Infection-related asthma

Advances in non-type 2 severe asthma: from molecular insights to novel treatment strategies

Asthma is a prevalent pulmonary disease that affects more than 300 million people worldwide and imposes a substantial economic burden. While medication can effectively control symptoms in some patients, severe asthma attacks, driven by airway inflammation induced by environmental and infectious exposures, continue to be a major cause of asthma-related mortality. Heterogeneous phenotypes of asthma include type 2 (T2) and non-T2 asthma. Non-T2 asthma is often observed in patients with severe and/or steroid-resistant asthma. This review covers the molecular mechanisms, clinical phenotypes, causes and promising treatments of non-T2 severe asthma. Specifically, we discuss the signalling pathways for non-T2 asthma including the activation of inflammasomes, interferon responses and interleukin-17 pathways, and their contributions to the subtypes, progression and severity of non-T2 asthma. Understanding the molecular mechanisms and genetic determinants underlying non-T2 asthma could form the basis for precision medicine in severe asthma treatment.

Multimorbidity and acute infectious diseases in urban and semi-urban settings in Peru: A mixed-methods study

Background

The co-occurrence of chronic diseases and acute infectious events exacerbates disability and diminishes quality of life, yet research in Low- and Middle-Income countries is scarce. We aimed to investigate the relationship between infectious events and multimorbidity in resource-constrained settings.

Methods

We conducted a sequential mixed-method study in Lima and Tumbes, Peru, with participants having multimorbidity from the CRONICAS Cohort Study. They completed a questionnaire on the occurrence, treatment, and health-seeking behaviour related to acute infectious events. Qualitative interviews explored the perceptions and links between multimorbidity and acute infectious events for a subgroup of participants.

Findings

Among individuals with multimorbidity, low awareness of chronic conditions and poor medication adherence. The cumulative incidence for respiratory and gastrointestinal infections, the most reported acute conditions, was 2.0 [95%CI: 1.8-2.2] and 1.6 [1.2-1.9] events per person per year, respectively. Individuals with cancer (6.4 [1.6-11.2] events per person per year) or gastrointestinal reflux (7.2 [4.4-10.1] events per person per year) reported higher cumulative incidence of infectious events than others, such as those with cardiovascular and metabolic conditions (5.2 [4.6-5.8] events per person per year). Those with three or more chronic conditions had a slightly higher cumulative incidence compared with individuals with two conditions (5.7 [4.4-7.0] vs 5.0 [4.4-5.6] events per person per year). Around 40% of individuals with multimorbidity sought healthcare assistance, while others chose drugstores or didn't seek help. Our qualitative analysis showed diverse perceptions among participants regarding the connections between chronic and acute conditions. Those who recognized a connection emphasized the challenges in managing these interactions.

Interpretation

Our study advances understanding of multimorbidity challenges in resource-limited settings, highlighting the impact of acute infections on patients' existing multimorbidity burden.

COVID-19 and chronic rhinosinusitis: management and comorbidity - what have we learned?

INTRODUCTION

Approximately 5%-12% of the population worldwide suffer from chronic rhinosinusitis (CRS). CRS is defined as a chronic respiratory disease and is considered to be a risk factor for COVID-19 patients.

AREAS COVERED

A non-systematic literature research was conducted on COVID-19 and treatment options for CRSwNP. The latest international publications in medical databases, international guidelines, and the internet were reviewed. Since there were no publications on all aspects of this topic during the pandemic, we included our own experience in this report. Based on the conducted literature research in addition to our previously reported experience, we discuss the treatment of CRSwNP during the COVID-19 pandemic and what can be taken for future pandemics.

EXPERT OPINION

Intranasal corticosteroids remain the standard treatment for CRS in patients with SARS-CoV-2 infection. Indications for surgical treatment of CRS should be critically evaluated and reserved for patients with complications and those with no other treatment options. For this purpose, COVID-19 status should be known if possible and, in case of unclear status (emergency), using appropriate personal protective equipment. Systemic corticosteroids should be avoided were possible. Biological treatment should be continued under careful monitoring in uninfected patients and should be temporarily interrupted during COVID-19 infection.

Potential Therapeutic Value of the STING Inhibitors

The stimulator of interferon genes (STING) is a critical protein in the activation of the immune system in response to DNA. It can participate the inflammatory response process by modulating the inflammation-preferred translation program through the STING-PKR-like endoplasmic reticulum kinase (PERK)-eIF2α pathway or by inducing the secretion of type I interferons (IFNs) and a variety of proinflammatory factors through the recruitment of TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3) or the regulation of the nuclear factor kappa-B (NF-κB) pathway. Based on the structure, location, function, genotype, and regulatory mechanism of STING, this review summarizes the potential value of STING inhibitors in the prevention and treatment of infectious diseases, psoriasis, systemic lupus erythematosus, non-alcoholic fatty liver disease, and other inflammatory and autoimmune diseases.

An impact of age on respiratory syncytial virus infection in air-liquid-interface culture bronchial epithelium

Background

Elderly people are known to be vulnerable to virus infection. However, this has not been appropriately tested in in vitro studies due to a lack of appropriate virus infection models. In this report, we investigated the impact of age on respiratory syncytial virus (RSV) in pseudostratified air-liquid-interface (ALI) culture bronchial epithelium, which more closely mimic human airway epithelium morphologically and physiologically, than submerged cancer cell line cultures.

Methods

RSV A2 was inoculated apically to the bronchial epithelium obtained from 8 donors with different ages (28–72 years old), and time-profiles of viral load and inflammatory cytokines were analyzed.

Results

RSV A2 replicated well in ALI-culture bronchial epithelium. The viral peak day and peak viral load were similar between donors at ≤60 years old (n = 4) and  > 65 years old (n = 4; elderly group), but virus clearance was impaired in the elderly group. Furthermore, area under the curve (AUC) analysis, calculated from viral load peak to the end of sample collection (from Day 3 to 10 post inoculation), revealed statistically higher live viral load (PFU assay) and viral genome copies (PCR assay) in the elderly group, and a positive correlation between viral load and age was observed. In addition, the AUCs of RANTES, LDH, and dsDNA (cell damage marker) were statistically higher in the elderly group, and the elderly group showed a trend of higher AUC of CXCL8, CXCL10 and mucin production. The gene expression of p21CDKN1A (cellular senescence marker) at baseline was also higher in the elderly group, and there was a good positive correlation between basal p21 expression and viral load or RANTES (AUC).

Conclusion

Age was found to be a key factor affecting viral kinetics and biomarkers post virus infection in an ALI-culture model. Currently, novel or innovative in vitro cell models are introduced for virus research, but when virus studies are conducted, similarly to working with other clinical samples, the age balance is important to obtain more accurate results.

Emerging strategies in nanotechnology to treat respiratory tract infections: realizing current trends for future clinical perspectives

A boom in respiratory tract infection cases has inflicted a socio-economic burden on the healthcare system worldwide, especially in developing countries. Limited alternative therapeutic options have posed a major threat to human health. Nanotechnology has brought an immense breakthrough in the pharmaceutical industry in a jiffy. The vast applications of nanotechnology ranging from early diagnosis to treatment strategies are employed for respiratory tract infections. The research avenues explored a multitude of nanosystems for effective drug delivery to the target site and combating the issues laid through multidrug resistance and protective niches of the bacteria. In this review a brief introduction to respiratory diseases and multifaceted barriers imposed by bacterial infections are enlightened. The manuscript reviewed different nanosystems, i.e. liposomes, solid lipid nanoparticles, polymeric nanoparticles, dendrimers, nanogels, and metallic (gold and silver) which enhanced bactericidal effects, prevented biofilm formation, improved mucus penetration, and site-specific delivery. Moreover, most of the nanotechnology-based recent research is in a preclinical and clinical experimental stage and safety assessment is still challenging.

An Overview on the Primary Factors That Contribute to Non-Allergic Asthma in Children

The prevalence of non-allergic asthma in childhood is low, peaking in late adulthood. It is triggered by factors other than allergens, like cold and dry air, respiratory infections, hormonal changes, smoke and air pollution. In the literature, there are few studies that describe non-allergic asthma in pediatric age. Even though it is a less common disorder in kids, it is crucial to identify the causes in order to keep asthma under control, particularly in patients not responding to conventional treatments. In this review, we discuss non-IgE-mediated forms of asthma, collecting the latest research on etiopathogenesis and treatment.

