Exhaled matrix metalloproteinase-9 (MMP-9) in different biological phenotypes of asthma

BACKGROUND AND OBJECTIVES

Airway remodeling is a main feature of asthma. Different biological phenotypes of severe asthma have been recently recognized by the ENFUMOSA study group and among these one is characterized by neutrophilic airway inflammation. Concentrations of MMP-9 in airways have been suggested as a marker to monitor airway remodeling in asthma.

OBJECTIVE

The aim of the present study was to explore airway remodeling in different biological phenotypes of asthma by measuring MMP-9 in EBC and correlating these with other variables.

METHODS

Sixty consecutive subjects with asthma and 20 healthy controls were enrolled in the study. Exhaled MMP-9, pH and NO levels and inflammatory cells in sputum were measured in all subjects enrolled.

RESULTS

We observed an increase of exhaled MMP-9 in asthmatic subjects compared to controls. Higher exhaled MMP-9 concentrations were described in severe asthmatics compared to mild to moderate especially in those with neutrophilic airway inflammation. We further found a correlation between exhaled MMP-9 and percentage of neutrophils in sputum, FEV1, exhaled NO and pH.

CONCLUSION

Our results seem to substantiate the feasibility of measuring exhaled MMP-9 in the breath of asthmatic patients. MMP-9 may be considered a proxy of the amount of the ongoing airway remodeling in asthma. MMP-9 has been shown to be differentially released in different phenotypes of asthma. The measure of exhaled MMP-9 could help to monitor the ongoing airway remodeling, recognize severe stages of asthma, and possibly help determine the appropriate choice of therapy.

A novel alternative to environmental monitoring to detect workers at risk for beryllium exposure-related health effects

The purpose of this study was to describe a methodology for surveillance and monitoring of beryllium exposure using biological monitoring to complement environmental monitoring. Eighty-three Israeli dental technicians (mean age 41.6 ± 1.36 years) and 80 American nuclear machining workers (54.9 ± 1.21 years) were enrolled. Biological monitoring was carried out by analyzing particle size (laser technique) and shape (image analysis) in 131/163 (80.3%) induced sputum samples (Dipa Analyser, Donner Tech, Or Aquiva, Israel). Environmental monitoring was carried out only in the United States (Sioutas impactor, SKC, Inc., Eighty Four, Pa.). Pulmonary function testing performance and induced sputum retrieval were done by conventional methods. Sixty-three Israeli workers and 37 American workers were followed up for at least 2 years. Biological monitoring by induced sputum indicated that a >92% accumulation of <5 μm particles correlated significantly to a positive beryllium lymphocyte proliferation test result (OR 3.8, 95% CI 1.2-11.4, p = 0.015) among all participants. Environmental monitoring showed that beryllium particles were <1 μm, and this small fraction (0.1-1 μ) was significantly more highly accumulated in nuclear machining workers compared to dental technicians. The small fractions positively correlated with induced sputum macrophages (r = 0.21 p = 0.01) and negatively correlated with diffusion lung carbon monoxide single breath (DLCO-SB r = 0.180 p = 0.04) in all subjects. Years of exposure were positively correlated to the number of accumulated particles 2-3 μ in diameter (r = 0.2, p = 0.02) and negatively correlated to forced expiratory volume in one second/forced vital capacity findings (r = -0.18, p = 0.02). DLCO was decreased in both groups after two years of monitoring. Biological monitoring is more informative than environmental monitoring in the surveillance and monitoring of workers in beryllium industries. Induced sputum is a feasible and promising biomonitoring method that should be included in the surveillance of exposed workers.

How variability in clinical phenotypes should guide research into disease mechanisms in asthma

Asthma is increasingly being considered as a collection of different phenotypes that present with intermittent wheezing. Unbiased approaches to classifying asthma have led to the identification of distinct phenotypes based on age of onset of disease, atopic state, disease severity or activity, degree of chronic airflow obstruction, and sputum eosinophilia. Linking phenotypes to known disease mechanism is likely to be more fruitful in determining the potential targets necessary for successful therapies of specific endotypes. A "Th2-high expression" signature from the epithelium of patients with asthma identifies a subset of patients with high eosinophilia and good therapeutic responsiveness to corticosteroids. Other characteristic traits of asthma include noneosinophilic asthma, corticosteroid insensitivity, obesity-associated, and exacerbation-prone. Further progress into asthma mechanisms will be driven by unbiased data integration of multiscale data sets from omics technologies with those phenotypic characteristics and by using mathematical modeling. This will lead to the discovery of new pathways and their integration into endotypes and also set up further hypothesis-driven research. Continued iteration through experimentation or modeling will be needed to refine the phenotypes that relate to outcomes and also delineate specific treatments for specific phenotypes.

