Controversies in Allergy: Is Asthma Chronic Obstructive Pulmonary Disease Overlap a Distinct Syndrome That Changes Treatment and Patient Outcomes?

While asthma/COPD overlap (ACO), like both asthma and COPD alone, is not a distinct syndrome, nonetheless it does have features that distinguish it from asthma and COPD only. Similar to the latter obstructive pulmonary disorders, it most likely represents a complex spectrum of diseases comprising several different phenotypes and underlying pathophysiologies. It also not yet clear how ACO is best defined, i.e., by clinical features (age, physiology, bronchodilator responsiveness, symptom variability, history of asthma), biomarkers or a combination of these features. The lack of generally agreed-on diagnostic criteria probably accounts for the marked heterogeneity of the results of published surveys of its prevalence. Until a true consensus is achieved regarding the definition of ACO, it will not be possible to determine with confidence not only its prevalence, but also its natural history (outcomes), its underlying biology or its optimal treatment based on findings from randomized controlled clinical trials focused specifically on patients with well-defined ACO.

[Clinical and inflammatory phenotypic features of asthmatic patients sensitive to cold stimulation]

OBJECTIVE

To explore the clinical symptoms, lung function and airway inflammation phenotype characteristics of asthmatic patients who are sensitive to cold stimulation.

METHODS

Eighty patients with newly diagnosed bronchial asthma or with mild to moderate acute exacerbation of previously diagnosed bronchial asthma but without regular treatment were selected. According to whether cold air stimulation could induce respiratory symptoms such as cough and wheeze, the patients were divided into cold-insensitive group (45 cases) and cold-sensitive group (35 cases). All the patients were treated with inhaled corticosteroid (ICS), long-acting β2 receptor agonist (LABA; salmeterol xinafoate and fluticasone propionate powder for inhalation, 50 μg/250 μg, twice daily) and montelukast sodium tablets (10 mg, once daily); short-acting β2 receptor agonist (SABA) and/or systemic glucocorticoid (prednisone acetate tablets, 10 mg, once daily; or injection of methylprednisolone sodium succinate, 40 mg) were given if necessary. Asthma Control Test (ACT) score before treatment and at 3 months of treatment was used to assess the clinical symptoms such as cough and wheeze; spirometry was performed to determine lung function impairment and recovery. Blood and induced sputum cell counts were examined to determine the characteristics of airway inflammation.

RESULTS

The two groups were comparable for age, gender, BMI, proportion of smokers and allergic rhinitis before treatment. The cold-sensitive patients experienced significantly more frequent acute exacerbations than the cold-insensitive patient within 1 year before the visit (P < 0.05), but the use of SABA and glucocorticoid for symptom control during the treatment did not differ significantly between the two groups (P > 0.05). The ACT scores of the cold-sensitive group were significantly lower than those of the cold-insensitive group both before and after the treatment (P < 0.01). Compared with the cold-insensitive patients, the cold-sensitive patients had more obvious impairment of FEV1/FVC% and FEV1%pred before treatment (P < 0.01), and also showed poorer recovery after treatment (P < 0.05). The percentages of eosinophils in blood and induced sputum samples did not differ significantly between the two groups either before and after the treatment, but the percentage of neutrophils was significantly higher in the cold-sensitive group (P < 0.01). In the induced sputum samples collected before treatment, the cell populations consisted mainly of eosinophilic subtype (60%) and neutrophilic subtype (20%) in the cold-insensitive group; in the cold-sensitive patients, the sputum neutrophilic subtype cells increased significantly to 42.86% (P=0.03) and the eosinophilic subtype cells were lowered to 31.43% (P=0.01).

CONCLUSIONS

The cold-sensitive asthmatic patients experience frequent recurrent and/or aggravated symptoms and have obvious lung function impairment. Different from that in patients with classic asthma, the airway inflammatory phenotype in these patients is characterized by the domination by neutrophilic subtype.

Metabolomic Analysis of Serum Glycerophospholipid Levels in Eosinophilic and Neutrophilic Asthma

OBJECTIVE

To compare the serum glycerophospholipid levels in the inflammatory subtypes of asthma by using targeted metabolomic analysis.

METHODS

Demographic and clinical data were collected from 51 patients with asthma between January 2015 and December 2015. Routine blood and sputum induction tests were performed. Eosinophilic asthma was defined as induced sputum containing ⪖ 3% eosinophils, and neutrophilic asthma, as induced sputum containing ⪖ 71% neutrophils. Serum metabolic glycerophospholipid profile was determined by liquid chromatography-mass spectrometry. Differences in glycerophospholipid levels between eosinophilic and non-eosinophilic asthma and between neutrophilic and non-neutrophilic asthma were analyzed using partial least squares discriminant analysis.

