Category: Respiratory Diseases

Categories : Metabolic Disorders Respiratory DiseasesTags :

TB Alters Liver Metabolism and could Promote Diabetes, Study Shows

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Tuberculosis bacteria. Credit: CDC

Scientists from the University of Leicester have discovered that tuberculosis disrupts glucose metabolism in the body. The findings, which have now been published in PLoSPathogens complement the understanding that diabetes worsens the symptoms of tuberculosis. Importantly, they now say, undiagnosed tuberculosis could be pushing vulnerable patients towards metabolic disease such as diabetes.

Tuberculosis (TB) remains one of the most devastating infectious diseases worldwide, killing over 4,000 people every day. Prevention through the development of improved vaccines remains a priority for the World Health Organisation. Currently only one vaccine exists for TB and this is predominantly given to infants and young children to help protect them from severe forms of infection. 

Scientists at the University are researching tuberculosis in the hope of creating improved vaccines and are specifically looking at ways in which undiagnosed and subclinical infection can impact health. This new discovery, they say, could pave the way to define the molecular pathways by which the immune response changes liver metabolism, thereby allowing for the creation of targeted interventions. 

Professor Andrea Cooper from the University’s Leicester Tuberculosis Research Group (LTBRG), is among the authors on the paper.

She said: “Our paper changes the focus from diabetes making TB worse to the possibility that late diagnosis of TB can contribute to disruption of glucose metabolism, insulin resistance and therefore can promote progress towards diabetes in those that are susceptible. 

“As diabetes compromises drug treatment, our paper also supports the idea that metabolic screening should be involved in any drug or vaccine trials.”

The study first used laboratory models of pulmonary TB to examine the changes happening within the liver during the early stages of infection. It found that an immune response was triggered within the liver cells and glucose metabolism was altered. 

First author Dr Mrinal Das then reanalysed published metabolic data from humans, where he found that liver glucose metabolism was also disrupted when people progressed to TB from latent infection.

Professor Cooper added: “Our future aim is to define the molecular pathways by which the immune response is changing liver metabolism, allowing us to potentially create targeted interventions.

 “We will also be investigating how latent TB (which is infection with the bacterial agent of TB without significant symptoms) might be impacting metabolic health in humans.” 

Source: University of Leicester

Categories : Paediatrics Respiratory DiseasesTags :

Elevated NK Cells Found in Children with Severe RSV

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Photo by Andrea Piacquadio on Unsplash

Respiratory syncytial virus (RSV) is the leading cause of hospitalisation in young children due to respiratory complications such as bronchiolitis and pneumonia. Yet little is understood about why some children develop only mild symptoms while others develop severe disease.

To better understand what happens in these cases, clinician-scientists from Brigham and Women’s Hospital, and Boston Children’s Hospital analysed samples from patients’ airways and blood, finding distinct changes in children with severe cases of RSV, including an increase in the number of natural killer (NK) cells in their airways.

The descriptive study, which focuses on understanding the underpinnings of severe disease, may help to lay groundwork for identifying new targets for future treatments. Results are published in Science Translational Medicine.

“As a physician, I help to care for children who have the most severe symptoms, and as a researcher, I’m driven to understand why they become so sick,” said corresponding author Melody G. Duvall, MD, PhD, of the Division of Pulmonary and Critical Care Medicine at Brigham and Women’s Hospital (BWH) and the Division of Critical Care Medicine at Boston Children’s Hospital. “NK cells are important first responders during viral infection – but they can also contribute to lung inflammation. Interestingly, our findings fit with data from some studies in COVID-19, which reported that patients with the most severe symptoms also had increased NK cells in their airways. Together with previous studies, our data link NK cells with serious viral illness, suggesting that these cellular pathways merit additional investigation.”

Duvall and colleagues, including lead author Roisin B. Reilly of the Division of Pulmonary and Critical Care Medicine at BWH, looked at samples from 47 children critically ill with RSV, analysing immune cells found in their airways and peripheral blood. Compared to uninfected children, those with severe illness had elevated levels of NK cells in their airways and decreased NK cells in their blood. In addition, they found that the cells themselves were altered, both in appearance and in their ability to perform their immunological function of killing diseased cells.

