Eosinophil and neutrophil activity in asthma in a one-year trial with inhaled budesonide. The impact of smoking

Fecal Biomarkers of Neutrophil and Eosinophil Origin Reflect the Response to Biological Therapy and Corticosteroids in Patients With Inflammatory Bowel Disease

INTRODUCTION

Fecal calprotectin (FC) is a noninvasive tool for examining response to biologics in inflammatory bowel disease (IBD), but its performance in relation to other novel fecal markers of various cellular origins is unknown.

METHODS

We performed a prospective multicenter cohort study and included patients with active IBD who provided a fecal sample at initiation of biological therapy. Levels of FC, myeloperoxidase (MPO), human neutrophil lipocalin (HNL), and eosinophil-derived neurotoxin (EDN) were analyzed and related to clinical remission status at 3 months. Changes in levels of markers at 3 months were calculated, and the impact of concomitant use of corticosteroids at baseline was estimated.

RESULTS

In patients achieving clinical remission (n = 27), a decrease in levels of FC ( P = 0.005), MPO ( P < 0.001), HNL ( P < 0.001), and EDN ( P < 0.001) was observed, whereas no significant decrease was seen in patients not achieving remission (n = 39). There was a significant difference in the change in the level of MPO ( P = 0.01) and HNL ( P = 0.02) between patients achieving clinical remission and those who did not, but changes in FC and EDN could not differentiate between these groups. Patients with concomitant systemic corticosteroids at inclusion had lower levels of HNL ( P = 0.01) and EDN ( P < 0.001) at baseline, compared with patients without corticosteroids.

DISCUSSION

Fecal MPO, HNL, and EDN are all promising biomarkers for assessing the treatment outcome of biologics in patients with IBD. Fecal levels of EDN and HNL are significantly affected by corticosteroids indicating a greater sensitivity to the effects of corticosteroids compared with levels of FC and MPO.

The Role of Eosinophil-Derived Neurotoxin and Vascular Endothelial Growth Factor in the Pathogenesis of Eosinophilic Asthma

Asthma is a chronic complex pulmonary disease characterized by airway inflammation, remodeling, and hyperresponsiveness. Vascular endothelial growth factor (VEGF) and eosinophil-derived neurotoxin (EDN) are two significant mediators involved in the pathophysiology of asthma. In asthma, VEGF and EDN levels are elevated and correlate with disease severity and airway hyperresponsiveness. Diversity in VEGF polymorphisms results in the variability of responses to glucocorticosteroids and leukotriene antagonist treatment. Targeting VEGF and eosinophils is a promising therapeutic approach for asthma. We identified lichochalcone A, bevacizumab, azithromycin (AZT), vitamin D, diosmetin, epigallocatechin gallate, IGFBP-3, Neovastat (AE-941), endostatin, PEDF, and melatonin as putative add-on drugs in asthma with anti-VEGF properties. Further studies and clinical trials are needed to evaluate the efficacy of those drugs. AZT reduces the exacerbation rate and may be considered in adults with persistent symptomatic asthma. However, the long-term effects of AZT on community microbial resistance require further investigation. Vitamin D supplementation may enhance corticosteroid responsiveness. Herein, anti-eosinophil drugs are reviewed. Among them are, e.g., anti-IL-5 (mepolizumab, reslizumab, and benralizumab), anti-IL-13 (lebrikizumab and tralokinumab), anti-IL-4 and anti-IL-13 (dupilumab), and anti-IgE (omalizumab) drugs. EDN over peripheral blood eosinophil count is recommended to monitor the asthma control status and to assess the efficacy of anti-IL-5 therapy in asthma.

Clinical Potential of Eosinophil-Derived Neurotoxin in Asthma Management

The assessment and management of patients with asthma is challenging because of the complexity of the underlying inflammatory mechanisms and heterogeneity of their clinical presentation. Optimizing disease management requires therapy individualization that should rely on reliable biomarkers to unravel the phenotypes and endotypes of asthma. The secretory activity and turnover of eosinophils, as assessed by measuring eosinophil-derived proteins, may provide an accurate and complementary tool that mirrors the eosinophil activation status. Emerging evidence suggests that eosinophil-derived neurotoxin has considerable potential as a precision medicine biomarker. In this review, we explore the suitability of eosinophil-derived neurotoxin as a biomarker in asthma management, with particular emphasis on its clinical significance in the management of both pediatric and adult populations.

Eosinophil-derived neurotoxin: An asthma exacerbation biomarker in children

Background: Asthma is a heterogeneous disease, characterized by chronic airway inflammation. Asthma exacerbations (AE) are episodes characterized by a progressive increase in symptoms of shortness of breath, cough, wheezing, or chest tightness with a decrease in lung function. There have been previous studies that examined the role of eosinophil-derived neurotoxin (EDN) in asthma, but there have been no studies of the role of EDN in children experiencing AE. Objective: In this study, we aimed to examine the association of EDN with lung function and prognosis in children admitted for severe AE. Methods: We enrolled 82 children who were admitted for severe AE at two different university hospitals in South Korea between January 2018 and December 2019. Blood tests, including white blood cell count, myeloperoxidase (MPO), total eosinophil count, EDN, C-reactive protein (CRP) level, and interleukin (IL) 4, IL-5, IL-10 values, and lung function were measured on admission and at discharge in each patient. Results: We observed significant decreases in the levels of MPO, EDN, CRP, and IL-4, with significant improvement in lung function after treatment. We then classified the subjects into two groups of different clinical phenotypes: eosinophilic asthma exacerbation (EAE) group and non-EAE group. EDN levels were higher and lung functions were lower in the EAE group. Also, we found that the EDN level was a significant biomarker useful for predicting the number of days for hospital stay. Conclusion: We found that EDN can act as a biomarker that reflects lung function, and that EDN could act as a prognostic biomarker, which demonstrated the complex role of EDN in children experiencing AE.

The commutability of enzyme linked immunosorbent assays for the quantification of serum eosinophil-derived neurotoxin (EDN)

Eosinophil-derived neurotoxin (EDN) is a surrogate biomarker of eosinophil activation and has considerable potential as a precision medicine biomarker in diseases where eosinophils may play a causative role. Clinical data for EDN have been generated using different quantitative immunoassays, but comparisons between these individual data sets are challenging as no internationally recognised EDN standards or orthogonal methods exist. In this study we aimed to compare commercial EDN assays from ALPCO, MBL, LSBio and CUSABIO for sample commutability. Firstly, we analytically validated the ALPCO enzyme linked immunosorbent assay (ELISA) and demonstrated appropriate analytical characteristics, including an intra/inter-assay precision coefficient-of-variation of between 1.9 and 6.8%. EDN purified from blood proved to be a good quality control material, whereas recombinant EDN, expressed in E.coli, did not react in the ALPCO immunoassay. Using healthy and asthma patient serum samples we confirmed that the ALPCO assay correlated well with the MBL assay, with a coefficient of determination (R²) of 0.92. However, the results from LSBio and CUSABIO assays were not commutable to the other assays.

Eosinophil-derived neurotoxin: A biologically and analytically attractive asthma biomarker

There is a growing body of evidence for the utility of eosinophil-derived neurotoxin (EDN) as a biomarker in asthma, including association with eosinophilic airway inflammation, assessment of disease severity and potential for predicting pathogenic risks, including exacerbations. However, to interpret any biomarker data with confidence, it is first important to understand the preanalytical factors and biological variation that may affect its reliable measurement and results interpretation. In this study we defined the healthy serum EDN reference range for men and women as 1.98 to 26.10 ng/mL, with no significant gender differences. Smoking did not impact the mean EDN levels and no circadian rhythm was identified for EDN, unlike blood eosinophils (EOS) where levels peaked at 00:00h. EDN expression in different cell types was investigated and shown to occur primarily in eosinophils, indicating they are likely to be the main cellular repository for EDN. We also confirm that the quantification of serum EDN is not influenced by the type of storage tube used, and it is stable at ambient temperature or when refrigerated for at least 7 days and for up to one year when frozen at -20°C or -80°C. In summary, EDN is a stable biomarker that may prove useful in precision medicine approaches by enabling the identification of a subpopulation of asthma patients with activated eosinophils and a more severe form of the disease.

