British Thoracic Society guideline for the use of long-term macrolides in adults with respiratory disease

Macrolide resistance through uL4 and uL22 ribosomal mutations in Pseudomonas aeruginosa

Macrolides are widely used antibiotics for the treatment of bacterial airway infections. Due to its elevated minimum inhibitory concentration in standardized culture media, Pseudomonas aeruginosa is considered intrinsically resistant and, therefore, antibiotic susceptibility testing against macrolides is not performed. Nevertheless, due to macrolides' immunomodulatory effect and suppression of virulence factors, they are used for the treatment of persistent P. aeruginosa infections. Here, we demonstrate that macrolides are, instead, effective antibiotics against P. aeruginosa airway infections in an Air-Liquid Interface (ALI) infection model system resembling the human airways. Importantly, macrolide treatment in both people with cystic fibrosis and primary ciliary dyskinesia patients leads to the accumulation of uL4 and uL22 ribosomal protein mutations in P. aeruginosa which causes antibiotic resistance. Consequently, higher concentrations of antibiotics are needed to modulate the macrolide-dependent suppression of virulence. Surprisingly, even in the absence of antibiotics, these mutations also lead to a collateral reduction in growth rate, virulence and pathogenicity in airway ALI infections which are pivotal for the establishment of a persistent infection. Altogether, these results lend further support to the consideration of macrolides as de facto antibiotics against P. aeruginosa and the need for resistance monitoring upon prolonged macrolide treatment.

Effects of Azithromycin on Blood Inflammatory Gene Expression and Cytokine Production in Sarcoidosis

INTRODUCTION

In sarcoidosis granulomas, monocyte-derived macrophages are activated by pro-inflammatory cytokines including TNF and IL-6. Current drug treatment for sarcoidosis aims to suppress inflammation but disabling side effects can ensue. The macrolide azithromycin may be anti-inflammatory. We aimed to determine whether treatment with azithromycin affects blood inflammatory gene expression and monocyte functions in sarcoidosis.

METHODS

Blood samples were collected from patients with chronic pulmonary sarcoidosis enrolled in a single arm, open label clinical trial who received oral azithromycin 250 mg once daily for 3 months. Whole blood inflammatory gene expression with or without LPS stimulation was measured using a 770-mRNA panel. Phenotypic analysis and cytokine production were conducted by flow cytometry and ELISA after 24h stimulation with growth factors and TLR ligands. mTOR activity was assessed by measuring phosphorylated S6RP.

RESULTS

Differential gene expression analysis indicated a state of heightened myeloid cell activation in sarcoidosis. Compared with controls, sarcoidosis patients showed increased LPS responses for several cytokines and chemokines. Treatment with azithromycin had minimal effect on blood gene expression overall, but supervised clustering analysis identified several chemokine genes that were upregulated. At the protein level, azithromycin treatment increased LPS-stimulated TNF and unstimulated IL-8 production. No other cytokines showed significant changes following azithromycin. Blood neutrophil counts fell during azithromycin treatment whereas mononuclear cells remained stable. Azithromycin had no detectable effects on mTOR activity or activation markers.

CONCLUSION

Blood myeloid cells are activated in sarcoidosis, but azithromycin therapy did not suppress inflammatory gene expression or cytokine production in blood.

TRIAL REGISTRATION

EudraCT 2019-000580-24 (17 May 2019).

Serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae isolates cultured from Japanese adult patients with community-acquired pneumonia in Goto City, Japan

Streptococcus pneumoniae is an important cause of community-acquired pneumonia (CAP) in Japan. Here, we report the serotype distribution and antimicrobial susceptibility of cultured pneumococcal isolates from Japanese adults aged ≥18 years with CAP. This was a prospective, population-based, active surveillance study conducted in Goto City, Japan from December 2015 to November 2020. Pneumococcal isolates from sterile sites (blood and pleural fluid) and non-sterile sites (sputum and bronchoalveolar lavage) were cultured as part of the standard of care. S. pneumoniae were serotyped using the Quellung reaction. Antimicrobial susceptibility was tested using microdilution and interpreted according to the Clinical and Laboratory Standards Institute criteria. Isolates resistant to erythromycin were phenotyped using the triple-risk test and genotyped by polymerase chain reaction. A total of 156 pneumococcal isolates were collected (138 from sputum, 15 from blood, and 3 from bronchoalveolar lavage) from 1992 patients. Of these, 142 were non-duplicate isolates from unique patients and were included in the analyses. Serotypes contained within the 13-valent pneumococcal conjugate vaccine (PCV13) (including 6C), PCV15 (including 6C), and PCV20 (including 6C and 15C) were detected in 39 (27%), 45 (32%), and 80 (56%) of 142 isolates, respectively. The most common serotypes were 35B (12%), 11A (11%), and 3 (11%). Multidrug resistance (MDR) was detected in 96/142 (68%) isolates. Of the 96 MDR isolates, 31, 32, and 59% were PCV13, PCV15, and PCV20 serotypes, respectively; the most common MDR serotypes were 35B (16%), 6C, 10A, and 15A (9% each), and 3 and 11A (8% each). A total of 119 isolates were resistant to macrolides; 41 (35%) had an M phenotype, 53 (45%) had an iMcLS phenotype, and 25 (21%) had a cMLS phenotype. In conclusion, pneumococcal serotypes 35B, 11A and 3 were most frequently associated with pneumonia and antimicrobial resistance was common among pneumococcal isolates from adults with CAP in Goto City, Japan. Implementing higher-valency PCVs May help reduce vaccine-type CAP among Japanese adults.

