Asthma exacerbations. 2: aetiology

Risk factors for asthma-related hospital and intensive care admissions in children, adolescents and adults: a cohort study using primary and secondary care data

BACKGROUND

Asthma remains a common cause of hospital admissions across the life course. We estimated the contribution of key risk factors to asthma-related hospital and intensive care unit (ICU) admissions in children, adolescents and adults.

METHODS

This was a UK-based cohort study using linked primary care (Clinical Practice Research Datalink Aurum) and secondary care (Hospital Episode Statistics Admitted Patient Care) data. Patients were eligible if they were aged 5 years and older and had been diagnosed with asthma. This included 90 989 children aged 5-11 years, 114 927 adolescents aged 12-17 years and 1 179 410 adults aged 18 years or older. The primary outcome was asthma-related hospital admissions from 1 January 2017 to 31 December 2019. The secondary outcome was asthma-related ICU admissions. Incidence rate ratios adjusted for demographic and clinical risk factors were estimated using negative binomial models. Population attributable fraction (PAF) was estimated for modifiable risk factors.

RESULTS

Younger age groups, females and those from ethnic minority and lower socioeconomic backgrounds had an increased risk of asthma-related hospital admissions. Increasing medication burden, including excessive use of short-acting bronchodilators, was also strongly associated with the primary outcome. Similar risk factors were observed for asthma-related ICU admissions. The key potentially modifiable or treatable risk factors were smoking in adolescents and adults (PAF 6.8%, 95% CI 0.9% to 12.3% and 4.3%, 95% CI 3.0% to 5.7%, respectively), and obesity (PAF 23.3%, 95% CI 20.5% to 26.1%), depression (11.1%, 95% CI 9.1% to 13.1%), gastro-oesophageal reflux disease (2.3%, 95% CI 1.2% to 3.4%), anxiety (2.0%, 95% CI 0.5% to 3.6%) and chronic rhinosinusitis (0.8%, 95% CI 0.3% to 1.3%) in adults.

CONCLUSIONS

There are significant sociodemographic inequalities in the rates of asthma-related hospital and ICU admissions. Treating age-specific modifiable risk factors should be considered an integral part of asthma management, which could potentially reduce the rate of avoidable hospital admissions.

[Burden and management of severe asthma in Russia: results from international observational study]

AIM

To assess clinical and demographic characteristics of severe asthma (SA) patients and their management in Russian Federation.

MATERIALS AND METHODS

This publication provides data for Russian part of population of the international observational study. In Phase I, retrospective analysis of medical records of patients with SA was performed with assessment of clinical and demographic data, medical history, comorbidities, treatment approaches and healthcare utilization. Phase II was a cross-sectional collection of patient-reported outcomes: level of asthma control assessed by ACT (Asthma Control Test) and health-related quality of life (HRQoL) measured using the EQ-5D-5L questionnaire. Phase I patients were enrolled into Phase II if they signed a written consent form.

RESULTS

A total of 315 patients were included in Phase I of the study, 106 (33.6%) of them entered Phase II. Majority of study participants were either obese (n=103; 39.8%) or overweight (n=94; 36.3%). The most common comorbidities were cardiovascular diseases (n=217; 71.4%), followed by chronic respiratory diseases (n=198; 68.8%). There were 268 (85.1%) patients who had at least one exacerbation during last 12 months. Data for blood eosinophil count were available in 176 patients; 81.3% of them (n=143) had only one test in the last 12 months. The mean (SD) last available blood eosinophil count was 161.2 (181.2) cells/mm3. Serum Immunoglobulin E (IgE) value was known for 88 patients, and the mean (SD) last measured IgE value was 254.3 (249.7) ng/mL. Only 4.7% of Phase II participants had ACT scores indicative of controlled asthma (>20). As much as 74.5% had scores ≤15 suggesting uncontrolled disease. Most patients also had impaired HRQoL.

CONCLUSION

Most SA patients had poor disease control with frequent exacerbations and high number of comorbidities. Blood eosinophils and IgE level measurements were not evaluated routinely which might be a barrier for appropriate phenotyping and treatment selection.

Predicting the risk of acute respiratory failure among asthma patients-the A2-BEST2 risk score: a retrospective study

Objectives

Acute respiratory failure (ARF) is a common complication of bronchial asthma (BA). ARF onset increases the risk of patient death. This study aims to develop a predictive model for ARF in BA patients during hospitalization.

Methods

This was a retrospective cohort study carried out at two large tertiary hospitals. Three models were developed using three different ways: (1) the statistics-driven model, (2) the clinical knowledge-driven model, and (3) the decision tree model. The simplest and most efficient model was obtained by comparing their predictive power, stability, and practicability.

Results

This study included 398 patients, with 298 constituting the modeling group and 100 constituting the validation group. Models A, B, and C yielded seven, seven, and eleven predictors, respectively. Finally, we chose the clinical knowledge-driven model, whose C-statistics and Brier scores were 0.862 (0.820-0.904) and 0.1320, respectively. The Hosmer-Lemeshow test revealed that this model had good calibration. The clinical knowledge-driven model demonstrated satisfactory C-statistics during external and internal validation, with values of 0.890 (0.815-0.965) and 0.854 (0.820-0.900), respectively. A risk score for ARF incidence was created: The A2-BEST2 Risk Score (A2 (area of pulmonary infection, albumin), BMI, Economic condition, Smoking, and T2(hormone initiation Time and long-term regular medication Treatment)). ARF incidence increased gradually from 1.37% (The A2-BEST2 Risk Score ≤ 4) to 90.32% (A2-BEST2 Risk Score ≥ 11.5).

Conclusion

We constructed a predictive model of seven predictors to predict ARF in BA patients. This predictor's model is simple, practical, and supported by existing clinical knowledge.

Rebound in asthma exacerbations following relaxation of COVID-19 restrictions: a longitudinal population-based study (COVIDENCE UK)

BACKGROUND

The imposition of restrictions on social mixing early in the COVID-19 pandemic was followed by a reduction in asthma exacerbations in multiple settings internationally. Temporal trends in social mixing, incident acute respiratory infections (ARI) and asthma exacerbations following relaxation of COVID-19 restrictions have not yet been described.

METHODS

We conducted a population-based longitudinal study in 2312 UK adults with asthma between November 2020 and April 2022. Details of face covering use, social mixing, incident ARI and severe asthma exacerbations were collected via monthly online questionnaires. Temporal changes in these parameters were visualised using Poisson generalised additive models. Multilevel logistic regression was used to test for associations between incident ARI and risk of asthma exacerbations, adjusting for potential confounders.

RESULTS

Relaxation of COVID-19 restrictions from April 2021 coincided with reduced face covering use (p<0.001), increased frequency of indoor visits to public places and other households (p<0.001) and rising incidence of COVID-19 (p<0.001), non-COVID-19 ARI (p<0.001) and severe asthma exacerbations (p=0.007). Incident non-COVID-19 ARI associated independently with increased risk of asthma exacerbation (adjusted OR 5.75, 95% CI 4.75 to 6.97) as did incident COVID-19, both prior to emergence of the omicron variant of SARS-CoV-2 (5.89, 3.45 to 10.04) and subsequently (5.69, 3.89 to 8.31).

CONCLUSIONS

Relaxation of COVID-19 restrictions coincided with decreased face covering use, increased social mixing and a rebound in ARI and asthma exacerbations. Associations between incident ARI and risk of severe asthma exacerbation were similar for non-COVID-19 ARI and COVID-19, both before and after emergence of the SARS-CoV-2 omicron variant.

STUDY REGISTRATION NUMBER

NCT04330599.

Influence of toll-like receptor-4 antagonist on bacterial load of asthma in Swiss albino mice: targeting TLR4/MD2 complex pathway

Air pollution and environmental issues significantly impact life, resulting in the emergence and exacerbation of allergic asthma and other chronic respiratory infections. The main objective of this study is to suppress allergic asthma by TAK-242 from lipopolysaccharide-induced airway inflammation primarily stimulating toll-like receptor-4, and also to determine the potential mechanism of asthma eradication. The TAK-242 anti-allergic action was assured through the ovalbumin murine model of asthma via bronchial hyperresponsiveness and inflammation of the respiration tract in a pre-existing allergic inflammation paradigm. Swiss albino mice were sensitized and then challenged by ovalbumin and lipopolysaccharide for 5 days straight. TAK-242 reaction was assessed by inflammatory cytokines, and inflammatory cell count was determined from blood serum and bronchoalveolar lavage fluid, as well as group-wise regular weight assessments. After ovalbumin, lipopolysaccharide infusion, toll-like receptor-4 agonists caused a substantial increase in airway hyperresponsiveness, specific cellular inflammation, histological alterations, and immune mediator synthesis, as well as dose-related body-weight variations. A decrease in lipopolysaccharide-induced leukocyte count and Th1/Th17 related cytokines, TNF-α, and IL-6 expression through the ELISA study was particularly noticeable. Finally in treated groups, TAK-242, a TLR4/MD2 complex inhibitor, reduced airway inflammation and histopathological changes, cytokine expression, and body-weight management. TAK-242 has been found in an ovalbumin allergic asthma model to be a potential inhibitor of lipopolysaccharide-induced respiratory infection.

Vitamin D for the management of asthma

BACKGROUND

Since the previous Cochrane Review on this topic in 2016, debate has continued surrounding a potential role for vitamin D in reducing risk of asthma exacerbation and improving asthma control. We therefore conducted an updated meta-analysis to include data from new trials completed since this date.

OBJECTIVES

To evaluate the effectiveness and safety of administration of vitamin D or its hydroxylated metabolites in reducing the risk of severe asthma exacerbations (defined as those requiring treatment with systemic corticosteroids) and improving asthma symptom control.

SEARCH METHODS

We searched the Cochrane Airways Group Trial Register and reference lists of articles. We contacted the authors of studies in order to identify additional trials. Date of last search: 8 September 2022.

