Therapeutic significance of distal airway inflammation in asthma

Small airway inflammation in atypical asthma

Background

Less attention has been paid to the pathophysiological changes in atypical asthma such as cough variant asthma (CVA) and chest tightness variant asthma (CTVA). The obstruction of large and small airways is the important component in the development of asthma. We investigated whether small airway inflammation (SAI) induced small airway dysfunction (SAD) in these atypical asthmatics.

Methods

Six hundred and eighty-six patients were enrolled and analyzed in the study. The partitioned airway inflammation was assessed by fractional exhaled nitric oxide (FeNO), such as FnNO, FeNO50, FeNO200, and calculated alveolar fraction of exhaled NO (CaNOdual). Correlations between exhaled NOs and SAD-related variables were assessed, whereas cell classification was evaluated by Spearman's rank tests. Classic asthma, CVA, and CTVA about potential risk were conducted using binary logistic regression models.

Results

The whole airway inflammation increased in classic and atypical asthma than controls, whereas the central and peripheral airway inflammation in the CVA and CTVA groups increased compared with the classic asthma group. Smoking exposure was found to increase the central and peripheral airway inflammation in patients with asthma. The exhaled NO of FeNO50 and FeNO200 was associated with SAD in classic asthma, but not in CVA and CTVA. FeNO200 was the main risk (adjusted odds ratio [OR], 1.591; 95 % CI, 1.121-2.259; P = .009) in classic asthma and (adjusted OR, 1.456; 95 % CI, 1.247-1.700; P = .000) in CVA. The blood eosinophil levels were correlated with FeNO50 and FeNO200 in classic asthma and atypical asthma.

Conclusion

More severe inflammatory process was present in central and peripheral airways in CVA and CTVA, which might reflect a pre-asthmatic state. SAI was the predominant risk factor in the development of asthma before SAD.

Comparison of Budesonide/formoterol versus Fluticasone furoate/vilanterol as maintenance and reliever therapy for asthma control: a real-world observational study

BACKGROUND

Previous studies have reported reduced acute exacerbation rates and improved symptom control in asthma patients treated using inhaled corticosteroids plus formoterol maintenance and reliever therapy (MART). Fluticasone furoate (FF) and vilanterol (VIL) also provide rapid bronchodilation and sustained anti-inflammatory effects, however no studies have investigated FF/VIL as MART for asthma control.

METHODS

From October 1, 2021 to September 30, 2023, this retrospective study included asthma patients classified as step 3 or 4 according to the Global Initiative for Asthma guidelines, who were then divided into two groups. One group received BUD/FOR as MART, while the other received FF/VIL as MART. Pulmonary function tests, exacerbation rates, Asthma Control Test (ACT), fractional exhaled nitric oxide (FeNO) levels, and blood eosinophil counts were measured before and after 12 months of treatment.

RESULTS

A total of 161 patients were included, of whom 36 received BUD/FOR twice daily as MART, and 125 received FF/VIL once daily as MART. After 12 months of treatment, the FF/VIL group showed a significant increase in ACT scores by 1.57 (p < 0.001), while the BUD/FOR group had an increase of 0.88 (p = 0.11). In terms of FeNO levels, the BUD/FOR group experienced a decline of -0.2 ppb (p = 0.98), whereas the FF/VIL group had a mild increase of + 0.8 ppb (p = 0.7). Notably, there was a significant difference in the change of FeNO between the two groups (∆ FeNO: -0.2 ppb in BUD/FOR; + 0.8 ppb in FF/VIL, p < 0.001). There were no significant alterations observed in FEV1, blood eosinophil count, or acute exacerbation decline in either group.

CONCLUSIONS

In the current study, patients treated with FF/VIL as MART showed improvements in ACT scores, while those treated with BUD/FOR as MART exhibited a reduction in FeNO levels. However, the difference between the two treatment groups did not reach clinical significance. Thus, FF/VIL as MART showed similar effectiveness to BUD/FOR as MART.

Adding oscillometry to spirometry in guidelines better identifies uncontrolled asthma, future exacerbations, and potential targeted therapy

The objective of this review is to provide new advances in our understanding of the clinical importance of establishing peripheral airway impairment (PAI) by impulse oscillometry (IOS) and targeted therapy, which could result in better asthma outcomes. Data sources include PubMed and Google search, limited to English language and human disease, with key words IOS and asthma. Key findings include PAI being consistently associated with uncontrolled asthma across ethnicities, using IOS reference equations factoring Hispanic and White reference algorithms. It is noted that PAI is common even in patients considered well-controlled by asthma guidelines. In a large longitudinal analysis (Assessment of Small Airways Involved in Asthma or ATLANTIS study), a composite of R5-R20, AX, and X5 ordinal scores were independently predictive of asthma control and exacerbation in a multivariate analysis, but forced expiratory volume in 1 second was not significantly predictive of morbidities. However, combining forced expiratory volume in 1 second less than 80% with PAI resulted in greater odds of identifying uncontrolled asthma and exacerbations, than either alone. Applying an external validation method in children with asthma offers the clinician the IOS reference equations best fit for their own specific population. Several clinical phenotypes can also identify PAI with high probability, useful when IOS is not available. Poor asthma outcomes for obese patients with asthma are associated with dysanapsis and PAI, not obesity alone. Extrafine inhaled corticosteroids achieve better asthma control and improve peripheral airway function with fewer exacerbations at lower dosages than nonextrafine inhaled corticosteroid aerosols. In conclusion, these data support the benefit of adding IOS to spirometry in future asthma guidelines and suggest the potential benefit from targeted therapy.

Anatomical and histopathological approaches to asthma phenotyping

Asthma is typically characterized by variable respiratory symptoms and airflow limitation. Along with the pathophysiology and symptoms are immunological and inflammatory processes. The last decades research has revealed that the immunology of asthma is highly heterogeneous. This has clinical consequences and identification of immunological phenotypes is currently used to guide biological treatment. The focus of this review is on another dimension of asthma diversity, namely anatomical heterogeneity. Immunopathological alterations may go beyond the central airways to also involve the distal airways, the alveolar parenchyma, and pulmonary vessels. Also, extrapulmonary tissues are affected. The anatomical distribution of inflammation in asthma has remained relatively poorly discussed despite its potential implication on both clinical presentation and response to treatment. There is today evidence that a significant proportion of the asthma patients has small airway disease with type 2 immunity, eosinophilia and smooth muscle infiltration of mast cells. The small airways in asthma are also subjected to remodelling, constriction, and luminal plugging, events that are likely to contribute to the elevated distal airway resistance seen in some patients. In cases when the inflammation extends into the alveolar parenchyma alveolar FCER1-high mast cells, eosinophilia, type 2 immunity and activated alveolar macrophages, together with modest interstitial remodelling, create a complex immunopathological picture. Importantly, the distal lung inflammation in asthma can be pharmacologically targeted by use of inhalers with more distal drug deposition. Biological treatments, which are readily distributed to the distal lung, may also be beneficial in eligible patients with more severe and anatomically widespread disease.

No-shaking and shake-fire delays affect respirable dose for suspension but not solution pMDIs

It has long been accepted that suspension pressurized metered-dose inhalers (pMDIs) must be shaken if a correct dose is to be delivered, if not, it will usually be higher than the label claim. The purpose of this work was to investigate the influence of the device being unshaken, shaken and after a period of delay in pMDI actuation on the Fine Particle Mass (<5 µm), Extra Fine Particle Mass (<2 µm) and MMAD. Solution and suspension commercial pMDIs containing one, two or three components were used in the study. Most of the suspension pMDIs produced variable amounts of respirable size drug following the shake-fire delays tested in terms of the label claim dose. The effect was even more critical if the inhaler was not shaken and the FPM was found to be between -82 % for Symbicort and 363 % for Ventolin compared with the control values. In the case of MMAD measurements, Seretide and Serzyl inhalers showed the largest change from around 3 µm to 4.2-5.1 µm when not shaken. Conversely, the FPM and MMAD for the solution aerosols remained unchanged whether or not they were shaken or when a progressive increase in the delay in actuation after shaking was employed.

