An antiinflammatory effect of salmeterol, a long-acting beta(2) agonist, assessed in airway biopsies and bronchoalveolar lavage in asthma

The effect of single pretreatment with salbutamol on recovery of bronchoalveolar lavage fluid in horses with suspected or confirmed severe equine asthma

BACKGROUND

Bronchoalveolar lavage (BAL) is a method for the recovery of respiratory secretion from the lower airways.

OBJECTIVES

To investigate if the administration of a single dose of a bronchodilatator in horses with a suspected or confirmed severe equine asthma could improve recovery of bronchoalveolar lavage fluid (BALF).

ANIMALS

Twenty-eight horses with severe equine asthma.

METHODS

Horses were divided into 2 groups: group "treated" was given salbutamol before endoscopic examination and BALF collection, whereas group "not treated" was not given. BAL was performed with BAL-catheter by instilling 350 mL of sterile saline. Amount of recovered fluid was recorded. Statistical analysis was performed with a two-tailed Student's t test.

RESULTS

The average fluid recovery in the horses treated with salbutamol was 52% ± 15% (mean +/- SD), compared with 38% ± 13% for the group of horses not treated with salbutamol (P = 0.013).

CONCLUSIONS AND CLINICAL IMPORTANCE

Clinicians should consider administration of salbutamol before performing BAL on horses with asthma.

Effect of a syringe aspiration technique versus a mechanical suction technique and use of N-butylscopolammonium bromide on the quantity and quality of bronchoalveolar lavage fluid samples obtained from horses with the summer pasture endophenotype of equine asthma

OBJECTIVE To evaluate the effect of 2 bronchoalveolar lavage (BAL) sampling techniques and the use of N-butylscopolammonium bromide (NBB) on the quantity and quality of BAL fluid (BALF) samples obtained from horses with the summer pasture endophenotype of equine asthma. ANIMALS 8 horses with the summer pasture endophenotype of equine asthma. PROCEDURES BAL was performed bilaterally (right and left lung sites) with a flexible videoendoscope passed through the left or right nasal passage. During lavage of the first lung site, a BALF sample was collected by means of either gentle syringe aspiration or mechanical suction with a pressure-regulated wall-mounted suction pump. The endoscope was then maneuvered into the contralateral lung site, and lavage was performed with the alternate fluid retrieval technique. For each horse, BAL was performed bilaterally once with and once without premedication with NBB (21-day interval). The BALF samples retrieved were evaluated for volume, total cell count, differential cell count, RBC count, and total protein concentration. RESULTS Use of syringe aspiration significantly increased total BALF volume (mean volume increase, 40 mL [approx 7.5% yield]) and decreased total RBC count (mean decrease, 142 cells/μL), compared with use of mechanical suction. The BALF nucleated cell count and differential cell count did not differ between BAL procedures. Use of NBB had no effect on BALF retrieval. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that retrieval of BALF by syringe aspiration may increase yield and reduce barotrauma in horses at increased risk of bronchoconstriction and bronchiolar collapse. Further studies to determine the usefulness of NBB and other bronchodilators during BAL procedures in horses are warranted.

Enhancing nuclear translocation: perspectives in inhaled corticosteroid therapy

Corticosteroids are widely used in the treatment of asthma and chronic obstructive pulmonary disease (COPD). In contrast to their use in mild-to-moderate asthma, they are less efficacious in improving lung function and controlling the underlying inflammation in COPD. In most clinical trials, corticosteroids have shown little benefit in COPD, but have shown a greater clinical effect in combination with long-acting bronchodilators. Impaired corticosteroid activation of the glucocorticoid receptor (GR) has been reported in corticosteroid-insensitive individuals. Reversal of corticosteroid-insensitivity by enhancing GR nuclear translocation is a potential therapeutic target. Preclinical studies suggest members of the nuclear receptor superfamily may facilitate glucocorticoid receptor nuclear translocation. Unravelling the mechanisms that govern GR nuclear translocation may identify novel therapeutic targets for reversing corticosteroid-insensitivity.

Evaluation of coagulation activation after rhinovirus infection in patients with asthma and healthy control subjects: an observational study

Background

Asthma exacerbations are frequently triggered by rhinovirus infections. Both asthma and respiratory tract infection can activate haemostasis. Therefore we hypothesized that experimental rhinovirus-16 infection and asthmatic airway inflammation act in synergy on the haemostatic balance.

Methods

28 patients (14 patients with mild allergic asthma and 14 healthy non-allergic controls) were infected with low-dose rhinovirus type 16. Venous plasma and bronchoalveolar lavage fluid (BAL fluid) were obtained before and 6 days after infection to evaluate markers of coagulation activation, thrombin-antithrombin complexes, von Willebrand factor, plasmin-antiplasmin complexes, plasminogen activator inhibitor type-1, endogenous thrombin potential and tissue factor-exposing microparticles by fibrin generation test, in plasma and/or BAL fluid. Data were analysed by nonparametric tests (Wilcoxon, Mann Whitney and Spearman correlation).

Results

13 patients with mild asthma (6 females, 19-29 y) and 11 healthy controls (10 females, 19-31 y) had a documented Rhinovirus-16 infection. Rhinovirus-16 challenge resulted in a shortening of the fibrin generation test in BAL fluid of asthma patients (t = -1: 706 s vs. t = 6: 498 s; p = 0.02), but not of controls (t = -1: 693 s vs. t = 6: 636 s; p = 0.65). The fold change in tissue factor-exposing microparticles in BAL fluid inversely correlated with the fold changes in eosinophil cationic protein and myeloperoxidase in BAL fluid after virus infection (r = -0.517 and -0.528 resp., both p = 0.01).

Rhinovirus-16 challenge led to increased plasminogen activator inhibitor type-1 levels in plasma in patients with asthma (26.0 ng/mL vs. 11.5 ng/mL in healthy controls, p = 0.04). Rhinovirus-16 load in BAL showed a linear correlation with the fold change in endogenous thrombin potential, plasmin-antiplasmin complexes and plasminogen activator inhibitor type-1.

Conclusions

Experimental rhinovirus infection induces procoagulant changes in the airways of patients with asthma through increased activity of tissue factor-exposing microparticles. These microparticle-associated procoagulant changes are associated with both neutrophilic and eosinophilic inflammation. Systemic activation of haemostasis increases with Rhinoviral load.

Trial registration

This trial was registered at the Dutch trial registry (http://www.trialregister.nl): NTR1677.

Treating the small airways

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

Effects of budesonide/formoterol combination therapy versus budesonide alone on airway dimensions in asthma

BACKGROUND AND OBJECTIVE

Combination therapy with inhaled corticosteroids and long-acting β(2)-agonists results in improved asthma symptom control compared with the use of inhaled corticosteroids alone. However, the effects of combination therapy on structural changes and inflammation of the airways are still unknown. The aim of this study was to compare the effects of budesonide/formoterol with those of budesonide alone on airway dimensions and inflammation in individuals with asthma.

METHODS

Fifty asthmatic patients were randomized to treatment with budesonide/formoterol (200/6 µg, two inhalations bd) or budesonide (200 µg, two inhalations bd) for 24 weeks. Airway dimensions were assessed using a validated computed tomography technique, and airway wall area (WA) corrected for body surface area (BSA), percentage WA (WA%), wall thickness/Ösquare root BSA, and luminal area (Ai)/BSA at the right apical segmental bronchus, were measured. The percentage of eosinophils in induced sputum, pulmonary function, and Asthma Quality of Life Questionnaires (AQLQ) were also evaluated.

RESULTS

There were significantly greater decreases in WA/BSA (P < 0.05), WA% (P < 0.001) and wall thickness/square root BSA (P < 0.05), and increases in Ai/BSA (P < 0.05), in subjects treated with budesonide/formoterol compared with those treated with budesonide. The reduction in sputum eosinophils and increase in per cent of predicted forced expiratory volume in 1 s (FEV(1) %) were greater for subjects treated with budesonide/formoterol compared with those treated with budesonide alone. In the budesonide/formoterol group, the changes in WA% were significantly correlated with changes in sputum eosinophils and FEV(1%) (r = 0.84 and r = 0.64, respectively). There were improvements in the AQLQ scores after treatment with budesonide/formoterol.

CONCLUSIONS

Budesonide/formoterol combination therapy is more effective than budesonide alone for reducing airway wall thickness and inflammation in individuals with asthma.

Addition of long-acting beta2-agonists to inhaled corticosteroids versus same dose inhaled corticosteroids for chronic asthma in adults and children

BACKGROUND

Long-acting inhaled ss(2)-adrenergic agonists (LABAs) are recommended as 'add-on' medication to inhaled corticosteroids (ICS) in the maintenance therapy of asthmatic adults and children aged two years and above.

OBJECTIVES

To quantify in asthmatic patients the safety and efficacy of the addition of LABAs to ICS in patients insufficiently controlled on ICS alone.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE and CINAHL), bibliographies of RCTs and correspondence with manufacturers until May 2008.

SELECTION CRITERIA

We included RCTs if they compared the addition of inhaled LABAs versus placebo to the same dose of ICS in children aged two years and above and in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for methodological quality and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was the relative risk (RR) of asthma exacerbations requiring rescue oral corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), rescue beta2-agonist use, symptoms, withdrawals and adverse events.