SELECTION CRITERIA

We included double-blind, randomised, placebo-controlled trials of vitamin D in children and adults with asthma evaluating exacerbation risk or asthma symptom control, or both.

DATA COLLECTION AND ANALYSIS

Four review authors independently applied study inclusion criteria, extracted the data, and assessed risk of bias. We obtained missing data from the authors where possible. We reported results with 95% confidence intervals (CIs). The primary outcome was the incidence of severe asthma exacerbations requiring treatment with systemic corticosteroids. Secondary outcomes included the incidence of asthma exacerbations precipitating an emergency department visit or requiring hospital admission, or both, end-study childhood Asthma Control Test (cACT) or Asthma Control Test (ACT) scores, and end-study % predicted forced expiratory volume in one second (FEV1). We performed subgroup analyses to determine whether the effect of vitamin D on risk of asthma exacerbation was modified by baseline vitamin D status, vitamin D dose, frequency of dosing regimen, form of vitamin D given, and age of participants.

MAIN RESULTS

We included 20 studies in this review; 15 trials involving a total of 1155 children and five trials involving a total of 1070 adults contributed data to analyses. Participant ages ranged from 1 to 84 years, with two trials providing data specific to participants under five years (n = 69) and eight trials providing data specific to participants aged 5 to 16 (n = 766). Across the trials, 1245 participants were male and 1229 were female, with two studies not reporting sex distribution. Fifteen trials contributed to the primary outcome analysis of exacerbations requiring systemic corticosteroids. The duration of trials ranged from three to 40 months; all but two investigated effects of administering cholecalciferol (vitamin D3). As in the previous Cochrane Review, the majority of participants had mild to moderate asthma, and profound vitamin D deficiency (25-hydroxyvitamin D (25(OH)D) < 25 nmol/L) at baseline was rare. Administration of vitamin D or its hydroxylated metabolites did not reduce or increase the proportion of participants experiencing one or more asthma exacerbations treated with systemic corticosteroids (odds ratio (OR) 1.04, 95% CI 0.81 to 1.34; I2 = 0%; 14 studies, 1778 participants; high-quality evidence). This equates to an absolute risk of 226 per 1000 (95% CI 185 to 273) in the pooled vitamin D group, compared to a baseline risk of 219 participants per 1000 in the pooled placebo group. We also found no effect of vitamin D supplementation on the rate of exacerbations requiring systemic corticosteroids (rate ratio 0.86, 95% CI 0.62 to 1.19; I2 = 60%; 10 studies, 1599 participants; high-quality evidence), or the time to first exacerbation (hazard ratio 0.82, 95% CI 0.59 to 1.15; I2 = 22%; 3 studies, 850 participants; high-quality evidence). Subgroup analysis did not reveal any evidence of effect modification by baseline vitamin D status, vitamin D dose, frequency of dosing regimen, or age. A single trial investigating administration of calcidiol reported a benefit of the intervention for the primary outcome of asthma control. Vitamin D supplementation did not influence any secondary efficacy outcome meta-analysed, which were all based on moderate- or high-quality evidence. We observed no effect on the incidence of serious adverse events (OR 0.89, 95% CI 0.56 to 1.41; I2 = 0%; 12 studies, 1556 participants; high-quality evidence). The effect of vitamin D on fatal asthma exacerbations was not estimable, as no such events occurred in any trial. Six studies reported adverse reactions potentially attributable to vitamin D. These occurred across treatment and control arms and included hypercalciuria, hypervitaminosis D, kidney stones, gastrointestinal symptoms and mild itch. In one trial, we could not ascertain the total number of participants with hypercalciuria from the trial report. We assessed three trials as being at high risk of bias in at least one domain; none of these contributed data to the analysis of the outcomes reported above. Sensitivity analyses that excluded these trials from each outcome to which they contributed did not change the null findings.

AUTHORS' CONCLUSIONS

In contrast to findings of our previous Cochrane Review on this topic, this updated review does not find evidence to support a role for vitamin D supplementation or its hydroxylated metabolites to reduce risk of asthma exacerbations or improve asthma control. Participants with severe asthma and those with baseline 25(OH)D concentrations < 25 nmol/L were poorly represented, so further research is warranted here. A single study investigating effects of calcidiol yielded positive results, so further studies investigating effects of this metabolite are needed.

Asthma Care in the Elderly: Practical Guidance and Challenges for Clinical Management - A Framework of 5 "Ps"

Uncontrolled asthma in the elderly is a public health issue recognized in developed countries such as the United States and among the European Union, both from patient safety and economic perspectives. Variations in the cutoff, which defines elderly age, contribute to epidemiological study difficulties. Nonetheless, the relevance of elderly asthma from a socioeconomic perspective is inarguable. The projected growth of the enlarging geriatric population in the United States portends an impending national health burden that may or may not be preventable with pharmacologic and non-pharmacologic treatments. Asthma in the elderly might be a consequence of uncontrolled disease that is carried throughout a lifetime. Or elderly asthmatics could suffer from uncontrolled asthma, which overlaps with other ailments common with advancing ages that merit consideration, eg, COPD, heart disease, OSA, diabetes mellitus, and other comorbidities. Because of the heterogeneity of asthma phenotypes and other conditions that could mimic the symptoms of elderly asthma, further cohort studies are needed to elucidate the elderly asthmatic pathophysiology and management. More studies to characterize elderly asthma can help address these patients' unmet need for evidence-based guidelines. We introduce the 5 "Ps" (phenotypes, partnership, pharmacology, practice in acute exacerbations, and problems or barriers for the elderly asthmatics) that establish a framework approach for clinical practice.

The CRTh2 polymorphism rs533116 G > A associates with asthma severity in older females

Background

CRTh2 is G protein coupled receptor for prostaglandin D2 (PGD)₂ expressed by immune cells that drive type 2 inflammation such as CD4⁺ T cells (Th2), eosinophils and group 2 innate lymphoid cells (ILC2) as well as structural cells including smooth muscle and epithelium. CRTh2-expressing cells are increased in the blood and airways of asthmatics and severe asthma is characterized by increased activity of the PGD₂-CRTh2 pathway. The CRTh2 single nucleotide polymorphism (SNP) rs533116 G > A is associated with development of asthma and increased Th2 cell differentiation.

Objective

To examine whether CRTh2 rs533116G > A associates with asthma severity. Since severe asthma is more common in females than males, we performed a sex-stratified analysis.

Methods

Clinical data from asthmatics (n = 170) were obtained from clinic visits and chart review. Asthma severity was assessed according to ERS/ATS guidelines. Peripheral blood cells were characterized by flow cytometry and qRT-PCR. Genotyping was performed by TaqMan assay.

Results

Older females (≥45 years) homozygous for minor A allele of rs533116 were more likely to have severe asthma, lower FEV₁, a higher prescribed dose of inhaled corticosteroid and more type 2 inflammation than females carrying GA or GG genotypes. Comparing females and males with the AA genotype also revealed that women had more type 2 inflammation.

Conclusions and significance

The polymorphism CRTh2 rs533116 G > A associates with severe asthma and type 2 inflammation in older females. This study reveals a gene-sex-aging interaction influencing the effect of CRTh2 on asthma severity.

Drivers of respiratory health care demand in Acre state, Brazilian Amazon: a cross-sectional study

Background

The scarce knowledge about the drivers of demand for respiratory health care in the Brazilian Amazon, where the gap of human and physical health care resources is wide, is expanded with two surveys conducted in the west of the region, in Acre state. Potential drivers, informed by a review of twelve recent papers, were classified into seven categories capturing the individual, household, community and macroeconomic dimensions.

Methods

Quantitative field surveys were conducted in 2017 and 2019 based on coupled conglomerate-quota randomization sampling. Adults responded about their own health or their children’s health. The probability of seeking physician care for the latest episode of respiratory illness or dry cough was analysed with multiple nonlinear regressions, having as covariates the potential predictors informed by the literature.

Results

The propensity to seek health care and to purchase medication was larger for children. Influenza-like illness (Despite the exact diagnostic stated by respondents being “influenza”, a virus detection test (such as the PCR test) is not commonly applied, as informed by the Acre state public health service. In consistency, the term “influenza-like illness” is used.) was the most frequently diagnosed disease, followed by pneumonia, suggesting that a health care-seeking rate below 40% may perpetuate health impairment and local contagion. Illnesses’ severity, including the pain experienced, was the main predictor, revealing that subjective perception was more influential than objective individual and household characteristics.

Conclusions

The results suggest that subjective underestimation of respiratory illnesses’ consequences for oneself and for local society could prevent health care from being sought. This is in line with some previous studies but departs from those emphasizing the role of objective factors. Social consequences, of, for instance, a macroeconomic nature, need to be highlighted based on studies detecting long-run relationships among health care demand, health and economic performance at the national level. Depending on the intensity of the trade-off between the costs imposed on the health system by increased demand and on the economy by the reduced productivity of the ill, policy could be adopted to change subjective perceptions of illnesses with nudges and educational and informational interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14171-z.

Acute asthma exacerbation due to SARS-CoV-2 vaccine (Pfizer-BioNTech BNT162b2 mRNA COVID-19 vaccine [Comirnaty®])

The messenger RNA vaccine against SARS-CoV-2 is effective at preventing COVID-19-associated hospitalization, and the Centers for Disease Control and Prevention has recommended vaccination for all eligible individuals. We demonstrate a case involving a patient who developed a life-threatening acute asthma exacerbation after receiving their third dose of the BNT16b2 vaccine. Because eosinophilia was observed after the second inoculation, it was considered likely that the patient had been sensitized to the BNT16b2 vaccine. Theoretically, the SARS-CoV-2 vaccine could trigger the exacerbation of asthma. It should be recognized that repeated SARS-CoV-2 vaccination may be a risk factor for the acute exacerbation of asthma.