RESULTS

The serum lysophosphatidylglycerol level was significantly higher in the group with ⪖ 3% eosinophils in sputum than in the group with < 3% eosinophils in sputum. The area under the receiver-operating characteristic curve was ⪖ 70%. There was no significant difference in the serum metabolic glycerophospholipid profile between the group with sputum neutrophils ⪖ 71% and the group with sputum neutrophils < 71%.

CONCLUSION

Serum lysophosphatidylglycerol is produced abundantly in eosinophilic asthma and may be a biomarker of eosinophilic asthma. This information is helpful for identifying and tailoring treatment for the common asthma subtypes.

Vitamin D3 supplementation in adults with bronchiectasis: A pilot study

Vitamin D supplementation prevents acute respiratory infections and, through modulating innate and adaptive immunity, could have a potential role in bronchiectasis management. The primary aims of this pilot study were to assess serum 25-hydroxyvitamin D (25(OH)D) levels in New Zealand adults with bronchiectasis, and their 25(OH)D levels after vitamin D3 supplementation. Adults with bronchiectasis received an initial 2.5 mg vitamin D3 oral loading dose and 0.625 mg vitamin D3 weekly for 24 weeks. The primary outcome was serum 25(OH)D levels before and after vitamin D3 supplementation. Secondary outcomes (time to first infective exacerbation, exacerbation frequency, spirometry, health-related quality of life measures, sputum bacteriology and cell counts and chronic rhinosinusitis) were also assessed. This study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN 12612001222831). The initial, average 25(OH)D level was 71 nmol/L (95% confidence interval (CI): [58, 84]), rising to 218 nmol/L (95% CI: [199, 237]) at 12 weeks and 205 nmol/L (95% CI: [186, 224]) at 24 weeks. The initial serum cathelicidin level was 25 nmol/L (95% CI: [17, 33]), rising to 102 nmol/L (95% CI: [48, 156]) at 12 weeks and 151 nmol/L (95% CI: [97, 205]) at 24 weeks. Over the 24-week study period, we observed statistically significant changes of 1.11 (95% CI: [0.08, 2.14]) in the Leicester Cough Questionnaire and -1.97 (95% CI: [-3.71, -0.23]) in the Dartmouth COOP charts score. No significant adverse effects were recorded. Many New Zealand adults with bronchiectasis have adequate 25(OH)D levels. Weekly vitamin D3 supplementation significantly improved 25(OH)D levels.

Diagnostic value of fractional exhaled nitric oxide for asthma-chronic obstructive pulmonary disease overlap syndrome

To examine the difference in the fractional exhaled nitric oxide (FeNO) between chronic obstructive pulmonary disease (COPD) patients with asthma-COPD overlap syndrome (ACOS) and patients with Non-ACOS COPD (Non-ACOS) and to investigate the correlation between FeNO levels and the differential cell counts of eosinophils in induced sputum, in order to explore the diagnostic value of FeNO in ACOS.A prospective, case-control study was performed on 53 cases of ACOS group and 53 cases of Non-ACOS group in the Respiratory Medicine Outpatient of Zhangzhou Municipal TCM Hospital, Affiliated to Fujian University of Traditional Chinese Medicine. The FeNO levels and induced sputum cell counts were determined and the correlation between FeNO levels and eosinophile percentage was analyzed by Pearson linear correlation analysis.The FeNO levels in patients with ACOS (37[24.5-53.0]) ppb were significantly higher than those of patients with Non-ACOS (20 [15.5-24.5] ppb) (P < .01). Also, the percentage of eosinophils in induced sputum in the ACOS group (5.70 [1.50-17.62]%) were significantly higher than those of the Non-ACOS group (0.50 [0.00-1.00]%) (P < .01). FeNO in both groups correlated positively with the percentage of eosinophils in induced sputum (P < .01), with a correlation coefficient r of 0.521. The area under the receiver operating curve of FeNO for the diagnosis of ACOS phenotype was 0.815 (P < .01), the sensitivity and specificity reach highest when the cut off value was 25.50 ppb.The FeNO in patients from the ACOS group were significantly higher than those in Non-ACOS group and were moderately correlated with the percentage of eosinophils in induced sputum. The results indicated that FeNO may be used as a diagnostic index for ACOS, in addition to the induced sputum.

Chronic obstructive pulmonary disease (COPD): neutrophils, macrophages and lymphocytes in patients with anterior tuberculosis compared to tobacco related COPD

OBJECTIVE

The inflammatory profile of chronic obstructive pulmonary disease (COPD) related to tobacco is known in certain studies while that of the post tuberculosis form is not yet known. This study aimed to evaluate the levels of neutrophils, macrophages and lymphocytes cells in sputum of COPD patients with history of smoking or anterior tuberculosis. Enumeration of cells in samples was analyzed using standard microscopy.

