"Refractory" eosinophilic airway inflammation in severe asthma: effect of parenteral corticosteroids

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

Managing severe asthma in adults: lessons from the ERS/ATS guidelines

PURPOSE OF REVIEW

To review the latest guidelines on severe asthma.

RECENT FINDINGS

An updated definition of severe asthma is provided together with the evaluation steps necessary to reach a diagnosis of severe asthma. The importance of phenotyping is emphasized, and recommendations are provided for therapies specifically directed for severe asthma.

SUMMARY

Severe asthma is widely recognized as a major unmet need. It is defined as asthma that requires treatment with high-dose inhaled corticosteroids and a second controller and/or systemic corticosteroid to prevent it from becoming 'uncontrolled' or that remains 'uncontrolled' despite this therapy. Severe asthma is a heterogeneous condition that consists of phenotypes such as eosinophilic asthma. More phenotypes need to be defined. Evaluation of the patient referred to as having severe or difficult-to-control asthma must take into account adherence to treatment, comorbidities and associated factors including side effects from therapies. These need to be addressed. Recommendations on the use of sputum eosinophil count and exhaled nitric oxide to guide therapy are presented. Treatment with anti-IgE antibody, methotrexate, macrolide antibiotics, antifungal agents and bronchial thermoplasty is reviewed and recommendations made. Research efforts into phenotyping of severe asthma will provide both biomarker-driven approaches and newer effective therapies to severe asthma management.

Diagnosis of asthma - new theories

INTRODUCTION

Recent studies have shown a remarkably high frequency of poorly controlled asthma. Several reasons for this treatment failure have been discussed, however, the basic question of whether the diagnosis is always correct has not been considered. Follow-up studies have shown that in many patients asthma cannot be verified despite ongoing symptoms. Mechanisms other than bronchial obstruction may therefore be responsible. The current definition of asthma may also include symptoms that are related to mechanisms other than bronchial obstruction, the clinical hallmark of asthma.

AIM

Based on a review of the four cornerstones of asthma - inflammation, hyperresponsiveness, bronchial obstruction and symptoms - the aim was to present some new aspects and suggestions related to the diagnosis of adult non-allergic asthma.

CONCLUSION

Recent studies have indicated that "classic" asthma may sometimes be confused with asthma-like disorders such as airway sensory hyperreactivity, small airways disease, dysfunctional breathing, non-obstructive dyspnea, hyperventilation and vocal cord dysfunction. This confusion may be one explanation for the high proportion of misdiagnosis and treatment failure. The current diagnosis, focusing on bronchial obstruction, may be too "narrow". As there may be common mechanisms a broadening to include also non-obstructive disorders, forming an asthma syndrome, is suggested. Such broadening requires additional diagnostic steps, such as qualitative studies with analysis of reported symptoms, non-effort demanding methods for determining lung function, capsaicin test for revealing airway sensory hyperreactivity, careful evaluation of the therapeutic as well as diagnostic effect of corticosteroids and testing of suggested theories.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION NUMBER

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

Cysteine oxidation impairs systemic glucocorticoid responsiveness in children with difficult-to-treat asthma

BACKGROUND

The mechanisms underlying glucocorticoid responsiveness are largely unknown. Although redox regulation of the glucocorticoid receptor (GR) has been reported, it has not been studied in asthmatic patients.

OBJECTIVE

We characterized systemic cysteine oxidation and its association with inflammatory and clinical features in healthy children and children with difficult-to-treat asthma. We hypothesized that cysteine oxidation would be associated with increased markers of oxidative stress and inflammation, increased features of asthma severity, decreased clinically defined glucocorticoid responsiveness, and impaired GR function.

METHODS

PBMCs were collected from healthy children (n = 16) and children with asthma (n = 118) aged 6 to 17 years. Children with difficult-to-treat asthma underwent glucocorticoid responsiveness testing with intramuscular triamcinolone. Cysteine, cystine, and inflammatory chemokines and reactive oxygen species generation were quantified, and expression and activity of the GR were assessed.

RESULTS

Cysteine oxidation was present in children with difficult-to-treat asthma and accompanied by increased reactive oxygen species generation and increased CCL3 and CXCL1 mRNA expression. Children with the greatest extent of cysteine oxidation had more features of asthma severity, including poorer symptom control, greater medication use, and less glucocorticoid responsiveness despite inhaled glucocorticoid therapy. Cysteine oxidation also modified the GR protein by decreasing available sulfhydryl groups and decreasing nuclear GR expression and activity.

CONCLUSIONS

A highly oxidized cysteine redox state promotes a posttranslational modification of the GR that might inhibit its function. Given that cysteine oxidation is prevalent in children with difficult-to-treat asthma, the cysteine redox state might represent a potential therapeutic target for restoration of glucocorticoid responsiveness in this population.

Developing and emerging clinical asthma phenotypes

For more than a century, clinicians have attempted to subdivide asthma into different phenotypes based on triggers that cause asthma attacks, the course of the disease, or the prognosis. The first phenotypes that were described included allergic asthma, intrinsic or nonallergic asthma, infectious asthma, and aspirin-exacerbated asthma. These phenotypes are being reviewed elsewhere in this issue of the journal. The present article focuses on developing and emerging clinical asthma phenotypes. First, asthma phenotypes that are associated with environmental exposures (occupational agents, cigarette smoke, air pollution, cold dry air); second, asthma phenotypes that are associated with specific symptoms or clinical characteristics (cough, obesity, adult onset of disease); and third, asthma phenotypes that are based on biomarkers. This latter approach is the most promising because it attempts to identify asthma phenotypes with different underlying mechanisms so that therapies can be better targeted toward disease-specific features and disease outcomes can be improved.

