Eosinophilic inflammation in sputum of poorly controlled asthmatics

Clinical significance of fractional exhaled nitric oxide and periostin as potential markers to assess therapeutic efficacy in patients with cough variant asthma

BACKGROUND

In Japan, cough variant asthma (CVA) is the most common etiology of chronic cough. Contrary to substantial progress in understanding the roles of various factors in classic asthma, little is known regarding the pathogenesis and development of CVA. Furthermore, few studies have explored valuable biomarkers for evaluating the therapeutic efficacy of patients with CVA.

METHODS

We conducted a single-center, prospective study to investigate the clinical significance of various clinical factors as potential "therapeutic" markers for CVA.

RESULTS

From December 2019 to September 2020, we enrolled 20 patients with CVA and 10 age-matched healthy control subjects. Fractional exhaled nitric oxide (FeNO) values were significantly higher in patients with CVA than those in healthy controls. All patients with CVA commenced treatment at the initial visit, which markedly alleviated symptoms 12 weeks after treatment. FeNO values and serum periostin levels were significantly decreased following treatment, and altered FeNO values correlated with improved visual analogue scale scores of symptoms. Moreover, changes in both FeNO values and serum periostin levels were significantly correlated with increased values of some pulmonary function tests while also correlating with each other.

CONCLUSIONS

Our observations indicate the usefulness of FeNO and periostin as potential "therapeutic" markers for CVA. To the best of our knowledge, this is the first report demonstrating the clinical significance of these factors as potential biomarkers to assess therapeutic efficacy in patients with CVA.

Impact of Blood Eosinophil Variability in Asthma: A Real-Life Population Study

RATIONALE

Blood eosinophil count predicts response to inhaled corticosteroids and specific biologic therapies in selected asthma patients. Despite this important role, fundamental aspects of eosinophil behavior in asthma have not been studied. Objectives To investigate the behavior of blood eosinophils in a population comparing their distribution with the general population and studying their intra-individual variability over time in relation to hospital episodes (emergency department visits and hospitalizations) in clinical practice.

METHODS

The distribution and variability of 35,703 eosinophil determinations in 10,059 stable asthma patients were investigated in the Majorca Real-Life Investigation in COPD and Asthma cohort (MAJORICA). Eosinophil distribution in the asthma population was compared with a control sample from the general population of 8,557 individuals. Eosinophil variability and hospital episodes were analyzed using correlations, ROC curves and multiple regression analysis. We defined the Eosinophil Variability Index (EVI) as (Eosmax-Eosmin/Eosmax) x 100%. The findings of the asthma population were re-tested in an external well-characterized asthma cohort.

RESULTS

The eosinophil count values and variability were higher in the asthma population than in the general population (p-value<0.001). Variability data showed a better association with hospital episodes than the counting values. An EVI≥50% was more strongly associated with hospital episodes than any of the absolute counting values. These results were validated in the external cohort.

CONCLUSION

The eosinophil variability in asthma patients better identifies the risk of any hospital episode than the absolute counting values currently used to target specific treatments.

As-needed anti-inflammatory reliever therapy for asthma management: evidence and practical considerations

Asthma is a chronic respiratory disease in which airway inflammation is a key feature, even in the milder expressions of the disease. The conventional pharmacological approach to mild asthma has long relied on reliever therapy with as-needed short-acting beta-agonists (SABAs), while anti-inflammatory maintenance with inhaled corticosteroids (ICSs) has been reserved for patients with more persistent asthma. Poor adherence to maintenance treatment is an important issue in asthma management, and can partly explain suboptimal symptom control. Over-reliance on SABA bronchodilators for rapid symptom relief is common in real life and potentially leads to an increased risk of asthma morbidity and mortality. Combined anti-inflammatory and reliever medications in a single inhaler have the potential to overcome these limitations. Recent studies in patients with mild asthma have shown that anti-inflammatory reliever therapy with budesonide-formoterol, given on an as-needed basis, is superior to SABA in ensuring asthma control and non-inferior to budesonide maintenance therapy in preventing exacerbations. To address the implications of these important findings for the management of patients with asthma, Italian specialists convened at a series of meetings held during the second half of 2018 across Italy. This article presents their position on these topics and includes a review of the evidence supporting the use of anti-inflammatory reliever therapy in mild asthma and the implementation of this novel approach in clinical practice.

Treatment strategies for asthma: reshaping the concept of asthma management

Asthma is a common chronic disease characterized by episodic or persistent respiratory symptoms and airflow limitation. Asthma treatment is based on a stepwise and control-based approach that involves an iterative cycle of assessment, adjustment of the treatment and review of the response aimed to minimize symptom burden and risk of exacerbations. Anti-inflammatory treatment is the mainstay of asthma management. In this review we will discuss the rationale and barriers to the treatment of asthma that may result in poor outcomes. The benefits of currently available treatments and the possible strategies to overcome the barriers that limit the achievement of asthma control in real-life conditions and how these led to the GINA 2019 guidelines for asthma treatment and prevention will also be discussed.

Soluble fibre supplementation with and without a probiotic in adults with asthma: A 7-day randomised, double blind, three way cross-over trial

Background

Soluble fibre modulates airway inflammation in animal models. The aim of this study was to investigate the effects of soluble fibre supplementation, with and without a probiotic, on plasma short chain fatty acids (SCFA), airway inflammation, asthma control and gut microbiome in adults with asthma.

Methods

A randomised, double-blinded, placebo controlled 3-way cross-over trial in 17 subjects with stable asthma at the Hunter Medical Research Institute, Newcastle, Australia. Subjects received 3 × 7 day oral interventions in random order; soluble fibre (inulin 12 g/day), soluble fibre + probiotic (inulin 12 g/day + multi-strain probiotic >25 billion CFU) and placebo. Plasma SCFA, sputum cell counts and inflammatory gene expression, asthma control gut microbiota, adverse events including gastrointestinal symptoms were measured.

Findings

There was no difference in change in total plasma SCFA levels (μmol/L) in the placebo versus soluble fibre (Δmedian [95% CI] 16·3 [−16·9, 49·5], p = 0·335) or soluble fibre+probiotic (18·7 [−14·5, 51·9], p = 0·325) group. Following the soluble fibre intervention there was an improvement in the asthma control questionnaire (ACQ6) (∆median (IQR) -0·35 (−0·5, −0·13), p = 0·006), sputum %eosinophils decreased (−1.0 (−2·5, 0), p = 0·006) and sputum histone deacetylase 9 (HDAC9) gene expression decreased (−0.49 (−0.83, −0.27) 2^-ΔCt, p = .008). Individual bacterial operational taxonomic units changed following both inulin and inulin+probiotic arms.

Interpretation

Soluble fibre supplementation for 7 days in adults with asthma did not change SCFA levels. Within group analysis showed improvements in airway inflammation, asthma control and gut microbiome composition following inulin supplementation and these changes warrant further investigation, in order to evaluate the potential of soluble fibre as a non-pharmacological addition to asthma management.

Fund

John Hunter Hospital Charitable Trust.

Use of Symptoms Scores, Spirometry, and Other Pulmonary Function Testing for Asthma Monitoring

Asthma is a global problem affecting millions of people all over the world. Monitoring of asthma both in children and in adulthood is an indispensable tool for the optimal disease management and for the maintenance of clinical stability. To date, several resources are available to assess the asthma control, first is the monitoring of symptoms, both through periodic follow-up visits and through specific quality of life measures addressed to the patient in first person or to parents. Clinical monitoring is not always sufficient to predict the risk of future exacerbations, which is why further instrumental examinations are available including lung function tests, the assessment of bronchial hyper-reactivity and bronchial inflammation. All these tools may help in quantifying the future risk for each patient and therefore they potentially may change the natural history of asthmatic disease. The monitoring of asthma in children as in adults is certainly linked by many aspects, however the asthmatic child is a future asthmatic adult and it is precisely during childhood and adolescence that we should implement all the efforts and strategies to prevent the progression of the disease and the subsequent impairment of lung function. For these reasons, asthma monitoring plays a crucial role and must be particularly close and careful. In this paper, we evaluate several tools currently available for asthma monitoring, focusing on current recommendations emerging from various guidelines and especially on the differences between the monitoring in pediatric age and adulthood.

