Efficacy of azithromycin in sepsis-associated acute respiratory distress syndrome: a retrospective study and propensity score analysis

Combinational therapy of mesenchymal stem cell-derived extracellular vesicles and azithromycin improves clinical and histopathological recovery in CLP sepsis model

BACKGROUND

Sepsis is a syndrome that occurs following an infection and marked by severe inflammatory responses, and if not treated in time, it can lead to multi-organ failure syndrome and death. This study examines the effects of a novel combination therapy using azithromycin and mesenchymal stem cell-derived extracellular vesicles (EVs) on a cecal ligation and puncture (CLP) model of sepsis.

METHODS

Human Wharton's jelly-mesenchymal stem cells were cultured, characterized, and used to extract EVs. The CLP sepsis model was induced in mice, followed by treatments: saline, AZM, EVs, and combination therapy (A+E). Clinical sepsis scores were recorded 24 h post-treatment. Serum, peritoneal fluid, and organ tissues (kidney, liver, lung) were collected and analyzed for biochemical parameters (AST ALT, and creatinine), inflammatory markers, bacterial load, and histopathological changes.

RESULTS

The A+E combined treatment improved the clinical scores of septic mice. The administration of A+E reduced bacterial loads in the peritoneum of septic mice, contributing to effective control of infection. Inflammatory markers of neutrophils-to-lymphocytes ratio (NLR) and TNF-α serum levels were significantly lower in the combinational therapy group, indicating significant anti-inflammatory effect of this combination. Additionally, combination of AZM and EVs alleviated organ damage mainly within liver, kidneys and lungs. Based on histopathological assessments and biochemical parameters, there was diminished tissue damage as well as reduced inflammation, which is correlated with improved functions of these vital organs.

CONCLUSION

The combined use of azithromycin and EVs offers a promising therapeutic approach for sepsis by effectively controlling infection and modulating the inflammatory response.

The ROX index (Index combining the respiratory rate with oxygenation) is a prognostic factor for acute respiratory distress syndrome

BACKGROUND

There is no existing reliable and practical method for predicting the prognosis of acute respiratory distress syndrome (ARDS).

OBJECTIVE

We aimed to clarify the association between the ROX index, which is calculated as the ratio of peripheral oxygen saturation divided by the fraction of inspired oxygen to the respiratory rate, and the prognosis of patients with ARDS under ventilator support.

METHODS

In this single-center retrospective cohort study from prospectively collected database, eligible patients were categorized into three groups based on ROX tertiles. The primary outcome was the 28-day survival, and the secondary outcome was 28-day liberation from ventilator support. We performed multivariable analysis using the Cox proportional hazards model.

RESULTS

Among 93 eligible patients, 24 (26%) patients died. The patients were divided into three groups according to the ROX index (< 7.4, 7.4-11, ≥ 11), with 13, 7, and 4 patients dying in the groups, respectively. A higher ROX index was associated with lower mortality; adjusted hazard ratios [95% CIs] for increasing tertiles of ROX index: 1[reference], 0.54[0.21-1.41], 0.23[0.074-0.72] (P = 0.011 for trend) and a higher rate of successful 28-day liberation from ventilator support; adjusted hazard ratios [95% CIs] for increasing tertiles of ROX index: 1[reference], 1.41[0.68-2.94], 2.80[1.42-5.52] (P = 0.001 for trend).

CONCLUSIONS

The ROX index at 24 h after initiating ventilator support is a predictor of outcomes in patients with ARDS and might inform initiation of more advanced treatments.

The role of bacterial translocation in sepsis: a new target for therapy

Sepsis is a leading cause of death in critically ill patients, primarily due to multiple organ failures. It is associated with a systemic inflammatory response that plays a role in the pathogenesis of the disease. Intestinal barrier dysfunction and bacterial translocation (BT) play pivotal roles in the pathogenesis of sepsis and associated organ failure. In this review, we describe recent advances in understanding the mechanisms by which the gut microbiome and BT contribute to the pathogenesis of sepsis. We also discuss several potential treatment modalities that target the microbiome as therapeutic tools for patients with sepsis.

Additional effect of azithromycin over β-lactam alone for severe community-acquired pneumonia-associated acute respiratory distress syndrome: a retrospective cohort study

Background

Community-acquired pneumonia (CAP) is the most common cause of acute respiratory distress syndrome (ARDS). Although previous studies have suggested that macrolide therapy is beneficial for ARDS, its benefit for severe CAP-associated ARDS remains uncertain. Previous studies were limited in that they had a small sample size and included patients with non-pulmonary ARDS and those with pulmonary ARDS. This study aimed to investigate the additional effect of azithromycin when used with β-lactam compared with the effect of β-lactam alone in mechanically ventilated patients with CAP-associated ARDS.

