Differential Diagnosis of Suspected Chronic Obstructive Pulmonary Disease Exacerbations in the Acute Care Setting: Best Practice.

Patients with chronic obstructive pulmonary disease (COPD) may suffer from acute episodes of worsening dyspnea, often associated with increased cough, sputum, and/or sputum purulence. These exacerbations of COPD (ECOPDs) impact health status, accelerate lung function decline, and increase the risk of hospitalization. Importantly, close to 20% of patients are readmitted within 30 days after hospital discharge, with great cost to the person and society. Approximately 25% and 65% of patients hospitalized for an ECOPD die within 1 and 5 years, respectively. Patients with COPD are usually older and frequently have concomitant chronic diseases, including heart failure, coronary artery disease, arrhythmias, interstitial lung diseases, bronchiectasis, asthma, anxiety, and depression, and are also at increased risk of developing pneumonia, pulmonary embolism, and pneumothorax. All of these morbidities not only increase the risk of subsequent ECOPDs but can also mimic or aggravate them. Importantly, close to 70% of readmissions after an ECOPD hospitalization result from decompensation of other morbidities. These observations suggest that in patients with COPD with worsening dyspnea but without the other classic characteristics of ECOPD, a careful search for these morbidities can help detect them and allow appropriate treatment. For most morbidities, a thorough clinical evaluation supplemented by appropriate clinical investigations can guide the healthcare provider to make a precise diagnosis. This perspective integrates the currently dispersed information available and provides a practical approach to patients with COPD complaining of worsening respiratory symptoms, particularly dyspnea. A systematic approach should help improve outcomes and the personal and societal cost of ECOPDs.

Patient and social factors related to nebulizer use in COPD patients at the transition of care: a qualitative study.

BACKGROUND: Transition from hospital to home is a vulnerable period for patients with COPD exacerbations, with a high risk for readmission and mortality. Twenty percent of patients with an initial hospitalization for a COPD exacerbation are readmitted to a hospital within 30 days, costing the health care system over $15 billion annually. While nebulizer therapy directed at some high-risk COPD patients may improve the transition from hospital to home, patient and social factors are likely to contribute to difficulties with their use. Current literature describing the COPD patient's experience with utilizing nebulizer therapy, particularly during care transitions, is limited. Therefore, the objective of this study was to explore underlying COPD patient and social factors contributing to practical difficulties with nebulizer use at the care transition from hospital to home. METHODS: This was a qualitative study conducted between September 2020 and June 2022. Patients were included if they were ≥ 40 years old, had a current diagnosis of COPD, had an inpatient admission at a hospital, and were discharged directly to home with nebulizer therapy. Semi-structured, one-on-one interviews with patients were conducted covering a broad range of patient and social factors and their relationships with nebulizer use and readmission. Interviews were recorded and transcribed verbatim. A thematic analysis was performed using a mixed inductive and deductive approach. RESULTS: Twenty-one interviews were conducted, and subjects had a mean age of 64 ± 8.4 years, 62% were female, and 76% were White. The predominant interview themes were health care system interactions and medication management. The interviews highlighted that discharge counseling methods and depth of counseling from hospitals were inconsistent and were not always patient-friendly. They also suggested that patients could appropriately identify, set up, and utilize their nebulizer treatment without difficulties, but additional patient education is required for nebulizer clean up and maintenance. CONCLUSIONS: Our interviews suggest that there is room for improvement within the health care system for providing consistent, effective discharge counseling. Also, COPD patients discharged from a hospital on nebulizer therapy can access and understand their treatment but require additional education for nebulizer clean up and maintenance.

Haemophilus influenzae genome evolution during persistence in the human airways in chronic obstructive pulmonary disease.

