Category: Respiratory Diseases

Researchers Pioneer New Breathing Test to Detect Lung Disease Earlier

Credit: Scientific Animations CC4.0

A new project led by Oxford University aims to develop a novel breathing test that could detect asthma and COPD earlier, more accurately, and closer to home – reducing pressure on the NHS and improving outcomes for patients.

This work is included in a portfolio of research funded by the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation, to make diagnostic testing more accessible by designing simple, affordable tools that can be used in everyday settings. The project, called ACCESS (A Community-based diagnostiC for early airwayS disease), focuses on airway diseases, and will receive £1.3 million over three years.

Chronic respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD) affect more than half a billion people worldwide and cause over four million deaths every year. In the UK, these conditions hit disadvantaged communities hardest, with people in areas of socioeconomic deprivation facing particular challenges in accessing hospital-based diagnostic care.

A volunteer undertaking a computed cardiopulmonography based breath test. (The volunteer is Dr Nick Smith, a member of the research team developing the CCP technology). Credit: Department of Chemistry, University of Oxford.

Currently, asthma and COPD diagnosis relies on a test called spirometry. This measures how much air a person can forcefully breathe out, but it is difficult for many patients to perform and often fails to detect disease in its earliest stages. By the time spirometry picks up abnormalities, damage to the lungs is usually irreversible, resulting in late diagnoses, missed chances for early treatment, and poorer outcomes.

The project is enabled by the strong ethos for collaborative and innovative research in this University and will be delivered by a multi-disciplinary team, working across university departments and the NHS.

Project lead Professor Grant Ritchie

To address these issues, Oxford researchers have developed a new test, known as computed cardiopulmonography (CCP), that could transform the way lung diseases are diagnosed. CCP is performed while a patient breathes normally for 12 minutes through a mouthpiece linked to a highly accurate gas analyser. Using cutting-edge laser technology and advanced mathematical modelling, the test captures a detailed picture of how evenly air flows through the lungs. This “fingerprint” of lung function changes early in the course of disease, making CCP a powerful tool for spotting subtle problems that spirometry can miss.

Early studies in people with asthma, COPD, and even in otherwise healthy smokers suggest CCP is a highly sensitive marker of small airways damage. But while the results are promising, the test currently takes too long and requires specialist gas supplies, restricting its use to hospitals and research labs.

The goal of the ACCESS project is to adapt CCP for community use, for instance in GP surgeries, pharmacies, and community diagnostic hubs. Specifically, the research team will work to reduce the time duration and volume of gas needed for each test, and speed up the data analysis so that results can be shared with the patient during the same appointment. Towards the end of the project, CCP will be trialled in a community diagnostic centre to gather feedback from patients and healthcare professionals.

The long-term goal is to support earlier diagnosis and treatment, helping reduce hospital visits and tackle health inequalities. By enabling earlier intervention and delivering care closer to home, CCP has the potential to improve outcomes for millions of people living with lung disease.

Source: Oxford University

Inhaling Cannabis May Greatly Increase Risk of Lung Disease

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For those looking to reduce their chances of developing lung disease, say experts at UC San Francisco, then it may be smart to avoid inhaling cannabis.

A new study in the Journal of General Internal Medicine found that inhaling marijuana every day is associated with a 44% increased chance of developing asthma. It also increases the odds of developing a common set of lung diseases known as chronic obstructive pulmonary disease (COPD) by 27%.

The risk of COPD, which includes emphysema and chronic bronchitis, may be understated. The disease takes decades to develop, and the researchers did not have detailed information on how long people in the study had been using cannabis.

Researchers defined “inhaling” as smoking, vaping, and so-called “dabbing,” which involves breathing in the vapors of concentrated marijuana. The study found an association between elevated risks to a person’s lungs and doing any of those things with cannabis even for those who had never smoked cigarettes.

For those who never smoked cigarettes, inhaling marijuana every day was linked to a 51% increased likelihood of developing asthma. The association with COPD was also elevated, but it was not statistically significant.