Inhalation of nebulized omega-3 fatty acids mitigate LPS-induced acute lung inflammation in rats: Implications for treatment of COPD and COVID-19

Many current treatment options for lung inflammation and thrombosis come with unwanted side effects. The natural omega-3 fatty acids (O3FA) are generally anti-inflammatory and antithrombotic. O3FA are always administered orally and occasionally by intravenous (IV) infusion. The main goal of this study is to determine if O3FA administered by inhalation of a nebulized formulation mitigates LPS-induced acute lung inflammation in male Wistar rats. Inflammation was triggered by intraperitoneal injection of LPS once a day for 14 days. One hour post-injection, rats received nebulized treatments consisting of egg lecithin emulsified O3, Budesonide and Montelukast, and blends of O3 and Melatonin or Montelukast or Cannabidiol; O3 was in the form of free fatty acids for all groups except one group with ethyl esters. Lung histology and cytokines were determined in n = 3 rats per group at day 8 and day 15. All groups had alveolar histiocytosis severity scores half or less than that of the disease control (Cd) treated with LPS and saline only inhalation. IL-6, TNF-α, TGF-β, and IL-10 were attenuated in all O3FA groups. IL-1β was attenuated in most but not all O3 groups. O3 administered as ethyl ester was overall most effective in mitigating LPS effects. No evidence of lipid pneumonia or other chronic distress was observed. These preclinical data suggest that O3FA formulations should be further investigated as treatments in lung inflammation and thrombosis related lung disorders, including asthma, chronic obstructive pulmonary disease, lung cancer and acute respiratory distress such as COVID-19.

Single-cell RNA transcriptomic analysis identifies Creb5 and CD11b-DCs as regulator of asthma exacerbations

Immune responses that result in asthma exacerbation are associated with allergen or viral exposure. Identification of common immune factors will be beneficial for the development of uniformed targeted therapy. We employed a House Dust Mite (HDM) mouse model of asthma and challenged allergic HDM mice with allergens (HDM, cockroach extract (CRE)) or respiratory syncytial virus (RSV). Purified lung immune cells underwent high-dimensional single-cell RNA deep sequencing (scRNA-seq) to generate an RNA transcriptome. Gene silencing with siRNA was employed to confirm the efficacy of scRNA-seq analysis. scRNA-seq UMAP analysis portrayed an array of cell markers within individual immune clusters. SCENIC R analysis showed an increase in regulon number and activity in CD11b^- DC cells. Analysis of conserved regulon factors further identified Creb5 as a shared regulon between the exacerbation groups. Creb5 siRNAs attenuated HDM, CRE or RSV-induced asthma exacerbation. scRNA-seq multidimensional analysis of immune clusters identified gene pathways that were conserved between the exacerbation groups. We propose that these analyses provide a strong framework that could be used to identify specific therapeutic targets in multifaceted pathologies.

Impact of long-acting muscarinic antagonists on small airways in asthma and COPD: A systematic review

Small airway disease is recognized as a cardinal pathological process of chronic obstructive pulmonary disease (COPD), and recently small airways have been recognized as a major site of airflow obstruction also in asthmatic patients. The transversal involvement of small airways in COPD and asthma has warranted research efforts to identify therapeutic strategies able to unlock the small airway compartment. The mainstay of COPD treatment is represented by long-acting β₂-adrenoceptor agonists (LABAs) and long-acting muscarinic antagonists (LAMAs). In asthma, the efficacy of LAMAs administered add-on to inhaled corticosteroids (ICSs) or ICS/LABA combinations has been investigated only in recent years. The aim of this systematic review was to examine the current literature concerning the impact of LAMAs on small airways and their lung deposition in both COPD and asthma. LAMAs administered either alone or in combination induced an effective bronchorelaxant effect of small airways, however the effectiveness of respiratory medications not only relies on the selected drug, but also on the employed inhalation device and patient's adherence. Tiotropium delivered via Respimat® SMI achieved a superior drug deposition in the peripheral lung compared to HandiHaler® dry powder inhaler and metered-dose inhalers (MDIs). The use of co-suspension™ delivery technology for MDIs and the introduction of the eFlow® nebulizer to deliver glycopyrronium improved aerosol drug delivery to the peripheral lung, by achieving uniform distribution of drug particles. This systematic review provides a synthesis of current literature concerning the impact of LAMAs on small airways and an insight on LAMAs distribution within the lung.

Extrafine HFA-beclomethasone-formoterol vs. nonextrafine combination of an inhaled corticosteroid and a long acting β2-agonist in patients with persistent asthma: A systematic review and meta-analysis

Objective

Airway inflammation in asthma involves not only the central airways but extends to peripheral airways. Lung deposition may be key for an appropriate treatment of asthma. We compared the clinical effects of extrafine hydrofluoroalkane (HFA)-beclomethasone-formoterol (BDP-F) versus equipotent doses of nonextrafine combination of an inhaled corticosteroid and a long acting β2-agonist (ICS-LABA) in asthma.

Methods

We identified eligible studies by a comprehensive literature search of PubMed, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL). Data analysis was performed with the Review Manager 5.3.5 software (Cochrane IMS, 2014).

Results

A total of 2326 patients with asthma from ten published randomized controlled trials (RCTs) were enrolled for analysis. Change from baseline in morning pre-dose peak expiratory flow (PEF), evening pre-dose PEF and forced expiratory volume in one second (FEV₁) were detected no significant differences between extrafine HFA-BDP-F and nonextrafine ICS-LABAs (p = 0.23, p = 0.99 and p = 0.23, respectively). Extrafine HFA-BDP-F did not show any greater benefit in forced expiratory flow between 25% and 75% of forced vital capacity (FEF25-75%), the parameter concerning peripheral airways (MD 0.03L/s, p = 0.65; n = 877). There were no substantial differences between interventions in fractional exhaled nitric oxide (FeNO) levels or in its alveolar fraction. The overall analysis showed no significant benefit of extrafine HFA-BDP-F over nonextrafine ICS-LABA in improving Asthma Control Test (ACT) score (p = 0.30) or decreasing the number of puffs of rescue medication use (p = 0.16). Extrafine HFA-BDP-F did not lead to less exacerbations than nonextrafine ICS-LABA (RR 0.61, 95% CI: 0.31 to 1.20; I² = 0; p = 0.15).

Conclusion

Enrolled RCTs of extrafine HFA-BDP-F have demonstrated no significant advantages over the equivalent combination of nonextrafine ICS-LABA in improving pulmonary function concerning central airways or peripheral airways, improving asthma symptom control or reducing exacerbation rate.

Small airways in asthma: from bench-to-bedside

INTRODUCTION

Historically, asthma was considered a disease predominantly of the large airways, but gradually small airways have been recognized as the major site of airflow obstruction. Small airway dysfunction (SAD) significantly contributes to the pathophysiology of asthma and it is present across all asthma severities. Promising pre-clinical findings documented enhanced beneficial effects of combination therapies on small airways compared to monocomponents, thus it was questioned whether this could translate into further clinical implications from bench-to-bedside. The aim of this review was to systematically assess the state of the art of small airway involvement in asthma, especially in response to different pharmacological treatments acting on the respiratory system.

EVIDENCE ACQUISITION

A comprehensive literature search was performed in MEDLINE for randomized controlled trials (RCTs) characterizing the impact on small airways of different pharmacological treatments acting on the respiratory system. The results were extracted and reported via qualitative synthesis.

EVIDENCE SYNTHESIS

Overall, 63 studies were identified from the literature search, whereas 23 RCTs met the inclusion criteria. Evidence confirms that both drug particle size and the type of inhalation devices represent two of the most important variables for an effective peripheral lung distribution.

CONCLUSIONS

Despite the numerous methodological tools to detect SAD, there is still no gold standard diagnostic method to assess small airways, especially in severe asthma. Further research should be directed to improve primary and secondary prevention strategies by supporting the combined approach of different non-invasive techniques for an early detection of peripheral abnormalities and optimization of asthma therapy.

IL-33 blockade affects mediators of persistence and exacerbation in a model of chronic airway inflammation

BACKGROUND

Severe inflammatory airway diseases are associated with inflammation that does not resolve, leading to structural changes and an overall environment primed for exacerbations.

OBJECTIVE

We sought to identify and inhibit pathways that perpetuate this heightened inflammatory state because this could lead to therapies that allow for a more quiescent lung that is less predisposed to symptoms and exacerbations.

METHODS

Using prolonged exposure to house dust mite in mice, we developed a mouse model of persistent and exacerbating airway disease characterized by a mixed inflammatory phenotype.

RESULTS

We show that lung IL-33 drives inflammation and remodeling beyond the type 2 response classically associated with IL-33 signaling. IL-33 blockade with an IL-33 neutralizing antibody normalized established inflammation and improved remodeling of both the lung epithelium and lung parenchyma. Specifically, IL-33 blockade normalized persisting and exacerbating inflammatory end points, including eosinophilic, neutrophilic, and ST2⁺CD4⁺ T-cell infiltration. Importantly, we identified a key role for IL-33 in driving lung remodeling because anti-IL-33 also re-established the presence of ciliated cells over mucus-producing cells and decreased myofibroblast numbers, even in the context of continuous allergen exposure, resulting in improved lung function.

CONCLUSION

Overall, this study shows that increased IL-33 levels drive a self-perpetuating amplification loop that maintains the lung in a state of lasting inflammation and remodeled tissue primed for exacerbations. Thus IL-33 blockade might ameliorate symptoms and prevent exacerbations by quelling persistent inflammation and airway remodeling.