The characterization of asthma with blood eosinophilia in adults in Latin America

Objective: To identify and characterize asthma with blood eosinophilia in adults. Methods: This cross-sectional study consisted of 164 asthma patients, aged 18 years or older. Multivariate analyses by logistic regression were performed to identify clinical characteristics and biomarkers associated with asthma with blood eosinophilia (defined as asthma and a peripheral blood eosinophil count ≥400 cells/mm³). To evaluate the diagnostic accuracy of these biomarkers, the sensitivity, specificity and predictive values were calculated. Additionally, the area under the receiver operating characteristic (ROC) curve (AUC) was estimated for each biomarker. Results: Overall, 37.8% (95%CI: 30.7-45.4%) of asthma patients had blood eosinophilia. The following factors were associated with this characteristic: patient age <50 years (OR 3.25; 95% CI: 1.33-7.94), a serum level of IgE ≥300 UI/mL (OR 2.32; 95%CI: 1.14-4.75), and an Asthma Control Test (ACT) score <20 points (OR 3.10; 95%CI: 1.35-4.75); asthma with blood eosinophilia was also associated with a baseline FEV₁/FVC <70% (OR 2.68; 95%CI: 1.28-5.59). On the other hand, age <50 years and ACT score <20 showed the highest sensitivity (above 80% each). Serum IgE level ≥300 UI/mL had the highest specificity (almost 68%). Finally, those with an ACT score <20 had the highest AUC (68%). Conclusions: In our study population, one-third of asthmatic adults had asthma with blood eosinophilia. Furthermore, the prevalence was greater in those ≤50 years of age; these patients experienced more severe, more poorly controlled asthma and had higher total serum IgE levels.

Eosinophil Cationic Protein Concentrations among Crop and Dairy Farmers with Asthma

OBJECTIVE

To assess the mean serum eosinophil cationic protein (s-ECP) concentrations among crop and dairy farmers and office controls, and further examine its relation to exposure duration, smoking habit, as well as presence or absence of asthma.

METHODS

A cross-sectional survey was performed including examined group (EG), composed by agricultural workers (87 crop - EG1 and 83 dairy farmers - EG2), and control group (CG) composed by 80 office workers within the same enterprise. We have used a questionnaire to record the chronic respiratory symptoms, detailed work history, specific farming activities and tasks performed and smoking history. Evaluation of examined subjects also included lung function tests, diagnosis of asthma, and measurement of s-ECP as a marker of inflammation.

RESULTS

The main finding of the present study is that s-ECP concentrations were raised in subjects with asthma independent of the smoking habit. The mean s-ECP concentrations were higher in subjects of EG1 and EG2 compared with those in CG, but without reaching statistical significance. Mean s-ECP concentrations were significantly higher among subjects in EG1 exposed more than 20 years, while mean s-ECP concentrations were non-significantly higher in subjects of EG2 exposed more than 20 years, compared to those exposed less than 20 years. Mean s-ECP concentrations were higher among smokers within all three groups, but without reaching statistical significance between smokers and non-smokers. Mean s-ECP concentrations were significantly higher in subjects with asthma within EG1 (P = 0.049) and EG2 (P = 0.040), but also within those in CG (P = 0.046).

CONCLUSION

Data obtained suggest that airway inflammation is present in farmers with asthma, and s-ECP is an important biomarker in means of reflecting disease severity and prognosis among exposed workers.

Regulation of Eosinophil and Group 2 Innate Lymphoid Cell Trafficking in Asthma

Asthma is an inflammatory disease usually characterized by increased Type 2 cytokines and by an infiltration of eosinophils to the airways. While the production of Type 2 cytokines has been associated with T_H2 lymphocytes, increasing evidence indicates that group 2 innate lymphoid cells (ILC2) play an important role in the production of the Type 2 cytokines interleukin (IL)-5 and IL-13, which likely amplifies the recruitment of eosinophils from the blood to the airways. In that regard, recent asthma treatments have been focusing on blocking Type 2 cytokines, notably IL-4, IL-5, and IL-13. These treatments mainly result in decreased blood or sputum eosinophil counts as well as decreased asthma symptoms. This supports that therapies blocking eosinophil recruitment and activation are valuable tools in the management of asthma and its severity. Herein, we review the mechanisms involved in eosinophil and ILC2 recruitment to the airways, with an emphasis on eotaxins, other chemokines as well as their receptors. We also discuss the involvement of other chemoattractants, notably the bioactive lipids 5-oxo-eicosatetraenoic acid, prostaglandin D₂, and 2-arachidonoyl-glycerol. Given that eosinophil biology differs between human and mice, we also highlight and discuss their responsiveness toward the different eosinophil chemoattractants.

Identification of Epithelial Phospholipase A2 Receptor 1 as a Potential Target in Asthma

Secreted phospholipase A₂s (sPLA₂s) regulate eicosanoid formation and have been implicated in asthma. Although sPLA₂s function as enzymes, some of the sPLA₂s bind with high affinity to a C-type lectin receptor, called PLA2R1, which has functions in both cellular signaling and clearance of sPLA₂s. We sought to examine the expression of PLA2R1 in the airway epithelium of human subjects with asthma and the function of the murine Pla2r1 gene in a model of asthma. Expression of PLA2R1 in epithelial brushings was assessed in two distinct cohorts of children with asthma by microarray and quantitative PCR, and immunostaining for PLA2R1 was conducted on endobronchial tissue and epithelial brushings from adults with asthma. C57BL/129 mice deficient in Pla2r1 (Pla2r1^-/-) were characterized in an ovalbumin (OVA) model of allergic asthma. PLA2R1 was differentially overexpressed in epithelial brushings of children with atopic asthma in both cohorts. Immunostaining for PLA2R1 in endobronchial tissue localized to submucosal glandular epithelium and columnar epithelial cells. After OVA sensitization and challenge, Pla2r1^-/- mice had increased airway hyperresponsiveness, as well as an increase in cellular trafficking of eosinophils to the peribronchial space and bronchoalveolar lavage fluid, and an increase in airway permeability. In addition, Pla2r1^-/- mice had more dendritic cells in the lung, higher levels of OVA-specific IgG, and increased production of both type-1 and type-2 cytokines by lung leukocytes. PLA2R1 is increased in the airway epithelium in asthma, and serves as a regulator of airway hyperresponsiveness, airway permeability, antigen sensitization, and airway inflammation.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Exacerbation risk in severe asthma is stratified by inflammatory phenotype using longitudinal measures of sputum eosinophils

BACKGROUND

Airway inflammatory phenotyping is increasingly applied to subjects with asthma. However, its relationship to clinical outcomes in difficult asthma is incompletely elucidated.

OBJECTIVE

The goal of our study was to determine the relationship between exacerbation rates and phenotypes of difficult asthma based on the longitudinal measures of sputum eosinophils and neutrophils.

METHODS

Subjects in the longitudinal observational study from two tertiary care centres that completed 1 year of observation and provided at least three sputum samples were classified by inflammatory phenotypes using previously established thresholds. Kaplan-Meier curves and univariable and multivariable Cox proportional hazard models were used to determine the association between inflammatory phenotypes and exacerbation rate.

RESULTS

During the study, 115 exacerbations occurred in 73 severe asthmatic subjects. Subjects with the persistently eosinophilic phenotype had a significantly shorter time to first exacerbation and greater risk of exacerbation over a 1-year period than those with the non-eosinophilic phenotype based on the univariable and multivariable Cox proportional hazard model (hazard ratio [HR], 3.24; 95% confidence interval [CI], 1.35-7.72; adjusted HR, 3.90; 95% CI, 1.34-11.36). No significant differences in time to first exacerbation or exacerbation risk over a 1-year period were observed among the neutrophilic phenotypes.

CONCLUSIONS

The persistent eosinophilic phenotype is associated with increased exacerbation risk compared with the non-eosinophilic phenotype in severe asthma. No differences in time to first exacerbation or exacerbation risk over a 1-year period were detected among neutrophilic phenotypes.

Asthma Control and Airway Inflammation in Patients with Eosinophilic Granulomatosis with Polyangiitis

BACKGROUND

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic necrotizing vasculitis that occurs in patients with asthma, nasal disease, blood and tissue eosinophilia, and extrapulmonary manifestations.

OBJECTIVE

The aim of our study was to assess the clinical, functional, and inflammatory status of upper and lower airways in 37 patients with EGPA, examined 6.4 ± 4.7 years after diagnosis, when they were in partial or complete remission from systemic involvement while on treatment with low-dose oral corticosteroids as maintenance therapy.

