Community study of role of viral infections in exacerbations of asthma in 9-11 year old children

How allergic conditions influence hygiene practices among adolescents: insights from a nationwide Youth Survey data

Effective handwashing is important for preventing exacerbation of allergic diseases, yet the relationship between allergic diseases in adolescents remains underexplored. Utilizing data from the Korea Youth Risk Behavior Survey (2009-2022), a nationwide study involving students aged 12-19, we analyzed the allergic condition, International Study of Asthma and Allergic Conditions (Never, Previous, Current), and their handwashing scores. We analyzed the trend of handwashing by allergic condition. And we conducted the ordinal logistic regression between allergic condition and handwashing, adjusted with gender, age, economic status, urbanization, smoking status, alcohol consumptions, surveyed year, and education on HW. A total of 3,258,610 adolescents were analyzed. We observed spikes in mean handwashing scores in 2009, 2013, 2015, and 2020, which corresponded with trends in allergic conditions. Adolescents with current asthma and allergic rhinitis had higher odds ratios (ORs) for better handwashing practices compared to those without these conditions. Conversely, those with current or previous atopic dermatitis had lower ORs compared to those without these conditions. In adolescent age, asthma and allergic rhinitis positively influence handwashing practices, while atopic dermatitis negatively influences handwashing practice, due to their comorbidities, highlighting the need for specialized handwashing guidelines that address the unique challenges of those with allergic diseases.

Targeting respiratory virus-induced reactive oxygen species in airways diseases

The immune response to virus infection in the respiratory tract must be carefully balanced to achieve pathogen clearance without excessive immunopathology. For chronic respiratory diseases where there is ongoing inflammation, such as in asthma and COPD, airway immune balance is perturbed, and viral infection frequently worsens (exacerbates) these conditions. Reactive oxygen species (ROS) are critical to the induction and propagation of inflammation, and when appropriately regulated, ROS are vital cell signalling molecules and contribute to innate immunity. However, extended periods of high ROS concentration can cause excessive cellular damage that dysregulates antiviral immunity and promotes inflammation. Traditional antioxidant therapeutics have had limited success treating inflammatory diseases such as viral exacerbations of asthma or COPD, owing to nonspecific pharmacology and poorly understood pharmacokinetic properties. These drawbacks could be addressed with novel drug delivery technologies and pharmacological agents. This review summarises current research on ROS imbalances during virus infection, discusses the commercially available mitochondrial antioxidant drugs that have progressed to clinical trial and assesses novel drug delivery approaches for antioxidant delivery to the airways. Additionally, it provides a perspective on future research into pharmacological targeting of ROS for the treatment of respiratory virus infection and disease.

Detection of Human Coronavirus-OC43 in Nasopharyngeal Swab Specimens Via Immunofluorescence Staining Using Human Serum and an Anti-human Antibody

Immunofluorescence methods using cell lines to detect seasonal human coronavirus (HCoV)-OC43 in nasopharyngeal swab specimens have not yet been established. A human rectal adenocarcinoma cell line (HRT-18) was exposed to the specimens obtained from patients with upper respiratory tract infections. Immunofluorescence staining was conducted using a combination of human serum containing an HCoV-OC43 anti-spike protein antibody and a fluorescence-labeled anti-human antibody. Positive staining in HRT-18 cells was detected after exposure to specimens obtained from nine of eleven patients in whom HCoV-OC43 RNA was detected using the FilmArray method. Increased viral RNA levels in the supernatant were also detected in HRT-18 cells exposed to specimens obtained from four of five patients. In contrast, positive staining was not detected in HRT-18 cells exposed to six patient specimens that tested negative for RNA from 17 types and subtypes of respiratory viruses, including HCoV-OC43. Cells inoculated with the established strain HCoV-OC43 (ATCC VR-759) also showed positive staining. These findings suggest that replication-competent HCoV-OC43 in the specimens can be detected via immunofluorescence staining of HRT-18 cells with human serum. Using this method, positive staining for viruses other than HCoV-OC43 may be obtained.

Impact of Demographic and Clinical Subgroups in Google Trends Data: Infodemiology Case Study on Asthma Hospitalizations

BACKGROUND

Google Trends (GT) data have shown promising results as a complementary tool to classical surveillance approaches. However, GT data are not necessarily provided by a representative sample of patients and may be skewed toward demographic and clinical groups that are more likely to use the internet to search for their health.

OBJECTIVE

In this study, we aimed to assess whether GT-based models perform differently in distinct population subgroups. To assess that, we analyzed a case study on asthma hospitalizations.

METHODS

We analyzed all hospitalizations with a main diagnosis of asthma occurring in 3 different countries (Portugal, Spain, and Brazil) for a period of approximately 5 years (January 1, 2012-December 17, 2016). Data on web-based searches on common cold for the same countries and time period were retrieved from GT. We estimated the correlation between GT data and the weekly occurrence of asthma hospitalizations (considering separate asthma admissions data according to patients' age, sex, ethnicity, and presence of comorbidities). In addition, we built autoregressive models to forecast the weekly number of asthma hospitalizations (for the different aforementioned subgroups) for a period of 1 year (June 2015-June 2016) based on admissions and GT data from the 3 previous years.

RESULTS

Overall, correlation coefficients between GT on the pseudo-influenza syndrome topic and asthma hospitalizations ranged between 0.33 (in Portugal for admissions with at least one Charlson comorbidity group) and 0.86 (for admissions in women and in White people in Brazil). In the 3 assessed countries, forecasted hospitalizations for 2015-2016 correlated more strongly with observed admissions of older versus younger individuals (Portugal: Spearman ρ=0.70 vs ρ=0.56; Spain: ρ=0.88 vs ρ=0.76; Brazil: ρ=0.83 vs ρ=0.82). In Portugal and Spain, forecasted hospitalizations had a stronger correlation with admissions occurring for women than men (Portugal: ρ=0.75 vs ρ=0.52; Spain: ρ=0.83 vs ρ=0.51). In Brazil, stronger correlations were observed for admissions of White than of Black or Brown individuals (ρ=0.92 vs ρ=0.87). In Portugal, stronger correlations were observed for admissions of individuals without any comorbidity compared with admissions of individuals with comorbidities (ρ=0.68 vs ρ=0.66).

CONCLUSIONS

We observed that the models based on GT data may perform differently in demographic and clinical subgroups of participants, possibly reflecting differences in the composition of internet users' health-seeking behaviors.

Quercetin-3-Methyl Ether Induces Early Apoptosis to Overcome HRV1B Immune Evasion, Suppress Viral Replication, and Mitigate Inflammatory Pathogenesis

Human rhinovirus (HRV) causes the common cold and exacerbates chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease. Despite its significant impact on public health, there are currently no approved vaccines or antiviral treatments for HRV infection. Apoptosis is the process through which cells eliminate themselves through the systematic activation of intrinsic death pathways in response to various stimuli. It plays an important role in viral infections and serves as a key immune defense mechanism in the interactions between viruses and the host. In the present study, we investigated the antiviral effects of quercetin-3-methyl ether, a flavonoid isolated from Serratula coronata, on human rhinovirus 1B (HRV1B). Quercetin-3-methyl ether significantly inhibited HRV1B replication in HeLa cells in a concentration-dependent manner, thereby reducing cytopathic effects and viral RNA levels. Time-course and time-of-addition analyses confirmed that quercetin-3-methyl ether exhibited antiviral activity during the early stages of viral infection, potentially targeting the replication and translation phases. Gene expression analysis using microarrays revealed that pro-apoptotic genes were upregulated in quercetin-3-methyl ether-treated cells, suggesting that quercetin-3-methyl ether enhances early apoptosis to counteract HRV1B-induced immune evasion. In vivo administration of quercetin-3-methyl ether to HRV1B-infected mice significantly reduced viral RNA levels and inflammatory cytokine production in the lung tissues. Our findings demonstrated the potential of quercetin-3-methyl ether as a novel antiviral agent against HRV1B, thereby providing a promising therapeutic strategy for the management of HRV1B infections and related complications.

Retrospective Cohort Study of Perioperative Complications in Symptomatic and Asymptomatic Children Testing SARS-CoV-2-Positive Within 21 Days Before Surgery

INTRODUCTION

COVID-19 increases anesthetic risk in children, but understanding of complication differences by symptom presence and severity is limited. We hypothesized that symptomatic COVID-19+ children, especially with lower respiratory symptoms, would have higher perioperative complications than asymptomatic patients and that complications would be higher in all patients diagnosed < 6 days before anesthesia.

METHODS

This single-center, retrospective cohort study reviewed records of children < 18 years old undergoing surgery with general anesthesia from March 1, 2020, to March 1, 2022, who tested COVID-19+. A total of 225 patients who tested positive ≤ 10 days before anesthesia were analyzed for the primary outcome, and an additional 298 patients who tested positive ≤ 21 days before anesthesia were analyzed for secondary outcomes. Data on demographics, comorbidities, vaccination, preoperative and perioperative care, complications, and mortality were collected. Primary outcome analysis used univariate regression; secondary outcome analysis used analysis of variance.

RESULTS

Primary Outcome: Symptomatic patients were more likely to experience postoperative respiratory complications (OR: 3.53, 1.18-10.6, p = 0.024), require postoperative medications (OR: 7.64, 2.29-25.51, p = 0.001), and require postoperative oxygen support (OR: 2.62, 1.19-5.79, p = 0.017) versus asymptomatic patients. Those with upper respiratory symptoms were less likely to require postoperative medications (OR: 0.1, 0.01-0.89, p = 0.039) and oxygen support (OR: 0.08, 0.01-0.45, p = 0.004) versus those with lower respiratory symptoms.

SECONDARY OUTCOME

Patients testing COVID-19+ < 6 days before anesthesia had longer PACU stays (p < 0.001) and more postoperative respiratory complications (p = 0.001), medication use (p = 0.038), and oxygen use (p = 0.002) versus other groups.

