Effect of erdosteine on the rate and duration of COPD exacerbations: the RESTORE study

Mucoactive drugs and multiple applications in pulmonary disease therapy

Mucus is a complex polymeric hydrogel that serves as a critical defense in several organs. In the lungs, it provides a formidable barrier against inhaled particles such as microorganisms. In addition, mucus is essential for normal lung physiology, as it promotes immune tolerance and facilitates a normal commensal pulmonary microbiome. Hypersecretion of airway mucus is a characteristic of numerous respiratory diseases, such as Chronic Obstructive Pulmonary Disease (COPD) and Cystic Fibrosis (CF), and creates pulmonary obstruction, limiting the effectiveness of inhaled therapies. Due to those alterations, therapeutic strategies must be optimal to limit airway obstruction and restore pulmonary function. Mucoactive drugs are common therapeutic options and are classified into different groups depending on their modes of action, i.e., expectorants, mucokinetics, mucoregulators and mucolytics. This review focuses on mucoactive drugs and their modes of action. A special focus will be made on two challenging pulmonary pathologies: COPD and CF, and on their clinical studies conducted with mucoactive drugs.

[Acute bronchitis - modern possibilities of mucactive therapy]

AIM

Analysis of the clinical effectiveness and safety of erdosteine use in comparison with standard (real practice) mucoactive therapy in patients with acute bronchitis (АВ) in adults.

MATERIALS AND METHODS

The observational program included 100 adult patients with АВ, 50 of them (group 1) received erdosteine, the group 2 also included 50 patients who received acetylcysteine, bromhexine and other mucolytics (real clinical practice). The following were assessed: cough severity, average time for resolution of night and daytime cough, satisfaction with treatment, NO concentration in exhaled air, levels of C-reactive protein (CRP) and interleukin-6 (IL-6).

RESULTS

The average duration of relief of severe daytime cough requiring continued therapy was: in group 1 - 3.7±0.46 days, night cough - 1.14±0.94 days. In the second group, daytime cough was relieved in 3.8±0.4 days, night cough - 1.08±0.7 days. The duration of mucoactive therapy in group 1 was 5.32±0.82 days, in group 2 this figure was 8.5±1.4 days (p<0.05). The number of АВ patients with a significant reduction in the severity of productive cough (1 point on cough severity scale) on the 6th day from the beginning of treatment in group 1 (erdosteine) amounted to 32 (64%), in group 2 - 27 (54%). Satisfaction with the treatment was higher in the group receiving erdosteine: according to the indicators "very satisfied" and "extremely satisfied" the patients of the group 1 - 42 - were the leaders in comparison with the group 2, where these positions were marked by 28 patients. The level of CRP in patients with АВ in group 1 was 24.7±21.24 mg/l, in group 2 - 16.37±16.5 mg/l, which indicates the viral etiology of the process and no need in the prescription of antimicrobial drugs. For the first time in Russian practice, the following were determined: the level of IL-6, which in the group 1 was 10.3±6.7 pc/ml; in the group 2 - 10.03±3.94 pc/ml; the level of exhaled NO in group 1 was 16.5±5.1 ppb, in group 2 - 14.9±4.6 ppb (the norm is up to 25 ppb). These indicators, against the background of mucoactive therapy, decreased to normal values by 6th day.

CONCLUSION

The findings expand our understanding of АВ in adults. New results have been obtained on the role of CRP, IL-6 and NO in exhaled air during АВ. The use of erdosteine was accompanied by a significant mucoactive effect in the form of a pronounced regression of cough in patients with АВ compared to the comparison group in shorter term.

Use of thiols and implications for the use of inhaled corticosteroids in the presence of oxidative stress in COPD

BACKGROUND

Oxidative stress and persistent airway inflammation are thought to be important contributors to the development of chronic obstructive pulmonary disease (COPD). This review summarizes the evidence for targeting oxidative stress and inflammation in patients with COPD with mucolytic/antioxidant thiols and inhaled corticosteroids (ICS), either alone or in combination.

MAIN BODY

Oxidative stress is increased in COPD, particularly during acute exacerbations. It can be triggered by oxidant air pollutants and cigarette smoke and/or by endogenous reactive oxygen species (ROS) released from mitochondria and activated inflammatory, immune and epithelial cells in the airways, together with a reduction in endogenous antioxidants such as glutathione (GSH). Oxidative stress also drives chronic inflammation and disease progression in the airways by activating intracellular signalling pathways and the release of further inflammatory mediators. ICS are anti-inflammatory agents currently recommended for use with long-acting bronchodilators to prevent exacerbations in patients with moderate-to-severe COPD, especially those with eosinophilic airway inflammation. However, corticosteroids can also increase oxidative stress, which may in turn reduce corticosteroid sensitivity in patients by several mechanisms. Thiol-based agents such as erdosteine, N-acetyl L-cysteine (NAC) and S-carboxymethylcysteine (S-CMC) are mucolytic agents that also act as antioxidants. These agents may reduce oxidative stress directly through the free sulfhydryl groups, serving as a source of reducing equivalents and indirectly though intracellular GSH replenishment. Few studies have compared the effects of corticosteroids and thiol agents on oxidative stress, but there is some evidence for greater antioxidant effects when they are administered together. The current Global Initiative for Chronic Obstructive Lung Disease (GOLD) report supports treatment with antioxidants (erdosteine, NAC, S-CMC) in addition to standard-of-care therapy as they have been demonstrated to reduce COPD exacerbations. However, such studies have demonstrated that NAC and S-CMC reduced the exacerbation risk only in patients not treated with ICS, whereas erdosteine reduced COPD exacerbations irrespective of concomitant ICS use suggesting that erdosteine has additional pharmacological actions to ICS.

CONCLUSIONS

Further clinical trials of antioxidant agents with and without ICS are needed to better understand the place of thiol-based drugs in the treatment of patients with COPD.

Bilirubin-associated single nucleotide polymorphism (SNP) and respiratory health outcomes: a mendelian randomization study

BACKGROUND

Observational studies have shown an association between higher bilirubin levels and improved respiratory health outcomes. Targeting higher bilirubin levels has been proposed as a novel therapeutic strategy in COPD. However, bilirubin levels are influenced by multiple intrinsic and extrinsic factors, and these observational studies are prone to confounding. Genetic analyses are one approach to overcoming residual confounding in observational studies.

OBJECTIVES

To test associations between a genetic determinant of bilirubin levels and respiratory health outcomes.

METHODS

COPDGene participants underwent genotyping at the baseline visit. We confirmed established associations between homozygosity for rs6742078 and higher bilirubin, and between higher bilirubin and decreased risk of acute respiratory events within this cohort. For our primary analysis, we used negative binomial regression to test associations between homozygosity for rs6742078 and rate of acute respiratory events.

RESULTS

8,727 participants (n = 6,228 non-Hispanic white and 2,499 African American) were included. Higher bilirubin was associated with decreased rate of acute respiratory events [incidence rate ratio (IRR) 0.85, 95% CI 0.75 to 0.96 per SD increase in bilirubin intensity]. We did not find significant associations between homozygosity for rs6742078 and acute respiratory events (IRR 0.94, 95% CI 0.70 to 1.25 for non-Hispanic white and 1.09, 95% CI 0.91 to 1.31 for African American participants).

