Combined with the claims for the device’s remarkable accuracy, that could be a boon not only for COVID-19 testing, but for testing other types of viruses as well.
Decision is part of UK effort to diagnose 75% of all cancers at stage I or stage II by 2028 and demonstrates to pathologists that the technology used in liquid biopsy tests is improving at a fast pace
Pathologists and medical laboratory scientists know that when it comes to liquid biopsy tests to detect cancer, there is plenty of both hope and hype. Nevertheless, following a successful pilot study at the Christie NHS Foundation Trust in Manchester, England, which ran from 2015-2021, the UK’s National Health Service (NHS) is pushing forward with the use of liquid biopsy tests for certain cancer patients, The Guardian reported.
NHS’ decision to roll out the widespread use of liquid biopsies—a screening tool used to search for cancer cells or pieces of DNA from tumor cells in a blood sample—across the UK is a hopeful sign that ongoing improvements in this diagnostic technology are reaching a point where it may be consistently reliable when used in clinical settings.
The national program provides personalized drug therapies based on the genetic markers found in the blood tests of cancer patients who have solid tumors and are otherwise out of treatment options. The liquid biopsy creates, in essence, a match-making service for patients and clinical trials.
Liquid Biopsy Genetic Testing for Cancer Patients
“The learnings from our original ‘Target’ study in Manchester were that genetic testing needs to be done on a large scale to identify rare genetic mutations and that broader access to medicines through clinical trials being undertaken across the country rather than just one site are required,” Matthew Krebs, PhD, Clinical Senior Lecturer in Experimental Cancer Medicine at the University of Manchester, told The Guardian.
Krebs, an honorary consultant in medical oncology at the Christie NHS Foundation Trust, led the Target National pilot study.
“This study will allow thousands of cancer patients in the UK to access genetic testing via a liquid biopsy. This will enable us to identify rare genetic mutations that in some patients could mean access to life-changing experimental medicines that can provide great treatment responses, where there are otherwise limited or no other treatment options available.”
Detecting cancers at earlier stages of disease—when treatment is more likely to result in improved survival—has become a strategic cancer planning priority in the UK, theBMJ noted.
“The NHS is committed to diagnosing 75% of all cancers at stage I or II by 2028, from around 50% currently,” the BMJ wrote. “Achieving such progress in less than a decade would be highly ambitious, even without disruption caused by the COVID-19 pandemic. In this context, considerable hope has been expressed that blood tests for circulating free DNA—sometimes known as liquid biopsy—could help achieve earlier detection of cancers.”
The Guardian noted that the UK’s initiative will use a liquid biopsy test made by Swiss-healthcare giant Roche.
“We can’t guarantee that we will find a fault in the genetic code of every cancer patient we recruit, or that if we do, there will be a suitable drug trial for them,” Matthew Krebs, PhD (above), lead scientist of the NHS’ Target National pilot study, told The Guardian. “However, as we learn more about the genetics of cancer in this study, it will help doctors and scientists develop new treatments to help people in the future. Ultimately, we hope liquid biopsy testing will be adopted into routine NHS care, but we need studies such as this to show the benefit of the test on a large scale and provide the evidence that patients can benefit from being matched to targeted medicines on the basis of the blood test.” (Photo copyright: Cancer Research UK Manchester Centre.)
In her article “The Promise of Liquid Biopsies for Cancer Diagnosis,” published in the American Journal of Managed Care (AJMC) Evidence-based Oncology, serial healthcare entrepreneur and faculty lecturer at Harvard Medical School Liz Kwo, MD, detailed the optimism surrounding the “revolutionary screening tool,” including its potential for:
identifying mechanisms of resistance to therapies,
measuring remaining disease after treatment,
assessing cancer relapse or resistance to treatment, and
eliminating risk surrounding traditional biopsies.
The AJMC article estimated the liquid biopsy market will be valued at $6 billion by 2030. However, Kwo also noted that clinical adoption of liquid biopsies in the US continues to face challenges.
Welch compared the investor hype surrounding liquid biopsies to that of the now-defunct blood testing company Theranos, which lured high-profile investors to pour millions into its unproven diagnostic technology.
“Effective cancer screening requires more than early detection. It also requires that starting therapy earlier helps people live to older ages than they would if they started treatment later,” he wrote. “If that doesn’t happen, liquid biopsies will only lead to people living longer with the knowledge they have a potentially incurable disease without extending their lives. These people would be subjected to cancer therapies and their toxicities earlier, but at a time when they would otherwise be experiencing no cancer-related signs or symptoms.”
