Effect of differing doses of inhaled budesonide on markers of airway inflammation in patients with mild asthma

Tailored interventions based on exhaled nitric oxide versus clinical symptoms for asthma in children and adults

BACKGROUND

The measurement of severity and control of asthma in both children and adults can be based on subjective or objective measures. It has been advocated that fractional exhaled nitric oxide (FeNO) can be used to monitor airway inflammation as it correlates with some markers of asthma. Interventions for asthma therapies have been traditionally based on symptoms and/or spirometry.

OBJECTIVES

To evaluate the efficacy of tailoring asthma interventions based on exhaled nitric oxide in comparison to clinical symptoms (with or without spirometry/peak flow) for asthma related outcomes in children and adults.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register of Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and reference lists of articles. The last search was completed in February 2009.

SELECTION CRITERIA

All randomised controlled comparisons of adjustment of asthma therapy based on exhaled nitric oxide compared to traditional methods (primarily clinical symptoms and spirometry/peak flow).

DATA COLLECTION AND ANALYSIS

Results of searches were reviewed against pre-determined criteria for inclusion. Relevant studies were independently selected in duplicate. Two authors independently assessed trial quality and extracted data. Authors were contacted for further information with response from one.

MAIN RESULTS

Two studies have been added for this update, which now includes six (2 adults and 4 children/adolescent) studies; these studies differed in a variety of ways including definition of asthma exacerbations, FeNO cut off levels, the way in which FeNO was used to adjust therapy and duration of study. Of 1053 participants randomised, 1010 completed the trials. In the meta-analysis, there was no significant difference between groups for the primary outcome of asthma exacerbations or for other outcomes (clinical symptoms, FeNO level and spirometry). In post-hoc analysis, a significant reduction in mean final daily dose inhaled corticosteroid per adult was found in the group where treatment was based on FeNO in comparison to clinical symptoms, (mean difference -450 mcg; 95% CI -677 to -223 mcg budesonide equivalent/day). However, the total amount of inhaled corticosteroid used in one of the adult studies was 11% greater in the FeNO arm. In contrast, in the paediatric studies, there was a significant increase in inhaled corticosteroid dose in the FeNO strategy arm (mean difference of 140 mcg; 95% CI 29 to 251, mcg budesonide equivalent/day).

AUTHORS' CONCLUSIONS

Tailoring the dose of inhaled corticosteroids based on exhaled nitric oxide in comparison to clinical symptoms was carried out in different ways in the six studies and found only modest benefit at best and potentially higher doses of inhaled corticosteroids in children. The role of utilising exhaled nitric oxide to tailor the dose of inhaled corticosteroids cannot be routinely recommended for clinical practice at this stage and remains uncertain.

Fractional exhaled nitric oxide in asthma: an update

In asthma, clinical symptoms and lung function are insensitive in reflecting the underlying airway inflammation, and monitoring of this process has only recently become available. Fractional exhaled nitric oxide (Fe(NO)) is now recognized as a reliable surrogate marker of eosinophilic airway inflammation and offers the advantage of being completely non-invasive and very easy to obtain. This review summarizes the clinical use of Fe(NO) in asthma. It covers the relationship between Fe(NO) and the underlying eosinophilic inflammation, the pathophysiology and production of Fe(NO), technical aspects of Fe(NO) measurement and potential confounding factors in interpreting levels. Fe(NO) reference values and the role of Fe(NO) in asthma assessment, diagnosis and management are also discussed.

Effects of inhaled versus systemic corticosteroids on exhaled nitric oxide in severe acute asthma

BACKGROUND

There is a paucity of information on the differential effects of systemic versus inhaled corticosteroids on airway inflammation in patients with acute asthma. This study aimed to evaluate the effects of stopping systemic corticosteroids while maintaining the inhaled corticosteroids (ICS) on airway inflammation, lung function and asthma symptoms in patients who had been discharged from hospital after treatment for severe acute asthma.

METHODS

Twenty-four adult patients with severe exacerbations of asthma were treated with both oral and inhaled corticosteroids after discharge from hospital. Oral corticosteroids were stopped after 1 week. Spirometry, asthma quality of life questionnaire (AQLQ) score and exhaled nitric oxide (NO) were measured at discharge, 1 week, and 2 weeks after discharge.

RESULTS

Withdrawal of oral corticosteroids resulted in significant rebound in mean exhaled NO by 11.0ppb (95% CI, 4.9-17.1ppb, p<0.001) or 47.7% (95% CI, 22.4-73.1%) despite uninterrupted ICS treatment. The rebound in exhaled NO occurred despite significant improvement in the mean AQLQ score (p=0.006) and frequency of reliever use (p=0.003) and was not associated with significant change in the mean FEV(1) (p=0.64).

CONCLUSIONS

In patients discharged from hospital after treatment for asthma exacerbations, withdrawal of oral corticosteroids resulted in increase in exhaled NO levels despite continued ICS treatment.

The use of exhaled nitric oxide in the management of asthma

It has recently become clear that airways disease associated with eosinophilic airway inflammation, but not other patterns of inflammation, is closely associated with favourable short-and long-term responses to corticosteroid therapy, irrespective of the clinical context in which it occurs. Moreover, a raised exhaled nitric oxide (FE(NO)) is a reasonable marker of eosinophilic airway inflammation, which has a number of advantages as a diagnostic and monitoring tool. In this review we outline essential background information on the use of FE(NO) in clinical practice and discuss some recent work evaluating the clinical value of this technique.

Biochemical markers as a response guide for steroid therapy in asthma

BACKGROUND

Exhaled breath condensate pH and hydrogen peroxide concentration is a non-invasive, simple and inexpensive assay that can be performed for monitoring in patients with asthma.

OBJECTIVE

To evaluate the possibility of usefulness of expired breath condensate pH and H(2)O(2) concentration as well as serum total antioxidant capacity and malondialdehyde as markers for steroid treatment response.

PATIENTS AND METHODS

A total of 153 patients were included in this study (age range 18 to 64 years). Asthmatic patients, regularly followed for at least 3 months, were randomly recruited for the study over a period of one month. All patients received inhaled beclomethasone dipropionate (1,000 microg daily in four divided doses) and salbutamol inhalers (800 microg daily in four divided doses) for 4 weeks. Expired breath condensate was collected at the end of the study to determine hydrogen peroxide concentration and pH. Venous blood samples were collected for determination of total antioxidant capacity and malondialdehyde as markers of peroxidation.

RESULTS

In asthmatic patients with poorly controlled asthma, expired breath condensate hydrogen peroxide concentration was higher and the pH was lower than stable asthma. Serum malondialdehyde concentration in poorly controlled asthma was higher (6.98 micromol/L), and total antioxidant capacity was lower (589 micromol/L) than in stable asthma.

CONCLUSION

Exhaled hydrogen peroxide concentration and pH can be used as predictors for monitoring of nonresponse to asthma treatment.

Partitioned exhaled nitric oxide to non-invasively assess asthma

Asthma is a chronic inflammatory disease of the lungs, characterized by airway hyperresponsiveness. Chronic repetitive bouts of acute inflammation lead to airway wall remodeling and possibly the sequelae of fixed airflow obstruction. Nitric oxide (NO) is a reactive molecule synthesized by NO synthases (NOS). NOS are expressed by cells within the airway wall and functionally, two NOS isoforms exist: constitutive and inducible. In asthma, the inducible isoform is over expressed, leading to increased production of NO, which diffuses into the airway lumen, where it can be detected in the exhaled breath. The exhaled NO signal can be partitioned into airway and alveolar components by measuring exhaled NO at multiple flows and applying mathematical models of pulmonary NO dynamics. The airway NO flux and alveolar NO concentration can be elevated in adults and children with asthma and have been correlated with markers of airway inflammation and airflow obstruction in cross-sectional studies. Longitudinal studies which specifically address the clinical potential of partitioning exhaled NO for diagnosis, managing therapy, and predicting exacerbation are needed.

Predictors for failed dose reduction of inhaled corticosteroids in childhood asthma

BACKGROUND AND OBJECTIVE

Studies of Western populations have shown that increased exhaled nitric oxide (FeNO) and/or sputum eosinophils (sp-Eos) are predictive of asthma exacerbations. However, the utility of these measurements in different populations and settings is unknown. This study aimed to determine the predictors for failure of reduction of inhaled corticosteroid (ICS) doses in children with stable asthma.