Correlation between impulse oscillometry parameters and asthma control in an adult population

Purpose: Impulse oscillometry (IOS) has been proposed as an alternative test to evaluate the obstruction of small airways and to detect changes in airways earlier than spirometry. In this study, we sought to determine the utility and association of IOS parameters with spirometry and asthma control in an adult population. Patients and methods: Adults 14-82 years of age with asthma were classified into uncontrolled asthma (n=48), partially controlled asthma (n=45), and controlled asthma (n=49) groups, and characterized with fractional exhaled nitric oxide (FE_NO), IOS, and spirometry in a transversal analysis planned as a one-visit study. The basic parameters evaluated in IOS are resistance at 5 Hz (R₅), an index affected by the large and small airway; resistance at 20 Hz (R₂₀), an index of the resistance of large airways; difference between R₅ and R₂₀ (R₅-R₂₀), indicative of the function of the small peripheral airways; reactance at 5 Hz (X₅), indicative of the capacitive reactance in the small peripheral airways; resonance frequency (Fres), the intermediate frequency at which the reactance is null, and reactance area (XA), which represents the total reactance (area under the curve) at all frequencies between 5 Hz to Fres. Results: There were statistical differences between groups in standard spirometry and IOS parameters reflecting small peripheral airways (R₅, R₁₀, R₅-R₂₀, Fres, XA and X₅) (P<0.001). Accuracy of IOS and/or spirometry to discriminate between controlled asthma vs partially controlled asthma and uncontrolled asthma was low (AUC=0.61). Using linear regression models, we found a good association between spirometry and IOS. In order to evaluate IOS as an alternative or supplementary method for spirometry, we designed a predictive model for spirometry from IOS applying a penalized regression model (Lasso). Then, we compared the original spirometry values with the values obtained from the predictive model using Bland-Altman plots, and the models showed an acceptable bias in the case of FEV₁/FVC, FEV₁%, and FVC%. Conclusion: IOS did not show a discriminative capacity to correctly classify patients according to the degree of asthma control. However, values of IOS showed good association with values of spirometry. IOS could be considered as an alternative and accurate complement to spirometry in adults. In a predictive model, spirometry values estimated from IOS tended to overestimate in low values of "real" spirometry and underestimate in high values.

Recognition of the peripheral airway impairment phenotype in children with well-controlled asthma

BACKGROUND

Peripheral airway impairment, although frequently unrecognized, is a risk factor for poor asthma control, loss of control, increased exacerbations, airway hyperresponsiveness, and loss of lung function with age, even in patients with well-controlled asthma.

OBJECTIVE

To determine the presence of peripheral airway impairment by impulse oscillometry and forced expiratory flow between 25% and 75% (FEF_25%-75%) in children whose asthma is well controlled by National Asthma Education and Prevention Program (NAEPP) guidelines.

METHODS

In this retrospective, cross-sectional analysis, outcomes were evaluated across 192 encounters in 139 patients with moderate to severe asthma, ages 4-18 years. Receiver operator characteristic curves were created and oscillometry thresholds determined by maximizing the sum of sensitivity and specificity to identify those whose condition is not well controlled. Impairment was then identified for those whose condition was well controlled when these age-dependent oscillometry thresholds were met for each IOS measure or FEF_25%-75% < 65% of predicted.

RESULTS

Reactance at 5 Hz (X5) appeared most robust to identify peripheral airway impairment. In 96 well-controlled asthma encounters, impairment was identified by X5 in approximately 20% and 45% for those younger than 12 years and adolescents, respectively, compared with a maximum of 10% with FEF_25%-75% in the adolescent cohort (P < .05).

CONCLUSION

We conclude that peripheral airway impairment, determined by oscillometry, is common in patients with well-controlled asthma across age cohorts. X5 with optimal cut points ≤ -3.8, ≤ -2.5, and ≤ -1.5 cmH₂O/L/s for ages 4-7, 8-11, and >12 years, provides the clinician with a practical tool to identify the presence of the peripheral airway impairment phenotype that is consistently superior to FEF_25%-75%. This recognition, if confirmed, may reduce the risk of asthma-associated consequences with earlier and more targeted therapy.

Preparation of a Sustained-Release Nebulized Aerosol of R-terbutaline Hydrochloride Liposome and Evaluation of Its Anti-asthmatic Effects via Pulmonary Delivery in Guinea Pigs

An aerosolized liposome formulation for the pulmonary delivery of an anti-asthmatic medication was developed. Asthma treatment usually requires frequent administration of medication for a sustained bronchodilator response. Liposomes are known for their sustained drug release capability and thus would be a suitable delivery system for prolonging the therapeutic effect of anti-asthmatic medication. Liposomes prepared by thin film hydration were loaded with a model drug, R-terbutaline hydrochloride(R-TBH), using an ammonium sulfate-induced transmembrane electrochemical gradient. This technique provided an encapsulation efficiency of up to 71.35% and yielded R-TBH liposomes with a particle size of approximately 145 ± 20 nm. According to stability studies, these R-TBH liposomes should be stored at 4°C before usage. Compared to R-TBH solution, which showed 90.84% release within 8 h, liposomal R-TBH had a cumulative release of 73.53% at 37°C over 192 h. A next generation impactor (NGI) was used to analyze the particle size distribution in the lungs of R-TBH liposome aerosol in vitro at 5°C. The therapeutic efficacy of the nebulized aerosol of the R-TBH liposomes was assessed via pulmonary delivery in guinea pigs. The results showed that, compared to the R-TBH solution group, the R-TBH liposome group had a prolonged anti-asthma effect.

Role of Small Airways in Asthma

Asthma is an inflammatory condition of both the small and large airways. Recently the small airways have gained attention as studies have shown significant inflammation in the small airways in all severities of asthma. This inflammation has correlated with peripheral airway resistance and as a result, noninvasive methods to reliably measure small airways have been pursued. In addition, recent changes in asthma inhalers have led to alterations in drug formulations and the development of extrafine particle inhalers that improve delivery to the distal airways.

Overall and peripheral lung function assessment by spirometry and forced oscillation technique in relation to asthma diagnosis and control

BACKGROUND

Classic spirometry is effort dependent and of limited value in assessing small airways. Peripheral airway involvement, and relation to poor control, in asthma, has been highlighted recently. Forced oscillation technique (FOT) offers an effort-independent assessment of overall and peripheral lung mechanics. We studied the association between lung function variables, obtained either by spirometry or multifrequency (5, 11 and 19 Hz) FOT, and asthma diagnosis and control.

METHODS

Spirometry measures, resistance at 5 (R5) and 19 Hz (R19), reactance at 5 Hz (X5), resonant frequency (f_res ), resistance difference between 5-19 Hz (R5-R19) and Asthma Control Test scores were determined in 234 asthmatic and 60 healthy subjects (aged 13-39 years). We used standardized lung function variables in logistic regression analyses, unadjusted and adjusted for age, height, gender and weight.

RESULTS

Lower FEV₁ /FVC (OR [95% CI] 0.47 [0.32, 0.69]) and FEF₅₀ (0.62 [0.46, 0.85]) per standard deviation increase, and higher R5 (3.31 [1.95, 5.62]) and R19 (2.54 [1.65, 3.91]) were associated with asthma diagnosis. Independent predictive effects of FEV₁ /FVC and R5 or R19, respectively, were found for asthma diagnosis. Lower FEV₁ /FVC and altered peripheral FOT measures (X5, f_res and R5-R19) were associated with uncontrolled asthma (P-values < .05).

CONCLUSIONS

Resistance FOT measures were equally informative as spirometry, related to asthma diagnosis, and, furthermore, offered additive information to FEV₁ /FVC, supporting a complementary role for FOT. Asthma control was related to FOT measures of peripheral airways, suggesting a potential use in identifying such involvement. Further studies are needed to determine a clinical value and relevant reference values in children, for the multifrequency FOT measurements.

Inhalation devices, delivery systems, and patient technique

BACKGROUND

In real-life clinical settings, physicians often consider the properties of various inhaled corticosteroids (ICSs), but typically little consideration is given to the properties of different inhalers and formulations.

OBJECTIVE

To discuss the effects of inhalation devices and user technique on efficacy, safety, and adherence with the aim of improving asthma management.

METHODS

Relevant publications were selected to augment discussion.

