Acute exacerbations of asthma: epidemiology, biology and the exacerbation-prone phenotype

Asthma exacerbations and airway redox imbalance under type 2 inflammatory conditions

Asthma is a chronic inflammatory airway disease characterized by bronchial hyperresponsiveness and reversibility. Despite considerable advances in asthma treatment based on our understanding of its pathophysiology, asthma exacerbations remain challenging. To reduce asthma exacerbations, it is essential to identify triggers, patients' risk factors, and underlying mechanisms. While exposure to viruses and environmental stimuli are known common triggers for asthma exacerbations, the key factors involved in asthma exacerbations have been identified as type 2 inflammation. Type 2 inflammatory biomarkers have been demonstrated to be useful in predicting individuals at risk of exacerbations. Furthermore, recent clinical trials of targeted biological therapy, which blocks the type 2 pathway, have supported the critical role of type 2 inflammation in asthma exacerbations. Although the specific mechanisms linking type 2 inflammation to asthma exacerbations have not yet been fully elucidated, increasing evidence shows that reduction/oxidation (redox) imbalance likely plays an important role in this association. Under type 2 inflammatory conditions, human airway epithelial cells activate 15-lipoxygenase-1 in complex with phosphatidylethanolamine binding protein-1, leading to the generation of electrophilic hydroperoxyl-phospholipids. When the accumulation of reactive lipid peroxidation surpasses a specific glutathione-dependent activity, these electrophilic compounds are not neutralized, leading to programmed cell death, ferroptosis. Reduced glutathione levels, caused by type 2 inflammation, may impair its ability to neutralize reactive lipid peroxidation. The accumulation of lipid peroxidation with intracellular redox imbalance may contribute to asthma exacerbations in individuals with type 2 inflammation. Inhibiting the ferroptotic pathway holds promise as a therapeutic strategy to alleviate asthma exacerbations.

Longitudinal association of exclusive and dual use of cigarettes and cigars with asthma exacerbation among US adults: a cohort study

BACKGROUND

Cigar use among adults in the United States has remained relatively stable in the past decade and occupies a growing part of the tobacco marketplace as cigarette use has declined. While studies have established the detrimental respiratory health effects of cigarette use, the effects of cigar use need further characterization. In this study, we evaluate the prospective association between cigar use, with or without cigarettes, and asthma exacerbation.

METHODS

We used data from Waves 1-5 (2013-2019) of the Population Assessment of Tobacco and Health Study to run generalized estimating equation models examining the association between time-varying, one-wave-lagged cigarette and cigar use and self-reported asthma exacerbation among US adults (18+). We defined our exposure as non-established (reference), former, exclusive cigarette, exclusive cigar, and dual use. We defined an asthma exacerbation event as a reported asthma attack in the past 12 months necessitating oral or injected steroid medication or asthma symptoms disrupting sleep at least once a week in the past 30 days. We adjusted for age, sex, race and ethnicity, household income, health insurance, established electronic nicotine delivery systems use, cigarette pack-years, secondhand smoke exposure, obesity, and baseline asthma exacerbation.

RESULTS

Exclusive cigarette use (incidence rate ratio (IRR): 1.26, 95% confidence interval (CI): 1.03-1.54) and dual use (IRR: 1.41, 95% CI: 1.08-1.85) were associated with a higher rate of asthma exacerbation compared to non-established use, while former use (IRR: 1.01, 95% CI: 0.80-1.28) and exclusive cigar use (IRR: 0.70, 95% CI: 0.42-1.17) were not.

CONCLUSION

We found no association between exclusive cigar use and self-reported asthma exacerbation. However, exclusive cigarette use and dual cigarette and cigar use were associated with higher incidence rates of self-reported asthma exacerbation compared to non-established use. Studies should evaluate strategies to improve cigarette and cigar smoking cessation among adults with asthma who continue to smoke.

Exacerbations of bronchiectasis

Bronchiectasis presents a significant challenge due to its rising prevalence, associated economic burden and clinical heterogeneity. This review synthesises contemporary understanding and literature of bronchiectasis exacerbations, addressing the transition from stable state to exacerbations, underlining the importance of early and precise recognition, rigorous severity assessment, prompt treatment, and prevention measures, as well as emphasising the need for strategies to assess and improve early and long-term patient outcomes. The review highlights the interplay between stable state phases and exacerbations in bronchiectasis, introducing the concept of "exogenous and endogenous changes in airways homeostasis" and the "adapted island model" with a particular focus on "frequent exacerbators", a group of patients associated with specific clinical characteristics and worse outcomes. The pathophysiology of exacerbations is explored through the lens of microbial and nonmicrobial triggers and the presence and the activity of comorbidities, elaborating on the impact of both exogenous insults, such as infections and pollution, and endogenous factors such as inflammatory endotypes. Finally, the review proposes a multidisciplinary approach to care, integrating advancements in precision medicine and biomarker research, paving the way for tailored treatments that challenge the traditional antibiotic paradigm.

Risk factors associated with uncontrolled asthma in children - a systematic review and meta-analysis

OBJECTIVE

We aim to assess the risk factors of uncontrolled asthma in children and adolescents.

METHODS

A systemic search was conducted from electronic databases (PubMed/Medline, Cochrane Library, and Google Scholar) from inception to July 17, 2023. All statistical analyses were conducted in Review Manager 5.4.1. Studies meeting inclusion criteria were selected. A random-effects model was used when heterogeneity was seen to pool the studies, and the result was reported in the odds ratio and the corresponding 95% confidence interval. We also used a narrative approach where it was not feasible to quantitatively assess the outcome.

RESULTS

Ten observational studies were used to conduct this systematic review and meta-analysis. A quantitative analysis of five factors was done. Pooled analysis showed a statistically significant risk of uncontrolled asthma in association with past hypersensitivity reactions (standardized mean difference [SMD] = 1.51 (1.16, 1.98); p = .002; I2 = 84%) and incomplete controller adherence (SMD = 3.15 (1.83, 5.41); p < .0001; I2 = 94%). While non-significant relation was seen in parental asthma (SMD = 1.23 (0.98, 1.55); p = .07; I2 = 15%), oral corticosteroid use (SMD = 0.99 (0.72, 1.36); p = .96; I2 = 81%) and education of caregivers (SMD = 0.99 (0.72, 1.36); p = .96; I2 = 81%). Some other factors were also discussed qualitatively.

CONCLUSION

Our study shows that some significant risk factors might cause uncontrolled asthma in children and adolescents like past hypersensitivity reactions and incomplete controller adherence.

Socioeconomic status, diet, and recurrent severe asthma exacerbations in Puerto Rican youth

Background

Why Puerto Rican youths have higher rates of severe asthma exacerbations (SAEs) than their non-Hispanic White peers is unclear.

Objective

We aimed to identify risk factors associated with recurrent SAEs in Puerto Rican youths with asthma.

Methods

We performed cross-sectional and longitudinal analyses of recurrent SAEs in 209 Puerto Rican youths with asthma who participated in 2 cross-sectional studies approximately 5.2 years apart: the Puerto Rico Genetics of Asthma and Lifestyle study (visit 1, participants aged 6-14 years) and the Epigenetic Variation and Childhood Asthma in Puerto Ricans study (visit 2, participants aged 9-20 years). Recurrent SAEs were defined as at least 2 SAEs in the previous year.

Results

Of the youths in our study, there were 80 (38.3%) and 47 (22.4%) with recurrent SAEs at visit 1 and visit 2, respectively, and 31 participants (14.8%) had persistent recurrent SAEs (ie, recurrent SAEs at both visits). In multivariable analyses, low household income was significantly associated with 2.4 to 12.3 times increased odds of recurrent SAEs in all analyses, with stronger longitudinal associations. Low parental education level, nonprivate or employer-based health insurance, overweight or obesity, residential proximity to a major road, and low or moderate level of outdoor activity were each significantly associated with recurrent SAEs in at least 1 analysis. Further, persistence of low parental numeracy level, low household income, and an unhealthy diet were each associated with persistent recurrent SAEs.

Conclusion

In this study of Puerto Rican youths with asthma, persistence of low parental numeracy level, a low household income, and an unhealthy diet were associated with persistent recurrent SAEs. Our findings support policies promoting equity and healthy lifestyles for Puerto Rican children and their families.

Targeting Asthma Remission as the Next Therapeutic Step Toward Improving Disease Control

The long-term goal of asthma management is to achieve disease control, comprising the assessment of 2 main domains: (1) symptom control and (2) future risk of adverse outcomes. Decades of progress in asthma management have correlated with increasingly ambitious disease control targets. Moreover, the introduction of precision medicines, such as biologics, has further expanded the limits of what can be achieved in terms of disease control. It is now believed that clinical remission, a term rarely associated with asthma, may be an achievable treatment goal. An expert framework published in 2020 took the first step toward developing a commonly accepted definition of clinical remission in asthma. However, there remains a widespread discussion about the clinical parameters and thresholds that should be included in a standardized definition of clinical remission. This review aims to discuss on-treatment clinical remission as an aspirational outcome in asthma management, drawing on experiences from other chronic diseases where remission has long been a goal. We also highlight the integral role of shared decision-making between patients and health care professionals and the need for a common understanding of the individual patient journey to remission as foundational elements in reducing disease burden and improving outcomes for patients with asthma.