Impact of Air Pollution on Asthma Outcomes

Asthma is a chronic respiratory disease characterized by variable airflow obstruction, bronchial hyperresponsiveness, and airway inflammation. Evidence suggests that air pollution has a negative impact on asthma outcomes in both adult and pediatric populations. The aim of this review is to summarize the current knowledge on the effect of various outdoor and indoor pollutants on asthma outcomes, their burden on its management, as well as to highlight the measures that could result in improved asthma outcomes. Traffic-related air pollution, nitrogen dioxide and second-hand smoking (SHS) exposures represent significant risk factors for asthma development in children. Nevertheless, a causal relation between air pollution and development of adult asthma is not clearly established. Exposure to outdoor pollutants can induce asthma symptoms, exacerbations and decreases in lung function. Active tobacco smoking is associated with poorer asthma control, while exposure to SHS increases the risk of asthma exacerbations, respiratory symptoms and healthcare utilization. Other indoor pollutants such as heating sources and molds can also negatively impact the course of asthma. Global measures, that aim to reduce exposure to air pollutants, are highly needed in order to improve the outcomes and management of adult and pediatric asthma in addition to the existing guidelines.

Eosinophil-Derived Neurotoxin and Respiratory Tract Infection and Inflammation: Implications for COVID-19 Management

The current pandemic of COVID-19 and the identification of accessible biomarkers of disease progression is of clinical importance in the management of this novel and serious disease. This study was completed to provide information regarding 1 possible uniquely upregulated marker in this illness, eosinophil-derived neurotoxin (EDN-1). A literature search was undertaken to provide medical data regarding EDN-1 as a biomarker in the clinical setting. The literature identified was further analyzed to identify its use in the clinical setting of viral disease and asthma.

Tiotropium Respimat® add-on therapy to inhaled corticosteroids in patients with symptomatic asthma improves clinical outcomes regardless of baseline characteristics

BACKGROUND

Despite currently available therapies and detailed treatment guidelines, many patients with asthma remain symptomatic. Tiotropium delivered by the soft mist inhaler Respimat®, as add-on therapy to medium-dose inhaled corticosteroids (ICS), has been shown to improve lung function and asthma control in patients with symptomatic moderate asthma.

OBJECTIVE

To determine whether the efficacy of tiotropium Respimat® in asthma differs by patients' study baseline characteristics.

METHODS

Two replicate Phase III, randomized, double-blind, placebo-controlled, parallel-group studies (MezzoTinA-asthma®; NCT01172808 and NCT01172821) of once-daily tiotropium Respimat 5 μg and 2.5 μg add-on to ICS were conducted in patients with symptomatic asthma despite treatment with medium-dose ICS with or without additional controllers. Subgroup analyses of peak forced expiratory volume in 1 s (FEV₁), trough FEV₁, risk of severe asthma exacerbation and Asthma Control Questionnaire responder rate were performed to determine whether results were influenced by patients' baseline characteristics.

RESULTS

In this analysis, 523 patients received placebo while 517 and 519 patients received the 5 μg and 2.5 μg dose of tiotropium Respimat, respectively. The magnitude of the improvements in lung function and asthma control, as well as the reduced risk of severe exacerbation with both doses of tiotropium Respimat versus placebo, was independent of a broad range of baseline characteristics.

CONCLUSIONS

Once-daily tiotropium Respimat as add-on to ICS is a beneficial treatment option for patients with asthma who remain symptomatic despite at least medium-dose ICS, regardless of baseline characteristics.

Sulforaphane ameliorates steroid insensitivity through an Nrf2-dependent pathway in cigarette smoke-exposed asthmatic mice

Oxidative stress induced by cigarette smoke and other environmental pollutants contributes to refractory asthma. To better understand the role of smoking in asthma, we investigated the effects of cigarette smoke on allergic airway responses in mice and examined expression of nuclear factor-E2-related factor-2 (Nrf2) and its downstream factors, because Nrf2 is known to play a pivotal role in antioxidant responses. OVA-sensitized and challenged BALB/c mice were exposed to cigarette smoke and then treated with dexamethasone, sulforaphane (an activator of Nrf2), or their combination. Upon exposure to cigarette smoke, Nrf2 and associated transcripts were upregulated in response to oxidative stress, and asthmatic responses were steroid resistant. In OVA-sensitized and challenged mice exposed to cigarette smoke and treated with sulforaphane, Nrf2-mediated antioxidant responses were upregulated to a greater extent, and steroid sensitivity of asthmatic responses was restored. Moreover, the expression and activity of histone deacetylase 2 (HDAC2), a key regulator of steroid responsiveness, was reduced in mice exposed to cigarette smoke, but restored by sulforaphane treatment. No effects of sulforaphane were observed in Nrf2-deficient mice. These findings indicate that cigarette smoke induces steroid unresponsiveness in asthmatic airways, and that sulforaphane restores steroid sensitivity via upregulation of Nrf2 and enhancement of HDAC2 expression and activity. Thus, Nrf2 may serve as a potential molecular target for cigarette smoke-related refractory asthma resistant to steroid therapy.

Large-Scale Label-Free Quantitative Mapping of the Sputum Proteome

Analysis of induced sputum supernatant is a minimally invasive approach to study the epithelial lining fluid and, thereby, provide insight into normal lung biology and the pathobiology of lung diseases. We present here a novel proteomics approach to sputum analysis developed within the U-BIOPRED (unbiased biomarkers predictive of respiratory disease outcomes) international project. We present practical and analytical techniques to optimize the detection of robust biomarkers in proteomic studies. The normal sputum proteome was derived using data-independent HDMS^E applied to 40 healthy nonsmoking participants, which provides an essential baseline from which to compare modulation of protein expression in respiratory diseases. The "core" sputum proteome (proteins detected in ≥40% of participants) was composed of 284 proteins, and the extended proteome (proteins detected in ≥3 participants) contained 1666 proteins. Quality control procedures were developed to optimize the accuracy and consistency of measurement of sputum proteins and analyze the distribution of sputum proteins in the healthy population. The analysis showed that quantitation of proteins by HDMS^E is influenced by several factors, with some proteins being measured in all participants' samples and with low measurement variance between samples from the same patient. The measurement of some proteins is highly variable between repeat analyses, susceptible to sample processing effects, or difficult to accurately quantify by mass spectrometry. Other proteins show high interindividual variance. We also highlight that the sputum proteome of healthy individuals is related to sputum neutrophil levels, but not gender or allergic sensitization. We illustrate the importance of design and interpretation of disease biomarker studies considering such protein population and technical measurement variance.

Modelling the asthma phenotype: impact of cigarette smoke exposure

Background

Asthmatics that are exposed to inhaled pollutants such as cigarette smoke (CS) have increased symptom severity. Approximately 25% of adult asthmatics are thought to be active smokers and many sufferers, especially in the third world, are exposed to high levels of inhaled pollutants. The mechanism by which CS or other airborne pollutants alter the disease phenotype and the effectiveness of treatment in asthma is not known. The aim of this study was to determine the impact of CS exposure on the phenotype and treatment sensitivity of rodent models of allergic asthma.

Methods

Models of allergic asthma were configured that mimicked aspects of the asthma phenotype and the effect of CS exposure investigated. In some experiments, treatment with gold standard asthma therapies was investigated and end-points such as airway cellular burden, late asthmatic response (LAR) and airway hyper-Reactivity (AHR) assessed.

Results

CS co-exposure caused an increase in the LAR but interestingly attenuated the AHR. The effectiveness of LABA, LAMA and glucocorticoid treatment on LAR appeared to be retained in the CS-exposed model system. The eosinophilia or lymphocyte burden was not altered by CS co-exposure, nor did CS appear to alter the effectiveness of glucocorticoid treatment. Steroids, however failed to reduce the neutrophilic inflammation in sensitized mice exposed to CS.

Conclusions

These model data have certain parallels with clinical findings in asthmatics, where CS exposure did not impact the anti-inflammatory efficacy of steroids but attenuated AHR and enhanced symptoms such as the bronchospasm associated with the LAR. These model systems may be utilised to investigate how CS and other airborne pollutants impact the asthma phenotype; providing the opportunity to identify novel targets.