Establishing a normal range for induced sputum cell counts in Western Canada

BACKGROUND

Induced sputum cell counts are a noninvasive, reliable method for evaluating the presence, type and degree of airway inflammation. Whether current reference values for induced sputum cell counts are applicable in other induced-sputum laboratories, particularly those in Western Canada or at elevated altitude, is not clear.

OBJECTIVES

To describe the normal range of induced sputum cell counts in healthy adults in Western Canada.

METHODS

A total of 105 healthy nonsmoking adults with normal bronchial responsiveness and no history of lung disease proceeded with sputum induction. Sputum samples were fixed in formalin.

RESULTS

Sixty-nine subjects were included in the final analyses. The mean ± SD and median (interquartile range) of the cell counts, respectively, were: total cell count 2.453 ± 2.108, 2.000 (2.512); neutrophils 1.212 ± 1.491, 0.721 (1.016); eosinophils 0.034 ± 0.069, 0.005 (0.043); macrophages 1.050 ± 1.213, 0.696 (1.005); lymphocytes 0.057 ± 0.161, 0.001 (0.049); and bronchial epithelial cells 0.041 ± 0.126, 0.000 (0.027). The respective differential cell percentages were: neutrophils 50.3 ± 23.5, 51.9 (32); eosinophils 1.4 ± 2.3, 0.3 (2); macrophages 43 ± 22.8, 39.3 (32); lymphocytes 2.6 ± 5.2, 0.4 (2.5); and bronchial epithelial cells 2.2 ± 4.8, 0.0 (2.9). Bland-Altman analysis and intraclass correlation coefficients revealed excellent interobserver agreement for measurement of sputum cell types.

DISCUSSION

The range of induced sputum cell counts performed in a laboratory in Western Canada in healthy nonsmoking adult subjects was described; cellular distributions were similar to previous studies. This was also the first description of normal values for formalin-fixed induced sputum samples.

CONCLUSIONS

These results confirm that current reference values for induced sputum are generalizable across different laboratories, including those in Western Canada and those at elevated altitude, and are also generalizable to formalin-fixed samples, allowing use in the broader Canadian asthma population.

Phenotypic predictors of response to oral glucocorticosteroids in severe asthma

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Expression of interleukin (IL)-10, IL-17A and IL-22 in serum and sputum of stable chronic obstructive pulmonary disease patients

Interleukin (IL)-17A, IL-22 and IL-10 have been implicated in the development of chronic obstructive pulmonary disease (COPD), but their expression in COPD is uncertain. Here we investigate the expression of IL-17A, IL-22 and IL-10 in the serum and sputum of COPD patients. Blood samples and induced sputum samples were collected from 94 patients with COPD, 23 healthy smokers, and 22 healthy control non-smokers. IL-17A, IL-22 and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA). We found that: 1) serum and sputum IL-17A were higher in COPD compared to healthy smokers and non-smokers; 2) serum IL-17A increased with COPD stages, it was inversely correlated with percentage of forced expiratory volume in the first second (FEV1%) reference and positively correlated with C-reactive protein (CRP), Sputum IL-17A levels in the severe COPD patients were positively correlated with sputum neutrophils, and reversely correlated with sputum macraphages (p < 0.01); 3) serum and sputum IL-22 were significantly higher in COPD and healthy smokers than those in the non-smoker group, sputum IL-22 was similar in severe COPD (stage III and IV), which were higher than those in the other groups (p < 0.05); and, 4) serum and sputum IL-10 were similiar in COPD and healthy smokers, which were decreased compared to non-smokers. These data suggest that the increased level of IL-17A in serum and sputum plays important roles in the pathogenesis of COPD. The increased sputum IL-22 might also play important roles in the pathogenesis of COPD, while IL-10 secretion might be not only affected by COPD but also by cigarette smoke.

Effects of benralizumab on airway eosinophils in asthmatic patients with sputum eosinophilia

BACKGROUND

Many asthmatic patients exhibit sputum eosinophilia associated with exacerbations. Benralizumab targets eosinophils by binding IL-5 receptor α, inducing apoptosis through antibody-dependent cell-mediated cytotoxicity.

OBJECTIVES

We sought to evaluate the safety of benralizumab in adults with eosinophilic asthma and its effects on eosinophil counts in airway mucosal/submucosal biopsy specimens, sputum, bone marrow, and peripheral blood.