Clinical characteristics of obese, fixed airway obstruction, exacerbation-prone phenotype and comorbidities among severe asthma patients: a single-center study

BACKGROUND

Severe asthma places a large burden on patients and society. The characteristics of patients with severe asthma in the Chinese population remain unclear.

METHODS

A retrospective review was conducted in patients with severe asthma. Demographic and clinical data were collected. Patients were grouped according to phenotypes in terms of exacerbations, body mass index (BMI) and fixed airway obstruction (FAO) status, and the characteristics of different groups were compared. Comorbidities, factors that influence asthma phenotypes, were also analyzed in the study.

RESULTS

A total of 228 patients with severe asthma were included in our study. They were more likely to be overweight or obese. A total of 41.7% of the patients received GINA step 5 therapy, and 43.4% had a history of receiving regular or intermittent oral corticosteroids (OCS). Severe asthmatic patients with comorbidities were prone to have more asthma symptoms and decreased quality of life than patients without comorbidities. Patients with exacerbations were characterized by longer duration of asthma, poorer lung function, and worse asthma control. Overweight or obese patients tended to have more asthma symptoms, poorer lung function and more asthma-related comorbidities. Compared to patients without FAO, those in the FAO group were older, with longer duration of asthma and more exacerbations.

CONCLUSION

The existence of comorbidities in patients with severe asthma could result in more asthma symptoms and decreased quality of life. Patients with exacerbations or with overweight or obese phenotypes were characterized by poorer lung function and worse asthma control. Patients with FAO phenotype tended to have more exacerbations.

Development and Dynamic Responsiveness of the Acute Asthma Exacerbation Survey in Patients With Moderate to Severe Disease

BACKGROUND

The recall periods and response scales of existing surveys of asthma control are poorly suited for studying acute exacerbations.

OBJECTIVE

To develop an instrument able to predict exacerbations after the onset of acute symptoms and with a recall window sufficiently short to study recovery.

METHODS

We developed the six-item Acute Asthma Exacerbation Survey (AAES). Data were collected at baseline, acute, and recovery visits within an established longitudinal protocol for participants with severe asthma. Participants scheduled acute study visits at the first sign of a cold. Nasal lavage samples and lung function measurements were also collected. The AAES data were analyzed using Cronbach α, Spearman correlations, and Kruskal-Wallace methods. We used logistic regression for predictors of bursts of oral corticosteroids (OCS).

RESULTS

Of 130 participants studied at baseline, 52 returned for an acute visit. The AAES scores were elevated at the acute visit and returned to baseline after recovery independently of respiratory virus detection. Cronbach α for the AAES was 0.853, 0.822, and 0.889 at the three respective visits. Compared with participants not needing burst OCS, those with exacerbations had higher acute AAES scores (16 [13.5-18] vs 11.5 [8.2-14], median [interquartile range]; P = .017) and a larger reduction from baseline in lung function. For each 3-point increase in AAES scores, the odds ratio for burst OCS use was 1.64 (95% CI, 1.04-2.57; P = .030).

CONCLUSIONS

The AAES is internally consistent and dynamically responsive during acute asthma exacerbations. Additional validation studies are warranted to support future trials and aid in clinical decision-making.

Quality of life in children with asthma compared to healthy children: a case-control study

OBJECTIVE

Asthma is a chronic condition characterized by episodic wheezing, cough, and shortness of breath resulting from airway hyperresponsiveness and inflammation. Over 300 million people are affected worldwide, and its prevalence is increasing by 50% every decade. Assessing the quality of life in children with asthma is fundamental, as consistently poor health-related quality of life is associated with poorly controlled asthma. This study is aimed to evaluate and compare factors associated with HRQOL between healthy controls and children with asthma.

METHODS

In the current case-control study, 50 children aged 8-12 years with asthma (cases) enrolled at outpatient hospital clinics by a trained pediatric allergist/immunologist (A.P.) and matched with 50 healthy controls by age and sex. All enrolled subjects were interviewed utilizing the PedsQL questionnaire to assess health-related quality of life; also, patient demographics, including age, sex, and family income status, were obtained from a questionnaire.

RESULTS

A total of 100 children comprising 62 males and 38 females with a mean age of 9.63 ± 1.38 years, participated in this study. The average score of children with asthma was 81.63 ± 9.38, and the average score for healthy participants was 89.58 ± 7.91. We found that asthma was associated with a significant drop in health-related quality of life in this sample.

CONCLUSIONS

The results indicated that the PedsQL score and its subscales, except social functioning, were significantly higher in children with asthma compared to healthy ones. Also, SABA use, nocturnal symptoms, and asthma severity are negatively related to the health-related quality of life.

The association between PM2.5 concentration and the severity of acute asthmatic exacerbation in hospitalized children: A retrospective study in Chongqing, China

BACKGROUND

Ambient PM2.5 is associated with asthma exacerbation. The association between the concentration of PM2.5 and the severity of asthma exacerbation has yet to be thoroughly clarified. The study aims to explore the association between the piror 30 days average concentration of PM2.5 and the severity of acute asthma exacerbation in hospitalized children.

METHODS

A total of 269 children with acute exacerbation of asthma were enrolled and divided into three groups according to the PM2.5 exposure concentrations: group 1 (PM2.5: <37.5 μg/m3 ), group 2 (PM2.5: 37.5-75 μg/m3 ), group 3 (PM2.5: ≥75 μg/m3 ), respectively. The ordered logistic regression modeling was conducted to explore the influence of daily PM2.5 concentration on the clinical severity of children's asthma exacerbation. Multiple linear regression was conducted to explore the association between the concentration of PM2.5 and the length of stay in the hospital (LOS). We also conducted a receiver operating characteristic (ROC) curve analysis to explore the cutoff value of PM2.5 to predict the children's asthma exacerbation.

RESULTS

There was no statistical difference among the three groups of children in gender, age, body mass index, ethnicity, the first diagnosis of asthma, allergic history, passive smoke exposure, or family history of asthma. There was a statistically significant difference in many hospitalization characteristics (p < 0.05) among the three groups of children. Significant differences were found in terms of accessory muscles of respiration (p = 0.005), respiratory failure (p = 0.012), low respiratory tract infectious (p = 0.020), and the severity of asthma exacerbation (p < 0.001) among the three groups. PM2.5 concentration was primarily positively correlated to neutrophile inflammation. The ordered multivariate logistic regression model showed that higher PM2.5 concentrations were significantly associated with greater odds of more severe asthma exacerbation in one and two-pollutant models. The adjusted odds ratio of severe asthma exacerbation was 1.029 (1.009, 1.049) in the one-pollutant model. The most significant odds ratio of severe asthma exacerbation was 1.050 (1.027, 1.073) when controlling NO2 in the two-pollutant models. Multiple linear regression showed that PM2.5 concentration was significantly associated with longer LOS in both one-pollutant and two-pollutant models. By performing ROC analysis, the average daily concentration of 44.5 µg/m3 of PM2.5 (AUC = 0.622, p = 0.002) provided the best performance to predict severe asthma of children exacerbation with a sensitivity of 59.2% and a specificity of 63.8%.

CONCLUSION

The increased prior 30 days average concentration of PM2.5 was associated with greater asthma exacerbation severity and longer length of stay in the hospital of children with asthma exacerbation.

Assessing the Impact of the COVID-19 Pandemic on the Severity of Pediatric Inflammatory Bowel Disease Admissions and New Diagnoses

Introduction

The COVID-19 pandemic has introduced new challenges to the diagnosis and management of pediatric inflammatory bowel disease (IBD). Many patients have had only limited access to their providers through telemedicine, and many chose to delay nonemergent treatment.

Methods

A retrospective chart review of patients with IBD seen by the Pediatric Gastroenterology Division at Doernbecher Children's Hospital from January 2018 to August 2021 was conducted. The study cohort was divided into 2 groups: those presenting before the onset of the COVID-19 pandemic (January 1, 2018 to February 28, 2020) and those presenting during the pandemic (March 1, 2020 to August 1, 2021). Variables collected included: age, sex, race, ethnicity, IBD type, insurance type, location of residence. Primary outcome measures selected focused on disease severity, initial type of treatment, or surgical intervention offered. A subgroup analysis of the new diagnosis patients was performed. Data were analyzed using independent t-tests, chi-squared analysis, and Wilcoxon rank sum tests.

Results

Two hundred and eleven patients met inclusion criteria, 107 (72 new diagnoses, 35 admissions) within the pre-COVID epoch and 104 (67 new diagnoses, 37 admissions) within the during-COVID epoch. Patients in the during-COVID epoch had higher fecal calprotectin level and were more likely to be started on a biologic as initial treatment. Patients admitted during COVID for IBD flare were more likely to require surgical intervention. Subgroup analysis of newly diagnosed patients revealed higher incidence of comorbid depression and anxiety.

Conclusions

Our review identified increased disease severity in newly diagnosed pediatric patients with IBD as well as pediatric patients admitted for flare during COVID. Increases in anxiety and depression rates during COVID may have contributed to worsened disease severity.

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.