Patient stratification and the unmet need in asthma

Asthma is often described as an inflammatory disease of the lungs and in most patients symptomatic treatment with bronchodilators or inhaled corticosteroids is sufficient to control disease. Unfortunately there are a proportion of patients who fail to achieve control despite treatment with the best current treatment. These severe asthma patients have been considered a homogeneous group of patients that represent the unmet therapeutic need in asthma. Many novel therapies have been tested in unselected asthma patients and the effects have often been disappointing, particularly for the highly specific monoclonal antibody-based drugs such as anti-IL-13 and anti-IL-5. More recently, it has become clear that asthma is a syndrome with many different disease drivers. Clinical trials of anti-IL-13 and anti-IL-5 have focused on biomarker-defined patient groups and these trials have driven the clinical progression of these drugs. Work on asthma phenotyping indicates that there is a group of asthma patients where T helper cell type 2 (Th2) cytokines and inflammation predominate and these type 2 high (T2-high) patients can be defined by biomarkers and response to therapies targeting this type of immunity, including anti-IL-5 and anti-IL-13. However, there is still a subset of T2-low patients that do not respond to these new therapies. This T2-low group will represent the new unmet medical need now that the T2-high-targeting therapies have made it to the market. This review will examine the current thinking on patient stratification in asthma and the identification of the T2-high subset. It will also look at the T2-low patients and examine what may be the drivers of disease in these patients.

Corticosteroid insensitivity in smokers with asthma : clinical evidence, mechanisms, and management

Corticosteroids are the most effective treatment for asthma, but the therapeutic response varies considerably between individuals. Several clinical studies have found that smokers with asthma are insensitive to the beneficial effects of short- to medium-term inhaled corticosteroid treatment compared with non-smokers with asthma. It is estimated that 25% of adults in most industrialized countries smoke cigarettes, and similar surveys amongst asthmatic individuals suggest that the prevalence of smoking in this grouping mirrors that found in the general population. Therefore, cigarette smoking is probably the most common cause of corticosteroid insensitivity in asthma. Cigarette smoking and asthma are also associated with poor symptom control and an accelerated rate of decline in lung function. The mechanism of corticosteroid insensitivity in smokers with asthma is currently unexplained but could be due to alterations in airway inflammatory cell phenotypes, changes in glucocorticoid receptor alpha/beta ratio, and/or reduced histone deacetylase activity. Smoking cessation should be encouraged in all smokers with asthma. Short-term benefits include improvements in lung function and asthma control. However, the numbers of sustained quitters is disappointingly small. Additional or alternative drugs need to be identified to treat those individuals who are unable to stop smoking or who have persistent symptoms following smoking cessation.

Effect of smoking status on the efficacy of the SMART regimen in high risk asthma

BACKGROUND AND OBJECTIVE

The optimal management of people with asthma with a significant smoking history is uncertain. The aim of this study was to determine whether the efficacy/safety profile of single combination inhaled corticosteroid (ICS)/long acting beta-agonist (LABA) inhaler maintenance and reliever therapy is influenced by smoking status.

METHODS

We undertook secondary analyses from an open-label 24-week randomized study of 303 high risk adult asthma patients randomized to budesonide/formoterol 200/6-µg-metred dose inhaler for maintenance (two actuations twice daily) and either budesonide/formoterol 200/6-µg-metred dose inhaler one actuation ('single ICS/LABA maintenance and reliever therapy (SMART)' regimen) or salbutamol 100 µg 1-2 actuations for symptom relief ('Standard' regimen). Smoking status was classified in to three groups, as 'current', 'ex' or 'never', and a smoking/treatment interaction term tested for each outcome variable. The primary outcome variable was number of participants with at least one severe exacerbation.

RESULTS

There were 59 current, 97 ex and 147 never smokers included in the analyses. The smoking status/treatment interaction term was not statistically significant for any of the outcome measures. With adjustment for smoking status, the number of participants with severe exacerbations was lower with the SMART regimen (OR 0.45, 95% CI: 0.26-0.77, P = 0.004; P value for interaction between smoking status and treatment 0.29).

CONCLUSION

We conclude that the favourable safety/efficacy profile of the SMART regimen applies to patients with high risk asthma, irrespective of smoking status.

Janeva E, Arsovska A, Isjanovski V. Altered therapeutic response towards inhaled corticosteroids in asthmatics –smokers with mild asthma

The exposure to tobacco smoke could cause bronchoconstriction and acute asthma attack. Smoking asthmatics have an insufficient therapeutic response to the standard therapy and unsatisfactory improvement of the respiratory function. In a randomized parallel study, a therapeutic response to inhaled fluticasone propionate in a dose of 250 µg twice per day was determined in 38 asthmatics with mild asthma, smokers and nonsmokers. Short-acting ß2 agonist (salbutamol) in a dosage of 0.1 mg/per inhaled dose was used as a rescue medication when needed. In patients, asthma was detected with a positive metacholine test and/or positive bronchodilatator response of > 12% with ≥ 200 ml increase of FEV1. They were randomized in two groups according to sex, age and starting values of FEV1. Before and after 6 weeks of treatment with fluticasone propionate of the previously corticosteroid-naive patients, lung function test (spirometry) was performed. A statistically significant effect (p<0.05) was achieved during the fluticasone propionate therapy in a group of non-smoking asthmatic patients. The same effect was not seen in the group of smoking asthmatics. Although the percentage of elevated FEV1 values was small, it was satisfactory because of the starting FEV1 values in patients with mild asthma. More studies are needed in asthmatics determining the asthma symptom score, the number of night awakenings due to asthma, the asthma exacerbations and the frequency of rescue therapy usage which will define the altered therapeutic response to inhaled corticosteroids in smoking asthmatics.

Use of asthma control indicators in measuring inhaled corticosteroid effectiveness in asthmatic smokers: a systematic review

OBJECTIVE

The objective of this review is to explore how current research measures the effectiveness of inhaled corticosteroids (ICS) in smokers with asthma.

DATA SOURCES

PubMed, CINAHL and PsycINFO databases were searched for combinations of terms relating to asthma, tobacco use and ICS effectiveness.

STUDY SELECTIONS

The search was limited to articles published between 2004 and 2015, in English language. Studies met inclusion criteria if reporting the use of guideline-based asthma control indicators to measure the therapeutic effects of ICS or ICS combination therapies. This review did not exclude articles based on study design. Data were extracted and summarized to describe how indicators were measured across studies in order to characterize and describe the effects of ICS in smokers.

RESULTS

Thirteen studies were included in this review. Six of these 13 studies used only one indicator to measure asthma control in smokers and ICS was found to improve asthma in only one of six of these studies. Of studies evaluating combination therapy, three of four studies reported a therapeutic benefit to smokers. In these studies of combination therapy multiple indicators of control were measured to assess drug effects.

CONCLUSIONS

To assess the therapeutic benefit of ICS drugs in smokers, multiple indicators should be measured to determine if current therapy is improving asthma control. Asthma therapy should then be adjusted based on the patient's current asthma status. The development of clinical treatment guidelines for asthmatic smokers may help clinicians make best-practice, evidence-based recommendations in order to optimize care for these patients.

Effect of smoking abstinence and reduction in asthmatic smokers switching to electronic cigarettes: evidence for harm reversal

Electronic cigarettes (e-cigs) are marketed as safer alternatives to tobacco cigarettes and have shown to reduce their consumption. Here we report for the first time the effects of e-cigs on subjective and objective asthma parameters as well as tolerability in asthmatic smokers who quit or reduced their tobacco consumption by switching to these products. We retrospectively reviewed changes in spirometry data, airway hyper-responsiveness (AHR), asthma exacerbations and subjective asthma control in smoking asthmatics who switched to regular e-cig use. Measurements were taken prior to switching (baseline) and at two consecutive visits (Follow-up/1 at 6 (±1) and Follow-up/2 at 12 (±2) months). Eighteen smoking asthmatics (10 single users, eight dual users) were identified. Overall there were significant improvements in spirometry data, asthma control and AHR. These positive outcomes were noted in single and dual users. Reduction in exacerbation rates was reported, but was not significant. No severe adverse events were noted. This small retrospective study indicates that regular use of e-cigs to substitute smoking is associated with objective and subjective improvements in asthma outcomes. Considering that e-cig use is reportedly less harmful than conventional smoking and can lead to reduced cigarette consumption with subsequent improvements in asthma outcomes, this study shows that e-cigs can be a valid option for asthmatic patients who cannot quit smoking by other methods.

