Bronchial microbial patterns in severe exacerbations of chronic obstructive pulmonary disease (COPD) requiring mechanical ventilation

A decision tree for predicting the causative pathogens of community-acquired pneumonia from thin-section computed tomography

PURPOSE

To determine whether decision trees are useful for predicting organisms that cause community-acquired pneumonia (CAP).

MATERIALS AND METHODS

We developed a decision tree for predicting the organisms that cause CAP based on previously reported characteristic computed tomography findings. Sixteen readers (two student doctors, six residents, and eight radiologists) separately diagnosed 68 randomly selected cases of CAP using chest computed tomography. The first, second, and third most likely causative organisms were estimated for each case, and the percentages of correct answers were evaluated for consistency with the isolated organisms. The same 68 cases were then read again using the decision tree, with the first three most likely organisms again being estimated, and the percentage of agreement was evaluated as the percentage of correct responses after using the decision tree.

RESULTS

For student doctors, residents, and radiologists, the percentage of correct responses increased significantly (p < 0.0001) when the decision tree was used to predict the first, second, and third most probable causative organism. The radiologists all obtained an accuracy rate of 80% or higher when estimating up to three candidate organisms using the decision tree. The organism for which the decision tree was most useful was Mycoplasma pneumoniae, followed by Haemophilus influenzae and Chlamydophila pneumoniae (p < 0.001).

CONCLUSION

Use of the decision tree made it possible to estimate the organisms responsible for CAP with a high correct response rate.

Reducing Hospital Readmissions in Chronic Obstructive Pulmonary Disease Patients: Current Treatments and Preventive Strategies

COPD is one of the leading causes of death worldwide, so it represents a significant public health challenge. Over the years, new effective therapies have been proposed. However, the burden of COPD is still conditioned by frequent acute events defined as exacerbations (exacerbation of COPD-ECOPD), which have a significant impact not only on the patient's quality of life but also on the progression of the disease, morbidity, and mortality. Related to the severity of the condition, ECOPD may require hospital admission and often repeatedly more admissions (readmission). The phenomenon of readmissions is a significant problem, contributing substantially to the utilisation of healthcare resources and the economic burden of COPD. Related contributing factors are still poorly understood, and managing the patients readmitted to the hospital with ECOPD may be challenging. Hospital readmissions should be optimally managed, including supporting and preventive strategies. Although early readmissions (30 days from discharge) are a marker of the quality of the patient's care, we need to consider COPD patients globally. It is not sufficient to address just the acute events, so multidimensional management is necessary, able to follow the patient over time to identify, by a personalised approach, the correct treatment during and post hospitalisation and intercept any factor affecting the natural history of the disease, comprising the risk of hospital readmissions. In the context of the literature concerning respiratory medicine, particularly COPD patients, our narrative review analyses recent evidence regarding the current management of COPD hospital readmissions, aiming to propose preventive strategies helpful in clinical practice. The proposed strategies can potentially improve clinical outcomes and reduce healthcare costs when effectively implemented in practice.

A Systematic Review of the Pulmonary Microbiome in Patients with Acute Exacerbation COPD Requiring ICU Admission

Background: Chronic obstructive pulmonary disease (COPD) is a major health concern. Acute exacerbations (AECOPD) may require intensive care unit (ICU) admission and mechanical ventilation. Acute infections and chronic colonization of the respiratory system are known to precipitate AECOPD. Detailed knowledge of the respiratory microbiome could lead to effective treatment and prevention of exacerbations. Objective: The aim of this review is to summarize the available evidence on the respiratory microbiome of patients with a severe AECOPD requiring mechanical ventilation and intensive care admission. Methods: A systematic literature search was conducted to identify the published papers until January 2023. The collected data were then subjected to qualitative analysis. After the first analysis, a secondary focused review of the most recent publications studying the relationship between microbiome and mortality in AECOPD was performed. Results: Out of 120 screened articles six articles were included in this review. Potentially pathogenic microorganisms (PPMs) were identified in 30% to 72% of the patients with community-acquired bacteria, gram-negative enteric bacilli, Stenotrophomonas and Pseudomonas being the most frequently isolated. During hospitalization, 21% of patients experienced colonization by PPMs. Adequate antimicrobial therapy resulted in the eradication of 77% of the identified PPMs. However, 24% of the bacteria displayed multi-drug resistance leading to prolonged or failure of eradication. Conclusion: PPMs are prevalent in a significant proportion of patients experiencing an AECOPD. The most identified PPMs include community-acquired pathogens and gram-negative enteric bacilli. Notably, no differences in mortality or duration of ventilation were observed between patients with and without isolated PPMs. However, the included studies did not investigate the virome of the patients, which may influence the microbiome and the outcome of infection. Therefore, further research is essential to comprehensively investigate the complete microbial and viral composition of the lower respiratory system in COPD patients admitted to the ICU.

Effect of YuPingFeng granules on clinical symptoms of stable COPD: study protocol for a multicenter, double-blind, and randomized controlled trial

BACKGROUND

Reducing current clinical symptoms and the risks of future exacerbations is the main goal of stable COPD management. Traditional Chinese medicine has unique advantages in chronic disease management. YuPingFeng (YPF), as a classical prescription, has been proven to reduce the risk of exacerbations, but there is a lack of high-quality evidence for the assessment of clinical symptoms and quality of life, particularly for the assessment of treatment response of microecology and immunity.

METHODS/DESIGN

This is a prospective, multicentre, randomized, double-blind, placebo-controlled clinical trial. A total of 316 eligible subjects with moderate to severe COPD will be randomized 1:1 to receive YPF or placebo. Participants will receive either YPF or a placebo at 5 g three times daily for 52 weeks. The primary outcome will be the change in the COPD Assessment Test (CAT) score after 52 weeks of treatment. Secondary outcomes will include changes in the St George's Respiratory Questionnaire (SGRQ) score and clinical symptom score, among others. Outcomes will be measured at each visit. The study will continue for 52 weeks and will include six visits to each subject (at day 0 and weeks 4,12,24,36 and 52). In the event of exacerbations, subjects will be required to go back to the hospital once on the first day of exacerbation or when their condition permits.

DISCUSSION

This trial will provide research methods to evaluate the clinical efficacy, safety, and the possible mechanism of YPF in the treatment of stable moderate-to-severe COPD patients. In addition, we hope to provide more possibilities for TCM to participate in the management of stable COPD.

TRIAL REGISTRATION

The trial was registered at the Chinese Clinical Trials Registry on 3 June 2022 (ChiCTR2200060476; date recorded: 3/6/2022, https://www.chictr.org.cn/ ).

Effect of Macrolide Antibiotics on In-Hospital Mortality Among Acute Exacerbation of COPD Patients: A Propensity Score-Matched Analysis

Objective

This study aimed to assess whether the short-term use of macrolide antibiotics during hospitalization can reduce in-hospital all-cause mortality compared to non-macrolide treatment in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Methods

A propensity score (PS) matching analysis was performed using retrospective data from the admission records of AECOPD patients in the medical general ward and medical intensive care unit of a tertiary care center between October 2015 and September 2018. The multivariable Cox proportional hazard model was performed to eliminate residual confounding after the PS analysis.

Results

The mortality rate was 11.1% of 1528 admissions in the PS matching cohort. Approximately 70% of patients had respiratory failure requiring intubation on initial admission, and 34% had pneumonia. Macrolide treatment significantly reduced in-hospital mortality among AECOPD patients (adjusted hazard ratio, 0.55; 95% confidence interval 0.32–0.96; P=0.034). Clarithromycin was the most commonly prescribed macrolide (80%).

