Relation between inflammation and symptoms in asthma

Can probiotics be used in the prevention and treatment of bronchial asthma?

Asthma is a lifelong condition with varying degrees of severity and susceptibility to symptom control. Recent studies have examined the effects of individual genus, species, and strains of probiotic microorganisms on the course of asthma. The present review aims to provide an overview of current knowledge on the use of probiotic microorganisms, mainly bacteria of the genus Lactobacillus and Bifidobacterium, in asthma prevention and treatment. Recent data from clinical trials and mouse models of allergic asthma indicate that probiotics have therapeutic potential in this condition. Animal studies indicate that probiotic microorganisms demonstrate anti-inflammatory activity, attenuate airway hyperresponsiveness (AHR), and reduce airway mucus secretion. A randomized, double-blind, placebo-controlled human trials found that combining multi-strain probiotics with prebiotics yielded promising outcomes in the treatment of clinical manifestations of asthma. It appears that probiotic supplementation is safe and significantly reduces the frequency of asthma exacerbations, as well as improved forced expiratory volume and peak expiratory flow parameters, and greater attenuation of inflammation. Due to the small number of available clinical trials, and the use of a wide range of probiotic microorganisms and assessment methods, it is not possible to draw clear conclusions regarding the use of probiotics as asthma treatments.

Machine learning-driven identification of air toxic combinations associated with asthma symptoms among elementary school children in Spokane, Washington, USA

Air toxics are atmospheric pollutants with hazardous effects on health and the environment. Although methodological constraints have limited the number of air toxics assessed for associations with health and disease, advances in machine learning (ML) enable the assessment of a much larger set of environmental exposures. We used ML methods to conduct a retrospective study to identify combinations of 109 air toxics associated with asthma symptoms among 269 elementary school students in Spokane, Washington. Data on the frequency of asthma symptoms for these children were obtained from Spokane Public Schools. Their exposure to air toxics was estimated by using the Environmental Protection Agency's Air Toxics Screening Assessment and National Air Toxics Assessment. We defined three exposure periods: the most recent year (2019), the last three years (2017-2019), and the last five years (2014-2019). We analyzed the data using the ML-based Data-driven ExposurE Profile (DEEP) extraction method. DEEP identified 25 air toxic combinations associated with asthma symptoms in at least one exposure period. Three combinations (1,1,1-trichloroethane, 2-nitropropane, and 2,4,6-trichlorophenol) were significantly associated with asthma symptoms in all three exposure periods. Four air toxics (1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, BIS (2-ethylhexyl) phthalate (DEHP), and 2,4-dinitrophenol) were associated only in combination with other toxics, and would not have been identified by traditional statistical methods. The application of DEEP also identified a vulnerable subpopulation of children who were exposed to 13 of the 25 significant combinations in at least one exposure period. On average, these children experienced the largest number of asthma symptoms in our sample. By providing evidence on air toxic combinations associated with childhood asthma, our findings may contribute to the regulation of these toxics to improve children's respiratory health.

Mild asthma is not mild: risk factors and predictive biomarkers for severe acute exacerbations and progression in mild asthma

INTRODUCTION

Asthma is a common chronic respiratory disease characterized by chronic airway inflammation, airway hyperresponsiveness, reversible airflow limitation, and airway remodeling. Mild asthma is the most common type of asthma, but it is the most neglected. Sometimes mild asthma can lead to acute severe exacerbations or even death.

AREAS COVERED

This article reviews the epidemiology, risk factors, and possible predictors of acute severe exacerbations and disease progression in mild asthma to improve the understanding of mild asthma and its severe acute exacerbations and progression.

EXPERT OPINION

There is a necessity to improve asthma patient categorization and redefine mild asthma's concept to heighten patient and physician attention. Identifying mild asthma patients that are highly vulnerable to severe acute exacerbations and researching the mechanisms are future prioritizations.

Associations of complete blood cell count-derived inflammatory biomarkers with asthma and mortality in adults: a population-based study

Objective

This study aims to assess the associations of complete blood cell count (CBC)-derived inflammatory biomarkers with the prevalence of asthma and mortality.

Methods

Data was collected from the 1999-2018 National Health and Nutrition Examination Survey (NHANES). Mortality was identified using the National Death Index until December 31, 2019. The study analyzed the relationship between CBC-derived inflammatory biomarkers, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic inflammatory response index (SIRI), and systemic immune-inflammation index (SII), and the prevalence of asthma using multiple logistic regressions. To assess the significance of CBC-derived inflammatory biomarkers in predicting all-cause and respiratory disease mortality in asthma patients, Cox proportional regressions and the random survival forest (RSF) analysis were utilized.

Results

A total of 48,305 participants were included, with a mean age of 47.27 ± 0.18 years and 49.44% male. Among them, 6,403 participants had asthma, with a prevalence of 13.28%. The all-cause and respiratory disease deaths at a median follow-up of 8.2 (4.5, 12.8) years were 929 and 137 respectively. After adjusting for confounders, the prevalence of asthma was found to be positively associated with NLR, PLR, MLR, SIRI and SII. Compared to the lowest quartile, the highest quartile of NLR (HR=1.765 [1.378-2.262]), MLR (HR=1.717 [1.316-2.241]), SIRI (HR=1.796 [1.353-2.383]) and SII (HR=1.432 [1.141-1.797]) were associated with an increased risk of all-cause mortality. These associations were more pronounced in respiratory disease mortality of asthma patients. RSF analysis showed that MLR had the highest predictive value for all-cause and respiratory disease mortality in adults with asthma. The sensitivity analysis demonstrated the stability of our results.