Primary lysis of eosinophils in severe desquamative asthma

Primary lysis of eosinophils liberates free eosinophil granules (FEGs) releasing toxic proteins in association with bronchial epithelial injury repair. Eosinophil lysis may be significantly pathogenic. Bronchial mucosal FEGs are associated with uncontrolled asthma, severe asthma, aspirin-sensitive asthma, and lethal asthma. FEGs in the bronchial wall may characterize severe asthma without sputum eosinophilia. Excessive numbers of sputum FEGs occur in severe exacerbations of asthma and are reduced along with clinical improvement. Occurrence of FEGs affects interpretation of other sputum biomarkers including numbers of eosinophils, ECP, and eosinophil-stained macrophages. Thus, eosinophil lysis produces FEGs as bronchial biomarkers of severe asthma. Blood eosinophils in severe asthma seem primed exhibiting a propensity to lyse that is greater the more severe the asthma. Proclivity of blood eosinophils to lyse also distinguished three levels of severity among children with exacerbations of asthma. Numerous FEGs releasing toxic proteins occur in association with grave derangement and shedding of epithelium in severe asthma. Subepithelial FEGs correlate negatively with intact bronchial epithelium in clinically uncontrolled asthma. Significant correlations between sputum ECP, Creola bodies, and severity of asthma exacerbations have also been demonstrated. Hence, eosinophil lysis apparently causes epithelial desquamation in severe asthma. Exaggerated epithelial repair in turn would contribute to inflammatory and remodelling features of severe asthma. Perseverance of FEGs together with maintained disease activity, despite treatment with 'eosinophil-depleting' steroids and anti-IL5 biologicals, agrees with the possibility that eosinophil lysis is worthy target for novel anti-asthma drugs. Priming and lysis of eosinophils, and protein release from FEGs, are regulated and can be targeted. Eosinophil lysis and FEGs belong to the disease picture of severe asthma and need consideration in asthma studies concerned with phenotypes, biomarkers, roles of epithelial injury/repair, and targeting novel drugs.

Frequent exacerbators--a distinct phenotype of severe asthma

BACKGROUND

Exacerbations represent a major source of morbidity and mortality in asthma and are a prominent feature of poorly controlled, difficult-to-treat disease.

OBJECTIVE

The goal of our study was to provide a detailed characterization of the frequent exacerbator phenotype and to identify risk factors associated with frequent and seasonal exacerbations.

METHODS

Ninety-three severe asthmatics (SA) and 76 mild-to-moderate patients (MA) were screened and prospectively followed up for 1 year (NCT00555607). Medical history, baseline clinical data and biomarkers were used to assess risk factors for frequent exacerbations.

RESULTS

During the study, 104 exacerbations were recorded in the SA group and 18 in the MA. Frequent exacerbators were characterized by use of higher doses of inhaled (1700 vs. 800 μg) and oral (6.7 vs. 1.7 mg) glucocorticosteroids, worse asthma control (ACQ score 2.3 vs. 1.4), lower quality of life (SGRQ score 48.5 vs. 33.3), higher sputum eosinophils (25.7% vs. 8.2%) and a more rapid decline in FEV1 /FVC ratio (-0.07 vs. -0.01 ΔFEV1 /FVC, frequent vs. non-frequent, respectively, P < 0.05). Exhaled NO > 45 p.p.b. and a history of smoking were associated with an increased risk of frequent exacerbations (odds ratios: 4.32 and 2.90 respectively).

CONCLUSION AND CLINICAL RELEVANCE

We were able to distinguish and characterize a subphenotype of asthma subjects--frequent exacerbators--who are significantly more prone to exacerbations. Patients with FeNO > 45 p.p.b. and a history of smoking are at increased risk of frequent exacerbations and require careful monitoring in clinical practice.

The NLRP3 inflammasome: role in airway inflammation

Asthma is characterized by airway inflammation, airway hyperresponsiveness and airway remodelling. Uncontrolled airway inflammation or repeated asthma exacerbations can lead to airway remodelling, which cannot be reversed by current pharmacological treatment, and consequently lead to decline in lung function. Thus, it is critical to understand airway inflammation in asthma and infectious exacerbation. The inflammasome has emerged as playing a key role in innate immunity and inflammation. Upon ligand sensing, inflammasome components assemble and self-oligomerize, leading to caspase-1 activation and maturation of pro-IL-1β and pro-IL-18 into bioactive cytokines. These bioactive cytokines then play a pivotal role in the initiation and amplification of inflammatory processes. In addition to facilitating the proteolytic activation of IL-1β and IL-18, inflammasomes also participate in cell death through caspase-1-mediated pyroptosis. In this review, we describe the structure and function of the inflammasome and provide an overview of our current understanding of role of the inflammasome in airway inflammation. We focus on nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3) inflammasome as it is the best-characterized subtype shown expressed in airway and considered to play a key role in chronic airway diseases such as asthma.

Sputum neutrophil counts are associated with more severe asthma phenotypes using cluster analysis

BACKGROUND

Clinical cluster analysis from the Severe Asthma Research Program (SARP) identified 5 asthma subphenotypes that represent the severity spectrum of early-onset allergic asthma, late-onset severe asthma, and severe asthma with chronic obstructive pulmonary disease characteristics. Analysis of induced sputum from a subset of SARP subjects showed 4 sputum inflammatory cellular patterns. Subjects with concurrent increases in eosinophil (≥2%) and neutrophil (≥40%) percentages had characteristics of very severe asthma.

OBJECTIVE

To better understand interactions between inflammation and clinical subphenotypes, we integrated inflammatory cellular measures and clinical variables in a new cluster analysis.

METHODS

Participants in SARP who underwent sputum induction at 3 clinical sites were included in this analysis (n = 423). Fifteen variables, including clinical characteristics and blood and sputum inflammatory cell assessments, were selected using factor analysis for unsupervised cluster analysis.

RESULTS

Four phenotypic clusters were identified. Cluster A (n = 132) and B (n = 127) subjects had mild-to-moderate early-onset allergic asthma with paucigranulocytic or eosinophilic sputum inflammatory cell patterns. In contrast, these inflammatory patterns were present in only 7% of cluster C (n = 117) and D (n = 47) subjects who had moderate-to-severe asthma with frequent health care use despite treatment with high doses of inhaled or oral corticosteroids and, in cluster D, reduced lung function. The majority of these subjects (>83%) had sputum neutrophilia either alone or with concurrent sputum eosinophilia. Baseline lung function and sputum neutrophil percentages were the most important variables determining cluster assignment.

CONCLUSION

This multivariate approach identified 4 asthma subphenotypes representing the severity spectrum from mild-to-moderate allergic asthma with minimal or eosinophil-predominant sputum inflammation to moderate-to-severe asthma with neutrophil-predominant or mixed granulocytic inflammation.

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.

