Macrolide antibiotics for treatment of asthma in adults: a meta-analysis of 18 randomized controlled clinical studies

Effects of azithromycin on bronchial remodeling in the natural model of severe neutrophilic asthma in horses

Steroid resistance in asthma has been associated with neutrophilic inflammation and severe manifestations of the disease. Macrolide add-on therapy can improve the quality of life and the exacerbation rate in refractory cases, possibly with greater effectiveness in neutrophilic phenotypes. The mechanisms leading to these beneficial effects are incompletely understood and whether macrolides potentiate the modulation of bronchial remodeling induced by inhaled corticosteroids (ICS) is unknown. The objective of this study was to determine if adding azithromycin to ICS leads to further improvement of lung function, airway inflammation and bronchial remodeling in severe asthma. The combination of azithromycin (10 mg/kg q48h PO) and inhaled fluticasone (2500 µg q12h) was compared to the sole administration of fluticasone for five months in a randomized blind trial where the lung function, airway inflammation and bronchial remodeling (histomorphometry of central and peripheral airways and endobronchial ultrasound) of horses with severe neutrophilic asthma were assessed. Although the proportional reduction of airway neutrophilia was significantly larger in the group receiving azithromycin, the lung function and the peripheral and central airway smooth muscle mass decreased similarly in both groups. Despite a better control of airway neutrophilia, azithromycin did not potentiate the other clinical effects of fluticasone.

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.

Azithromycin Attenuates Bleomycin-Induced Pulmonary Fibrosis Partly by Inhibiting the Expression of LOX and LOXL-2

Pulmonary fibrosis (PF) is a chronic and progressive process of tissue repair. Azithromycin (AZM) may be beneficial for the treatment of PF because AZM has anti-inflammatory and immune regulatory roles and inhibits remodeling, but the mechanism is not entirely clear. In this study, we established a mouse PF model induced by bleomycin (BLM) and primary mouse lung fibroblasts stimulated by transforming growth factor (TGF)-β1 to explore the possible mechanisms of AZM in PF. Results showed that AZM reduces mortality and lung inflammation and attenuates BLM-induced PF in mice. AZM effectively reduced the expression of α-smooth muscle actin (SMA) and type I collagen. Meanwhile, expression of lysyl oxidase (LOX) and lysyl oxidase-like protein (LOXL)-2 in the lung tissue of mice after AZM treatment was significantly lower than in the BLM group. In addition, this study found that AZM significantly inhibits the TGF-β1/Smad and JNK/c-Jun signaling pathways in vivo, and expression of a-SMA, type I collagen, LOX and LOXL-2 in the lung tissue of mice treated with AZM was significantly lower than that in the BLM group. In vitro, AZM also effectively inhibited type I collagen, LOX, LOXL-2 and JNK-c-Jun signaling pathways in TGF-β1-stimulated primary mouse fibroblasts, and this effect was similar to that of a JNK-specific inhibitor (SP600125). In conclusion, AZM effectively attenuated BLM-induced PF in mice, which may play a role by partially inhibiting the JNK/c-Jun and TGF-β1/Smad signaling pathways and reducing production of LOX and LOXL2.

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.

Nonantimicrobial Actions of Macrolides: Overview and Perspectives for Future Development