RESULTS

There are many types of devices available, each with advantages, disadvantages, ease of use, and rate of misuse. Aerosol particle size influences the deposition pattern of a drug in the lungs, and the optimal particle size range is 1 to 5 μm. Retrospective reviews suggest that smaller particles (1-2 μm) could provide improved asthma control, but randomized, prospective studies are needed. Multiple studies have demonstrated high misuse rates in patients for pressurized metered-dose inhalers and dry powder inhalers. Because of this, repeated education should include physical demonstrations of using the device, checking the patient's technique, correcting the technique, and rechecking the technique. This also means that dedicated, trained staff and placebo devices should be available for instructing patients. Furthermore, the device should be selected to be cost effective and to fit the patient's preference and ability to use it correctly to enhance compliance. Asthma management guidelines and algorithms are available to guide the clinician.

CONCLUSION

The choice of inhaler device should depend on cost effectiveness and the patient's preference and ability to use it correctly. Patient inhaler technique should be checked and, if necessary, corrected and rechecked, with retraining if needed, at every opportunity.

The case for impulse oscillometry in the management of asthma in children and adults

OBJECTIVE

To provide a clinical rationale for including impulse oscillometry (IOS) as a part of standard office-based asthma assessment.

DATA SOURCES

PubMed and Google search, limited to English language and human disease, with the keywords IOS and asthma.

STUDY SELECTIONS

Articles included in this review were based on the expert opinion and previous publications by the authors.

RESULTS

In children, IOS was more useful than spirometry in identifying asthma and uncontrolled asthma and predicting loss of control and exacerbations. IOS predicts young children at risk for loss of lung function with age and the potential for early intervention to prevent further sequelae. In adults, peripheral airway impairment detected by IOS or spirometry (ie, forced expiratory flow between 25% and 75%) commonly occurs across severity, and each measure may be complementary in predicting loss of control even with normal forced expiratory volume in 1 second. Extrafine inhaled corticosteroids with or without long-acting β-agonists proved superior to standard particle aerosols in improving IOS-detected peripheral airway obstruction. Our data also suggest that currently available commercial reference values for lung resistance at 5 Hz and lung reactance at 5 Hz are applicable across diverse populations, but further studies are needed.

CONCLUSION

The findings of this review suggest that IOS can add value to traditional clinical and spirometric assessment and thus improve management of asthma in children and adults, as well as have the potential to detect early dysfunction of the peripheral airways, which may result in better outcomes.

Effect of nebulized budesonide on respiratory mechanics and oxygenation in acute lung injury/acute respiratory distress syndrome: Randomized controlled study

Background:

We tested the hypothesis that nebulized budesonide would improve lung mechanics and oxygenation in patients with early acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS) during protective mechanical ventilation strategy without adversely affecting systemic hemodynamics.

Methods:

Patients with ALI/ARDS were included and assigned into two groups; budesonide group (30 cases) in whom 1 mg–2 ml budesonide suspension was nebulized through the endotracheal tube and control group (30 cases) in whom 2 ml saline (placebo) were nebulized instead of budesonide. This regimen was repeated every 12 h for three successive days alongside with constant ventilator settings in both groups. Hemodynamics, airway pressures, and PaO₂/FiO₂ were measured throughout the study period (72 h) with either nebulized budesonide or saline. Furthermore, tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) were analyzed serologically as markers of inflammation at pre- and post-nebulization sessions.

Results:

We found a significant difference between the two groups regarding PaO₂/FiO₂ (P = 0.023), peak (P = 0.021), and plateau (P = 0.032) airway pressures. Furthermore, TNF-α, IL-1β, and IL-6 were significantly reduced after budesonide nebulizations. No significant difference was found between the two groups regarding hemodynamic variables.

Conclusion:

Nebulized budesonide improved oxygenation, peak, and plateau airway pressures and significantly reduced inflammatory markers (TNF-α, IL-1β and IL-6) without affecting hemodynamics.

Trial Registry:

Australian New Zealand Clinical Trial Registry (ANZCTR) at the number: ACTRN12615000373572.

Effectiveness of initiating extrafine-particle versus fine-particle inhaled corticosteroids as asthma therapy in the Netherlands

Background

Most randomised clinical trials typically exclude a significant proportion of asthma patients, including those at higher risk of adverse events, with comorbidities, obesity, poor inhaler technique and adherence, or smokers. However, these patients might differentially benefit from extrafine-particle inhaled corticosteroids (ICS). This matched cohort, database study, compared the effectiveness of extrafine-particle with fine-particle ICS in a real-life population initiating ICS therapy in the Netherlands.

Methods

Data were from the Pharmo Database Network, comprising pharmacy and hospital discharge records, representative of 20 % of the Dutch population. The study population included patients aged 12 − 60, with a General Practice-recorded diagnosis for asthma (International Classification of Primary Care code R96), when available, ≥2 prescriptions for asthma therapy at any time in their recorded history, and receiving first prescription of ICS therapy as either extrafine-particle (ciclesonide or hydrofluoroalkane beclomethasone dipropionate [BDP]) or fine-particle ICS (fluticasone propionate or non-extrafine-particle-BDP). Patients were matched (1:1) on relevant demographic and clinical characteristics over 1-year baseline. Primary outcomes were severe exacerbation rates, risk domain asthma control and overall asthma control during the year following first ICS prescription. Secondary outcomes, treatment stability and being prescribed higher versus lower category of short-acting β2 agonists (SABA) dose, were compared over a 1-year outcome period using conditional logistic regression models.

Results

Following matching, 1399 patients were selected in each treatment cohort (median age: 43 years; males: 34 %). Median (interquartile range) initial ICS doses (fluticasone-equivalents in μg) were 160 (160 − 320) for extrafine-particle versus 500 (250 − 500) for fine-particle ICS (p < 0.001). Following adjustment for residual confounders, matched patients prescribed extrafine-particle ICS had significantly lower rates of exacerbations (adjusted rate ratio [95 % CI], 0.59 [0.47–0.73]), and significantly higher odds of achieving asthma control and treatment stability in the year following initiation than those prescribed fine-particle ICS, and this occurred at lower prescribed doses. Patients prescribed extrafine-particle ICS had lower odds of being prescribed higher doses of SABA (0.50 [0.44–0.57]).

Conclusion

In this historical, matched study, extrafine-particle ICS was associated with better odds of asthma control than fine-particle ICS in patients prescribed their first ICS therapy in the Netherlands. Of importance, this was reached at significantly lower prescribed dose.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0234-0) contains supplementary material, which is available to authorized users.

Mouse models of acute exacerbations of allergic asthma

Most of the healthcare costs associated with asthma relate to emergency department visits and hospitalizations because of acute exacerbations of underlying chronic disease. Development of appropriate animal models of acute exacerbations of asthma is a necessary prerequisite for understanding pathophysiological mechanisms and assessing potential novel therapeutic approaches. Most such models have been developed using mice. Relatively few mouse models attempt to simulate the acute-on-chronic disease that characterizes human asthma exacerbations. Instead, many reported models involve relatively short-term challenge with an antigen to which animals are sensitized, followed closely by an unrelated triggering agent, so are better described as models of potentiation of acute allergic inflammation. Triggers for experimental models of asthma exacerbations include (i) challenge with high levels of the sensitizing allergen (ii) infection by viruses or fungi, or challenge with components of these microorganisms (iii) exposure to environmental pollutants. In this review, we examine the strengths and weaknesses of published mouse models, their application for investigation of novel treatments and potential future developments.

Biomarkers of in vivo fluorescence imaging in allergic airway inflammation

Airway inflammation is a central component of the manifestation of asthma but is relatively inaccessible to study. Current imaging techniques such as X-ray CT, MRI, and PET, have advanced noninvasive research on pulmonary diseases. However, these techniques mainly facilitate the anatomical or structural assessment of the diseased lung and/or typically use radioactive agents. In vivo fluorescence imaging is a novel method for noninvasive, real-time, and specific monitoring of lung airway inflammation, which is particularly important to gain a further understanding asthma. Compared to conventional techniques, fluorescent imaging has the advantages of rapid feedback, as well as high sensitivity and resolution. Recently, there has been an increase in the identification of biomarkers, including matrix metalloproteinases, cathepsins, selectins, folate receptor-beta, nanoparticles, as well as sialic acid-binding immunoglobulin-like lectin-F to assess the level of airway inflammation in asthma. Recent advances in our understanding of these biomarkers as molecular probes for in vivo imaging are discussed in this review.

Comparison of early effects of budesonide/formoterol maintenance and reliever therapy with fluticasone furoate/vilanterol for asthma patients requiring step-up from inhaled corticosteroid monotherapy

BACKGROUND

If asthma patients fail to achieve symptom control using a medium dose of inhaled corticosteroid (ICS) alone, addition of a long-acting β2 agonist (LABA) is the preferred treatment. Currently, there are several combinations of ICS/LABA that are available, each of which has a different property. Here, we aimed to compare the early effects of budesonide/formoterol (BUD/FM; Symbicort(®)) for maintenance and reliever therapy (SMART) with a fixed dose of fluticasone furoate/vilanterol (FF/VI; Relvar(®)).