MAIN RESULTS

Seventy-seven studies met the entry criteria and randomised 21,248 participants (4625 children and 16,623 adults). Participants were generally symptomatic at baseline with moderate airway obstruction despite their current ICS regimen. Formoterol or salmeterol were most frequently added to low-dose ICS (200 to 400 microg/day of beclomethasone (BDP) or equivalent) in 49% of the studies. The addition of a daily LABA to ICS reduced the risk of exacerbations requiring oral steroids by 23% from 15% to 11% (RR 0.77, 95% CI 0.68 to 0.87, 28 studies, 6808 participants). The number needed to treat with the addition of LABA to prevent one use of rescue oral corticosteroids is 41 (29, 72), although the event rates in the ICS groups varied between 0% and 38%. Studies recruiting adults dominated the analysis (6203 adult participants versus 605 children). The subgroup estimate for paediatric studies was not statistically significant (RR 0.89, 95% CI 0.58 to 1.39) and includes the possibility of the superiority of ICS alone in children.Higher than usual dose of LABA was associated with significantly less benefit. The difference in the relative risk of serious adverse events with LABA was not statistically significant from that of ICS alone (RR 1.06, 95% CI 0.87 to 1.30). The addition of LABA led to a significantly greater improvement in FEV(1) (0.11 litres, 95% 0.09 to 0.13) and in the proportion of symptom-free days (11.88%, 95% CI 8.25 to 15.50) compared to ICS monotherapy. It was also associated with a reduction in the use of rescue short-acting ss(2)-agonists (-0.58 puffs/day, 95% CI -0.80 to -0.35), fewer withdrawals due to poor asthma control (RR 0.50, 95% CI 0.41 to 0.61), and fewer withdrawals due to any reason (RR 0.80, 95% CI 0.75 to 0.87). There was no statistically significant group difference in the risk of overall adverse effects (RR 1.00, 95% 0.97 to 1.04), withdrawals due to adverse health events (RR 1.04, 95% CI 0.86 to 1.26) or any of the specific adverse health events.

AUTHORS' CONCLUSIONS

In adults who are symptomatic on low to high doses of ICS monotherapy, the addition of a LABA at licensed doses reduces the rate of exacerbations requiring oral steroids, improves lung function and symptoms and modestly decreases use of rescue short-acting ss(2)-agonists. In children, the effects of this treatment option are much more uncertain. The absence of group difference in serious adverse health events and withdrawal rates in both groups provides some indirect evidence of the safety of LABAs at usual doses as add-on therapy to ICS in adults, although the width of the confidence interval precludes total reassurance.

Addition of long-acting beta2-agonists to inhaled steroids versus higher dose inhaled steroids in adults and children with persistent asthma

BACKGROUND

In asthmatic patients inadequately controlled on inhaled corticosteroids and/or those with moderate persistent asthma, two main options are recommended: the combination of a long-acting inhaled ss2 agonist (LABA) with inhaled corticosteroids (ICS) or use of a higher dose of inhaled corticosteroids.

OBJECTIVES

To determine the effect of the combination of long-acting ss(2) agonists and inhaled corticosteroids compared to a higher dose of inhaled corticosteroids on the risk of asthma exacerbations, pulmonary function and on other measures of asthma control, and to look for characteristics associated with greater benefit for either treatment option.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (MEDLINE, EMBASE and CINAHL), bibliographies of RCTs, clinical trial registries and correspondence with manufacturers until May 2008.

SELECTION CRITERIA

RCTs that compared the combination of inhaled LABA and ICS to a higher dose of inhaled corticosteroids, in children and adults with asthma.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed methodological quality and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was the number of patients experiencing one or more asthma exacerbations requiring oral corticosteroids.

MAIN RESULTS

This review included 48 studies (15,155 participants including 1155 children and 14,000 adults). Participants were inadequately controlled on their current ICS regimen, experiencing ongoing symptoms and with generally moderate (FEV1 60% to 79% of predicted) airway obstruction. The studies tested the combination of salmeterol or formoterol with a median dose of 400 mcg/day of beclomethasone or equivalent (BDP-eq) compared to a median of 1000 mcg/day of BDP-eq, usually for 24 weeks or less. There was a statistically significantly lower risk of exacerbations requiring systemic corticosteroids in patients treated with LABA and ICS (RR 0.88, 95% CI 0.78 to 0.98, 27 studies, N = 10,578) from 11.45% to 10%, with a number needed to treat of 73 (median study duration: 12 weeks). The study results were dominated by adult studies; trial data from three paediatric studies showed a trend towards increased risk of rescue oral steroids (RR 1.24, 95% CI 0.58 to 2.66) and hospital admission (RR 2.21, 95% CI 0.74 to 6.64) associated with combination therapy. Overall, there was no statistically significant difference in the risk ratios for either hospital admission (RR 1.02, 95% CI 0.67 to 1.56) or serious adverse events (RR 1.12, 95% CI 0.91 to 1.37). The combination of LABA and ICS resulted in significantly greater but modest improvement from baseline in lung function, symptoms and rescue medication use than with higher ICS dose. Despite no significant group difference in the risk of overall adverse events (RR 0.99, 95% CI 0.95 to 1.03), there was an increase in the risk of tremor (RR 1.84, 95% CI 1.20 to 2.82) and a lower risk of oral thrush (RR 0.58, 95% CI 0.40 to 0.86)) in the LABA and ICS compared to the higher ICS group. There was no significant difference in hoarseness or headache between the treatment groups. The rate of withdrawals due to poor asthma control favoured the combination of LABA and ICS (RR 0.65, 95% CI 0.51 to 0.83).

AUTHORS' CONCLUSIONS

In adolescents and adults with sub-optimal control on low dose ICS monotherapy, the combination of LABA and ICS is modestly more effective in reducing the risk of exacerbations requiring oral corticosteroids than a higher dose of ICS. Combination therapy also led to modestly greater improvement in lung function, symptoms and use of rescue ss(2) agonists and to fewer withdrawals due to poor asthma control than with a higher dose of inhaled corticosteroids. Apart from an increased rate of tremor and less oral candidiasis with combination therapy, the two options appear relatively safe in adults although adverse effects associated with long-term ICS treatment were seldom monitored. In children, combination therapy did not lead to a significant reduction, but rather a trend towards an increased risk, of oral steroid-treated exacerbations and hospital admissions. These trends raised concern about the safety of combination therapy in view of modest improvement in children under the age of 12 years.

Targeting abnormal airway vascularity as a therapeutical strategy in asthma

Asthma is a chronic inflammatory disease of airways, characterized by airway hyperresponsiveness and airflow limitation with acute bronchoconstriction, swelling of the airway wall, chronic mucus plug formation and airway wall remodelling. Functional and structural changes in the vasculature of asthmatic airways have been documented, and the signalling mechanisms are complex and have recently attracted much attention. The vascular changes may affect inflammatory cell recruitment, airway hyperresponsiveness and the regulation of airway calibre, and further, the level of disease control. Many critical factors are involved in the pathophysiological regulation of vascular changes in bronchial asthma, and the actions of these factors must be very carefully orchestrated. By better understanding the complicated actions of each factor, we may be able to advance further in asthma treatment.

Inhaled salmeterol and/or fluticasone alters structure/function in a murine model of allergic airways disease

BACKGROUND

The relationship between airway structural changes (remodeling) and airways hyperresponsiveness (AHR) is unclear. Asthma guidelines suggest treating persistent asthma with inhaled corticosteroids and long acting beta-agonists (LABA). We examined the link between physiological function and structural changes following treatment fluticasone and salmeterol separately or in combination in a mouse model of allergic asthma.

METHODS

BALB/c mice were sensitized to intraperitoneal ovalbumin (OVA) followed by six daily inhalation exposures. Treatments included 9 daily nebulized administrations of fluticasone alone (6 mg/ml), salmeterol (3 mg/ml), or the combination fluticasone and salmeterol. Lung impedance was measured following methacholine inhalation challenge. Airway inflammation, epithelial injury, mucus containing cells, and collagen content were assessed 48 hours after OVA challenge. Lungs were imaged using micro-CT.

RESULTS AND DISCUSSION

Treatment of allergic airways disease with fluticasone alone or in combination with salmeterol reduced AHR to approximately naüve levels while salmeterol alone increased elastance by 39% compared to control. Fluticasone alone and fluticasone in combination with salmeterol both reduced inflammation to near naive levels. Mucin containing cells were also reduced with fluticasone and fluticasone in combination with salmeterol.

CONCLUSIONS

Fluticasone alone and in combination with salmeterol reduces airway inflammation and remodeling, but salmeterol alone worsens AHR: and these functional changes are consistent with the concomitant changes in mucus metaplasia.

Increased vascular permeability precedes cellular inflammation as asthma control deteriorates

BACKGROUND

Airway microcirculation is abnormal in asthma but the role of vascular changes in asthma deteriorations remains poorly defined. We prospectively assessed the vascular changes accompanying worsening of asthma control by using an inhaled corticosteroid (ICS) dose-reduction model.

OBJECTIVES

To evaluate airway vascularity, vascular permeability and expression of vascular endothelial growth factor (VEGF) in early asthma deterioration induced by ICS back-titration.

METHODS

Twenty mild-to-moderate persistent symptomatic asthmatics on low-to-moderate ICS were recruited and treated with 4 weeks of high-dose fluticasone propionate (1000 microg/day) to achieve symptom control. This was followed by dose reduction to half of the pre-study doses for 4-8 weeks until the symptoms began to return. Endobronchial biopsy and bronchoalveolar lavage (BAL) samples were obtained after both treatment periods.

RESULTS

Vascularity as measured by the number and size of blood vessels, as well as VEGF expression did not change following ICS reduction. Even on high-dose ICS, perivascular albumin staining and BAL microalbumin levels in asthmatic subjects, as markers of permeability, were elevated when compared with normal subjects and both further increased significantly after ICS reduction. There was a significant association between changes in vascular leakiness and clinical deterioration. Increases in airway albumin correlated with previously reported increases in airway wall infiltration with T lymphocytes.

CONCLUSIONS

Our results suggest that airway vascular leakage is a major pathophysiologic feature of early asthma deterioration, occurring before recrudescence of cellular inflammation.

Effects of budesonide and formoterol on allergen-induced airway responses, inflammation, and airway remodeling in asthma

BACKGROUND

Combining inhaled corticosteroids with long-acting beta(2)-agonists results in improved asthma symptom control and fewer asthma exacerbations compared with those seen after inhaled corticosteroids alone. However, there are limited data as to whether these beneficial effects are due to enhanced anti-inflammatory actions or whether such combination therapies affect airway remodeling in patients with asthma.

OBJECTIVE

We sought to determine the effects of inhaled budesonide/formoterol combination therapy versus inhaled budesonide alone or inhaled placebo on allergen-induced airway responses, airway inflammation, and airway remodeling.

