Induced sputum is a reproducible method to assess airway inflammation in asthma

Proteomic and metabolomic proof of concept for unified airways in chronic rhinosinusitis and asthma

BACKGROUND

The pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) with comorbid asthma remains unclear.

OBJECTIVE

To assess upper and lower airway unity and identify a possible common pathogenesis in CRSwNP with asthma.

METHODS

This study analyzed the expression of proteins and metabolites in nasal lavage fluid cells (NLFCs) and induced sputum cells (ISCs). Differentially expressed proteins and their function-related metabolites in the upper and lower airways of patients having CRSwNP with or without asthma were identified; relevant signaling pathways were analyzed, and key pathway-related proteins were identified. Parallel reaction monitoring was used to verify these target proteins.

RESULTS

Protein or metabolite expression between NLFCs and ISCs was highly correlated and conservative on the basis of expression profiles and weighted gene coexpression network analysis. There were 17 differentially coexpressed proteins and their function-related 13 metabolites that were identified in the NLFCs and ISCs of CRSwNP, whereas 11 proteins and 11 metabolites were identified in CRSwNP with asthma. An asthma pathway was involved in the copathogenesis of upper and lower airways in whether CRSwNP or CRSwNP with asthma. The asthma pathway-related proteins proteoglycan 2 and eosinophil peroxidase, as the core of the protein-metabolism interaction networks between the upper and lower airways, were both highly coexpressed in NLFCs and ISCs in patients having either CRSwNP or CRSwNP with asthma by parallel reaction monitoring validation.

CONCLUSION

Proteomics and metabolomics reveal upper and lower airway unity. Asthma pathway-related proteins proteoglycan 2 and eosinophil peroxidase from the upper airway could be used to assess the potential risk of lower airway dysfunction in CRSwNP.

Upper airway disease diagnosis as a predictive biomarker of therapeutic response to biologics in severe asthma

Asthma is a heterogeneous disease sharing airway instability but with different biology, risk factors, and response-to-therapy patterns. Biologics have revolutionized the one-size-fits-to-all approach to personalized medicine in severe asthma (SA), which relies on the identification of biomarkers that define distinct endotypes. Thus, blood eosinophils and, to some extent, exhaled nitric oxide (FeNO) can predict the response to approved anti-type 2 (T2) biologics (anti-IgE, anti-IL-5, and anti-IL-4R alpha), whereas age at onset and comorbidities such as anxiety/depression, obesity, reflux, and upper airway disease (UAD) also influence therapeutic responses in SA. In this article, focusing on the predictive value of biomarkers for the therapeutic response to biologics in SA, we first summarize the level of prediction achieved by T2 biomarkers (blood eosinophils, FeNO) and then review whether data support the predictive value of upper airway diagnosis on such outcomes. Post hoc analysis of most studies with T2 biologics suggests that chronic rhinosinusitis with nasal polyps (CRSwNP) and, to a lower extent, allergic rhinitis may help in predicting clinical response. Considering that T2 biologics are now also approved for the treatment of severe CRSwNP, diagnosis of upper airway disease is a key step in determining eligibility for such therapy.

Characteristics of inflammatory phenotypes among patients with asthma: relationships of blood count parameters with sputum cellular phenotypes

BACKGROUND

There is a need to identify the asthma inflammatory phenotypes of patients to facilitate personalized asthma treatment. Sputum induction is time-consuming and requires expert clinical technique. This study aimed to assess the distribution and characteristics of asthma inflammatory phenotypes in Jilin Province, China; it also aimed to identify an easier method for characterization of an asthma phenotype, rather than sputum cellular analysis.

METHODS

In this study, 232 asthma patients underwent sputum induction following clinical assessment and blood collection. Inflammatory cell counts in sputum were used to classify asthma inflammatory phenotypes. Receiver operating characteristic curve and Spearman correlation coefficient analyses were used to identify correlations between clinical parameters.

RESULTS

Among the included patients, there had 52.1% paucigranulocytic, 38.4% eosinophilic, 4.3% neutrophilic, and 5.2% mixed granulocytic asthma phenotypes, respectively. In total, 129 (55.6%) patients had asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO); these patients had higher proportion of smokers, higher sputum neutrophil count, worse lung function, and worse asthma control, compared with patients who had asthma alone (p < 0.05). Sputum eosinophil/neutrophil counts were positively correlated with blood eosinophil/neutrophil counts (p < 0.01). To identify the presence of sputum eosinophil proportion ≥ 3%, optimal cut-off values for blood eosinophil count and fractional exhaled nitric oxide (FeNO) were 0.2 × 10⁹/L and 30.25 ppd (area under the curve (AUC) = 0.744; AUC = 0.653, p < 0.001). AUCs did not significantly differ between FeNO and blood eosinophil count (p = 0.162), but both exhibited poor specificity (57% and 49%, respectively). To identify the presence of sputum neutrophil proportion ≥ 61%, the optimal cut-off value for blood neutrophil proportion was 69.3% (AUC = 0.691, p = 0.0003); however, this exhibited poor sensitivity (50%).