METHODS

Inadequately controlled asthma patients (defined as having an Asthma Control Questionnaire, 5-item version [ACQ5] score≥1.5) with a fractional exhaled nitric oxide (FeNO) value > 35 ppb, who had been treated with a medium dose of ICS alone, were enrolled. Patients were randomized into two groups and treated with two inhalations twice-daily of BUD/FM 160/4.5 μg plus as-needed BUD/FM (SMART group, n = 15) or one inhalation once-daily of FF/VI 100/25 μg plus as-needed procaterol (FF/VI group, n = 15) for 4 weeks. Outcomes including FeNO, impulse oscillometry (IOS) parameters and ACQ5 scores were measured at 0, 2 and 4 weeks.

RESULTS

Both groups showed improvement in airway inflammation, pulmonary function and symptoms from baseline to 2 weeks. From 2 to 4 weeks, the SMART group exhibited continuous improvement in most measured parameters, whereas improvement in the FF/VI group seemed to reach a plateau transiently. Consequently, the SMART group showed significant improvement in the FeNO, IOS parameters (resonance frequency and integrated area of low frequency reactance) and ACQ5 score as compared with the FF/VI group at 4 weeks.

CONCLUSION

As compared with the FF/VI group, the SMART group achieved a greater improvement in FeNO, small airway parameters regarding IOS and ACQ score, in patients with airway inflammation and uncontrolled symptoms treated with a medium dose of ICS alone. In this 4-week study, these two ICS/LABA combination therapies showed different treatment outcomes; they must be investigated further to clarify suitable patient characters and the long term efficacies for each combination.

Extra-fine particle inhaled corticosteroids, pharma-cokinetics and systemic activity in children with asthma

During recent years, extra-fine particle inhaled corticosteroids with a median aerodynamic diameter ≤2 μm have been introduced in the treatment of asthma. The aim of this paper was to review pharmacokinetics and systemic activity of extra-fine particle hydroalkane pressurized metered dose inhaled (pMDI) ciclesonide and beclomethasone dipropionate in children. A literature review was performed. Systemic bioavailability of oral and pulmonary deposition of extra-fine ciclesonide and beclomethasone dipropionate was 52% and 82%, the half-life in serum 3.2 and 1.5 h and first-pass hepatic metabolism >99% and 60%, respectively. Secondary analyses of urine cortisol/creatinine excretion found no effects of ciclesonide pMDI between 40 and 320 μg/day or of beclomethasone dipropionate pMDI between 80 and 400 μg/day. Ciclesonide pMDI 40, 80 and 160 μg/day caused no effects on short-term lower leg growth rate as assessed by knemometry. Ciclesonide 320 μg/day was associated with a numerically short-term growth suppression equivalent to 30% which was similar to 25% and 36% suppression caused by beclomethasone dipropionate HFA and CFC 200 μg/day, respectively. Consistent with the differences in key pharmacokinetic features, beclomethasone dipropionate is associated with a systemic activity detected by knemometry at a lower dose than ciclesonide. Whether that correlates with a clinically important difference remains to be explored. Assessments of systemic activity of beclomethasone dipropionate <200 μg/day and of ciclesonide >180 μg/day as well as head-to-head comparisons are warranted. Preferably, such studies should apply the sensitive method of knemometry.

Association between personal exposure to ambient metals and respiratory disease in Italian adolescents: a cross-sectional study

Background

Release of ambient metals during ferroalloy production may be an important source of environmental exposure for nearby communities and exposure to these metals has been linked to adverse respiratory outcomes. We sought to characterize the association between personal air levels of metals and respiratory health in Italian adolescents living in communities with historic and current ferroalloy activity.

Methods

As part of a study in the industrial province of Brescia, Italy, 410 adolescents aged 11–14 years were recruited. Participants were enrolled from three different communities with varying manganese (Mn) levels: Bagnolo Mella which has current ferroalloy activity, Valcamonica, which has historic ferroalloy activity and Garda Lake which has no history of ferroalloy activity. Particulate matter <10 μm in diameter (PM₁₀) was collected for 24 h in filters using personal sampling. Mn, nickel (Ni), zinc (Zn), chromium (Cr) and iron (Fe) were measured in filters using x-ray fluorescence. Data on respiratory health was collected through questionnaire. Data for 280 adolescents were analyzed using a modified Poisson regression, and risk ratios were calculated for an interquartile (IQR) range increase in each pollutant.

Results

In adjusted models including PM₁₀ as a co-pollutant, we found significant associations between concentrations of Mn (RR: 1.09, 95 % CI [1.00, 1.18] per 42 ng/m³ increase), Ni (RR: 1.11, 95 % CI [1.03, 1.21] per 4 ng/m³ increase) and Cr (RR: 1.08, 95 % CI [1.06, 1.11] per 9 ng/m³ increase) and parental report of asthma. We also found significant associations between increased Mn and Ni and increased risk of asthma medication use in the past 12 months (RR: 1.13, 95 % CI [1.04, 1.29] and (RR: 1.13, 95 % CI [1.01, 1.27] respectively).

Conclusions

Our findings suggest that exposure to ambient Mn, Ni and Cr may be associated with adverse respiratory outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0173-9) contains supplementary material, which is available to authorized users.

Respiratory Tract Deposition of HFA-Beclomethasone and HFA-Fluticasone in Asthmatic Patients

BACKGROUND

The asthmatic patient's respiratory tract deposition of HFA fluticasone (Flovent HFA(™)) has not been established. There is a known large particle size difference with another commercial inhaled HFA steroid (QVAR(™)). This study compared the 2D and 3D respiratory tract deposition of each inhaled steroid.

METHODS

This study was an open label, crossover study in eight patients diagnosed with asthma. The regional respiratory and oropharyngeal deposition of the two steroids were compared and contrasted using planar and SPECT imaging following delivery of the (99m)Tc-radiolabeled drug in each product. The SPECT images were merged with computed tomography images to quantify regional deposition within the patients.

RESULTS

Two-dimensional (2D) planar images indicated that 24% of the Flovent HFA dose and 55% of the QVAR dose deposited in the lungs. 2D oropharyngeal deposition indicated that 75% of the Flovent HFA dose was deposited in the oropharynx, while 42% of the QVAR dose deposited in the oropharynx. Three-dimensional (3D) SPECT data indicated that 22% of the Flovent HFA dose and 53% of the QVAR dose deposited in the lungs. 3D oropharyngeal and gut deposition indicated 78% of the Flovent HFA dose was deposited in the oropharynx, while 47% of the QVAR dose deposited in the oropharynx. The increased lung deposition and decreased oropharynx deposition for both 2D and 3D image data of QVAR were statistically different from Flovent HFA.

CONCLUSIONS

QVAR exhibited a significant increase in lung delivery compared to Flovent HFA. Conversely, QVAR delivered a significantly lower dose to the oropharynx than Flovent HFA. The findings were presumed to be driven by the smaller particle size of QVAR (0.7 microns MMAD) compared with Flovent HFA (2.0 microns MMAD).

A randomised controlled trial of small particle inhaled steroids in refractory eosinophilic asthma (SPIRA)

BACKGROUND

Some patients with refractory asthma have evidence of uncontrolled eosinophilic inflammation in the distal airways. While traditional formulations of inhaled steroids settle predominantly in the large airways, newer formulations with an extra-fine particle size have a more peripheral pattern of deposition. Specifically treating distal airway inflammation may improve asthma control.

METHODS

30 patients with refractory asthma despite high dose inhaled corticosteroids were identified as having persistent airway eosinophilia. Following 2 weeks of prednisolone 30 mg, patients demonstrating an improvement in asthma control were randomised to receive either ciclesonide 320 µg twice daily or placebo in addition to usual maintenance therapy for 8 weeks. The primary outcome measure was sputum eosinophil count at week 8. Alveolar nitric oxide was measured as a marker of distal airway inflammation.

RESULTS

There was continued suppression of differential sputum eosinophil counts with ciclesonide (median 2.3%) but not placebo (median 4.5%) though the between-group difference was not significant. When patients who had changed their maintenance prednisolone dose during the trial were excluded the difference between groups was significant (1.4% vs 4.5%, p=0.028). Though alveolar nitric oxide decreased with ciclesonide the value did not reach statistical significance.

CONCLUSIONS

These data demonstrate that patients with ongoing eosinophilic inflammation are not truly refractory, and that suppression of airway eosinophilia may be maintained with additional inhaled corticosteroid. Further work is needed with a focus on patient-orientated outcome measures such as exacerbation rate, with additional tests of small airway function.

TRIAL REGISTRATION NUMBER

NCT01171365. Protocol available at http://www.clinicaltrials.gov.