Asthma mortality attributable to ambient temperatures: A case-crossover study in China

BACKGROUND

Whether ambient temperature exposure contributes to death from asthma remains unknown to date. We therefore conducted a case-crossover study in China to quantitatively evaluate the association and burden of ambient temperature exposure on asthma mortality.

METHODS

Using data from the National Mortality Surveillance System in China, we conducted a time-stratified case-crossover study of 15 888 individuals who lived in Hubei and Jiangsu province, China and died from asthma as the underlying cause in 2015-2019. Individual-level exposures to air temperature and apparent temperature on the date of death and 21 days prior were assessed based on each subject's residential address. Distributed lag nonlinear models based on conditional logistic regression were used to quantify exposure-response associations and calculate fraction and number of deaths attributable to non-optimum ambient temperatures.

RESULTS

We observed a reverse J-shaped association between air temperature and risk of asthma mortality, with a minimum mortality temperature of 21.3 °C. Non-optimum ambient temperature is responsible for substantial excess mortality from asthma. In total, 26.3% of asthma mortality were attributable to non-optimum temperatures, with moderate cold, moderate hot, extreme cold and extreme hot responsible for 21.7%, 2.4%, 2.1% and 0.9% of asthma mortality, respectively. The total attributable fraction and number was significantly higher among adults aged less than 80 years in hot temperature.

CONCLUSIONS

Exposure to non-optimum ambient temperature, especially moderate cold temperature, was responsible for substantial excess mortality from asthma. These findings have important implications for planning of public-health interventions to minimize the adverse respiratory damage from non-optimum ambient temperature.

Primary antibody deficiencies represent an underestimated comorbidity in asthma patients: efficacy of immunoglobulin replacement therapy in asthma control

OBJECTIVE

Primary antibody deficiencies (PAD) are an underestimated comorbidity in asthma and its treatment could improve disease control.

METHODS

a retrospective cohort of asthmatics, affected by IgG subclass deficiency or unclassified antibody deficiency and treated with low-dose intravenous immunoglobulin replacement therapy (IRT) was recruited. Demographic and clinical data, chest CT scan, blood eosinophils, atopy, chronic oral corticosteroid (OCS) therapy were evaluated at baseline. Asthma exacerbations, lower respiratory tract infections (LRTI), upper respiratory tract infections (URTI) and asthma-related hospitalizations were assessed after one and two years of IRT.

RESULTS

57 moderate-to-severe asthmatics were enrolled, mostly affected by T2 low asthma (39/57, 68.4%). After one year, IRT was effective in improving, irrespective of bronchiectasis, atopy, eosinophils and PAD type: 1) trough IgG (826.9 ± 221.3 vs 942.2 ± 195.1 mg/dl; p < 0.0001) and IgG subclasses (IgG1 355.4 ± 88.4 vs 466.7 ± 122.3, p < 0.0001; IgG2 300.1 ± 130.1 vs 347.6 ± 117.3, p < 0.0005) serum levels. 2) asthma exacerbations (6.4 ± 4.1 vs 2.4 ± 1.9, p < 0.0001), LRTI (4.3 ± 3.9 vs 1.3 ± 1.5, p < 0.0001) and hospitalization rate (0.26 ± 0.7 vs 0.05 ± 0.2, p < 0.01). These results persisted after 2 years of therapy. Estimated mean cumulative OCS exposure was reduced by 4500 mg over the 2-year period.

CONCLUSIONS

low-dose IRT is effective in improving asthma control and lessening OCS burden in asthmatics affected by PAD.

Mechanical Forces Govern Interactions of Host Cells with Intracellular Bacterial Pathogens

To combat infectious diseases, it is important to understand how host cells interact with bacterial pathogens. Signals conveyed from pathogen to host, and vice versa, may be either chemical or mechanical. While the molecular and biochemical basis of host-pathogen interactions has been extensively explored, relatively less is known about mechanical signals and responses in the context of those interactions. Nevertheless, a wide variety of bacterial pathogens appear to have developed mechanisms to alter the cellular biomechanics of their hosts in order to promote their survival and dissemination, and in turn many host responses to infection rely on mechanical alterations in host cells and tissues to limit the spread of infection. In this review, we present recent findings on how mechanical forces generated by host cells can promote or obstruct the dissemination of intracellular bacterial pathogens. In addition, we discuss how in vivo extracellular mechanical signals influence interactions between host cells and intracellular bacterial pathogens. Examples of such signals include shear stresses caused by fluid flow over the surface of cells and variable stiffness of the extracellular matrix on which cells are anchored. We highlight bioengineering-inspired tools and techniques that can be used to measure host cell mechanics during infection. These allow for the interrogation of how mechanical signals can modulate infection alongside biochemical signals. We hope that this review will inspire the microbiology community to embrace those tools in future studies so that host cell biomechanics can be more readily explored in the context of infection studies.

Allergen immunotherapy during the COVID-19 pandemic-A survey of the German Society for Allergy and Clinical Immunology

Background

When the coronavirus pandemic 2019 (COVID‐19) emerged, concerns were also raised regarding the safety of allergen immunotherapy (AIT). The German Society for Allergology and Clinical Immunology (DGAKI) conducted a survey to collect real‐world data on the daily routine of administering subcutaneous AIT (SCIT) and sublingual AIT (SLIT) during the COVID‐19 pandemic.

Methods

A web‐based retrospective survey using the online platform survio with 26 standardized questions was used to survey physicians treating allergic patients during the pandemic.

Results

Three hundred and forty‐five physicians who regularly offer and perform AIT in German‐speaking countries responded to the questions. 70.4% of the respondents stated that they regularly initiated and dosed up SCIT for inhalant allergies (41.4% venom‐SCIT, 73.6% SLIT), and 85.2% of the respondents stated that they continued SCIT for inhalant allergies during the maintenance phase in a regular way (59.1% venom‐SCIT, 90.4% SLIT) in healthy patients without current symptoms indicating an infection with COVID‐19. With regard to tolerability, there was no evidence for increased occurrence of adverse events in patients without current symptoms of COVID‐19 infection during the pandemic.

Conclusions

This retrospective study demonstrated adherence to national and international position papers of AIT during the COVID‐19 pandemic in German‐speaking countries. Besides, the survey has confirmed a good tolerability of AIT for both SCIT and SLIT.

Geraniol relieves mycoplasma pneumonia infection-induced lung injury in mice through the regulation of ERK/JNK and NF-κB signaling pathways

BACKGROUND

Pneumonia is a serious pediatric lung injury disease caused by Mycoplasma pneumoniae (M. pneumoniae) with increasing global prevalence every year. The WHO has reported that nearly 19% of children die due to pneumonia worldwide.

OBJECTIVE

The present research was conducted to discover the ameliorative properties of geraniol against M. pneumoniae-provoked pneumonia in mice through the modulation of inflammatory responses.

METHODOLOGY

The pneumonia was provoked in the male Swiss albino mice via infecting animals with 100 µl of M. pneumoniae for 2 days and supplemented concurrently with 20 mg/kg of geraniol for 3 days. 100 mg/kg of azithromycin was used as a standard drug. The nitric oxide (NO) level and MPO activity were measured using kits. The SOD activity, GSH, and MDA levels were studied using standard methods. The polymerase chain reaction (PCR) study was performed to examine the M. pneumoniae DNA load. The inflammatory cytokines status was assessed by assay kits. The ERK1/2, JNK1/2, and NF-κB expressions were studied by reverse-transcription (RT-PCR). The lung tissues were analyzed microscopically to investigate the histological alterations.

RESULTS

Geraniol treatment effectively reduced lung weight, NO level, and MPO activity in the pneumonia mice. The total cells and M. pneumoniae DNA load were also decreased by the geraniol. The SOD activity and GSH level were improved and MDA was decreased by the geraniol treatment. The IL-1, IL-6, IL-8, TNF-α, and TGF status were appreciably depleted by the geraniol in the pneumonia mice. Geraniol also suppressed the ERK1/2 and NF-κB expressions in the lung tissues. Histological findings also suggest the therapeutic roles of geraniol against pneumonia in mice.