CONCLUSIONS

Paucigranulocytic asthma was the most common phenotype, followed by eosinophilic asthma. Higher proportion of smokers, poor patient compliance, insufficient treatment, and poor asthma control may have been the main causes of high ACO proportion among patients in this study. Blood eosinophil/neutrophil counts exhibited poor specificity and sensitivity for prediction of airway eosinophilic/neutrophilic inflammation.

A snapshot of exhaled nitric oxide and asthma characteristics: experience from high to low income countries

Nitric oxide is a gas produced in the airways of asthmatic subjects and related to T2 inflammation. It can be measured as fractional nitric oxide (FeNO) in the exhaled air and used as a non-invasive, easy to evaluate, rapid marker. It is now widely used in many settings to determine airway inflammation. The aim of this narrative review is to report relationship between FeNO and the physiopathologic characteristics of asthmatic patients. Factors affecting FeNO levels have also been analysed as well as the impact of corticosteroid, target therapies and rehabilitation programs. Considering the availability of the test, spreading this methodology to low income countries has also been considered as a possibility for evaluating airway inflammation and monitoring adherence to inhaled corticosteroid therapy. PubMed data search has been performed restricted to English language papers. Research was limited to studies in adults unless studies in children were the only ones reported for a particular issue. This revision could be useful to summarize the role of FeNO in relation to asthma characteristics and help in the use of FeNO in different clinical settings particularly in low income countries.

The six-gene expression signature in whole sampled sputum provides clinically feasible inflammatory phenotyping of asthma

Processing of induced sputum is time consuming and requires trained personnel, and consequently the use of induced sputum is limited to few sites globally. The six-gene signature (6GS) is an mRNA-based gene signature that was developed to provide a clinically feasible method for inflammatory phenotyping. In this study, we assessed whether the 6GS would perform similarly in induced sputum sampled using a simplified method, by which induced sputum can be sampled and stored directly for later qPCR analyses, to the conventional method of manual plug selection. Two separate sputum samples were collected from 27 patients with asthma; one processed as a whole sample in an Oragene-RNA RE 100 vial and one processed using manual plug selection. Expression of 6GS was measured in both samples, of which 20 pairs (74%) had enough samples and results of sufficient quality of gene expression for further analyses. We found a significantly higher median RNA concentration in whole sampled sputum and consistently stronger gene expression compared to the plug method. Further, we found the two methods to agree, as 97% of observations were within the limits of agreement, as well as having a good-to-excellent reliability using intraclass correlation. Finally, we found 6GS in the whole sampled sputum to perform equal to or better than the manually selected plugs for discriminating inflammatory phenotypes defined by sputum differential count. In conclusion, whole sampling of induced sputum provides a clinically feasible method for inflammatory phenotyping.

Tailored interventions based on sputum eosinophils versus clinical symptoms for asthma in children and adults

BACKGROUND

Asthma severity and control can be measured both subjectively and objectively. Sputum analysis for evaluation of percentage of sputum eosinophilia directly measures airway inflammation, and is one method of objectively monitoring asthma. Using sputum analysis to adjust or tailor asthma medications is potentially superior to traditional methods based on symptoms and spirometry.

OBJECTIVES

To evaluate the efficacy of tailoring asthma interventions based on sputum analysis in comparison to traditional methods (usually symptom-based with or without spirometry/peak flow) for asthma-related outcomes in children and adults.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, trials' registries, and reference lists of articles. The last search was conducted in February 2017.

SELECTION CRITERIA

All randomised controlled comparisons of adjustment of asthma therapy based on sputum eosinophils 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. In this update, two reviewers selected relevant studies, independently assessed trial quality and extracted the data. We contacted authors for further information when relevant. We analysed data as 'treatment received' and performed sensitivity analyses.

MAIN RESULTS

Three new studies were added in this update, resulting in a total of six included studies (five in adults and one involving children/adolescents). These six studies were clinically and methodologically heterogeneous (use of medications, cut-off for percentage of sputum eosinophils and definition of asthma exacerbation). Of 374 participants randomised, 333 completed the trials. In the meta-analysis, there was a significant reduction in the occurrence of any exacerbations when treatment was based on sputum eosinophil counts, compared to that based on clinical symptoms with or without lung function; pooled odds ratio (OR) was 0.57 (95% confidence interval (CI) 0.38 to 0.86). The risk of having one or more exacerbations over 16 months was 82% in the control arm and 62% (95% CI 49% to 74%) in the sputum strategy arm, resulting in a number needed to treat to benefit (NNTB) of 6 (95% CI 4 to 13).There were also differences between the groups in the rate of exacerbation (any exacerbation per year) and severity of exacerbations defined by requirement for use of oral corticosteroids and hospitalisations: the risk of one or more hospitalisations over 16 months was 24% in controls compared to 8% (95% CI 3% to 21%) in the sputum arm. Data for clinical symptoms, quality of life and spirometry were not significantly different between groups. The mean dose of inhaled corticosteroids per day was also similar in both groups. However sputum induction was not always possible. The included studies did not record any adverse events.One study was not blinded and thus was considered to have a high risk of bias. However, when this study was removed in a sensitivity analysis, the difference between the groups for the primary outcome (exacerbations) remained statistically significant between groups. The GRADE quality of the evidence ranged from moderate (for the outcomes 'Occurrence of any exacerbation' and 'Hospitalisation' ) to low (for the outcome 'Mean dose of inhaled corticosteroids per person per day') due to the inconsistency in defining exacerbations and the small number of hospital admissions.