Patients at risk of nontuberculous mycobacterial pulmonary disease who need testing evaluated using a modified Delphi process by European experts

Background

Identifying patients at risk of nontuberculous mycobacterial pulmonary disease (NTM-PD) is challenging. Delays in NTM-PD identification and management are associated with declining lung function and increased morbidity and mortality.

Study design and methods

European NTM-PD experts (n=12) participated in a three-round modified Delphi process to score symptoms and comorbidities potentially associated with NTM-PD as reasons to test for nontuberculous mycobacteria.

Results

Experts reached a consensus on the symptoms and comorbidities that should and should not prompt testing for nontuberculous mycobacteria. Requirements for testing were scored as high (mean ≥7), medium (mean ≥4-<7) or low (mean <4). Nontuberculous mycobacteria testing should be undertaken when multiple suggestive symptoms are present simultaneously in all patients except those with cancer (7.3-8.8), or when radiology is indicative of NTM-PD (≥8.9). Symptoms of persistent sputum production, recurrent respiratory infection and haemoptysis should prompt testing for nontuberculous mycobacteria, particularly in those with underlying respiratory diseases. Symptomatic patients with bronchiectasis or previous tuberculosis/NTM-PD or those being prescribed or undergoing long-term macrolide therapy for a respiratory condition should also be tested. Testing is not warranted in patients without an underlying respiratory disorder or in those without a history of respiratory disorders unless presenting with multiple symptoms.

Conclusions

Assessing patients' risk of NTM-PD is challenging. This Delphi consensus process provides insight into symptoms and clinical characteristics that should prompt NTM-PD assessment. Timely testing and diagnosis would enable initiation of appropriate management.

Clinical Predictors of Nontuberculous Mycobacteria Lung Disease and Coisolates of Potential Pathogenic Microorganisms in Noncystic Fibrosis Bronchiectasis

Background

In bronchiectasis, nontuberculous mycobacteria (NTM) lung disease (NTM-LD) is a well-known coexisting infection. However, microorganism coisolates and clinical NTM-LD predictors are poorly studied.

Methods

Patients with bronchiectasis diagnosed by means of computed tomography between January 2017 and June 2020 were screened, using the date of computed tomography as the index date. Those with a major bronchiectasis diagnosis in ≥2 follow-up visits after the index date were enrolled in the study, and NTM-LD occurrence and its association with pneumonia and hospitalization within 1 year were analyzed.

Results

Of the 2717 participants, 79 (2.9%) had NTM-LD diagnosed. The factors associated with NTM-LD included hemoptysis, postinfectious bronchiectasis, a tree-in-bud score ≥2, a modified Reiff score ≥4, and chronic obstructive pulmonary disease (adjusted odds ratios, 1.80, 2.36, 1.78, 2.95, and 0.51, respectively). Compared with patients in the non-NTM group, those with NTM-LD had higher rates of hospitalization (15.9% vs 32.9%; P < .001) and pneumonia (9.8% vs 20.3%; P = .003). Pseudomonas aeruginosa was the most common microorganism in those with NTM-LD and those in the non-NTM group (10.1% vs 7.8%; P = .40). However, compared with those in the non-NTM group, Acinetobacter baumannii and Escherichia coli were more prevalent in patients with NTM-LD (0.7% vs 3.8% [P = .03%] and 1.0% vs 3.8% [P = .05], respectively).

Conclusions

Postinfectious bronchiectasis with hemoptysis, higher radiological involvement, and a tree-in-bud pattern were associated with NTM-LD risk. The rate of A baumannii and E coli coisolation was higher in bronchiectasis populations with NTM-LD.

Efficacy and safety of macrolides in the treatment of children with bronchiectasis: a meta-analysis

BACKGROUND

This study summarized the available randomized controlled trials (RCTs) to assess the efficacy and safety of macrolides on pathogens, lung function, laboratory parameters, and safety in children with bronchiectasis.