Methods

We identified mechanically ventilated patients with CAP-associated ARDS between July 2010 and March 2015 using data in the Diagnosis Procedure Combination database, a Japanese nationwide inpatient database. We performed propensity score matching analysis to assess 28-day mortality and in-hospital mortality in mechanically ventilated patients with CAP-associated ARDS who received β-lactam with and without azithromycin within hospital 2 days after admission. The inverse probability of treatment weighting analysis was also conducted.

Results

Eligible patients (n = 1257) were divided into the azithromycin group (n = 226) and the control group (n = 1031). The one-to-four propensity score matching analysis included 139 azithromycin users and 556 non-users. No significant difference was observed between the groups with respect to 28-day mortality (34.5% vs. 37.6%, p = 0.556) or in-hospital mortality (46.0% vs. 49.1%, p = 0.569). The inverse probability of treatment weighting analysis showed similar results.

Conclusions

Compared with treatment with β-lactam alone, treatment with azithromycin plus β-lactam had no significant additional effect on 28-day mortality or in-hospital mortality in mechanically ventilated patients with CAP-associated ARDS. To the best of our knowledge, this study is the first to determine the effect of azithromycin in mechanically ventilated patients with CAP-associated ARDS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41479-021-00093-8.

Antibiotics as immunomodulators: a potential pharmacologic approach for ARDS treatment

First described in the mid-1960s, acute respiratory distress syndrome (ARDS) is a life-threatening form of respiratory failure with an overall mortality rate of approximately 40%. Despite significant advances in the understanding and treatment of ARDS, no substantive pharmacologic therapy has proven to be beneficial, and current management continues to be primarily supportive. Beyond their antibacterial activity, several antibiotics such as macrolides and tetracyclines exert pleiotropic immunomodulatory effects that might be able to rectify the dysregulated inflammatory response present in patients with ARDS. This review aims to provide an overview of preclinical and clinical studies that describe the immunomodulatory effects of antibiotics in ARDS. Moreover, the underlying mechanisms of their immunomodulatory properties will be discussed. Further studies are necessary to investigate their full therapeutic potential and to identify ARDS phenotypes which are most likely to benefit from their immunomodulatory effects.

Immunomodulation of endothelial cells induced by macrolide therapy in a model of septic stimulation

Objectives

Sepsis is defined as the host's inflammatory response to a life‐threatening infection. The endothelium is implicated in immunoregulation during sepsis. Macrolides have been proposed to display immunomodulatory properties. The goal of this study was to analyze whether macrolides can exert immunomodulation of endothelial cells (ECs) in an experimental model of sepsis.

Methods

Human ECs were stimulated by proinflammatory cytokines and lipopolysaccharide before exposure to macrolides. ECs phenotypes were analyzed by flow cytometry. Cocultures of ECs and peripheral blood mononuclear cells (PBMCs) were performed to study the ECs ability to alter T‐cell viability and differentiation in the presence of macrolides. Soluble factor production was assessed.

Results

ECs act as non‐professional antigen presenting cells and expressed human leukocyte antigen (HLA) antigens, the adhesion molecules CD54, CD106, and the coinhibitory molecule CD274 after septic stimulation. Incubation with macrolides induced a significant decrease of HLA class I and HLA class II HLA‐DR on septic‐stimulated ECs, but did not alter either CD54, CD106, nor CD274 expression. Interleukin‐6 (IL‐6) and IL‐8 production by stimulated ECs were unaltered by incubation with macrolides, whereas Clarithromycin exposure significantly decreased IL‐6 gene expression. In cocultures of septic ECs with PBMCs, neither the proportion of CD4 ⁺, CD8 ⁺T nor their viability was altered by macrolides. T‐helper lymphocyte subsets Th1, Th17, and Treg polarization by stimulated ECs were unaltered by macrolides.

Conclusion

This study reports phenotypic and gene expression changes in septic‐stimulated ECs exposed to macrolides, without resulting in altered immunogenicity of ECs in co‐cultures with PBMCs. In vivo studies may help to further understand the impact of macrolide therapy on ECs immune homeostasis during sepsis.

