Paul Newbold

Acute exacerbations of chronic obstructive pulmonary disease: identification of biologic clusters and their biomarkers.

RATIONALE Exacerbations of chronic obstructive pulmonary disease (COPD) are heterogeneous with respect to inflammation and etiology. OBJECTIVES Investigate biomarker expression in COPD exacerbations to identify biologic clusters and determine biomarkers that recognize clinical COPD exacerbation phenotypes, namely those associated with bacteria, viruses, or eosinophilic airway inflammation. METHODS Patients with COPD were observed for 1 year at stable and exacerbation visits. Biomarkers were measured in sputum and serum. Viruses and selected bacteria were assessed in sputum by polymerase chain reaction and routine diagnostic bacterial culture. Biologic phenotypes were explored using unbiased cluster analysis and biomarkers that differentiated clinical exacerbation phenotypes were investigated. MEASUREMENTS AND MAIN RESULTS A total of 145 patients (101 men and 44 women) entered the study. A total of 182 exacerbations were captured from 86 patients. Four distinct biologic exacerbation clusters were identified. These were bacterial-, viral-, or eosinophilic-predominant, and a fourth associated with limited changes in the inflammatory profile termed “pauciinflammatory.” Of all exacerbations, 55%, 29%, and 28% were associated with bacteria, virus, or a sputum eosinophilia. The biomarkers that best identified these clinical phenotypes were sputum IL-1β, 0.89 (area under receiver operating characteristic curve) (95% confidence interval [CI], 0.83–0.95); serum CXCL10, 0.83 (95% CI, 0.70–0.96); and percentage peripheral eosinophils, 0.85 (95% CI, 0.78–0.93), respectively. CONCLUSIONS The heterogeneity of the biologic response of COPD exacerbations can be defined. Sputum IL-1β, serum CXCL10, and peripheral eosinophils are biomarkers of bacteria-, virus-, or eosinophil-associated exacerbations of COPD. Whether phenotype-specific biomarkers can be applied to direct therapy warrants further investigation.

Profiling of Sputum Inflammatory Mediators in Asthma and Chronic Obstructive Pulmonary Disease

Background: Asthma and chronic obstructive pulmonary disease (COPD) display features of overlap in airway physiology and airway inflammation. Whether inflammatory phenotypes in airway disease describe similar mediator expression is unknown. Objectives: To explore the relationship of airway inflammation and cytokine and chemokine expression in asthma and COPD. Methods: Subjects with asthma and COPD (n = 54 and n = 49) were studied. Clinical characteristics and sputum were collected at entry into the study. A 2-step sputum processing method was performed for supernatant and cytospin preparation. Meso Scale Discovery and Luminex platforms were used to measure cytokines, chemokines and matrix metalloproteinase levels. Results: Analytes sensitive to dithiothreitol (DTT) that had increased recovery in the 2-step sputum process were IL-1β, 4, 5, 10, 13, IFN-γ, TNFRI, GM-CSF, CCL2, 3, 4, 5, 13 and 17. There was a differential expression in IL-8, TNFRI and TNFRII between asthma and COPD [mean fold difference (95% CI): IL-8, 2.6 (1.3–5.4), p = 0.01; TNFRI, 2.1 (1.3–5.4), p = 0.03; TNFRII, 2.6 (1.2–5.6), p = 0.02]. In neutrophilic and eosinophilic airway inflammation, TNFα, TNFRI, TNFRII, IL-6, IL-8 and IL-5 could differentiate between these phenotypes. However, these phenotypes were unrelated to the diagnosis of asthma or COPD. Conclusion: Recovery of sputum mediators sensitive to DTT can be improved using the described sputum processing technique. Within airway inflammatory sub-phenotypes there is a differential pattern of mediator expression that is independent of disease. Whether these inflammatory phenotypes in asthma and COPD confer distinct pathogeneses, therapeutic responses and clinical phenotypes needs to be further evaluated.