METHODS

PubMed, EMBASE, and the Cochrane Library were searched for available papers published up to June 2021. The outcomes were the pathogens, adverse events (AEs), and the forced expiratory volume in one second (FEV1%) predicted.

RESULTS

Seven RCTs (633 participants) were included. The long-term use of macrolides reduced the risk of the presence of Moraxella catarrhalis (RR = 0.67, 95% CI: 0.30-1.50, P = 0.001; I2 = 0.0%, Pheterogeneity = 0.433), but not Haemophilus influenza (RR = 0.19, 95% CI: 0.08-0.49, P = 0.333; I2 = 57.0%, Pheterogeneity = 0.040), Streptococcus pneumonia (RR = 0.91, 95% CI: 0.61-1.35, P = 0.635; I2 = 0.0%, Pheterogeneity = 0.515), Staphylococcus aureus (RR = 1.01, 95% CI: 0.36-2.84, P = 0.986; I2 = 61.9%, Pheterogeneity = 0.033), and any pathogens present (RR = 0.61, 95% CI: 0.29-1.29, P = 0.195; I2 = 80.3%, Pheterogeneity = 0.006). Long-term macrolides had no effect on FEV1% predicted (WMD = 2.61, 95% CI: -1.31, 6.53, P = 0.192; I2 = 0.0%, Pheterogeneity = 0.896). Long-term macrolides did not increase the risk of AEs or serious AEs.

CONCLUSION

Macrolides do not significantly reduce the risk of pathogens present (except for Moraxella catarrhalis) or increase FEV1% predicted among children with bronchiectasis. Moreover, macrolides were not associated with AEs. Considering the limitations of the meta-analysis, further larger-scale RCTs are needed to confirm the findings.

IMPACT

Macrolides do not significantly reduce the risk of pathogens present (except for Moraxella catarrhalis) among children with bronchiectasis. Macrolides do not significantly increase FEV1% predicted among children with bronchiectasis. This meta-analysis reports on the efficacy and safety of macrolides in the treatment of children with bronchiectasis, providing evidence for the management of children with bronchiectasis. This meta-analysis does not support the use of macrolides in the management of children with bronchiectasis unless the presence of Moraxella catarrhalis is provenor suspected.

The Impact of Long-Term Macrolide Exposure on the Gut Microbiome and Its Implications for Metabolic Control

Long-term low-dose macrolide therapy is now widely used in the treatment of chronic respiratory diseases for its immune-modulating effects, although the antimicrobial properties of macrolides can also have collateral impacts on the gut microbiome. We investigated whether such treatment altered intestinal commensal microbiology and whether any such changes affected systemic immune and metabolic regulation. In healthy adults exposed to 4 weeks of low-dose erythromycin or azithromycin, as used clinically, we observed consistent shifts in gut microbiome composition, with a reduction in microbial capacity related to carbohydrate metabolism and short-chain fatty acid biosynthesis. These changes were accompanied by alterations in systemic biomarkers relating to immune (interleukin 5 [IL-5], IL-10, monocyte chemoattractant protein 1 [MCP-1]) and metabolic (serotonin [5-HT], C-peptide) homeostasis. Transplantation of erythromycin-exposed murine microbiota into germ-free mice demonstrated that changes in metabolic homeostasis and gastrointestinal motility, but not systemic immune regulation, resulted from changes in intestinal microbiology caused by macrolide treatment. Our findings highlight the potential for long-term low-dose macrolide therapy to influence host physiology via alteration of the gut microbiome. IMPORTANCE Long-term macrolide therapy is widely used in chronic respiratory diseases although its antibacterial activity can also affect the gut microbiota, a key regulator of host physiology. Macrolide-associated studies on the gut microbiota have been limited to short antibiotic courses and have not examined its consequences for host immune and metabolic regulation. This study revealed that long-term macrolides depleted keystone bacteria and impacted host regulation, mediated directly by macrolide activity or indirectly by alterations to the gut microbiota. Understanding these macrolide-associated mechanisms will contribute to identifying the risk of long-term exposure and highlights the importance of targeted therapy for maintenance of the gut microbiota.