Duvall and co-authors have previously described a post-pandemic surge in paediatric RSV infections. While clinicians can only provide supportive care to the most severely sick children, vaccines to prevent RSV are now available for children 19 months and younger, adults 60 years and over, and people who are pregnant.

Source: Brigham and Women’s Hospital

Categories : HIV Respiratory DiseasesTags :

Promising TB Therapy for Patients with HIV Safe with Antiretrovirals

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Tuberculosis bacteria. Credit: CDC

A therapy showing promise to help control tuberculosis (TB) does not interfere with combined antiretroviral therapy (cART), according to research by Texas Biomedical Research Institute (Texas Biomed) which was recently published in JCI Insight.

“This is an important hurdle that this host-directed therapy had to clear in order to help patients battling both HIV and TB,” said study leader Professor Smriti Mehra, PhD of Texas Biomed.

TB is responsible for more than 1.3 million deaths worldwide every year. Dr. Mehra and her team have been investigating a therapy currently used in cancer as a potential treatment for patients with drug-resistant TB and/or comorbid HIV. While many cases of TB can be controlled with months of antibiotics, the infection can return in people who are immunocompromised as a result of HIV. Now that cART is so effective at controlling HIV, a resurging TB infection can often be deadly to those individuals.

Dr Mehra is studying a host-directed therapy that blocks or inhibits an immune system protein naturally found in the body. The protein, called IDO (short for Indoleamine-2,3-dioxygenase), normally suppresses the immune system, preventing it from causing excessive inflammation and organ damage. Inhibiting IDO for short intervals of time has led to more successful cancer treatments. Dr. Mehra’s team has previously shown the same approach improves control of TB in conjunction with antibiotics.

This current study in nonhuman primates with both TB and simian immunodeficiency virus, the nonhuman primate version of HIV, showed the IDO inhibitor does not interfere with cART.  

Researchers compare the impacts of cART by itself versus cART plus the IDO inhibitor in lung tissue of nonhuman primates with both TB and SIV. Left: Following just cART, significantly more IDO is detected in pink. Right: With the IDO inhibitor and cART, immune cells recruited to fight bacteria are observed inside the granuloma, a hallmark structure of TB. Specifically, CD4+ T cells are in green and CD68 proteins expressed by macrophages are in red.

“There was no increase in viral load in animals given cART and the IDO inhibitor, compared with animals only given cART, proving the inhibitor is safe to give to patients with HIV,” Dr. Mehra said.

Now that the researchers have shown the inhibitor works well in conjunction with TB antibiotics and with cART separately, they plan to study how it performs when given in conjunction with both antibiotics and cART together. This treatment regimen is standard for patients with both HIV and active TB. Dr. Mehra said that longer-term studies are also needed to confirm there are no unintended side effects.

The IDO inhibitor is already FDA-approved for use in patients with cancer, which shortens the path to potential approval for patients with TB/HIV when compared with developing a brand-new drug.

Source: Texas Biomedical Research Institute

Categories : Respiratory DiseasesTags :

Herbal Compound Found to Kill TB in the Inactive State

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Mycobacterium tuberculosis drug susceptibility test. Photo by CDC on Unsplash

A compound found in African wormwood – a plant used medicinally for thousands of years to treat many types of illness – could be effective against tuberculosis, according to a new study available online in the Journal of Ethnopharmacology.

The team, co-led by Penn State researchers, found that the chemical compound, an O-methylflavone, can kill Mycobacterium tuberculosis, or Mtb, that causes tuberculosis in both its active state and its slower, hypoxic state, which the mycobacteria enters when it is stressed.

Bacteria in this state are much harder to destroy and make infections more difficult to clear, according to co-corresponding author Joshua Kellogg, assistant professor of veterinary and biomedical sciences in the College of Agricultural Sciences.