Macrolides are among the most widely prescribed broad spectrum antibacterials, particularly for respiratory infections. It is now recognized that these drugs, in particular azithromycin, also exert time-dependent immunomodulatory actions that contribute to their therapeutic benefit in both infectious and other chronic inflammatory diseases. Their increased chronic use in airway inflammation and, more recently, of azithromycin in COVID-19, however, has led to a rise in bacterial resistance. An additional crucial aspect of chronic airway inflammation, such as chronic obstructive pulmonary disease, as well as other inflammatory disorders, is the loss of epithelial barrier protection against pathogens and pollutants. In recent years, azithromycin has been shown with time to enhance the barrier properties of airway epithelial cells, an action that makes an important contribution to its therapeutic efficacy. In this article, we review the background and evidence for various immunomodulatory and time-dependent actions of macrolides on inflammatory processes and on the epithelium and highlight novel nonantibacterial macrolides that are being studied for immunomodulatory and barrier-strengthening properties to circumvent the risk of bacterial resistance that occurs with macrolide antibacterials. We also briefly review the clinical effects of macrolides in respiratory and other inflammatory diseases associated with epithelial injury and propose that the beneficial epithelial effects of nonantibacterial azithromycin derivatives in chronic inflammation, even given prophylactically, are likely to gain increasing attention in the future. SIGNIFICANCE STATEMENT: Based on its immunomodulatory properties and ability to enhance the protective role of the lung epithelium against pathogens, azithromycin has proven superior to other macrolides in treating chronic respiratory inflammation. A nonantibiotic azithromycin derivative is likely to offer prophylactic benefits against inflammation and epithelial damage of differing causes while preserving the use of macrolides as antibiotics.

Targeting neutrophils in asthma: A therapeutic opportunity?

Suppression of airway inflammation with inhaled corticosteroids has been the key therapeutic approach for asthma for many years. Identification of inflammatory phenotypes in asthma has moreover led to important breakthroughs, e.g. with specific targeting of the IL-5 pathway as add-on treatment in difficult-to-treat eosinophilic asthma. However, the impact of interfering with the neutrophilic component in asthma is less documented and understood. This review provides an overview of established and recent insights with regard to the role of neutrophils in asthma, focusing on research in humans. We will describe the main drivers of neutrophilic responses in asthma, the heterogeneity in neutrophils and how they could contribute to asthma pathogenesis. Moreover we will describe findings from clinical trials, in which neutrophilic inflammation was targeted. It is clear that neutrophils are important actors in asthma development and play a role in exacerbations. However, more research is required to fully understand how modulation of neutrophil activity could lead to a significant benefit in asthma patients with airway neutrophilia.

Challenges faced in managing adult asthma: A perspective from Asian countries

Asthma imposes a significant burden on the health system and patients' quality of life. Within Asia, there is large variability in several cultural, social and economic factors ultimately influencing the management of asthma. Differences in risk factors and asthma management practices across Asia make asthma a truly 'mixed-bag' phenomenon. With the advent of biological agents and the consequent emphasis on asthma phenotyping and endotyping, it is more important than ever to understand the diverse nature of asthma as a disease. This is a collaborative review within Asia to highlight the differences in management of adult asthma, and the local modifications that are made to international guidelines. This review paves the way for a future Asian collaborative network in asthma epidemiological research.

Randomised study of the immunomodulatory effects of azithromycin in severely asthmatic horses

Neutrophilic inflammation is believed to contribute to the airway obstruction and remodelling in equine asthma. Azithromycin, an antibiotic with immunomodulatory properties, reduces pulmonary neutrophilia and hyper-responsiveness in human asthmatics and decreases airway remodelling in rodent models of asthma. It was therefore hypothesised that azithromycin would improve lung function, mucus accumulation and central airway remodelling by decreasing luminal neutrophilia in severe equine asthma. The effects of a 10-day treatment with either azithromycin or ceftiofur, an antimicrobial without immune-modulating activity, were assessed using a blind, randomised, crossover design with six severe asthmatic horses in clinical exacerbation. Lung function, tracheal mucus accumulation, tracheal wash bacteriology, bronchial remodelling, airway neutrophilia and mRNA expression of proinflammatory cytokines (interleukin (IL)-8, IL-17A, IL-1β, tumour necrosis factor-α) in bronchoalveolar lavage fluid were evaluated. Azithromycin decreased the expression of IL-8 (P=0.03, one-tailed) and IL-1β (P=0.047, one-tailed) but failed to improve the other variables evaluated. Ceftiofur had no effect on any parameter. The reduction of neutrophilic chemoattractants (IL-8, IL-1β) justifies further efforts to investigate the effects of a prolonged treatment with macrolides on airway neutrophilia and remodelling. The lack of efficacy of ceftiofur suggests that severe equine asthma should not be treated with antibiotics at first-line therapy.