METHODS

In this multicenter, double-blind, placebo-controlled phase I study, 13 subjects were randomized to single-dose intravenous placebo or 1 mg/kg benralizumab (day 0; cohort 1), and 14 subjects were randomized to 3 monthly subcutaneous doses of placebo or 100 or 200 mg of benralizumab (days 0, 28, and 56; cohort 2). Cohorts 1 and 2 were consecutive.

RESULTS

The incidence of adverse events was similar between groups. No serious adverse events related to benralizumab occurred. In cohort 1 intravenous benralizumab produced a median decrease from baseline of 61.9% in airway mucosal eosinophil counts (day 28; placebo: +19.6%; P = .28), as well as an 18.7% decrease (day 21) in sputum and a 100% decrease (day 28) in blood counts. Eosinophils were not detectable in bone marrow of benralizumab-treated subjects (day 28, n = 4). In cohort 2 subcutaneous benralizumab demonstrated a combined (100 + 200 mg) median reduction of 95.8% in airway eosinophil counts (day 84; placebo, 46.7%; P = .06), as well as an 89.9% decrease (day 28) in sputum and a 100% decrease (day 84) in blood counts.

CONCLUSION

Single-dose intravenous and multiple-dose subcutaneous benralizumab reduced eosinophil counts in airway mucosa/submucosa and sputum and suppressed eosinophil counts in bone marrow and peripheral blood. The safety profile supports further development. Additional studies are needed to assess the clinical benefit in asthmatic patients.

Identification of genes expressed by human airway eosinophils after an in vivo allergen challenge

Background

The mechanism for the contribution of eosinophils (EOS) to asthma pathophysiology is not fully understood. Genome-wide expression analysis of airway EOS by microarrays has been limited by the ability to generate high quality RNA from sufficient numbers of airway EOS.

Objective

To identify, by genome-wide expression analyses, a compendium of expressed genes characteristic of airway EOS following an in vivo allergen challenge.

Methods

Atopic, mild asthmatic subjects were recruited for these studies. Induced sputum was obtained before and 48h after a whole lung allergen challenge (WLAC). Individuals also received a segmental bronchoprovocation with allergen (SBP-Ag) 1 month before and after administering a single dose of mepolizumab (anti-IL-5 monoclonal antibody) to reduce airway EOS. Bronchoalveolar lavage (BAL) was performed before and 48 h after SBP-Ag. Gene expression of sputum and BAL cells was analyzed by microarrays. The results were validated by qPCR in BAL cells and purified BAL EOS.

Results

A total of 299 transcripts were up-regulated by more than 2-fold in total BAL cells following SBP-Ag. Mepolizumab treatment resulted in a reduction of airway EOS by 54.5% and decreased expression of 99 of the 299 transcripts. 3 of 6 post-WLAC sputum samples showed increased expression of EOS-specific genes, along with the expression of 361 other genes. Finally, the intersection of the 3 groups of transcripts (increased in BAL post SBP-Ag (299), decreased after mepolizumab (99), and increased in sputum after WLAC (365)) was composed of 57 genes characterizing airway EOS gene expression.

Conclusion

We identified 57 genes that were highly expressed by BAL EOS compared to unseparated BAL cells after in vivo allergen challenge. 41 of these genes had not been previously described in EOS and are thus potential new candidates to elucidate EOS contribution to airway biology.

Vitamin E, γ-tocopherol, reduces airway neutrophil recruitment after inhaled endotoxin challenge in rats and in healthy volunteers

Epidemiologic studies suggest that dietary vitamin E is an important candidate intervention for asthma. Our group has shown that daily consumption of vitamin E (γ-tocopherol, γT) has anti-inflammatory actions in both rodent and human phase I studies. The objective of this study was to test whether γT supplementation could mitigate a model of neutrophilic airway inflammation in rats and in healthy human volunteers. F344/N rats were randomized to oral gavage with γT versus placebo, followed by intranasal LPS (20μg) challenge. Bronchoalveolar lavage fluid and lung histology were used to assess airway neutrophil recruitment. In a phase IIa clinical study, 13 nonasthmatic subjects completed a double-blinded, placebo-controlled crossover study in which they consumed either a γT-enriched capsule or a sunflower oil placebo capsule. After 7 days of daily supplementation, they underwent an inhaled LPS challenge. Induced sputum was assessed for neutrophils 6 h after inhaled LPS. The effect of γT compared to placebo on airway neutrophils post-LPS was compared using a repeated-measures analysis of variance. In rats, oral γT supplementation significantly reduced tissue infiltration (p<0.05) and accumulation of airway neutrophils (p<0.05) that are elicited by intranasal LPS challenge compared to control rats. In human volunteers, γT treatment significantly decreased induced sputum neutrophils (p=0.03) compared to placebo. Oral supplementation with γT reduced airway neutrophil recruitment in both rat and human models of inhaled LPS challenge. These results suggest that γT is a potential therapeutic candidate for prevention or treatment of neutrophilic airway inflammation in diseased populations.

