C E Brightling

Analysis of induced sputum in adults with asthma: identification of subgroup with isolated sputum neutrophilia and poor response to inhaled corticosteroids

Background: The debate as to whether asthma is a single or heterogeneous disease remains unresolved although pathological studies, mostly using fibreoptic bronchoscopy on small numbers of subjects, have emphasised the similarities between different clinical phenotypes. Methods: Lower airway inflammation was assessed non-invasively using induced sputum in 34 normal controls and 259 adults with symptomatic asthma receiving treatment at steps 1–3 of the British Thoracic Society (BTS) guidelines. A subgroup of 49 patients treated with as required β2 agonists only who met BTS criteria for a step up in treatment were studied before and 2 months after treatment with inhaled budesonide 400 μg twice daily. Results: There was considerable heterogeneity in induced sputum cell counts, particularly in non-atopic patients. A subgroup of 60 patients had a distinctive sputum cell profile with a neutrophil count higher than our normal range (>65.3%) and a normal sputum eosinophil count (<1.9%). These patients were older, predominantly female, and were more likely to be non-atopic but otherwise had similar clinical and physiological features to the group as a whole. Among the 49 subjects studied before and after inhaled budesonide, 11 patients had an isolated sputum neutrophilia. Following treatment, these patients showed significantly less improvement in visual analogue symptom scores (–5.5 v –19.4 mm; mean difference 13.9; 95% CI 0.7 to 27.0), forced expiratory volume in 1 second (FEV1) (–0.08 v 0.13 l; mean difference 0.21; 95% CI 0.03 to 0.39), and concentration of methacholine provoking a fall in FEV1 of 20% or more (PC20) (0.15 v 1.29 doubling doses; mean difference 1.11; 95% CI 0.13 to 2.15) than the remaining 38 patients. Conclusions: These results suggest the presence of a distinct subgroup of patients with mild to moderate asthma who have predominantly neutrophilic airway inflammation and who respond less well to treatment with inhaled corticosteroids.

Sputum eosinophilia and the short term response to inhaled mometasone in chronic obstructive pulmonary disease

Background: An association between the sputum eosinophil count and the response to a 2 week course of prednisolone has previously been reported in patients with chronic obstructive pulmonary disease (COPD). Whether the response to inhaled corticosteroids is related to the presence of eosinophilic inflammation is unclear. Methods: A randomised, double blind, crossover trial of placebo and mometasone furoate (800 μg/day), each given for 6 weeks with a 4 week washout period, was performed in subjects with COPD treated with bronchodilator therapy only. Spirometric tests, symptom scores, chronic respiratory disease questionnaire (CRQ), and induced sputum were performed before and after each treatment phase. Results: Ninety five patients were recruited of which 60 were randomised. Overall there were no treatment associated changes in forced expiratory volume in 1 second (FEV1), total CRQ, or sputum characteristics. After stratification into tertiles by baseline eosinophil count, the net improvement in post-bronchodilator FEV1 increased with mometasone compared with placebo progressively from the least to the most eosinophilic tertile. The mean change in post-bronchodilator FEV1 with mometasone compared with placebo in the highest tertile was 0.11 l (95% CI 0.03 to 0.19). This improvement was not associated with a fall in the sputum eosinophil count. Conclusions: An increased sputum eosinophil count is related to an improvement in post-bronchodilator FEV1 following treatment with inhaled mometasone in COPD, but the improvement is not associated with a reduction in the sputum eosinophil count.

Benralizumab for chronic obstructive pulmonary disease and sputum eosinophilia: a randomised, double-blind, placebo-controlled, phase 2a study