Conclusion

The findings suggest that CBC-derived inflammatory biomarkers are associated with a higher risk of all-cause and respiratory disease mortality in adults with asthma.

Nanomaterial-induced toxicity in pathophysiological models representative of individuals with pre-existing medical conditions

The integration of nanomaterials (NMs) into an ever-expanding number of daily used products has proven to be highly desirable in numerous industries and applications. Unfortunately, the same "nano" specific physicochemical properties, which make these materials attractive, may also contribute to hazards for individuals exposed to these materials. In 2021, it was estimated that 7 out of 10 deaths globally were accredited to chronic diseases, such as chronic liver disease, asthma, and cardiovascular-related illnesses. Crucially, it is also understood that a significant proportion of global populace numbering in the billions are currently living with a range of chronic undiagnosed health conditions. Due to the significant number of individuals affected, it is important that people suffering from chronic disease also be considered and incorporated in NM hazard assessment strategies. This review examined and analyzed the literature that focused on NM-induced adverse health effects in models which are representative of individuals exhibiting pre-existing medical conditions with focus on the pulmonary, cardiovascular, hepatic, gastrointestinal, and central nervous systems. The overall objective of this review was to outline available data, highlighting the important role of pre-existing disease in NM-induced toxicity with the aim of establishing a weight of evidence approach to inform the public on the potential hazards posed by NMs in both healthy and compromised persons in general population.

Managing Apoptosis in Lung Diseases using Nano-assisted Drug Delivery System

Several factors exist that limit the efficacy of lung cancer treatment. These may be tumor-specific delivery of therapeutics, airway geometry, humidity, clearance mechanisms, presence of lung diseases, and therapy against tumor cell resistance. Advancements in drug delivery using nanotechnology based multifunctional nanocarriers, have emerged as a viable method for treating lung cancer with more efficacy and fewer adverse effects. This review does a thorough and critical examination of effective nano-enabled approaches for lung cancer treatment, such as nano-assisted drug delivery systems. In addition, to therapeutic effectiveness, researchers have been working to determine several strategies to produce nanotherapeutics by adjusting the size, drug loading, transport, and retention. Personalized lung tumor therapies using sophisticated nano modalities have the potential to provide great therapeutic advantages based on individual unique genetic markers and disease profiles. Overall, this review provides comprehensive information on newer nanotechnological prospects for improving the management of apoptosis in lung cancer.

Age at asthma diagnosis is related to prevalence and characteristics of asthma symptoms

Background

Although asthma may begin at any age, knowledge about relationship between asthma age of onset and the prevalence and character of different symptoms is scarce.

Objectives

The aim of this study was to investigate if adult-diagnosed asthma is associated with more symptoms and different symptom profiles than child-diagnosed asthma.

Methods

A FinEsS postal survey was conducted in a random sample of 16 000 20-69-year-old Finnish adults in 2016. Those reporting physician-diagnosed asthma and age at asthma diagnosis were included. Age 18 years was chosen to delineate child- and adult-diagnosed asthma.

Results

Of responders (N = 8199, 51.5%), 842 (10.3%) reported asthma diagnosis. Adult-diagnosed asthma was reported by 499 (59.3%) and child-diagnosed by 343 (40.7%). Of responders with adult-diagnosed and child-diagnosed asthma, 81.8% versus 60.6% used asthma medication (p < 0.001), respectively. Current asthma was also more prevalent in adult-diagnosed asthma (89.2% versus 72.0%, p < 0.001). Risk factors of attacks of breathlessness during the last 12 months were adult-diagnosis (OR = 2.41, 95% CI 1.64–3.54, p < 0.001), female gender (OR = 1.49, 1.07–2.08, p = 0.018), family history of asthma (OR = 1.48, 1.07–2.04, p = 0.018) and allergic rhinitis (OR = 1.49, 1.07–2.09, p = 0.019). All the analysed asthma symptoms, except dyspnea in exercise, were more prevalent in adult-diagnosed asthma in age- and gender-adjusted analyses (p = 0.032-<0.001) which was also more often associated with 5 or more asthma symptoms (p < 0.001) and less often with non-symptomatic appearance (p < 0.001) than child-diagnosed asthma.

Conclusion

Responders with adult-diagnosed asthma had more often current asthma and a higher and multiform asthma symptom burden, although they used asthma medication more often compared to responders with child-diagnosed asthma.

Expert Opinion on Practice Patterns in Mild Asthma After the GINA 2019 Updates: A Major Shift in Treatment Paradigms from a Long-Standing SABA-Only Approach to a Risk Reduction-Based Strategy with the Use of Symptom-Driven (As-Needed) Low-Dose ICS/LABA

PURPOSE OF REVIEW

This expert opinion, prepared by a panel of chest disease specialists, aims to review the current knowledge on practice patterns in real-life management of mild asthma and to address the relevant updates in asthma treatment by The Global Initiative for Asthma (GINA) to guide clinicians for the best clinical practice in applying these new treatment paradigms.