Diagnosis and management of eosinophilic asthma: a US perspective

Eosinophilic asthma is now recognized as an important subphenotype of asthma based on the pattern of inflammatory cellular infiltrate in the airway. Eosinophilic asthma can be associated with increased asthma severity, atopy, late-onset disease, and steroid refractoriness. Induced sputum cell count is the gold standard for identifying eosinophilic inflammation in asthma although several noninvasive biomarkers, including fractional exhaled nitric oxide and periostin, are emerging as potential surrogates. As novel therapies and biologic agents become increasingly available, there is an increased need for specific phenotype-directed treatment strategies. Greater recognition and understanding of the unique immunopathology of this asthma phenotype has important implications for management of the disease and the potential to improve patient outcomes. The present review provides a summary of the clinical features, pathogenesis, diagnosis, and management of eosinophilic asthma.

The nucleotide-binding domain and leucine-rich repeat protein-3 inflammasome is not activated in airway smooth muscle upon toll-like receptor-2 ligation

Inflammasomes have emerged as playing key roles in inflammation and innate immunity. A growing body of evidence has suggested that the nucleotide-binding domain and leucine-rich repeat protein-3 (NLRP3) inflammasome is important in chronic airway diseases such as asthma and chronic obstructive pulmonary disease. Inflammasome activation results, in part, in pro-IL-1β processing and the secretion of the proinflammatory cytokine IL-1β. Because asthma exacerbations are associated with elevated concentrations of secreted IL-1β, we addressed whether the NLRP3 inflammasome is activated under in vitro conditions that mimic infectious exacerbations in asthma. Primary cultures of airway smooth muscle (ASM) cells were treated with infectious stimuli (mimicked using the Toll-like receptor-2 agonist Pam3CSK4, a synthetic bacterial lipopeptide). Whereas Pam3CSK4 robustly up-regulated ASM cytokine expression in response to TNF-α and significantly enhanced IL-1β mRNA expression, we were unable to detect IL-1β in the cell supernatants. Thus, IL-1β was not secreted and therefore was unable to act in an autocrine manner to promote the amplification of ASM inflammatory responses. Moreover, Toll-like receptor-2 ligation did not enhance NLRP3 or caspase-1 expression in ASM cells, and NLRP3 and caspase-1 protein were not present in the ASM layer of tracheal sections from human donors. In conclusion, these data demonstrate that the enhanced synthetic function of ASM cells, induced by infectious exacerbations of airway inflammation, is NLRP3 inflammasome-independent and IL-1β-independent. Activation of the NLRP3 inflammasome by invading pathogens may prove cell type-specific in exacerbations of airway inflammation in asthma.

Asthma exacerbations: predisposing factors and prediction rules

PURPOSE OF REVIEW

Asthma is a multifaceted disease that is associated with decreased lung function, multiple symptoms, varying levels of asthma control, and risk of acute exacerbations. The ability to predict the risk of developing acute exacerbations may improve the management of asthmatics and facilitate identification of these patients for interventional studies.

RECENT FINDINGS

Factors that are associated with different manifestations of asthma differ. Biomarkers that are correlated with airways hyper-responsiveness do not necessarily correlate with risk of future exacerbations. Genetic factors that segregate with exacerbation risk are beginning to emerge. Outcome measures that demonstrate predictive validity have been developed and may facilitate patient management and provide novel clinically meaningful endpoints in clinical trials.

SUMMARY

This review will emphasize underlying factors associated with asthma exacerbations and clinical prediction rules that correlate with the risk of developing severe exacerbations of asthma.

Use of antioxidants to prevent cyclosporine a toxicity

Cyclosporine A (CsA) is a potent immunosuppressor that is widely used in transplant surgery and the treatment of several autoimmune diseases. However, major side effects of CsA such as nephrotoxicity, hepatotoxicity, neurotoxicity and cardiovascular diseases have substantially limited its usage. Although molecular mechanisms underlying these adverse effects are not clearly understood, there is some evidence that suggests involvement of reactive oxygen species (ROS) . In parallel, protective effects of various antioxidants have been demonstrated by many research groups. Extensive studies of CsA-induced nephrotoxcity have confirmed that the antioxidants can restore the damaged function and structure of kidney. Subsequently, there have appeared numerous reports to demonstrate the positive antioxidant effects on liver and other organ damages by CsA. It may be timely to review the ideas to envisage the relationship between ROS and the CsA-induced toxicity. This review is comprised of a brief description of the immunosuppressive action and the secondary effects of CsA, and a synopsis of reports regarding the antioxidant treatments against the ROS-linked CsA toxicity. A plethora of recent reports suggest that antioxidants can help reduce many CsA’s adverse effects and therefore might help develop more effective CsA treatment regimens.

Reaching beyond disparity: safely improving asthma control in the at-risk African-American population

In the United States, substantial racial disparities exist in asthma prevalence, etiology, morbidity and mortality, particularly between African Americans and white Americans. African-American patients with asthma have inadequate access to appropriate healthcare, insufficient asthma management guidance from their physicians and poor adherence to asthma medications-all factors that may contribute to disproportionate morbidity. Historically, African Americans have been under-represented in clinical asthma studies, and a paucity of data exists surrounding asthma treatment response. One controversial study from 2006 suggests an increased safety risk with the use of long-acting beta2-adrenergic agonists (LABAs) in African Americans. More recently, several studies have evaluated the use of LABAs in combination with an ICS in African-American populations. This article reviews the existing data on asthma treatment outcomes, with particular emphasis on the recently published short- and long-term studies of ICS/LABA products conducted in African-American populations with moderate-to-severe asthma. Overall, evidence suggests that if African-American patients with asthma are provided with access to well-trained physicians, appropriate asthma management and effective medications, existing disparities in asthma control between African-American and white populations may be overcome.

Three phenotypes of adult-onset asthma

RATIONALE

Adult-onset asthma differs from childhood-onset asthma in many respects. It is more heterogeneous, often severe and frequently associated with loss of lung function. To identify underlying mechanisms of adult-onset asthma and to capture predictors of disease progression, detailed characterization and phenotyping is necessary.

OBJECTIVES

To characterize adult-onset asthma and identify subphenotypes of adult-onset asthma.

METHODS

A cohort of 200 patients with adult-onset (>18 year) asthma (age 54 (26-75) year) was recruited from one academic and three nonacademic pulmonary outpatient clinics in Amsterdam, the Netherlands. These patients were fully characterized with respect to clinical, functional and inflammatory markers. After data reduction, K-means nonhierarchical cluster analysis was performed to identify clusters of adult-onset asthma.

