Long-Term Erythromycin Treatment Alters the Airway and Gut Microbiota: Data from Chronic Obstructive Pulmonary Disease Patients and Mice with Emphysema

INTRODUCTION

Although long-term macrolide antibiotics could reduce the recurrent exacerbation of chronic obstructive pulmonary disease (COPD), the side effect of bacterial resistance and the impact on the microbiota remain concerning. We investigated the influence of long-term erythromycin treatment on the airway and gut microbiota in mice with emphysema and patients with COPD.

METHODS

We conducted 16S rRNA gene sequencing to explore the effect of erythromycin treatment on the lung and gut microbiota in mice with emphysema. Liquid chromatography-mass spectrometry was used for lung metabolomics. A randomized controlled trial was performed to investigate the effect of 48-week erythromycin treatment on the airway and gut microbiota in COPD patients.

RESULTS

The mouse lung and gut microbiota were disrupted after cigarette smoke exposure. Erythromycin treatment depleted harmful bacteria and altered lung metabolism. Erythromycin treatment did not alter airway or gut microbial diversity in COPD patients. It reduced the abundance of pathogens, such as Burkholderia, in the airway of COPD patients and increased levels of symbiotic bacteria, such as Prevotella and Veillonella. The proportions of Blautia, Ruminococcus, and Lachnospiraceae in the gut were increased in COPD patients after erythromycin treatment. The time to the first exacerbation following treatment was significantly longer in the erythromycin treatment group than in the COPD group.

CONCLUSION

Long-term erythromycin treatment reduces airway and gut microbe abundance in COPD patients but does not affect microbial diversity and restores microbiota balance in COPD patients by reducing the abundance of pathogenic bacteria.

WHO's essential medicines and AWaRe: recommendations on first- and second-choice antibiotics for empiric treatment of clinical infections

The WHO Model List of Essential Medicines (EML) prioritizes medicines that have significant global public health value. The EML can also deliver important messages on appropriate medicine use. Since 2017, in response to the growing challenge of antimicrobial resistance, antibiotics on the EML have been reviewed and categorized into three groups: Access, Watch, and Reserve, leading to a new categorization called AWaRe. These categories were developed taking into account the impact of different antibiotics and classes on antimicrobial resistance and the implications for their appropriate use. The 2023 AWaRe classification provides empirical guidance on 41 essential antibiotics for over 30 clinical infections targeting both the primary health care and hospital facility setting. A further 257 antibiotics not included on the EML have been allocated an AWaRe group for stewardship and monitoring purposes. This article describes the development of AWaRe, focussing on the clinical evidence base that guided the selection of Access, Watch, or Reserve antibiotics as first and second choices for each infection. The overarching objective was to offer a tool for optimizing the quality of global antibiotic prescribing and reduce inappropriate use by encouraging the use of Access antibiotics (or no antibiotics) where appropriate. This clinical evidence evaluation and subsequent EML recommendations are the basis for the AWaRe antibiotic book and related smartphone applications. By providing guidance on antibiotic prioritization, AWaRe aims to facilitate the revision of national lists of essential medicines, update national prescribing guidelines, and supervise antibiotic use. Adherence to AWaRe would extend the effectiveness of current antibiotics while helping countries expand access to these life-saving medicines for the benefit of current and future patients, health professionals, and the environment.

The Role of Non-Typeable Haemophilus influenzae Biofilms in Chronic Obstructive Pulmonary Disease

Non-typeable Haemophilus influenzae (NTHi) is an ubiquitous commensal-turned-pathogen that colonises the respiratory mucosa in airways diseases including Chronic Obstructive Pulmonary Disease (COPD). COPD is a progressive inflammatory syndrome of the lungs, encompassing chronic bronchitis that is characterised by mucus hypersecretion and impaired mucociliary clearance and creates a static, protective, humid, and nutrient-rich environment, with dysregulated mucosal immunity; a favourable environment for NTHi colonisation. Several recent large COPD cohort studies have reported NTHi as a significant and recurrent aetiological pathogen in acute exacerbations of COPD. NTHi proliferation has been associated with increased hospitalisation, disease severity, morbidity and significant lung microbiome shifts. However, some cohorts with patients at different severities of COPD do not report that NTHi is a significant aetiological pathogen in their COPD patients, indicating other obligate pathogens including Moraxella catarrhalis, Streptococcus pneumoniae and Pseudomonas aeruginosa as the cause. NTHi is an ubiquitous organism across healthy non-smokers, healthy smokers and COPD patients from childhood to adulthood, but it currently remains unclear why NTHi becomes pathogenic in only some cohorts of COPD patients, and what behaviours, interactions and adaptations are driving this susceptibility. There is emerging evidence that biofilm-phase NTHi may play a significant role in COPD. NTHi displays many hallmarks of the biofilm lifestyle and expresses key biofilm formation-promoting genes. These include the autoinducer-mediated quorum sensing system, epithelial- and mucus-binding adhesins and expression of a protective, self-produced polymeric substance matrix. These NTHi biofilms exhibit extreme tolerance to antimicrobial treatments and the immune system as well as expressing synergistic interspecific interactions with other lung pathogens including S. pneumoniae and M. catarrhalis. Whilst the majority of our understanding surrounding NTHi as a biofilm arises from otitis media or in-vitro bacterial monoculture models, the role of NTHi biofilms in the COPD lung is now being studied. This review explores the evidence for the existence of NTHi biofilms and their impact in the COPD lung. Understanding the nature of chronic and recurrent NTHi infections in acute exacerbations of COPD could have important implications for clinical treatment and identification of novel bactericidal targets.