AUTHORS' CONCLUSIONS

In this updated review, tailoring asthma interventions based on sputum eosinophils is beneficial in reducing the frequency of asthma exacerbations in adults with asthma. Adults with frequent exacerbations and severe asthma may derive the greatest benefit from this additional monitoring test, although we were unable to confirm this through subgroup analysis. There is insufficient data available to assess tailoring asthma medications based on sputum eosinophilia in children.Further robust RCTs need to be undertaken and these should include participants with different underlying asthma severities and endotypes.

Detailed analysis of sputum and systemic inflammation in asthma phenotypes: are paucigranulocytic asthmatics really non-inflammatory?

Background

The technique of induced sputum has allowed to subdivide asthma patients into inflammatory phenotypes according to their level of granulocyte airway infiltration. There are very few studies which looked at detailed sputum and blood cell counts in a large cohort of asthmatics divided into inflammatory phenotypes. The purpose of this study was to analyze sputum cell counts, blood leukocytes and systemic inflammatory markers in these phenotypes, and investigate how those groups compared with healthy subjects.

Methods

We conducted a retrospective cross-sectional study on 833 asthmatics recruited from the University Asthma Clinic of Liege and compared them with 194 healthy subjects. Asthmatics were classified into inflammatory phenotypes.

Results

The total non-squamous cell count per gram of sputum was greater in mixed granulocytic and neutrophilic phenotypes as compared to eosinophilic, paucigranulocytic asthma and healthy subjects (p < 0.005). Sputum eosinophils (in absolute values and percentages) were increased in all asthma phenotypes including paucigranulocytic asthma, compared to healthy subjects (p < 0.005). Eosinophilic asthma showed higher absolute sputum neutrophil and lymphocyte counts than healthy subjects (p < 0.005), while neutrophilic asthmatics had a particularly low number of sputum macrophages and epithelial cells. All asthma phenotypes showed an increased blood leukocyte count compared to healthy subjects (p < 0.005), with paucigranulocytic asthmatics having also increased absolute blood eosinophils compared to healthy subjects (p < 0.005). Neutrophilic asthma had raised CRP and fibrinogen while eosinophilic asthma only showed raised fibrinogen compared to healthy subjects (p < 0.005).

Conclusions

This study demonstrates that a significant eosinophilic inflammation is present across all categories of asthma, and that paucigranulocytic asthma may be seen as a low grade inflammatory disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0208-2) contains supplementary material, which is available to authorized users.

Neutrophilic Bronchial Inflammation Correlates with Clinical and Functional Findings in Patients with Noncystic Fibrosis Bronchiectasis

Background. Neutrophilic bronchial inflammation is a main feature of bronchiectasis, but not much is known about its relationship with other disease features. Aim. To compare airway inflammatory markers with clinical and functional findings in subjects with stable noncystic fibrosis bronchiectasis (NCFB). Methods. 152 NFCB patients (62.6 years; females: 57.2%) underwent clinical and functional cross-sectional evaluation, including microbiologic and inflammatory cell profile in sputum, and exhaled breath condensate malondialdehyde (EBC-MDA). NFCB severity was assessed using BSI and FACED criteria. Results. Sputum neutrophil percentages inversely correlated with FEV1 (P < 0.0001; rho = -0.428), weakly with Leicester Cough Questionnaire score (P = 0.068; rho = -0.58), and directly with duration of the disease (P = 0.004; rho = 0.3) and BSI severity score (P = 0.005; rho = 0.37), but not with FACED. Sputum neutrophilia was higher in colonized subjects, P. aeruginosa colonized subjects showing greater sputum neutrophilia and lower FEV1. Patients with ≥3 exacerbations in the last year showed a significantly greater EBC-MDA than the remaining patients. Conclusions. Sputum neutrophilic inflammation and biomarkers of oxidative stress in EBC can be considered good biomarkers of disease severity in NCFB patients, as confirmed by pulmonary function, disease duration, bacterial colonization, BSI score, and exacerbation rate.