While the findings are preliminary, Kellogg said the work is a promising first step in finding new therapies against tuberculosis.

“Now that we’ve isolated this compound, we can move forward with examining and experimenting with its structure to see if we can improve its activity and make it even more effective against tuberculosis,” he said. “We’re also still studying the plant itself to see if we can identify additional molecules that might be able to kill this mycobacterium.”

Tuberculosis is one of the world’s leading killers among infectious diseases, according to the Centers for Disease Control and Prevention. There are about 10 million cases a year globally, with approximately 1.5 million of those being fatal.

While effective therapies exist for TB, the researchers said there are several factors that make the disease difficult to treat. A standard course of antibiotics lasts six months, and if a patient contracts a drug-resistant strain of the bacteria, it stretches to two years, making treatment costly and time consuming.

Additionally, the bacteria can take two forms in the body, including one that is significantly harder to kill.

“There’s a ‘normal’ microbial bacterial form, in which it’s replicating and growing, but when it gets stressed – when drugs or the immune system is attacking it – it goes into a pseudo-hibernation state, where it shuts down a lot of its cellular processes until it perceives that the threat has passed,” Kellogg said. “This makes it really hard to kill those hibernating cells, so we were really keen to look at potential new chemicals or molecules that are capable of attacking this hibernation state.”

Multiple species of the Artemisia plant have been used in traditional medicine for centuries, the researchers said, including African wormwood, which has been used to treat cough and fever. Recent studies in Africa have suggested that the plant also has clinical benefits in treating TB.

“When we look at the raw plant extract that has hundreds of molecules in it, it’s pretty good at killing TB,” Kellogg said. “Our question was: There seems to be something in the plant that’s really effective – what is it?”

For their study, the researchers took raw extract of the African wormwood plant and separated it into “fractions” – versions of the extract that have been separated into simpler chemical profiles. They then tested each of the fractions against Mtb, noting whether they were effective or ineffective against the bacteria. At the same time, they created a chemical profile of all of the tested fractions.

“We also used machine learning to model how the changes in chemistry correlated with the changes in activity that we saw,” Kellogg said. “This allowed us to narrow our focus to two fractions that were really active.”

From these, the researchers identified and tested a compound that effectively killed the bacteria in the pathogen’s active and inactive states, which the researchers said is significant and rare to see in TB treatments. Further testing in a human cell model showed that it had minimal toxicity.

Kellogg said the findings have the potential to open new avenues for developing new, improved therapeutics.

“While the potency of this compound is too low to use directly as an anti-Mtb treatment, it may still be able to serve as the foundation for designing more potent drugs,” he said. “Furthermore, there appear to be other, similar chemicals in African wormwood that may also have the same type of properties.”

The researchers said that in the future, more studies are needed to continue exploring the potential for using African wormwood for treating TB.

Source: Penn State

Categories : Lab Tests and Imaging Respiratory DiseasesTags :

New Images of RSV may Expose Weak Points in the Stubborn Virus

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Photo by Andrea Piacquadio on Pexels

The complex shape of respiratory syncytial virus is one hurdle limiting the development of treatments for an infection that leads to hospitalisation or worse. New images of the virus published in Nature from researchers at the University of Wisconsin–Madison may hold the key to preventing or slowing RSV infections.

RSV is of greatest concern in young children, the elderly and adults at high risk for respiratory complications. Yet unlike the flu and other common, communicable respiratory illnesses that annually sweep through schools, there are few options for fighting RSV. In the US, prophylactic treatments are available for young children, and existing vaccines are approved only for pregnant women and the elderly.

The virus’s structure, which consists of tiny, bending filaments, have eluded researchers. This has made it difficult to identify key drug targets, including viral components that are conserved across related viruses.

