Macrolide therapy in respiratory viral infections

Potential Anti-COVID-19 Therapeutics that Block the Early Stage of the Viral Life Cycle: Structures, Mechanisms, and Clinical Trials

The ongoing pandemic of coronavirus disease-2019 (COVID-19) is being caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The disease continues to present significant challenges to the health care systems around the world. This is primarily because of the lack of vaccines to protect against the infection and the lack of highly effective therapeutics to prevent and/or treat the illness. Nevertheless, researchers have swiftly responded to the pandemic by advancing old and new potential therapeutics into clinical trials. In this review, we summarize potential anti-COVID-19 therapeutics that block the early stage of the viral life cycle. The review presents the structures, mechanisms, and reported results of clinical trials of potential therapeutics that have been listed in clinicaltrials.gov. Given the fact that some of these therapeutics are multi-acting molecules, other relevant mechanisms will also be described. The reviewed therapeutics include small molecules and macromolecules of sulfated polysaccharides, polypeptides, and monoclonal antibodies. The potential therapeutics target viral and/or host proteins or processes that facilitate the early stage of the viral infection. Frequent targets are the viral spike protein, the host angiotensin converting enzyme 2, the host transmembrane protease serine 2, and clathrin-mediated endocytosis process. Overall, the review aims at presenting update-to-date details, so as to enhance awareness of potential therapeutics, and thus, to catalyze their appropriate use in combating the pandemic.

Granulocyte-targeted therapies for airway diseases

The average respiration rate for an adult is 12-20 breaths per minute, which constantly exposes the lungs to allergens and harmful particles. As a result, respiratory diseases, which includes asthma, chronic obstructive pulmonary disease (COPD) and acute lower respiratory tract infections (LTRI), are a major cause of death worldwide. Although asthma, COPD and LTRI are distinctly different diseases with separate mechanisms of disease progression, they do share a common feature - airway inflammation with intense recruitment and activation of granulocytes and mast cells. Neutrophils, eosinophils, basophils, and mast cells are crucial players in host defense against pathogens and maintenance of lung homeostasis. Upon contact with harmful particles, part of the pulmonary defense mechanism is to recruit these cells into the airways. Despite their protective nature, overactivation or accumulation of granulocytes and mast cells in the lungs results in unwanted chronic airway inflammation and damage. As such, understanding the bright and the dark side of these leukocytes in lung physiology paves the way for the development of therapies targeting this important mechanism of disease. Here we discuss the role of granulocytes in respiratory diseases and summarize therapeutic strategies focused on granulocyte recruitment and activation in the lungs.

Should azithromycin be used to treat COVID-19? A rapid review

BACKGROUND

There are no established effective treatments for COVID-19. While novel drugs are being developed, azithromycin has been identified as a candidate treatment in the interim.

AIM

To review the evidence for the effectiveness and safety of azithromycin in treating COVID-19.

DESIGN & SETTING

A rapid review of the literature was conducted.

METHOD

Electronic searches were conducted on 16 April 2020 of PubMed, TRIP, EPPI COVID Living Map, MedRxiv, GoogleScholar, and Google. In vivo and in vitro studies were included assessing the safety and effectiveness of azithromycin for treatment of COVID-19, and/or the activity of azithromycin against SARS-CoV-2. In vivo studies needed to include a comparator group.

RESULTS

Three studies were identified, two in vitro and one in vivo, which were suitable for inclusion. All three were published as pre-prints. The in vitro studies revealed conflicting results, with one finding anti-SARS-CoV-2 activity for azithromycin alone, while the other found activity against SARS-CoV-2 only when azithromycin was combined with hydroxychloroquine. A small trial of 36 patients, with high risk of bias, found superior viral clearance in patients with COVID-19 treated with azithromycin and hydroxychloroquine combined, compared with hydroxychloroquine alone.

CONCLUSION

There is no evidence to support the use of azithromycin for the treatment of COVID-19 outside of the context of clinical trials, unless it is used to treat bacterial super-infection. There is extremely limited evidence of a possible synergy between azithromycin and hydroxychloroquine. The adverse events profile of azithromycin in the context of COVID-19 has not yet been established. Well-conducted clinical trials are urgently needed in this area.

Potential Role of Nrf2 Activators with Dual Antiviral and Anti-Inflammatory Properties in the Management of Viral Pneumonia

The outbreak of coronavirus disease 2019 (COVID-19) pandemic has already caused a huge burden to the global healthcare system, with the death toll reached tens of thousands. Although some antiviral agents were identified and used to inhibit viral replication, the management of cytokine storm is also a critical issue. In this article, we reviewed the literature on drug candidates for severe acute respiratory syndrome (SARS-CoV-1) and provided a brief overview of a class of drugs that exert antiviral and anti-inflammatory effects. These molecules mitigated inflammatory cytokine cascades induced by viral infections via Nrf2 activating capacity and might have additional anti-fibrotic and anti-remodeling properties. Besides, their effects on the regulation of scavenger receptors expression by macrophages may offer some benefits to the pulmonary antibacterial defense system after viral infection. The potential roles of these agents assessed on the basis of the pathophysiology of viral pneumonia and acute respiratory distress syndrome were also discussed. Further research is needed to ascertain whether Nrf2 activators are useful in the management of viral pneumonia.