METHODS

Fourteen asthmatic subjects with dual responses after allergen inhalation were included in this prospective, randomized, double-blind, 3-period crossover study. Outcomes included early and late asthmatic responses, changes in airway responsiveness, sputum eosinophilia measured before and after allergen challenge, numbers of airway submucosal myofibroblasts, and smooth muscle area measured before and after study treatment.

RESULTS

Allergen-induced sputum eosinophilia was significantly reduced by combination treatment to a greater extent than by budesonide alone. Allergen inhalation resulted in a significant increase in submucosal tissue myofibroblast numbers and produced a significant decrease in percentage smooth muscle area. Combination therapy, but not budesonide monotherapy, significantly attenuated these changes in myofibroblast numbers and smooth muscle area.

CONCLUSIONS

The effects on allergen-induced changes in sputum eosinophils, airway myofibroblast numbers, and smooth muscle seen with combination therapy suggest that the benefits associated with this treatment might relate to effects on airway inflammation and remodeling. The attenuation of early asthmatic responses and airway hyperresponsiveness by combination treatment was likely due to the known functional antagonistic effect of formoterol.

Bromotyrosines in sputum proteins and treatment effects of terbutaline and budesonide in asthma

BACKGROUND

Inhaled corticosteroids are widely used in the treatment of persistent asthma, usually combined with inhaled beta2-agonists. Previous research suggests that short-acting beta2-agonists (SABAs) may downregulate the anti-inflammatory effects of inhaled corticosteroids, thereby increasing asthma morbidity.

OBJECTIVE

To determine whether 3-bromotyrosine and 3,5-dibromotyrosine levels, specific markers of eosinophil activation, reflect treatment effects on airway inflammation of inhaled corticosteroids and SABAs and support previous conclusions.

METHODS

Levels of 3-bromotyrosine and 3,5-dibromotyrosine were measured in sputum supernatants using stable isotope dilution gas chromatography-mass spectrometry in a randomized, placebo-controlled, crossover study of treatment with terbutaline, budesonide, and their combination in patients with persistent asthma. Thirty-four individuals were randomized, and 28 completed the study.

RESULTS

Treatment with budesonide lowered median 3-bromotyrosine levels compared with treatment with placebo, terbutaline, and budesonide-terbutaline (0.24 vs 0.64, 0.62, and 0.43 3-bromotyosine/tyrosine [mmol/mol]; P < .05) and lowered median 3,5-dibromotyrosine levels compared with placebo and terbutaline treatments (0.04 vs 0.11 and 0.07 3,5-dibromotyrosine/ tyrosine [mmol/mol], P < .05). Unlike eosinophil numbers, 3-bromotyrosine and 3,5-dibromotyrosine levels did not increase with terbutaline treatment compared with placebo treatment but were significantly raised when terbutaline was added to budesonide treatment. 3-Bromotyrosine levels correlated significantly with eosinophil cationic protein levels in all groups.

CONCLUSIONS

3-Bromotyrosine and 3,5-dibromotyrosine levels reflect treatment effects in asthma and support previous findings that SABAs impair the anti-inflammatory effects of inhaled corticosteroids. In addition to eosinophil numbers and eosinophil cationic protein levels, these modified tyrosine residues provide useful information about the inflammatory state of the airways.

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

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

Addition of inhaled long-acting beta2-agonists to inhaled steroids as first line therapy for persistent asthma in steroid-naive adults and children

BACKGROUND

Consensus statements recommend the addition of long-acting inhaled ss2-agonists (LABA) only in asthmatic patients who are inadequately controlled on inhaled corticosteroids (ICS). It is not uncommon for some patients to be commenced on ICS and LABA together as initial therapy.

OBJECTIVES

To compare the efficacy of combining inhaled corticosteroids with long-acting ss2-agonists (ICS+LABA) with inhaled corticosteroids alone (ICS alone) in steroid-naive children and adults with persistent asthma. We assessed two protocols: (1) LABA + ICS versus a similar dose of ICS (comparison 1) and (2) LABA + ICS versus a higher dose of ICS (comparison 2).

SEARCH STRATEGY

We identified randomised controlled trials through electronic database searches (May 2008).

SELECTION CRITERIA

Randomised trials comparing ICS + LABA with ICS alone in children and adults with asthma who had no inhaled corticosteroids in the preceding 28 days prior to enrolment.

DATA COLLECTION AND ANALYSIS

Each author assessed studies independently for risk of bias and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was rate of patients with one or more asthma exacerbations requiring rescue systemic corticosteroids. Results are expressed as relative risks (RR) for dichotomous data and as mean differences (MD) or standardised mean differences (SMD) for continuous data.

MAIN RESULTS

Twenty-eight study comparisons drawn from 27 trials (22 adult; five paediatric) met the review entry criteria (8050 participants). Baseline data from the studies indicated that trial populations had moderate or mild airway obstruction (FEV1>/=65% predicted), and that they were symptomatic prior to randomisation. In comparison 1, the combination of ICS and LABA was not associated with a significantly lower risk of patients with exacerbations requiring oral corticosteroids (RR 1.04; 95% confidence interval (CI) 0.73 to 1.47) or requiring hospital admissions (RR 0.38; 95% CI 0.09 to 1.65) compared to a similar dose of ICS alone. The combination of LABA and ICS led to a significantly greater improvement from baseline in FEV1 (0.12 L/sec; 95% CI 0.07 to 0.17), in symptoms (SMD -0.26; 95% CI -0.37 to -0.14) and in rescue ss2-agonist use (-0.41 puffs/day; 95% CI -0.73 to -0.09) compared with a similar dose of ICS alone. There was no significant group difference in the risk of serious adverse events (RR 1.15; 95% CI 0.64 to 2.09), any adverse events (RR 1.02; 95% CI 0.96 to 1.09), study withdrawals (RR 0.95; 95% CI 0.82 to 1.11), or withdrawals due to poor asthma control (RR 0.94; 95% CI 0.63 to 1.41).In comparison 2, the combination of LABA and ICS was associated with a higher risk of patients requiring oral corticosteroids (RR 1.24; 95% CI 1 to 1.53) and study withdrawal (RR 1.31; 95% CI 1.07 to 1.59) than a higher dose of ICS alone. For every 100 patients treated over 43 weeks, nine patients using a higher dose ICS compared to 11 (95% CI 9 to 14) on LABA and ICS suffered one or more exacerbations requiring rescue oral corticosteroids. There was a high level of statistical heterogeneity for FEV1 and morning peak flow. There was no statistically significant group difference in the risk of serious adverse events. Due to insufficient data we could not aggregate results for hospital admission, symptoms and other outcomes.

AUTHORS' CONCLUSIONS

In steroid-naive patients with mild to moderate airway obstruction, the combination of ICS and LABA does not significantly reduce the risk of patients with exacerbations requiring rescue oral corticosteroids over that achieved with a similar dose of ICS alone. However, it significantly improves lung function, reduces symptoms and marginally decreases rescue ss2-agonist use. Initiation of a higher dose of ICS is more effective at reducing the risk of exacerbations requiring rescue systemic corticosteroids, and of withdrawals, than combination therapy. Although children appeared to respond similarly to adults, no firm conclusions can be drawn regarding combination therapy in steroid-naive children, given the small number of children contributing data.

Effects of salmeterol and fluticasone propionate combination versus fluticasone propionate on airway function and eosinophilic inflammation in mild asthma

BACKGROUND

Salmeterol and fluticasone propionate combination (SFC) provides better asthma control than fluticasone propionate (FP) alone, however, little is known on the effects of differential treatments on airway function and inflammation in patients with mild asthma.

METHODS

We randomized 27 mild persistent asthma patients treated with the equivalent of 400 microg beclomethasone dipropionate to receive SFC (50/100 microg , 13 patients) or FP (100 microg , 14 patients) twice daily for 8 weeks. We compared the effects of SFC and FP on pulmonary function assessed by spirometry and impulse oscillometry (IOS), eosinophil percentage of induced sputum and serum, and with asthma symptoms and control after each treatment.

RESULTS

We observed that SFC significantly improved forced expiratory volume in one second (p < 0.05), IOS measurements of total resistance R5 (p < 0.01), central resistance R20 (p < 0.05), and distal reactance X5 (p < 0.01) compared with FP. The percentage of eosinophils in sputum, but not in serum, decreased significantly more in the SFC group than in the FP group (p < 0.05). There was also a significant improvement in symptom control in the SFC group (p < 0.05).

CONCLUSIONS

These findings suggest that SFC is more useful than FP in mild asthma cases. The clinical benefit of SFC provides evidence that IOS and induced sputum allows for the detection of changes in airway function and inflammation.

Asthma drugs counter-regulate interleukin-8 release stimulated by sodium sulfite in an A549 cell line

BACKGROUND

Clinical manifestations suggest that air pollution may induce deterioration of respiratory health. Some air pollutants, including sulfite, may play a role in the exacerbation of asthma. Sulfites are formed at bronchial mucosa from inhaled sulfur dioxide. It has been previously reported that sodium sulfite (Na(2)SO(3)) has pro-inflammatory properties and enhances neutrophil adhesion to A549 cells. Interleukin-8 (IL-8) plays a critical role in attracting inflammatory cells and is an excellent marker of pulmonary cell activation. To date, there have not been any reports on the effect of asthma drugs on the suppression of IL-8 production induced by sulfite in A549 cells or the involvement of specific signal transduction pathways. Thus, our study assessed the effects of salmeterol, fluticasone, and montelukast on human epithelial lung cell inflammation as well as the inhibitors in different signal transduction pathways.

METHODS

A549 human lung epithelial cells were cultured under the following conditions: (1) treated with sodium sulfite (0, 100, 500, 1000, 2500 uM) for 16 hours; (2) cultured for 1 hour in the presence of SB203580, PD98059, SP600125, or wedeloactone, then co-incubated with sodium sulfite for another 16 hours; (3) cultured for 4 hours in the presence of salmeterol, fluticasone, or montelukast, then stimulated with sodium sulfite at a concentration of 1000 uM for 16 hours. We collected the supernatants from the above conditions and performed enzyme-linked immunosorbent assay (ELISA) to measure the IL-8 concentration.