RSV F proteins, shown in this image created by University of Wisconsin–Madison researchers using a technique called cryo-electron tomography, may make RSV more potent by keeping it from infecting cells prematurely. Image by Wright Lab, UW–Madison

“There are a number of viruses related to RSV that are also significant human pathogens, including measles,” says Elizabeth Wright, a UW–Madison biochemistry professor. “What we know about related viruses gives us clues about RSV protein structures, but to identify drug targets we need a closer look at RSV proteins that are intimately associated with the membranes of host cells.”

Using an imaging technique called cryo-electron tomography, Wright and her team have now revealed details of molecules and structures essential to RSV’s form and function. They published their findings recently in Nature.

Cryo-ET freezes viral particles or other molecules at ultracold temperatures, stopping biological processes in action. This allows researchers to examine the structures of organisms, cells and organelles, and viruses and capture small-scale images of structures frozen in time. Flash-freeze many RSV particles, and cryo-ET imaging will capture (nearly) all the virus’s possible configurations from many different angles. These 2D images are combined to produce a representation of the virus’s 3D structures at high resolutions – even at the level of individual atoms.

Wright’s recent study produced high-resolution images detailing the structure of two RSV proteins, RSV M protein and RSV F protein, that are crucial to the interaction between the virus and the host cell membrane. Both proteins are also present in related viruses.

RSV M protein interacts with host cell membranes, holding together the virus’s filamentous structure and coordinating viral components and other proteins – including RSV F proteins. RSV F proteins sit on the viral surface, ready to engage with host cell receptors and regulate the virus’s fusion and entry into the host cell. The scientists’ images reveal that in RSV, two F proteins come together to form a more stable unit. Wright says that this association may prevent the F proteins from prematurely infecting the host cell.

“Our primary findings reveal structural details that allow us to better understand not only how the protein regulates assembly of viral particles, but also the coordination of proteins that enable the virus to be infectious,” says Wright.

The scientists believe that F protein pairs may be a key to destabilising the virus before it is ready to infect its next host, making pairs of F proteins a possible target for future drug development. They will continue to explore how RSV proteins interact with each other to cause infection.

Source: University of Wisconsin-Madison

Categories : Paediatrics Respiratory DiseasesTags :

Signs of Developing Asthma are Evident in the First Year of Life

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Respiratory tract. Credit: Scientific Animations CC4.0

What factors lead to chronic respiratory disease? Researchers investigated this question using health data from about 780 infants. Their analysis, published in The Lancet Digital Health, shows that children’s risk of developing asthma later in life can be more reliably predicted by observing the dynamic development of symptoms during the first year of life.

Genetic predisposition, passive smoking, high levels of air pollution and infections are only a few of the risk factors for asthma. Each factor has only a small influence on its own. It is their interplay that makes asthma more likely, according to the hypothesis of an international research committee, of which Professor Urs Frey of the University of Basel and the University Children’s Hospital Basel is a member.

Together with Dr Uri Nahum from his team and international colleagues, Frey investigated how the interaction of these factors during the course of the first year of life affected children’s developing respiratory systems. The analysis was based on health data from two cohorts, amounting to around 780 healthy infants born in various European countries.

A new way of looking at chronic illness

For both cohorts the researchers calculated the network of interactions between a range of known risk factors for every week of each child’s life, and then compared these with the appearance of symptoms such as coughing or wheezing. “Observing this interaction of risk factors in the context of dynamic development over time is a new way of looking at chronic illnesses,” underlines Frey. It is a case of watching the developing lungs adapting to their environment.

And it was exactly this, the adaptation of the lungs, that differentiated the group of children who developed asthma at between two and six years of age from those who had not developed it by the time they started school (generally at six years old in Switzerland). “It’s a nice, practical example of the value of digital health data, which were first quantified mathematically using these kinds of dynamic network analyses,” says Frey.

The findings cannot yet be used for early diagnosis in individual children. However, according to Frey: “With greater amounts of data and machine learning, it would certainly be conceivable to calculate a risk profile for individual children in the future.” Nowadays, digital health data is relatively easy to collect with the help of smartphone apps.