DISCUSSION

Preoperative symptoms, especially of the lower respiratory tract, increased the risk for perioperative complications in children diagnosed with COVID-19 within 10 days of surgery.

CONCLUSION

The presence of symptoms, particularly of the lower respiratory tract, should be strongly considered in the shared decision-making process between providers and families when discussing the potential delay of procedures in the setting of COVID-19.

Indoor bioaerosols and asthma: Overview, implications, and mitigation strategies

Aerosolized particles with a biological origin are called bioaerosols. Bioaerosols from plants, animals, fungi, bacteria, and viruses are an important class of environmental exposures that are clinically relevant to asthma. However, there are important differences in the pathways by which various bioaerosols affect asthma. Additionally, differences in individual susceptibility to different bioaerosols affect exposure reduction and mitigation strategies. Strategies to reduce exposures to potential triggers of asthma are routinely considered as part of standard clinical care and asthma management guidelines. Ventilation standards in buildings may reduce bioaerosol exposure for everyone, but they are not necessarily designed specifically to protect patients with asthma. Direct measurement of a bioaerosol is not generally necessary for practical applications where the relevant source of the bioaerosol has been identified. Different types of bioaerosols can be controlled with similar strategies that prioritize source control (eg, reducing resuspension, integrated pest management, controlling moisture), and these can be supplemented by enhancing air filtration. The goal of this review is to summarize the latest information on bioaerosols, including allergens, fungi, bacteria, and viruses, that have been associated with adverse asthma outcomes and to discuss mitigation options.

Antiviral roles of eosinophils in asthma and respiratory viral infection

Eosinophils are immune cells that are crucial for the pathogenesis of allergic diseases, such as asthma. These cells play multifunctional roles in various situations, including infection. They are activated during viral infections and exert antiviral activity. Pattern recognition receptors, toll-like receptor 7 and retinoic acid inducible gene-I, are important for the recognition and capture of RNA viruses. In addition, intracellular granule proteins (eosinophil cationic protein and eosinophil-derived neurotoxin) and intracellular nitric oxide production inactivate and/or degrade RNA viruses. Interestingly, eosinophil-synthesizing specialized pro-resolving mediators possess antiviral properties that inhibit viral replication. Thus, eosinophils may play a protective role during respiratory virus infections. Notably, antiviral activities are impaired in patients with asthma, and eosinophil activities are perturbed in proportion with the severity of asthma. The exact roles of eosinophils in RNA virus (rhinovirus, respiratory syncytial virus, and influenza virus)-induced type 2 inflammation-based asthma exacerbation remain unclear. Our research demonstrates that interferons (IFN-α and IFN-γ) stimulate human eosinophils to upregulate antiviral molecules, including guanylate-binding proteins and tripartite motifs. Furthermore, IFN-γ specifically increases the expression of IL5RA, ICAM-1, and FCGR1A, potentially enhancing cellular responsiveness to IL-5, ICAM-1-mediated adhesion to rhinoviruses, and IgG-induced inflammatory responses, respectively. In this review, we have summarized the relationship between viral infections and asthma and the mechanisms underlying the development of antiviral functions of human and mouse eosinophils in vivo and in vitro.

The Association Between Respiratory Viruses and Asthma Exacerbation in Children Visiting Pediatric Emergency Department: A Retrospective Cohort Study

Background/Objectives: Respiratory viral infections are a major cause of asthma exacerbations. However, studies examining the association between symptoms, signs, treatments, outcomes of asthma exacerbations, and various respiratory viruses in children are limited. This study aims to investigate the association between respiratory viral infections and clinical symptoms and signs, treatment, and hospital admission in children with asthma exacerbations visiting the pediatric emergency department. Methods: This study examined 395 children under 15 years of age who had a previous diagnosis of bronchial asthma, experienced asthma exacerbation, and visited an emergency center between 1 July 2015 and 30 June 2017. Among the 395 participants, respiratory virus polymerase chain reaction (PCR) was conducted in 96 patients (24.3%). The symptoms and signs of asthma exacerbation (dyspnea, tachypnea, chest retraction, wheezing, and gastrointestinal symptoms), treatment (oxygen supplementation and systemic steroid administration), symptom relief within 1 h, and hospital admission were analyzed. Results: Among the 96 patients who underwent respiratory virus PCR, at least one respiratory virus was detected in 72 (75.0%), and over two viruses were detected in 21 children (21.9%). Three common viruses were detected: rhinovirus in 59 (61.5%), adenovirus in 10 (10.4%), and respiratory syncytial virus (RSV) in nine children (9.4%). Rhinovirus infection was associated with tachypnea (adjusted odd ratio (aOR) 4.457, p = 0.007), chest retraction (aOR 3.142, p = 0.013), and systemic steroid administration (aOR 3.065, p = 0.034). Adenovirus infection was associated with oxygen supplementation via nasal cannula (aOR 5.297, p = 0.042). Conclusions: Rhinovirus was associated with tachypnea, chest retraction, and systemic steroid administration, while adenovirus was linked to oxygen supplementation in childhood asthma exacerbations. These findings will help clinicians to better observe asthma symptoms, select appropriate treatments, and improve outcomes for asthma exacerbations.

Association between cadherin-related family member 3 rs6967330-A and human rhinovirus-C induced wheezing in children

BACKGROUND

The heterogeneity of childhood wheezing illnesses is associated with viral and host factors. Human rhinoviruses (HRV) are the major pathogens in severe wheezing in young children. The single nucleotide polymorphism (SNP) rs6967330 G > A proved to heighten the risk of wheezing. However, the relation between rs6967330 variants of cadherin-related family member 3 (CDHR3) and wheezing induced by human rhinovirus (HRV)-C has not been determined.

METHODS

A total of 11,756 respiratory specimens collected from hospitalized children with acute respiratory infections (ARIs) between September 2017 and March 2023 were screened for enterovirus (EV)/HRVs by the capillary electrophoresis-based multiplex PCR (CEMP) assay, and those positive only for HRVs were amplified and sequenced for HRV and CDHR3 genotyping. The clinical data of the enrolled patients were obtained and analyzed.

RESULTS

EV/HRVs (15.2%; 1,616/10,608) were the more common viruses detected in inpatients with ARIs. Among the enrolled samples, 148 were positive for HRV-A (49.83%; 148/297), 129 for HRV-C (43.4%; 129/297), and 20 for HRV-B (6.7%; 20/297). More patients infected with HRV-C had history of allergy (P = 0.004), family history of asthma (P = 0.001), wheezing (P = 0.005) and asthma (P = 0.001) than those infected with HRV-A or HRV-B, while patients infected with HRV-C were less likely to have older siblings compared to those infected with HRV-A (P = 0.014). The rs6967330-A variant was related to a high incidence of the three concave signs (P = 0.047), asthma exacerbation (P = 0.025), a higher risk of HRV-C infection determined by the dominant model (OR 1.91, 95% confidence interval 1.05-3.48; P = 0.033), and a high proportion of wheezing (56.67%) in patients infected with HRV-C.

CONCLUSIONS

HRV-C is the dominant species responsible for HRV-induced wheezing. The rs6967330-A variant is a risk factor for HRV-C infection, and was associated with the high rate of wheezing induced by HRV-C.

Infection of Immature Mice with Rhinovirus for the Study of Asthma Pathogenesis

Early-life wheezing-associated respiratory infection with rhinovirus (RV) is a risk factor for asthma development in combination with allergen sensitization and family history. RV infection of immature mice is a useful model to decipher potential immunological mechanisms underlying asthma development following RV infection. Increased type 2 immune response, expansion of group 2 innate lymphoid cells (ILC2s), eosinophilic inflammation, mucous metaplasia, and airway hyperresponsiveness have been observed in RV-infected six-day-old mice. Herein, we present several materials and methods used for propagating and partially purifying RV, measuring RV titers, infecting immature mice with RV, and harvesting lung tissue for whole lung mRNA extraction and flow cytometry.

Viral Determinants of Childhood Asthma Exacerbation Severity and Treatment Response

BACKGROUND

Although respiratory viruses are common triggers of asthma exacerbations, the influence of viral infection characteristics on exacerbation presentation and treatment response in the pediatric emergency department (ED) is unclear.

OBJECTIVE

To assess viral infection characteristics of children experiencing ED asthma exacerbations and to test their associations with severity and treatment response.

METHODS

This is a prospective study of children, aged 4 to 18 years, who received standard ED asthma exacerbation treatment with inhaled bronchodilators and systemic corticosteroids. Nasal swabs collected for viral metagenomic analyses determined virus presence, load, and species. Outcomes included exacerbation severity (Pediatric Asthma Severity [PAS] score, clinician impression, and vital signs) and treatment response (discharge home without needing additional asthma therapies).

RESULTS

Of 107 children, 47% had moderate/severe exacerbations by PAS and 64% demonstrated treatment response. Viral metagenomic analysis on nasal swabs from 73 children detected virus in 86%, with 10 different species identified, primarily rhinovirus A (RV-A), RV-C, and enterovirus D68. Exacerbations involving RV-A were milder (odds ratio [OR] = 0.25; 95% confidence interval [CI] = 0.07-0.83) and tended to be more responsive to treatment than non-RV-A infections, whereas exacerbations involving enterovirus D68 were more severe (OR = 8.3; 95% CI = 1.3-164.7) and had no treatment response association. Viral load was not associated with treatment response but exhibited a strong linear relationship with heart rate (rpartial = 0.48), respiratory rate (rpartial = 0.25), and oxygen saturation (rpartial = -0.25), indicative of severity.

CONCLUSIONS

The majority of ED asthma exacerbations are triggered by respiratory viruses. Viral species are associated with severity and treatment response, suggesting that early pathogen detection could inform ED treatment decisions. Additional studies are needed to identify differences in pathobiology underlying exacerbations triggered by different viral species, and how to effectively treat these heterogeneous exacerbations.

Indoor allergen exposure and its association to upper respiratory infections and pulmonary outcomes among children with asthma

BACKGROUND

Certain environmental allergen exposures are more common in disadvantaged communities and may contribute to differences in susceptibility to upper respiratory infections (URIs).