Vulnerability for Respiratory Infections in Asthma Patients: A Systematic Review

Asthma is a non-communicable and long-term condition affecting children and adults. The air passages in the lungs become narrow due to inflammation and tightening of the muscles around the small airways. Symptoms of asthma are intermittent and include cough, wheeze, shortness of breath, and chest tightness. Asthma is very often underdiagnosed and under-treated in many regions, especially in developing countries. While many studies show that viral infections can precipitate asthmatic attacks, very few studies have been conducted to see if history or current asthmatic attack increases the risk of viral infections. Our study aims to determine the predisposition of asthmatics to develop various viral infections and susceptibility toward certain viruses that cause upper respiratory tract infections.

We performed a literature review of both published and unpublished articles. We included case reports, case series, reviews, clinical trials, cohort, and case-control studies, written only in English. Commentaries, letters to editors, and book chapters were excluded. Our initial search yielded 948 articles, of which 826 were rejected either because they were irrelevant or because they did not meet our inclusion criteria. We finally screened 122 abstracts and identified 24 relevant articles.

People with a history of asthma have an abnormal innate immune response, making them potentially slower in clearing the infection and susceptible to both infections and virus-induced cell cytotoxicity. Also, in these studies, deficiencies in the interferon alpha response of peripheral blood mononuclear cells and plasmacytoid dendritic cells have been observed in asthmatics, both adults and children. Asthmatics with a viral infection usually present with an acute exacerbation of asthma, represented by dyspnea and cough, with other prodromal symptoms including vomiting and general malaise.

The review includes an update on the relevance of dysregulated immune pathways in causing viral infections in asthmatic populations. It focuses on the evidence to suggest that people with asthma are at increased risk of viral infection, and viral infections in turn are known to precipitate and worsen the asthmatic status, making this a vicious cycle. The authors also suggest that further studies be undertaken to elucidate the pathophysiology and identify the critical therapeutic steps to break this vicious cycle and improve the quality of life for people with asthma.

Real-life Effectiveness of Omalizumab in Patients with Severe Allergic Asthma: RELIEF Study

Introduction:

Patients with severe allergic asthma (SAA) are at risk of severe exacerbations. Omalizumab is recommended as an add-on treatment for patients with uncontrolled SAA, despite high-dose inhaled corticosteroids and long acting β2-agonist combination therapy (standard therapy).

RELIEF was a prospective, open label, multicenter study conducted to assess the real-life effectiveness of omalizumab co-administered with standard therapy in patients with SAA for 24 months.

Methods:

A total of 347 patients aged ≥ 6 years with SAA were enrolled, 285 of whom (8 pediatrics and 277 adolescents and adults) completed this 24-month study. Compared with the 12 months prior to baseline, the mean number of exacerbations was reduced in the overall population at any time interval during the study. Proportion of patients with no exacerbations increased to 77.7% at 24 months from 32.6% at 12 months prior to baseline. A reduction in healthcare resource utilization was also observed. The mean number of specialist visits reduced from baseline (5.8 visits) to 2.4 visits at Month 24.

Results:

The mean asthma control test score was >19 at every time-point during the study. The rate of Global Evaluation of Treatment Effectiveness (GETE) for asthma response significantly increased at Months 18 and 24 (P <0.05) compared to baseline. Pulmonary function remained relatively stable for the overall study population. There were no new or unexpected safety findings in the study.

Conclusion:

RELIEF study showed that add-on therapy with omalizumab is effective in reducing exacerbations, healthcare utilization, and improving GETE score in patients with SAA uncontrolled by standard therapy.

Serum Amyloid A1: A Biomarker for Neutrophilic Airway Inflammation in Adult Asthmatic Patients

Purpose

We evaluated the role of serum amyloid A1 (SAA1) in the pathogenesis of airway inflammation according to the phenotype of asthma.

Methods

One hundred twenty-two asthmatic patients and 60 healthy control subjects (HCs) were enrolled to measure SAA1 levels. The production of SAA1 from airway epithelial cells (AECs) and its effects on macrophages and neutrophils were investigated in vitro and in vivo.

Results

The SAA1 levels were significantly higher in sera of asthmatic patients than in those of HCs (P = 0.014); among asthmatics, patients with neutrophilic asthma (NA) showed significantly higher SAA1 levels than those with non-NA (P < 0.001). In vitro, polyinosinic:polycytidylic acid (Poly I-C) treatment markedly enhanced the production of SAA1 from AECs, which was further augmented by neutrophils; SAA1 could induce the production of interleukin (IL)-6, IL-8, and S100 calcium-binding protein A9 from AECs. Additionally, SAA1 activated neutrophils and macrophages isolated from peripheral blood of asthmatics, releasing neutrophil extracellular traps (NETs) and secreting proinflammatory cytokines presenting M1 phenotype, respectively. In ovalbumin-induced asthma mice, Poly I-C treatment significantly increased SAA1 levels as well as IL-17A/interferon-gamma/IL-33 levels in bronchoalveolar lavage fluid (BALF), leading to airway hyperresponsiveness and inflammation. The highest levels of SAA1 and neutrophilia were noted in the BALF and sera of the NA mouse model, followed by the mixed granulocytic asthma (MA) model. Especially, SAA1 induced IL-17/retinoic acid receptor-related orphan receptor γt expression from activated CD4+ T lymphocytes in asthmatic mice.

Conclusions

The results show that SAA1 could induce neutrophilic airway inflammation by activating neutrophils along with NET formation, M1 macrophages, and Th2/Th17 predominant cells, contributing to the phenotype of NA or MA.

Viral burden and diversity in acute respiratory tract infections in hospitalized children in wet and dry zones of Sri Lanka

The present study was done to identify the viral diversity, seasonality and burden associated with childhood acute respiratory tract infection (ARTI) in Sri Lanka. Nasopharyngeal aspirates (NPA) of hospitalized children (1 month-5 years) with ARTI were collected in 2 centers (wet and dry zones) from March 2013 to August 2014. Respiratory viral antigen detection by immunofluorescence assay (IFA) was used to identify the infecting viruses. IFA negative 100 NPA samples were tested for human metapeumovirus (hMPV), human bocavirus and corona viruses by polymerase chain reaction. Of the 443 and 418 NPAs, 37.2% and 39.4% were positive for any of the 8 different respiratory viruses tested from two centers studied. Viral co-infection was detected with respiratory syncytial virus (RSV) in both centers. Peak viral detection was noted in the wet zone from May-July 2013 and 2014 and in the dry zone from December-January 2014 suggesting a local seasonality for viral ARTI. RSV showed a clear seasonality with a direct correlation of monthly RSV infections with rainy days in the wet zone and an inverse correlation with temperature in both centers. The case fatality rate was 2.7% for RSV associated ARTI. The overall disability adjusted life years was 335.9 and for RSV associated ARTI it was 241.8. RSV was the commonly detected respiratory virus with an annual seasonality and distribution in rainy seasons in the dry and wet zones of Sri Lanka. Identifying the virus and seasonality will contribute to employ preventive measures and reduce the empirical use of antibiotics in resource limited settings.

Current Knowledge of Asthma-COPD Overlap (ACO) Genetic Risk Factors, Characteristics, and Prognosis

Asthma-COPD overlap (ACO) is a newly identified phenotype of chronic obstructive airway diseases with shared asthma and COPD features. Patients with ACO are poorly defined, and some evidence suggests that they have worse health outcomes and greater disease burden than patients with COPD or asthma. Generally, there is no evidence-based and universal definition for ACO; several consensus documents have provided various descriptions of the phenotype. In addition, the mechanisms underlying the development of ACO are not fully understood. Whether ACO is a distinct clinical entity with its particular discrete genetic determinant different from asthma and COPD alone or an intermediate phenotype with overlapping genetic markers within asthma and COPD spectrum of obstructive airway disease remains unproven. This review summarizes the current knowledge of the genetic risk factors, characteristics, and prognosis of ACO.

Effect of exacerbation history on clinical response to dupilumab in moderate-severe uncontrolled asthma

Background

The phase 3 LIBERTY ASTHMA QUEST study (ClinicalTrials.gov: NCT02414854) in patients with uncontrolled, moderate-to-severe asthma has demonstrated the efficacy and safety of dupilumab 200 and 300 mg every 2 weeks versus placebo. This post hoc analysis assessed the effect of dupilumab on efficacy outcomes and asthma control across a range of historical exacerbation rates in patients with type 2-high asthma.

Methods

Annualised severe exacerbation rates over the 52-week treatment period, pre-bronchodilator forced expiratory volume in 1 s (FEV₁) at weeks 12 and 52, and the five-item Asthma Control Questionnaire (ACQ-5) score at weeks 24 and 52 were assessed in patients with ≥1, ≥2 or ≥3 exacerbations in the previous year. Subgroups were stratified by baseline blood eosinophils ≥150 or ≥300 cells·μL⁻¹ or baseline exhaled nitric oxide fraction ≥25 ppb and baseline inhaled corticosteroid (ICS) dose.

Results

Across all type 2-high subgroups, dupilumab versus placebo significantly reduced severe exacerbations by 54–90%, with greater improvements in patients with more exacerbations prior to study initiation. Similarly, improvements in FEV₁ (least squares (LS) mean difference versus placebo: ≥1 exacerbations, 0.15–0.25 L; ≥2 exacerbations, 0.12–0.32 L; ≥3 exacerbations, 0.09–0.38 L; majority p<0.05) and ACQ-5 score (LS mean difference range: ≥1 exacerbations, −0.30 to −0.57; ≥2 exacerbations, −0.29 to −0.56; ≥3 exacerbations, −0.43 to −0.61; all p<0.05) were observed, irrespective of prior exacerbation history, across all subgroups.