METHODS

Fifty children (median age 11.8 years, interquartile range (IQR) 5.9 years) had their dose of ICS halved every 8 weeks until they reached the study end-point (exacerbation or weaned off ICS). Spirometry, FeNO and induced sputum cells were measured at baseline and at each stage of ICS reduction.

RESULTS

Eleven subjects suffered an asthma exacerbation and the remainder was successfully weaned off ICS. Subjects with an exacerbation were older (15.4 years (IQR 5.4) vs 11.4 years (IQR 3.9), P = 0.019) and more likely to be boys (P = 0.035). FeNO (median 156 p.p.b. (IQR 131) vs 76.1 p.p.b. (IQR 79.5), P = 0.013) and sp-Eos (17.3% (IQR 33.8%) vs 7.1% (IQR 9.9%), P = 0.019) were significantly greater in those who had an exacerbation. The areas under the receiver operating characteristic curves for FeNO (0.78, 95% CI: 0.59-0.97, P = 0.013) and sp-Eos (0.76, 95% CI: 0.56-0.96, P = 0.016) were similar (P = 0.88) and both were significantly greater than that for FEV(1)% predicted (0.12, 95% CI: 0.08-0.56, P = 0.0013).

CONCLUSIONS

Older boys with raised FeNO and sp-Eos are at higher risk of failure of reduction in their ICS dose. Monitoring airway inflammation in children with asthma using FeNO or sp-Eos is clinically useful in guiding ICS dose reduction in a non-Western outpatient setting.

The value of FeNO measurement in asthma management: the motion against FeNO to help manage childhood asthma--reality bites

Since exhaled nitric oxide (FeNO) was first demonstrated to be raised in asthmatic patients in the early 1990s, there has been a strong interest in its potential role in the diagnosis and management of asthma. This culminated in 2003 when the US Food and Drug Administration cleared the NIOX nitric oxide analyser for clinical application in patients with asthma. The interest in FeNO is based on the assumptions that FeNO is a marker of asthma and asthma control, and that it reflects eosinophilic airway inflammation. However, the literature remains unconvincing and inconclusive. Furthermore, studies which have management algorithms that include FeNO as a guide to asthma treatment have failed to observe any improvement in asthma control compared with the use of standard asthma guidelines. At present, the cost of including FeNO in management guidelines far outweighs any potential benefits.

Tailored interventions based on exhaled nitric oxide versus clinical symptoms for asthma in children and adults

BACKGROUND

The measurement of severity and control of asthma in both children and adults can be based on subjective or objective measures. It has been advocated that fractional exhaled nitric oxide (FeNO) can be used to monitor airway inflammation as it correlates with some markers of asthma. Interventions for asthma therapies have been traditionally based on symptoms and/or spirometry.

OBJECTIVES

To evaluate the efficacy of tailoring asthma interventions based on exhaled nitric oxide in comparison to clinical symptoms (with or without spirometry/peak flow) for asthma related outcomes in children and adults.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register of Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and reference lists of articles. The last search was completed in December 2006.

SELECTION CRITERIA

All randomised controlled comparisons of adjustment of asthma therapy based on exhaled nitric oxide compared to traditional methods (primarily clinical symptoms and spirometry/peak flow).

DATA COLLECTION AND ANALYSIS

Results of searches were reviewed against pre-determined criteria for inclusion. Relevant studies were independently selected in duplicate. Two authors independently assessed trial quality and extracted data. Authors were contacted for further information but none were received. Data was analysed as "intervention received" and sensitivity analyses performed.

MAIN RESULTS

Four (2 adult and 2 paediatric) studies were included; these studies differed in a variety of ways including definition of asthma exacerbations, FeNO cut off levels and duration of study. Of 356 participants randomised, 324 completed the trials. In the meta-analysis, there was no difference between groups for the primary outcome of asthma exacerbations or for other outcomes (clinical symptoms, FeNO level and spirometry). In post-hoc analysis, a significant reduction in mean final daily dose inhaled corticosteroid per adult was found in the group where treatment was based on FeNO in comparison to clinical symptoms; WMD -282.46 (95% CI -422.08 to -142.84). There was no difference in ICS dose between the groups in the overall daily dose in the adult studies or in the paediatric studies.

AUTHORS' CONCLUSIONS

Tailoring the dose of inhaled corticosteroids based on exhaled nitric oxide in comparison to clinical symptoms was carried out in different ways in the four studies that were found, and the results show only modest differences. The role of utilising exhaled nitric oxide to tailor the dose of inhaled corticosteroids is currently uncertain.

Rapid effect of inhaled ciclesonide in asthma: a randomized, placebo-controlled study

BACKGROUND

Ciclesonide is a novel inhaled corticosteroid for the treatment of asthma, and it is important to measure the onset of effect of this therapy on airway hyperresponsiveness (AHR), exhaled nitric oxide (NO), and levels of eosinophils in induced sputum.

METHODS

In a randomized, double-blind, crossover study, 21 patients with mild asthma inhaled ciclesonide 320 microg (ex-actuator) qd, ciclesonide 640 microg (ex-actuator) bid, and placebo for 7 days. Exhaled NO and AHR to adenosine monophosphate (AMP), measured as the provocative concentration of AMP producing a 20% reduction in FEV1 (PC20FEV1), were assessed after inhalation on days 1, 3 and 7. Eosinophil levels in induced sputum were also measured.

RESULTS

Ciclesonide 320 microg qd and 640 microg bid produced significantly greater improvements in PC20FEV1 compared with placebo on day 1 (within 2.5 h), and on days 3 and 7 (all p < 0.0001). On day 3, both ciclesonide doses significantly reduced exhaled NO levels by - 17.7 parts per billion (p < 0.0001) and - 15.4 parts per billion (p < 0.003) vs placebo, respectively. Significant reductions were maintained during the study with both ciclesonide doses (p < 0.01). A nonsignificant trend towards a decrease in eosinophil cell numbers was observed after 7 days of ciclesonide treatment, especially in patients receiving the higher dose.

CONCLUSIONS

A single dose of ciclesonide decreased AHR to AMP and exhaled NO within 3 h, while FEV, improved at 3 days and 7 days.

Exhaled nitric oxide distinguishes between subgroups of preschool children with respiratory symptoms

BACKGROUND

Respiratory symptoms are common in early childhood. The clinical characterization of disease presentation and hence its likely disease progression has so far been proven difficult.

OBJECTIVE

To investigate whether exhaled nitric oxide (NO) could be helpful to distinguish between subgroups of nonwheezy and wheezy young children less than 4 years of age.

METHODS

Exhaled NO was measured in 391 children (age 3-47 months) with nonwheezy and wheezy respiratory symptoms. Children were divided into 3 groups: children with recurrent cough but no history of wheeze (group 1), with early recurrent wheeze and a loose index for the prediction of asthma at school age (group 2), and with frequent recurrent wheeze and a stringent index for the prediction of asthma at school age (group 3).

RESULTS

Children from group 3 showed significantly higher median (interquartile range) fractional exhaled NO (FeNO) levels (11.7 [11.85]) than children from groups 1 (6.5 [5.5]; P < .001) and 2 (6.4 [6.5]; P < .001). No difference in FeNO levels was found between children from groups 1 and 2 (P = .91).

CONCLUSION

Wheezy young children less than 4 years of age with a stringent index for the prediction of asthma at school age have elevated levels of FeNO compared with children with recurrent wheeze and a loose index for the prediction of asthma at school age or children with recurrent cough.

Exhaled nitric oxide in childhood asthma: a review

As an 'inflammometer', the fraction of nitric oxide in exhaled air (Fe(NO)) is increasingly used in the management of paediatric asthma. Fe(NO) provides us with valuable, additional information regarding the nature of underlying airway inflammation, and complements lung function testing and measurement of airway hyper-reactivity. This review focuses on clinical applications of Fe(NO) in paediatric asthma. First, Fe(NO) provides us with a practical tool to aid in the diagnosis of asthma and distinguish patients who will benefit from inhaled corticosteroids from those who will not. Second, Fe(NO) is helpful in predicting exacerbations, and predicting successful steroid reduction or withdrawal. In atopic asthmatic children Fe(NO) is beneficial in adjusting steroid doses, discerning those patients who require additional therapy from those whose medication dose could feasibly be reduced. In pre-school children Fe(NO) may be of help in the differential diagnosis of respiratory symptoms, and may potentially allow for better targeting and monitoring of anti-inflammatory treatment.