Long-term macrolide therapy for chronic obstructive pulmonary disease: a population-based time series analysis

BACKGROUND

Macrolides are recommended as an adjunctive treatment for patients with moderate to severe chronic obstructive pulmonary disease (COPD) who experience recurrent exacerbations. The objective of this study was to examine temporal trends in the provision of long-term macrolide therapy, specifically before and after publication of the landmark MACRO trial in August 2011 showing efficacy of macrolides for this indication.

METHODS

We performed an interrupted time series analysis using population-level health administrative data. The study cohort consisted of all Ontario residents who had COPD, were using at least 1 long-acting inhaler, and were aged 65 years and older between Apr. 1, 2004, and Mar. 31, 2018. We compared the baseline characteristics of eligible patients before and after publication of the MACRO trial. Our primary outcome was overall prevalence of long-term macrolide therapy; secondary outcomes were incidence of COPD-related hospitalizations, emergency department visits and outpatient exacerbations requiring high-dose steroids in each quarter. We performed an interrupted time series analysis to assess for changes in the incidence of macrolide prophylaxis by quarter-year over the study period.

RESULTS

The rate of long-term macrolide use increased from 0.8 per 1000 people in 2004 to 13.8 per 1000 people in 2018 (in the severe COPD group, the rate increased from 1.3 to 32.3 per 1000 people). The interrupted time series analysis showed that, before 2011, the prevalence of macrolide prophylaxis increased at a rate of 0.44 (95% confidence interval [CI] 0.39-0.50) per 1000 people per year; after 2011, the rate of increase grew by 1.18 (95% CI 1.07-1.29) per 1000 people to 1.63 (95% CI 1.56-1.69) per 1000 people per year. The seasonal pattern of COPD-related health care visits remained stable over the study period, and there was no detectable reduction in hospitalizations or emergency department visits at the population level.

INTERPRETATION

In the past decade, there has been a significant rise in the use of long-term macrolide therapy for patients with COPD. As this practice becomes increasingly common, it will be important to monitor its potential benefits on COPD exacerbations but also its potential effects on adverse events and antimicrobial resistance patterns.

Prophylactic antibiotics for adults with chronic obstructive pulmonary disease: a network meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory condition characterised by persistent respiratory symptoms and airflow limitation. Acute exacerbations punctuate the natural history of COPD and are associated with increased morbidity and mortality and disease progression. Chronic airflow limitation is caused by a combination of small airways (bronchitis) and parenchymal destruction (emphysema), which can impact day-to-day activities and overall quality of life. In carefully selected patients with COPD, long-term, prophylactic use of antibiotics may reduce bacterial load, inflammation of the airways, and the frequency of exacerbations.

OBJECTIVES

To assess effects of different prophylactic antibiotics on exacerbations, quality of life, and serious adverse events in people with COPD in three separate network meta-analyses (NMAs), and to provide rankings of identified antibiotics.

SEARCH METHODS

To identify eligible randomised controlled trials (RCTs), we searched the Cochrane Airways Group Specialised Register of trials and clinical trials registries. We conducted the most recent search on 22 January 2020.

SELECTION CRITERIA

We included RCTs with a parallel design of at least 12 weeks' duration evaluating long-term administration of antibiotics prophylactically compared with other antibiotics, or placebo, for patients with COPD.

DATA COLLECTION AND ANALYSIS

This Cochrane Review collected and updated pair-wise data from two previous Cochrane Reviews. Searches were updated and additional studies included. We conducted three separate network meta-analyses (NMAs) within a Bayesian framework to assess three outcomes: exacerbations, quality of life, and serious adverse events. For quality of life, we collected data from St George's Respiratory Questionnaire (SGRQ). Using previously validated methods, we selected the simplest model that could adequately fit the data for every analysis. We used threshold analysis to indicate which results were robust to potential biases, taking into account each study's contributions to the overall results and network structure. Probability ranking was performed for each antibiotic class for exacerbations, quality of life, and serious adverse events.