Conclusions

Dupilumab significantly reduced severe exacerbations and improved FEV₁ and asthma control in patients with elevated type 2 biomarkers irrespective of exacerbation history and baseline ICS dose.

Dupilumab reduced severe exacerbations and improved lung function and asthma control in patients with type 2-high asthma, irrespective of exacerbation history and baseline ICS dose. These data will aid clinicians managing patients with severe disease.https://bit.ly/2PjnSm6

Single-cell transcriptomic analysis reveals the immune landscape of lung in steroid-resistant asthma exacerbation

Exaggerated airway hyperresponsiveness and inflammation are hallmarks of asthma, and lipopolysaccharide (LPS) exposure is linked to the severity of the disease and steroid resistance. To investigate the mechanisms underlying asthma exacerbation, we established a mouse model of LPS-induced steroid-resistant exacerbation on the background of house dust mite (HDM)-induced asthma to profile the immune cells in lung by using single-cell RNA deep sequencing. Twenty immune subsets were identified by their molecular and functional properties. Specific cell clusters of basophils, type 2 innate lymphoid cells (ILC2), and CD8+ memory T cells were the predominant sources of interleukin (IL)-4 and IL-13 transcripts whose expressions were dexamethasone resistant. Production of IL-13 by these cells was validated by IL-13-reporter mice. Neutralization of IL-13 abolished HDM/LPS-induced airway hyperresponsiveness, airway inflammation, and decreased mucus hypersecretion. Furthermore, using Ingenuity Pathway Analysis systems, we identified canonical pathways and upstream regulators that regulate the activation of basophils, ILC2, and CD8+ memory T cells. Our study provides mechanistic insights and an important reference resource for further understanding of the immune landscape during asthma exacerbation.

Inhibition of miR-99a-5p prevents allergen-driven airway exacerbations without compromising type-2 memory responses in the intestine following helminth infection

Acute exacerbations (AE) of asthma, remain one of the biggest concerns for patients living with asthma. As such, identifying the causes, the molecular mechanisms involved and new therapeutic interventions to prevent AE is a high priority. Immunity to intestinal helminths involves the reactivation of type-2 immune responses leading to smooth muscle contraction and mucus hypersecretion-physiological processes very similar to acute exacerbations in the airways following allergen exposure. In this study, we employed a murine model of intestinal helminth infection, using Heligmosomoides polygyrus, to identify miRNAs during active expulsion, as a system for the identification of miRNAs that may contribute to AE in the airways. Concomitant with type-2 immunity and expulsion of H. polygyrus, we identified miR-99a-5p, miR-148a-3p and miR-155-5p that were differentially regulated. Systemic inhibition of these miRNAs, alone or in combination, had minimal impact on expulsion of H. polygyrus, but inhibition of miR-99a-5p or miR-155-5p significantly reduced house dust mite (HDM)-driven acute inflammation, modelling human acute exacerbations. Immunological, pathological and transcriptional analysis identified that miR-155-5p or miR-99a-5p contribute significantly to HDM-driven AE and that transient inhibition of these miRNAs may provide relief from allergen-driven AE, without compromising anti-helminth immunity in the gut.

TLR3/TAK1 signalling regulates rhinovirus-induced interleukin-33 in bronchial smooth muscle cells

Background

Asthma exacerbations are commonly associated with rhinovirus (RV) infection. Interleukin-33 (IL-33) plays an important role during exacerbation by enhancing Type 2 inflammation. Recently we showed that RV infects bronchial smooth muscle cells (BSMCs) triggering production of interferons and IL-33. Here we compared levels of RV-induced IL-33 in BSMCs from healthy and asthmatic subjects, and explored the involvement of pattern-recognition receptors (PRRs) and downstream signalling pathways in IL-33 expression.

Method

BSMCs from healthy and severe and non-severe asthmatic patients were infected with RV1B or stimulated with the PRR agonists poly(I:C) (Toll-like receptor 3 (TLR3)), imiquimod (TLR7) and poly(I:C)/LyoVec (retinoic acid-inducible gene 1 (RIG-I)/melanoma differentiation-associated protein 5 (MDA5)). Knockdown of TLR3, RIG-I and MDA5 was performed, and inhibitors targeting TBK1, nuclear factor-κB (NF-κB) and transforming growth factor (TGF)-β-activated kinase 1 (TAK1) were used. Gene and protein expression were assessed.

Results

RV triggered IL-33 gene and protein expression in BSMCs. BSMCs from patients with non-severe asthma showed higher baseline and RV-induced IL-33 gene expression compared to cells from patients with severe asthma and healthy controls. Furthermore, RV-induced IL-33 expression in BSMCs from healthy and asthmatic individuals was attenuated by knockdown of TLR3. Inhibition of TAK1, but not NF-κB or TBK1, limited RV-induced IL-33. The cytokine secretion profile showed higher production of IL-33 in BSMCs from patients with non-severe asthma compared to healthy controls upon RV infection. In addition, BSMCs from patients with non-severe asthma had higher levels of RV-induced IL-8, TNF-α, IL-1β, IL-17A, IL-5 and IL-13.

Conclusion

RV infection caused higher levels of IL-33 and increased pro-inflammatory and Type 2 cytokine release in BSMCs from patients with non-severe asthma. RV-induced IL-33 expression was mainly regulated by TLR3 and downstream via TAK1. These signalling molecules represent potential therapeutic targets for treating asthma exacerbations.

Rhinovirus-induced IL-33 is overexpressed in bronchial smooth muscle cells from asthmatics, and the production of IL-33 following infection is mediated by activation of TLR3 and downstream TAK1 signallinghttps://bit.ly/3fXH0h3

Variability in airway inflammation, symptoms, lung function and reliever use in asthma: anti-inflammatory reliever hypothesis and STIFLE study design

Asthma is a chronic inflammatory airway disease. Increase in airway inflammation is hypothesised to contribute to worsening of asthma symptoms and deterioration in lung function, resulting in the use of reliever medication. Short-acting β₂-agonists only treat the symptoms, whereas an anti-inflammatory reliever is believed to treat both symptoms and the underlying inflammation, thereby arresting the progression to an exacerbation. As-needed budesonide/formoterol as an anti-inflammatory reliever reduces the risk of severe exacerbations. However, supporting mechanistic evidence has not yet been described, specifically the temporal dynamics of parameters including airway inflammation, over time and during asthma worsening. The STIFLE study aims to characterise daily variability in airway inflammation, symptoms, lung function and reliever use in people with asthma. This phase IV, open-label, parallel-group, multicentre, exploratory study will enrol 60-80 adult patients with asthma receiving low- or medium-dose inhaled corticosteroids/long-acting β₂-agonists (EudraCT identifier number 2018-003467-64). Participants will be randomised 1:1 to either as-needed budesonide/formoterol dry-powder inhaler or salbutamol reliever for 24 weeks, in addition to their maintenance therapy. Daily data will be captured for fractional exhaled nitric oxide, spirometry, asthma symptoms and medication use using devices connected to a smartphone via the STIFLE application. STIFLE will thereby enable not only characterisation of the variability of airway inflammation and clinical outcomes in relation to asthma worsening, but also elucidate the effect of as-needed budesonide/formoterol on airway inflammation against a background of daily maintenance therapy.

Prevalence of viral respiratory infections amongst asthmatics: Results of a meta-regression analysis

Viral respiratory infections (VRI) can act as triggers for acute asthma exacerbations and contribute significantly to asthma-related healthcare costs. Knowing the patterns of viruses amongst asthmatics can be useful in treating and preventing these exacerbations and help decrease the burden they impose on patients and healthcare systems. We aimed to quantify the viral prevalence in asthmatics presenting with exacerbations and identify influencing factors. A meta-analysis with a systematic search was conducted. Random-effect analysis was performed to quantify prevalence of viruses. A meta-regression was conducted to explain sources of heterogeneity and identify confounding factors. A VRI was detected in 52%-65% of the cases, and the detection rate was higher in children compared to adults. Rhinovirus was most often detected [51-71%], followed by respiratory syncytial virus [8-18%], influenza virus [7-15%], human parainfluenza virus [4-11%] and metapneumovirus virus [3-9%]. Meta-regression showed that the variables age and hemisphere contributed to the heterogeneity observed and were significantly associated with the detection of viruses in asthmatics. The climate variable reached significance for RSV and indicated a higher detection rate of viruses in asthmatics living in temperate compared to tropical regions. Besides age, geographic location and related variables significantly influence to what extent respiratory viruses are detected amongst asthmatics with exacerbations. Our results indicate that health authorities should adopt region- and population specific prevention and treatment strategies. Prevention and detection of viral respiratory infections in asthmatics could reduce asthma related disease burden and decrease antibiotic misuse.

Lung Microbiome in Asthma: Current Perspectives

A growing body of evidence implicates the human microbiome as a potentially influential player actively engaged in shaping the pathogenetic processes underlying the endotypes and phenotypes of chronic respiratory diseases, particularly of the airways. In this article, we specifically review current evidence on the characteristics of lung microbiome, and specifically the bacteriome, the modes of interaction between lung microbiota and host immune system, the role of the “lung–gut axis”, and the functional effects thereof on asthma pathogenesis. We also attempt to explore the possibilities of therapeutic manipulation of the microbiome, aiming at the establishment of asthma prevention strategies and the optimization of asthma treatment.

Lipopolysaccharide induces steroid-resistant exacerbations in a mouse model of allergic airway disease collectively through IL-13 and pulmonary macrophage activation

BACKGROUND

Acute exacerbations of asthma represent a major burden of disease and are often caused by respiratory infections. Viral infections are recognized as significant triggers of exacerbations; however, less is understood about the how microbial bioproducts such as the endotoxin (lipopolysaccharide (LPS)) trigger episodes. Indeed, increased levels of LPS have been linked to asthma onset, severity and steroid resistance.

OBJECTIVE

The goal of this study was to identify mechanisms underlying bacterial-induced exacerbations by employing LPS as a surrogate for infection.