And so, while there’s much excitement about the possibility of a minimally invasive way to detect cancer, anatomic pathology groups and clinical laboratories will have to wait and see if the hype and hope surrounding liquid biopsies is substantiated by further research.
Its low cost may advance liquid biopsy cancer testing used by anatomic pathologists and improve outcomes by speeding time to diagnosis and treatment
Researchers in Japan say they have created a circulating tumor cell (CTC) detection solution that is inexpensive and easy to run. Such a device would be of huge interest to investors and companies wishing to develop clinical laboratory tests that use circulating tumor cells in the blood to identify patients with cancer.
In a proof-of-concept study, researchers at Kumamoto University (KU) in Japan have developed and tested a microfilter device they claim can separate and capture CTCs in blood without large equipment, a KU news release reported.
According to Medgadget, the device is an “inexpensive, convenient, and highly sensitive filter that can successfully work in samples containing as few as five tumor cells in one milliliter of blood and does not require expensive equipment or reagents, unlike certain pre-existing cell capture technologies.”
This Technology Could Give Pathologists a Less-Invasive Cancer Test
As medical laboratory scientists and anatomic pathologists know, a CTC test is less invasive than tissue biopsy, which benefits patients. Furthermore, such a CTC test may enable earlier detection of cancer and start of treatment improving odds for success.
Still, there are many pitfalls to overcome when the challenge is to detect cancer cells in a milliliter (about .03 fluid ounce) of blood. As Medgadget put it, “A needle in a haystack doesn’t even come close.”
“Cancer cell count in the blood of cancer patients is extremely low. If these cells are easily detectable, cancer diagnosis may be possible by simply using a blood test, thus reducing patient burden,” the researchers wrote in their paper.
“This work demonstrates that our microfilter device can accurately detect trace amounts of cancer cells in blood,” said study leader Yuta Nakashima, PhD (above), Associate Professor, Department of Mechanical System Engineering at Kumamoto University, in the news release. “We expect it will be adopted for cancer diagnosis and treatment, including for early diagnosis of cancers that cannot be detected by imaging like CT and PET scans, post-operative follow-up, recurrence monitoring, and tailor-made treatments. In the future, we plan to use blood samples donated by cancer patients to verify the practical and clinical application of the method,” he added. Were it to become available, such a CTC test would be a boon for clinical laboratories and anatomic pathologists engaged in cancer diagnostics and treatment. (Photo copyright: Kumamoto University.)
How Does the CTC Filter Device Work?
The KU scientists created a palm-size “cancer detection device using a microfilter and nucleic acid aptamer,” the paper said, adding:
It includes slits to enable a deformation with force of blood pumping through the device.
As blood flows over the microfilter, cancer cells bind to the nucleic acid aptamer.
Force of blood flow opens microfilter slits, pushing away the healthy cells.
Cancer cells are left on the microfilter.
To test the microfilter the researchers used one milliliter of blood that was “spiked with cancer cells,” according to the paper. Findings include:
Detection of five CTCs in one milliliter of blood.
Blood cell removal rate of 98% suggested “no blood cells were absorbed by the microfilter,” the news release said.
The method “showed higher accuracy than the CellSearch System,” the Talanta paper noted.
The KU research team compared their microfluidic device to CellSearch, an FDA-cleared system for detecting CTCs from a blood sample.
CellSearch enables “identification, isolation, and enumeration of CTCs of epithelial origin,” according to Menarini Silicon Biosystems of Castel Maggiore, Italy. It works from a blood sample of 7.5 millimeters with “high level of sensitivity and specificity,” notes the company’s website.
According to Menarini, labs offering CellSearch CTC testing include:
The UK scientists admit that their research needs further study. Nakashima indicated he plans to test blood samples donated by cancer patients in subsequent device trials.
“Although great progress has been made, there is a long way to go before CTC-based liquid biopsy is widely used as a routine test in clinical application,” the authors of that study noted.
Nevertheless, even with more to do, liquid biopsy testing has come a long way, as multiple Dark Daily eBriefs reported over the years.
If the KU scientists succeed in bringing to market a microfilter that can reduce the cost of CTC detection by clinical laboratories while also improving cancer diagnostics, that will have a huge impact on cancer patients and is worthy of clinical laboratory leaders’ attention.
Group’s report also suggests that at-home clinical laboratory tests for COVID-19 that are difficult to use may lead to inaccurate results
At-home clinical laboratory tests for COVID-19 have become quite popular. But how accurate are they? Now, an independent safety organization has investigated COVID-19 rapid antigen tests to find out how easy—or not—they are to use and what that means for the accuracy of the tests’ results.