CONCLUSIONS

A genetic determinant of higher bilirubin levels was not associated with better respiratory health outcomes. These results do not support targeting higher bilirubin levels as a therapeutic strategy in COPD.

Exacerbation in patients with stable COPD in China: analysis of a prospective, 52-week, nationwide, observational cohort study (REAL)

BACKGROUND

Chronic obstructive pulmonary disease (COPD) management in China is inadequate and there is a need to improve care and outcomes for patients nationwide.

OBJECTIVES

The REAL study was designed to generate reliable information on COPD management from a representative sample of Chinese patients with COPD. Here, we present study outcomes related to acute exacerbations.

DESIGN

A 52-week, multicentre, prospective, observational study.

METHODS

Outpatients (aged ⩾ 40 years) enrolled from 25 tertiary and 25 secondary hospitals across six geographic regions in China were followed for 12 months. Risk factors for COPD exacerbation and disease severity by exacerbation were assessed using multivariate Poisson and ordinal logistic regression models, respectively.

RESULTS

Between June 2017 and January 2019, 5013 patients were enrolled, with 4978 included in the analysis. Mean (standard deviation) age was 66.2 (8.9) years. More patients presented with exacerbations in secondary versus tertiary hospitals (59.4% versus 40.2%) and in rural versus urban areas (53.2% versus 46.3%). Overall exacerbation rates differed across regions (range: 0.27-0.84). Patients from secondary versus tertiary hospitals had higher rates of overall exacerbation (0.66 versus 0.47), severe exacerbation (0.44 versus 0.18) and exacerbation that resulted in hospitalisation (0.41 versus 0.16). Across regions and hospital tiers, the rates of overall exacerbation and exacerbations that resulted in hospitalisation were highest in patients with very severe COPD (based on the severity of airflow limitation or GOLD 2017 combined assessment). Strong predictors of exacerbation included demographic and clinical characteristics, modified Medical Research Council scores, mucus purulence, exacerbation history and the use of maintenance mucolytic treatment.

CONCLUSION

COPD exacerbation rates varied across regions and were higher in secondary compared with tertiary hospitals in China. Understanding the factors associated with COPD exacerbation may facilitate improved management of COPD exacerbations in China.

REGISTRATION

The trial was registered on 20 March 2017 (ClinicalTrials.gov: NCT03131362; https://clinicaltrials.gov/ct2/show/NCT03131362).

PLAIN LANGUAGE SUMMARY

Exacerbations in patients with chronic obstructive pulmonary disease in ChinaBackground: Chronic obstructive pulmonary disease (COPD) causes progressive and irreversible airflow limitation. As the disease progresses, patients often experience a flare up of symptoms referred to as an exacerbation. There is inadequate management of COPD in China and, therefore, there is a need to improve care and outcomes for patients across the country.Objective: This study aimed to generate reliable information on exacerbations among Chinese patients with COPD to help inform future management strategies.Study design and methods: Patients (aged ⩾ 40 years) were enrolled from 25 secondary and 25 tertiary hospitals across six regions of China. Physicians collected data over 1 year during routine outpatient visits.Results: There were more patients who experienced an exacerbation in secondary versus tertiary hospitals (59% versus 40%) and in rural versus urban areas (53% versus 46%). Patients in different geographic regions experienced varying frequencies of exacerbations over 1 year. Compared with patients from tertiary hospitals, patients from secondary hospitals experienced exacerbations (including exacerbations that were severe and those that resulted in hospitalisation) at a higher frequency over 1 year. Patients with very severe disease experienced exacerbations (including exacerbations that resulted in hospitalisation) at the highest frequency over 1 year, regardless of the patient's geographic region or hospital tier. Patients who had certain characteristics and symptoms, had exacerbation(s) over the previous year, or received medication that aids in the clearance of mucus were more likely to experience exacerbations.Conclusion: The frequency of exacerbations among Chinese patients with COPD varied between patients living in different geographic regions and between patients presenting to different hospital tiers. Understanding the factors related to the occurrence of an exacerbation may help physicians better manage the disease.

Aging and aging-related diseases: from molecular mechanisms to interventions and treatments

Aging is a gradual and irreversible pathophysiological process. It presents with declines in tissue and cell functions and significant increases in the risks of various aging-related diseases, including neurodegenerative diseases, cardiovascular diseases, metabolic diseases, musculoskeletal diseases, and immune system diseases. Although the development of modern medicine has promoted human health and greatly extended life expectancy, with the aging of society, a variety of chronic diseases have gradually become the most important causes of disability and death in elderly individuals. Current research on aging focuses on elucidating how various endogenous and exogenous stresses (such as genomic instability, telomere dysfunction, epigenetic alterations, loss of proteostasis, compromise of autophagy, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, deregulated nutrient sensing) participate in the regulation of aging. Furthermore, thorough research on the pathogenesis of aging to identify interventions that promote health and longevity (such as caloric restriction, microbiota transplantation, and nutritional intervention) and clinical treatment methods for aging-related diseases (depletion of senescent cells, stem cell therapy, antioxidative and anti-inflammatory treatments, and hormone replacement therapy) could decrease the incidence and development of aging-related diseases and in turn promote healthy aging and longevity.

The Effect of Maintenance Treatment with Erdosteine on Exacerbation Treatment and Health Status in Patients with COPD: A Post-Hoc Analysis of the RESTORE Dataset

Purpose

To explore the effect of erdosteine on COPD exacerbations, health-related quality of life (HRQoL), and subjectively assessed COPD severity.

Patients and methods

This post-hoc analysis of the RESTORE study included participants with COPD and spirometrically moderate (GOLD 2; post-bronchodilator forced expiratory volume in 1 second [FEV₁] 50‒79% predicted; n = 254), or severe airflow limitation (GOLD 3; post-bronchodilator FEV₁ 30‒49% predicted; n = 191) who received erdosteine 300 mg twice daily or placebo added to usual maintenance therapy for 12 months. Antibiotic and oral corticosteroid use was determined together with patient-reported HRQoL (St George’s Respiratory Questionnaire, SGRQ). Patient and physician subjective COPD severity scores (scale 0‒4) were rated at baseline, 6 and 12 months. Data were analyzed using descriptive statistics for exacerbation severity, COPD severity, and treatment group. Comparisons between treatment groups used Student’s t-tests or ANCOVA as appropriate.

Results

Among GOLD 2 patients, 43 of 126 erdosteine-treated patients exacerbated (7 moderate-to-severe exacerbations), compared to 62 of 128 placebo-treated patients (14 moderate-to-severe exacerbations). Among those with moderate-to-severe exacerbations, erdosteine-treated patients had a shorter mean duration of corticosteroid treatment (11.4 days vs 13.3 days for placebo, P = 0.043), and fewer patients required antibiotic treatment with/without oral corticosteroids (71.4% vs 85.8% for placebo, P < 0.001). Erdosteine-treated GOLD 2 patients who exacerbated showed significant improvements from baseline in SGRQ total scores and subjective disease severity scores (patient- and physician-rated), compared with placebo-treated patients regardless of exacerbation severity. Among GOLD 3 patients, there were no significant differences between treatment groups on any of these measures.

Conclusion

Adding erdosteine to the usual maintenance therapy of COPD patients with moderate airflow limitation reduced the number of exacerbations, the duration of treatment with corticosteroids and the episodes requiring treatment with antibiotics. Additionally, treatment with erdosteine improved HRQoL and patient-reported disease severity.