METHODS

We developed a mouse model of LPS-induced exacerbation on the background of pre-existing type-2 allergic airway disease (AAD).

RESULTS

LPS-induced exacerbation was characterized by steroid-resistant airway hyperresponsiveness (AHR) and an exaggerated inflammatory response distinguished by increased numbers of infiltrating neutrophils/macrophages and elevated production of lung inflammatory cytokines, including TNFα, IFNγ, IL-27 and MCP-1. Expression of the type-2 associated inflammatory factors such as IL-5 and IL-13 were elevated in AAD but not altered by LPS exposure. Furthermore, AHR and airway inflammation were no longer suppressed by corticosteroid (dexamethasone) treatment after LPS exposure. Depletion of pulmonary macrophages by administration of 2-chloroadenosine into the lungs suppressed AHR and reduced IL-13, TNFα and IFNγ expression. Blocking IL-13 function, through either IL-13-deficiency or administration of specific blocking antibodies, also suppressed AHR and airway inflammation.

CONCLUSIONS & CLINICAL RELEVANCE

We present evidence that IL-13 and innate immune pathways (in particular pulmonary macrophages) contribute to LPS-induced exacerbation of pre-existing AAD and provide insight into the complex molecular processes potentially underlying microbial-induced exacerbations.

Risk of Acute Myocardial Infarction and Ischemic Stroke in Patients with Asthma Exacerbation: A Population-Based, Self-Controlled Case Series Study

BACKGROUND

Patients with asthma have a high incidence of acute myocardial infarction and ischemic stroke.

OBJECTIVE

To investigate the acute effect of asthma exacerbation on these cardiovascular events.

METHODS

Using population-based inpatient data of 3 geographically diverse US states (Florida, Nebraska, and New York) during the period 2011 to 2014, we conducted a self-controlled case series study of adults (aged ≥40 years) hospitalized with asthma exacerbation. The primary outcome was a composite of acute myocardial infarction and ischemic stroke. We used conditional Poisson regression to compare each patient's incidence rate of the outcome during 3 sequential risk periods (1-7, 8-14, and 15-28 days after asthma exacerbation) with that of the reference period (ie, summed period before and after the 3 risk periods).

RESULTS

We identified 4607 adults hospitalized for asthma exacerbation who had a first episode of acute myocardial infarction or ischemic stroke. During the reference period, the incidence rate of acute myocardial infarction or ischemic stroke was 25.0/100 person-years. Compared with the reference period, the incidence rate significantly increased during the first risk period (129.1/100 person-years), with a corresponding adjusted incidence rate ratio of 5.04 (95% CI, 4.29-5.88; P < .001). In the 2 subsequent risk periods, the incidence rate declined but remained high-50.1/100 person-years (adjusted incidence rate ratio, 1.96; 95% CI, 1.51-2.48; P < .001) and 38.0/100 person-years (adjusted incidence rate ratio, 1.48; 95% CI, 1.20-1.81; P < .001), respectively. The findings were similar when the 2 outcomes were examined separately.

CONCLUSIONS

In this population-based study of adults with asthma, the risk of acute myocardial infarction and ischemic stroke increased significantly after asthma exacerbation.

Vitamin D for secondary prevention of acute wheeze attacks in preschool and school-age children

INTRODUCTION

Vitamin D is best known for its role in bone health; however, the discovery of the vitamin D receptor and the expression of the gene encoding the vitamin D 1α-hydroxylase (CYP27B1) enzyme in a wide variety of tissues including immune cells and respiratory epithelium has led to the discovery of potential roles for vitamin D in the prevention of acute wheeze.

METHODS

We review here the literature concerning the relationships between circulating 25-hydroxyvitamin D (25(OH)D) concentration and secondary prevention of acute wheeze attacks in preschool and school-age children.

RESULTS

Epidemiological data suggest that vitamin D insufficiency (25(OH)D <75 nmol/L) is highly prevalent in preschool and school-age children with wheeze. Preschool age children with a history of wheeze attacks and circulating 25(OH)D <75 nmol/L are at increased risk and frequency of future acute wheeze. However, no consistent association between low vitamin D status and risk of acute wheeze is reported in school-age children. Seven randomised controlled trials (RCTs) with relatively small sample sizes (30-430) and variable quality showed inconsistent results regarding the effect of oral vitamin D supplementation during childhood on the risk of asthma attacks, asthma symptom control, inhaled corticosteroid requirements, spirometry and unscheduled healthcare attendances for wheeze. A RCT showed that vitamin D supplementation had no effect on the frequency of unplanned healthcare attendances due to acute wheeze in 22 preschool children.

DISCUSSION

An evidence-based recommendation for the use of vitamin D as a preventive therapy for wheeze attacks cannot be made until results of further trials are available. The assessment of circulating 25(OH)D concentration and the optimisation of vitamin D status to prevent acute respiratory tract infections, and to maintain skeletal and general health in preschool and school-age children with acute wheeze is worthwhile in its own right, but whether this will reduce the risk of acute wheeze attacks is unclear.

Airway Microbiome in Different Inflammatory Phenotypes of Asthma: A Cross-Sectional Study in Northeast China

Background and Objective: Asthma is a common respiratory disease with a high prevalence and morbidity that can seriously affect quality of life. Microbial colonization of the airway may participate in the pathogenesis of asthma, however the mechanisms involved have not been established. In the present study, we aimed to determine the composition of the microbiota in different asthmatic phenotypes from Northeast China. Methods: 24 mild-to-moderate asthmatics (10 eosinophilic asthma and 14 non-eosinophilic asthma) and 12 healthy volunteers participated in this cross-sectional study. DNA was extracted from their induced sputum and amplified for 16s rRNA gene sequencing on Illumina Miseq platform. Bioinformatic analysis on the microbiome was performed. Results: Alpha-diversity analysis showed that the asthmatics had a decreased richness, evenness and diversity. Non-eosinophilic asthmatics showed a decreased richness, evenness and diversity compared with eosinophilic patients. A different taxonomy of 1 phylum and 6 genera taxa between the phenotypes was identified. Compared with heathy controls, asthmatics existed a larger taxonomic difference (P<0.05 for both EA and NEA vs. HC). 5 genera as the dominance in the microbial co-occurrence network correlated with the spirometry and disease progression of asthma. The function of microbiota genes was predicted to be related with infectious, immune and metabolic diseases. Conclusion: The diversity and composition of the airway microbiome was associated with the pathogenesis of asthma in different phenotypes. The diverse composition has been identified in the present study.

T cells and ILC2s are major effector cells in influenza-induced exacerbation of allergic airway inflammation in mice

Influenza virus infection is an important cause of severe asthma exacerbations, but it remains unclear how a Th1‐mediated antiviral response triggers a prototypical Th2 disease. We investigated CD4⁺ T cells and group 2 innate lymphoid cells (ILC2s) in influenza virus‐infected mice. We found that ILC2s accumulated in the lung rapidly after influenza virus infection, but the induction of IL‐5 and IL‐13 secretion was delayed and concomitant with T cell activation. In an influenza‐induced exacerbation of allergic airway inflammation model we noticed an initial reduction of ILC2 numbers and cytokine production in broncho‐alveolar lavage compared to chronic house dust mite (HDM)‐mediated airway inflammation alone. ILC2s phenotype was characterized by low T1/ST2, ICOS, KLRG1, and CD25 expression, resembling naïve ILC2s. The contribution of ILC2s to type 2 cytokine production in the early stage of the influenza‐induced exacerbation was limited. In contrast, T cells showed increased IL‐4 and IL‐5 production when exposed to both HDM and influenza virus. Upon virus clearance, ILC2s regained an activated T1/ST2^highICOS^highKLRG1^highCD25^high phenotype paired with cytokine production and were major contributors to the type 2 cytokine milieu. Collectively, our data indicate that both T cells and ILC2s contribute to influenza‐induced exacerbation of allergic airway inflammation, but with different kinetics.

Mechanical bacterial lysate administration prevents exacerbation in allergic asthmatic children-The EOLIA study

BACKGROUND

Despite progress in asthma management, prevention of asthma exacerbation remains challenging in school-aged children with allergic asthma. New therapeutic approaches are needed. Previously, a chemical bacterial lysate has been successfully used in preschool children to reduce wheezing attacks. We assessed the effect of Polyvalent Mechanical Bacterial Lysate (PMBL^® ) Tablet on asthma clinical course and control in 6- to 16-year-old children with partly controlled or uncontrolled allergic asthma.

METHODS

A randomized, double-blind, placebo-controlled, parallel-group study was performed in 152 patients exhibiting allergic asthma assigned to receive Placebo or PMBL^® . Eligible patients underwent four visits during the 9-month study. Asthma control level was assessed by ACT/C-ACT score.

RESULTS

The main criterion was not achieved as ACT/C-ACT changes were similar in both groups at the end of the 3-month treatment period. However, the mean number (±SD) of asthma exacerbations was significantly lower with PMBL^® Tablet than with Placebo at Week 12 (0.3 ± 0.6 vs 0.8 ± 1.1, P = .009) and over the total study period (1.1 ± 1.3 vs 1.9 ± 2.0, P = .01). Consistently, the mean number of days with exacerbation per patient was significantly lower with PMBL^® Tablet (13.3 ± 11.2 vs 19.8 ± 15.7 over the whole study, P = .009). Treatment with PMBL^® Tablet prolonged the time to second exacerbation by 55% (Hazard Ratio [HR]=0.45; 95% Confidence Interval [CI] 0.27 to 0.77, P = .002) and to third exacerbation by 74% (HR=0.26; 95% CI 0.12 to 0.58, P < .001). No serious adverse event related to PMBL^® Tablet administration was recorded.

CONCLUSION

Administration of PMBL^® Tablet represents a safe and effective means for significantly reducing the rate of exacerbations in school-aged allergic asthmatic children. (EudraCT 2013-000737-12 and NCT02541331).