Investigation of oral macrolide prescriptions in Japan using a retrospective claims database, 2013-2018

Macrolide usage in Japan exceeds that in Europe and the United States. Investigating the actual conditions in which macrolides are used is important for identifying further interventions for appropriate antimicrobial use; however, this situation has not been evaluated in Japan. Therefore, we aimed to clarify the number of macrolide prescriptions and their changes before and after implementation of the Antimicrobial Resistance (AMR) Action Plan. In addition, we also investigated the names of diseases for which macrolides have been prescribed and the number of days of prescription. A retrospective observational study was conducted using JMDC claims data from January 2013 to December 2018. The proportion of all oral antimicrobials and macrolides used during this period and the diseases for which macrolides were used in the 3 years before and after the AMR Action Plan were determined separately for acute (< 14 prescription days) and chronic (> 14 prescription days) diseases. The number of prescriptions for macrolides constituted approximately 30% of those for all oral antimicrobials; of these, clarithromycin accounted for approximately 60%. Most prescriptions for acute diseases were for common cold, whereas allergic and dermatological diseases were included among chronic diseases. The names of these illnesses did not change before and after the AMR Action Plan. Overall, these results indicate that appropriate macrolide use involves a review of their use for common cold along with appropriate evaluation of their long-term use for skin and allergic diseases. They also indicate the need for further fact-finding studies and ongoing AMR measures.

Maternal antibiotic administration during gestation can affect the memory and brain structure in mouse offspring

Maternal antibiotics administration (MAA) is among the widely used therapeutic approaches in pregnancy. Although published evidence demonstrates that infants exposed to antibiotics immediately after birth have altered recognition memory responses at one month of age, very little is known about in utero effects of antibiotics on the neuronal function and behavior of children after birth. Therefore, this study aimed to evaluate the impact of MAA at different periods of pregnancy on memory decline and brain structural alterations in young mouse offspring after their first month of life. To study the effects of MAA on 4-week-old offspring, pregnant C57BL/6J mouse dams (2-3-month-old; n = 4/group) were exposed to a cocktail of amoxicillin (205 mg/kg/day) and azithromycin (51 mg/kg/day) in sterile drinking water (daily/1 week) during either the 2nd or 3rd week of pregnancy and stopped after delivery. A control group of pregnant dams was exposed to sterile drinking water alone during all three weeks of pregnancy. Then, the 4-week-old offspring mice were first evaluated for behavioral changes. Using the Morris water maze assay, we revealed that exposure of pregnant mice to antibiotics at the 2nd and 3rd weeks of pregnancy significantly altered spatial reference memory and learning skills in their offspring compared to those delivered from the control group of dams. In contrast, no significant difference in long-term associative memory was detected between offspring groups using the novel object recognition test. Then, we histologically evaluated brain samples from the same offspring individuals using conventional immunofluorescence and electron microscopy assays. To our knowledge, we observed a reduction in the density of the hippocampal CA1 pyramidal neurons and hypomyelination in the corpus callosum in groups of mice in utero exposed to antibiotics at the 2nd and 3rd weeks of gestation. In addition, offspring exposed to antibiotics at the 2nd or 3rd week of gestation demonstrated a decreased astrocyte cell surface area and astrocyte territories or depletion of neurogenesis in the dentate gyrus and hippocampal synaptic loss, respectively. Altogether, this study shows that MAA at different times of pregnancy can pathologically alter cognitive behavior and brain development in offspring at an early age after weaning.

Possible convulsion and electroencephalographic abnormality in a patient taking long-term oral clarithromycin: A case report

BACKGROUND

Clarithromycin is a macrolide antibiotic commonly prescribed to patients with upper respiratory and otolaryngological infections. Neuropsychiatric adverse effects of clarithromycin include agitation, insomnia, delirium, psychosis, and seizure.

CASE SUMMARY

A 52-year-old man was admitted to our hospital with a convulsion. He had > 10-year history of clarithromycin intake for chronic sinusitis. One week before admission, he started to take diltiazem for angina pectoris. On admission, his convulsion subsided. His electroencephalography showed frontal intermittent rhythmic delta activity. One week after he ceased clarithromycin, his electroencephalographic abnormalities disappeared. We suggested that the patient developed convulsions due to increased blood levels of clarithromycin caused by oral administration of diltiazem, which is involved in CYP3A metabolism.

CONCLUSION

Clarithromycin has a relatively high safety profile and is a frequently prescribed drug. However, there are a few previous reports of clarithromycin-related convulsive disorders. Clinicians should be aware of the drug interaction and rare side effects of seizures.

Macrolides for asthma evidence

Overview of: Undela K, Goldsmith L, Kew KM, et al Macrolides for chronic asthma. Cochrane Database Syst Rev 2021;11:10.1002/14651857.CD002997.pub5.

Evidence-based management approaches for patients with severe chronic obstructive pulmonary disease (COPD): A practice review

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) face limited treatment options and inadequate access to palliative care.

AIM

To provide a pragmatic overview of clinical guidelines and produce evidence-based recommendations for severe COPD. Interventions for which there is inconsistent evidence to support their use and areas requiring further research were identified.

DESIGN

Practice review of guidelines supported by scoping review methodology to examine the evidence reporting the use of guideline-recommended interventions.