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Oxidative Stress in Chronic Obstructive Pulmonary Disease

There is a marked increase in oxidative stress in the lungs of patients with COPD, as measured by increased exhaled 8-isoprostane, ethane, and hydrogen peroxide in the breath. The lung may be exposed to exogenous oxidative stress from cigarette smoking and indoor or outdoor air pollution and to endogenous oxidative stress from reactive oxygen species released from activated inflammatory cells, particularly neutrophils and macrophages, in the lungs. Oxidative stress in COPD may be amplified by a reduction in endogenous antioxidants and poor intake of dietary antioxidants. Oxidative stress is a major driving mechanism of COPD through the induction of chronic inflammation, induction of cellular senescence and impaired autophagy, reduced DNA repair, increased autoimmunity, increased mucus secretion, and impaired anti-inflammatory response to corticosteroids. Oxidative stress, therefore, drives the pathology of COPD and may increase disease progression, amplify exacerbations, and increase comorbidities through systemic oxidative stress. This suggests that antioxidants may be effective as disease-modifying treatments. Unfortunately, thiol-based antioxidants, such as N-acetylcysteine, have been poorly effective, as they are inactivated by oxidative stress in the lungs, so there is a search for more effective and safer antioxidants. New antioxidants in development include mitochondria-targeted antioxidants, NOX inhibitors, and activators of the transcription factor Nrf2, which regulates several antioxidant genes.

Severity distribution and treatment of chronic obstructive pulmonary disease in China: baseline results of an observational study

Background

Chronic obstructive pulmonary disease (COPD) receives low awareness and is undertreated in China. Understanding the burden and treatment of COPD across the nation is important for improving quality of care for this disease. This study aims to reveal the current situation of COPD severity distribution and management across China.

Methods

Baseline data from REALizing and Improving Management of Stable COPD in China, a multicentre, prospective, longitudinal, observational study, were analysed. Patients diagnosed with COPD as per Global Initiative for Chronic Obstructive Lung Disease 2016 (GOLD 2016) criteria were enrolled from 50 randomly selected hospitals (tertiary, 25; secondary, 25) across six geographical regions. Data were collected in routine clinical settings.

Results

Between 15 December 2017 and 6 August 2020, 5013 patients were enrolled and 4978 included in the full analysis set. Of these, 2459 (49.4%) reported ≥ 1 exacerbation within 12 months prior to study enrolment, with a mean annual rate of 0.9/patient, including 0.2/patient and 0.5/patient leading to emergency room visits and hospitalisation, respectively. Spirometry graded 458 (10.1%), 1886 (41.7%), 1558 (34.5%), and 616 (13.6%) were GOLD stage I–IV, and 536 (11.4%), 1034 (22.0%), 563 (12.0%), and 2566 (54.6%) were classified as GOLD 2016 Group A–D, respectively, without evident regional variations. Inhaled corticosteroids plus long-acting beta₂-agonist (ICS/LABA, 1316 [26.4%]), ICS/LABA plus long-acting muscarinic antagonist (ICS/LABA + LAMA, 871 [17.5%]), and LAMA (754 [15.1%]) were prescribed at high rates across all groups and regions. Medications not recommended by GOLD were commonly prescribed (TCM, 578 [11.6%]; others, 951 [19.1%]), and 681 (13.7%) were not given ICS or long-acting bronchodilators.

Conclusions

Disease burden among Chinese COPD outpatients is high. Improved guideline adherence for COPD treatment is needed.

Trial registration ClinicalTrials.gov identifier, NCT03131362.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02021-w.

New drugs under development for COPD

The characteristic features of chronic obstructive pulmonary disease (COPD) include inflammation and remodelling of the lower airways and lung parenchyma together with activation of inflammatory and immune processes. Due to the increasing habit of cigarette smoking worldwide COPD prevalence is increasing globally. Current therapies are unable to prevent COPD progression in many patients or target many of its hallmark characteristics which may reflect the lack of adequate biomarkers to detect the heterogeneous clinical and molecular nature of COPD. In this chapter we review recent molecular data that may indicate novel pathways that underpin COPD subphenotypes and indicate potential improvements in the classes of drugs currently used to treat COPD. We also highlight the evidence for new drugs or approaches to treat COPD identified using molecular and other approaches including kinase inhibitors, cytokine- and chemokine-directed biologicals and small molecules, antioxidants and redox signalling pathway inhibitors, inhaled anti-infectious agents and senolytics. It is important to consider the phenotypes/molecular endotypes of COPD patients together with specific outcome measures to target new therapies to particular COPD subtypes. This will require greater understanding of COPD molecular pathologies and a focus on biomarkers of predicting disease subsets and responder/non-responder populations.

Role of oxidative stress in the pathogenesis of COPD

Chronic inhalation of cigarette smoke is a prominent cause of chronic obstructive pulmonary disease (COPD) and provides an important source of exogenous oxidants. In addition, several inflammatory and structural cells are a source of endogenous oxidants in the lower airways of COPD patients, even in former smokers. This suggests that oxidants play a key role in the pathogenesis of COPD. This oxidative stress is counterbalanced by the protective effects of the various endogenous antioxidant defenses of the lower airways. A large amount of data from animal models and patients with COPD have shown that both the stable phase of the disease, and during exacerbations, have increased oxidative stress in the lower airways compared with age-matched smokers with normal lung function. Thus, counteracting the increased oxidative stress may produce clinical benefits in COPD patients. Smoking cessation is currently the most effective treatment of COPD patients and reduces oxidative stress in the lower airways. In addition, many drugs used to treat COPD have some antioxidant effects, however, it is still unclear if their clinical efficacy is related to pharmacological modulation of the oxidant/antioxidant balance. Several new antioxidant compounds are in development for the treatment of COPD.

The influence of erdosteine administration on lead-induced oxidative stress in rat muscle

Lead-exposure is known to disrupt the redox balance of tissues leading to oxidative stress. Due to the fact that a mucolytic drug, erdosteine, exerts also antioxidant properties, we decided to perform a pilot study on rats to evaluate its therapeutic potency in lead poisoning. Male Wistar rats were divided randomly into the following seven groups having 10 animals in each. Group I served as the control group. During 8-week period, rats in groups II-IV, except standard alimentation, received: erdosteine in a dose 350 mg/kg (collateral control group), 1200 ppm of lead acetate in drinking water and placebo, as well as the same doses of lead and erdosteine, respectively. Rats in group V-VII received 1200 ppm of lead acetate in drinking water for the initial 6-week period and then administered: placebo, erdosteine and EDTA for 2 weeks, respectively. The levels of malondialdehyde (MDA) were significantly higher in groups III and V compared to the control group. The activities of catalase (CAT) were significantly higher in groups IV, V, and VI compared to the control group. The activities of glutathione-S-transferase (GST) were significantly lower in group II and significantly higher in groups VI and VII compared to the control group, while the activities of glutathione reductase (GR) were significantly lower in group III and significantly higher in group VI. Erdosteine has an effect of protection against lead-induced oxidative stress which is not worse than that of EDTA.

NT-pro BNP in AECOPD-PH: old biomarker, new insights-based on a large retrospective case-controlled study

Background

Pulmonary hypertension (PH) is one of the common complications in chronic obstructive pulmonary disease (COPD). The study aimed to evaluate the predicting ability of N-terminal pro brain natriuretic peptide (NT-pro BNP) in patients with AECOPD-PH and its relationship with the severity of PH.