Lung inflammation induced by exposure to Bisphenol-A is associated with mTOR-mediated autophagy in adolescent mice

Epidemiologic studies show that there is a link between Bisphenol A (BPA) exposure and lung inflammation. Despite this, the molecular mechanisms are not entirely known. This study sought to determine whether exposure to BPA affected the development of ovalbumin (OVA) induced lung inflammation in adolescent female mice and whether the mechanism was related to mTOR-mediated autophagy pathway. Female 4-week-old C57BL/6 mice after one week of domestication were randomly divided into five groups (8/group): control group, OVA group, 0.1 μg mL^-1 BPA + OVA group, 0.2 μg mL^-1 BPA + OVA group and 0.4 μg mL^-1 BPA + OVA group. BPA exacerbated airway hyperresponsiveness (AHR), induced the pathological changes in the lung, which also enhanced inflammatory cells and cytokine levels. In addition, BPA exposure affected expression of autophagy associated proteins and genes. This research results indicated that BPA aggravated OVA-induced lung inflammation and induced abnormal immune function in mice, and its mechanism was related to the activation of autophagy pathway by down-regulation expression of mTOR. These findings suggest that therapeutic strategies to target autophagy may offer a new approach for severe asthma therapy.

Azithromycin as an add-on treatment for persistent uncontrolled asthma in adults: protocol of a systematic review and meta-analysis

INTRODUCTION

Clinical management of asthma remains a public challenge. Despite standard treatment with inhaled corticosteroids (ICS) and long-acting beta-agonists (LABAs), asthma remains uncontrolled in a substantial number of chronic asthma patients who risk reduced lung function and severe exacerbations. Azithromycin could have add-on effects for these patients. This study is proposed to systematically evaluate the efficacy of azithromycin as an add-on treatment for adults with persistent uncontrolled symptomatic asthma.

METHODS AND ANALYSIS

Two reviewers will perform a comprehensive search of PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL) and four Chinese electronic databases including China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), WanFang Data and VIP Database from inception to May 2019. Only randomised controlled trials will be included. There is no restriction on language or publication status. Combined oral azithromycin and an ICS or/and a LABA will be compared with standard treatment alone or with a placebo. The primary outcomes are the number or frequency of asthma exacerbations, changes in asthma symptoms and lung function. Secondary outcomes include the number or frequency of inhalations of beta-agonists with or without corticosteroids for rescue use, eosinophil counts in blood or sputum, adverse events and others. A meta-analysis will be attempted to provide an estimate of the pooled treatment effect. Otherwise, qualitative descriptions of individual studies will be given.

ETHICS AND DISSEMINATION

Ethical approval is not required because no primary data will be collected. Study findings will be presented at scientific conferences or published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019117272.

Management of asthma COPD overlap

OBJECTIVE

To review the latest literature on management approaches to patients with asthma chronic obstructive pulmonary disease (COPD) overlap (ACO).

DATA SOURCES

Studies and reports were identified from the databases of PubMed/Medline and ClinicalTrials.gov from the US National Institutes of Health and the Cochrane Register of Controlled Trials.

STUDY SELECTIONS

Studies on the management of asthma, COPD, and ACO were included in this review.

RESULTS

Patients with asthma COPD overlap tend to have greater morbidity than those with asthma or COPD alone, but the information on the best therapeutic approach to this group of patients is still limited. Current treatment recommendations rely on expert opinions, roundtable discussions, and strategy documents, because most clinical studies in asthma and COPD have excluded patients with ACO. Because of the potential risk described in patients with asthma with the use of long-acting 2 agonist monotherapy, initial therapy for patients with ACO is recommended to include a long-acting bronchodilator in conjunction with inhaled corticosteroids. Long-acting muscarinic antagonists are effective in both asthma and COPD and should be considered in ACO as an add-on treatment. If inhaler therapy is not effective, advanced therapies based on phenotyping and identification of treatable traits may be considered.