Clinical phenotypes from fatal cases of acute respiratory distress syndrome caused by pneumonia

There have been no report of objective clinical characteristics or prognostic factors that predict fatal outcome of acute respiratory distress syndrome (ARDS) since the Berlin definition was published. The aim of this study is to identify clinically available predictors that distinguish between two phenotypes of fatal ARDS due to pneumonia. In total, 104 cases of Japanese patients with pneumonia-induced ARDS were extracted from our prospectively collected database. Fatal cases were divided into early (< 7 days after diagnosis) and late (≥ 7 days) death groups, and clinical variables and prognostic factors were statistically evaluated. Of the 50 patients who died within 180 days, 18 (36%) and 32 (64%) were in the early (median 2 days, IQR [1, 5]) and late (median 16 days, IQR [13, 29]) death groups, respectively. According to multivariate regression analyses, the APACHE II score (HR 1.25, 95%CI 1.12–1.39, p < 0.001) and the disseminated intravascular coagulation score (HR 1.54, 95%CI 1.15–2.04, p = 0.003) were independent prognostic factors for early death. In contrast, late death was associated with high-resolution computed tomography (HRCT) score indicating early fibroproliferation (HR 1.28, 95%CI 1.13–1.42, p < 0.001) as well as the disseminated intravascular coagulation score (HR 1.24, 95%CI 1.01–1.52, p = 0.039). The extent of fibroproliferation on HRCT, and the APACHE II scores along with coagulation abnormalities, should be considered for use in predictive enrichment and personalized medicine for patients with ARDS due to pneumonia.

Direct antivirals working against the novel coronavirus: azithromycin (DAWn-AZITHRO), a randomized, multicenter, open-label, adaptive, proof-of-concept clinical trial of new antivirals working against SARS-CoV-2-azithromycin trial

BACKGROUND

The rapid emergence and the high disease burden of the novel coronavirus SARS-CoV-2 have created a medical need for readily available drugs that can decrease viral replication or blunt the hyperinflammatory state leading to severe COVID-19 disease. Azithromycin is a macrolide antibiotic, known for its immunomodulatory properties. It has shown antiviral effect specifically against SARS-CoV-2 in vitro and acts on cytokine signaling pathways that have been implicated in COVID-19.

METHODS

DAWn-AZITHRO is a randomized, open-label, phase 2 proof-of-concept, multicenter clinical trial, evaluating the safety and efficacy of azithromycin for treating hospitalized patients with COVID-19. It is part of a series of trials testing promising interventions for COVID-19, running in parallel and grouped under the name DAWn-studies. Patients hospitalized on dedicated COVID wards are eligible for study inclusion when they are symptomatic (i.e., clinical or radiological signs) and have been diagnosed with COVID-19 within the last 72 h through PCR (nasopharyngeal swab or bronchoalveolar lavage) or chest CT scan showing typical features of COVID-19 and without alternate diagnosis. Patients are block-randomized (9 patients) with a 2:1 allocation to receive azithromycin plus standard of care versus standard of care alone. Standard of care is mostly supportive, but may comprise hydroxychloroquine, up to the treating physician's discretion and depending on local policy and national health regulations. The treatment group receives azithromycin qd 500 mg during the first 5 consecutive days after inclusion. The trial will include 284 patients and recruits from 15 centers across Belgium. The primary outcome is time from admission (day 0) to life discharge or to sustained clinical improvement, defined as an improvement of two points on the WHO 7-category ordinal scale sustained for at least 3 days.

DISCUSSION

The trial investigates the urgent and still unmet global need for drugs that may impact the disease course of COVID-19. It will either provide support or else justify the discouragement of the current widespread, uncontrolled use of azithromycin in patients with COVID-19. The analogous design of other parallel trials of the DAWN consortium will amplify the chance of identifying successful treatment strategies and allow comparison of treatment effects within an identical clinical context.

TRIAL REGISTRATION

EU Clinical trials register EudraCT Nb 2020-001614-38 . Registered on 22 April 2020.

Rationale for azithromycin in COVID-19: an overview of existing evidence

Azithromycin has rapidly been adopted as a repurposed drug for the treatment of COVID-19, despite the lack of high-quality evidence. In this review, we critically appraise the current pharmacological, preclinical and clinical data of azithromycin for treating COVID-19. Interest in azithromycin has been fuelled by favourable treatment outcomes in other viral pneumonias, a documented antiviral effect on SARS-CoV-2 in vitro and uncontrolled case series early in the pandemic. Its antiviral effects presumably result from interfering with receptor mediated binding, viral lysosomal escape, intracellular cell-signalling pathways and enhancing type I and III interferon expression. Its immunomodulatory effects may mitigate excessive inflammation and benefit tissue repair. Currently, in vivo reports on azithromycin in COVID-19 are conflicting and do not endorse its widespread use outside of clinical trials. They are, however, mostly retrospective and therefore inherently biased. The effect size of azithromycin may depend on when it is started. Also, extended follow-up is needed to assess benefits in the recovery phase. Safety data warrant monitoring of drug-drug interactions and subsequent cardiac adverse events, especially with hydroxychloroquine. More prospective data of large randomised controlled studies are expected and much-needed. Uniform reporting of results should be strongly encouraged to facilitate data pooling with the many ongoing initiatives.