Biological clustering supports both “Dutch” and “British” hypotheses of asthma and chronic obstructive pulmonary disease

Background Asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous diseases. Objective We sought to determine, in terms of their sputum cellular and mediator profiles, the extent to which they represent distinct or overlapping conditions supporting either the “British” or “Dutch” hypotheses of airway disease pathogenesis. Methods We compared the clinical and physiological characteristics and sputum mediators between 86 subjects with severe asthma and 75 with moderate-to-severe COPD. Biological subgroups were determined using factor and cluster analyses on 18 sputum cytokines. The subgroups were validated on independent severe asthma (n = 166) and COPD (n = 58) cohorts. Two techniques were used to assign the validation subjects to subgroups: linear discriminant analysis, or the best identified discriminator (single cytokine) in combination with subject disease status (asthma or COPD). Results Discriminant analysis distinguished severe asthma from COPD completely using a combination of clinical and biological variables. Factor and cluster analyses of the sputum cytokine profiles revealed 3 biological clusters: cluster 1: asthma predominant, eosinophilic, high TH2 cytokines; cluster 2: asthma and COPD overlap, neutrophilic; cluster 3: COPD predominant, mixed eosinophilic and neutrophilic. Validation subjects were classified into 3 subgroups using discriminant analysis, or disease status with a binary assessment of sputum IL-1β expression. Sputum cellular and cytokine profiles of the validation subgroups were similar to the subgroups from the test study. Conclusions Sputum cytokine profiling can determine distinct and overlapping groups of subjects with asthma and COPD, supporting both the British and Dutch hypotheses. These findings may contribute to improved patient classification to enable stratified medicine.

Inter-relationships between inflammatory markers in patients with stable COPD with bronchitis: intra-patient and inter-patient variability

Background: Measurements of pulmonary biomarkers can be used to monitor airway inflammation in chronic obstructive pulmonary disease (COPD), but the variability of sampled biomarkers and their inter-relationships are poorly understood. A study was undertaken to examine the intra- and inter-patient variability in spontaneous sputum samples from patients in the stable state and to describe the relationship between biomarkers, cell counts and markers of disease. Methods: Sputum interleukin-1β, tumour necrosis factor α, interleukin 8, myeloperoxidase, leucotriene B4, growth-related oncogene α and differential cell counts were measured in patients with moderate to severe stable COPD (n = 14) on 11 occasions over a 1-month period. Results: There was significant variability in all inflammatory indices (median intra-patient coefficient of variation (CV) 35% (IQR 22–69), median inter-patient CV 102% (IQR 61–145)). Variability could be reduced by using a rolling mean of individual patient data points. Sample size calculations were undertaken to determine the number of patients required to detect a 50% reduction in neutrophil count. Using a crossover design of a putative effective treatment, the number needed using one data point per patient was 72, reducing to 23 when a mean of three data points was used. Significant correlations were demonstrated both between the inflammatory biomarkers themselves and between inflammatory biomarkers and markers of disease. Some relationships were not apparent when results from a single sample were used. The reliability of inter-relationships improved as more data points were used for each patient. Conclusions: Clear relationships exist between inflammatory biomarkers in patients with stable COPD. Sequential sampling reduced the variability of individual mediators and the potential number of patients needed to power proof of concept interventional studies.

The clinical utility of biomarkers in asthma and COPD

Biomarkers with potential utility in the diagnosis and prognosis of asthma and chronic obstructive pulmonary disease (COPD), and in monitoring the natural history of these diseases and the effect of therapeutic interventions, are being widely researched. This review critically describes the methodologies used for obtaining and analysing appropriate biofluid, tissue and exhaled breath samples for biomarker analysis. Currently measurements of sputum eosinophils and exhaled nitric oxide in asthmatics are the best established markers for disease activity and response to anti-inflammatory therapy. Circulating C-reactive protein (CRP) levels have been shown to predict risk of hospitalisation and death from COPD. Biomarker measurements in exhaled breath condensate are the least well-validated techniques. Other assessments in both conditions have potential value in clinical use but require further research and validation.

A randomised controlled trial of the effect of automated interactive calling combined with a health risk forecast on frequency and severity of exacerbations of COPD assessed clinically and using EXACT PRO.