RECENT FINDINGS

On the basis of the emerging body of evidence suggesting the non-safety of short-acting β2-agonists (SABA)-only therapy and comparable efficacy of the as-needed inhaled corticosteroids (ICS)-formoterol combinations with maintenance ICS regimens, GINA recently released their updated Global Strategy for Asthma Management and Prevention Guide (2019). The new GINA 2019 recommendations no longer support the SABA-only therapy in mild asthma but instead includes new off-label recommendations such as symptom-driven (as-needed) low-dose ICS-formoterol and "low dose ICS taken whenever SABA is taken." The GINA 2019 asthma treatment recommendations include a major shift from long-standing approach of clinical practice regarding the use of symptom-driven SABA treatment alone in the management of mild asthma. This expert opinion supports the transition from a long-standing SABA-only approach to a risk reduction-based strategy, with the use of symptom-driven (as-needed) low-dose ICS/LABA in mild asthma patients, particularly in those with poor adherence to controller medications. The thoughtful and comprehensive approach of clinicians to these strategies is important, given that the exact far-reaching impact of this major change in management of mild asthma in the real-world settings will only be clarified over time.

The Toxicity of Wiped Dust and Airborne Microbes in Individual Classrooms Increase the Risk of Teachers' Work-Related Symptoms: A Cross-Sectional Study

Background: The causes and pathophysiological mechanisms of building-related symptoms (BRS) remain open. Objective: We aimed to investigate the association between teachers’ individual work-related symptoms and intrinsic in vitro toxicity in classrooms. This is a further analysis of a previously published dataset. Methods: Teachers from 15 Finnish schools in Helsinki responded to the symptom survey. The boar sperm motility inhibition assay, a sensitive indicator of mitochondrial dysfunction, was used to measure the toxicity of wiped dust and cultured microbial fallout samples collected from the teachers’ classrooms. Results: 231 teachers whose classroom toxicity data had been collected responded to the questionnaire. Logistic regression analysis adjusted for age, gender, smoking, and atopy showed that classroom dust intrinsic toxicity was statistically significantly associated with the following 12 symptoms reported by teachers (adjusted ORs in parentheses): nose stuffiness (4.1), runny nose (6.9), hoarseness (6.4), globus sensation (9.0), throat mucus (7.6), throat itching (4.4), shortness of breath (12.2), dry cough (4.7), wet eyes (12.7), hypersensitivity to sound (7.9), difficulty falling asleep (7.6), and increased need for sleep (7.7). Toxicity of cultured microbes was found to be associated with nine symptoms (adjusted ORs in parentheses): headache (2.3), nose stuffiness (2.2), nose dryness (2.2), mouth dryness (2.8), hoarseness (2.2), sore throat (2.8), throat mucus (2.3), eye discharge (10.2), and increased need for sleep (3.5). Conclusions: The toxicity of classroom dust and airborne microbes in boar sperm motility inhibition assay significantly increased teachers’ risk of work-related respiratory and ocular symptoms. Potential pathophysiological mechanisms of BRS are discussed.

Angiotensin-converting enzyme insertion/deletion polymorphism and susceptibility to pediatric asthma: A meta-analysis

Objective:

The correlation of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism with pediatric asthma risk was assessed in this meta-analysis.

Methods:

PubMed, Web of Science, Embase and CNKI databases were systematically searched for relevant literature, followed by application of odds ratios (OR) along with 95% confidence interval (CI) for determining the strength of relationship.

Results:

Seven articles with 802 cases and 632 controls fulfilled the inclusion criteria. As a result, the ACE I/D polymorphism was related to elevated pediatric asthma risk (D vs I: OR = 1.87, 95% CI = 1.59–2.20; dominant model: OR =1.53, 95% CI = 1.28–1.81; recessive model: OR =1.54, 95% CI = 1.28–1.85; DD vs II: OR =2.95, 95% CI = 2.19–3.98; DI vs II: OR = 0.96, 95% CI = 0.78–1.19). Subgroup analysis stratified by race revealed significant interrelation in Asians.

Conclusion:

This meta-analysis demonstrated that the ACE I/D polymorphism might be related to the risk of pediatric asthma.

The C79G Polymorphism of the β2-Adrenergic Receptor Gene, ADRB2, and Susceptibility to Pediatric Asthma: Meta-Analysis from Review of the Literature

Background

The ADRB2 gene encodes the β2-adrenergic receptor (β2-AR). This study aimed to determine the association between the C79G polymorphism of the ADRB2 gene and its association with pediatric asthma using a meta-analysis of the published data.

Material/Methods

Review of publications up to May 2018 was from the PubMed, EMBASE, China National Knowledge Infrastructure (CNKI), and WanFang databases. The odds ratio (ORs) with 95% confidence interval (CI) were used in evaluating the strength of the reported association between the C79G polymorphism of the ADRB2 gene and pediatric asthma.

Results

There were 18 controlled studies that included 2,982 pediatric cases of asthma and 2,651 controls. Expression of the C79G polymorphism of the ADRB2 gene was significantly associated with risk of pediatric asthma associated with the C or G allele with comparison of the co-dominant model (GG vs. CC: OR, 0.69; 95% CI, 0.55–0.88) and the recessive model (GG vs. CC+CG: OR, 0.65; 95% CI, 0.53–0.81). Subgroup analysis by ethnicity showed a significantly reduced risk of pediatric asthma in Asian patients for comparison of the co-dominant model (GG vs. CC: OR, 0.59; 95% CI, 0.45–0.78), the recessive model (GG vs. CC+CG: OR, 0.58; 95% CI, 0.45–0.76), and the allelic model (G vs. C: OR, 0.89; 95% CI, 0.79–0.99).

Conclusions

The C79G polymorphism of the ADRB2 gene encoding β2-AR was associated with a reduced risk for the development of pediatric asthma, particularly in the Asian population.