CONCLUSION

In summary, our results proved the beneficial roles of geraniol against the M. pneumoniae-provoked pneumonia. Geraniol could be a hopeful therapeutic agent to treat pneumonia in the future.

Halotherapy-An Ancient Natural Ally in the Management of Asthma: A Comprehensive Review

The increasing production of modern medication emerges as a new source of environmental pollution. The scientific community is interested in developing alternative, ecological therapies in asthma. Halotherapy proved its benefits in asthma diagnosis, treatment, and prevention and may represent a reliable therapeutic addition to the allopathic treatment, due to its ecological and environment-friendly nature, in order to prevent or prolong the time to exacerbations in patients with asthma. We aimed to review up-to-date research regarding halotherapy benefits in asthma comprehensively. We searched the electronic databases of PubMed, MEDLINE, EMBASE for studies that evaluated the exposure of asthmatic patients to halotherapy. Eighteen original articles on asthma were included. Five studies in adults and five in children assessed the performance of hypertonic saline bronchial challenges to diagnose asthma or vocal cord dysfunction in asthmatic patients. Three papers evaluated the beneficial effects of halotherapy on mucociliary clearance in asthmatic adults. The therapeutic effect of halotherapy on acute or chronic asthma was appraised in three studies in adults and one in children. The preventive role was documented in one paper reporting the ability of halotherapy to hinder nocturnal asthma exacerbations. All studies seem to sustain the overall positive effects of halotherapy as adjuvant therapy on asthma patients with no reported adverse events. Halotherapy is a crucial natural ally in asthma, but further evidence-based studies on larger populations are needed.

Allergic Diseases: A Comprehensive Review on Risk Factors, Immunological Mechanisms, Link with COVID-19, Potential Treatments, and Role of Allergen Bioinformatics

The prevalence of allergic diseases is regarded as one of the key challenges in health worldwide. Although the precise mechanisms underlying this rapid increase in prevalence are unknown, emerging evidence suggests that genetic and environmental factors play a significant role. The immune system, microbiota, viruses, and bacteria have all been linked to the onset of allergy disorders in recent years. Avoiding allergen exposure is the best treatment option; however, steroids, antihistamines, and other symptom-relieving drugs are also used. Allergen bioinformatics encompasses both computational tools/methods and allergen-related data resources for managing, archiving, and analyzing allergological data. This study highlights allergy-promoting mechanisms, algorithms, and concepts in allergen bioinformatics, as well as major areas for future research in the field of allergology.

Nasal Administration of Lipopolysaccharide Exacerbates Allergic Rhinitis through Th2 Cytokine Production from Mast Cells

Background: Microbial infection or exposure to endotoxin later in life exacerbates established asthma. Mast cells are involved in the exacerbation of asthma. This exacerbation involves a toll-like receptor (TLR)–mediated response of mast cells. In the clinical practice of otolaryngology, otolaryngologists experience an exacerbation of nasal congestion when infectious rhinitis develops in patients with allergic rhinitis, but the mechanisms are unknown. Therefore, this study investigated the effect of lipopolysaccharide (LPS) on allergic rhinitis using a mouse allergic rhinitis model. Methods: Female BALB/c mice, TLR4 gene mutant C3H/HeJ mice or mast cell–deficient WBB6F1-W/Wv mice were sensitized intraperitoneally with ovalbumin (OVA)/alum, and were intranasal challenged with OVA and/or LPS. Nasal symptoms and histologic changes were examined. Cytokines in nasal tissue were examined by Western blot. The effects of LPS on degranulation and cytokine production of bone marrow–derived mast cells (BMMCs) were investigated. Results: Nasal administration of LPS together with the antigen exacerbated nasal symptoms, eosinophil infiltration of the nasal mucosa, and increased IL-5 production in the nasal mucosa. It was not observed in C3H/HeJ mice and WBB6F1-W/Wv mice. The addition of LPS increased the production of IL-5 from BMMCs in a dose-dependent manner, but no effect on degranulation was observed. Conclusions: Intranasal administration of LPS exacerbates allergic rhinitis through Th2 cytokine production from mast cells. This observation provides clues to the mechanism of exacerbation of allergic rhinitis caused by an infection in daily clinical practice.

Pediatric thalassemic patients have higher incidence of asthma: A nationwide population-based retrospective cohort study

Introduction

Patients with hemoglobinopathies have been reported to have higher rates of pulmonary complications. Few studies have investigated the association between thalassemia and asthma in children.

Methods

We used the data of one million individuals randomly selected from the Registry for Beneficiaries of the National Health Insurance Research Database. One thalassemic child was matched with four control children without thalassemia according to sex, birth year, birth season, prematurity, and previous enteroviral infection.

Results

A total of 800 hundred thalassemic children and 3200 controls were included. Children with thalassemia had higher rates of developing asthma (41.81 vs 25.70 per 1000 person-years, P < 0.001) than the non-thalassemia controls with an adjusted hazard ratio of 1.37 (95% confidence interval [CI] = 1.19–1.58). Boys in the thalassemia cohort had a significantly higher adjusted incidence hazard ratio (IRR) of asthma than those in the non-thalassemia cohort (adjusted IRR = 1.45, 95% CI = 1.02–1.73). The risk of atopic and nonatopic asthma was higher in the thalassemia cohort than in the non-thalassemia cohort (IRR = 1.3, 1.61, respectively).

Conclusions

Children with thalassemia were more likely to develop asthma. More attention should be paid to the early diagnosis of asthma and prevention of asthma attacks.

Angiotensin-(1-7) Peptide Hormone Reduces Inflammation and Pathogen Burden during Mycoplasma pneumoniae Infection in Mice

The peptide hormone, angiotensin (Ang-(1–7)), produces anti-inflammatory and protective effects by inhibiting production and expression of many cytokines and adhesion molecules that are associated with a cytokine storm. While Ang-(1–7) has been shown to reduce inflammation and airway hyperreactivity in models of asthma, little is known about the effects of Ang-(1–7) during live respiratory infections. Our studies were developed to test if Ang-(1–7) is protective in the lung against overzealous immune responses during an infection with Mycoplasma pneumonia (Mp), a common respiratory pathogen known to provoke exacerbations in asthma and COPD patients. Wild type mice were treated with infectious Mp and a subset of was given either Ang-(1–7) or peptide-free vehicle via oropharyngeal delivery within 2 h of infection. Markers of inflammation in the lung were assessed within 24 h for each set of animals. During Mycoplasma infection, one high dose of Ang-(1–7) delivered to the lungs reduced neutrophilia and Muc5ac, as well as Tnf-α and chemokines (Cxcl1) associated with acute respiratory distress syndrome (ARDS). Despite decreased inflammation, Ang-(1-7)-treated mice also had significantly lower Mp burden in their lung tissue, indicating decreased airway colonization. Ang-(1–7) also had an impact on RAW 264.7 cells, a commonly used macrophage cell line, by dose-dependently inhibiting TNF-α production while promoting Mp killing. These new findings provide additional support to the protective role(s) of Ang1-7 in controlling inflammation, which we found to be highly protective against live Mp-induced lung inflammation.

Repeated exposure to inactivated Streptococcus pneumoniae induces asthma-like pathological changes in mice in the presence of IL-33

While environmental aeroallergens and epithelial alarmins such as IL-33 are firmly implicated in asthma, the possible role of Streptococcus pneumoniae (S. pneumoniae) antigens is less clear. To explore this, wild-type BALB/c mice were repeatedly challenged per-nasally with IL-33 and inactivated S. pneumoniae, either agent alone or diluent control. Some animals were rested then later re-challenged with inactivated S. pneumoniae alone. Serum concentrations of S. pneumoniae lysates-specific IgE were measured in patients with asthma and control subjects. Interestingly, in the presence of IL-33, repeated exposure to inactivated S. pneumoniae induced asthma-like pathological changes accompanied by a systemic adaptive immune response. Subsequent re-exposure of the sensitized animals to inactivated S. pneumoniae alone was able to induce such changes. The concentration of S. pneumoniae lysates-specific IgE was significantly elevated in the asthma patients. These data suggest that antigens derived from infectious microorganisms may participate in generating the mucosal inflammation which characterizes asthma.