RESULTS

IL-8 production increased after treatment with sodium sulfite at 1000 to 2500 uM (p <or= 0.001). SB203580, PD98059, and wedeloactone decreased IL-8 production stimulated by Na(2)SO(3) (p < 0.01). Salmeterol, fluticasone, and montelukast significantly suppressed IL-8 secretion from sodium sulfite-stimulated A549 cells (p < 0.01).

CONCLUSIONS

Sodium sulfite has pro-inflammatory properties in vitro and can induce potent chemotactic factor IL-8 production. Possible signal transduction pathways required for IL-8 gene expression following exposure to sulfite are the NF-kappa B, ERK, and p-38-dependent pathways. Salmeterol, fluticasone, and montelukast all have inhibitory effects on sodium sulfite-induced IL-8 production in A549 cells.

Antiinflammatory effects of long-acting beta2-agonists in patients with asthma: a systematic review and metaanalysis

BACKGROUND

Long-acting beta(2)-agonists (LABAs) are recommended as add-on therapy to antiinflammatory treatment in patients with chronic persistent asthma. Results from individual studies evaluating the in vivo antiinflammatory effect of LABAs are conflicting. The purpose of this metaanalysis was to determine whether LABAs have an in vivo antiinflammatory effect compared to placebo and whether the addition of a LABA to therapy with inhaled corticosteroids (ICSs) has a synergistic or additive antiinflammatory effect.

METHODS

A systematic search was performed of online databases for randomized controlled trials evaluating the antiinflammatory effects of the following: (1) LABAs compared to placebo; and (2) a LABA plus ICS vs ICS alone in adults and children with asthma. Inflammatory outcome measures included cell counts and markers of cell activation in sputum, BAL fluid, bronchial biopsy specimens, serum, and exhaled nitric oxide (ENO). Data were independently extracted by two study investigators and analyzed to generate standardized mean differences using either a fixed or random-effects metaanalysis depending on the degree of heterogeneity.

RESULTS

Thirty-two studies (n = 1,105 participants) met the inclusion criteria. The mean number of participants and mean number of studies for each inflammatory outcome in the metaanalysis was 113.1 (SD, 46.2) and 3.5 (SD, 1.3), respectively. There was no effect of LABA therapy on sputum, BAL fluid, or mucosal inflammatory cells in adults or in children. LABA therapy decreased ENO levels and BAL fluid albumin levels in adults. In children, LABA therapy was associated with a small decrease in serum eosinophils and interleukin-4.

CONCLUSION

LABA therapy does not appear to have any clinically important antiinflammatory or proinflammatory effect. LABA therapy decreases BAL fluid albumin levels, suggesting a possible modulating effect on microvascular leakage.

Fluticasone versus placebo for chronic asthma in adults and children

BACKGROUND

Inhaled fluticasone propionate (FP) is a relatively new inhaled corticosteroid for the treatment of asthma.

OBJECTIVES

To assess efficacy and safety outcomes in studies that compared FP to placebo for treatment of chronic asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register (January 2008), reference lists of articles, contacted trialists and searched abstracts of major respiratory society meetings (1997-2006).

SELECTION CRITERIA

Randomised trials in children and adults comparing FP to placebo in the treatment of chronic asthma. Two reviewers independently assessed articles for inclusion and risk of bias.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data. Quantitative analyses were undertaken using Review Manager software.

MAIN RESULTS

Eighty-six studies met the inclusion criteria, recruiting 16,160 participants. In non-oral steroid treated asthmatics with mild and moderate disease FP resulted in improvements from baseline compared with placebo across all dose ranges (100 to 1000 mcg/d) in FEV1 (between 0.1 to 0.43 litres); morning PEF (between 23 and 46 L/min); symptom scores (based on a standardised scale, between 0.44 and 0.7); reduction in rescue beta-2 agonist use (between 1 and 1.4 puffs/day). High dose FP increased the number of patients who could withdraw from prednisolone: FP 1000-1500 mcg/day Peto Odds Ratio 14.07 (95% CI 7.17 to 27.57). FP at all doses led to a greater likelihood of sore throat, hoarseness and oral Candidiasis.

AUTHORS' CONCLUSIONS

Doses of FP in the range 100-1000 mcg/day are effective. In most patients with mild-moderate asthma improvements with low dose FP are only a little less than those associated with high doses when compared with placebo. High dose FP appears to have worthwhile oral-corticosteroid reducing properties. FP use is accompanied by an increased likelihood of oropharyngeal side effects.

Inflammatory and functional effects of increasing asthma treatment with formoterol or double dose budesonide

Adding a long-acting beta(2)-agonist to inhaled corticosteroids (ICS) for asthma treatment is better than increasing ICS dose in improving clinical status, although there is no consensus about the impact of this regimen on inflammation. In this double-blind, randomized, parallel group study, asthmatics with moderate to severe disease used budesonide (400 mcg/day) for 5 weeks (run-in period); then they were randomized to use budesonide (800 mcg/day--BUD group) or budesonide plus formoterol (400 mcg and 24 mcg/day, respectively--FORMO group) for 9 weeks (treatment period). Home PEF measurements, symptom daily reporting, spirometry, sputum induction (for differential cell counts and sputum cell cultures), and hypertonic saline bronchial challenge test were performed before and after treatments. TNF-alpha, IL-4 and eotaxin-2 levels in the sputum and cell culture supernatants were determined. Morning and night PEF values increased in the FORMO group during the treatment period (p<0.01), from 435+/-162 to 489+/-169 and 428+/-160 to 496+/-173 L/min, respectively. The rate of exacerbations in the FORMO group was lower than in the BUD group (p<0.05). Neutrophil counts in sputum increased in both groups (p<0.05) and leukocyte viability after 48 h-culture increased in the FORMO group (p<0.05). No other parameter changed significantly in either group. This study showed that adding formoterol to budesonide improved home PEF and provided protection from exacerbations, although increase of leukocyte viability in cell culture may be a matter of concern and needs further investigation.

Asthma exacerbations in African Americans treated for 1 year with combination fluticasone propionate and salmeterol or fluticasone propionate alone

OBJECTIVE

This long-term prospective study was conducted in African Americans with persistent asthma to examine the safety and effectiveness of the combination of the inhaled corticosteroid, fluticasone propionate (FP), and the long-acting beta-agonist, salmeterol, compared with FP alone.

RESEARCH AND DESIGN METHODS

This was a randomized, double-blind, parallel group, multi-center trial in adolescent and adult subjects >/=12 years of age symptomatic on a low dose of an inhaled corticosteroid (ICS). The study consisted of a 2-week screening period on low dose ICS; a 4-week open-label FP 250 mcg twice daily (BID) run-in; a 52-week double-blind period (FP/salmeterol [FSC] 100/50 mcg [n=239] or FP 100 mcg [n=236] BID), and a 4-week FP 250 mcg BID run-out period. Annualized exacerbation rate was the primary outcome for comparing the two treatments. Other measures of asthma control included peak expiratory flow, asthma symptoms, and albuterol use. Safety was assessed through adverse events.

RESULTS

Exacerbation rates were not significantly different in those treated with FSC 100/50 mcg (0.449 per year) compared with FP 100 mcg (0.529 per year, p=0.169). When the per-protocol analysis was applied, the rates were 0.465 and 0.769 per year for FSC 100/50 mcg and FP 100 mcg, respectively. Treatment with FSC 100/50 mcg provided statistically greater improvements in lung function measures and nighttime awakenings (p</=0.050) and demonstrated numerically lower daily symptoms (p=0.216) and albuterol use (p=0.122). Two subjects treated with FSC 100/50 mcg were hospitalized for an asthma exacerbation compared to three treated with FP 100 mcg. The overall incidence of adverse effects during double-blind treatment was similar between the FSC 100/50 mcg and FP 100 mcg treatment groups (61% and 68%, respectively). Frequent study visits were required of subjects during this long-term study, and it remains unknown whether this intervention may affect generalizability.

CONCLUSION

In this large, prospective study among African Americans with asthma, the addition of salmeterol to FP resulted in a similar low rate of exacerbations and improved other markers of asthma control. Both FSC 100/50 mcg and FP 100 mcg were well-tolerated, and the overall safety-profiles were similar over 1 year of treatment.

Inhaled corticosteroids and long-acting beta-agonists in adult asthma: a winning combination in all?

In the recent years, considerable insight has been gained in to the optimal management of adult asthma. Most adult patients with asthma have mild intermittent and persistent disease, and it is acknowledged that many patients do not reach full control of all symptoms and signs of asthma. Those with mild persistent asthma are usually not well controlled without inhaled corticosteroids (ICS). Studies have provided firm evidence that these patients can be well controlled when receiving ICS, especially when disease is of recent onset. This treatment should be given on a daily basis at a low dose and when providing a good response should be maintained to prevent severe exacerbations and disease deterioration. Intermittent ICS treatment at the time of an exacerbation has also been suggested as a strategy for mild persistent asthma, but it is less effective than low-dose regular treatment for most outcomes. Adding a long-acting beta-agonist (LABA) to ICS appears to be unnecessary in most of these patients for optimising control of their asthma. Patients with moderate persistent asthma can be regarded as those who are not ideally controlled on low-dose ICS alone. The combination of an ICS and LABA is preferred in these patients, irrespective of the brand of medicine, and this combination is better than doubling or even quadrupling the dose of ICS to achieve better asthma control and reduce exacerbation risks. An ICS/LABA combination in a single inhaler represents a safe, effective and convenient treatment option for the management of patients with asthma unstable on inhaled steroids alone. Ideally, once asthma is under full control, the dose of inhaled steroids should be reduced, which is possible in many patients. The duration of treatment before initiating this dose reduction has, however, not been fully established. One of the combinations available to treat asthma (budesonide and formoterol) has also been assessed as both maintenance and rescue therapy with a further reduction in the risk for a severe exacerbation. Clinical effectiveness in the real world now has to be established, since this approach likely improves compliance with regular maintenance therapy.