DATA SOURCES

An electronic search was undertaken in MEDLINE, EMBASE, PsycINFO, CINAHL and The Cochrane Database of Systematic Reviews, complemented by web searching for guidelines and publications providing primary evidence (July 2021). Guidelines published within the last 5 years and evidence in the last 10 years were included.

RESULTS

Severe COPD should be managed using a multidisciplinary approach with a holistic assessment. For stable patients, long-acting beta-agonist/long-acting muscarinic antagonist and pulmonary rehabilitation are recommended. Low dose opioids, self-management, handheld fan and nutritional support may provide small benefits, whereas routine corticosteroids should be avoided. For COPD exacerbations, systematic corticosteroids, non-invasive ventilation and exacerbation action plans are recommended. Short-acting inhaled beta-agonists and antibiotics may be considered but pulmonary rehabilitation should be avoided during hospitalisation. Long term oxygen therapy is only recommended for patients with chronic severe hypoxaemia. Short-acting anticholinergic inhalers, nebulised opioids, oral theophylline or telehealth are not recommended.

CONCLUSIONS

Recommended interventions by guidelines are not always supported by high-quality evidence. Further research is required on efficacy and safety of inhaled corticosteroids, antidepressants, benzodiazepines, mucolytics, relaxation and breathing exercises.

Case studies to illustrate good practice in the management of non-tuberculous mycobacterial pulmonary disease

Pulmonary disease caused by non-tuberculous mycobacteria (NTM-PD) can be a complex condition for health care providers to manage, and delayed diagnosis and treatment failure are common. Here we present three case studies that illustrate key challenges in the diagnosis and treatment of NTM-PD, and provide guidance on these issues. In addition, we make recommendations on how the overall management of NTM-PD may be improved, through strategies such as physician education to recognise NTM-PD, and the development of multidisciplinary teams and patient-support groups.

Meeting the challenges of NTM-PD from the perspective of the organism and the disease process: innovations in drug development and delivery

Non-tuberculous mycobacterial pulmonary disease (NTM-PD) poses a substantial patient, healthcare, and economic burden. Managing NTM-PD remains challenging, and factors contributing to this include morphological, species, and patient characteristics as well as the treatment itself. This narrative review focusses on the challenges of NTM-PD from the perspective of the organism and the disease process. Morphological characteristics of non-tuberculous mycobacteria (NTM), antimicrobial resistance mechanisms, and an ability to evade host defences reduce NTM susceptibility to many antibiotics. Resistance to antibiotics, particularly macrolides, is of concern, and is associated with high mortality rates in patients with NTM-PD. New therapies are desperately needed to overcome these hurdles and improve treatment outcomes in NTM-PD. Amikacin liposome inhalation suspension (ALIS) is the first therapy specifically developed to treat refractory NTM-PD caused by Mycobacterium avium complex (MAC) and is approved in the US, EU and Japan. It provides targeted delivery to the lung and effective penetration of macrophages and biofilms and has demonstrated efficacy in treating refractory MAC pulmonary disease (MAC-PD) in the Phase III CONVERT study. Several other therapies are currently being developed including vaccination, bacteriophage therapy, and optimising host defences. Newly developed antibiotics have shown potential activity against NTM-PD and include benzimidazole, delamanid, and pretomanid. Antibiotics commonly used to treat other infections have also been repurposed for NTM-PD, including clofazimine and bedaquiline. Data from larger-scale studies are needed to determine the potential of many of these therapies for treating NTM-PD.

Long-term, low-dose macrolide antibiotic treatment in pediatric chronic airway diseases

Macrolide antibiotics are one of the most commonly used broad-spectrum antibiotics. They have an inhibitory effect on a variety of respiratory pathogens; besides, they have non-anti-infective effects, including anti-inflammatory, regulating airway secretion, immune regulation, and other effects. A growing number of studies have shown that the non-anti-infective effects of macrolides have important and potential value in the treatment of pediatric chronic airway diseases; the therapy was described as "long-term, low-dose usage"; unfortunately, there is no guideline or consensus that applies to children. To better carry out the mechanism and clinical research of non-anti-infective effect and promote its rational use in children, the authors summarize the evidence of the usage of long-term, low-dose macrolide antibiotic therapy (LLMAT) in the treatment of chronic airway diseases in children and the progress in recent years. IMPACT: This review summarizes the evidence (mostly in recent 5 years) of the usage of long-term, low-dose macrolide antibiotic therapy in the treatment of chronic airway diseases. The recent studies and guidelines support and enrich the point that long-term, low-dose macrolide antibiotic therapy has potential benefit for children with severe asthma, CF, non-CF bronchiectasis, and BO, which provides clinical references and is of clinical interest. Long-term, low-dose macrolide antibiotic therapy has good safety, and no serious events have been reported; however, potential cardiac side effects and macrolide resistance should be clinically noted.