RESULTS

We enrolled 92 participants, 46 (50%) were COPD subjects comprising 22 (47.83%) smokers and 24 (52.17%) with anterior tuberculosis while 46 (50%) healthy persons constituted the control group. The levels of neutrophils, lymphocytes and monocytes were statistically higher in COPD patients compared to the control group with p-values of 0.0001 respectively. Neutrophils levels were higher in COPD patients with history of tobacco than in COPD patients with anterior tuberculosis with a mean rate of 4.72 × 106/ml and 2.48 × 106/ml respectively (p = 0.04). The monocytes and lymphocytes levels were not statistically different between the two sub-groups of COPD patients with p-value of 0.052 and 0.91 respectively. Neutrophils are the only inflammatory cells that were significantly higher in COPD patients with history of smoking as compared to COPD patients with anterior tuberculosis.

Safety and effectiveness of the high-frequency chest wall oscillation vs intrapulmonary percussive ventilation in patients with severe COPD

Purpose

Chest physiotherapy is an important tool in the treatment of COPD. Intrapulmonary percussive ventilation (IPV) and high-frequency chest wall oscillation (HFCWO) are techniques designed to create a global percussion of the lung which removes secretions and probably clears the peripheral bronchial tree. We tested the hypothesis that adding IPV or HFCWO to the best pharmacological therapy (PT) may provide additional clinical benefit over chest physiotherapy in patients with severe COPD.

Methods

Sixty patients were randomized into three groups (20 patients in each group): IPV group (treated with PT and IPV), PT group with (treated with PT and HFCWO), and control group (treated with PT alone). Primary outcome measures included results on the dyspnea scale (modified Medical Research Council) and Breathlessness, Cough, and Sputum scale (BCSS), as well as an evaluation of daily life activity (COPD Assessment Test [CAT]). Secondary outcome measures were pulmonary function testing, arterial blood gas analysis, and hematological examinations. Moreover, sputum cell counts were performed at the beginning and at the end of the study.

Results

Patients in both the IPV group and the HFCWO group showed a significant improvement in the tests of dyspnea and daily life activity evaluations (modified Medical Research Council scale, BCSS, and CAT) compared to the control group, as well as in pulmonary function tests (forced vital capacity, forced expiratory volume in 1 second, forced expiratory volume in 1 second/forced vital capacity%, total lung capacity, residual volume, diffusing lung capacity monoxide, maximal inspiratory pressure, maximal expiratory pressure) and arterial blood gas values. However, in the group comparison analysis for the same variables between IPV group and HFCWO group, we observed a significant improvement in the IPV group maximal inspiratory pressure, maximal expiratory pressure, BCSS, and CAT. Similar results were observed in changes of sputum cytology with reduction of inflammatory cells (neutrophils and macrophages).

Conclusion

The two techniques improved daily life activities and lung function in patients with severe COPD. IPV demonstrated a significantly greater effectiveness in improving some pulmonary function tests linked to the small bronchial airways obstruction and respiratory muscle strength and scores on health status assessment scales (BCSS and CAT) as well as a reduction of sputum inflammatory cells compared with HFCWO.

[Airway metaplasia related to smoking and environmental pollution through sputum]

BACKGROUND

Both environmental pollution and smoking affect the respiratory epithelium, causing cellular adaptation changes. Therefore, this work explores the presence of metaplasia in smokers compared with non-smokers from Mexico City.

METHODS

A prospective cohort study was performed. The sample was performed through a home interview covering the five Mexico City zones delimited to the study and monitoring of air quality. We searched metaplastic cells and inflammation in sputum cytology stained with Papanicolaou technique, and we assessed the air quality in Mexico City. We calculated relative risk (RR) and attributable risk (AR) in relation to the presence of metaplasia and smoking.

RESULTS

We performed 1897 home interviews obtaining a final sample of 30 participants. There were no significant differences between smokers and non-smokers with the presence of metaplastic cells (p = 0.269), although the association of metaplastic cells and inflammation showed a significant difference in the non-smokers group (p = 0.010). The RR in association with the presence of metaplasia in sputum cytology and smoking was 1.6, and the RA was 0.2.

CONCLUSIONS

The air quality in this city has led the population to undergo changes of cellular adaptation in the respiratory epithelium by the simple fact of being exposed to environmental pollution. Metaplastic changes in non-smokers suggest strongly that pollution causes the same effect as smoking.

Association of sputum and blood eosinophil concentrations with clinical measures of COPD severity: an analysis of the SPIROMICS cohort

BACKGROUND

Increased concentrations of eosinophils in blood and sputum in chronic obstructive pulmonary disease (COPD) have been associated with increased frequency of exacerbations, reduced lung function, and corticosteroid responsiveness. We aimed to assess whether high eosinophil concentrations in either sputum or blood are associated with a severe COPD phenotype, including greater exacerbation frequency, and whether blood eosinophils are predictive of sputum eosinophils.