CONCLUSION

Few studies have evaluated prospectively therapies in the ACO population, and future studies need to determine best strategies for the treatment of these patients, focusing on targeting its different phenotypes and its treatable traits.

Erythromycin relaxes BALB/c mouse airway smooth muscle

AIMS

Bitter taste receptor (TAS2R) agonists have bronchodilatory potentials. Erythromycin is a ligand of TAS2R10, but its relaxant profile is unknown. This study was performed to understand the relaxant effects of erythromycin and its potential mechanism.

MAIN METHODS

Airway resistance was tested by the whole body plethysmography in the ovalbumin-aluminum hydroxide induced asthma model mice. Tracheal ring segment myography was used to investigate the isometric tension of the smooth muscle. The cyclic adenosine monophosphate (cAMP) concentration was measured by enzyme immunoassay kit. Changes in the calcium influx in airway smooth muscle cells (ASMCs) were surveyed using a real-time confocal microscopy.

KEY FINDINGS

Erythromycin significantly relieved airway hyperreactivity in asthma model mice. Erythromycin relaxed mouse tracheal segments precontracted with carbachol, KCl, 5-hydroxytryptamine and U46619, and further dilated the tracheal rings relaxed by isoprenaline or atropine. Epithelium removal, indomethacin or NS-398 partially reduced the relaxation. U73122, 2-APB, iberiotoxin or ouabain did not change the concentration-relaxation curves of erythromycin on tracheal segments. Erythromycin didn't elevate cAMP level. CaCl₂-induced contraction in the K⁺-rich solution was impaired by erythromycin in the Ca²⁺-free solution. The intercellular Ca²⁺ level in the ASMCs was decreased by erythromycin, which was partly inhibited by Bay K8644 but not gallein.

SIGNIFICANCE

Erythromycin had marked bronchodilatory effect. The relaxation might be related to the L-type voltage-dependent calcium channel, but not the gustducin-associated βγ/phospholipase-Cβ/inositol 1,4,5-tri-phosphate receptor/large conductance Ca²⁺-activated K⁺ channel pathway or a cAMP-dependent way.

Autoinflammatory disease in the lung

Ascertaining the dominant cell type driving an immunological disease is essential to understanding the causal pathology and, therefore, selecting or developing an effective treatment. Classifying immunological diseases in this way has led to successful treatment regimens for many monogenic diseases; however, when the dominant cell type is unclear and there is no obvious causal genetic mutation, then identifying the correct disease classification and appropriate therapy can be challenging. In this review we focus on pulmonary immunological diseases where an innate immune signature has been identified as a predominant aspect of the immunopathology. We describe the molecular pathology of 'autoinflammatory diseases of the lung' and propose that small molecule and biological therapies, including recombinant interleukin-1 receptor antagonist, that target key innate immune pathways, are likely be beneficial in the control of pulmonary and systemic inflammation in these conditions. In addition, the successful use of macrolide antibiotics to treat lung infections in these conditions further confirms that the innate immune system is the key conductor of inflammation in these pulmonary diseases, as there is a strong body of evidence that macrolides are able to modulate the NLRP3 inflammasome and interleukin-1β and interleukin-18 secretion, both of which are central players in the innate immune response. Throughout this review we highlight the published evidence of autoinflammatory disease in chronic obstructive pulmonary disease, bronchiectasis, cystic fibrosis and rheumatoid lung disease and suggest that the fundamental pathology of these diseases places them towards the autoinflammatory pole of the immunological disease continuum.

Effect of azithromycin on asthma exacerbations and quality of life in adults with persistent uncontrolled asthma (AMAZES): a randomised, double-blind, placebo-controlled trial

BACKGROUND

Exacerbations of asthma cause a substantial global illness burden. Adults with uncontrolled persistent asthma despite maintenance treatment require additional therapy. Since macrolide antibiotics can be used to treat persistent asthma, we aimed to assess the efficacy and safety of oral azithromycin as add-on therapy in patients with uncontrolled persistent asthma on medium-to-high dose inhaled corticosteroids plus a long-acting bronchodilator.