Nontypeable Haemophilus influenzae (NTHi) exclusively colonize and infect humans and are critical to the pathogenesis of chronic obstructive pulmonary disease (COPD). In vitro and animal models do not accurately capture the complex environments encountered by NTHi during human infection. We conducted whole-genome sequencing of 269 longitudinally collected cleared and persistent NTHi from a 15-y prospective study of adults with COPD. Genome sequences were used to elucidate the phylogeny of NTHi isolates, identify genomic changes that occur with persistence in the human airways, and evaluate the effect of selective pressure on 12 candidate vaccine antigens. Strains persisted in individuals with COPD for as long as 1,422 d. Slipped-strand mispairing, mediated by changes in simple sequence repeats in multiple genes during persistence, regulates expression of critical virulence functions, including adherence, nutrient uptake, and modification of surface molecules, and is a major mechanism for survival in the hostile environment of the human airways. A subset of strains underwent a large 400-kb inversion during persistence. NTHi does not undergo significant gene gain or loss during persistence, in contrast to other persistent respiratory tract pathogens. Amino acid sequence changes occurred in 8 of 12 candidate vaccine antigens during persistence, an observation with important implications for vaccine development. These results indicate that NTHi alters its genome during persistence by regulation of critical virulence functions primarily by slipped-strand mispairing, advancing our understanding of how a bacterial pathogen that plays a critical role in COPD adapts to survival in the human respiratory tract.

Magnetic Resonance Imaging Provides Useful Diagnostic Information Following Equivocal Ultrasound in Children With Suspected Appendicitis [Formula: see text].

PURPOSE: In Canada, ultrasonography is the primary imaging modality for children with suspected appendicitis, yet equivocal studies are common. Magnetic resonance imaging provides promise as an adjunct imaging strategy. The primary objective of this study was to determine the proportion of children with suspected appendicitis and equivocal ultrasound where magnetic resonance imaging determined a diagnosis. METHODS: A prospective consecutive cohort of children aged 5-17 years presenting to a tertiary pediatric Emergency Department with suspected appendicitis were enrolled. Participants underwent diagnostic and management strategies according to our local suspected appendicitis pathway, followed by magnetic resonance (Siemens Avanto 1.5 Tesla) imaging. Sub-specialty pediatric radiologists reported all images. RESULTS: Magnetic resonance imaging was performed in 101 children with suspected appendicitis. The mean age was 11.9 (SD 3.4) years and median Pediatric Appendicitis Score was 6 [IQR 4,8]. Ultrasonography was completed in 98/101 (97.0%). Of 53/98 (54.1%) with equivocal ultrasound, magnetic resonance imaging provided further diagnostic information in 41 (77.4%; 10 positive, 31 negative; 12 remained equivocal). Secondary findings of appendicitis on magnetic resonance imaging in children with equivocal ultrasound included abdominal free fluid (24, 45.3%), peri-appendiceal fluid (12, 22.6%), intraluminal appendiceal fluid (9, 17.0%), fat stranding (8, 15.1%), appendicolith (2, 3.8%), and peri-appendiceal abscess (1, 1.9%). The observed agreement between magnetic resonance imaging results and final diagnosis was 94.9% (kappa = 0.89).

Benefits of glycopyrrolate/formoterol fumarate metered dose inhaler (GFF MDI) in improving lung function and reducing exacerbations in patients with moderate-to-very severe COPD: a pooled analysis of the PINNACLE studies.