Conclusion

Macrolide antibiotics reduced in-hospital mortality in hospitalized AECOPD patients. The combination of antimicrobial and immunomodulatory effects of macrolide treatment could play an essential role.

Lung microbiome in children with hematological malignancies and lower respiratory tract infections

Background

Respiratory infectious complications remain a major cause of morbidity and mortality in children with hematological malignancies. Knowledge regarding the lung microbiome in aforementioned children is limited.

Methods

A prospective cohort was conducted, enrolling 16 children with hematological malignancies complicated with moderate-to-severe lower respiratory tract infections (LRTIs) versus 21 LRTI children with age, gender, weight, and infection severity matched, with no underlying malignancies, to evaluate the lung microbiome from bronchoalveolar lavage fluid samples in different groups.

Results

The lung microbiome from children with hematological malignancies and LRTIs showed obviously decreased α and β diversity; increased microbial function in infectious disease:bacteria/parasite; drug resistance:antimicrobial and human pathogenesis than the control group; a significantly reduced proportion of Firmicutes, Bacteroidota, Actinobacteriota; increased Proteobacteria at the phylum level; and distinctly elevated Parabacteroides, Klebsiella, Grimontia, Escherichia_Shigella, unclassified_Enterobacteriaceae at the genus level than the control group. Furthermore, it was revealed that α diversity (Shannon), β diversity (Bray-Curtis dissimilarity), Proteobacteria at the phylum level, and unclassified_Enterobacteriaceae and Escherichia_Shigella at the genus level were significantly negatively associated with hospitalization course whereas Firmicutes at the phylum level was established positively correlated with the hospitalization course.

Conclusions

Children with hematological malignancies and LRTIs showed obviously decreased α and β diversity, significantly increased function in infectious disease pathogenesis, antimicrobial drug resistance, and unfavorable environment tolerance. Moreover, α diversity (Shannon), β diversity (Bray-Curtis dissimilarity), and Proteobacteria may be used as negative correlated predictors for hospitalization course in these children whereas Firmicutes may be utilized as a positive correlated predictor.

Characterization and Fitness Cost of Tn7100, a Novel Integrative and Conjugative Element Conferring Multidrug Resistance in Haemophilus influenzae

A multidrug-resistant (MDR) strain of Haemophilus influenzae, Hi-228, with phenotypic resistance toward ampicillin, cefotaxime, chloramphenicol, gentamicin, and azithromycin, was isolated in Oslo, Norway. The strain was part of a clonal outbreak (2016–2017) comprising five ST143 strains with identical resistotypes. Hi-228 carries a novel integrative and conjugative element (ICE), Tn7100, contributing to this remarkable and previously unreported MDR profile. Tn7100 contains the following resistance genes: blaTEM−1B, catA2, aac(6′)-Im, aph(2″)-Ib, mef (E), and mel. The latter four are previously unreported or rarely reported in H. influenzae. In this study, we investigated the genetic environment, mechanisms of transfer, impact on phenotypic susceptibility, and fitness cost of this ICE. We found that Tn7100 has an overall structure similar to the previously described ICE Tn6686, with blaTEM−1B and catA2 carried by Tn3 and Tn10, respectively. The major difference between Tn7100 and Tn6686 is that Tn7100 lacks tet(B) but carries the resistance gene pairs aac(6′)-Im and aph(2″)-Ib and mef (E) and mel. The gene pairs are located on the novel transposable elements Tn7470 and Tn7471, which have high sequence identities to a plasmid in Enterobacterales and an ICE in streptococcal species, respectively. Tn7100 does circularize and is transferable, however, at a low frequency. Head-to-head competition experiments showed that uptake of Tn7100 reduces bacterial fitness. Our study shows that MDR strains are capable of clonal spread and that the H. influenzae supragenome comprises an increasingly wide range of transferable resistance genes, with evidence of transfer from unrelated genera. The findings offer a glimpse into the genome dynamics of H. influenzae, highlighting the importance of rational antibiotic usage to contain antimicrobial resistance and the emergence of MDR strains in this important pathogen.

Clinico-bacteriological profile and antibiotic resistance pattern in patients with acute exacerbation of COPD

Background

Repeated attacks of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) have been attributed to bacterial infections. However, sputum microbiology for identifying the bacteriological profile is not performed usually and remains controversial. Thus, we performed a prospective, cross-sectional study to assess the clinico-bacteriological profile of the patients with AECOPD and antibiotic resistance pattern of bacteria isolated from sputum samples. The study involved 104 consecutive hospitalized patients, of either gender, aged 40–90 years, and diagnosed with AECOPD. Before initiating an empirical antibiotic therapy, the sputum samples of all the patients were collected and subjected to Gram staining, bacterial culture, and antibiotic sensitivity.

Results

The most common bacterial isolates were P. aeruginosa (30.7%) followed by K. pneumoniae (20.3%) and S. pneumoniae (8.6%). Both Gram-positive and Gram-negative bacteria were most sensitive to Meropenem (91%) followed by Amoxicillin-clavulanic acid (83%). However, these bacteria were most resistant to Cefoperazone-sulbactam (43%) followed by Levofloxacin (41%). P. aeruginosa and K. pneumoniae were most resistant to Cefoperazone-sulbactam (23%) followed by Fluoroquinolones (23–35%), while S. pneumoniae was most resistant to Ciprofloxacin (44%) followed by Amoxicillin-clavulanic acid (33%).

Conclusions

Isolation of P. aeruginosa, as the most common agent, further confirms its roles in severe attacks of AECOPD. The regularly used antibiotics were found to be resistant to most isolates, thereby suggesting that severity of AECOPD may be attributed to the prevalence of antibiotic-resistant strains.

Inhaled corticosteroid dose is associated with Pseudomonas aeruginosa infection in severe COPD

INTRODUCTION

Patients with chronic obstructive pulmonary disease (COPD) with frequent exacerbations (ExCOPD) are commonly treated with inhaled corticosteroids (ICS) and are at risk of infections caused by potential pathogenic bacteria (PPB) including Pseudomonas aeruginosa (PsA).

OBJECTIVES

To investigate the association between the use of ICS and PsA infection among ExCOPD.

METHODS

Case-control study with longitudinal follow-up that recruited ExCOPD after a hospitalisation due to exacerbation between 2012 and 2020. Patients with isolation of PsA (COPD-PsA) in sputum either during admission or follow-up were compared with those with other or no PPB. Clinical, functional characteristics, DDD, use of ICS and survival were evaluated. Cox regression analysis was performed to evaluate the risk factors associated to PsA infection and mortality.

RESULTS

358 patients (78% male, mean age 73±9 years) were enrolled and followed up for a median of 4 years (IQR=3-8). 173 patients (48.3%) had at least a positive culture for PsA. COPD-PsA had more frequent exacerbations, more severe airflow limitation and higher mortality (69.4% vs 46.5%, p<0.001). There were no differences in the use of ICS between groups but the dose of ICS was significantly higher among COPD-PsA (median of 500 µg fluticasone propionate equivalents (IQR=250-1000) vs 400 µg (IQR=200-1000), p=0.007). Blood eosinophil count (BEC) was not different between ICS users and non-users. In multivariate analysis, the dose of ICS was an independent risk factor for PsA infection and mortality but not ICS use.

