Accelerated Lung Function Decline and Mucus-Microbe Evolution in Chronic Obstructive Pulmonary Disease.

RATIONALE: Progressive lung function loss is recognized in COPD; however, no study concurrently evaluates how accelerated lung function decline relates to mucus properties and the microbiome in COPD. OBJECTIVE: Longitudinal assessment of mucus and microbiome changes accompanying accelerated lung function decline in COPD patients. METHODS: Prospective, longitudinal assessment of the London COPD cohort exhibiting the greatest FEV1 decline (n=30; "accelerated decline"; 156 mL/year FEV1 loss) and with no FEV1 decline (n=28; "non-decline"; 49 mL/year FEV1 gain) over time. Lung microbiomes from "paired" sputum (total 116 specimens) were assessed by shotgun metagenomics and corresponding mucus profiles evaluated for biochemical and biophysical properties. RESULTS: Biochemical and biophysical mucus properties are significantly altered in the accelerated decline group. Unsupervised principal component analysis showed clear separation, with mucus biochemistry associated with accelerated decline, while biophysical mucus characteristics contributed to inter-individual variability. When mucus and microbes are considered together, an accelerated decline mucus-microbiome association emerges, characterized by increased mucin (MUC5AC and MUC5B) concentration and the presence of Achromobacter and Klebsiella. As COPD progresses, mucus-microbiome shifts occur, initially characterized by low mucin concentration and transition from viscous to elastic dominance accompanied by the commensals Veillonella, Gemella, Rothia and Prevotella (GOLD A and B) before transition to increased mucus viscosity, mucins, and DNA concentration along with the emergence of pathogenic microorganisms including Haemophilus, Moraxella and Pseudomonas (GOLD E). CONCLUSION: Mucus-microbiome associations evolve over time with accelerated lung function decline, symptom progression and exacerbations affording fresh therapeutic opportunities for early intervention. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

RSV-related Community COPD Exacerbations and Novel Diagnostics: A Binational Prospective Cohort Study.

RATIONALE: Respiratory syncytial virus (RSV) is a common global respiratory virus increasingly recognized as a major pathogen in frail older adults and as a cause of chronic obstructive pulmonary disease (COPD) exacerbations. There is no single test for RSV in adults with acceptable diagnostic accuracy. Trials of RSV vaccines have recently shown excellent safety and efficacy against RSV in older adults; defining the frequency of RSV-related community infections and COPD exacerbations is important for vaccine deployment decisions. OBJECTIVES: This prospective study aimed to establish the frequency of outpatient-managed RSV-related exacerbations of COPD in two well-characterized patient cohorts using a combination of diagnostic methods. METHODS: Participants were recruited at specialist clinics in London, UK and Groningen, NL from 2017 and observed for three consecutive RSV seasons, during exacerbations and at least twice yearly. RSV infections were detected by reverse transcription-polymerase chain reaction (RT-PCR) and serologic testing. MEASUREMENTS AND MAIN RESULTS: 377 patients with COPD attended 1,999 clinic visits and reported 310 exacerbations. There were 27 RSV-related exacerbations (8·7% of total); of these, seven were detected only on PCR, 16 only on serology and 4 by both methods. Increases in RSV specific N-protein antibody were as sensitive as antibody to pre-F or post-F for serodiagnosis of RSV related exacerbations. CONCLUSIONS: RSV is associated with 8.7% of outpatient managed COPD exacerbations in this study. Antibodies to RSV-N protein may have diagnostic value, potentially important in a vaccinated population. The introduction of vaccines that prevent RSV is expected to benefit patients with COPD. This article is open access and distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).

Structural Predictors of Lung Function Decline in Young Smokers with Normal Spirometry.