MEASUREMENTS AND MAIN RESULTS

Patients with adult-onset asthma were predominately female (61%) and nonatopic (55%). Within this group of patients were identified three clusters of adult-onset asthma. Cluster 1 (n = 69) consisted of patients with severe eosinophilic inflammation-predominant asthma and persistent airflow limitation despite high-intensity anti-inflammatory treatment, with relatively low symptom scores. The second cluster was characterized by obese women with frequent symptoms, high healthcare utilization and low sputum eosinophils. The third cluster consisted of patients with mild-to-moderate, well-controlled asthma with normal lung function and low inflammatory markers. Repeatability accuracy was 98.2%.

CONCLUSIONS

Amongst patients with adult-onset asthma, three subphenotypes can be identified with distinct clinical and inflammatory characteristics. These subphenotypes help to understand the underlying pathobiology and provide clinicians with directions for personalized management.

Alveolar nitric oxide concentration reflects peripheral airway obstruction in stable asthma

BACKGROUND AND OBJECTIVE

Increased fraction of exhaled nitric oxide (FeNO) has been shown to reflect airway inflammation in asthma. Central airway NO flux (J'awNO; nL/s) and peripheral airway/alveolar NO concentration (CANO; ppb) can be calculated separately. CANO has been reported to reflect small airway inflammation. The aim of the present study is to correlate CANO levels with clinical and physiological parameters in patients with stable asthma.

METHODS

Seventy-three well-controlled asthmatics (mean age 61) were enrolled. Measurement of FeNO (at 50, 100, 150 and 200 mL/s) and pulmonary function test were performed. J'awNO(TMAD) and CANO(TMAD) were calculated and corrected by the trumpet shape of the airway tree and axial back-diffusion (TMAD).

RESULTS

CANO(TMAD) was significantly correlated with forced expiratory flow between 25-75% of the forced vital capacity (FVC) (FEF(25 -75)), FEF(25 -75) percentage of the predicted value (%pred), forced expiratory flow at 50% of the FVC (FEF(50)) and FEF(50) %pred (R = -0.39 P = 0.002, R = -0.29 P = 0.02, R = -0.39 P = 0.001, R = -0.29 P = 0.02, respectively). CANO(TMAD) was positively correlated with age (R = -0.45 P = 0.0002) and weakly correlated with duration of asthma (R = -0.27 P = 0.03). Forced expiratory volume in 1 s/FVC was negatively correlated with CANO(TMAD), J'awNO(TMAD) and FeNO 50 mL/s. Among these, correlation between forced expiratory volume in 1 s/FVC and FeNO 50 mL/s was the strongest (R = -0.34 P = 0.004).

CONCLUSIONS

CANO(TMAD) may be a more specific marker of peripheral airway obstruction than FeNO and J'awNO(TMAD) in stable asthma.

Predictors for identifying the efficacy of systemic steroids on sustained exhaled nitric oxide elevation in severe asthma

BACKGROUND

Some patients with asthma have high levels of exhaled nitric oxide fraction (FENO) despite inhaled corticosteroids (ICS) therapy. Early studies suggested that this might be explained by the presence of heterogeneous airway inflammation. We aimed to assess the predictors for identifying the efficacy of systemic corticosteroids on residual FENO elevations in severe asthma.

METHODS

Twenty severe asthmatics with persistent FENO elevation (≥40ppb) despite maintenance therapy including high-daily-dose ICS were enrolled. Asthma Control Questionnaire (ACQ), lung function, blood eosinophils, and FENO were assessed before and after 14 days treatment with 0.5mg/kg oral prednisolone/day.

RESULTS

ACQ, blood eosinophils, FENO level, FVC, FEV1, FEV1/FVC ratio and the slope of the single nitrogen washout curve (ΔN2) were significantly improved by treatment with prednisolone. 70% of the subjects showed ≥20% reductions in the FENO levels. The reduction in FENO levels was significantly correlated with the improvements in ACQ (p < 0.0001), FVC (p < 0.01), FEV1 (p < 0.0001), and ΔN2 (p < 0.05). Among the measurements at baseline, the FENO levels and blood eosinophil numbers were identified as significant predictors of ≥20% reductions in the FENO levels by systemic steroid therapy.

CONCLUSIONS

Systemic corticosteroids could suppress the residual FENO elevations in more than half of the patients with severe asthma and the reduction in FENO levels was associated with improvements in asthma control and airflow limitation. The FENO levels and blood eosinophil numbers were the predictors of improved residual airway inflammation by systemic steroid therapy in severe asthma.

Phenotypic predictors of response to oral glucocorticosteroids in severe asthma

BACKGROUND

Systemic glucocorticosteroids are side-effect prone but often necessary for the treatment of severe asthma (SA). Our goal was to assess the usefulness of medical history, physiological variables and biomarkers as predictors of response to oral steroids.

METHODS

After 4 weeks of treatment optimization, 84 patients with SA and 62 with mild-to-moderate asthma (MA) underwent a 2 week double-blind placebo-controlled oral prednisolone intervention (0.5 mg/kg BW daily) (NCT00555607).

RESULTS

Responders had a lower FEV1% (73.7 vs. 88.0), lower FEV1/FVC ratio (0.65 vs. 0.73), lower quality of life (SGRQ score 39.1 vs. 31.4), lower total sputum cell number (1.0 vs. 4.5×10(6)) and higher number of sputum eosinophils (16.8% vs. 6.3%) (p<0.05). For all asthmatics, the degree of improvement in FEV1 correlated with sputum eosinophils, level of asthma control, FeNO, quality of life, age of asthma onset and blood eosinophils. In SA, sputum eosinophils≥3% (OR 9.91), FEV1≤60% (OR 3.7), and SGRQ>42.2 (OR 3.25) were associated with a good response to oral prednisolone. The highest sensitivity and specificity to predict more than 12% increase in FEV1 in SA after oral prednisolone was found for sputum eosinophils≥3% and FeNO>45 ppb.

CONCLUSIONS

Sputum eosinophils and FeNO were the best predictors of favorable response to oral prednisolone in severe asthmatics. A guided approach to glucocorticosteroid treatment should be recommended as it favors better control of the disease and presumably a lower rate of adverse events. The study has been registered at the site: clinicaltrials.gov with number: NCT00555607.

Inhaled and systemic corticosteroid response in severe asthma assessed by alveolar nitric oxide: a randomized crossover pilot study of add-on therapy

AIMS

Alveolar nitric oxide (CA(NO)) is a potential biomarker of small airway inflammation. We investigated effects on CA(NO) of the addition of coarse and fine particle inhaled corticosteroids to standard therapy in severe asthma.