Macrolides versus placebo for chronic asthma

BACKGROUND

Asthma is a chronic disease in which inflammation of the airways causes symptomatic wheezing, coughing and difficult breathing. Macrolides are antibiotics with antimicrobial and anti-inflammatory activities that have been explored for the long-term control of asthma symptoms.

OBJECTIVES

To assess the effects of macrolides compared with placebo for managing chronic asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register up to March 2021. We also manually searched bibliographies of previously published reviews and conference proceedings and contacted study authors. We included records published in any language in the search.

SELECTION CRITERIA

We included randomised controlled clinical trials (RCTs) involving both children and adults with asthma treated with macrolides versus placebo for four or more weeks. Primary outcomes were exacerbation requiring hospitalisation, severe exacerbations (exacerbations requiring emergency department (ED) visits or systemic steroids, or both), symptom scales, asthma control questionnaire (ACQ, score from 0 totally controlled, to 6 severely uncontrolled), Asthma Quality of Life Questionnaire (AQLQ, with score from 1 to 7 with higher scores indicating better QoL), rescue medication puffs per day, morning and evening peak expiratory flow (PEF; litres per minutes), forced expiratory volume in one second (FEV1; litres), bronchial hyperresponsiveness, and oral corticosteroid dose. Secondary outcomes were adverse events (including mortality), withdrawal, blood eosinophils, sputum eosinophils, eosinophil cationic protein (ECP) in serum, and ECP in sputum.

DATA COLLECTION AND ANALYSIS

Two review authors independently examined all records identified in the searches then reviewed the full text of all potentially relevant articles before extracting data in duplicate from all included studies. As per protocol, we used a fixed-effect model. We conducted a sensitivity analysis for analyses with high heterogeneity (I2 greater than 30%). GRADE was used to assess the certainty of the body of evidence.

MAIN RESULTS

Twenty-five studies met the inclusion criteria, randomising 1973 participants to receive macrolide or placebo for at least four weeks. Most of the included studies reported data from adults (mean age 21 to 61 years) with persistent or severe asthma, while four studies included children. All participants were recruited in outpatient settings. Inclusion criteria, interventions and outcomes were highly variable. The evidence suggests macrolides probably deliver a moderately sized reduction in exacerbations requiring hospitalisations compared to placebo (odds ratio (OR) 0.47, 95% confidence interval (CI) 0.20 to 1.12; studies = 2, participants = 529; moderate-certainty evidence). Macrolides probably reduce exacerbations requiring ED visits and/or treatment with systemic steroids (rate ratio (RaR) 0.65, 95% CI 0.53 to 0.80; studies = 4, participants = 640; moderate-certainty evidence). Macrolides may reduce symptoms (as measured on symptom scales) (standardised mean difference (SMD) -0.46, 95% CI -0.81 to -0.11; studies = 4, participants = 136 ; very low-certainty evidence). Macrolides may result in a little improvement in ACQ (SMD -0.17, 95% CI -0.31 to -0.03; studies = 5, participants = 773; low-certainty evidence). Macrolides may have little to no effect on AQLQ (mean difference (MD) 0.24, 95% CI 0.12 to 0.35; studies = 6, participants = 802; very low-certainty evidence). For both the ACQ and the AQLQ the suggested effect of macrolides versus placebo did not reach a minimal clinically important difference (MCID, 0.5 for ACQ and AQLQ) (ACQ: low-certainty evidence; AQLQ: very low-certainty evidence). Due to high heterogeneity (I2 > 30%), we conducted sensitivity analyses on the above results, which reduced the size of the suggested effects by reducing the weighting on the large, high quality studies.  Macrolides may result in a small effect compared to placebo in reducing need for rescue medication (MD -0.43 puffs/day, 95% CI -0.81 to -0.04; studies = 4, participants = 314; low-certainty evidence). Macrolides may increase FEV1, but the effect is almost certainly below a level discernible to patients (MD 0.04 L, 95% CI 0 to 0.08; studies = 10, participants = 1046; low-certainty evidence). It was not possible to pool outcomes for non-specific bronchial hyperresponsiveness or lowest tolerated oral corticosteroid dose (in people requiring oral corticosteroids at baseline). There was no evidence of a difference in severe adverse events (including mortality), although less than half of the studies reported the outcome (OR 0.80, 95% CI 0.49 to 1.31; studies = 8, participants = 854; low-certainty evidence). Reporting of specific adverse effects was too inconsistent across studies for a meaningful analysis.