MAIN RESULTS

Characteristics of studies and participants Eight trials were conducted at multiple sites that included hospital clinics or academic health centres. Seven were single-centre trials conducted in hospital clinics. Two trials did not report settings. Trials durations ranged from 12 to 52 weeks. Most participants had moderate to severe disease. Mean age ranged from 64 years to 73 years, and more males were recruited (51% to 100%). Forced expiratory volume in one second (FEV₁) ranged from 0.935 to 1.36 L. Most participants had previous exacerbations. Data from 12 studies were included in the NMAs (3405 participants; 16 treatment arms including placebo). Prophylactic antibiotics evaluated were macrolides (azithromycin and erythromycin), tetracyclines (doxycyclines), quinolones (moxifloxacin) and macrolides plus tetracyclines (roxithromycin plus doxycycline). Risk of bias and threshold analysis Most studies were at low risk across domains, except detection bias, for which only seven studies were judged at low risk. In the threshold analysis for exacerbations, all comparisons in which one antibiotic was compared with another were robust to sampling variation, especially macrolide comparisons. Comparisons of classes with placebo were sensitive to potential bias, especially macrolide versus placebo, therefore, any bias in the comparison was likely to favour the active class, so any adjustment would bring the estimated relative effect closer to the null value, thus quinolone may become the best class to prevent exacerbations. Exacerbations Nine studies were included (2732 participants) in this NMA (exacerbations analysed as time to first exacerbation or people with one or more exacerbations). Macrolides and quinolones reduced exacerbations. Macrolides had a greater effect in reducing exacerbations compared with placebo (macrolides: hazard ratio (HR) 0.67, 95% credible interval (CrI) 0.60 to 0.75; quinolones: HR 0.89, 95% CrI 0.75 to 1.04), resulting in 127 fewer people per 1000 experiencing exacerbations on macrolides. The difference in exacerbations between tetracyclines and placebo was uncertain (HR 1.29, 95% CrI 0.66 to 2.41). Macrolides ranked first (95% CrI first to second), with quinolones ranked second (95% CrI second to third). Tetracyclines ranked fourth, which was lower than placebo (ranked third). Contributing studies were considered as low risk of bias in a threshold analysis. Quality of life (SGRQ) Seven studies were included (2237 participants) in this NMA. SGRQ scores improved with macrolide treatment compared with placebo (fixed effect-fixed class effect: mean difference (MD) -2.30, 95% CrI -3.61 to -0.99), but the mean difference did not reach the minimally clinical important difference (MCID) of 4 points. Tetracyclines and quinolones did not improve quality of life any more than placebo, and we did not detect a difference between antibiotic classes. Serious adverse events Nine studies were included (3180 participants) in the NMA. Macrolides reduced the odds of a serious adverse event compared with placebo (fixed effect-fixed class effect: odds ratio (OR) 0.76, 95% CrI 0.62 to 0.93). There was probably little to no difference in the effect of quinolone compared with placebo or tetracycline plus macrolide compared with placebo. There was probably little to no difference in serious adverse events between quinolones or tetracycline plus macrolide. With macrolide treatment 49 fewer people per 1000 experienced a serious adverse event compared with those given placebo. Macrolides ranked first, followed by quinolones. Tetracycline did not rank better than placebo. Drug resistance Ten studies reported drug resistance. Results were not combined due to variation in outcome measures. All studies concluded that prophylactic antibiotic administration was associated with the development of antimicrobial resistance.

AUTHORS' CONCLUSIONS

This NMA evaluated the safety and efficacy of different antibiotics used prophylactically for COPD patients. Compared to placebo, prolonged administration of macrolides (ranked first) appeared beneficial in prolonging the time to next exacerbation, improving quality of life, and reducing serious adverse events. No clear benefits were associated with use of quinolones or tetracyclines. In addition, antibiotic resistance was a concern and could not be thoroughly assessed in this review. Given the trade-off between effectiveness, safety, and risk of antibiotic resistance, prophylactic administration of antibiotics may be best reserved for selected patients, such as those experiencing frequent exacerbations. However, none of the eligible studies excluded patients with previously isolated non-tuberculous mycobacteria, which would contraindicate prophylactic administration of antibiotics, due to the risk of developing resistant non-tuberculous mycobacteria.

Expert recommendations on the role of macrolides in chronic respiratory diseases

Background:

India contributes to 32% of the total global disability-adjusted life years, due to chronic respiratory diseases. This has led to a high rate of health loss from these diseases. Antibiotics are commonly used in the management of respiratory disorders. With excellent tissue penetration, prolonged tissue persistence, and favorable side effect profile, macrolides are one of the best treatment options being recommended for respiratory, urogenital, dermal, and other bacterial infections. Still, there is a lack of clinical trial data on the use of macrolides in the management of respiratory chronic disease, and hence, there is a need for clinical guidance on their use in Indian setting.

Methods:

A systematic review of the literature was conducted on PubMed, Cochrane database, and Google Scholar. Existing guidelines, meta-analyses, systematic reviews, randomized controlled trials (RCTs), non-RCTs, landmark studies, and key-cited articles were selected. Recommendations were based on available evidence and expert panel's logical empiricism and consensus.

Results and Discussion:

This article discusses evidence-based and clinical practice based management of chronic respiratory conditions including chronic obstructive pulmonary disease, asthma, bronchiectasis, diffusive panbronchiolitis, and organizing pneumonia. The authors reviewed different respiratory conditions, role of macrolides in their management, adverse events and antimicrobial resistance associated with macrolides, evidence review of various clinical trials, guideline recommendations, and clinical recommendations.

The pharmacological management of asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS)