Macrolides and viral infections: focus on azithromycin in COVID-19 pathology

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It is necessary to quickly find therapeutic options for treating novel SARS-CoV2

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Azithromycin has been demonstrated to have antiviral and immunomodulatory effects, which could be effective in the hyper-inflammatory syndrome caused by SARS-CoV2

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Azithromycin has also shown clinical efficacy in respiratory distress syndrome and viral infections

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Preliminary results regarding the efficacy of the combination of azithromycin and hydroxychloroquine in COVID-19 are conflicting

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There are some concerns regarding the association of azithromycin and hydroxychloroquine because of QT prolongation

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Further studies have to be performed to investigate the safety and efficacy of azithromycin and the combination with hydroxychloroquine in COVID-19

The emergence of the new COVID-19 virus is proving to be a challenge in seeking effective therapies. Since the most severe clinical manifestation of COVID-19 appears to be a severe acute respiratory syndrome, azithromycin has been proposed as a potential treatment. Azithromycin is known to have immunomodulating and antiviral properties. In vitro studies have demonstrated the capacity of azithromycin in reducing production of pro-inflammatory cytokines such as IL-8, IL-6, TNF alpha, reduce oxidative stress, and modulate T-helper functions. At the same time there are multiple clinical evidences of the role of azithromycin in acute respiratory distress syndrome and against Middle East Respiratory syndrome (MERS). Some preliminary evidence has demonstrated controversial results regarding efficacy of azithromycin in combination with hydroxychloroquine in COVID-19. First, a French trial demonstrated 100% virological negativizing of six patients treated with azithromycin plus hydroxychloroquine vs. 57.1% of patients treated with only hydroxychloroquine and 12.5% of the control group (P < 0.05). On the other hand, another case series revealed no efficacy at all on 11 patients treated with the same combination and doses. Furthermore, there are some concerns regarding the association of azithromycin and hydroxychloroquine because of potential QT prolongation. In fact, both drugs have this as a potential side effect and evidence regarding the safe use of this combination is controversial. Despite the necessity to quickly find solutions for COVID-19, extreme caution must be used in evaluating the risk-benefit balance. However, based on preclinical and clinical evidence and some preliminary results in COVID-19, azithromycin could have potential in the fight against this new disease.

Widely available lysosome targeting agents should be considered as potential therapy for COVID-19

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Lysosome targeting agents can disrupt endolysosomal maturation and inhibit viral replication

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Lysosome targeting agents and lysosomotropic drugs should be explored as antiviral drugs for severe acute respiratory syndrome coronavirus-2

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Some lysosomotropic drugs are commonly used pharmacological agents

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Particular attention should be directed towards macrolides (e.g. azithromycin), non-steroidal anti-inflammatory drugs (e.g. indomethacin) and other lysosomotoropic agents

While the coronavirus disease 2019 (COVID-19) pandemic advances, the scientific community continues to struggle in the search for treatments. Several improvements have been made, including discovery of the clinical efficacy of chloroquine (CQ) in patients with COVID-19, but effective treatment protocols remain elusive. In the search for novel treatment options, many scientists have used the in-silico approach to identify compounds that could interfere with the key molecules involved in entrance, replication or dissemination of severe acute respiratory syndrome coronavirus-2. However, most of the identified molecules are not available as pharmacological agents at present, and assessment of their safety and efficacy could take many months. This review took a different approach based on the proposed pharmacodynamic model of CQ in COVID-19. The main mechanism of action responsible for the favourable outcome of patients with COVID-19 treated with CQ seems to be related to a pH-modulation-mediated effect on endolysosomal trafficking, a characteristic of chemical compounds often called ‘lysosomotropic agents’ because of the physico-chemical properties that enable them to diffuse passively through the endosomal membrane and undergo protonation-based trapping in the lumen of the acidic vesicles. This review discusses lysosomotropic and lysosome targeting drugs that are already in clinical use and are characterized by good safety profiles, low cost and wide availability. Some of these drugs –particularly azithromycin and other macrolides, indomethacin and some other non-steroidal anti-inflammatory drugs, proton pump inhibitors and fluoxetine – could provide additional therapeutic benefits in addition to the potential antiviral effect that is still to be confirmed by well-controlled clinical trials. As some of these drugs have probably been used empirically in the treatment of COVID-19, it is hoped that colleagues worldwide will publish patient data to enable evaluation of the potential efficacy of these agents in the clinical context, and rapid implementation in therapeutic protocols if they are shown to have a beneficial effect on clinical outcome.

The Rationale for Potential Pharmacotherapy of COVID-19

On 11 March 2020, the coronavirus disease (COVID-19) was defined by the World Health Organization as a pandemic. Severe acute respiratory syndrome-2 (SARS-CoV-2) is the newly evolving human coronavirus infection that causes COVID-19, and it first appeared in Wuhan, China in December 2019 and spread rapidly all over the world. COVID-19 is being increasingly investigated through virology, epidemiology, and clinical management strategies. There is currently no established consensus on the standard of care in the pharmacological treatment of COVID-19 patients. However, certain medications suggested for other diseases have been shown to be potentially effective for treating this infection, though there has yet to be clear evidence. Therapies include new agents that are currently tested in several clinical trials, in addition to other medications that have been repurposed as antiviral and immune-modulating therapies. Previous high-morbidity human coronavirus epidemics such as the 2003 SARS-CoV and the 2012 Middle East respiratory syndrome coronavirus (MERS-CoV) prompted the identification of compounds that could theoretically be active against the emerging coronavirus SARS-CoV-2. Moreover, advances in molecular biology techniques and computational analysis have allowed for the better recognition of the virus structure and the quicker screening of chemical libraries to suggest potential therapies. This review aims to summarize rationalized pharmacotherapy considerations in COVID-19 patients in order to serve as a tool for health care professionals at the forefront of clinical care during this pandemic. All the reviewed therapies require either additional drug development or randomized large-scale clinical trials to be justified for clinical use.