Sputum eosinophils and the response of exercise-induced bronchoconstriction to corticosteroid in asthma

BACKGROUND

The relationship between eosinophilic airway inflammation and exercise-induced bronchoconstriction (EIB), and the response to inhaled corticosteroid (ICS) therapy was examined.

METHODS

Twenty-six steroid-naïve asthmatic patients with EIB were randomized to two parallel, double-blind, crossover study arms (13 subjects in each arm). Each arm compared two dose levels of inhaled ciclesonide that were administered for 3 weeks with a washout period of 3 to 8 weeks, as follows: (1) 40 vs 160 microg daily; and (2) 80 vs 320 microg daily. Baseline and weekly assessments with exercise challenge and sputum analysis were performed.

RESULTS

Data were pooled and demonstrated that 10 subjects had baseline sputum eosinophilia >or= 5%. Only high-dose ICS therapy (ie, 160 and 320 microg) significantly attenuated the sputum eosinophil percentage. Sputum eosinophil percentage significantly correlated with EIB severity, and predicted the magnitude and temporal response of EIB to high-dose therapy, but not to low-dose therapy (ie, 40 and 80 microg). Low-dose ICS therapy provided a significant reduction in EIB at 1 week, with little additional improvement thereafter, irrespective of baseline sputum eosinophil counts. In contrast, high-dose ICS therapy provided a significantly greater improvement in EIB in subjects with sputum eosinophilia compared to those with an eosinophil count of < 5%. The difference between the eosinophilic groups in the magnitude of improvement in EIB was evident after the first week of high-dose ICS therapy and increased with time.

CONCLUSIONS

These results suggest that eosinophilic airway inflammation may be important in modifying the severity of EIB and the response to ICS therapy. Measurements of sputum eosinophil percentage may, therefore, be useful in predicting the magnitude and temporal response of EIB to different dose levels of ICSs.

TRIAL REGISTRATION

clinicaltrial.gov; Identifier: NCT00525772.

Exhaled nitric oxide and carbon monoxide in respiratory diseases

Breath tests have gained increasing interest in recent years mainly driven by the unmet clinical need to monitor airway diseases and to obtain information on unravelled aspects of respiratory disorders. A prototype of such measurement reaching clinical significance besides its use as a research tool is the measurement of exhaled nitric oxide (NO). It took hardly more than a decade after the discovery that exhaled breath contains NO for this measurement to be approved for clinical practice to monitor anti-inflammatory treatment in asthma. Recent studies demonstrate that using exhaled NO measurement to guide anti-inflammatory treatment in asthma may help clinical decision making. A similarly small molecule present in exhaled breath is carbon monoxide, which is not only a biomarker of cigarette smoking but has also been suggested to reflect ongoing oxidative stress/antioxidant defense. The scope of this review is the exciting field of exhaled monoxides. Since several other biomarkers have also been studied in the exhaled breath this review will provide a brief introduction to them.

A study to evaluate safety and efficacy of mepolizumab in patients with moderate persistent asthma

RATIONALE

Accumulation of eosinophils in the bronchial mucosa of individuals with asthma is considered to be a central event in the pathogenesis of asthma. In animal models, airway eosinophil recruitment and airway hyperresponsiveness in response to allergen challenge are reduced by specific targeting of interleukin-5. A previous small dose-finding study found that mepolizumab, a humanized anti-interleukin-5 monoclonal antibody, had no effect on allergen challenge in humans.

OBJECTIVES

To investigate the effect of three intravenous infusions of mepolizumab, 250 or 750 mg at monthly intervals, on clinical outcome measures in 362 patients with asthma experiencing persistent symptoms despite inhaled corticosteroid therapy (400-1,000 mug of beclomethasone or equivalent).

METHODS

Multicenter, randomized, double-blind, placebo-controlled study.

MEASUREMENTS AND MAIN RESULTS

Morning peak expiratory flow, forced expiratory volume in 1 second, daily beta(2)-agonist use, symptom scores, exacerbation rates, and quality of life measures. Sputum eosinophil levels were also measured in a subgroup of 37 individuals. Mepolizumab was associated with a significant reduction in blood and sputum eosinophils in both treatment groups (blood, P < 0.001 for both doses; sputum, P = 0.006 for 250 mg and P = 0.004 for 750 mg). There were no statistically significant changes in any of the clinical end points measured. There was a nonsignificant trend for decrease in exacerbation rates in the mepolizumab 750-mg treatment group (P = 0.065).

CONCLUSIONS

Mepolizumab treatment does not appear to add significant clinical benefit in patients with asthma with persistent symptoms despite inhaled corticosteroid therapy. Further studies are needed to investigate the effect of mepolizumab on exacerbation rates, using protocols specifically tailored to patients with asthma with persistent airway eosinophilia.

Nasal nitric oxide: longitudinal reproducibility and the effects of a nasal allergen challenge in patients with allergic rhinitis

BACKGROUND

Exhaled nitric oxide (eNO) is a validated noninvasive marker of airway inflammation in asthma. In patients with allergic rhinitis (AR), increased levels of nasal nitric oxide (nNO) have also been measured. However, the applicability of nNO as a marker of upper airway inflammation awaits validation.

AIM

To test the longitudinal reproducibility of standardized nNO measurements in patients with AR and the effects of nasal allergen challenge.

METHODS

Twenty patients with clinically stable, untreated AR participated in a combined study design. First, reproducibility of nNO was tested over 1, 7, and 14-21 days. Subsequently, the effect of nasal allergen challenge on nNO was studied in a placebo-controlled, parallel design. Nasal NO was measured with a chemoluminescence analyzer. Ten subjects randomly underwent a standardized nasal allergen challenge; 10 subjects received placebo. Response to nasal challenge was monitored by composite symptom scores.

RESULTS

There was a good reproducibility of nNO up to 7 days [coefficient of variation (CV) over 1 (16.45%) and 7 days (21.5%)], decreasing over time [CV (14-21 days): 38.3%]. As compared with placebo, allergen challenge caused a significant increase in symptom scores (P < 0.001), accompanied by a decrease in nNO at 20 min postchallenge (P = 0.001). Furthermore, there was a gradual increase in nNO at 7 h, reaching significance at 24-h postallergen (P = 0.04).

CONCLUSIONS

Similar to eNO in asthma, nNO is a noninvasive marker, potentially suitable to monitor upper airway inflammation following allergen-induced late response. Present data show a good reproducibility of nNO measurements, decreasing over time, probably because of subclinical seasonal influences.

Assessment of airway inflammation with exhaled NO measurement

Assessing airway inflammation is important for investigating the underlying mechanisms of many lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), bronchiectasis, primary ciliary dyskinesia (PCD) and cystic fibrosis. A growing interest has recently directed toward non-invasive methods for the assessment of airway inflammation. Measurement of exhaled nitric oxide in exhaled air is an exciting innovative technique that gives new insights into the pathophysiology of lung disease and asthma in particular, with many potential clinical applications. Careful standardisation of measurement techniques has facilitated the use of this new measurement in paediatric respiratory medicine. Non-invasiveness and instantaneous results potentially make it a suitable instrument for use in children starting from the age of 4, with useful applications both in asthma diagnosis and monitoring.

The relationship between exhaled nitric oxide measured with an off-line method and airway reversible obstruction in Japanese adults with asthma

BACKGROUND

Exhaled nitric oxide (eNO) is a useful marker of eosinophilic airway inflammation in asthma patients. There is no study to show the relationship between the eNO measured by using an off-line method and the degree of reversibility of airflow limitation in Japanese asthma patients. We sought to investigate the relationship between the eNO level measured by using an off-line method and the degree of reversibility of bronchial constriction in Japanese asthma patients.

METHODS

The study population comprised 97 asthma patients in our outpatient clinic with some patients in both groups who received inhaled corticosteroid treatment. We measured eNO levels, forced expiratory volume in one second (FEV1) before and after treatment, reversible airway obstruction (DeltaFEV1) after inhalation of bronchodilator, and other parameters.

RESULTS

eNO was significantly correlated with peripheral blood eosinophil counts in asthma patients (in steroid-naïve asthma patients, r=0.544, p<0.0001; in asthma patients treated with inhaled corticosteroid, r=0.463, p=0.026), and subjects with severe eosinophilia in sputum showed high levels of eNO (mild eosinophilia versus severe, p=0.0152). Among patients with obstructive impairment, eNO levels were correlated with DeltaFEV1 regardless of whether patients received (r=0.527, p=0.0435) or did not receive (r=0.64, p = 0.0056) inhaled corticosteroid. In subjects with normal pulmonary function, there was no significant relationship between eNO and DeltaFEV1 with or without inhaled corticosteroid.