OBJECTIVES

We examined associations between indoor allergens and: (1) URI; (2) URI + cold symptoms; (3) URI + cold symptoms + pulmonary eosinophilic inflammation (fraction of exhaled nitric oxide ≥20 ppb); and (4) URI + cold symptoms + reduced lung function (percent predicted forced expiratory volume in 1 second of <80%).

METHODS

We used data from the Environmental Control as Add-on Therapy for Childhood Asthma (ECATCh) study. Allergen concentrations were measured in air (mouse) and settled dust (mouse, cockroach, dog, and cat). URI was determined by testing nasal mucus for upper respiratory viruses. We evaluated associations between allergen concentrations and URI-associated outcomes accounting for age, sex, study month, season, health insurance, and household size.

RESULTS

Ninety participants (92% Black, 92% public insurance) with 192 observations were included; 52 (27%) of observations were positive for URI. A doubling in cockroach allergen concentration increased the odds of a URI with cold symptoms by 18% (odds ratio [OR] = 1.18, 95% confidence interval [CI], 0.99-1.40), the odds of a URI + cold symptoms + pulmonary eosinophilic inflammation by 31% (OR = 1.31, 95% CI, 1.10-1.57), and the odds of a URI + cold symptoms + reduced lung function by 45% (OR = 1.45, 95% CI, 1.13-1.85). Mouse allergen concentrations were positively associated with all outcomes. Associations were suggestively stronger among children sensitized to pest allergens.

CONCLUSIONS

Cockroach and mouse, but not dog or cat, allergen exposure may predispose children with asthma to URIs with colds and lower respiratory outcomes.

Does lung function in preschoolers help to predict asthma in later life?

The earliest respiratory function assessments, within or close to the neonatal period, consistently show correlations with lung function and with the development of asthma into adulthood. Measurements of lung function in infancy reflect the in utero period of lung development, and if early enough, show little influence of postnatal environmental exposures. Later in the preschool and school age periods, influences of the environment are superimposed on initial levels. Fetal exposures before birth such as maternal smoking during pregnancy, lead to reduced lung function and an increased risk of asthma in females particularly those with certain glutathione S-transferase genotypes. Lung function measurements later in the preschool period are also associated with development of asthma. Although lung function in preschoolers does help predict asthma in later life and these observations have increased our understanding of the physiology underlying asthma, the findings have not led to thewidespread use of lung function measurements being in preschoolers as clinical predictors of asthma due to the practicalities of testing in this age group.

Cilomilast Modulates Rhinovirus-Induced Airway Epithelial ICAM-1 Expression and IL-6, CXCL8 and CCL5 Production

Background: Cilomilast, a phosphodiesterase-4 (PDE4) selective inhibitor, has anti-inflammatory effects in vitro and in vivo and reduces COPD exacerbations. We tested the hypothesis that cilomilast inhibits virus-induced airway epithelial intercellular adhesion molecule-1 (ICAM-1) expression and inflammatory cytokine/chemoattractants, IL-6, CXCL8, and CCL5 production in vitro. Methods: BEAS-2B bronchial epithelial cells were incubated with 0.5-2 MOI (multiplicity of infection-infectious units/cell) of rhinovirus 16 (RV16). Then, 0.1-10 μM cilomilast or 10 nM dexamethasone, as inhibition control, were added pre- or post-1 h RV16 infection. Supernatant and cells were sampled at 8, 24, 48, and 72 h after infection. Cell surface ICAM-1 expression was detected by immunogold labelling and visualised by high-resolution scanning electron microscopy (HR-SEM), while IL-6, CXCL8, and CCL5 protein release and mRNA expression were measured using an ELISA and RT-PCR. Results: Cilomilast significantly decreased RV16-induced ICAM-1 expression to approximately 45% (p < 0.01). CXCL8 protein/mRNA production was reduced by about 41% (p < 0.05), whereas IL-6 protein/mRNA production was increased to between 41-81% (p < 0.001). There was a trend to reduction by cilomilast of RV16-induced CCL5. Conclusions: Cilomilast has differential effects on RV16-induced ICAM-1 and interleukins, inhibiting virus-induced ICAM-1 expression and CXCL8 while increasing IL-6 production. These in vitro effects may help to explain the beneficial actions of this PDE4 inhibitor in vivo.

Rhinovirus as a Driver of Airway T-Cell Dynamics in Children with Severe Asthma

Severe asthma in children is notoriously difficult to treat, and its immunopathogenesis is complex. In particular, the contribution of T cells and relationships to anti-viral immunity, remain enigmatic. Here, we coupled deep phenotyping with machine learning methods to resolve the dynamics of T cells in the diseased lower airways, and examined rhinovirus (RV) as a driver. Our strategy revealed a T-cell landscape dominated by type 1 and type 17 CD8+ signatures. Interrogation of phenotypic relationships coupled with trajectory mapping identified T-cell migratory and differentiation pathways spanning the blood and airways that culminated in tissue residency, and included transitions between type 1 and type 17 tissue-resident types. These T-cell dynamics were reflected in cytokine polyfunctionality in situ . Use of machine learning to cross-compare T-cell populations that were enriched in the airways of RV-positive children with those induced in the blood after RV challenge in an experimental infection model, precisely pinpointed RV-responsive signatures that mapped to T-cell differentiation pathways. Despite their rarity, these signatures were detected in the airways of uninfected children. Together, our results underscore the aberrant nature of type 1 immunity in the airways of children with severe asthma, and implicate an important viral trigger as a driver.

Bronchomotor tone imbalance evokes airway hyperresponsiveness

INTRODUCTION

Obstructive airway diseases asthma and COPD represent a significant healthcare burden. Airway hyperresponsiveness (AHR), a salient feature of these two diseases, remains the main therapeutic target. Airway smooth muscle (ASM) cell is pivotal for bronchomotor tone and development of AHR in airway diseases. The contractile and relaxation processes in ASM cells maintain a homeostatic bronchomotor tone. It is critical to understand the molecular mechanisms that disrupt the homeostasis to identify novel therapeutic strategies for AHR.

AREAS COVERED

Based on review of literature and published findings from our laboratory, we describe intrinsic and extrinsic factors - disease phenotype, toxicants, inflammatory/remodeling mediators- that amplify excitation-contraction (E-C) coupling and ASM shortening and or diminish relaxation to alter bronchomotor homeostasis. We posit that an understanding of the ASM mechanisms involved in bronchomotor tone imbalance will provide platforms to develop novel therapeutic approaches to treat AHR in asthma and COPD.

EXPERT OPINION

Contractile and relaxation processes in ASM cell are modulated by intrinsic and extrinsic factors to elicit bronchomotor tone imbalance. Innovative experimental approaches will serve as essential tools for elucidating the imbalance mechanisms and to identify novel therapeutic targets for AHR.

Developing a mouse model of human coronavirus NL63 infection: comparison with rhinovirus-A1B and effects of prior rhinovirus infection

Human coronavirus (HCoV)-NL63 causes respiratory tract infections in humans and uses angiotensin-converting enzyme 2 (ACE2) as a receptor. We sought to establish a mouse model of HCoV-NL63 and determine whether prior rhinovirus (RV)-A1B infection affected HCoV-NL63 replication. HCoV-NL63 was propagated in LLC-MK2 cells expressing human ACE2. RV-A1B was grown in HeLa-H1 cells. C57BL6/J or transgenic mice expressing human ACE2 were infected intranasally with sham LLC-MK2 cell supernatant or 1 × 105 tissue culture infectious dose (TCID50) units HCoV-NL63. Wild-type mice were infected with 1 × 106 plaque-forming units (PFU) RV-A1B. Lungs were assessed for vRNA, bronchoalveolar lavage (BAL) cells, histology, HCoV-NL63 nonstructural protein 3 (nsp3), and host gene expression by next-generation sequencing and qPCR. To evaluate sequential infections, mice were infected with RV-A1B followed by HCoV-NL63 infection 4 days later. We report that hACE2 mice infected with HCoV-NL63 showed evidence of replicative infection with increased levels of vRNA, BAL neutrophils and lymphocytes, peribronchial and perivascular infiltrates, and expression of nsp3. Viral replication peaked 3 days after infection and inflammation persisted 6 days after infection. HCoV-NL63-infected hACE2 mice showed increased mRNA expression of IFNs, IFN-stimulated proteins, and proinflammatory cytokines. Infection with RV-A1B 4 days before HCoV-NL63 significantly decreased both HCoV-NL63 vRNA levels and airway inflammation. Mice infected with RV-A1B prior to HCoV-NL63 showed increased expression of antiviral proteins compared with sham-treated mice. In conclusion, we established a mouse model of HCoV-NL63 replicative infection characterized by relatively persistent viral replication and inflammation. Prior infection with RV-A1B reduced HCoV-NL63 replication and airway inflammation, indicative of viral interference.NEW & NOTEWORTHY We describe a mouse model of human coronavirus (HCoV) infection. Infection of transgenic mice expressing human angiotensin-converting enzyme 2 (ACE2) with HCoV-NL63 produced a replicative infection with peribronchial inflammation and nonstructural protein 3 expression. Mice infected with RV-A1B 4 days before HCoV-NL63 showed decreased HCoV-NL63 replication and airway inflammation and increased expression of antiviral proteins compared with sham-treated mice. This research may shed light on human coronavirus infections, viral interference, and viral-induced asthma exacerbations.

Clinical Characteristics of Pediatric Parainfluenza Virus Infections: A Comparative Analysis of Parainfluenza Virus Serotypes 1-4 From April 2021 to October 2023 in Hokkaido, Japan

BACKGROUND

Parainfluenza virus (PIV) is widely known as a causative virus of acute respiratory tract infections in children, and 4 serotypes (PIV-1-PIV-4) have been identified. The purpose of the present study was to clarify the clinical characteristics of the PIV serotypes in pediatric PIV infections in Japan.

