Tag Archives: #COVID-19

A Test That Detects COVID-19 Variants in Your Spit (Medicine)

Low-cost device could allow consumers to test themselves for multiple strains of SARS-CoV-2 at home

With the Delta variant wreaking havoc on unvaccinated populations and COVID-19 cases spiking around the world, the pandemic is far from over. Despite the impressively fast development of SARS-CoV-2 diagnostic tests over the last year and a half, the vast majority of patient samples must still be sent to a lab for processing, which slows down the pace of COVID-19 case tracking. If a sample is to be tested for a specific variant of the virus, it must be genetically sequenced, which takes even more time and resources.

Now, researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard University, the Massachusetts Institute of Technology (MIT), and several Boston-area hospitals have created an inexpensive, CRISPR-based diagnostic test that allows users to test themselves for SARS-CoV-2 and multiple variants of the virus using a sample of their saliva at home, with no extra instrumentation needed.

The diagnostic device, called Minimally Instrumented SHERLOCK (miSHERLOCK), is easy to use and provides results that can be read and verified by an accompanying smartphone app within one hour. It successfully distinguished between three different variants of SARS-CoV-2 in experiments, and can be rapidly reconfigured to detect additional variants like Delta. The device can be assembled using a 3D printer and commonly available components for about $15, and re-using the hardware brings the cost of individual assays down to $6 each.

“miSHERLOCK eliminates the need to transport patient samples to a centralized testing location and greatly simplifies the sample preparation steps, giving patients and doctors a faster, more accurate picture of individual and community health, which is critical during an evolving pandemic,” said co-first author Helena de Puig, Ph.D., a Postdoctoral Fellow at the Wyss Institute and MIT.

The diagnostic device is described in a paper published today in Science Advances.

From supply chain to SHERLOCK

An accompanying smartphone app analyzes the fluorescent readout generated by the assay, giving users a clear “Positive” or “Negative” result. The results can also be shared with doctors and health organizations to track a disease’s spread. Credit: Wyss Institute at Harvard University

As an Instructor in Pediatrics at Boston Children’s Hospital with a specialization in infectious diseases, co-first author Rose Lee, M.D. has been working on the front lines of the COVID-19 pandemic for more than a year. Her experiences in the clinic provided inspiration for the project that would ultimately become miSHERLOCK.

“Simple things that used to be ubiquitous in the hospital, like nasopharyngeal swabs, were suddenly hard to get, so routine sample processing procedures were disrupted, which is a big problem in a pandemic setting,” said Lee, who is also a Visiting Fellow at the Wyss Institute. “Our team’s motivation for this project was to eliminate these bottlenecks by providing accurate diagnostics for COVID-19 that were less dependent on global supply chains and could accurately detect the variants that were starting to emerge.”

For the SARS-CoV-2 detection piece of their diagnostic, the group turned to a CRISPR-based technology created in the lab of Wyss Core Faculty member and senior paper author Jim Collins, Ph.D. called “specific high sensitivity enzymatic reporter unlocking” (SHERLOCK). SHERLOCK makes use of CRISPR’s “molecular scissors” to snip DNA or RNA at specific locations, with an added bonus: upon recognizing its target sequence, this specific type of scissors also cuts other pieces of DNA in the surrounding area, allowing it to be engineered to produce a signal indicating that the target has been successfully cut.

A CRISPR-based reaction within the diagnostic device produces a fluorescent signal in response to the presence of SARS-CoV-2 viral RNA in a patient’s saliva within an hour. Credit: Wyss Institute at Harvard University

The researchers created a SHERLOCK reaction designed to cut SARS-CoV-2 RNA at a specific region of a gene called Nucleoprotein that is conserved across multiple variants of the virus.  When the molecular scissors – an enzyme called Cas12a – successfully binds to and cuts the Nucleoprotein gene, single-stranded DNA probes are also cut, producing a fluorescent signal. They also created additional SHERLOCK assays designed to target a panel of viral mutations in Spike protein sequences that represent three SARS-CoV-2 genetic variants: Alpha, Beta, and Gamma.

Armed with assays that could reliably detect viral RNA within the accepted concentration range for FDA-authorized diagnostic tests, the team next focused their efforts on solving what is arguably the most difficult challenge in diagnostics: sample preparation.

Spit, wait, scan

“When you’re testing a sample for nucleic acids [like DNA or RNA], there are a lot of steps you need to do to prepare the sample so you can actually extract and amplify those nucleic acids. You have to protect the sample while it’s in transit to the testing facility, and also make sure it’s not infectious if you’re dealing with a transmissible disease. In order to make this a truly easy-to-use diagnostic test, it was important for us to simplify that as much as possible,” said co-first author Xiao Tan, M.D., Ph.D., a Clinical Fellow at the Wyss Institute and Instructor of Medicine in Gastroenterology at Massachusetts General Hospital.

The team chose to use saliva rather than nasopharyngeal swab samples as their diagnostic source material, because it’s easier for users to collect saliva and studies have shown that SARS-CoV-2 is detectable in saliva for a greater number of days post-infection. But unprocessed saliva presents challenges of its own: it contains enzymes that degrade various molecules, producing a high rate of false positives.

The diagnostic procedure only requires that a user spit into the sample preparation chamber and then transfer the collection disc to the reaction chamber and press a plunger, which activates the reaction and minimizes the risk of cross-contamination. Credit: Wyss Institute at Harvard University

The researchers developed a novel technique to solve that problem. First, they added two chemicals called DTT and EGTA to saliva and heated the sample to 95°C for three minutes, deactivated the enzymes producing the false positive signal from the untreated saliva and sliced open any viral particles. They then incorporated a porous membrane that was engineered to trap RNA on its surface, which could finally be added directly to the SHERLOCK reaction to generate a result.