Eosinophils and Bacteria, the Beginning of a Story

Eosinophils are granulocytes primarily associated with TH2 responses to parasites or immune hyper-reactive states, such as asthma, allergies, or eosinophilic esophagitis. However, it does not make sense from an evolutionary standpoint to maintain a cell type that is only specific for parasitic infections and that otherwise is somehow harmful to the host. In recent years, there has been a shift in the perception of these cells. Eosinophils have recently been recognized as regulators of immune homeostasis and suppressors of over-reactive pro-inflammatory responses by secreting specific molecules that dampen the immune response. Their role during parasitic infections has been well investigated, and their versatility during immune responses to helminths includes antigen presentation as well as modulation of T cell responses. Although it is known that eosinophils can present antigens during viral infections, there are still many mechanistic aspects of the involvement of eosinophils during viral infections that remain to be elucidated. However, are eosinophils able to respond to bacterial infections? Recent literature indicates that Helicobacter pylori triggers TH2 responses mediated by eosinophils; this promotes anti-inflammatory responses that might be involved in the long-term persistent infection caused by this pathogen. Apparently and on the contrary, in the respiratory tract, eosinophils promote TH17 pro-inflammatory responses during Bordetella bronchiseptica infection, and they are, in fact, critical for early clearance of bacteria from the respiratory tract. However, eosinophils are also intertwined with microbiota, and up to now, it is not clear if microbiota regulates eosinophils or vice versa, or how this connection influences immune responses. In this review, we highlight the current knowledge of eosinophils as regulators of pro and anti-inflammatory responses in the context of both infection and naïve conditions. We propose questions and future directions that might open novel research avenues in the future.

Respiratory Viral and Bacterial Factors That Influence Early Childhood Asthma

Asthma is a chronic respiratory condition characterised by episodes of shortness of breath due to reduced airway flow. The disease is triggered by a hyperreactive immune response to innocuous allergens, leading to hyper inflammation, mucus production, changes in structural cells lining the airways, and airway hyperresponsiveness. Asthma, although present in adults, is considered as a childhood condition, with a total of about 6.2 million children aged 18 and below affected globally. There has been progress in understanding asthma heterogeneity in adults, which has led to better patient stratification and characterisation of multiple asthma endotypes with distinct, but overlapping inflammatory features. The asthma inflammatory profile in children is not well-defined and heterogeneity of the disease is less described. Although many factors such as genetics, food allergies, antibiotic usage, type of birth, and cigarette smoke exposure can influence asthma development particularly in children, respiratory infections are thought to be the major contributing factor in poor lung function and onset of the disease. In this review, we focus on viral and bacterial respiratory infections in the first 10 years of life that could influence development of asthma in children. We also review literature on inflammatory immune heterogeneity in asthmatic children and how this overlaps with early lung development, poor lung function and respiratory infections. Finally, we review animal studies that model early development of asthma and how these studies could inform future therapies and better understanding of this complex disease.

Asthma in patients with suspected and diagnosed coronavirus disease 2019

BACKGROUND

Patients with asthma are comparatively susceptible to respiratory viral infections and more likely to develop severe symptoms than people without asthma. During the coronavirus disease 2019 (COVID-19) pandemic, it is necessary to adequately evaluate the characteristics and outcomes of the population with asthma in the population tested for and diagnosed as having COVID-19.

OBJECTIVE

To perform a study to assess the impact of asthma on COVID-19 diagnosis, presenting symptoms, disease severity, and cytokine profiles.

METHODS

This was an analysis of a prospectively collected cohort of patients suspected of having COVID-19 who presented for COVID-19 testing at a tertiary medical center in Missouri between March 2020 and September 2020. We classified and analyzed patients according to their pre-existing asthma diagnosis and subsequent COVID-19 testing results.

RESULTS

Patients suspected of having COVID-19 (N = 435) were enrolled in this study. The proportions of patients testing positive for COVID-19 were 69.2% and 81.9% in the groups with asthma and without asthma, respectively. The frequencies of relevant symptoms were similar between the groups with asthma with positive and negative COVID-19 test results. In the population diagnosed as having COVID-19 (n = 343), asthma was not associated with several indicators of COVID-19 severity, including hospitalization, admission to an intensive care unit, mechanical ventilation, death due to COVID-19, and in-hospital mortality after multivariate adjustment. Patients with COVID-19 with asthma exhibited significantly lower levels of plasma interleukin-8 than patients without asthma (adjusted P = .02).

CONCLUSION

The population with asthma is facing a challenge in preliminary COVID-19 evaluation owing to an overlap in the symptoms of COVID-19 and asthma. However, asthma does not increase the risk of COVID-19 severity if infected.

Identification and seasonality of rhinovirus and respiratory syncytial virus in asthmatic children in tropical climate

INTRODUCTION

Asthma is a disease that has been associated with the presence of different genetic and socio-environmental factors.

OBJECTIVE

To identify and evaluate the seasonality of respiratory syncytial virus (RSV) and human rhinovirus (RV) in asthmatic children and adolescents in tropical climate, as well as to assess the socioeconomic and environmental factors involved.

METHODS

The study was conducted in a referral hospital, where a total of 151 children were recruited with a respiratory infection. The International Study of Asthma and Allergies in Childhood (ISAAC) protocol and a questionnaire were applied, and a skin prick test was performed. The nasal swab was collected to detect RV and RSV through molecular assay. National Meteorological Institute (INMET) database was the source of climatic information.

RESULTS

The socio-environmental characterization of asthmatic children showed the family history of allergy, disturbed sleep at night, dry cough, allergic rhinitis, individuals sensitized to at least one mite. We identified RV in 75% of children with asthma and 66.7% of RSV in children with asthma. There was an association between the presence of RV and the dry season whereas the presence of the RSV was associated with the rainy season. Contributing to these results, a negative correlation was observed between the RSV and the wind speed and the maximum temperature (T. Max) and a positive correlation with precipitation.

CONCLUSIONS

The results suggest a high prevalence of RV and RSV in asthmatic children and the seasonality of these viruses were present in different climatic periods. This has significant implications for understanding short- and long-term clinical complications in asthmatic patients.

Management of patients with chronic rhinosinusitis during the COVID-19 pandemic-An EAACI position paper

BACKGROUND

Chronic rhinosinusitis is regarded as a chronic airway disease. According to WHO recommendations, it may be a risk factor for COVID-19 patients. In most CRSwNP cases, the inflammatory changes affecting the nasal and paranasal mucous membranes are type-2 (T2) inflammation endotypes.

METHODS

The current knowledge on COVID-19 and on treatment options for CRS was analyzed by a literature search in Medline, Pubmed, international guidelines, the Cochrane Library and the Internet.

RESULTS

Based on international literature, on current recommendations by WHO and other international organizations as well as on previous experience, a panel of experts from EAACI and ARIA provided recommendations for the treatment of CRS during the COVID-19 pandemic.

CONCLUSION

Intranasal corticosteroids remain the standard treatment for CRS in patients with SARS-CoV-2 infection. Surgical treatments should be reduced to a minimum and surgery preserved for patients with local complications and for those with no other treatment options. Systemic corticosteroids should be avoided. Treatment with biologics can be continued with careful monitoring in noninfected patients and should be temporarily interrupted during the course of the COVID-19 infection.

COVID-19 pandemic: Practical considerations on the organization of an allergy clinic-An EAACI/ARIA Position Paper

BACKGROUND

The coronavirus disease 2019 (COVID-19) has evolved into a pandemic infectious disease transmitted by the severe acute respiratory syndrome coronavirus (SARS-CoV-2). Allergists and other healthcare providers (HCPs) in the field of allergies and associated airway diseases are on the front line, taking care of patients potentially infected with SARS-CoV-2. Hence, strategies and practices to minimize risks of infection for both HCPs and treated patients have to be developed and followed by allergy clinics.

METHOD

The scientific information on COVID-19 was analysed by a literature search in MEDLINE, PubMed, the National and International Guidelines from the European Academy of Allergy and Clinical Immunology (EAACI), the Cochrane Library, and the internet.