METHODS

We did a multicentre observational study analysing comprehensive baseline data from SPIROMICS in patients with COPD aged 40-80 years who had a smoking history of at least 20 pack-years, recruited from six clinical sites and additional subsites in the USA between Nov 12, 2010, and April 21, 2015. Inclusion criteria for this analysis were SPIROMICS baseline visit data with complete blood cell counts and, in a subset, acceptable sputum counts. We stratified patients on the basis of blood and sputum eosinophil concentrations and compared their demographic characteristics, as well as results from questionnaires, clinical assessments, and quantitative CT (QCT). We also analysed whether blood eosinophil concentrations reliably predicted sputum eosinophil concentrations. This study is registered with ClinicalTrials.gov (NCT01969344).

FINDINGS

Of the 2737 patients recruited to SPIROMICS, 2499 patients were smokers and had available blood counts, and so were stratified by mean blood eosinophil count: 1262 patients with low (<200 cells per μL) and 1237 with high (≥200 cells per μL) blood eosinophil counts. 827 patients were eligible for stratification by mean sputum eosinophil percentage: 656 with low (<1·25%) and 171 with high (≥1·25%) sputum eosinophil percentages. The high sputum eosinophil group had significantly lower median FEV1 percentage predicted than the low sputum eosinophil group both before (65·7% [IQR 51·8-81·3] vs 75·7% [59·3-90·2], p<0·0001) and after (77·3% [63·1-88·5] vs 82·9% [67·8-95·9], p=0·001) bronchodilation. QCT density measures for emphysema and air trapping were significantly higher in the high sputum eosinophil group than the low sputum eosinophil group. Exacerbations requiring corticosteroids treatment were more common in the high versus low sputum eosinophil group (p=0·002). FEV1 percentage predicted was significantly different between low and high blood eosinophil groups, but differences were less than those observed between the sputum groups. The high blood eosinophil group had slightly increased airway wall thickness (0·02 mm difference, p=0·032), higher St George Respiratory Questionnaire symptom scores (p=0·037), and increased wheezing (p=0·018), but no evidence of an association with COPD exacerbations (p=0·35) or the other indices of COPD severity, such as emphysema measured by CT density, COPD assessment test scores, Body-mass index, airflow Obstruction, Dyspnea, and Exercise index, or Global Initiative for Chronic Obstructive Lung Disease stage. Blood eosinophil counts showed a weak but significant association with sputum eosinophil counts (receiver operating characteristic area under the curve of 0·64, p<0·0001), but with a high false-discovery rate of 72%.

INTERPRETATION

In a large, well characterised cohort of former and current smoking patients with a broad range of COPD severity, high concentrations of sputum eosinophils were a better biomarker than high concentrations of blood eosinophils to identify a patient subgroup with more severe disease, more frequent exacerbations, and increased emphysema by QCT. Blood eosinophils alone were not a reliable biomarker for COPD severity or exacerbations, or for sputum eosinophils. Clinical trials targeting eosinophilic inflammation in COPD should consider assessing sputum eosinophils.

FUNDING

National Institutes of Health, and National Heart, Lung, and Blood Institute.

Effectiveness of inhaled corticosteroids in real life on clinical outcomes, sputum cells and systemic inflammation in asthmatics: a retrospective cohort study in a secondary care centre

OBJECTIVES

The impact of inhaled corticosteroids (ICS) on eosinophilic inflammation in asthma is well established, but their effect in a real-life setting has not been extensively studied. Our purpose was to investigate the effect of ICS on airway and systemic inflammation as well as on clinical outcomes in patients with asthma from clinical practice.

DESIGN, SETTING AND PARTICIPANTS

We conducted a retrospective analysis on asthmatics from a secondary care centre in whom ICS were initiated/increased (n=101), stopped/decreased (n=60) or remained stable (n=63, used as a control group) between two visits with available sputum and blood cell counts.

RESULTS

The median time between both visits ranged from 1 to 2 years. Initiating or increasing ICS (median variation (IQR): 800 (400-1200) µg beclomethasone equivalent dose per day) reduced sputum eosinophils and fractional exhaled nitric oxide (P<0.0001) and to a lesser extent blood eosinophils (P<0.0001), while withdrawing or decreasing ICS (median variation (IQR): 900 (500-1200) µg beclomethasone equivalentdose per day) resulted in increased sputum eosinophils (P=0.008). No change was found in patients with a stable dose. The effectiveness of ICS in improving asthma control, quality of life, forced expiratory volume in 1 s (FEV₁), bronchial hyper-responsiveness and exacerbation rate was only observed in the eosinophilic phenotype (sputum eosinophils ≥3%, n=79). In non-eosinophilic asthmatics, stepping-down ICS resulted in an improvement in asthma control and quality of life, without any significant change in FEV₁ (n=38).

CONCLUSIONS

Our results confirm the effectiveness of ICS on eosinophilic inflammation in real life and demonstrate that their clinical benefit seems to be restricted to eosinophilic asthmatics. Our data also support a try for stepping-down ICS in non-eosinophilic asthmatics.