Noninvasive effects measurements for air pollution human studies: methods, analysis, and implications

Human exposure studies, compared with cell and animal models, are heavily relied upon to study the associations between health effects in humans and air pollutant inhalation. Human studies vary in exposure methodology, with some work conducted in controlled settings, whereas other studies are conducted in ambient environments. Human studies can also vary in the health metrics explored, as there exists a myriad of health effect end points commonly measured. In this review, we compiled mini reviews of the most commonly used noninvasive health effect end points that are suitable for panel studies of air pollution, broken into cardiovascular end points, respiratory end points, and biomarkers of effect from biological specimens. Pertinent information regarding each health end point and the suggested methods for mobile collection in the field are assessed. In addition, the clinical implications for each health end point are summarized, along with the factors identified that can modify each measurement. Finally, the important research findings regarding each health end point and air pollutant exposures were reviewed. It appeared that most of the adverse health effects end points explored were found to positively correlate with pollutant levels, although differences in study design, pollutants measured, and study population were found to influence the magnitude of these effects. Thus, this review is intended to act as a guide for researchers interested in conducting human exposure studies of air pollutants while in the field, although there can be a wider application for using these end points in many epidemiological study designs.

Repeatability of induced sputum measurements in moderate to severe asthma

BACKGROUND

Novel therapies are being developed for patients with moderate to severe asthma. These patients may have neutrophilic airway inflammation. Induced sputum is commonly used as an endpoint in clinical trials of asthma therapies. We have performed repeated induced sputum sampling in moderate to severe asthma patients to understand the variability of cell counts, including neutrophils, and performed power calculations for studies in this group of patients.

METHODS

Nineteen patients with moderate to severe asthma with evidence of airflow obstruction (FEV1 ≤ 80% predicted) and suboptimal control (ACQ ≥ 1) performed repeated induced sputum separated by 1 month.

RESULTS

The Ri of neutrophil percentage and absolute eosinophil count demonstrated good (0.61) and moderate (0.56) repeatability respectively, but there was a poor level of agreement for eosinophil percentage and absolute neutrophil counts. The within subject SD for sputum neutrophil percentage was 15.8. In cross over studies, sample sizes of n = 14 and n = 54 are required to detect changes in neutrophil percentages by 20 and 10 % respectively at 90% power.

CONCLUSIONS

Sputum neutrophil percentage has good reproducibility in patients with moderate to severe asthma.

Disease models of chronic inflammatory airway disease: applications and requirements for clinical trials

PURPOSE OF REVIEW

This review will discuss methodologies and applicability of key inflammatory models of respiratory disease in proof of concept or proof of efficacy clinical studies. In close relationship with these models, induced sputum and inflammatory cell counts will be addressed for phenotype-directed drug development. Additionally, important regulatory aspects regarding noninvestigational medicinal products used in bronchial challenges or clinical inflammatory models of respiratory disease will be highlighted.

RECENT FINDINGS

The recognition of an ever increasing number of phenotypes and endotypes within conditions such as asthma and chronic obstructive pulmonary disease urges phenotyping of study populations already in early clinical phases of drug development. Apart from the choice of a relevant disease model, recent studies show that especially targeted therapies need to be tested in well defined disease subsets for adequate efficacy assessment. Noninvasive biomarkers, especially sputum inflammatory cell counts, aid phenotyping and are useful outcome measures for novel, targeted therapies.

SUMMARY

Disease phenotyping becomes increasingly important for efficient and cost-effective drug development and subsequent disease management. Inflammatory models of respiratory disease combined with sputum biomarkers are important tools in this approach.

Association of pro-inflammatory cytokines, cortisol and depression in patients with chronic obstructive pulmonary disease

Evidence suggests that pro-inflammatory cytokines and cortisol play a crucial role in the etiology of chronic obstructive pulmonary disease (COPD) and depression. Depression occurs commonly among COPD patients and an earlier diagnosis would be beneficial. This study investigated the associations between depression, sputum cytokines and salivary cortisol in COPD patients. The diurnal rhythms of sputum IL-1, IL-6, TNF-α and salivary cortisol were measured in COPD patients with depression compared to those only with depression, or COPD and healthy controls. The area under the diurnal variation curves (AUC) over the 24h time course and relative diurnal variation (VAR) were calculated while correlation and regression analysis were performed. Patients with co-morbid depression and COPD showed an increasing sputum IL-1, sputum TNF-α AUC and a decreasing salivary cortisol VAR (P<0.001). The combination of sputum TNF-α AUC, sputum IL-1 AUC, sputum IL-6 AUC and salivary cortisol VAR performed best as a potential biomarker in the diagnosis of depression in COPD patients, with a sensitivity of 94.74% and a specificity of 96.67%. Positive correlations were found between sputum IL-1 AUC and sputum TNF-α AUC versus depressive symptoms, respectively a negative correlation was found between salivary cortisol VAR and depression. They were independently associated with depression in logistic regression models. Depression in COPD is associated with higher 24-h overall levels of sputum IL-1, TNF-α and flattened diurnal salivary cortisol. These non-invasive sputum and salivary biomarkers may serve as a simple clinical tool for the early diagnosis of depression in COPD patients.