Validation of ATS clinical practice guideline cut-points for FeNO in asthma

BACKGROUND

The American Thoracic society (ATS) has suggested using fractional exhaled nitric oxide (FeNO) to monitor the level of eosinophilic (EOS) airway inflammation in asthma, but validation of the proposed cut-points is required in real-life populations.

OBJECTIVE

To validate FeNO cut-points suggested by ATS in relation to sputum EOS count in a real life population of asthma patients.

METHODS

All patients referred consecutively over a 12-months period for specialist assessment of asthma, were examined with FeNO and induced sputum, and re-examined 12 months later. The predicted values of a positive and a negative test (PPV and NPV) for a cut off ≥3% EOS in sputum were calculated. Change in FeNO was defined in accordance with ATS (>20% or 10 ppb if FeNO was <50 ppb).

RESULTS

144 adult asthma patients were examined (59% female). Low FeNO (<25 ppb) at baseline was found in 94 (65%), FeNO between 25 and 50 ppb in 34 (24%) subjects and high FeNO >50 ppb in 16 (11%) subjects. The PPV for FeNO >25 ppb and >50 ppb to predict EOS ≥3% was 45% and 77%, NPV was 88% and 83%. The sensitivity decreased from 70% to 37% at the >50 ppb cut-off. A significant reduction in FeNO was associated with a reduction in sputum EOS (p = 0.01).

CONCLUSION

The findings support the validity of the FeNO cut-points suggested by ATS to monitor eosinophilic airway inflammation in asthma. However, in this real-life population, a large proportion of patients had intermediate FeNO values, which may limit the clinical usefulness of the ATS FeNO cut-points.

Association Between TGF-β1 Polymorphisms and Asthma Susceptibility Among the Chinese: A Meta-Analysis

OBJECTIVE

Asthma is the most common chronic pulmonary disease in China and is characterized by airway inflammation and episodic airflow obstruction. The aim of this meta-analysis was to evaluate the relation of two transforming growth factor-β1 (TGF-β1) polymorphisms with asthma risk in Chinese population.

METHODS

PubMed, Springer, EMBASE, MEDLINE, CNKI (China National Knowledge Infrastructure), and Wanfang databases were used to search and retrieve relevant eligible case-control studies published through December 2017. The odds ratios (OR) and 95% confidence intervals (CI) were used to evaluate the effect.

RESULTS

A total of 2040 asthma patients and 1952 controls from 12 studies were analyzed. Two polymorphic sites of TGF-β1 gene were identified: -509C/T and +869T/C. We found that the -509C/T polymorphism was associated with increased asthma risk under the heterozygous model (CT vs. CC: OR = 1.40, 95% CI = 1.03-1.90, p = 0.03) and the dominant model (TT+CT vs. CC: OR = 1.41, 95% CI = 1.05-1.90, p = 0.02). Subgroup analyses by age suggested that -509C/T variant was associated with childhood asthma. Analysis of disease severity indicated that this variant was associated with both mild-to-moderate asthma and severe asthma. However, the +869T/C polymorphism was not associated with asthma susceptibility in subgroup analysis by age or disease severity.

CONCLUSIONS

This study demonstrated that the -509C/T polymorphism of the TGF-β1 gene might be a risk factor for asthma in the Chinese population, especially in Chinese children. Further large-scale case-control studies are still required.

Asthma Control and Sputum Eosinophils: A Longitudinal Study in Daily Practice

BACKGROUND

Longitudinal trials have suggested that asthma control may be influenced by fluctuations in eosinophilic inflammation. This association has however never been confirmed in daily practice.

OBJECTIVE

To investigate the relationship between asthma control and sputum eosinophils in clinical practice.

METHODS

A retrospective longitudinal study was conducted on 187 patients with asthma with at least 2 successful sputum inductions at our Asthma Clinic. Linear mixed models were used to assess the relationship between asthma control and individual changes in sputum eosinophils. Receiver-operating characteristic curves were constructed to define minimal important differences (MIDs) of sputum eosinophils associated with a change of at least 0.5 in Asthma Control Questionnaire (ACQ) score. Then, a validation cohort of 79 patients with asthma was recruited to reassess this relationship and the accuracy of the MID values.

RESULTS

A multivariate analysis showed that asthma control was independently associated with individual fluctuations in sputum eosinophil count (P < .001). In patients with intermittent/persistently eosinophilic asthma, we calculated a minimal important decrease of 4.3% in the percentage of sputum eosinophils (area under the curve [AUC], 0.69; P < .001) or 3.4-fold (AUC, 0.65; P = .003) for a significant improvement in asthma control and a minimal important increase of 3.5% (AUC, 0.67; P = .004) or 1.8-fold (AUC, 0.63; P = .02) for a significant worsening in asthma control. The association between asthma control and sputum eosinophils and the accuracy of the MIDs of sputum eosinophils were confirmed in the validation cohort.

CONCLUSIONS

At the individual level, asthma control was associated with fluctuations in sputum eosinophil count over time.

A Recombinant DNA Plasmid Encoding the sIL-4R-NAP Fusion Protein Suppress Airway Inflammation in an OVA-Induced Mouse Model of Asthma

Asthma is a chronic inflammatory airway disease. It was prevalently perceived that Th2 cells played the crucial role in asthma pathogenesis, which has been identified as the important target for anti-asthma therapy. The soluble IL-4 receptor (sIL-4R), which is the decoy receptor for Th2 cytokine IL-4, has been reported to be effective in treating asthma in phase I/II clinical trail. To develop more efficacious anti-asthma agent, we attempt to test whether the Helicobacter pylori neutrophil-activating protein (HP-NAP), a novel TLR2 agonist, would enhance the efficacy of sIL-4R in anti-asthma therapy. In our work, we constructed a pcDNA3.1-sIL-4R-NAP plasmid, named PSN, encoding fusion protein of murine sIL-4R and HP-NAP. PSN significantly inhibited airway inflammation, decreased the serum OVA-specific IgE levels and remodeled the Th1/Th2 balance. Notably, PSN is more effective on anti-asthma therapy comparing with plasmid only expressing sIL-4R.