Comparison Of Ziehl-Neelsen Based Light Microscopy With Led Fluorescent Microscopy For Tuberculosis Diagnosis: An Insight From A Limited Resource-High Burden setting

BACKGROUND

Microscopy is the most widely used tool for Tuberculosis screening. Conventionally, Ziehl-Neelsen (ZN) staining has been the widely used for staining Acid-Fast Bacilli (AFB) but with the advent of Fluorescent staining, Auramine O stain is now being adapted as the preferred method for setups with high workload as it has the advantage of being less laborious, since bacteria fluoresce in front of a dark background and are easier to count. This study was performed to compare the efficiency of the two methods in a high-burden, limited resource setting to see the magnitude of diagnostic accuracy between ZN and Fluorescent Microscopy, using culture as the standard..

METHODS

Altogether 987 culturally confirmed cases were considered from the period 36 months during January 2011 to December 2013 and data were compiled from the records maintained at the Provincial Tuberculosis Reference Laboratory at Ojha Institute of Chest Diseases, Dow University of Health Sciences, Karachi. The results from 523 cases examined using ZN and 464 cases using Fluorescent staining method were compared for diagnostic accuracy on the basis of Mycobacterial culture results. Smears are prepared from the clinical samples obtained from presumptive tuberculosis patients.

RESULTS

The results of ZN method showed 94.23% [95% CI 91.32-96.39%] sensitivity and 84.91% [95% CI 78.38-90.08%] specificity. While FM showed a sensitivity of 97.15% [95% CI 94.82-98.63%] and specificity of 83.19% [95% CI 74.99-89.56%]..

CONCLUSIONS

The results showed that Fluorescent microscopy was slightly more sensitive than ZN light Microscopy, while specificity of both the methods were comparable.

Airway basophils are increased and activated in eosinophilic asthma

BACKGROUND

The impact of basophils on asthma pathogenesis remains largely unexplored, particularly in humans. Here, we evaluated the frequencies and activation status of basophils in the sputum of adult asthmatic patients and related our findings to other parameters of eosinophilic airway inflammation.

METHODS

We enrolled 44 adult asthmatic patients who were being treated with inhaled corticosteroids (ICS). Analysis of the induced sputum, exhaled nitric oxide fraction (FeNO) measurement, and asthma control test (ACT) were carried out together with standard blood and pulmonary function tests. The cellular composition of the sputum was examined by flow cytometry, and the phenotypes of blood and sputum basophils were compared.

RESULTS

Basophils were increased in the sputum of asthmatic patients. The expression of CD203c on sputum basophils was significantly higher than that on blood basophils. The percentage of sputum basophils was positively correlated with those of eosinophils and mast cells; it was also correlated with that of blood eosinophils and FeNO. However, sputum basophils were not correlated with serum IgE, lung function, or the percentage of blood basophils. A receiver-operating characteristic (ROC) curve showed the superiority of sputum basophils as a surrogate marker of the percentages of sputum eosinophils compared with absolute numbers of blood eosinophils and FeNO.

CONCLUSION

The number of activated basophils was increased in the sputum of patients with eosinophilic asthma and correlated with airway and blood eosinophils. Our observations suggest that sputum basophils may serve as a biomarker to monitor new therapeutic approaches for the treatment of eosinophilic asthma.

Sputum cell count: biomarkers in the differentiation of asthma, COPD and asthma-COPD overlap

INTRODUCTION

Cell count in induced sputum is a noninvasive biomarker to assess airway inflammation phenotypes. Accordingly, sputum cell counts are extensively used in the treatment of asthma and COPD. Nevertheless, the clinical application of sputum cell counts in patients with asthma-COPD overlap (ACO) remains elusive. The aim of this study was to investigate sputum cell counts in patients with ACO which are different from those in patients with asthma and COPD and also to examine the relationship between sputum cell counts in bronchial reversibility and bronchial hyperresponsiveness (BHR).

PATIENTS AND METHODS

A total of 374 patients participated in the study, including 142 patients with asthma, 160 patients with COPD and 72 patients with ACO. All patients underwent the following tests on the same day: pulmonary function test (PFT), BHR test or bronchodilator reversibility test and inducing sputum. They were classified into the asthma group, COPD group or ACO group based on a clinical history, PFT values and BHR test or bronchodilator reversibility test.

RESULTS

The three groups had different PFT values (p<0.001) except for forced vital capacity (FVC) between the asthma and ACO groups (p=0.378). The sputum levels of eosinophil% were decreased in patients with COPD when compared with those in patients with asthma and ACO (p<0.001 and p<0.001, respectively). There was a difference in sputum neutrophil% and macrophage% counts among the three groups (p<0.001 and p<0.001, respectively); there was no difference in sputum eosinophil% counts between patients with ACO and asthma (p=0.668) and there was no difference in the percentage of induced sputum cells between the stage of airway obstruction and the stage of BHR.

