Children with asthma and allergies who live with one or more cats do not experience worse asthma outcomes than children without cats at home. This is according to a comprehensive Swedish registry study from Karolinska Institutet, published in Frontiers in Allergy.
Many families with asthmatic children are advised to avoid keeping furry pets in the home. At the same time, previous studies on how cats as pets affect children with asthma and allergies have often been small and produced conflicting results.
The new study covers over 30 000 children in Sweden aged 4–17 with diagnosed asthma and allergies. The researchers followed the children for two years, comparing those living in households with cats with those who did not. Data on cat ownership was obtained from the national cat register and combined with data from several Swedish health and quality registers.
“We found no evidence that living with cats worsens asthma in children who already have asthma and allergies,” says Resthie R. Putri, postdoctoral researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet. “Unfortunately, however, we had no information on the specific allergies the children had, so we do not know whether they were allergic to cats or not.”
Individual advice is needed
The researchers analysed asthma exacerbations leading to emergency care, asthma severity based on medication use, asthma control, and lung function in the children. Children living with one or more cats experienced similar asthma outcomes to those without a cat. Nor could the number of cats in the home, or the age or sex of the cat, be linked to differences in asthma outcomes.
One strength of the study is the large number of participants from across Sweden. However, differences between countries may limit the applicability of the results to other contexts. As the Cat Register is relatively new, some cat exposure may not have been captured in the study. Furthermore, there was no information on how long the children had been exposed to cats for, or how much time the cats spent indoors. The researchers also cannot rule out the possibility that families with children suffering from more severe allergies may have chosen not to keep a cat.
“Clinical advice always needs to be tailored to the individual, and our study can contribute to the evidence base in discussions with families about pets and asthma,” says Catarina Almqvist Malmros, professor at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, and paediatrician at Astrid Lindgren Children’s Hospital.
Will continue to follow the children
The researchers now plan to continue studying how different types of allergies may affect the outcome, and whether it makes a difference if the child is allergic to cats. They also plan to follow the children for a longer period to see how cat ownership may affect asthma over time.
New research presented at this year’s European Congress on Obesity in Istanbul, Turkey (12-15 May) shows the use of the new GLP-1 class of obesity drugs in people with asthma is associated with a 26% fall in the number of asthma exacerbations and a 14% drop in use of asthma inhaler reliever use. The study is by Simon Høj and Dr Kjell Erik Julius Håkansson Copenhagen University Hospital, Copenhagen Denmark and colleagues.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are now widely used to treat overweight, obesity and type 2 diabetes (T2DM), with growing evidence of benefits that extend beyond blood sugar control.
In asthma, where overweight, obesity and metabolic dysfunction can lead to increased severity of symptoms and adverse events such as acute exacerbations, the authors suggest that GLP-1 RAs may improve asthma outcomes through weight loss, modulation of airway inflammation, and improvements in metabolic functions. Reductions in occurrence of asthma exacerbations are likely to reduce systemic corticosteroid exposure (a common treatment for acute asthma exacerbations orally or intravenously) and thus may reduce the risk of corticosteroid exposure-associated adverse events such as osteoporosis or new-onset T2DM. As such, as the clinical use of GLP-1 RAs expands, reliable estimates of their impact on asthma control are needed for individuals living with both asthma and overweight, obesity or T2DM.
The researchers conducted a nationwide self-controlled cohort study using linked Danish health registers. Adult individuals with a prior asthma diagnosis or ≥2 asthma inhaler prescriptions redeemed within 12 months) were included on the date of their first GLP-1 RA dispensing (index date). Eligible individuals had continuous registration data for at least 12 months before and after the index date.
Individuals with COPD or patients with severe asthma treated with new and relatively expensive biologic drugs within 12 months before or after the index date were excluded. Overweight or obesity was defined using ICD-10 codes for those conditions. Those who had no evidence of T2DM – with no diagnosis recorded or no evidence of other first line diabetes drugs prescribed – were also placed in the with obesity/overweight group. Those with a T2DM diagnosis or prescriptions recorded for first line diabetes drugs such as metformin were placed in the T2DM group.