Screening for lung cancer

BACKGROUND

This is an updated version of the original review published in The Cochrane Library in 1999 and updated in 2004 and 2010. Population-based screening for lung cancer has not been adopted in the majority of countries. However it is not clear whether sputum examinations, chest radiography or newer methods such as computed tomography (CT) are effective in reducing mortality from lung cancer.

OBJECTIVES

To determine whether screening for lung cancer, using regular sputum examinations, chest radiography or CT scanning of the chest, reduces lung cancer mortality.

SEARCH METHODS

We searched electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 5), MEDLINE (1966 to 2012), PREMEDLINE and EMBASE (to 2012) and bibliographies. We handsearched the journal Lung Cancer (to 2000) and contacted experts in the field to identify published and unpublished trials.

SELECTION CRITERIA

Controlled trials of screening for lung cancer using sputum examinations, chest radiography or chest CT.

DATA COLLECTION AND ANALYSIS

We performed an intention-to-screen analysis. Where there was significant statistical heterogeneity, we reported risk ratios (RRs) using the random-effects model. For other outcomes we used the fixed-effect model.

MAIN RESULTS

We included nine trials in the review (eight randomised controlled studies and one controlled trial) with a total of 453,965 subjects. In one large study that included both smokers and non-smokers comparing annual chest x-ray screening with usual care there was no reduction in lung cancer mortality (RR 0.99, 95% CI 0.91 to 1.07). In a meta-analysis of studies comparing different frequencies of chest x-ray screening, frequent screening with chest x-rays was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, 95% CI 1.00 to 1.23); however several of the trials included in this meta-analysis had potential methodological weaknesses. We observed a non-statistically significant trend to reduced mortality from lung cancer when screening with chest x-ray and sputum cytology was compared with chest x-ray alone (RR 0.88, 95% CI 0.74 to 1.03). There was one large methodologically rigorous trial in high-risk smokers and ex-smokers (those aged 55 to 74 years with ≥ 30 pack-years of smoking and who quit ≤ 15 years prior to entry if ex-smokers) comparing annual low-dose CT screening with annual chest x-ray screening; in this study the relative risk of death from lung cancer was significantly reduced in the low-dose CT group (RR 0.80, 95% CI 0.70 to 0.92).

AUTHORS' CONCLUSIONS

The current evidence does not support screening for lung cancer with chest radiography or sputum cytology. Annual low-dose CT screening is associated with a reduction in lung cancer mortality in high-risk smokers but further data are required on the cost effectiveness of screening and the relative harms and benefits of screening across a range of different risk groups and settings.

Association of eosinophilic inflammation with FKBP51 expression in sputum cells in asthma

BACKGROUND

Airway eosinophilia is a predictor of steroid responsiveness in steroid-naïve asthma. However, the relationship between airway eosinophilia and the expression of FK506-binding protein 51 (FKBP51), a glucocorticoid receptor co-chaperone that plays a role in steroid insensitivity in asthma, remains unknown.

OBJECTIVE

To evaluate the relationship between eosinophilic inflammation and FKBP51 expression in sputum cells in asthma.

METHODS

The FKBP51 mRNA levels in sputum cells from steroid-naïve patients with asthma (n = 31) and stable asthmatic patients on inhaled corticosteroid (ICS) (n = 28) were cross-sectionally examined using real-time PCR. Associations between FKBP51 levels and clinical indices were analyzed.

RESULTS

In steroid-naïve patients, the FKBP51 levels were negatively correlated with eosinophil proportions in blood (r = -0.52) and sputum (r = -0.57), and exhaled nitric oxide levels (r = -0.42) (all p<0.05). No such associations were observed in patients on ICS. In steroid-naïve patients, improvement in forced expiratory volume in one second after ICS initiation was correlated with baseline eosinophil proportions in blood (r = 0.74) and sputum (r = 0.76) and negatively correlated with FKBP51 levels (r = -0.73) (all p<0.0001) (n = 20). Lastly, the FKBP51 levels were the lowest in steroid-naïve asthmatic patients, followed by mild to moderate persistent asthmatic patients on ICS, and the highest in severe persistent asthmatic patients on ICS (p<0.0001).

CONCLUSIONS

Lower FKBP51 expression in sputum cells may reflect eosinophilic inflammation and glucocorticoid responsiveness in steroid-naïve asthmatic patients.