PM2.5 aggravates airway inflammation in asthmatic mice: activating NF-κB via MyD88 signaling pathway

The role of PM2.5 in the bronchial asthma remains unclear. In this study, the deficient mice of TLR4-/-, TLR2-/- and MyD88 -/- were used to establish asthma model. The effects of PM2.5 on the inflammatory response in lung tissue of these mice were observed. PM2.5 increased alveolar macrophages and neutrophils, up-regulated the IL-12 and KC expression in WT mice, but down-regulated their levels in TLR2 -/-, TLR4 -/- and MyD88 -/- mice. OVA+PM2.5 stimulated neutrophil count in WT mice, but it decreased in TLR2 -/- and TLR4 -/- mice. OVA+PM2.5 also increased the Eotaxin, IL-5, IL-13 and MCP-3 expression levels, and OVA specific IgE and IgG1 in serum also increased in WT group. PM2.5 may activate NF-κB through the TLR2/TLR4/MyD88 signaling pathway and aggravate allergic inflammation of lung in asthmatic mice. The microelements in PM2.5 granules, such as lipopolysaccharide, may be an important factor in the high incidence of asthma.

Occupation and occurrence of respiratory infections among adults with newly diagnosed asthma

BACKGROUND

Work environments are potential areas for spreading respiratory infections. We hypothesized that certain occupations increase susceptibility to respiratory infections among adults with asthma. Our objective was to compare the occurrence of respiratory infections among different occupations in adults with newly diagnosed asthma.

METHODS

We analysed a study population of 492 working-age adults with newly diagnosed asthma who were living in the geographically defined Pirkanmaa Area in Southern Finland during a population-based Finnish Environment and Asthma Study (FEAS). The determinant of interest was occupation at the time of diagnosis of asthma. We assessed potential relations between occupation and occurrence of both upper and lower respiratory tract infections during the past 12 months. The measures of effect were incidence rate ratio (IRR) and risk ratio (RR) adjusted for age, gender, and smoking habits. Professionals, clerks, and administrative personnel formed the reference group.

RESULTS

The mean number of common colds in the study population was 1.85 (95% CI 1.70, 2.00) infections in the last 12 months. The following occupational groups showed increased risk of common colds: forestry and related workers (aIRR 2.20, 95% CI 1.15-4.23) and construction and mining (aIRR 1.67, 95% CI 1.14-2.44). The risk of lower respiratory tract infections was increased in the following groups: glass, ceramic, and mineral workers (aRR 3.82, 95% CI 2.54-5.74), fur and leather workers (aRR 2.06, 95% CI 1.01-4.20) and metal workers (aRR 1.80, 95% CI 1.04-3.10).

CONCLUSIONS

We provide evidence that the occurrence of respiratory infections is related to certain occupations.

Toward a Predict and Prevent Approach in Obstructive Airway Diseases

Asthma and chronic obstructive pulmonary disease are currently diagnosed and treated after the demonstration of variable airflow limitation and symptoms. Under this framework, undiagnosed and unchecked airway inflammation is associated with recurrent acute attacks, airway remodeling, airflow limitation, adverse effects of corticosteroids, and impaired quality of life, ultimately leading to the collection of side effects termed "people remodeling." This one-size-fits-all damage control approach aims to control symptoms and treat exacerbations rather than modify the underlying disease process. The advent of highly effective therapies targeting proximal drivers of airway inflammation calls for a paradigm shift; upstream-acting therapies offer potential to alter the disease course and achieve clinical remission. We propose moving away from downstream firefighting and toward a "predict and prevent" model, measuring inflammation and providing anti-inflammatory therapy early, without waiting for further clinical deterioration. Much in the same way that high blood pressure and cholesterol are used to predict and prevent heart attacks, in asthma, elevated blood eosinophils and/or exhaled nitric oxide can be used to predict and prevent asthma attacks. We also advocate moving research further upstream by identifying patients with subclinical airway inflammation or disease who may be at risk of progressing to airflow limitation and associated morbidities and intervening early to prevent them. In summary, we call for a predict and prevent approach in obstructive airway disease.

The Lung Microbiome: A New Frontier for Lung and Brain Disease

Due to the limitations of culture techniques, the lung in a healthy state is traditionally considered to be a sterile organ. With the development of non-culture-dependent techniques, the presence of low-biomass microbiomes in the lungs has been identified. The species of the lung microbiome are similar to those of the oral microbiome, suggesting that the microbiome is derived passively within the lungs from the oral cavity via micro-aspiration. Elimination, immigration, and relative growth within its communities all contribute to the composition of the lung microbiome. The lung microbiome is reportedly altered in many lung diseases that have not traditionally been considered infectious or microbial, and potential pathways of microbe-host crosstalk are emerging. Recent studies have shown that the lung microbiome also plays an important role in brain autoimmunity. There is a close relationship between the lungs and the brain, which can be called the lung-brain axis. However, the problem now is that it is not well understood how the lung microbiota plays a role in the disease-specifically, whether there is a causal connection between disease and the lung microbiome. The lung microbiome includes bacteria, archaea, fungi, protozoa, and viruses. However, fungi and viruses have not been fully studied compared to bacteria in the lungs. In this review, we mainly discuss the role of the lung microbiome in chronic lung diseases and, in particular, we summarize the recent progress of the lung microbiome in multiple sclerosis, as well as the lung-brain axis.

Asthma Exacerbations: Patient Features and Potential Long-Term Implications

Asthma exacerbations occur in the context of a complex interplay between external exposures and host factors. Respiratory tract viral infections, in particular rhinovirus, are dominant initiators of exacerbations, with allergens and other inhalation exposures as additional key contributors. The presence of underlying type II inflammation, with associated biomarker elevations, is a major driver of exacerbation risk and mechanism, as evidenced by the consistent reduction of exacerbations seen with biologics targeting these pathways. Several genetic polymorphisms are associated with exacerbations, and while they may individually have small effects, they are cumulatively important and magnified by environmental exposures. A history of exacerbations predicts future exacerbations with potentially negative implications on long-term lung health.

Six Diagnoses of Separation: Impact of COVID-19 on Pediatric Emergency Department Visits: A Multicenter Study

BACKGROUND

Coronavirus disease 2019 (COVID-19) arrived in the New York metropolitan area in early March 2020. Recommendations were made to self-quarantine within households and limit outside visits, including those to clinics and hospitals, to limit the spread of the virus. This resulted in a decrease in pediatric emergency department (ED) visits. However, it is unclear how this affected visits for some common diagnoses such as anxiety, appendicitis, asthma, headaches, seizures, and urinary tract infection (UTI). These diagnoses were chosen a priori, as they were felt to represent visits to the ED, for which the diagnoses would likely not be altered based on COVID exposure or quarantine due to their acute nature.

OBJECTIVES

Our goal was to investigate the effect of COVID-19 on common pediatric diagnoses seen in the pediatric ED using a large multihospital database.

METHODS

We conducted a retrospective cohort study of consecutive pediatric patients (age ≤ 21 years) between March 1 and November 30 in 2019 and 2020 in 28 hospital EDs within 150 miles of New York City. We compared the change in the number of visits from 2019 to 2020 for the following diagnoses: anxiety, appendicitis, asthma, headache, seizures, and UTI.

RESULTS

Our database contained 346,230 total pediatric visits. From 2019 to 2020, total visits decreased by 61%. Decreases for specific diagnoses were 75% for asthma, 64% for headaches, 47% for UTI, 32% for anxiety, 28% for seizures, and 18% for appendicitis (p value for each comparison < 0.0001).

CONCLUSIONS

We found a marked decrease in ED visits for six common pediatric diagnoses after COVID-19 arrived in our area. We suspect that this decrease was due to recommendations to quarantine and fear of contracting the virus. Further studies on other diagnoses and potential complications due to the delay in seeking care are needed.

Endogenous Adenosine 5'-Monophosphate, But Not Acetylcholine or Histamine, is Associated with Asthma Control, Quality of Life, and Exacerbations

OBJECTIVE

Endogenous adenosine 5'-monophosphate (AMP), acetylcholine (ACh), and histamine (HA) are known to be important in bronchial contraction, but their clinical relevance to asthma is poorly understood. We aimed to quantify endogenous AMP, ACh, and HA in induced sputum samples and explore their relationships with asthma control and exacerbations.

METHODS

20 healthy subjects and 112 asthmatics underwent clinical assessment, sputum induction, and blood sampling. The level of asthma control was determined by the asthma control test (ACT) questionnaire. Asthma exacerbation was evaluated according to the criteria of the American Thoracic Society/European Respiratory Society. Levels of AMP, ACh, and HA in sputum were measured by liquid chromatography coupled to tandem mass spectrometry. IL-β, IL-4, IL-5, IL-6, IL-8, IL-13, IL-17A, TNF-α, IFN-γ, and macrophage-derived chemokine (MDC) were also measured.

RESULTS

Compared to healthy controls, asthmatics had higher levels of HA, lower levels of ACh, and similar levels of AMP in induced sputum samples. Compared to controlled asthma (n = 54), uncontrolled asthma (n = 58) showed higher AMP levels (P = 0.002), but similar HA and ACh levels. AMP was negatively correlated with ACT scores (r = - 0.348) and asthma quality of life questionnaire scores (r = - 0.188) and positively correlated with blood monocytes percentage (r = 0.195), sputum MDC (r = 0.214), and IL-6 levels (r = 0.196). Furthermore, AMP was associated with an increased risk of exacerbations in the preceding year.

CONCLUSION

Endogenous AMP, but not ACh or HA, was associated with asthma control, quality of life, and exacerbations in the previous year, which indicates that AMP could be a clinically useful biomarker of asthma.