CONCLUSIONS

ICS dose, but not its use, could be a risk factor for PsA infection in patients with severe COPD regardless of BEC.

Combination antibiotic therapy versus monotherapy in the treatment of acute exacerbations of chronic obstructive pulmonary disease: an open-label randomized trial

Background

The role of antibiotics in the treatment of chronic obstructive pulmonary disease (COPD) exacerbations and their effectiveness in combination have not been clearly established. To determine whether using a combination of fluoroquinolones and beta-lactams improves the clinical and microbiological efficacy of antibiotics on day 20 of treatment, we conducted an open-label randomized trial based on clinical outcomes, microbiological clearance, spirometry tests, and signs of systemic inflammation in patients hospitalized with acute exacerbations of COPD.

Methods

We enrolled 139 subjects with COPD exacerbations, defined as acute worsening of respiratory symptoms leading to additional treatment. Patients were divided randomly into two groups: 79 patients using beta-lactam antibiotics alone and 60 using beta-lactam antibiotics plus fluoroquinolones. Clinical and microbiological responses, spirometry tests, symptom scores, and serum C-reactive protein (CRP) levels were evaluated.

Results

Clinical success, lung function, and symptoms were similar in patients with or without fluoroquinolone administration on days 10 and 20. Combination therapy was superior in terms of microbiological outcomes and reduction in serum CRP value. Although equivalent to monotherapy in terms of clinical success, the combination showed superiority in terms of microbiological success and a decrease in CRP. The combination therapy group had a higher microbiological success rate with gram-negative bacteria than the monotherapy group with Pseudomonas aeruginosa (100% vs. 33.3%, respectively) and Acinetobacter baumanii (100% vs. 20%, respectively) (P < 0.05).

Conclusions

Concomitant use of fluoroquinolone and beta-lactam antibiotics for bacterial infections during COPD exacerbations caused by gram-negative bacteria appear to be effective and should be applied in clinical practice.

Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and results in an economic and social burden that is both substantial and increasing. The natural history of COPD is punctuated by exacerbations, which have major short- and long-term implications on the patient and health care system. Evidence-based guidelines stipulate that early detection and prompt treatment of exacerbations are essential to ensure optimal outcomes and to reduce the burden of COPD. In this review, we provide a concise overview of COPD exacerbations and their risk factors and etiology (infection vs noninfectious), outlining the initial evaluation, triaging, and current management including invasive and noninvasive ventilation, in addition to the prognosis and the preventive strategies.

Molecular Mechanisms of Lipid Metabolism Disorders in Infectious Exacerbations of Chronic Obstructive Pulmonary Disease

Exacerbations largely determine the character of the progression and prognosis of chronic obstructive pulmonary disease (COPD). Exacerbations are connected with changes in the microbiological landscape in the bronchi due to a violation of their immune homeostasis. Many metabolic and immune processes involved in COPD progression are associated with bacterial colonization of the bronchi. The objective of this review is the analysis of the molecular mechanisms of lipid metabolism and immune response disorders in the lungs in COPD exacerbations. The complex role of lipid metabolism disorders in the pathogenesis of some infections is only beginning to be understood, however, there are already fewer and fewer doubts even now about its significance both in the pathogenesis of infectious exacerbations of COPD and in general in the progression of the disease. It is shown that the lipid rafts of the plasma membranes of cells are involved in many processes related to the detection of pathogens, signal transduction, the penetration of pathogens into the cell. Smoking disrupts the normally proceeded processes of lipid metabolism in the lungs, which is a part of the COPD pathogenesis.

Effects of indacaterol on the LPS-evoked changes in fluid secretion rate and pH in swine tracheal membrane

An acquired dysregulation of airway secretion is likely involved in the pathophysiology of chronic bronchitis and chronic obstructive pulmonary disease (COPD). Nowadays, it is widely known that several kinds of long-acting bronchodilators reduce the frequency of COPD exacerbations. However, limited data are available concerning the complementary additive effects on airflow obstruction. Using an optical method and a selective pH indicator, we succeeded in evaluating the gland secretion rate and the pH in swine tracheal membrane. A physiologically relevant concentration of acetylcholine (ACh) 100 nM induced a gradual increase in the amount of gland secretion. Lipopolysaccharides (LPS) accelerated the ACh-induced secretory responses up to around threefold and lowered the pH level significantly. Long-acting β₂-agonists (LABAs) including indacaterol (IND), formoterol, and salmeterol restored the LPS-induced changes in both the hypersecretion and acidification. The subsequent addition of the long-acting muscarine antagonist, glycopyrronium, further increased the pH values. Two different inhibitors for cystic fibrosis transmembrane conductance regulator (CFTR), NPPB and CFTR_inh172, abolished the IND-mediated pH normalization in the presence of both ACh and ACh + LPS. Both immunofluorescence staining and western blotting analysis revealed that LPS downregulated the abundant expression of CFTR protein. However, IND did not restore the LPS-induced decrease in CFTR expression on Calu-3 cells. These findings suggest that the activation of cAMP-dependent HCO₃⁻ secretion through CFTR would be partly involved in the IND-mediated pH normalization in gland secretion and may be suitable for the maintenance of airway defense against exacerbating factors including LPS.

Bacterial Membrane Vesicles in Pneumonia: From Mediators of Virulence to Innovative Vaccine Candidates

Pneumonia due to respiratory infection with most prominently bacteria, but also viruses, fungi, or parasites is the leading cause of death worldwide among all infectious disease in both adults and infants. The introduction of modern antibiotic treatment regimens and vaccine strategies has helped to lower the burden of bacterial pneumonia, yet due to the unavailability or refusal of vaccines and antimicrobials in parts of the global population, the rise of multidrug resistant pathogens, and high fatality rates even in patients treated with appropriate antibiotics pneumonia remains a global threat. As such, a better understanding of pathogen virulence on the one, and the development of innovative vaccine strategies on the other hand are once again in dire need in the perennial fight of men against microbes. Recent data show that the secretome of bacteria consists not only of soluble mediators of virulence but also to a significant proportion of extracellular vesicles-lipid bilayer-delimited particles that form integral mediators of intercellular communication. Extracellular vesicles are released from cells of all kinds of organisms, including both Gram-negative and Gram-positive bacteria in which case they are commonly termed outer membrane vesicles (OMVs) and membrane vesicles (MVs), respectively. (O)MVs can trigger inflammatory responses to specific pathogens including S. pneumonia, P. aeruginosa, and L. pneumophila and as such, mediate bacterial virulence in pneumonia by challenging the host respiratory epithelium and cellular and humoral immunity. In parallel, however, (O)MVs have recently emerged as auspicious vaccine candidates due to their natural antigenicity and favorable biochemical properties. First studies highlight the efficacy of such vaccines in animal models exposed to (O)MVs from B. pertussis, S. pneumoniae, A. baumannii, and K. pneumoniae. An advanced and balanced recognition of both the detrimental effects of (O)MVs and their immunogenic potential could pave the way to novel treatment strategies in pneumonia and effective preventive approaches.

Clinical features of Japanese patients with exacerbations of chronic obstructive pulmonary disease

Background

Exacerbations are critical events in chronic pulmonary obstructive disease (COPD). The frequency of COPD exacerbations is associated with the prognosis, including mortality, but no useful biomarker has been established.