BACKGROUND We have developed a winter forecasting service to predict when patients with COPD are at higher risk of an exacerbation and alert them via an automated telephone call. AIMS To assess the effect of the service and its ability to predict periods of increased risk. METHODS A 4-month prospective randomised controlled trial using clinical criteria and the EXACT PRO questionnaire to identify exacerbations. Patients were randomly allocated to receive alert calls. All patients completed a diary including the EXACT PRO questionnaire on a BlackBerry Smartphone each day. They were contacted and assessed if they appeared to be exacerbating. RESULTS 79 patients participated, 40 received alert calls. The exacerbation frequency per patient per week was significantly greater during periods of predicted high risk (0.086 ± 0.010 v 0.055 ± 0.010). The exacerbation frequency (± standard error of the mean, SEM) in patients receiving alert calls was lower (0.95 ± 0.27 v 1.17 ± 0.29) but this was not statistically significant. Fewer patients receiving alert calls had one or more EXACT event compared to the controls (34% v 53%, p=0.11), their duration was shorter (8.2 ± 2.0 v10.1 ± 1.9 days, p=0.481) and they were less severe (AUC 65 ± 21 v 115 ± 22, p=0.118). There were no significant differences in the mean change (± SEM) in SGRQ scores between the groups. CONCLUSIONS The ability of the forecast to predict high risk periods was confirmed unequivocally. Alert calls appeared to reduce the frequency and severity of exacerbations but these effects did not reach statistical significance, perhaps because of the number of participants, lower than expected exacerbation rates, and the fact that there was contact with patients in both groups whenever they appeared to be exacerbating.

Sputum IL-5 Concentration Is Associated with a Sputum Eosinophilia and Attenuated by Corticosteroid Therapy in COPD

Background: Airway inflammation in chronic obstructive pulmonary disease (COPD) is predominately neutrophilic, but some subjects demonstrate eosinophilic airway inflammation. Whether these inflammatory phenotypes have differential cytokine and chemokine expression is unknown. Objectives: To assess the sputum concentrations of cytokines and chemokines and their response to oral corticosteroid therapy in COPD subjects with or without a sputum eosinophilia. Methods: Cytokine and chemokine concentrations were measured using the meso-scale device platform. To assess validity, recovery of exogenous spikes was examined. The concentrations of the validated mediators were measured in COPD sputum from subjects with or without a sputum eosinophilia. In a subgroup with a sputum eosinophilia, the response to oral prednisolone 10 mg for 1 month was examined. Results: The recovery in sputum of exogenous spiked mediators was >80% in 11/26 cytokines and chemokines. In supernatants from eosinophilic (n = 39) versus non-eosinophilic (n = 59) sputa, the geometric mean (95% CI) concentration was increased for IL-5 [9.0 (4.5–18) pg/ml vs. 3.6 (2.7–6.3) pg/ml, p = 0.03]. IL-5 alone was correlated with sputum eosinophil counts (r = 0.33, p = 0.001), and was attenuated following treatment with prednisolone [n = 9; mean difference 2.3 pg/ml (0.2–4.3), p = 0.032]. Conclusion: We have validated the use of the meso-scale device platform for cytokine and chemokine measurements in the sputum supernatants in COPD. Sputum IL-5 was associated with a sputum eosinophilia and was attenuated following oral corticosteroid therapy. Whether this cytokine is important in the pathogenesis of COPD in a subgroup of patients warrants further investigation.

Predictors of enhanced response with benralizumab for patients with severe asthma: pooled analysis of the SIROCCO and CALIMA studies

BACKGROUND Benralizumab is an anti-eosinophilic, anti-interleukin-5 receptor α monoclonal antibody that has been shown to significantly reduce asthma exacerbations and improve lung function for patients with severe, uncontrolled asthma. We further explored the efficacy of benralizumab for patients with different baseline blood eosinophil thresholds and exacerbation histories. METHODS This study is a pooled analysis of the results from the randomised, double-blind, placebo-controlled SIROCCO (NCT01928771) and CALIMA (NCT01914757) phase 3 studies. In these studies, patients with severe, uncontrolled asthma were randomly assigned (1:1:1) to receive subcutaneous benralizumab 30 mg, either every 4 weeks or every 8 weeks (with first three doses given every 4 weeks), or placebo every 4 weeks. The primary endpoint was annual exacerbation rate (AER) ratio versus placebo, analysed by baseline eosinophil counts (≥0, ≥150, ≥300, or ≥450 cells per μL) and by number of exacerbations (two vs three or more) during the year before enrolment. The analyses were done in accordance with the intention-to-treat principle. FINDINGS Of 2295 patients, 756 received benralizumab every 4 weeks, 762 received benralizumab every 8 weeks, and 777 patients received placebo. AER among patients with baseline blood eosinophil counts of at least 0 cells per μL was 1·16 (95% CI 1·05-1·28) in patients who received placebo versus 0·75 (0·66-0·84) in patients who received benralizumab every 8 weeks (rate ratio 0·64, 0·55-0·75; p<0·0001). In patients who received benralizumab every 4 weeks who had eosinophil counts of 0 or more cells per μL, AER was 0·73 (0·65-0·82); rate ratio versus placebo was 0·63 (0·54-0·74; p<0·0001). The extent to which exacerbation rates were reduced increased with increasing blood eosinophil thresholds and with greater exacerbation history in patients in the 4-weekly and 8-weekly benralizumab groups. Greater improvements in AER were seen with benralizumab compared with placebo for patients with a combination of high blood eosinophil thresholds and a history of more frequent exacerbations. INTERPRETATION These results will help to guide clinicians when they are deciding whether to use benralizumab to treat patients with severe, uncontrolled, eosinophilic asthma. FUNDING AstraZeneca.