BACKGROUND: The Phase III PINNACLE studies assessed the efficacy and safety of glycopyrrolate/formoterol fumarate metered dose inhaler (GFF MDI), a dual long-acting bronchodilator for chronic obstructive pulmonary disease (COPD). Here we present a pre-specified pooled analysis of PINNACLE-1, PINNACLE-2, and PINNACLE-4. METHODS: PINNACLE-1, -2, and -4 were multicenter, double-blind, randomized controlled trials that enrolled patients with moderate-to-very severe COPD, with no requirement for exacerbation history or a high symptom burden. Patients received GFF MDI 18/9.6 µg, glycopyrrolate (GP) MDI 18 µg, formoterol fumarate (FF) MDI 9.6 µg, or placebo MDI, twice-daily for 24 weeks. The primary endpoint of the pooled analysis was the change from baseline in morning pre-dose trough forced expiratory volume in 1 s (FEV1) at week 24. Secondary endpoints included COPD exacerbations and clinically important deterioration (CID). Adverse events were also assessed. RESULTS: The pooled intent-to-treat population included 4983 patients; of these, 61.9% had a COPD assessment test (CAT) score ≥15, and 25.0% had experienced ≥1 moderate/severe exacerbation in the past year. At week 24, GFF MDI improved morning pre-dose trough FEV1 versus GP MDI (least squares mean [LSM] difference [95% confidence interval (CI)]: 59 mL [43, 75]), FF MDI (65 mL [48, 81]), and placebo MDI (146 mL [125, 166]); all p < 0.0001. GFF MDI reduced the risk of a moderate/severe exacerbation by 18% (p = 0.0168), 15% (p = 0.0628), and 28% (p = 0.0012) compared with GP MDI, FF MDI, and placebo MDI, respectively. In general, exacerbation risk reduction with GFF MDI versus comparators was greater in subgroups of symptomatic patients (CAT ≥15) and those who had an exacerbation history, than in the pooled intent-to-treat population. The risk of CID was also lower with GFF MDI versus GP MDI (23% decrease), FF MDI (17%), and placebo MDI (49%); all p < 0.0001. All treatments were well tolerated, with no unexpected safety signals. CONCLUSIONS: This pooled analysis of the PINNACLE studies demonstrated that GFF MDI improved lung function and reduced the risk of exacerbations compared with monocomponents and placebo in patients with COPD. Exacerbation reductions with GFF MDI versus comparators were generally greater in patients with higher symptom burden and those with exacerbation history. TRIAL REGISTRATION: ClinicalTrials.gov NCT01854645, NCT01854658, and NCT02343458. Registered 13 May 2013 (NCT01854645, NCT01854658) and 6 January 2015 (NCT02343458).

Oral-lung microbiome interactions in lung diseases.

The proximity and continuity of the oral cavity and the lower respiratory tract allows the oropharyngeal microbiome to be a major determinant of the lung microbiome. In addition, host-pathogen interactions related to the oropharyngeal microbiome or its metabolites could propagate systemic inflammation or modulate host defense mechanisms that could affect other organs, including the lung. There is increasing appreciation of the pathophysiologic significance of the lung microbiome, not only in the classical infection-related diseases, pneumonia, bronchiectasis, and cystic fibrosis, but also in chronic noninfectious lung diseases, such as chronic obstructive pulmonary disease, asthma, and pulmonary fibrosis. In this review, we will explore the relationship of the oral microbiome with lung diseases, such as pneumonia, chronic obstructive pulmonary disease, asthma, and cystic fibrosis.

Chronic Obstructive Pulmonary Disease in the Intensive Care Unit: Antibiotic Treatment of Severe Chronic Obstructive Pulmonary Disease Exacerbations.

Patients who suffer from chronic obstructive pulmonary disease (COPD) often experience deterioration of baseline respiratory symptoms, acute exacerbations of COPD (AECOPD), that become more frequent with disease progression. Based on symptom severity, approximately 20% of these patients will require hospitalization. The most common indicators for intensive care unit (ICU) admission have been found to be worsening or impending respiratory failure and hemodynamic instability. Bacterial and viral bronchial infections are the causative triggers in the majority of COPD exacerbations in the ICU, with a comprehensive assessment revealing them in 72% of cases. The distribution of bacterial pathogens involved in AECOPD requiring ICU admission show an increased incidence of gram-negative respiratory isolates, including Pseudomonas and Enterobacteriaceae spp., when compared with outpatient exacerbations. Evaluation of these patients requires careful attention to comorbid conditions. An effort to rapidly obtain lower respiratory samples for microbiological samples prior to initiation of antibiotics should be made as adequate samples can guide subsequent modifications of antibiotic treatment if the clinical response to empiric treatment is poor. Empiric antibiotic treatment should be promptly initiated in all patients with a major consideration for the choice being the presence of risk factors for Pseudomonas infection. Evaluation of clinical response at 48 to 72 hours is crucial, and total duration of antibiotics of 5 to 7 days should be adequate.

Acute exacerbations in chronic obstructive pulmonary disease: should we use antibiotics and if so, which ones?