METHODS

We did a randomised, double-blind, placebo controlled parallel group trial to determine whether oral azithromycin decreases the frequency of asthma exacerbations in adults (≥18 years) with symptomatic asthma despite current use of inhaled corticosteroid and long-acting bronchodilator, and who had no hearing impairment or abnormal prolongation of the corrected QT interval. Patients were randomly assigned (1:1) to receive azithromycin 500 mg or placebo three times per week for 48 weeks. Patients were centrally allocated using concealed random allocation from a computer-generated random numbers table with permuted blocks of 4 or 6 and stratification for centre and past smoking. Primary efficacy endpoints were the rate of total (severe and moderate) asthma exacerbations over 48 weeks and asthma quality of life. Data were analysed on an intention-to-treat basis. The trial is registered at the Australian and New Zealand Clinical Trials Registry (ANZCTR), number 12609000197235.

FINDINGS

Between June 12, 2009, and Jan 31, 2015, 420 patients were randomly assigned (213 in the azithromycin group and 207 in the placebo group). Azithromycin reduced asthma exacerbations (1·07 per patient-year [95% CI 0·85-1·29]) compared with placebo (1·86 per patient-year [1·54-2·18]; incidence rate ratio [IRR] 0·59 [95% CI 0·47-0·74]; p<0·0001). The proportion of patients experiencing at least one asthma exacerbation was reduced by azithromycin treatment (127 [61%] patients in the placebo group vs 94 [44%] patients in the azithromycin group, p<0·0001). Azithromycin significantly improved asthma-related quality of life (adjusted mean difference, 0·36 [95% CI 0·21-0·52]; p=0·001). Diarrhoea was more common in azithromycin-treated patients (72 [34%] vs 39 [19%]; p=0·001).

INTERPRETATION

Adults with persistent symptomatic asthma experience fewer asthma exacerbations and improved quality of life when treated with oral azithromycin for 48 weeks. Azithromycin might be a useful add-on therapy in persistent asthma.

FUNDING

National Health and Medical Research Council of Australia, John Hunter Hospital Charitable Trust.

Phloretin Attenuates Allergic Airway Inflammation and Oxidative Stress in Asthmatic Mice

Phloretin (PT), isolated from the apple tree, was previously demonstrated to have antioxidative and anti-inflammatory effects in macrophages and anti-adiposity effects in adipocytes. Inflammatory immune cells generate high levels of reactive oxygen species (ROS) for stimulated severe airway hyperresponsiveness (AHR) and airway inflammation. In this study, we investigated whether PT could reduce oxidative stress, airway inflammation, and eosinophil infiltration in asthmatic mice, and ameliorate oxidative and inflammatory responses in tracheal epithelial cells. BALB/c mice were sensitized with ovalbumin (OVA) to induce asthma symptoms. Mice were randomly assigned to the five experimental groups: normal controls; OVA-induced asthmatic mice; and OVA-induced mice injected intraperitoneally with one of the three PT doses (5, 10, or 20 mg/kg). In addition, we treated inflammatory human tracheal epithelial cells (BEAS-2B cells) with PT to assess oxidative responses and the levels of proinflammatory cytokines and chemokines. We found that PT significantly reduced goblet cell hyperplasia and eosinophil infiltration, which decreased AHR, inflammation, and oxidative responses in the lungs of OVA-sensitized mice. PT also decreased malondialdehyde levels in the lung and reduced Th2 cytokine production in bronchoalveolar lavage fluids. Furthermore, PT reduced ROS, proinflammatory cytokines, and eotaxin production in BEAS-2B cells. PT also suppressed monocyte cell adherence to inflammatory BEAS-2B cells. These findings suggested that PT alleviated pathological changes, inflammation, and oxidative stress by inhibiting Th2 cytokine production in asthmatic mice. PT showed therapeutic potential for ameliorating asthma symptoms in the future.