METHODS

Severe asthmatics taking ≥1600 µg day(-1) budesonide or equivalent performed a randomized open-label crossover study. Subjects with FEV(1) < 80%, gas trapping and CA(NO) ≥2 ppb entered a 6 week dose-ramp run-in of fluticasone/salmeterol(FPSM) 250/50 µg twice daily for 3 weeks, then 500/50 µg twice daily for 3 weeks. Patients then received additional HFA-beclomethasone diproprionate (BDP) 200 µg twice daily or FP 250 µg twice daily for 3 weeks in a crossover. Participants then received prednisolone(PRED) 25 mg day(-1) for 1 week. Nitric oxide, lung function, mannitol challenge, systemic inflammatory markers and urinary cortisol were measured.

RESULTS

Fifteen completed per protocol: mean (SD) age 51 (12) years, FEV(1) 58 (13)% predicted, residual volume 193 (100)% predicted and mannitol(PD10) 177 (2.8) µg. There was no significant difference between FPSM and add-on therapy for CA(NO). FPSM/BDP and FPSM/PRED suppressed broncial flux (Jaw(NO)) and FE(NO) compared with FPSM alone, but there was no significant difference between FPSM/BDP and FPSM/FP. ECP, e-selectin and ICAM-1 were suppressed by FPSM/PRED compared with FPSM and FPSM/FP but not FPSM/BDP. Plasma cortisol was significantly suppressed by FPSM/PRED.

CONCLUSION

In severe asthma, CA(NO) is insensitive to changes in dose and delivery of inhaled corticosteroids and is not suppressed by systemic corticosteroids. Additional inhaled HFA-BDP reduced FE(NO) and Jaw(NO) without adrenal suppression. There was a trend to reduction in FE(NO) and Jaw(NO) with additional FP but this did not reach statistical significance. PRED reduced FE(NO) and Jaw(NO) with suppression of systemic inflammatory markers and urinary cortisol.

The nitrated fatty acid 10-nitro-oleate attenuates allergic airway disease

Asthma is a serious, growing problem worldwide. Inhaled steroids, the current standard therapy, are not always effective in this chronic inflammatory disease and can cause adverse effects. We tested the hypothesis that nitrated fatty acids (NFAs) may provide an effective alternative treatment. NFAs are endogenously produced by nonenzymatic reaction of NO with unsaturated fatty acids and exert anti-inflammatory actions both by activating the nuclear hormone receptor peroxisome proliferator-activated receptor (PPAR)γ and via PPAR-independent mechanisms, but whether they might ameliorate allergic airway disease was previously untested. We found that pulmonary delivery of the NFA 10-nitro-oleic acid (OA-NO2) reduced the severity of murine allergic airway disease, as assessed by various pathological and molecular markers. Fluticasone, an inhaled steroid commonly used to treat asthma, produced similar effects on most end points, but only OA-NO2 induced robust apoptosis of neutrophils and their phagocytosis by alveolar macrophages. This suggests that OA-NO2 may be particularly effective in neutrophil-rich, steroid-resistant severe asthma. In primary human bronchial epithelial cells, OA-NO2 blocked phosphorylation and degradation of IκB and enhanced inhibitory binding of PPARγ to NF-κB. Our results indicate that the NFA OA-NO2 is efficacious in preclinical models of allergic airway disease and may have potential for treating asthma patients.

Newer treatments in the management of pediatric asthma

Asthma control remains a significant challenge in the pediatric age range in which ongoing loss of lung function in children with persistent asthma has been reported, despite the use of regular preventer therapy. This has important implications for observed mortality and morbidity during adulthood. Over the past decade, there has been an emergence of other treatment adjuncts, such as anti-Immunoglobulin E (IgE)-directed therapy, low dose theophylline, and the use of macrolide antibiotics, yet their exact role in asthma management remains unclear, despite omalizumab now being incorporated into several international asthma guidelines. As with many aspects of pediatric care, this is driven by a lack of appropriately designed pediatric trials. Extrapolation of data reported in adult studies may be appropriate for adolescent asthma, but is not for younger age groups, in which important pathophysiological differences exist. Novel drugs under development offer potential for benefit in the future, but to date existing data are in most cases limited to adults. Pediatric asthma also offers unique potential to prevent or modify the underlying pathophysiology. Although attempts to do so have been unsuccessful to date, advances may yet come from this approach, as our understanding about the interaction between genetics, environmental factors, and viral illness improve. This review provides an overview of the newer treatment options available for management of pediatric asthma and discusses the merits of other novel therapies in development, as we search to optimize management and improve future outcomes.

[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.

Biomarker surrogates do not accurately predict sputum eosinophil and neutrophil percentages in asthmatic subjects

BACKGROUND

Sputum eosinophil percentages are a strong predictor of airway inflammation and exacerbations and aid asthma management, whereas sputum neutrophil percentages indicate a different severe asthma phenotype that is potentially less responsive to TH2-targeted therapy. Variables, such as blood eosinophil counts, total IgE levels, fraction of exhaled nitric oxide (Feno) levels, or FEV1 percent predicted, might predict airway eosinophil percentages, whereas age, FEV1 percent predicted, or blood neutrophil counts might predict sputum neutrophil percentages. Availability and ease of measurement are useful characteristics, but accuracy in predicting airway eosinophil and neutrophil percentages either individually or combined is not established.

OBJECTIVES

We sought to determine whether blood eosinophil counts, Feno levels, and IgE levels accurately predict sputum eosinophil percentages and whether age, FEV1 percent predicted, and blood neutrophil counts accurately predict sputum neutrophil percentages.

METHODS

Subjects in the Wake Forest Severe Asthma Research Program (n = 328) were characterized by blood and sputum cell counts, health care use, lung function, Feno levels, and IgE levels. Multiple analytic techniques were used.

RESULTS

Despite significant association with sputum eosinophil percentages, blood eosinophil counts, Feno levels, and total IgE levels did not accurately predict sputum eosinophil percentages, and combinations of these variables did not improve prediction. Age, FEV1 percent predicted, and blood neutrophil counts were similarly unsatisfactory for the prediction of sputum neutrophil percentages. Factor analysis and stepwise selection found Feno levels, IgE levels, and FEV1 percent predicted, but not blood eosinophil counts, correctly predicted 69% of sputum eosinophil percentages of less than 2% or 2% and greater. Likewise, age, asthma duration, and blood neutrophil counts correctly predicted 64% of sputum neutrophil percentages of less than 40% or 40% and greater. A model to predict both sputum eosinophil and neutrophil percentages accurately assigned only 41% of samples.