The study is the largest yet to examine the association between inhaling cannabis and risks to respiratory health among people who have not smoked cigarettes. Of the 380 000 adult participants, nearly 222 000 had never smoked tobacco. The data comes from the Behavioral Risk Factor Surveillance System, a national survey by the Centers for Disease Control and Prevention (CDC).

Experts say the broad legalization of marijuana across much of the country and the perception that it is healthier than tobacco has led people to minimize the risks.

“The message about smoking tobacco being bad for you has gotten out there, but for cannabis, it’s much less clear,” said Alison Rustagi, MD, PhD, assistant professor at UCSF and first author of the paper.

“If people are looking to reduce their likelihood of developing a chronic lung disease, they should not start using cannabis,” she said. “And if they already smoke cannabis, they should do it less often.”

Source: University of California – San Francisco

Study Finds that Even Healthy Children Are Vulnerable to RSV

Photo by William Fortunato

It is not only premature babies and children with underlying diseases who suffer from serious respiratory syncytial virus (RSV) infections. Even healthy, full-term babies are at significant risk of intensive care or prolonged hospitalisation – especially during the first three months of life. This is according to a comprehensive registry study from Karolinska Institutet published in The Lancet Regional Health – Europe.

RSV is a common cause of respiratory infections in young children and accounts for around 245,000 hospital admissions annually in Europe. Researchers have now analysed data from over 2.3 million children born in Sweden between 2001 and 2022 to find out who is at greatest risk of suffering serious complications or dying from an RSV infection.

Preventive treatment available

It is well-known that premature babies and children with chronic diseases are at increased risk of developing severe illness when infected with RSV. It is also known that children under three months of age are particularly vulnerable, but it has not been entirely clear how common severe disease is among previously healthy children. The study shows that the largest group among the children who needed intensive care or were hospitalised for a long period of time were under three months of age, previously healthy and born at full term.

“When shaping treatment strategies, it is important to take into account that even healthy infants can be severely affected by RSV,” says the study’s first author, Giulia Dallagiacoma, a physician and doctoral student at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet. “The good news is that there is now preventive treatment that can be given to newborns, and a vaccine that can be given to pregnant women.”

Starting September 10, 2025, all newborns in Sweden are being offered preventive treatment with antibodies during the RSV season. The drug works much like a vaccine and protects against severe RSV infection for about six months.

Several risk factors identified

A total of 1.7 per cent of the children in the study were diagnosed with RSV infection. Among those, just under 12 per cent (4,621 children) had a severe course of illness. The median age of children who needed intensive care was just under two months, and the majority of them had no underlying disease.

The researchers identified several factors that were linked to an increased risk of needing intensive care or dying. Children who were born in the winter, or had siblings aged 0–3 years or a twin, had approximately a threefold increased risk, while children who were small at birth had an almost fourfold increased risk. Children with underlying medical conditions had more than a fourfold increased risk of severe illness or death.

“We know that several underlying diseases increase the risk of severe RSV infection, and it is these children who have so far been targeted for protection with the preventive treatment that has been available,” says the study’s last author, Samuel Rhedin, resident physician at Sachs’ Children and Youth Hospital and associate professor at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet. “However, the study highlights that a large proportion of children who require intensive care due to their RSV infection were previously healthy. Now that better preventive medicines are available, it is therefore positive that the definition of risk groups is being broadened to offer protection during the RSV season to previously healthy infants as well.”

Source: Karolinska Institutet

Publication

“Risk factors for severe outcomes of respiratory syncytial virus infection in children: a nationwide cohort study in Sweden”, Giulia Dallagiacoma, Cecilia Lundholm, Awad I Smew, Emma Caffrey Osvald, Pekka Vartiainen, Santtu Heinonen, Tobias Alfvén, Catarina Almqvist, Samuel Rhedin, The Lancet Regional Health – Europe, online 10 September 2025, doi: 10.1016/j.lanepe.2025.101447.

Researchers Identify Promising New Compound to Treat Tuberculosis

As part of the ongoing fight against tuberculosis, scientists within Texas A&M AgriLife Research and Calibr-Skaggs have developed a promising new compound targeting a key bacterial enzyme on M. tuberculosis. The compound, using a novel mechanism, proved effective against even drug-resistant strains of tuberculosis in early studies. (Inna Krieger/Texas A&M AgriLife)

Scientists have developed a new compound that could offer a breakthrough in the global fight against tuberculosis, history’s deadliest infectious disease.