Decreased CTLA4(+) and Foxp3(+) CD25(high)CD4(+) cells in induced sputum from patients with mild atopic asthma

BACKGROUND

Details of the comparisons between airway and peripheral blood regulatory T cells (Tregs) in patients with atopic asthma are still unclear. The objective of this study is to investigate the profiles of both airway and circulating Tregs in atopic asthma.

METHODS

We measured the numbers of Tregs and eosinophils in induced sputum and peripheral blood in 28 patients with mild atopic asthma and compared these with numbers in 18 healthy controls. The frequency (%) of Tregs (surface CTLA4+, intracellular Foxp3+, and CTLA4+Foxp3+ on CD25highCD4+ T cells) in sputum and blood was determined by intracellular 5-color flow cytometry. We also correlated the numbers with the level of airway hyperresponsiveness (AHR) in asthmatics.

RESULTS

The mean frequencies of cells expressing CTLA4+ (19.4 ± 2.1%, p = 0.075), Foxp3+ (16.4 ± 3.3%, p = 0.001), and CTLA4+Foxp3+ (7.0 ± 1.1%, p = 0.008) in induced sputum from asthmatics were significantly lower than controls (27.2 ± 3.7%, 37.4 ± 4.7%, and 18.2 ± 3.6%, respectively), whereas in peripheral blood, there was no inter-group difference in the frequencies of cells expressing CTLA4+ (7.1 ± 1.5% vs 5.7 ± 1.7%, p > 0.05), Foxp3+ (35.7 ± 3.2% vs 21.1 ± 3.9%, p > 0.05), and CTLA4+Foxp3+ (6.6 ± 1.5% vs 4.2 ± 1.0%, p > 0.05). Moreover, the frequency of CD25highCD4+ cells expressing CTLA4+, but not Foxp3+, in induced sputum was associated with AHR (r = 0.60, p = 0.009) and airway eosinophilic inflammation (r = -0.60, p = 0.008) in asthmatics.

CONCLUSIONS

Airway, but not circulating, Tregs are decreased in mild atopic asthmatics, and are negatively correlated to an increase of airway eosinophilic inflammation and AHR.

[Interest for evaluation of bronchial inflammation in asthma]

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

Obesity impairs apoptotic cell clearance in asthma

BACKGROUND

Asthma in obese adults is typically more severe and less responsive to glucocorticoids than asthma in nonobese adults.

OBJECTIVE

We sought to determine whether the clearance of apoptotic inflammatory cells (efferocytosis) by airway macrophages was associated with altered inflammation and reduced glucocorticoid sensitivity in obese asthmatic patients.

METHODS

We investigated the relationship of efferocytosis by airway (induced sputum) macrophages and blood monocytes to markers of monocyte programming, in vitro glucocorticoid response, and systemic oxidative stress in a cohort of adults with persistent asthma.

RESULTS

Efferocytosis by airway macrophages was assessed in obese (n=14) and nonobese (n=19) asthmatic patients. Efferocytosis by macrophages was 40% lower in obese than nonobese subjects, with a mean efferocytic index of 1.77 (SD, 1.07) versus 3.00 (SD, 1.25; P<.01). A similar reduction of efferocytic function was observed in blood monocytes of obese participants. In these monocytes there was also a relative decrease in expression of markers of alternative (M2) programming associated with efferocytosis, including peroxisome proliferator-activated receptor δ and CX3 chemokine receptor 1. Macrophage efferocytic index was significantly correlated with dexamethasone-induced mitogen-activated protein kinase phosphatase 1 expression (ρ=0.46, P<.02) and baseline glucocorticoid receptor α expression (ρ=0.44, P<.02) in PBMCs. Plasma 4-hydroxynonenal levels were increased in obese asthmatic patients at 0.33 ng/mL (SD, 0.15 ng/mL) versus 0.16 ng/mL (SD, 0.08 ng/mL) in nonobese patients (P=.006) and was inversely correlated with macrophage efferocytic index (ρ=-0.67, P=.02).

CONCLUSIONS

Asthma in obese adults is associated with impaired macrophage/monocyte efferocytosis. Impairment of this anti-inflammatory process is associated with altered monocyte/macrophage programming, reduced glucocorticoid responsiveness, and systemic oxidative stress.

Efficacy of anti-interleukin-5 therapy with mepolizumab in patients with asthma: a meta-analysis of randomized placebo-controlled trials

Background

Interleukin (IL)-5 is believed to be a key cytokine in eosinophil inflammatory infiltration in asthma. Previous clinical trials have evaluated the efficacy and safety of mepolizumab, a monoclonal antibody against IL-5, in patients with asthma. However, most of these studies were small, the conclusions were inconsistent, and the precise effects are therefore debatable.