Mast cells are associated with exacerbations and eosinophilia in children with severe asthma

The role of mast cells in the pathogenesis of childhood asthma is poorly understood. We aimed to estimate the implication of airway mucosal mast cells in severe asthma and their relationship with clinical, functional, inflammatory and remodelling parameters.Bronchial biopsies were performed in 36 children (5-18 years) with severe asthma: 24 had frequent severe exacerbations and/or daily symptoms in the previous year (symptomatic group), and 12 had few symptoms and a persistent obstructive pattern (paucisymptomatic group). Nine children without asthma were included as control subjects. We assessed mast cells in the submucosa and airway smooth muscle using c-kit antibodies and in the entire biopsy area using Giemsa.The number of submucosal mast cells was higher in the symptomatic group than in the paucisymptomatic group (p=0.02). The number of submucosal mast cells correlated with the number of severe exacerbations (p=0.02, r=0.37). There were positive correlations between the number of submucosal mast cells (p<0.01, r=0.44), airway smooth muscle mast cells (p=0.02, r= 0.40), mast cells stained by Giemsa (p<0.01, r=0.44) and submucosal eosinophils.Mast cells are associated with severe exacerbations and submucosal eosinophilic inflammation in children with severe asthma.

Exhaled nitric oxide in childhood allergic asthma management: a randomised controlled trial

OBJECTIVE

We investigated the potential yield of incorporating fractional exhaled nitric oxide (FeNO) measurements in childhood allergic asthma management.

METHODS

Ninety-nine children with persistent allergic asthma were included in this multicentre, single-blind, randomized controlled trial. Treatment was based on the Global Initiative for Asthma (GINA) guidelines. In the FeNO group, asthma management was also guided by FeNO measurements. Health outcomes were evaluated over a 52-week timeframe.

RESULTS

Fewer asthma exacerbations were registered in the FeNO group. 24% of the children in the FeNO group experienced one or more exacerbations per year, compared with 48% in the clinical group (P = 0.017). The proportion of symptom-free days did not differ between groups. In the FeNO group, more months of leukotriene receptor antagonist use (median (interquartile range)) were observed: 12 (9-12) months, compared with 9 (3-12) months in the clinical group (P = 0.019). Next, the evolution of inhaled corticosteroid doses between visits 1 and 5 (median change (interquartile range)) showed a significant increase of +100 µg (0, +400) in the FeNO group and a change of 0 µg (-200, +80) in the clinical group (P = 0.016).

CONCLUSIONS

FeNO measurements in childhood asthma management did not improve the proportion of symptom-free days, but did result in fewer asthma exacerbations associated with an increased leukotriene receptor antagonist use and an augmentation of the inhaled corticosteroid doses.

CD53, a suppressor of inflammatory cytokine production, is associated with population asthma risk via the functional promoter polymorphism -1560 C>T

BACKGROUND

In this study, the association of asthma with CD53, a member of the tetraspanin family, was assessed for the first time in a mechanism-based study.

METHODS

Genetic polymorphisms of CD53 were analyzed in 591 subjects and confirmed in a replication study of 1001 subjects. CD53 mRNA and protein levels were measured in peripheral blood leukocytes, and the effects of the promoter polymorphisms on nuclear factor binding were examined by electrophoretic mobility shift assay. Cellular functional studies were conducted by siRNA transfections.

RESULTS

Among tagging SNPs of CD53, the -1560 C>T in the promoter region was significantly associated with asthma risk. Compared with the CC genotype, the CT and TT genotypes were associated with a higher asthma risk, with odd ratios of 1.74 (P=0.009) and 2.03 (P=0.004), respectively. These findings were confirmed in the replication study with odd ratios of 1.355 (P=0.047) and 1.495 (P=0.039), respectively. The -1560 C>T promoter SNP had functional effects on nuclear protein binding as well as mRNA and protein expression levels in peripheral blood leukocytes. When CD53 was knocked down by siRNA in THP-1 human monocytic cells stimulated with house dust mite, the production of inflammatory cytokines as well as NFκB activity was significantly over-activated, suggesting that CD53 suppresses over-activation of inflammatory responses.

CONCLUSIONS

The -1560 C>T SNP is a functional promoter polymorphism that is significantly associated with population asthma risk, and is thought to act by directly modulating nuclear protein binding, thereby altering the expression of CD53, a suppressor of inflammatory cytokine production.

Relationship between the airway wall area and asthma control score in moderate persistent asthma

OBJECTIVES

To assess the association between airway wall area and clinical asthma control, assessed by the Asthma Control Test (ACT).

METHODS

This cross-sectional study evaluated 96 adults for asthma control ["at least well controlled" (ACT ≥ 20; n = 52) or "not well controlled" (ACT < 20; n = 44) and airway dimensions: luminal area (LA), wall area (WA) and WA%], obtained using automated dedicated software measurements from volumetric CT images. Results were analysed for segmental bronchi, subsegmental bronchi in the right upper lobe and basilar segments, both uncorrected and corrected for body surface area (BSA).