Budesonide/formoterol decreases expression of vascular endothelial growth factor (VEGF) and VEGF receptor 1 within airway remodelling in asthma

INTRODUCTION

Angiogenesis and microvascular remodelling may play a vital role in the chronic inflammatory process within asthma. One of the most important factors involved in angiogenesis is vascular endothelial growth factor (VEGF). In this study we hypothesised that an increased expression of VEGF may be involved in airway remodelling in asthma patients. To this end, we compared the histology and expression levels of VEGF and one of its receptors (VEGFR1) in bronchial tissues of patients with asthma compared with control patients. We also investigated the effect of treatment with budesonide/formoterol (Symbicort; AstraZeneca, Lund, Sweden) in the relationship between VEGF and airway remodelling.

METHODS

Bronchial tissues were obtained from patients attending the West China Hospital from April to November 2006. Thirteen patients were diagnosed with moderate asthma and 10 others were treated as control. Histological and immunohistochemical comparisons between asthmatic and control patients were made at baseline, and (for asthmatic subjects) following 6 months of treatment with budesonide/formoterol.

RESULTS

Compared with control patients, asthmatic patients had significantly decreased respiratory parameters, including forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV(1)) (% predictive). Furthermore, patients with asthma had submucosal gland hyperplasia, increased smooth muscle mass, increased subepithelial fibrosis and neovascularisation. Asthmatic patients also exhibited increased expression of VEGF and VEGFR1 within epithelial cells. The increased expression of VEGF and its receptor correlated well with airway remodelling, airflow obstruction and airway hyper-responsiveness. After treatment with budesonide/formoterol for 6 months, the expression of VEGF and VEGFR1 was decreased, with correlatory decreased airway remodelling in patients with asthma.

CONCLUSION

The increased expression of VEGF and VEGFR(1) in asthmatic patients is accompanied by an increased number and size of blood vessels in asthmatic airways, as well as airway remodelling. Budesonide/formoterol therapy for 6 months can decrease the expression of VEGF and VEGFR(1) alongside airway remodelling in asthma. The inhibition of VEGF and its receptor may be a good therapeutic strategy for asthma.

Does measuring BHR add to guideline derived clinical measures in determining treatment for patients with persistent asthma?

RATIONALE

Little is known about the use of biomarkers in guiding treatment decisions in routine asthma management. The objective of this study was to determine whether adding a LABA to an ICS would control bronchial hyperresponsiveness (BHR) at an overall lower dose of ICS when titration of medication was based upon the assessment of routine clinical measures with or without the measurement of BHR.

METHODS

After a 2-week run-in period, subjects (> or = 12 years) were randomized to one of three treatment groups. Two groups followed a BHR treatment strategy (based on clinical parameters [lung function, asthma symptoms, and bronchodilator use] and BHR) and were treated with either fluticasone propionate/salmeterol (FSC(BHR) group) or fluticasone propionate (FP(BHR) group) (n=156 each). The third group followed a clinical treatment algorithm (based on clinical parameters alone) and were treated with fluticasone propionate (FP(REF) group; n=154). All treatments were administered via Diskus. Treatment doses were adjusted as needed every 8 weeks for 40 weeks according to the subject's derived severity class, which was based on clinical measures of asthma control with or without BHR.

RESULTS

The mean total daily inhaled corticosteroids (ICS) dose during the double-blind treatment period was lower, although not statistically significant, in the FSC(BHR) group compared with the FP(BHR) group (a difference of -42.9 mcg; p=0.07). Compared with the FP(REF) group, the mean total daily ICS dose was higher in the FSC(BHR) group (a difference of 85.2 mcg) and was significantly higher in the FP(BHR) group (a difference of 131.2 mcg, p=0.037).

CONCLUSION

This study demonstrated that for most subjects, control of BHR was maintained when treatment was directed toward control of clinical parameters. In addition, there was a trend towards control of BHR and clinical measures at a lower dose of ICS when used concurrently with salmeterol.

Airway cell and cytokine changes in early asthma deterioration after inhaled corticosteroid reduction

BACKGROUND

Back-titration of inhaled corticosteroid (ICS) dose in well-controlled asthma patients is emphasized in clinical guidelines, but there are few published data on the airway cell and cytokine changes in relation to ICS reduction. In our study, 20 mild-to-moderate persistent (inspite of low-moderate dose ICS treatment) asthmatic subjects prospectively rendered largely asymptomatic by high-dose ICS were assessed again by clinical, physiological, and airway inflammatory indices after 4-8 weeks of reduced ICS treatment. We aimed at assessing the underlying pathological changes in relation to clinical deterioration.

METHODS

Patients recorded daily symptom scores and peak expiratory flows (PEF). Spirometry and airways hyperreactivity (AHR) were measured and bronchoscopy was performed with assessment of airway biopsies (mast cells, eosinophils, neutrophils, and T lymphocytes), bronchoalveolar lavage (BAL) IL-5 and eotaxin levels and cellular profiles at the end of high-dose ICS therapy and again after ICS dose reduction. Baseline data were compared with symptomatic steroid-free asthmatics (n=42) and non-asthmatic controls (n=28).

RESULTS

After ICS reduction, subjects experienced a variable but overall significant increase in symptoms and reductions in PEF and forced expiratory volume in 1 s. There were no corresponding changes in AHR or airways eosinophilia. The most relevant pathogenic changes were increased CD4(+)/CD8(+) T cell ratio, and decreased sICAM-1 and CD18 macrophage staining (potentially indicating ligand binding). However, there was no relationship between the spectrum of clinical deterioration and the changes in cellular profiles or BAL cytokines.

CONCLUSIONS

These data suggest that clinical markers remain the most sensitive measures of early deterioration in asthma during back-titration of ICS, occurring at a time when AHR and conventional indices of asthmatic airway inflammation appear unchanged. These findings have major relevance to management and to how back-titration of ICS therapy is monitored.

Tolerability profiles of leukotriene receptor antagonists and long-acting beta2-adrenoceptor agonists in combination with inhaled corticosteroids for treatment of asthma: a review

Inhaled corticosteroids, long-acting beta2-adrenoceptor agonists, and leukotriene receptor antagonists are widely used for treatment of asthma. Inhaled corticosteroids are recommended as first-line therapy, whereas long-acting beta2-adrenoceptor agonists and leukotriene receptor antagonists are indicated as add-on therapy in patients not adequately controlled with corticosteroids alone. A number of studies have investigated the efficacy of combinations of these drugs in asthma, but several issues concerning the safety of these treatments are highly debated. This review provides a critical appraisal of the tolerability profiles of long-acting beta2-agonists and leukotriene receptor antagonists used in combination with inhaled corticosteroids for the treatment of asthma.

Effect of procaterol, a beta(2) selective adrenergic receptor agonist, on airway inflammation and hyperresponsiveness

BACKGROUND

beta-agonists are frequently used as bronchodilators for asthma as not only a reliever but also a controller, and their utility has increased with the development of long-acting beta(2) selective drugs. Although anti-inflammatory effects of beta(2) selective-agonists have been reported in vitro, side effects on augmentation of airway hyperresponsiveness by chronic use of beta(2) selective-agonists have been described in several reports. In this study, we investigated the effects of procaterol, a second-generation beta(2)-agonist, on airway inflammation in vivo using an antigen-specific murine model of asthma.

METHODS

Mice immunized with ovalbumin (OVA) + alum and challenged with inhaled ovalbumin were orally administered procaterol during the challenge. After inhalation, the mice were tracheostomized and placed in a body box under controlled ventilation to measure airway resistance before and after acetylcholine inhalation.

RESULTS

Administration of procaterol at a clinical dose equivalent did not augment airway hyperresponsiveness, inflammation of the airway wall, or subsequent airway wall thickening induced by OVA inhalation. BALF cell analysis revealed that the eosinophil number in the BALF was significantly reduced in procaterol-treated mice compared to untreated mice.

CONCLUSIONS

Oral administration of procaterol at a clinical dose did not augment airway responsiveness, but did reduce eosinophil inflammation.

Beta2-agonists and bronchial hyperresponsiveness

Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma, and individuals with this disease respond to a range of physiological and chemical insults that are otherwise innocuous to healthy subjects, suggesting that the mechanisms underlying this phenomenon are characteristic of the asthma phenotype. BHR can be increased following exposure to environmental allergens in suitably sensitized individuals, pollutants, and certain viruses and can also be exacerbated by exposure to certain drugs, including nonsteroidal anti-inflammatory agents and beta-blockers. Although beta2-agonists administered acutely remain the treatment for the symptoms of asthma, paradoxically, regular treatment with these drugs can result in an increase in BHR, and this has been suggested to contribute to the increase in asthma morbidity and mortality that has been reported by numerous investigators. This article highlights our current understanding of this phenomenon and examines the potential mechanisms responsible for this effect.

Interactions between corticosteroids and beta2-agonists

In vitro studies have demonstrated numerous ways in which beta2-agonists and corticosteroids may interact. Together with evidence of improved control of airway diseases using a combination therapy of inhaled corticosteroids and long-acting beta-agonists compared with treatment with either drug alone, this suggests that there may be a beneficial synergy between these two classes of medication. However, a positive interaction has not been clearly demonstrated in vivo. There is little evidence that beta2-agonists enhance the anti-inflammatory actions of inhaled corticosteroids. Corticosteroids do not enhance the bronchodilator response to beta2- agonists, nor do they appear to prevent the development of tolerance during chronic beta2-agonist treatment. The evidence that high doses of corticosteroids can reverse tolerance to beta2-agonists is conflicting. Most of the clinical benefits from combinations using inhaled corticosteroids and long-acting beta-agonists to treat asthma could result from additive or complimentary effects of the drugs on different parts of the disease process. Nevertheless, there are several studies in which the combination of a long- or short-acting beta-agonist with an inhaled corticosteroid appears to have provided more than additive clinical benefits. The issue warrants further study. Combined inhaled corticosteroid/beta-agonist treatment will remain the basis of asthma management for the foreseeable future, and although the overall clinical benefit of the combination is no longer in doubt, there is more to learn about maximizing this benefit and minimizing adverse effects.