CONCLUSIONS

In patients with obstructive impairment, eNO reflects the degree of reversible airflow limitation. In subjects with normal pulmonary function, eNO may facilitate the diagnosis and management of asthma, rather than indicate reversible bronchial obstruction. eNO measurement by off-line methods is applicable as a potential tool for the diagnosis of asthma and management of asthma patients.

Exhaled nitric oxide measurements: clinical application and interpretation

The use of exhaled nitric oxide measurements (F(E)NO) in clinical practice is now coming of age. There are a number of theoretical and practical factors which have brought this about. Firstly, F(E)NO is a good surrogate marker for eosinophilic airway inflammation. High F(E)NO levels may be used to distinguish eosinophilic from non-eosinophilic pathologies. This information complements conventional pulmonary function testing in the assessment of patients with non-specific respiratory symptoms. Secondly, eosinophilic airway inflammation is steroid responsive. There are now sufficient data to justify the claim that F(E)NO measurements may be used successfully to identify and monitor steroid response as well as steroid requirements in the diagnosis and management of airways disease. F(E)NO measurements are also helpful in identifying patients who do/do not require ongoing treatment with inhaled steroids. Thirdly, portable nitric oxide analysers are now available, making routine testing a practical possibility. However, a number of issues still need to be resolved, including the diagnostic role of F(E)NO in preschool children and the use of reference values versus individual F(E)NO profiles in managing patients with difficult or severe asthma.

Non-invasive measurement of airway inflammation in asthma

Assessing the severity and control of a patient's asthma is of great importance to ensure that pharmacotherapy is optimized. Measures such as lung function, symptoms, and reliever use have traditionally been used as objective means of undertaking this assessment, but until now the level of airway inflammation has not been quantified. As asthma is primarily an inflammatory disorder, it would be desirable to include a measure of this process when evaluating disease control. The following article outlines methods of non-invasively measuring asthmatic airway inflammation and highlights their potential role in clinical practice.

Interpreting the histopathology of chronic cough: a prospective, controlled, comparative study

HYPOTHESIS

Trauma from chronic coughing produces airway inflammation similar to diseases causing cough.

DESIGN

Prospective, cross-sectional, controlled, clinicopathologic correlation study in four groups: group 1, cough from intrapulmonary diseases; group 2, cough from extrapulmonary diseases; group 3, cough that was unexplained; and group 4, nonsmoking, asymptomatic control subjects.

METHODS

Patients with chronic cough underwent a standardized workup including endobronchial biopsies before treatment. Causes were determined by a favorable response to therapy. Bronchial biopsy samples from control subjects were obtained from surgical specimens.

RESULTS

There were 24 adult subjects (13 women and 11 men) with mean cough duration of 8.6 +/- 7.4 years (+/- SD). Thirteen patients had cough due to a specific disease: intrapulmonary diseases in 5 patients, and extrapulmonary diseases in 8 patients. Eleven patients had unexplained cough. Compared to control subjects, there was minimal-to-moderate chronic inflammation in all coughers (p < or = 0.0004), in group 1 (p < or = 0.039), group 2 (p = 0.061), and group 3 (p < or = 0.025) diseases that were not correlated with cough duration. There was no difference in type of inflammation, cough duration, or smoking history between groups, nor were there histologic differences between subjects with explained causes of cough compared with unexplained cough.

CONCLUSIONS

Our findings suggest that airway inflammation associated with chronic cough, assessed on morphologic appearance and inflammatory cell counting in hematoxylin-eosin-prepared samples, may be due to the trauma of coughing, and the inflammation may be similar to that seen with diseases putatively thought to cause chronic cough. Investigators must be cautious when attributing pathogenic importance to observed inflammatory changes in airways of coughing subjects.

Strategy aimed at reduction of sputum eosinophils decreases exacerbation rate in patients with asthma

Under Global Initiative for Asthma guidelines, the clinical control of disease activity and the adjustment of treatment in patients with asthma are based on symptoms, use of rescue medication, lung function and peak expiratory flow measurement (standard strategy). We investigated whether a strategy to reduce the number of sputum eosinophils (EOS strategy) gives better clinical control and a lower exacerbation rate compared with the standard strategy. Fifty-five patients with moderate to severe asthma entered this open, randomized, parallel-group study and visited the out-patient department every 3 months for 18 months. The dose of corticosteroids was adjusted according to the standard strategy or the percentage of sputum eosinophils (EOS strategy). During the study period, the EOS strategy led to a significantly lower incidence of asthma exacerbations compared with the standard strategy group (0.22 and 0.78 exacerbations per year per patient, respectively). There were significant differences between the strategies in time to first exacerbation.

Effect of ciclesonide dose and duration of therapy on exercise-induced bronchoconstriction in patients with asthma

BACKGROUND

Inhaled corticosteroid therapy improves exercise symptoms in asthmatic subjects.

OBJECTIVE

We sought to evaluate exercise-induced bronchoconstriction (EIB) as a method of determining the dose and time responses of inhaled corticosteroid therapy.

METHODS

In this double-blind, randomized, cross-over study with 2 parallel arms, 4 doses of inhaled ciclesonide (40 microg and 160 microg or 80 microg and 320 microg) were compared over 3 weeks of treatment. Twenty-six asthmatic subjects (age range, 14-27 years) with baseline FEV1 values of greater than 70% of predicted value were enrolled. The primary outcome was the maximum percentage decrease in FEV1 after standardized exercise challenge.

RESULTS

After 1 week of therapy, the mean +/- SEM reduction in maximum decrease in FEV1 in the ciclesonide 40-microg/80-microg dose group was 9% +/- 2.6% (95% CI, 3.9% to 14%), with no additional reduction thereafter. In the ciclesonide 160-microg/320-microg dose group, there was an 8.7% +/- 2.5% (95% CI, 3.7% to 13.7%) reduction in maximum decrease in FEV1 after week 1, which continued in a linear fashion during subsequent weeks of treatment. No difference was found between the 2 treatment arms in the temporal response of EIB to ciclesonide treatment. The maximum percentage attenuation in EIB achieved was 51.1% +/- 7.9%, which was achieved by using the 320-microg dose after 3 weeks of treatment.

CONCLUSIONS

A significant improvement in EIB was demonstrated for all doses of ciclesonide. Use of 160 microg/320 microg of ciclesonide resulted in a continuing improvement in FEV1 with time, and no plateau was seen in protective effect during 3 weeks of treatment.

CLINICAL IMPLICATIONS

Attenuation in exercise-induced decrease can be seen as early as after 1 week of therapy with inhaled ciclesonide at doses greater than 40 microg. However, maximal attenuation in exercise response continues to increase at doses greater than or equal to 200 microg, even after 3 weeks of therapy.

Airway inflammation in asymptomatic children with episodic wheeze

Airway pathologies have been comprehensively researched in adult asthma, but in children, the extent of airway inflammation associated with episodic wheeze, often diagnosed as asthma, has not been fully characterized. It is not clear whether persistent airway inflammation is present in the absence of wheezing symptoms, and there is controversy regarding the role of age and atopy. This study assessed cellular and cytokine markers of airway inflammation in asymptomatic children with a history of episodic wheeze. Children with a history of episodic wheeze and cough (study group) and nonasthmatic patients requiring elective surgery (control group) were recruited. All subjects in the study group had a history of significant episodic wheezing (>2 episodes per year), and used only as-needed beta-agonist treatment. Bronchoalveolar lavage (BAL) was obtained using bronchoscopic lavage (study group) and nonbronchoscopic lavage (control group). Differential cell counts of BAL and flow cytometry were performed to identify T-lymphocyte phenotypes, and intracellular cytokine profiles were measured after phorbol-12-myristate 13-acetate (PMA) stimulation of BAL fluid T-cells. Twenty-one children with a history of 2-12 episodes of wheeze per year and 21 nonasthmatic subjects without respiratory symptoms were recruited. Study and control subjects were matched for age (median age, 5 years) and demographic characteristics. Study subjects had higher IgE levels, but their measurements were still within normal range. No significant differences in BAL differential cell counts were noted, and in both groups, the majority of T-cells were CD3+ CD8+, with a median CD4:CD8 ratio of 0.6. There was no significant difference in T-cell expression of the activation markers HLA-DR and CD25 (IL-2 receptor), or in PMA-induced production of the intracellular cytokines IFN-gamma, IL-2, IL-4, IL-5, and IL-10. The results of this study suggest that significant T-cell-driven airway inflammation is absent in mild or nonatopic, asymptomatic children of this age group who have episodic wheeze. Our findings support asthma management guidelines that do not recommend long-term treatment of this group of patients with anti-inflammatory medications.