Changes in the Mean and Variance of the Numbers of Medical Visits for Allergic Diseases before and during the COVID-19 Pandemic in Korea

The implementation of precautionary measures, such as wearing a mask and social distancing, may have affected allergic diseases during the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to compare the numbers of medical visits for allergic diseases before and during the COVID-19 pandemic. Data were obtained from the Korean National Health Insurance claims database. Monthly numbers of patients for four allergic diseases, i.e., allergic rhinitis (AR), asthma, atopic dermatitis (AD), and allergic conjunctivitis (AC), were evaluated using ICD-10 codes and compared between the ‘before COVID-19’ period from January 2018 to February 2020, and the ‘during COVID-19’ period from March 2020 to June 2021, since the first COVID-19 patient was detected on 20 January 2020, in Korea. Subgroup analyses were performed according to age and sex. The mean numbers of medical visits for AR and asthma were significantly greater before COVID-19 than those during COVID-19 (both p < 0.001). The variance in the number of medical visits for asthma decreased during the COVID-19 pandemic. However, the mean number of medical visits for AD increased slightly during COVID-19 and that for AC did not change before and during the COVID-19 pandemic. In subgroup analyses, the results showed a similar pattern to that of the total number of participants, regardless of age and sex. In conclusion, medical visits for AR and asthma significantly decreased during the COVID-19 pandemic, regardless of age and sex.

16-year trends in asthma hospital admissions in Canada

BACKGROUND

Asthma hospitalizations declined rapidly in many parts of the world, including Canada, in the 1990s and early 2000s.

OBJECTIVE

To examine whether the declining trend of asthma hospitalizations persisted in recent years in Canada.

METHODS

Using the Canadian comprehensive nationwide hospitalization data (2002-2017), we identified hospital admissions with the main International Classification of Diseases codes for asthma. We analyzed sex-specific age-standardized trends in annual hospitalization rates among pediatric (< 19 years) and adult (19+ years) patients. We used change-point analysis to evaluate any substantial changes in the trends in the sex-age groups.

RESULTS

There were 254,672 asthma-related hospital admissions (59% pediatric, 50% female) during the study period. Among children, age-adjusted annual rates per 100,000 decreased by 55% in females (152-69) and by 60% in males (270-108) from 2002 to 2017. Among adults, the rates decreased by 59% in both sexes (females: 61-25; males: 27-11). Change-point analysis indicated a substantial plateauing of the annual rate in both pediatric (from -15.3 [females] and -25.8 [males] before 2010 to -0.6 [females] and -0.8 [males] after 2010) and adult (from -5.4 [females] and -2.6 [males] before 2008 to -0.6 [females] and -0.2 [males] after 2008) groups.

CONCLUSION

After a substantial decline in hospital admissions for acute asthma, there has been minimal further decline since 2010 for children and 2008 for adults. In addition to adhering to the contemporary standards of asthma care, novel, disruptive strategies are likely needed to further reduce the burden of asthma.

Racial and Ethnic Disparities in Acute Care Use for Pediatric Asthma

PURPOSE

Previous work has shown that asthma-related emergency department (ED) use is greatest among Black and Latine populations, but it is unknown whether health care use for exacerbations differs across settings (outpatient, ED, inpatient) and correlates with use of routine outpatient services. We aimed to measure disparities by race, ethnicity, and language in pediatric acute asthma care using data from US primary care community health centers.

METHODS

In an observational study using electronic health records from community health centers in 18 states, we compared non-Hispanic Black, English-preferring Latine, Spanish-preferring Latine, and non-Hispanic White children aged 3 to 17 years on visits for clinic-coded asthma exacerbations (2012-2018). We further evaluated asthma-related ED use and inpatient admissions in a subsample of Oregon-Medicaid recipients. Covariate-adjusted odds ratios (ORs) and rate ratios (RRs) were derived using logistic or negative binomial regression analysis with generalized estimating equations.

RESULTS

Among 41,276 children with asthma, Spanish-preferring Latine children had higher odds of clinic visits for asthma exacerbation than non-Hispanic White peers (OR = 1.10; 95% CI, 1.02-1.18). Among the subsample of 6,555 children insured under Oregon-Medicaid, non-Hispanic Black children had higher odds and rates of asthma-related ED use than non-Hispanic White peers (OR = 1.40; 95% CI, 1.04-1.89 and RR = 1.49; 95% CI, 1.09-2.04, respectively). We observed no differences between groups in asthma-related inpatient admissions.

CONCLUSIONS

This study is the first to show that patterns of clinic and ED acute-care use differ for non-Hispanic Black and Spanish-preferring Latine children when compared with non-Hispanic White peers. Non-Hispanic Black children had lower use of clinics, whereas Spanish-preferring Latine children had higher use, including for acute exacerbations. These patterns of clinic use were accompanied by higher ED use among Black children. Ensuring adequate care in clinics may be important in mitigating disparities in asthma outcomes.VISUAL ABSTRACT.

Effects of non-steroidal anti-inflammatory drugs and other eicosanoid pathway modifiers on antiviral and allergic responses: EAACI task force on eicosanoids consensus report in times of COVID-19

Non‐steroidal anti‐inflammatory drugs (NSAIDs) and other eicosanoid pathway modifiers are among the most ubiquitously used medications in the general population. Their broad anti‐inflammatory, antipyretic, and analgesic effects are applied against symptoms of respiratory infections, including SARS‐CoV‐2, as well as in other acute and chronic inflammatory diseases that often coexist with allergy and asthma. However, the current pandemic of COVID‐19 also revealed the gaps in our understanding of their mechanism of action, selectivity, and interactions not only during viral infections and inflammation, but also in asthma exacerbations, uncontrolled allergic inflammation, and NSAIDs‐exacerbated respiratory disease (NERD). In this context, the consensus report summarizes currently available knowledge, novel discoveries, and controversies regarding the use of NSAIDs in COVID‐19, and the role of NSAIDs in asthma and viral asthma exacerbations. We also describe here novel mechanisms of action of leukotriene receptor antagonists (LTRAs), outline how to predict responses to LTRA therapy and discuss a potential role of LTRA therapy in COVID‐19 treatment. Moreover, we discuss interactions of novel T2 biologicals and other eicosanoid pathway modifiers on the horizon, such as prostaglandin D2 antagonists and cannabinoids, with eicosanoid pathways, in context of viral infections and exacerbations of asthma and allergic diseases. Finally, we identify and summarize the major knowledge gaps and unmet needs in current eicosanoid research.

Prescription Patterns of Oral Corticosteroids for Asthma Treatment and Related Asthma Phenotypes in University Hospitals in Korea

Purpose

Oral corticosteroids (OCSs) are frequently prescribed for asthma management despite their adverse effects. An understanding of the pattern of OCS treatment is required to optimize asthma treatment and reduce OCS usage. This study evaluated the prescription patterns of OCSs in patients with asthma.

Methods

This is a retrospective multicenter observational study. We enrolled adult (≥18 years) patients with asthma who had been followed up by asthma specialists in 13 university hospitals for ≥3 years. Lung function tests, the number of asthma exacerbations, and prescription data, including the days of supply and OCS dosage, were collected. The clinical characteristics of OCS-dependent and exacerbation-prone asthmatic patients were evaluated.

Results

Of the 2,386 enrolled patients with asthma, 27.7% (n = 660) were OCS users (the median daily dose of OCS was 20 mg/day prednisolone equivalent to a median of 14 days/year). OCS users were more likely to be female, to be treated at higher asthma treatment steps, and to show poorer lung function and more frequent exacerbations in the previous year than non-OCS users. A total of 88.0% of OCS users were treated with OCS burst with a mean dose of 21.6 ± 10.2 mg per day prednisolone equivalent to 7.8 ± 3.2 days per event and 2.4 times per year. There were 2.1% (51/2,386) of patients with OCS-dependent asthma and 9.5% (227/2,386) with exacerbation-prone asthma. These asthma phenotypes were consistent over the 3 consecutive years in 47.1% of OCS-dependent asthmatic patients and 34.4% of exacerbation-prone asthmatic patients when assessed annually over the 3-year study period.

Conclusions

We used real-world data from university hospitals in Korea to describe the OCS prescription patterns and relievers in asthma. Novel strategies are required to reduce the burden of OCS use in patients with asthma.

Long-term modulation of airway remodelling in severe asthma following bronchial thermoplasty

Rationale

Bronchial thermoplasty is a mechanical therapeutic intervention that has been advocated as an effective treatment option for severe asthma. The mechanism is promoted as being related to the attenuation of airway smooth muscle which has been shown to occur in the short-term. However, long-term studies of the effects of bronchial thermoplasty on airway remodelling are few, with only limited assessment of airway remodelling indices.

Objectives

To evaluate the effect of bronchial thermoplasty on 1) airway epithelial and smooth muscle cells in culture and 2) airway remodelling in patients with severe asthma who have been prescribed bronchial thermoplasty up to 12 months post-treatment.

Methods

The distribution of heat within the airway by bronchial thermoplasty was assessed in a porcine model. Culture of human airway smooth muscle cells and bronchial epithelial cells evaluated the impact of thermal injury. Histological evaluation and morphometric assessment were performed on bronchial biopsies obtained from severe asthma patients at baseline, 6 weeks and 12 months following bronchial thermoplasty.