CONCLUSION

Despite statistically significant associations, Feno levels, IgE levels, blood eosinophil and neutrophil counts, FEV1 percent predicted, and age are poor surrogates, both separately and combined, for accurately predicting sputum eosinophil and neutrophil percentages.

Persistent elevation of exhaled nitric oxide and modification of corticosteroid therapy in asthma

BACKGROUND

Persistent airway inflammation, detected by fractional exhaled nitric oxide (FENO), is occasionally observed in asthmatic patients, even in those treated with inhaled corticosteroids (ICS). However, improvement in residual airway inflammation and pulmonary function through modification of corticosteroid therapy has not been proven.

METHODS

Thirteen asthmatic patients whose FENO levels were over 40 parts per billion (ppb), despite dry-powder ICS therapy, were enrolled. A 3-step change in steroid treatment was undertaken until FENO was less than 40ppb. In the first step, the powder formula was changed to an ultra-fine particle compound as an equipotent ICS dose. In the second step, the ICS dose was doubled. In the third step, oral corticosteroids were added. We measured pulmonary function and FENO and alveolar NO concentrations (CAlvNO).

RESULTS

Doubling the ICS dose and changing the ICS formula significantly improved FVC (p<0.001), FEV1 (p<0.05), the slope of the single nitrogen washout curve (dN2) (p<0.01), FENO (p<0.001), and CAlvNO (p<0.05), relative to baseline. The reductions in FENO were significantly associated with the improvement in airflow limitation assessed by dN2 (r=0.73, p=0.007). The remaining FENO elevation, even after doubling the ICS dose, did not decrease after oral corticosteroid administration.

CONCLUSIONS

These results suggest that modification of ICS therapy can suppress residual FENO elevation, and that reduction in FENO levels is associated with improvement in airflow limitation. However, steroid-resistance mechanisms may exist in some asthmatic patients with sustained FENO elevations.

Severe asthma: an expanding and mounting clinical challenge

Although all patients with asthma have variable airflow obstruction, airway inflammation, and bronchial hyperresponsiveness, some have disease that is severe in many aspects: persistent airflow obstruction, ongoing symptoms, increased frequency of exacerbations, and, most importantly, a diminished response to medications. A number of definitions have emerged to characterize the clinical features of severe asthma, but a central feature of this phenotype is the need for high doses of medications, especially corticosteroids, in attempts to achieve disease control. The prevalence of severe asthma is also undergoing reevaluation from the usual estimate of 10% to larger numbers on the basis of medication needs and the lack of disease control achieved. At present, the underlying mechanisms of severe asthma are not established but likely reflect a heterogeneous pattern, rather than a single unifying process. Guideline-directed treatment for severe asthma has limits with usual approaches centered on high doses of inhaled corticosteroids, long-acting β-agonists, and trials with omalizumab, the monoclonal antibody to IgE. With the development of approaches to recognize asthma phenotypes with distinct pathogenesis and hence unique therapeutic targets, it is hoped that a personalized strategy in treatment directed toward disease-specific features will improve outcomes for this high-risk, severely affected population of patients.

Corticosteroid resistance in patients with asthma and chronic obstructive pulmonary disease

Reduced responsiveness to the anti-inflammatory effects of corticosteroids is a major barrier to effective management of asthma in smokers and patients with severe asthma and in the majority of patients with chronic obstructive pulmonary disease (COPD). The molecular mechanisms leading to steroid resistance are now better understood, and this has identified new targets for therapy. In patients with severe asthma, several molecular mechanisms have been identified that might account for reduced steroid responsiveness, including reduced nuclear translocation of glucocorticoid receptor (GR) α after binding corticosteroids. This might be due to modification of the GR by means of phosphorylation as a result of activation of several kinases (p38 mitogen-activated protein kinase α, p38 mitogen-activated protein kinase γ, and c-Jun N-terminal kinase 1), which in turn might be due to reduced activity and expression of phosphatases, such as mitogen-activated protein kinase phosphatase 1 and protein phosphatase A2. Other mechanisms proposed include increased expression of GRβ, which competes with and thus inhibits activated GRα; increased secretion of macrophage migration inhibitory factor; competition with the transcription factor activator protein 1; and reduced expression of histone deacetylase (HDAC) 2. HDAC2 appears to mediate the action of steroids to switch off activated inflammatory genes, but in patients with COPD, patients with severe asthma, and smokers with asthma, HDAC2 activity and expression are reduced by oxidative stress through activation of phosphoinositide 3-kinase δ. Strategies for managing steroid resistance include alternative anti-inflammatory drugs, but a novel approach is to reverse steroid resistance by increasing HDAC2 expression, which can be achieved with theophylline and phosphoinositide 3-kinase δ inhibitors. Long-acting β2-agonists can also increase steroid responsiveness by reversing GRα phosphorylation. Identifying the molecular mechanisms of steroid resistance in asthmatic patients and patients with COPD can thus lead to more effective anti-inflammatory treatments.

The utility of fractional exhaled nitric oxide suppression in the identification of nonadherence in difficult asthma

RATIONALE

Nonadherence to inhaled corticosteroid therapy (ICS) is a major contributor to poor control in difficult asthma, yet it is challenging to ascertain.

OBJECTIVES

Identify a test for nonadherence using fractional exhaled nitric oxide (Fe(NO)) suppression after directly observed inhaled corticosteroid (DOICS) treatment.

METHODS

Difficult asthma patients with an elevated Fe(NO) (>45 ppb) were recruited as adherent (ICS prescription filling >80%) or nonadherent (filling <50%). They received 7 days of DOICS (budesonide 1,600 μg) and a test for nonadherence based on changes in Fe(NO) was developed. Using this test, clinic patients were prospectively classified as adherent or nonadherent and this was then validated against prescription filling records, prednisolone assay, and concordance interview.

MEASUREMENTS AND MAIN RESULTS

After 7 days of DOICS nonadherent (n = 9) compared with adherent subjects (n = 13) had a greater reduction in Fe(NO) to 47 ± 21% versus 79 ± 26% of baseline measurement (P = 0.003), which was also evident after 5 days (P = 0.02) and a Fe(NO) test for nonadherence (area under the curve = 0.86; 95% confidence interval, 0.68-1.00) was defined. Prospective validation in 40 subjects found the test identified 13 as nonadherent; eight confirmed nonadherence during interview (three of whom had excellent prescription filling but did not take medication), five denied nonadherence, two had poor inhaler technique (unintentional nonadherence), and one also denied nonadherence to prednisolone despite nonadherent blood level. Twenty-seven participants were adherent on testing, which was confirmed in 21. Five admitted poor ICS adherence but of these, four were adherent with oral steroids and one with omalizumab.