Retrospective cohort study of leukotriene receptor antagonist therapy for preventing upper respiratory infection-induced acute asthma exacerbations

Upper respiratory tract infections (URIs) represent the most frequent cause of acute asthma exacerbations. It has yet to be determined whether leukotriene receptor antagonist (LTRA) treatment prevents URI-induced acute asthma exacerbations in adults. The objective of the present study was to evaluate the preventive effects of LTRA treatment on URI-induced acute asthma exacerbations. The incidences of URI alone, acute asthma exacerbation without URI, and URI-induced acute asthma exacerbation were determined retrospectively by analyzing diary and medical records of 321 adult asthmatic patients (mean age, 56.3 ± 17.2 years; male/female ratio, 117:204) over 1 year. Results were compared between patients who had been taking an LTRA (n = 137) and those who had never taken any LTRA (n = 184) during the study periods. Significantly fewer URIs alone and acute asthma exacerbations without URI occurred in patients with than in those without prophylactic daily use of LTRA. LTRA treatment significantly reduced the durations of URIs alone and of total acute asthma exacerbations, as well as the incidence of mild exacerbations of asthma. In contrast, in patients with URI-induced acute asthma exacerbations, LTRA treatment failed to significantly reduce the interval between URI onset and acute asthma exacerbation, as well as the duration and severity of both URIs and acute asthma exacerbations. Use of an LTRA for adult asthmatic patients appears to reduce the incidences of URIs alone and acute asthma exacerbations without URI, but it failed to prevent URI-induced acute asthma exacerbations once a URI occurred.

Glucocorticoid-resistant asthma: more than meets the eye

INTRODUCTION

For decades glucocorticoids have been considered as the gold standard for the treatment of asthma. We present a case report of typical glucocorticoid-resistant asthma and current consensus in definitions of "severe refractory", "difficult" and "glucocorticoid-resistant" asthma.

METHODS

Full-text papers and abstracts were identified on the basis of a comprehensive literature search primarily in MEDLINE (1966 to June 2012) but also in the Cochrane Central Register of Controlled Trials database.

RESULTS

Glucocorticoid-resistant asthmatics are a small subset of patients who pose noteworthy diagnostic challenges while contributing disproportionately to health care costs. Recognition of various asthma phenotypes has aided in characterizing groups with severe asthma and given a better understanding of its pathophysiological process. The molecular mechanism of glucocorticoid action is complicated and several pathways have been identified to explain drug resistance, which in turn is crucial for drug development. Tobacco smoking appears to be the single most important contributor of glucocorticoid resistance. We present the emerging and promising concepts in the management of glucocorticoid-resistant asthma, which mainly include drugs targeting specific molecules, receptors, inflammatory cells or immune processes.

CONCLUSION

The challenges in making a diagnosis of glucocorticoid-resistant asthma may contribute to underestimating its prevalence and impact on patient care. Considerable progress has been made in identifying distinct phenotypes and mechanisms of glucocorticoid resistance; therefore the future of new drug development in management of asthma is promising.

Sex-differences in quality of life and asthma control in Swedish asthma patients

BACKGROUND

To study sex-related differences in quality of life, asthma control and asthma management in different age groups.

METHODS

A cross-sectional survey and patient record study in primary and secondary care. A total of 1226 patients in primary and 499 in secondary care, ages 18-75 and randomly selected, with a response rate of 71%. Patients were classified into four groups, 18-34, 35-49, 50-64 and 65-75 years.

RESULTS

Younger women (18-49 years) had a lower total MiniAQLQ score than men in the same age group (5.41 vs. 5.80, p < 0.001), while no significant difference was found between older women and men (50-75 years) (5.08 vs. 5.16, p = 0.42). The sex differences in the younger group remained significant after adjusting for medication, educational level, smoking, body mass index, allergy and depression (p = 0.008). The odds ratios for younger women to have night-awakenings was 1.7 (95%CI 1.07-2.57), for asthma exacerbations 1.9 (95%CI 1.21-2.98) and for not achieving asthma control 1.5 (95%CI 1.00-2.13) when adjusting for smoking, educational level and body mass index. No differences in asthma control were found when comparing older women with men of similar ages.

CONCLUSIONS

Younger women had lower quality of life and less often asthma control than men in the same age range, while no corresponding sex differences were found between older women and men of similar ages. Female sex hormones could be an important factor affecting these outcomes.

Smoking in asthma is associated with elevated levels of corticosteroid resistant sputum cytokines-an exploratory study

Background

Current cigarette smoking is associated with reduced acute responses to corticosteroids and worse clinical outcomes in stable chronic asthma. The mechanism by which current smoking promotes this altered behavior is currently unclear. Whilst cytokines can induce corticosteroid insensitivity in-vitro, how current and former smoking affects airway cytokine concentrations and their responses to oral corticosteroids in stable chronic asthma is unclear.

Objectives

To examine blood and sputum cytokine concentrations in never, ex and current smokers with asthma before and after oral corticosteroids.

Methods

Exploratory study utilizing two weeks of oral dexamethasone (equivalent to 40 mg/day prednisolone) in 22 current, 21 never and 10 ex-smokers with asthma. Induced sputum supernatant and plasma was obtained before and after oral dexamethasone. 25 cytokines were measured by multiplex microbead system (Invitrogen, UK) on a Luminex platform.

Results

Smokers with asthma had elevated sputum cytokine interleukin (IL) -6, -7, and -12 concentrations compared to never smokers with asthma. Few sputum cytokine concentrations changed in response to dexamethasone IL-17 and IFNα increased in smokers, CCL4 increased in never smokers and CCL5 and CXCL10 reduced in ex-smokers with asthma. Ex-smokers with asthma appeared to have evidence of an ongoing corticosteroid resistant elevation of cytokines despite smoking cessation. Several plasma cytokines were lower in smokers with asthma compared to never smokers with asthma.

Conclusion

Cigarette smoking in asthma is associated with a corticosteroid insensitive increase in multiple airway cytokines. Distinct airway cytokine profiles are present in current smokers and never smokers with asthma and could provide an explanatory mechanism for the altered clinical behavior observed in smokers with asthma.

Molecular mechanisms of reactive oxygen species-related pulmonary inflammation and asthma

Asthma is a highly relevant disorder that can be induced by many environmental factors such as allergens and pollutants. One of the most critical pathological symptoms of asthma is airway inflammation. In order to identify a cause of respiratory inflammation, we thoroughly examine the unique role of reactive oxygen species (ROS). Evidence supports that the inhalation of aggravating compounds such as allergens can promote the increased generation of ROS. Accordingly, ROS have a proven role in the cellular signaling cascades of many respiratory diseases that cause respiratory inflammation, including asthma. Although there is no known cure for asthma, current treatments effectively lessen the inflammation symptom. Based on the investigations of asthma pathogenesis and the mechanism of ROS formation, we have identified several novel anti-inflammatory therapeutic treatments, shedding light on a fundamental understanding for the cure of this disorder. In this review, we will outline the pathogenesis of asthma and its relationship to ROS, oxidative stress, and pulmonary inflammation.

Effect of montelukast for treatment of asthma in cigarette smokers

OBJECTIVE

Many asthmatic patients are unable to quit cigarettes; therefore information is needed on treatment options for smokers. This study evaluates 10 mg/d montelukast and 250 μg of fluticasone propionate twice daily, each compared with placebo, in patients with self-reported active smoking (unable to quit) and asthma.

METHODS

Patients (ages 18-55 years, with asthma [≥1 year], FEV1 of 60% to 90% of predicted value, airway reversibility [≥12%], and self-reported active smoking [≥0.5 to ≤2 packs per day]) were randomized (after a 3-week, single-blind, placebo, run-in period) to 1 of 3 parallel, 6-month, double-blind treatment arms. The primary efficacy end point was the percentage of days with asthma control during treatment. Adverse experiences (AEs) were also evaluated.

RESULTS

There were 347, 336, and 336 patients randomized to montelukast, fluticasone, and placebo, respectively. The mean percentage of days with asthma control over 6 months of treatment was 45% (montelukast, P < .05 vs placebo), 49% (fluticasone, P < .001 vs placebo), and 39% (placebo); the difference between montelukast and fluticasone was not significant (P = .14). Patients with a smoking history of ≤11 pack years (the median value) tended to show more benefit with fluticasone, whereas those with a smoking history of >11 pack years tended to show more benefit with montelukast. AEs occurred in similar proportions among treatment groups.

CONCLUSIONS

In a population of asthmatic patients actively smoking cigarettes, both 10 mg/d montelukast and 250 μg of fluticasone propionate twice daily significantly increased the mean percentage of days with asthma control compared with placebo.