To integrate the saliva sample preparation and the SHERLOCK reaction into one diagnostic, the team designed a simple battery-powered device with two chambers: a heated sample preparation chamber, and an unheated reaction chamber. A user spits into the sample preparation chamber, turns on the heat, and waits three to six minutes for the saliva to be wicked into the filter. The user removes the filter and transfers it to the reaction chamber column, then pushes a plunger that deposits the filter into the chamber and punctures a water reservoir to activate the SHERLOCK reaction. 55 minutes later, the user looks through the tinted transilluminator window into the reaction chamber and confirms the presence of a fluorescent signal. They can also use an accompanying smartphone app that analyzes the pixels being registered by the smartphone’s camera to provide a clear positive or negative diagnosis.

The researchers tested their diagnostic device using clinical saliva samples from 27 COVID-19 patients and 21 healthy patients, and found that miSHERLOCK correctly identified COVID-19-positive patients 96% of the time and patients without the disease 95% of the time. They also tested its performance against the Alpha, Beta, and Gamma SARS-CoV-2 variants by spiking healthy human saliva with full-length synthetic viral RNA containing mutations representing each variant, and found that the device was effective across a range of viral RNA concentrations.

This video demonstrates the miSHERLOCK diagnostic device and how a patient would use it to test themselves for the presence of SARS-CoV-2 in their spit. Credit: Wyss Institute at Harvard University

“One of the great things about miSHERLOCK is that it’s entirely modular. The device itself is separate from the assays, so you can plug in different assays for the specific sequence of RNA or DNA you’re trying to detect,” said co-first author Devora Najjar, a Research Assistant at the MIT Media Lab and in the Collins Lab. “The device costs about $15, but mass production would bring the housing costs down to about $3. Assays for new targets can be created in about two weeks, enabling the rapid development of tests for new variants of SARS-CoV-2 as well as for other infectious diseases.”

Ready for the real world

The four first authors of the miSHERLOCK paper, pictured right to left: Devora Najjar, Rose A. Lee, Helena de Puig, and Xiao Tan. Credit: Wyss Institute at Harvard University

The miSHERLOCK team created their device with low-resource settings in mind, as the pandemic has brought to light the vast inequalities in healthcare access that exist between different parts of the world. The device’s hardware can be built by anyone with access to a 3D printer, and the files and circuitry designs are all publicly available online. The addition of a smartphone app was also aimed at resource-limited settings, as mobile phone service is available virtually anywhere in the world, even in areas that are difficult to reach on foot. The team is eager to work with manufacturers who are interested in producing miSHERLOCK at scale for global distribution.

“When the miSHERLOCK project started, there was almost no SARS-CoV-2 variant monitoring happening. We knew that variant tracking was going to be incredibly important when evaluating the long-term effects of COVID-19 on local and global communities, so we pushed ourselves to create a truly decentralized, flexible, user-friendly diagnostic platform,” said Collins, who is also the Termeer Professor of Medical Engineering & Science at MIT. “By solving the sample prep problem, we’ve ensured that this device is virtually ready for consumers to use as-is, and we’re excited to work with industrial partners to make it commercially available.”

“By combining cutting-edge biotechnology with low-cost materials, this team has created a powerful diagnostic device that can be manufactured and used on a local level by people without advanced medical degrees. It’s a perfect example of the Wyss Institute’s mission in action: to put life-changing innovations in the hands of people who need them,” said Wyss Founding Director Don Ingber, M.D., Ph.D., who is also the Judah Folkman Professor of Vascular Biology at Harvard Medical School and Boston Children’s Hospital, and Professor of Bioengineering at the Harvard John A. Paulson School of Engineering and Applied Sciences.

Additional authors of the paper include Luis R. Soekensen, Nicolaas Angenent-Mari, and Angelo Mao from the Wyss Institute and MIT; and Nina Donghia, Nicole Weckman, Audrey Ory, Carlos Ng, Peter Nguyen, Thomas Ferrante, Geoffrey Lansberry, Hani Sallum, and James Niemi from the Wyss Institute.

This research was supported by the Wyss Institute for Biologically Inspired Engineering at Harvard University, the Paul G. Allen Frontiers Group, the Harvard University Center for AIDS Research (an NIH-funded program that is supported by the following NIH co-funding and participating Institutes and Centers: NIAID, NCI, NICHD, NIDCR, NHLBI, NIDA, NIMH, NIA, NIDDK, NINR, NIMHD, FIC, OAR), The Burroughs-Wellcome American Society of Tropical Medicine and Hygiene, an American Gastroenterological Association Takeda Pharmaceutical Research Scholar Award, and an MIT-TATA Center fellowship.

Featured image: miSHERLOCK is a self-contained at-home diagnostic platform that allows users to test their own saliva for the presence of SARS-CoV-2 and can distinguish between multiple variants of the virus. Credit: Wyss Institute at Harvard University



Provided by Wyss Institute

How COVID-19 Delta Variant is Impacting Younger People? (Medicine)

The number of COVID-19 infections, mostly with the delta variant, continues to rise, especially in parts of the U.S. where vaccination rates are low. Dr. Nipunie Rajapakse, a pediatric infectious diseases physician at Mayo Clinic Children’s Center, says younger people are among those being infected with the highly contagious virus.