BACKGROUNDnChronic obstructive pulmonary disease (COPD) is associated with eosinophilic airway inflammation in 10-20% of patients. Benralizumab, an anti-interleukin-5 receptor α monoclonal antibody, depletes blood and sputum eosinophils. We aimed to establish whether benralizumab reduces acute exacerbations of COPD in patients with eosinophilia and COPD.nnnMETHODSnWe did this randomised, double-blind, placebo-controlled, phase 2a study between Nov 18, 2010, and July 13, 2013, at 26 sites in the UK, Poland, Germany, Canada, the USA, Denmark, and Spain. Adults aged 40-85 years, with moderate-to-severe COPD, at least one acute exacerbation of COPD, and a sputum eosinophil count of 3·0% or more within the previous year, were randomly assigned (1:1) via computer-generated permuted block randomisation (block size of four), with an interactive voice or web-response system, to receive placebo or 100 mg benralizumab subcutaneously, every 4 weeks (three doses), then every 8 weeks (five doses) over 48 weeks. Study site personnel included in study assessments, participants, and data analysts, were masked to treatment allocation. The primary endpoint was the annualised rate of acute exacerbations of COPD at week 56, defined as the number of acute exacerbations divided by total duration of person-year follow-up. Secondary and exploratory endpoints included COPD-specific Saint Georges Respiratory Questionnaire (SGRQ-C), Chronic Respiratory Questionnaire self-administered standardised format (CRQ-SAS), pre-bronchodilator forced expiratory volume in 1 second (FEV1), and safety. We did a prespecified subgroup analysis by baseline blood eosinophil count. Analyses were by intention to treat and per-protocol. This trial is registered with ClinicalTrials.gov, number NCT01227278.nnnFINDINGSnWe randomly assigned 101 patients to receive placebo (n=50) or benralizumab (n=51), of whom 88 (87%) patients completed the study. Six patients who completed the study were excluded from the per-protocol population because of major protocol violations; the per-protocol population thus included 82 patients. Benralizumab did not reduce the annualised rate of acute exacerbations of COPD compared with placebo in the per-protocol population, with rates of 0·95 (0·68-1·29; n=40) versus 0·92 (0·67-1·25; n=42). Mean pre-bronchodilator FEV1 change from baseline to week 56 was -0·06 L (SD 0·24) with placebo, and 0·13 L (0·41) with benralizumab (p=0·014). Numerical, albeit non-significant, improvement in acute exacerbations of COPD, SGRQ-C, CRQ-SAS, and FEV1 were greater in benralizumab-treated patients with baseline blood eosinophil concentrations of 200 cells per μL or more or 300 cells per μL or more. Incidence of treatment-emergent adverse events was similar between the two groups, with the most common events being respiratory disorders (31 [62%] of 50 patients given placebo vs 32 [63%] of 51 given benralizumab) and infections (28 [56%] vs 27 [53%]). A higher incidence of serious treatment-emergent adverse events were recorded in patients in the benralizumab group than in those in the placebo group (14 vs nine patients), although none of these events were considered by the investigator to be benralizumab related.nnnINTERPRETATIONnCompared with placebo, benralizumab did not reduce the rate of acute exacerbations of COPD. However, the results of prespecified subgroup analysis support further investigation of benralizumab in patients with COPD and eosinophilia.nnnFUNDINGnMedImmune.

Medical research council united kingdom refractory asthma stratification programme (RASP-UK)

The UK Refractory Asthma Stratification Programme (RASP-UK) will explore novel biomarker stratification strategies in severe asthma to improve clinical management and accelerate development of new therapies. Prior asthma mechanistic studies have not stratified on inflammatory phenotype and the understanding of pathophysiological mechanisms in asthma without Type 2 cytokine inflammation is limited. RASP-UK will objectively assess adherence to corticosteroids (CS) and examine a novel composite biomarker strategy to optimise CS dose; this will also address what proportion of patients with severe asthma have persistent symptoms without eosinophilic airways inflammation after progressive CS withdrawal. There will be interactive partnership with the pharmaceutical industry to facilitate access to stratified populations for novel therapeutic studies.