Acupuncture for asthma: Protocol for a systematic review

BACKGROUND

Asthma is a common chronic disease in both adults and children. Inhaled corticosteroids (ICS) and β2-agonists are the major medications treating asthma with many side effects. Acupuncture has been used in many diseases including asthma. We aim to assess the efficacy and safety of acupuncture for asthma.

METHODS

The following electronical databases will be searched from inception to January 1, 2017: Medline, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), SinoMed, the China National Knowledge Infrastructure Database (CNKI), the Chinese Scientific Journal Database (VIP database), and the Wanfang database. We will also search reference lists of identified studies, potential gray literatures, relevant conference abstracts, and registers of clinical trials. Two reviewers will independently undertake study selection, data extraction, and quality assessment. Data will be synthesized by either the fixed-effects or random-effects model according to a heterogeneity test. Changes in lung function will be assessed as the primary outcome. The level of control, medication usage, quality of life, exacerbations, symptoms, adverse events will be evaluated as the secondary outcomes. The RevMan V.5.3.5 will be employed for meta-analysis. Continuous outcomes will be presented as mean difference or standard mean difference, while dichotomous data will be expressed as relative risk.

RESULTS

This study will provide a high-quality synthesis of current evidence of acupuncture for asthma from several aspects including lung function, the level of control, medication usage, quality of life, exacerbations, symptoms and adverse events.

CONCLUSION

The conclusion of our study will provide updated evidence to judge whether acupuncture is an effective intervention for children with asthma.

ETHICS AND DISSEMINATION

It is not necessary for ethical approval because individuals cannot be identified. The protocol will be disseminated in a peer-reviewed journal or presented at a relevant conference.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42017054562.

Activation of Eosinophils Interacting with Bronchial Epithelial Cells by Antimicrobial Peptide LL-37: Implications in Allergic Asthma

The role of antimicrobial peptide LL-37 in asthma exacerbation is unclear. Microbial infection, which is the most common inducer of asthma exacerbation, is accompanied by elevated LL-37. The present study found that co-culture of eosinophils and bronchial epithelial cell line BEAS-2B significantly enhanced intercellular adhesion molecule-1 on both cells and CD18 expression on eosinophils upon LL-37 stimulation. IL-6, CXCL8 and CCL4 were substantially released in co-culture in the presence of LL-37. LL-37 triggered the activation of eosinophils interacting with BEAS-2B cells in a P2X purinoceptor 7/epidermal growth factor receptor-dependent manner. Eosinophils and BEAS-2B cells differentially contribute to the expression of cytokines/chemokines in co-culture, while soluble mediators were sufficient to mediate the intercellular interactions. Intracellular p38-mitogen-activated protein kinase, extracellular signal-regulated kinase and NF-κB signaling pathways were essential for LL-37-mediated activation of eosinophils and BEAS-2B cells. By using the ovalbumin-induced asthmatic model, intranasal administration of mCRAMP (mouse ortholog of LL-37) in combination with ovalbumin during the allergen challenge stage significantly enhanced airway hyperresponsiveness and airway inflammation in sensitized mice, thereby implicating a deteriorating role of LL-37 in allergic asthma. This study provides evidence of LL-37 in triggering asthma exacerbation via the activation of eosinophils interacting with bronchial epithelial cells in inflammatory airway.

An early innate response underlies severe influenza-induced exacerbations of asthma in a novel steroid-insensitive and anti-IL-5-responsive mouse model

BACKGROUND

Acute worsening of asthma symptoms (exacerbation) is predominantly triggered by respiratory viruses, with influenza causing the most severe exacerbations. The lack of an adequate animal model hampers mechanistic insight and the development of new therapeutics.

AIM

We developed and characterized a robust, consistent, and reproducible mouse model of severe exacerbation of chronic allergic asthma.

METHODS

Chronic allergic airway inflammation was induced following a house dust mite (HDM) sensitization protocol. HDM-sensitized mice and controls were infected with influenza virus A/X31 H3N2 and either or not treated with inhaled fluticasone propionate (FP), systemic corticosteroids (Pred), or anti-IL-5. Mice were killed at different time points after infection: Cellular accumulation and cytokines levels in the airways, PenH as a measure of airway hyper-responsiveness (AHR), and lung histology and viral replication were assessed.

RESULTS

Infection with low-dose A/X31 H3N2 led to prolonged deterioration of lung function, aggravated mucus production, peri-vascular, peri-bronchial, and allergic inflammation that was unresponsive to inhaled corticosteroids, but responsive to systemic corticosteroids. The exacerbation was preceded at 14 h after virus exposure by a marked innate, but no Th2 and Th1 response subsequently followed by enhanced numbers of eosinophils, neutrophils, dendritic, and T cells into the lung lumen, parenchyma, and draining lymph nodes in HDM-sensitized mice. Anti-IL-5 treatment attenuated eosinophils and prevented the X31-induced exacerbation.

CONCLUSIONS

Together, these findings indicate that an early innate response that involves eosinophils underlies the exacerbation. This model recapitulates all major features of severe asthma exacerbations and can serve to discern driving mechanisms and promote the development of novel therapeutics.

Macrophage Dysfunction in Respiratory Disease

In the healthy lung, macrophages maintain homeostasis by clearing inhaled particles, bacteria, and removing apoptotic cells from the local pulmonary environment. However, in respiratory diseases including chronic obstructive pulmonary disease (COPD), asthma, and cystic fibrosis, macrophages appear to be dysfunctional and may contribute to disease pathogenesis. In COPD, phagocytosis of bacterial species and apoptotic cells by both alveolar macrophages and monocyte-derived macrophages is significantly reduced, leading to colonization of the lung with pathogenic bacteria. COPD macrophages also release high levels of pro-inflammatory cytokines and chemokines, including CXCL8, TGFβ, and CCL2, driving recruitment of other inflammatory cells including neutrophils and monocytes to the lungs and promoting disease progression.In asthma, defective phagocytosis and efferocytosis have also been reported, and macrophages appear to have altered cell surface receptor expression; however, it is as yet unclear how this contributes to disease progression but may be important in driving Th2-mediated inflammation. In cystic fibrosis, macrophages also display defective phagocytosis, and reduced bacterial killing, which may be driven by the pro-inflammatory environment present in the lungs of these patients.The mechanisms behind defective macrophage function in lung diseases are not currently understood, but potential mechanisms include alterations in phagocytic receptor expression levels, oxidative stress, but also the possibility that specific diseases are associated with a specific, altered, macrophage phenotype that displays reduced function. Identification of the mechanisms responsible may present novel therapeutic opportunities for treatment.

PARP inhibition treatment in a nonconventional experimental mouse model of chronic asthma

Allergic asthma is an immunological disease that occurs as a consequence of aeroallergen exposure. Inhibition of poly(ADP-ribose) polymerases (PARPs) in conventional models of asthma-like reaction has emerged as an effective anti-inflammatory and airway remodeling intervention. In a house dust mite (HDM) exposure mouse model, we investigated the impact of PARP inhibition on allergic airway inflammation, sensitization, and remodeling. Mice were intranasally exposed to a HDM extract for 5 days per week for up to 5 weeks. Mice were administered, or not, by PARP inhibitors 3-aminobenzamide (3-ABA) or 5-aminoisoquinolinone (5-AIQ) during the last 2 weeks of HDM treatment. Mice treated with PARP inhibitors after HDM stimulation showed a significant decrease in the number of total cells and eosinophils detectable in the bronchoalveolar lavage fluid as compared with the HDM-stimulated ones. In vitro HDM-stimulated splenocyte culture produced considerable amounts of the Th2 cytokines that were not affected by treatment with PARP inhibitors. Immunoglobulin levels in the serum were also unchanged. In the lung tissue, collagen deposition was decreased, whereas α-smooth muscle actin thickening was not significantly affected. Moreover, in HDM-stimulated PARP inhibitor-treated groups, we found a downregulation in the activation of signal transducer and activator of trascription-6 (STAT-6) and a significant decrease in the mRNA levels of C-C motif chemokine 11 (CCL11). In this mouse model of chronic asthma PARP inhibition treatment, although it does not affect sensitization, it effectively reduces the allergic airway inflammation and affects the remodeling through a mechanism involving STAT6 and CCL11.

Vitamin D for the management of asthma

BACKGROUND

Several clinical trials of vitamin D to prevent asthma exacerbation and improve asthma control have been conducted in children and adults, but a meta-analysis restricted to double-blind, randomised, placebo-controlled trials of this intervention is lacking.

OBJECTIVES

To evaluate the efficacy of administration of vitamin D and its hydroxylated metabolites in reducing the risk of severe asthma exacerbations (defined as those requiring treatment with systemic corticosteroids) and improving asthma symptom control.

SEARCH METHODS

We searched the Cochrane Airways Group Trial Register and reference lists of articles. We contacted the authors of studies in order to identify additional trials. Date of last search: January 2016.

SELECTION CRITERIA

Double-blind, randomised, placebo-controlled trials of vitamin D in children and adults with asthma evaluating exacerbation risk or asthma symptom control or both.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied study inclusion criteria, extracted the data, and assessed risk of bias. We obtained missing data from the authors where possible. We reported results with 95% confidence intervals (CIs).