Alveolar T-helper type-2 immunity in atopic asthma is associated with poor clinical control

Real-world evaluation studies have shown that many patients with asthma remain symptomatic despite treatment with inhaled corticosteroids (ICSs). As conventional ICSs have poor access to the peripheral airways, the aim of the present paper was to study the relationship between peripheral airway inflammation and clinical control in allergic asthma. Consequently, bronchial and transbronchial biopsies were obtained from patients with poorly controlled asthma [n=12, asthma control test (ACT) score<20], patients with well-controlled asthma (n=12, ACT score≥20) and healthy controls (n=8). Tissue sections were immunostained to assess multiple leucocyte populations. To determine the degree of T-helper type-2 (Th2) immunity, the logarithmic value of the ratio between Th2 cells/mm2 and Th1 cells/mm2 was used as a surrogate score for Th2-skewed immunity. In the bronchi, the leucocyte infiltration pattern and the Th2-score were similar between patients with well-controlled asthma and those with poorly controlled asthma. In contrast, in the alveolar parenchyma, the expression of T-helper cells was significantly higher in patients with poorly controlled asthma than in patients with well-controlled asthma (P<0.01). Furthermore, the alveolar Th2-score was significantly higher in patients with poorly controlled asthma (median 0.4) than in the controlled patients (median -0.10, P<0.05). In addition, in contrast with bronchial Th2-score, the alveolar Th2-score correlated significantly with ACT score (rs=-0.62, P<0.01) in the pooled asthma group. Collectively, our data reveal an alveolar Th2-skewed inflammation, specifically in asthmatic patients who are poorly controlled with ICSs, and suggest that pharmacological targeting of the peripheral airways may be beneficial in this large patient category.

Pharmacological consequences of inhaled drug delivery to small airways in the treatment of asthma

Small peripheral airways are an important target for the anti-inflammatory treatment of asthma. To make anti-inflammatory drugs (inhaled corticosteroids [ICS]) effectively reach small airways, they should be delivered using inhalation techniques containing high proportions of fine or super-fine particles. Higher proportions of fine particles are associated with higher systemic absorption of ICS leading to an increased risk of endogenous cortisol suppression. Ciclesonide, despite the highest proportion of fine and super-fine particle fractions, is the only ICS not associated with an increased risk of systemic adverse effects, including cortisol suppression. In contrary to ICS, bronchodilators should not be administered to peripheral airways. This does not improve their efficacy and may increase their risk of cardiotoxicity. Thus, from a pharmacological point of view and the theory of aerosols' deposition, fixed combinations of ICS and long-acting beta agonists are always suboptimal. In many cases, the best solution may be to use fine-particle ciclesonide and a non-fine particle beta agonist administered from separate inhalers.

Controlled and uncontrolled asthma display distinct alveolar tissue matrix compositions

OBJECTIVE

Whether distal inflammation in asthmatics also leads to structural changes in the alveolar parenchyma remains poorly examined, especially in patients with uncontrolled asthma. We hypothesized that patients who do not respond to conventional inhaled corticosteroid therapy have a distinct tissue composition, not only in central, but also in distal lung.

METHODS

Bronchial and transbronchial biopsies from healthy controls, patients with controlled atopic and patients with uncontrolled atopic asthma were processed for immunohistochemical analysis of fibroblasts and extracellular matrix molecules: collagen, versican, biglycan, decorin, fibronectin, EDA-fibronectin, matrix metalloproteinase (MMP)-9 and tissue-inhibitor of matrix metalloproteinase (TIMP)-3.

RESULTS

In central airways we found increased percentage areas of versican and decorin in patients with uncontrolled asthma compared to both healthy controls and patients with controlled asthma. Percentage area of biglycan was significantly higher in both central airways and alveolar parenchyma of patients with uncontrolled compared to controlled asthma. Ratios of MMP-9/TIMP-3 were decreased in both uncontrolled and controlled asthma compared to healthy controls. In the alveolar parenchyma, patients with uncontrolled asthma had increased percentage areas of collagen, versican and decorin compared to patients with controlled asthma. Patients with uncontrolled asthma had significantly higher numbers of myofibroblasts in both central airways and alveolar parenchyma compared to patients with controlled asthma.

CONCLUSIONS

Tissue composition differs, in both central and distal airways, between patients with uncontrolled and controlled asthma on equivalent doses of ICS. This altered structure and possible change in tissue elasticity may lead to abnormal mechanical properties, which could be a factor in the persistent symptoms for patients with uncontrolled asthma.

Gene expression analysis of membrane transporters and drug-metabolizing enzymes in the lung of healthy and COPD subjects

This study describes for the first time the expression levels of genes encoding membrane transporters and drug-metabolizing enzymes in the lungs of ex-smoking patients with chronic obstructive pulmonary disease (COPD). Membrane transporters and drug-metabolizing enzymes are key determinants of drug uptake, metabolism, and elimination for systemically administered as well as inhaled drugs, with consequent influence on clinical efficacy and patient safety. In this study, while no difference in gene expression was found between healthy and COPD subjects, we identified a significant regional difference in mRNA expression of both membrane transporters and drug-metabolizing enzymes between central and peripheral tissue in both healthy and COPD subjects. The majority of the differentially expressed genes were higher expressed in the central airways such as the transporters SLC2A1 (GLUT1), SLC28A3 (CNT3), and SLC22A4 (OCTN1) and the drug-metabolizing enzymes GSTZ1, GSTO2, and CYP2F1. Together, this increased knowledge of local pharmacokinetics in diseased and normal lung may improve modeling of clinical outcomes of new chemical entities intended for inhalation therapy delivered to COPD patients. In addition, based on the similarities between COPD and healthy subjects regarding gene expression of membrane transporters and drug-metabolizing enzymes, our results suggest that clinical pharmacological studies in healthy volunteers could be a valid model of COPD patients regarding drug disposition of inhaled drugs in terms of drug metabolism and drug transporters.

Association of recent exposure to ambient metals on fractional exhaled nitric oxide in 9-11 year old inner-city children

Exposure to ambient metals in urban environments has been associated with wheeze, and emergency room visits and hospitalizations due to respiratory illness. However, the effect of ambient metals exposure on airway inflammation, and how these associations may be modified by seroatopy, has not been determined. Fractional exhaled nitric oxide (FENO) is a reliable proxy marker of airway inflammation. We hypothesized that recent ambient concentrations of Ni, V, Zn and Fe would be associated differentially with proximal and distal fractions of exhaled NO, and that these associations would be modified by seroatopy. As part of the Columbia Center for Children's Environmental Health (CCCEH) birth cohort study, 9-11 year old children (n=192) were evaluated. Ambient measures of Ni, V, Zn and Fe were obtained from a local central monitoring site and averaged over 9 days based on three 24h measures every third day. Fractional exhaled nitric oxide (FENO) samples were obtained at constant flows of 50 (FENO50), 83 and 100mL/s, and used to determine surrogate measures for proximal (JNO) and alveolar (Calv) inflammation. Seroatopy was determined by specific IgE at age 7. Data were analyzed using multivariable linear regression. Ambient V and Fe concentrations were associated positively with FENO50 (p=0.018, p=0.027). Ambient Fe was associated positively with JNO (p=0.017). Ambient Ni and V concentrations were associated positively with Calv (p=0.004, p=0.018, respectively). A stronger association of Ni concentrations with Calv was observed among the children with seroatopy. These results suggest that ambient metals are associated differentially with different fractions of FENO production, and this relationship may be modified by seroatopy.

Resolvin E1 promotes resolution of inflammation in a mouse model of an acute exacerbation of allergic asthma

Endogenous mediators, such as RvE1 (resolvin E1), promote resolution of an inflammatory response and have potential as novel therapeutic agents. In the present study, we investigated the activity of RvE1 in a model of an acute exacerbation of chronic allergic asthma in mice. Animals sensitized to OVA (ovalbumin) received controlled low-level challenge with aerosolized antigen for 4 weeks, followed by a single moderate-level challenge to simulate an allergen-induced exacerbation of asthmatic inflammation. Induction of an exacerbation was associated with rapid recruitment of neutrophils, lymphocytes and eosinophils, together with increased levels of Th2 and pro-inflammatory cytokines. When administered before the final moderate-level challenge, RvE1 had only a modest effect on airway inflammation. To assess its effects when administered after induction of an exacerbation, we first characterized the cellular and molecular events associated with spontaneous resolution of airway inflammation over the following 96 h. Subsequently, we showed that administration of RvE1 at 2 and 8 h after the final challenge accelerated this process significantly. Specifically, RvE1 promoted a decline in the number of inflammatory cells, concentration of cytokines in lavage fluid and expression of mRNA for cytokines by macrophages, confirming its pro-resolution activity. In vitro, RvE1 had no apparent effect on lymphocytes, but suppressed significantly cytokine production by pulmonary macrophages, with evidence of down-regulation of the nuclear translocation of NF-κB (nuclear factor κB) p65 in these cells. The present study provides novel evidence that RvE1 can facilitate resolution of airway inflammation in a clinically relevant model of an acute exacerbation of asthma, possibly via its effects on activated pulmonary macrophages.