Initial corticosteroid therapy for asthma

PURPOSE OF REVIEW

This review examines the commencement of maintenance pharmacotherapy for asthma: inhaled corticosteroids alone or in combination with long-acting beta2 agonists.

RECENT FINDINGS

A systematic review of randomized controlled trials has examined the starting dose of inhaled corticosteroids (high, moderate, low) and the dose regimen (step down versus constant) in asthma. There was no significant difference in key asthma outcomes for step down compared with a constant inhaled corticosteroid dose. There was no significant difference between high or moderate dose inhaled corticosteroid groups (n=11) for morning peak expiratory flow, symptoms and rescue medication use. There may be a benefit from high-dose inhaled corticosteroids for airway hyperresponsiveness. There was a significant improvement in peak expiratory flow and nocturnal symptoms in favour of a moderate inhaled corticosteroid dose compared with low-dose treatment. Long-acting beta2 agonists combined with inhaled corticosteroids as initial asthma therapy has been examined in a systematic review of nine randomized controlled trials. Inhaled corticosteroids combined with long-acting beta2 agonists led to significant improvements in forced expiratory volume in 1 s, morning peak expiratory flow, symptom score and symptom-free days but no difference in exacerbations requiring oral corticosteroids. A randomized controlled trial of patients with uncontrolled asthma found a benefit of escalating doses of salmeterol/fluticasone compared with fluticasone on asthma control.

SUMMARY

Initial inhaled corticosteroid therapy should begin with a constant, moderate dose. Initial therapy with long-acting beta2 agonist and inhaled corticosteroids achieves superior improvement in symptoms and lung function, and at a quicker rate than inhaled corticosteroids alone. There is no benefit in terms of reduced exacerbations unless an escalating inhaled corticosteroid dose strategy is used.

A critical appraisal of methods used in early clinical development of novel drugs for the treatment of asthma

Asthma is a heterogeneous disorder characterized by chronic airway inflammation, hyperresponsiveness and remodeling. Being the hallmark of asthma, airway inflammation has become the most important target for therapeutic agents. Consequently, during the past decade various semi-and non-invasive methods have been explored to sample the airway inflammation in asthma. In this review, we provide a practical overview of the current status of various sampling techniques including sputum induction, exhaled breath analysis, and bronchoprovocation tests (BPTs). We focus on their applicability for monitoring in clinical practice and in intervention trials in asthma.

High fractional concentration of nitric oxide in exhaled air despite steroid treatment in asthmatic children

BACKGROUND

The fractional concentration of nitric oxide in exhaled air (FENO) is elevated in atopic asthma and typically responds to treatment with inhaled corticosteroids (ICS). However, some patients have persistently high FENO levels despite treatment.

OBJECTIVE

We studied how optimizing the inhalation technique and increasing ICS doses would affect FENO in stable atopic asthmatic children who had elevated FENO while using ICS.

METHODS

In 41 stable asthmatic children who were treated with ICS (median daily dose 800 microg budesonide equivalent, range 100-1600 microg) and maintained FENO> or =20 p.p.b., we optimized the inhalation technique by thorough instruction and measured FENO 2 weeks later. Then, if FENO remained > or =20 p.p.b., we increased the ICS dose and reassessed FENO 2 weeks later.

RESULTS

Improving the inhalation technique did not reduce FENO. Increasing ICS from a daily median dose of 800 to 1200 microg budesonide had no significant effect on FENO. FENO correlated positively with symptom scores in the following 2 and 4 weeks (P=0.001, 0.002) and beta2-agonist use the 2 and 4 weeks following FENO measurement (P=0.02, 0.004).

CONCLUSION

We conclude that common steps in asthma treatment, i.e. inhalation instruction and increasing ICS dose, were both ineffective in reducing FENO in atopic asthmatic children with elevated FENO values despite treatment with ICS. This implies that FENO cannot simply be incorporated in current treatment guidelines.

Flunisolide decreases exhaled nitric oxide and nitrotyrosine levels in asthmatic children

BACKGROUND

Exhaled nitric oxide (FeNO) has been reported to be elevated in the oxidative stress involved in asthmatic patients, and the reaction of nitric oxide (NO) with superoxide anions results in the formation of nitrotyrosine. The purpose of this study was to investigate the effect of inhaled steroid treatment on nitrotyrosine levels collected by exhaled breath condensate (EBC) and on FeNO.

METHODS

This was a single-blind placebo-controlled study. The lung function, FeNO, and nitrotyrosine levels were evaluated in 10 asthmatic children.

RESULTS

The nitrotyrosine levels were stable during the placebo period (T0 = 1.16 ng/ml versus T1 = 1.05 ng/ml; NS.), whereas they decreased after the treatment with flunisolide (T2 = 1.14 ng/ml versus T3 = 0.88 ng/ml; P < .001). No significant reduction in FeNO levels was observed after placebo treatment (T0 = 38.4 ppb versus T1 = 34.7 ppb, NS.). In contrast, FeNO values decreased significantly being at T3 = 14.9 ppb (T1 versus T3; P = .024).

CONCLUSIONS

This study shows that corticosteroid treatment reduces nitrotyrosine levels in EBC of asthmatic subjects.

Exhaled nitric oxide predicts airway hyper-responsiveness to hypertonic saline in children that wheeze

BACKGROUND

Exhaled nitric oxide (eNO) has shown good validity for the assessment of airway inflammation in asthmatic children. In large-scale epidemiological studies, this method would be preferred above airway challenge tests, because it is a quick and easy applicable tool.

OBJECTIVE

In this study, we aimed to assess the discriminatory capacity of eNO, and prechallenge FEV1 for airway hyper-responsiveness (AHR) in 8-13-year old schoolchildren.

MATERIALS AND METHODS

Parents completed the ISAAC questionnaire, and children were tested for atopy, AHR to hypertonic (4.5%) saline (HS), and eNO. Diagnostic value was assessed by the area under the receiver operating curves (ROC), and calculation of positive and negative predicted values at different cut-off points for eNO and prechallenge FEV1.

RESULTS

Areas under the ROC-curves of AHR were 0.65 for eNO and 0.62 for FEV1. Values increased to 0.71 and respectively 0.75 for a combined occurrence of AHR and current wheeze. Highest sensitivity and specificity were obtained at a cut-off value of 43 ppb for eNO and 103% predicted for FEV1. At these cut-off values, the positive predictive values for the presence of AHR in symptomatic children were respectively 83% (eNO) and 33% (FEV1), and negative predictive values in asymptomatic children were, respectively, 90 (eNO) and 80% (FEV1).

CONCLUSION

Exhaled nitric oxide is a valid screening tool for AHR to HS in children that present with current wheeze, and it outperforms FEV1 as a predictor of AHR.

Formoterol added to low-dose budesonide has no additional antiinflammatory effect in asthmatic patients

STUDY OBJECTIVE

Adding inhaled long-acting beta2-agonists to a low dose of inhaled corticosteroids (ICSs) results in better asthma control than increasing the dose of ICSs. An important, but as yet unresolved, question is whether this is due to an additional reduction of airway inflammation.

DESIGN

Double-blind, parallel-group trial.

PATIENTS

Forty asthma patients (FEV1, 50 to 90% predicted; provocative concentration of a substance [methacholine] causing a 20% fall in FEV1 of < 8 mg/mL; no ICSs in the last 4 weeks).

INTERVENTIONS

Randomization to 8 weeks of treatment with 100 microg of budesonide bid plus placebo (BUD200) or 100 microg of budesonide bid plus 12 microg of formoterol (BUD200 + F). Then the dose of budesonide (BUD) was increased to 400 microg bid in both groups for another 8 weeks. Bronchial biopsy specimens were collected before, and after 8 and 16 weeks of treatment. Eosinophils (major basic protein [MBP]) and mast cells (tryptase) were analyzed by immunohistochemistry.