Rationale: Chronic obstructive pulmonary disease (COPD) due to tobacco smoking commonly presents when extensive lung damage has occurred. Objectives: We hypothesized that structural change would be detected early in the natural history of COPD and would relate to loss of lung function with time. Methods: We recruited 431 current smokers (median age, 39 yr; 16 pack-years smoked) and recorded symptoms using the COPD Assessment Test (CAT), spirometry, and quantitative thoracic computed tomography (QCT) scans at study entry. These scan results were compared with those from 67 never-smoking control subjects. Three hundred sixty-eight participants were followed every six months with measurement of postbronchodilator spirometry for a median of 32 months. The rate of FEV1 decline, adjusted for current smoking status, age, and sex, was related to the initial QCT appearances and symptoms, measured using the CAT. Measurements and Main Results: There were no material differences in demography or subjective CT appearances between the young smokers and control subjects, but 55.7% of the former had CAT scores greater than 10, and 24.2% reported chronic bronchitis. QCT assessments of disease probability-defined functional small airway disease, ground-glass opacification, bronchovascular prominence, and ratio of small blood vessel volume to total pulmonary vessel volume were increased compared with control subjects and were all associated with a faster FEV1 decline, as was a higher CAT score. Conclusions: Radiological abnormalities on CT are already established in young smokers with normal lung function and are associated with FEV1 loss independently of the impact of symptoms. Structural abnormalities are present early in the natural history of COPD and are markers of disease progression. Clinical trial registered with www.clinicaltrials.gov (NCT03480347).

Early childhood lower respiratory tract infection and premature adult death from respiratory disease in Great Britain: a national birth cohort study.

BACKGROUND: Lower respiratory tract infections (LRTIs) in early childhood are known to influence lung development and lifelong lung health, but their link to premature adult death from respiratory disease is unclear. We aimed to estimate the association between early childhood LRTI and the risk and burden of premature adult mortality from respiratory disease. METHODS: This longitudinal observational cohort study used data collected prospectively by the Medical Research Council National Survey of Health and Development in a nationally representative cohort recruited at birth in March, 1946, in England, Scotland, and Wales. We evaluated the association between LRTI during early childhood (age <2 years) and death from respiratory disease from age 26 through 73 years. Early childhood LRTI occurrence was reported by parents or guardians. Cause and date of death were obtained from the National Health Service Central Register. Hazard ratios (HRs) and population attributable risk associated with early childhood LRTI were estimated using competing risks Cox proportional hazards models, adjusted for childhood socioeconomic position, childhood home overcrowding, birthweight, sex, and smoking at age 20-25 years. We compared mortality within the cohort studied with national mortality patterns and estimated corresponding excess deaths occurring nationally during the study period. FINDINGS: 5362 participants were enrolled in March, 1946, and 4032 (75%) continued participating in the study at age 20-25 years. 443 participants with incomplete data on early childhood (368 [9%] of 4032), smoking (57 [1%]), or mortality (18 [<1%]) were excluded. 3589 participants aged 26 years (1840 [51%] male and 1749 [49%] female) were included in the survival analyses from 1972 onwards. The maximum follow-up time was 47·9 years. Among 3589 participants, 913 (25%) who had an LRTI during early childhood were at greater risk of dying from respiratory disease by age 73 years than those with no LRTI during early childhood (HR 1·93, 95% CI 1·10-3·37; p=0·021), after adjustment for childhood socioeconomic position, childhood home overcrowding, birthweight, sex, and adult smoking. This finding corresponded to a population attributable risk of 20·4% (95% CI 3·8-29·8) and 179 188 (95% CI 33 806-261 519) excess deaths across England and Wales between 1972 and 2019. INTERPRETATION: In this prospective, life-spanning, nationally representative cohort study, LRTI during early childhood was associated with almost a two times increased risk of premature adult death from respiratory disease, and accounted for one-fifth of these deaths. FUNDING: National Institute for Health and Care Research Imperial Biomedical Research Centre, Royal Brompton and Harefield National Health Service (NHS) Foundation Trust, Royal Brompton and Harefield Hospitals Charity and Imperial College Healthcare NHS Trust, UK Medical Research Council.

Phenotypes, Etiotypes, and Endotypes of Exacerbations of Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease is a major health problem with a high prevalence, a rising incidence, and substantial morbidity and mortality. Its course is punctuated by acute episodes of increased respiratory symptoms, termed exacerbations of chronic obstructive pulmonary disease (ECOPD). ECOPD are important events in the natural history of the disease, as they are associated with lung function decline and prolonged negative effects on quality of life. The present-day therapy for ECOPD with short courses of antibiotics and steroids and escalation of bronchodilators has resulted in only modest improvements in outcomes. Recent data indicate that ECOPD are heterogeneous, raising the need to identify distinct etioendophenotypes, incorporating traits of the acute event and of patients who experience recurrent events, to develop novel and targeted therapies. These characterizations can provide a complete clinical picture, the severity of which will dictate acute pharmacological treatment, and may also indicate whether a change in maintenance therapy is needed to reduce the risk of future exacerbations. In this review we discuss the latest knowledge of ECOPD types on the basis of clinical presentation, etiology, natural history, frequency, severity, and biomarkers in an attempt to characterize these events.