Methods

A large retrospective case-controlled study (n = 1072) was performed in the First Affiliated Hospital of Xinjiang Medical University from January 2018 to December 2020, and patients were divided into stable COPD (n = 178), AECOPD (n = 688) and AECOPD-PH group (n = 206). Different statistical models were used to screen for reliable and stable biomarkers.

Results

In unadjusted analysis and PSM (model 1, 2, 3), red cell distribution width (RDW), total bilirubin (TBIL), and NT-pro BNP were higher in patients with AECOPD-PH than those in AECOPD group. Logistic regression analysis showed, when the range of NT-proBNP was 271–1165 pg/mL (OR: 0.293; 95%CI: 0.184–0.467; P < 0.001) and NT-proBNP > 1165 pg/mL (OR: 0.559; 95%CI: 0.338–0.926; P = 0.024), the morbidity risk of PH in AECOPD patients was increased, so did TBIL. In receiver operating characteristic (ROC) curves, at the cut-off value of NT-proBNP was 175.14 pg/mL, AUC was 0.651 (P < 0.001), which was better than TBIL (AUC: 0.590, P < 0.001). As for the results of rank correlation analysis, NT-proBNP had a weak correlation with severity of PH with AECOPD (r_s = 0.299, P = 0.001) and its relative relevance with other biomarkers (RDW was 0.359 and TBIL was 0.238, P < 0.001).

Conclusions

Our findings suggest that NT-proBNP has a diagnostic efficacy in AECOPD-PH and NT-proBNP has a weak correlation with severity of PH with AECOPD.

Multifaceted Beneficial Effects of Erdosteine: More than a Mucolytic Agent

Erdosteine is a drug approved for the treatment of acute and chronic pulmonary diseases, originally developed as a mucolytic agent. It belongs to the thiol-based family of drugs that are known to also possess potentially important antioxidant and anti-inflammatory properties, and exhibit antibacterial activity against a variety of medically important bacterial species. Erdosteine is a prodrug that is metabolized to the ring-opening compound metabolite M1 (MET 1), which has mucolytic properties. Experimental studies have documented that erdosteine prevents or reduces lung tissue damage induced by oxidative stress and, in particular, that Met 1 also regulates reactive oxygen species production. The RESTORE study, which has been the only trial that investigated the effects of a thiol-based drug in chronic obstructive pulmonary disease (COPD) frequent exacerbators, documented that erdosteine significantly reduces the risk of acute exacerbations of COPD (AECOPDs), shortens their course, and also decreases the risk of hospitalization from COPD. The preventive action of erdosteine on AECOPDs was not affected by the presence or absence of inhaled corticosteroids (ICSs) or blood eosinophil count. These findings clearly contrast with the Global Initiative for Chronic Obstructive Lung Disease strategy’s approach to use erdosteine only in those COPD patients not treated simultaneously with an ICS. Furthermore, they support the possibility of using erdosteine in a step-down approach that in COPD is characterized by the withdrawal of the ICS.

Endothelial Dysfunction in Atherosclerotic Cardiovascular Diseases and Beyond: From Mechanism to Pharmacotherapies

The endothelium, a cellular monolayer lining the blood vessel wall, plays a critical role in maintaining multiorgan health and homeostasis. Endothelial functions in health include dynamic maintenance of vascular tone, angiogenesis, hemostasis, and the provision of an antioxidant, anti-inflammatory, and antithrombotic interface. Dysfunction of the vascular endothelium presents with impaired endothelium-dependent vasodilation, heightened oxidative stress, chronic inflammation, leukocyte adhesion and hyperpermeability, and endothelial cell senescence. Recent studies have implicated altered endothelial cell metabolism and endothelial-to-mesenchymal transition as new features of endothelial dysfunction. Endothelial dysfunction is regarded as a hallmark of many diverse human panvascular diseases, including atherosclerosis, hypertension, and diabetes. Endothelial dysfunction has also been implicated in severe coronavirus disease 2019. Many clinically used pharmacotherapies, ranging from traditional lipid-lowering drugs, antihypertensive drugs, and antidiabetic drugs to proprotein convertase subtilisin/kexin type 9 inhibitors and interleukin 1β monoclonal antibodies, counter endothelial dysfunction as part of their clinical benefits. The regulation of endothelial dysfunction by noncoding RNAs has provided novel insights into these newly described regulators of endothelial dysfunction, thus yielding potential new therapeutic approaches. Altogether, a better understanding of the versatile (dys)functions of endothelial cells will not only deepen our comprehension of human diseases but also accelerate effective therapeutic drug discovery. In this review, we provide a timely overview of the multiple layers of endothelial function, describe the consequences and mechanisms of endothelial dysfunction, and identify pathways to effective targeted therapies. SIGNIFICANCE STATEMENT: The endothelium was initially considered to be a semipermeable biomechanical barrier and gatekeeper of vascular health. In recent decades, a deepened understanding of the biological functions of the endothelium has led to its recognition as a ubiquitous tissue regulating vascular tone, cell behavior, innate immunity, cell-cell interactions, and cell metabolism in the vessel wall. Endothelial dysfunction is the hallmark of cardiovascular, metabolic, and emerging infectious diseases. Pharmacotherapies targeting endothelial dysfunction have potential for treatment of cardiovascular and many other diseases.

Mucus, Microbiomes and Pulmonary Disease

The respiratory tract harbors a stable and diverse microbial population within an extracellular mucus layer. Mucus provides a formidable defense against infection and maintaining healthy mucus is essential to normal pulmonary physiology, promoting immune tolerance and facilitating a healthy, commensal lung microbiome that can be altered in association with chronic respiratory disease. How one maintains a specialized (healthy) microbiome that resists significant fluctuation remains unknown, although smoking, diet, antimicrobial therapy, and infection have all been observed to influence microbial lung homeostasis. In this review, we outline the specific role of polymerizing mucin, a key functional component of the mucus layer that changes during pulmonary disease. We discuss strategies by which mucin feed and spatial orientation directly influence microbial behavior and highlight how a compromised mucus layer gives rise to inflammation and microbial dysbiosis. This emerging field of respiratory research provides fresh opportunities to examine mucus, and its function as predictors of infection risk or disease progression and severity across a range of chronic pulmonary disease states and consider new perspectives in the development of mucolytic treatments.

Romanian clinical guideline for diagnosis and treatment of COPD

Chronic obstructive pulmonary disease (COPD) is a disease with increasing prevalence and burden for health systems worldwide. Every country collects its own epidemiological data regarding COPD prevalence, morbidity and mortality while taking steps to educate the population and medical community to improve early detection and treatment. The rising COPD prevalence creates a need for comprehensive guidelines. In 2012 and 2017–2018, the Romanian Society of Pneumology (SRP) organised national inquiries for COPD, while lung physicians in Romania began receiving education regarding the correct algorithms for COPD diagnosis and therapy. During 2019, a Romanian clinical guideline for diagnosis and treatment of COPD was published, and a condensed version of key points from this guideline are presented herein. COPD is diagnosed based on the presence of three major components: relevant exposure history, respiratory symptoms, and airway limitation that is not fully reversible. Clinical evaluation of patients diagnosed with COPD should include the level of symptoms, exacerbation rate, the presence of comorbidities and determination of phenotypes. The present abridged guideline is designed to be accessible and practical for assessing and managing patients with COPD. The application of up-to-date COPD guidelines may enhance the optimism of physicians and patients in managing this disease.