Sputum interleukin-6, tumor necrosis factor-α and Salivary cortisol as new biomarkers of depression in lung cancer patients

Depression is common among lung cancer patients. Increasing evidence has suggested that hypothalamic-pituitary-adrenal (HPA) axis and pro-inflammatory cytokines may play a key role in the pathophysiology of depression as well as cancer. This pilot study investigated the efficacy of sputum interleukin (IL)-6, tumor necrosis factor (TNF)-α and salivary cortisol as new markers to support the diagnosis of depression in lung cancer patients. The diurnal rhythms of sputum IL-6, sputum TNF-α and salivary cortisol were measured in lung cancer patients with and without depression as well as depressed controls and healthy controls. The area under the diurnal variation curves (AUC) over the 24h time course and relative diurnal variation (VAR) were calculated. Receiver operating characteristic (ROC) analysis was performed. Patients with co-morbid depression and lung cancer showed highest level of sputum IL-6 AUC, sputum TNF-α AUC and lowest level of cortisol VAR (P<0.001). As a biomarker for depression, salivary cortisol VAR demonstrated an optimal cutoff point at 77.8% (AUC=0.94; 95% CI, 0.85-0.98), which is associated with a sensitivity of 82.1% and a specificity of 96.0%. Sputum IL-6 AUC demonstrated a sensitivity of 74.4% and a specificity of 92.0% (AUC=0.81; 95% CI, 0.69-0.90). These findings suggested that higher 24h overall levels of sputum IL-6, TNF-α and flattened diurnal salivary cortisol slopes were associated with depression in lung cancer patients. Sputum IL-6 AUC and salivary cortisol VAR performed best as biomarkers in the diagnosis of depression in lung cancer patients.

Baseline airway inflammation may be a determinant of the response to ozone exposure in asthmatic patients

CONTEXT

It is well known that ozone exposure decreases lung function and increases airway neutrophilia, but large variability has been observed among asthmatic patients.

OBJECTIVE

To find possible predictors of functional and inflammatory airway response to ozone in asthmatic patients.

MATERIALS AND METHODS

We studied 120 patients with mild-to-moderate asthma, randomly exposed to either air or ozone (0.3 ppm for 2 h) in a challenge chamber. Symptoms and pulmonary function test (PFT) were measured before and immediately after exposure. Six hours after exposure, induced sputum was collected. Patients were evaluated according to their functional (FEV₁ responders) or neutrophilic (neutrophil responders) response to ozone. We considered, as possible predictors of response: age, baseline FEV₁, previous treatment with inhaled corticosteroids (ICS), baseline sputum neutrophils, baseline sputum eosinophils, methacholine responsiveness, atopy and smoking habit.

RESULTS

FEV₁ responders had lower baseline FEV₁, and a lower percentage of these had received ICS treatment. Neutrophil responders were younger, with lower baseline sputum inflammation and greater methacholine responsiveness. These results were confirmed by multivariate logistic analysis.

DISCUSSION AND CONCLUSION

Patients not previously treated with ICS and patients with lower FEV₁ are more prone to functional response to ozone. Lower baseline airway inflammation and greater bronchial hyperresponsiveness may predict neutrophilic airway response to ozone in asthmatic patients. Thus, determinants of functional and inflammatory responses to ozone are different.

Airway inflammation and hypothalamic-pituitary-adrenal axis activity in asthmatic adults with depression

OBJECTIVE

To investigate the features of airway inflammation and hypothalamic-pituitary-adrenal axis (HPAA) activity in patients with asthma accompanied by depression.

METHODS

Adult asthmatics were recruited and enrolled into one of the two groups based on scores on the Hamilton Depression Rating Scale (HAMD): asthmatics with depression (HAMD score ≥8, n = 23), and asthmatics without depression (HAMD score <8, n = 41). In addition, 27 healthy individuals and 21 adults with depression only were enrolled as controls. Induced sputum and blood samples were collected for measurement of cytokines and other inflammatory factors. The diurnal rhythm profiles of salivary cortisol and other hormones were obtained for assessment of the HPAA activity.

RESULTS

For the group of asthmatics with depression, the mean HAMD score was 19.0, and for the group of asthmatics without depression, the HAMD score averaged 4.9(p < .001). Serum and sputum tumor necrosis factor alpha (TNF-α) were significantly higher in asthmatics with depression than those in the other groups (p < .05) while serum interferon-gamma (IFN-γ) was lower in asthmatics with depression than that in the other groups (p < .05). Twenty-four-hour urinary cortisol, salivary cortisol at 8 a.m. and 4 p.m. were lower in asthmatics with depression compared to other groups (p < .05).