MAIN RESULTS

We included seven trials involving a total of 435 children and two trials involving a total of 658 adults in the primary analysis. Of these, one trial involving 22 children and two trials involving 658 adults contributed to the analysis of the rate of exacerbations requiring systemic corticosteroids. Duration of trials ranged from four to 12 months, and the majority of participants had mild to moderate asthma. Administration of vitamin D reduced the rate of exacerbations requiring systemic corticosteroids (rate ratio 0.63, 95% CI 0.45 to 0.88; 680 participants; 3 studies; high-quality evidence), and decreased the risk of having at least one exacerbation requiring an emergency department visit or hospitalisation or both (odds ratio (OR) 0.39, 95% CI 0.19 to 0.78; number needed to treat for an additional beneficial outcome, 27; 963 participants; 7 studies; high-quality evidence). There was no effect of vitamin D on % predicted forced expiratory volume in one second (mean difference (MD) 0.48, 95% CI -0.93 to 1.89; 387 participants; 4 studies; high-quality evidence) or Asthma Control Test scores (MD -0.08, 95% CI -0.70 to 0.54; 713 participants; 3 studies; high-quality evidence). Administration of vitamin D did not influence the risk of serious adverse events (OR 1.01, 95% CI 0.54 to 1.89; 879 participants; 5 studies; moderate-quality evidence). One trial comparing low-dose versus high-dose vitamin D reported two episodes of hypercalciuria, one in each study arm. No other study reported any adverse event potentially attributable to administration of vitamin D. No participant in any included trial suffered a fatal asthma exacerbation. We did not perform a subgroup analysis to determine whether the effect of vitamin D on risk of severe exacerbation was modified by baseline vitamin D status, due to unavailability of suitably disaggregated data. We assessed two trials as being at high risk of bias in at least one domain; neither trial contributed data to the analysis of the outcomes reported above.

AUTHORS' CONCLUSIONS

Meta-analysis of a modest number of trials in people with predominantly mild to moderate asthma suggests that vitamin D is likely to reduce both the risk of severe asthma exacerbation and healthcare use. It is as yet unclear whether these effects are confined to people with lower baseline vitamin D status; further research, including individual patient data meta-analysis of existing datasets, is needed to clarify this issue. Children and people with frequent severe asthma exacerbations were under-represented; additional primary trials are needed to establish whether vitamin D can reduce the risk of severe asthma exacerbation in these groups.

The anti-inflammatory and pro-resolution effects of aspirin-triggered RvD1 (AT-RvD1) on peripheral blood mononuclear cells from patients with severe asthma

Asthma is an inflammatory disease that is characterized by a predominance of eosinophils and/or neutrophils in the airways. In the resolution of inflammation, lipid mediators such as resolvin D1 (RvD1) and its epimer aspirin-triggered RvD1 (AT-RvD1) are produced and demonstrate anti-inflammatory and pro-resolution effects. In experimental models such as airway allergic inflammation induced by ovalbumin in mice, RvD1 and AT-RvD1 alleviate some of the most important phenotypes of asthma. Here, we demonstrated the effects of AT-RvD1 on peripheral blood mononuclear cells (PBMCs) from healthy individuals and patients with severe asthma stimulated with lipopolysaccharide (LPS) or Dermatophagoides pteronyssinus (DM). AT-RvD1 (100nM) reduced the concentration of TNF-α in PBMCs from healthy individuals and patients with severe asthma stimulated with LPS or DM. In addition, AT-RvD1 lowered the production of IL-10 only in PBMCs from patients with severe asthma stimulated with LPS. These effects were associated in part with decreasing NF-κB activation. Moreover, AT-RvD1 significantly increased phagocytosis of apoptotic neutrophils by monocytes from patients with severe asthma. In conclusion, AT-RvD1 demonstrated both anti-inflammatory and pro-resolution effects in PBMCs from patients with severe asthma and could become in the future an alternative treatment for asthma.

Epidemiology of asthma exacerbations and their relation with environmental factors in the Basque Country

BACKGROUND

Asthma is a highly prevalent chronic inflammatory disease characterised by reversible airflow obstruction and hyperreactivity and inflammation of the airways. Factors that cause and/or trigger asthma attacks include host-related factors (genetic predisposition, obesity and sex) and environmental factors (allergens, infections, occupational sensitisation, smoking status, pollution and diet).

OBJECTIVE

To describe the epidemiology of asthma exacerbations (AEs) in the Basque Country and to explore its relationship with potentially associated environmental variables. We studied a total of 31,579 emergency department (ED) visits and 28,189 hospitalisations due to asthma. We describe the trends, incidence, seasonality and the influence of age and sex, as well as of exposure to NO2 , CO, PM, O3 , and pollen, temperature, relative humidity and flu status. We calculated the Pearson's R correlation coefficient for the study variables.

RESULTS

The incidence was 486 and 88.9 cases per 100,000 people for ED visits and hospitalisations, respectively. Slightly over half (53.5%) of the ED cases were male, while females represented 62.6% of the hospital admissions. Hospitalisations are tending to decrease in children and increase in over 64-year-olds. Peaks in cases occur at the beginning of autumn in children and in winter in adults. AEs were correlated positively with exposure to NO2 , CO and to the influenza virus and negatively with temperature and exposure to O3 . These relationships vary, however, with age and season.

CONCLUSIONS AND CLINICAL RELEVANCE

Rates of hospitalisation for AEs and trends in these rates over time are different in adults and children with the patterns varying by sex, season and environmental conditions.

Asthma in adults (acute): magnesium sulfate treatment

INTRODUCTION

About 10% of adults have suffered an attack of asthma, and up to 5% of these have severe disease that responds poorly to treatment. Patients with severe disease have an increased risk of death, but patients with mild to moderate disease are also at risk of exacerbations. Most guidelines about the management of asthma follow stepwise protocols. This overview does not endorse or follow any particular protocol, but presents the evidence about a specific intervention, magnesium sulfate.

METHODS AND OUTCOMES

We conducted a systematic overview, aiming to answer the following clinical question: What are the effects of magnesium sulfate for acute asthma? We searched: Medline, Embase, The Cochrane Library, and other important databases up to November 2014 (Clinical Evidence overviews are updated periodically; please check our website for the most up-to-date version of this overview).

RESULTS

At this update, searching of electronic databases retrieved 50 studies. After deduplication and removal of conference abstracts, 24 records were screened for inclusion in the overview. Appraisal of titles and abstracts led to the exclusion of 10 studies and the further review of 14 full publications. Of the 14 full articles evaluated, one systematic review was updated and one systematic review was added at this update. We performed a GRADE evaluation for five PICO combinations.

CONCLUSIONS

In this systematic overview, we categorised the efficacy for two comparisons based on information about the effectiveness and safety of magnesium sulfate (iv) versus placebo and magnesium sulfate (nebulised) plus short-acting beta2 agonists (inhaled) versus short-acting beta2 agonists (inhaled) alone.

Incident asthma and Mycoplasma pneumoniae: A nationwide cohort study

BACKGROUND

Previous studies investigating the relationship between Mycoplasma pneumoniae and incident asthma in the general population have been inconclusive.

OBJECTIVE

We conducted a nationwide cohort study to clarify this relationship.

METHODS

Using the National Health Insurance Research Database of Taiwan, we identified 1591 patients with M pneumoniae infection (International Classification of Diseases, Ninth Revision, Clinical Modification code 4830) given diagnoses between 2000 and 2008. We then frequency matched 6364 patients without M pneumoniae infection from the general population according to age, sex, and index year. Cox proportional hazards regression analysis was performed to determine the adjusted hazard ratio (aHR) of the occurrence of asthma in the M pneumoniae cohort compared with that in the non-M pneumoniae cohort.

RESULTS

Regardless of comorbidities and the use of antibiotic or steroid therapies, patients with M pneumonia infection had a higher risk of incident asthma than those without it. The aHR of asthma was 3.35 (95% CI, 2.71-4.15) for the M pneumoniae cohort, with a significantly higher risk when patients were stratified by age, sex, follow-up time, and comorbidities, including allergic rhinitis, atopic dermatitis, or allergic conjunctivitis. Patients with M pneumoniae infection had a higher risk of having early-onset (age, <12 years; aHR, 2.87) and late-onset (age, ≥12 years; aHR, 3.95) asthma. The aHR was also higher within the less than 2-year follow-up in the M pneumoniae cohort (aHR, 4.41; 95% CI, 3.40-5.74) than in the cohort without the infection.

CONCLUSION

This study found that incident cases of early-onset and late-onset asthma are closely related to M pneumoniae infection, even in nonatopic patients.

Molecular Regulation of Toll-like Receptors in Asthma and COPD

Asthma and chronic obstructive pulmonary disease (COPD) have both been historically associated with significant morbidity and financial burden. These diseases can be induced by several exogenous factors, such as pathogen-associated molecular patterns (PAMPs) (e.g., allergens and microbes). Endogenous factors, including reactive oxygen species, and damage-associated molecular patterns (DAMPs) recognized by toll-like receptors (TLRs), can also result in airway inflammation. Asthma is characterized by the dominant presence of eosinophils, mast cells, and clusters of differentiation (CD)4⁺ T cells in the airways, while COPD typically results in the excessive formation of neutrophils, macrophages, and CD8⁺ T cells in the airways. In both asthma and COPD, in the respiratory tract, TLRs are the primary proteins of interest associated with the innate and adaptive immune responses; hence, multiple treatment options targeting TLRs are being explored in an effort to reduce the severity of the symptoms of these disorders. TLR-mediated pathways for both COPD and asthma have their similarities and differences with regards to cell types and the pro-inflammatory cytotoxins present in the airway. Because of the complex TLR cascade, a variety of treatments have been used to minimize airway hypersensitivity and promote bronchodilation. Although unsuccessful at completely alleviating COPD and severe asthmatic symptoms, new studies are focused on possible targets within the TLR cascade to ameliorate airway inflammation.

The changing face of asthma and its relation with microbes

During the past 50 years, the prevalence of asthma has increased and this has coincided with our changing relation with microorganisms. Asthma is a complex disease associated with local tissue inflammation of the airway that is determined by environmental, immunological, and host genetic factors. In a subgroup of sufferers, respiratory infections are associated with the development of chronic disease and more frequent inflammatory exacerbations. Recent studies suggest that these infections are polymicrobial in nature. Furthermore, there is increasing evidence that the recently discovered asthma airway microbiota may play a critical role in pathophysiological processes associated with the disease. Here, we discuss the current data regarding a possible role for infection in chronic asthma with a particular focus on the role bacteria may play. We discuss recent advances that are beginning to elucidate the complex relations between the microbiota and the immune response in asthma patients. We also highlight the clinical implications of these recent findings in regards to the development of novel therapeutic strategies.