METHODS

Between April 2021 and October 2023, 8821 children aged <16 years who presented with respiratory symptoms underwent multiplex polymerase chain reaction analyses at the Department of Pediatrics, NTT Medical Center Sapporo. All 1490 cases in which PIV was detected were analyzed for their clinical characteristics by PIV serotypes.

RESULTS

Of the 1490 cases, 608 were positive for a single PIV serotype: 91 (13.5%) for PIV-1, 54 (4.8%) for PIV-2, 361 (62.1%) for PIV-3 and 102 (19.6%) for PIV-4. The median ages were 3.5 years for PIV-1, 5.4 years for PIV-2, 1.9 years for PIV-3 and 2.2 years for PIV-4, with a significantly older age for PIV-2. Compared with the other serotypes, croup was significantly more common in PIV-1 and lower respiratory tract infection was significantly more common in PIV-4. Of the 608 cases with a single PIV serotype, 114 were hospitalized. The proportion of hospitalized patients was higher for PIV-4 than for the other PIV serotypes, but the difference was not significant.

CONCLUSIONS

Lower respiratory tract infection was more frequent in PIV-4 than in the other PIV serotypes, and PIV-4 infection may increase the risk of hospitalization.

Membrane lipid composition of bronchial epithelial cells influences antiviral responses during rhinovirus infection

Lipids and their mediators have important regulatory functions in many cellular processes, including the innate antiviral response. The aim of this study was to compare the lipid membrane composition of in vitro differentiated primary bronchial epithelial cells (PBECs) with ex vivo bronchial brushings and to establish whether any changes in the lipid membrane composition affect antiviral defense of cells from donors without and with severe asthma. Using mass spectrometry, we showed that the lipid membrane of in vitro differentiated PBECs was deprived of polyunsaturated fatty acids (PUFAs) compared to ex vivo bronchial brushings. Supplementation of the culture medium with arachidonic acid (AA) increased the PUFA-content to more closely match the ex vivo membrane profile. Rhinovirus (RV16) infection of AA-supplemented cultures from healthy donors resulted in significantly reduced viral replication while release of inflammatory mediators and prostaglandin E2 (PGE2) was significantly increased. Indomethacin, an inhibitor of prostaglandin-endoperoxide synthases, suppressed RV16-induced PGE2 release and significantly reduced CXCL-8/IL-8 release from AA-supplemented cultures indicating a link between PGE2 and CXCL8/IL-8 release. In contrast, in AA-supplemented cultures from severe asthmatic donors, viral replication was enhanced whereas PTGS2 expression and PGE2 release were unchanged and CXCL8/IL-8 was significantly reduced in response to RV16 infection. While the PTGS2/COX-2 pathway is initially pro-inflammatory, its downstream products can promote symptom resolution. Thus, reduced PGE2 release during an RV-induced severe asthma exacerbation may lead to prolonged symptoms and slower recovery. Our data highlight the importance of reflecting the in vivo lipid profile in in vitro cell cultures for mechanistic studies.

Analysis of exacerbating factors of pediatric asthma before and after the COVID-19 pandemic

Purpose

The incidence of the existing respiratory virus and air pollutants had disappeared or decreased due to social distancing during the coronavirus disease 2019 (COVID-19) pandemic. Therefore, there was no increase in asthma exacerbations in 2020. This study aimed to analyze the emergency department (ED) visits of children and adolescent patients with asthma before and after the COVID-19 outbreak and examine the effects of respiratory virus infection and air pollutants.

Methods

This study included pediatric and adolescent patients with asthma aged 2-18 years who visited 419 EDs nationwide during February to December in 2018, 2019, and 2020. The patients who were diagnosed with asthma, ie, J45 or J46 (International Classification of Diseases, 10th revision) in the ED medical history, diagnosis history at discharge, and diagnosis at discharge after hospitalization through the ED were included using the National Emergency Department Information System. Data were analyzed by dividing the period as follows: pre-COVID-19 (from February to December 2018 and 2019) and COVID-19 pandemic (from February to December 2020).

Results

The monthly average of 673 visiting patients (95% confidence interval [CI], 474-872) during the pre-COVID-19 period decreased to 176 (95% CI, 113-239) during the COVID-19 pandemic, which is a 73.8% decrease (p < 0.001).In the pre-COVID-19 period, peaks were observed in spring and autumn. Meanwhile, during the COVID-19 pandemic, a peak was observed only during autumn. During the COVID-19 pandemic, no relationship was found between the rhinovirus infection and asthma exacerbations (p < 0.001).

Conclusions

Respiratory virus infections are strongly associated with asthma exacerbations in children and adolescents. In this study, air pollution is not a major factor for ER visits due to asthma exacerbations. Even though the prevalence of respiratory viruses is decreasing, ED visits due to worsening asthma are trending in the fall. This phenomenon may indicate that asthma has worsened due to other causes such as pollen or fluctuations in temperature and air pressure.

Genetic predisposition to high BMI increases risk of early life respiratory infections and episodes of severe wheeze and asthma

BACKGROUND

High body mass index (BMI) is an established risk factor for asthma, but the underlying mechanisms remain unclear.

OBJECTIVE

To increase understanding of the BMI-asthma relationship by studying the association between genetic predisposition to higher BMI and asthma, infections and other asthma traits during childhood.

METHODS

Data were obtained from the two ongoing Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) mother-child cohorts. Polygenic risk scores for adult BMI were calculated for each child. Replication was done in the large-scale register-based Integrative Psychiatric Research (iPSYCH) cohort using data on hospitalisation for asthma and infections.

RESULTS

In the COPSAC cohorts (n=974), the adult BMI polygenic risk score was significantly associated with lower respiratory tract infections (incidence rate ratio (IRR) 1.20, 95% CI 1.08-1.33, false discovery rate p-value (pFDR)=0.005) at age 0-3 years and episodes of severe wheeze (IRR 1.30, 95% CI 1.06-1.60, pFDR=0.04) at age 0-6 years. Lower respiratory tract infections partly mediated the association between the adult BMI polygenic risk score and severe wheeze (proportion mediated: 0.59, 95% CI 0.28-2.24, p-value associated with the average causal mediation effect (pACME)=2e-16). In contrast, these associations were not mediated through the child's current BMI and the polygenic risk score was not associated with an asthma diagnosis or reduced lung function up to age 18 years. The associations were replicated in iPSYCH (n=114 283), where the adult BMI polygenic risk score significantly increased the risk of hospitalisations for lower respiratory tract infections and wheeze or asthma throughout childhood to age 18 years.

CONCLUSION

Children with genetic predisposition to higher BMI had increased risk of lower respiratory tract infections and severe wheeze, independent of the child's current BMI. These results shed further light on the complex relationship between body mass BMI and asthma.

A novel syndrome of silent rhinovirus-associated bronchoalveolitis in children with recurrent wheeze

BACKGROUND

Rhinovirus (RV) infections trigger wheeze episodes in children. Thus, understanding of the lung inflammatory response to RV in children with wheeze is important.

OBJECTIVES

This study sought to examine the associations of RV on bronchoalveolar lavage (BAL) granulocyte patterns and biomarkers of inflammation with age in children with treatment-refractory, recurrent wheeze (n = 616).

METHODS

Children underwent BAL to examine viral nucleic acid sequences, bacterial cultures, granulocyte counts, and phlebotomy for both general and type-2 inflammatory markers.

RESULTS

Despite the absence of cold symptoms, RV was the most common pathogen detected (30%), and when present, was accompanied by BAL granulocytosis in 75% of children. Compared to children with no BAL pathogens (n = 341), those with RV alone (n = 127) had greater (P < .05) isolated neutrophilia (43% vs 16%), mixed eosinophils and neutrophils (26% vs 11%), and less pauci-granulocytic (27% vs 61%) BAL. Children with RV alone furthermore had biomarkers of active infection with higher total blood neutrophils and serum C-reactive protein, but no differences in blood eosinophils or total IgE. With advancing age, the log odds of BAL RV alone were lower, 0.82 (5th-95th percentile CI: 0.76-0.88; P < .001), but higher, 1.58 (5th-95th percentile CI: 1.01-2.51; P = .04), with high-dose daily corticosteroid treatment.

CONCLUSIONS

Children with severe recurrent wheeze often (22%) have a silent syndrome of lung RV infection with granulocytic bronchoalveolitis and elevated systemic markers of inflammation. The syndrome is less prevalent by school age and is not informed by markers of type-2 inflammation. The investigators speculate that dysregulated mucosal innate antiviral immunity is a responsible mechanism.

Viral respiratory infections requiring hospitalization in early childhood related to subsequent asthma onset and exacerbation risks

Viral lower respiratory tract infections (LRTIs), including rhinovirus and respiratory syncytial virus during early childhood, have been linked to subsequent asthma. However, the impact of other respiratory viruses remains unclear. We analyzed nationwide Korean data from January 1, 2008, to December 31, 2018, utilizing the national health insurance database. Our study focused on 19 169 meticulously selected children exposed to severe respiratory infections requiring hospitalization with documented viral pathogens, matched with 191 690 unexposed children at a ratio of 1:10 using incidence density sampling. Our findings demonstrate that asthma exacerbation rates were higher among the exposed cohort than the unexposed cohort over a mean follow-up of 7.8 years. We observed elevated risks of asthma exacerbation and newly developed asthma compared to the unexposed cohort. Hospitalization due to rhinovirus, respiratory syncytial virus, influenza, metapneumovirus, and adenovirus was related to increased asthma exacerbations. Notably, we found a stronger association in cases of multiple LRTI hospitalizations. In conclusion, our study shows that early childhood respiratory viral infections are related to subsequent asthma exacerbations and new asthma diagnoses.

Patterns of asthma medication use and hospital discharges in New Zealand

Background

In New Zealand a progressive increase in budesonide/formoterol dispensing, accompanied by a reduction in dispensing of short-acting β2-agonists (SABAs), inhaled corticosteroids (ICSs), and other ICS/long-acting β2-agonists (ICSs/LABAs), occurred in the 18-month period following publication of the 2020 New Zealand asthma guidelines, which recommended budesonide/formoterol anti-inflammatory reliever therapy.