PURPOSE OF REVIEW: Acute exacerbations are a major cause of morbidity and mortality in chronic obstructive pulmonary disease (COPD) with evidence suggesting at least 50% of exacerbations involve bacteria that benefit from antibiotic treatment. Here, we review the most relevant data regarding the use of antibiotics in exacerbations of COPD and provide insights on the selection of initial antibiotic therapy for their treatment. RECENT FINDINGS: Identification of bacterial exacerbations still relies on clinical assessment rather than laboratory biomarkers. Several recent studies, including a meta-analysis and placebo-controlled trials, demonstrate improved outcomes with antibiotics in all but mild exacerbations of COPD, including both inpatient and outpatient. A broader antibiotic regimen should be used for patients who have risk factors for poor outcomes. A risk-stratification approach can guide antibiotic choice, although the stratification algorithm still needs to be validated in a randomized controlled trial. SUMMARY: The use of antibiotics for the treatment of moderate-to-severe suspected bacterial exacerbations in COPD is supported by published trials and evidence-based systematic reviews. Recent trials also show differences in outcomes based on antibiotic choice. More research is necessary to evaluate risk stratification approaches when selecting initial antibiotic therapy.

Maintained therapeutic effect of revefenacin over 52 weeks in moderate to very severe Chronic Obstructive Pulmonary Disease (COPD).

BACKGROUND: Revefenacin is a long-acting muscarinic antagonist that was recently approved for the nebulized treatment of chronic obstructive pulmonary disease (COPD). Although shorter duration studies have documented the efficacy of revefenacin in COPD, longer-term efficacy has not been described. In a recent 52-week safety trial, revefenacin was well tolerated and had a favorable benefit-risk profile. Here we report exploratory efficacy and health outcomes in patients receiving revefenacin 175 µg or 88 µg daily during the 52-week trial. METHODS: In this randomized, parallel-group, 52-week trial (NCT02518139), 1055 participants with moderate to very severe COPD received revefenacin 175 µg or 88 µg in a double-blind manner, or open-label active control tiotropium. RESULTS: Over the 52-week treatment period, both doses of revefenacin, as well as tiotropium, elicited significant (all p < 0.0003) improvements from baseline in trough forced expiratory volume in 1 s (FEV1). The trough FEV1 profile (least squares mean change from baseline) for revefenacin 175 µg ranged from 52.3-124.3 mL and the trough FEV1 profile for tiotropium ranged from 79.7-112.8 mL. In subgroup comparisons, the effect of revefenacin on trough FEV1 was comparable in patients taking concomitant long-acting ß-agonists, with or without inhaled corticosteroids, with patients who were not taking these medications. There were statistically significant (p < 0.05) improvements in all measured health status outcomes (evaluated using St. George's Respiratory Questionnaire, COPD Assessment Test, Clinical COPD Questionnaire and Baseline and Transition Dyspnea Index) from 3 months onward, in all treatment arms. CONCLUSIONS: Significant sustained improvements from baseline in trough FEV1 and respiratory health outcomes were demonstrated for 175-µg revefenacin over 52 weeks, further supporting its use as a once-daily bronchodilator for the nebulized treatment of patients with COPD. TRIAL REGISTRATION: NCT02518139 ; Registered 5 August 2015.

Compartmentalization of anti-oxidant and anti-inflammatory gene expression in current and former smokers with COPD.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) have high oxidative stress associated with the severity of the disease. Nuclear factor erythroid-2 related factor 2 (Nrf2)-directed stress response plays a critical role in the protection of lung cells to oxidative stress by upregulating antioxidant genes in response to tobacco smoke. There is a critical gap in our knowledge about Nrf-2 regulated genes in active smokers and former-smokers with COPD in different cell types from of lungs and surrogate peripheral tissues. METHODS: We compared the expression of Nrf2 and six of its target genes in alveolar macrophages, nasal, and bronchial epithelium and peripheral blood mononuclear cells (PBMCs) in current and former smokers with COPD. We compared cell-type specific of Nrf2 and its target genes as well as markers of oxidative and inflammatory stress. RESULTS: We enrolled 89 patients; expression all Nrf2 target gene measured were significantly higher in the bronchial epithelium from smokers compared to non-smokers. None were elevated in alveolar macrophages and only one was elevated in each of the other compartments. CONCLUSION: Bronchial epithelium is the most responsive tissue for transcriptional activation of Nrf2 target genes in active smokers compared to former-smokers with COPD that correlated with oxidative stress and inflammatory markers. There were no consistent trends in gene expression in other cell types tested. TRIAL REGISTRATION: Clinicaltrials.gov : NCT01335971.