A Precision Medicine Approach to SARS-CoV-2 Pandemic Management

Purpose of review

Precision medicine (PM) represents a new paradigm in disease diagnosis, prevention, and treatment. To apply PM premises in an emerging coronavirus pandemic acquires potentially greater relevance in order to allow the selection of specific preventive measures as well as biomarkers that will be useful in disease management.

Recent findings

The identification of the new coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the responsible for the coronavirus disease 2019 (COVID-19) pandemic had led to a plethora of strategies to contain viral dissemination, affecting life styles and personal behaviors. Viral genomic sequencing has shown that SARS-CoV-2 spike protein utilizes angiotensin-converting enzyme 2 (ACE2) found on ciliated epithelial cells of the human lungs as its specific receptor. Neutralizing antibodies to the receptor-binding domain of the spike protein were detected in patients recovered from COVID-19; however, both T cells and NK cells were reduced in severe cases. Excessive and uncontrolled releases of pro-inflammatory cytokines such as IL-1B, IL-1RA, IL-7, IL-8, IL-9, IL-10, fibroblast growth factor (FGF), granulocyte–macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor (TNFα) were increased in severe patients. These cytokines might be useful biomarkers of disease worsening and potential targets for new biological therapies currently under investigation.

Summary

Present knowledge and recent developments in PM approach to COVID-19 disease prevention, evaluation, and management are pointed out. Better understanding of pathogenic pathways together with an accurate phenotype classification of patients presented with SARS-CoV-2 infection and symptoms might contribute to a more accurate definition of biomarkers and other diagnostic tools, which may lead to more precise mitigation strategies, personalized pharmacologic options, as well as new biological therapy developments.

Excessive lysosomal ion-trapping of hydroxychloroquine and azithromycin

A recent report identified significant reductions or disappearance of viral load in COVID-19 patients given a combination of hydroxychloroquine and azithromycin. The present communication discusses some common pharmacokinetic properties of these two drugs that may be linked to a potential underlying mechanism of action for these antiviral effects. The physicochemical properties of both hydroxychloroquine and azithromycin are consistent with particularly high affinity for the intracellular lysosomal space, which has been implicated as a target site for antiviral activity. The properties of both drugs predict dramatic accumulation in lysosomes, with calculated lysosomal drug concentrations that exceed cytosolic and extracellular concentrations by more than 50 000-fold. These predictions are consistent with previously reported experimentally measured cellular and extracellular concentrations of azithromycin. This is also reflected in the very large volumes of distribution of these drugs, which are among the highest of all drugs currently in use. The combination of hydroxychloroquine and azithromycin produces very high local concentrations in lysosomes. The clinical significance of this observation is unclear; however, the magnitude of this mechanism of drug accumulation via ion-trapping in lysosomes could be an important factor for the pharmacodynamic effects of this drug combination.

Efficacy of Macrolides on Acute Asthma or Wheezing Exacerbations in Children with Recurrent Wheezing: A Systematic Review and Meta-analysis

INTRODUCTION

The role of macrolides for treatment of children with acute asthma or wheezing exacerbations is unclear.

OBJECTIVE

The aim of this systematic review was to evaluate the effectiveness of macrolides in children with recurrent wheezing presenting with acute asthma or wheezing exacerbation.

METHODS

We conducted an electronic search in MEDLINE, EMBASE, CINAHL, LILACS, CENTRAL, and ClinicalTrials.gov.

STUDY SELECTION CRITERIA

Randomized controlled trials of macrolides (any macrolide) compared with placebo or standard treatment in children up to 18 years with recurrent wheezing/asthma presenting with an acute exacerbation.

OUTCOMES

Primary outcomes were need for hospitalization and/or time of acute asthma/wheezing symptoms resolution; secondary outcomes were duration of stay in the emergency department (ED)/clinic, severity of symptoms of the index episode, use of additional systemic corticosteroids or short active β-2 agonists, changes in lung function measures, ED visit/hospitalization during first week after index episode, time to next exacerbation, or adverse effects (AEs).

RESULTS

Only three studies met the inclusion criteria (n = 334 children, 410 treated episodes); two studies included recurrent wheezers and the third included asthmatic children. There was no difference in hospitalization between groups, but children treated with macrolides had a significantly lower time to symptoms resolution than controls, although the magnitude of benefit remains to be quantified due to no normal distribution data presented. There was no difference in time to next episode of exacerbation (HR 0.96; 95% CI 0.71-1.28; I² = 0%; p = 0.77). In one study, children receiving macrolides had a significant decrease in the severity of symptoms, decrease use of salbutamol, and another study showed improved lung function. No study evaluated antibiotic resistance development.

CONCLUSIONS

Limited evidence support that a macrolide trial could be considered in children with acute asthma or recurrent wheezing exacerbation.

Approaches for the Treatment of SARS-CoV-2 Infection: A Pharmacologic View and Literature Review

The emergence of a novel Coronavirus disease (COVID-19) inducing acute respiratory distress syndrome (ARDS) was identified in Hubei province of China in December 2019 and rapidly spread worldwide as pandemic and became a public health concern. COVID-19 disease is caused by a new virus known as SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), which has recently offered many challenges and efforts to identify effective drugs for its prevention and treatment. Currently, there is no proven effective approach and medication against this virus. Quickly expanding clinical trials and studies on Coronavirus disease 2019 increase our knowledge regarding SARS-CoV-2 virus and introduce several potential drugs targeting virus moiety or host cell elements. Overall, 3 stages were suggested for SARS-CoV-2 infection according to the disease severity, clinical manifestations, and treatment outcomes, including mild, moderate, and severe. This review aimed to classify and summarize several medications and potential therapies according to the disease 3 stages; however, it is worth noting that no medication and therapy has been effective so far.