Objective

Our aim was to investigate more recent trends in asthma medication use and asthma hospital discharges in New Zealand.

Methods

New Zealand national dispensing data for inhalers for the period from January 2010 to December 2022 were reviewed for patients aged 12 years and older. Monthly rates of dispensing of budesonide/formoterol, ICSs, other ICS/LABAs, and SABAs were displayed graphically by locally weighted scatterplot smoother plots. The rates of dispensing and hospital discharge for asthma were compared between the past 6 months for which dispensing data were available (July-December 2022) and the corresponding period from July to December 2019.

Results

There has been a progressive increase in dispensing of budesonide/formoterol since 2019, with a 108% increase between the period from July to December 2019 and the period from July to December 2022 in adolescents and adults. In contrast, there was a reduction in rates of dispensing of other ICS/LABAs, ICSs, and SABAs by 3%, 18%, and 5%, respectively. During this period, there was a 17% reduction in hospital discharges for asthma.

Conclusion

There has been a further widespread uptake of ICS/formoterol reliever and/or maintenance therapy in adolescents and adults with asthma in New Zealand. The changes in prescribing practice have been temporally associated with a reduction in hospital admissions for asthma.

Distinguishing Childhood Asthma Exacerbations from Stable Asthma: The Utility of Inflammatory White Blood Cell Biomarkers

BACKGROUND

Asthma is a chronic inflammatory condition characterized by episodes of acute asthma exacerbations (AAEs), in addition to chronic airway inflammation, which has a huge impact on both the affected patients and their parents. The main objective of this study was to explore the utility of available white-blood-cell-derived inflammatory markers in diagnosing AAEs and identifying children at risk for severe exacerbations requiring admission to the pediatric intensive care unit (PICU).

METHODS

This study was a retrospective cohort study. The medical records of 128 children diagnosed with asthma exacerbation and 131 children with stable asthma between the ages of 2 and 12 years were reviewed.

RESULTS

A total of 259 participants were enrolled. Children with AAE demonstrated significantly higher white blood cell counts (WBC: 10.0 ± 4.2 × 103/μL vs. 7.1 ± 2.2 × 103/μL, p < 0.001), absolute neutrophil counts (ANC: 7398.5 ± 4600 cells/μL vs. 2634.8 ± 1448 cells/μL, p < 0.001), and neutrophil-to-lymphocyte ratios (NLR: 7.0 ± 6.8 vs. 0.9 ± 0.7, p < 0.001) but significantly lower absolute lymphocyte counts (ALC: 1794.1 ± 1536 × 103/μL vs. 3552.9 ± 1509 × 103/μL, p < 0.001). Interestingly, blood eosinophil count displayed an opposite trend: children with stable asthma had significantly more eosinophils compared to those experiencing an exacerbation (370.1 ± 342.7 cells/mm3 vs. 0.9 ± 1.9 cells/mm3, p < 0.001). Two criteria that are indicative of AAE were identified: NLR values greater than 1.2, with good discriminative ability (area under the curve [AUC] 0.90; 95% confidence interval [CI] 0.85-0.94; sensitivity 82.5%; specificity 79.5%), and ANC values exceeding 3866, with moderate discriminative ability (AUC 0.86; 95% CI 0.81-0.91; sensitivity 75.0%; specificity 82.3%). Moreover, a comparative analysis of these markers (NLR, ANC, PLR, WBC, AEC, and ALC) in patients with AAE did not demonstrate significant differences between those requiring PICU admission and those who did not require it.

CONCLUSIONS

This study contributes two major findings. The first is that NLR, ANC, WBC, and PLR are significantly higher in AAE patients compared to those with stable asthma. The second is that children with stable asthma have higher AEC and ALC levels compared to those with AAE. Furthermore, this study has revealed that the studied markers (NLR, ANC, PLR, WBC, AEC, and ALC) did not differentiate between AAE patients requiring PICU admission and those managed in the general ward, suggesting a need for alternative predictive factors.

Building a human lung from pluripotent stem cells to model respiratory viral infections

To protect against the constant threat of inhaled pathogens, the lung is equipped with cellular defenders. In coordination with resident and recruited immune cells, this defence is initiated by the airway and alveolar epithelium following their infection with respiratory viruses. Further support for viral clearance and infection resolution is provided by adjacent endothelial and stromal cells. However, even with these defence mechanisms, respiratory viral infections are a significant global health concern, causing substantial morbidity, socioeconomic losses, and mortality, underlining the need to develop effective vaccines and antiviral medications. In turn, the identification of new treatment options for respiratory infections is critically dependent on the availability of tractable in vitro experimental models that faithfully recapitulate key aspects of lung physiology. For such models to be informative, it is important these models incorporate human-derived, physiologically relevant versions of all cell types that normally form part of the lungs anti-viral response. This review proposes a guideline using human induced pluripotent stem cells (iPSCs) to create all the disease-relevant cell types. iPSCs can be differentiated into lung epithelium, innate immune cells, endothelial cells, and fibroblasts at a large scale, recapitulating in vivo functions and providing genetic tractability. We advocate for building comprehensive iPSC-derived in vitro models of both proximal and distal lung regions to better understand and model respiratory infections, including interactions with chronic lung diseases.

Effects of Nasal Solution Incorporating Resveratrol and Carboxymethyl-Β-Glucan in Preschool Non-Atopic Children with Wheezing

Upper respiratory tract infections (URTI) account for more than 80% of wheezing episodes in children with a high incidence of hospitalization in preschool age. Most children with symptoms of wheezing during an URTI are usually non-atopic. As the majority of wheezing episodes resulting from URTI are attributed to viral triggers, several studies have suggested the potential anti-inflammatory and antiviral properties of resveratrol. This study aims to identify the effect of resveratrol for pediatric non-atopic patients with recurrent wheezing triggered by URTIs. We conducted a prospective single-blind study to assess the effectiveness of a short course of nasal solutions incorporating resveratrol and carboxymethyl-β-glucan, administered for 7 days at the onset of URTIs, compared to standard nasal lavage with 0.9% saline solution. A total of 19 patients entered the active group, 20 patients were assigned to the placebo group. The comparison of overall wheezing days (p < 0.001), mean wheezing days per month (p < 0.01), and wheezing episodes per patient (p < 0.001) in the two groups showed a significant reduction in the group receiving resveratrol compared with the placebo group, with less hospital access (p < 0.001) and oral corticosteroid administration (p < 0.01). Our findings seem to suggest that, in non-atopic children with recurrent wheezing secondary to URTIs, nasal resveratrol could be effective to prevent or reduce the occurrence of wheezing, when started from the onset of upper airway symptoms.

Evolution and the critical role of the microbiota in the reduced mental and physical health associated with low socioeconomic status (SES)

The evolution of the gut-microbiota-brain axis in animals reveals that microbial inputs influence metabolism, the regulation of inflammation and the development of organs, including the brain. Inflammatory, neurodegenerative and psychiatric disorders are more prevalent in people of low socioeconomic status (SES). Many aspects of low SES reduce exposure to the microbial inputs on which we are in a state of evolved dependence, whereas the lifestyle of wealthy citizens maintains these exposures. This partially explains the health deficit of low SES, so focussing on our evolutionary history and on environmental and lifestyle factors that distort microbial exposures might help to mitigate that deficit. But the human microbiota is complex and we have poor understanding of its functions at the microbial and mechanistic levels, and in the brain. Perhaps its composition is more flexible than the microbiota of animals that have restricted habitats and less diverse diets? These uncertainties are discussed in relation to the encouraging but frustrating results of attempts to treat psychiatric disorders by modulating the microbiota.

Novel synthesis of the first new class of triazine sulfonamide thioglycosides and the evaluation of their anti-tumor and anti-viral activities against human coronavirus

Novel class of triazine sulfonamide thioglycosides was designed and synthesized. Those novel structures comprising three essential and pharmacological significant moieties such as the triazine, sulfonamide, and thioglycosidic scaffolds. The triazine sulfonamides were furnished via a direct approach starting from potassium cyanocarbonimidodithioate, then the corresponding triazine sulfonamide thioglycosides were generated using the peracylated α-d-gluco- and galacto-pyranosyl bromides. Anti-viral evaluation of compounds in vitro against HCoV-229E virus revealed that some compounds possess promising activity. Compounds 4a, 4b, 4d, 6d and 6e indicate from moderate to low antiviral activity against low pathogenic coronavirus 229E in comparison with remdesivir at a concentration of 100 µg/mL. Additionally their in vitro anti-proliferative effects against NCI 60 cancer cell lines cell lines were also investigated. Compound 4a, the most potent compound among the estimated compounds, revealed remarkably lowest cell growth promotion against CNS cancer SNB-75, and renal cancer UO-31.

17q21 Variants Disturb Mucosal Host Defense in Childhood Asthma

Rationale: The strongest genetic risk factor for childhood-onset asthma, the 17q21 locus, is associated with increased viral susceptibility and disease-promoting processes.Objectives: To identify biological targets underlying the escalated viral susceptibility associated with the clinical phenotype mediated by the 17q21 locus.Methods: Genome-wide transcriptome analysis of nasal brush samples from 261 children (78 healthy, 79 with wheezing at preschool age, 104 asthmatic) within the ALLIANCE (All-Age-Asthma) cohort, with a median age of 10.0 (range, 1.0-20.0) years, was conducted to explore the impact of their 17q21 genotype (SNP rs72163891). Concurrently, nasal secretions from the same patients and visits were collected, and high-sensitivity mesoscale technology was employed to measure IFN protein levels.Measurements and Main Results: This study revealed that the 17q21 risk allele induces a genotype- and asthma/wheeze phenotype-dependent enhancement of mucosal GSDMB expression as the only relevant 17q21-encoded gene in children with preschool wheeze. Increased GSDMB expression correlated with the activation of a type-1 proinflammatory, cell-lytic immune, and natural killer signature, encompassing key genes linked to an IFN type-2-signature (IFNG, CXCL9, CXCL10, KLRC1, CD8A, GZMA). Conversely, there was a reduction in IFN type 1 and type 3 expression signatures at the mRNA and protein levels.Conclusions: This study demonstrates a novel disease-driving mechanism induced by the 17q21 risk allele. Increased mucosal GSDMB expression is associated with a cell-lytic immune response coupled with compromised airway immunocompetence. These findings suggest that GSDMB-related airway cell death and perturbations in the mucosal IFN signature account for the increased vulnerability of 17q21 risk allele carriers to respiratory viral infections during early life, opening new options for future biological interventions.The All-Age-Asthma (ALLIANCE) cohort is registered at www.clinicaltrials.gov (pediatric arm, NCT02496468).