Cardiovascular safety of revefenacin, a once-daily, lung-selective, long-acting muscarinic antagonist for nebulized therapy of chronic obstructive pulmonary disease: Evaluation in phase 3 clinical trials.

The cardiovascular safety of revefenacin, an anticholinergic indicated for the maintenance treatment of patients with chronic obstructive lung disease (COPD), was evaluated in phase 3 trials in patients with moderate to very severe COPD. No clinically meaningful changes in 12-lead electrocardiogram recordings were observed with up to 52 weeks of once-daily revefenacin 88 or 175 µg. In a pooled analysis of Studies 0126 and 0127, the incidence of prolonged QT interval corrected for heart rate using the Fridericia correction formula (QTcF; >450 msec) for revefenacin 88 µg (n = 23, 5.6%) and revefenacin 175 µg (n = 23, 5.9%) was similar to that for placebo (n = 22, 5.3%). In Study 0128, the incidence of prolonged QTcF was similar in the revefenacin 175 µg (n = 25, 7.7%) and tiotropium (n = 26, 7.3%) groups and lower in the revefenacin 88 µg (n = 15, 4.2%) group. There were four major adverse cardiac events (MACEs) in Study 0126 (one, two, and one in the placebo, revefenacin 88 µg, and revefenacin 175 µg groups, respectively), no MACEs in Study 0127 and 26 MACEs in Study 0128 (9, 10 and 7 in the revefenacin 88 µg, revefenacin 175 µg and tiotropium groups, respectively). In Study 0128, only one MACE was considered possibly/probably related to revefenacin (atrial fibrillation in the revefenacin 175 µg group). Thus, revefenacin may provide beneficial nebulized therapy for patients with COPD without further elevating their risk of cardiovascular events.

Validation of fitness tracker for sleep measures in women with asthma.

OBJECTIVE: Nighttime wakening with asthma symptoms is a key to assessment and therapy decisions, with no gold standard objective measure. The study aims were to (1) determine the feasibility, (2) explore equivalence, and (3) test concordance of a consumer-based accelerometer with standard actigraphy for measurement of sleep patterns in women with asthma as an adjunct to self-report. METHODS: Panel study design of women with poorly controlled asthma from a university-affiliated primary care clinic system was used. We assessed sensitivity and specificity, equivalence and concordance of sleep time, sleep efficiency, and wake counts between the consumer-based accelerometer Fitbit Charge™ and Actigraph wGT3X+. We linked data between devices for comparison both automatically by 24-hour period and manually by sleep segment. RESULTS: Analysis included 424 938 minutes, 738 nights, and 833 unique sleep segments from 47 women. The fitness tracker demonstrated 97% sensitivity and 40% specificity to identify sleep. Between device equivalence for total sleep time (15 and 42-minute threshold) was demonstrated by sleep segment. Concordance improved for wake counts and sleep efficiency when adjusting for a linear trend. CONCLUSIONS: There were important differences in total sleep time, efficiency, and wake count measures when comparing individual sleep segments versus 24-hour measures of sleep. Fitbit overestimates sleep efficiency and underestimates wake counts in this population compared to actigraphy. Low levels of systematic bias indicate the potential for raw measurements from the devices to achieve equivalence and concordance with additional processing, algorithm modification, and modeling. Fitness trackers offer an accessible and inexpensive method to quantify sleep patterns in the home environment as an adjunct to subjective reports, and require further informatics development.

Determinants of Response to Roflumilast in Severe Chronic Obstructive Pulmonary Disease. Pooled Analysis of Two Randomized Trials.