RESULTS

BUD200 reduced the MBP staining (p = 0.008) and tryptase staining (p = 0.048) in the epithelium compared to baseline levels. There were no significant differences between the BUD200 and BUD200 + F groups. In both groups, increasing the dosage of BUD to 800 microg had no significant additional antiinflammatory effect.

CONCLUSIONS

Our results demonstrate that BUD administered at a low dose has significant antiinflammatory effects in patients with mild asthma. No significant additional antiinflammatory effects could be demonstrated either by adding formoterol or by increasing the dose of BUD.

Budesonide once versus twice-daily administration: meta-analysis

OBJECTIVES

The aim of this study was to examine the efficacy of budesonide administered once daily compared to twice daily in asthma.

METHODOLOGY

Meta-analysis of randomised controlled trials comparing budesonide administered once versus twice a day that presented data on at least one clinical outcome measure was conducted.

RESULTS

A total of 10 studies, with 1922 children and adults with asthma, met the inclusion criteria. These studies were performed predominantly with mild to moderate asthmatic patients, using doses of budesonide ranging from 200 to 800 microg per day. There was no significant difference between daily dosing once or twice for all the clinical outcome variables, including withdrawals due to asthma, for which the odds ratio was 1.0 (95% confidence interval, 0.65-1.52).

CONCLUSIONS

In mild to moderate asthma a once-daily budesonide regimen has a similar efficacy to a twice-daily regimen in doses up to 800 microg per day. A once-daily regimen has potential advantages in terms of patient compliance and satisfaction, when used in clinical practice.

Sputum eosinophil counts predict asthma control after discontinuation of inhaled corticosteroids

BACKGROUND

Although inhaled corticosteroids (ICSs) are effective in preventing deterioration in asthma control, at least half of subjects with mild-to-moderate asthma will remain stable when these agents are discontinued.

OBJECTIVE

We sought to determine whether noninvasive markers of inflammation predict which individuals maintain asthma control after discontinuation of ICSs.

METHODS

We analyzed data obtained from 164 subjects with mild-to-moderate asthma who participated in a 16-week trial comparing the effects of continued ICS use with the effects of a switch to salmeterol or placebo.

RESULTS

In comparison with continued ICS use, a switch to salmeterol or placebo was associated with increased rates of asthma deterioration over 16 weeks (9.3% vs 24.1% and 37.5%, respectively; P = .04 and P < .001, respectively). We found that neither exhaled nitric oxide nor methacholine PC 20 , when measured at randomization or 2 weeks after randomization, were significant predictors of subsequent asthma control in subjects who discontinued ICSs. However, both induced sputum eosinophil counts measured 2 weeks after a switch from ICS to placebo and changes in sputum eosinophil counts from before cessation of ICSs to after a switch to placebo predicted subsequent asthma deterioration (area under the receiver-operating characteristic curve, 0.771 [ P < .001] and 0.825 [ P < .001], respectively).

CONCLUSION

On the basis of a model treatment strategy, we estimate that allocating subjects to ICS therapy on the basis of changes in sputum eosinophil counts after a trial discontinuation could allow 48% of subjects with mild-to-moderate asthma to discontinue ICS therapy without an increased risk of asthma deterioration over a period of at least 14 weeks.

Exhaled nitric oxide predicts asthma relapse in children with clinical asthma remission

BACKGROUND

Nitric oxide in exhaled air (FE(NO)) is a marker of eosinophilic airway inflammation. A study was undertaken to determine whether FE(NO) predicts asthma relapse in asymptomatic asthmatic children in whom inhaled corticosteroids are discontinued.

METHODS

Forty children (21 boys) of mean age 12.2 years on a median dose of 400 mug budesonide or equivalent (range 100-400) were included. FE(NO) was measured before and 2, 4, 12, and 24 weeks after withdrawal of steroids. A relapse was defined as more than one exacerbation per month, or need for beta agonist treatment on 4 days per week for at least 2 weeks, or diurnal peak flow variability of >20%. FE(NO) measurements were performed online with an expiratory flow of 50 ml/s.

RESULTS

Nine patients relapsed. Two and 4 weeks after withdrawal of steroids geometric mean FE(NO) in children who were about to relapse was higher than in those who did not relapse: 35.3 ppb v 15.7 ppb at 2 weeks (ratio 2.3; 95% CI 1.2 to 4.1; p = 0.01) and 40.8 ppb v 15.9 ppb at 4 weeks (ratio 2.6; 95% CI 1.3 to 5.1). An FE(NO) value of 49 ppb at 4 weeks after discontinuation of steroids had the best combination of sensitivity (71%) and specificity (93%) for asthma relapse.

CONCLUSION

FE(NO) 2 and 4 weeks after discontinuation of steroids in asymptomatic asthmatic children may be an objective predictor of asthma relapse.

Step-down compared to fixed-dose treatment with inhaled fluticasone propionate in asthma

BACKGROUND

Inhaled corticosteroids (ICSs) are an effective treatment of asthma even when administered at a low dose. Once asthma is controlled, current guidelines recommend that the dose of ICS be reduced to the lowest possible and effective dose. Although the most appropriate strategy for the stepping down has not yet been defined, quantification of sputum eosinophils and bronchial hyperresponsiveness (BHR) are indeed measures of asthma control.

OBJECTIVE

To compare the efficacy of step-down and fixed-dose strategies in the control of BHR to methacholine and eosinophilic inflammation patients with mild-to-moderate asthma.

METHODS

We performed a double-blind, randomized study to compare inhaled fluticasone propionate (FP), 1,000 microg/d, then reduced to 200 microg/d (group 1; n = 18) to a fixed dose of FP, 200 microg/d (group 2; n = 17) administered for 6 weeks and then 8 weeks in reducing the provocative dose of methacholine causing a 20% fall in FEV1 (PD20) and sputum eosinophils in 35 patients. The duration of the efficacy was also followed subsequently after 8 weeks of placebo treatment.

RESULTS

PD20 remarkably increased with both treatment strategies, but differences between groups were not significant. Sputum eosinophils (median values, percentage) at baseline and after each treatment period were not different (group 1, 16.4 to 1.0 to 2.7%; group 2, 16.7 to 2.8 to 2.8%, respectively). The percentages of patients in whom sputum eosinophilia was normalized (< or = 3%) were as follows: group 1, 69% and 60%; group 2, 50% and 57%. After placebo treatment, sputum eosinophils were still "normalized" in approximately one third of patients.

CONCLUSION

Step-down and fixed-dose strategies with FP improved PD20 and sputum eosinophilia to a similar degree. The effect on sputum eosinophils persisted longer than that on methacholine.

Nitric oxide and redox signaling in allergic airway inflammation

A number of diseases of the respiratory tract, as exemplified in this review by asthma, are associated with increased amounts of nitric oxide (NO) in the expired breath. Asthma is furthermore characterized by increased production of reactive oxygen species that scavenge NO to form more reactive nitrogen species as demonstrated by the enhanced presence of nitrated proteins in the lungs of these patients. This increased oxidative metabolism leaves less bioavailable NO and coincides with lower amounts of S-nitrosothiols. In this review, we speculate on mechanisms responsible for the increased amounts of NO in inflammatory airway disease and discuss the apparent paradox of higher levels of NO as opposed to decreased amounts of S-nitrosothiols. We will furthermore give an overview of the regulation of NO production and biochemical events by which NO transduces signals into cellular responses, with a particular focus on modulation of inflammation by NO. Lastly, difficulties in studying NO signaling and possible therapeutic uses for NO will be highlighted.

Initial starting dose of inhaled corticosteroids in adults with asthma: a systematic review

BACKGROUND

Asthma guidelines vary in their recommendations for the initial dose of inhaled corticosteroid (ICS) in asthma. A systematic review of the literature was conducted to establish the optimal starting dose of ICS for asthma in adults.

METHODS

Randomised controlled trials comparing two doses of the same ICS in adults with asthma and no concomitant inhaled or oral corticosteroid were assessed. Included trials were analysed according to the following ICS dose comparisons: high (> or =800 microg/day beclomethasone (BDP)) versus moderate (400<800 microg/day BDP) (n = 7); moderate versus low (<400 microg/day BDP) (n = 6); step down versus constant dose (n = 4).

RESULTS

Fourteen publications describing 13 trials were included in the review. Studies (n = 4) that compared a step down approach with a constant moderate/low dose of ICS found no difference in lung function, symptoms, or rescue medications between the two treatment approaches (p>0.05). There was no difference in the change in morning peak flow after treatment with high compared with moderate dose ICS. When compared with low dose ICS, moderate dose ICS significantly improved morning peak flow (change from baseline WMD 11.14 l/min, 95% CI 1.34 to 20.93) and nocturnal symptoms (SMD -0.29, 95% CI -0.53 to -0.06).