Association Between Pathogens Detected Using Quantitative Polymerase Chain Reaction With Airway Inflammation in COPD at Stable State and Exacerbations

BACKGROUND: Relationships between airway inflammation and respiratory potentially pathogenic microorganisms (PPMs) quantified using quantitative polymerase chain reaction (qPCR) in subjects with COPD are unclear. Our aim was to evaluate mediators of airway inflammation and their association with PPMs in subjects with COPD at stable state and during exacerbations. METHODS: Sputum from 120 stable subjects with COPD was analyzed for bacteriology (colony-forming units; total 16S; and qPCR targeting Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae), differential cell counts, and inflammatory mediators using the Meso-Scale Discovery Platform. Subjects were classified as colonized if any PPM was identified above the threshold of detection by qPCR. Symptoms were quantified using the visual analog scale. RESULTS: At stable state, 60% of subjects were qPCR positive for H influenzae, 48% for M catarrhalis, and 28% for S pneumoniae. Elevated sputum concentrations of IL-1β, IL-10, and tumor necrosis factor (TNF)-α were detected in samples qPCR positive for either H influenzae or M catarrhalis. Bacterial loads of H influenzae positively correlated with IL-1β, IL-8, IL-10, TNF-α, and symptoms; and M catarrhalis correlated with IL-10 and TNF-α. H influenzae qPCR bacterial load was an independent predictor of sputum TNF-α and IL-1β. In 55 subjects with paired exacerbation data, qPCR bacterial load fold change at exacerbation in M catarrhalis but not H influenzae correlated to changes in sputum TNF-α and IL-1β concentrations. CONCLUSIONS: At stable state, H influenzae is associated with increased airway inflammation in COPD. The relationship between bacterial load changes of specific pathogens and airway inflammation at exacerbation and recovery warrants further investigation.

P174 Identifying non-adherence with asthma medication and the relationship to clinical outcomes amongst adults with difficult-to-control asthma

Background The failure of patients to adhere to prescribed medication regimens is well documented. The clinical effects of non-adherence can include treatment failure, unnecessary, potentially dangerous and costly intensification of therapy, complications and hospitalisations. The extent of non-adherence and the clinical implications in difficult-to-treat asthma were audited. Method A total of 161 adult asthma patients attending a difficult asthma clinic during July/August 2009 were included in the audit. GPs retrospective prescription refill data for asthma medicines, patient demographics and clinical outcome data were collated. The medication adherence ratio was calculated as the number of doses refilled/number of doses prescribed ×100 for a mean duration of 12u2005months. Adherence was defined as adequate if the ratio was ≥80%. Results Prescription refill data for 132 patients were available (82%), and 115 patients were included in the audit. Poor adherence was identified in 75/115 patients (65.2%) on inhaled corticosteroids (ICS) overall – 64/101 (63.4%) taking combined ICS and long acting β2 agonist (LABA) inhalers and 11/14 (78.6%) patients taking separate ICS and LABA inhalers (p=0.24). In the 14 patients using separate ICS and LABA, adherence to the LABA (50%) was significantly better than adherence to the ICS (14.3%) (p=0.043). Patients with poor adherence to ICS had a lower post-bronchodilator FEV1 (75.4 (20.9) vs 84.3 (23.5), p=0.049) and higher sputum eosinophil counts (4.6 (0.66)% vs 2.3 (0.54)%, p=0.05) than those with adequate ICS adherence. There were no significant differences in age, gender, racial origin, smoking history or courses of rescue oral prednisolone between these two groups. Patients with poor ICS adherence were more likely to have been ventilated for asthma (19.2% vs 2.6%, p=0.02). In a multivariate logistic regression model, the adherence ratio was the only independent predictor of previous need for ventilation for acute severe asthma (p=0.008). Thus for each 10% decrease in adherence to ICS, the estimated odds of having been ventilated for asthma increased by 1.85 times. Conclusion The majority of patients with difficult-to-control asthma are non-adherent with their asthma medication. Patients using separate ICS and LABA inhalers use the LABA more than the ICS. Non-adherence is correlated with several poor clinical outcomes.

Quadrupling Inhaled Glucocorticoid Dose to Abort Asthma Exacerbations.