RATIONALE: Roflumilast reduces exacerbations in patients with severe chronic obstructive pulmonary disease associated with chronic bronchitis and a history of exacerbations. Further characterization of patients most likely to benefit is warranted. OBJECTIVES: Define characteristics that most robustly identify patients who derive greatest exacerbation risk reduction with roflumilast. METHODS: Predefined, pooled analyses of REACT (Roflumilast in the Prevention of COPD Exacerbations While Taking Appropriate Combination Treatment; NCT01329029) and RE2SPOND (Roflumilast Effect on Exacerbations in Patients on Dual [LABA/ICS] Therapy; NCT01443845) multicenter, randomized, double-blind, placebo-controlled studies. The primary endpoint was rate of moderate or severe exacerbations per patient per year. MEASUREMENTS AND MAIN RESULTS: In the overall intention-to-treat population (n = 4,287), roflumilast reduced moderate or severe exacerbations by 12.3% (rate ratio, 0.88, 95% confidence interval, 0.80-0.97; P = 0.0086) and severe exacerbations by 16.1% (0.84; 0.71-0.99; P = 0.0409) versus placebo. The reduction in moderate or severe exacerbations with roflumilast was most pronounced in patients who had been hospitalized for an exacerbation in the prior year (0.74; 0.63-0.88; P = 0.0005); had more than two exacerbations in the prior year (0.79; 0.65-0.96; P = 0.0160); or had baseline eosinophils ≥150 cells/µl (0.81; 0.71-0.93; P = 0.0020), ≥150 to <300 cells/µl (0.84; 0.71-0.98; P = 0.0282), or ≥300 cells/µl (0.77; 0.61-0.97; P = 0.0264). Similar subgroup results were noted for severe exacerbations. In patients with prior hospitalization and higher baseline blood eosinophil concentrations, roflumilast reduced moderate or severe exacerbations by 34.5% at ≥150 cells/µl (0.65; 0.52-0.82; P = 0.0003) and 42.7% at ≥300 cells/µl (0.57; 0.37-0.88; P = 0.0111) versus placebo. CONCLUSIONS: This prespecified, pooled analysis confirms the benefit of roflumilast in decreasing exacerbations in patients with prior hospitalization for exacerbation, greater exacerbation frequency, and higher (≥150 cells/µl, ≥150 to <300 cells/µl, or ≥300 cells/µl) baseline blood eosinophil count.

Future Research Directions in Pneumonia. NHLBI Working Group Report.

Pneumonia is a complex pulmonary disease in need of new clinical approaches. Although triggered by a pathogen, pneumonia often results from dysregulations of host defense that likely precede infection. The coordinated activities of immune resistance and tissue resilience then dictate whether and how pneumonia progresses or resolves. Inadequate or inappropriate host responses lead to more severe outcomes such as acute respiratory distress syndrome and to organ dysfunction beyond the lungs and over extended time frames after pathogen clearance, some of which increase the risk for subsequent pneumonia. Improved understanding of such host responses will guide the development of novel approaches for preventing and curing pneumonia and for mitigating the subsequent pulmonary and extrapulmonary complications of pneumonia. The NHLBI assembled a working group of extramural investigators to prioritize avenues of host-directed pneumonia research that should yield novel approaches for interrupting the cycle of unhealthy decline caused by pneumonia. This report summarizes the working group's specific recommendations in the areas of pneumonia susceptibility, host response, and consequences. Overarching goals include the development of more host-focused clinical approaches for preventing and treating pneumonia, the generation of predictive tools (for pneumonia occurrence, severity, and outcome), and the elucidation of mechanisms mediating immune resistance and tissue resilience in the lung. Specific areas of research are highlighted as especially promising for making advances against pneumonia.

Azithromycin Pharmacodynamics against Persistent Haemophilus influenzae in Chronic Obstructive Pulmonary Disease.

The pharmacodynamic profile of azithromycin against persistent strains of nontypeable Haemophilus influenzae (NTHi) from chronic obstructive pulmonary disease (COPD) patients was characterized. Azithromycin displayed differential concentration-dependent activities (R2 ≥ 0.988); the pharmacodynamic response was attenuated when we compared the "first" and "last" strains of NTHi that persisted in the airways of the same patient for 819 days (the 50% effective concentration [EC50] increased more than 50 times [0.0821 mg/liter versus 4.23 mg/liter]). In the hollow-fiber infection model, NTHi viability was maintained throughout simulated azithromycin (Zithromax) Z-Pak regimens over 10 days.

Lower Airway Bacterial Colonization Patterns and Species-Specific Interactions in Chronic Obstructive Pulmonary Disease.