A Double-Blind, Randomized, Placebo-controlled Trial of Long-Term Doxycycline Therapy on Exacerbation Rate in Patients with Stable Chronic Obstructive Pulmonary Disease.

Rationale: Chronic obstructive pulmonary disease (COPD) exacerbations are a major cause of morbidity and mortality, and preventing them is a key treatment target. Long-term macrolide treatment is effective at reducing exacerbations, but there is a paucity of evidence for other antibiotic classes. Objectives: To assess whether 12-month use of doxycycline reduces the exacerbation rate in people with COPD. Methods: People with moderate to very severe COPD and an exacerbation history were recruited from three UK centers and randomized to 12 months of doxycycline 100 mg once daily or placebo. The primary study outcome was the exacerbation rate per person-year. Results: A total of 222 people were randomized. Baseline mean FEV1 was 1.35 L (SD, 0.35 L), 52.5% predicted (SD, 15.9% predicted). The median number of treated exacerbations in the year before the study was 2 (SD, 1-4). A total of 71% of patients reported two or more exacerbations, and 81% were already prescribed inhaled corticosteroids at baseline. The COPD exacerbation rate did not differ between the groups (doxycycline/placebo rate ratio [RR], 0.86; 95% confidence interval [CI], 0.67-1.10; P = 0.23). No difference was seen if only treated exacerbations or hospitalizations were considered. In preplanned subgroup analysis, doxycycline appeared to better reduce the exacerbation rate among people with severe COPD (RR, 0.36; 95% CI, 0.15-0.85; P = 0.019) and in those with an eosinophil count <300 cells/µl (RR, 0.50; 95% CI, 0.29-0.84; P = 0.01). Health status measured by St. George's Respiratory Questionnaire was 5.2 points worse in the doxycycline group at 12 months (P < 0.007). Conclusions: Doxycycline did not significantly reduce the exacerbation rate, over 12 months, in participants with COPD who exacerbated regularly, but it may have benefitted those with more severe COPD or blood eosinophil counts <300 cells/µl. Clinical trial registered with www.clinicaltrials.gov (NCT02305940).

Treatment Trials in Young Patients with Chronic Obstructive Pulmonary Disease and Pre-Chronic Obstructive Pulmonary Disease Patients: Time to Move Forward.

Chronic obstructive pulmonary disease (COPD) is the end result of a series of dynamic and cumulative gene-environment interactions over a lifetime. The evolving understanding of COPD biology provides novel opportunities for prevention, early diagnosis, and intervention. To advance these concepts, we propose therapeutic trials in two major groups of subjects: "young" individuals with COPD and those with pre-COPD. Given that lungs grow to about 20 years of age and begin to age at approximately 50 years, we consider "young" patients with COPD those patients in the age range of 20-50 years. Pre-COPD relates to individuals of any age who have respiratory symptoms with or without structural and/or functional abnormalities, in the absence of airflow limitation, and who may develop persistent airflow limitation over time. We exclude from the current discussion infants and adolescents because of their unique physiological context and COPD in older adults given their representation in prior randomized controlled trials (RCTs). We highlight the need of RCTs focused on COPD in young patients or pre-COPD to reduce disease progression, providing innovative approaches to identifying and engaging potential study subjects. We detail approaches to RCT design, including potential outcomes such as lung function, patient-reported outcomes, exacerbations, lung imaging, mortality, and composite endpoints. We critically review study design components such as statistical powering and analysis, duration of study treatment, and formats to trial structure, including platform, basket, and umbrella trials. We provide a call to action for treatment RCTs in 1) young adults with COPD and 2) those with pre-COPD at any age.

Inhaled corticosteroids reduce senescence in endothelial progenitor cells from patients with COPD.