“The most important thing we can do to protect kids under 12 years of age, who are not yet eligible to be vaccinated themselves, is to ensure that as many people who are around them and who are interacting with them are vaccinated.”

Dr. Nipunie Rajapakse

Watch: Dr. Nipunie Rajapakse discusses children, younger people affected by delta variant.

Journalists: Broadcast-quality sound bites are in the downloads at the bottom of the page. Please courtesy: “Nipunie Rajapakse, M.D./Pediatric Infectious Diseases/Mayo Clinic.”

Dr. Rajapakse answered these questions about the delta variant and how it is affecting young people in this Q&A with the Mayo Clinic News Network:

Who is being impacted by the delta variant?

With the delta variant, we are seeing an increased number of cases amongst children. In the last couple of weeks, the American Academy of Pediatrics has reported a significant increase in COVID-19 cases amongst people under 18 years of age. We know that the delta variant is much more transmissible than the other prior variants of COVID-19. 

And that extends to children as much as to older teenagers and adults as well. What we’re still working to understand is whether people get more sick with delta variant or not. These are somewhat surprisingly difficult things to tease out. When you have a large increase in the number of people getting infected, that proportionately results in more people in hospital and more people die. But it doesn’t necessarily mean that the virus itself is more deadly. 

What are ways adults can protect their children?

The most important thing we can do to protect kids under 12 years of age who are not yet eligible to be vaccinated themselves is to ensure that as many people who are around them and who are interacting with them are vaccinated. Anyone over 12 years of age should be getting their vaccine, both to protect themselves, but also to protect people who are not yet eligible, such as children under 12 years of age.

We know the vaccines are highly effective in preventing serious illness, hospitalizations and deaths in people who get the vaccine. We also know that they will significantly reduce your risk of spreading the infection to someone else. 

What about the delta breakthrough cases in vaccinated people?

I want to emphasize those cases are getting a lot of headlines, but they’re very rare events. And they are not what is driving the current surge in cases that we’re seeing. The current surge is really amongst unvaccinated people predominantly young and middle-aged, who are winding up in hospital or in ICU because of infection. And we know that these are largely preventable.

Why should 12- to 18-year-olds get their COVID-19 vaccine before returning to school?

We do want kids to return to school, we know all the benefits of going to school. But right now, with what’s going on in our country and in our communities with delta variant spread, you’re really making a choice between getting vaccinated or getting COVID-19. This delta variant is just that contagious.


Provided by Mayo Clinic

A COVID-19 Biomarker: Low Blood Levels of Sphingosine Predict Symptomatic Infections (Medicine)

Researchers remain perplexed as to why some patients infected with SARS-CoV-2, the virus responsible for COVID-19, remain asymptomatic while other patients develop severe disease symptoms. This question is once again at the front of mind as the Delta variant spreads across the country. In a new retrospective study, researchers at the Medical University of South Carolina (MUSC) discovered a specific and sensitive biomarker in blood samples that predicts which patients will develop COVID-19 symptoms. Their results, published online on July 9 in Scientific Reports, show that reduced levels of a specific lipid, sphingosine, are significantly associated with developing COVID-19 symptoms. Conversely, elevated levels of sphingosine, as well as a protein involved in its production, acid ceramidase (AC), are associated with asymptomatic infections.

“We developed this project at a time when there wasn’t a successful vaccine,” said Besim Ogretmen, Ph.D., director of the Lipidomics Shared Resource at Hollings Cancer Center and leader of the Hollings Developmental Cancer Therapeutics Research Program. “We wanted to contribute to the field and know which patients who were exposed to this virus would be symptomatic versus asymptomatic.”

Over the past 16 months several waves of SARS-CoV-2 infections in the U.S. have resulted in more than 35 million cases and almost 630,000 deaths. Despite the development of multiple safe and effective vaccines, we are currently experiencing another wave of infections.

The mortality of COVID-19 is thought to result from an overactive immune response to the virus in the lungs of infected patients that causes severe respiratory distress. However, symptoms vary widely, and scientists and clinicians don’t understand why some patients develop severe symptoms while others remain asymptomatic.

“If we can separate asymptomatic patients from symptomatic patients, we can use limited remedies and resources for patients who are more vulnerable.”, said Dr. Besim Ogretmen.

It is known that sphingolipids, a class of molecules that are important for the integrity of the cell membrane and communication between cells, can regulate inflammation and the immune system in response to various infections. The Ogretmen laboratory has decades of expertise in analyzing the production and processing of different lipids, including sphingolipids, using a global measurement method called lipidomics.

Using this expertise, the Ogretmen lab undertook an unbiased analysis of COVID-19 patient serum samples from the MUSC COVID-19 Biorepository to look for changes in sphingolipid levels.

The results were striking.

“Just by looking at the data, you can clearly separate the different patient groups, even without doing technical statistical analyses,” said Alhaji Janneh, lead author and graduate student in the Department of Biochemistry and Molecular Biology.

In asymptomatic patients who tested positive for a SARS-CoV-2 antibody, the researchers found a slight increase in serum sphingosine levels – and only sphingosine – compared to patients who tested negative. Remarkably, in patients who developed COVID-19 symptoms, there was a 15-fold reduction in sphingosine levels. Conversely, almost 75% of asymptomatic patients had elevated AC levels while most symptomatic patients had no detectable AC. The presence of serum AC correlates with the increased levels of sphingosine.

“Can this be an alternative way to predict which patients are the most vulnerable to severe disease?” asked Ogretmen, who is also a professor in the Department of Biochemistry and Molecular Biology and the SmartState Endowed Chair in Lipidomics and Drug Discovery. “If we can separate asymptomatic patients from symptomatic patients, we can use limited remedies and resources for patients who are more vulnerable.”