A study recently published in Nature describes the treatment potential of the novel compound known as CMX410. The drug uniquely targets a crucial enzyme in Mycobacterium tuberculosis, the bacterium responsible for tuberculosis. Importantly, this compound even proved effective against drug-resistant infections, which are common globally and pose a significant challenge for controlling the disease’s spread and progression.

The study was led by James Sacchettini, PhD, the Rodger J. Wolfe-Welch Foundation Chair in Science, Texas A&M AgriLife Research scientist and professor in the Texas A&M College of Agriculture and Life Sciences Department of Biochemistry and Biophysics and College of Arts and Sciences Department of Chemistry. He was joined by Case McNamara, PhD, senior director of infectious disease at Calibr-Skaggs Institute for Innovative Medicines, the nonprofit drug development division of Scripps Research dedicated to accelerating next-generation medicines.

The discovery was made possible through collaborations formed by the TB Drug Accelerator program, an initiative funded by The Gates Foundation to support research focused on developing the most promising tuberculosis treatments.

“A lot of people think of tuberculosis as a disease of the past,” Sacchettini said. “But in reality, it remains a major public health issue requiring significant attention, collaboration and innovation to overcome.”

A smarter way to fight back

The new compound identified by AgriLife Research and Calibr-Skaggs works by blocking a crucial enzyme, polyketide synthase 13 or Pks13, that M. tuberculosis needs to build its protective cell wall. Without the functionality of this protein, the bacteria can’t survive to cause infection.

For over a decade, scientists have recognised this protein as a high-value target in the fight against tuberculosis. Yet, despite its potential, drug development efforts have repeatedly fallen short – largely because compounds must clear a high bar for both safety and therapeutic performance.

The unique mechanism of CMX410 makes it highly specific for its target, which translates to a favourable safety profile. By incorporating a reactive chemical group that forms an irreversible bond with a critical site on Pks13, the researchers enhanced the compound’s selectivity, minimising potentially negative off-target effects. This modification also reduces the likelihood of resistance emerging.

The addition of this key chemical group was accomplished with click chemistry, a method that snaps molecules together like puzzle pieces. Click chemistry was developed by co-author Barry Sharpless, Ph.D., W.M. Keck Professor of Chemistry at Scripps Research and two-time Nobel Laureate, and it has led to the development of extensive libraries of chemical compounds.

“This technique represents a new tool for drug design,” said McNamara. “We expect to see its uses expand in the coming years to help address public health concerns with a critical need, including tuberculosis.”

Early results prove safe and effective

The team began by investigating a library of compounds shared by the Sharpless lab to identify molecules that could inhibit bacterial growth of M. tuberculosis.

After intensive optimization to improve compound potency and other pharmacological properties led by Calibr-Skaggs tuberculosis team members and co-first authors Baiyuan Yang, Ph.D., associate director of medicinal chemistry, and Paridhi Sukheja, Ph.D., investigator of infectious diseases, CMX410 was identified as a strong contender.

Yang, who led the chemistry optimisation, said the team explored more than 300 analogues to identify a compound with the right balance of potency, selectivity and safety. The team ultimately tested CMX410 against 66 strains of M. tuberculosis and found that it worked on both laboratory and multidrug-resistant strains collected from real patients.

“Identifying this novel target was an exciting moment,” said Sukheja, who led many early studies showing CMX410 could target a previously unexplored gene. “It opened up a completely new path forward, especially against strains that have learned to evade existing treatments.”

In other early experiments, the researchers determined that CMX410 could be safely combined with other tuberculosis antibiotics. This was an especially important factor for this disease, as treatment regimens require multiple drugs to be taken together for months at a time.

Researchers found no adverse effects in their initial tests in animal models even at the maximum dose level. And because CMX410 is highly specific to its target protein, they see it as unlikely to disrupt other beneficial bacteria or cause broader microbiome imbalances, a common side effect of conventional antibiotics.