Cellular senescence contributes to the pathophysiology of chronic obstructive pulmonary disease (COPD) and cardiovascular disease. Using endothelial colony-forming-cells (ECFC), we have demonstrated accelerated senescence in smokers and patients with COPD compared with non-smokers. Subgroup analysis suggests that ECFC from patients with COPD on inhaled corticosteroids (ICS) (n=14; eight on ICS) exhibited significantly reduced senescence (Senescence-associated-beta galactosidase activity, p21CIP1), markers of DNA damage response (DDR) and IFN-γ-inducible-protein-10 compared with patients with COPD not on ICS. In vitro studies using human-umbilical-vein-endothelial-cells showed a protective effect of ICS on the DDR, senescence and apoptosis caused by oxidative stress, suggesting a protective molecular mechanism of action of corticosteroids on endothelium.

Inflammatory Endotype-associated Airway Microbiome in Chronic Obstructive Pulmonary Disease Clinical Stability and Exacerbations: A Multicohort Longitudinal Analysis.

Rationale: Understanding the role of the airway microbiome in chronic obstructive pulmonary disease (COPD) inflammatory endotypes may help to develop microbiome-based diagnostic and therapeutic approaches. Objectives: To understand the association of the airway microbiome with neutrophilic and eosinophilic COPD at stability and during exacerbations. Methods: An integrative analysis was performed on 1,706 sputum samples collected longitudinally from 510 patients with COPD recruited at four UK sites of the BEAT-COPD (Biomarkers to Target Antibiotic and Systemic COPD), COPDMAP (Chronic Obstructive Pulmonary Disease Medical Research Council/Association of the British Pharmaceutical Industry), and AERIS (Acute Exacerbation and Respiratory Infections in COPD) cohorts. The microbiome was analyzed using COPDMAP and AERIS as a discovery data set and BEAT-COPD as a validation data set. Measurements and Main Results: The airway microbiome in neutrophilic COPD was heterogeneous, with two primary community types differentiated by the predominance of Haemophilus. The Haemophilus-predominant subgroup had elevated sputum IL-1ß and TNFα (tumor necrosis factor α) and was relatively stable over time. The other neutrophilic subgroup with a balanced microbiome profile had elevated sputum and serum IL-17A and was temporally dynamic. Patients in this state at stability were susceptible to the greatest microbiome shifts during exacerbations. This subgroup can temporally switch to both neutrophilic Haemophilus-predominant and eosinophilic states that were otherwise mutually exclusive. Time-series analysis on the microbiome showed that the temporal trajectories of Campylobacter and Granulicatella were indicative of intrapatient switches from neutrophilic to eosinophilic inflammation, in track with patient sputum eosinophilia over time. Network analysis revealed distinct host-microbiome interaction patterns among neutrophilic Haemophilus-predominant, neutrophilic balanced microbiome, and eosinophilic subgroups. Conclusions: The airway microbiome can stratify neutrophilic COPD into subgroups that justify different therapies. Neutrophilic and eosinophilic COPD are interchangeable in some patients. Monitoring temporal variability of the airway microbiome may track patient inflammatory status over time.

Virus-induced Volatile Organic Compounds Are Detectable in Exhaled Breath during Pulmonary Infection.

Rationale: Chronic obstructive pulmonary disease (COPD) is a condition punctuated by acute exacerbations commonly triggered by viral and/or bacterial infection. Early identification of exacerbation triggers is important to guide appropriate therapy, but currently available tests are slow and imprecise. Volatile organic compounds (VOCs) can be detected in exhaled breath and have the potential to be rapid tissue-specific biomarkers of infection etiology. Objectives: To determine whether volatile organic compound measurement could distinguish viral from bacterial infection in COPD. Methods: We used serial sampling within in vitro and in vivo studies to elucidate the dynamic changes that occur in VOC production during acute respiratory viral infection. Highly sensitive gas chromatography-mass spectrometry techniques were used to measure VOC production from infected airway epithelial-cell cultures and in exhaled breath samples from healthy subjects experimentally challenged with rhinovirus (RV)-A16 and from subjects with COPD with naturally occurring exacerbations. Measurements and Main Results: We identified a novel VOC signature comprising decane and other long-chain alkane compounds that is induced during RV infection of cultured airway epithelial cells and is also increased in the exhaled breath from healthy subjects experimentally challenged with RV and from patients with COPD during naturally occurring viral exacerbations. These compounds correlated with the magnitude of antiviral immune responses, viral burden, and exacerbation severity but were not induced by bacterial infection, suggesting that they represent a specific virus-inducible signature. Conclusions: Our study highlights the potential for measurement of exhaled breath VOCs as rapid, noninvasive biomarkers of viral infection. Further studies are needed to determine whether measurement of these signatures could be used to guide more targeted therapy with antibiotic/antiviral agents for COPD exacerbations.