CONCLUSIONS

Fe(NO) suppression after DOICS provides an objective test to distinguish adherent from nonadherent patients with difficult asthma. Clinical trial registered with www.clinicaltrials.gov (NCT 01219036).

Steroid-resistant asthma

Steroid-resistant asthma (SRA) refers to patients with symptoms consistent with asthma who show very poor or no response at all to high doses of inhaled or even of systemic corticosteroids. The current article reviews the SRA related literature focusing on the problems associated with the definition of SRA (especially its association with difficult to control, or severe asthma), its various phenotypes, its molecular basis, and the potential treatment options. The article also discusses the limitations of some of the key criteria used for the determination of SRA and proposes a modified set of criteria that are more applicable to children.

Severe asthma in adults: an orphan disease?

Severe asthma affects fewer than 10% of patients with asthma, is associated with a severe risk of death and disability, has a great impact on health and quality of life, and represents a huge cost to patients and society. Given the poor response to treatment and the side effects associated with medications for severe asthma, more efficient, cost-effective, and phenotype-specific medications are needed. Considering severe asthma as an orphan disease could encourage the pharmaceutical industry to stratify studies based on a more detailed characterization of study subjects at baseline, resulting in the development of novel therapeutic approaches.

U.S. and European severe asthma cohorts: what can they teach us about severe asthma?

Asthma is a global health problem affecting around 300 million patients of all ages and ethnic groups in all countries around the world. In the majority of subjects with persistent, mild-to-moderate asthma (MA), the disease can be relatively well controlled by the use of currently available medications; however, five to ten per cent of patients suffer from a particularly severe disease that is poorly controlled clinically and often refractory to usual treatment. Improved care of severe asthma (SA) is a major unmet medical need and several international consortia aim at improving our understanding of mechanisms in SA. To manage SA better, standardized definitions and concepts of asthma severity, risk and level of control are critical. In the following sections, we present several guidelines approaches and definitions followed by an overview of U.S. (SARP) and European (ENFUMOSA, BIOAIR, U-BIOPRED) SA networks. Key findings regarding SA phenotypes, risk factors and pathophysiology are discussed. International cooperation in the area of respiratory diseases, including SA, across the Atlantic Ocean, will lead to a better understanding of asthma pathology, especially of those severe, not well controlled or difficult-to-treat cases.

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.

Omalizumab modulates bronchial reticular basement membrane thickness and eosinophil infiltration in severe persistent allergic asthma patients

Severe persistent asthma causes a substantial morbidity and mortality burden and is frequently not well controlled, despite intensive guideline-based therapy. The unique monoclonal antibody approved for patients with severe allergic asthma is omalizumab: a recombinant humanised murine against IgE antibodies. The aim of the present study is to investigate the effect of long-term anti-IgE on the thickening of the reticular basement membrane (RBM) and eosinophil infiltration in bronchial biopsies from patients with severe persistent allergic asthma. Biopsies were obtained from 11 patients with severe persistent allergic asthma before and after (12 months) treatment with omalizumab. RBM thickness and eosinophils were measured by using light microscope image analysis. A significant mean reduction in RBM thickness and eosinophil infiltration were measured after one-year omalizumab treatment. No correlation between eosinophil reduction and RBM thickness reduction was found. No correlation between each of the previous two parameters and clinical parameters was detected. In conclusion, our study showed that a substantial proportion of severe asthmatics reduced the original bronchial RBM thickness and eosinophil infiltration after one-year treatment with anti-IgE, thus emphasizing the possible role of omalizumab in affecting airway remodeling in severe persistent allergic asthma.

Corticosteroids: still at the frontline in asthma treatment?

Inhaled corticosteroids (ICS) have led to improved asthma control and reduced asthma mortality in the Western world. ICS are effective in combating T-helper type 2-driven inflammation featuring mast cell and eosinophilic airway infiltration. Their effect on innate immunity-driven neutrophilic inflammation is poor and their ability to prevent airway remodeling and accelerated lung decline is controversial. Although ICS remain pivotal drugs in asthma management, research is needed to find drugs complementary to the combination ICS/long-acting β2-agonist in refractory asthma and perhaps a new class of drugs as a first-line treatment in mild to moderate noneosinophilic asthma.

Severe asthma: advances in current management and future therapy

Effective treatment of severe asthma is a major unmet need because patients' symptoms are not controlled on maximum treatment with inhaled therapy. Asthma symptoms can be poorly controlled because of poor adherence to controller therapy, and this might be addressed by using combination inhalers that contain a corticosteroid and long-acting β(2)-agonist as reliever therapy in addition to maintenance treatment. New bronchodilators with a longer duration of action are in development, and recent studies have demonstrated the benefit of a long-acting anticholinergic bronchodilator in addition to β(2)-agonists in patients with severe asthma. Anti-IgE therapy is beneficial in selected patients with severe asthma. Several new blockers of specific mediators, including prostaglandin D(2), IL-5, IL-9, and IL-13, are also in clinical trials and might benefit patients with subtypes of severe asthma. Several broad-spectrum anti-inflammatory therapies that target neutrophilic inflammation are in clinical development for the treatment of severe asthma, but adverse effects after oral administration might necessitate inhaled delivery. Macrolides might benefit some patients with infection by atypical bacteria, but recent results are not encouraging, although there could be an effect in patients with predominant neutrophilic asthma. Corticosteroid resistance is a major problem in patients with severe asthma, and several molecular mechanisms have been described that might lead to novel therapeutic approaches, including drugs that could reverse this resistance, such as theophylline and nortriptyline. In selected patients with severe asthma, bronchial thermoplasty might be beneficial, but thus far, clinical studies have not been encouraging. Finally, several subtypes of severe asthma are now recognized, and in the future, it will be necessary to find biomarkers that predict responses to specific forms of therapy.

Asthma phenotypes: the evolution from clinical to molecular approaches

Although asthma has been considered as a single disease for years, recent studies have increasingly focused on its heterogeneity. The characterization of this heterogeneity has promoted the concept that asthma consists of multiple phenotypes or consistent groupings of characteristics. Asthma phenotypes were initially focused on combinations of clinical characteristics, but they are now evolving to link biology to phenotype, often through a statistically based process. Ongoing studies of large-scale, molecularly and genetically focused and extensively clinically characterized cohorts of asthma should enhance our ability to molecularly understand these phenotypes and lead to more targeted and personalized approaches to asthma therapy.