Asthma-community acquired pneumonia co-diagnosis in children: a scoping review

OBJECTIVE

This scoping review investigated the existing literature and identified the evidence gaps related to diagnosis and management in children aged 2-18 years presenting to hospitals with a co-diagnosis of asthma and community-acquired pneumonia.

DATA SOURCES

We designed a scoping review following Arksey and O'Malley's scoping review framework and PRISMA extension for a scoping review. We searched literature using five electronic databases: PubMed, CINAHL, Scopus, Web of Science, and Embase from 2003 to June 2023.

RESULTS

A total of 1599 abstracts with titles were screened and 12 abstracts were selected for full review. Separate guidelines including Modified Global Initiative for Asthma (GINA) guidelines; modified Integrated Management of Childhood Illness (IMCI) guidelines; and a consensus guideline developed by the Pediatric Infectious Diseases Society (PIDS) and Infectious Diseases Society of America (IDSA) were used for diagnosing asthma and CAP individually. Chest X-rays were used in 83.3% (10/12) of studies to establish the co-diagnosis of asthma-CAP in children. Variations were observed in using different laboratory investigations across the studies. Infectious etiologies were detected in five (41.7%) studies. In 75% (9/12) of studies, children with asthma-CAP co-diagnosis were treated with antimicrobials, however, bacterial etiology was not reported in 44.4% (4/9) of the studies.

CONCLUSIONS

Our scoping review suggests that chest X-rays are commonly used to establish the co-diagnosis of asthma-CAP and antibiotics are often used without laboratory confirmation of a bacterial etiology. Clinical practice guidelines for the management of asthma and pneumonia in children who present with co-diagnosis may standardize clinical care and reduce variation.

Racial and Ethnic Identity and Vulnerability to Upper Respiratory Viral Infections Among US Children

BACKGROUND

It is unclear whether there are racial/ethnic disparities in the risk of upper respiratory viral infection acquisition and/or lower respiratory manifestations.

METHODS

We studied all children and children with asthma aged 6 to 17 years in the National Health and Nutrition Examination Survey (2007-2012) to evaluate (1) the association between race/ethnicity and upper respiratory infection (URI) and (2) whether race/ethnicity is a risk factor for URI-associated pulmonary eosinophilic inflammation or decreased lung function.

RESULTS

Children who identified as Black (adjusted odds ratio [aOR], 1.38; 95% CI, 1.10-1.75) and Mexican American (aOR, 1.50; 95% CI, 1.16-1.94) were more likely to report a URI than those who identified as White. Among those with asthma, Black children were more than twice as likely to report a URI than White children (aOR, 2.28; 95% CI, 1.31-3.95). Associations between URI and pulmonary eosinophilic inflammation or lung function did not differ by race/ethnicity.

CONCLUSIONS

Findings suggest that there may be racial and ethnic disparities in acquiring a URI but not in the severity of infection. Given that upper respiratory viral infection is tightly linked to asthma exacerbations in children, differences in the risk of infection among children with asthma may contribute to disparities in asthma exacerbations.

Postacute Sequelae of SARS-CoV-2 in Children

The coronavirus disease 2019 (COVID-19) pandemic has caused significant medical, social, and economic impacts globally, both in the short and long term. Although most individuals recover within a few days or weeks from an acute infection, some experience longer lasting effects. Data regarding the postacute sequelae of severe acute respiratory syndrome coronavirus 2 infection (PASC) in children, or long COVID, are only just emerging in the literature. These symptoms and conditions may reflect persistent symptoms from acute infection (eg, cough, headaches, fatigue, and loss of taste and smell), new symptoms like dizziness, or exacerbation of underlying conditions. Children may develop conditions de novo, including postural orthostatic tachycardia syndrome, myalgic encephalomyelitis/chronic fatigue syndrome, autoimmune conditions and multisystem inflammatory syndrome in children. This state-of-the-art narrative review provides a summary of our current knowledge about PASC in children, including prevalence, epidemiology, risk factors, clinical characteristics, underlying mechanisms, and functional outcomes, as well as a conceptual framework for PASC based on the current National Institutes of Health definition. We highlight the pediatric components of the National Institutes of Health-funded Researching COVID to Enhance Recovery Initiative, which seeks to characterize the natural history, mechanisms, and long-term health effects of PASC in children and young adults to inform future treatment and prevention efforts. These initiatives include electronic health record cohorts, which offer rapid assessments at scale with geographical and demographic diversity, as well as longitudinal prospective observational cohorts, to estimate disease burden, illness trajectory, pathobiology, and clinical manifestations and outcomes.

Genomic attributes of airway commensal bacteria and mucosa

Microbial communities at the airway mucosal barrier are conserved and highly ordered, in likelihood reflecting co-evolution with human host factors. Freed of selection to digest nutrients, the airway microbiome underpins cognate management of mucosal immunity and pathogen resistance. We show here the initial results of systematic culture and whole-genome sequencing of the thoracic airway bacteria, identifying 52 novel species amongst 126 organisms that constitute 75% of commensals typically present in heathy individuals. Clinically relevant genes encode antimicrobial synthesis, adhesion and biofilm formation, immune modulation, iron utilisation, nitrous oxide (NO) metabolism and sphingolipid signalling. Using whole-genome content we identify dysbiotic features that may influence asthma and chronic obstructive pulmonary disease. We match isolate gene content to transcripts and metabolites expressed late in airway epithelial differentiation, identifying pathways to sustain host interactions with microbiota. Our results provide a systematic basis for decrypting interactions between commensals, pathogens, and mucosa in lung diseases of global significance.

Pediatric asthma exacerbation and COVID-19 pandemic: Impacts, challenges, and future considerations

OBJECTIVE

Asthma, a common disease among children and adolescents, poses a great health risk when ignored; therefore, a thorough follow-up to prevent exacerbations is emphasized. The aim of the present study is to investigate asthma exacerbation in children during the Coronavirus disease 2019 (COVID-19) era.

DATA SOURCES

This narrative review has been done by searching the PubMed and Embase databases using Asthma, COVID-19, Pandemic, and Symptom flare up as keywords.

STUDY SELECTIONS

Studies related to asthma exacerbation in COVID-19 pandemic were included.

RESULTS

Based on studies, controlled or mild to moderate asthma has not been considered a risk factor for COVID-19 severity and has not affected hospitalization, intensive care unit (ICU) admission, and mortality. Surprisingly, emergent and non-emergent visits and asthmatic attacks decreased during the pandemic. The three main reasons for decreased incidence and exacerbation of asthma episodes in the COVID-19 era included reduced exposure to environmental allergens, increasing the acceptance of treatment by pediatrics and caregivers, and decreased risk of other respiratory viral infections. Based on the available studies, COVID-19 vaccination had no serious side effects, except in cases of uncontrolled severe asthma, and can be injected in these children. Also, there was no conclusive evidence of asthma exacerbation after the injection of COVID-19 vaccines.

CONCLUSION

Further studies are recommended to follow the pattern of asthma in the post-pandemic situation and to become prepared for similar future conditions.

Rhinovirus protease cleavage of nucleoporins: perspective on implications for airway remodeling

Human Rhinoviruses (RV) are a major cause of common colds and infections in early childhood and can lead to subsequent development of asthma via an as yet unknown mechanism. Asthma is a chronic inflammatory pulmonary disease characterized by significant airway remodeling. A key component of airway remodeling is the transdifferentiation of airway epithelial and fibroblast cells into cells with a more contractile phenotype. Interestingly, transforming growth factor-beta (TGF-β), a well characterized inducer of transdifferentiation, is significantly higher in airways of asthmatics compared to non-asthmatics. RV infection induces TGF-β signaling, at the same time nucleoporins (Nups), including Nup153, are cleaved by RV proteases disrupting nucleocytoplasmic transport. As Nup153 regulates nuclear export of SMAD2, a key intermediate in the TGF-β transdifferentiation pathway, its loss of function would result in nuclear retention of SMAD2 and dysregulated TGF-β signaling. We hypothesize that RV infection leads to increased nuclear SMAD2, resulting in sustained TGF-β induced gene expression, priming the airway for subsequent development of asthma. Our hypothesis brings together disparate studies on RV, asthma and Nup153 with the aim to prompt new research into the role of RV infection in development of asthma.