Myrothecine A modulates the proliferation of HCC cells and the maturation of dendritic cells through downregulating miR-221

Myrothecine A, characterized from the extracts of myrothecium roridum strain IFB-E012, isolated as endophytic fungi found in the traditional Chinese medicinal plant Artemisia annua. Here we investigated its roles on anti-tumor and immune regulation in vitro. Dendritic cells (DCs) are the most potent antigen presenting cells in immune responses. Recent studies have indicated that miRNAs are indispensable in regulating the development, differentiation, maturation and function of DC. MiR-221, acted as an oncogene, is an important regulator in cancer development by binding to 3' untranslated regions (3' UTR) of target mRNA. Here, we investigated whether myrothecine A could inhibit cell proliferation in hepatocellular carcinoma (HCC) cell line SMMC-7721 by regulating miR-221. The HCC cells were treated with myrothecine A at different concentration, and the cell growth ability was measured by MTT assay. Then we observed whether myrothecine A could affect the maturation of DC by regulating miR-221. The HCC cell line was co-cultured with immature DC from mice bone marrow, and the levels of CD86 and CD40 was detected by FCM. Our results showed that myrothecine A could rescue miR-221-induced cell proliferation and influence the protein level of p27 by inhibiting the expression of miR-221. In addition, myrothecine A could enhance the expression of CD86 and CD40 by reversing the function of miR-221. Therefore, myrothecine A may be acted as an anti-tumor drug to promote the maturation of DC in the microenvironment of hepatocellular carcinoma.

Macrolides in critically ill patients with Middle East Respiratory Syndrome

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More than one-third of critically ill patients with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) received empiric therapy with macrolides.

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Macrolide therapy is not significantly associated with a reduction in 90-day mortality of critically ill patients with MERS-CoV.

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Macrolide therapy is not significantly associated with improvement in MERS-CoV RNA clearance of critically ill patients with MERS-CoV.

Objectives

Macrolides have been reported to be associated with improved outcomes in patients with viral pneumonia related to influenza and other viruses, possibly because of their immune-modulatory effects. Macrolides have frequently been used in patients with Middle East Respiratory Syndrome (MERS). This study investigated the association of macrolides with 90-day mortality and MERS coronavirus (CoV) RNA clearance in critically ill patients with MERS.

Methods

This retrospective analysis of a multicenter cohort database included 14 tertiary-care hospitals in five cities in Saudi Arabia. Multivariate logistic-regression analysis was used to determine the association of macrolide therapy with 90-day mortality, and the Cox-proportional hazard model to determine the association of macrolide therapy with MERS-CoV RNA clearance.

Results

Of 349 critically ill MERS patients, 136 (39%) received macrolide therapy. Azithromycin was most commonly used (97/136; 71.3%). Macrolide therapy was commonly started before the patient arrived in the intensive care unit (ICU) (51/136; 37.5%), or on day1 in ICU (53/136; 39%). On admission to ICU, the baseline characteristics of patients who received and did not receive macrolides were similar, including demographic data and sequential organ failure assessment score. However, patients who received macrolides were more likely to be admitted with community-acquired MERS (P = 0.02). Macrolide therapy was not independently associated with a significant difference in 90-day mortality (adjusted odds ratio [OR]: 0.84; 95% confidence interval [CI] :0.47–1.51; P = 0.56) or MERS-CoV RNA clearance (adjusted HR: 0.88; 95% CI:0.47–1.64; P = 0.68).

Conclusions

These findings indicate that macrolide therapy is not associated with a reduction in 90-day mortality or improvement in MERS-CoV RNA clearance.

Role of prophylactic azithromycin to reduce airway inflammation and mortality in a RSV mouse infection model

BACKGROUND

Respiratory syncytial virus (RSV) infection is an important cause of morbidity and mortality in vulnerable populations. Macrolides have received considerable attention for their anti-inflammatory actions beyond their antibacterial effect. We hypothesize that prophylactic azithromycin will be effective in reducing the severity of RSV infection in a mouse model.

METHODS

Four groups of BALB/c mice were studied for 8 days: Control (C), RSV-infected (R), early prophylaxis with daily azithromycin from days 1 to 8, (E), and late prophylaxis with daily azithromycin from days 4 to 8 (L). Mice were infected with RSV on day 4, except for the control group. All groups were followed for a total of 8 days when bronchoalveolar lavage cell count and cytokines levels were measured. Mouse weight, histopathology, and mortality data were obtained.

RESULTS

Prophylactic azithromycin significantly attenuated post-viral weight loss between group R and both groups E and L (P = 0.0236, 0.0179, respectively). IL-6, IL-5, and Interferon-Gamma were significantly lower in group L (P = 0.0294, 0.0131, and 0.0056, respectively) compared with group R. The total cell count was significantly lower for group L as compared with group R (P < 0.05). Mortality was only observed in group R (8%). Lung histology in the prophylactic groups showed diminished inflammatory infiltrates and cellularity when compared with group R.

CONCLUSION

Prophylactic azithromycin effectively reduced weight loss, airway inflammation, cytokine levels and mortality in RSV-infected mice. These results support the rationale for future clinical trials to evaluate the effects of prophylactic azithromycin for RSV infection.