RESULTS

For all bronchi corrected for BSA, there was no correlation between airway wall area and ACT score. There was a weak but statistically significant correlation between uncorrected WA and ACT score (r = -0.203; P = 0.047); WA values were numerically higher in the "not well-controlled" versus the "at least well-controlled asthma" subgroups. For sub-segmental bronchi, there was a correlation between the ACT score and both WA/BSA (r = -0.204; P = 0.047) and WA (r = -0.249; P = 0.014), and for upper lobe bronchi, between the ACT score and WA (r = -0.207; P = 0.044).

CONCLUSION

We demonstrated a correlation between subsegmental bronchial airway measurements and clinical control of asthma; this is probably a reflection of airway remodelling and structural changes in chronic poorly controlled asthma.

KEY POINTS

• Volumetric computed tomography offers new insights into bronchial morphology. • The relationship between current asthma control and airway wall abnormalities is assessed. • Some relationships between airway wall area and clinical control were demonstrated. • We observed less shape variation of bronchi in "not well-controlled" asthma patients.

The relationship between hs-CRP and asthma control test in asthmatic patients

BACKGROUND

High sensitive C-reactive protein (hs-CRP) has been shown to be associated with asthma in recent studies. However, the relationship between hs-CRP and the control of asthma has not been clearly identified yet.

OBJECTIVE

To investigate the association of hs-CRP with asthma control test (ACT), which reveals the degree of asthma control, and to compare hs-CRP in adults with mild and moderate asthma in chronic, stable asthmatic patients.

METHODS

Thirty patients with physician-diagnosed asthma (11 mild, 19 moderate), and 30 healthy patients were enrolled in the study. In addition to medical history and physical examination, asthma was assessed according to GINA guideline. Respiratory function tests (RFT) and ACT were performed. The serum hs-CRP levels of all cases patients were measured.

RESULTS

The levels of hs-CRP in asthmatic patients were significantly higher than those in the control cases (p=0.002). The serum hs-CRP levels in the moderate asthmatics were significantly higher than those in the mild asthmatic ones (p=0.04). When asthmatic cases were divided into two groups according to ACTs; the levels of hs-CRP in the groups of ACT≤20 (uncontrolled groups) were significantly higher than the groups of ACT≥20 (controlled groups) (p=0.02). The hs-CRP levels showed significant correlations with ACT (p=0.00, r=-0.91) and asthma severity (p=0.04, r=038) in asthmatic patients.

CONCLUSION

In conclusion it was shown that hs-CRP is related with asthma severity and ACT, and hs-CRP is a potential sensitive marker which reveals the severity and the control of asthma.

Neuronal modulation of airway and vascular tone and their influence on nonspecific airways responsiveness in asthma

The autonomic nervous system provides both cholinergic and noncholinergic neural inputs to end organs within the airways, which includes the airway and vascular smooth muscle. Heightened responsiveness of the airways to bronchoconstrictive agents is a hallmark feature of reactive airways diseases. The mechanisms underpinning airways hyperreactivity still largely remain unresolved. In this paper we summarize the substantial body of evidence that implicates dysfunction of the autonomic nerves that innervate smooth muscle in the airways and associated vasculature as a prominent cause of airways hyperresponsiveness in asthma.

Local glucocorticoid production in the mouse lung is induced by immune cell stimulation

BACKGROUND

Glucocorticoids (GC) are potent anti-inflammatory and immunosuppressive steroid hormones, mainly produced by the adrenal glands. However, increasing evidence supports the idea of additional extra-adrenal sources of bioactive GC. The lung epithelium is constantly exposed to a plethora of antigenic stimuli, and local GC synthesis could contribute to limit uncontrolled immune reactions and tissue damage.

METHODS

Expression of steroidogenic enzymes and GC synthesis in ex vivo organ cultures was studied in mouse lung tissue after in vivo stimulation of immune cells.

RESULTS

Mouse lung tissue was found to express steroidogenic enzymes required for the synthesis of corticosterone from cholesterol and to synthesize corticosterone in large quantities after immune cell activation by anti-CD3 antibody, lipopolysaccharide, or TNFα. In marked contrast, ovalbumin-induced allergic airway inflammation failed to promote lung GC synthesis. Although the lung expresses all steroidogenic enzymes necessary for de novo synthesis of corticosterone from cholesterol, functional data indicated that inactive serum-derived dehydrocorticosterone is converted to active corticosterone by 11β-hydroxysteroid dehydrogenase 1.

CONCLUSION

Our results support the notion that local GC synthesis represents a novel immunoregulatory mechanism to limit uncontrolled immune responses in the lung and indicate that defective local steroidogenesis may contribute to the pathogenesis of allergic airway inflammation.

Asthma control, quality of life and successful sputum induction

INTRODUCTION

Induced sputum is widely used in clinical practice and scientific studies. This technique has become enormously useful in assessment of airway inflammation. However, some asthmatics are unable to expectorate sputum of sufficient quality and quantity necessary for further processing, therefore not providing reliable results. This research study aimed to examine whether asthma control and asthma quality of life influence the results of sputum induction.

MATERIAL AND METHODS

Fourty-seven adult subjects, current non-smokers with symptomatic asthma, were studied. All participants underwent clinical assessment, skin prick testing, spirometry and sputum induction. Before sputum induction, subjects were asked to fill in the Mini Asthma Quality of Life Questionnaire (MiniAQLQ) and Asthma Control Questionnaire (ACQ).