Impact of add-on pranlukast in stable asthma; the additive effect on peripheral airway inflammation

BACKGROUND

The importance of airway inflammation has been highlighted in the pathophysiology of asthma. Even in controlled asthmatics treated with inhaled corticosteroid (ICS), residual airway inflammation is reported. Systemic therapy with oral leukotriene receptor antagonist, pranlukast, may have additive effects to improve asthma control.

METHODS

Twenty-five controlled asthmatics treated with ICS or ICS plus long-acting β2-agonist (LABA) were enrolled for a randomized crossover trial evaluating the effect of additional oral pranlukast. The patients were assigned to two groups receiving ICS (+LABA) or ICS (+LABA) + pranlukast for 8 weeks. After washout period, two groups were switched over for another 8 weeks. Fraction of exhaled nitric oxide (FeNO), lung function tests, peak expiratory flow (PEF) and asthma control test (ACT) were evaluated at the beginning and end of each period. Central airway NO flux (J'(awNO)) and peripheral airway/alveolar NO concentration (C(ANO)) were measured and adjusted for axial NO back-diffusion.

RESULTS

FEV1, % predicted, forced expired flow (FEF) (25-75), % predicted, morning PEF and ACT were significantly increased after the addition of pranlukast. Oral pranlukast administration significantly decreased both C(ANO) and corrected C(ANO).

CONCLUSIONS

The addition of oral pranlukast to ICS or ICS + LABA therapy may improve asthma control with reducing distal airway inflammation.

TRIAL REGISTRATION

UMIN 000003781.

Current treatment of severe asthma

Severe asthma is considered a heterogeneous disease in which a variety of clinical, physiological and inflammatory markers determine disease severity. Pivotal studies in the last 5 years have led to substantial progress in many areas, ranging from a more accurate definition of truly severe, refractory asthma, to classification of the disease into distinct clinical phenotypes, and introduction of new therapies. This review focuses on three common clinical phenotypes of severe asthma in adults (early onset severe allergic asthma, late onset non-atopic eosinophilic asthma, late onset non-eosinophilic asthma with obesity), and provides an overview of recent developments regarding treatment options that are best suited for each of these phenotypes.

How to set up a severe asthma service

Severe asthma affects 5-20% of the asthma population but is discordantly responsible for the major burden of illness and impairment to quality of life. Patients with severe asthma continue to experience ongoing symptoms despite maximal therapy. A severe asthma service provides a systematic approach to the management of the disease and aids in confirming the correct diagnosis, managing comorbid conditions that may mimic or aggravate asthma, and provides the environment to optimize treatment and asthma self-management skills and education. A severe asthma service is also the ideal environment for trialling add-on therapies and hence can improve patient outcomes and clinical practice. Within such a service there are many opportunities for training and research. In this article we describe the purpose of a severe asthma clinic, the necessary components of a service including staffing and facilities and the processes for trialling additional therapies used in the management of severe asthma.

Limited short-term steroid responsiveness is associated with thickening of bronchial basement membrane in severe asthma

BACKGROUND

The clinical manifestations of bronchial remodeling in asthma and the potential impact of this process on lung function remain unclear. We aimed to determine whether the presence of pathologic features of airway remodeling in patients with asthma was associated with steroid responsiveness in the short term.

METHODS

Sixty-three consecutive patients with severe asthma with chronic airflow impairment (post-bronchodilator FEV(1) < 80% predicted values) were recruited, clinically characterized, and had an initial bronchoscopy where endobronchial biopsy and BAL were performed. BAL cellular content was reported and reticular basement membrane (RBM) thickness was measured by validated repeated measures. Patients were then treated with 1 mg/kg/d of methyl prednisone, directly administered IV, for 10 days. A threshold of 15% FEV(1) improvement was used to discriminate responsive (group 1) and refractory patients (group 2).

RESULTS

Thirty-eight patients had a steroid responsiveness > 15% (group 1) and a thinner RBM at the biopsy level (5.78 ± 2.0 μm vs 7.60 ± 2.2 μm; P = .001) compared with nonsteroid responsive group 2 patients as defined. The best predictors for being unresponsive were no long-term treatment with oral steroids and increased RBM thickness. The associated receiver operating characteristic curve indicated that RBM thickness could predict steroid responsiveness below 15% with an area under the curve of 0.747 (P = .0002) at a threshold of 7 μm.

CONCLUSIONS

Features of airway remodeling are associated with limited short-term steroid responsiveness in severe asthma.

Clinical characteristics and possible phenotypes of an adult severe asthma population

BACKGROUND

Currently, there are no studies of well-characterized severe asthmatics in Brazil. We aimed to study a population of severe treated asthmatics still uncontrolled to characterize them and define possible phenotypes.

METHODS

Descriptive cross-sectional outpatient study of severe asthmatics, evaluating functional and inflammatory markers, health-related quality of life, anxiety and depression symptoms, clinical control status, and characteristics related to atopy, age of asthma onset, induced sputum eosinophil levels, and airflow limitation. We also grouped the subgroups characteristics to identify phenotypes. The study is registered on ClinicalTrial.gov NCT 01089322.

RESULTS

From 128 eligible patients with severe/uncontrolled asthma, 74 fulfilled the inclusion criteria. The cohort was comprised of 85% women, frequently with a body mass index higher than 31 kg m(-2), atopy (60%), early-onset disease (50%), sputum eosinophilia (80%), comorbidities, and reduced quality of life. Nonatopics had significant higher asthma onset (19 y.a.) and twice level of induced sputum eosinophil. Late-onset patients had significantly less atopy (57%) and higher levels of induced sputum eosinophils. Non-eosinophilics had lower levels of inflammatory markers. Patients with airflow limitation had more intensive care unit admissions (56%) and 1.5 times more airway resistance. Subgroups characteristics identified a priori four well-characterized phenotypes, with 55% presenting sputum eosinophilia.

CONCLUSION

Our data emphasize the high burden of disease, the persistence of inflammation and the existence of clinical possible phenotypes population sharing common features with published cohorts. Despite the necessity of further investigation into pathogenic mechanisms, this study with clinically difficult patient group may help to improve future asthma care.