Proteases, Mucus, and Mucosal Immunity in Chronic Lung Disease

Dysregulated protease activity has long been implicated in the pathogenesis of chronic lung diseases and especially in conditions that display mucus obstruction, such as chronic obstructive pulmonary disease, cystic fibrosis, and non-cystic fibrosis bronchiectasis. However, our appreciation of the roles of proteases in various aspects of such diseases continues to grow. Patients with muco-obstructive lung disease experience progressive spirals of inflammation, mucostasis, airway infection and lung function decline. Some therapies exist for the treatment of these symptoms, but they are unable to halt disease progression and patients may benefit from novel adjunct therapies. In this review, we highlight how proteases act as multifunctional enzymes that are vital for normal airway homeostasis but, when their activity becomes immoderate, also directly contribute to airway dysfunction, and impair the processes that could resolve disease. We focus on how proteases regulate the state of mucus at the airway surface, impair mucociliary clearance and ultimately, promote mucostasis. We discuss how, in parallel, proteases are able to promote an inflammatory environment in the airways by mediating proinflammatory signalling, compromising host defence mechanisms and perpetuating their own proteolytic activity causing structural lung damage. Finally, we discuss some possible reasons for the clinical inefficacy of protease inhibitors to date and propose that, especially in a combination therapy approach, proteases represent attractive therapeutic targets for muco-obstructive lung diseases.

Management of Cough in Patients with Chronic Obstructive Pulmonary Disease: Results of the Multicenter Randomized Placebo-Controlled Clinical Trial

Background

Chronic cough declines quality of life and increases risk of complications in patients with chronic obstructive pulmonary disease (COPD). Reducing cough severity and associated negative effects is important therapeutic goal in COPD. Rengalin with anti- and protussive activity is based on technologically processed antibodies to bradykinin, histamine and morphine.

Aim

To evaluate efficacy and safety of Rengalin in treatment of cough in patients with COPD.

Methods

Patients (n=238, mean age 64.3±8.2 years) with stable COPD and persistent cough despite maintenance therapy (anticholinergics, beta-2-adrenergic agonists, inhaled corticosteroids) were included and randomized in the study. The severity of cough assessment (according to the “Cough Severity Score”), COPD impact on patient’s life (COPD Assessment Test, CAT), and spirometry were performed at screening. Patients took Rengalin or Placebo 2 tablets 2 times daily for 4 weeks. The endpoints were proportion of patients who responded to treatment, dynamics of cough severity, and severity of COPD symptoms. Intention-to-treat (per protocol) analysis was performed.

Results

Positive response to Rengalin was recorded in 83.6 [85.7]% (vs 72.6 [72.7]% in Placebo group, p=0.0422 [p=0.0163]). Double decrease of cough severity was reported in 42.2 [43.8]% in Rengalin group (versus 32.7 [32.7]% in Placebo; p=0.1373 [p=0.0907]). The total CAT score decreased by 3.3±4.2 [3.6±3.9] points (versus 2.5±4.1 [2.5±4.2] in Placebo group); the difference between groups was 0.79±4.16 [1.04±4.02] points (p=0.0870 [p=0.0416]). The number of patients with adverse events (AEs) in Rengalin (n=13) and Placebo (n=12) groups did not have significant differences (p=1.00). No AEs with certain relationship with study drug were registered.

Conclusion

Rengalin is an effective and safe drug in patients with stable COPD and persistent cough, despite stable doses of maintenance therapy according to the GOLD guidelines. Four-week therapy decreases severity of cough by two times in more than 40% of patients.

Trial Registration

ClinicalTrials.gov (id: NCT03159091).

Chronic obstructive pulmonary disease exacerbation fundamentals: Diagnosis, treatment, prevention and disease impact

In chronic obstructive pulmonary disease (COPD), exacerbations (ECOPD), characterized by an acute deterioration in respiratory symptoms, are fundamental events impacting negatively upon disease progression, comorbidities, wellbeing and mortality. ECOPD also represent the largest component of the socioeconomic burden of COPD. ECOPDs are currently defined as acute worsening of respiratory symptoms that require additional therapy. Definitions that require worsening of dyspnoea and sputum volume/purulence assume that acute infections, especially respiratory viral infections, and/or exposure to pollutants are the main cause of ECOPD. But other factors may contribute to ECOPD, such as the exacerbation of other respiratory diseases and non-respiratory diseases (e.g., heart failure, thromboembolism). The complexity of worsening dyspnoea has suggested a need to improve the definition of ECOPD using objective measurements such as blood counts and C-reactive protein to improve accuracy of diagnosis and a personalized approach to management. There are three time points when we can intervene to improve outcomes: acutely, to attenuate the length and severity of an established exacerbation; in the aftermath, to prevent early recurrence and readmission, which are common, and in the long-term, establishing preventative measures that reduce the risk of future events. Acute management includes interventions such as corticosteroids or antibiotics and measures to support the respiratory system, including non-invasive ventilation (NIV). Current therapies are broad and better understanding of clinical phenotypes and biomarkers may help to establish a more tailored approach, for example in relation to antibiotic prescription. Other unmet needs include effective treatment for viruses, which commonly cause exacerbations. Preventing early recurrence and readmission to hospital is important and the benefits of interventions such as antibiotics or anti-inflammatories in this period are not established. Domiciliary NIV in those patients who are persistently hypercapnic following discharge and pulmonary rehabilitation can have a positive impact. For long-term prevention, inhaled therapy is key. Dual bronchodilators reduce exacerbation frequency but in patients with continuing exacerbations, triple therapy should be considered, especially if blood eosinophils are elevated. Other options include phosphodiesterase inhibitors and macrolide antibiotics. ECOPD are a key component of the assessment of COPD severity and future outcomes (quality of life, hospitalisations, health care resource utilization, mortality) and are a central component in pharmacological management decisions. Targeted therapies directed towards specific pathways of inflammation are being explored in exacerbation prevention, and this is a promising avenue for future research.

Antitussive, Antioxidant, and Anti-Inflammatory Effects of a Walnut (Juglans regia L.) Septum Extract Rich in Bioactive Compounds

The antitussive, antioxidant, and anti-inflammatory effects of a walnut (Juglans regia L.) septum extract (WSE), rich in bioactive compounds were investigated using the citric acid aerosol-induced cough experimental model in rodents. Wistar male rats were treated orally for three days with distilled water (control), codeine (reference), and WSE in graded doses. On the third day, all rats were exposed to citric acid aerosols, the number of coughs being recorded. Each animal was sacrificed after exposure, and blood and lung tissue samples were collected for histopathological analysis and the assessment of oxidative stress and inflammatory biomarkers. The results of the experiment showed a significant antitussive effect of WSE, superior to codeine. This activity could be due to cellular protective effect and anti-inflammatory effect via the stimulation of the antioxidant enzyme system and the decrease of IL-6 and CXC-R1 concentration in the lung tissue of WSE-treated animals. The antioxidant and anti-inflammatory effects of WSE were confirmed by biochemical assays and histopathological analysis. This is the first scientific study reporting the antitussive effect of walnut septum, a new potential source of non-opioid antitussive drug candidates, and a valuable bioactive by-product that could be used in the treatment of respiratory diseases.