Efficacy and safety of high-dose ciclesonide for the treatment of severe asthma

Asthma severity is classified according to the level of treatment required to control symptoms. Inhaled corticosteroids are the recommended first-line therapy for the treatment of persistent asthma, and when asthma remains uncontrolled, one option is to increase the inhaled corticosteroids dose. However, there is a concomitant risk of increasing local and systemic adverse events, which may impact patient adherence and physician prescribing practices. Ciclesonide is delivered as a prodrug, has high peripheral lung deposition and high protein-binding capabilities, and is rapidly eliminated from the systemic circulation. This article reviews the use of high-dose ciclesonide in patients with severe asthma and considers whether the pharmacology of ciclesonide translates into it being an efficacious and well-tolerated option for patients requiring a step-up in their asthma treatment.

Pediatric exercise-induced bronchoconstriction: contemporary developments in epidemiology, pathogenesis, presentation, diagnosis, and therapy

Exercise-induced bronchoconstriction is transient narrowing of the airways following strenuous exercise. It is the earliest sign of asthma and the last to resolve. EIB is found in 90 % of asthmatics and reflects underlying control of asthma. This review is focused on the contemporary developments in pediatric EIB: the epidemiology, pathogenesis, presentation, diagnosis and management. Proper diagnosis by objective pulmonary function and/or exercise challenge and therapy should allow the pediatric asthmatic to enjoy a healthy lifestyle including participation in the chosen sport.

Comparison of the effects of budesonide/formoterol maintenance and reliever therapy with fluticasone/salmeterol fixed-dose treatment on airway inflammation and small airway impairment in patients who need to step-up from inhaled corticosteroid monotherapy

BACKGROUND

If asthma patients fail to achieve symptom control using a medium dose of inhaled corticosteroid (ICS) alone, adding a long-acting β2 agonist (LABA) is the preferred treatment. We aimed to compare the effect of two widely available ICS/LABA combinations in these patients in real-life conditions: budesonide/formoterol (BUD/FM; Symbicort(®)) for maintenance and reliever therapy (SMART) and a fixed dose of fluticasone propionate/salmeterol (FP/SM).

METHODS

Inadequately controlled asthma patients treated with a medium dose of ICS alone, with an Asthma Control Questionnaire (ACQ) score >0.75 and using a short-acting β2-agonist (SABA) 2-6 occasions/week, were enrolled. Patients were randomized into two groups and treated with two inhalation twice-daily BUD/FM 160/4.5 μg plus as-needed BUD/FM (SMART group, n = 15) or one inhalation twice-daily FP/SM 250/50 μg plus as-needed procaterol (FP/SM group, n = 15) for 8 weeks.

RESULTS

Both groups showed significant improvement in airway inflammation, pulmonary functions and symptoms from baseline. The SMART group showed significant improvement in the fraction of nitric oxide, ACQ score, rescue medication use and small airway parameter R5-R20 measured by impulse oscillometry compared with the FP/SM group.

CONCLUSION

For stepping up treatment from ICS alone to an ICS/LABA combination, SMART is preferable for controlling asthma symptoms by suppressing airway inflammation and improving small airway impairment compared with a fixed dose of FP/SM. It may be achieved by the property of BUD/FM itself and as-needed use, but the degree of each contribution must be investigated further.

Effects of Rho-kinase inhibition in lung tissue with chronic inflammation

We evaluated whether Rho-kinase inhibition (Y-27632) modulated distal lung responsiveness, inflammation, extracellular matrix remodeling and oxidative stress activation in guinea pigs (GPs) with chronic allergic inflammation. GPs were submitted to inhalation of ovalbumin (OVA-2×/week/4 weeks). From the 5th inhalation on, the Rho-kinase inhibitor group animals were submitted to Y-27632 inhalation 10min before each inhalation of OVA. Seventy-two hours after the seventh inhalation, the oscillatory mechanics of the distal lung strips were assessed under the baseline condition and after the ovalbumin challenge. Subsequently, the lung slices were submitted to morphometry. Rho-kinase inhibition in the ovalbumin-exposed animals attenuated distal lung elastance and resistance, eosinophils, IL-2, IL-4, IL-5, IL-13, TIMP-1, MMP-9, TGF-β, IFN-γ, NF-κB and iNOS-positive cells and the volume fraction of 8-iso-PGF2α, elastic, collagen and actin in alveolar walls compared with the OVA group (P<0.05). Rho-kinase inhibition contributed to the control of distal lung responsiveness, eosinophilic and Th1/Th2 responses and extracellular matrix remodeling in an animal model of chronic allergic inflammation.

Distal airway impairment in obese normoreactive women

Background. Asthma-like symptoms are frequent in overweight and obesity, but the mechanism is unclear when airway hyperresponsiveness (AHR) is lacking. In this study, we focused on obese women with a clinical suspicion of asthma but negative methacholine challenge and tested distal airway hyperreactivity, explored by Forced Vital Capacity dose-response slope (FVC DRS). Objective. To question AHR at the distal airway level in obese women. Methods. A total of 293 symptomatic obese and nonobese women free of treatment were investigated. Methacholine challenge tests were undertaken, and patients were divided according to their results to the test. In hyperreactive and nonhyperreactive patients and in our total population, correlations, regression analyses, and analyses of covariance were performed to compare distal airway hyperreactivity in three groups of body mass index (BMI). Results. After adjusting for age and baseline respiratory values, the relationship between FVC and FEV1 (forced expiratory volume in one second) DRS was influenced by BMI, with a lower slope in obese than overweight and normal patients in our total population (P = 0.008) and in our nonhyperreactive one (P = 0.028). Conclusion. Distal airway hyperresponsiveness was observed in symptomatic wheezing obese women negative to methacholine challenge.

Interleukin-33 drives activation of alveolar macrophages and airway inflammation in a mouse model of acute exacerbation of chronic asthma

We investigated the role of interleukin-33 (IL-33) in airway inflammation in an experimental model of an acute exacerbation of chronic asthma, which reproduces many of the features of the human disease. Systemically sensitized female BALB/c mice were challenged with a low mass concentration of aerosolized ovalbumin for 4 weeks to induce chronic asthmatic inflammation and then received a single moderate-level challenge to trigger acute airway inflammation simulating an asthmatic exacerbation. The inflammatory response and expression of cytokines and activation markers by alveolar macrophages (AM) were assessed, as was the effect of pretreatment with a neutralizing antibody to IL-33. Compared to chronically challenged mice, AM from an acute exacerbation exhibited significantly enhanced expression of markers of alternative activation, together with enhanced expression of proinflammatory cytokines and of cell surface proteins associated with antigen presentation. In parallel, there was markedly increased expression of both mRNA and immunoreactivity for IL-33 in the airways. Neutralization of IL-33 significantly decreased both airway inflammation and the expression of proinflammatory cytokines by AM. Collectively, these data indicate that in this model of an acute exacerbation of chronic asthma, IL-33 drives activation of AM and has an important role in the pathogenesis of airway inflammation.

Inhaled corticosteroid and long-acting β2-agonist pharmacological profiles: effective asthma therapy in practice

Fixed-dose combinations of inhaled corticosteroids (ICSs) and long-acting β2-agonists (LABAs) have been used to manage asthma for several years. They are the preferred therapy option for patients who do not achieve optimal control of their asthma with low-dose ICS monotherapy. In Europe, four ICS/LABA products are commercially available for asthma maintenance therapy (fluticasone propionate/formoterol fumarate, fluticasone propionate/salmeterol xinafoate, budesonide/formoterol fumarate and beclometasone dipropionate/formoterol fumarate), and other combinations are likely to be developed over the next few years (e.g. mometasone/formoterol fumarate, fluticasone furoate/vilanterol, mometasone/indacaterol). Data from randomized, controlled, clinical trials do not demonstrate a clear overall efficacy difference among ICS/LABA combinations approved for asthma therapy. Conversely, pharmacological data indicate that there may be certain advantages to using one ICS or LABA over another because of the specific pharmacodynamic and pharmacokinetic profiles associated with particular treatments. This review article summarizes the pharmacological characteristics oft he various ICSs and LABAs available for the treatment of asthma, including the potential for ICS and LABA synergy, and gives an insight into the rationale for the development of the latest ICS/LABA combination approved for asthma maintenance therapy.