Results

Bronchial thermoplasty resulted in heterogeneous heating of the airway wall. Airway smooth muscle cell cultures sustained thermal injury, whilst bronchial epithelial cells were relatively resistant to heat. Airway smooth muscle and neural bundles were significantly reduced at 6 weeks and 12 months post-treatment. At 6 weeks post-treatment, submucosal collagen was reduced and vessel density increased, with both indices returning to baseline at 12 months. Goblet cell numbers, submucosal gland area and sub-basement membrane thickness were not significantly altered at any time point examined.

Conclusions

Bronchial thermoplasty primarily affects airway smooth muscle and nerves with the effects still present at 12 months post-treatment.

Phenotype and severity of asthma determines bronchial epithelial immune responses to a viral mimic

BACKGROUND

Asthma is characterised by an aggravated immune response to respiratory viral infections: This phenomenon is a clinically well-recognised driver of acute exacerbations, but how different phenotypes of asthma respond immunologically to virus is unclear.

OBJECTIVES

To describe the association between different phenotypes and severity of asthma and bronchial epithelial immune responses to viral stimulation.

METHODS

In the Immunoreact study, healthy subjects (n=10) and 50 patients with asthma were included; 30 (60%) were atopic, and 34 (68%) were eosinophilic; 14 (28%) had severe asthma. All participants underwent bronchoscopy with collection of bronchial brushings. Bronchial epithelial cells (BECs) were expanded and stimulated with the viral replication mimic poly (I:C) (TLR3 agonist) in vitro. The expression of TLR3-induced pro-inflammatory and anti-viral responses of BECs were analysed using RT-qPCR and multiplex ELISA and compared across asthma phenotypes and severity of disease.

RESULTS

Patients with atopic asthma had increased induction of IL-4, IFN-β, IL-6, TNF-α, and IL-1β after poly (I:C) stimulation compared to non-atopic patients, whereas in patients with eosinophilic asthma only IL-6 and IL-8 induction was higher than in non-eosinophilic asthma. Patients with severe asthma displayed a decreased antiviral IFN-β, and increased expression of IL-8, most pronounced in atopic and eosinophilic asthmatics. Furthermore, induction of IL-33 in response to poly (I:C) was increased in severe atopic and in severe eosinophilic asthma, but TSLP only in severe eosinophilic asthma.

CONCLUSIONS

The bronchial epithelial immune response to a viral mimic stimulation differs between asthma phenotypes and severities, which may be important to consider when targeting novel asthma treatments.

The effects of nebulized ketamine and intravenous magnesium sulfate on corticosteroid resistant asthma exacerbation; a randomized clinical trial

BACKGROUND AND AIMS

Asthma exacerbation is defined as an acute attack of shortness of breath with more than 25% decrease in morning peak flow compared to the baseline on 2 consecutive days, which requires immediate standard therapy. The majority of asthmatic patients are considered to be steroid-sensitive; however, corticosteroid-resistant asthma is a subset of asthma with poor response to corticosteroids and is responsible for frequent hospital admissions. In this study we aimed to compare the effects of two enhancing strategies, the nebulized ketamine and IV magnesium sulfate, in treatment of severe steroid resistant asthma.

MATERIALS AND METHODS

This double-blind randomized clinical trial was conducted on patients who presented to a referral clinic in Alborz, Iran. Using random allocation, patients were divided into two groups. The first group was treated with nebulized ketamine and the second group was treated with intravenous magnesium sulfate. Peak expiratory flow rates were assessed before the intervention, 30 and 60 min after the intervention and compared with the aid of SPSS software.

RESULTS

The Peak expiratory flow rates before the intervention, 30 min and 60 min after the intervention was statistically significantly different in both ketamine and magnesium sulfate groups. Peak expiratory flow rates change between 0 and 60 min were 29.4 and 15.2% in the ketamine and magnesium sulfate group respectively. Although the ketamine group showed much higher increase in mean PEFR compared to the MgSO4 groups, there was no statistically significant difference across both groups.

CONCLUSION

Our study concluded that combined with standard therapy, both ketamine and IV magnesium sulfate are effective agents in the improvement of PEFR in patients with acute severe asthma that failed to respond to traditional therapies. However, there were no statistically significant difference between the two groups.

Parents' self-reported experiences and information needs related to acute pediatric asthma exacerbations: A mixed studies systematic review

Objective

To systematically review the scientific literature examining parents' experiences and information needs for the management of their child's asthma exacerbations.

Methods

We searched five databases for quantitative and qualitative studies in Canada and the United States from 2002 onwards. A convergent integrated approach and the Mixed Method Appraisal Tool were used to analyze and appraise the evidence, respectively.

Results

We included 84 studies (27 quantitative, 54 qualitative, 3 mixed methods). Some parents lacked confidence in recognizing or managing exacerbations. A few parents were uncertain when and where to seek medical help. The main barrier to accessing care was cost. Impacts on parents included poor sleep, distress, and lifestyle disruptions. Parents felt they lacked information and wanted education on treatments and how to recognize and manage exacerbations via education sessions, written materials, community outreach and online resources.

Conclusion

Improved education for parents may help reduce parents' stress, asthma-related morbidities for children and use of urgent health services.

Innovation

The development of tailored interventions and knowledge translation strategies with input from target audiences (e.g. parents, health care providers) is necessary to meet their information needs and support adherence to clinical recommendations.

•

84 studies reviewed and analyzed using the convergent integrated approach

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Parents lacked confidence in recognizing, treating or seeking care for exacerbations

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Cost was a barrier to care; parents affected by psychosocial impacts

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Parent's desired education on treatments and how to recognize and manage exacerbations

•

Interventions and knowledge translation strategies must be developed with parents

Inflammation in Asthma Pathogenesis: Role of T cells, Macrophages, Epithelial Cells and Type 2 Inflammation

Asthma is a chronic disease with abnormal inflammatory and immunological responses. The disease initiated by antigens in subjects with genetic susceptibility. However, environmental factors play a role in the initiation and exacerbation of asthma attack. Asthma is T helper 2 (Th2)-cell-mediated disease. Recent studies indicated that asthma is not a single disease entity, but it is with multiple phenotypes and endotypes. The pathophysiological changes in asthma included a series of subsequent continuous vicious circle of cellular activation contributed to induction of chemokines and cytokines that potentiate inflammation. The heterogeneity of asthma influenced the treatment response. The asthma pathogenesis driven by varied set of cells such as eosinophils, basophils, neutrophils, mast cells, macrophages, epithelial cells and T cells. In this review the role of T cells, macrophage, and epithelial cells are discussed.

Evaluation of Risk Scores to Predict Pediatric Severe Asthma Exacerbations

BACKGROUND

Asthma exacerbations commonly lead to unplanned health care utilization and are costly. Early identification of children at increased risk of asthma exacerbations would allow a proactive management approach.

OBJECTIVE

We evaluated common asthma risk factors to predict the probability of exacerbation for individual children aged 0-21 years using data from the electronic medical record (EMR).

METHODS

We analyzed longitudinal EMR data for over 3000 participants with asthma seen at Cincinnati Children's Hospital Medical Center over a 7-year period. The study population was divided into 3 age groups: 0-4, 5-11, and 12-21 years. Each age group was divided into a derivation cohort and a validation cohort, which were used to build a risk score model. We predicted risk of exacerbation in the next 12 months, validated the scores by risk stratum, and developed a clinical tool to determine the risk level based on this model.

RESULTS

Risk model results were confirmed with validation cohorts by calendar year and age groups. Race, allergic sensitization, and smoke exposure were each important risk factors in the 0-4 age group. Abnormal spirometry and obesity were more sensitive predictors of exacerbation in children >12 years. For each age group, a higher expanded score was associated with a higher predicted probability of an asthma exacerbation in the subsequent year.

CONCLUSION

This asthma exacerbation prediction model, and the associated clinical tool, may assist clinicians in identifying children at high risk for exacerbation that may benefit from more aggressive management and targeted risk mitigation.

Understanding the key issues in the treatment of uncontrolled persistent asthma with type 2 inflammation

Asthma is a complex respiratory disease that varies in severity and response to treatment. Several asthma phenotypes with unique clinical and inflammatory characteristics have been identified. Endotypes, based on distinct molecular profiles, help to further elucidate the heterogeneity within asthma. Type 2 inflammation, involving both the innate (type 2 innate lymphoid cell) and adaptive (T-helper type 2 cells) immune systems, underpins the complex pathophysiology of chronic inflammation in asthma, as well as the presence of comorbid disease (e.g. chronic rhinosinusitis with nasal polyps, allergic rhinitis and atopic dermatitis). Type 2 inflammation is characterised by upregulation of the type 2 cytokines interleukin (IL)-4, IL-5 and IL-13, IgE-mediated release of immune mediators and dysfunction of epithelial or epidermal barriers. Targeting these key proximal type 2 cytokines has shown efficacy in recent studies adopting a personalised approach to treatment using targeted biologics. Elevated levels of biomarkers downstream of type 2 cytokines, including fractional exhaled nitric oxide, serum IgE and blood and sputum eosinophils, have been linked to mechanisms involved in type 2 inflammation. They have the potential to aid diagnosis, and to predict and monitor response to treatment. The objective of this review is to summarise the current understanding of the biology of type 2 inflammation in asthma, examine its influence on type 2 inflammatory comorbidities, and discuss how type 2 inflammatory biomarkers can be harnessed to further personalise treatments in the age of biologic medicines.