Use of mucolytics in COPD: A Delphi consensus study

BACKGROUND

International guidelines recommend mucolytic agents as add-on therapy in selected patients with COPD because they may reduce exacerbations and improve health status. As the evidence varies among mucolytic agents, we used the Delphi method to assess consensus amongst an international panel of COPD experts on mucolytics use in COPD.

METHODS

53 COPD experts from 12 countries were asked to complete an online questionnaire and rate their agreement with 15 statements using a 5-point scale. The mucolytic agents evaluated were carbocysteine, erdosteine and N-acetylcysteine (NAC). Data were collected anonymously and consensus presented using descriptive statistics.

RESULTS

The 47 respondents reached consensus on the statements. They agreed that regular treatment with mucolytic agents effectively reduces the frequency of exacerbations, reduces the duration of mild-to-moderate exacerbations, and can increase the time to first exacerbation and symptom-free time in COPD patients. Consensus was consistently highest for erdosteine. The experts agreed that all three mucolytics display antioxidant and anti-inflammatory activity. Erdosteine and NAC were thought to improve the efficacy of some classes of antibacterial drugs. All three mucolytics were considered effective for the short-term treatment of symptoms of acute exacerbations when added to other drugs. The panel agreed that approved doses of mucolytic agents have favorable side-effect profiles and can be recommended for regular use in patients with a bronchitic phenotype.

CONCLUSIONS

Consensus findings support the wider use of mucolytic agents as add-on therapy for COPD. However, the differences in pharmacological actions and clinical effectiveness must be considered when deciding which mucolytic to use.

Postoperative Physical Therapy to Prevent Hospital-acquired Pneumonia in Patients Over 80 Years Undergoing Hip Fracture Surgery-A Quasi-experimental Study

Background

Hip fracture requiring surgical fixation is a common condition with high mortality and morbidity in the geriatric population. The patients are usually frail, and vulnerable to postoperative complications and delayed recovery. Few studies have investigated physical therapy methods to prevent hospital-acquired pneumonia (HAP) after hip fracture surgery.

Objective

To explore whether an intensified physical therapy regimen can prevent HAP and reduce hospital length of stay in patients aged 80 and older, following hip fracture surgery.

Patients and Methods

The inclusion criterion was patients aged 80 or older who had undergone hip fracture surgery at Örebro University Hospital, Sweden during eight months in 2015–2016 (the “physical therapy group”) (n=69). The study has a quasi-experimental design with a historical control group (n=64) who had received routine physical therapy treatment. The physical therapy group received intensified postoperative physical therapy treatment, which included daily supervised early mobilization and coached deep breathing exercises with positive expiratory pressure (PEP). The patients were instructed to take deep breaths, and then exhale through the PEP-valve in three sessions of 10 deep breaths, at least four times daily. Early mobilization to a sitting position and walking was advised as soon as possible after surgery.

Results

There was a significantly lower incidence of HAP in the physical therapy group; 2/69 (3%, 95%CI: 1– 10) compared to the historical control group 13/64 (20%, 95%CI: 12–32%) (p=0.002). Patients in the physical therapy group had a significantly shorter length of stay than the control group (10.6±4 vs 13.4±9 days, p=0.022).

Conclusion

Intensified physical therapy treatment after hip fracture surgery may be of benefit to reduce the incidence of HAP in patients over 80 years; however, the results need to be confirmed in randomized controlled trials.

The mental health of emergency services personnel in the UK Biobank: a comparison with the working population

Background: There is evidence that mental disorders are more frequently reported among emergency services personnel due to the stressful nature of the job in combination with a high exposure to traumatic events. However, most of this research is based on occupational surveys that may lead to a contextual bias in the prevalence estimates or lack an adequate comparison group. Objectives: To investigate mental health outcomes and associations with individual, job and trauma related characteristics among emergency services personnel compared to other workers. Method: Participants were identified from the UK Biobank, a large study that collected a variety of genetic, physical and health data on individuals from across the UK. UK Biobank participants were aged between 40-69 years at recruitment. Those employed in the emergency services were identified based on job titles. A comparison sample of other workers was selected and matched to the gender composition of emergency services personnel. Results: 5052 participants were included, and 842 were currently working in the emergency services. The majority were male (77.4%) and the mean age at Biobank enrolment was 52.5 years. Alcohol misuse was reported in 32.8% of emergency services personnel compared to 29.2% in non-emergency services personnel, followed by PTSD (9.2% vs 6.0%), depression (6.8% vs 5.1%) and anxiety (3.9% vs 3.6%). An increased risk of PTSD was found among emergency services personnel compared to other workers (odds ratio 1.58, 95% confidence interval 1.21-2.06), but this association was no longer significant after adjustment for exposure to traumatic events and job characteristics. Conclusions: The substantial levels of alcohol misuse and increased risk of PTSD, possibly as a result of traumatic exposures in the line of duty in combination with job stressors such as shift work, call for continued monitoring of the health and wellbeing of emergency services personnel.

Targeting Aging Pathways in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) has become a global epidemic and is the third leading cause of death worldwide. COPD is characterized by chronic airway inflammation, loss of alveolar-capillary units, and progressive decline in lung function. Major risk factors for COPD are cigarette smoking and aging. COPD-associated pathomechanisms include multiple aging pathways such as telomere attrition, epigenetic alterations, altered nutrient sensing, mitochondrial dysfunction, cell senescence, stem cell exhaustion and chronic inflammation. In this review, we will highlight the current literature that focuses on the role of age and aging-associated signaling pathways as well as their impact on current treatment strategies in the pathogenesis of COPD. Furthermore, we will discuss established and experimental COPD treatments including senolytic and anti-aging therapies and their potential use as novel treatment strategies in COPD.

Inhibitors of the Autotaxin-Lysophosphatidic Acid Axis and Their Potential in the Treatment of Interstitial Lung Disease: Current Perspectives

Idiopathic pulmonary fibrosis is a progressive fibrosing interstitial lung disease for which there is no known cure. Currently available therapeutic options have been shown at best to slow the progression of the disease and thus there remains an urgent unmet need to identify new therapies. In this article, we will discuss the mechanisms of action, pre-clinical and clinical trial data surrounding inhibitors of the autotaxin-lysophosphatidic acid axis, which show promise as emerging novel therapies for fibrotic lung disease.

Oxidative stress-based therapeutics in COPD

Oxidative stress is a major driving mechanism in the pathogenesis of COPD. There is increased oxidative stress in the lungs of COPD patients due to exogenous oxidants in cigarette smoke and air pollution and due to endogenous generation of reactive oxygen species by inflammatory and structural cells in the lung. Mitochondrial oxidative stress may be particularly important in COPD. There is also a reduction in antioxidant defences, with inactivation of several antioxidant enzymes and the transcription factors Nrf2 and FOXO that regulate multiple antioxidant genes. Increased systemic oxidative stress may exacerbate comorbidities and contribute to skeletal muscle weakness. Oxidative stress amplifies chronic inflammation, stimulates fibrosis and emphysema, causes corticosteroid resistance, accelerates lung aging, causes DNA damage and stimulates formation of autoantibodies. This suggests that treating oxidative stress by antioxidants or enhancing endogenous antioxidants should be an effective strategy to treat the underlying pathogenetic mechanisms of COPD. Most clinical studies in COPD have been conducted using glutathione-generating antioxidants such as N-acetylcysteine, carbocysteine and erdosteine, which reduce exacerbations in COPD patients, but it is not certain whether this is due to their antioxidant or mucolytic properties. Dietary antioxidants have so far not shown to be clinically effective in COPD. There is a search for more effective antioxidants, which include superoxide dismutase mimetics, NADPH oxidase inhibitors, mitochondria-targeted antioxidants and Nrf2 activators.