The role of adjuvant immunomodulatory agents for treatment of severe influenza

A severe inflammatory immune response with hypercytokinemia occurs in patients hospitalized with severe influenza, such as avian influenza A(H5N1), A(H7N9), and seasonal A(H1N1)pdm09 virus infections. The role of immunomodulatory therapy is unclear as there have been limited published data based on randomized controlled trials (RCTs). Passive immunotherapy such as convalescent plasma and hyperimmune globulin have some studies demonstrating benefit when administered as an adjunctive therapy for severe influenza. Triple combination of oseltamivir, clarithromycin, and naproxen for severe influenza has one study supporting its use, and confirmatory studies would be of great interest. Likewise, confirmatory studies of sirolimus without concomitant corticosteroid therapy should be explored as a research priority. Other agents with potential immunomodulating effects, including non-immune intravenous immunoglobulin, N-acetylcysteine, acute use of statins, macrolides, pamidronate, nitazoxanide, chloroquine, antiC5a antibody, interferons, human mesenchymal stromal cells, mycophenolic acid, peroxisome proliferator-activated receptors agonists, non-steroidal anti-inflammatory agents, mesalazine, herbal medicine, and the role of plasmapheresis and hemoperfusion as rescue therapy have supportive preclinical or observational clinical data, and deserve more investigation preferably by RCTs. Systemic corticosteroids administered in high dose may increase the risk of mortality and morbidity in patients with severe influenza and should not be used, while the clinical utility of low dose systemic corticosteroids requires further investigation.

Effectiveness of β-Lactam Monotherapy vs Macrolide Combination Therapy for Children Hospitalized With Pneumonia

IMPORTANCE

β-Lactam monotherapy and β-lactam plus macrolide combination therapy are both common empirical treatment strategies for children hospitalized with pneumonia, but few studies have evaluated the effectiveness of these 2 treatment approaches.

OBJECTIVE

To compare the effectiveness of β-lactam monotherapy vs β-lactam plus macrolide combination therapy among a cohort of children hospitalized with pneumonia.

DESIGN, SETTING, AND PARTICIPANTS

We analyzed data from the Etiology of Pneumonia in the Community Study, a multicenter, prospective, population-based study of community-acquired pneumonia hospitalizations conducted from January 1, 2010, to June 30, 2012, in 3 children's hospitals in Nashville, Tennessee; Memphis, Tennessee; and Salt Lake City, Utah. The study included all children (up to 18 years of age) who were hospitalized with radiographically confirmed pneumonia and who received β-lactam monotherapy or β-lactam plus macrolide combination therapy. Data analysis was completed in April 2017.

MAIN OUTCOMES AND MEASURES

We defined the referent as β-lactam monotherapy, including exclusive use of an oral or parenteral second- or third-generation cephalosporin, penicillin, ampicillin, ampicillin-sulbactam, amoxicillin, or amoxicillin-clavulanate. Use of a β-lactam plus an oral or parenteral macrolide (azithromycin or clarithromycin) served as the comparison group. We modeled the association between these groups and patients' length of stay using multivariable Cox proportional hazards regression. Covariates included demographic, clinical, and radiographic variables. We further evaluated length of stay in a cohort matched by propensity to receive combination therapy. Logistic regression was used to evaluate secondary outcomes in the unmatched cohort, including intensive care admission, rehospitalizations, and self-reported recovery at follow-up.

RESULTS

Our study included 1418 children (693 girls and 725 boys) with a median age of 27 months (interquartile range, 12-69 months). This cohort was 60.1% of the 2358 children enrolled in the Etiology of Pneumonia in the Community Study with radiographically confirmed pneumonia in the study period; 1019 (71.9%) received β-lactam monotherapy and 399 (28.1%) received β-lactam plus macrolide combination therapy. In the unmatched cohort, there was no statistically significant difference in length of hospital stay between children receiving β-lactam monotherapy and combination therapy (median, 55 vs 59 hours; adjusted hazard ratio, 0.87; 95% CI, 0.74-1.01). The propensity-matched cohort (n = 560, 39.5%) showed similar results. There were also no significant differences between treatment groups for the secondary outcomes.

CONCLUSIONS AND RELEVANCE

Empirical macrolide combination therapy conferred no benefit over β-lactam monotherapy for children hospitalized with community-acquired pneumonia. The results of this study elicit questions about the routine empirical use of macrolide combination therapy in this population.

Iminosugars: Promising therapeutics for influenza infection

Influenza virus causes three to five million severe respiratory infections per year in seasonal epidemics, and sporadic pandemics, three of which occurred in the twentieth century and are a continuing global threat. Currently licensed antivirals exclusively target the viral neuraminidase or M2 ion channel, and emerging drug resistance necessitates the development of novel therapeutics. It is believed that a host-targeted strategy may combat the development of antiviral drug resistance. To this end, a class of molecules known as iminosugars, hydroxylated carbohydrate mimics with the endocyclic oxygen atom replaced by a nitrogen atom, are being investigated for their broad-spectrum antiviral potential. The influenza virus glycoproteins, hemagglutinin and neuraminidase, are susceptible to inhibition of endoplasmic reticulum α-glucosidases by certain iminosugars, leading to reduced virion production or infectivity, demonstrated by in vitro and in vivo studies. In some experiments, viral strain-specific effects are observed. Iminosugars may also inhibit other host and virus targets with antiviral consequences. While investigations of anti-influenza iminosugar activities have been conducted since the 1980s, recent successes of nojirimycin derivatives have re-invigorated investigation of the therapeutic potential of iminosugars as orally available, low cytotoxicity, effective anti-influenza drugs.

Anti-inflammatory effects of adjunctive macrolide treatment in adults hospitalized with influenza: A randomized controlled trial

INTRODUCTION

- Macrolides can ameliorate inflammation in respiratory diseases, providing clinical benefits. Data in influenza is lacking.

METHOD

- A randomized, open-label, multicenter trial among adults hospitalized for laboratory-confirmed influenza was conducted. Study treatments of oseltamivir and azithromycin (500 mg/day), or oseltamivir alone, both for 5 days, were allocated at 1:1 ratio. The primary outcome was plasma cytokine/chemokine concentration change over time (Day 0-10); secondary outcomes were viral load and symptom score changes. Generalized Estimating Equation (GEE) models were used to analyze longitudinal data.