Long lasting effects of smoking: breast cancer survivors' inflammatory responses to acute stress differ by smoking history

Cigarette smoking continues to be the most preventable cause of illness and death and has been linked to the development and prognosis of cancer. Current smokers have higher levels of inflammation than nonsmokers, and inflammation can remain elevated in former smokers even years following cessation. Inflammation can also be enhanced by stress. This study examined cortisol and inflammatory responses to a laboratory stressor in breast cancer survivors who formerly smoked compared to their counterparts who had never smoked. Participants included 89 women (age=51.6±8.9 years) who had completed treatment for stage 0-IIIA breast cancer within the past three years and were at least two months post surgery, radiation or chemotherapy, whichever occurred last. Cortisol and interleukin-6 (IL-6) were evaluated in response to a standardized laboratory speech and mental arithmetic stressor. Former (n=25) and never (n=64) smokers did not differ by cancer stage, cancer treatment, comorbidities, time since cancer treatment, depression, or stress. Despite having similar cortisol responses to the stressor, former smokers had exaggerated IL-6 responses two hours post-stressor compared to never smokers. This effect persisted after controlling for age, BMI, time since treatment, education, and antidepressant use. An exaggerated and prolonged inflammatory response to stress could be one mechanism underlying the persistent inflammation observed in former smokers.

Phosphodiesterase-4 inhibition improves corticosteroid insensitivity in pulmonary endothelial cells under oxidative stress

BACKGROUND

Several clinical studies have shown that smoking in asthmatics and chronic obstructive pulmonary disease patients is closely associated with corticosteroid refractoriness. In this work, we have analyzed glucocorticoid insensitivity in human pulmonary artery endothelial cells (HPAECs) under cigarette smoke extract (CSE) exposure as well as the possible additive effects of the combination therapy with a phosphodiesterase (PDE)-4 inhibitor.

METHODS

Interleukin (IL)-8 was measured in cell supernatants by ELISA. Histone deacetylase (HDAC), histone acetylase (HAT), and intracellular cAMP levels were measured by colorimetric assays and enzyme immunoassay, respectively. PDE4 isotypes and glucocorticoid receptor (GR)-α and β expression were measured by real-time RT-PCR.

RESULTS

The PDE4 inhibitor rolipram dose dependently inhibited the IL-8 secretion induced by CSE 5%. In contrast, dexamethasone 1 μM did not show inhibitory effect on IL-8 secretion. Combination of subeffective rolipram concentrations at 10 nM increased the inhibitory effect of dexamethasone to ~45% of inhibition. Cigarette smoke extract 5% inhibited HDAC activity and increased HAT activity generating glucocorticoid insensitivity. Rolipram did not modify the HDAC activity, however partially inhibited the increase in HAT activity at 1 μM. PDE4 isotypes were up-regulated by CSE 5% with the consequent cAMP down-regulation. Dexamethasone reduced all PDE4 isotypes expression and showed additive effects with rolipram enhancing cAMP levels. Furthermore, rolipram enhanced GR-α expression and inhibited the increase in GR-β induced by CSE.

CONCLUSIONS

Combination of rolipram and dexamethasone shows additive properties in HPAECs under glucocorticoid insensitive conditions. These results may be of potential value in future anti-inflammatory therapies using combination of PDE4 inhibitors and glucocorticoids.

Smoking influences response to inhaled corticosteroids in patients with asthma: a meta-analysis

OBJECTIVE

To determine the effects of smoking on efficacy of inhaled corticosteroids in asthmatics.

RESEARCH DESIGN AND METHODS

Prospective/retrospective, controlled studies published up to May 2012 in smokers versus non-smokers with asthma using inhaled corticosteroids (ICSs) were retrieved from PubMed, Highwire and Embase databases.

MAIN OUTCOME MEASURES

The primary outcomes were pulmonary function parameters [FEV(1) (forced expiratory volume in 1 second), a.m. PEF (a.m. peak expiratory flow) and p.m. PEF (p.m. peak expiratory flow)]. Secondary outcomes included differential eosinophil counts in sputum and peripheral blood, asthma control questionnaire-5 (ACQ-5) and concomitant use of medication. Pooled SMDs (standardized mean differences) were estimated by using a random-effect model and a fixed-effect model based on between-study heterogeneity.

RESULTS

Of 242 studies identified, ten (N = 4070) met the inclusion criteria (seven of budesonide-based interventions, two of fluticasone and one unknown ICS trial). Both smokers and non-smokers were similar in age and baseline FEV(1). Smoking yielded considerably reduced mean change in FEV(1) [SMD = -0.197, 95% CI: (-0.327, -0.066), p = 0.003], morning PEF [SMD = -0.796, 95% CI: (-1.047, -0.545), p < 0.001], night-time PEF [SMD = -0.501, 95% CI: (-0.797, -0.204), p = 0.001] and post-treatment FEV(1) [SMD = -0.178, 95% CI: (-0.309, -0.046), p = 0.008] and increased use of concomitant medications [SMD = 0.537, 95% CI: (0.166, 0.908), p = 0.005] in smokers, but not non-smokers with asthma, although there was no statistical difference in allergy-related endpoints and asthma score (ACQ-5).

CONCLUSION

Smoking is associated with attenuated response to inhaled corticosteroids in asthmatics. This offers a rationale for persuasion of smoking cessation. Treatment outcomes might be improved by smoking cessation leading to improved lung function and ameliorated symptoms.

[Asthma exacerbations: pharmacological prevention]

Asthma exacerbations are responsible for many emergency medical interventions and account for a significant proportion of the health costs of the disease. Increased airway inflammation is a key feature of exacerbations in asthma and therefore inhaled corticosteroids (ICS) are considered as first-line therapy for long-term asthma control. ICS have been demonstrated to reduce the risk of asthma exacerbations, as well as improving lung function. Oral leukotriene receptor antagonists also reduce the incidence of asthma exacerbations but are less effective than ICS. In patients with inadequately controlled persistent asthma despite low-dose ICS, the addition of a long-acting inhaled beta-agonist (LABA) should be considered. LABA should not be given alone and should always be associated with ICS in asthma. The anti-immunoglobulin E antibody, omalizumab, reduces severe exacerbations and emergency visits in patients with severe allergic asthma. In clinical trials measurement of the inflammatory response in induced sputum could provide information concerning appropriate drug therapy. Asthma-associated comorbidities should be investigated and treated, particularly in severe asthma. Despite a high prevalence of both gastro-oesophageal reflux and allergic rhinitis among patients with asthma, treatment with proton-pump inhibitors or nasal corticosteroids does not reduce the rate of asthma exacerbations.

The effects of cigarette smoke on airway inflammation in asthma and COPD: therapeutic implications

Asthma and COPD are two chronic inflammatory disorders of the airway characterized by airflow limitation. While many similarities exist between these two diseases, they are pathologically distinct due to the involvement of different inflammatory cells; predominantly neutrophils, CD8 lymphocytes in COPD and eosinophils and CD4 lymphocytes in asthma. Cigarette smoking is associated with accelerated decline of lung function, increased mortality, and worsening of symptoms in both asthma and COPD. Furthermore, exposure to cigarette smoke can alter the inflammatory mechanisms in asthma to become similar to that seen in COPD with increasing CD8 cells and neutrophils and may therefore alter the response to therapy. Cigarette smoke exposure has been associated with a poor response to inhaled corticosteroids which are recommended as first line anti-inflammatory medications in asthma and as an add-on therapy in patients with severe COPD with history of exacerbations. While the main proposed mechanism for this altered response is the reduction of the histone deacetylase 2 (HDAC2) enzyme system, other possible mechanisms include the overexpression of GR-β, activation of p38 MAPK pathway and increased production of inflammatory cytokines such as IL-2, 4, 8, TNF-α and NF-Kß. Few clinical trials suggest that leukotriene modifiers may be an alternative to corticosteroids in smokers with asthma but there are currently no drugs which effectively reduce the progression of inflammation in smokers with COPD. However, several HDAC2 enhancers including low dose theophylline and other potential anti-inflammatory therapies including PDE4 inhibitors and p38 MAPK inhibitors are being evaluated.

Do asthmatic smokers benefit as much as non-smokers on budesonide/formoterol maintenance and reliever therapy? Results of an open label study

BACKGROUND

Studies with inhaled corticosteroids (ICS) in smoking asthmatics have mostly shown poorer treatment responses than in non-smoking asthmatics.

METHODS

EuroSMART, an open, randomised, 6-month study, compared budesonide/formoterol (Symbicort (®) Turbuhaler(®))(h) maintenance and reliever therapy (Symbicort SMART(®)) at two maintenance doses of budesonide/formoterol (160/4.5 μg), 1 × 2 and 2 × 2, in patients with asthma who were symptomatic despite treatment with ICS ± long-acting β(2)-agonists. The 8424 randomised patients included 886 smokers (11%; aged <40 years or with a smoking history <10 pack-years if older), who were compared with a propensity-matched group of non-smokers. At baseline, smokers had lower post-bronchodilator peak expiratory flow, lower peak flow reversibility and used more reliever medication per day. Severe asthma exacerbations were counted and changes in five-item Asthma Control Questionnaire (ACQ-5) scores from baseline calculated.