RESULTS

Twenty-nine (62%) subjects produced sputum eligible for processing. This group had a significantly lower ACQ score (0.83 ±0.65 vs. 1.37 ±0.77; p = 0.02), higher MiniAQLQ total score (5.67 ±0.99 vs. 4.86 ±1.07; p = 0.011), higher MiniAQLQ symptoms domain score (5.54 ±1.13 vs. 4.63 ±1.24; p = 0.013) and higher MiniAQLQ activity limitations domain score (6.08 ±0.92 vs. 5.07 ±1.37; p= 0.014). The noted differences between groups of patients were not only statistically but were clinically important.

CONCLUSIONS

The study results suggest that successful sputum induction may be expected in patients with better asthma control and better quality of life.

Preventing asthma exacerbations: what are the targets?

Exacerbations of asthma are the main cause of asthma morbidity. They induce acute respiratory failure, and sometimes death. Two immunological signals acting in synergy are necessary for inducing asthma exacerbations. The first, triggered by allergens and/or unknown agents leads to the chronic Th2 inflammation characteristic of asthma. The second, caused by either viral infection, allergens, pollutants or a combination of these, results in an acute Th1 and Th2 inflammation precipitating symptoms. In both, innate and adaptive immunities are involved, providing a series of potential targets for therapy. Molecules associated to the first, chronic inflammation constitute targets for preventing therapies, when these related to the second, acute signal provide the rationale for curative treatments. Toll like receptors and bronchial epithelial cell-derived cytokines, engaged upstream of inflammation constitute interesting candidates for future treatments. The great heterogeneity of asthma has to be taken into account when considering targets for therapy to identify clusters of responders and nonresponders, and an integrative system biology approach will be necessary to go further.

[Adult asthma exacerbations in questions]

In this article a French working party critically review the international literature to revise the definition, pathophysiology, treatment and cost of exacerbations of adult asthma. The various guidelines do not always provide a consistent definition of exacerbations of asthma. An exacerbation can be defined as deterioration of clinical and/or functional parameters lasting more than 24 hours, without return to baseline, requiring a change of treatment. No single clinical or functional criterion can be used as an early marker of an exacerbation. Innate and acquired immune mechanisms, modified by contact with infectious, irritant or allergenic agents, participate in the pathogenesis of exacerbations, which are accompanied by bronchial inflammation. In 2010, mortality is related to progression of exacerbations, often occurring before the patient seeks medical attention. The objective of treatment is to control asthma and prevent exacerbations. However, many factors can trigger exacerbations and often cannot be controlled. The efficacy of inhaled corticosteroids has been demonstrated on reduction of the number of exacerbations and the number of asthma-related deaths. This treatment is cost-effective, especially in terms of reduction of exacerbations.

Exhaled NO and exhaled breath condensate pH in the evaluation of asthma control

BACKGROUND

Asthma is a chronic inflammatory airways disorder. However, no biomarker of airways inflammation has been included in the assessment of asthma control.

OBJECTIVE

To evaluate exhaled NO (FeNO) and exhaled breath condensate (EBC) pH in patients with asthma according to the level of control, and their performance in the identification of not well-controlled patients.

METHODS

FeNO and EBC pH after Argon deaeration were measured in 274 consecutive patients. Asthma control was evaluated by two asthma specialists blinded to FeNO and pH measurements according to GINA guidelines, as well as by asthma control test (ACT) and asthma control questionnaire (ACQ).

RESULTS

FeNO was higher and EBC pH was lower in patients with not well-controlled compared to controlled asthma. In ROC analysis, FeNO presented an AUC of 0.790 for the identification of not well-controlled asthma performing better in non-smokers; EBC pH presented an AUC of 0.791 for the identification of not well-controlled asthma, performing better in smokers. The performance of both biomarkers was inferior to that of ACT and ACQ. FeNO values >30 ppb presented positive predictive values (PPV) > 0.85 with the exception of smokers treated with inhaled corticosteroids. EBC pH values ≤7.20 presented PPV >0.80 in all groups. The presence of FeNO >30 ppb and/or EBC pH ≤7.20 was indicative of not well-uncontrolled asthma in 88.3% of the patients.

CONCLUSION

FeNO and EBC pH levels may identify patients with not well-controlled asthma. However, their performance was inferior to clinical judgment and may be limited to selected subgroups of asthmatic patients.

Translating airway biomarker information into practice: from theoretical science to applied medicine

Biomarkers ranging from simple to sophisticated have been used by man for many years of his existence. The main use for biomarkers over that time has been to assess relative states health and well-being, including the presence of functional limitations that presage debilitation and even death. In recent years, there has been intense interest in the development of non-invasive biomarkers to accurately predict disease state and progression, as well as potential drug therapy to assist in early mitigation of morbidity and possibly, forestall premature mortality. The development of biomarkers of airway status has followed a similar pattern, and in recent years, several biomarkers have followed the progression from basic and pre-clinical development, to clinical/translational application, and finally to potential clinical therapeutic application. Inherent in this progression is the refinement of technology that has allowed measurement of these biomarkers in a fast, convenient, and reliable fashion, such that they can be obtainable within a clinical practice setting, to allow the physician to make treatment decisions for diseases such as asthma and COPD. While the clinical therapeutic application of airway biomarkers such as exhaled nitric oxide and β(2)-adrenoreceptor Arg-16 polymorphism are still in their infancy, they have followed this common pathway of development, and now will require some years of application to demonstrate their true utility as predictive biomarkers of airway status and treatment response.