The primary outcome was exacerbations, defined as an inpatient asthma hospital contact(s) and/or systemic oral or intravenous corticosteroid course(s). Secondary outcomes were the use of rescue medication (inhaled short-acting β2-agonists), inhaled corticosteroid exposure, and chest infection events defined as redemption of antibiotics commonly used for lower airway infections
The cohort comprised 27,523 individuals (mean age 54 years, 66% female) with asthma and comorbid overweight or obesity (49%) or T2DM (61%) and 26% recorded as having both conditions. Around 50% of the GLP-1 prescriptions were liraglutide, 48% semaglutide, and 2% others (exenatide, dulaglutide, lixisenatide).
Compared with the year before GLP-1 RA treatment, GLP-1 RA treatment was associated with a 26% lower exacerbation rate overall; and 28% lower in men compared with 23% lower in women. When stratified according to GLP1 RA treatment indication, the analysis showed individuals with asthma and comorbid overweight or obesity and individuals with asthma and comorbid T2DM had similar effect estimates – a 22% reduction in those with overweight or obesity and a 26% reduction in those with T2D.
Reliever medication use fell by 14% overall, suggesting fewer symptoms despite daily inhaled corticosteroid exposure also decreasing by 23% (inhaled corticosteroids are used to prevent exacerbations and treat symptoms in asthma). Furthermore, pneumonia events were reduced by 10%. People also living with allergic rhinitis saw similar decreases (23%) in exacerbations to those living without allergic rhinitis (28%). The authors are also working on updated analyses to show differences between men and women for these specific outcomes.
The authors conclude: “In this nationwide cohort of over 27,000 individuals with asthma and also overweight, obesity or type 2 diabetes, use of GLP-1 drugs was associated with significant reductions in exacerbation burden as well as reliever use, exposure to inhaled corticosteroids and pneumonia events, irrespective of whether the drugs were being used to treat obesity or type 2 diabetes.”
The authors explain that their study did not have access to clinical records (just if people had used GLP-1 and hospital admissions), so data on BMI and weight loss for participants were not available.
But Dr Håkansson says: “There’s a high chance that the weight loss is a major contributor to these results. A common symptom in both asthma and obesity is shortness of breath, and the presence of excess fatty tissue creates a pro-inflammatory state in the body in general. There’s also evidence from other studies suggesting that the inflammation caused by excess adipose tissue is distinct from the ‘classic’ asthma inflammation which often is driven by allergies or cells called eosinophils.”
And he adds: “As the use of GLP-1 therapies increase, researchers are finding an increasing number of effects outside of weight loss.”
Join our podcast as we unpack a study exploring the potential of the asthma medication formoterol as a novel treatment for Metabolic Dysfunction-Associated Steatohepatitis (MASH), a severe liver condition often linked to diabetes.
The researchers used experiments involving high-fat diet mice and human liver cell cultures to show that this beta 2 adrenergic receptor agonist effectively reduces liver fat accumulation. It does so by stimulating mitochondrial biogenesis and enhancing metabolic efficiency. In addition, a massive retrospective analysis of nearly 60 000 patients revealed that those using long-acting versions of these drugs experienced significantly lower rates of liver complications and reduced mortality.
Asthma can lead to childhood hospitalisations, missed school days, missed workdays for caregivers, and a lower quality of life for both children and their caregivers. The global prevalence of asthma has increased over the past fifty years. A study published April 9th in the open-access journal PLOS Medicine by Annelise Blomberg at Lund University, Lund, Sweden and colleagues suggests that high prenatal PFAS exposure is associated with a higher incidence of asthma in childhood.
PFAS (Perfluoroalkyl substances) are widespread synthetic chemicals that impact the immune system and may play a role in the development of asthma. Previous epidemiological studies of PFAS and asthma only investigated low exposure levels and had inconclusive results. Due to decades-long contamination of a municipal waterworks in Ronneby, Sweden, researchers were able to study the impacts of high PFAS exposure. They accessed a register-based open cohort of all children born in Blekinge County between 2006 and 2013, including Ronneby. The researchers then linked maternal addresses during the exposure period to water distribution records to estimate prenatal exposure, and used asthma diagnosis data from the National Patient Register to assess individual asthma outcomes and prenatal exposure levels.