RESULTS

There were 48 and 47 exacerbations in smokers and non-smokers, respectively. Mean time to first severe exacerbation was not statistically different between the two groups. The mean change in ACQ-5 score was significantly greater in non-smokers. Considering the two treatment options there was a statistically significant prolonged time to first severe exacerbation with 2 × 2 versus 1 × 2 in the smokers, but not in the non-smokers. In smokers, the reductions in ACQ-5 scores, asthma symptoms, use of as-needed medication and awakenings were also all significant in favour of 2 × 2 with similar or greater changes than in smokers treated with 1 × 2.

CONCLUSION

Asthmatic patients with a limited smoking history benefit from treatment with budesonide/formoterol maintenance and reliever therapy with dosing 2 × 2 being superior to 1 × 2.

Urinary leukotriene E₄ levels identify children with tobacco smoke exposure at risk for asthma exacerbation

BACKGROUND

Children with asthma exposed to secondhand smoke (SHS) might be at higher risk for severe exacerbations, but biomarkers of susceptibility to SHS exposure have not been previously reported.

OBJECTIVES

We sought to assess the usefulness of urinary leukotriene E(4) (uLTE₄) levels in the prediction of increased risk of severe asthma exacerbations requiring emergency department (ED) or urgent care (UC) visits.

METHODS

Forty-four schoolchildren with moderate-to-severe asthma receiving inhaled corticosteroids were followed for 5 months with repeated measurements of uLTE₄ and monitoring of ED and UC visits. SHS exposure status was determined by using prestudy questionnaires and repeated measurements of urinary cotinine during the study.

RESULTS

Nine (45%) of 20 children with SHS exposure experienced a severe exacerbation requiring an ED or UC visit compared with 3 (12.5%) of 24 children without significant SHS exposure (relative risk, 3.6; 95% CI, 1.1-11.5; P = .02). The uLTE₄ level was a significant predictor of exacerbation risk in children exposed to SHS (area under the curve, 0.85; P = .003). Other predictors, such as nighttime symptom frequency, prebronchodilator and postbronchodilator lung function, and exhaled nitric oxide levels, were not related to exacerbations in this group. uLTE₄ levels at or greater than 106 pg/mg achieved 67% (6/9) sensitivity and 100% (11/11) specificity for predicting children with SHS exposure who required an ED or UC visit.

CONCLUSIONS

Children exposed to SHS are at increased risk for severe asthma exacerbations, despite use of inhaled corticosteroids. uLTE₄ levels identify children exposed to SHS at high risk for asthma exacerbations.

Diesel exhaust particulates exacerbate asthma-like inflammation by increasing CXC chemokines

Particulate matter heavily pollutes the urban atmosphere, and several studies show a link between increased ambient particulate air pollution and exacerbation of pre-existing pulmonary diseases, including asthma. We investigated how diesel exhaust particulates (DEPs) aggravate asthma-like pulmonary inflammation in a mouse model of asthma induced by a house dust extract (HDE) containing cockroach allergens and endotoxin. BALB/c mice were exposed to three pulmonary challenges via hypopharyngeal administration of an HDE collected from the home of an asthmatic child. One hour before each pulmonary challenge, mice were exposed to DEP or PBS. Pulmonary inflammation was assessed by histological features, oxidative stress, respiratory physiological features, inflammatory cell recruitment, and local CXC chemokine production. To prove the role of CXC chemokines in the augmented inflammation, CXC chemokine-specific antibodies were delivered to the lungs before DEP exposure. DEP exacerbated HDE-induced airway inflammation, with increased airway mucus production, oxidative stress, inflammatory cell infiltration, bronchoalveolar lavage concentrations of CXC chemokines, and airway hyperreactivity. Neutralization of airway keratinocyte-derived chemokine and macrophage inflammatory protein-2 significantly improves the respiratory function in addition to decreasing the infiltration of neutrophils and eosinophils. Blocking the chemokines also decreased airway mucus production. These results demonstrate that DEP exacerbates airway inflammation induced by allergen through increased pulmonary expression of the CXC chemokines (keratinocyte-derived chemokine and macrophage inflammatory protein-2).

Smoking and nonsmoking asthma: differences in clinical outcome and pathogenesis

Cigarette smoking in asthma is frequently present and is associated with worsening of symptoms, accelerated lung-function decline, a higher frequency of hospital admissions, a higher degree of asthma severity, poorer asthma control and reduced responsiveness to corticosteroids. Furthermore, it is associated with reduced numbers of eosinophils and higher numbers of mast cells in the submucosa of the airway wall. Airway remodeling is increased as evidenced by increased epithelial thickness and goblet cell hyperplasia in smoking asthmatics. The pathogenesis responsible for smoking-induced changes in airway inflammation and remodeling in asthma is complex and largely unknown. The underlying mechanism of reduced corticosteroid responsiveness is also unknown. This article discusses differences between smoking and nonsmoking asthmatics regarding the clinical expression of asthma, lung function, response to corticosteroids, airway inflammation and remodeling processes. Possible pathogenetic mechanisms that may explain the links between cigarette smoking and changes in the clinical expression of asthma will be discussed, as well as the beneficial effects of smoking cessation.

Protocol: influence of budesonide and budesonide/formoterol on asthma control in smoking asthmatic adults

RATIONALE

A reduced response to inhaled corticosteroids (ICS) has been reported in smoking asthmatic patients but the effects of other medications remain to be evaluated in this population.

SUBJECTS AND METHODS

We evaluated the effects of a combined therapy of budesonide 200 microg twice daily and formoterol 6 microg twice daily compared with budesonide 200 microg twice daily alone on asthma control questionnaire (ACQ), asthma quality of life questionnaire (AQLQ- Juniper), pulmonary function and airway inflammation, in a cross-over randomized double-blind study with treatment periods of two months separated by a one-month wash-out period. Seventeen smoking and 22 non-smoking patients not using inhaled corticosteroids with slightly uncontrolled mild asthma completed the study.

RESULTS

ACQ and AQLQ scores were similar in both groups at baseline and improved similarly after treatments. beta2-agonist use was higher in smokers, regardless of the treatment received (p=0.03), as it was on baseline (p=0.003). Smokers treated with budesonide/formoterol showed an increase in the number of asthma episodes (intercurrent asthma symptoms, p=0.016) while non-smoking subjects had a significant decrease in these episodes (p=0.009). No difference was found between smokers and non-smokers in regard to post-treatment airway inflammatory parameters.

CONCLUSIONS

No significant differences were found between smoking and non-smoking subjects with mild asthma in regard to clinical changes in asthma control, pulmonary function and airway inflammation following a 2-month treatment period with budesonide or the association of budesonide and formoterol for a period of 2 months. This should be further explored in larger groups of subjects.

Impact of comorbidities on asthma

Asthma is a common and serious illness with suboptimal outcomes of care. Epidemiological studies show certain comorbidities occurring more frequently than expected with asthma, with some being associated with poor control and a differential response to therapy options. This review summarizes the evidence of clinically important comorbidities, focusing on the best-explored conditions, including rhinitis and rhinosinusitis, anxiety and depression, obesity, gastroesophageal reflux, smoking and dysfunctional breathing. The evidence of epidemiological and pathophysiological associations for these comorbidities is explored, and the practical therapeutic implications are considered. Comorbidities are important for clinicians treating asthma as they may be markers of patients at risk of poor outcomes, they may point to specific effective treatment options and they are important to researchers as possible confounding factors in clinical trials.

The glucocorticoid receptor: a revisited target for toxins

The hypothalamic-pituitary-adrenal (HPA) axis activation and glucocorticoid responses are critical for survival from a number of bacterial, viral and toxic insults, demonstrated by the fact that removal of the HPA axis or GR blockade enhances mortality rates. Replacement with synthetic glucocorticoids reverses these effects by providing protection against lethal effects. Glucocorticoid resistance/insensitivity is a common problem in the treatment of many diseases. Much research has focused on the molecular mechanism behind this resistance, but an area that has been neglected is the role of infectious agents and toxins. We have recently shown that the anthrax lethal toxin is able to repress glucocorticoid receptor function. Data suggesting that the glucocorticoid receptor may be a target for a variety of toxins is reviewed here. These studies have important implications for glucocorticoid therapy.