Detection of COPD Exacerbations and Compliance With Patient-Reported Daily Symptom Diaries Using a Smartphone-Based Information System

Background Paper-based diaries and self-report of symptom worsening in COPD may lead to underdetection of exacerbations. Epidemiologically, COPD exacerbations exhibit seasonal patterns peaking at year-end. We examined whether the use of a BlackBerry-based daily symptom diary would detect 95% or more of exacerbations and enable characterization of seasonal differences among them. Methods Fifty participants with GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage I to IV COPD began a community-based study in December 2007. Another 30 began in December 2008. Participants transmitted daily symptom diaries using a BlackBerry. Alerts were triggered when symptom changes, missed diary transmissions, or medical care for a respiratory problem occurred. Participant encounters were initiated if COPD exacerbations were suspected. Participants used their BlackBerrys to report returns to normal breathing. Results Participants transmitted 99.9% of 28,514 possible daily diaries. All 191 (2.5/participant-year) COPD exacerbations meeting Anthonisen criteria were detected. During 148 of the 191 exacerbations (78%, 1.97/participant-year), patients were hospitalized and/or ordered prednisone, an antibiotic, or both. Respiratory viruses were detected in 78 of the 191 exacerbations (41%). Those coinciding with a respiratory viral infection averaged 12.0 days, and those without averaged 8.9 days (P < .04), with no difference in Anthonisen score. Respiratory symptom scores before exacerbations and after normal breathing return showed no differences. Exacerbations were more frequent during the Christmas period than the rest of the year but were not more frequent than in the rest of winter alone. Conclusions Smartphone-based collection of COPD symptom diaries enables near-complete identification of exacerbations at inception. Exacerbation rates in the Christmas season do not reach levels that necessitate changes in disease management.

Monoclonal antibody therapy for the treatment of asthma and chronic obstructive pulmonary disease with eosinophilic inflammation

ABSTRACT Eosinophils have been linked with asthma for more than a century, but their role has been unclear. This review discusses the roles of eosinophils in asthma and chronic obstructive pulmonary disease (COPD) and describes therapeutic antibodies that affect eosinophilia. The aims of pharmacologic treatments for pulmonary conditions are to reduce symptoms, slow decline or improve lung function, and reduce the frequency and severity of exacerbations. Inhaled corticosteroids (ICS) are important in managing symptoms and exacerbations in asthma and COPD. However, control with these agents is often suboptimal, especially for patients with severe disease. Recently, new biologics that target eosinophilic inflammation, used as adjunctive therapy to corticosteroids, have proven beneficial and support a pivotal role for eosinophils in the pathology of asthma. Nucala® (mepolizumab; anti‐interleukin [IL]‐5) and Cinquair® (reslizumab; anti‐IL‐5), the second and third biologics approved, respectively, for the treatment of asthma, exemplifies these new treatment options. Emerging evidence suggests that eosinophils may contribute to exacerbations and possibly to lung function decline for a subset of patients with COPD. Here we describe the pharmacology of therapeutic antibodies inhibiting IL‐5 or targeting the IL‐5 receptor, as well as other cytokines contributing to eosinophilic inflammation. We discuss their roles as adjuncts to conventional therapeutic approaches, especially ICS therapy, when disease is suboptimally controlled. These agents have achieved a place in the therapeutic armamentarium for asthma and COPD and will deepen our understanding of the pathogenic role of eosinophils.