METHODS

All patients performed spirometry and were assessed for bronchial hyperreactivity, sputum eosinophilia, and fractional exhaled nitric oxide; asthma control was evaluated according to the Global Initiative for Asthma (GINA) guidelines and the Asthma Control Test. Markers of systemic disease were compared with the data available at diagnosis. Nasal involvement was evaluated by using the Sino-Nasal Outcome Test, nasal endoscopy, and nasal cytology. The impact on the quality of life was evaluated by using generic (36-item short form health survey) and organ-specific questionnaires.

RESULTS

At the time of the study visit, almost all patients were receiving low-dose oral corticosteroids and immunomodulating drugs, but only 50% were being treated with inhaled corticosteroids. Although low systemic disease activity was documented in the large majority of patients, poorly controlled asthma and rhinosinusitis with eosinophilic airway inflammation were demonstrated in almost all patients. A significant correlation was found between sputum and blood eosinophilia and between fractional exhaled nitric oxide and asthma control. The 36-item short form health survey questionnaire results significantly correlated with the Sino-Nasal Outcome Test but not with the Asthma Control Test.

CONCLUSIONS

Systemic treatment controls systemic involvement in EGPA, but not asthma and nasal diseases, which negatively affects patients' quality of life.

Management of the patient with eosinophilic asthma: a new era begins

Now that it is generally accepted that asthma is a heterogeneous condition, phenotyping of asthma patients has become a mandatory part of the diagnostic workup of all patients who do not respond satisfactorily to standard therapy with inhaled corticosteroids. Late-onset eosinophilic asthma is currently one of the most well-defined asthma phenotypes and seems to have a different underlying pathobiology to classical childhood-onset, allergic asthma. Patients with this phenotype can be identified in the clinic by typical symptoms (few allergies and dyspnoea on exertion), typical lung function abnormalities (“fixed” airflow obstruction, reduced forced vital capacity and increased residual volume), typical comorbidities (nasal polyposis) and a good response to systemic corticosteroids. The definitive diagnosis is based on evidence of eosinophilia in bronchial biopsies or induced sputum, which can be estimated with reasonable accuracy by eosinophilia in peripheral blood. Until recently, patients with eosinophilic asthma had a very poor quality of life and many suffered from frequent severe exacerbations or were dependent on oral corticosteroids. Now, for the first time, novel biologicals targeting the eosinophil have become available that have been shown to be able to provide full control of this type of refractory asthma, and to become a safe and efficacious substitute for oral corticosteroids.

Late-onset eosinophilic asthma has a distinct clinical and functional profile with treatment implicationshttp://ow.ly/MH7AH

Fluticasone propionate in clinically suspected asthma patients with negative methacholine challenge test

INTRODUCTION

Despite reports of response to steroid inhaler in some clinically suspected asthma patients with negative methacholine challenge test (CSA/MCT-), treatment in these patients has not been prospectively studied.

OBJECTIVE

We studied the role of a 12 week high dose inhaled fluticasone trial in CSA/MCT- patients.

METHODS

After a 2 week run-in period, CSA/MCT-patients were treated with 12 weeks of Fluticasone propionate 1000 µg/day. The Asthma Control Test (ACT), numeric cough score (NCS) and bronchodilator use were compared with their pretreatment values.

RESULTS

Thirty-four of 42 CSA/MCT-patients completed the study. Mean pretreatment ACT score (pACT) was significantly increased after treatment (14.7 ± 3.37 to 20.9 ± 3.1, P < 0.001). Posttreatment values of daytime (1.0 ± 1.0) and night-time (0.6 ± 0.9) NCS decreased compared to their pretreatment values (2.8 ± 1.1 and 1.9 ± 1.3, respectively; P < 0.001). ACT score change (ΔACT) were significantly greater in those with pACT < 15 than in those ≥15 (P < 0.001) . Fifteen of 21 patients with ΔACT > 5 did not need to use bronchodilator for their symptom relief. Wheeze disappeared in all six patients with ΔACT > 5 after the trial. Six months after the study, steroid inhaler continued to be used by 72.2% of patients.

CONCLUSION

A significant portion of CSA/MCT- (especially those with pretreatment ACT score <15) respond to high dose fluticasone inhaler in terms of symptoms relief, disappearance of wheeze and need to bronchodilator use. ΔACT could not be predicted with any individual symptoms or signs before MCT, % FEV1 decline or symptoms during MCT and exhaled nitric oxide.

Endogenous secreted phospholipase A2 group X regulates cysteinyl leukotrienes synthesis by human eosinophils

BACKGROUND

Phospholipase A2s mediate the rate-limiting step in the formation of eicosanoids such as cysteinyl leukotrienes (CysLTs). Group IVA cytosolic PLA2α (cPLA2α) is thought to be the dominant PLA2 in eosinophils; however, eosinophils also have secreted PLA2 (sPLA2) activity that has not been fully defined.

OBJECTIVES

To examine the expression of sPLA2 group X (sPLA2-X) in eosinophils, the participation of sPLA2-X in the formation of CysLTs, and the mechanism by which sPLA2-X initiates the synthesis of CysLTs in eosinophils.

METHODS

Peripheral blood eosinophils were obtained from volunteers with asthma and/or allergy. A rabbit polyclonal anti-sPLA2-X antibody identified sPLA2-X by Western blot. We used confocal microscopy to colocalize the sPLA2-X to intracellular structures. An inhibitor of sPLA2-X (ROC-0929) that does not inhibit other mammalian sPLA2s, as well as inhibitors of the mitogen-activated kinase cascade (MAPK) and cPLA2α, was used to examine the mechanism of N-formyl-methionyl-leucyl-phenylalanine (fMLP)-mediated formation of CysLT.

RESULTS

Eosinophils express the mammalian sPLA2-X gene (PLA2G10). The sPLA2-X protein is located in the endoplasmic reticulum, golgi, and granules of eosinophils and moves to the granules and lipid bodies during fMLP-mediated activation. Selective sPLA2-X inhibition attenuated the fMLP-mediated release of arachidonic acid and CysLT formation by eosinophils. Inhibitors of p38, extracellular-signal-regulated kinases 1/2 (p44/42 MAPK), c-Jun N-terminal kinase, and cPLA2α also attenuated the fMLP-mediated formation of CysLT. The sPLA2-X inhibitor reduced the phosphorylation of p38 and extracellular-signal-regulated kinases 1/2 (p44/42 MAPK) as well as cPLA2α during cellular activation, indicating that sPLA2-X is involved in activating the MAPK cascade leading to the formation of CysLT via cPLA2α. We further demonstrate that sPLA2-X is activated before secretion from the cell during activation. Short-term priming with IL-13 and TNF/IL-1β increased the expression of PLA2G10 by eosinophils.

CONCLUSIONS

These results demonstrate that sPLA2-X plays a significant role in the formation of CysLTs by human eosinophils. The predominant role of the enzyme is the regulation of MAPK activation that leads to the phosphorylation of cPLA2α. The sPLA2-X protein is regulated by proteolytic cleavage, suggesting that an inflammatory environment may promote the formation of CysLTs through this mechanism. These results have important implications for the treatment of eosinophilic disorders such as asthma.

Effects of prednisone on eosinophilic bronchitis in asthma: a systematic review and meta-analysis

OBJECTIVE:

To evaluate the effect size of oral corticosteroid treatment on eosinophilic bronchitis in asthma, through systematic review and meta-analysis.

METHODS:

We systematically reviewed articles in the Medline, Cochrane Controlled Trials Register, EMBASE, and LILACS databases. We selected studies meeting the following criteria: comparing at least two groups or time points (prednisone vs. control, prednisone vs. another drug, or pre- vs. post-treatment with prednisone); and evaluating parameters before and after prednisone use, including values for sputum eosinophils, sputum eosinophil cationic protein (ECP), and sputum IL-5-with or without values for post-bronchodilator FEV₁-with corresponding 95% CIs or with sufficient data for calculation. The independent variables were the use, dose, and duration of prednisone treatment. The outcomes evaluated were sputum eosinophils, IL-5, and ECP, as well as post-bronchodilator FEV₁.

RESULTS:

The pooled analysis of the pre- vs. post-treatment data revealed a significant mean reduction in sputum eosinophils (↓8.18%; 95% CI: 7.69-8.67; p < 0.001), sputum IL-5 (↓83.64 pg/mL; 95% CI: 52.45-114.83; p < 0.001), and sputum ECP (↓267.60 µg/L; 95% CI: 244.57-290.63; p < 0.0001), as well as a significant mean increase in post-bronchodilator FEV₁ (↑8.09%; 95% CI: 5.35-10.83; p < 0.001).