Overall, there is a 99% probability of correctly determining which patients, who have tested positive for SARS-CoV-2 antibodies, will develop disease symptoms versus remain asymptomatic, using blood levels of sphingosine.

These striking results would not have been possible without the MUSC COVID-19 Biorepository and collaboration with the South Carolina Clinical & Translational Research Institute (SCTR). SCTR set up the biorepository to serve as a resource for COVID-19 research, and SCTR co-principal investigator Patrick Flume, M.D. is its director and one of the authors of the article.

Analyzing levels of various lipids from patient samples is expensive and requires sophisticated equipment, making this type of analysis prohibitive under most circumstances. However, the development of an ELISA-based assay – like those used to diagnose HIV infection – to detect levels of AC could provide a cost-effective alternative that could be widely implemented.

There are several outstanding questions remaining. How does vaccination impact sphingosine levels? How do sphingosine levels change with the introduction of more variants? Nevertheless, the ability to identify at-risk patients quickly could vastly improve treatment of COVID-19 and allow for effective distribution of scarce resources.

Featured image: Dr. Besim Ogretmen (left) and graduate student Alhaji Janneh (right) in the laboratory. © MUSC


Reference: Alhaji H. Janneh et al, Alterations of lipid metabolism provide serologic biomarkers for the detection of asymptomatic versus symptomatic COVID-19 patients, Scientific Reports (2021). DOI: 10.1038/s41598-021-93857-7


Provided by MUSC

Continuous Positive Airway Pressure (CPAP) Reduces Need For Invasive Ventilation in Hospitalised COVID-19 Patients (Medicine)

  • Landmark UK trial compared three commonly used respiratory interventions to establish which works best for COVID-19 patients with acute respiratory failure.
  • Participants who received continuous positive airway pressure (CPAP) were less likely to require invasive mechanical ventilation from COVID-19.
  • Researchers found no benefit from high flow nasal oxygenation (HFNO) over standard oxygen therapy.
  • Based on this evidence, the authors say CPAP should be considered for hospitalised patients with COVID-19 needing increasing oxygen – reducing the need for invasive ventilation and relieving pressure on intensive care services.

The Respiratory Strategies in COVID-19; CPAP, High-flow, and Standard Care (RECOVERY-RS) trial has demonstrated that treating hospitalised COVID-19 patients who have acute respiratory failure with continuous positive airway pressure (CPAP) reduces the need for invasive mechanical ventilation.

Preliminary data from the trial also suggests that the routine use of high flow nasal oxygenation (HFNO), which can consume large amounts of oxygen, should be reconsidered as it did not improve outcomes for COVID-19 patients compared with conventional oxygen therapy.

RECOVERY-RS, led by the University of Warwick and Queen’s University Belfast, is the world’s largest non-invasive respiratory support trial for COVID-19 – with over 1200 participants taking part across 48 UK hospitals. The multi-centre, adaptive, randomised controlled trial compared the use of CPAP (oxygen and positive pressure delivered via a tightly fitting mask), with HFNO (high pressure oxygen delivered up the nose), against standard care (standard oxygen therapy).

All three interventions are commonly used to treat COVID-19 patients before they are moved onto invasive ventilation in a critical care bed, but it was not known which, if any, resulted in better outcomes.

Results

Over 13 months, between April 2020 and May 2021, a total of 1,272 hospitalised COVID-19 patients with acute respiratory failure, aged over the age of 18, were recruited to the study and randomly allocated to receive one of three respiratory support interventions as part of their hospital care.

380 (29.9%) participants received CPAP; 417 (32.8%) participants received HFNO; and 475 (37.3%) received conventional oxygen therapy.

The primary outcomes assessed through the trial were whether the patient went on to require tracheal intubation (invasive mechanical ventilation) or died within 30-days of beginning treatment through the trial.

In the comparison of CPAP and conventional oxygen therapy, the likelihood of patients going on to require invasive mechanical ventilation or die within 30-days of treatment was significantly lower in those who were treated with CPAP, than those who received standard care. In the CPAP group, 137 of 377 participants (36.3%) either needed mechanical ventilation or died within 30 days, compared with 158 of 356 participants (44.4%) in the conventional oxygen therapy group.

There was no difference in primary outcomes between patients in the HFNO and conventional oxygen therapy groups. In the HFNO group, 184 of 414 participants (44.4%) went on to require mechanical ventilation or die, compared with 166 of 368 participants (45.1%) in the conventional oxygen therapy group.

Based on these results, 1 person would avoid needing invasive ventilation within intensive care units (ICU) for every 12 people treated with CPAP instead of standard oxygen therapy.

Professor Gavin Perkins, Chief Investigator and Professor in Critical Care Medicine at Warwick Medical School at the University of Warwick said: “The RECOVERY-RS trial showed that CPAP was effective at reducing the need for invasive ventilation, thus reducing pressures on critical care beds. The routine use of high flow nasal oxygenation, which can consume large amounts of oxygen, should be reconsidered as it did not improve outcomes. By giving patients the most effective treatment to begin with, we can help prevent resource shortages in our NHS and make sure the right type of ventilation is available to patients when it is required.

“This is the first large trial of different types of ventilation in COVID-19. While it is encouraging that these results can help reduce the number of people who require invasive ventilation, it is important to stress that, where it is needed, invasive ventilation can be lifesaving.”