Progress toward better treatments

The addition of a specialised chemical group that allows CMX410 to irreversibly bind to its target makes the compound extremely selective. These types of inhibitors remain an exciting and underexplored class of drugs, and further research will be needed to confirm their safety for humans.

Nonetheless, the precision, unique mechanism, good safety profile and other key features all make CMX410 a promising candidate for treating tuberculosis.

“These early results are very encouraging,” said Inna Krieger, Ph.D., senior research scientist in Sacchettini’s lab and co-first author of the study. “Cell wall-targeting antibiotics have long been a cornerstone of tuberculosis treatment. However, after decades of widespread use, their effectiveness is waning due to the rise of drug-resistant strains.

“We are working to discover new drugs that disrupt essential biological processes and identify optimal combinations with existing drugs to enable shorter, safer and more effective treatment regimens. Through these efforts, we hope to help move the world closer to a future free from tuberculosis.”

Source: Scripps Research

COVID Infection Linked to Increased Risk of Asthma – Vaccination Offers Protection

Respiratory tract. Credit: Scientific Animations CC4.0

People who have had COVID are at increased risk of developing certain inflammatory diseases of the airways, such as asthma, hay fever and chronic sinusitis. However, vaccination against the SARS-CoV-2 virus appears to reduce the risk, according to a comprehensive epidemiological study led by researchers at Karolinska Institutet.

The international research team used an electronic health database in the United States, TriNetX, to investigate the link between COVID and so-called type-2 inflammatory diseases, a group of chronic conditions in which the immune system overreacts to allergens or infections.

The researchers compared 973 794 people who had had COVID with 691 270 people who had been vaccinated against the SARS-CoV-2 virus and 4 388 409 healthy controls with no documented infection or vaccination.

Inflammation in the airways

The results are presented in The Journal of Allergy and Clinical ImmunologyPeople who had had COVID had a 66% higher risk of developing asthma, a 74% higher risk of chronic sinusitis and a 27% higher risk of hay fever compared with healthy controls. However, no increased risk was seen for the skin disease atopic eczema or for eosinophilic oesophagitis, an inflammation of the oesophagus.

“Our results suggest that COVID-19 can trigger type-2 inflammation in the airways, but not in other organs,” says Philip Curman, a physician and researcher at the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet, Sweden, who led the research.

Vaccination against the virus had the opposite effect. The risk of asthma was 32% lower among vaccinated individuals compared with healthy unvaccinated individuals. The risk of sinusitis and hay fever was also slightly lower.

More than twice the risk

When people who had had COVID were compared with vaccinated individuals, an even clearer effect was seen. Infected individuals had more than twice the risk of developing asthma or chronic sinusitis and a 40% higher risk of developing hay fever compared with those who had been vaccinated.

“It is interesting to see that vaccination not only protects against the infection itself, but also appears to provide good protection against certain respiratory complications,” says Philip Curman.

The study is retrospective, i.e. based on data that has already been collected. This means that the researchers cannot draw any firm conclusions about causal links. Another limitation is that some infections may have gone undiagnosed, especially if they were detected through self-testing.

The research was conducted in close collaboration with the University of Lübeck and the Lübeck Institute of Experimental Dermatology in Germany, the Technical University of Madrid in Spain and Bar-Ilan University in Israel. It was mainly funded by the German Research Foundation (Deutsche Forschungsgemeinschaft), Region Stockholm and Karolinska Institutet. Two researchers received travel grants from TriNetX, which provides the database used in the study, and one of the authors is employed by the company.

Source: Karolinska Institutet

RSV Infection Significantly Affects Cardiac Risks of Older Adults

Photo by Anna Shvets

Respiratory syncytial virus (RSV) is a well-known cause of infections in children, but it’s understudied in older individuals. In a retrospective study published in the Journal of the American Geriatrics Society, adults aged 65 and older hospitalised for RSV in Ontario, Canada experienced significantly higher rates of adverse outcomes such as longer length of hospital stay, transfer to intensive care, and 30-day mortality, compared with patients hospitalised with influenza, urinary tract infection, or fracture.