Introduction: Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is a disease phenotype that shares T helper lymphocyte cell Th1/neutrophilic/non-Type-2 Inflammation pathways thought to be key in COPD and Th2/eosinophilic/Type-2 inflammatory pathways of asthma. The pharmacology of treating ACOS is challenging in severe circumstances.Areas covered: This review evaluates the stepwise treatment of ACOS using pharmacological treatments used in both COPD and asthma. The most common medications involve the same inhalers used to treat COPD and asthma patients. Advanced stepwise therapies for ACOS patients are based on patient characteristics and biomarkers. Very few clinical trials exist that focus specifically on ACOS patients.Expert opinion: After inhalers, advanced therapies including phosphodiesterase inhibitors, macrolides, N-acetylcysteine and statin therapy for those ACOS patients with a COPD appearance and exacerbations are available. In atopic ACOS patients with exacerbations, advanced asthma therapies (leukotriene receptor antagonists and synthesis blocking agents.) are used. ACOS patients with elevated blood eosinophil/IgE levels are considered for immunotherapy or therapeutic monoclonal antibodies blocking specific Th2/Type-2 interleukins or IgE. Symptom control, stabilization/improvement in pulmonary function and reduced exacerbations are the metrics of success. More pharmacological trials of ACOS patients are needed to better understand which patients benefit from specific treatments.Abbreviations: 5-LOi: 5-lipoxygenase inhibitor; ACOS: asthma - COPD overlap syndrome; B₂AR: Beta₂ adrenergic receptors; cAMP: cyclic adenosine monophosphate; cGMP: cyclic guanosine monophosphate; CI: confidence interval; COPD: chronic obstructive pulmonary disease; CRS : chronic rhinosinusitis; cys-LT: cysteinyl leukotrienes; DPI: dry powder inhaler; EMA: European Medicines Agency; FDA: US Food and Drug Administration; FDC: fixed-dose combination; FeNO: exhaled nitric oxide; FEV₁: forced expiratory volume in one second; FVC: forced vital capacity; GM-CSF: granulocyte-macrophage colony-stimulating factor; ICS : inhaled corticosteroids; IL: interleukin; ILC2: Type 2 innate lymphoid cells; IP₃: Inositol triphosphate; IRR: incidence rate ratio; KOLD: Korean Obstructive Lung Disease; LABA: long-acting B₂ adrenergic receptor agonist; LAMA: long-acting muscarinic receptor antagonist; LRA: leukotriene receptor antagonist; LT: leukotrienes; MDI: metered-dose inhalers; M_N: M-subtype muscarinic receptors; MRA: muscarinic receptor antagonist; NAC: N-acetylcysteine; NEB: nebulization; OR: odds ratio; PDE: phosphodiesterase; PEFR: peak expiratory flow rate; PGD2: prostaglandin D2; PRN: as needed; RR: risk ratio; SABA: short-acting B₂ adrenergic receptor agonist; SAMA: short-acting muscarinic receptor antagonist; SDMI: spring-driven mist inhaler; Th1: T helper cell 1 lymphocyte; Th2: T helper cell 2 lymphocytes; TNF-α: tumor necrosis factor alpha; US : United States.

Management of bronchiectasis in adults

Once neglected in research and underappreciated in practice, there is renewed interest in bronchiectasis unrelated to cystic fibrosis. Bronchiectasis is a chronic lung disease characterised by chronic cough, sputum production and recurrent pulmonary exacerbations. It is diagnosed radiologically on high resolution computed tomography chest scan by bronchial dilatation (wider than the accompanying artery). The causes of bronchiectasis are diverse and include previous respiratory tract infections, chronic obstructive pulmonary disease, asthma, immunodeficiency and connective tissue diseases. A large proportion of cases are idiopathic, reflecting our incomplete understanding of disease pathogenesis. Progress in the evidence base is reflected in the 2017 European management guidelines and the 2015 update to the Australian guidelines. Effective airway clearance remains the cornerstone of bronchiectasis management. This should be personalised and reviewed regularly by a respiratory physiotherapist. There is now robust evidence for the long term use of oral macrolide antibiotics in selected patients to reduce exacerbation frequency. The routine use of long term inhaled corticosteroids and/or long-acting bronchodilators should be avoided, unless concomitant chronic obstructive pulmonary disease or asthma exists. The evidence for nebulised agents including hypertonic saline, mannitol and antibiotics is evolving; however, access is challenging outside tertiary clinics, and nebulising equipment is required. Smokers should be supported to quit. All patients should receive influenza and pneumococcal vaccination. Patients with impaired exercise capacity should attend pulmonary rehabilitation. There is an important minority of patients for whom aetiology-specific treatment exists. The prevalence of bronchiectasis is increasing worldwide; however, the burden of disease within Australia is not well defined. To this end, the Australian Bronchiectasis Registry began recruitment in 2016 and is interoperable with the European and United States bronchiectasis registries to enable collaborative research. The recent addition of a bronchiectasis diagnosis-related group to the Australian Refined Diagnostic Related Group classification system will allow definition of the disease burden within the Australian hospital system.

Head-to-head oral prophylactic antibiotic therapy for chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD; including chronic bronchitis and emphysema) is a chronic respiratory condition characterised by shortness of breath, cough and recurrent exacerbations. Long-term antibiotic use may reduce both bacterial load and inflammation in the airways. Studies have shown a reduction of exacerbations with antibiotics in comparison to placebo in people with COPD, but there are concerns about antibiotic resistance and safety.

OBJECTIVES

To compare the safety and efficacy of different classes of antibiotics (continuous, intermittent or pulsed) for prophylaxis of exacerbations in patients with COPD.

SEARCH METHODS

We searched the Cochrane Airways Group Trials Register and bibliographies of relevant studies. The latest literature search was conducted on 6 February 2019.

SELECTION CRITERIA

Randomised controlled trials (RCTs) were selected that compared one prophylactic antibiotic with another in patients with COPD.

DATA COLLECTION AND ANALYSIS

We used the standard Cochrane methods. Two independent review authors selected trials for inclusion, extracted data and assessed risk of bias. Discrepancies were resolved by involving a third review author.