AUTHORS' CONCLUSIONS

Existing evidence suggests an effect of macrolides compared with placebo on the rate of exacerbations requiring hospitalisation. Macrolides probably reduce severe exacerbations (requiring ED visit and/or treatment with systemic steroids) and may reduce symptoms. However, we cannot rule out the possibility of other benefits or harms because the evidence is of very low quality due to heterogeneity among patients and interventions, imprecision and reporting biases. The results were mostly driven by a well-designed, well powered RCT, indicating that azithromycin may reduce exacerbation rate and improve symptom scores in severe asthma. The review highlights the need for researchers to report outcomes accurately and according to standard definitions. Macrolides can reduce exacerbation rate in people with severe asthma. Future trials could evaluate if this effect is sustained across all the severe asthma phenotypes, the comparison with newer biological drugs, whether effects persist or wane after treatment cessation and whether effects are associated with infection biomarkers.

The immunomodulatory effects of macrolide antibiotics in respiratory disease

Macrolide antibiotics are well known for their antibacterial properties, but extensive research in the context of inflammatory lung disease has revealed that they also have powerful immunomodulatory properties. It has been demonstrated that these drugs are therapeutically beneficial in various lung diseases, with evidence they significantly reduce exacerbations in patients with COPD, asthma, bronchiectasis and cystic fibrosis. The efficacy demonstrated in patients infected with macrolide tolerant organisms such as Pseudomonas aeruginosa supports the concept that their efficacy is at least partly related to immunomodulatory rather than antibacterial effects. Inconsistent data and an incomplete understanding of their mechanisms of action hampers the use of macrolide antibiotics as immunomodulatory therapies. Macrolides recently demonstrated no clinically relevant immunomodulatory effects in the context of COVID-19 infection. This review provides an overview of macrolide antibiotics and discusses their immunomodulatory effects and mechanisms of action in the context of inflammatory lung disease.

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.

Inhaled antibiotics for treatment of adults with non-cystic fibrosis bronchiectasis: A systematic review and meta-analysis

BACKGROUND

Inhaled antibiotics (IA) in non-cystic fibrosis bronchiectasis (NCFB) are recommended by some clinical practice guidelines for prevention or treatment of NCFB exacerbations.

METHODS

We performed a systematic review and meta-analysis to evaluate the efficacy and safety of IA use for treatment of adults with NCFB and Pseudomonas aeruginosa chronic bronchial infection. The search was performed in the Cochrane Library, PubMed, and Web of Science databases from 2000 to 2019. Studies of IA for treatment of stable or exacerbated NCFB adults (≥18 years) with P. aeruginosa infection were considered eligible. PROSPERO Registration number: CRD42019136154.

RESULTS

Twelve trials (2476 participants) were included. IA therapy increased P. aeruginosa eradication from sputum in patients with exacerbations (OR: 3.19, 95%CI: 1.70-5.99) with similar effects on stable patients (OR: 7.22, 95%CI: 2.81-18.59), and a trend to reduced emergence of new respiratory pathogens (OR: 0.58, 95%CI: 0.28-1.18). IA achieved significant reduced exacerbation rates (RR: 0.90; 95%CI: 0.82-0.98) in stable patients, with a number needed to treat (NNT) of 59, but no significant changes in FEV₁, mortality, hospitalizations or quality of life were identified. In stable patients, IA use increased antimicrobial resistance (RR: 2.10, 95%CI: 1.35-3.27) at the end of therapy, with a number needed to treat of 6.

CONCLUSIONS

IA therapy achieved a statistically significant eradication of P. aeruginosa from sputum, with a 10% reduction of exacerbations in stable patients. This effect has to be balanced with significant increases in antimicrobial resistance. Our meta-analysis failed to show a significant benefit in terms of patient-centered outcomes.

How I do it. Work-up of severe asthma

CASE EXAMPLE

A 56-year-old gentleman has difficult to control asthma and a history of four exacerbations in the prior 12 months despite high-dose inhaled corticosteroids (ICS) and additional controller therapies. Is he suitable for more advanced therapeutic options?

SCOPE OF REVIEW

We herein review the clinical assessment of a patient with suspected severe asthma, discuss factors contributing to poor asthma control and how biomarkers assist in disease investigation and stratification.

HOW I DO IT

The key components of our multidisciplinary approach are to confirm an asthma diagnosis and adherence to treatment, to assess any contributing comorbidities or confounding factors, and to stratify what type of asthma our patient has. The combination of spirometry and repeated measures of key biomarkers of type-2 airway inflammation - the blood eosinophil count and fractional exhaled nitric oxide - identifies whether poor disease control is driven by uncontrolled, ICS-resistant type-2 airway inflammation or ongoing airflow obstruction. A failure to elicit evidence of either suggests an alternative driver for the patient's symptoms including chronic airway infection and non-asthma causes. Each phenotype represents a treatable trait that requires a specific targeted approach. Critically, steroids can cause harm and their use should be guided by objective evidence of inflammation rather than symptoms alone.