Interestingly, RSV hospitalisation was also associated with higher rates of heart failure and atrial fibrillation up to 1-year post-discharge, regardless of prior cardiovascular conditions.

“Unlike other respiratory viruses, immunity against RSV tends to decline relatively quickly. This means that a previous infection will not afford the same long-term protection as it might for influenza or COVID-19,” said corresponding author Chris Verschoor, PhD, HSN, Foundation Research Chair in Healthy Aging at Health Sciences North Research Institute. “Our findings reinforce the importance of RSV vaccination in older adults and suggest that monitoring for signs of heart disease following an RSV illness may be pragmatic.”

Source: Wiley

Study Uncovers Large Burden of Potentially Preventable Hospitalisations for Pneumococcal Pneumonias

This illustration depicts a 3D computer-generated image of a group of Gram-positive, Streptococcus pneumoniae bacteria. The artistic recreation was based upon scanning electron microscopic (SEM) imagery. Credit: CDC on Unsplash

In a recent multicentre prospective study conducted at three hospitals in Tennessee and Georgia, including Vanderbilt University Medical Center, researchers at VUMC found a substantial burden of hospitalisations for community-acquired pneumonia (CAP) among adults. 

Community-acquired pneumonia refers to a case of the disease contracted without prior exposure to a health care setting, otherwise known as hospital-acquired pneumonia (HAP). 

The study, published in JAMA Network Open, included data from 2018 to 2022 and used a novel serotype-specific urinary test that can identify infections caused by 30 different Streptococcus pneumoniae serotypes. A serotype refers to a distinct strain of microorganism, such as bacteria. 

An important aspect of the study was the identification of noninvasive pneumococcal infections, said Carlos Grijalva, MD, MPH, professor of Health Policy and Biomedical Informatics and the study’s lead author. 

“Standard clinical diagnostic methods such as bacterial cultures of blood are helpful for identifying invasive cases of pneumococcal disease, but the majority of pneumococcal pneumonias are thought to be noninvasive,” Grijalva added. “Using a novel and more sensitive urinary antigen detection method allowed us to identify a number of pneumococcal infections that may have otherwise passed unrecognised.” 

Based on current population estimates, some 114 800 U.S. adults may be hospitalised for pneumococcal pneumonia each year, a figure made up in large part by older adults. And according to the study’s findings, each year sees approximately 340 hospitalisations for community-acquired pneumonia per 100 000 adults, approximately 14% of which had evidence of Streptococcus pneumoniae infection. 

“Our study results show that Streptococcus pneumoniae remains an important cause of severe community-acquired pneumonia,” said Wesley Self, MD, MPH, professor of Emergency Medicine, Senior Vice President for Clinical Research and the paper’s senior author. 

Many of the serotypes identified by pneumococcal detections corresponded with those covered by a recently licensed adult-specific pneumococcal conjugate vaccine, V116, which includes 21 serotypes but was not commercially available during the study period. 

“Vaccines with coverage of additional pneumococcal serotypes could be quite beneficial in lessening the burden of severe pneumonia on the U.S. population, especially among older adults,” added Self, who holds the Directorship in Emergency Care Research. 

Source: Vanderbilt University Medical Center

Researchers Debunk Concerns over Common Flu Antiviral in Children

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For decades, medical professionals debated whether a common antiviral medication used to treat flu in children caused neuropsychiatric events or if the infection itself was the culprit.

Now researchers at Monroe Carell Jr. Children’s Hospital at Vanderbilt have debunked a long-standing theory about oseltamivir, known as Tamiflu.

According to the study, published in JAMA Neurology, oseltamivir treatment during flu episodes was associated with a reduced risk of serious neuropsychiatric events, such as seizures, altered mental status and hallucination.

“Our findings demonstrated what many pediatricians have long suspected, that the flu, not the flu treatment, is associated with neuropsychiatric events,” said principal investigator James Antoon, MD, PhD, MPH, assistant professor of Pediatrics in the Division of Pediatric Hospital Medicine at Monroe Carell. “In fact, oseltamivir treatment seems to prevent neuropsychiatric events rather than cause them.”