MAIN RESULTS

We included two RCTs, both published in 2015 involving a total of 391 participants with treatment duration of 12 to 13 weeks. One RCT compared a quinolone (moxifloxacin pulsed, for 5 days every 4 weeks), with a tetracycline (doxycycline continuous) or a macrolide (azithromycin intermittent).The second RCT compared a tetracycline (doxycycline continuous) plus a macrolide (roxithromycin continuous), with roxithromycin (continuous) alone.The trials recruited participants with a mean age of 68 years, with moderate-severity COPD. Both trials included participants who had between two and five exacerbations in the previous one to two years. In one trial, 17% of patients had previously been using inhaled corticosteroids. In the other study, all patients were positive for Chlamydophila pneumoniae (C pneumoniae).Overall, we judged the evidence presented to be of very low-certainty, mainly due to imprecision, but we also had concerns about indirectness and methodological quality of the included studies. The primary outcome measures for this review included exacerbations, quality of life, drug resistance and serious adverse events.Macrolide + tetracycline versus macrolide There was no clear difference between treatments in improvement in quality of life as assessed by the Chronic Respiratory Questionnaire (CRQ). The CRQ scale ranges from 0 to 10 and higher scores on the scale indicate better quality of life. CRQ sub-scales for dyspnoea (mean difference (MD) 0.58, 95% confidence interval (CI) -0.84 to 2.00; 187 participants; very low-certainty evidence), fatigue (MD 0.02, 95% CI -1.08 to 1.12; 187 participants; very low-certainty evidence), emotional function (MD -0.37, 95% CI -1.74 to 1.00; 187 participants; very low-certainty evidence), or mastery (MD -0.79, 95% CI -1.86 to 0.28; 187 participants; very low-certainty evidence) at 12 weeks. For serious adverse events, it was uncertain if there was a difference between combined roxithromycin and doxycycline versus roxithromycin alone at 48 weeks follow-up after active treatment of 12 weeks (odds ratio (OR) 1.00, 95% CI 0.52 to 1.93; 198 participants; very low-certainty evidence). There were five deaths reported in the combined treatment arm, versus three in the single treatment arm at 48 weeks follow-up after active treatment of 12 weeks (OR 1.63, 95% CI 0.38 to 7.02; 198 participants; very low-certainty evidence).Quinolone versus tetracycline There was no clear difference between moxifloxacin and doxycycline for the number of participants experiencing one or more exacerbations (OR 0.44, 95% CI 0.14 to 1.38; 50 participants, very low-certainty evidence) at 13 weeks. There were no serious adverse events or deaths reported in either treatment groups. We did not identify any evidence for our other primary outcomes.Quinolone versus macrolide There was no clear difference between moxifloxacin and azithromycin for the number of participants experiencing one or more exacerbations (OR 1.00, 95% CI 0.32 to 3.10; 50 participants; very low-certainty evidence) at 13 weeks. There were no serious adverse events or deaths reported in either treatment groups. We did not identify any evidence for our other primary outcomes.Marcolide versus tetracycline There was no clear difference between azithromycin and doxycycline for the number of participants experiencing one or more exacerbations (OR 0.44, 95% CI 0.14 to 1.38; 50 participants; very low-certainty evidence) at 13 weeks. There were no serious adverse events or deaths reported in either treatment groups. We did not identify any evidence for our other primary outcomes.We did not find head-to-head evidence for impact of antibiotics on drug resistance.

AUTHORS' CONCLUSIONS

It is not clear from the evidence included in this review whether there is a difference in efficacy or safety between different classes or regimens of prophylactic antibiotic, given for 12 to 13 weeks to people with COPD. Whilst no head-to-head comparisons of antibiotic resistance were identified, concerns about this continue. The sample size in this review is small and both included studies are of short duration. Thus, there is considerable uncertainty in effects observed and the effects of different prophylactic antibiotics requires further research.

Meta-analysis of macrolide maintenance therapy for prevention of disease exacerbations in patients with noncystic fibrosis bronchiectasis

BACKGROUND

Macrolide maintenance treatment remains controversial for patients with noncystic fibrosis (non-CF) bronchiectasis, we performed a meta-analysis to estimate the benefits and safety of macrolides therapy in adults and children with non-CF bronchiectasis.

METHODS

PubMed, Embase, the Cochrane Library, and Web of Science databases were searched for all the randomized controlled trials of macrolides for treating non-CF bronchiectasis. The primary outcome was improvement of bronchiectasis exacerbations. Secondary outcomes included adverse events and macrolide resistance.

RESULTS

A total of 10 studies involving 602 patients were included in the analysis. Pooled results showed that macrolide therapy significantly reduced the number of patients who suffered from exacerbations (RR = 1.56, 95% CI = 1.14-2.14, P = .006, I = 72%), number of patients who experienced at least 3 exacerbations (RR = 0.55, 95% CI = 0.39-0.77, P = .0005, I = 40%), average exacerbations per patient during the observation time (SMD = -0.69, 95% CI = -1.06 to -0.32, P = .0002, I = 60%), and bronchiectasis exacerbation-related admissions (RR = 0.46, 95% CI = 0.23-0.96, P = .04, I = 0%). Specified subgroup analyses of the number of patients free from exacerbations were further performed; macrolide therapy showed a significant benefit in both children (RR 5.03, 95% CI 2.02-12.50, P = .0005, I = 45%) and adults (RR = 1.66, 95% CI = 1.37-2.02, P < .00001, I = 79%); azithromycin showed a significant reduction on the number of patients who suffered from exacerbations (RR = 2.25, 95% CI = 1.67-3.02, P < .00001, I = 0%), was different from erythromycin (RR = 1.33, 95% CI = 0.92-1.94, P = .13, I = 0%) and roxithromycin (RR = 1.14, 95% CI = 0.97-1.35, P = .11, I = 0%). The pooled results also showed no higher risk of adverse events (RR = 0.98, 95% CI = 0.85-1.13, P = .80, I = 8%), even a lower risk of severe adverse events (RR = 0.53, 95% CI = 0.33-0.85, P = .009, I = 0%). However, a higher risk of macrolide resistance (RR = 3.59, 95% CI 2.6-4.96, P < .00001, I = 0%) was observed.