CONCLUSION

The clinical relevance of this study provides evidence that sputum cell counts as an inflammatory biomarker could carry some information to distinguish ACO, asthma and COPD, and these biomarkers need more studies to provide diagnostic value in the differentiation between ACO, asthma and COPD.

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.

The success and safety profile of sputum induction in patients with chronic obstructive pulmonary disease: An Indian experience

BACKGROUND

Neutrophilic inflammation is common in chronic obstructive pulmonary disease while Asthma COPD overlap syndrome has eosinophilic predominance. Identifying the type of inflammation will aid in better management of COPD, but published studies show that induced sputum examination is more frequently used in asthma than COPD, with safety being the limiting factor. We aimed to determine the success and safety of sputum induction (SI) in COPD patients.

METHODS

116 stable COPD patients underwent SI. Success was defined as adequate sputum sample resulting in a cytospin sufficient to assess differential count while safety by the fall in FEV₁.

RESULTS

The mean (SD) FEV₁% predicted post bronchodilator was 58.8 (17.8) and 59 (51.8%) patients had moderate COPD. Success was 98.28%. The procedure was safe with overall fall in FEV₁ of 11.1% (5.1, 15.2). ≥20% fall was noted in 13 (11.4%) patients, 10-20% in 24 (21.0%) patients, and less than 10% in 29 (25.4%) patients while 48 (42.1%) had no fall. There was an inverse correlation between reversibility in FEV₁ and percentage fall in FEV1; r=-0.437 and p=0.001. Stepwise multivariate linear regression showed reversibility as an independent predictor of fall in FEV₁; R²=0.137.

CONCLUSIONS

Sputum induction is successful and safe in COPD. Even a fall in FEV₁>20% is reversible.

Race is associated with differences in airway inflammation in patients with asthma

BACKGROUND

African American subjects have a greater burden from asthma compared with white subjects. Whether the pattern of airway inflammation differs between African American and white subjects is unclear.

OBJECTIVE

We sought to compare sputum airway inflammatory phenotypes of African American and white subjects treated or not with inhaled corticosteroids (ICSs; ICS+ and ICS-, respectively).

METHODS

We performed a secondary analysis of self-identified African American and white subjects with asthma enrolled in clinical trials conducted by the National Heart, Lung, and Blood Institute-sponsored Asthma Clinical Research Network and AsthmaNet. Demographics, clinical characteristics, and sputum cytology after sputum induction were examined. We used a sputum eosinophil 2% cut point to define subjects with either an eosinophilic (≥2%) or noneosinophilic (<2%) inflammatory phenotype.

RESULTS

Among 1018 participants, African American subjects (n = 264) had a lower FEV1 percent predicted (80% vs 85%, P < .01), greater total IgE levels (197 vs 120 IU/mL, P < .01), and a greater proportion with uncontrolled asthma (43% vs 28%, P < .01) compared with white subjects (n = 754). There were 922 subjects in the ICS+ group (248 African American and 674 white subjects) and 298 subjects in the ICS- group (49 African American and 249 white subjects). Eosinophilic airway inflammation was not significantly different between African American and white subjects in either group (percentage with eosinophilic phenotype: ICS+ group: 19% vs 16%, P = .28; ICS- group: 39% vs 35%, P = .65; respectively). However, when adjusted for confounding factors, African American subjects were more likely to exhibit eosinophilic airway inflammation than white subjects in the ICS+ group (odds ratio, 1.58; 95% CI, 1.01-2.48; P = .046) but not in the ICS- group (P = .984).

CONCLUSION

African American subjects exhibit greater eosinophilic airway inflammation, which might explain the greater asthma burden in this population.

Is the Morning Sputum Sample Superior to the Fresh Sputum Sample for the Detection of Malignant Cells?

INTRODUCTION

Sputum cytology is a well-established technique for the detection of lung malignancies. Generally, random or morning samples are used.

OBJECTIVES

To evaluate the diagnostic yield of morning sputum and compare it with that of fresh samples.

MATERIALS AND METHODS

Patients were instructed to bring a morning sputum sample to the laboratory in a clean plastic container, without any fixative and within 2-3 h of collection. Fresh sputum was then collected in the laboratory from these same patients. Two smears were prepared from each sample by the "pick and smear" technique and then stained by the Papanicolaou method. One hundred samples from each method (total 200 samples; 400 slides) were evaluated by 3 investigators for their adequacy, preservation, and yield of diagnostic cells. The results were analyzed by using the Pearson χ2 test.

RESULTS

Cytomorphological details were preserved in 82/84 satisfactory morning samples and in 80/81 satisfactory fresh samples, respectively. Malignancy was detected in 37 morning samples (44%) and 25 fresh samples (30.8%). In the malignant samples, there were more abundant tumor cells in the morning samples than in the fresh samples (65 and 40%, respectively) with a 2+ cellularity in the morning samples. The morning samples showed a better cell yield (25% more), with a 13% increase in the rate of detection of malignancy and an increased sensitivity of 19.68% compared to the fresh samples.