Methods

A meta-analysis of randomized placebo-controlled trials was conducted to evaluate the effect of intravenous infusion of mepolizumab on clinical outcomes in patients with asthma. Trials were searched in PubMed, Embase, Web of Science, Cochrane CENTRAL, Scopus, reviews, and reference lists of relevant articles. The outcome variables analyzed included eosinophil counts in blood and sputum, airways outcome measures, exacerbations, asthma control, and quality of life scores.

Results

Seven studies met final inclusion criteria (total n = 1131). From the pooled analyses, mepolizumab significantly reduced eosinophils in blood (MD −0.29×10⁹/L, 95% CI −0.44 to −0.14×10⁹/L, P = 0.0001) and sputum (MD −6.05%, 95% CI −9.34 to −2.77%, P = 0.0003). Mepolizumab was also associated with significantly decreased exacerbation risk than placebo (OR 0.30, 95%CI 0.13 to 0.67, P = 0.004), and with a significant improvement in the scores on the Asthma Quality of Life Questionnaire (AQLQ) (MD 0.26, 95% CI 0.03 to 0.49, P = 0.03) in patients with eosinophilic asthma. There were no statistical differences between the groups with respect to FEV₁, PEF, or histamine PC₂₀ (all P>0.05)_, and a non-significant trend for improvement in scores on the Juniper Asthma Control Questionnaire (JACQ) (MD −0.21, 95% CI −0.43 to 0.01, P = 0.06) in the mepolizumab group was observed.

Conclusions

Mepolizumab reduces the risk of exacerbations and improves quality of life in patients with eosinophilic asthma, but no significant improvement in lung function outcomes was observed. Further research is required to establish the possible role of anti–IL-5 as a therapy for asthma.

Validation of the Human Ozone Challenge Model as a Tool for Assessing Anti-Inflammatory Drugs in Early Development

This study aimed to test the utility of the ozone challenge model for profiling novel compounds designed to reduce airway inflammation. The authors used a randomized, double-dummy, double-blind, placebo-controlled 3-period crossover design alternating single orally inhaled doses of fluticasone propionate (inhaled corticosteroids, 2 mg), oral prednisolone (oral corticosteroids, 50 mg), or matched placebo. At a 2-week interval, 18 healthy ozone responders (>10% increase in sputum neutrophils) underwent a 3-hour ozone (250 ppb)/intermittent exercise challenge starting 1 hour after drug treatment. Airway inflammation was assessed at 2 hours (breath condensate) and 3 hours (induced sputum) after ozone challenge. Compared to placebo, pretreatment with inhaled corticosteroids or oral corticosteroids resulted in a significant reduction (mean [95% confidence interval]) of sputum neutrophils by 62% (35%, 77%) and 64% (39%, 79%) and of sputum supernatant myeloperoxidase by 55% (41%, 66%) and 42% (25%, 56%), respectively. The authors conclude that an optimized ozone challenge model (including ozone responders and ensuring adequate drug levels during exposure) may be useful for testing novel anti-inflammatory compounds in early development.

Respiratory impairment and systemic inflammation in cedar asthmatics removed from exposure

BACKGROUND

Prior research has shown that removing occupational asthmatics from exposure does not routinely lead to significant improvements in respiratory impairment. These studies were of limited duration and factors determining recovery remain obscure. Our objective was to evaluate residual respiratory impairment and associated sputum and blood biomarkers in subjects with Western red cedar asthma after exposure cessation.

METHODS

Subjects previously diagnosed with cedar asthma, and removed from exposure to cedar dust for at least one year, were recruited. Subjects completed a questionnaire and spirometry. PC20 (methacholine concentration that produces 20% fall in FEV1 (forced expiratory volume at 1 second)) sputum cellularity and select Th1/Th2 (T helper cells 1 and 2) cytokine concentrations in peripheral blood were determined. The asthma impairment class was determined and multivariate analyses were performed to determine its relationship with sputum cell counts and serum cytokines.

RESULTS

40 non-smoking males (mean age 62) were examined at a mean interval of 25 years from cedar asthma diagnosis and 17 years from last cedar exposure. 40% were in impairment class 2/3. On average, the PC20 had increased by 2.0 mg/ml; the FEV1 decreased by 1.5 L, with greater decrease in those with greater impairment. Higher impairment was associated with serum interferon-gamma (mean = 1.3 pg/ml in class 2/3 versus 0.62 pg/ml in class 0/1, p = 0.04), mainly due to the FEV1 component (correlation with interferon-gamma = -0.46, p = 0.005).