CONCLUSIONS:

In patients with moderate-to-severe eosinophilic bronchitis, treatment with prednisone caused a significant reduction in sputum eosinophil counts, as well as in the sputum levels of IL-5 and ECP. This reduction in the inflammatory response was accompanied by a significant increase in post-bronchodilator FEV₁.

Regular versus as-needed budesonide and formoterol combination treatment for moderate asthma: a non-inferiority, randomised, double-blind clinical trial

BACKGROUND

Treatment guidelines for patients with moderate persistent asthma recommend regular therapy with a combination of an inhaled corticosteroid and a longacting β2 agonist plus as-needed rapid-acting bronchodilators. We investigated whether symptom-driven budesonide and formoterol combination therapy administered as needed would be as effective as regular treatment with this combination plus as-needed symptom-driven terbutaline for patients with moderate asthma.

METHODS

In this non-inferiority randomised clinical trial, we recruited adult patients (18-65 years of age) with stable moderate persistent asthma, according to 2006 Global Initiative for Asthma guidelines. Patients were recruited from outpatient clinics of secondary and tertiary referral hospitals and university centres. After a 6-week run-in period of inhaled regular budesonide and formoterol plus as-needed terbutaline, the patients were randomly assigned in a 1:1 ratio to receive placebo twice daily plus as-needed treatment with inhaled 160 μg budesonide and 4·5 μg formoterol (as-needed budesonide and formoterol therapy) or twice-daily 160 μg budesonide and 4·5 μg formoterol combination plus symptom-driven 500 μg terbutaline (regular budesonide/formoterol therapy) for 1 year. Randomisation was done according to a list prepared with the use of a random number generator and a balanced-block design stratified by centre. Patients and investigators were masked to treatment assignment. The primary outcome was time to first treatment failure measured after 1 year of treatment using Kaplan-Meier estimates, and the power of the study was calculated based on the rate of treatment failure. Analyses were done on the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT00849095.

FINDINGS

Between April 20, 2009, and March 31, 2012, we screened 1010 patients with moderate asthma and randomly assigned 866 eligible patients to the two treatment groups (424 to as-needed budesonide and formoterol therapy and 442 to regular budenoside and formoterol therapy). Compared with regular budesonide and formoterol therapy, as-needed budesonide and formoterol treatment was associated with a lower probability of patients having no treatment failure at 1 year (Kaplan-Meier estimates 53·6% for as-needed treatment vs 64·0% for regular treatment; difference 10·3% [95% CI 3·2-17·4], at a predefined non-inferiority limit of 9%). Patients in the as-needed budesonide and formoterol group had shorter time to first treatment failure than those in the regular therapy group (11·86 weeks vs 28·00 weeks for the first quartile [ie, the time until the first 25% of patients experienced treatment failure]). The difference in treatment failures was largely attributable to nocturnal awakenings (82 patients in the as-needed treatment group vs 44 in the regular treatment group). Both treatment regimens were well tolerated.

INTERPRETATION

In patients with moderate stable asthma, as-needed budesonide and formoterol therapy is less effective than is the guideline-recommended regular budesonide and formoterol treatment, even though the differences are small.

FUNDING

Italian Medicines Agency.

CCL11 as a potential diagnostic marker for asthma?

OBJECTIVE

Asthma is an inflammatory airway disease characterized by airway eosinophilia, in which CCL11 (eotaxin) plays a crucial role. The aim of study is to determine the elevation of CCL11 levels in bronchoalveolar lavage fluid (BALF), blood, exhaled breath condensate (EBC) and sputum in asthma patients and to identify which medium yields the most significant change in CCL11 level.

METHODS

The databases of PubMed, Embase and Cochrane Centre Register of Controlled Trials were systematically searched from inception to September 2013. Controlled clinical trials that focused on CCL11 concentrations in asthma patients and controls, and their correlations with other asthma indicators were obtained. Data were analysed using Stata 12.0.

RESULTS

Thirty studies were included in this investigation. CCL11 levels in blood, EBC and sputum were significantly higher in asthma patients than in healthy subjects. Sputum CCL11 concentrations were significantly elevated in unstable asthma patients versus stable asthma patients and in uncontrolled asthma patients versus partially controlled asthma patients. CCL11 levels in sputum and blood were negatively correlated with the lung function as measured by FEV1% predicted, and were positively correlated with BALF, EBC and sputum eosinophil counts. Similarly, CCL11 concentrations were positively correlated with eosinophil cationic protein in EBC, blood and sputum as well as with interleukin-5 in sputum and fractional exhaled nitric oxide in EBC. Steroid treatment had no significant effect on CCL11 levels.

CONCLUSIONS

CCL11 is a potentially useful biomarker for the diagnosis and assessment of asthma severity and control, especially in sputum. CCL11 is crucial in eosinophil chemoattraction and activation in asthma pathogenesis. Further studies using anti-CCL11 approaches are needed to confirm a role for CCL11 in asthma pathogenesis particularly in patients with more severe disease.

Recent changes in the drug treatment of allergic asthma

Asthma is a heterogeneous condition with multiple phenotypes that respond to treatments in different ways. Allergic asthma is an important phenotype and although currently available treatments are effective, about 5% of affected patients have severe, treatment-refractory disease. Despite advances in our understanding of the disease, there remains an unmet need in this group of patients. The most recent and significant advance in treatment has been anti--immunoglobulin E (IgE) therapy, which improves symptoms and quality of life in patients with severe allergic asthma. Clinical trials are ongoing with novel biologic agents that demonstrate potential efficacy; determining the subsets of patients for which they are suitable will be crucial to ensure cost effectiveness. Personalised medicine and targeted therapies may hold the key to long-term control in this group of patients.

[Targeted therapies in severe asthma: the discovery of new molecules]

The pathophysiological mechanisms involved in the chronicity and phenotypic heterogeneity of asthma offer the prospect of new therapeutic opportunities. A better clinical and biological characterisation of selected patients has led to the development of targeted therapies. Studies are under way to demonstrate their efficacy and tolerance and also their impact on the natural history of the disease. This revue aims to examine the therapies, developed during the last ten years, that are based on the immunological mechanisms involved in the pathophysiology of asthma, essentially in its severe form. The rapid expansion of human monoclonal antibodies has allowed testing of various immunological pathways. Anti-IgE, anti- IL-5, and anti-IL-13 strategies seem the most promising. Antagonists to TNF-alpha and I'IL-4 have not succeeded in reducing the events related to severe asthma in a convincing manner. Molecules targeted against thymic stromal lymphopoietin (TSLP) and I'IL-9 are under development. These approaches are involved in the development of therapeutic programmes adapted to the patient's phenotype, that is to say a personalised approach to care.

[Interest for evaluation of bronchial inflammation in asthma]

Asthma is a heterogeneous chronic inflammatory disease. The respiratory functional tests are sometimes insufficient to confirm the diagnosis. Other tools are developed to estimate the bronchial inflammation such as tests of bronchial provocation, measure of exhaled nitric oxide, induced sputum and exhaled breath condensate. This review presents these non-invasive methods, approaches their interests on the identification of the disease and the treatment.

Distribution of sputum cellular phenotype in a large asthma cohort: predicting factors for eosinophilic vs neutrophilic inflammation

Background

Phenotyping asthma according to airway inflammation allows identification of responders to targeted therapy. Induced sputum is technically demanding. We aimed to identify predictors of sputum inflammatory phenotypes according to easily available clinical characteristics.

Methods

This retrospective study was conducted in 508 asthmatics with successful sputum induction recruited from the University Asthma Clinic of Liege. Receiver-operating characteristic (ROC) curve and multiple logistic regression analysis were used to assess the relationship between sputum eosinophil or neutrophil count and a set of covariates. Equations predicting sputum eosinophils and neutrophils were then validated in an independent group of asthmatics.

Results

Eosinophilic (≥3%) and neutrophilic (≥76%) airway inflammation were observed in 46% and 18% of patients respectively. Predictors of sputum eosinophilia ≥3% were high blood eosinophils, FE_NO and IgE level and low FEV₁/FVC. The derived equation was validated with a Cohen’s kappa coefficient of 0.59 (p < 0.0001). ROC curves showed a cut-off value of 220/mm³ (AUC = 0.79, p < 0.0001) or 3% (AUC = 0.81, p < 0.0001) for blood eosinophils to identify sputum eosinophilia ≥3%. Independent predictors of sputum neutrophilia were advanced age and high FRC but not blood neutrophil count.