Professor Danny McAuley, Chief Investigator and Professor and Consultant in Intensive Care Medicine at the Royal Victoria Hospital and Queen’s University Belfast said: “Over the COVID pandemic, we’ve seen a large number of patients requiring high levels of oxygen and admission to ICU for invasive ventilation, causing a huge strain on staff and beds.

“The results of this trial are really encouraging as they have shown that by using CPAP, invasive ventilation may not be needed for many patients with COVID-19 requiring high oxygen levels. Avoiding invasive ventilation is not only better for the patients, but it also has important resource implications as it frees up ICU capacity. This research should help healthcare professionals in the UK and beyond manage patients with COVID-19, to improve patient outcomes while helping to lessen the burden on resources.”

Professor Jonathan Van-Tam, Deputy Chief Medical Officer said: “COVID-19 has placed huge pressure on our hospitals and intensive care units, and our doctors, nurses and all NHS staff have stepped up to meet that challenge. A key part of tackling COVID has been the improvements that staff have identified and then implemented in terms of how to best care for COVID patients.

“This study, funded by the NIHR, provides valuable evidence around how non-invasive respiratory support can be used to improve patient outcomes. Reducing invasive mechanical ventilation is better for patients and reduces pressures on mechanical ventilator capacity across the NHS.

“I want to thank the team of doctors, researchers and patient volunteers involved in today’s excellent results – hospitals across the country can now use these data to further improve care for patients and reduce the demand for mechanical ventilation as we get closer to what might still be a challenging winter period.”

Professor Lucy Chappell, Chief Scientific Adviser (CSA) for the DHSC and the National Institute for Health Research (NIHR) Chief Executive Officer, said: “Research such as this has been a huge asset to the COVID-19 response, allowing us to fine-tune our approach and improve care for patients in hospital.

“I am hugely grateful to the teams at the University of Warwick and Queen’s University Belfast for their contribution to our understanding of the virus through this NIHR-funded study, and particularly how to treat it.

“This data will help ensure hospitalised patients with COVID-19 get the best possible care, making a difference to patients and intensive care units across the country.”

Professor Nick Lemoine, Medical Director at the National Institute for Health Research (NIHR) Clinical Research Network said: “Preliminary results from this NIHR-supported trial provide important evidence which will help shape clinical practice worldwide around respiratory support interventions for hospitalised COVID-19 patients. The study will undoubtedly help improve outcomes for patients – while potentially alleviating pressure on hospital beds and critical care services.

“We sincerely want to thank everybody involved – the patients who took part in their darkest hour, and the NHS doctors and nurses who helped deliver the study right across the UK.”

Professor Simon Ball, Executive Medical Officer at University Hospitals Birmingham said: “This is an important study that will significantly influence treatment decisions. It is an example of how well NHS hospitals can deliver studies to improve clinical practice. This includes the definition of treatments that are beneficial, in this case CPAP, but just as importantly those with no apparent benefit, in this case high flow nasal oxygen. The best possible care we deliver is that focused by evidence.”

About RECOVERY-RS

Both CPAP and HFNO have been widely used worldwide in the management of COVID-19 throughout the pandemic for patients who need high levels of additional oxygen. If these treatments are not successful, patients need to be sedated and treated with a ventilator in intensive care. Although both CPAP and HFNO are commonly used in other lung conditions, prior to the RECOVERY-RS study, it was unknown how safe and effective they were for people with breathing difficulties arising from COVID-19.

The trial is led by Joint Chief Investigators Professor Gavin Perkins at the University of Warwick, and Professor Danny McAuley at Queen’s University Belfast.

It was funded and supported by the National Institute for Health Research (NIHR) as a prioritised urgent public health COVID-19 study.

RECOVERY-RS was one of the first COVID-19 studies to be classed as urgent public health research by the UK’s Chief Medical Officers in order to urgently identify strategies to reduce the need for invasive mechanical ventilation. Launched in April 2020 as COVID-19 hospitalisation began to soar, the NIHR Clinical Research Network provided prioritised support to rapidly set the study up at hospital sites across the UK and enroll participants. The NIHR’s research infrastructure, expertise and delivery support has been critical to the trial’s success.

The preliminary results of this evaluation of the data will be available as a pre-print on medRxiv on 5 August 2021 and will be submitted to a leading peer-reviewed medical journal. The results will be presented in detail at a free virtual Critical Care Reviews conference session (https://criticalcarereviews.com) on Thursday 5 August at 7.30pm.

Notes to editors:

Taking part in RECOVERY-RS: Lisa’s story

Lisa Broadhurst, 42, from Birmingham, took part in the RECOVERY-RS trial in January after contracting COVID-19.

She was rushed to hospital by ambulance on 13 January with breathing problems and dropping oxygen levels, 11 days after first experiencing symptoms of aches and pains, loss of taste and smell and a severe headache.

Diagnosed with severe COVID-19 and pneumonitis, Lisa, who is also asthmatic, said: “I’ve never been so scared in my life. I had no control of my deteriorating health. I remember Face Timing my family and letting them know how poorly I was. All I could think about was whether I’d go home or whether covid would kill me like so many other patients. The nurses would squeeze my hand and reassure me to stay strong. It was a heartbreaking time and I wouldn’t wish that feeling on anyone.”

Lisa, who received CPAP as part of the trial, remembers being connected to the machine: “The pressure of the oxygen took a little while to get used to. It was a scary experience and took my breath away at first. All I could think about was making it home to my family. I fought as hard as I could to stay alive, I cried a lot and I was scared and overwhelmed.