BACKGROUND Asthma exacerbations are frightening for patients and are occasionally fatal. We tested the concept that a plan for patients to manage their asthma (self‐management plan), which included a temporary quadrupling of the dose of inhaled glucocorticoids when asthma control started to deteriorate, would reduce the incidence of severe asthma exacerbations among adults and adolescents with asthma. METHODS We conducted a pragmatic, unblinded, randomized trial involving adults and adolescents with asthma who were receiving inhaled glucocorticoids, with or without add‐on therapy, and who had had at least one exacerbation in the previous 12 months. We compared a self‐management plan that included an increase in the dose of inhaled glucocorticoids by a factor of 4 (quadrupling group) with the same plan without such an increase (non‐quadrupling group), over a period of 12 months. The primary outcome was the time to a first severe asthma exacerbation, defined as treatment with systemic glucocorticoids or an unscheduled health care consultation for asthma. RESULTS A total of 1922 participants underwent randomization, of whom 1871 were included in the primary analysis. The number of participants who had a severe asthma exacerbation in the year after randomization was 420 (45%) in the quadrupling group as compared with 484 (52%) in the non‐quadrupling group, with an adjusted hazard ratio for the time to a first severe exacerbation of 0.81 (95% confidence interval, 0.71 to 0.92; P=0.002). The rate of adverse effects, which were related primarily to local effects of inhaled glucocorticoids, was higher in the quadrupling group than in the non‐quadrupling group. CONCLUSIONS In this trial involving adults and adolescents with asthma, a personalized self‐management plan that included a temporary quadrupling of the dose of inhaled glucocorticoids when asthma control started to deteriorate resulted in fewer severe asthma exacerbations than a plan in which the dose was not increased. (Funded by the Health Technology Assessment Programme of the National Institute for Health Research; Current Controlled Trials number, ISRCTN15441965.)

MUC5AC and a Glycosylated Variant of MUC5B Alter Mucin Composition in Children With Acute Asthma

BACKGROUND: Diffuse airway mucus obstruction is an important feature of severe and fatal asthma. MUC5AC and MUC5B are the principal gel‐forming mucins found in airway mucus. The mucin composition of airway mucus likely affects its functional properties. METHODS: We quantified the principal airway mucins MUC5AC and MUC5B in the sputum of age‐matched children with acute and stable asthma and healthy control subjects by using Western blotting. RESULTS: Sputum samples from 38 children (13 with acute asthma, 15 with stable asthma, 10 control subjects) were obtained. Sputum MUC5AC concentrations were 7.6 &mgr;g/mL in control subjects, 22.4 &mgr;g/mL in those with stable asthma (P = .17), and 44.7 &mgr;g/mL in those with acute asthma (P < .05). MUC5B concentrations showed less variation, with 238.5, 208.4 and 165.9 &mgr;g/mL in control subjects, those with stable asthma, and those with acute asthma, respectively. The greater MUC5AC concentration in those with acute asthma resulted in a significantly altered MUC5B:MUC5AC ratio between control subjects and those with acute asthma (P < .05). Significant differences in MUC5B glycoforms were present between the groups, with the low‐charge‐only glycoform being found uniquely in those with acute asthma. CONCLUSIONS: Increased MUC5AC and the presence of a low‐charge‐only MUC5B glycoform significantly altered mucin composition in children with acute asthma. These changes may be important contributory factors to the airway mucus obstruction observed during acute asthma.

P20 The eligibility of patients with difficult asthma for omalizumab since the change to the treatment criteria

Omalizumab is a humanised monoclonal anti-IgE agent which is useful as an add-on therapy for severe atopic asthma. We have previously shown that 13.5% of patients attending our adult difficult asthma clinic were eligible for treatment with omalizumab. There has recently been a change to its prescribing licence with a widening of the eligible range of IgE from 30–700u2009iu/ml to 30–1500u2009iu/ml. Other prescribing criteria are (1) weight between 20 and 150u2009kg, (2) FEV1 <80% predicted, (3) positive skin prick tests or specific IgE to perennial aeroallergens and (4) ongoing symptoms despite a high-dose combination inhaler. In addition NICE guidance now recommends that its use is confined to patients who, within the past year, have had two or more hospital admissions or one admission plus two A&E attendances for asthma exacerbations. We aimed to determine how the new licensing criteria and the NICE guidelines have affected the proportion of patients attending our difficult asthma clinic eligible for treatment with omalizumab. We assessed 510 patients recording body weight (kg), FEV1 (% predicted), symptoms, total IgE (iU/ml) and skin prick tests. Our data demonstrate that 240 had an IgE outside the eligible range, 242 patients had an FEV1>80%, 46 patients had negative skin prick tests and a further 2 patients′ weight was outside the range for dosing. 67/510 (13.1%) patients met all the licensing criteria for omalizumab. There has therefore not been any increase in the proportion of eligible patients since the widening of the IgE range. Of these 67, 27 patients had two or more admissions with asthma exacerbations in the previous year. A further 16 patients had one admission but less than 2 A&E attendances. 12 patients required maintenance oral prednisolone but did not have sufficient admissions to meet the NICE prescribing guidelines. In total, 27/510 (5.3%) of patients with difficult-to-treat asthma were eligible for treatment with omalizumab according to NICE guidance. Although omalizumab is a helpful additional therapy for allergy-mediated asthma, its licensing criteria and current NICE guidelines limits its use in the UK to a small proportion of patients with difficult asthma.