Little is known about interactions between nontypeable Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Pseudomonas aeruginosa in the lower respiratory tract in chronic obstructive pulmonary disease (COPD) patients. We characterized colonization by these four bacterial species, determined species-specific interactions, and estimated the effects of host factors on bacterial colonization among COPD patients. We conducted a prospective cohort study in veterans with COPD that involved monthly clinical assessment and sputum cultures with an average duration of follow-up of 4.5 years. Cultures were used for bacterial identification. We analyzed bacterial interactions using generalized linear mixed models after controlling for clinical and demographic variables. The outcomes of interest were the relationships between bacteria based on clinical status (stable or exacerbation). One hundred eighty-one participants completed a total of 8,843 clinic visits, 30.8% of which had at least one of the four bacteria isolated. H. influenzae was the most common bacterium isolated (14.4%), followed by P. aeruginosa (8.1%). In adjusted models, S. pneumoniae colonization was positively associated with H. influenzae colonization (odds ratio [OR], 2.79; 95% confidence interval [CI], 2.03 to 3.73). We identified negative associations between P. aeruginosa and H. influenzae (OR, 0.15; 95% CI, 0.10 to 0.22) and P. aeruginosa and M. catarrhalis (OR, 0.51; 95% CI, 0.35 to 0.75). Associations were similar during stable and exacerbation visits. Recent antimicrobial therapy was associated with a lower prevalence of S. pneumoniae, H. influenzae, and M. catarrhalis, but not P. aeruginosa Our findings support the presence of specific interspecies interactions between common bacteria in the lower respiratory tracts of COPD patients. Further work is necessary to elucidate the mechanisms of these complex interactions that shift bacterial species.

The microbiome in respiratory medicine: current challenges and future perspectives.

The healthy lung has previously been considered to be a sterile organ because standard microbiological culture techniques consistently yield negative results. However, culture-independent techniques report that large numbers of microorganisms coexist in the lung. There are many unknown aspects in the field, but available reports show that the lower respiratory tract microbiota: 1) is similar in healthy subjects to the oropharyngeal microbiota and dominated by members of the Firmicutes, Bacteroidetes and Proteobacteria phyla; 2) shows changes in smokers and well-defined differences in chronic respiratory diseases, although the temporal and spatial kinetics of these changes are only partially known; and 3) shows relatively abundant non-cultivable bacteria in chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cystic fibrosis and bronchiectasis, with specific patterns for each disease. In all of these diseases, a loss of diversity, paralleled by an over-representation of Proteobacteria (dysbiosis), has been related to disease severity and exacerbations. However, it is unknown whether dysbiosis is a cause or a consequence of the damage to bronchoalveolar surfaces.Finally, little is known about bacterial functionality and the interactions between viruses, fungi and bacteria. It is expected that future research in bacterial gene expressions, metagenomics longitudinal analysis and host-microbiome animal models will help to move towards targeted microbiome interventions in respiratory diseases.

A randomised, placebo-controlled trial of anti-interleukin-1 receptor 1 monoclonal antibody MEDI8968 in chronic obstructive pulmonary disease.

BACKGROUND: Interleukin-1 receptor 1 (IL-1R1) inhibition is a potential strategy for treating patients with chronic obstructive pulmonary disease (COPD). MEDI8968, a fully human monoclonal antibody, binds selectively to IL-1R1, inhibiting activation by IL-1α and IL-1ß. We studied the efficacy and safety/tolerability of MEDI8968 in adults with symptomatic, moderate-to-very severe COPD. METHODS: This was a phase II, randomised, double-blind, placebo-controlled, multicentre, parallel-group study. Subjects aged 45-75 years and receiving standard maintenance therapy with ≥2 exacerbations in the past year were randomised 1:1 to receive placebo or MEDI8968 300 mg (600 mg intravenous loading dose) subcutaneously every 4 weeks, for 52 weeks. The primary endpoint was the moderate/severe acute exacerbations of COPD (AECOPD) rate (week 56 post-randomisation). Secondary endpoints were severe AECOPD rate and St George's Respiratory Questionnaire-COPD (SGRQ-C) score (week 56 post-randomisation). RESULTS: Of subjects randomised to placebo (n = 164) and MEDI8968 (n = 160), 79.3% and 75.0%, respectively, completed the study. There were neither statistically significant differences between treatment groups in moderate/severe AECOPD rate ([90% confidence interval]: 0.78 [0.63, 0.96], placebo; 0.71 [0.57, 0.90], MEDI8968), nor in severe AECOPD rate or SGRQ-C scores. Post-hoc analysis of subject subgroups (by baseline neutrophil count or tertiles of circulating neutrophil counts) did not alter the study outcome. The incidence of treatment-emergent adverse events (TEAEs) with placebo and MEDI8968 treatment was similar. The most common TEAE was worsening of COPD. CONCLUSIONS: In this phase II study, MEDI8968 did not produce statistically significant improvements in AECOPD rate, lung function or quality of life. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01448850 , date of registration: 06 October 2011.