Source: University of Basel

Categories : Obstetrics & Gynaecology Respiratory DiseasesTags :

Higher Odds of Miscarriage, Needing Fertility Treatment for Women with Asthma

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Credit: Pixabay CC0

Women who are being treated for asthma are more likely to miscarry and need fertility treatment to get pregnant, according to a large study presented at the European Respiratory Society (ERS) Congress in Vienna, Austria. The study also suggests that most women with asthma are able to have babies.

The study was presented by Dr Anne Vejen Hansen from the department of respiratory medicine at Copenhagen University Hospital, Denmark.

She said: “Asthma is common in women of reproductive age. Previous studies have shown that it takes women with asthma longer to get pregnant than those without asthma when undergoing fertility treatment, and that asthmatic women who succeed in getting pregnant have more often had fertility treatment than non-asthmatic women. But most existing studies are on women who have actually got pregnant, so we wanted to examine fertility outcomes on a national scale, to also include those that might not become pregnant at all.”

The team analysed reproductive outcomes for all Danish women born from 1976 to 1999, following them from 1994 to 2017. In total, 769,880 women were included and followed; anyone who took anti-asthma medication on a regular basis was classified as asthmatic.

They found that women with asthma experienced a higher degree of foetal loss compared to women without asthma (17.0% vs. 15.7%) and more use of fertility treatment (5.6% vs. 5.0%). However, the proportion who subsequently gave birth was 77% in women with and without asthma, suggesting that asthma does not seem to affect the number of live births.

Dr Vejen Hansen said: “We found that women fulfilling the definition of asthma had a higher rate of foetal loss and an increased use of fertility treatment. The more severe the asthma and the more flare ups the women experienced, the more likely they were to need fertility treatment. Why this is, is not clear. It might be related to systemic inflammation throughout the body, including women’s reproductive organs.

“But the numbers also show that these same women who redeem asthma medication still have as many live births in the end as women who don’t. This suggests that most women with asthma probably do manage to become pregnant and have babies in the end.

“We also plan to investigate the possible effect of male asthma on fertility, and, therefore, have another similar registry-based study in the pipeline.”

Professor Lena Uller is Chair of the ERS group on Airway Pharmacology and Treatment and Head of the Respiratory Immunopharmacology research group at Lund University, Sweden, and was not involved in the research. She said: “It’s reassuring that women seem to have the same live birth rate regardless of their asthma. However, the results also indicate that women with asthma should take into consideration potential reproductive challenges in their family planning. If women with asthma are worried about their fertility, they should speak to their doctor.

“The results of this study also underscore the importance of managing asthma in reproductive-aged women. The fact that the more severe the asthma, the more the problems with fertility, suggests that uncontrolled asthma is the problem and we should be helping women to get their asthma under control.”

Source: European Respiratory Society

Categories : Respiratory DiseasesTags :

24hrs Oxygen Therapy for Hypoxaemia no Better than 15hrs

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Photo by Samuel Ramos on Unsplash

There were no differences in quality of life, symptoms, hospital admissions or mortality between a group of patients with pulmonary disease and low oxygen levels in the blood that received oxygen therapy at home for 24 hours a day, and a group that received the same therapy for 15 hours a day, according to a study in the New England Journal of Medicine.

“This has considerable significance for patients with chronic obstructive pulmonary disease and other pulmonary diseases who are undergoing long-term oxygen therapy at home,” says study leader Magnus Ekström of Lund University.

Every year, there are about a million patients in the US alone with severe sub-optimal oxygen levels who begin oxygen therapy at home. The patient must wear a nasal oxygen mask 24 hours a day, which is often felt to be restrictive and burdensome. In addition, the gas is cold and dry, which may cause problems such as dryness, ulcers and inflammation of the airways. Using the equipment may also be perceived as stigmatising by patients.

The aim of the therapy is to prolong life, but its application differs and the scientific evidence for the therapy’s efficacy has been inadequate. 