Methods

The present retrospective study investigated 481 COPD patients. Clinical features in the stable period were compared between patients who experienced severe exacerbation (n = 88, 18.3%) and those who never experienced severe exacerbation (n = 393, 81.7%). In the patients who experienced exacerbations, clinical features were also compared between frequent exacerbators (exacerbation rate ≥ 2 times/year, n = 27, 30.7%) and infrequent exacerbators (1 time/year, n = 61, 69.3%).

Results

Compared to COPD patients who never experienced exacerbations, body mass index (BMI), serum albumin, and pulmonary functions were significantly lower, and the cardiovascular disease comorbidity rate, COPD assessment test score, modified Medical Research Council dyspnea scale, and use of long-term oxygen therapy, long-acting β₂ adrenergic agonist therapy, inhaled corticosteroid therapy, and macrolide therapy were significantly higher in COPD patients with exacerbations (all p < 0.01). In patients who experienced exacerbations, frequent exacerbators had significantly lower % forced expiratory volume in 1.0 s and a higher risk of critical exacerbations, percentage of blood eosinophils, history of mechanical ventilation use, and use of long-term oxygen therapy and of macrolide therapy than infrequent exacerbators (all p < 0.01). On multivariate analysis, the percentage of blood eosinophils was the parameter most correlated with exacerbation frequency (β value [95% confidence interval] 1.45 [1.12–1.88], p < 0.01).

Conclusion

Blood eosinophil in the stable period is the factor most correlated with the frequency of severe exacerbations.

Trial registration: The patients in this study was registered retrospectively

Use of Antibiotics in Chronic Obstructive Pulmonary Disease: What is Their Current Role in Older Patients?

Chronic obstructive pulmonary disease (COPD) has considerable morbidity and mortality in the older adult population. The role of antibiotics in the management of acute exacerbations of COPD (AECOPD) is currently evolving. Despite only mild benefits, most patients with AECOPD in ambulatory settings receive antibiotics based on clinical criteria. Utilization of point-of-care C-reactive protein (CRP) has reduced antibiotic prescriptions by 20% without compromising clinical outcomes. A strict protocol allowing antibiotic use only in patients with clinical criteria and CRP ≥ 20 mg/L has the potential to reduce antibiotic prescriptions for AECOPD in ambulatory settings by nearly 50%. Amoxicillin and doxycycline are commonly prescribed for AECOPD based on a favorable benefit-to-risk ratio. Prophylactic antibiotics have also been used in selected patients with severe COPD and frequent exacerbations. The use of continuous or intermittent azithromycin has demonstrated efficacy in reducing the frequency of AECOPD in this population; however, this approach has potential for the development of antibiotic resistance and adverse effects. The use of azithromycin prophylaxis in older patients with frequent AECOPD should be determined on a case-by-case basis after careful review, discussion, and counseling of the potential benefits and risks. The role of continuous doxycycline and pulsed moxifloxacin prophylaxis for frequent AECOPD remains controversial.

Consensus Document on the Diagnosis and Treatment of Chronic Bronchial Infection in Chronic Obstructive Pulmonary Disease

Although the chronic presence of microorganisms in the airways of patients with stable chronic obstructive pulmonary disease (COPD) confers a poor outcome, no recommendations have been established in disease management guidelines on how to diagnose and treat these cases. In order to guide professionals, the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) has prepared a document which aims to answer questions on the clinical management of COPD patients in whom microorganisms are occasionally or habitually isolated. Since the available scientific evidence is too heterogeneous to use in the creation of a clinical practice guideline, we have drawn up a document based on existing scientific literature and clinical experience, addressing the definition of different clinical situations and their diagnosis and management. The text was drawn up by consensus and approved by a large group of respiratory medicine experts with extensive clinical and scientific experience in the field, and has been endorsed by the SEPAR Scientific Committee.

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.

Pneumonic versus Nonpneumonic Exacerbations of Chronic Obstructive Pulmonary Disease

Patients with chronic obstructive pulmonary disease (COPD) often suffer acute exacerbations (AECOPD) and community-acquired pneumonia (CAP), named nonpneumonic and pneumonic exacerbations of COPD, respectively. Abnormal host defense mechanisms may play a role in the specificity of the systemic inflammatory response. Given the association of this aspect to some biomarkers at admission (e.g., C-reactive protein), it can be used to help to discriminate AECOPD and CAP, especially in cases with doubtful infiltrates and advanced lung impairment. Fever, sputum purulence, chills, and pleuritic pain are typical clinical features of CAP in a patient with COPD, whereas isolated dyspnea at admission has been reported to predict AECOPD. Although CAP may have a worse outcome in terms of mortality (in hospital and short term), length of hospitalization, and early readmission rates, this has only been confirmed in a few prospective studies. There is a lack of methodologically sound research confirming the impact of severe AECOPD and COPD + CAP. Here, we review studies reporting head-to-head comparisons between AECOPD and CAP + COPD in hospitalized patients. We focus on the epidemiology, risk factors, systemic inflammatory response, clinical and microbiological characteristics, outcomes, and treatment approaches. Finally, we briefly discuss some proposals on how we should orient research in the future.

An overview of exacerbations of chronic obstructive pulmonary disease: Can tests of small airways' function guide diagnosis and management?

Chronic obstructive pulmonary disease (COPD) is common and debilitating. Most patients with COPD experience intermittent, acute deterioration in symptoms which require additional therapy, termed exacerbations. Exacerbations are prevalent in COPD and are associated with poor clinical outcomes including death, a faster decline in lung health, and a reduced quality of life. Current guidelines highlight the need to treat exacerbations promptly and then mitigate future risk. However, exacerbations are self-reported, difficult to diagnose and are treated with pharmacological therapies which have largely been unchanged over 30 years. Recent research has highlighted how exacerbations vary in their underlying cause, with specific bacteria, viruses, and cell types implicated. This variation offers the opportunity for new targeted therapies, but to develop these new therapies requires sensitive tools to reliably identify the cause, the start, and end of an exacerbation and assess the response to treatment. Currently, COPD is diagnosed and monitored using spirometric measures, principally the forced expiratory volume in 1 s and forced vital capacity, but these tests alone cannot reliably diagnose an exacerbation. Measures of small airways' function appear to be an early marker of COPD, and some studies have suggested that these tests might also provide physiological biomarkers for exacerbations. In this review, we will discuss how exacerbations of COPD are currently defined, stratified, monitored, and treated and review the current literature to determine if tests of small airways' function might improve diagnostic accuracy or the assessment of response to treatment.

Influence of the Lung Microbiota Dysbiosis in Chronic Obstructive Pulmonary Disease Exacerbations: The Controversial Use of Corticosteroid and Antibiotic Treatments and the Role of Eosinophils as a Disease Marker

Chronic obstructive pulmonary disease (COPD) is a debilitating lung disease associated with loss of lung function, poorer quality of life, co-morbidities, significant mortality, and higher health care costs. Frequent acute exacerbations of COPD are sudden worsening of symptoms, the nature of which is associated with bacterial or viral infections. However, one-third of exacerbations remain of undetermined origin. Although it is largely discussed and controversial, current guidelines recommend treatment of exacerbations with bronchodilators, antibiotics, and systemic corticosteroids; this is despite being associated with limited benefits in term of reducing mortality, side effects and without paying attention to the heterogeneity of these exacerbations. Increasing evidence suggests that the lung microbiota plays an important role in COPD and numerous studies have reported differences in the microbiota between healthy and disease states, as well as between exacerbations and stable COPD, leading to the hypothesis that frequent acute exacerbation is more likely to experience significant changes in lung microbiota composition. These findings will need further examination to explain the causes of lung dysbiosis, namely microbial composition, the host response, including the recruitment of eosinophils, lifestyle, diet, cigarette smoking and the use of antibiotics and corticosteroids. It is now important to assess: 1) Whether alterations in the lung microbiota contribute to disease pathogenesis, especially in exacerbations of unknown origin; 2) The role of eosinophils; and 3) Whether the microbiota of the lung can be manipulated therapeutically to improve COPD exacerbation event and disease progression. In summary, we hypothesize that the alterations of the lung microbiota may explain the undetermined origins of exacerbations and that there is an urgent need to facilitate the design of intervention studies that aim at conserving the lung microbial flora.