Key points:

  • Influenza itself was associated with an increase in neuropsychiatric events compared to children with no influenza, regardless of oseltamivir use.
  • Among children with influenza, those treated with oseltamivir had about 50% reduction in neuropsychiatric events.
  • Among children without influenza, those who were treated with oseltamivir prophylactically had the same rate of events as the baseline group with no influenza.

“Taken together, these three findings do not support the theory that oseltamivir increases the risk of neuropsychiatric events,” said Antoon. “It’s the influenza.”

The team reviewed the de-identified data from a cohort of children and adolescents ages 5-17 who were enrolled in Tennessee Medicaid between July 1, 2016, and June 30, 2020.

During the four-year period, 692 295 children, with a median age of 11 years, were included in the study cohort. During follow-up, study children experienced 1230 serious neuropsychiatric events (898 neurologic and 332 psychiatric).

The clinical outcomes definition included both neurologic (seizures, encephalitis, altered mental status, ataxia/movement disorders, vision changes, dizziness, headache, sleeping disorders) and psychiatric (suicidal or self-harm behaviours, mood disorders, psychosis/hallucination) events.

“The 2024-2025 influenza season highlighted the severity of influenza-associated neurologic complications, with many centres reporting increased frequency and severity of neurologic events during the most recent season,” said Antoon. “It is important for patients and families to know the true risk-benefit profile of flu treatments, such as oseltamivir, that are recommended by the American Academy of Pediatrics.”

“These flu treatments are safe and effective, especially when used early in the course of clinical disease,” added senior author Carlos Grijalva, MD, MPH, professor of Health Policy and Biomedical Informatics at Vanderbilt University Medical Center.

Investigators hope the findings will provide reassurance to both caregivers and medical professionals about the safety of oseltamivir and its role in preventing flu-associated complications.

Source: Vanderbilt University Medical Center

No Benefits Seen from Conservative Oxygen in the ICU

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A UK trial involving 16 500 mechanically ventilated intensive care unit (ICU) patients found no 90-day survival benefit for conservative supplemental oxygen over usual oxygen therapy. Nevertheless, the study, published in JAMA, did demonstrate the accuracy and cost-effectiveness of conducting a large trial with a simple intervention.

Oxygen is one of the most commonly administered treatments to patients in ICUs, but liberal oxygen therapy to avoid the risks of hypoxaemia may lead to harm, so finding the right level could optimise outcomes. Trials to date have shown mixed results.

For COVID patients admitted to the ICU with severe hypoxaemia, survival without life support was extended with conservative oxygen therapy. In a paediatric ICU study, conservative oxygen therapy resulted in a reduction in a composite of organ support at 30 days or death. A meta-analysis of 13 trials showed no differences between liberal and conservative oxygen therapy.

Even with just a small difference in survival benefit, with tens of millions of patients mechanically ventilated in the ICU would still mean significant numbers of lives saved. Other tests of new drugs and procedures in the ICU are hampered by high cost, as Seitz et al. noted in an accompanying editorial, so this sort of trial comparing two approaches to a common therapy is much more affordable.

The UK Intensive Care Unit Randomised Trial Comparing Two Approaches to Oxygen Therapy (UK-ROX) trial was initiated to determine if there was a difference between conservative and usual oxygen therapy.

The trial randomised 16 500 patients across 97 ICUs in the UK to either conservative oxygen therapy or usual oxygen therapy, in adults receiving mechanical ventilation and supplemental oxygen in the ICU. The primary outcome was mortality at 90 days. Conservative oxygen therapy targeted a peripheral oxygen saturation (Spo2) of 90% (range, 88%-92%), while usual oxygen therapy was at the discretion of the treating clinician.

Patients were early in mechanical ventilation (median, 5 hours), were severely ill (median predicted mortality risk, 35%), had a range of critical illnesses (eg, > 5000 patients with sepsis and > 1500 patients with hypoxic-ischaemic encephalopathy) and with significant hypoxaemia (eg, > 11 000 patients with a Pao2:Fio2 ratio, consistent with acute respiratory distress syndrome). Obtaining informed consent from the patients was, of course, largely not feasible, so this requirement was waived for the study.