From inhaler to lung: clinical implications of the formulations of ciclesonide and other inhaled corticosteroids

Asthma continues to be a global health problem and currently available treatments such as corticosteroids can cause unwanted side effects. Inhaled corticosteroids (ICS) are recommended as first-line therapy for reducing airway inflammation and have a distinct advantage over oral preparations as they provide a direct route of delivery to the lungs. However, local deposition of ICS in the oropharynx can lead to oral candidiasis, dysphonia, and pharyngitis. The pharmaceutical quality is a primary concern of any ICS asthma treatment, with a higher quality product resulting in improved efficacy and safety profiles. The particle size distribution and the spray force velocity of an ICS may directly influence lung deposition, and the spray duration of a device is another important factor when coordinating inhalation. Recent advances in ICS device and formulation technology have resulted in significant improvements in the efficacy of available asthma treatments. In particular, hydrofluoroalkane (HFA) solution technology and the development of smaller particle sizes have resulted in the production of new ICS formulations that have the ability to directly target drug delivery to the site of airway inflammation. Both the ICS formulation and the pressurized metered-dose inhaler device used to administer ciclesonide (CIC) HFA have been developed to treat the underlying chronic inflammation associated with asthma. CIC is administered as a prodrug which is activated in the lungs, leading to minimal oropharyngeal deposition. The small particle size of CIC results in the delivery of a high fraction of respirable particles to the small airways of the lungs, resulting in high lung deposition and continual dose consistency. This review summarizes how CIC administered as an HFA formulation is an effective treatment for asthma.

Treating the small airways

The final article in this series evaluates the approaches undertaken to treating the small-airway region of the lungs and the clinical implications of inhaled therapy targeting the periphery in patients with asthma and chronic obstructive pulmonary disease.

Peripheral airway impairment measured by oscillometry predicts loss of asthma control in children

BACKGROUND

We previously showed that impulse oscillometry (IOS) indices of peripheral airway function are associated with asthma control in children. However, little data exist on whether dysfunction in the peripheral airways can predict loss of asthma control.

OBJECTIVE

We sought to determine the utility of peripheral airway impairment, as measured by IOS, in predicting loss of asthma control in children.

METHODS

Fifty-four children (age, 7-17 years) with controlled asthma were enrolled in the study. Spirometric and IOS indices of airway function were obtained at baseline and at a follow-up visit 8 to 12 weeks later. Physicians who were blinded to the IOS measurements assessed asthma control (National Asthma Education and Prevention Program guidelines) on both visits and prescribed no medication change between visits.

RESULTS

Thirty-eight (70%) patients maintained asthma control between 2 visits (group C-C), and 16 patients had asthma that became uncontrolled on the follow-up visit (group C-UC). There was no difference in baseline spirometric results between the C-C and C-UC groups, except for FEV1/forced vital capacity ratio (86% vs 82%, respectively; P < .01). Baseline IOS results, including resistance of the respiratory system at 5 Hz (R5; 6.4 vs 4.3 cm H2O · L(-1) · s), frequency dependence of resistance (difference of R5 and resistance of the respiratory system at 20 Hz [R5-20]; 2.0 vs 0.7 cm H2O · L(-1) · s), and reactance area (13.1 vs 4.1 cm H2O · L(-1)), of group C-UC were significantly higher than those of group C-C (P < .01). Receiver operating characteristic analysis showed baseline R5-20 and reactance area effectively predicted asthma control status at the follow-up visit (area under the curve, 0.91 and 0.90).

CONCLUSION

Children with controlled asthma who have increased peripheral airway IOS indices are at risk of losing asthma control.

Assessing and accessing the small airways; implications for asthma management

Despite the wealth of experience in the management of asthma, the disease remains inadequately controlled in some patients, who face long-term respiratory impairment and disability. The disease has been characterised as an inflammatory condition affecting first the larger airways and eventually the smaller airways, but there is evidence that peripheral airway involvement defines a particular and more severe phenotype of asthma. For this reason, assessing functional and biological parameters reflective of small airways involvement is important prognostically. No assessment method is universally and directly representative of peripheral airway function, but the traditional spirometric tests, including vital capacity, residual volume and forced vital capacity, are somewhat correlated with this function; useful methods for further assessment include the single-breath nitrogen wash-out test, impulse oscillometry, nitrous oxide and exhaled breath concentrate measurements, as well as computed tomography to reflect air trapping and response to treatment. Formulation advancements have made for easier treatment access to the smaller airways, with the new extrafine formulations resulting in better asthma control compared with non-extrafine formulations.

Impulse oscillometry; therapeutic impacts of transdermal long-acting Beta-2 agonist patch in elderly asthma with inhaled corticosteroid alone

Growing interest had been focused on the involvement of the small airways in asthma, and impulse oscillometry (IOS) has been utilized as pulmonary functions for detecting large and small airways diseases separately. IOS can measure respiratory resistance and reactance at multiple frequencies, not available by spirometry or body plethysmography, is non-invasive techniques and convenient for elderly patients with a low dependency on cooperation during tidal breathing. IOS indices were well correlated with not only predicted FEV1 but also FEF25-75, residual volume/total lung capacity, delta N2 of a single nitrogen washout test which representing air trapping and inhomogeneous ventilation in the distal lung. These parameters and QOL scores were improved by additional transdermal long-acting beta-2 agonist patch even in well-controlled elderly asthma treating with inhaled corticosteroids alone. IOS may have a complementary role of spirometry in detecting subtle airways changes in general practice. However, systemic studies are required to investigate the clinical implication of each IOS index.

Relating small airways to asthma control by using impulse oscillometry in children

BACKGROUND

Previous reports suggest that the peripheral airways are associated with asthma control. Patient history, although subjective, is used largely to assess asthma control in children because spirometric results are many times normal values. Impulse oscillometry (IOS) is an objective and noninvasive measurement of lung function that has the potential to examine independently both small- and large-airway obstruction.

OBJECTIVE

We sought to determine the utility of IOS in assessing asthma control in children.

METHODS

Asthmatic and healthy children (6-17 years) were enrolled in the study. Spirometric and IOS (resistance of the respiratory system at 5 Hz [R5] and 20 Hz [R20], reactance of the respiratory system at 5 Hz [X5], resonant frequency of reactance [Fres], and area under the reactance curve between 5 Hz and Fres [reactance area {AX}]) values were collected in triplicate before and after a bronchodilator was administered. The physicians were blinded to the IOS measurements and assessed asthma control using American Thoracic Society guidelines.

RESULTS

Small-airway IOS measurements, including the difference of R5 and R20 [R5-20], X5, Fres, and AX, of children with uncontrolled asthma (n = 44) were significantly different from those of children with controlled asthma (n = 57) and healthy children (n = 14), especially before the administration of a bronchodilator. However, there was no difference in large-airway IOS values (R20). No differences were found between children with controlled asthma and healthy children in any of the end points. Receiver operating characteristic analysis showed cut points for baseline R5-20 (1.5 cm H(2)O · L(-1) · s) and AX (9.5 cm H(2)O · L(-1)) that effectively discriminated controlled versus uncontrolled asthma (area under the curve, 0.86 and 0.84) and correctly classified more than 80% of the population.

CONCLUSION

Uncontrolled asthma is associated with small-airways dysfunction, and IOS might be a reliable and noninvasive method to assess asthma control in children.

Alveolar mast cells shift to an FcεRI-expressing phenotype in mild atopic asthma: a novel feature in allergic asthma pathology

BACKGROUND

A unique feature of alveolar mast cells is their low high-affinity IgE receptor (FcεRI) expression. Recent discoveries in uncontrolled asthma suggest that the appearance of FcεRI-expressing alveolar mast cells may be a novel disease-specific feature of allergic asthma. This study investigates whether increased FcεRI-expressing alveolar mast cells are present in patients with mild allergic asthma or even in non-asthmatic allergic rhinitis patients (AR) who have developed bronchial hyperactivity (BHR).

METHODS

Bronchial and alveolar tissues were obtained from healthy controls, AR patients with or without BHR, and AR patients with concurrent asthma. Samples were processed for immunohistochemical identification of MC(T) and MC(TC) and expression of FcεRI and surface-bound IgE.

RESULTS

Bronchial mast cell expression of FcεRI was high in all groups. In contrast, in the alveolar tissue, the expression of FcεRI on mast cells was low in healthy controls and in the AR patient groups, whereas a high expression was present in AR patients with concurrent asthma (P = 0.006 compared to controls). The asthmatics had a 29-fold increase in numbers (P = 0.006) and a 19-fold increase in proportion (P = 0.007) of alveolar mast cells that expressed surface-bound IgE.

CONCLUSIONS

The present data show that alveolar mast cells in patients with mild atopic asthma, but not atopic patients with AR, have turned into a highly FcεRI- and IgE-expressing phenotype. These data support the hypothesis that increased FcεRI expression on alveolar mast cells is a novel disease-specific feature of allergic asthma that is important for understanding asthma phenotypes and designing new therapeutic strategies.