Resolution of cell-mediated airways diseases

"Inflammation resolution" has of late become a topical research area. Activation of resolution phase mechanisms, involving select post-transcriptional regulons, transcription factors, 'autacoids', and cell phenotypes, is now considered to resolve inflammatory diseases. Critical to this discourse on resolution is the elimination of inflammatory cells through apoptosis and phagocytosis. For major inflammatory diseases such as asthma and COPD we propose an alternative path to apoptosis for cell elimination. We argue that transepithelial migration of airway wall leukocytes, followed by mucociliary clearance, efficiently and non-injuriously eliminates pro-inflammatory cells from diseased airway tissues. First, it seems clear that numerous infiltrated granulocytes and lymphocytes can be speedily transmitted into the airway lumen without harming the epithelial barrier. Then there are a wide range of 'unexpected' findings demonstrating that clinical improvement of asthma and COPD is not only associated with decreasing numbers of airway wall inflammatory cells but also with increasing numbers of these cells in the airway lumen. Finally, effects of inhibition of transepithelial migration support the present hypothesis. Airway inflammatory processes have thus been much aggravated when transepithelial exit of leukocytes has been inhibited. In conclusion, the present hypothesis highlights risks involved in drug-induced inhibition of transepithelial migration of airway wall leukocytes. It helps interpretation of common airway lumen data, and suggests approaches to treat cell-mediated airway inflammation.

New production of eosinophils and the corresponding TH1/TH2 balance in the lungs after allergen exposure in BALB/c and C57BL/6 mice

Allergic asthma is associated with eosinophilic inflammation in the airways. Animal models commonly used to elucidate allergic inflammation mechanisms include BALB/c and C57BL/6 mice. Our aim was to evaluate lung eosinophilia and the corresponding Th1/Th2 balance in the two strains after allergen exposure. BALB/c and C57BL/6 mice were subjected to ovalbumin-induced allergic airway inflammation using BrdU to label newly produced cells. The numbers of new eosinophils were evaluated by differential cell count and immunocytochemistry (MBP+BrdU+). Proliferation rate of lung eosinophils was measured by analysis of CD45+CCR3+BrdU+ cells by FACS. Distribution of newly produced eosinophils in the lung and the Th1/Th2 (CD4+T-bet+/CD4+GATA-3+) balance was evaluated by immunohistochemistry. Allergen challenge with ovalbumin induced comparable eosinophilia in bone marrow (BM), blood and lung tissue in both strains of mice compared to phosphate-buffered saline controls, which was confirmed by immunocytochemistry. There was a small increase in the number of lung MBP+BrdU(-) eosinophils in C57BL/6 mice compared to BALB/c mice, which suggests a basal increase in this strain following sensitization. While there was no difference in eosinophilic proliferation in the lung, the distribution of the newly produced eosinophils differs between the two strains. BALB/c mice showed staining primarily around vessels and airways, whereas C57BL/6 mice showed a more even distribution in the lung tissue. No difference in the Th1/Th2 balance was observed between two strains. This study shows that there is a difference in the distribution of eosinophils in the lung between the C57BL/6 and BALB/c mice, but no difference in eosinophil production or Th1/Th2 balance.

Psychological status in uncontrolled asthma is not related to airway hyperresponsiveness

BACKGROUND

Airway hyperresponsiveness (AHR) is the characteristic functional abnormality of asthma, and previous studies have shown the potential for AHR to be influenced by psychological factors, yet the relationship between anxiety and/or depression and AHR remains unclear in patients with asthma.

OBJECTIVE

To explore the relationship between psychological status and AHR in asthma patients.

METHODS

In a cross-sectional study, 168 adult subjects were recruited with physician-diagnosed uncontrolled asthma and a positive result for AHR in methacholine (Mch) challenge test. Psychological status, asthma control, and asthma quality of life were assessed using Zung self-rating anxiety/depression scale, asthma control test (ACT), and asthma quality of life questionnaire (AQLQ), respectively. AHR severity was evaluated and quantified by the provocative concentration of Mch, which evoked a given decrease of 20% in FEV(1).

RESULTS

A total of 70.23% of recruited patients (n = 118) met the diagnostic criteria for anxiety and/or depression. There was a trend between negative psychological status and AHR in asthma patients that did not reach statistical significance, but no independent effects of negative mood states (anxiety, depression, or both) on AHR were established. Further, analyses revealed that only anxiety is associated with worse asthma control (p = 0.029), and a significant interaction effect of depression and anxiety accounted for lower asthma-related quality-of-life scores (p < 0.001).

CONCLUSIONS

AHR and psychological status are loosely related to each other even if in uncontrolled asthma.

Measuring asthma control is the first step to patient management: a literature review

Asthma control is recognized as a critical aspect of the evaluation and management of the disease. Here we evaluate and compare existing instruments for measuring asthma control in an attempt to evaluate their clinical utility. Based on a literature review, we identified validated instruments used to assess asthma control in adults. We examined the specific measurement properties and the strengths and weaknesses of each instrument, and evaluated a single instrument, the Asthma Control Questionnaire (ACQ), more closely as an example, evaluating its applicability in the clinical setting. Our review identified five validated instruments designed to measure asthma control: the Asthma Control Questionnaire (ACQ), Asthma Control Scoring System (ACSS), Asthma Control Test (ACT), Asthma Therapy Assessment Questionnaire (ATAQ), and the Lara Asthma Symptom Scale (LASS). None of the instruments covered all relevant control characteristics, but most were aligned with guideline definitions of control. All instruments demonstrated validity and responsiveness, with some measure of reliability. All instruments were short and easily administered, easy to interpret, and all had evidence to support their use in clinical decision making.