Bacterial infections in acute exacerbation of chronic obstructive pulmonary disease: a systematic review and meta-analysis

OBJECTIVE

Due to the importance of Chronic obstructive pulmonary disease (COPD) as the fourth cause of mortality worldwide and the lack of studies evaluating the prevalence of bacterial infections in disease exacerbation, this systematic review and meta-analysis was performed to determine the prevalence rate of bacterial infections in COPD patients.

METHODS

PubMed, ISI Web of Science, and Scopus databases were systematically searched for population-based prevalence studies (1980-2018). MeSH terms for "Bacterial infections" and "AECOPD" were used as search keywords. The selected studies were filtered according to the inclusion and exclusion criteria. Fixed and random-effects models were used for estimation of summary effect sizes. Between-study heterogeneity, as well as publication bias, were calculated.

RESULTS

Finally, 118 out of 31,440 studies were selected. The overall estimation of the prevalence of bacterial infection was 49.59% [95% confidence interval (CI) 0.4418-0.55]. The heterogeneity in estimating the pooled prevalence of bacterial infections was shown in the studies (Cochran Q test: 6615, P < 0.0001, I² = 98.23%). In addition, S. pneumoniae, H. influenzae, M. catarrhalis, A. baumannii, P. aeruginosa, and S. aureus were the most prevalent reported bacteria.

CONCLUSIONS

Our results as the first meta-analysis for the issue demonstrated that bacterial infections are an important risk factor for AECOPD. Further studies must be performed for understanding the exact role of bacterial agents in AECOPD and help physicians for more applicable preventive and therapeutic measurements.

Procalcitonin-guided antibiotic therapy in acute exacerbation of chronic obstructive pulmonary disease: An updated meta-analysis

BACKGROUND

The benefit of a procalcitonin (PCT)-guided antibiotic strategy in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) remains uncertain.

OBJECTIVES

This updated meta-analysis was performed to reevaluate the therapeutic potential of PCT-guided antibiotic therapy in AECOPD.

DATA SOURCES

We searched PubMed, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov up to February 2019 to identify randomized controlled trials (RCTs) investigating the role of PCT-guided antibiotic strategies in treating adult patients with AECOPD. Relative risk (RR) or mean differences (MD) with accompanying 95% confidence intervals (CIs) were calculated with a random-effects model.

RESULTS

Eight RCTs with a total of 1376 participants were included. The results suggested that a PCT-guided antibiotic strategy reduced antibiotic prescriptions (RR: 0.55; 95% CI: 0.39-0.76; P = .0003). However, antibiotic exposure duration (MD: -1.34; 95% CI: -2.83-0.16; P = .08), antibiotic use after discharge (RR: 1.61; 95% CI: 0.61-4.23; P = .34), clinical success (RR: 1.02; 95% CI: 0.96-1.08; P = .47), all-cause mortality (RR: 1.05; 95% CI: 0.72-1.55; P = .79), exacerbation at follow-up (RR: 0.97; 95% CI: 0.80-1.18; P = .78), readmission at follow-up (RR: 1.12; 95% CI: 0.82-1.53; P = .49), length of hospital stay (MD: -0.36; 95% CI: -1.36-0.64; P = .48), and adverse events (RR: 1.33; 95% CI: 0.79-2.23; P = .28) were similar in both groups.

IMPLICATIONS OF KEY FINDINGS

A PCT-guided antibiotic strategy is associated with fewer antibiotic prescriptions, and has similar efficacy and safety compared with standard antibiotic therapy in AECOPD patients.

A Novel Animal Model of Emphysema Induced by Anti-Elastin Autoimmunity

Loss of immune tolerance to self-antigens can promote chronic inflammation and disrupt the normal function of multiple organs, including the lungs. Degradation of elastin, a highly insoluble protein and a significant component of the lung structural matrix, generates proinflammatory molecules. Elastin fragments (EFs) have been detected in the serum of smokers with emphysema, and elastin-specific T cells have also been detected in the peripheral blood of smokers with emphysema. However, an animal model that could recapitulate T cell-specific autoimmune responses by initiating and sustaining inflammation in the lungs is lacking. In this study, we report an animal model of autoimmune emphysema mediated by the loss of tolerance to elastin. Mice immunized with a combination of human EFs plus rat EFs but not mouse EFs showed increased infiltration of innate and adaptive immune cells to the lungs and developed emphysema. We cloned and expanded mouse elastin-specific CD4+ T cells from the lung and spleen of immunized mice. Finally, we identified TCR sequences from the autoreactive T cell clones, suggesting possible pathogenic TCRs that can cause loss of immune tolerance against elastin. This new autoimmune model of emphysema provides a useful tool to examine the immunological factors that promote loss of immune tolerance to self.

Airway host-microbiome interactions in chronic obstructive pulmonary disease

Background

Little is known about the interactions between the lung microbiome and host response in chronic obstructive pulmonary disease (COPD).

Methods

We performed a longitudinal 16S ribosomal RNA gene-based microbiome survey on 101 sputum samples from 16 healthy subjects and 43 COPD patients, along with characterization of host sputum transcriptome and proteome in COPD patients.

Results

Dysbiosis of sputum microbiome was observed with significantly increased relative abundance of Moraxella in COPD versus healthy subjects and during COPD exacerbations, and Haemophilus in COPD ex-smokers versus current smokers. Multivariate modeling on sputum microbiome, host transcriptome and proteome profiles revealed that significant associations between Moraxella and Haemophilus, host interferon and pro-inflammatory signaling pathways and neutrophilic inflammation predominated among airway host-microbiome interactions in COPD. While neutrophilia was positively correlated with Haemophilus, interferon signaling was more strongly linked to Moraxella. Moreover, while Haemophilus was significantly associated with host factors both in stable state and during exacerbations, Moraxella-associated host responses were primarily related to exacerbations.

Conclusions

Our study highlights a significant airway host-microbiome interplay associated with COPD inflammation and exacerbations. These findings indicate that Haemophilus and Moraxella influence different components of host immune response in COPD, and that novel therapeutic strategies should consider targeting these bacteria and their associated host pathways in COPD.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1085-z) contains supplementary material, which is available to authorized users.

The rationale, design, and methods of a randomized, controlled trial to evaluate the efficacy and safety of an active strategy for the diagnosis and treatment of acute pulmonary embolism during exacerbations of chronic obstructive pulmonary disease

Introduction

Some previous studies have suggested a high prevalence of pulmonary embolism (PE) during exacerbations of chronic obstructive pulmonary disease (ECOPD). The SLICE trial aims to assess the efficacy and safety of an active strategy for the diagnosis and treatment of PE (vs usual care) in patients hospitalized because of ECOPD.