The researchers found that very high prenatal PFAS exposure was associated with a higher incidence of asthma in childhood. Future studies are needed to better understand exposure-response relationships and to address potential confounding variables, such as exposure beyond the prenatal period into early-childhood, exposure to other environmental contaminants or smoking among household members.
According to the authors, “PFAS contamination is a major source of high environmental exposure globally, and evidence from Ronneby offers important insights into the potential health effects of such contamination in affected communities. These results point to a substantial and previously unrecognized public health consequence of PFAS contamination.”
Blomberg adds, “We found that children whose mothers were exposed to very high levels of PFAS during pregnancy had a substantially higher incidence of clinically diagnosed asthma. The association was not observed at lower exposure levels, which may help explain why previous studies in general populations have reported mixed results.”
“Most previous research has examined populations exposed only to background levels of PFAS. In Ronneby, drinking water contamination resulted in exposure levels hundreds of times higher than the general population. This allowed us to evaluate potential health effects across a much broader exposure range.”
“Communities around the world have been affected by PFAS contamination from aqueous film-forming foams and other industrial sources. Our findings suggest that very high prenatal exposure may have lasting consequences for children’s respiratory health. At the same time, replication in other highly exposed populations will be important to confirm these results.”
Biologics may be more effective with earlier treatment initiation, especially among children with early polysensitisation or multiple early-childhood risk factors, according to the results of a new study published in Annals of the American Thoracic Society. Screening for these risk factors may help inform targeted early initiation of biologics for asthma.
Robust real-world data on the effectiveness of biologic therapies in children with severe asthma remain limited, particularly across different ages and early-life risk profiles. This evidence gap constrains precision in treatment decisions and clinical guidance.
Children with moderate to severe asthma requiring biologic therapy are most affected, especially those initiating biologic treatment at younger ages and those with early indicators of allergic disease or high-risk asthma histories.
Initiating biologic therapy earlier in childhood – particularly in children with significant early-life risk factors and allergic sensitisation – is associated with greater reductions in severe asthma exacerbations in real-world practice.
Findings highlight the importance of treatment timing and patient history when optimizing outcomes with asthma biologics.
Risks of delayed treatment initiation
Delayed initiation of biologic therapy until adolescence or failure to account for early-childhood risk profiles may reduce potential treatment benefit. These findings highlight the risk of suboptimal outcomes when treatment timing or patient selection does not align with underlying disease risk.
Clinicians should prioritise earlier identification and risk-stratified initiation of biologics in children with severe asthma, particularly those with high early-life risk burden, to maximise treatment benefits.
Study findings support development of care pathways that incorporate earlier, risk-stratified biologic initiation. Decision-making algorithms may benefit from integrating age at treatment initiation and early-life risk indicators, such as polysensitisation and high early disease burden, to better identify children most likely to benefit and reduce severe exacerbations.
Future research may also explore the role of clinical artificial intelligence in supporting these approaches. Clinical AI tools could help identify high-risk paediatric patients earlier and guide treatment timing and patient selection by detecting patterns in real-world clinical data, potentially improving precision in biologic therapy use.
Case Western Reserve University researchers say discovery of new inflammatory molecules could transform treatment
For decades, scientists have thought they understood the biochemical machinery that causes asthma: inflammation in the lungs that constricts airways and makes it hard to breathe. Leukotrienes – molecules that get released from white blood cells due to airway irritation or allergen inhalation – were labelled the culprits. Medications have been developed to block the molecular cascade they initiate that leads to difficulty breathing.
“We’ve found molecules that are alike in structure but generated through a completely different chemical pathway in the body,” said lead researcher Robert Salomon, the Charles Frederic Mabery Professor of Research in Chemistry. “We think the molecules we’re calling ‘pseudo leukotrienes,’ may be the dominant players in the inflammatory cascade that causes disease.”
The research opens new avenues for treating asthma as well as other inflammatory diseases, possibly including neurological diseases like Parkinson’s and Alzheimer’s diseases. The research, funded by the U.S. National Institutes of Health, is available online as a pre-proof ahead of publication in the Journal of Allergy and Clinical Immunology.