CONCLUSION

For both children and adults with non-CF bronchiectasis, macrolide maintenance therapy can effectively reduce bronchiectasis exacerbations, especially for patients with more frequent exacerbations and needing hospital treatment. Azithromycin was more effective than other macrolides. Macrolide maintenance therapy did not increase the risk of adverse events, but may increase the risk of macrolide resistance.

Long-term macrolide treatment for the prevention of acute exacerbations in COPD: a systematic review and meta-analysis

Background

Acute exacerbation of COPD (AECOPD) is associated with an increased hospitalization and mortality. Azithromycin and erythromycin are the recommended drugs to reduce the risk of exacerbations. However, the most suitable duration of therapy and drug-related adverse events are still a matter of debate. The aim of this meta-analysis was to assess the current evidence regarding the efficacy and safety of long-term macrolide treatment for COPD.

Materials and methods

We comprehensively searched PubMed, Embase, the Cochrane Library, and the Web of Science and performed a systematic review and cumulative meta-analysis of all randomized controlled trials (RCTs) and retrospective studies.

Results

Eleven RCTs and one retrospective study including a total of 2,151 cases were carried out. Long-term macrolide treatment significantly reduced the total number of cases with one or more exacerbations (OR=0.40; 95% CI=0.24–0.65; P<0.01) and the rate of exacerbations per patient per year (risk ratio [RR]=0.60; 95% CI=0.45–0.78; P<0.01). Subgroup analyses showed that the minimum duration for drug efficacy for both azithromycin and erythromycin therapy was 6 months. In addition, macrolide therapy could improve the St George Respiratory Questionnaire (SGRQ) total score (P<0.01) but did not achieve the level of clinical significance. The frequency of hospitalizations was not significantly different between the treatment and control groups (P=0.50). Moreover, chronic azithromycin treatment was more likely to increase adverse events (P<0.01).

Conclusion

Prophylactic azithromycin or erythromycin treatment has a significant effect in reducing the frequency of AECOPD in a time-dependent manner. However, long-term macrolide treatment could increase the occurrence of adverse events and macrolide resistance. Future large-scale, well-designed RCTs with extensive follow-up are required to identify patients in whom the benefits outweigh risks.

A 12-week combination of clarithromycin and prednisone compared to a 24-week prednisone alone treatment in cryptogenic and radiation-induced organizing pneumonia

Background: Some data suggest that anti-inflammatory macrolides may be effective to treat organizing pneumonia (OP) and prevent relapses, but no formal comparison with prednisone alone is available. To explore this issue, we retrospectively compared the efficacy of a 12-week combined regimen of clarithromycin and prednisone with a 24-week prednisone alone regimen in OP. Methods: A standard 12-week regimen of combined clarithromycin and prednisone was designed for the treatment of cryptogenic or radiation-induced OP, aiming at reducing the cumulated prednisone dose and the relapse rate. Its use was left to the discretion of the treating physicians, members of the Groupe d'Etudes et de Recherche sur les Maladies Orphelines Pulmonaires. Data were compared to a historical control group treated with a standard 24-week prednisone alone regimen. Results: 16 patients were treated with combined therapy and 21 with prednisone alone. Complete radiological remission was achieved in 63% of the combined therapy group and 81% of the prednisone alone group (p=0.38). Symptomatic relapses occurred in 81% of the combined therapy group, and 52% of the prednisone alone group (p=0.14). No side effect of clarithromycin was reported. Conclusions: In patients with cryptogenic or radiation-induced OP, a 12-week regimen of clarithromycin and prednisone showed no benefit on remission rate and relapse rate as compared to a 24-week prednisone only regimen. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 230-238).

The Immunomodulatory Effects of Macrolides-A Systematic Review of the Underlying Mechanisms

Background

The mechanisms underlying the non-antimicrobial immunomodulatory properties of macrolides are not well understood.

Objectives

To systematically review the evidence for the immunomodulatory properties of macrolides in humans and to describe the underlying mechanism and extent of their influence on the innate and adaptive immune system.

Methods

A systematic literature search was done in MEDLINE using the OVID interface from 1946 to December 2016 according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA). Original articles investigating the influence of four macrolides (azithromycin, clarithromycin, erythromycin, and roxithromycin) on immunological markers in humans were included.

Results

We identified 22 randomized, controlled trials, 16 prospective cohort studies, and 8 case–control studies investigating 47 different immunological markers (186 measurements) in 1,834 participants. The most frequently reported outcomes were a decrease in the number of neutrophils, and the concentrations of neutrophil elastase, interleukin (IL)-8, IL-6, IL-1beta, tumor necrosis factor (TNF)-alpha, eosinophilic cationic protein, and matrix metalloproteinase 9. Inhibition of neutrophil function was reported more frequently than eosinophil function. A decrease in T helper (Th) 2 cells cytokines (IL-4, IL-5, IL-6) was reported more frequently than a decrease in Th1 cytokines (IL-2, INF-gamma).

Conclusion

Macrolides influence a broad range of immunological mechanisms resulting in immunomodulatory effects. To optimize the treatment of chronic inflammatory diseases by macrolides, further studies are necessary, particularly comparing different macrolides and dose effect relationships.

Management of airway mucus hypersecretion in chronic airway inflammatory disease: Chinese expert consensus (English edition)

Airway mucus hypersecretion is one of the most important characteristics of chronic airway inflammatory diseases. Evaluating and managing airway mucus hypersecretion is of great importance for patients with chronic airway inflammatory diseases. This consensus statement describes the pathogenesis, clinical features, and the management of airway mucus hypersecretion in patients with chronic airway inflammatory diseases in the People's Republic of China. The statement has been written particularly for respiratory researchers, pulmonary physicians, and patients.