Effects of low-dose clarithromycin added to fluticasone on inflammatory markers and pulmonary function among children with asthma: A randomized clinical trial

BACKGROUND

Macrolides exert anti-inflammatory and immunomodulatory effects beyond their purely antibacterial action, as demonstrated by several bronchial inflammatory disorders, including asthma.

METHODS

Fifty-eight children with newly diagnosed mild persistent asthma were selected by using the Global Initiative for Asthma guidelines and were randomly divided into the study (group I) (n = 36) and control (group II) (n = 22) groups. Mycoplasma pneumonia-specific immunoglobulin G and -specific immunoglobulin M antibody levels of each participant were measured by enzyme-linked immunosorbent assay. Clarithromycin 5 mg/kg daily and placebo were given to groups I and II, respectively, for 4 weeks. All of the children had maintenance inhaled corticosteroid (fluticasone propionate, one puff twice [50 μg/puff] daily). Forced expiratory volume in 1 second, forced expiratory flow at 25-75% of the pulmonary volume, exhaled nitric oxide value, total IgE level, absolute eosinophil count, and eosinophilic cation protein value were measured at baseline and at the end of the treatment.

RESULTS

There are significantly increased forced expiratory volume in 1 second and forced expiratory flow at 25-75% of the pulmonary volume levels and decreased exhaled nitric oxide values after the 4-week clarithromycin treatment. The study group also had a decreased peripheral blood absolute eosinophil count and eosinophilic cation protein level, but not for the total IgE level, after the treatment.

CONCLUSION

Four weeks of sub-antimicrobial doses of clarithromycin may improve pulmonary function and decrease eosinophilic inflammation in children with asthma.

Respiratory drugs and macrolides prevent asthma exacerbations: A real-world investigation

OBJECTIVE

We investigated the real-world effectiveness of several drugs (including short- and long-acting beta-agonists [SABAs and LABAs], inhaled corticosteroids [ICS], and antibiotics) in preventing severe asthma exacerbations by carrying-out a large observational study based on the healthcare utilization databases of the Italian Lombardy Region.

METHODS

We identified all patients aged 6-40 years who performed an Emergency Department visit for asthma during 2010-2012 as cases. To address bias due to unmeasured confounders, we implemented a case-crossover (CC) design. Addressing other specific sources of systematic errors (e.g. protopathic bias) was of particular concern in this study.

RESULTS

A total of 7300 cases were included in the study. The CC odds ratios (95% confidence intervals) for current vs. past use were 0.81 (0.71, 0.92) for SABAs, 0.83 (0.72, 0.96) for ICS, 0.78 (0.66, 0.91) for LABA/ICS fixed combinations, 0.79 (0.65, 0.97) for other respiratory drugs, and 0.79 (0.69, 0.92) for macrolides antibiotics. Sensitivity analyses showed that our results were robust with respect to several sources of bias.

CONCLUSIONS

Our study provides evidence from the real-world clinical practice on the effectiveness of several respiratory drugs and macrolides in reducing the risk of severe asthma exacerbations.

Pharmacological Therapy of Bronchial Asthma: The Role of Biologicals

Bronchial asthma is a heterogeneous, complex, chronic inflammatory and obstructive pulmonary disease driven by various pathways to present with different phenotypes. A small proportion of asthmatics (5-10%) suffer from severe asthma with symptoms that cannot be controlled by guideline therapy with high doses of inhaled steroids plus a second controller, such as long-acting β2 agonists (LABA) or leukotriene receptor antagonists, or even systemic steroids. The discovery and characterization of the pathways that drive different asthma phenotypes have opened up new therapeutic avenues for asthma treatment. The approval of the humanized anti-IgE antibody omalizumab for the treatment of severe allergic asthma has paved the way for other cytokine-targeting therapies, particularly those targeting interleukin (IL)-4, IL-5, IL-9, IL-13, IL-17, and IL-23 and the epithelium-derived cytokines IL-25, IL-33, and thymic stromal lymphopoietin. Knowledge of the molecular basis of asthma phenotypes has helped, and continues to help, the development of novel biologicals that target a diverse array of phenotype-specific molecular targets in patients suffering from severe asthma. This review summarizes potential therapeutic approaches that are likely to show clinical efficacy in the near future, focusing on biologicals as promising novel therapies for severe asthma.