A Brief History of Human Challenge Studies (1900-2021) Emphasising the Virology, Regulatory and Ethical Requirements, Raison D'etre, Ethnography, Selection of Volunteers and Unit Design

Venetian quarantine 400 years ago was an important public health measure. Since 1900 this has been refined to include "challenge" or deliberate infection with pathogens be they viruses, bacteria, or parasites. Our focus is virology and ranges from the early experiments in Cuba with Yellow Fever Virus to the most widespread pathogen of our current times, COVID-19. The latter has so far caused over four million deaths worldwide and 190 million cases of the disease. Quarantine and challenge were also used to investigate the Spanish Influenza of 1918 which caused over 100 million deaths. We consider here the merits of the approach, that is the speeding up of knowledge in a practical sense leading to the more rapid licensing of vaccines and antimicrobials. At the core of quarantine and challenge initiatives is the design of the unit to allow safe confinement of the pathogen and protection of the staff. Most important though is the safety of volunteers. We can see now, as in 1900, that members of our society are prepared and willing to engage in these experiments for the public good. Our ethnology study, where the investigator observed the experiment from within the quarantine, gave us the first indication of changing attitudes amongst volunteers whilst in quarantine. These quarantine experiments, referred to as challenge studies, human infection studies, or "controlled human infection models" involve thousands of clinical samples taken over two to three weeks and can provide a wealth of immunological and molecular data on the infection itself and could allow the discovery of new targets for vaccines and therapeutics. The Yellow Fever studies from 121 years ago gave the impetus for development of a successful vaccine still used today whilst also uncovering the nature of the Yellow Fever agent, namely that it was a virus. We outline how carefully these experiments are approached and the necessity to have high quality units with self-contained air-flow along with extensive personal protective equipment for nursing and medical staff. Most important is the employment of highly trained scientific, medical and nursing staff. We face a future of emerging pathogens driven by the increasing global population, deforestation, climate change, antibiotic resistance and increased global travel. These emerging pathogens may be pathogens we currently are not aware of or have not caused outbreaks historically but could also be mutated forms of known pathogens including viruses such as influenza (H7N9, H5N1 etc.) and coronaviruses. This calls for challenge studies to be part of future pandemic preparedness as an additional tool to assist with the rapid development of broad-spectrum antimicrobials, immunomodulators and new vaccines.

The Effectiveness of Some Chronic Pulmonary Management Units for Patients With COPD and Asthma in Vietnam

Background

Asthma and chronic obstructive pulmonary diseases are chronic diseases and have high mortality rates in Vietnam and other countries. Chronic pulmonary disease Management Unit is a management model connecting inpatient and outpatient treatment for asthma and COPD patients. Patients receive long-term management and full consultation to share experiences and be provided with necessary information about the disease.

Objective

The main purpose was to evaluate the effectiveness of the unit for patients with COPD and asthma in Vietnam.

Methods

A Combined cross-sectional study and retrospective longitudinal study was conducted in 310 COPD and asthma patients at Hai Duong, Bac Giang, Thai Nguyen. The questionnaires included 30 questions with two sections including sociodemographic data and using management and treatment services.

Results

After 24 months of management and treatment, knowledge of the disease, medicine use, symptoms, range of activities, eating, sleeping status, and disease control of patients were improved better. For ACT score, the points increased by 2.1 points, 3.4 points, and 4 points, respectively. For the CAT score, the point reduced by 3.7 points, 6.4 points, and 9.1 points, respectively. Improved severe breathlessness efficiency index from 0.6% at 6 months to 9.5% after 24 months.

Conclusion

Our findings suggest that the government need to invest in facilities, equipment, and human resources to maintain and replicate the CMU to help patients receive timely management and treatment, contributing to reducing treatment costs and improving quality of life for asthma and COPD patients.

Tollip deficiency exaggerates airway type 2 inflammation in mice exposed to allergen and influenza A virus: role of the ATP/IL-33 signaling axis

Toll-interacting protein (Tollip) is a negative regulator of the pro-inflammatory response to viruses, including influenza A virus (IAV). Genetic variation of Tollip has been associated with reduced airway epithelial Tollip expression and poor lung function in patients with asthma. Whether Tollip deficiency exaggerates type 2 inflammation (e.g., eosinophils) and viral infection in asthma remains unclear. We sought to address this critical, but unanswered question by using a Tollip deficient mouse asthma model with IAV infection. Further, we determined the underlying mechanisms by focusing on the role of the ATP/IL-33 signaling axis. Wild-type and Tollip KO mice were intranasally exposed to house dust mite (HDM) and IAV with or without inhibitors for IL-33 (i.e., soluble ST2, an IL-33 decoy receptor) and ATP signaling (i.e., an antagonist of the ATP receptor P2Y13). Tollip deficiency amplified airway type 2 inflammation (eosinophils, IL-5, IL-13 and mucins), and the release of ATP and IL-33. Blocking ATP receptor P2Y13 decreased IL-33 release during IAV infection in HDM-challenged Tollip KO mice. Furthermore, soluble ST2 attenuated airway eosinophilic inflammation in Tollip KO mice treated with HDM and IAV. HDM challenges decreased lung viral load in wild-type mice, but Tollip deficiency reduced the protective effects of HDM challenges on viral load. Our data suggests that during IAV infection, Tollip deficiency amplified type 2 inflammation and delayed viral clearance, in part by promoting ATP signaling and subsequent IL-33 release. Our findings may provide several therapeutic targets, including ATP and IL-33 signaling inhibition for attenuating excessive airway type 2 inflammation in human subjects with Tollip deficiency and IAV infection.

Incidence and causative agent distribution of viral-induced paediatric asthma exacerbations under strict infection control measures: a single-centre retrospective study in Japan

BACKGROUND

The prevalence of respiratory viruses in children changed under strict infection control measures during the coronavirus disease 2019 (COVID-19) outbreak. In this study, we investigated the frequency of viral detection in the nasopharynx of paediatric patients with asthma exacerbations requiring hospitalization during the COVID-19 pandemic, as well as the distribution of causative viruses.

METHODS

We included paediatric patients admitted for asthma exacerbations between November 2020 and December 2022 at a single centre in Kobe, Japan. Demographic, clinical, and laboratory data were collected from their medical records and using additional questionnaires. All patients enrolled in this study met the diagnostic criteria for asthma exacerbations outlined in the Japanese Pediatric Guideline for the Treatment and Management of Bronchial Asthma 2020. Statistical differences were calculated using univariate analyses (chi-square or Mann‒Whitney U test).

RESULTS

We enrolled 203 children hospitalized for asthma attacks and collected nasopharyngeal samples from 189 patients. The median patient age was 3.0 years. Asthma severity was classified as mild (4.0%), moderate (82.3%), or severe (13.8%). The proportion of viral respiratory infections was 95.2% (180/189). The rate of patients with multiple viral infections was 20.6% (39/189). The most frequently detected pathogens were rhinovirus and enterovirus (RV/EV) at 69.3% (131/189), allowing for duplicate detection, followed by respiratory syncytial virus (RSV) at 28.6% (54/189). We also detected RV/EV almost every month compared to RSV and other viruses. In addition, RV/EV-positive patients were significantly older (p = 0.033), exhibited higher WBC counts (p < 0.001) and higher Eos counts (p < 0.001), had elevated total IgE levels (p < 0.001) and house dust mite-specific IgE levels (p = 0.019), had a shorter duration of hospitalization (p < 0.001), and had a shorter duration of oxygen therapy (p < 0.001). In patients positive for RV/EV, the use of ICSs significantly reduced the severity of the condition (p < 0.001).

CONCLUSION

Even under strict infection control measures, respiratory viruses were detected in the nasopharynx of almost all paediatric patients who had asthma exacerbations requiring hospitalization.

Prevalence and clinical implications of respiratory viruses in asthma during stable disease state and acute attacks: Protocol for a meta-analysis

INTRODUCTION

Viruses are detected in over 50% of acute asthma attacks and in a notable proportion of patients with asthma during stable disease state They are associated with worse outcomes. We will conduct a series of systematic reviews and meta-analyses to quantify the prevalence and clinical burden of various respiratory viruses in stable asthma and acute asthma attacks. In addition, we will assess the viral loads of respiratory viruses during stable and acute asthma, to explore whether viral load could differentiate attacks triggered by viruses versus those where viruses are present as "innocent bystanders".

MATERIALS AND METHODS

Based on a prospectively registered protocol (PROSPERO, ID: CRD42023375108) and following standard methodology recommended by Cochrane, we will systematically search Medline/PubMed, EMBASE, the Cochrane Library and relevant conference proceedings for studies assessing the prevalence or clinical burden of respiratory viruses in asthma. Methodological rigour of the included studies will be appraised using a tool specific for prevalence studies and the Newcastle-Ottawa Scale respectively. In anticipation of significant clinical and methodological heterogeneity, we will conduct random effect meta-analyses. For evaluating the prevalence of viruses, we will perform meta-analyses of proportions using the inverse variance method, and the Freeman-Tukey transformation. We will conduct meta-regression analyses for exploring heterogeneity.

CONCLUSION

We envisage that these systematic reviews and meta-analyses will quantify the prevalence and burden of respiratory viruses in stable and acute asthma and will drive future research and clinical practice.

Early-immune development in asthma: A review of the literature

This review presents a comprehensive examination of the various factors contributing to the immunopathogenesis of asthma from the prenatal to preschool period. We focus on the contributions of genetic and environmental components as well as the role of the nasal and gut microbiome on immune development. Predisposing genetic factors, including inherited genes associated with increased susceptibility to asthma, are discussed alongside environmental factors such as respiratory viruses and pollutant exposure, which can trigger or exacerbate asthma symptoms. Furthermore, the intricate interplay between the nasal and gut microbiome and the immune system is explored, emphasizing their influence on allergic immune development and response to environmental stimuli. This body of literature underscores the necessity of a comprehensive approach to comprehend and manage asthma, as it emphasizes the interactions of multiple factors in immune development and disease progression.

Ingredients of Vicks VapoRub inhibit rhinovirus-induced ATP release

Background

Over-the-counter therapies, such as Vicks VapoRub, are frequently used in the management of upper respiratory tract infection symptoms. Of these, acute cough is the most bothersome; however, the mechanisms involved have not been fully elucidated. The temperature-sensitive transient receptor potential (TRP) channels, including TRPA1, TRPV1, TRPM8 and TRPV4, are potential candidates. TRPV4 is also thought to be involved in cough through the TRPV4-ATP-P2X3 pathway. Here, we hypothesise that Vicks VapoRub ingredients (VVRIs) modulate the TRP cough channels.

Methods

Stably transfected HEK cells expressing TRP channels were challenged with VVRIs, individually or in combination, and the agonist and antagonist effects were measured using calcium signalling responses. In addition, rhinovirus serotype-16 (RV16)-infected A549 airway epithelial cells were pre-incubated with individual or combinations of VVRIs prior to hypotonic challenge and extracellular ATP release analysis.