Macrolides: a promising pharmacologic therapy for chronic obstructive pulmonary disease

Chronic inflammation plays a central role in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, there are no effective anti-inflammatory pharmacologic therapies available for COPD so far. Recent evidence suggests that an immunologic mechanism has a role in the pathogenesis of COPD. Macrolides possess anti-inflammatory and immune-modulating effects may be helpful in the treatment of COPD. Several clinical studies have shown that long-term use of macrolides reduces the frequency of COPD exacerbations. However, the subgroups that most effectively respond to long-term treatment of macrolides still need to be determined. The potential adverse events to individuals and the microbial resistance in community populations raises great concern on the long-term use of macrolides. Thus, novel macrolides have anti-inflammatory and immuno-modulating effects, but without antibiotic effects, and are promising as an anti-inflammatory agent for the treatment of COPD. In addition, the combination of macrolides and other anti-inflammatory pharmacologic agents may be a new strategy for the treatment of COPD.

Are prophylactic antibiotics useful in chronic obstructive pulmonary disease?

Bacterial infections are one of the main causes of chronic obstructive pulmonary disease exacerbation, so the use of prophylactic antibiotics, especially macrolides, has been proposed in these patients. However, it is unclear whether antibiotics use is worth the risk and cost. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified five systematic reviews including eight randomized trials. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded prophylactic antibiotics probably decrease exacerbations in chronic obstructive pulmonary disease, but have no effect on hospitalizations or mortality.

Prophylactic use of macrolide antibiotics for the prevention of chronic obstructive pulmonary disease exacerbation: a meta-analysis

BACKGROUND

Acute exacerbations of chronic obstructive pulmonary disease (AECOPDs) can lead to high frequencies and rates of hospitalization and mortality. Macrolides are a class of antibiotics that possess both antimicrobial and anti-inflammatory properties. Since the occurrence of AECOPDs is associated with aggravation of airway inflammation and bacterial infections, prophylactic macrolide treatment may be an effective approach towards the prevention of AECOPDs.

METHODS

We systemically searched the PubMed, Embase and Cochrane Library databases to identify randomized controlled trials (RCTs) that evaluated the effect of prophylactic macrolide therapy on the prevention of AECOPDs. The primary outcomes were the total number of patients with one or more exacerbations as well as the rate of exacerbations per patient per year.

RESULTS

Nine RCTs comprising 1666 patients met the inclusion criteria. Pooled evidence showed macrolides could reduce the frequency of exacerbations in patients with COPD by both unweighted (RR = 0.70; 95% CI: 0.56-0.87; P < 0.01) and weighted approaches (RR = 0.58, 95% CI: 0.43-0.78, P < 0.01). Subgroup analysis showed only 6-12 months of erythromycin or azithromycin therapy could be effective. Moreover, among studies with 6-12 months of azithromycin therapy, both the daily dosing regimen and the intermittent regimen significantly reduced exacerbation rates. The overall number of hospitalizations and the all-cause rate of death were not significantly different between the treatment and control groups. A tendency for more adverse events was found in the treatment groups (OR = 1.55, 95%CI: 1.003-2.39, P = 0.049).

CONCLUSIONS

Our results suggest 6-12 months erythromycin or azithromycin therapy could effectively reduce the frequency of exacerbations in patients with COPD. However, Long-term treatment may bring increased adverse events and the emergence of macrolide-resistance. A recommendation for the prophylactic use of macrolide therapy should weigh both the advantages and disadvantages.

Inhalation of macrolides: a novel approach to treatment of pulmonary infections

Systemic antibiotic treatment is established for many pulmonary diseases, e.g., cystic fibrosis (CF), bronchiectasis and chronic obstructive pulmonary disease (COPD) where recurrent bacterial infections cause a progressive decline in lung function. In the last decades inhalative administration of antibiotics was introduced into clinical routine, especially tobramycin, colistin, and aztreonam for treatment of CF and bronchiectasis. Even though they are important in systemic treatment of these diseases due to their antimicrobial spectrum and anti-inflammatory and immunomodulatory properties, macrolides (e.g., azithromycin, clarithromycin, erythromycin, and telithromycin) up to now are not administered by inhalation. The number of in vitro aerosol studies and in vivo inhalation studies is also sparse. We analyzed publications on preparation and administration of macrolide aerosols available in PUBMED focusing on recent publications. Studies with solutions and dry powder aerosols were published. Publications investigating physicochemical properties of aerosols demonstrated that macrolide aerosols may serve for inhalation and will achieve sufficient lung deposition and that the bitter taste can be masked. In vivo studies in rats demonstrated high concentrations and areas under the curve sufficient for antimicrobial treatment in alveolar macrophages and epithelial lining fluid without lung toxicity. The obtained data demonstrate the feasibility of macrolide inhalation which should be further investigated.

ALAT-2014 Chronic Obstructive Pulmonary Disease (COPD) Clinical Practice Guidelines: questions and answers

ALAT-2014 COPD Clinical Practice Guidelines used clinical questions in PICO format to compile evidence related to risk factors, COPD screening, disease prognosis, treatment and exacerbations. Evidence reveals the existence of risk factors for COPD other than tobacco, as well as gender differences in disease presentation. It shows the benefit of screening in an at-risk population, and the predictive value use of multidimensional prognostic indexes. In stable COPD, similar benefits in dyspnea, pulmonary function and quality of life are achieved with LAMA or LABA long-acting bronchodilators, whereas LAMA is more effective in preventing exacerbations. Dual bronchodilator therapy has more benefits than monotherapy. LAMA and combination LABA/IC are similarly effective, but there is an increased risk of pneumonia with LABA/IC. Data on the efficacy and safety of triple therapy are scarce. Evidence supports influenza vaccination in all patients and anti-pneumococcal vaccination in patients <65years of age and/or with severe airflow limitation. Antibiotic prophylaxis may decrease exacerbation frequency in patients at risk. The use of systemic corticosteroids and antibiotics are justified in exacerbations requiring hospitalization and in some patients managed in an outpatient setting.