RESULTS

Based on the diagnostic and treatment standards developed by EAACI, on international information regarding COVID-19, on guidelines of the World Health Organization (WHO) and other international organizations, and on previous experience, a panel of experts including clinicians, psychologists, IT experts, and basic scientists along with EAACI and the "Allergic Rhinitis and its Impact on Asthma (ARIA)" initiative have developed recommendations for the optimal management of allergy clinics during the current COVID-19 pandemic. These recommendations are grouped into nine sections on different relevant aspects for the care of patients with allergies.

CONCLUSIONS

This international Position Paper provides recommendations on operational plans and procedures to maintain high standards in the daily clinical care of allergic patients while ensuring the necessary safety measures in the current COVID-19 pandemic.

Neutrophils in asthma: the good, the bad and the bacteria

Airway inflammation plays a key role in asthma pathogenesis but is heterogeneous in nature. There has been significant scientific discovery with regard to type 2-driven, eosinophil-dominated asthma, with effective therapies ranging from inhaled corticosteroids to novel biologics. However, studies suggest that approximately 1 in 5 adults with asthma have an increased proportion of neutrophils in their airways. These patients tend to be older, have potentially pathogenic airway bacteria and do not respond well to classical therapies. Currently, there are no specific therapeutic options for these patients, such as neutrophil-targeting biologics.Neutrophils comprise 70% of the total circulatory white cells and play a critical defence role during inflammatory and infective challenges. This makes them a problematic target for therapeutics. Furthermore, neutrophil functions change with age, with reduced microbial killing, increased reactive oxygen species release and reduced production of extracellular traps with advancing age. Therefore, different therapeutic strategies may be required for different age groups of patients.The pathogenesis of neutrophil-dominated airway inflammation in adults with asthma may reflect a counterproductive response to the defective neutrophil microbial killing seen with age, resulting in bystander damage to host airway cells and subsequent mucus hypersecretion and airway remodelling. However, in children with asthma, neutrophils are less associated with adverse features of disease, and it is possible that in children, neutrophils are less pathogenic.In this review, we explore the mechanisms of neutrophil recruitment, changes in cellular function across the life course and the implications this may have for asthma management now and in the future. We also describe the prevalence of neutrophilic asthma globally, with a focus on First Nations people of Australia, New Zealand and North America.

Safety and Antiviral Effects of Nebulized PC786 in a Respiratory Syncytial Virus Challenge Study

Background

PC786 is a nebulized nonnucleoside respiratory syncytial virus (RSV) polymerase inhibitor designed to treat RSV, which replicates in the superficial layer of epithelial cells lining the airways.

Methods

Fifty-six healthy volunteers inoculated with RSV-A (Memphis 37b) were randomly dosed with either nebulized PC786 (5 mg) or placebo, twice daily for 5 days, from either 12 hours after confirmation of RSV infection or 6 days after virus inoculation. Viral load (VL), disease severity, pharmacokinetics, and safety were assessed until discharge. RSV infection was confirmed by reverse-transcription quantitative polymerase chain reaction with any positive value (intention-to-treat infected [ITT-I] population) or RSV RNA ≥1 log₁₀ plaque-forming unit equivalents (PFUe)/mL (specific intention-to-treat infection [ITT-IS] population) in nasal wash samples.

Results

In the ITT-I population, the mean VL area under the curve (AUC) was lower in the PC786 group than the placebo group (274.1 vs 406.6 log₁₀ PFUe/mL × hour; P = .0359). PC786 showed a trend toward reduction of symptom score and mucous weight. In ITT-IS (post hoc analysis), the latter was statistically significant as well as VL AUC (P = .0126). PC786 showed an early time to maximum plasma concentration, limited systemic exposure, and long half-life and consequently a 2-fold accumulation over the 5-day dosing period. PC786 was well tolerated.

Conclusions

Nebulized PC786 demonstrated a significant antiviral effect against RSV, warranting further clinical study.

Clinical Trials Registration

ClinicalTrials.gov: NCT03382431; EudraCT: 2017-002563-18.

A retrospective survey of Chlamydia pneumoniae infection rates in paediatric patients from a single centre in Wuxi, China

Objective

To provide some epidemiological data on Chlamydia pneumoniae infection rates in paediatric patients at a single centre in Wuxi, China.

Methods

This was a retrospective analysis of serum samples from paediatric patients (<12 years) with a respiratory tract infection (RTI) and who had been admitted to the Department of Paediatrics, Wuxi No.2 People’s Hospital, China, from 01 January 2015 to 31 December 2016. C. pneumoniae IgM antibodies had been analysed using enzyme-linked immunosorbent assay (ELISA).

Results

Of the 3866 children (2073 boys, 1793 girls) with a RTI that provided serum samples, 19% were positive for C. pneumoniae IgM antibodies. Among these children, 56% were positive for other infections.

Conclusions

Children over 6 years of age with a RTI had a higher C.pneumoniae infection rate than younger children and the infection rate was more common in winter months compared with other times of the year.

Host-microbe cross-talk in the lung microenvironment: implications for understanding and treating chronic lung disease

Chronic respiratory diseases are highly prevalent worldwide and will continue to rise in the foreseeable future. Despite intensive efforts over recent decades, the development of novel and effective therapeutic approaches has been slow. However, there is new and increasing evidence that communities of micro-organisms in our body, the human microbiome, are crucially involved in the development and progression of chronic respiratory diseases. Understanding the detailed mechanisms underlying this cross-talk between host and microbiota is critical for development of microbiome- or host-targeted therapeutics and prevention strategies. Here we review and discuss the most recent knowledge on the continuous reciprocal interaction between the host and microbes in health and respiratory disease. Furthermore, we highlight promising developments in microbiome-based therapies and discuss the need to employ more holistic approaches of restoring both the pulmonary niche and the microbial community.

The reciprocal interaction between microbes and host in the lung is increasingly recognised as an important determinant of health. The complexity of this cross-talk needs to be taken into account when studying diseases and developing future new therapies.https://bit.ly/2VKYUfT

Positionspapier: Empfehlungen zur Behandlung der chronischen Rhinosinusitis während der COVID-19-Pandemie im deutschen Gesundheitssystem – Empfehlungen des Ärzteverbandes Deutscher Allergologen (AeDA) und der Deutschen Gesellschaft für HNO-Heilkunde, Kopf- und Halschirurgie (DGHNO-KHC) – Diese Empfehlungen basieren auf dem EAACI Positionspapier „Treatment of chronic RhinoSinusitis with nasal polyps (CRSwNP) in the COVID-19 pandemics – An EAACI Position Paper”, Allergy, 2020 und wurden auf die Situation im deutschen Gesundheitswesen angepasst

Hintergrund  Von der chronischen Rhinosinusitis (CRS) sind weltweit etwa 5–12 % der Allgemeinbevölkerung betroffen. Die CRS gilt als chronische Atemwegserkrankung, die nach den Empfehlungen der WHO ein Risikofaktor für COVID-19-Patienten sein kann. Die entzündlichen Veränderungen der Nasenschleimhäute bei chronischer Rhinosinusitis mit Nasenpolypen (CRSwNP) sind in den meisten Fällen vom Entzündungsendotyp 2 (T2).

Methoden  Der aktuelle Wissensstand sowohl zu COVID-19 als auch zu den Behandlungsmöglichkeiten von CRSwNP wurde durch eine Literaturrecherche in Medline, Pubmed, internationalen Leitlinien, der Cochrane Library und im Internet analysiert.

Ergebnisse  Auf Grundlage der internationalen Literatur, der aktuellen Empfehlungen der WHO und anderer internationaler Organisationen sowie der bisherigen Erfahrungen gab ein Expertengremium von EAACI und ARIA Empfehlungen für die Behandlung von CRSwNP während der COVID-19-Pandemien.

Schlussfolgerung  Intranasale Kortikosteroide stellen die Standardbehandlung für CRS bei Patienten mit einer SARS-CoV-2-Infektion dar. Chirurgische Behandlungen sollten auf ein Minimum reduziert werden und nur bei Patienten mit lokalen Komplikationen und solchen, für die keine anderen Behandlungsmöglichkeiten bestehen, durchgeführt werden. Systemische Kortikosteroide sollten bei COVID-19-Patienten vermieden werden. Die Behandlung mit Biologika kann bei nicht infizierten Patienten unter sorgfältiger Überwachung fortgesetzt werden und sollte während einer SARS-CoV-2-Infektion vorübergehend unterbrochen werden.