“But throughout the time on the machine I could see I was getting better. It was the best feeling ever leaving the hospital and walking outside into the fresh air knowing I was going home to my loved ones.”

COVID-19 still has a lasting impact on her health and her lungs are much more sensitive.

But she added: “I’m extremely grateful I took part in the trial – the level of care I received from everyone was amazing. The nurses and doctors showed so much support. I couldn’t have asked for better and taking part in the trial saved my life. I will always forever be in debt to the NHS – they helped me to go back home to my family. Research really does help benefit others and it’s the reason I’m alive today.”

Featured image credit: Unsplash


Provided by University of Warwick

Full-dose Blood Thinners Reduce The Need For Organ Support in Moderately Ill COVID-19 Patients (Medicine)

A large clinical trial conducted worldwide shows that treating moderately ill hospitalized COVID-19 patients with a full-dose blood thinner reduced their need for organ support, such as mechanical ventilation, and improved their chances of leaving the hospital. However, the use of this treatment strategy for critically ill COVID-19 patients requiring intensive care did not result in the same outcomes. The formal conclusions from the trial, which was supported in part by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, appear online in The New England Journal of Medicine.

“These results make for a compelling example of how important it is to stratify patients with different disease severity in clinical trials. What might help one subgroup of patients might be of no benefit, or even harmful, in another,” said NHLBI Director Gary H. Gibbons, M.D.

Researchers have observed that in some people who died from COVID-19, blood clots had formed throughout their bodies, even in their smallest blood vessels. Antithrombotics, which include blood thinners or anticoagulants, help prevent clot formation in certain diseases. Doctors did not know which antithrombotic drug, what dose, and at what point during the course of COVID-19, antithrombotics might be effective. To answer these urgent questions, three international partners came together and harmonized their trial protocols to  study the effects of using a full, or therapeutic dose, of the blood thinner heparin versus a low, or prophylactic dose, of heparin in moderately and critically ill patients hospitalized with COVID-19.

Researchers defined moderately ill patients as those hospitalized for COVID-19 without the requirement of organ support, and critically ill patients as those hospitalized for COVID-19 requiring intensive care level of support, including respiratory and/or cardiovascular organ support.

In April 2020, hospitalized COVID-19 patients received either a low or full dose of heparin for up to 14 days after enrollment. By December 2020, interim results indicated that full-dose anticoagulation did not reduce the need for organ support and may even cause harm in critically ill patients. However, one month later, interim results indicated that full doses of heparin likely benefited moderately ill patients.

“The formal conclusions from these studies suggest that initiating therapeutic anticoagulation is beneficial for moderately ill patients and once patients develop severe COVID-19, it may be too late for anticoagulation with heparin to alter the consequences of this disease,” said Judith Hochman, M.D., senior associate dean for Clinical Sciences at New York University, a corresponding author of the moderately ill study and study chair of the NIH-funded portion of the combined platform trials, Accelerating COVID-19 Therapeutic Interventions and Vaccines-4 (ACTIV-4a) Antithrombotics Inpatient trial. “The medication evaluated in these trials is familiar to doctors around the world and is widely accessible, making the findings highly applicable to moderately ill COVID-19 patients.”

The final analysis of trial data included 1,098 critically ill and 2,219 moderately ill patients. For both moderately and critically ill patients, researchers looked at how long they were free of organ support up to 21 days after enrollment. Among moderately ill patients, researchers found that the likelihood of full-dose heparin to reduce the need for organ support compared to those who received low-dose heparin was 99%. A small number of patients experienced major bleeding, though this happened infrequently. For critically ill patients, full-dose heparin also decreased the number of major thrombotic events, but it did not reduce the need for organ support or increase their chances of leaving the hospital early after receiving treatment.

The participating partners in the multicenter trials include: Randomized, Embedded, Multi-factorial Adaptive Platform Trial for Community-Acquired Pneumonia (REMAP-CAPexternal link) Therapeutic Anticoagulation; Antithrombotic Therapy to Ameliorate Complications of COVID-19 (ATTACCexternal link); and ACTIV-4a Antithrombotics Inpatient A Multicenter, Adaptive, Randomized Controlled Platform Trial of the Safety and Efficacy of Antithrombotic Strategies in Hospitalized Adults with COVID-19. In the United States, ACTIV-4a Antithrombotics Inpatient is being led by a collaborative effort with several universities, including the University of Pittsburgh, a trial coordinating center, and New York University, the study chairs’ office and a coordinating center. ACTIV-4a Antithrombotics Inpatient is also conducting another study to test the effects of adding an anti-platelet agent to anticoagulation.

“More work needs to be done to continue to improve outcomes in patients with COVID-19,” said Matthew D. Neal, M.D., the Roberta G. Simmons Associate Professor of Surgery at the University of Pittsburgh, co-senior author of the severely ill study, co-first author of the moderately ill study, and co-chair of ACTIV-4a Antithrombotics Inpatient. “Given what we know about the type of blood clots in patients with COVID-19, testing anti-platelet agents is a particularly exciting approach.”

The collaborative trials are supported by multiple international funding organizations, including the Canadian Institutes of Health Research, the National Institute for Health Research (U.K.), the National Health and Medical Research Council (Australia), the National Institutes of Health (U.S.), and the PREPARE and RECOVER consortia (EU).

Study: Therapeutic Anticoagulation in Critically Ill Patients with Covid-19 – Preliminary Report. DOI: 10.1056/NEJMoa2103417.

Study: Therapeutic Anticoagulation in Non-Critically Ill Patients Hospitalized for Covid-19. DOI: 10.1056/NEJMoa2105911.