Targeted Retreatment of Incompletely Recovered Chronic Obstructive Pulmonary Disease Exacerbations with Ciprofloxacin. A Double-Blind, Randomized, Placebo-controlled, Multicenter, Phase III Clinical Trial.

Rationale: Chronic obstructive pulmonary disease (COPD) exacerbations are prone to nonrecovery, but there are no data about the effectiveness of retreatment for these prolonged events. We examined whether further therapy with ciprofloxacin for incompletely resolved COPD exacerbations prolonged the time until the next event.Objectives: To assess whether incompletely recovered COPD exacerbations benefit from additional treatment with ciprofloxacin, at Day 14.Methods: In a multicenter, randomized double-blind placebo-controlled trial, we studied retreatment with oral ciprofloxacin 500 mg or matched placebo twice daily for 7 days in patients with Global Initiative for Chronic Obstructive Lung Disease stage II-IV COPD and persistent symptoms and/or serum C-reactive protein ≥8 mg/L initiated 14 (±3) days after an index COPD exacerbation. The primary outcome was the time to the next exacerbation within a 90-day period.Measurements and Main Results: Among 826 patients screened at four centers, 144 eligible participants with incomplete recovery were randomized to receive ciprofloxacin (n = 72) or placebo (n = 72). Within 90 days of randomization, 57% of the patients in the ciprofloxacin group and 53% in the placebo group experienced one or more exacerbations. The median time to the next exacerbation was 32.5 days (interquartile range 13-50) in the placebo arm and 34 days (interquartile range 17-62) in the ciprofloxacin arm, which was not significantly different (adjusted hazard ratio, 1.07; 95% confidence interval, 0.68-1.68; P = 0.76). No significant differences were seen in quality-of-life scores or lung function between the treatment groups.Conclusions: In patients with persistent symptoms and/or raised C-reactive protein 14 days after a COPD exacerbation, an additional course of ciprofloxacin resulted in no additional benefit compared with placebo. This suggests that nonrecovered exacerbations are not driven by ongoing bacterial infection and may potentially be targeted with antiinflammatory therapy.Clinical trial registered with www.clinicaltrials.gov (NCT02300220).

Pharmacologic Management of Chronic Obstructive Pulmonary Disease. An Official American Thoracic Society Clinical Practice Guideline.

Background: This document provides clinical recommendations for the pharmacologic treatment of chronic obstructive pulmonary disease (COPD). It represents a collaborative effort on the part of a panel of expert COPD clinicians and researchers along with a team of methodologists under the guidance of the American Thoracic Society.Methods: Comprehensive evidence syntheses were performed on all relevant studies that addressed the clinical questions and critical patient-centered outcomes agreed upon by the panel of experts. The evidence was appraised, rated, and graded, and recommendations were formulated using the Grading of Recommendations, Assessment, Development, and Evaluation approach.Results: After weighing the quality of evidence and balancing the desirable and undesirable effects, the guideline panel made the following recommendations: 1) a strong recommendation for the use of long-acting ß2-agonist (LABA)/long-acting muscarinic antagonist (LAMA) combination therapy over LABA or LAMA monotherapy in patients with COPD and dyspnea or exercise intolerance; 2) a conditional recommendation for the use of triple therapy with inhaled corticosteroids (ICS)/LABA/LAMA over dual therapy with LABA/LAMA in patients with COPD and dyspnea or exercise intolerance who have experienced one or more exacerbations in the past year; 3) a conditional recommendation for ICS withdrawal for patients with COPD receiving triple therapy (ICS/LABA/LAMA) if the patient has had no exacerbations in the past year; 4) no recommendation for or against ICS as an additive therapy to long-acting bronchodilators in patients with COPD and blood eosinophilia, except for those patients with a history of one or more exacerbations in the past year requiring antibiotics or oral steroids or hospitalization, for whom ICS is conditionally recommended as an additive therapy; 5) a conditional recommendation against the use of maintenance oral corticosteroids in patients with COPD and a history of severe and frequent exacerbations; and 6) a conditional recommendation for opioid-based therapy in patients with COPD who experience advanced refractory dyspnea despite otherwise optimal therapy.Conclusions: The task force made recommendations regarding the pharmacologic treatment of COPD based on currently available evidence. Additional research in populations that are underrepresented in clinical trials is needed, including studies in patients with COPD 80 years of age and older, those with multiple chronic health conditions, and those with a codiagnosis of COPD and asthma.