CONCLUSIONS

Adequacy and preservation was similar in both sample types. While the morning samples showed a higher sensitivity and a larger number of tumor cells than the fresh samples, the difference was not statistically significant (p < 0.054).

Sputum biomarkers in IPF: Evidence for raised gene expression and protein level of IGFBP-2, IL-8 and MMP-7

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a rare lung disease of unknown origin leading rapidly to death. This paper addresses the issue of whether sputum induction is a suitable tool to study respiratory tract inflammation and potential biomarkers in IPF compared to COPD, a fibrosing airway wall disease.

METHODS

In a cross-sectional analysis, 15 IPF patients, 32 COPD and 30 healthy subjects underwent sputum induction. Total sputum cell counts and the amount of TGF- β, IGF-1, IGF-2, IGFBP-1, IGFBP-2, IGFBP-3, IL-8, IL-13, MMP-7, MMP-9, YKL-40, TNF-α and KL-6 in sputum supernatant were analysed. We also profiled gene expression of cells in the induced sputum for TGF-β, MMP-7, YKL-40, IGFBP-2, IL-6, IL-8 and TNF-α.

RESULTS

IPF patients, like COPD, had increased sputum absolute number of neutrophils, eosinophils, macrophages and epithelial cells compared to HS. IPF sputum supernatants had increased concentrations of IGFBP-2, IL-8, TGF-β, MMP-7, MMP-9 and KL-6 (p<0.05, p<0.0001, p<0.05, p<0.05, p<0.0001, p<0.05 respectively) when compared to healthy subjects where COPD had higher IL-6 and TNF-α levels than IPF (p<0.05 and p<0.05 respectively) and HS (p<0.0001 and p<0.001 respectively) and higher IL-8 and MMP-9 than HS (p<0.0001 and p<0.001 respectively). Conversely to IL-6 and TNF-α, MMP-7 was increased in IPF compared to COPD (p<0.05). The KL-6 and MMP-7 protein levels in sputum were inversely correlated with total lung capacity (TLC, % of predicted) in IPF patients (r = -0.73 and r = -0.53 respectively). Sputum gene expression analysis identified a significant increase for IGFBP-2, IL-6, IL-8 and MMP-7 in IPF compared to HS (p<0.05, p<0.01, p<0.05 and p<0.0001 respectively) and for IGFBP-2, YKL-40, IL-6, IL-8 and MMP-7 compared to COPD (p<0.01, p<0.01, p<0.05, p<0.01 and p<0.0001 respectively). Furthermore, gene expression of TGF-β was increased in IPF compared to COPD (p<0.001) but not to HS.

CONCLUSION

Our data show clear increase in expression and production of IGFBP-2, IL-8 and MMP-7 in sputum from patients with IPF that may contribute to the disease.

Multiparameter Single Cell Profiling of Airway Inflammatory Cells

Airway diseases affect over 7% of the U.S. population and millions of patients worldwide. Asthmatic patients have wide variation in clinical severity with different clinical and physiologic manifestations of disease that may be driven by distinct biologic mechanisms. Further, the immunologic underpinnings of this complex trait disease are heterogeneous and treatment success depends on defining subgroups of asthmatics. Because of the limited availability and number of cells from the lung, the active site, in-depth investigation has been challenging. Recent advances in technology support transcriptional analysis of cells from induced sputum. Flow cytometry studies have described cells present in the sputum but a detailed analysis of these subsets is lacking. Mass cytometry or CyTOF (Cytometry by Time-Of-Flight) offers tremendous opportunities for multiparameter single cell analysis. Experiments can now allow detection of up to ∼40 markers to facilitate unprecedented multidimensional cellular analyses. Here we demonstrate the use of CyTOF on primary airway samples obtained from well-characterized patients with asthma and cystic fibrosis. Using this technology, we quantify cellular frequency and functional status of defined cell subsets. Our studies provide a blueprint to define the heterogeneity among subjects and underscore the power of this single cell method to characterize airway immune status. © 2016 International Clinical Cytometry Society.

Eosinophilic airway inflammation in asthmatic patients is associated with an altered airway microbiome

BACKGROUND

Asthmatic patients have higher microbiome diversity and an altered composition, with more Proteobacteria and less Bacteroidetes compared with healthy control subjects. Studies comparing airway inflammation and the airway microbiome are sparse, especially in subjects not receiving anti-inflammatory treatment.

OBJECTIVE

We sought to describe the relationship between the airway microbiome and patterns of airway inflammation in steroid-free patients with asthma and healthy control subjects.

METHODS

Bronchoalveolar lavage fluid was collected from 23 steroid-free nonsmoking patients with asthma and 10 healthy control subjects. Bacterial DNA was extracted from and subjected to Illumina MiSeq sequencing of the 16S rDNA V4 region. Eosinophils and neutrophils in the submucosa were quantified by means of immunohistochemical identification and computerized image analysis. Induced sputum was obtained, and airway hyperresponsiveness to mannitol and fraction of exhaled nitric oxide values were measured. Relationships between airway microbial diversity and composition and inflammatory profiles were analyzed.