Does lung function change in the months after an asthma exacerbation in children?

BACKGROUND

There are limited data describing lung function changes in children after an asthma exacerbation. Our hypothesis was that lung function does not fully recover in children in the months following an asthma exacerbation.

METHODS

We used a data set of children with asthma where lung function (including FEV₁ , FEV₁ /FVC ratio and FEF_25-75 ) was measured at 3-month intervals over a year. Mixed-level models compared spirometry measured on two occasions 3 months apart before a single exacerbation (assessments 1 and 2) with measurements made on two occasions after the exacerbation (assessments 3 and 4), with adjustment for covariates. Changes in spirometry over a year were also analysed across those with exacerbations in no, one or more than one 3-month periods.

RESULTS

For the 113 children who had a single exacerbation, spirometry measured at assessments 1 or 2 did not differ from measurements at assessments 3 or 4 when the whole population was considered. When stratified into tertiles by change in %FEV₁ between assessments 2 and 3, those with the greater reduction were more likely to be treated with long-acting beta-agonist, but in this category, %FEV₁ at assessment 4 had returned to the value at assessment 1. %FEV₁ did not change over a 12-month period within and between the three exacerbation categories (n = 809).

CONCLUSION

One or more asthma exacerbation was not associated with a fall in lung function for the whole population. In a subset of individuals, lung function does fall after an exacerbation but returns to pre-exacerbation values after a period of months.

Characteristics of Treated Asthmatics Experiencing Exacerbations in a US Database: A Retrospective Cohort Study

Rationale

The National Heart, Lung, and Blood Institute (NHLBI) recommend a stepwise approach to asthma management, with the goals of maintaining asthma control and reducing exacerbations. Although asthma treatments reduce the frequency of exacerbations, they still occur. We aimed to characterize the treated United States of America (US) adult asthma population, including those experiencing exacerbations, in terms of socio-demographics, clinical characteristics, and healthcare resource utilization (HRU).

Patients and Methods

A retrospective cohort of asthma patients aged ≥18 years on 01 January 2014 with ≥1 ICD-9 asthma code (493.xx) enrolled in a US healthcare claims database during 2013–2014. Patients who had ≥2 asthma medication dispensings during 2013 (baseline), including ≥1 in the 90-day period before index date, were classified according to NHLBI step. Patients with chronic obstructive pulmonary disease, cystic fibrosis, or lung cancer diagnoses were excluded. Demographics, comorbidities, clinical characteristics, and HRU were described during baseline. Exacerbations and HRU were described during 2014 (follow-up period).

Results

In total, 72,156 patients were included; 10,590 (14.7%) had ≥1 exacerbation during follow-up. Approximately 44% of patients were classified as NHLBI Steps 1–2, 41% as Steps 3–4, and 11% as Steps 5–6. Exacerbation frequency increased with step (Steps 1, 2, and 3: 12–14%; Steps 4, 5, and 6: 16–26%). Compared with the overall population during baseline, patients with an exacerbation had similar demographics, but differences were observed for comorbid allergic rhinitis (46.4% vs 40.1%, respectively), blood eosinophil counts ≥300 cells/μL (45.5% vs 39.6%, respectively), and asthma-related healthcare encounters (62.9% vs 52.4%, respectively). Overall, asthma-related HRU during follow-up increased with NHLBI step.

Conclusion

Exacerbations were observed among patients classified at each NHLBI step and were more frequent with increasing step. Exacerbations and asthma-related HRU highlight the continued unmet need in the treated US asthma population.

Predicting asthma-related crisis events using routine electronic healthcare data

BACKGROUND

There is no published algorithm predicting asthma crisis events (Accident and Emergency (A&E) attendance, hospitalisation or death) using routinely available electronic health record (EHR) data.

AIM

To develop an algorithm to identify individuals at high risk of an asthma crisis event.

DESIGN AND SETTING

Database analysis from primary care EHRs.

METHOD

Multivariable logistic regression was applied to a dataset of 61,861 people with asthma from England and Scotland using the Clinical Practice Research Datalink. External validation was performed using the Secure Anonymised Information Linkage databank of 174,240 patients from Wales. Outcomes were one or more hospitalisation (development dataset) and asthma-related hospitalisation, A&E attendance or death (validation dataset) within a 12-month period.

RESULTS

Risk factors for asthma-related crisis events included previous hospitalisation, older age, underweight, smoking and blood eosinophilia. The prediction algorithm had acceptable predictive ability with a Receiver Operating Characteristic (ROC) of 0.71 (0.70, 0.72) in the validation dataset. Using a cut-point based on the 7% of the population at greatest risk results in a positive predictive value of 5.7% (95% CI 5.3 - 6.1) and a negative predictive value of 98.9% (98.9 - 99.0), with sensitivity of 28.5% (26.7 - 30.3) and specificity of 93.3% (93.2 - 93.4); they had an event risk of 6.0% compared 1.1% for the remaining population. Eighteen people would be "needed to follow" to identify one admission.

CONCLUSIONS

This externally validated algorithm has acceptable predictive ability for identifying patients at high risk of asthma-related crisis events and excluding individuals not at high risk.

COPD-associated miR-145-5p is downregulated in early-decline FEV1 trajectories in childhood asthma

BACKGROUND

Many microRNAs (miRNAs) have been associated with asthma and chronic obstructive pulmonary disease (COPD). Longitudinal lung function growth trajectories of children with asthma-normal growth, reduced growth (RG), early decline (ED), and RG with an ED (RGED)-have been observed, with RG and RGED associated with adverse outcomes, including COPD.

OBJECTIVE

Our aim was to determine whether circulating miRNAs from an early age in children with asthma would be prognostic of reduced lung function growth patterns over the next 16 years.

METHODS

We performed small RNA sequencing on sera from 492 children aged 5 to 12 years with mild-to-moderate asthma from the CAMP clinical trial, who were subsequently followed for 12 to 16 years. miRNAs were assessed for differential expression between previously assigned lung function growth patterns.

RESULTS

We had 448 samples and 259 miRNAs for differential analysis. In a comparison of the normal and the most severe group (ie, normal growth compared with RGED), we found 1 strongly dysregulated miRNA, hsa-miR-145-5p (P < 8.01E-05). This miR was downregulated in both ED groups (ie, ED and RGED). We verified that miR-145-5p was strongly associated with airway smooth muscle cell growth in vitro.

CONCLUSION

Our results showed that miR-145-5p is associated with the ED patterns of lung function growth leading to COPD in children with asthma and additionally increases airway smooth muscle cell proliferation. This represents a significant extension of our understanding of the role of miR-145-5p in COPD and suggests that reduced expression of miR-145-5p is a risk factor for ED of long-term lung function.

Real-World Experience with Dupilumab in Severe Asthma: One-Year Data from an Italian Named Patient Program

INTRODUCTION

Dupilumab is a monoclonal antibody targeting IL-4Rα recently licensed for severe asthma (SA). A Named Patients Program (NPP) was created in Italy before its commercial availability for SA patients with no other available therapeutic options. We aimed to assess the real-world effectiveness of dupilumab in patients with SA and unmet needs.

METHODS

We performed a multicentre retrospective study, including SA patients admitted to the NPP treated with dupilumab for 12 months. Data on the number of exacerbations, Asthma Control Test (ACT), pre-bronchodilator FEV1%, oral corticosteroids (OCSs) use, FeNO and eosinophils count in peripheral blood were recorded at baseline and after 3, 6, and 12 months.

RESULTS

We included 18 SA patients (mean age 53.3±12.4 years, 66.7% female). Eleven (61.1%) were OCSs dependent. Five patients (27.8%) received previous anti-IgE and/or anti-IL-5 agents. A significant improvement in ACT score (from 15.7±5.1 to 18.8±4.8, p=0.023), OCSs intake [10 (5-25) mg/day to 0 (0-5) mg/day, p=0.0333] and FeNO [from 25 (20-80) ppb to 21 (10.9-55.3) ppb, p=0.0190] was already detected after 3 months of treatment. After 12 months, a statistically significant decrease in the number of exacerbations from 2 (0-3) to 0 (0-1) (p<0.0068) and increase in FEV1% from 73.5±19.5% to 87.1±19.2% (p=0.0407) and ACT to a mean value of 22.4±1.7 (p<0.0001) and the interruption of OCSs in all the patients (p<0.0001) was observed. A transient increase in the eosinophil count was observed in five patients (above 1000 cells/μL in 2 cases) after 3 months, without any clinical effect.

CONCLUSION

Dupilumab improved all the explored clinical outcomes after 12 months, and the transient hypereosinophilia did not modify treatment response. These real-world data confirm the results reported in randomized controlled trials and provide an important opportunity to characterize the clinical impact of the treatment in a non-trial setting. Further real-world studies with a larger cohort of patients are needed to confirm these findings.