Conclusion

Eosinophilic and paucigranulocytic asthma are the dominant inflammatory phenotypes. Blood eosinophils provide a practical alternative to predict sputum eosinophilia but sputum neutrophil count is poorly related to blood neutrophils.

Targeting interleukins to treat severe asthma

Severe asthma is thought to be a heterogeneous disease with different phenotypes predicated primarily on the nature of the inflammatory cell infiltrate and response to corticosteroid therapy. This group of patients often has refractory disease with an associated increase in morbidity and mortality, and there remains a need for better therapies for severe asthmatics. Inflammatory changes in asthma are driven by immune mechanisms, within which interleukins play an integral role. Interleukins are cell-signaling cytokines that are produced by a variety of cells, predominantly T cells. Knowledge about their actions has improved the understanding of the pathogenesis of asthma and provided potential targets for novel therapies. To date, this has not translated into clinical use. However, there are ongoing clinical trials that use monoclonal antibodies for various interleukins, some of which have shown to be promising in Phase II studies.

Monoclonal antibodies for asthma and chronic obstructive pulmonary disease

INTRODUCTION

In asthma and chronic obstructive pulmonary disease (COPD), the inflammation in the airways cannot always be controlled with conventional therapies, such as inhaled corticosteroids. Addition of more specific anti-inflammatory therapies, such as monoclonal antibodies, against inflammation pathways might improve the disease outcome.

AREAS COVERED

This review individually discusses the major inflammation pathways and their potential blocking monoclonal antibodies in asthma and COPD.

EXPERT OPINION

The current use of omalizumab in asthma provides a good example on the potential therapeutic role of monoclonal antibodies in both asthma and COPD. There are many other monoclonal antibodies which are currently investigated as possible therapies in these diseases. The identification of the disease subsets in which such antibodies might exert the maximum benefit opens the door for personalized medicine and for targeted biological therapy in asthma and COPD.

Asthma biomarkers in sputum

Studies have shown that induced sputum can provide information regarding the cellular and molecular processes involved in asthma and other obstructive pulmonary diseases, and can aid in the diagnosis of asthma and in distinguishing asthma from chronic obstructive pulmonary disease in patients who present with evidence for fixed airflow obstruction. Sputum eosinophils are associated with both asthma severity and level of asthma control. By effectively treating sputum eosinophilia, the number of asthma exacerbations can be significantly reduced compared with managing asthma based on symptoms and lung function.

Airway disease: similarities and differences between asthma, COPD and bronchiectasis

Airway diseases are highly prevalent worldwide; however, the prevalence of these diseases is underestimated. Although these diseases present several common characteristics, they have different clinical outcomes. The differentiation between asthma, chronic obstructive pulmonary disease and bronchiectasis in the early stage of disease is extremely important for the adoption of appropriate therapeutic measures. However, because of the high prevalence of these diseases and the common pathophysiological pathways, some patients with different diseases may present with similar symptoms. The objective of this review is to highlight the similarities and differences between these diseases in terms of the risk factors, pathophysiology, symptoms, diagnosis and treatment.

Immunologic therapeutic interventions in asthma: impact on natural history

The discovery of new pathobiological pathways involved in asthma chronicity and reliefs offers novel therapeutic avenues. Enhanced phenotyping criteria associated with simple biologic characterization allowed to test targeted interventions in selected patients. Long-term studies are de facto lacking but required to address their impact on the natural history of the disease. Here, the authors review all potential available therapeutics based on immunologic pathways involved in asthma pathophysiology during the last decade.

Relationship between levels of secreted phospholipase A₂ groups IIA and X in the airways and asthma severity

Background Secreted phospholipase A(2) (sPLA(2) ) may be important mediators of asthma, but the specific sPLA(2) s involved in asthma are not known. Objective To evaluate sPLA(2) group IIA, V, and X proteins (sPLA(2) -IIA, sPLA(2) -V, and sPLA(2) -X) in bronchoalveolar lavage (BAL) fluid, BAL cells, and airway epithelial cells of subjects with and without asthma, and examine the relationship between the levels of specific sPLA(2) enzymes and airway inflammation, asthma severity, and lung function. Methods The expression of sPLA(2) -IIA, sPLA(2) -V, and sPLA(2) -X in BAL cells and epithelial brushings was assessed by qPCR. The levels of these sPLA(2) proteins and sPLA(2) activity with and without group II and group X-specific inhibitors were measured in BAL fluid from 18 controls and 39 asthmatics. Results The airway epithelium expressed sPLA(2) -X at higher levels than either sPLA(2) -IIA or sPLA(2) -V, whereas BAL cells expressed sPLA(2) -IIA and sPLA(2) -X at similar levels. The majority of sPLA(2) activity in BAL fluid was attributed to either sPLA(2) -IIA or sPLA(2) -X. After 10-fold concentration of BAL fluid, the levels of sPLA(2) -X normalized to total protein were increased in asthma and were associated with lung function, the concentration of induced sputum neutrophils, and prostaglandin E(2) . The levels of sPLA(2) -IIA were elevated in asthma when normalized to total protein, but were not related to lung function, markers of airway inflammation or eicosanoid formation. Conclusions and Clinical Relevance These data indicate that sPLA(2) -IIA and sPLA(2) -X are the major sPLA(2) s in human airways, and suggest a link between the levels of sPLA(2) -X in the airways and several features of asthma.

Eosinophil cysteinyl leukotriene synthesis mediated by exogenous secreted phospholipase A2 group X

Secreted phospholipase A(2) group X (sPLA(2)-X) has recently been identified in the airways of patients with asthma and may participate in cysteinyl leukotriene (CysLT; C(4), D(4), and E(4)) synthesis. We examined CysLT synthesis and arachidonic acid (AA) and lysophospholipid release by eosinophils mediated by recombinant human sPLA(2)-X. We found that recombinant sPLA(2)-X caused marked AA release and a rapid onset of CysLT synthesis in human eosinophils that was blocked by a selective sPLA(2)-X inhibitor. Exogenous sPLA(2)-X released lysophospholipid species that arise from phospholipids enriched in AA in eosinophils, including phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine as well as plasmenyl phosphatidylcholine and phosphatidylethanolamine. CysLT synthesis mediated by sPLA(2)-X but not AA release could be suppressed by inhibition of cPLA(2)α. Exogenous sPLA(2)-X initiated Ser(505) phosphorylation of cPLA(2)α, an intracellular Ca(2+) flux, and translocation of cPLA(2)α and 5-lipoxygenase in eosinophils. Synthesis of CysLTs in response to sPLA(2)-X or lysophosphatidylcholine was inhibited by p38 or JNK inhibitors but not by a MEK 1/2 inhibitor. A further increase in CysLT synthesis was induced by the addition of sPLA(2)-X to eosinophils under conditions of N-formyl-methionyl-leucyl-phenylalanine-mediated cPLA(2)α activation. These results indicate that sPLA(2)-X participates in AA and lysophospholipid release, resulting in CysLT synthesis in eosinophils through a mechanism involving p38 and JNK MAPK, cPLA(2)α, and 5-lipoxygenase activation and resulting in the amplification of CysLT synthesis during cPLA(2)α activation. Transactivation of eosinophils by sPLA(2)-X may be an important mechanism leading to CysLT formation in the airways of patients with asthma.

[Inflammatory response of rapid onset asthma exacerbation]

The association between onset of asthma exacerbation and the inflammatory response has not been sufficiently studied.

OBJECTIVE

To determine the differential mechanisms of the rapid onset (RO) asthma exacerbation.

METHODS

We designed a prospective, multicentre study that included 34 patients who suffered from asthma exacerbation. They were distributed into three groups of asthmatics, depending of the time of onset: from 0 to 24h, from 25 to 144h and more than 145h. We collected clinical data, sputum, blood and urine samples when first seen at the clinic and the next 24h later, and differential cell counts and biomarkers were determined

RESULTS

The asthmatics who suffered a RO exacerbation showed a higher elastase concentration, (1.028±1.140; 310±364; 401±390ng/ml) (P<0.05) and albumin (46.2±4.3; 42±3.4; 39.9±4.8g/l) (P<0.05) in the blood sample. Neutrophils, eosinophils (blood or sputum), eosinophil cationic protein (ECP) (blood), interleukin 8 (IL(8)) (blood) and leukotriene E4 (LTE(4)) (urine) were high in the three groups (P>0.05). We demonstrated an association between the onset of exacerbation and the severity of obstruction (FEV(1)) (r=-0.360; P=0.037), eosinophils in sputum (r=-0.399; P=0.029), albumin (r=-0.442; P=0.013), and IL(8) in sputum (r=0.357; P=0.038).