ECRI (Emergency Care Research Institute) of Plymouth Meeting, Penn., “conducted a usability evaluation to determine if there were any differences in ease of use for the rapid COVID-19 tests,” according to the company’s website.The nonprofit was founded in the 1960s by surgeon and inventor Joel J. Nobel to evaluate medical devices that have been approved by the U.S. Food and Drug Administration (FDA).
“Because of the urgency in providing useful information to consumers as quickly as possible, ECRI selected the seven test kits based on retail availability,” ECRI noted.
ECRI ranked the seven over-the-counter (OTC) at-home rapid antigen tests according to their SUS usability ratings. The System Usability Scale (SUS), invented by John Brooke in 1986, “rates products on a scale of 0 to 100 with 100 being the easiest to use. More than 30 points separated the top and bottom tests analyzed,” according to Managed Healthcare Executive.
Of the seven rapid antigen test kits for COVID-19, ECRI found “noteworthy usability concerns” and “significant differences in ease of use.” None of the tests achieved a SUS rating of “excellent,” ECRI stated in a press release.
“Our evaluation shows that some rapid [COVID-19] tests are much easier to use than others. If given options, consumers should choose tests that are the easiest to use because when a [COVID-19] test is difficult for a consumer to use, it may lead to an inaccurate result,” said ECRI President and CEO Marcus Schabacker, MD, PhD, in a news release. Marcus “is a board-certified anesthesiologist and intensive care specialist with more than 35 years of healthcare experience in complex global environments, and more than 20 years of senior leadership responsibilities serving the medical device and pharmaceutical industries across the healthcare value chain,” states ECRI. (Photo copyright: Biz Journals.)
Seven Rapid Antigen Tests for SARS-CoV-2 Evaluated
As clinical laboratory scientists and pathologists know, it’s possible for different test methodologies for the same biomarker to produce dissimilar results. Another factor affecting medical laboratory test accuracy is the variability from one manufacturing batch or lot to another. And, as the ECRI report suggests, how a specimen is collected and handled can affect accuracy, reliability, and reproducibility of the test results generated by that specimen.
These are the OTC COVID-19 rapid antigen tests ECRI evaluated and their SUS ratings:
Some tests, the ECRI analysts found, required “fine motor control” or were packed with written instructions ECRI determined were too small for older adults to read.
How ECRI Evaluated the COVID-19 Rapid Antigen Tests
SUS reviewers took each rapid test and completed questionnaires specifying their level of agreement (on a range of one to five) with these statements. (Edited by Dark Daily for space):
Desire to use
Perception of unnecessary complexity
Easy to use
Support of a technical person needed
Functions well-integrated
Too much system inconsistency
Easy to learn for most people
A very cumbersome system to use
Feeling of confidence in use
A need to learn before getting going
ECRI then used an algorithm to derive an aggregate score (from 0 to 100) for each test, the report noted.
“Based on the aggregate SUS scores, none of the COVID-19 test kits would be judged to have ‘excellent’ usability. The On/Go, CareStart, Flowflex test kits we rate as ‘very good’ as the usability score for these kits falls just short of ‘excellent,’” the report said.
Some of the positive responses ECRI received from the SUS participants included:
“One of the simpler tests to use with good, printed instructions,” (On/Go and CareStart).
“Cassette makes handling without touching test strip easy,” (CareStart and Flowflex).
“The QR (quick-response) code-linked instructional video is helpful, but probably not needed,” (QuickVue).
“Once the swab is inserted into the test card, the test seems less likely to be spilled or disturbed than other test kits,” (BinaxNOW).
Is it Time for Rapid COVID-19 Antigen Tests?
Unlike RT-PCR tests that can take hours or days to return results, rapid antigen tests provide a quick result that’s used for screening worldwide. And with the COVID-19 Omicron variant spreading rapidly around the world, speed is much needed, according to Stephen Kissler, PhD, Research Fellow in the department of immunology and infectious diseases at Harvard’s T.H. Chan School of Public Health.
“I think the rapid tests provide some of the best protection we have against the spread of disease, especially as we now have a variant on hand that’s going to be able to cause an awful lot of breakthrough infections,” Kissler told The Atlantic-Journal Constitution.
One way clinical laboratory leaders can help is to reach out in their local markets and provide information on the importance of appropriate sampling and collection for accurate results from rapid COVID-19 antigen testing.