Methods

SLICE is a phase III, prospective, international, multicenter, randomized, open‐label, and parallel‐group trial. A total of 746 patients hospitalized because of ECOPD will be randomized in a 1:1 fashion to receive either an active strategy for the diagnosis and anticoagulant treatment of PE or usual care (ie, standard care without any diagnostic test for diagnosing PE). The primary outcome is a composite of all‐cause death, non‐fatal (recurrent) venous thromboembolism (VTE), or readmission for ECOPD within 90 days after enrollment. Secondary outcomes are (a) death from any cause within 90 days after enrollment, (b) non‐fatal (recurrent) VTE within 90 days after enrollment, (c) readmission within 90 days after enrollment, and (d) length of hospital stay.

Results

Enrollment started in September 2014 and is expected to proceed until 2020. Median age of the first 443 patients was 71 years (interquartile range, 64‐78), and 26% were female.

Conclusions

This multicenter trial will determine the value of detecting PEs in patients with ECOPD. This has implications for COPD patient morbidity and mortality.

Trial registration number: NCT02238639.

Management of severe acute exacerbations of COPD: an updated narrative review

Background

Patients with chronic obstructive pulmonary disease (COPD) may experience an acute worsening of respiratory symptoms that results in additional therapy; this event is defined as a COPD exacerbation (AECOPD). Hospitalization for AECOPD is accompanied by a rapid decline in health status with a high risk of mortality or other negative outcomes such as need for endotracheal intubation or intensive care unit (ICU) admission. Treatments for AECOPD aim to minimize the negative impact of the current exacerbation and to prevent subsequent events, such as relapse or readmission to hospital.

Main body

In this narrative review, we update the scientific evidence about the in-hospital pharmacological and non-pharmacological treatments used in the management of a severe AECOPD. We review inhaled bronchodilators, steroids, and antibiotics for the pharmacological approach, and oxygen, high flow nasal cannulae (HFNC) oxygen therapy, non-invasive mechanical ventilation (NIMV) and pulmonary rehabilitation (PR) as non-pharmacological treatments. We also review some studies of non-conventional drugs that have been proposed for severe AECOPD.

Conclusion

Several treatments exist for severe AECOPD patients requiring hospitalization. Some treatments such as steroids and NIMV (in patients admitted with a hypercapnic acute respiratory failure and respiratory acidosis) are supported by strong evidence of their efficacy. HFNC oxygen therapy needs further prospective studies. Although antibiotics are preferred in ICU patients, there is a lack of evidence regarding the preferred drugs and optimal duration of treatment for non-ICU patients. Early rehabilitation, if associated with standard treatment of patients, is recommended due to its feasibility and safety. There are currently few promising new drugs or new applications of existing drugs.

Chronic Obstructive Pulmonary Disease Exacerbations: A Need for Action

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality, with exacerbations contributing strongly to the overall severity and burden of disease at the individual level. Many patients with COPD are managed predominantly in the primary care setting; therefore, primary care physicians (PCPs) must be aware of and understand the causes, effects, and management of COPD exacerbations. This review offers practical information about how exacerbations are defined in the treatment setting, pathogenic and environmental causes, options for exacerbation treatment and prevention, and suggestions for improving care in the clinic. Exacerbations have a strong negative effect on patients and are associated with an increased risk of further exacerbations and decreases in lung function. Thus, it is important that exacerbations not requiring hospitalization be identified and confidently managed in the clinical setting. Understanding treatment options for acute exacerbations and maintenance treatment to prevent future exacerbations may help PCPs better understand what they can do to support their patients. This review aims to provide useful guidance for PCPs to identify exacerbations and adjust their practice for optimal management of exacerbations in patients with COPD. It also aims to encourage PCPs that they have an important task in integrating effective COPD management into the primary care setting.

Use of serology and polymerase chain reaction to detect atypical respiratory pathogens during acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND/AIMS

To use serological and multiplex polymerase chain reaction (PCR) assays to examine sputum samples from patients experiencing acute exacerbation of chronic obstructive pulmonary disease (AECOPD) for the presence of atypical pathogens, including Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneumophila.

METHODS

From September 2012 to February 2014, 341 patients with AECOPD attending outpatient clinics were enrolled as part of a randomized, double-blind, multicenter study. A commercial enzyme-linked immunosorbent assay was used to measure serum immunoglobulin M (IgM) and IgG antibody titers on the first day of the study and at 36 days post-enrollment. Multiplex PCR was used to test sputum samples for the presence of atypical pathogens. A urinary antigen test for L. pneumophila was performed on the first day.

RESULTS

Nineteen patients (5.6%) showed serological evidence of acute infection with M. pneumoniae. Also, one and seven patients (2%) showed serological evidence of acute infection with C. pneumoniae and L. pneumophila, respectively. All DNA samples were negative for M. pneumoniae, C. pneumoniae, and L. pneumophila according to PCR. Only one urine sample was positive for L. pneumophila antigen, but serologic evidence was lacking.

CONCLUSION

Serological testing suggested that infection by atypical pathogens during AECOPD was relatively uncommon. In addition, PCR provided no direct evidence of infection by atypical pathogens. Thus, atypical pathogens may not be a major cause of AECOPD in South Korea.

Microorganisms resistant to conventional antimicrobials in acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Antimicrobial treatment for acute exacerbations of chronic obstructive pulmonary disease (AECOPD) remains controversial. In some cases AECOPD are caused by microorganisms that are resistant to treatments recommended by guidelines. Our aims were: 1) identify the risk factors associated with infection by microorganisms resistant to conventional treatment (MRCT), 2) Compare the clinical characteristics and outcomes of patients with AECOPD resulting from MRCT against those with AECOPD from other causes.

METHODS

We prospective analysed a cohort of patients admitted with severe AECOPD (2009 to 2015) who were assigned to three groups: patients with MRCT (those patients with germs resistant to antibiotics recommended in guidelines), patients with microorganisms sensitive to conventional antimicrobial treatment (MSCT), and patients with negative microbiology results who had not previously received antibiotics. Multinomial logistic regression analyses were used to examine the associations between microbial aetiology groups and risk factors. The association between LOS and risk factors was also tested in simple and multiple analyses, and similar inclusion criteria were applied for the linear regression analysis.

RESULTS

Of the 451 patients admitted, 195 patients (43%) were included. Respiratory cultures were positive in 86(44%) and negative in 109(56%). MRCT were isolated in 34 cases (40%) and MSCT in 52 (60%). Patients with MRCT had more AECOPD in the previous year, received more antibiotic treatment in the previous three months, had more severe disease, higher dyspnoea and a positive respiratory culture in the previous year (mainly for Pseudomonas aeruginosa). The following conditions were independent factors for MRCT isolation: non-current smoker (odds ratio [OR] 4.19 [95% confidence interval [CI] 1.29-13.67], p = 0.017), ≥ 2 AECOPD or ≥ 1 admission for AECOPD in the previous year (OR 4.13 [95% CI 1.52-11.17], p = 0.005), C-reactive protein < 5 mg/dL; (OR 3.58 [95% CI 1.41-9.07], p = 0.007). Mortality rates were comparable at 30-days, one year and 3 years; however, patients in the MRCT group had longer hospital stays.

CONCLUSION

In conclusion, there are risk factors for resistant germs in AECOPD; however, the presence of these germs does not increase mortality. Patients with isolation of MRCT had longer length of stay.

Procalcitonin algorithm to guide initial antibiotic therapy in acute exacerbations of COPD admitted to the ICU: a randomized multicenter study

PURPOSE

To compare the efficacy of an antibiotic protocol guided by serum procalcitonin (PCT) with that of standard antibiotic therapy in severe acute exacerbations of COPD (AECOPDs) admitted to the intensive care unit (ICU).