Daycare attendance and asthma control, Asthma Call-back Survey 2012-2014

OBJECTIVE

To examine the association between daycare attendance and asthma control among children aged 0 to 4 years with asthma.

METHODS

We analyzed 2012-2014 data from the Behavioral Risk Factor Surveillance System Asthma Call-back Survey on 388 children with asthma aged 0 to 4 years with information on daycare attendance in the past 12 months. We calculated weighted prevalence ratios to assess the association between daycare attendance and asthma control (categorized based on day-time and nighttime asthma symptoms, activity limitation, and short-acting beta agonist use). Adjusted models controlled for parent or guardian education, household income, race, sex, cost barriers to asthma care, long-term control medication use, and the number of other children in the child's household.

RESULTS

In this sample of children with asthma, representative of 520,400 children in 26 U.S. states, 34% attended daycare in the past 12 months. Only 32% of children who attended daycare in the past 12 months reported having an asthma action plan on file at the daycare they most recently attended. Presence of the asthma triggers of pets, mold, and smoking in a child's daycare were reported to be uncommon. Prevalence of uncontrolled asthma was 44% in children who attended daycare in the past 12 months and 68% in children who did not. The adjusted prevalence ratio between daycare attendance and uncontrolled asthma was 0.96 (95% confidence interval 0.73, 1.25).

CONCLUSIONS

When adjusting for covariates, we observed no evidence of an association between daycare attendance in early life and uncontrolled asthma.

Deconstructing the Chlamydial Cell Wall

The evolutionary separated Gram-negative Chlamydiales show a biphasic life cycle and replicate exclusively within eukaryotic host cells. Members of the genus Chlamydia are responsible for many acute and chronic diseases in humans, and Chlamydia-related bacteria are emerging pathogens. We revisit past efforts to detect cell wall material in Chlamydia and Chlamydia-related bacteria in the context of recent breakthroughs in elucidating the underlying cellular and molecular mechanisms of the chlamydial cell wall biosynthesis. In this review, we also discuss the role of cell wall biosynthesis in chlamydial FtsZ-independent cell division and immune modulation. In the past, penicillin susceptibility of an invisible wall was referred to as the "chlamydial anomaly." In light of new mechanistic insights, chlamydiae may now emerge as model systems to understand how a minimal and modified cell wall biosynthetic machine supports bacterial cell division and how cell wall-targeting beta-lactam antibiotics can also act bacteriostatically rather than bactericidal. On the heels of these discussions, we also delve into the effects of other cell wall antibiotics in individual chlamydial lineages.

Effects of physical therapy on lung function in children with asthma: Study protocol for a systematic review and meta-analysis

BACKGROUND

Morbidity of asthma in children is increasing, which is significantly affecting children's life quality. Despite the medication therapy, physical therapies, including breathing exercises, inspiratory muscle training and physical training, are widely used to improve children's condition. However, the effectiveness of physical therapy remains unclear. This systematic review and meta-analysis is aiming to evaluate the effects of physical therapy on lung function in children with asthma and to assess which physical therapy is more effective.

METHODS

Three main databases (PubMed, Embase, and the Cochrane Library) will be searched from inception to November 30, 2018 for randomized controlled trials investigating the effects of physical therapy on lung function in children (age < 18 years old) with asthma published in English. In addition, a manual search of the references of relevant published studies in English will also be considered.Two independent reviewers will conduct studies selection, data extraction, and risk of bias assessment. Outcome measures will be the Peak Expiratory Flow (PEF), the Forced Expiratory Volume in the first second (FEV1), and the Forced Vital Capacity (FVC). Subgroup analyses will be performed according to the physical therapy (breathing exercises, inspiratory muscle training, and physical training) and the outcome (PEF, FEV1, FVC).

RESULTS

The results will provide useful information about the effect of physical therapy on lung function in children with asthma and demonstrate which physical therapy is more effective.

CONCLUSION

The findings of this study will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019121627.

House dust mite exposure attenuates influenza A infection in a mouse model of pulmonary allergic inflammation

Environmental allergens elicit complex immune responses in the lungs that can promote the development of asthma or exacerbate preexisting asthma in susceptible individuals. House dust mites are one of the most common indoor allergens and are a significant driver of allergic disease. Respiratory infections are known factors in acute exacerbations of asthma but the impact of allergen on the pathogen is not well understood. We investigated the pathogenesis of influenza A infection following exposure to house dust mites. Mice exposed to house dust mites lose less weight following infection and had more transcription of interferon-lambda than controls. These data correlated with less transcription of the influenza polymerase acidic gene suggesting diminished viral replication in house dust mite exposed mice. Altogether, these data suggest that exposure to environmental allergens can influence the pathogenesis of influenza infection.

Respiratory tract infection-induced asthma exacerbations in adults with asthma: assessing predictors and outcomes

Objective: To evaluate clinical and economic burden associated with respiratory tract infection (RTI)-induced asthma exacerbations and to identify risk factors associated with these exacerbations. Factors associated with these exacerbations are understudied and little information is available about consequent expenditures. Methods: In this retrospective case-control study, medical records and pharmacy data in King Abdullah University Hospital in Northern Jordan were reviewed for adults with asthma aged 40 years and older, over the period 2013-2016. Cases of RTI-induced asthma exacerbations were identified, and controls were selected randomly from asthmatic adults who did not experience any RTI-induced asthma exacerbation during the same period. Independent-samples t-tests and chi-square tests were conducted to compare patient characteristics of cases and controls. Predictors of RTI-induced asthma exacerbations and the resultant complications were evaluated using multivariable logistic regression. Multivariable regression on log-transformed charges was used to predict expenditures of these exacerbations. Results: A total of 137 cases and 548 controls were identified. Using inhaled corticosteroid + long-acting beta-agonists (ICS + LABA) was significantly associated with lower odds of RTI-induced asthma exacerbations (OR = 0.4; 95% CI, 0.21-0.77; p = 0.006), and lower odds of resultant serious complications (OR = 0.23; 95% CI, 0.07-0.69; p = 0.009), compared to being untreated with any asthma maintenance treatment. Asthma severity and co-morbidities were associated with increased susceptibility to these exacerbations. The average charges of RTI-induced asthma admissions and outpatient exacerbations were 1042.9 JD ($1471.0) and 81.1 JD ($114.4), respectively. Conclusions: ICS + LABA, asthma severity and co-morbidities appeared to affect the clinical and economic burden associated with RTI-induced asthma exacerbations. Efforts to prevent these exacerbations in patients with risk factors are warranted.

Combined administration of anti-IL-13 and anti-IL-17A at individually sub-therapeutic doses limits asthma-like symptoms in a mouse model of Th2/Th17 high asthma

BACKGROUND

Recent studies have demonstrated that Th2 responses have the ability to antagonize Th17 responses. In mouse models of allergic asthma, blockade of Th2-effector cytokines results in elaboration of Th17 responses and associated increases in pulmonary neutrophilia. While these can be controlled by simultaneous blockade of Th17-associated effector cytokines, clinical trials of anti-IL-17/IL-17RA blocking therapies have demonstrated increased of risk of bacterial and fungal infections. Identification of minimally effective doses of cytokine-blocking therapies with the goal of reducing the potential emergence of infection-related complications is a translationally relevant goal.

OBJECTIVE

In the current report, we examine whether combined blockade of IL-13 and IL-17A, at individually sub-therapeutic levels, can limit the development of allergic asthma while sparing expression of IL-17A-associated anti-microbial effectors.

METHODS

House dust mite was given intratracheally to A/J mice. Anti-IL-13 and anti-IL-17A antibodies were administered individually, or concomitantly at sub-therapeutic doses. Airway hyper-reactivity, lung inflammation, magnitude of Th2- and Th17-associated cytokine production and expression of IL-13- and IL-17A-induced genes in the lungs was assessed.

RESULTS

Initial dosing studies identified sub-therapeutic levels of IL-13 and IL-17A blocking mAbs that have a limited effect on asthma parameters and do not impair responses to microbial products or infection. Subsequent studies demonstrated that combined sub-therapeutic dosing with IL-13 and IL-17A blocking mAbs resulted in significant improvement in airway hyperresponsiveness (AHR) and expression of IL-13-induced gene expression. Importantly, these doses neither exacerbated nor inhibited production of Th17-associated cytokines, or IL-17A-associated gene expression.