Summing up 100 years of asthma

In this review, we aim to lead the readers through the historical highlights of pathophysiological concepts and treatment of asthma. Understanding the nature and links of asthma has modeled our diagnostic, pathophysiological and therapeutic thinking and acting. The recognition of its heterogeneous nature in combination with several refined and sophisticated technologies will mark a new era of phenotype-specific approach and treatment of asthma.

Long-acting beta2-agonists for chronic asthma in adults and children where background therapy contains varied or no inhaled corticosteroid

BACKGROUND

Asthma is a common respiratory disease among both adults and children and short acting inhaled beta-2 agonists are used widely for 'reliever' bronchodilator therapy. Long acting beta-2 agonists (LABA) were introduced as prospective 'symptom controllers' in addition to inhaled corticosteroid 'preventer' therapy (ICS). In this updated review we have included studies in which patients were either not on ICS as a group, or in which some patients, but not all, were on ICS to complement previous systematic reviews of studies where LABA was given in patients uniformly receiving ICS. We have focussed particularly on serious adverse events, given previous concerns about potential risks, especially of death, from regular beta-2 agonist use.

OBJECTIVES

This review aimed to determine the benefit or detriment on the primary outcome of asthma control with the regular use of LABA compared with placebo, in mixed populations in which only some were taking ICS and in populations not using ICS therapy.

SEARCH STRATEGY

We carried out searches using the Cochrane Airways Group trial register, most recently in October 2005. We searched bibliographies of identified RCTs for additional relevant RCTs and contacted authors of identified RCTs for other published and unpublished studies.

SELECTION CRITERIA

All randomised studies of at least four weeks duration, comparing a LABA given twice daily with a placebo, in chronic asthma. Selection criteria to this updated review have been altered to accommodate recently published Cochrane reviews on combination and addition of LABA to ICS therapy. Studies in which all individuals were uniformly taking ICS were excluded from this review.

DATA COLLECTION AND ANALYSIS

Two reviewers performed data extraction and study quality assessment independently. We contacted authors of studies for missing data.

MAIN RESULTS

Sixty-seven studies (representing 68 experimental comparisons) randomising 42,333 participants met the inclusion criteria. Salmeterol was used as long-acting agent in 50 studies and formoterol fumarate in 17. The treatment period was four to nine weeks in 29 studies, and 12 to 52 weeks in 38 studies. Twenty-four studies did not permit the use of ICS, and forty permitted either inhaled corticosteroid or cromones (in three studies this was unclear). In these studies between 22% and 92% were taking ICS, with a median of 62%. There were significant advantages to LABA treatment compared to placebo for a variety of measurements of airway calibre including morning peak expiratory flow (PEF), evening PEF and FEV1. They were associated with significantly fewer symptoms, less use of rescue medication and higher quality of life scores. This was true whether patients were taking LABA in combination with ICS or not. Findings from SMART (a recently published surveillance study) indicated significant increases in asthma related deaths, respiratory related deaths and combined asthma related deaths and life threatening experiences. The absolute increase in asthma-related mortality was consistent with an increase of around one per 1250 patients treated with LABA for six months, but the confidence intervals are wide (from 700 to 10,000). Post-hoc exploratory subgroups suggested that African-Americans and those not on inhaled corticosteroids were at particular risk for the primary end-point of death or life-threatening asthma event. There was also a suggestion of an increase in exacerbation rate in children. Pharmacologically predicted side effects such as headache, throat irritation, tremor and nervousness were more frequent with LABA treatment.

AUTHORS' CONCLUSIONS

LABA are effective in the control of chronic asthma in the "real-life" subject groups included. However there are potential safety issues which call into question the safety of LABA, particularly in those asthmatics who are not taking ICS, and it is not clear why African-Americans were found to have significant differences in comparison to Caucasians for combined respiratory-related death and life threatening experiences, but not for asthma-related death.

Efficacy and safety of formoterol delivered through the Novolizer, a novel dry powder inhaler (DPI) compared with a standard DPI in patients with moderate to severe asthma

BACKGROUND & OBJECTIVE

Because of environmental concerns CFC-containing pressurised metered dose inhalers (pMDI) had to be replaced by dry powder inhalers (DPI). The Novolizer, a novel DPI has previously been shown to be as effective as the Turbuhaler in delivering budesonide. The objective of this study was to show non-inferiority of inhaled formoterol therapy delivered through the Novolizer compared to formoterol delivered through the Aerolizer in patients suffering from moderate to severe asthma.

METHODS

In this double-blind, double-dummy, multicentre study 392 patients were randomised and received a dose of 12 microg formoterol twice daily for 4 weeks either through the Aerolizer or the Novolizer. FEV1 after 4 weeks of treatment was the primary variable. Secondary variables were FVC, PEF, consumption of short-acting; 2 adrenoceptor agonists, asthma symptoms, tolerability and safety.

RESULTS

After 4 weeks of treatment, the mean trough FEV1 (95% CI) was 2.34 L (2.24-2.45) for the Novolizer and 2.31 L (2.21-2.41) for the Aerolizer. Non-inferiority was proven (p<0.0001, pre-defined; of 0.25 L). All secondary variables (incl. PEF) confirmed these findings. Treatment with both devices was safe and well tolerated.

CONCLUSION

Inhalation of 12 microg formoterol twice daily via Novolizer was shown to be equally therapeutically effective compared to the inhalation via Aerolizer in the treatment of moderate to severe persistent asthma. Treatment via both inhalers was safe and well tolerated.

Long-acting beta2-agonists in asthma: not so SMART?

Asthma is a worldwide chronic disorder that is characterised by airway inflammation and hyper-responsiveness, which results in intermittent airflow obstruction and subsequent perception of symptoms and exacerbations. Inhaled corticosteroids are a fundamental component in the prevention of the short- and long-term complications associated with inadequately controlled asthma. However, many individuals experience persistent symptoms and exacerbations despite receiving low-to-medium doses of an inhaled corticosteroid (400-800 microg/day of beclometasone or equivalent). In these symptomatic asthmatic patients, guidelines advocate the initiation of a long-acting beta2-adrenoceptor agonist (LABA) as additional second-line controller therapy. The recent SMART (Salmeterol Multi-centre Asthma Research Trial) study was designed to compare the effects of add-on salmeterol 42 microg (ex-actuator) twice daily with placebo over 28 weeks in a randomised, double-blind, parallel-group fashion, with the intention to enrol 60,000 asthmatic patients. However, the study was halted prematurely because preliminary data revealed an increased mortality associated with regular use of salmeterol. Moreover, concerning rates of respiratory-related deaths, asthma-related deaths and life-threatening events were observed among African Americans, who constituted up to 18% of the study population. This in turn prompted the US FDA to announce important safety information regarding inhalers containing LABAs and advise that new labelling be produced outlining the "small but significant risk in asthma-related deaths" associated with their regular use. This evidence-based review discusses the data from SMART and highlights potentially important drawbacks with regular use of LABAs in persistent asthma.

Isoproterenol suppresses cytokine-induced RANTES secretion in human lung epithelial cells through the inhibition of c-jun N-terminal kinase pathway

It has been reported that beta2-agonists may potentially exert some anti-inflammatory action in addition to bronchodilation that may contribute to their beneficial effects on asthma control. Bronchial epithelial cells are well known to respond to a range of stimuli by producing various biologically active mediators that can influence airway inflammation. RANTES (regulated on activation, normal T cells expressed and secreted) plays an important role in the pathophysiology of airway inflammation of asthmatics through its chemotactic activity for eosinophils. In this study, the authors investigated whether cytokine-induced RANTES release from BEAS-2B human bronchial epithelial cells could be modulated by beta-agonist isoproterenol (ISO). The possible involvement of c-jun N-terminal kinase (JNK) pathway was also studied. Combination of tumor necrosis factor-alpha and interleukin-1beta (cytokine mix) increased RANTES release from BEAS-2B cells and stimulated JNK activity. Similar to JNK inhibitor SP600125, ISO inhibited not only the production of RANTES but also the activation of JNK pathway in cytokine mix-stimulated BEAS-2B cells. The effect of ISO was mediated by the beta2-adrenoceptor, since it was blocked by ICI 118,551, a selective beta2-receptor antagonist, but not by atenolol, a selective beta1-receptor antagonist. Adenylyl cyclase activator forskolin reproduced the effects of ISO. Isoproterenol was found to inhibit the release of RANTES from the human bronchial epithelial cells, at least in part, through the inhibition of JNK signaling pathway.

Randomised trial comparing as-needed versus regular treatment with formoterol in patients with persistent asthma

PURPOSE

The aim of this study was to demonstrate the equivalent efficacy of inhaled formoterol in asthmatic patients, either given as-needed or on a regular twice-daily schedule.

METHODS

Randomised, open 12-week study in patients with mild to moderate asthma not adequately controlled with inhaled glucocorticosteroids alone. Patients received inhaled formoterol as needed or on a regular schedule (2x2 puffs/day with 6 microg formoterol per puff). Patients in the twice-daily formoterol group could use salbutamol as a rescue medication. The primary endpoint was the number of patients with asthma exacerbations in each group.

RESULTS

Thirty-nine centres randomised 359 patients. The number of patients with asthma exacerbations showed neither a clinically relevant nor a statistically significant difference between groups: formoterol as-needed: 3.95% (7 of 177); twice daily: 3.45% (6 of 174). Patients in the formoterol as-needed group used significantly less formoterol (-1.5 puffs per day; P<0.0001). Including the saved rescue medication (up to one puff per day), total beta-2 agonist use in the formoterol as-needed group decreased by approximately 2-2.5 puffs per day. Both formoterol treatment schedules were well tolerated. Musculoskeletal pain and tremor were less frequent in the formoterol as-needed group: headaches were slightly more frequent.

CONCLUSION

Formoterol given as needed and without additional beta-2 agonist, and formoterol given on a regular basis twice daily, supplemented by salbutamol as a rescue medication, appeared equally effective in this clinical study. Drug consumption was markedly lower in the former group.

Continuous nebulized albuterol attenuates acute lung injury in an ovine model of combined burn and smoke inhalation

OBJECTIVE

Albuterol, due to its bronchodilatory and anti-inflammatory effects, is given via continuous nebulization in children with severe asthma. Combined burn and smoke inhalation injury frequently results in acute lung injury due to a combination of airway obstruction and inflammation. We hypothesized that albuterol administered via continuous nebulization would mitigate acute lung injury after smoke inhalation injury and burn.