METHODS

We conducted a multicenter, randomized trial in France. Patients experiencing severe AECOPDs were assigned to groups whose antibiotic therapy was guided by (1) a 5-day PCT algorithm with predefined cutoff values for the initiation or stoppage of antibiotics (PCT group) or (2) standard guidelines (control group). The primary endpoint was 3-month mortality. The predefined noninferiority margin was 12%.

RESULTS

A total of 302 patients were randomized into the PCT (n = 151) and control (n = 151) groups. Thirty patients (20%) in the PCT group and 21 patients (14%) in the control group died within 3 months of admission (adjusted difference, 6.6%; 90% CI - 0.3 to 13.5%). Among patients without antibiotic therapy at baseline (n = 119), the use of PCT significantly increased 3-month mortality [19/61 (31%) vs. 7/58 (12%), p = 0.015]. The in-ICU and in-hospital antibiotic exposure durations, were similar between the PCT and control group (5.2 ± 6.5 days in the PCT group vs. 5.4 ± 4.4 days in the control group, p = 0.85 and 7.9 ± 8 days in the PCT group vs. 7.7 ± 5.7 days in the control group, p = 0.75, respectively).

CONCLUSION

The PCT group failed to demonstrate non-inferiority with respect to 3-month mortality and failed to reduce in-ICU and in-hospital antibiotic exposure in AECOPDs admitted to the ICU.

Wnt5A Signaling Promotes Defense Against Bacterial Pathogens by Activating a Host Autophagy Circuit

Bacterial pathogens are associated with severe infections (e.g., sepsis) and exacerbation of debilitating conditions such as chronic obstructive pulmonary disease (COPD). The interactions of bacterial pathogens with macrophages, a key component of innate immunity and host defense, are not clearly understood and continue to be intensively studied. Having previously demonstrated a role of Wnt5A signaling in phagocytosis, we proceeded to decipher the connection of Wnt5A signaling with infection by pathogenic bacteria, namely Pseudomonas aeruginosa (PA) and Streptococcus pneumoniae (SP), which are related with the progression of COPD and sepsis. We found that during the initial hours of infection with PA and SP, there is decrease in the steady state levels of the Wnt5A protein in macrophages. Suppression of Wnt5A signaling, moreover, impairs macrophage clearance of the bacterial infection both in vitro and in vivo. Activation of Wnt5A signaling, on the other hand, enhances clearance of the infection. Macrophage-mediated containment of bacterial infection in our study is dependant on Wnt5A-induced Rac1/Disheveled activation and cytochalasin D inhibitable actin assembly, which is associated with ULK1 kinase activity and LC3BII accumulation. Our experimental findings are consistent with Wnt5A signaling-dependent induction of autophagic killing (xenophagy) of PA and SP, as further substantiated by transmission electron microscopy. Overall, our study unveils the prevalence of a Wnt5A-Rac1-Disheveled-mediated actin-associated autophagy circuit as an important component of innate immunity in host macrophages that may turn out crucial for restricting infection by leading bacterial pathogens.

Dysregulated Functions of Lung Macrophage Populations in COPD

Chronic obstructive pulmonary disease (COPD) is a diverse respiratory disease characterised by bronchiolitis, small airway obstruction, and emphysema. Innate immune cells play a pivotal role in the disease's progression, and in particular, lung macrophages exploit their prevalence and strategic localisation to orchestrate immune responses. To date, alveolar and interstitial resident macrophages as well as blood monocytes have been described in the lungs of patients with COPD contributing to disease pathology by changes in their functional repertoire. In this review, we summarise recent evidence from human studies and work with animal models of COPD with regard to altered functions of each of these myeloid cell populations. We primarily focus on the dysregulated capacity of alveolar macrophages to secrete proinflammatory mediators and proteases, induce oxidative stress, engulf microbes and apoptotic cells, and express surface and intracellular markers in patients with COPD. In addition, we discuss the differences in the responses between alveolar macrophages and interstitial macrophages/monocytes in the disease and propose how the field should advance to better understand the implications of lung macrophage functions in COPD.

Sputum microbiome temporal variability and dysbiosis in chronic obstructive pulmonary disease exacerbations: an analysis of the COPDMAP study

Background

Recent studies suggest that lung microbiome dysbiosis, the disease associated disruption of the lung microbial community, might play a key role in chronic obstructive pulmonary disease (COPD) exacerbations. However, characterising temporal variability of the microbiome from large longitudinal COPD cohorts is needed to better understand this phenomenon.

Methods

We performed a 16S ribosomal RNA survey of microbiome on 716 sputum samples collected longitudinally at baseline and exacerbations from 281 subjects with COPD at three UK clinical centres as part of the COPDMAP consortium.

Results

The microbiome composition was similar among centres and between stable and exacerbations except for a small significant decrease of Veillonella at exacerbations. The abundance of Moraxella was negatively associated with bacterial alpha diversity. Microbiomes were distinct between exacerbations associated with bacteria versus eosinophilic airway inflammation. Dysbiosis at exacerbations, measured as significant within subject deviation of microbial composition relative to baseline, was present in 41% of exacerbations. Dysbiosis was associated with increased exacerbation severity indicated by a greater fall in forced expiratory volume in one second, forced vital capacity and a greater increase in CAT score, particularly in exacerbations with concurrent eosinophilic inflammation. There was a significant difference of temporal variability of microbial alpha and beta diversity among centres. The variation of beta diversity significantly decreased in those subjects with frequent historical exacerbations.

Conclusions

Microbial dysbiosis is a feature of some exacerbations and its presence, especially in concert with eosinophilic inflammation, is associated with more severe exacerbations indicated by a greater fall in lung function.

Trial registration number

Results, NCT01620645.

A Prospective Study of Bacteriological Etiology in Hospitalized Acute Exacerbation of COPD Patients: Relationship with Lung Function and Respiratory Failure

OBJECTIVES

Bacterial infections are the major cause of acute exacerbation of COPD (AE-COPD). The relationship between lung functions and respiratory failure (arterial blood gas parameters) with the etiology of AE-COPD has not been clearly understood. We conducted this study to determine the bacterial profile in AE-COPD and to identify the associated risk factors and drug sensitivity pattern.

MATERIAL AND METHODS

Seventy-two patients hospitalized for AE-COPD were prospectively evaluated. Quantitative sputum culture, blood gas analysis, and drug sensitivity testing were performed at the time of admission, and pulmonary function testing was performed 6 weeks after discharge as per standard guidelines.

RESULTS

Bacterial pathogens were isolated in 34 (47.22%) cases. Pathogens isolated were Pseudomonas aeruginosa (38.23%), Klebsiella pneumoniae (29.41%), Staphylococcus aureus (23.53%), Streptococcus pneumoniae (5.88%), and Acinetobacter spp. (2.94%). Isolation of bacterial pathogen was observed in patients with advancing age (p=0.02), frequent exacerbations (p<0.001), systemic steroid use (p=0.005), and deranged lung function (p=0.02). Binary logistic regression analysis revealed that higher partial pressure of carbon dioxide (PaCO2) was independently associated with isolation of K. pneumoniae (p=0.025) and P. aeruginosa (p=0.001). Additional independent factors that favor isolation of K. pneumoniae were age >55 years (p=0.017) and systemic steroid use (p=0.017). Antibiotic sensitivity testing showed that ciprofloxacin and piperacillin/tazobactum were effective in 27/34 (79.41%) of isolates followed by gentamycin in 26/34 (76%).