CONCLUSION

This study suggests that combining blockade of individual Th2 and Th17 effector cytokines, even at individually sub-therapeutic levels, may be sufficient to limit disease development while preserving important anti-microbial pathways. Such a strategy may therefore have reduced potential for adverse events associated with blockade of these pathways.

Sphingolipids and their enigmatic role in asthma

Asthma is defined as a chronic inflammatory condition in the lung and is characterized by episodic shortness of breath with expiratory wheezing and cough. Asthma is a serious public health concern globally with an estimated incidence over 300 million. Asthma is a complex disease in that it manifests as disease of gene and environmental interactions. Sphingolipids are a unique class of lipids involved in a host of biological functions ranging from serving as key cellular membrane lipids to acting as critical signaling molecules. To date sphingolipids have been studied across various human conditions ranging from neurological disorders to cancer to infection to autoimmunity. This review will focus on the role of sphingolipids in asthma development and pathology with particular focus on the role of mast cell sphingolipid biology.

Influenza burden, prevention, and treatment in asthma-A scoping review by the EAACI Influenza in asthma task force

To address uncertainties in the prevention and management of influenza in people with asthma, we performed a scoping review of the published literature on influenza burden; current vaccine recommendations; vaccination coverage; immunogenicity, efficacy, effectiveness, and safety of influenza vaccines; and the benefits of antiviral drugs in people with asthma. We found significant variation in the reported rates of influenza detection in individuals with acute asthma exacerbations making it unclear to what degree influenza causes exacerbations of underlying asthma. The strongest evidence of an association was seen in studies of children. Countries in the European Union currently recommend influenza vaccination of adults with asthma; however, coverage varied between regions. Coverage was lower among children with asthma. Limited data suggest that good seroprotection and seroconversion can be achieved in both children and adults with asthma and that vaccination confers a degree of protection against influenza illness and asthma-related morbidity to children with asthma. There were insufficient data to determine efficacy in adults. Overall, influenza vaccines appeared to be safe for people with asthma. We identify knowledge gaps and make recommendations on future research needs in relation to influenza in patients with asthma.

The Burden of Pediatric Asthma

Asthma is the most common chronic disease in children, imposing a consistent burden on health system. In recent years, prevalence of asthma symptoms became globally increased in children and adolescents, particularly in Low-Middle Income Countries (LMICs). Host (genetics, atopy) and environmental factors (microbial exposure, exposure to passive smoking and air pollution), seemed to contribute to this trend. The increased prevalence observed in metropolitan areas with respect to rural ones and, overall, in industrialized countries, highlighted the role of air pollution in asthma inception. Asthma accounts for 1.1% of the overall global estimate of "Disability-adjusted life years" (DALYs)/100,000 for all causes. Mortality in children is low and it decreased across Europe over recent years. Children from LMICs particularly suffer a disproportionately higher burden in terms of morbidity and mortality. Global asthma-related costs are high and are usually are classified into direct, indirect and intangible costs. Direct costs account for 50-80% of the total costs. Asthma is one of the main causes of hospitalization which are particularly common in children aged < 5 years with a prevalence that has been increased during the last two decades, mostly in LMICs. Indirect costs are usually higher than in older patients, including both school and work-related losses. Intangible costs are unquantifiable, since they are related to impairment of quality of life, limitation of physical activities and study performance. The implementation of strategies aimed at early detect asthma thus providing access to the proper treatment has been shown to effectively reduce the burden of the disease.

Toll-Like Receptor 4 Is Essential for the Expression of Sphingosine-1-Phosphate-Dependent Asthma-Like Disease in Mice

Sphingosine-1-phosphate (S1P) levels significantly increase in bronchoalveolar lavage (BAL) of asthmatic patients following segmental allergen challenge and this increase well correlates with pulmonary inflammation. Epidemiological, genetic, clinical, and experimental data indicate a potential for the toll-like receptor 4 (TLR4) to initiate and exacerbate allergic airway diseases. The aim of this study was to evaluate the contribution of TLR4 in S1P-dependent asthma-like disease in mice. BALB/c or TLR4 defective (C3H/HeJ) mice received S1P (10 ng/mouse), LPS (0.1 μg/mouse) or S1P + LPS. Furthermore, S1P-treated BALB/c mice were injected with the purified rabbit anti-TLR4 antibody (10 μg/mouse). S1P administration induced airway hyperreactivity and pulmonary inflammation associated to an increase in the percentage of dendritic cells (DCs) and macrophages into the lung of BALB/c mice. These effects were coupled to a reduction of DCs in the mediastinic lymph node. All these S1P-mediated effects were absent in TLR4 defective mice or reversed by treatment with a purified rabbit anti-TLR4 antibody. Confocal analysis of pulmonary sections showed a significant increase in TLR4⁺ cells and a similar presence of S1P₁ and TLR4 following S1P challenge. Accordingly, the immunoprecipitation evidenced an increased S1P₁/TLR4 interaction. In conclusion, our findings suggest that a functional interaction between S1P₁ and TLR4 leads to an enhanced allergic inflammatory response. Thus, S1P pathway contributes to the sentinel role played by innate immunity providing new targets for prevention and treatment of allergic airway diseases.

Preclinical Characterization of PC786, an Inhaled Small-Molecule Respiratory Syncytial Virus L Protein Polymerase Inhibitor

Although respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infection in infants and young children, attempts to develop an effective therapy have so far proved unsuccessful. Here we report the preclinical profiles of PC786, a potent nonnucleoside RSV L protein polymerase inhibitor, designed for inhalation treatment of RSV infection. PC786 demonstrated a potent and selective antiviral activity against laboratory-adapted or clinical isolates of RSV-A (50% inhibitory concentration [IC₅₀], <0.09 to 0.71 nM) and RSV-B (IC₅₀, 1.3 to 50.6 nM), which were determined by inhibition of cytopathic effects in HEp-2 cells without causing detectable cytotoxicity. The underlying inhibition of virus replication was confirmed by PCR analysis. The effects of PC786 were largely unaffected by the multiplicity of infection (MOI) and were retained in the face of established RSV replication in a time-of-addition study. Persistent anti-RSV effects of PC786 were also demonstrated in human bronchial epithelial cells. In vivo intranasal once daily dosing with PC786 was able to reduce the virus load to undetectable levels in lung homogenates from RSV-infected mice and cotton rats. Treatment with escalating concentrations identified a dominant mutation in the L protein (Y1631H) in vitro. In addition, PC786 potently inhibited RSV RNA-dependent RNA polymerase (RdRp) activity in a cell-free enzyme assay and minigenome assay in HEp-2 cells (IC₅₀, 2.1 and 0.5 nM, respectively). Thus, PC786 was shown to be a potent anti-RSV agent via inhibition of RdRp activity, making topical treatment with this compound a novel potential therapy for the treatment of human RSV infections.

Comparison of the ameliorative effects of Qingfei Tongluo formula and azithromycin on Mycoplasma pneumoniae pneumonia

Mycoplasma pneumoniae pneumonia (MPP) is a common disease in children. Qingfei Tongluo formula (QTF) has been used for the treatment of MPP clinically, but the therapeutic effect remains unclear compared to conventional treatments with Western medicines. Therefore, the aim of this study was to assess changes in the expression levels of relevant factors associated with microcirculation after MPP and to compare the therapeutic effect of QTF with that of azithromycin (AZM) on experimental mice with MPP. A total of 174 children admitted with clinical diagnoses of pneumonia (80 MPP and 94 non-MPP) were used to identify differences in the expression patterns of factors in the microcirculation using an enzyme-linked immunosorbent assay. A BALB/c mouse model of MPP infection was established to determine the therapeutic effect of QTF. The results showed that the expression level of thrombomodulin (TM), vascular endothelial growth factor (VEGF), d-dimer (D-D), interleukin (IL)-6, and IL-10 were upregulated after MPP both clinically in children and in the mouse model. After 3 days of therapy, the amount of total MPP DNA decreased, especially in the mid- and high-dose QTF treatment groups. The expression levels of VEGF, IL-6, and IL-10 also decreased in response to treatment with QTF or AZM. However, there was no influence on D-D levels. QTF treatment also decreased TM expression. In conclusion, QTF treatment inhibited the progression of MPP, reduced vascular permeability, and improved pulmonary microcirculation more effectively than conventional treatment with Western medicine.