Conventional and Nanotechnology Based Approaches to Combat Chronic Obstructive Pulmonary Disease: Implications for Chronic Airway Diseases

Chronic obstructive pulmonary disease (COPD) is the most prevalent obstructive lung disease worldwide characterized by decline in lung function. It is associated with airway obstruction, oxidative stress, chronic inflammation, mucus hypersecretion, and enhanced autophagy and cellular senescence. Cigarette smoke being the major risk factor, other secondary risk factors such as the exposure to air pollutants, occupational exposure to gases and fumes in developing countries, also contribute to the pathogenesis of COPD. Conventional therapeutic strategies of COPD are based on anti-oxidant and anti-inflammatory drugs. However, traditional anti-oxidant pharmacological therapies are commonly used to alleviate the impact of COPD as they have many associated repercussions such as low diffusion rate and inappropriate drug pharmacokinetics. Recent advances in nanotechnology and stem cell research have shed new light on the current treatment of chronic airway disease. This review is focused on some of the anti-oxidant therapies currently used in the treatment and management of COPD with more emphasis on the recent advances in nanotechnology-based therapeutics including stem cell and gene therapy approaches for the treatment of chronic airway disease such as COPD and asthma.

Heterozygous Genotype rs17580 AT (PiS) in SERPINA1 is Associated with COPD Secondary to Biomass-Burning and Tobacco Smoking: A Case-Control and Populational Study

Purpose

The protease inhibitor S (PiS) and Z (PiZ) variants have been stated as the only genetic cause of chronic obstructive pulmonary disease (COPD) in Caucasians. However, its frequency in admixed populations is low. We aimed to identify genetic susceptibility between PiS (rs17580) and PiZ (rs28929474) polymorphisms with COPD related to tobacco smoking and biomass-burning smoke as well as to determine its frequencies in Mestizo and Amerindian populations from Mexico.

Patients and Methods

One thousand and eight hundred seventy-eight subjects were included in two comparisons of cases and controls, (1) smokers with and without COPD (COPD-S, n=399; SWOC, n=1106); (2) Biomass-burning smoke-exposed subjects with and without COPD (COPD-BS, n=98; BBES, n=275). In addition, 2354 Mexican subjects identified as Mestizos (n=1952) and Amerindian (n=402) were included. The population structure was evaluated using 59 informative ancestry markers.

Results

The AT genotype of rs17580 is associated with COPD in both comparisons (COPD-S vs SWOC p<0.001, OR=2.16; COPD-BS vs BBES p<0.0001, OR=11.50). The population of the Mexico-North has a greater Caucasian contribution (54.7%) compared to the center (46.9%) and southeast (42.7%).

Conclusion

The rs17580, AT genotype, is associated with COPD in Mexican-Mestizo smokers and exposed to biomass-burning smoke. The rs17580 AT is more frequent in the Mexican-Mestizo population of the North of the country, which has a high Caucasian component.

Role of the mucins in pathogenesis of COPD: implications for therapy

Introduction: Evidence accumulated in the last decade has started to reveal the enormous complexity in the expression, interactions and functions of the large number of different mucins present in the different compartments of the human lower airways. This occurs both in normal subjects and in COPD patients in different clinical phases and stages of severity.Areas covered: We review the known physiological mechanisms that regulate mucin production in human lower airways of normal subjects, the changes in mucin synthesis/secretion in COPD patients and the clinical efficacy of drugs that modulate mucin synthesis/secretion.Expert opinion: It is evident that the old simplistic concept that mucus hypersecretion in COPD patients is associated with negative clinical outcomes is not valid and that the therapeutic potential of 'mucolytic drugs' is under-appreciated due to the complexity of the associated molecular network(s). Likewise, our current knowledge of the effects of the drugs already available on the market that target mucin synthesis/secretion/structure in the lower airways is extremely limited and often indirect and more well-controlled clinical trials are needed in this area.

Effect of Erdosteine on COPD Exacerbations in COPD Patients with Moderate Airflow Limitation

Background

The RESTORE study, a multi-national randomized, placebo-controlled study, showed that erdosteine - a muco-active antioxidant that modulates bacterial adhesiveness - reduced the rate and duration of exacerbations in moderate and severe COPD with a history of exacerbations. How much benefit patients with less severe disease experience when taking this drug remains unclear.

Methods

This post hoc analysis of the 254 RESTORE participants with spirometrically-defined moderate COPD (post-bronchodilator forced expiratory volume in 1 second [FEV₁] 50‒79% predicted) examined exacerbation rate and duration, time to first exacerbation, and exacerbation-free time. Data were analyzed using descriptive statistics and comparisons between treatment groups used Wilcoxon rank-sum tests, Mann-Whitney U-tests, or log rank tests.

Results

Patients with moderate COPD received erdosteine 300 mg twice daily (n=126) or placebo (n=128) added to usual COPD therapy for 12 months. During this time, there were 53 exacerbations in the erdosteine group and 74 in the placebo group, with 42.1% and 57.8% of patients, respectively, experiencing an exacerbation. There was a 47% reduction in the mean exacerbation rate with erdosteine compared to placebo (0.27 vs 0.51 exacerbations per-patient per-year, respectively, P=0.003), and a 58.3% reduction in the mild exacerbation rate (0.23 vs 0.53 mild exacerbations per-patient per-year, P=0.001). Mean duration of exacerbations was 26% shorter in erdosteine-treated patients (9.1 vs 12.3 days for placebo, P=0.022), with significant reductions in the duration of mild and moderate-to-severe exacerbations. Mean time to first exacerbation was prolonged by 7.7% (182 days for erdosteine vs 169 days for placebo, P<0.001) and the mean exacerbation-free time was increased by 51 days (279 days for erdosteine vs 228 days for placebo; P<0.001).

Conclusion

These results indicate that adding erdosteine to usual COPD maintenance therapy reduces the number of mild, and duration of all, exacerbations in patients with moderate COPD and a history of exacerbations.

Efficacy and safety profile of mucolytic/antioxidant agents in chronic obstructive pulmonary disease: a comparative analysis across erdosteine, carbocysteine, and N-acetylcysteine

Background

To date there are no head-to-head studies comparing different mucolytic/antioxidant agents. Considering the inconsistent evidence resulting from the pivotal studies on mucolytic/antioxidant agents tested in chronic obstructive pulmonary disease (COPD), and the recent publication of Reducing Exacerbations and Symptoms by Treatment with ORal Erdosteine in COPD (RESTORE) study, we have performed a meta-analysis to compare the efficacy and safety of erdosteine 600 mg/day, carbocysteine 1500 mg/day, and N-acetylcysteine (NAC) 1200 mg/day in COPD.

Methods

A pairwise and network meta-analyses were performed to assess the efficacy of erdosteine, carbocysteine, and NAC on acute exacerbation of COPD (AECOPD), duration of AECOPD, and hospitalization. The frequency of adverse events (AEs) was also investigated.