CONCLUSIONS

As compared to healthy individuals and those with asthma or depression alone, individuals with comorbid depression and asthma showed the highest level of pro-inflammatory cytokines and the lowest level of anti-inflammatory cytokines and cortisol. These observations may serve as a valuable reference for diagnosis and clinic therapies of depression in asthmatics.

Asthma control test (ACT): comparison with clinical, functional, and biological markers of asthma control

BACKGROUND

Asthma Control Test (ACT) is a simple tool for assessing the level of asthma control in clinical practice, and it has been validated in comparison with a general clinical assessment of asthma control, including forced expiratory volume in the first second (FEV(1)).

OBJECTIVE

To evaluate the relationship between ACT score and clinical and functional findings of asthma control and biomarkers of airway inflammation.

METHODS

A total of 68 asthmatic patients observed in our asthma clinic (33 regularly treated with inhaled corticosteroids (ICS) and 35 ICS-naïve) filled ACT questionnaire and underwent the following measurements: (a) FEV(1) before and after salbutamol; (b) exhaled nitric oxide; (c) bronchial hyperresponsiveness to methacholine; (d) sputum eosinophil count; and (e) daytime and nighttime symptoms, rescue salbutamol, and twice-daily peak expiratory flow (PEF) recording on a 4-week diary card.

RESULTS

ACT score significantly correlated with symptom score, rescue medication use, and PEF variability, but not with FEV(1), FEV(1) reversibility, and markers of airway inflammation, which could not distinguish controlled from uncontrolled patients according to ACT, regardless of ICS treatment.

CONCLUSION

ACT score is a valid tool to simply assess the current level of asthma control in terms of symptoms, rescue medication use, and PEF variability. Pulmonary function and biomarkers of airway inflammation are not related to the clinical asthma control as assessed by ACT and may represent additional measurements potentially useful in asthma management.

Basement membrane and vascular remodelling in smokers and chronic obstructive pulmonary disease: a cross-sectional study

Background

Little is known about airway remodelling in bronchial biopsies (BB) in smokers and chronic obstructive pulmonary disease (COPD). We conducted an initial pilot study comparing BB from COPD patients with nonsmoking controls. This pilot study suggested the presence of reticular basement membrane (Rbm) fragmentation and altered vessel distribution in COPD.

Methods

To determine whether Rbm fragmentation and altered vessel distribution in BB were specific for COPD we designed a cross-sectional study and stained BB from 19 current smokers and 14 ex-smokers with mild to moderate COPD and compared these to 15 current smokers with normal lung function and 17 healthy and nonsmoking subjects.

Results

Thickness of the Rbm was not significantly different between groups; although in COPD this parameter was quite variable. The Rbm showed fragmentation and splitting in both current smoking groups and ex-smoker COPD compared with healthy nonsmokers (p < 0.02); smoking and COPD seemed to have additive effects. Rbm fragmentation correlated with smoking history in COPD but not with age. There were more vessels in the Rbm and fewer vessels in the lamina propria in current smokers compared to healthy nonsmokers (p < 0.05). The number of vessels staining for vascular endothelial growth factor (VEGF) in the Rbm was higher in both current smoker groups and ex-smoker COPD compared to healthy nonsmokers (p < 0.004). In current smoker COPD VEGF vessel staining correlated with FEV1% predicted (r = 0.61, p < 0.02).

Conclusions

Airway remodelling in smokers and mild to moderate COPD is associated with fragmentation of the Rbm and altered distribution of vessels in the airway wall. Rbm fragmentation was also present to as great an extent in ex-smokers with COPD. These characteristics may have potential physiological consequences.

Increase in markers of airway inflammation after ozone exposure can be observed also in stable treated asthmatics with minimal functional response to ozone

Background

The discrepancy between functional and inflammatory airway response to ozone has been reported in normal subjects, but few data are available for stable asthmatics regularly treated with inhaled corticosteroids.

Methods

Twenty-three well controlled, regularly treated, mild-to-moderate asthmatic patients underwent two sequential randomised exposures to either filtered air or ozone (0.3 ppm for 2 hours) in a challenge chamber. Pulmonary function (PF) was monitored, and patients with FEV1 decrease greater than 10% from pre-challenge value were considered as responders. Immediately after each exposure, exhaled breath condensate (EBC) was collected to measure malondialdehyde (MDA). Six hours after each exposure, PF and EBC collection were repeated, and sputum was induced to measure inflammatory cell counts and soluble mediators (IL-8 and neutrophil elastase). The response to ozone was also evaluated according to the presence of polymorphism in oxidative stress related NQO1 and GSTM1 genes.

Results

After ozone exposure, sputum neutrophils significantly increased in responders (n = 8), but not in nonresponders (n = 15). Other markers of neutrophil activation in sputum supernatant and MDA in EBC significantly increased in all patients, but only in nonresponders the increase was significant. In nonresponders, sputum eosinophils also significantly increased after ozone. There was a positive correlation between ozone-induced FEV1 fall and increase in sputum neutrophils. No difference in functional or inflammatory response to ozone was observed between subjects with or without the combination of NQO1wt- GSTM1null genotypes.