Anti-inflammatory drug therapy in asthma

Asthma is a disease with chronic inflammation of the airways and and-inflammatory treatment is a logical treatment. Inhaled corticosteroids [ICS] remain the cornerstone of anti-inflammatory therapy in recent international guidelines. Asthma cannot be cured by any medication: if the drug is discontinued, the disease manifestations return. This has been proven at all ages. In preschool children the diagnosis of asthma is difficult to establish. In this heterogeneous group ICS or leukotriene receptor antagonists [LTRA] are just as effective as placebo; in the future it will hopefully be possible to describe characteristics of responders. LTRA are an alternative in mild asthma, especially when mono-triggered viral related wheeze is present. Theophylline is effective and also has bronchodilatory properties, which need to be balanced against the relatively frequent side effects. The working mechanisms of anti-inflammatory asthma medications including ICS, LTRA, cromones, macrolides and theophylline are described.

Pharmacological strategies for improving the efficacy and therapeutic ratio of glucocorticoids in inflammatory lung diseases

Glucocorticoids are widely used to treat various inflammatory lung diseases. Acting via the glucocorticoid receptor (GR), they exert clinical effects predominantly by modulating gene transcription. This may be to either induce (transactivate) or repress (transrepress) gene transcription. However, certain individuals, including those who smoke, have certain asthma phenotypes, chronic obstructive pulmonary disease (COPD) or some interstitial diseases may respond poorly to the beneficial effects of glucocorticoids. In these cases, high dose, often oral or parental, glucocorticoids are typically prescribed. This generally leads to adverse effects that compromise clinical utility. There is, therefore, a need to enhance the clinical efficacy of glucocorticoids while minimizing adverse effects. In this context, a long-acting beta(2)-adrenoceptor agonist (LABA) can enhance the clinical efficacy of an inhaled corticosteroid (ICS) in asthma and COPD. Furthermore, LABAs can augment glucocorticoid-dependent gene expression and this action may account for some of the benefits of LABA/ICS combination therapies when compared to ICS given as a monotherapy. In addition to metabolic genes and other adverse effects that are induced by glucocorticoids, there are many other glucocorticoid-inducible genes that have significant anti-inflammatory potential. We therefore advocate a move away from the search for ligands of GR that dissociate transactivation from transrepression. Instead, we submit that ligands should be functionally screened by virtue of their ability to induce or repress biologically-relevant genes in target tissues. In this review, we discuss pharmacological methods by which selective GR modulators and "add-on" therapies may be exploited to improve the clinical efficacy of glucocorticoids while reducing potential adverse effects.

Prevalence of active and passive smoking in a population of patients with asthma

Smoking causes an intense inflammatory reaction in the airways and is associated with worse clinical outcomes in patients with asthma. The objective of this study was to determine the prevalence of active and passive smoking in a population of patients with asthma. The sample of asthma patients (n = 100) consisted of 47 nonsmokers, 33 former smokers, 17 passive smokers and 3 active smokers. Most had moderate or severe asthma. Mean exhaled CO was 9.34 ppb in smokers, 4.19 ppb in passive smokers, 3.98 ppb in nonsmokers and 3.98 ppb in former smokers. We conclude that the prevalence of exposure to tobacco smoke is high among asthma patients.

Severe asthma: what makes it so hard to manage?

Severe asthma presents significant management challenges. Patients can be difficult to control despite use of current standard-of-care therapy, including inhaled corticosteroids and long-acting beta-agonists. Alternative diagnoses, noncompliance, and comorbidities all can influence asthma control, future risk, and response to currently available therapy. Definitions of severe asthma evaluate and address these confounding variables, and yet patients are still symptomatic despite aggressive, appropriate therapy. Severe asthma has a distinct pathophysiology including airway remodeling that contributes to the decreased effectiveness of standard therapy. Multiple phenotypes exist within severe asthma that likely require distinct therapeutic approaches to achieve control and improve long-term health outcomes. New therapeutic approaches to these distinct phenotypes will improve our understanding and treatment of this difficult-to-manage disease.

Severe asthma patients in Korea overestimate their adherence to inhaled corticosteroids

Good adherence to inhaled corticosteroid (ICS) therapy is essential for effective asthma control. The factors affecting ICS therapy adherence vary among individuals and countries. As few data on adherence have been reported in Korea, the factors influencing such adherence, and the clinical implications thereof, were evaluated in Korean asthma patients. A total of 185 asthma patients who had taken ICS regularly for over 1 year were randomly selected from the recently established domestic adult asthma cohort, COREA (Cohort for Reality and Evolution of Adult Asthma Korea). To obtain adherence to ICS, both prescription refill adherence and self-reported adherence over 1 year (these are objective and subjective measurements respectively) were assessed without any interventions that might affect patients' adherence to ICS. Patients' information such as age, sex, smoking history and number of medication taken, was collected. Assessment of asthma severity, pulmonary function tests, and asthma symptom score were performed to evaluate the possible clinical implication of adherence to ICS. Approximately half of the patients (50.9%) showed less than 80% of prescription refill adherence. There was a considerable discrepancy between prescription refill adherence and self-reported adherence especially in the patients whose refill adherence was under than 50%. Younger asthma patients showed lower adherence to ICS than did older (> or = 60 years old) patients. Higher asthma severity was significantly associated with lower refill adherence to ICS. However, asthma symptom scores and forced expiratory volume in 1 second (FEV(1)) values were not directly related with refill adherence. To improve asthma control in Korea, enhancement of adherence to ICS is critical: our findings emphasize the need to use objective measurements when adherence to asthma medication is to be assessed in clinical practice.

Inhaled steroid/tobacco smoke particle interactions: a new light on steroid resistance

BACKGROUND

Inhaled steroid resistance is an obstacle to asthma control in asthmatic smokers. The reasons of this phenomenon are not yet entirely understood. Interaction of drug particles with environmental tobacco smoke (ETS) could change the aerodynamic profile of the drug through the particle coagulation phenomenon. Aim of the present study was to examine whether steroid particles interact with smoke when delivered in the presence of ETS.

METHODS

Beclomethasone-hydrofluoralkane (BDP-HFA) pMDI particle profile was studied after a single actuation delivered in ambient air or in the presence of ETS in an experimental chamber using a light scattering Optical Particle Counter capable of measuring the concentrations of particle sized 0.3-1.0, 1.1-2.0, 2.1-3.0, 3.1-4.0, 4.1-5.0, and > 5.1 microm in diameter with a sampling time of one second. The number of drug particles delivered after a single actuation was measured as the difference between total particle number after drug delivery and background particle number. Two groups of experiments were carried out at different ambient background particle concentrations. Two-tail Student's t-test was used for statistical analysis.

RESULTS

When delivered in ambient air, over 90% of BDP-HFA particles were found in the 0.3-1.0 microm size class, while particles sized 1.1-2.0 microm and 2.1-3.0 represented less than 6.6% and 2.8% of total particles, respectively. However, when delivered in the presence of ETS, drug particle profile was modified, with an impressive decrease of 0.3-1.0 microm particles, the most represented particles resulting those sized 1.1-2.0 microm (over 66.6% of total particles), and 2.1-3.0 microm particles accounting up to 31% of total particles.

CONCLUSION

Our data suggest that particle interaction between inhaled BDP-HFA pMDI and ETS takes place in the first few seconds after drug delivery, with a decrease in smaller particles and a concurrent increase of larger particles. The resulting changes in aerosol particle profile might modify regional drug deposition with potential detriment to drug efficacy, and represent a new element of steroid resistance in smokers. Although the present study does not provide any functional or clinical assessment, it might be useful to advise smokers and non smokers with obstructive lung disease such as asthma or COPD, to avoid to act inhaled drugs in the presence of ETS in order to obtain the best therapeutic effect.

Persistence of oxidant and protease burden in the airways after smoking cessation

BACKGROUND

Oxidative stress is associated with the pathogenesis of cigarette smoke related lung diseases, but longitudinal effects of smoking cessation on oxidant markers in the airways are unknown.

METHODS

This study included 61 smokers; 21 with chronic bronchitis or COPD, 15 asthmatics and 25 asymptomatic smokers followed up for 3 months after smoking cessation. Fractional exhaled nitric oxide (FeNO), sputum neutrophil counts, sputum 8-isoprostane, nitrotyrosine and matrix metalloproteinase-8 (MMP-8) were investigated at baseline and 1 and 3 months after smoking cessation.