CONCLUSION

Hypercapnic respiratory failure is an independent risk factor for isolation of K. pneumoniae and P. aeruginosa in addition to advanced age and systemic steroid use. These findings may be an important adjunct in deciding the initial antibiotic therapy.

The association between serological features of chronic Chlamydia pneumoniae infection and markers of systemic inflammation and nutrition in COPD patients

INTRODUCTION

Chlamydia pneumoniae is an obligatory human pathogen involved in lower and upper airway infections, including pneumonia, bronchitis. Asymptomatic C. pneumoniae carriage is also relatively common. The association of C. pneumoniae infections with the chronic obstructive pulmonary disease (COPD) course is unclear.

OBJECTIVES

The aim of the study was to investigate the association between chronic C. pneumoniae infection and clinical features of COPD, markers of inflammation and metabolic dysfunction.

PATIENTS AND METHODS

The study included 59 patients with stable COPD who had no, or had ≥2 acute exacerbations during last year. The level of IgA and IgG antibody against C. pneumoniae, IL-6, IL-8, resistin, insulin, adiponectin and acyl ghrelin was measured in serum by enzyme-linked immunosorbent assay (ELISA).

RESULTS

No differences in clinical and functional data were observed between COPD patients without serological features of C. pneumoniae infection and chronic C. pneumoniae infection. The level of anti C. pneumoniae IgA significantly correlated with IL-8, IL-6, resistin concentration in group of frequent exacerbators. IgG level correlated negatively with acetyl ghrelin and body mass index (BMI) in patients without frequent exacerbations, in contrast to frequent COPD exacerbation group where significant correlations between IgG level and BMI was demonstrated. Serum IL-6 correlated positively with resistin and insulin and negatively with adiponectin in group of patients with serological features of chronic C. pneumoniae infection only.

CONCLUSIONS

Our study showed that chronic C. pneumoniae infection does not influence the clinical course of COPD in the both study groups. Chronic C. pneumoniae infections might be associated with a distinct COPD phenotype that affects metabolic dysfunction.

Sputum bacteriology and clinical response to antibiotics in moderate exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Presence of purulent sputum during an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is considered sufficient indication for starting empirical antibiotics. We investigated the relationship between detection of potentially pathogenic bacteria (PPB) using sputum culture or polymerase chain reaction (PCR) and clinical response and sought the risk factors for PPB growth.

METHODS

In 342 outpatients with AECOPD, we compared detection rates of H. influenzae (HI) and S. pneumoniae (SP) using conventional sputum culture versus PCR. The utility of either technique to predict clinical cure or failure after effective antibiotics was assessed. The factors predicting positive sputum cultures were evaluated using logistic regression.

RESULTS

Using sputum culture, 132 PPB were detected. The predominant bacteria were HI (40.9%) and SP (19.7%). Detection of HI or SP in sputum was higher using PCR than culture growth (60.8% vs 18.6%; P < .001). Clinical response was not affected by the results of either technique. Independent risk factors for PPB isolation were Gram-negative bacteria on sputum smear (OR 15.78, 95% CI 6.38-39.06; P < .001), sputum purulence (OR 2.31, 95% CI, 1.05-5.11; P = .04), body temperature (OR 0.16, 95% CI 0.05-0.54; P = .003), albumin level (OR 0.29, 95% CI 0.09-0.88; P = .03) and dyspnea grade (OR 0.51, 95% CI 0.27-0.96; P = .04).

CONCLUSIONS

Neither culture growth nor PCR positivity for HI or SP in sputum predicted clinical response to antibiotics; therefore, these tests are not necessary for outpatients with AECOPD. Examining Gram-staining and purulence on sputum smear, however, was significant to predict PPB growth in sputum.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report. GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 report focuses primarily on the revised and novel parts of the document. The most significant changes include: (1) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; (2) for each of the groups A to D, escalation strategies for pharmacologic treatments are proposed; (3) the concept of deescalation of therapy is introduced in the treatment assessment scheme; (4) nonpharmacologic therapies are comprehensively presented; and (5) the importance of comorbid conditions in managing chronic obstructive pulmonary disease is reviewed.

Nontypeable Haemophilus influenzae and chronic obstructive pulmonary disease: a review for clinicians

Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of morbidity and mortality worldwide. In the lower airways of COPD patients, bacterial infection is a common phenomenon and Haemophilus influenzae is the most commonly identified bacteria. Haemophilus influenzae is divided into typeable and nontypeable (NTHi) strains based on the presence or absence of a polysaccharide capsule. While NTHi is a common commensal in the human nasopharynx, it is associated with considerable inflammation when it is present in the lower airways of COPD patients, resulting in morbidity due to worsening symptoms and increased frequency of COPD exacerbations. Treatment of lower airway NTHi infection with antibiotics, though successful in the short term, does not offer long-term protection against reinfection, nor does it change the course of the disease. Hence, there has been much interest in the development of an effective NTHi vaccine. This review will summarize the current literature concerning the role of NTHi infections in COPD patients and the consequences of using prophylactic antibiotics in patients with COPD. There is particular focus on the rationale, findings of clinical studies and possible future directions of NTHi vaccines in patients with COPD.

Global Strategy for the Diagnosis, Management and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: (i) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; (ii) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; (iii) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; (iv)non-pharmacological therapies are comprehensively presented and (v) the importance of co-morbid conditions in managing COPD is reviewed.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: 1) the assessment of COPD has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; 2) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; 3) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; 4) nonpharmacologic therapies are comprehensively presented and; 5) the importance of comorbid conditions in managing COPD is reviewed.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: 1) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; 2) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; 3) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; 4) nonpharmacologic therapies are comprehensively presented and; 5) the importance of comorbid conditions in managing COPD is reviewed.

Diagnostic and Prognostic Value of Inflammatory Parameters Including Neopterin in the Setting of Pneumonia, COPD, and Acute Exacerbations

Acute exacerbations and community-acquired pneumonia (CAP) are severe complications in patients with chronic obstructive pulmonary disease (COPD). In this study, we analyzed inflammatory parameters in serum including C-reactive protein (CRP), procalcitonin (PCT), and serum neopterin (NPT) to determine their potential to differentiate between patients with CAP+COPD and with acute exacerbations of COPD (AECOPD) without pneumonia. 102 (39 women and 63 men) patients were included in this retrospective study, of whom 48 presented with CAP without underlying COPD, 20 with CAP+COPD and 34 with AECOPD. CRP, PCT, and blood counts were determined by routine automated tests, and NPT concentrations were determined by ELISA. The ratios of CRP to NPT levels were calculated. Upon patient admission, CRP, PCT, and NPT levels were significantly higher in patients with CAP compared to those in AECOPD patients. CRP/NPT ratio was lower in AECOPD compared to CAP (+/-COPD) patients. Positive correlations were found between duration of hospitalization and CRP levels and the CRP/NPT ratio at study entry. Patients who were readmitted within 30 days tended to have higher NPT levels at initial presentation. Patients under ongoing corticosteroid treatment presented with lower inflammatory parameters. The CRP/NPT-ratio was suited well to discriminate between AECOPD and CAP on the basis of COPD, a CRP/NPT cutoff of 0.346 provided a sensitivity of 65% and a specificity of 79%. The combinatory use of inflammatory patterns might help to differentiate patients with AECOPD from those with CAP on the basis of COPD.