The ‘flames’ of oxidation
The presumed culprits in inflammatory diseases – the leukotrienes – are formed under the control of enzymes that transform lipids. By contrast, the pseudo leukotrienes Salomon and his team discovered, are formed by adding oxygen to lipids by molecules called “free radicals.”
“The free radical process is almost like an explosion or a fire,” said Salomon, who is also professor of ophthalmology in the Case Western Reserve School of Medicine. “It’s just like when oxygen reacts with fuel and you get flames. It can easily get out of control.”
People who suffer from asthma may lack enzymes and antioxidant molecules that normally keep a damper on free radicals by scavenging for and destroying them.
The leukotrienes and their mimics initiate inflammation by fitting into a receptor, like a key in an ignition, starting a molecular cascade that constricts the airways of asthmatics. Effective asthma drugs like Singulair block the ignition so the key won’t fit.
“The real importance of this discovery is the possibility of treating these diseases with drugs that prevent the free radical process or moderate it rather than drugs that block the receptor,” Salomon said.
Inflammation: a curse or a benefit?
Not all inflammation is harmful. The body needs inflammation to direct white blood cells to the site of a wound to heal, and it is also involved in memory and development.
Asthma drugs are being repurposed off-label to treat neurological diseases. But these treatments could also block the beneficial effects of the leukotrienes.
“If the molecules that are causing the problem are not the leukotrienes but these other molecules,” Salomon said, “a better treatment would be to just stop the formation of these other molecules rather than gumming up the ignition.”
The study
Salomon and his colleagues used their decades of experience studying the oxidation of lipids – and some chemical intuition – to guess that pseudo leukotrienes existed. They made the molecules in the laboratory to develop methods to detect them.
They obtained urine samples from patients designated with mild or severe asthma and compared them to urine from people who don’t suffer from the disease.
Not only were pseudo leukotrienes found in the asthma patients’ urine, but also the amounts correlated directly to the severity of the disease. Severe asthma sufferers or even those suffering mild asthma had four to five times more than the controls. The researchers suggest this could be a new biomarker to test for the severity of disease and monitor the effectiveness of therapies.
The researchers next plan to investigate whether these pseudo leukotrienes are involved in other respiratory diseases, like respiratory syncytial virus (commonly known as RSV) and bronchiolitis in babies, and chronic obstructive pulmonary disease.
A monthly injection has helped 90% of severe asthma patients reduce daily steroid tablets, which are associated with long-term side effects.More than half of the participants who had received the injection were able to stop their daily steroid tablets entirely, without any impact on their symptoms.
The clinical trial led by a King’s College London academic followed patients who had been injected with tezepelumab every four weeks for a year. Tezepelumab is a type of antibody which targets parts of the immune system, reducing lung inflammation.
Treatment with tezepelumab was also shown to significantly improve asthma symptoms, lung function, and overall quality of life. During the study, two-thirds of patients stopped having any asthma attacks. These improvements were seen as early as two weeks into treatment and lasted for the duration of the study.
Scientists are trying to identify alternative treatments for managing severe asthma, as long-term daily steroid use can lead to serious health problems, including osteoporosis, diabetes, and increased vulnerability to infections.
The WAYFINDER study, published inThe LancetRespiratory Medicine, is among long-standing research into severe asthma at King’s College London. Last year, another team at King’s discovered that another antibody, benralizamab, could be injected during some asthma and COPD attacks to reduce the need for further treatment. The latest discovery could help people manage their asthma long term.
Participants in the trial had a diagnosis of severe asthma and were recruited from 68 clinical centres across 11 countries. They received tezepelumab every four weeks and completed questionnaires on their asthma symptoms and medication at 28 and 52 weeks.
Professor David Jackson, Respiratory Medicine expert at King’s College London, and Clinical Lead of the asthma services across Guy’s and Royal Brompton Hospitals, Guy’s and St Thomas’ NHS Foundation Trust, said: “The WAYFINDER study is an important step forward for patients with the most severe form of asthma who require daily oral steroids in order to achieve reasonable disease control.