Immunological and Inflammatory Biomarkers of Susceptibility and Severity in Adult Respiratory Syncytial Virus Infections.

BACKGROUND: Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis in young infants. However, it is also a significant pathogen in older adults. Validated biomarkers of RSV disease severity would benefit diagnostics, treatment decisions, and prophylactic interventions. This review summarizes knowledge of biomarkers for RSV disease in adults. METHODS: A literature review was performed using Ovid Medline, Embase, Global health, Scopus, and Web of Science for articles published 1946-October 2016. Nine articles were identified plus 9 from other sources. RESULTS: From observational studies of natural infection and challenge studies in volunteers, biomarkers of RSV susceptibility or disease severity in adults were: (1) lower anti-RSV neutralizing antibodies, where neutralizing antibody (and local IgA) may be a correlate of susceptibility/severity; (2) RSV-specific CD8+ T cells in bronchoalveolar lavage fluid preinfection (subjects with higher levels had less severe illness); and (3) elevated interleukin-6 (IL-6), IL-8, and myeloperoxidase levels in the airway are indicative of severe infection. CONCLUSIONS: Factors determining susceptibility to and severity of RSV disease in adults have not been well defined. Respiratory mucosal antibodies and CD8+ T cells appear to contribute to preventing infection and modulation of disease severity. Studies of RSV pathogenesis in at-risk populations are needed.

Development and Reporting of Prediction Models: Guidance for Authors From Editors of Respiratory, Sleep, and Critical Care Journals.

Prediction models aim to use available data to predict a health state or outcome that has not yet been observed. Prediction is primarily relevant to clinical practice, but is also used in research, and administration. While prediction modeling involves estimating the relationship between patient factors and outcomes, it is distinct from casual inference. Prediction modeling thus requires unique considerations for development, validation, and updating. This document represents an effort from editors at 31 respiratory, sleep, and critical care medicine journals to consolidate contemporary best practices and recommendations related to prediction study design, conduct, and reporting. Herein, we address issues commonly encountered in submissions to our various journals. Key topics include considerations for selecting predictor variables, operationalizing variables, dealing with missing data, the importance of appropriate validation, model performance measures and their interpretation, and good reporting practices. Supplemental discussion covers emerging topics such as model fairness, competing risks, pitfalls of "modifiable risk factors", measurement error, and risk for bias. This guidance is not meant to be overly prescriptive; we acknowledge that every study is different, and no set of rules will fit all cases. Additional best practices can be found in the Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis (TRIPOD) guidelines, to which we refer readers for further details.

The stability of blood Eosinophils in chronic obstructive pulmonary disease.

Blood eosinophils are a predictive biomarker of inhaled corticosteroid response in chronic obstructive pulmonary disease (COPD). We investigated blood eosinophil stability over 1 year using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2019 thresholds of < 100, 100- < 300 and ≥ 300 eosinophils/µL in 225 patients from the COPDMAP cohort. Blood eosinophils showed good stability (rho: 0.71, p < 0.001, ICC 0.84), and 69.3% of patients remained in the same eosinophil category at 1 year. 85.3% of patients with eosinophils < 100 cells/µL had stable counts. The majority of blood eosinophil counts remain stable over 1 year using the GOLD 2019 thresholds.

Bacteria and sputum inflammatory cell counts; a COPD cohort analysis.