CONCLUSIONS

The results suggest a rapid inflammatory response, both neutrophilic and eosinophilic, in the asthmatic exacerbation. However, the swelling in the bronchi may play an important role in the initial inflammatory response in the exacerbations depending of time of onset.

Cytokine antagonists for the treatment of asthma: progress to date

Asthma is a disease of the airways in which several cytokines such as interleukin (IL)-4, IL-5, IL-13 and tumor necrosis factor-alpha (TNFalpha) play a major role in the development and progression of inflammation, airway hyperresponsiveness, mucus production, and airway remodeling. The conventional anti-inflammatory therapies, represented by inhaled corticosteroids and antileukotrienes, are not always able to provide optimal disease control and it is therefore hoped that cytokine antagonists could achieve this goal in such situations. Anticytokine therapies have been tested in preclinical studies and some have entered clinical trials. Anti-IL-4 therapies have been tested in animal models of allergy-related asthma, but because of unclear efficacy their development was discontinued. However, IL-4/IL-13 dual antagonists and IL-13-specific blocking agents are more promising, as they exhibit more sustained anti-inflammatory effects. IL-5 antagonists have been found to be of limited efficacy in clinical studies but might be useful in conditions characterized by severe hypereosinophilia, and in which asthma is one of the disease manifestations. Unlike other chronic inflammatory conditions, such as rheumatoid arthritis, the use of anti-TNFalpha therapies in asthma might be limited by the unfavorable risk/benefit ratio associated with long-term use. The identification of so-called asthma TNFalpha phenotypes and perhaps the use of a less aggressive treatment regimen might address this important aspect. Other cytokine antagonists (for example for IL-9 or IL-25) are currently being evaluated in the asthma setting, and could open new therapeutic perspectives based on their efficacy and safety.

Nasal eosinophilia: an indicator of eosinophilic inflammation in asthma

BACKGROUND

It is noteworthy that there is a clear clinical, epidemiological and pathophysiological association between upper and lower airway inflammation in rhinitis and asthma.

OBJECTIVE

The aim of this study was to compare the eosinophil counts in induced sputum and nasal lavage fluids in asthma, checking their association and the accuracy of nasal eosinophilia as a predictor of sputum eosinophilia by a cross-sectional study.

METHODS

The clinical evaluation, asthma control questionnaire (ACQ), pre- and post-bronchodilator spirometry, nasal and sputum sample was performed. The nasal eosinophilia was analysed by a receiver operating curve and logistic regression model.

RESULTS

In 140 adults, the post-bronchodilator forced expiratory volume in 1 s (FEV(1)) did not differ between patients with or without sputum eosinophilia (0.18). After adjusted for upper airway symptoms, age, ACQ score and post-bronchodilator FEV(1), sputum eosinophilia was associated with 52 times increase in odds of nasal eosinophilia, whereas each 1% increase in bronchodilator response was associated with 7% increase in odds of nasal eosinophilia.

CONCLUSION

This study brings further evidence that upper airway diseases are an important component of the asthma syndrome. Furthermore, monitoring of nasal eosinophilia by quantitative cytology may be useful as a surrogate of sputum cytology in as a component of composite measurement for determining airway inflammation.

Association between asthma control and bronchial hyperresponsiveness and airways inflammation: a cross-sectional study in daily practice

BACKGROUND

The primary end-point in the management of asthma is to obtain optimal control. The aim of this study was to assess the relationships between the markers of airway inflammation (sputum eosinophilia and exhaled nitric oxide), bronchial hyperresponsiveness (BHR) and asthma control.

METHODS

One hundred and thirty-four patients were recruited from our asthma clinic between January 2004 and September 2005 [mean age: 42 years, mean forced expiratory volume in 1 s (FEV(1)): 86% predicted]. Eighty-six of them were treated by inhaled corticosteroids, 99 were atopic and 23 were current smokers. They all underwent detailed investigations including fractional-exhaled nitric oxide (FE(NO)) measurement, sputum induction and methacholine challenge when FEV(1) was >70% predicted, and filled in a validated asthma control questionnaire (ACQ6 Juniper).

RESULTS

When dividing patients into the three groups according to their level of asthma control determined by ACQ [well-controlled asthma (ACQ score <or=0.75), borderline (0.75<ACQ score <1.5) and uncontrolled asthma (ACQ score >or=1.5)], it appeared that uncontrolled asthmatics had a greater BHR to methacholine and sputum eosinophilia than controlled asthma (P<0.05, P<0.001, respectively). By contrast, we failed to show significant differences in the FE(NO) levels between the groups. With receiver-operating characteristic curves for differentiating uncontrolled (ACQ>or=1.5) from controlled and borderline (ACQ<1.5) asthma, sputum eosinophilia and methacholine responsiveness were found to be more accurate than FE(NO) (area under the curve: 0.72, 0.72 and 0.59, respectively).

CONCLUSION

In a broad spectrum of asthmatics encountered in clinical practice, sputum eosinophilia and methacholine bronchial hyperresponsiveness, but not FE(NO), are associated with uncontrolled asthma.

Mepolizumab for difficult-to-control asthma with persistent sputum eosinophilia

BACKGROUND

In asthma, anti-inflammatory therapy can usually reduce airway eosinophilic inflammation; but in certain subgroups this persists despite maximal therapy, and disease control is suboptimal. Mepolizumab is an anti IL-5. antibody that might reduce airway inflammation in such subgroups.

METHODS AND RESULTS

Evaluation of the efficacy and safety data on mepolizumab in two studies performed in patients with refractory and corticosteroid-dependent asthma with persistent sputum eosinophilia. Mepolizumab given intravenously once a month was able to reduce sputum/blood eosinophilia and asthma exacerbations and to improve quality of life.

CONCLUSIONS

Mepolizumab may be a promising anti-inflammatory therapy in asthma subgroups with heavy eosinophilic load in which conventional anti-inflammatory therapy is only partially effective.

Rescue treatment in asthma. More than as-needed bronchodilation

International guidelines recommend the use of rapid-onset inhaled beta(2)-agonists alone for symptom relief in all asthmatic patients. However, recent clinical trials have shown that the "as-required," or PRN, use of inhaled combinations of a corticosteroid and a rapid-onset beta(2)-agonist provides clinical advantages over the traditional PRN inhaled rapid-onset beta(2)-agonists alone in patients with different degrees of asthma severity. Asthma symptoms are associated not only with bronchoconstriction but also with increased airway inflammation. Inhaled beta(2)-agonists have a rapid onset of bronchodilator action that is mainly mediated by a relaxing effect on airway smooth muscle. Inhaled corticosteroids also have rapid clinical effects that can suppress lower airway inflammation, and there is a rapid synergistic potentiation of the antiinflammatory effect of corticosteroids and of the bronchodilatory action of beta(2)-agonists when the two drugs are given simultaneously. On the basis of this emerging evidence, we propose that the current rescue use of rapid-onset inhaled beta(2)-agonists alone should now be replaced by an inhaled rapid-acting beta(2)-agonist combined with a corticosteroid as preferred PRN strategy. We conclude with a call for clinical trials aimed to test the superiority of this approach in all degrees of asthma severity in a real-world setting in addition to any of the regular treatments recommended by international guidelines. In the future it might even be possible to control asthma entirely with PRN combination inhalers without maintenance therapy, at least in patients with less severe disease.

Relation between inflammation and symptoms in asthma

Asthma symptoms are the main reason for healthcare utilization and are a fundamental parameter for the evaluation of asthma control. Currently, asthma is defined as a chronic inflammatory disease. A French expert group studied the association between inflammation and asthma symptoms by carrying out a critical review of the international literature. Uncontrolled asthmatics have an increased number of polynuclear eosinophils in the induced sputum and an increased production of exhaled NO. Control by anti-inflammatory treatment is accompanied by a reduction in bronchial eosinophilia and exhaled NO. Asthma symptoms are the result of complex mechanisms and many factors modify their perception. Experimental data suggest that there is a relationship between the perception of symptoms and eosinophilic inflammation and that inhaled corticoid therapy improves this perception. Although they are still not applicable in routine practice, follow-up strategies based on the evaluation of inflammation are thought to be more effective in reducing exacerbations than those usually recommended based on symptoms and sequential analysis of respiratory function. Inhaled corticosteroid therapy is the reference disease-modifying therapy for persistent asthma. Recent studies demonstrated that adjustment of anti-inflammatory treatment based on symptoms is an effective strategy to prevent exacerbations and reduce the total number of doses of inhaled corticosteroids.