ClinicalTrials.gov Identifier(s): NCT04505774; NCT04359277.


Provided by NIH/NHLBI

Macrophages Play Key Role in Lung Damage During COVID-19 (Biology)

A KAIST immunology research team found that a specific subtype of macrophages that originated from blood monocytes plays a key role in the hyper-inflammatory response in SARS-CoV-2 infected lungs, by performing single-cell RNA sequencing of bronchoalveolar lavage fluid cells. This study provides new insights for understanding dynamic changes in immune responses to COVID-19.

In the early phase of COVID-19, SARS-CoV-2 infected lung tissue and the immediate defense system is activated. This early and fast response is called ‘innate immunity,” provided by immune cells residing in lungs. Macrophages are major cell types of the innate immune system of the lungs, and newly differentiated macrophages originating from the bloodstream also contribute to early defenses against viruses.

Professor Su-Hyung Park and his collaborators investigated the quantitative and qualitative evaluation of immune responses in the lungs of SARS-CoV-2 infected ferrets. To overcome the limitations of research using patient-originated specimens, the researchers used a ferret infection model to obtain SARS-CoV-2 infected lungs sequentially with a defined time interval.

The researchers analyzed the 10 subtypes of macrophages during the five-day course of SARS-CoV-2 infection, and found that infiltrating macrophages originating from activated monocytes in the blood were key players for viral clearance as well as damaged lung tissue. Moreover, they found that the differentiation process of these inflammatory macrophages resembled the immune responses in the lung tissue of severe COVID-19 patients.

Currently, the research team is conducting a follow-up study to identify the dynamic changes in immune responses during the use of immunosuppressive agents to control hyper-inflammatory response called ‘cytokine storm’ in patients with COVID-19.

Dr. Jeong Seok Lee, the chief medical officer at Genome Insight Inc., explained, “Our analysis will enhance the understanding of the early features of COVID-19 immunity and provide a scientific background for the more precise use of immunosuppressive agents targeting specific macrophage subtypes.”

“This study is the first longitudinal study using sequentially obtained immune cells originating from SARS-CoV-2 infected lungs. The research describes the innate immune response to COVID-19 using single cell transcriptome data and enhances our understanding of the two phases of inflammatory responses,” Professor Park said.

Featured image: Identification of distinct macrophage subtypes that trigger lung damage during SARS-CoV-2 infection. Credit: The Korea Advanced Institute of Science and Technology (KAIST)


Reference: Jeong Seok Lee et al, Single-cell transcriptome of bronchoalveolar lavage fluid reveals sequential change of macrophages during SARS-CoV-2 infection in ferrets, Nature Communications (2021). DOI: 10.1038/s41467-021-24807-0


Provided by The Korea Advanced Institute of Science and Technology (KAIST)

How SARS-CoV-2 Promotes Inflammation? (Biology)

Juan Robles and colleagues revealed for the first time that the spike protein of SARS-CoV-2 promotes endothelial inflammation through integrin α5β1 and NF-κB pathway. Their study recently appeared in BioRxiv.

Endothelial cells (ECs) mostly exist in the inner layer of all blood vessels and are normally protected by pericytes. They form a critical interface between blood and tissues that maintains whole-body homeostasis. In COVID-19, disruption of the EC barrier results in edema, vascular inflammation, leukocyte infiltration and coagulation, the hallmarks of the severe disease. However, the mechanisms by which EC are dysregulated in COVID-19 are unclear. Now, Juan Robles and colleagues revealed that the spike activates NF-κB pathway through its interaction with integrin α5β1 in EC to elicit inflammation and leukocyte infiltration.

They also suggested that spike promotes hyperpermeability of EC monolayers and leukocyte adhesion via integrin α5β1 by regulating Rho GTPases and eNOS phosphorylation, and we can prevent or block the leukocyte adhesion and hyperpermeability in response to spike and spike receptor-binding domain by using ‘volociximab’, which is a chimeric anti-integrin α5β1 monoclonal antibody and ‘ATN-161’, which is the integrin α5β1 binding peptide.

“Our findings uncover a new direct action of SARS-CoV-2 on EC dysfunction and introduce integrin ⍺5β1 as a promising target for treating vascular inflammation in COVID-19.”

— they concluded.

Their work was supported by grants A1-S-9620B and 289568 from “Consejo Nacional de Ciencia y Tecnología” (CONACYT) to C.C. Magdalena Zamora is a doctoral student from ‘Programa de Doctorado en Ciencias Biomédicas, Universidad Nacional Autónoma de México (UNAM)’ and received fellowship 768182 from CONACYT.


Reference: Juan Pablo Robles, Magdalena Zamora, Gonzalo Martinez de la Escalera, Carmen Clapp, “The spike protein of SARS-CoV-2 induces endothelial inflammation through integrin α5β1 and NF-κB”, bioRxiv 2021.08.01.454605; doi: https://doi.org/10.1101/2021.08.01.454605


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More Variants of TLR7 Gene Found in Young, Healthy Men With Severe COVID-19 (Biology)

Spanish-Dutch research has revealed two new mutations in the TLR7 gene in healthy young men who became seriously ill with severe Covid-19. It’s becoming increasingly plausible that such mutations undermine a sufficient immune response against SARS-CoV-2, the researchers write in Frontiers in Immunology.

An infection with SARS-CoV-2 can lead to serious inflammation and even death in some individuals. Older age, male gender and chronic diseases such as diabetes and obesity increase the risk for a severe outcome. But these risk factors cannot explain why (very) severe Covid-19 also occurs in young, healthy men without a medical history.