Exacerbation-Prone Asthma: A Biological Phenotype or a Social Construct

Asthma is a complex syndrome with multiple phenotypes and endotypes. Asthma exacerbations are not only the clearest indictor of the morbidity of asthma and of the risk for mortality due to asthma, but also comprise a significant amount of the cost to care for poorly controlled asthma. There continues to be significant disparity in the prevalence, mortality, and morbidity due to asthma. Patients with asthma who suffer recurrent exacerbations are considered to have exacerbation-prone asthma (EPA). Efforts to characterize patients with frequent exacerbations show that the etiology is likely multifactorial. Research to determine the intrinsic risk factors for EPA include studies of both genetic and inflammatory biomarkers. External factors contributing to exacerbations have been extensively reviewed and include viral infection, environmental exposures, air pollution, and psychosocial and economic barriers to optimizing health. It is likely that EPA occurs when patients who have an increased underlying intrinsic/biological risk are placed in a given exposome (environments with a variety of exposures and triggers including allergens, pollution, stress, barriers, and occupational exposures). It is the social construct combined with underlying biology that frequently drives an EPA phenotype.

Using Computational Methods to Improve Integrated Disease Management for Asthma and Chronic Obstructive Pulmonary Disease: Protocol for a Secondary Analysis

Background

Asthma and chronic obstructive pulmonary disease (COPD) impose a heavy burden on health care. Approximately one-fourth of patients with asthma and patients with COPD are prone to exacerbations, which can be greatly reduced by preventive care via integrated disease management that has a limited service capacity. To do this well, a predictive model for proneness to exacerbation is required, but no such model exists. It would be suboptimal to build such models using the current model building approach for asthma and COPD, which has 2 gaps due to rarely factoring in temporal features showing early health changes and general directions. First, existing models for other asthma and COPD outcomes rarely use more advanced temporal features, such as the slope of the number of days to albuterol refill, and are inaccurate. Second, existing models seldom show the reason a patient is deemed high risk and the potential interventions to reduce the risk, making already occupied clinicians expend more time on chart review and overlook suitable interventions. Regular automatic explanation methods cannot deal with temporal data and address this issue well.

Objective

To enable more patients with asthma and patients with COPD to obtain suitable and timely care to avoid exacerbations, we aim to implement comprehensible computational methods to accurately predict proneness to exacerbation and recommend customized interventions.

Methods

We will use temporal features to accurately predict proneness to exacerbation, automatically find modifiable temporal risk factors for every high-risk patient, and assess the impact of actionable warnings on clinicians’ decisions to use integrated disease management to prevent proneness to exacerbation.

Results

We have obtained most of the clinical and administrative data of patients with asthma from 3 prominent American health care systems. We are retrieving other clinical and administrative data, mostly of patients with COPD, needed for the study. We intend to complete the study in 6 years.

Conclusions

Our results will help make asthma and COPD care more proactive, effective, and efficient, improving outcomes and saving resources.

International Registered Report Identifier (IRRID)

PRR1-10.2196/27065

Total IgE Variability Is Associated with Future Asthma Exacerbations: A 1-Year Prospective Cohort Study

BACKGROUND

Few prospective studies have investigated the relationship between IgE variability and risk for asthma exacerbations (AEs).

OBJECTIVE

To explore the relationship between IgE variability and AEs.

METHODS

Recruited patients with stable asthma underwent two serum total IgE tests within a month (at screening [baseline IgE] and at 1 month) to obtain the coefficient of variation (CV) of base 10 log-transformed IgE. Patients with IgE CV were divided into IgE CV-high and IgE CV-low cohorts based on the CV median and were observed within 12 months, during which the association between IgE variability and AEs was explored using a negative binomial regression model.

RESULTS

The IgE CV levels obtained from 340 patients classified patients into two groups (n = 170 for the IgE CV-high and IgE CV-low groups, respectively) based on the serum total IgE CV median of 2.12% (quartiles 1 and 3: 0.98% and 3.91%, respectively). The IgE CV-high patients exhibited worse asthma control and lung function and more marked airway inflammation, and received more intensive medication use compared with IgE CV-low patients. The IgE CV-high patients exhibited increased rates of moderate-to-severe (adjusted rate ratio = 2.88; 95% confidence interval, 1.65-5.03; P < .001) and severe (adjusted rate ratio = 2.16; 95% confidence interval, 1.08-4.32; P = .029) AEs during the follow-up year compared with IgE CV-low patients. Furthermore, sputum IL-6 partially mediated the associations between IgE CV with moderate-to-severe and severe AEs.

CONCLUSIONS

Variability in total serum IgE levels is an easily obtained and practical measure for predicting AEs. Future studies are needed to investigate whether IgE variability can be used to guide precision medicine in asthma.

Modeling Airway Dysfunction in Asthma Using Synthetic Mucus Biomaterials

As asthma worsens, occlusion of airways with mucus significantly contributes to airflow obstruction and reduced lung function. Recent evidence from clinical studies has shown mucus obtained from adults and children with asthma possesses altered mucin composition. However, how these changes alter the functional properties of the mucus gel is not yet fully understood. To study this, we have engineered a synthetic mucus biomaterial to closely mimic the properties of native mucus in health and disease. We demonstrate that this model possesses comparable biophysical and transport properties to native mucus ex vivo collected from human subjects and in vitro isolated from human airway epithelial (HAE) tissue cultures. We found by systematically varying mucin composition that mucus gel viscoelasticity is enhanced when predominantly composed of mucin 5AC (MUC5AC), as is observed in asthma. As a result, asthma-like synthetic mucus gels are more slowly transported on the surface of HAE tissue cultures and at a similar rate to native mucus produced by HAE cultures stimulated with type 2 cytokine IL-13, known to contribute to airway inflammation and MUC5AC hypersecretion in asthma. We also discovered that the barrier function of asthma-like synthetic mucus toward influenza A virus was impaired as evidenced by the increased frequency of infection in MUC5AC-rich hydrogel-coated HAE cultures. Together, this work establishes a biomaterial-based approach to understand airway dysfunction in asthma and related muco-obstructive lung diseases.

Direct healthcare costs associated with management of asthma: comparison of two treatment regimens in Indonesia, Thailand and Vietnam

OBJECTIVE

Daily inhaled corticosteroid (ICS) and long-acting beta-2-agonist (LABA) combinations comprising either regular maintenance therapy with ICS/LABA plus as-needed short-acting beta-2-agonist (SABA) or ICS-formoterol combinations used as maintenance and reliever therapy (MART) are recommended for moderate asthma. This analysis compares the direct costs of twice-daily fluticasone propionate/salmeterol (FP/salm) and budesonide/formoterol MART in three Southeast Asian countries.

METHODS

A literature review identified three randomized trials in patients with asthma (≥ 12 years) comparing regular twice-daily FP/salm with as-needed SABA versus MART in moderate asthma: AHEAD (NCT00242775/17 countries/2309 patients), COMPASS (AstraZeneca study SD-039-0735/16 countries/3335 patients), and COSMOS (AstraZeneca study SD-039-0691/16 countries/2143 patients). Economic analyses, conducted from a healthcare sector perspective (medication costs + healthcare utilization costs), applied unit costs from countries where healthcare costs are publicly available: Indonesia, Thailand and Vietnam. Results are expressed in British pound sterling (GBP/patient/year).

RESULTS

Annual exacerbation rates were low and differences between treatment strategies were small (range, FP/salm: 0.31-0.38, MART: 0.24-0.25) although statistically significant in favor of MART. Total average (minimum-maximum) direct costs (in GBP/patient/year) across the three studies were £187 (£137-£284), £158 (£125-£190), and £151 (£141-£164) for those who used FP/salm, and £242 (£217-£267), £284 (£237-£340) and £266 (£224-£315) for MART in Indonesia, Thailand and Vietnam, respectively. On average, total direct costs/patient/year with FP/salm were 22.8%, 44.6% and 43.0% lower than with MART for Indonesia, Thailand and Vietnam, respectively.

CONCLUSIONS

In the three countries evaluated, total treatment costs with regular twice-daily FP/salm were consistently lower than with budesonide/formoterol MART due to lower direct healthcare costs.

Clinical and economic burden of severe asthma among US patients treated with biologic therapies

BACKGROUND

Patients with severe asthma may remain uncontrolled despite biologic therapy in addition to standard therapy, but this disease burden has not been quantified.

OBJECTIVE

To estimate the clinical and economic burden in a US national sample.

METHODS

Patients who have severe asthma with indicated biologic treatment (earliest use = index date) were selected from the MarketScan database between January 1, 2013, and June 30, 2018. Inclusion criteria were continuous enrollment for 12 months postindex with a minimum of 2 biologic fills, greater than or equal to 12 years of age, evidence of medium- to high-dose inhaled corticosteroids and long-acting β-agonist combination before the index, and absence of other respiratory diagnoses and malignancies. Disease exacerbations (used to classify asthma control), health care costs, and treatment characteristics were reported during the 12-month postindex period.

RESULTS

The sample included 3262 biologic patients; 88% with anti-immunoglobulin E therapy (omalizumab) and 12% non-anti-immunoglobulin E (reslizumab, mepolizumab, benralizumab). The mean age was 49 (±15) years; 64% were women. Prescriptions included inhaled corticosteroids and long-acting β-agonist (82%), systemic corticosteroids (76%), and leukotriene receptor antagonists (68%). Notably, 63% of patients presented greater than or equal to 1 asthma exacerbation (mean 1.3 per patient/year). Furthermore, 35% of patients were categorized as having controlled asthma, whereas 28% were suboptimally controlled and 29% were uncontrolled. Patients with uncontrolled disease had higher all-cause and asthma-related costs ($69,206 and $45,693, respectively) than patients with suboptimally controlled ($59,407 and $40,793, respectively) or controlled disease ($53,083 and $38,393, respectively). Furthermore, 62% of newly treated patients were persistent with their index biologic.