Preventing the development of severe COVID-19 by modifying immunothrombosis

BACKGROUND

COVID-19-associated acute respiratory distress syndrome (ARDS) is associated with significant morbidity and high levels of mortality. This paper describes the processes involved in the pathophysiology of COVID-19 from the initial infection and subsequent destruction of type II alveolar epithelial cells by SARS-CoV-2 and culminating in the development of ARDS.

MAIN BODY

The activation of alveolar cells and alveolar macrophages leads to the release of large quantities of proinflammatory cytokines and chemokines and their translocation into the pulmonary vasculature. The presence of these inflammatory mediators in the vascular compartment leads to the activation of vascular endothelial cells platelets and neutrophils and the subsequent formation of platelet neutrophil complexes. These complexes in concert with activated endothelial cells interact to create a state of immunothrombosis. The consequence of immunothrombosis include hypercoagulation, accelerating inflammation, fibrin deposition, migration of neutrophil extracellular traps (NETs) producing neutrophils into the alveolar apace, activation of the NLRP3 inflammazome, increased alveolar macrophage destruction and massive tissue damage by pyroptosis and necroptosis Therapeutic combinations aimed at ameliorating immunothrombosis and preventing the development of severe COVID-19 are discussed in detail.

Can endolysosomal deacidification and inhibition of autophagy prevent severe COVID-19?

The possibility is examined that immunomodulatory pharmacotherapy may be clinically useful in managing the pandemic coronavirus disease 2019 (COVID-19), known to result from infection by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a positive-sense single-stranded RNA virus. The dominant route of cell entry of the coronavirus is via phagocytosis, with ensconcement in endosomes thereafter proceeding via the endosomal pathway, involving transfer from early (EEs) to late endosomes (LEs) and ultimately into lysosomes via endolysosomal fusion. EE to LE transportation is a rate-limiting step for coronaviruses. Hence inhibition or dysregulation of endosomal trafficking could potentially inhibit SARS-CoV-2 replication. Furthermore, the acidic luminal pH of the endolysosomal system is critical for the activity of numerous pH-sensitive hydrolytic enzymes. Golgi sub-compartments and Golgi-derived secretory vesicles also depend on being mildly acidic for optimal function and structure. Activation of endosomal toll-like receptors by viral RNA can upregulate inflammatory mediators and contribute to a systemic inflammatory cytokine storm, associated with a worsened clinical outcome in COVID-19. Such endosomal toll-like receptors could be inhibited by the use of pharmacological agents which increase endosomal pH, thereby reducing the activity of acid-dependent endosomal proteases required for their activity and/or assembly, leading to suppression of antigen-presenting cell activity, decreased autoantibody secretion, decreased nuclear factor-kappa B activity and decreased pro-inflammatory cytokine production. It is also noteworthy that SARS-CoV-2 inhibits autophagy, predisposing infected cells to apoptosis. It is therefore also suggested that further pharmacological inhibition of autophagy might encourage the apoptotic clearance of SARS-CoV-2-infected cells.

Hydroxychloroquine vs. Azithromycin for Hospitalized Patients with COVID-19 (HAHPS): Results of a Randomized, Active Comparator Trial

RATIONALE

The COVID-19 pandemic struck an immunologically naïve, globally interconnected population. In the face of a new infectious agent causing acute respiratory failure for which there were no known effective therapies, rapid, often pragmatic trials were necessary to evaluate potential treatments, frequently starting with medications that are already marketed for other indications. Early in the pandemic, hydroxychloroquine and azithromycin were two such candidates.

OBJECTIVE

Assess the relative efficacy of hydroxychloroquine and azithromycin among hospitalized patients with COVID-19.

METHODS

We performed a randomized clinical trial of hydroxychloroquine vs. azithromycin among hospitalized patients with COVID-19. Treatment was 5 days of study medication. The primary endpoint was the COVID Ordinal Outcomes scale at day 14. Secondary endpoints included hospital-, ICU-, and ventilator-free days at day 28. The trial was stopped early after enrollment of 85 patients when a separate clinical trial concluded that a clinically important effect of hydroxychloroquine over placebo was definitively excluded. Comparisons were made a priori using a proportional odds model from a Bayesian perspective.