Important factor in the immune system

Last year researchers from Radboudumc published an article in JAMA describing for the first time that mutations in the TLR7 gene were a possible rare genetic risk factor. Two unrelated pairs of brothers became seriously ill with Covid-19 and one of them died, they reported. They all had a mutation in the TLR7 gene, which encodes the receptor that plays a role in the recognition of the coronavirus and initiates the antiviral immune response through induction of interferons. TLR7 thus appears to be an important factor in the defense against SARS-CoV-2.

Support

After this first publication, the findings were repeated in several studies. An Italian study of men over 60 years of age with severe COVID-19 found that more than 2 percent of severely affected men carried a genetic mutation in TLR7, leading to an impaired functioning TLR7 receptor. These variants were not found in any individual in the control group. The researchers again observed a hampered activation of interferon signaling, signifying that an optimal immune response could not be mounted. “A recently published study in the American Journal of Human Genetics, which looked for rare genetic risk factors through an association study in more than half a million people, also revealed TLR7 as the most important factor for severe Covid-19,” says geneticist Alexander Hoischen from Radboudumc Nijmegen, the Netherlands.

Two new variants

With Caspar van der Made, Frank van de Veerdonk and other Radboudumc researchers who were involved as well in the first publication on TLR7, Hoischen has now published another study on TLR7 together with Spanish researchers. This time they screened 14 cases of severe Covid-19 in young, healthy men under the age of fifty, of whom 10 from Spain and 4 from the Netherlands. Hoischen says that “hitherto unknown mutations of the TLR7 gene were found in both a Spanish and a Dutch patient. In the Dutch patient again we saw the defective activation of the signaling and impaired production of interferon.”

Preventive vaccination and more active screening

What made the Dutch case special is two of the patient’s cousins had the same mutation. Although they were not yet eligible for vaccination at that time due to their young age, they were given priority based on the research. Van der Made says that “as far as we know, these family members had not yet been exposed to the coronavirus. We therefore decided to vaccinate them preventively, in order to greatly reduce the risk of serious illness from Covid-19. In our small-scale study, we provide an impetus for screening a selected group of young men, precisely because a diagnosis of TLR7 deficiency due to mutations in this gene can have consequences for treatment, such as the mentioned preventive vaccination.” Hoischen: “Mutations in the TLR7 gene are now also listed as immune deficiency in OMIM – the international website where such information is registered.”


Reference: Xavier Solanich et al, Genetic Screening for TLR7 Variants in Young and Previously Healthy Men With Severe COVID-19, Frontiers in Immunology (2021). DOI: 10.3389/fimmu.2021.719115


Provided by Radboud University

People With A Weakened Immune System Can Develop A Good Immune Response After Vaccination Against SARS-CoV-2 (Medicine)

Patients with a weakened immune system due to immunosuppressive therapies can develop good immune responses to a corona vaccination. A third dose of vaccine may be necessary for those patients who do not produce antibodies. This is shown by a current study by MedUni Vienna.

People affected by autoimmune diseases often need therapy that weakens the immune system. It is precisely in this group that COVID-19 can develop severely. Up until now it was unclear whether a vaccination against SARS-CoV-2 would guarantee a sufficient response, especially in patients who are receiving so-called B-cell-depleting drugs (e.g. rituximab for rheumatoid arthritis). In a recently published study by a cross-departmental team from the Medical University of Vienna coordinated by the Clinical Department for Rheumatology (Head: Daniel Aletaha) of the University Clinic for Internal Medicine III, this question has now been answered. Senior author Michael Bonelli and his study team were able to show that the majority of these patients are still able to develop a humoral and cellular immune response.

Michael Bonelli says: “B cells represent an important cell population for the development of antibodies. We were able to show that patients under B-cell-depleting therapy with rituximab still develop antibodies against SARS-CoV-2 in more than 50% of cases there is possible additional protection through a cellular immune response. This underlines the importance of vaccinating immunosuppressed patients against SARS-CoV-2. “

Sometimes a third vaccination is needed

Daniel Aletaha, Head of the Clinical Department for Rheumatology, explains further: “The findings of this work formed the basis for a now completed randomized booster vaccination study in which we examined whether that group of patients under therapy with rituximab were after Standard vaccination could not produce antibodies, but a third vaccination with a new mRNA vaccine or a switch to vector vaccine still developed humoral or cellular immunity. The results of the first vaccination study are about to be published and will hopefully contribute to the creation of guidelines for the vaccination strategy against SARS-CoV-2 in immunosuppressed patients.”

A follow-on study of the same design, for which volunteers are currently being recruited, will now extend the rituximab study to all patients with immunosuppression and different indications from the fields of rheumatology, neurology, hematology, transplantation, and others. This project is a collaboration between many researchers from different divisions/institutes of MedUni Vienna.

Service: Annals of the Rheumatic Diseases
SARS-CoV-2 vaccination in rituximab-treated patients: B cells promote humoral immune responses in the presence of T-cell-mediated immunity. Mrak D, Tobudic S, Koblischke M, Graninger M, Radner H, Sieghart D, Hofer P, Perkmann T, Haslacher H, Thalhammer R, Winkler S, Blüml S, Stiasny K, Aberle JH, Smolen JS, Heinz LX, Aletaha D , Bonelli M. Ann Rheum Dis. 2021 Jul 20: annrheumdis-2021-220781. doi: 10.1136 / annrheumdis-2021-220781.


Provided by Medical University of Vienna