DESIGN

Randomized prospective animal model.

SUBJECTS

Twenty adult female sheep (mean weight, 33.1+/-0.9 kg).

INTERVENTIONS

Adult ewes were subjected to a 40% body surface area third-degree flame burn and smoke inhalation injury after tracheostomy. Sheep were allocated to a) sham group, b) saline continuous nebulization group, c) 20 mg of albuterol continuous nebulization group, or d) 40 mg of albuterol continuous nebulization group (n=5 animals per group). All groups received intravenous lactated Ringer's solution at 4 mL.kg-1.%burn(-1).24 hrs-1 for resuscitation and were equally mechanically ventilated throughout the 48-hr study period. Pulmonary and cardiac function, lung lymph flow, bronchial obstruction score, and wet/dry lung weights were recorded.

RESULTS

Compared with saline and control groups, the albuterol groups had lower pause and peak inspiratory pressures, decreased pulmonary transvascular fluid flux, a significantly higher Pao2/Fio2 ratio, and decreased shunt fraction at 48 hrs postinjury. The wet-to-dry lung weight ratio and bronchial obstruction scores were lower for sheep receiving albuterol.

CONCLUSIONS

Continuous nebulization of albuterol improves pulmonary function via improved airway clearance and decreased fluid flux in a combined burn/smoke inhalation injury model.

Effects of intranasal fluticasone and salmeterol on allergen-induced nasal responses

BACKGROUND

Combination of inhaled steroid and long-acting beta-agonists has synergistic effects in asthma.

OBJECTIVE

To investigate whether nasal corticosteroid and long-acting beta-agonists have synergistic effects on allergen-induced nasal responses.

METHODS

The effects of intranasal treatment with fluticasone p-MDI (50 microg bid), salmeterol p-MDI (25 microg bid), their combination, and placebo, on nasal symptoms, eosinophil differential cell count and albumin in nasal lavage fluid (measures of inflammation and leakage respectively) and nasal electrical potential difference (measure of epithelial integrity) were studied in 11 atopic subjects with rhinitis, in a randomized, partially-blinded, 4-period, cross-over study. The measurements were made at baseline, at the end of 1 week of treatment, and immediately after a nasal allergen provocation.

RESULTS

Allergen-induced sneeze, postnasal drip and nasal obstruction were significantly reduced by fluticasone, but not by salmeterol. Eosinophil count in postallergen nasal lavage fluid was significantly less after fluticasone (median 1.9%, IQR 4.6) and salmeterol treatment (median 2.5%, IQR 8.5) compared with placebo (median 12.5%, IQR 27.9). Compared with placebo, both fluticasone and salmeterol attenuated allergen-induced change in nasal potential (mean change from baseline -18.5, +0.4 and -7.2% respectively) and the increase in nasal albumin (median 154, 119 and 130 ng/ml respectively). Combination treatment did not have any additional benefits over the individual therapies.

CONCLUSIONS

Although salmeterol has anti-inflammatory properties, intranasal salmeterol or its combination with fluticasone do not offer any added benefit over intranasal fluticasone alone for allergen-induced nasal responses.

Structural changes in airway diseases: characteristics, mechanisms, consequences, and pharmacologic modulation

In airway diseases such as asthma and COPD, specific structural changes may be observed, very likely secondary to an underlying inflammatory process. Although it is still controversial, airway remodeling may contribute to the development of these diseases and to their clinical expression and outcome. Airway remodeling has been described in asthma in various degrees of severity, and correlations have been found between such features as increase in subepithelial collagen or proteoglycan deposits and airway responsiveness. Although the clinical significance of airway remodeling remains a matter of debate, it has been suggested as a potential target for treatments aimed at reducing asthma severity, improving its control, and possibly preventing its development. To date, drugs used to treat airway diseases have a little influence on airway structural changes. More research should be done to identify key changes, valuable treatments, and proper interventional timing to counteract these changes. The potential of novel therapeutic agents to reverse or prevent airway remodeling is an exciting avenue and warrants further evaluation.

Adding salmeterol to an inhaled corticosteroid: long term effects on bronchial inflammation in asthma

BACKGROUND

Addition of the long acting beta2 agonist salmeterol to inhaled corticosteroids leads to better symptomatic asthma control than increasing the dose of inhaled corticosteroids. However, little is known about the long term effects of adding salmeterol on the asthmatic inflammatory process, control of which is considered important for the long term outcome of asthma.

METHODS

After a 4 week fluticasone run-in period, 54 patients with allergic asthma were randomised to receive twice daily treatment with fluticasone 250 microg with or without salmeterol 50 microg for 1 year in a double blind, parallel group design (total daily dose of fluticasone 500 microg in both treatment groups). Primary outcomes were sputum eosinophil numbers and eosinophil cationic protein concentrations. Secondary outcomes were neutrophil associated sputum parameters and a respiratory membrane permeability marker. The effects on allergen induced changes were determined before and at the end of the treatment period.

RESULTS

Adding salmeterol to fluticasone resulted in improved peak expiratory flow, symptom scores, rescue medication usage, and bronchial hyperresponsiveness (p < 0.05 for all). There was no sustained effect on sputum cell differential counts and cytokine concentrations during the treatment period or on changes induced by allergen challenge at the end of treatment (p > 0.05). However, adding salmeterol significantly reduced sputum ratios of alpha2-macroglobulin and albumin during the treatment period (p = 0.001).

CONCLUSIONS

The addition of salmeterol to fluticasone produces no sustained effect on allergen induced cellular bronchial inflammation but leads to a significant improvement in size selectivity of plasma protein permeation across the respiratory membrane. This may contribute to the improved clinical outcome seen in patients with allergic asthma when a long acting beta2 agonist is combined with inhaled corticosteroids.

Therapeutic approach to vascular remodelling in asthma

Bronchial asthma can be characterized by some significant changes in airway blood vessels, which may contribute to airway remodelling. Despite the clinical and functional consequences of bronchial microvascular remodelling in asthma, up to now, little data have been published on the therapeutic approach to this phenomenon. Corticosteroids are the only anti-asthma drugs that act positively on the three aspects of bronchial vascular remodelling: angiogenesis, dilatation and permeability. Modest positive effects of treatments with beta2-agonists and leukotrienes receptor antagonists on bronchial microcirculatory changes have been reported. In the future, agents that specifically inhibit angiogenesis could represent a novel approach for positively acting on bronchial microvascular changes in chronic inflammatory airway diseases, such as chronic bronchitis and asthma.

Phagocytosis stimulates mobilization and shedding of intracellular CD16A in human monocytes and macrophages: inhibition by HIV-1 infection

Surface and intracellular staining coupled with flow cytometric analysis was used to show for the first time that human macrophages and a minor subset of peripheral blood monocytes have an internal pool of CD16A, which is mobilized and shed during Fc receptor for immunoglobulin G-mediated phagocytosis. Human immunodeficiency virus type 1 (HIV-1) infection of monocyte-derived macrophages in vitro led to a reduction in the phagocytosis-induced up-regulation in CD16A shedding. These results suggest that monocytes and macrophages may be a source of soluble CD16A, which is elevated in the serum of patients in a variety of disease states and that the mobilization and shedding of CD16A in response to phagocytosis are disrupted by HIV-1 infection.

Control of mild to moderate asthma over 1-year with the combination of salmeterol and fluticasone propionate

OBJECTIVE

The aim of this study was to assess asthma control using salmeterol plus fluticasone propionate (FP) in combination (SFC) versus salmeterol or FP as monotherapy in patients with mild to moderate asthma.

METHODS

In this randomised, double-blind, parallel-group study, 322 symptomatic patients were recruited, of which 282 were randomised to receive either salmeterol (50 microg), FP (250 microg), or SFC (50 microg/250 microg), via a single Diskus inhaler twice daily for 12 months. Outcome variables included the number of patients requiring an increase in study medication and the number experiencing 2 exacerbations during the 12-month treatment period. Airway hyper-responsiveness (AHR) and lung function tests were performed at clinic visits. Peak expiratory flow, rescue medication use, symptom scores and adverse events were recorded in diary cards.

RESULTS

Fewer patients required an increase in study medication with SFC (10.5%) than with either FP (34.8%) or salmeterol (61.1%) (P<0.001). Significantly fewer patients experienced 2 exacerbations with SFC (4.2%), compared with FP (17.4%; P<0.01) or salmeterol (40%; P<0.001). SFC improved AHR to a significantly greater extent than FP (methacholine PC20=1.8 mg/ml vs. 1.1 mg/ml; P<0.05) or salmeterol (methacholine PC20=1.8 mg/ml vs. 0.7 mg/ml; P<0.001).

CONCLUSIONS

The protection against exacerbations may be attributed to better control of inflammation, AHR and lung function parameters achieved with salmeterol and FP in combination, compared with either treatment alone.

Fluticasone versus placebo for chronic asthma in adults and children

BACKGROUND

Inhaled fluticasone propionate (FP) is a relatively new inhaled corticosteroid for the treatment of asthma.

OBJECTIVES

1. To assess efficacy and safety outcomes in studies that compared FP to placebo for treatment of chronic asthma.2. To explore the presence of a dose-response effect.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register (January 2005), reference lists of articles, contacted trialists and searched abstracts of major respiratory society meetings (1997-2004).

SELECTION CRITERIA

Randomised trials in children and adults comparing FP to placebo in the treatment of chronic asthma. Two reviewers independently assessed articles for inclusion and methodological quality.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted data. Quantitative analyses were undertaken using RevMan 4.2

MAIN RESULTS

Seventy-five studies met the inclusion criteria (14,208 participants). Methodological quality was high. In non-oral steroid treated asthmatics with mild and moderate disease FP resulted in improvements from baseline compared with placebo across all dose ranges (100 to 1000 mcg/d) in FEV1 (between 0.13 to 0.45 litres); morning PEF (between 23 and 47 L/min); symptom scores (based on a standardised scale, between 0.5 and 0.85); reduction in rescue beta-2 agonist use (between 1.2 and 2.2 puffs/day). High dose FP increased the number of patients who could withdraw from prednisolone: FP 1000-1500 mcg/day Peto Odds Ratio 14.07 (95% CI 7.17 to 27.57). FP at all doses led to a greater likelihood of sore throat, hoarseness and oral Candidiasis. Twenty-one patients would need to be treated for one extra to develop Candidiasis (FP 500 mcg/day), whilst only three or four patients need to be treated to avoid one extra patient being withdrawn due to lack of efficacy at all doses of FP.