[The relationship between inflammation and symptoms in asthma]

In asthma, symptoms are the main reason for recourse to healthcare and are a fundamental parameter for the evaluation of asthma control. Currently, asthma is defined as a chronic inflammatory disease. Uncontrolled asthmatics have an increased number of eosinophils in induced sputum and an increased production of exhaled NO. Control by anti-inflammatory treatment is accompanied by a reduction in bronchial eosinophilia and exhaled NO. Asthma symptoms are the result of complex mechanisms and many factors modify their perception. Experimental data suggests that there is a relationship between the perception of symptoms and eosinophilic inflammation, and that inhaled corticoid therapy improves this perception. Although they are still not applicable in routine practice, follow-up strategies based on the evaluation of inflammation are thought to be more effective in reducing exacerbations than those usually recommended based on retrospective evaluation of symptoms and sequential analysis of respiratory function. Inhaled corticosteroid therapy is the reference maintenance therapy for persistent asthma and adjustment of anti-inflammatory treatment based on symptoms is an effective strategy to prevent exacerbations and reduce the total dose of inhaled corticosteroids. A French expert group has undertaken a study of the association between inflammation and asthma symptoms by carrying out a critical review of the international literature.

Use of omalizumab in a severe asthma clinic

There is an urgent need to define new treatment strategies for severe persistent asthma. Using a severe asthma clinic model, it is possible to systematically assess diagnosis, self-management skills, and treatment efficacy. The addition of single-patient trials of therapy is useful to detect individual responders to drugs where use is limited because of access, cost, or toxicity. Omalizumab is effective in severe asthma, however access is restricted by cost and availability. We conducted single patient efficacy trials of omalizumab in 12 subjects with severe refractory asthma. There were 2 definite and 6 partial responders. Patients with difficult/therapy resistant or refractory asthma can respond to omalizumab, and this response can be detected in individual patients using a single patient controlled trial conducted in the setting of a severe asthma clinic.

Asthma biomarkers in sputum

Several inflammatory cells are thought to contribute to the pathogenesis of asthma. Among these, the eosinophil appears to be a major effector cell. This review focuses primarily on the clinical utility of sputum eosinophil counts in asthma. Several studies have shown sputum eosinophils to be associated with both asthma severity and level of asthma control. In addition, the presence of sputum eosinophilia is strongly predictive of a favorable response to glucocorticoid therapy. Conversely, the absence of sputum eosinophilia is predictive of a poor response to glucocorticoid therapy. Sputum eosinophilia also predicts asthma relapse in subjects who have their inhaled glucocorticoid reduced or withdrawn. Lastly, inhaled glucocorticoid therapy can be titrated to keep the sputum eosinophil count at or below 2%.

Rescue use of beclomethasone and albuterol in a single inhaler for mild asthma

BACKGROUND

Treatment guidelines recommend the regular use of inhaled corticosteroids for patients with mild persistent asthma. We investigated whether the symptom-driven use of a combination of beclomethasone dipropionate and albuterol (also known as salbutamol) in a single inhaler would be as effective as the regular use of inhaled beclomethasone and superior to the as-needed use of inhaled albuterol.

METHODS

We conducted a 6-month, double-blind, double-dummy, randomized, parallel-group trial. After a 4-week run-in, patients with mild asthma were randomly assigned to receive one of four inhaled treatments: placebo twice daily plus 250 microg of beclomethasone and 100 microg of albuterol in a single inhaler as needed (as-needed combination therapy); placebo twice daily plus 100 microg of albuterol as needed (as-needed albuterol therapy); 250 microg of beclomethasone twice daily and 100 microg of albuterol as needed (regular beclomethasone therapy); or 250 microg of beclomethasone and 100 microg of albuterol in a single inhaler twice daily plus 100 microg of albuterol as needed (regular combination therapy). The primary outcome was the morning peak expiratory flow rate.

RESULTS

In 455 patients with mild asthma who had a forced expiratory volume in 1 second of 2.96 liters (88.36% of the predicted value), the morning peak expiratory flow rate during the last 2 weeks of the 6-month treatment was higher (P=0.04) and the number of exacerbations during the 6-month treatment was lower (P=0.002) in the as-needed combination therapy group than in the as-needed albuterol therapy group, but the values in the as-needed combination therapy group were not significantly different from those in the groups receiving regular beclomethasone therapy or regular combination therapy. The cumulative dose of inhaled beclomethasone was lower in the as-needed combination therapy group than in the groups receiving regular beclomethasone therapy or regular combination therapy (P<0.001 for both comparisons).

CONCLUSIONS

In patients with mild asthma, the symptom-driven use of inhaled beclomethasone (250 microg) and albuterol (100 microg) in a single inhaler is as effective as regular use of inhaled beclomethasone (250 microg twice daily) and is associated with a lower 6-month cumulative dose of the inhaled corticosteroid. (ClinicalTrials.gov number, NCT00382889 [ClinicalTrials.gov].).

Decreased T-bet expression and changes in chemokine levels in adults with asthma

T-bet is a novel transcription factor regulating lineage commitment of T helper (Th) lymphocytes to a predominant Th1 phenotype. Previous studies on T-bet and asthma focused mainly on bronchial biopsy specimens. This study assessed the relationship between T-bet expression and levels of selected chemokines in the peripheral blood of asthmatics. Blood was collected from 24 steroid-naive asthmatics, 39 asthmatics on inhaled corticosteroid and 32 age- and sex-matched controls for assay of T-bet expression, specific IgE and chemokines (interferon-gamma inducible protein-10 (IP-10/CXCL10), monokines induced by interferon-gamma (MIG/CXCL9), monocyte chemotactic protein-1 (MCP-1/CCL2), regulated upon activation normal T cell expressed and secreted (RANTES/CCL5) and interleukin-8 (IL-8/CXCL8) levels. T-bet mRNA expression was assessed by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). Chemokine levels were assessed by immunofluorescence flow cytometry. The mean (s.d.) age and forced expiratory volume in 1 s (FEV(1))% predicted of the asthmatics were 43 x 6 (14 x 6) years and 85 x 9 (20.0)%, respectively. The median (IQR) T-bet expression after normalization with beta-actin was suppressed in asthmatics versus controls [asthmatics 0 x 71 (0 x 59) versus controls 1 x 07 (1 x 14), P=0 x 03].The median (IQR) of plasma RANTES was elevated, whereas IP-10 was suppressed in asthmatics versus controls (RANTES: 13658 x 0 (13673 x 3) versus 6299 x 5 (19407 x 8) pg/ml, P=0 x 03; IP-10: 1047 x 6 (589 x 8) versus 1306 x 4 (759 x 9) pg/ml, P=0 x 001). There was a weak and negative correlation between T-bet expression and RANTES level in the asthmatics (r=-0 x 29, P=0 x 032). T-bet could be measured in peripheral blood and its expression was suppressed in asthmatics. This is in keeping with asthma being a predominantly Th2 disease and T-bet probably plays a role in the pathogenesis of asthma. Further studies are needed to explore the potential application of peripheral blood monitoring of T-bet.

An investigation of airway acidification in asthma using induced sputum: a study of feasibility and correlation

RATIONALE

Acidification of the airways seems to be involved in asthma pathophysiology, but its assessment might be difficult.

OBJECTIVES

The aim of our study is to assess the feasibility and validity of airway acidification measurement by induced sputum and its clinical significance in asthma.

METHODS

Induced-sputum samples were obtained in 57 outpatients with asthma. The between-sample repeatability after 48 hours was measured in an independent population of 14 patients with asthma. pH was measured using a pH meter. The control of asthma was established by the Asthma Control Questionnaire.

MEASUREMENTS AND MAIN RESULTS

The pH measurement was feasible in all samples and repeatable both within (intraclass correlation coefficient [ICC], 0.96) and between samples (ICC, 0.621). The mean pH was significantly different between healthy subjects and patients with asthma, including in those with controlled (mean pH: 7.54 in healthy subjects vs. 7.28 in subjects with controlled asthma; p = 0.0105) and uncontrolled disease (mean pH: 7.54 in healthy subjects vs. 7.06 in subjects with uncontrolled disease; p < 0.0001), and between patients with stable asthma and those with poorly controlled asthma (7.28 vs. 7.06, respectively; p = 0.0134). The validity of the method was assessed with the receiver operating characteristic curves and induced-sputum lower pH values (with a cutoff value of 7.3; sensitivity, 72.1%; specificity, 100%).