RESULTS

We enrolled 85 patients at 13 hospitals over 11 weeks. Adherence to study medication was high. The estimated odds ratio for less favorable status on the ordinal scale for hydroxychloroquine vs. azithromycin from the primary analysis was 1.07, with a 95% credible interval from 0.63 to 1.83 with a posterior probability of 60% that hydroxychloroquine was worse than azithryomycin. Secondary outcomes displayed a similar, slight preference for azithromycin over hydroxychloroquine. QTc prolongation was rare and did not differ between groups. The twenty safety outcomes were similar between arms with the possible exception of post-randomization onset acute kidney injury, which was more common with hydroxychloroquine (15% vs. 0%). Patients in the hydroxychloroquine arm received remdesivir more often than in the azithromycin arm (19% vs. 2%). There was no apparent association between remdesivir use and acute kidney injury.

CONCLUSIONS

While early termination limits the precision of our results, we found no suggestion of substantial efficacy for hydroxychloroquine over azithromycin. Acute kidney injury may be more common with hydroxychloroquine than azithromycin, although this may be due to the play of chance. Differential use of remdesivir may have biased our results in favor of hydroxychloroquine. Our results are consistent with conclusions from other trials that hydroxychloroquine cannot be recommended for inpatients with COVID-19; azithromycin may merit additional investigation.

CLINICAL TRIAL REGISTRATION

This trial was prospectively registered (NCT04329832) before enrollment of the first patient.

Effect of Combination Therapy of Hydroxychloroquine and Azithromycin on Mortality in Patients With COVID-19

Conflicting evidence regarding the use of hydroxychloroquine (HCQ) and azithromycin for the treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection do exist. We performed a retrospective single-center cohort study including 377 consecutive patients admitted for pneumonia related to coronavirus disease 2019 (COVID-19). Of these, 297 were in combination treatment, 17 were on HCQ alone, and 63 did not receive either of these 2 drugs because of contraindications. The primary end point was in-hospital death. Mean age was 71.8 ± 13.4 years and 34.2% were women. We recorded 146 deaths: 35 in no treatment, 7 in HCQ treatment group, and 102 in HCQ + azithromycin treatment group (log rank test for Kaplan-Meier curve P < 0.001). At multivariable Cox proportional hazard regression analysis, age (hazard ratio (HR) 1.057, 95% confidence interval (CI) 1.035-1.079, P < 0.001), mechanical ventilation/continuous positive airway pressure (HR 2.726, 95% CI 1.823-4.074, P < 0.001), and C reactive protein above the median (HR 2.191, 95% CI 1.479-3.246, P < 0.001) were directly associated with death, whereas use of HCQ + azithromycin (vs. no treatment; HR 0.265, 95% CI 0.171-0.412, P < 0.001) was inversely associated. In this study, we found a reduced in-hospital mortality in patients treated with a combination of HCQ and azithromycin after adjustment for comorbidities. A large randomized trial is necessary to confirm these findings.

Hydroxychloroquine versus Azithromycin for Hospitalized Patients with Suspected or Confirmed COVID-19 (HAHPS). Protocol for a Pragmatic, Open-Label, Active Comparator Trial

Coronavirus disease (COVID-19) is a potentially fatal illness with no proven therapy beyond excellent supportive care. Treatments are urgently sought. Adaptations to traditional trial logistics and design to allow rapid implementation, evaluation of trials within a global trials context, flexible interim monitoring, and access outside traditional research hospitals (even in settings where formal placebos are unavailable) may be helpful. Thoughtful adaptations to traditional trial designs, especially within the global context of related studies, may also foster collaborative relationships among government, community, and the research enterprise. Here, we describe the protocol for a pragmatic, active comparator trial in as many as 300 patients comparing two current "off-label" treatments for COVID-19-hydroxychloroquine and azithromycin-in academic and nonacademic hospitals in Utah. We developed the trial in response to local pressures for widespread, indiscriminate off-label use of these medications. We used a hybrid Bayesian-frequentist design for interim monitoring to allow rapid, contextual assessment of the available evidence. We also developed an inference grid for interpreting the range of possible results from this trial within the context of parallel trials and prepared for a network meta-analysis of the resulting data. This trial was prospectively registered (ClinicalTrials.gov Identifier: NCT04329832) before enrollment of the first patient.Clinical trial registered with www.clinicaltrials.gov (NCT04329832).

A Scoring System with High-Resolution Computed Tomography to Predict Drug-Associated Acute Respiratory Distress Syndrome: Development and Internal Validation