RESULTS

- Fifty patients were randomized to the oseltamivir-azithromycin or oseltamivir groups, with comparable baseline characteristics (age, 57 ± 18 years; A/H3N2, 70%), complications (72%), and viral load. Pro-inflammatory cytokines IL-6 (GEE: β -0.037, 95%CI-0.067,-0.007, P = 0.016; reduction from baseline -83.4% vs -59.5%), CXCL8/IL-8 (β -0.018, 95%CI-0.037,0.000, P = 0.056; -80.5% vs -58.0%), IL-17 (β -0.064, 95%CI-0.117,-0.012, P = 0.015; -74.0% vs -34.3%), CXCL9/MIG (β -0.010, 95%CI-0.020,0.000, P = 0.043; -71.3% vs -56.0%), sTNFR-1, IL-18, and CRP declined faster in the oseltamivir-azithromycin group. There was a trend toward faster symptom resolution (β -0.463, 95%CI-1.297,0.371). Viral RNA decline (P = 0.777) and culture-negativity rates were unaffected. Additional ex vivo studies confirmed reduced induction of IL-6 (P = 0.017) and CXCL8/IL-8 (P = 0.005) with azithromycin.

CONCLUSION

- We found significant anti-inflammatory effects with adjunctive macrolide treatment in adults with severe influenza infections. Virus control was unimpaired. Clinical benefits of a macrolide-containing regimen deserve further study. [ClinicalTrials.gov NCT01779570].

Anti-inflammatory effect of prophylactic macrolides on children with chronic lung disease: a protocol for a double-blinded randomised controlled trial

INTRODUCTION

Recent studies suggest that the high mortality rate of respiratory viral infections is a result of an overactive neutrophilic inflammatory response. Macrolides have anti-inflammatory properties, including the ability to downregulate the inflammatory cascade, attenuate excessive cytokine production in viral infections, and may reduce virus-related exacerbations. In this study, we will test the hypothesis that prophylactic macrolides will reduce the severity of respiratory viral illness in children with chronic lung disease by preventing the full activation of the inflammatory cascade.

METHODS AND ANALYSIS

A randomised double-blind placebo-controlled trial that will enrol 92 children to receive either azithromycin or placebo for a period of 3-6 months during two respiratory syncytial virus (RSV) seasons (2015-2016 and 2016-2017). We expect a reduction of at least 20% in the total number of days of unscheduled face-to-face encounters in the treatment group as compared with placebo group. Standard frequentist and Bayesian analyses will be performed using an intent-to-treat approach.

DISCUSSION

We predict that the prophylactic use of azithromycin will reduce the morbidity associated with respiratory viral infections during the winter season in patients with chronic lung disease as evidenced by a reduction in the total number of days with unscheduled face-to-face provider encounters.

ETHICS AND DISSEMINATION

This research study was approved by the Institutional Review Board of the University of Texas Health Science Center in Houston on 9 October 2014. On completion, the results will be published.

TRIAL REGISTRATION NUMBER

NCT02544984.

Update on Human Rhinovirus and Coronavirus Infections

Human rhinovirus (HRV) and coronavirus (HCoV) infections are associated with both upper respiratory tract illness (“the common cold”) and lower respiratory tract illness (pneumonia). New species of HRVs and HCoVs have been diagnosed in the past decade. More sensitive diagnostic tests such as reverse transcription-polymerase chain reaction have expanded our understanding of the role these viruses play in both immunocompetent and immunosuppressed hosts. Recent identification of severe acute respiratory syndrome and Middle East respiratory syndrome viruses causing serious respiratory illnesses has led to renewed efforts for vaccine development. The role these viruses play in patients with chronic lung disease such as asthma makes the search for antiviral agents of increased importance.

Nanotechnological applications for the control of pulmonary infections

Pulmonary infections are the major global problem. According to the global burden of disease study, lower respiratory infections were ranked third among the leading causes of death after ischaemic heart disease and cerebrovascular disease. Despite the availability of treatment options and diagnostic methods, the severity of pulmonary infections is increasing due to the emergence of multiple drug resistance and lack of sensitivity in pathogenic microbes.

In this context, nanotechnology based treatment therapies have emerged as a promising approach to circumvent the limitations of conventional therapies and also manage the problem of drug resistance in pulmonary infections. The present chapter is focused on the global status of existing management strategies of pulmonary infections and their limitations. Moreover, the role of nanotechnology for the management of pulmonary infections with a special reference to different type of nanomaterials has also been discussed.

Dendritic cells from aged subjects contribute to chronic airway inflammation by activating bronchial epithelial cells under steady state

The mechanisms underlying the increased susceptibility of the elderly to respiratory infections are not well understood. The crosstalk between the dendritic cells (DCs) and epithelial cells is essential in maintaining tolerance as well as in generating immunity in the respiratory mucosa. DCs from aged subjects display an enhanced basal level of activation, which can affect the function of epithelial cells. Our results suggest that this is indeed the scenario as exposure of primary bronchial epithelial cells (PBECs) to supernatants from unstimulated DCs of aged subjects resulted in activation of PBECs. The expression of CCL20, CCL26, CXCL10, mucin, and CD54 was significantly increased in the PBECs exposed to aged DC supernatants, but not to young DC supernatants. Furthermore, aged DC supernatants also enhanced the permeability of the PBEC barrier. We also found that DCs from aged subjects spontaneously secreted increased levels of pro-inflammatory mediators, interleukin-6, tumor necrosis factor (TNF)-α, and metalloproteinase A disintegrin family of metalloproteinase 10, which can affect the functions of PBECs. Finally, we demonstrated that TNF-α, present in the supernatant of DCs from aged subjects, was the primary pro-inflammatory mediator that affected PBEC functions. Thus, age-associated alterations in DC-epithelial interactions contribute to chronic airway inflammation in the elderly, increasing their susceptibility to respiratory diseases.