Macrolides for chronic asthma

BACKGROUND

Asthma is a chronic disease in which inflammation of the airways causes symptomatic coughing, wheezing, and difficult breathing. The inflammation may have different underlying causes, including a reaction to infection in the lungs. Macrolides are antibiotics with antimicrobial and antiinflammatory activities that have been used long-term to control asthma symptoms.

OBJECTIVES

To assess the effects of macrolides for managing chronic asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register up to April 2015. 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

Randomised controlled clinical trials involving both children and adults with chronic asthma treated with macrolides versus placebo for more than four weeks .

DATA COLLECTION AND ANALYSIS

Two reviewers 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.

MAIN RESULTS

Twenty-three studies met the inclusion criteria, randomising a total of 1513 participants to receive macrolide or placebo. The quality of evidence was generally very low due to incomplete reporting of study methodology and clinical data, suspected publication bias, indirectness of study populations, risk of bias and imprecision (because of small numbers of patients and events). Most of the included studies reported data from patients with persistent or severe asthma, but inclusion criteria, interventions and outcomes were highly variable.Macrolides were not found to be better than placebo for the majority of clinical outcomes including exacerbations requiring hospital admission (odds ratio (OR) 0.98, 95% confidence interval (CI) 0.13 to 7.23; participants = 143; studies = 2; I(2) = 0%) or at least treatment with oral steroids (OR 0.82, 95% CI 0.43 to 1.57; participants = 290; studies = 5; I(2) = 0%). The evidence on symptom scales (standard mean difference (SMD) -0.04, 95% CI -0.36 to 0.28), asthma control (SMD -0.05, 95% CI -0.26 to 0.15), quality of life (mean difference (MD) 0.06, 95% CI -0.12 to 0.24) and rescue medication use (MD -0.26, 95% CI -0.65 to 0.12) was all of very low quality and did not show a benefit of macrolide treatment. There was some evidence that macrolides led to some improvement in lung function (forced expiratory volume in one second (FEV1): MD 0.08, 95% CI 0.02 to 0.14), although not on all the measures we assessed. Measures of bronchial hyperresponsiveness were too varied to pool, but most studies showed no clear benefit of macrolide over placebo. Two studies recruiting people taking regular oral corticosteroids suggested macrolides may have a steroid-sparing effect in this population. Macrolides were well tolerated with respect to severe adverse events, although less than half of the studies reported the outcome (OR 0.80, 95% CI 0.24 to 2.68; participants = 434; studies = 7; I(2) = 0%). Reporting of specific side effects was too patchy across studies to analyse meaningfully. As already reported in the previous versions of the systematic review, biomarkers of asthma activity, such as sputum and serum level of eosinophil cationic protein (ECP) or sputum and serum eosinophils, were lower in patients treated with macrolides, but this was not associated with clinical benefits.Two within-study subgroup analyses showed a possible benefit of macrolides for non-eosinophilic asthma, but it was not possible to investigate this further using the data available for this review.

AUTHORS' CONCLUSIONS

Existing evidence does not show macrolides to be better than placebo for the majority of clinical outcomes. However, they may have a benefit on some measures of lung function, and 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 review highlights the need for researchers to report clinically relevant outcomes accurately and completely using guideline definitions of exacerbations and validated scales. The possible benefit of macrolides in patients with non-eosinophilic asthma based on subgroup analyses in two of the included studies may require further investigation.