“In this International, multicentre clinical trial of more than 300 patients, the NICE-approved asthma treatment tezepelumab, a biologic therapy that targets asthma-related inflammation but without all the side effects of steroids, was capable of allowing the vast majority of patients to wean their steroids down to a low dose with over half able to stop their steroids altogether.
“As tezepelumab also suppresses allergy related symptoms and improves chronic rhinosinusitis as well, the results are particularly exciting for patients with severe asthma who suffer with both upper and lower airway symptoms.”
Dr Samantha Walker, Director of Research & Innovation at Asthma + Lung UK, said: “This study is a promising sign that tezepelumab injections support certain people with severe asthma to reduce or stop taking steroid tablets, which can have serious unwanted health consequences. Tezepelumab, an injectable biologic, significantly improves asthma symptoms, lung function and overall quality of life for participants.
“This is an incredibly encouraging development for the future of asthma care that could transform the lives of people with severe asthma. It’s vital that research into new types of treatment continues but we know current funding for lung health research is on life-support, despite lung conditions remaining the third biggest cause of death in the UK. Studies like this show the positive impact that research can make on providing potentially life-changing treatment for people with asthma and other lung conditions.”
The findings of the WAYFINDER study will be presented at the British Thoracic Society Winter Meeting 2025 on Thursday 27th November 2025.
Findings from a trial comparing the real-world effectiveness of asthma inhalers could reshape how children with asthma are treated.
In the first randomised controlled trial to investigate the use of a 2-in-1 inhaler as the sole reliever therapy for children aged 5 to 15, an international team found the combined treatment to be more effective than salbutamol, the current standard for asthma symptom relief in children, with no additional safety concerns.
The results show that using a single 2-in-1 anti-inflammatory reliever inhaler – which combines the inhaled corticosteroid (ICS) budesonide and the fast-acting bronchodilator formoterol – reduced children’s asthma attacks by an average of 45%, compared to the widely-used salbutamol inhaler.
Asthma attacks in children may be life-threatening and reducing their frequency and severity is a public health priority.
The 2-in-1 budesonide-formoterol inhaler is widely recommended as the preferred reliever treatment for adults, but children are still usually prescribed salbutamol.
Researchers say the findings, published in The Lancet, provide the evidence needed to bring children’s global asthma guidelines into line with adults’, which could benefit millions of children around the world with mild-to-moderate asthma.
The CARE study (Children’s Anti-inflammatory REliever) was designed and led by the Medical Research Institute of New Zealand (MRINZ), in collaboration with Imperial College London, University of Otago Wellington, Starship Children’s Hospital, and the University of Auckland. It recruited 360 children across New Zealand who were then randomly assigned to receive either budesonide-formoterol or salbutamol for on-demand symptom relief.
The trial lasted a year and the budesonide-formoterol reliever resulted in a lower rate of asthma attacks than salbutamol reliever, with rates of 0.23 versus 0.41 per participant per year. This means that for every 100 children with mild asthma who are switched from salbutamol to a 2-in-1 budesonide-formoterol inhaler, there would be 18 fewer asthma attacks per year. Importantly, the study also confirmed the safety of the combined-inhaler approach, with no significant differences in children’s growth, lung function, or asthma control between the two groups.
Dr Lee Hatter, lead author of the study and Senior Clinical Research Fellow at the MRINZ, said: “This is a key step in addressing the evidence gap that exists between asthma management in adults and children. For the first time, we have demonstrated that the budesonide-formoterol 2-in-1 inhaler, used as needed for symptom relief, can significantly reduce asthma attacks in children with mild asthma. This evidence-based treatment could lead to improved asthma outcomes for children worldwide.”
Professor Richard Beasley, Director of MRINZ and senior author of the study, said: “Implementing these findings could be transformative for asthma management on a global scale. The evidence that budesonide-formoterol is more effective than salbutamol in preventing asthma attacks in children with mild asthma has the potential to redefine the global standard of asthma management.”