CONCLUSIONS

Patients with asthma show lower pH than healthy subjects. Patients with poorly controlled asthma seem to have the lowest induced-sputum pH, independent of the GINA (Global Initiative for Asthma) severity level. In conclusion, induced sputum is a feasible, repeatable, noninvasive method to measure airway pH. The pH in induced sputum may reflect a different aspect of asthma from sputum eosinophils and be related to different pathophysiologic factors.

Profiles of proinflammatory cytokines in sputum from different groups of severe asthmatic patients

BACKGROUND

Severe asthma represents a heterogeneous group of patients whose characteristics of airway inflammation are poorly known.

OBJECTIVE

To evaluate the sputum cytokine profiles of different phenotypes of severe asthma.

METHODS

Severe asthmatic patients (n = 45) were divided into 3 groups: frequent exacerbations, persistent bronchoconstriction, and both features. Two other groups (9 patients with untreated mild asthma and 10 control subjects) were also studied. Selected sputum portions were assayed for differential cell count, supernatant interleukin 5 (IL-5), granulocyte-macrophage colony-stimulating factor, IL-8, and eosinophil cationic protein.

RESULTS

There were no statistically significant differences among the 3 severe asthma groups in terms of sputum inflammatory cell percentages, IL-8 levels, and eosinophil cationic protein levels, although IL-8 levels tended to be higher in patients with persistent bronchoconstriction. Sputum concentrations of granulocyte-macrophage colony-stimulating factor and IL-5 were significantly higher in patients with frequent exacerbations compared with the other 2 groups. Levels of IL-5 and IL-8 were higher in severe asthmatic patients compared with mild asthmatic patients and controls, whereas sputum eosinophil percentages were intermediate between those of mild asthmatic patients and controls.

CONCLUSIONS

Proeosinophilic cytokine levels are increased in severe asthmatic patients with frequent exacerbations but not in severe asthmatic patients with persistent bronchoconstriction, suggesting that different cytokine profiles could be associated with different phenotypes of severe asthma.

Severe asthma: an overview

Severe asthma represents less than 10% of all asthma, but these patients are responsible for a disproportionate share of the health care costs and morbidity associated with the disease. A significant challenge in the diagnosis and management of severe asthma is the ability to identify accurately the patients most at risk for adverse outcomes, such as medication side effects, emergency department visits, hospitalization, near-fatal events, or disability from persistent symptoms or chronic lung function abnormalities. To improve the treatment of these patients, we must improve our understanding of the mechanisms responsible for severe disease. To achieve this goal, it is imperative to develop a common definition of severe asthma to allow adequate characterization of the disease clinically and provide the opportunity to compare results from many studies. Several severe asthma phenotypes have been described in the literature on the basis of the age of patients, age of disease onset, corticosteroid resistance, chronic airflow obstruction, and evidence for eosinophilic airway inflammation on biopsy. These phenotypes have led to an emerging interest in the use of noninvasive methods to monitor airway inflammation in severe asthma. Treatment algorithms based on markers of airway inflammation may decrease measures of health care utilization in severe asthma.

[Is the seric eosinophil cationic protein level a valuable tool of diagnosis in clinical practice?]

SCOPE

The eosinophil cationic protein (ECP) is one of the mediators released during eosinophil activation. These cells are effector cells taking part into the Th2-lymphocyte dependent allergic inflammation. Assaying ECP concentrations in blood and sputum may be useful in evaluating allergic inflammation (asthma and rhinitis). This summary considers the value of measuring ECP levels for the diagnosis of various diseases where an eosinophil-mediated tissue inflammation plays a role.

CURRENT SITUATION AND SALIENT POINTS

Levels of eosinophil cationic protein have been determined in nasal secretions, sputum, gastric secretions, feces and serum. They are increased during seasonal allergic rhinitis and perennial rhinitis, allergic asthma and atopic dermatitis. They are also increased in various gastro-intestinal disorders, some of which are associated with IgE: eosinophil intestinal diseases (esophagitis, gastro-enteritis and colitis), gastro-intestinal food allergy and intestinal parasitoses. Finally, they are increased in non IgE-dependent disorders: non allergic asthma with aspirin intolerance, respiratory infections, sinonasal polyposis, Churg-Strauss disease and idiopathic hyper-eosinophilia (HES) syndrome.

PERSPECTIVES

Assaying serum ECP could help in the diagnosis of several diseases. With parasitic disease the pathogenic progression may be accurately assessed, when serological tests are less indicative. ECP assay may point to non allergic asthma, either Fernand-Widal syndrome or Churg-Strauss disease. As for gastro-intestinal disorders, it indicates an eosinophilic tissue reaction. In the event of isolated hypereosinophilia, ECP assay may clarify whether it is benign or tending towards idiopathic HES. The assay of peroxidase and eosinophil-derived neurotoxin (EDN) should be also considered.

Cysteinyl-leukotrienes contribute to sputum eosinophil chemotactic activity in asthmatics

BACKGROUND

Cysteinyl-leukotrienes are lipid derived mediators involved in asthma. They are able to stimulate eosinophil chemotaxis in vitro. Induced sputum from asthmatics has been shown to contain eosinophil chemotactic activity. The purpose of our study was to evaluate the contribution of cysteinyl-leukotrienes to sputum eosinophil chemotactic activity in asthmatics and to seek whether there might be differences between asthmatics free of inhaled corticosteroids vs those regularly receiving this treatment.

METHODS

Twenty-two patients (11 corticosteroid free, mean FEV1 99% predicted, 11 corticosteroid-treated, mean FEV1 77% predicted) recruited from our asthma clinic underwent a sputum induction. Sputum was processed according to standard procedure. Eosinophil chemotactic activity contained in the fluid phase was assessed using Boyden microchamber model and expressed as chemotaxis index (CI). Cysteinyl-leukotrienes were measured in sputum supernatant by ELISA and their role in sputum eosionophil chemotactic activity was evaluated by using montelukast, a selective antagonist of a cys-LT1 receptor.

RESULTS

Cysteinyl-leukotrienes were well detectable in sputum supernatants from both steroid-naive (247 +/- 42 pg/ml) and steroid-treated (228 +/- 26 pg/ml) asthmatics. Sputum eosinophil chemotactic activity was indiscriminately present in both corticosteroid-naive (CI: 2.61 +/- 0.22) and corticosteroid-treated (2.98 +/- 0.35) asthmatics. Montelukast (100 microM) significantly inhibited the eosinophil chemotactic activity in both groups achieving a mean inhibition of 54.2 +/- 9.2% (P < 0.001) and 64.7 +/- 7.8% (P < 0.001) in steroid-naive and steroid-treated asthmatics respectively.

CONCLUSION

Cysteinyl-leukotrienes actively participate in sputum eosinophil chemotactic activity found in asthmatics irrespective of whether they are or not under treatment with inhaled corticoids.

Inhaled fluticasone propionate is effective as well as oral prednisone in reducing sputum eosinophilia during exacerbations of asthma which do not require hospitalization

The aim of this study was to evaluate whether fluticasone propionate (FP) is effective as well as prednisone (P) in reducing sputum eosinophilia and in improving airway obstruction due to asthma exacerbations not requiring hospitalization. We measured, in a parallel-group, double-blind double-dummy, randomized study, sputum and blood inflammatory cell counts and soluble mediators in 37 asthmatic subjects during a spontaneous exacerbation of asthma (Visit 1) and after a 2 week (Visit 2) treatment with inhaled FP (1000microg bid) (Group A, n=18) or a reducing course of oral P (Group B, n=19). Asthma exacerbation was accompanied by sputum eosinophilia (eosinophils >2%) in almost all patients (95%). FP improved FEV(1) (from 53.9%+/-16.8 at Visit 1 to 76.4%+/-21.2 at Visit 2, p=0.0001) and reduced the percentage of sputum eosinophils (from 38%[0-78] to 3%[1-31, p=0.0008) as well as oral P (FEV(1): from 51.5%+/-14.4 to 83.6%+/-21.1, p=0.0001; sputum eosinophils: from 52%[1-96] to 11%[0-64], p=0.0003). At Visit 2, sputum eosinophils were significantly lower in Group A than in Group B. P but not FP induced significant decrease in blood and sputum ECP. Oxygen saturation, PEF variability, symptom score and use of rescue medication similarly improved in both groups. We conclude that FP is effective at least as well as P in reducing sputum eosinophilia and in improving airway obstruction due to asthma exacerbation. However, the cost/effectiveness ratio of this option should be further evaluated.