Results

Calcium signalling reconfirmed some previously defined activation of TRP channels by specific VVRIs. The combined VVRIs containing menthol, camphor and eucalyptus oil activated TRPV1, TRPV4, TRPM8 and untransfected wild-type HEK293 cells. However, pre-incubation with VVRIs did not significantly inhibit any of the channels compared with the standard agonist responses. Pre-incubation of RV16-infected A549 cells with individual or combined VVRIs, except menthol, resulted in a 0.45-0.55-fold reduction in total ATP release following hypotonic stimulation, compared with infected cells not treated with VVRIs.

Conclusion

These findings suggest that some VVRIs may reduce symptoms associated with upper respiratory tract infection by modulating specific TRP receptors and by reducing RV16-induced ATP release.

Effects of Allergen Exposure and Environmental Risk Factors in Schools on Childhood Asthma

PURPOSE OF REVIEW

This review aims to assess the prevalence of common allergen exposures and environmental risk factors for asthma in schools, examine the underlying mechanisms of these environmental risk factors, and explore possible prevention strategies.

RECENT FINDINGS

Cockroach, mouse, dust mites, fungi, viral infections, ozone pollution, and cleaning products are common allergen exposures and environmental risk factors in schools which may affect asthma morbidity. Novel modifiable environmental risk factors in schools are also being investigated to identify potential associations with increased asthma morbidity. While several studies have investigated the benefit of environmental remediation strategies in schools and their impact on asthma morbidity, future studies are warranted to further define the effects of modifiable risk factors in schools and determine whether school mitigation strategies may help improve asthma symptoms in students with asthma.

Interactive effects between CDHR3 genotype and rhinovirus species for diagnosis and severity of respiratory tract infections in hospitalized children

Rhinovirus (RV) is the leading pathogen causing childhood wheezing, with rhinovirus C (RV-C) species reported to cause asthma exacerbation. Allele A of single-nucleotide polymorphism (SNP) CDHR3_rs6967330 upregulates epithelial expression of RV-C receptors which results in more severe asthma exacerbations in children. Nevertheless, there are limited data on interactions between CDHR3 variants and their impact on severity of RV-related pediatric respiratory tract infections (RTIs). Medical records of RV-related RTIs in children aged below 18 years who were hospitalized in two public hospitals in 2015-2016 were independently reviewed by two paediatricians. Archived nasopharyngeal aspirates were retrieved for RV detection and sequencing as well as CDHR3 genotyping. HaploView v.5.0 and generalized multifactor dimensionality reduction (GMDR) analysis were employed for haplotypic assignment and gene-environment interaction analyses. Among 1019 studied cases, our results confirmed the relationship between RV-C species and more severe RTIs. Besides the top risk variant rs6967330-A, we identified rs140154310-T to be associated with RV-C susceptibility under the additive model [odds ratio (OR) 2.53, 95% CI 1.15-5.56; P = 0.021]. Rs140154310 was associated with wheezing illness (OR 2.38, 95% CI 1.12-5.04; P = 0.024), with such association being stronger in subjects who wheezed due to RV-C infections (OR 2.71, 95% CI 1.32-5.58; P = 0.007). Haplotype GAG constructed from rs4730125, rs6967330, and rs73195665 was associated with increased risk of RV-C infection (OR 1.71, 95% CI 1.11-2.65; P = 0.016) and oxygen supplementation (OR 1.93, 95% CI 1.13-3.30; P = 0.016). GMDR analyses revealed epistatic interaction between rs140154310 and rs6967330 of CDHR3 for RV-C infection (P = 0.001), RV-C-associated lower RTI (P = 0.004), and RV-C-associated wheeze (P = 0.007). There was synergistic gene-environmental interaction between rs3887998 and RV-C for more severe clinical outcomes (P < 0.001). To conclude, rs140154310-T is another risk variant for RV-C susceptibility and more severe RTIs. Synergistic epistatic interaction is found between CDHR3 SNPs and RV-C for RTI severity, which is likely mediated by susceptibility to RV-C. Haplotypic analysis and GMDR should be included in identifying prediction models of CDHR3 for childhood asthma and RTIs. IMPORTANCE This case-control study investigated the interaction between CDHR3 genotypes and rhinovirus (RV) species on disease severity in Hong Kong children hospitalized for respiratory tract infection (RTI). There were synergistic effects between RV-C and CDHR3 SNPs for RTI severity, which was mainly driven by RV-C. Specifically, rs6967330 and rs140154310 alone and their epistatic interaction were associated with RV-C-related and severe RTIs in our subjects. Therefore, genotyping of CDHR3 SNPs may help physicians formulate prediction models for severity of RV-associated RTIs.

Epidemiology and Immunopathogenesis of Virus Associated Asthma Exacerbations

Asthma is a common airway disease, affecting millions of people worldwide. Although most asthma patients experience mild symptoms, it is characterized by variable airflow limitation, which can occasionally become life threatening in the case of a severe exacerbation. The commonest triggers of asthma exacerbations in both children and adults are viral infections. In this review article, we will try to investigate the most common viruses triggering asthma exacerbations and their role in asthma immunopathogenesis, since viral infections in young adults are thought to trigger the development of asthma either right away after the infection or at a later stage of their life. The commonest viral pathogens associated with asthma include the respiratory syncytial virus, rhinoviruses, influenza and parainfluenza virus, metapneumovirus and coronaviruses. All these viruses exploit different molecular pathways to infiltrate the host. Asthmatics are more prone to severe viral infections due to their unique inflammatory response, which is mostly characterized by T2 cytokines. Unlike the normal T1 high response to viral infection, asthmatics with T2 high inflammation are less potent in containing a viral infection. Inhaled and/or systematic corticosteroids and bronchodilators remain the cornerstone of asthma exacerbation treatment, and although many targeted therapies which block molecules that viruses use to infect the host have been used in a laboratory level, none has been yet approved for clinical use. Nevertheless, further understanding of the unique pathway that each virus follows to infect an individual may be crucial in the development of targeted therapies for the commonest viral pathogens to effectively prevent asthma exacerbations. Finally, biologic therapies resulted in a complete change of scenery in the treatment of severe asthma, especially with a T2 high phenotype. All available data suggest that monoclonal antibodies are safe and able to drastically reduce the rate of viral asthma exacerbations.

Breathing zone pollutant levels are associated with asthma exacerbations in high-risk children

Background

Indoor and outdoor air pollution levels are associated with poor asthma outcomes in children. However, few studies have evaluated whether breathing zone pollutant levels associate with asthma outcomes.

Objective

Determine breathing zone exposure levels of NO 2 , O 3 , total PM 10 and PM 10 constituents among children with exacerbation-prone asthma, and examine correspondence with in-home and community measurements and associations with outcomes.

Methods

We assessed children's personal breathing zone exposures using wearable monitors. Personal exposures were compared to in-home and community measurements and tested for association with lung function, asthma control, and asthma exacerbations.

Results

81 children completed 219 monitoring sessions. Correlations between personal and community levels of PM 10 , NO 2 , and O 3 were poor, whereas personal PM 10 and NO 2 levels correlated with in-home measurements. However, in-home monitoring underdetected brown carbon (Personal:79%, Home:36.8%) and ETS (Personal:83.7%, Home:4.1%) personal exposures, and detected black carbon in participants without these personal exposures (Personal: 26.5%, Home: 96%). Personal exposures were not associated with lung function or asthma control. Children experiencing an asthma exacerbation within 60 days of personal exposure monitoring had 1.98, 2.21 and 2.04 times higher brown carbon (p<0.001), ETS (p=0.007), and endotoxin (p=0.012), respectively. These outcomes were not associated with community or in-home exposure levels.

Conclusions

Monitoring pollutant levels in the breathing zone is essential to understand how exposures influence asthma outcomes, as agreement between personal and in-home monitors is limited. Inhaled exposure to PM 10 constituents modifies asthma exacerbation risk, suggesting efforts to limit these exposures among high-risk children may decrease their asthma burden.

CLINICAL IMPLICATIONS

In-home and community monitoring of environmental pollutants may underestimate personal exposures. Levels of inhaled exposure to PM 10 constituents appear to strongly influence asthma exacerbation risk. Therefore, efforts should be made to mitigate these exposures.

CAPSULE SUMMARY

Leveraging wearable, breathing-zone monitors, we show exposures to inhaled pollutants are poorly proxied by in-home and community monitors, among children with exacerbation-prone asthma. Inhaled exposure to multiple PM 10 constituents is associated with asthma exacerbation risk.

The old friends hypothesis: evolution, immunoregulation and essential microbial inputs

In wealthy urbanised societies there have been striking increases in chronic inflammatory disorders such as allergies, autoimmunity and inflammatory bowel diseases. There has also been an increase in the prevalence of individuals with systemically raised levels of inflammatory biomarkers correlating with increased risk of metabolic, cardiovascular and psychiatric problems. These changing disease patterns indicate a broad failure of the mechanisms that should stop the immune system from attacking harmless allergens, components of self or gut contents, and that should terminate inappropriate inflammation. The Old Friends Hypothesis postulates that this broad failure of immunoregulation is due to inadequate exposures to the microorganisms that drive development of the immune system, and drive the expansion of components such as regulatory T cells (Treg) that mediate immunoregulatory mechanisms. An evolutionary approach helps us to identify the organisms on which we are in a state of evolved dependence for this function (Old Friends). The bottom line is that most of the organisms that drive the regulatory arm of the immune system come from our mothers and family and from the natural environment (including animals) and many of these organisms are symbiotic components of a healthy microbiota. Lifestyle changes that are interrupting our exposure to these organisms can now be identified, and many are closely associated with low socioeconomic status (SES) in wealthy countries. These insights will facilitate the development of education, diets and urban planning that can correct the immunoregulatory deficit, while simultaneously reducing other contributory factors such as epithelial damage.