Drugs can cause acute respiratory distress syndrome (ARDS). However, there is no established clinical prediction rule for drug-associated ARDS (DARDS). We aimed to develop and validate a scoring system for DARDS prediction. We analysed data collected from a prospective, single-centre, cohort study that included ARDS patients. The ARDS diagnosis was based on the American-European Consensus Conference or Berlin definition. Drug-associated acute lung injury (DALI) was defined as previous exposure to drugs which cause ALI and presence of traditional risk factors for ALI. High-resolution computed tomography (HRCT; indicating extent of lung damage with fibroproliferation), Acute Physiology and Chronic Health Evaluation (APACHE) II, and disseminated intravascular coagulation (DIC; indicating multiorgan failure) scores and PaO₂/FiO₂ were evaluated for their ability to predict DARDS. Twenty-nine of 229 patients had DARDS. The HRCT, APACHE II, and DIC scores and PaO₂/FiO₂ were assessed. The model-based predicted probability of DARDS fitted well with the observed data, and discrimination ability, assessed through bootstrap with an area under the receiver-operating curve, improved from 0.816 to 0.875 by adding the HRCT score. A simple clinical scoring system consisting of the APACHE II score, PaO₂/FiO₂, and DIC and HRCT scores can predict DARDS. This model may facilitate more appropriate clinical decision-making.

Azithromycin does not improve disease severity in acute experimental pancreatitis

Acute pancreatitis is a severe systemic disease triggered by a sterile inflammation and initial local tissue damage of the pancreas. Immune cells infiltrating into the pancreas are main mediators of acute pancreatitis pathogenesis. In addition to their antimicrobial potency, macrolides possess anti-inflammatory and immunomodulatory properties which are routinely used in patients with chronic airway infections and might also beneficial in the treatment of acute lung injury. We here tested the hypothesis that the macrolide antibiotic azithromycin can improve the course of acute experimental pancreatitis via ameliorating the damage imposed by sterile inflammation, and could be used as a disease specific therapy. However, our data show that azithromycin does not have influence on caerulein induced acute pancreatitis in terms of reduction of organ damage, and disease severity. Furthermore Infiltration of immune cells into the pancreas or the lungs was not attenuated by azithromycin as compared to controls or ampicillin treated animals with acute experimental pancreatitis. We conclude that in the chosen model, azithromycin does not have any beneficial effects and that its immunomodulatory properties cannot be used to decrease disease severity in the model of caerulein-induced pancreatitis in mice.

Cell Type-Specific Roles of NF-κB Linking Inflammation and Thrombosis

The transcription factor NF-κB is a central mediator of inflammation with multiple links to thrombotic processes. In this review, we focus on the role of NF-κB signaling in cell types within the vasculature and the circulation that are involved in thrombo-inflammatory processes. All these cells express NF-κB, which mediates important functions in cellular interactions, cell survival and differentiation, as well as expression of cytokines, chemokines, and coagulation factors. Even platelets, as anucleated cells, contain NF-κB family members and their corresponding signaling molecules, which are involved in platelet activation, as well as secondary feedback circuits. The response of endothelial cells to inflammation and NF-κB activation is characterized by the induction of adhesion molecules promoting binding and transmigration of leukocytes, while simultaneously increasing their thrombogenic potential. Paracrine signaling from endothelial cells activates NF-κB in vascular smooth muscle cells and causes a phenotypic switch to a “synthetic” state associated with a decrease in contractile proteins. Monocytes react to inflammatory situations with enforced expression of tissue factor and after differentiation to macrophages with altered polarization. Neutrophils respond with an extension of their life span—and upon full activation they can expel their DNA thereby forming so-called neutrophil extracellular traps (NETs), which exert antibacterial functions, but also induce a strong coagulatory response. This may cause formation of microthrombi that are important for the immobilization of pathogens, a process designated as immunothrombosis. However, deregulation of the complex cellular links between inflammation and thrombosis by unrestrained NET formation or the loss of the endothelial layer due to mechanical rupture or erosion can result in rapid activation and aggregation of platelets and the manifestation of thrombo-inflammatory diseases. Sepsis is an important example of such a disorder caused by a dysregulated host response to infection finally leading to severe coagulopathies. NF-κB is critically involved in these pathophysiological processes as it induces both inflammatory and thrombotic responses.

RETRACTED: MicroRNA-494 inhibition alleviates acute lung injury through Nrf2 signaling pathway via NQO1 in sepsis-associated acute respiratory distress syndrome

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figures 5G,H+I, which appear to have a similar phenotype as many other publications, as detailed here: https://pubpeer.com/publications/7C9483B2551952AD53CCFCE206C4EB; and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. The journal requested that the corresponding author comment on these concerns and provide the raw data. The authors did not respond to this request and therefore the Editor-in-Chief decided to retract the article.

Clinical differences between pulmonary and extrapulmonary acute respiratory distress syndrome: a retrospective cohort study of prospectively collected data in Japan

Background

Although acute respiratory distress syndrome (ARDS) reportedly shows various clinical phenotypes with different risk and prognostic factors, few studies have assessed the clinical features and prognosis of pulmonary and extrapulmonary ARDS. The aim of the present study was to investigate clinical differences between pulmonary and extrapulmonary ARDS.