P122 The use of impulse oscillometry (IOS) to study fractal scaling and sample entropy in airway resistance time series in severe asthma

Introduction Severe asthma affects airway calibre and can be monitored using IOS. Sample entropy (SampEn) is a measure of complexity and is defined as the probability that sequences of patterns (template size) in time series which are initially closely related, that is, within a fraction of the standard deviation (tolerance level) of the time-series remain so within subsequent time frames. Fractal scaling is a measure of self similarity and scale invariance measured in a time-series and quantifies the memory found within as a consequence. We hypothesised that fractal scaling and SampEn will be useful in characterising severe asthma. Methods 66 GINAstage 4–5 severe asthmatics (Mean(Sem) age; 54.1(1.4), Sex M:F; 31:35, post-bronchodilator FEV1% predicted; 81.02 (2.7)%) and 27 Controls (Mean(Sem) age; 48.4(2.2), Sex M:F;9:18, post-bronchodilator FEV1% predicted; 108.2 (2.8)%) were recruited. Impulse oscillometry was performed at 5–35u2005Hz, with impulses triggered every 0.2u2005s for 150u2005s, at baseline and 15u2005min after 400u2005mcg inhaled salbutamol. Detrended fluctuation analysis was used to derive the fractal scaling exponent α1. SampEn was derived using a custom program. SampEn and α1 were both obtained from airway resistance at 10u2005Hz over the 150u2005s time-series. Triplicate measurements of 150u2005s were repeated in 18 randomly selected asthmatics from our cohort after 6u2005months. Results SampEn was significantly increased compared to controls (Abstract P122 Table 1) and correlated significantly with exacerbation frequency from the previous 12u2005months (Asthma Baseline- p=0.007, rs=0.3; Post-Bronchodilator- p=0.009, rs=0.3). Fractal scaling was also found to be present in airway resistance in severe asthma (α1=0.94 (0.03)) and showed an inverse relationship with SampEn (p=0.0352, r=−0.4). Increased SampEn was associated with worse ACQ scores (p=0.027, rs=0.3) and lower AQLQ scores (p=0.023, rs=−0.2). SampEn measurements were repeatable (an Intra-class correlation of 0.74) in the triplicate series. In keeping with other studies, airway resistance was significantly increased in severe asthma. Conclusions SampEn a measure of complexity is (1) increased in severe asthma (2) a repeatable measure (3) associated with a lower quality of life and exacerbation frequency. The ability of this technique to monitor asthma stability and to predict future exacerbations by stochastic modelling needs to be explored.Abstract P122 Table 1 Asthma n=66 Baseline Post-bronchodilator Controls n=27 Controls Asthma Controls Asthma Resistance at 10u2005Hz (KPa/(l/s)) 0.34(0.02) 0.48(0.02)† 0.31(0.02)* 0.42(0.02)* † SampEn 0.09(0.02) 0.16(0.02)† 0.09(0.02) 0.12(0.01)† * Mean (sem) data.* Comparison against baseline p<0.05.† Comparison against control p<0.05. */†Paired t-tests/equivalent. R10-approximated to total airway resistance in our cohort and had a coherence of 0.9, SampEn: template size=2 and tolerance level=0.2.