CONCLUSIONS

For patients with asthma who require ICS, starting with a moderate dose is equivalent to starting with a high dose and stepping down. The small non-significant benefits of starting with a high ICS dose are not of sufficient clinical benefit to warrant its use. Initial moderate ICS doses appear to be more effective than an initial low ICS dose.

Tools to assess (and achieve?) long-term asthma control

Assessment tools are needed to monitor asthma control and to detect exacerbations before the alteration of functional parameters and the occurrence of symptoms. The ability to effectively monitor asthma control would enable clinicians to increase corticosteroid dose or to stop corticosteroid tapering before symptoms occur. As a few severe exacerbations are expected per year in treated patients, these tools must be suitable for long-term use. They must also be reproducible, acceptable to patients and be non-invasive. Tools currently available to assess asthma control include assessment of: clinical parameters (e.g. nocturnal awakenings; bronchodilator intake; symptom scores); lung function (e.g. peak expiratory flow and forced expiratory volume in 1 s); subjective parameters of asthma control (e.g. asthma control questionnaire (ACQ)); bronchial hyper-responsiveness; eosinophilia in induced sputum; and exhaled nitric oxide (NO) concentration. Clinical symptoms, lung function and the ACQ have proved to be inadequate markers of asthma control, as changes in these parameters occur at the same time as symptom manifestation. By contrast, sputum eosinophilia and exhaled NO concentrations are truly predictive of asthma exacerbations; monitoring these parameters are useful in preventing exacerbations from occurring in the first instance. They also assess, and help to achieve asthma control in the long term.

Add-on therapy options in asthma not adequately controlled by inhaled corticosteroids: a comprehensive review

Many patients with persistent asthma can be controlled with inhaled corticosteroids (ICS). However, a considerable proportion of patients remain symptomatic, despite the use of ICS. We present systematically evidence that supports the different treatment options. A literature search was made of Medline/PubMed to identify randomised and blinded trials. To demonstrate the benefit that can be obtained by increasing the dose of ICS, dose-response studies with at least three different ICS doses were identified. To demonstrate whether more benefit can be obtained by adding long-acting beta2-agonist (LABA), leukotriene antagonist (LTRA) or theophylline than by increasing the dose of ICS, studies comparing these options were identified. Thirdly, studies comparing the different "add-on" options were identified. The addition of a LABA is more effective than increasing the dose of ICS in improving asthma control. By increasing the dose of ICS, clinical improvement is likely to be of small magnitude. Addition of a LTRA or theophylline to the treatment regimen appears to be equivalent to doubling the dose of ICS. Addition of a LABA seems to be superior to an LTRA in improving lung function. However, addition of LABA and LTRA may be equal with respect to asthma exacerbations. However, more and longer studies are needed to better clarify the role of LTRAs and theophylline as add-on therapies.

Sputum tests in the diagnosis and monitoring of asthma

OBJECTIVE

To review the techniques of sputum analysis with relevance to the diagnosis and monitoring of asthma.

DATA SOURCES

MEDLINE databases were searched to identify all publications involving sputum studies related to the diagnosis and treatment of asthma from 1990 to October 2003. We also used internal reference files related to sputum and searched bibliographies of relevant articles. The review was limited to human data in English-language publications.

STUDY SELECTION

Studies were selected by the expert opinions of the authors for quality and relevance to the evaluation of asthmatic inflammation by induced sputum.

RESULTS

During the past 10 years, there have been an increasing number of publications concerning the diagnosis and treatment of asthma using sputum analysis. Analysis of induced sputum provides similar data to secretions obtained through bronchial wash, bronchoalveolar lavage, and, to some extent, bronchial biopsy. The techniques of cellular counting and immunochemical analysis are described along with potential problems and pitfalls of these methods. Clinical application of sputum analysis is discussed as it pertains to the diagnosis and monitoring of asthma and asthma-related conditions.

CONCLUSIONS

Analysis of induced sputum is increasingly being considered as a noninvasive means of evaluating airway inflammation and may provide useful information with regard to the diagnosis and monitoring of asthma in select individuals.

Inhaled fluticasone dipropionate decreases levels of nitric oxide in recurrenty wheezy infants

We examined the effect of inhaled fluticasone diproprionate (FDP) on symptoms, lung function (FEV(0.5)), and exhaled nitric oxide (Fe(NO)) in infants with recurrent wheeze and raised Fe(NO). Thirty-one infants aged 6-19 months (mean, 12.7 months; 12 girls) completed the study. All infants had a history of recurrent wheeze and a parental history of atopy. All children had raised Fe(NO), as determined by an offline tidal breathing technique prior to randomization. Lung function and Fe(NO) were assessed before and after 4 weeks of treatment with FDP or placebo. The parents recorded daily symptoms during the treatment period. Sixteen infants received FDP and 15 the placebo for 4 weeks. At completion of the study, infants treated with FDP had a significant reduction in Fe(NO) (35.0 ppb to 16.5 ppb) compared to those that received placebo (35.2 ppb to 30.2 ppb) (P = 0.05). Small increases in FEV(0.5) were observed in both groups, but these changes were not different between groups (P = 0.8). Symptom scores were not significantly different in either group following the intervention. We showed that a moderate dose of inhaled FDP reduces levels of Fe(NO), a potential marker of airway inflammation, even in the absence of significant changes in lung function and symptoms.

Nitric oxide in health and disease of the respiratory system

During the past decade a plethora of studies have unravelled the multiple roles of nitric oxide (NO) in airway physiology and pathophysiology. In the respiratory tract, NO is produced by a wide variety of cell types and is generated via oxidation of l-arginine that is catalyzed by the enzyme NO synthase (NOS). NOS exists in three distinct isoforms: neuronal NOS (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS). NO derived from the constitutive isoforms of NOS (nNOS and eNOS) and other NO-adduct molecules (nitrosothiols) have been shown to be modulators of bronchomotor tone. On the other hand, NO derived from iNOS seems to be a proinflammatory mediator with immunomodulatory effects. The concentration of this molecule in exhaled air is abnormal in activated states of different inflammatory airway diseases, and its monitoring is potentially a major advance in the management of, e.g., asthma. Finally, the production of NO under oxidative stress conditions secondarily generates strong oxidizing agents (reactive nitrogen species) that may modulate the development of chronic inflammatory airway diseases and/or amplify the inflammatory response. The fundamental mechanisms driving the altered NO bioactivity under pathological conditions still need to be fully clarified, because their regulation provides a novel target in the prevention and treatment of chronic inflammatory diseases of the airways.

Induced sputum in children with newly diagnosed mild asthma: the effect of 6 months of treatment with budesonide or disodium cromoglycate

BACKGROUND

There are few controlled studies on the effects of anti-inflammatory treatment on airway inflammation in newly diagnosed childhood asthma.

METHODS

Sixty children with newly diagnosed mild persistent asthma, 5-10 years of age, and 17 healthy control subjects were studied. Asthmatic children were randomized into an open study with two treatment groups: (1) budesonide 400 microg twice daily for 1 month, 200 microg twice daily for 5 months and (2) disodium cromoglycate (DSCG) 10 mg three-times daily for 6 months. All exacerbations were treated with budesonide 400 microg twice daily for 2 weeks. Symptoms and lung function were recorded throughout the study.

RESULTS

Sputum induction was safe and the overall success rate was 71%. This improved with age and decreased after treatment. At baseline, the asthmatic children had more eosinophils in blood (0.26 vs 0.18 x 10(9)/l, P = 0.03) and sputum (1.1 vs 0.0 %, P = 0.0001) than the control subjects. The numbers of sputum eosinophils correlated with bronchial responsiveness (R = -0.58, P = 0.0002). Eosinophils were higher in children with atopic asthma than with nonatopic asthma (P < 0.0001), and in children with a history wheezing than in children without wheezing (P = 0.02). Six months of budesonide treatment, but not of DSCG, improved lung function (P = 0.007), decreased symptoms (P = 0.007) and sputum eosinophils (P = 0.003). The effects of budesonide were pronounced in children with intense sputum eosinophilia (>3%).