Methods

In total, 200 patients who met the Berlin criteria and were diagnosed with ARDS between October 2004 and September 2017 were included. We classified the patients into pulmonary and extrapulmonary ARDS groups. Both groups were assessed for 60-day mortality, duration of ventilation, and other clinical features.

Results

There were 150 and 50 patients in the pulmonary and extrapulmonary ARDS groups, respectively. The two groups showed no significant differences in any assessment parameters except the serum lactate dehydrogenase (LDH) level, which was higher in the extrapulmonary ARDS group (P=0.01). After adjustment for potentially confounding covariates, there were no significant differences in 60-day mortality (P=0.99) and the duration of ventilation (P=0.45) between the two groups. Mortality was significantly associated with the disseminated intravascular coagulation (DIC) score, high-resolution computed tomography (HRCT) score, and serum LDH level in the pulmonary ARDS group and the DIC score and HRCT score in the extrapulmonary ARDS group.

Conclusions

Pulmonary and extrapulmonary ARDS may be comparable in terms of the prognosis and duration of ventilation. DIC and HRCT scores may be common clinical predictors of mortality with ARDS.

Adjunctive therapy with azithromycin for moderate and severe acute respiratory distress syndrome: a retrospective, propensity score-matching analysis of prospectively collected data at a single center

Effective pharmacological therapy has not been established for patients with acute respiratory distress syndrome (ARDS). Macrolides are antibiotics with potent immunomodulatory and anti-inflammatory effects that may be beneficial in ARDS treatment. The objective of this study was to determine the adjunctive effect of azithromycin on survival for patients with ARDS. This single-center, retrospective cohort evaluation of hospitalized patients with moderate or severe ARDS was conducted to assess the impact of intravenous azithromycin on clinical outcomes using a propensity score analysis. All data were collected prospectively as part of ongoing research on the utility of high-resolution computed tomography in ARDS. The primary outcome was 90-day mortality, and the secondary analysis assessed the effect of azithromycin on time to successful discontinuation of mechanical ventilation and 28-day mortality. Of 191 eligible patients with severe or moderate ARDS, 62 were treated with azithromycin. The 62 patients treated with azithromycin and 62 not treated with azithromycin were matched and analysed. Azithromycin use was associated with a statistically significant improvement in 90-day survival rate (Hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.27-0.87; P = 0.015) and a shorter time to successful discontinuation of mechanical ventilation (HR, 1.74; 95% CI, 1.07-2.81; P = 0.026). The 28-day mortality rate tended to be higher in the azithromycin cohort than in the non-azithromycin cohort, but this was not statistically significant. Adjunctive intravenous azithromycin therapy was effective in patients with moderate or severe ARDS. Further prospective randomized controlled trials are needed to confirm this result.

Acute Respiratory Distress Syndrome: Bench-to-Bedside Approaches to Improve Drug Development

Despite 50 years of extensive research, no definite drug is currently available to treat acute respiratory distress syndrome (ARDS), and the supportive therapies remain the mainstay of treatment. To improve drug development for ARDS, researchers need to deeply analyze the “omics” approaches, reevaluate the suitable therapeutic targets, resolve the problems of inadequate animal modeling, develop the strategies to reduce the heterogeneity, and reconsider new therapeutic and analytical approaches for better designs of clinical trials.

Macrolide therapy is associated with reduced mortality in acute respiratory distress syndrome (ARDS) patients

Background

Macrolides have been associated with favorable immunological effects in various inflammatory disease states. We investigated the association between macrolide therapy and mortality in patients with the acute respiratory distress syndrome (ARDS).

Methods

This was an unplanned secondary analysis of patients with ARDS within a large prospective observational study of critically ill patients in the intensive care units (ICUs) of two university-affiliated hospitals in the Netherlands. The exposure of interest was low-dose macrolide use prescribed for another reason than infection; we excluded patients who received high-dose macrolides for an infection. The primary endpoint was 30-day mortality. The association between macrolide therapy and mortality was determined in the whole cohort, as well as in a propensity score matched cohort; the association was compared between pulmonary versus non-pulmonary ARDS, and between two biological phenotypes based on plasma levels of 20 biomarkers.

Results

In total, 873 patients with ARDS were analyzed, of whom 158 patients (18%) received macrolide therapy during stay in ICU for a median duration of 3 (interquartile range, 1-4) days. Erythromycin was the most frequent prescribed macrolide (97%). Macrolide therapy was associated with reduced 30-day mortality in the whole cohort [22.8% vs. 31.6%; crude odds ratio (OR), 0.64 (interquartile range, 0.43-0.96), P=0.03]. The association in the propensity score matched cohort remained significant [22.8% vs. 32.9%; OR, 0.62 (interquartile range, 0.39-0.96), P=0.03]. Propensity matched associations with mortality were different in patients with non-pulmonary ARDS vs. pulmonary ARDS and also varied by biological phenotype.