In a randomised, controlled large multicentre study, the researchers have now examined the effect of different durations of oxygen therapy on important health outcomes. A total of 241 patients with chronic and severely low oxygen levels in the blood from 20 different clinics in Sweden were randomised to receive oxygen therapy for either 24 hours a day or 15 hours a day. The patients were followed for one year, and all completed the study. There was a high level of compliance with the prescribed daily therapy duration.  

“There were no differences between the groups regarding hospital admission or the risk of dying. And again, when we compare self-reported quality of life and physical activity, symptoms and fatigue between the groups, we see no differences or indication of advantages if oxygen is used for more than 15 hours a day,” says Magnus Ekström, researcher in respiratory and palliative medicine at Lund University.

 The results differ from previous studies conducted in the 1970s, which suggested that therapy for 24 hours a day could increase the survival rate. 

“The older studies were small and only included patients with chronic obstructive pulmonary disease, not least because it is difficult to recruit such seriously ill individuals for a randomised study. Also, the patients included in the older studies differ from those who start oxygen therapy at home nowadays. The strength of this study is  that we have been able to include twice as many patients, and that it represents the reality nowadays in which many of those receiving oxygen therapy at home are older, also have cardiovascular diseases and are women,” says Josefin Sundh, adjunct senior lecturer at Örebro University and pulmonologist at the University Hospital in Örebro, who was co-leader of the study.

“The group treated with oxygen 15 hours a day received this during the night when, in general, oxygenation is poorer. The results show that it seems to be safe for this type of patient to be without oxygen for quite a large part of the day. This is important as it may reduce the side effects of the therapy and mean that the patients can adapt it more to their everyday life,” says Magnus Ekström.

The researchers based the study on data from Swedevox, the Swedish National Registry for Respiratory Failure. 

The researchers are now moving on to examine whether therapy using a high flow rate of warmed-up, more humidified oxygen at night can improve prognoses and patient well-being.

Source: Lund University

Categories : Paediatrics Respiratory DiseasesTags :

Saline Nasal Drops Shorten the Common Cold in Children by Two Days

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Photo by Andrea Piacquadio on Unsplash

Using hypertonic saline nasal drops can reduce the length of the common cold in children by two days, according to a study presented at the European Respiratory Society (ERS) Congress in Vienna, Austria [1]. They can also reduce the onward transmission of colds to family members.

The results of the ELVIS-Kids randomised controlled trial were presented by Professor Steve Cunningham from Child Life and Health, University of Edinburgh, UK.

He said: “Children have up to 10 to 12 upper respiratory tract infections, what we refer to as colds, per year, which have a big impact on them and their families. There are medicines to improve symptoms, such as paracetamol and ibuprofen, but no treatments that can make a cold get better quicker.”

ELVIS-Kids Chief Investigator Dr Sandeep Ramalingam, consultant virologist, NHS Lothian, Edinburgh, UK, had noted that salt-water solutions are often used by people in South Asia, as nasal irrigation and gargling, to treat a cold and wanted to explore if this clinical benefit could be replicated in a large study.

The research team recruited 407 children aged up to six years to a study where they were given either hypertonic saline ~2.6% (salt-water) nasal drops or usual care when they developed a cold. Overall, 301 children developed a cold; for 150 of these, their parents were given sea salt and taught to make and apply salt-water nose drops to the children’s noses (three drops per nostril, a minimum of four times per day, until well) and 151 children had usual cold care.

Professor Cunningham explains: “We found that children using salt-water nose drops had cold symptoms for an average of six days where those with usual care had symptoms for eight days. The children receiving salt water nose drops also needed fewer medicines during their illness.

“Salt is made up of sodium and chloride. Chloride is used by the cells lining the nose and windpipes to produce hypochlorous acid within cells, which they use to defend against virus infection. By giving extra chloride to the lining cells this helps the cells produce more hypochlorous acid, which helps suppress viral replication, reducing the length of the virus infection, and therefore the duration of symptoms.”

When children got salt-water nose drops, fewer households reported family members catching a cold (46% vs 61% for usual care). Eighty-two per cent of parents said the nose drops helped the child get better quickly and 81% said they would use nose drops in the future.