Exposure to supplemental oxygen was 29% lower for those in the conservative oxygen therapy group compared with the usual oxygen therapy group. Of the patients randomised to conservative oxygen therapy, 35.4% died by 90 days compared with 34.9% of patients receiving usual oxygen therapy.

No differences were seen for secondary outcomes, including ICU stay, days free of life support and mortality at various time points. No interactions for confirmed or suspected COVID, ethnicity or other illnesses were observed.

Post hoc analysis showed weak evidence of increased harm from conservative oxygen therapy among the first 10 patients in each site but no difference for the random enhanced data collection sample compared with standard data collection.

Seitz et al. pointed out that the high level of adherence to the conservative target resulted in a mean oxygen saturation of 93.3%, versus 95.1% for usual care. The differences in oxygen saturation (1.9%) and Fio2 (0.04) between the trial groups in UK-ROX were about half the magnitude of some prior trials, due to not aiming for widely separated targets, and usual care varies considerably depending on location and clinical considerations.

Therefore, the researchers concluded that the findings do not support an approach of reducing oxygen exposure by targeting an Spo2 of 90% in mechanically ventilated adults receiving oxygen in the ICU. They suggest that future research may involve using AI to determine specific situations where conservative or liberal oxygen therapy may have beneficial outcomes.

References:

Martin DS, Gould DW, Shahid T, et al. Conservative Oxygen Therapy in Mechanically Ventilated Critically Ill Adult Patients: The UK-ROX Randomized Clinical Trial. JAMA. 2025;334(5):398–408. doi:10.1001/jama.2025.9663

Seitz KP, Casey JD, Semler MW. Patient, Treatment, Outcome—Large Simple Trials of Common Therapies. JAMA. 2025;334(5):395–397. doi:10.1001/jama.2025.9657

Study Reveals Trained Immunity May Cause Lung Damage

Discovery could help explain why some people are more vulnerable to lung damage during severe inflammation

Photo by Anna Shvets

Trained immunity – a process being explored in vaccine and therapy development to boost immune defences – appears to be counterproductive in certain contexts, researchers at McGill University and the Research Institute of the McGill University Health Centre (The Institute) have found.

Trained immunity is when the body’s first line of defence remembers past threats and becomes more reactive, responding more strongly to future infections even if they are different, by changing immune cells’ behaviour.

In an earlier study, the researchers had determined beta-glucan, a molecule found in the cell walls of fungi like yeast and mushrooms, can reduce lung damage during influenza infection. That study had focused on beta-glucan’s impact on neutrophils.

However, in a new study, published in the journal eLifethe team found exposure to beta-glucan can reprogram alveolar macrophages in a way that worsens lung damage during severe inflammation caused by viral or bacterial products. These cells help keep the lungs clean by clearing out dust, debris and pathogens.

“To date, most trained immunity research has focused on circulating immune cells that arise from the bone marrow,” said lead author Renaud Prével, a postdoctoral fellow at the Meakins-Christie Laboratories at The Institute. “We wanted to explore whether beta-glucan could induce trained immunity in alveolar macrophages, and whether that might be helpful or harmful.”

The researchers exposed mice to beta-glucan, which is known to trigger trained immunity and is found in some health supplements. A week later, the mice were exposed to signals that mimic severe viral or bacterial infections with sepsis-like phenotype. Using high-resolution microCT scans and fluid analysis, they found that mice given beta-glucan developed significantly more severe lung damage compared to the untreated control group.

To confirm the immune cells were causing the damage, researchers removed them from the mice, and the inflammation went away. When they put trained alveolar macrophages into other mice, the inflammation came back. The cells showed signs of immune training, but surprisingly, this didn’t happen through the usual immune pathways. It needed signals from infections and help from other immune cells.

“Our study shows that immune memory in the lungs is more dynamic than previously thought,” said senior author Maziar Divangahi, Professor of Medicine at McGill and Associate Director of the Meakins-Christie Laboratories. “This could help explain why some individuals develop more severe lung inflammation, especially in settings like sepsis.”

Source: McGill University