RESULTS

In asthmatic patients airway microbial composition was associated with airway eosinophilia and AHR to mannitol but not airway neutrophilia. The overall composition of the airway microbiome of asthmatic patients with the lowest levels of eosinophils but not asthmatic patients with the highest levels of eosinophils deviated significantly from that of healthy subjects. Asthmatic patients with the lowest levels of eosinophils had an altered bacterial abundance profile, with more Neisseria, Bacteroides, and Rothia species and less Sphingomonas, Halomonas, and Aeribacillus species compared with asthmatic patients with more eosinophils and healthy control subjects.

CONCLUSION

The level of eosinophilic airway inflammation correlates with variations in the microbiome across asthmatic patients, whereas neutrophilic airway inflammation does not. This warrants further investigation on molecular pathways involved in both patients with eosinophilic and those with noneosinophilic asthma.

Indoor particulate matter exposure is associated with increased black carbon content in airway macrophages of former smokers with COPD

INTRODUCTION

Exposure to fine particulate matter (PM2.5) is associated with worse morbidity in individuals with COPD. Inhaled PM is phagocytosed by airway macrophages (AM), and black carbon measured in AM may serve as a biomarker of air pollution exposure. As there is little data on how indoor PM exposure may influence AM black carbon content in those with respiratory disease, we investigated the association of indoor PM2.5 concentration to AM black carbon content in adults with COPD.

METHODS

Former smokers (>10 pack-years smoking history, quit date >1 year prior to enrollment) older than 40 years of age with moderate-severe COPD were eligible. Indoor air PM2.5 concentrations were measured over 5-7 days at baseline, 3 month, and 6 month intervals. Sputum induction was performed during clinic visits concordant with home monitoring. A total of 50 macrophages per sputum specimen were photographed and quantified using appropriate software by trained staff blinded to PM concentrations. Longitudinal analyses using generalized estimating equations were used to assess the relationship between indoor PM exposure and AM black carbon content.

RESULTS

Participants (n=20) were older (mean (SD) age 67 (4) years), predominantly Caucasian (85%) and male (70%), with an average smoking history of 52 pack-years and mean (SD) quit date of 13 (9) years prior to enrollment. The majority of daily time was reported to be spent indoors (>23h). Mean indoor PM2.5 concentration was 12.8 (13.5)µg/m(3). The mean area of black carbon quantified in airway macrophages was 1.2 (0.7)µm(2). In multivariate cross-sectional and longitudinal analyses, each 10µg/m(3) increase in indoor PM2.5 was significantly associated with a 0.26µm(2) and 0.19µm(2) increase in airway macrophage black carbon total area, respectively (p<0.05).

CONCLUSION

Higher indoor PM2.5 concentration is associated with an increase in black carbon content of AM in individuals with COPD. These data support the potential for AM black carbon content to be a useful non-invasive biomarker of exposure to indoor PM.

Assessment of anti-inflammatory effect from addition of a long-acting beta-2 agonist to inhaled corticosteroid

BACKGROUND

Inhaled corticosteroids (ICS) and long-acting beta-2 agonists (LABA) are thought to enhance the pharmacologic action of one another by a synergistic effect.

OBJECTIVE

We compared a group of patients who used ICS monotherapy with a group treated with ICS/LABA combination and evaluated the LABAs with regard to the synergistic effect on the anti-inflammatory action of the ICS.

METHODS

This study was conducted with 107 adult patients with mild-to-moderate bronchial asthma. The patients were randomly assigned to either ICS monotherapy (n = 55) or an ICS/LABA combination (n = 52). Both groups were assessed for respiratory function, fractional exhaled nitric oxide, induced sputum, and airway hyperresponsiveness before and after 6 months of treatment.

RESULTS

The ICS/LABA combination group showed significantly greater improvement than the ICS monotherapy group in the forced expiratory volume in 1 second/forced vital capacity (p < 0.01), forced expiratory volume in 1 second % predicted (p < 0.05), % predicted maximal expiratory flow at 50% (p < 0.01), % predicted maximal expiratory flow at 25% (p < 0.05), and airway hyperresponsiveness (p < 0.01). However, the two groups did not show significant differences in changes in the fractional exhaled nitric oxide (p = 0.47) or the percentage of eosinophils in the central (p = 0.85) or peripheral sputum (p = 0.98).

CONCLUSION

The significant improvement in respiratory function in the ICS/LABA combination treatment group compared with the ICS monotherapy group indicated an additive bronchodilator effect of the LABA. However, the two groups did not differ in airway inflammation, which indicated that a synergistic effect of the LABA on enhancing the anti-inflammatory action of the ICS was not clinically apparent.