The burden of asthma in the estimated 113 million children and adolescents with asthma worldwide is substantial. The latest study builds on previous studies in adults led by MRINZ researchers which shaped international asthma treatment guidelines. These findings contributed to the recommended use of the 2-in-1 ICS–formoterol reliever inhaler as the preferred reliever treatment for adults with asthma around the world.
The incorporation of findings from the CARE study into global asthma treatment strategies could help reduce disparities in care and ensure that more children access effective, evidence-based treatments.
The researchers say that global health organisations have long advocated for child-targeted asthma interventions, and their findings provide crucial evidence to support those efforts.
However, the authors acknowledge some limitations of the clinical trial. It was undertaken during the COVID-19 pandemic, during which stringent public health measures and fewer circulating respiratory viruses contributed to the lower than predicted rate of severe asthma attacks. The authors also acknowledge the challenges with the identification of asthma attacks in children, and the potential bias with the lack of blinding of the randomised treatments. They say though that the study’s findings are generalisable to clinical practice due to its pragmatic, real-world design.
Professor Andrew Bush, from Imperial College London, senior respiratory paediatrician and co-author of the CARE study, said: “Having an asthma attack can be very scary for children and their parents. I’m so pleased that we’ve been able to prove that an inhaler that significantly reduces attacks – already a game-changer for adults – is safe for children with mild asthma too. We believe this will transform asthma care worldwide and are excited to be building on this work with the CARE UK study.”
Professor Helen Reddel, Chair of the Science Committee of the Global Initiative for Asthma (GINA), commented on the global significance of the study, saying that it fills a critically important gap for asthma management globally. Professor Reddel said: “Asthma attacks have a profound impact on children’s physical, social and emotional development and their prevention is a high priority for asthma care. It is in childhood, too, that lifelong habits are established, particularly reliance on traditional medications like salbutamol that only relieve symptoms and don’t prevent asthma attacks.”
Professor Bob Hancox, Medical Director of the New Zealand Asthma and Respiratory Foundation, said: “This is a very important study for children with mild asthma. We have known for some time that 2-in-1 budesonide/formoterol inhalers are better than the traditional reliever treatment in adults, but this had not been tested in children. This research shows that this 2-in-1 inhaler is effective and safe for children as young as 5. This information will help to reduce the burden of asthma for many children, and both they and their families will breathe easier because of it.”
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 Immunology. People 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.
Biological drugs have improved the lives of many people with severe asthma. However, a new study from Karolinska Institutet shows that some immune cells with high inflammatory potential are not completely eradicated after treatment.
Biological drugs have become an important tool in the treatment of severe asthma.
“They help most patients to keep their symptoms under control, but exactly how these drugs affect the immune system has so far remained unknown,” says Valentyna Yasinska, consultant in pulmonary medicine at Karolinska University Hospital and doctoral student at Karolinska Institutet’s Department of Medicine in Huddinge.
Increased in blood
In a new study published in the scientific journal Allergy, researchers at Karolinska Institutet have explored what happens to the immune cells of patients being treated with biologics. By analysing blood samples from 40 patients before and during treatment, they found that instead of disappearing during treatment, certain types of immune cell – which play a key part in asthma inflammation – actually increased.
“This suggests that biologics might not attack the root of the problem, no matter how much they help asthma patients during treatment,” says Jenny Mjösberg, professor of tissue immunology at Karolinska Institutet’s Department of Medicine in Huddinge. “Continued treatment might be necessary to keep the disease under control.”
Surprising finding
The study is based on data from patients with severe asthma sourced from the BIOCROSS study. The researchers used advanced methods such as flow cytometry and single-cell sequencing to determine the properties and function of the immune cells.
“We were surprised to find that blood levels of inflammatory cells increased rather than decreased,” says Lorenz Wirth, doctoral student at the same department at Karolinska Institutet. “This could explain why inflammation of the airways often returns when the treatment is tapered or discontinued. It is important that we understand the long-term immunological effects of these drugs.”
Relatively new drugs
Little is still known about the long-term effects of biologics like mepolizumab and dupilumab since they are relatively new, having been prescribed to asthmatics for less than ten years.
The next stage of the study will be to analyse samples from patients with a long treatment history and to study lung tissue to see how the immune cells are affected in the airways.