CONCLUSION

Biologic therapies are effective in reducing exacerbations, but a substantial proportion of patients with severe asthma treated with current biologics continue to experience uncontrolled disease, highlighting a remaining unmet need for patients with severe uncontrolled asthma.

Therapeutic targets in lung tissue remodelling and fibrosis

Structural changes involving tissue remodelling and fibrosis are major features of many pulmonary diseases, including asthma, chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). Abnormal deposition of extracellular matrix (ECM) proteins is a key factor in the development of tissue remodelling that results in symptoms and impaired lung function in these diseases. Tissue remodelling in the lungs is complex and differs between compartments. Some pathways are common but tissue remodelling around the airways and in the parenchyma have different morphologies. Hence it is critical to evaluate both common fibrotic pathways and those that are specific to different compartments; thereby expanding the understanding of the pathogenesis of fibrosis and remodelling in the airways and parenchyma in asthma, COPD and IPF with a view to developing therapeutic strategies for each. Here we review the current understanding of remodelling features and underlying mechanisms in these major respiratory diseases. The differences and similarities of remodelling are used to highlight potential common therapeutic targets and strategies. One central pathway in remodelling processes involves transforming growth factor (TGF)-β induced fibroblast activation and myofibroblast differentiation that increases ECM production. The current treatments and clinical trials targeting remodelling are described, as well as potential future directions. These endeavours are indicative of the renewed effort and optimism for drug discovery targeting tissue remodelling and fibrosis.

γδ T Lymphocytes in Asthma: a Complicated Picture

A minor subset (approximately 5%) of peripheral T cells has their TCR build up from γ and δ chains instead of α and β—those are the γδ T lymphocytes. They can be functionally divided into subsets, e.g., Th1-, Th2-, Th9-, Th17-, Tfh-, and Treg-like γδ T cells. They share some specifics of both innate and adaptive immunity, and are capable of rapid response to a range of stimuli, including some viral and bacterial infections. Atopic diseases, including asthma, are one of major health-related problems of modern western societies. Asthma is one of the most common airway diseases, affecting people of all ages and having potential life-threatening consequences. In this paper, we review the current knowledge about the involvement of γδ T cells in the pathogenesis of asthma and its exacerbations. We summarize both the studies performed on human subjects as well as on the murine model of asthma. γδ T cells seem to be involved in the pathogenesis of asthma, different subsets probably perform opposite functions, e.g., symptom-exacerbating Vγ1 and symptom-suppressing Vγ4 in mice model of asthma.

Trends in US Pediatric Hospital Admissions in 2020 Compared With the Decade Before the COVID-19 Pandemic

IMPORTANCE

In early 2020, the United States declared a public health emergency in response to coronavirus disease 2019 (COVID-19) and implemented a variety of social distancing measures. The association between the COVID-19 pandemic and the number of pediatric admissions is unclear.

OBJECTIVE

To determine the changes in patterns of pediatric admissions in 2020 compared with the prior decade.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included 49 US hospitals contributing to the Pediatric Health Information Systems database. Inpatient admissions were transformed into time-series data, and ensemble forecasting models were generated to analyze admissions across a range of diagnoses in 2020 compared with previous years. The setting was inpatient admissions. All patients discharged between January 1, 2010, and June 30, 2020, from an inpatient hospital encounter were included.

MAIN OUTCOMES AND MEASURES

Number of hospital admissions by primary diagnosis for each encounter.

RESULTS

Of 5 424 688 inpatient encounters among 3 372 839 patients (median [interquartile range] age, 5.1 [0.7-13.3] years; 2 823 748 [52.1%] boys; 3 171 224 [58.5%] White individuals) at 49 hospitals, 213 571 (3.9%) were between January 1, 2020, and June 30, 2020. There was a decrease in the number of admissions beginning in March 2020 compared with the period from 2010 to 2019. At the nadir, admissions in April 2020 were reduced 45.4% compared with prior years (23 798 in April 2020 compared with a median [interquartile range] of 43 550 [42 110-43 946] in April 2010-2019). Inflation-adjusted hospital charges decreased 27.7% in the second quarter of 2020 compared with prior years ($4 327 580 511 in 2020 compared with a median [interquartile range] of $5 983 142 102 [$5 762 690 022-$6 324 978 456] in 2010-2019). Seasonal patterns were evident between 2010 and 2019 for a variety of common pediatric conditions, including asthma, atrial septal defects, bronchiolitis, diabetic ketoacidosis, Kawasaki syndrome, mental health admissions, and trauma. Ensemble models were able to discern seasonal patterns in admission diagnoses and accurately predicted admission rates from July 2019 until December 2019 but not from January 2020 to June 2020. All diagnoses except for birth decreased below the model 95% CIs between January 2020 and June 2020.

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, pediatric admissions to US hospitals decreased in 2020 across an array of pediatric conditions. Although some conditions may have decreased in incidence, others may represent unmet needs in pediatric care during the COVID-19 pandemic.

The dental management of the asthmatic patients

Asthma is the most common chronic respiratory condition characterized by airway inflammation and obstruction. Our increased knowledge and understanding of the etiology and pathogenesis of this condition has widely assisted us in delivering effective therapies. Physicians strive to provide the best treatment modality to achieve symptom-control and minimize the adverse effects of medication use. Nonetheless, patients continue to endure oral complications from the use of asthma medications. As dentists, it is prudent to address these oral complications and promote the oral health of these patients by way of early preventive and therapeutic dental intervention. This must be accomplished by adhering to certain precautionary measures for the sake of avoiding intraoperative problems while optimizing oral care. In this article, we discuss the diagnosis, oral findings, dental care, and emergency management of the asthmatic patients.

Noninvasive Ventilation Use in Critically Ill Patients with Acute Asthma Exacerbations

Rationale: Noninvasive ventilation decreases the need for invasive mechanical ventilation and mortality among patients with chronic obstructive pulmonary disease but has not been well studied in asthma.Objectives: To assess the association between noninvasive ventilation and subsequent need for invasive mechanical ventilation and in-hospital mortality among patients admitted with asthma exacerbation to the ICU.Methods: We performed a retrospective cohort study using administrative data collected during 2010-2017 from 682 hospitals in the United States. Outcomes included receipt of invasive mechanical ventilation and in-hospital mortality. Generalized estimating equations, propensity-matched models, and marginal structural models were used to assess the association between noninvasive ventilation and outcomes.Measurements and Main Results: The study population included 53,654 participants with asthma exacerbation. During the study period, 13,540 patients received noninvasive ventilation (25.2%; 95% confidence interval [CI], 24.9-25.6%), 14,498 underwent invasive mechanical ventilation (27.0%; 95% CI, 26.7-27.4%), and 1,291 died (2.4%; 95% CI, 2.3-2.5%). Among those receiving noninvasive ventilation, 3,013 patients (22.3%; 95% CI, 21.6-23.0%) required invasive mechanical ventilation after first receiving noninvasive ventilation, 136 of whom died (4.5%; 95% CI, 3.8-5.3%). Across all models, the use of noninvasive ventilation was associated with a lower odds of receiving invasive mechanical ventilation (adjusted generalized estimating equation odds ratio, 0.36; 95% CI, 0.32-0.40) and in-hospital mortality (odds ratio, 0.48; 95% CI 0.40-0.58). Those who received noninvasive ventilation before invasive mechanical ventilation were more likely to have comorbid pneumonia and severe sepsis.Conclusions: Noninvasive ventilation use during asthma exacerbation was associated with improved outcomes but should be used cautiously with acute comorbid conditions.

Risk Factors Associated With Frequent Acute Exacerbations of Asthma

Introduction: Asthma can lead to fatigue, frequent hospital visits, psychological problems, and learning problems in children. One of the complications of asthma is its life-threatening acute exacerbation. It is important to identify precipitating factors responsible for frequent acute exacerbations of asthma.

Methods: This case-control study was conducted in the pulmonology ward of Liaquat University of Medical and Health Sciences, Jamshoro, from May 2019 to February 2020. Sampling was done by convenient probability technique. The case group was identified as patients with two or more episodes of acute exacerbation of asthma and the control group was identified as asthmatic patients without acute exacerbation in the last year.

Results: Factors leading to acute exacerbation of asthma include number of asthma attacks in the past seven days (4.9 ± 3.4 vs. 2.2 ± 2.0; p < 0.0001) and number of nights with troublesome cough in the past 28 days (12.2 ± 8.1 vs. 4.3 ± 3.1; p < 0.0001). Participants with recent upper respiratory tract infection (38.4% vs. 10%; odds ratio [OR] 5.62), smoking history (30.7% vs. 12%; OR 3.25), gastroesophageal reflux disease (26.9% vs. 8.0%; OR 4.2) and non-adherence to medication (26.9% vs. 8.0%; OR 4.2) were more likely to experience from exacerbation of asthma.

Conclusion: It is important to identify risk factors that may cause acute exacerbation of asthma in the patients. Patients should be educated of the risk factors and complications of the exacerbation episode of asthma.