Conclusions

Markers of neutrophilic inflammation and oxidative stress increase also in asthmatic subjects not responding to ozone. A greater functional response to ozone is associated with greater neutrophil airway recruitment in asthmatic subjects.

Magnitude of late asthmatic response to allergen in relation to baseline and allergen-induced sputum eosinophilia in mild asthmatic patients

BACKGROUND

Late asthmatic response (LAR) to allergen challenge is a validated method for studying the pathogenesis of and new treatments for asthma in the laboratory.

OBJECTIVE

To evaluate the relationship between the magnitude of allergen-induced LAR and clinical and biological determinants, including sputum and blood eosinophil percentages and eosinophil cationic protein concentrations.

METHODS

Thirty-eight untreated mild asthmatic patients (mean age, 21.2 years) were selected for the presence of allergen-induced early asthmatic response (EAR) and LAR. Each patient measured methacholine responsiveness (provocation dose that caused a decrease in forced expiratory volume in 1 second of 20% [PD20FEV1]) at baseline, differential blood cell counts and eosinophil cationic protein levels in blood and induced sputum, and serum neutrophil chemotactic activity at baseline and 24 hours after allergen challenge.

RESULTS

A correlation was found between LAR (as area under the curve [AUC]) and sputum eosinophil percentages at baseline (r = 0.51; P = .001) and 24 hours after allergen challenge (r = 0.44; P < .007). Furthermore, we found significant correlations between AUC LAR and AUC EAR, baseline methacholine PD20FEV1, baseline blood eosinophil percentages, and baseline serum neutrophil chemotactic activity. A stepwise multiple regression analysis showed that the stronger determinants of AUC LAR were baseline sputum eosinophilia and AUC EAR.

CONCLUSION

Baseline sputum eosinophilia and functional findings are determinants of the magnitude of allergen-induced LAR.

Tailored interventions based on sputum eosinophils versus clinical symptoms for asthma in children and adults

BACKGROUND

Asthma severity and control can be measured both subjectively and objectively. Sputum analysis for evaluation of percentage of sputum eosinophilia directly measures airway inflammation, and is one method of objectively monitoring asthma. Interventions for asthma therapies have been traditionally based on symptoms and spirometry.

OBJECTIVES

To evaluate the efficacy of tailoring asthma interventions based on sputum analysis 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 on 31 October 2006.

SELECTION CRITERIA

All randomised controlled comparisons of adjustment of asthma therapy based on sputum eosinophils 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. Three sets of reviewers selected relevant studies. Two review authors independently assessed trial quality extracted data. Authors were contacted for further information but none were received. Data was analysed as "treatment received" and sensitivity analyses performed.

MAIN RESULTS

Three adult studies were included; these studies were clinically and methodologically heterogenous (use of medications, cut off for percentage of sputum eosinophils and definition of asthma exacerbation). There were no eligible paediatric studies. Of 246 participants randomised, 221 completed the trials. In the meta-analysis, a significant reduction in number of participants who had one or more asthma exacerbations occurred when treatment was based on sputum eosinophils in comparison to clinical symptoms; pooled odds ratio (OR) was 0.49 (95% CI 0.28 to 0.87); number needed to treat to benefit (NNTB) was 6 (95% CI 4 to 32). There were also differences between groups in the rate of exacerbation (any exacerbation per year) and severity of exacerbations defined by requirement for use of oral corticosteroids but the reduction in hospitalisations was not statistically significant. Data for clinical symptoms, quality of life and spirometry were not significantly different between groups. The mean dose of inhaled corticosteroids per day was similar in both groups and no adverse events were reported. However sputum induction was not always possible.

AUTHORS' CONCLUSIONS

Tailored asthma interventions based on sputum eosinophils is beneficial in reducing the frequency of asthma exacerbations in adults with asthma. This review supports the use of sputum eosinophils to tailor asthma therapy for adults with frequent exacerbations and severe asthma. Further studies need to be undertaken to strengthen these results and no conclusion can be drawn for children with asthma.

Low sputum eosinophils predict the lack of response to beclomethasone in symptomatic asthmatic patients

BACKGROUND

The prognostic role of low sputum eosinophils in steroid-naïve, symptomatic asthmatic patients is controversial.

AIM

To verify whether low sputum eosinophils predict poor response to treatment with inhaled corticosteroids.

METHODS

Sixty-seven symptomatic asthmatic patients with moderate asthma were examined before and after 2 weeks and 4 weeks of treatment with beclomethasone dipropionate, 500 microg bid. None received corticosteroids in the 3 months preceding the study. At each visit, all patients underwent spirometry, methacholine challenge, and sputum induction. The patients recorded symptom scores and peak expiratory flow (PEF) throughout the study.