RESULTS

After 3 months 15 subjects had succeeded in quitting of smoking and in these subjects symptoms improved significantly. Unexpectedly, however, sputum neutrophils increased (p = 0.046) after smoking cessation in patients with chronic bronchitis/COPD. At baseline, the other markers did not differ between the three groups so these results were combined for further analysis. Sputum 8-isoprostane declined significantly during the follow-up at 3 months (p = 0.035), but levels still remained significantly higher than in non-smokers. The levels of FeNO, nitrotyrosine and MMP-8 did not change significantly during the 3 months after smoking cessation.

CONCLUSION

Whilst symptoms improve after smoking cessation, the oxidant and protease burden in the airways continues for months.

Impact of environmental tobacco smoke and active tobacco smoking on the development and outcomes of asthma and rhinitis

PURPOSE OF REVIEW

We aim to discuss current insights on the influence of active smoking and environmental tobacco smoke in lower and upper respiratory inflammatory illnesses.

RECENT FINDINGS

Insight has been gained on the effect of tobacco smoking on the development of asthma from the womb to adolescence. Secondhand tobacco exposure and active smoking play a major role not only in the inception of asthma epidemiological community studies but also in patients already suffering from allergic rhinitis. Tobacco seems to influence innate immunity predisposing to Th2-associated respiratory diseases and increasing the risk for IgE-mediated sensitization. Tobacco smoking is related to worst outcomes in both asthma and rhinitis.

SUMMARY

Several deleterious effects have been described in asthma because of smoking: accelerated decline in lung function, more severe symptoms, impairment in quality of life and diminished therapeutic response to steroids. The harmful effect of tobacco smoking is not only on asthma but also on rhinitis playing a role in disease outcomes. Tobacco exposure can influence innate immunity diminishing innate production of antigen-presenting cells cytokines, as well as an impaired response to toll-like receptor ligands. Active smoking is associated with current symptoms of asthma and rhinitis and seems to be a risk factor for developing new asthma in patients with rhinitis. Tobacco smoking has been also found among the factors inducing nasal obstruction and decreased muco-ciliary clearance in nonallergic rhinitis.

Asthma in smokers: challenges and opportunities

PURPOSE OF REVIEW

Cigarette smoking in asthma is associated with poor symptom control and reduced sensitivity to corticosteroids. We summarize recent evidence supporting the adverse effects of smoking in asthma and consider strategies to manage these patients.

RECENT FINDINGS

Smokers have more severe symptoms and are more likely to be admitted to hospital due to poorly controlled asthma compared with nonsmokers with asthma. Possible causes of reduced sensitivity to inhaled corticosteroids in smokers with asthma are noneosinophilic airway inflammation, impaired glucocorticoid receptor function, and/or reduced histone deacetylase activity. Smoking cessation improves asthma control, but quit rates are low. The optimal drug therapy for smokers with asthma is not established due, in part, to the small number of clinical trials performed in these patients. Preliminary data, however, suggest that leukotriene-receptor antagonists may have a beneficial effect in smokers with mild asthma.

SUMMARY

Cigarette smoking in asthma is a risk factor for poor asthma control and reduced sensitivity to corticosteroids. Every effort should be made to encourage individuals with asthma who smoke to quit. Clinical trials are required to identify therapies that restore corticosteroid sensitivity or directly improve symptom control in individuals with asthma who are unable to stop smoking.

Treating patients with respiratory disease who smoke

The high prevalence of cigarette smoking in patients with respiratory disease puts them at risk of developing clinically important drug interactions. Cigarette smoking reduces the therapeutic response to certain drugs such as theophyllines through the induction of hepatic cytochrome P450 isoenzymes. Smokers with asthma and patients with COPD have reduced sensitivity to corticosteroids, possibly due to non-eosinophilic airway inflammation, altered glucocorticoid receptor activity or reduced histone deacetylase activity. Although all smokers should be encouraged to stop smoking, there is limited information on the influence of smoking cessation on the therapeutic and anti-inflammatory effects of a number of the drugs used in the treatment of respiratory disease.

Evaluating combination therapies for asthma: pros, cons, and comparative benefits

Combination therapies with inhaled corticosteroids (ICS) and either long-acting beta2 agonists (LABA) or leukotriene receptor antagonists (LTRA) are commonly used to help patients maintain control of their asthma. LABA and LTRA have different mechanisms of action and both provide complementary benefits when combined with ICS. This paper compares the two regimens based on recent clinical trial data, evaluates their efficacy on various clinical and quality of life outcomes, and discusses the importance of therapy choice in people with specific asthma phenotypes. The potential of new dosing strategies, including adjustable maintenance therapy and single-inhaler maintenance and reliever therapy is also reviewed. Given the variety of outcomes, phenotypes, and treatment strategies that must be considered, the importance of individualized management is emphasized.

Acute severe asthma: new approaches to assessment and treatment

The precise definition of a severe asthmatic exacerbation is an issue that presents difficulties. The term 'status asthmaticus' relates severity to outcome and has been used to define a severe asthmatic exacerbation that does not respond to and/or perilously delays the repetitive or continuous administration of short-acting inhaled beta(2)-adrenergic receptor agonists (SABA) in the emergency setting. However, a number of limitations exist concerning the quantification of unresponsiveness. Therefore, the term 'acute severe asthma' is widely used, relating severity mostly to a combination of the presenting signs and symptoms and the severity of the cardiorespiratory abnormalities observed, although it is well known that presentation does not foretell outcome. In an acute severe asthma episode, close observation plus aggressive administration of bronchodilators (SABAs plus ipratropium bromide via a nebulizer driven by oxygen) and oral or intravenous corticosteroids are necessary to arrest the progression to severe hypercapnic respiratory failure leading to a decrease in consciousness that requires intensive care unit (ICU) admission and, eventually, ventilatory support. Adjunctive therapies (intravenous magnesium sulfate and/or others) should be considered in order to avoid intubation. Management after admission to the hospital ward because of an incomplete response is similar. The decision to intubate is essentially based on clinical judgement. Although cardiac or respiratory arrest represents an absolute indication for intubation, the usual picture is that of a conscious patient struggling to breathe. Factors associated with the increased likelihood of intubation include exhaustion and fatigue despite maximal therapy, deteriorating mental status, refractory hypoxaemia, increasing hypercapnia, haemodynamic instability and impending coma or apnoea. To intubate, sedation is indicated in order to improve comfort, safety and patient-ventilator synchrony, while at the same time decrease oxygen consumption and carbon dioxide production. Benzodiazepines can be safely used for sedation of the asthmatic patient, but time to awakening after discontinuation is prolonged and difficult to predict. The most common alternative is propofol, which is attractive in patients with sudden-onset (near-fatal) asthma who may be eligible for extubation within a few hours, because it can be titrated rapidly to a deep sedation level and has rapid reversal after discontinuation; in addition, it possesses bronchodilatory properties. The addition of an opioid (fentanyl or remifentanil) administered by continuous infusion to benzodiazepines or propofol is often desirable in order to provide amnesia, sedation, analgesia and respiratory drive suppression. Acute severe asthma is characterized by severe pulmonary hyperinflation due to marked limitation of the expiratory flow. Therefore, the main objective of the initial ventilator management is 2-fold: to ensure adequate gas exchange and to prevent further hyperinflation and ventilator-associated lung injury. This may require hypoventilation of the patient and higher arterial carbon dioxide (PaCO(2)) levels and a more acidic pH. This does not apply to asthmatic patients intubated for cardiac or respiratory arrest. In this setting the post-anoxic brain oedema might demand more careful management of PaCO(2) levels to prevent further elevation of intracranial pressure and subsequent complications. Monitoring lung mechanics is of paramount importance for the safe ventilation of patients with status asthmaticus. The first line of specific pharmacological therapy in ventilated asthmatic patients remains bronchodilation with a SABA, typically salbutamol (albuterol). Administration techniques include nebulizers or metered-dose inhalers with spacers. Systemic corticosteroids are critical components of therapy and should be administered to all ventilated patients, although the dose of systemic corticosteroids in mechanically ventilated asthmatic patients remains controversial. Anticholinergics, inhaled corticosteroids, leukotriene receptor antagonists and methylxanthines offer little benefit, and clinical data favouring their use are lacking. In conclusion, expertise, perseverance, judicious decisions and practice of evidence-based medicine are of paramount importance for successful outcomes for patients with acute severe asthma.