CONCLUSION

Years after exposure cessation, patients with Western red cedar asthma have persistent airflow obstruction and respiratory impairment, associated with systemic inflammation.

A challenge to the seven widely believed concepts of COPD

This review proposes a critical reassessment (based entirely on published evidence) of the following seven common beliefs about chronic obstructive pulmonary disease (COPD): (1) COPD is one disease. (2) There is a valid definition for COPD. (The current definition includes cases of irreversible asthma and bronchiectasis, and occasionally, other obstructive lung conditions). (3) Irreversible asthma in smokers and COPD cannot be differentiated. (4) A "chronic bronchitis" form of COPD exists and is characterized by blue bloater status and normal carbon monoxide diffusion studies. (5) Phenotyping has no bearing on medication choice in COPD. (6) Computerized scoring of lung attenuation on CT scans can diagnose emphysema. (Emphysema scores overlap in irreversible asthma and COPD); however, qualitative visual changes may be useful for differentiation. (7) A definable entity called the overlap (of COPD and asthma) syndrome exists. Conflict over the above-mentioned points denies patients proper phenotype-guided therapy and encourages a multidrug approach to COPD management. The recently coined term, overlap syndrome, invites a double-barreled therapy aimed at asthma and COPD, despite the absence of any agreement about how to define the syndrome and the lack of any related drug trials (in the area of inhaled corticosteroids). A diagnosis of COPD is associated with high morbidity and escalating costs, suggesting the need for a thorough new examination of the evidence.

Value of sputum differential count in chronic obstructive airway disease

BACKGROUND

Sputum differential count is a useful tool to evaluate airway inflammation in chronic airway diseases. Since COPD (chronic obstructive airway disease) is so common in our setting this simple tool can be used to initiate and follow up treatment and progression of disease process.

METHODS

A prospective cross sectional study was done in Department of Medicine, in a Teaching Hospital from June 2011 to June 2012. All patients admitted with acute exacerbation of chronic airway disease to the Department of Medicine were included in the study and their sputum was sent for differential count.

RESULTS

Predominant cause of chronic airway disease was COPD 61 (85.9%). The sputum of these patients predominantly showed neutrophilia in the differential count with a mean neutrophil count of 82.06%. This was significantly high than the stated 60% in stable COPD. None of the COPD patients had eosinophilia or lymphocytosis. One patient with asthma showed eosinophil count of 12%. In these patients the peripheral blood smear differential did not show correlation with sputum neutrophilia (r2≥002, p≥0.05).

CONCLUSIONS

Sputum differential has an important role in management of chronic airway diseases.

Cellular composition of induced sputum in sarcoidosis

INTRODUCTION

The aim of this study was to evaluate the cellular composition of induced sputum (IS) in sarcoidosis and its role in assessing the disease activity. The safety of the procedure was also determined.

MATERIAL AND METHODS

Sputum induction by inhalation of hypertonic saline was performed. Twenty-one samples from the healthy controls, 32 from patients with active disease, and 33 from subjects with inactive disease were analysed.

RESULTS

The percentage of lymphocytes in IS was significantly higher in active sarcoidosis than in inactive disease and the control group (9.7% vs. 3.1% vs. 2.9%), and was the highest in the patients with parenchymal changes and active disease (13.3%). The percentage of macrophages was significantly lower in active sarcoidosis than in normal subjects (76.8% vs. 83.4%). It was also significantly lower in IS in active disease and stages II and III than in both subgroups with active and inactive stage I of sarcoidosis. There were no significant differences in the IS cell percentages between the whole sarcoidosis group and the controls. Sputum induction was well tolerated and stopped only four times, two of them because of dyspnoea or the decrease of PEF. The symptoms were well reversible after administering salbutamol.

CONCLUSIONS

Sputum induction by inhalation of hypertonic saline is safe, but the evaluation of IS differential cell counts is not useful in sarcoidosis diagnosing. However, it could be used in assessing the activity of the disease, especially in patients with interstitial lung changes.

CCR1 and CCR5 expression on inflammatory cells is related to cigarette smoking and chronic obstructive pulmonary disease severity

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a progressive disease associated with a cellular inflammatory response mostly concerned with cigarette smoking. Chemokine receptors CCR1/5 play an important role in the inflammatory cells recruitment in the lung of COPD patients. The aim of this study was to determine the impact of cigarette smoking on the expression of CCR1/5 on inflammatory cells in induced sputum, and the relationship between the receptors expression and COPD severity.