CONCLUSION

Sputum eosinophilia is present in children with newly diagnosed mild persistent asthma. Treatment with inhaled budesonide, but not with DSCG, decreases sputum eosinophils along with clinical and functional improvement.

Exhaled NO and eosinophil markers in blood, nasal lavage and sputum in children with asthma after withdrawal of budesonide

BACKGROUND

There is a need for controlled trials among children with asthma to evaluate and compare different markers of inflammation.

OBJECTIVE

Our goal was to investigate the effect of withdrawal of inhaled budesonide on repeated measurements of exhaled NO (ENO), peripheral blood eosinophils (PBE), sputum/NAL/serum-eosinophil cationic protein (ECP), bronchial hyperresponsiveness (BHR) and forced expiratory volume in 1 s (FEV(1)) in children with allergic asthma.

METHODS

Eighteen asthmatic children were randomly allocated to continue or discontinue use of inhaled budesonide. They were followed up, at six visits for 4 months with regular blood, serum, sputum, and NAL samples. Sixteen age-matched healthy children served as controls.

RESULTS

ENO, PBE, and S-ECP increased significantly in the withdrawal group (p < 0.05) but not in the continuous treatment group. No trend could be observed during the study for markers in sputum or in NAL in either group.

CONCLUSION

The present data provide evidence for the clinical usefulness of measuring ENO, PBE, and S-ECP and when combined they could help to avoid over- and undertreatment with corticosteroids in the growing child.

Exhaled nitric oxide levels and airway responsiveness to adenosine 5'-monophosphate in subjects with nasal polyposis

BACKGROUND

It is widely appreciated that asthma is an inflammatory disease of the airways associated with airway hyperresponsiveness, and that nasal polyposis and asthma are related diseases. The objective of this study was to determine differences in exhaled nitric oxide (ENO) levels and airway responsiveness to adenosine 5'-monophosphate (AMP) between nonasthmatic patients with nasal polyposis and healthy controls.

METHODS

Twenty patients without asthma with nasal polyposis and 16 healthy control subjects were enrolled in the study. Participants were challenged with increasing concentrations of AMP and methacholine. ENO was measured with the single-exhalation method.

RESULTS

Bronchoconstriction in response to AMP was detected in 7 (35%) subjects with nasal polyposis. The geometric mean (95% CI) of ENO for subjects with nasal polyposis was 33.1 parts per billion (ppb) (24.0-45.7 ppb) compared with 12.3 ppb (8.5-18.2 ppb) for the healthy controls (p = 0.0002). ENO values were significantly higher in atopic than in nonatopic subjects with nasal polyposis [51.3 ppb (32.3-83.2 ppb) vs. 24.5 ppb (16.2-37.1 ppb), p = 0.02]. Nonatopic subjects with nasal polyposis also had higher concentrations of ENO than healthy control subjects (p = 0.016).

CONCLUSIONS

Inhaled AMP causes airway narrowing in a significantly higher proportion of nonasthmatic subjects with nasal polyposis than in healthy controls. Furthermore, increased concentrations of ENO are detected in atopic and nonatopic subjects with nasal polyposis. These results suggest that bronchial inflammation is present in nonasthmatic subjects with nasal polyposis.

Biological markers in diagnosing, monitoring, and treating asthma: a focus on noninvasive measurements

Asthma is a major concern for society, healthcare professionals, and individuals and families directly affected by asthma due to rising morbidity rates and costs associated with the disease. The pathological hallmark of asthma is airway inflammation that is considered to be a major cause of exacerbations and persistent structural alterations of the airways. Assessing airway inflammation is important for investigating the underlying mechanisms of the disease and possibly for following the progression and resolution of the disease. The presence and type of airway inflammation can be difficult to detect clinically, and may result in delays in initiating appropriate therapy. The purpose of this article is to review noninvasive methods for assessing biological markers of airway inflammation and their potential role in the future for diagnosing, monitoring, and treating asthma. The article reviews the noninvasive measurements of induced sputum and exhaled nitric oxide as indicators of airway inflammation.

Exhaled nitric oxide in the assessment of asthma

PURPOSE

Asthma is now defined as a TH2-mediated inflammatory disease involving both large and small airways. However, assessment of airways inflammation is limited by techniques that are time consuming and possibly distressing to the patient. Exhaled nitric oxide, an easily and rapidly obtained noninvasive study, is a potential surrogate for measuring airways inflammation, but its clinical utility remains to be determined. This review examines the role of exhaled nitric oxide in assessing and directing therapy of asthmatic airways inflammation.

RECENT FINDINGS

It is well established that exhaled nitric oxide is increased in patients with untreated asthma and decreases with corticosteroid treatment. Exhaled nitric oxide also generally correlates with eosinophilic inflammation in asthmatic patients. Recent studies show that this correlation is especially pronounced in atopic subjects with asthma when compared with nonatopic subgroups. Recent studies also show that exhaled nitric oxide may be useful in identifying subclinical inflammation, assessing the antiinflammatory effects of asthma medications other than inhaled or oral corticosteroids, and heralding an asthma exacerbation. A number of new studies assert the utility of exhaled nitric oxide as a diagnostic tool for asthma.

SUMMARY

Exhaled nitric oxide may be a useful parameter for monitoring asthmatic inflammation, adjusting therapy, and diagnosing asthma, although prospective longitudinal trials investigating the correlation between exhaled nitric oxide and clinical outcomes are necessary to determine its utility.

Expected characteristics of an ideal, all-purpose inhaled corticosteroid for the treatment of asthma

BACKGROUND

Inhaled corticosteroids (ICSs) are well established as the mainstay of asthma therapy. A number of ICSs are now available, each with unique pharmacokinetic/pharmacodynamic profiles and physical characteristics.

OBJECTIVE

This article reviews the key characteristics of an ideal ICS and uses examples of existing agents to indicate the extent to which therapies reach these goals.

RESULTS

Improved therapeutic efficacy in an ICS may be offset by an increase in systemic effects. The ideal characteristics of an ICS include optimal clinical efficacy and no toxicity in combination with a convenient and easy-to-use inhaler device. To achieve this optimal profile, an ICS should have the following: a high affinity for and potency at the glucocorticoid receptor; prolonged retention in the lung; minimal or no oral bioavailability (ie, high first-pass inactivation); and rapid, complete systemic inactivation. The formulation and type of inhaler device are also important considerations: they should provide deposition in the lung in both large and small airways with no absorption effects outside the lung. ICSs should be evaluated for administration with several different delivery devices to ensure ease of use by patients of all ages with different asthma severities. An ICS that can be administered QD is also likely to improve patient adherence by simplifying the treatment regimen.

CONCLUSION

An ideal ICS should have a large therapeutic margin, be used safely and effectively for long periods, be administered QD, be suitable for use in patients of all ages and asthma severities, and offer both control and prevention of asthma symptoms and exacerbations.

Heterogeneity of FeNO response to inhaled steroid in asthmatic children

BACKGROUND

Nitric oxide in exhaled air is regarded as an inflammation marker, and may be used to monitor the anti-inflammatory control from inhaled corticosteroids (ICSs). However, this response to ICSs exhibits a heterogeneous pattern.

OBJECTIVE

The study aimed to describe the independent variables associated with the heterogeneity in the response of exhaled nitric oxide to ICSs.

METHODS

Exhaled nitric oxide (FeNO), lung function, bronchial hyper-responsiveness (BHR), specific IgE to common inhalant allergens, blood eosinophils, other atopic manifestations and variants in nitric oxide synthethase 1 (NOS1) gene were studied in a double-blind, placebo-controlled crossover comparison of budesonide (BUD) Turbohaler 1600 mcg daily vs. placebo in asthmatic schoolchildren.

RESULTS

Forty children were included in the study from a screening of 184 asthmatic children with moderately persistent asthma, well controlled on regular BUD 400 mcg daily: 20 children with normal FeNO and 20 with raised FeNO. FeNO, BHR and forced expiratory volume in 1 s improved significantly after BUD 1600 mcg (BUD1600). However, FeNO after ICS treatment exhibited a Gaussian distribution and FeNO was significantly raised in 15 children. Allergy and BHR, but none of the other independent variables under study were significantly related to FeNO after BUD1600.

CONCLUSION

Exhaled nitric oxide exhibited a heterogeneous response to ICS in asthmatic schoolchildren. Allergy and BHR were driving FeNO level independently of high-dose steroid treatment. This should be considered when using FeNO for steroid dose titration and monitoring of ICS anti-inflammatory control in asthmatic children.