Conclusions

These data together show that low-dose macrolide therapy prescribed for another reason than infection is associated with decreased mortality in patients with ARDS.

Clinical characteristics and prognosis of drug-associated acute respiratory distress syndrome compared with non-drug-associated acute respiratory distress syndrome: a single-centre retrospective study in Japan

OBJECTIVES

To report the clinical features and prognosis of drug-associatedacute respiratory distress syndrome (ARDS).

DESIGN

A retrospective analysis of data collected during a prospective cohort study.

SETTING

Intensive care unit in a teaching hospital.

PARTICIPANTS

A total of 197 Japanese patients with ARDS diagnosed by the Berlin definition who were admitted to the Division of Respiratory Medicine from October 2004 to December 2015 were enrolled in the study and were classified as two groups according to their causes: a drug-associated ARDS group (n=27) and a non-drug-associated ARDS group (n=170). Primary outcome measure is 28-day mortality, and the secondaryoutcome measure is ventilator-free days.

RESULTS

The Acute Physiology and Chronic Health Evaluation II scores were significantly lower in the drug-associated ARDS group than in the non-drug-associated ARDS group (median (IQR): 18.0 (16.5-21.0) vs 23.0 (18.0-26.0), p<0.001), and the arterial oxygen tension/fractional inspired oxygen ratio was higher (148.0 (114.1-177.5) vs 101.0 (71.5-134.0), p=0.003). In the drug-associated ARDS group, although high-resolution CT scores indicative of the extent of fibroproliferation (301.6 (244.1-339.8) vs 208.3 (183.4-271.6), p<0.001), serum lactate dehydrogenase levels (477 (365-585) vs 322 (246-434), p=0.003) and the McCabe scores (score 1/2/3, n (%): 20 (74)/4 (15)/3 (11)vs154 (91)/7 (4)/9 (5), p=0.04) were significantly higher, ventilator weaning was earlier (p<0.001) and 28-day mortality was better (p=0.043). After adjusting for potentially confounding covariates, drug-associated ARDS group was associated with lower 28-day mortality (adjusted HR (HR) 0.275; 95% CI 0.106 to 0.711; p=0.008).

CONCLUSIONS

Although more severe lung damage with fibroproliferation was observed in patients with drug-associated ARDS, ventilator weaning was earlier, and their prognosis was better than the others. Further well-designed prospective studies are needed.

Azithromycin for idiopathic acute exacerbation of idiopathic pulmonary fibrosis: a retrospective single-center study

Background

Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) is a fatal condition without an established pharmaceutical treatment. Most patients are treated with high-dose corticosteroids and broad-spectrum antibiotics. Azithromycin is a macrolide with immunomodulatory activity and may be beneficial for treatment of acute lung injury. The objective of this study was to determine the effect of azithromycin on survival of patients with idiopathic AE of IPF.

Methods

We evaluated 85 consecutive patients hospitalized in our department for idiopathic AE of IPF from April 2005 to August 2016. The initial 47 patients were treated with a fluoroquinolone-based regimen (control group), and the following 38 consecutive patients were treated with azithromycin (500 mg/day) for 5 days. Idiopathic AE of IPF was defined using the criteria established by the 2016 International Working Group.

Results

Mortality in patients treated with azithromycin was significantly lower than in those treated with fluoroquinolones (azithromycin, 26% vs. control, 70%; p < 0.001). Multivariate analysis revealed that the two variables were independently correlated with 60-day mortality as determined by the Acute Physiology and Chronic Health Evaluation II score (p = 0.002) and azithromycin use (p < 0.001).

Conclusion

Azithromycin may improve survival in patients with idiopathic AE of IPF.

Immunomodulatory indications of azithromycin in respiratory disease: a concise review for the clinician

Azithromycin has a well-characterized bacteriostatic activity. However, it also has a robust immunomodulatory effect that has proven beneficial in a variety of chronic illnesses. This effect results in decreased production of pro-inflammatory cytokines in the acute phase and promotes resolution of chronic inflammation in the later phases. Specifically, azithromycin has direct activity on airway epithelial cells to maintain their function and reduce mucus secretion. These characteristics have resulted in the use of azithromycin in the management of a variety of chronic lung diseases including chronic obstructive pulmonary disease, cystic fibrosis (CF), non-CF bronchiectasis, bronchiolitis obliterans syndrome, diffuse panbronchiolitis, and asthma. In this review, we present the evidence supporting the role of azithromycin in these conditions with an emphasis on the clinical aspects for the practicing physician.