Professor Cunningham added: “Reducing the duration of colds in children means that fewer people in their house also get a cold, with clear implications for how quickly a household feels better and can return to their usual activities like school and work etc.

“Our study also showed that parents can safely make and administer nose drops to their children and therefore have some control over the common cold affecting their children.”

Professor Alexander Möeller is Head of the ERS Paediatric Assembly and Head of the Department for Respiratory Medicine at the University Children’s Hospital Zurich, Switzerland, and was not involved in the research. He said: “This is an important study that is the first of its kind to investigate the impact of salty nose drops in children with colds. Although most colds usually don’t turn into anything serious, we all know how miserable they can be, especially for young children and their families.

“This extremely cheap and simple intervention has the potential to be applied globally; providing parents with a safe and effective way to limit the impact of colds in their children and family would represent a significant reduction in health and economic burden of this most common condition.”

The team hope to further investigate the effect of saltwater nose drops on wheeze during colds, after initial results from this study showed that children who received the drops had significantly fewer episodes of wheeze (5% vs 19%).

Reference

[1] Abstract no: OA1985 “A randomised controlled trial of hypertonic saline nose drops as a treatment in children with the common cold (ELVIS-Kids trial)”, by Dr Sandeep Ramalingam et al; Presented in session “Advancements in paediatric infectious respiratory health” at 15:45–17:00 CEST on Sunday 8 September 2024.

https://live.ersnet.org/programme/session/92864

Source: European Respiratory Society

Categories : Respiratory DiseasesTags :

Chronic Cough may be a Hereditary Condition

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Chronic cough is among the most common reasons for seeking medical care, with middle-aged women the group most affected. A pair of new studies published in ERJ Open Research and PLOS ONE suggest that this may be a hereditary condition.

“More than 10% of the population has a chronic cough, which has been shown to entail several negative consequences: reduced quality of life, reduced ability to work and voice problems. At present, we have insufficient knowledge about what causes coughing and how best to treat it,” notes Össur Ingi Emilsson, Docent in Lung, Allergy and Sleep Research at the Department of Medical Sciences at Uppsala University.

The two studies from the department have investigated both how cough is currently managed in Swedish healthcare, and whether chronic cough can be hereditary.

The PLOS ONE study, based on data from the Swedish healthcare register, showed that 1–2% of the entire Swedish population sought care for chronic cough between 2016 and 2018, usually in primary care. Of those who sought care, the majority appear to have had a long-standing cough. The prevalence is highest among women between the ages of 40 and 60, with around 21 000 women seeking treatment for cough in these three years.

“Women generally seem to have a slightly more sensitive cough reflex, so the threshold for abnormal coughing is lower in women than in men. For me, it was unexpected that only one to two percent of patients seek help for a troublesome cough when over ten percent are affected. This can be partly explained by the lack of effective treatments. There also appeared to be some differences in care between different parts of the country, suggesting that better guidelines are needed for investigating and treating chronic cough,” continues Emilsson.

The other study, in ERJ Open Research, has provided a clue as to why some individuals develop chronic cough. Cough appears to be a hereditary phenomenon. In a large population study in northern Europe of 7155 parents and their 8176 adult children aged 20 years and over, it was found that if one parent has had chronic dry cough, their offspring were over 50% more likely to have chronic dry cough. This link was independent of confounding factors such as asthma, biological sex and smoking.

“A similar relationship was seen for productive cough, but in those cases smoking had a greater impact on prevalence. These results suggest that there is a genetic link to chronic cough,” adds Emilsson.

The research team has already begun a treatment study into chronic cough. Based on these new findings, the group is now moving forward with studies on genetic variants in collaboration with the Icelandic company deCODE genetics, which analyses the human genome. The aim is to identify which genetic variants are linked to chronic cough.

“This could provide a better understanding of the occurrence of chronic cough, which may ultimately result in better treatments for this difficult-to-treat condition,” explains Emilsson.

Source: Uppsala University