AUTHORS' CONCLUSIONS

Doses of FP in the range 100-1000 mcg/day are effective. In most patients with mild-moderate asthma improvements with low dose FP are only a little less than those associated with high doses when compared with placebo. High dose FP appears to have worthwhile oral-corticosteroid reducing properties. FP use is accompanied by an increased likelihood of oropharyngeal side effects.

Long-acting beta2-agonists versus placebo in addition to inhaled corticosteroids in children and adults with chronic asthma

BACKGROUND

Long-acting inhaled beta2-adrenergic agonists are recommended as 'add-on' medication to inhaled corticosteroids in the maintenance therapy of asthmatic adults and children aged two years and above.

OBJECTIVES

To quantify in asthmatic patients the safety and efficacy of the addition of long-acting beta2-agonists to inhaled corticosteroids on the incidence of asthma exacerbations, pulmonary function and other measures of asthma control.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE and CINAHL), bibliographies of RCTs and correspondence with manufacturers, until April 2004.

SELECTION CRITERIA

RCTs were included that compared the addition of inhaled long-acting beta2-agonists to corticosteroids with inhaled corticosteroids alone for asthma therapy in children aged two years and above and in adults.

DATA COLLECTION AND ANALYSIS

Studies were assessed independently by two review authors for methodological quality and data extraction. Confirmation was obtained from the trialists when possible. The primary endpoint was rate of asthma exacerbations requiring systemic corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), symptom scores, adverse events and withdrawal rates.

MAIN RESULTS

Of 594 identified citations, 49 trials met the inclusion criteria: 27 full-text publications, one unpublished full-text report and 21 abstracts. Twenty-three citations (21 abstracts and two full-text publications) provided data in insufficient detail, 26 trials contributed to this systematic review. All but three trials were of high methodological quality. Most interventions (N = 26) were of four-month duration or less. Eight trials focused on children and 18 on adults, with participants generally symptomatic with moderate airway obstruction despite their current inhaled steroid regimen. If a trial had more than one intervention or control group, additional control to intervention comparisons were considered separately. Formoterol (N = 17) or salmeterol (N = 14) were most frequently added to low-dose inhaled corticosteroids (200 to 400 microg/day of beclomethasone (BDP) or equivalent). The addition of a daily long-acting beta2-agonist (LABA) reduced the risk of exacerbations requiring systemic steroids by 19% (relative risk (RR) 0.81, 95% CI 0.73 to 0.90). The number needed to treat for one extra patient to be free from exacerbation for one year was 18 (95% CI 13 to 33). The addition of LABA significantly improved FEV1 (weighted mean difference (WMD) 170 mL, 95% CI 110 to 240) using a random-effects model, increased the proportion of symptom-free days (WMD 17%, 95% CI 12 to 22, N = 6 trials) and rescue-free days (WMD 19%, 95% CI 12 to 26, N = 2 trials). The group treated with LABA plus inhaled corticosteroid showed a reduction in the use of rescue short-acting beta2-agonists (WMD -0.7 puffs/day, 95% CI -1.2 to -0.2), experienced less withdrawals due to poor asthma control (RR 0.5, 95% CI 0.4 to 0.7) and less withdrawals due to any reason (RR 0.9, 95% CI 0.8 to 0.98), using a random-effects model. There was no group difference in risk of overall adverse effects (RR 0.98, 95% CI 0.92 to 1.05), withdrawals due to adverse health events (RR 1.29, 95% CI 0.96 to 1.75) or specific adverse health events.

AUTHORS' CONCLUSIONS

In patients who are symptomatic on low to high doses of inhaled corticosteroids, the addition of a long-acting beta2-agonist reduces the rate of exacerbations requiring systemic steroids, improves lung function, symptoms and use of rescue short-acting beta2-agonists. The similar number of serious adverse events and withdrawal rates in both groups provides some indirect evidence of the safety of long-acting beta2-agonists as add-on therapy to inhaled corticosteroids.

Lung myofibroblasts as targets of salmeterol and fluticasone propionate: inhibition of alpha-SMA and NF-kappaB

Lung myofibroblasts play a major role in the pathophysiology of asthma, contributing not only to tissue remodelling but also to airway inflammation. Nevertheless, only recently, attention has been focused on these cells as potential targets for anti-allergic drugs. Herein, we analysed the pharmacological response of lung myofibroblasts to beta2-agonists associated or not to inhaled corticosteroids, investigating their effects on (i) the constitutive and transforming growth factor-beta (TGF-beta)-induced expression of alpha-smooth muscle actin (alpha-SMA), the main functional marker of myofibroblastic differentiation and contractility; (ii) isometric contraction and (iii) tumour necrosis factor-alpha (TNF-alpha)-induced nuclear translocation of the pro-inflammatory transcription factor nuclear factor-kappaB (NF-kappaB). The beta2-agonist salmeterol (SMl) has on human lung myofibroblasts new direct anti-contractile/anti-inflammatory effects that are amplified by the combined use of low concentrations of the glucocorticoid fluticasone propionate (FP). First, SMl and/or FP (10(-12) M) inhibits the constitutive and TGF-beta-induced expression of alpha-SMA. Second, the two drugs block the TNF-alpha-induced nuclear translocation of the pro-inflammatory transcription factor NF-kappaB. Finally, SMl decreases TNF- alpha-induced production of the inflammatory cytokine IL-6. The complementary anti-inflammatory/ anti-contractile effects displayed by SMl and FP on lung myofibroblasts in vitro may be related to the improvement in lung function and symptom control obtained in vivo by the early use of low doses of glucocorticoids in combination with long-acting beta2-agonists.

Adding salmeterol to an inhaled corticosteroid reduces allergen-induced serum IL-5 and peripheral blood eosinophils

BACKGROUND

Adding a long-acting beta(2)-agonist to inhaled corticosteroids results in better symptomatic asthma control than increasing the dose of inhaled corticosteroids.

OBJECTIVE

Investigating whether adding the long-acting beta(2)-agonist salmeterol to the inhaled corticosteroid fluticasone propionate has an effect on allergen-induced allergic inflammation in asthma.

METHODS

Bronchial allergen challenges were performed in 26 patients with allergic asthma, pretreating them with a single dose of either fluticasone/salmeterol (100/50 microg) or fluticasone alone (100 microg), in a double-blind, randomized, cross-over design. Sputum and serum markers of bronchial inflammation were measured after allergen challenge, as well as lung function parameters. Primary outcomes were sputum eosinophil numbers and eosinophil cationic protein.

RESULTS

Asthmatic responses after allergen challenge were significantly reduced after pretreatment with fluticasone/salmeterol relative to fluticasone alone. Sputum inflammatory markers after allergen challenge were not significantly affected by fluticasone/salmeterol pretreatment. By contrast, serum IL-5 was significantly reduced (geometric mean serum IL-5 [SEM]: 0.5 [0.3] vs 1.1 [0.3] pg/mL 1 hour and 0.6 [0.3] vs 1.1 [0.3] pg/mL 6 hours after challenge with fluticasone/salmeterol vs fluticasone alone pretreatment, respectively; P values < .05). Also, peripheral blood eosinophils were significantly reduced (geometric mean number x 10(6)/L [SEM]: 172 [0.1] vs 237 [0.1] at 6 hours and 271 [0.1] vs 351 [0.1] at 24 hours with fluticasone/salmeterol vs fluticasone alone pretreatment, respectively; P < .05).

CONCLUSION

Adding salmeterol to fluticasone reduces allergen-induced serum IL-5 and peripheral blood eosinophils. This phenomenon may contribute to the improved clinical outcomes that result from adding a long-acting beta(2)-agonist to inhaled corticosteroids.

Long-acting beta2-agonists in asthma: an overview of Cochrane systematic reviews

According to major asthma management guidelines, long-acting beta2-agonists (LABAs) should be used only when asthma remains symptomatic in patients already receiving regular inhaled corticosteroids (ICSs). A large Cochrane systematic review provides evidence that LABAs are safe and beneficial in control of asthma; sub-group analyses indicating that this is true when ICSs are used and in their absence. Two other Cochrane systematic reviews have found that LABAs are more effective than regular short-acting beta2-agonists, and are as effective as theophylline with fewer side-effects. These reviews support guidelines in the use of LABA as additional therapy when asthma is inadequately controlled by ICS at moderate dose. However, guidelines may be too conservative, and more studies in stable mild asthma comparing their use and safety with placebo and ICS are required.

Long-acting beta2-agonists: comparative pharmacology and clinical outcomes

Salmeterol and formoterol are both long-acting beta(2)-adrenoceptor agonists (beta(2)-agonists). They both provide excellent bronchodilating and bronchoprotective effects in patients with asthma but their are some differences between these two long-acting beta(2)-agonists in vitro and in vivo. Formoterol has a greater potency and intrinsic activity than salmeterol, which can become especially apparent at higher doses than that clinically recommended, and in contracted bronchi. Long-term use of long-acting beta(2)-agonists can induce tolerance, which can be partially reversed with corticosteroids. Long-acting beta(2)-agonists have some anti-inflammatory effects in vitro, but data in vivo are less convincing. Compared with doubling the dose of inhaled corticosteroids, the addition of inhaled long-acting beta(2)-agonists to inhaled corticosteroids improves symptom control in patients with asthma and reduces both the exacerbation rate of asthma and hospital admission rate. No enhanced airway responsiveness or loss of perception of dyspnea has been observed with the use of inhaled long-acting beta(2)-agonists. Monotherapy with long-acting beta(2)-agonists is not recommended.