The Influence of Asthma and/or Hay Fever on Pregnancy: Data from the 1995 National Survey of Family Growth

BACKGROUND

Asthma is associated with adverse pregnancy outcomes. At the same time there is a worldwide increase in asthma and hay fever.

OBJECTIVE

This study addresses whether asthma and/or hay fever adversely influence pregnancy outcomes.

METHODS

Data from the 1995 National Survey of Family Growth that include a history of diagnosed asthma, hay fever, and adverse pregnancy outcomes in 10,847 women representative of the US population aged 15 to 44 years were analyzed.

RESULTS

Women with the allergic phenotypes asthma and hay fever and hay fever only had no significant increase in adverse pregnancy outcomes (spontaneous pregnancy loss, preterm birth, infant low birth weight), whereas women with the nonatopic phenotype asthma only (without hay fever) did. The study did not evaluate endotypes.

CONCLUSIONS

This study provides new data that the allergic phenotypes, asthma and hay fever and hay fever only, are compatible with healthy pregnancy, whereas the nonatopic asthma phenotype, asthma only, adversely impacts pregnancy.

Mycoplasma pneumoniae CARDS toxin elicits a functional IgE response in Balb/c mice

Mycoplasma pneumoniae is strongly associated with new onset asthma and asthma exacerbations. Until recently, the molecular mechanisms utilized by M. pneumoniae to influence asthma symptoms were unknown. However, we recently reported that an ADP-ribosylating and vacuolating toxin called the Community Acquired Respiratory Distress Syndrome toxin, CARDS toxin, produced by M. pneumoniae was sufficient to promote allergic inflammation and asthma-like disease in mice. A mouse model of CARDS toxin exposure was used to evaluate total and CARDS-toxin specific serum IgE responses. Mast cell sensitization, challenge, and degranulation studies determined functionality of the CARDS toxin-specific IgE. In the current study, we report that a single mucosal exposure to CARDS toxin was sufficient to increase total serum IgE and CARDS toxin-specific IgE in mice. Mice given a second mucosal challenge of CARDS toxin responded with significant increases in total and CARDS toxin-specific IgE. CARDS toxin-specific IgE bound to an N-terminal peptide of CARDS toxin but not the C-terminal peptide. Likewise, full-length CARDS toxin and the N-terminal peptide induced mast cell degranulation. Altogether, these data demonstrate that exposure to CARDS toxin is sufficient to generate functional IgE in mice. M. pneumoniae and CARDS toxin are strongly associated with asthma exacerbations raising the possibility that the CARDS toxin-specific IgE-mast cell axis contributes to disease pathogenesis.

Epithelial-mesenchymal transition promotes reactivity of human lung adenocarcinoma A549 cells to CpG ODN

BACKGROUND

Epithelial-mesenchymal transition (EMT) is reported to promote airway remodeling in asthmatics, which is the main histological change that causes complex and severe symptoms in asthmatics. However, little is known about whether EMT also plays a role in acute exacerbations of asthma evoked by respiratory tract infections.

METHODS

A human lung adenocarcinoma line, A549, was incubated with TGF-β1 at 10 ng/ml to induce EMT. Then the cells were stimulated with CpG ODN. Expression of surface and intracellular molecules was analyzed by flow cytometry. IL-6, IL-8 and MCP-1 in the culture supernatant were measured by Cytometric Bead Assay, and the expression of mRNA was quantitated by real-time PCR. CpG ODN uptake was analyzed by flow cytometry.

RESULTS

The culture supernatant levels of IL-6, IL-8 and MCP-1 and the expression of mRNA for these cytokines in CpG ODN-stimulated A549 cells that had undergone EMT was significantly higher compared to those that had not. Addition of ODN H154, a TLR9-inhibiting DNA, significantly suppressed the CpG ODN-induced production of those cytokines. However, flow cytometry found the level of TLR9 expression to be slightly lower in A549 cells that had undergone EMT compared to those that had not. On the other hand, CpG ODN uptake was increased in cells that had undergone EMT.

CONCLUSIONS

EMT induction of A549 cells enhanced CpG ODN uptake and CpG ODN-induced production of IL-6, IL-8 and MCP-1. These results suggest that EMT plays an important role in exacerbation in asthmatics with airway remodeling by enhancing sensitivity to extrinsic pathogens.

[Distribution characteristics of Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila in hospitalized children with acute respiratory tract infection: an analysis of 13 198 cases]

OBJECTIVE

To investigate the distribution characteristics of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae (CP), and Legionella pneumophila (LP) in hospitalized children with acute respiratory tract infection (ARTI).

METHODS

A total of 13 198 hospitalized children with ARTI were enrolled as study subjects. Whole blood and urine were collected. The passive agglutination was used to detect serum MP-IgM, ELISA was used to detect serum CP-IgM, and immunochromatography was performed to detect urinary LP antigen.

RESULTS

Among the 13 198 hospitalized ARTI children, the detection rates of MP, CP, and LP were 25.31%, 12.74% and 3.27%, suggesting that MP had the highest detection rate (P<0.0125). The detection rates of MP in 2013 and 2014 were significantly higher than that in 2012 (P<0.0125). CP had the highest detection rate in 2013, and LP had the highest detection rate in 2014 (P<0.0125). These three pathogens were detected all around the year, and MP had the highest detection rate in all seasons (P<0.0125). The detection rate of mixed infection with three pathogens was 4.35%, and mixed infection with MP and CP was the most common (P<0.0071). Among the children in different age groups, the patients aged 5-16 years showed the highest overall detection rate of three pathogens (P<0.0071). Among the children with different types of ARTI, the children with bronchopneumonia showed the highest overall detection rate of three pathogens (P<0.0045).

CONCLUSIONS

MP, CP, and LP, particularly MP, are important pathogens for children with ARTI in the local area. LP infection tends to increase year by year and should be taken seriously in clinical practice.

[Distribution characteristics of Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila in hospitalized children with acute respiratory tract infection: an analysis of 13 198 cases]

OBJECTIVE

To investigate the distribution characteristics of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae (CP), and Legionella pneumophila (LP) in hospitalized children with acute respiratory tract infection (ARTI).

METHODS

A total of 13 198 hospitalized children with ARTI were enrolled as study subjects. Whole blood and urine were collected. The passive agglutination was used to detect serum MP-IgM, ELISA was used to detect serum CP-IgM, and immunochromatography was performed to detect urinary LP antigen.

RESULTS

Among the 13 198 hospitalized ARTI children, the detection rates of MP, CP, and LP were 25.31%, 12.74% and 3.27%, suggesting that MP had the highest detection rate (P<0.0125). The detection rates of MP in 2013 and 2014 were significantly higher than that in 2012 (P<0.0125). CP had the highest detection rate in 2013, and LP had the highest detection rate in 2014 (P<0.0125). These three pathogens were detected all around the year, and MP had the highest detection rate in all seasons (P<0.0125). The detection rate of mixed infection with three pathogens was 4.35%, and mixed infection with MP and CP was the most common (P<0.0071). Among the children in different age groups, the patients aged 5-16 years showed the highest overall detection rate of three pathogens (P<0.0071). Among the children with different types of ARTI, the children with bronchopneumonia showed the highest overall detection rate of three pathogens (P<0.0045).

CONCLUSIONS

MP, CP, and LP, particularly MP, are important pathogens for children with ARTI in the local area. LP infection tends to increase year by year and should be taken seriously in clinical practice.

Chronic Infection and Severe Asthma

Chronic bacterial infection is implicated in both the development and severity of asthma. The atypical bacteria Mycoplasma pneumoniae and Chlamydophila pneumoniae have been identified in the airways of asthmatics and correlated with clinical features such as adult onset, exacerbation risks, steroid sensitivity, and symptom control. Asthmatic patients with evidence of bacterial infection may benefit from antibiotic treatment directed towards these atypical organisms. Examination of the airway microbiome may identify microbial communities that confer risk for or protection from severe asthma.