An Allergic Lung Microenvironment Suppresses Carbon Nanotube-Induced Inflammasome Activation via STAT6-Dependent Inhibition of Caspase-1

Background

Multi-walled carbon nanotubes (MWCNTs) represent a human health risk as mice exposed by inhalation display pulmonary fibrosis. Production of IL-1β via inflammasome activation is a mechanism of MWCNT-induced acute inflammation and has been implicated in chronic fibrogenesis. Mice sensitized to allergens have elevated T-helper 2 (Th2) cytokines, IL-4 and IL-13, and are susceptible to MWCNT-induced airway fibrosis. We postulated that Th2 cytokines would modulate MWCNT-induced inflammasome activation and IL-1β release in vitro and in vivo during allergic inflammation.

Methods

THP-1 macrophages were primed with LPS, exposed to MWCNTs and/or IL-4 or IL-13 for 24 hours, and analyzed for indicators of inflammasome activation. C57BL6 mice were sensitized to house dust mite (HDM) allergen and MWCNTs were delivered to the lungs by oropharyngeal aspiration. Mice were euthanized 1 or 21 days post-MWCNT exposure and evaluated for lung inflammasome components and allergic inflammatory responses.

Results

Priming of THP-1 macrophages with LPS increased pro-IL-1β and subsequent exposure to MWCNTs induced IL-1β secretion. IL-4 or IL-13 decreased MWCNT-induced IL-1β secretion by THP-1 cells and reduced pro-caspase-1 but not pro-IL-1β. Treatment of THP-1 cells with STAT6 inhibitors, either Leflunomide or JAK I inhibitor, blocked suppression of caspase activity by IL-4 and IL-13. In vivo, MWCNTs alone caused neutrophilic infiltration into the lungs of mice 1 day post-exposure and increased IL-1β in bronchoalveolar lavage fluid (BALF) and pro-caspase-1 immuno-staining in macrophages and airway epithelium. HDM sensitization alone caused eosinophilic inflammation with increased IL-13. MWCNT exposure after HDM sensitization increased total cell numbers in BALF, but decreased numbers of neutrophils and IL-1β in BALF as well as reduced pro-caspase-1 in lung tissue. Despite reduced IL-1β mice exposed to MWCNTs after HDM developed more severe airway fibrosis by 21 days and had increased pro-fibrogenic cytokine mRNAs.

Conclusions

These data indicate that Th2 cytokines suppress MWCNT-induced inflammasome activation via STAT6-dependent down-regulation of pro-caspase-1 and suggest that suppression of inflammasome activation and IL-1β by an allergic lung microenvironment is a mechanism through which MWCNTs exacerbate allergen-induced airway fibrosis.

Association of airborne Aspergillus with asthma exacerbation in Southern Pakistan

BACKGROUND

Exposure to airborne fungi has been related with exacerbation of asthma in adults and children leading to increased outpatient, emergency room visits, and hospitalizations. Hypersensitivity to these airborne fungi may be an important initial predisposing factor in the development and exacerbation of asthma.

OBJECTIVE

This study was conducted to determine an association between fungal types and spore concentrations with the risk of asthma exacerbation in adults.

METHODS

This cross-sectional study was conducted from May 2008 to August 2009 at the Aga Khan University Hospital Karachi, Pakistan. All adult (age≥16 years) patients presenting to the hospital with acute asthma exacerbation were enrolled after informed consent. A home survey was conducted for each patient to assess their environmental characteristics. Indoor air samples were also obtained from the patient's home to determine the type and spore concentration of fungi within the week of their enrollment in the study.

RESULTS

Three hundred and ninety-one patients with an acute asthma exacerbation were enrolled during the study period. The mean age of participants was 46 years (standard deviation, ±18 years) and 247 (63.2%) were females. A trend of higher asthma enrollment associated with higher Aspergillus concentrations was found in two consecutive summers. A total of nineteen types of fungi were found in air samples. Aspergillus spp. was the most frequently isolated fungus with acute asthma exacerbation.

CONCLUSION

An association of higher concentration of indoor Aspergillus spp. with asthma exacerbation in adults was observed in this study.

Types, frequency and impact of asthma triggers on patients' lives: a quantitative study in five European countries

OBJECTIVE

To identify the types, frequency and impact of asthma triggers and the relationship to asthma control among adults with asthma in Europe.

METHODS

Adults with self-reported physician-diagnosed asthma receiving maintenance asthma treatment and self-reported exposure to known asthma triggers completed an online questionnaire; a subset completed a diary over 3-4 weeks. Information on asthma control (Asthma Control Test™ [ACT]), asthma triggers, frequency of exposure and behaviours in response or to avoid asthma triggers and the perceived impact on daily life was captured. A post-hoc analysis evaluated the impact of high trigger burden on the frequency of severe asthma exacerbations, hospitalisations and days lost at work/study.

RESULTS

A total of 1202 adults participated and 177 completed the diary. Asthma was uncontrolled for the majority (76%) of participants and most (52%) reported exposure to 6-15 asthma triggers. As trigger burden increased, behavioural changes to manage trigger exposure had a significantly increased impact on daily life (p < 0.0001) and job choice (p = 0.002). Participants reporting a high trigger burden (>16) were more likely to report uncontrolled asthma than those with a low trigger burden (1-5). Participants with a high trigger burden had previously experienced on average two more severe asthma attacks during a lifetime (p < 0.001), two more hospitalisations (p < 0.001) and 3.5 more missed days at work or study in the last year due to their asthma (p < 0.001) than those with a low trigger burden.

CONCLUSIONS

Adults with asthma reporting a high trigger burden (>16 different triggers) experience more severe asthma attacks than those reporting lower trigger burdens.

Asthma medication adherence: the role of God and other health locus of control factors

BACKGROUND

Medication adherence is an important determinant of disease outcomes, yet medication use on average tends to be low among patients with chronic conditions, including asthma. Although several predictors of non-adherence have been assessed, more research is needed on patients' beliefs about God and how these relate to medication use.

OBJECTIVE

To examine the relationship between perceptions about "God's" role in health and other locus of control factors with inhaled corticosteroid (ICS) adherence among asthma patients.

METHODS

Participants were from a clinical trial to improve ICS adherence and were 5-56 years old, had a diagnosis of asthma, and were receiving ICS medication. Baseline adherence was estimated from electronic prescription and pharmacy fill records. Patients were considered to be adherent if ICS use was ≥80% of prescribed. A baseline survey with the Multidimensional Health Locus of Control scale was used to assess five sources (God, doctors, other people, chance, and internal).

RESULTS

Medication adherence was low (36%). Patients' who had a stronger belief that God determined asthma control were less likely to be adherent (odds ratio [OR] 0.82, 95% confidence interval [CI] 0.70-0.96). This relationship was stronger among African American (OR 0.68, 95% CI0.47-0.99) compared to white patients (OR 0.89, 95% CI 0.75-1.04), and among adults (OR 0.81, 95% CI 0.69-0.96) compared to children (OR 0.84, 95% CI 0.58-1.22).

CONCLUSION

Patients' belief in God's control of health appears to be a factor in asthma controller use, and therefore should be considered in physician-patient discussions concerning course of treatment.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00459368.

The neonatal immune system: immunomodulation of infections in early life

The innate and adaptive immune responses in neonates are usually functionally impaired when compared with their adult counterparts. The qualitative and quantitative differences in the neonatal immune response put them at risk for the development of bacterial and viral infections, resulting in increased mortality. Newborns often exhibit decreased production of Th1-polarizing cytokines and are biased toward Th2-type responses. Studies aimed at understanding the plasticity of the immune response in the neonatal and early infant periods or that seek to improve neonatal innate immune function with adjuvants or special formulations are crucial for preventing the infectious disease burden in this susceptible group. Considerable studies focused on identifying potential immunomodulatory therapies have been performed in murine models. This article highlights the strategies used in the emerging field of immunomodulation in bacterial and viral pathogens, focusing on preclinical studies carried out in animal models with particular emphasis on neonatal-specific immune deficits.

Defective phagocytosis in airways disease

Maintaining an airway clear of inhaled particles, pathogens, and cellular debris is paramount for lung homeostasis. In healthy individuals, the phagocytes of the innate immune system act as sentinels to patrol the airway and ensure sterility. However, in airways diseases, including asthma, COPD, and cystic fibrosis, there is a propensity for bacterial colonization that may contribute to disease worsening. Evidence suggests that this may be due to dysfunctional phagocytosis. In patients with COPD, phagocytosis of several bacterial species and removal of apoptotic cells (efferocytosis) by alveolar macrophages are significantly reduced; however, these cells can remove inert beads normally. Attenuated phagocytosis is also apparent in monocyte-derived macrophages from the same patients, suggesting an inherent defect in these cells. Reduced expression of cell surface recognition receptors has been suggested as one mechanism for these observations; however, the literature is currently contradictory and requires further clarification. In cystic fibrosis, a similar defect is also observed in both airway neutrophils and macrophages, leading to ineffective bacterial uptake and subsequent killing. In asthma and other airways diseases, there are also reports of defective phagocytosis of bacterial pathogens, although the relevance to disease pathophysiology is not understood. Oxidative stress is emerging as a common mechanism that may be altering both macrophage and neutrophil functions that can be reversed by various antioxidant strategies. The identification of this and other mechanisms underlying phagocyte dysfunction may present novel therapeutic opportunities for the treatment of many of these intractable diseases and improve patient morbidity and mortality.