CASE CONCLUSION

After assessment of treatment adherence and exclusion of relevant comorbidities, the patient was found to have severe asthma with ICS-resistant type-2 airway inflammation. We will consider additional treatment options at our next appointment (Part 2/2 of this How I Do It series).

Pseudomonas aeruginosa in bronchiectasis: infection, inflammation, and therapies

Introduction: Bronchiectasis is a chronic endobronchial suppurative disease characterized by irreversibly dilated bronchi damaged by repeated polymicrobial infections and predominantly, neutrophilic airway inflammation. Some consider bronchiectasis a syndromic consequence of several different causes whilst others view it as an individual disease entity. In most patients, identifying an underlying cause remains challenging. The acquisition and colonization of affected airways by Pseudomonas aeruginosa represent a critical and adverse clinical consequence for its progression and management.Areas covered: In this review, we outline clinical and pre-clinical peer-reviewed research published in the last 5 years, focusing on the pathogenesis of bronchiectasis and the role of P. aeruginosa and its virulence in shaping host inflammatory and immune responses in the airway. We further detail its role in airway infection, the lung microbiome, and address therapeutic options in bronchiectasis.Expert opinion: P. aeruginosa represents a key pulmonary pathogen in bronchiectasis that causes acute and/or chronic airway infection. Eradication can prevent adverse clinical consequence and/or disease progression. Novel therapeutic strategies are emerging and include combination-based approaches. Addressing airway infection caused by P. aeruginosa in bronchiectasis is necessary to prevent airway damage, loss of lung function and exacerbations, all of which contribute to adverse clinical outcome.

Azithromycin for sarcoidosis cough: an open-label exploratory clinical trial

Background

Chronic cough is a distressing symptom for many people with pulmonary sarcoidosis. Continuous treatment with a macrolide antibiotic may improve cough. We aimed to assess the potential efficacy of azithromycin in patients with sarcoidosis and self-reported cough.

Methods

We conducted a noncontrolled, open-label clinical trial of azithromycin 250 mg once daily for 3 months in patients with pulmonary sarcoidosis who reported a chronic cough. The primary outcome was number of coughs in 24 h. Secondary outcomes were cough visual analogue scales and quality of life measured using the Leicester Cough Questionnaire and King's Sarcoidosis Questionnaire. Safety outcomes included QTc interval on ECG. Measurements were made at baseline and after 1 and 3 months of treatment.

Results

All 21 patients were white, median age 57 years, 9 males, 12 females, median 3 years since diagnosis. Five were taking oral corticosteroids and none were taking other immunosuppressants. Twenty patients completed the trial. The median (range) number of coughs in 24 h was 228 (43–1950) at baseline, 122 (20–704) at 1 month, and 81 (16–414) at 3 months (p=0.002, Friedman's test). The median reduction in cough count at 3 months was 49.6%. There were improvements in all patient-reported outcomes. Azithromycin was well tolerated.

Conclusion

In a noncontrolled open-label trial in people with sarcoidosis who reported a chronic cough, 3 months of treatment with azithromycin led to improvements in a range of cough metrics. Azithromycin should be tested as a treatment for sarcoidosis cough in a randomised placebo-controlled trial.

In a noncontrolled open-label trial in people with sarcoidosis who reported a chronic cough, 3 months of treatment with azithromycin led to improvements in a range of cough metricshttps://bit.ly/2FB5tfq

BTS guideline on long-term macrolides in adults with respiratory disease: not quite a panacea

The British Thoracic Society (BTS) guideline on the use of long-term macrolides in adults with respiratory disease has been published. It indicates where there is evidence to support the use of long-term low-dose macrolides and where there is not. It discusses the potential benefits of such therapy for patients and also describes the potential risks to individuals and wider populations. It seeks to provide a pragmatic approach for clinicians considering long-term macrolide therapy for their patients. This guideline has also acted as a learning exercise for the BTS in introducing the Grading of Recommendations Assessment, Development and Evaluation approach to guideline development, which will be used going forwards.

British Thoracic Society guideline for the use of long-term macrolides in adults with respiratory disease

The full British Thoracic Society (BTS) guideline for the use of long-term macrolides in adults with respiratory disease is published in Thorax. The following is a summary of the recommendations and good practice points. The sections referred to in the summary refer to the full guideline. The appendices are available in the full guideline and online appendices are available on the BTS website. This is the first BTS guideline to use the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach as part of the process of guideline development and the guideline was used to pilot the new methodology.