The role of macrolides in asthma: current evidence and future directions

Macrolides, such as clarithromycin and azithromycin, possess antimicrobial, immunomodulatory, and potential antiviral properties. They represent a potential therapeutic option for asthma, a chronic inflammatory disorder characterised by airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing. Results from clinical trials, however, have been contentious. The findings could be confounded by many factors, including the heterogeneity of asthma, treatment duration, dose, and differing outcome measures. Recent evidence suggests improved effectiveness of macrolides in patients with sub-optimally controlled severe neutrophilic asthma and in asthma exacerbations. We examine the evidence from clinical trials and discuss macrolide properties and their relevance to the pathophysiology of asthma. At present, the use of macrolides in chronic asthma or acute exacerbations is not justified. Further work, including proteomic, genomic, and microbiome studies, will advance our knowledge of asthma phenotypes, and help to identify a macrolide-responsive subgroup. Future clinical trials should target this subgroup and place emphasis on clinically relevant outcomes such as asthma exacerbations.

Epidemiology of virus-induced asthma exacerbations: with special reference to the role of human rhinovirus

Viral respiratory infections may be associated with the virus-induced asthma in adults as well as children. Particularly, human rhinovirus is strongly suggested a major candidate for the associations of the virus-induced asthma. Thus, in this review, we reviewed and focused on the epidemiology, pathophysiology, and treatment of virus-induced asthma with special reference on human rhinovirus. Furthermore, we added our preliminary data regarding the clinical and virological findings in the present review.

[Long-term macrolide treatment in adult chronic bronchial diseases: benefits and limits]

Decreased frequency of pulmonary exacerbations, mainly related to immunomodulatory effects of macrolide antibiotics, has been demonstrated in bronchiectasis and chronic obstructive pulmonary diseases (COPD). Due to its tolerance, azithromycin is the antibiotic of choice for maintenance therapy at the dose of 250 mg per day or 500 mg × 3 per week (for body weight >55 kg). Maintenance therapy with macrolide could be proposed in selected patients with bronchiectasis or COPD with more than 3 acute exacerbations in the previous year or decreased lung function despite compliance with optimum treatment. The risk of sudden cardiac death with azithromycin is rare and controversial. It should be avoided in patients with a high baseline risk of cardiovascular disease, QT>450 msec, pulse rate>100 bpm and potential drug interactions, particularly those known to cause QT prolongation. It is recommended to search for hearing deficit (audiometry) and sputum culture positive for mycobacteria. Patients must also be aware that it can rapidly lead to macrolide resistance in commensal or pathogenic flora. Follow-up evaluation every 3 month can be proposed with medical history (hearing deficit) and electrocardiography. After one year, the treatment should be stopped in the absence of reduction in the frequency of exacerbations.

The common cold: potential for future prevention or cure

The common cold is the most frequent, although generally mild, human disease. Human Rhinoviruses are the prevalent causative agents, but other viruses are also implicated. Being so common, viral colds, have significant implications on public health and quality of life, but may also be life-threatening for vulnerable groups of patients. Specific diagnosis and treatment of the common cold still remain unmet needs. Molecular diagnostic techniques allow specific detection of known pathogens as well as the identification of newly emerging viruses. Although a number of medications or natural treatments have been shown to have some effect, either on the number or on the severity of common colds, no single agent is considerably effective. Virus-specific management remains in most cases a challenging potential as many factors have to be taken into account, including the diversity of the viral genomes, the heterogeneity of affected individuals, as well as the complexity of this long standing host-virus relationship.

Azithromycin: mechanisms of action and their relevance for clinical applications

Azithromycin is a macrolide antibiotic which inhibits bacterial protein synthesis, quorum-sensing and reduces the formation of biofilm. Accumulating effectively in cells, particularly phagocytes, it is delivered in high concentrations to sites of infection, as reflected in rapid plasma clearance and extensive tissue distribution. Azithromycin is indicated for respiratory, urogenital, dermal and other bacterial infections, and exerts immunomodulatory effects in chronic inflammatory disorders, including diffuse panbronchiolitis, post-transplant bronchiolitis and rosacea. Modulation of host responses facilitates its long-term therapeutic benefit in cystic fibrosis, non-cystic fibrosis bronchiectasis, exacerbations of chronic obstructive pulmonary disease (COPD) and non-eosinophilic asthma. Initial, stimulatory effects of azithromycin on immune and epithelial cells, involving interactions with phospholipids and Erk1/2, are followed by later modulation of transcription factors AP-1, NFκB, inflammatory cytokine and mucin release. Delayed inhibitory effects on cell function and high lysosomal accumulation accompany disruption of protein and intracellular lipid transport, regulation of surface receptor expression, of macrophage phenotype and autophagy. These later changes underlie many immunomodulatory effects of azithromycin, contributing to resolution of acute infections and reduction of exacerbations in chronic airway diseases. A sub-group of post-transplant bronchiolitis patients appears to be sensitive to azithromycin, as may be patients with severe sepsis. Other promising indications include chronic prostatitis and periodontitis, but weak activity in malaria is unlikely to prove crucial. Long-term administration of azithromycin must be balanced against the potential for increased bacterial resistance. Azithromycin has a very good record of safety, but recent reports indicate rare cases of cardiac torsades des pointes in patients at risk.