The effect of azithromycin in adults with stable neutrophilic COPD: a double blind randomised, placebo controlled trial

Background

Chronic Obstructive Pulmonary Disease (COPD) is a progressive airway disease characterised by neutrophilic airway inflammation or bronchitis. Neutrophilic bronchitis is associated with both bacterial colonisation and lung function decline and is common in exacerbations of COPD. Despite current available therapies to control inflammation, neutrophilic bronchitis remains common. This study tested the hypothesis that azithromycin treatment, as an add-on to standard medication, would significantly reduce airway neutrophil and neutrophils chemokine (CXCL8) levels, as well as bacterial load. We conducted a randomised, double-blind, placebo-controlled study in COPD participants with stable neutrophilic bronchitis.

Methods

Eligible participants (n = 30) were randomised to azithromycin 250 mg daily or placebo for 12 weeks in addition to their standard respiratory medications. Sputum was induced at screening, randomisation and monthly for a 12 week treatment period and processed for differential cell counts, CXCL8 and neutrophil elastase assessment. Quantitative bacteriology was assessed in sputum samples at randomisation and the end of treatment visit. Severe exacerbations where symptoms increased requiring unscheduled treatment were recorded during the 12 week treatment period and for 14 weeks following treatment. A sub-group of participants underwent chest computed tomography scans (n = 15).

Results

Nine participants with neutrophilic bronchitis had a potentially pathogenic bacteria isolated and the median total bacterial load of all participants was 5.22×10⁷ cfu/mL. Azithromycin treatment resulted in a non-significant reduction in sputum neutrophil proportion, CXCL8 levels and bacterial load. The mean severe exacerbation rate was 0.33 per person per 26 weeks in the azithromycin group compared to 0.93 exacerbations per person in the placebo group (incidence rate ratio (95%CI): 0.37 (0.11,1.21), p = 0.062). For participants who underwent chest CT scans, no alterations were observed.

Conclusions

In stable COPD with neutrophilic bronchitis, add-on azithromycin therapy showed a trend to reduced severe exacerbations sputum neutrophils, CXCL8 levels and bacterial load. Future studies with a larger sample size are warranted.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN12609000259246

Neutrophils and emerging targets for treatment in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by a decreased airflow due to airway narrowing that, once it occurs, is not fully reversible. The disease usually is progressive and associated with an enhanced inflammatory response in the lungs after exposure to noxious particles or gases. After removal of the noxious particles, the inflammation can continue in a self-sustaining manner. It has been established that improper activation of neutrophils lies at the core of the pathology. This paper provides an overview of the mechanisms by which neutrophils can induce the pulmonary damage of COPD. As the pathogenesis of COPD is slowly being unraveled, new points of intervention are discovered, some of which with promising results.

Macrolide therapy in adults and children with non-cystic fibrosis bronchiectasis: a systematic review and meta-analysis

Background

A systematic review and meta-analysis was conducted to evaluate the efficacy and safety of macrolide therapy in adults and children with bronchiectasis.

Methods

We searched the PUBMED, EMBASE, CENTRAL databases to identify relevant studies. Two reviewers evaluated the studies and extracted data independently. The primary outcome was the number of bronchiectasis exacerbations. Secondary outcomes included exacerbation-related admissions, quality of life (QoL), spirometry, 6-minute walk test (6MWT) and adverse events.

Results

Nine eligible trials with 559 participants were included. Six were conducted on adults, and the remaining on children. Macrolide therapy significantly reduced the number of patients experiencing one or more exacerbation in adults [risk ratio (RR) = 0.59; 95% CI, 0.40 to 0.86; P = 0.006; I² = 65%] and children [RR = 0.86; 95% CI, 0.75–0.99; P = 0.04; I² = 0%], but not the number of patients with admissions for exacerbation. Macrolide therapy was also associated with reduced frequency of exacerbations in adults (RR = 0.42; 95% CI, 0.29 to 0.61; P<0.001; I² = 64%) and children (RR = 0.50; 95% CI, 0.35 to 0.71; P<0.001). Pooled analyses suggested that spirometry, including FEV₁ and FVC, were significantly improved in adults but not in children. Macrolide therapy improved the QoL (WMD, −6.56; 95% CI, −11.99 to −1.12; P = 0.02; I² = 86%) but no significant difference in 6MWT (WMD, 4.15; 95% CI, −11.83 to 20.13; P = 0.61; I² = 31%) and the overall adverse events (RR, 0.96; 95% CI, 0.82 to 1.13; P = 0.66; I² = 0%) in adults. However, reports of diarrhea and abdominal discomforts were higher with macrolide therapy.

Conclusions

Macrolide maintenance therapy, both in adults and children, was effective and safe in reducing bronchiectasis exacerbations, but not the admissions for exacerbations. In addition, macrolide administration in adults was associated with improvement in QoL and spirometry, but not 6WMT. Future studies are warranted to verify the optimal populations and clarify its potential effects on antimicrobial resistance.