METHODS

Differential cells in induced sputum were counted and the optical densities of CCR1 and CCR5 on inflammatory cells in induced sputum from COPD patients (n = 29), healthy smokers (n = 11), and nonsmokers (n = 6) were measured using immunocytochemistry. Concentrations of CCL3, the ligand of CCR1/5, in supernatant of induced sputum were detected by enzyme-linked immunosorbent assay.

RESULTS

The expressions of CCR1 and CCR5 on inflammatory cells in healthy smokers were significantly higher than those in nonsmokers, and the expression of CCR1 in patients with COPD was significantly increased when compared with nonsmokers but not healthy smokers. The expressions of CCR1 and CCR5 on inflammatory cells in severe and very severe COPD patients were higher compared with mild and moderate COPD patients. CCL3 level was positively correlated with the total cell counts in induced sputum and smoking history, and negatively correlated with percentage of predicted FEV(1).

CONCLUSIONS

Cigarette smoking could increase the expression of CCR1 on the inflammatory cells. Both CCR1 and CCR5 expressions on the inflammatory cells in induced sputum could be associated with COPD severity.

Occupational non-immediate type allergic asthma due to ammonium persulfate

While numerous cases of immediate-type occupational asthma due to persulfates with positive skin prick test reactions to ammonium persulfate are well documented, few non-immediate type reactions have been described in the literature. We report the case of an atopic worker who developed work-related asthmatic symptoms shortly after he began his job in persulfate production. The diagnosis of asthma was corroborated by methacholine testing. The patient showed a positive patch test reaction to ammonium persulfate, while skin prick test was negative. He presented an isolated late symptomatic airway obstruction after a cumulative dose of 0.6 mg ammonium persulfate administered by a dosimeter method. An immunologic mechanism was demonstrated by a significant increase in exhaled nitric oxide and the number of eosinophils in induced sputum. These findings suggest that isolated late bronchial reactions to persulfates are mediated by eosinophilic inflammatory responses.

Correlation of eosinophil counts in induced sputum and fractional concentration of exhaled nitric oxide and lung functions in patients with mild to moderate asthma

BACKGROUND

The airway inflammation could be assessed by some noninvasive approaches. To investigate the value of eosinophil counts in induced sputum and fractional concentration of exhaled nitric oxide (FENO) for the regimen adjustment in patients with asthma, the correlation was analyzed between the two parameters and lung function parameter (forced expiratory volume in one second (FEV(1))).

METHODS

Sixty-five outpatients with mild to moderate non-exacerbation asthma from Beijing Chao-Yang Hospital were enrolled as treatment group. Combined medications of inhaled corticosteroids plus long-acting beta-2 agonist were administered for one year. Lung function parameters, eosinophil counts in induced sputum, concentration of exhaled nitric oxide and the Asthma Control Test scores were recorded, at regular intervals in the follow-up period. Twenty-one healthy volunteers were enrolled as control group and underwent examination of eosinophil counts in induced sputum, lung function and concentration of exhaled nitric oxide.

RESULTS

Sixty-three subjects from treatment group completed follow-up period for one year or longer. Mean FEV(1) value of the 63 subjects was (2.75 ± 0.54) L at baseline, (2.97 ± 0.56) L and (3.07 ± 0.52) L at month 3 and month 6, respectively, and maintained as (3.14 ± 0.51) L in the following six months. Mean FENO decreased from (61 ± 25) parts per billion (ppb) at baseline to (32 ± 19) ppb at month 3 (P < 0.05), and continued to decrease to (22 ± 12) ppb at month 6, the difference being significant when compared to both baseline and control group ((13 ± 8) ppb). Mean eosinophil counts decreased to (0.032 ± 0.011) × 10(6)/ml at month 3, which was significantly different from baseline ((0.093 ± 0.023)×10(6)/ml) and the control group ((0.005 ± 0.003)×10(6)/ml (both P < 0.05). The eosinophil counts in induced sputum correlated positively with concentration of FENO in the first six months (all P < 0.05). The concentration of FENO had a significant negative correlation with FEV(1) value (all P < 0.05) in any time point in the follow-up period. The Asthma Control Test scores were 18 ± 5, 19 ± 7, 23 ± 2, 24 ± 1 and 24 ± 1 at months 1, 3, 6, 9 and 12, respectively, which were significantly different from the score at baseline (14 ± 3) (P < 0.05). The most rapid clinical effect was observed at the second month after treatment.

CONCLUSION

Eosinophil counts in induced sputum and FENO are sensitive parameters to detect airway inflammation and may be useful in evaluating the efficacy of treatment and adjusting medication regimens.