RESULTS

Seventeen patients had low sputum eosinophils despite being symptomatic. Patients with high (> 3%) sputum eosinophils at baseline showed significant improvement in symptoms, pulmonary function, and bronchial hyperresponsiveness after treatment, whereas patients with low sputum eosinophils showed no significant improvement in most clinical and functional outcomes. Among the baseline indexes examined, sputum eosinophils had the highest negative predictive value but low positive predictive value for the response to treatment. Multiple stepwise regression showed that only baseline FEV(1) and sputum eosinophil percentages significantly correlated with changes in FEV(1) after treatment.

CONCLUSIONS

We suggest that, among the indexes examined, low sputum eosinophils are the best predictor for poor corticosteroid effects in asthma.

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

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

One week treatment with salmeterol does not prevent early and late asthmatic responses and sputum eosinophilia induced by allergen challenge in asthmatics

Salmeterol is an effective long-acting beta(2)-agonist bronchodilator, able to inhibit, as a single dose, asthmatic responses induced by several stimuli including allergen, and the subsequent increase in sputum eosinophilia. Aim of the present study was to investigate whether these effects of salmeterol persisted after 1 week of continuous treatment, or whether a loss of the bronchoprotective effects of salmeterol can occur over time. We investigated in a cross-over double blind placebo-controlled study, the protective effect of 1 week treatment with salmeterol on allergen-induced early and late responses and the associated airway inflammation in 15 atopic asthmatic subjects. Eosinophil percentage and Eosinophil Cationic Protein (ECP) concentration in peripheral blood and in hypertonic saline induced sputum were measured at baseline and 24 h after allergen inhalation. Salmeterol partially inhibited early asthmatic response, but it did not inhibit late asthmatic response in comparison with placebo. Salmeterol did not inhibit also the increase in sputum eosinophils percentage 24 h after allergen inhalation (E%, median: 22.7 and 15%, after placebo and after salmeterol respectively, p=n.s. between two post-allergen sputum samples). Also, the increase in blood eosinophils and both sputum and serum ECP at 24 h after allergen challenge was not affected by salmeterol pre-treatment. In conclusion, 1 week treatment with salmeterol causes a loss of its protective effect on allergen-induced airway bronchoconstriction, and does not prevent the subsequent increase in sputum and serum eosinophilic markers.

Clinical assessment of asthma severity partially corresponds to sputum eosinophilic airway inflammation

In the aim to evaluate the relationship between sputum eosinophil percentages and eosinophil cationic protein (ECP) concentrations, as markers of airway inflammation, and different Levels of asthma severity, we examined 223 patients consecutively observed in our asthma clinic. Diagnosis of asthma was made according to internationally accepted criteria. Asthma severity was evaluated according to frequency of symptoms, FEV1, peak expiratory flow variability and level of asthma treatment needed to control asthma. Spontaneous or induced sputum was collected. Adequate sputum samples were obtained in 68 untreated subjects and in 117 subjects regularly treated with ICS. A control group of 14 normal subjects was also examined. In untreated subjects, mild intermittent asthmatics showed a lower sputum eosinophil percentage in comparison with other groups of asthma severity, while no difference in ECP levels was detected. In treated subjects, severe asthmatics showed higher levels of sputum eosinophils and ECP in comparison with other groups of asthma severity. Mild persistent and moderate persistent patients did not differ for sputum eosinophils or ECP in both untreated and treated subjects. Controls were significantly different from all groups of untreated and treated asthmatics. In conclusion, the assessment of asthma severity according to clinical and functional findings only partially corresponds to the severity of eosinophilic airway inflammation as assessed by induced sputum analysis.

Fifty microg b.i.d. of inhaled fluticasone propionate (FP) are effective in stable asthmatics previously treated with a higher dose of FP

Twenty-seven subjects with moderate asthma at the time of diagnosis, well controlled under regular fluticasone propionate (FP) (250 microg b.i.d.) for 6 months at least, were randomized to receive in double-blind fashion: FP 125 microg b.i.d. (Group 1) or FP 50 microg b.i.d. (Group 2) or placebo (Group 3) for 3 months or until symptom recurrence. Daily symptom score and peak expiratory flow were monitored. At the beginning and at the end of the study subjects underwent methacholine challenge and sputum induction. Recurrence of symptoms occurred shortly after randomization in all subjects receiving placebo. None from Group 1 or 2 experienced symptom recurrence during the study. No significant difference in clinical and functional data, and in sputum eosinophil percentages was observed between the beginning and the end of the study in both Groups 1 and 2. Subjects from Group 3 showed a significant increase of sputum eosinophils (P<0.05) and a significant decrease in provocative dose of methacholine (P<0.05) when asthma symptoms recurred. Therefore, very low doses of FP (50 microg b.i.d.) are effective in maintaining for 3 months a good control of the disease in asthmatics already stable under high-dose fluticasone, considering both clinical and functional outcomes and markers of airway inflammation.