BACKGROUND: There is evidence that bacterial colonisation in chronic obstructive pulmonary disease (COPD) is associated with increased neutrophilic airway inflammation. This study tested the hypothesis that different bacterial phyla and species cause different inflammatory profiles in COPD patients. METHODS: Sputum was analysed by quantitative polymerase chain reaction (qPCR) to quantify bacterial load and 16S rRNA gene sequencing to identify taxonomic composition. Sputum differential cell counts (DCC) and blood DCC were obtained at baseline and 6 months. Patients were categorised into five groups based on bacterial load defined by genome copies/ml of ≥ 1 × 104, no colonisation and colonisation by Haemophilus influenzae (H. influenzae), Moraxella catarrhalis (M. catarrhalis), Streptococcus pneumoniae (S. pneumoniae), or > 1 potentially pathogenic microorganism (PPM). RESULTS: We observed an increase in sputum neutrophil (%), blood neutrophil (%) and neutrophil-lymphocyte ratio (NLR) in patients colonised with H. influenzae (82.6, 67.1, and 3.29 respectively) compared to those without PPM colonisation at baseline (69.5, 63.51 and 2.56 respectively) (p < 0.05 for all analyses), with similar findings at 6 months. The bacterial load of H. influenzae and Haemophilus determined by qPCR and 16s rRNA gene sequencing respectively, and sputum neutrophil % were positively correlated between baseline and 6 months visits (p < 0.0001, 0.0150 and 0.0002 with r = 0.53, 0.33 and 0.44 respectively). CONCLUSIONS: These results demonstrate a subgroup of COPD patients with persistent H. influenzae colonisation that is associated with increased airway and systemic neutrophilic airway inflammation, and less eosinophilic airway inflammation.

The sputum microbiome is distinct between COPD and health, independent of smoking history.

BACKGROUND: Airway bacterial dysbiosis is a feature of chronic obstructive pulmonary disease (COPD). However, there is limited comparative data of the lung microbiome between healthy smokers, non-smokers and COPD. METHODS: We compared the 16S rRNA gene-based sputum microbiome generated from pair-ended Illumina sequencing of 124 healthy subjects (28 smokers and 96 non-smokers with normal lung function), with single stable samples from 218 COPD subjects collected from three UK clinical centres as part of the COPDMAP consortium. RESULTS: In healthy subjects Firmicutes, Bacteroidetes and Actinobacteria were the major phyla constituting 88% of the total reads, and Streptococcus, Veillonella, Prevotella, Actinomyces and Rothia were the dominant genera. Haemophilus formed only 3% of the healthy microbiome. In contrast, Proteobacteria was the most dominant phylum accounting for 50% of the microbiome in COPD subjects, with Haemophilus and Moraxella at genus level contributing 25 and 3% respectively. There were no differences in the microbiome profile within healthy and COPD subgroups when stratified based on smoking history. Principal coordinate analysis on operational taxonomic units showed two distinct clusters, representative of healthy and COPD subjects (PERMANOVA, p = 0·001). CONCLUSION: The healthy and COPD sputum microbiomes are distinct and independent of smoking history. Our results underline the important role for Gammaproteobacteria in COPD.

Increased Chronic Obstructive Pulmonary Disease Exacerbations of Likely Viral Etiology Follow Elevated Ambient Nitrogen Oxides.

RATIONALE: Epidemiologic research strongly supports an association between air pollution and chronic obstructive pulmonary disease exacerbations. Numerous mechanisms may underlie any association because pollutants are toxic to pulmonary cells and may increase susceptibility to respiratory infections. The relationship between ambient pollution and exacerbation etiology has not been studied. OBJECTIVES: To evaluate the characteristics of pollution-associated exacerbations and whether the association is specific to exacerbations of infective or noninfective etiology. METHODS: We analyzed the effect of preceding ambient particulate matter less than or equal to 10 µm in aerodynamic diameter, oxides of nitrogen (NOx), and ozone on characterized chronic obstructive pulmonary disease exacerbations in a regression model adjusted for temperature, seasonality, and long-term trend. We specifically examined associations with exacerbations of suspected viral and/or bacterial, or noninfective etiology. For the associations identified we further examined the characteristics of pollution-associated exacerbations. MEASUREMENTS AND MAIN RESULTS: A total of 4,173 exacerbations occurred over the 20-year study period. Higher ambient NOx was consistently associated with increased viral-type exacerbations at 2-4 days lag (P = 0.010). Recovery for viral-type exacerbations after higher ambient NOx was significantly prolonged. These findings were consistent in the subset of 2,841 exacerbations treated with oral corticosteroids or antibiotics, with recovery 1.29 (95% confidence interval, 1.17-1.42; P < 0.001) times longer with viral-type exacerbations of onset 3 days after above- versus below-median ambient NOx. A likely bimodal association of particulate matter less than or equal to 10 µm in aerodynamic diameter with infective exacerbations was also evident and supported by a daily time-series analysis. CONCLUSIONS: Higher levels of ambient NOx are associated with prolonged exacerbations of likely viral etiology, supporting toxicologic effects of air pollution that increase susceptibility to, and severity of, infection.