IL-18 associated with lung lymphoid aggregates drives IFNγ production in severe COPD.

BACKGROUND: Increased interferon gamma (IFNγ) release occurs in Chronic Obstructive Pulmonary Disease (COPD) lungs. IFNγ supports optimal viral clearance, but if dysregulated could increase lung tissue destruction. METHODS: The present study investigates which mediators most closely correlate with IFNγ in sputum in stable and exacerbating disease, and seeks to shed light on the spatial requirements for innate production of IFNγ, as reported in mouse lymph nodes, to observe whether such microenvironmental cellular organisation is relevant to IFNγ production in COPD lung. RESULTS: We show tertiary follicle formation in severe disease alters the dominant mechanistic drivers of IFNγ production, because cells producing interleukin-18, a key regulator of IFNγ, are highly associated with such structures. Interleukin-1 family cytokines correlated with IFNγ in COPD sputum. We observed that the primary source of IL-18 in COPD lungs was myeloid cells within lymphoid aggregates and IL-18 was increased in severe disease. IL-18 released from infected epithelium or from activated myeloid cells, was more dominant in driving IFNγ when IL-18-producing and responder cells were in close proximity. CONCLUSIONS: Unlike tight regulation to control infection spread in lymphoid organs, this local interface between IL-18-expressing and responder cell is increasingly supported in lung as disease progresses, increasing its potential to increase tissue damage via IFNγ.

Effect of Roflumilast and Inhaled Corticosteroid/Long-Acting ß2-Agonist on Chronic Obstructive Pulmonary Disease Exacerbations (RE(2)SPOND). A Randomized Clinical Trial.

RATIONALE: Moderate and severe exacerbations are incompletely prevented by maximal inhalation therapy in patients with severe chronic obstructive pulmonary disease. OBJECTIVES: To determine whether roflumilast reduces moderate and/or severe chronic obstructive pulmonary disease exacerbations in patients at risk for exacerbations despite treatment with inhaled corticosteroid/long-acting ß2-agonist with or without a long-acting muscarinic antagonist (LAMA). METHODS: In this 52-week, phase 4, double-blind, placebo-controlled RE(2)SPOND (Roflumilast Effect on Exacerbations in Patients on Dual [LABA/ICS] Therapy) trial (NCT01443845), participants aged 40 years or older with severe/very severe chronic obstructive pulmonary disease, chronic bronchitis, two or more exacerbations and/or hospitalizations in the previous year, and receiving inhaled corticosteroid/long-acting ß2-agonist with or without LAMA daily for 3 or more months were equally randomized to once-daily roflumilast, 500 µg (n = 1,178), or placebo (n = 1,176). Stratification was based on LAMA use. MEASUREMENTS AND MAIN RESULTS: Although rate of moderate or severe exacerbations per patient per year (primary endpoint) was reduced by 8.5% with roflumilast versus placebo, the between-group difference was not statistically significant (rate ratio, 0.92; 95% confidence interval, 0.81-1.04; P = 0.163). However, roflumilast improved lung function, and in a post hoc analysis roflumilast significantly reduced the rate of moderate or severe exacerbations in participants with a history of more than three exacerbations and/or one or more hospitalizations in the prior year. Adverse event-related discontinuations occurred in 11.7% roflumilast-treated and 5.4% placebo-treated participants. Deaths occurred in 2.5% roflumilast and 2.1% placebo participants. CONCLUSIONS: Roflumilast failed to statistically significantly reduce moderate and/or severe exacerbations in the overall population. Roflumilast improved lung function and reduced exacerbations in participants with frequent exacerbations and/or hospitalization history. The safety profile of roflumilast was consistent with that of previous studies. Clinical trial registered with www.clinicaltrials.gov (NCT01443845).