The effect of intravenous peramivir, compared with oral oseltamivir, on the outcome of post-influenza pneumococcal pneumonia in mice

BACKGROUND

Pneumococcal pneumonia often occurs secondary to influenza infection and accounts for a large proportion of the morbidity and mortality associated with seasonal and pandemic influenza outbreaks. Peramivir is a novel, intravenous neuraminidase inhibitor that exhibits potent antiviral activity against influenza A and B viruses. We investigated the efficacy of peramivir for modulating the severity of secondary pneumococcal pneumonia.

METHODS

CBA/JNCrlj mice, infected with influenza virus and superinfected with Streptococcus pneumoniae, were treated with either intravenous peramivir (single or multiple doses of 60 mg/kg/day) or oral oseltamivir at doses of 10 or 40 mg/kg/day in divided doses. The survival rate, viable bacterial count and virus titre in the lungs, as well as cytokine/chemokine concentration and histopathological findings were compared between both groups.

RESULTS

The median duration of survival of coinfected mice was significantly prolonged by treatment with multiple doses of peramivir, relative to mice treated with oseltamivir at either dose. Viable bacterial counts and virus titres in the lungs were significantly reduced by intravenous peramivir treatment compared with no treatment or oral oseltamivir treatment. The production of inflammatory cytokines/chemokines was also significantly suppressed by multiple dosing of peramivir compared with oseltamivir. Increased survival appeared to be mediated by decreased inflammation, manifested as lower levels of inflammatory cells and proinflammatory cytokines in the lungs and less severe histopathological findings. The lungs of mice treated with multiple doses of peramivir showed mild inflammatory changes compared to oseltamivir.

CONCLUSIONS

This study demonstrated that a multiple-dose regimen of intravenous peramivir was more efficacious than a single peramivir dose or multiple doses of oseltamivir for improving outcomes in pneumococcal pneumonia following influenza virus infection in mice.

Immunopathogenesis of 2009 pandemic influenza

Three years after the pandemic, major advances have been made in our understanding of the innate and adaptive immune responses to the influenza A(H1N1)pdm09 virus and those responses' contribution to the immunopathology associated with this infection. Severe disease is characterized by early secretion of proinflammatory and immunomodulatory cytokines. This cytokine secretion persisted in patients with severe viral pneumonia and was directly associated with the degree of viral replication in the respiratory tract. Cytokines play important roles in the antiviral defense, but persistent hypercytokinemia may cause inflammatory tissue damage and participate in the genesis of the respiratory failure observed in these patients. An absence of pre-existing protective antibodies was the rule for both mild and severe cases. A role for pathogenic immunocomplexes has been proposed for this disease. Defective T cell responses characterize severe cases of infection caused by the influenza A(H1N1)pdm09 virus. Immune alterations associated with accompanying conditions such as obesity, pregnancy or chronic obstructive pulmonary disease may interfere with the normal development of the specific response to the virus. The role of host immunogenetic factors associated with disease severity is also discussed in this review. In conclusion, currently available information suggests a complex immunological dysfunction/alteration that characterizes the severe cases of 2009 pandemic influenza. The potential benefits of prophylactic/therapeutic interventions aimed at preventing/correcting such dysfunction warrant investigation.

Modulation of protease activated receptor 1 influences human metapneumovirus disease severity in a mouse model

Human metapneumovirus (hMPV) infection causes acute respiratory tract infections (RTI) which can result in hospitalization of both children and adults. To date, no antiviral or vaccine is available for this common viral infection. Immunomodulators could represent an interesting strategy for the treatment of severe viral infection. Recently, the role of protease-activated receptors (PAR) in inflammation, coagulation and infection processes has been of growing interest. Herein, the effects of a PAR1 agonist and a PAR1 antagonist on hMPV infection were investigated in BALB/c mice. Intranasal administration of the PAR1 agonist resulted in increased weight loss and mortality of infected mice. Conversely, the PAR1 antagonist was beneficial to hMPV infection by decreasing weight loss and clinical signs and by significantly reducing pulmonary inflammation, pro-inflammatory cytokine levels (including IL-6, KC and MCP-1) and recruitment of immune cells to the lungs. In addition, a significant reduction in pulmonary viral titers was also observed in the lungs of PAR1 antagonist-treated mice. Despite no apparent direct effect on virus replication during in vitro experiments, an important role for PAR1 in the regulation of furin expression in the lungs was shown for the first time. Further experiments indicated that the hMPV fusion protein can be cleaved by furin thus suggesting that PAR1 could have an effect on viral infectivity in addition to its immunomodulatory properties. Thus, inhibition of PAR1 by selected antagonists could represent an interesting strategy for decreasing the severity of paramyxovirus infections.

From sneeze to wheeze: what we know about rhinovirus Cs

While the discovery of HRV-Cs is recent, there are no indications that they are new viruses, or that they are emerging in real-time. Genetically, HRV-Cs are most closely related to the members of HRV-A and HRV-B but even a small genetic difference can impart encompass significant changes to their clinical impact, complicated by a diverse human background of prior virus exposure and underlying host immune and disease variability. It is well known that HRVs are a major trigger of asthma exacerbations and HRV-Cs are now under investigation for their potential involvement in asthma inception. The newly described HRV-Cs account for a large proportion of HRV-related illness, including common colds and wheezing exacerbations. HRV-Cs are genetically diverse and appear to circulate with seasonal variation, exchanging dominance with HRV-A. Whether HRV-Cs are consistently more pathogenic or "asthmagenic" is unproven. Antigenic diversity complicates passive and active prophylactic interventions (i.e. antibodies or vaccines), so further identification and characterisation of individual types (and their neutralising antigens) is likely to inform future preventive strategies. In the meantime, new antivirals should benefit groups at risk of the most severe disease.