Human Rhinovirus Impairs the Innate Immune Response to Bacteria in Alveolar Macrophages in Chronic Obstructive Pulmonary Disease.

Rationale: Human rhinovirus (HRV) is a common cause of chronic obstructive pulmonary disease (COPD) exacerbations. Secondary bacterial infection is associated with more severe symptoms and delayed recovery. Alveolar macrophages clear bacteria from the lung and maintain lung homeostasis through cytokine secretion. These processes are defective in COPD. The effect of HRV on macrophage function is unknown. Objectives: To investigate the effect of HRV on phagocytosis and cytokine response to bacteria by alveolar macrophages and monocyte-derived macrophages (MDM) in COPD and healthy control subjects. Methods: Alveolar macrophages were obtained by bronchoscopy and MDM by adherence. Macrophages were exposed to HRV16 (multiplicity of infection 5), polyinosinic:polycytidylic acid (poly I:C) 30 µg/ml, IFN-ß 10 µg/ml, IFN-γ 10 µg/ml, or medium control for 24 hours. Phagocytosis of fluorescently labeled Haemophilus influenzae or Streptococcus pneumoniae was assessed by fluorimetry. CXCL8 (IL-8), IL-6, TNF-α (tumor necrosis factor-α), and IL-10 release was measured by ELISA. Measurements and Main Results: HRV significantly impaired phagocytosis of H. influenzae by 23% in MDM (n = 37; P = 0.004) and 18% in alveolar macrophages (n = 20; P < 0.0001) in COPD. HRV also significantly reduced phagocytosis of S. pneumoniae by 33% in COPD MDM (n = 20; P = 0.0192). There was no effect in healthy control subjects. Phagocytosis of H. influenzae was also impaired by poly I:C but not IFN-ß or IFN-γ in COPD MDM. HRV significantly reduced cytokine responses to H. influenzae. The IL-10 response to H. influenzae was significantly impaired by poly I:C, IFN-ß, and IFN-γ in COPD cells. Conclusions: HRV impairs phagocytosis of bacteria in COPD, which may lead to an outgrowth of bacteria. HRV also impairs cytokine responses to bacteria via the TLR3/IFN pathway, which may prevent resolution of inflammation leading to prolonged exacerbations in COPD.

Patient-reported Outcomes for the Detection, Quantification, and Evaluation of Chronic Obstructive Pulmonary Disease Exacerbations.

An exacerbation of chronic obstructive pulmonary disease (COPD) is an acute worsening of respiratory symptoms accompanied by a variable degree of physiological deterioration. The traditional assessment of an exacerbation consists of the reporting of symptoms by the patient to a clinician and subsequent clinical assessment. It would be valuable to also gather symptom reports directly from patients, and thus patient-reported outcome (PRO) tools should be ideally suited to the evaluation of COPD exacerbations. However, most pharmaceutical industry- and large academy-sponsored studies have used a healthcare resource use definition alone, which is based on sustained worsening of a patient's condition from the stable state that requires a change in regular medication. This Review explores the use of PROs for the detection, quantification, and evaluation of COPD exacerbations. It examines symptom diary cards as exacerbation detection tools and their evolution into electronic diaries used in pharmaceutical trials. This paper also describes the development of specifically designed PROs that have been used in exacerbation settings, focusing on the Exacerbations and Symptoms in COPD e-Diary, Exacerbations of Chronic Obstructive Pulmonary Disease Tool, COPD Assessment Test, and Chronic Respiratory Disease Questionnaire, highlighting the strengths and weaknesses of these instruments. We describe the effectiveness of these tools to enhance exacerbation reporting; quantify exacerbation characteristics, including the frequency, duration, and severity of events; and evaluate the outcome. We also explore the potential use of PROs in future studies to discriminate the effect of therapies on different exacerbation phenotypes and thus enhance personalized therapeutic approaches.