Results

Data obtained from 2753 COPD patients were extracted from 7 RCTs published between 2004 and 2017. In the pairwise meta-analysis mucolytic/antioxidant agents significantly reduced the risk of AECOPD (RR 0.74 95%CI 0.68–0.80). The network meta-analysis provided the following rank of effectiveness: erdosteine>carbocysteine>NAC. Only erdosteine reduced the risk of experiencing at least one AECOPD (P < 0.01) and the risk of hospitalization due to AECOPD (P < 0.05). Erdosteine and NAC both significantly reduced the duration of AECOPD (P < 0.01). The AEs induced by erdosteine, carbocysteine, and NAC were mild in severity and generally well tolerated. The quality of evidence of this quantitative synthesis is moderate.

Conclusions

The overall efficacy/safety profile of erdosteine is superior to that of both carbocysteine and NAC. Future head-to-head studies performed on the same COPD populations are needed to definitely confirm the results of this meta-analysis.

Trial registration

CRD42016053762.

Mucolytic agents versus placebo for chronic bronchitis or chronic obstructive pulmonary disease

BACKGROUND

Individuals with chronic bronchitis or chronic obstructive pulmonary disease (COPD) may suffer recurrent exacerbations with an increase in volume or purulence of sputum, or both. Personal and healthcare costs associated with exacerbations indicate that therapies that reduce the occurrence of exacerbations are likely to be useful. Mucolytics are oral medicines that are believed to increase expectoration of sputum by reducing its viscosity, thus making it easier to cough it up. Improved expectoration of sputum may lead to a reduction in exacerbations of COPD.

OBJECTIVES

Primary objective• To determine whether treatment with mucolytics reduces exacerbations and/or days of disability in patients with chronic bronchitis or COPDSecondary objectives• To assess whether mucolytics lead to improvement in lung function or quality of life• To determine frequency of adverse effects associated with use of mucolytics SEARCH METHODS: We searched the Cochrane Airways Group Specialised Register and reference lists of articles on 12 separate occasions, most recently on 23 April 2019.

SELECTION CRITERIA

We included randomised studies that compared oral mucolytic therapy versus placebo for at least two months in adults with chronic bronchitis or COPD. We excluded studies of people with asthma and cystic fibrosis.

DATA COLLECTION AND ANALYSIS

This review analysed summary data only, most derived from published studies. For earlier versions, one review author extracted data, which were rechecked in subsequent updates. In later versions, review authors double-checked extracted data and then entered data into RevMan 5.3 for analysis.

MAIN RESULTS

We added four studies for the 2019 update. The review now includes 38 trials, recruiting a total of 10,377 participants. Studies lasted between two months and three years and investigated a range of mucolytics, including N-acetylcysteine, carbocysteine, erdosteine, and ambroxol, given at least once daily. Many studies did not clearly describe allocation concealment, and we had concerns about blinding and high levels of attrition in some studies. The primary outcomes were exacerbations and number of days of disability.Results of 28 studies including 6723 participants show that receiving mucolytics may be more likely to be exacerbation-free during the study period compared to those given placebo (Peto odds ratio (OR) 1.73, 95% confidence interval (CI) 1.56 to 1.91; moderate-certainty evidence). However, more recent studies show less benefit of treatment than was reported in earlier studies in this review. The overall number needed to treat with mucolytics for an average of nine months to keep an additional participant free from exacerbations was eight (NNTB 8, 95% CI 7 to 10). High heterogeneity was noted for this outcome (I² = 62%), so results need to be interpreted with caution. The type or dose of mucolytic did not seem to alter the effect size, nor did the severity of COPD, including exacerbation history. Longer studies showed smaller effects of mucolytics than were reported in shorter studies.Mucolytic use was associated with a reduction of 0.43 days of disability per participant per month compared with use of placebo (95% CI -0.56 to -0.30; studies = 9; I² = 61%; moderate-certainty evidence). With mucolytics, the number of people with one or more hospitalisations was reduced, but study results were not consistent (Peto OR 0.68, 95% CI 0.52 to 0.89; participants = 1788; studies = 4; I² = 58%; moderate-certainty evidence). Investigators reported improved quality of life with mucolytics (mean difference (MD) -1.37, 95% CI -2.85 to 0.11; participants = 2721; studies = 7; I² = 64%; moderate-certainty evidence). However, the mean difference did not reach the minimal clinically important difference of -4 units, and the confidence interval includes no difference. Mucolytic treatment was associated with a possible reduction in adverse events (OR 0.84, 95% CI 0.74 to 0.94; participants = 7264; studies = 24; I² = 46%; moderate-certainty evidence), but the pooled effect includes no difference if a random-effects model is used. Several studies that could not be included in the meta-analysis reported high numbers of adverse events, up to a mean of five events per person during follow-up. There was no clear difference between mucolytics and placebo for mortality, but the confidence interval is too wide to confirm that treatment has no effect on mortality (Peto OR 0.98, 95% CI 0.51 to 1.87; participants = 3527; studies = 11; I² = 0%; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

In participants with chronic bronchitis or COPD, we are moderately confident that treatment with mucolytics leads to a small reduction in the likelihood of having an acute exacerbation, in days of disability per month and possibly hospitalisations, but is not associated with an increase in adverse events. There appears to be limited impact on lung function or health-related quality of life. Results are too imprecise to be certain whether or not there is an effect on mortality. Our confidence in the results is reduced by high levels of heterogeneity in many of the outcomes and the fact that effects on exacerbations shown in early trials were larger than those reported by more recent studies. This may be a result of greater risk of selection or publication bias in earlier trials, thus benefits of treatment may not be as great as was suggested by previous evidence.

Targeted Treatments for Chronic Obstructive Pulmonary Disease (COPD) Using Low-Molecular-Weight Drugs (LMWDs)

Chronic obstructive pulmonary disease (COPD) is a very common and frequently fatal airway disease. Current therapies for COPD depend mainly on long-acting bronchodilators, which cannot target the pathogenic mechanisms of chronic inflammation in COPD. New pharmaceutical therapies for the inflammatory processes of COPD are urgently needed. Several anti-inflammatory targets have been identified based on increased understanding of the pathogenesis of COPD, which raises new hopes for targeted treatment of this fatal respiratory disease. In this review, we discuss the recent advances in bioactive low-molecular-weight drugs (LMWDs) for the treatment of COPD and, in addition to the first-line drug bronchodilators, focus particularly on low-molecular-weight anti-inflammatory agents, including modulators of inflammatory mediators, inflammasome inhibitors, protease inhibitors, antioxidants, PDE4 inhibitors, kinase inhibitors, and other agents. We also provide new insights into targeted COPD treatments using LMWDs, particularly small-molecule agents.

Mucoactive Agents in the Therapy of Upper Respiratory Airways Infections: Fair to Describe Them Just as Mucoactive?

Background

Upper and lower respiratory tract infections are common conditions for which medical advice is sought, and their management relies on the use of prescription and over-the-counter (OTC) medicines. Ambroxol, bromhexine, carbocysteine, erdosteine, N-acetyl cysteine (NAC), and sobrerol are mucoactive agents for which clinical trials have been conducted, have been awarded well-established status by regulatory authorities, and are available as OTC or prescription products.

Objective

To briefly review the evidence-based efficacy and safety of these substances in the therapy of upper respiratory airways infections.

Methods

We conducted searches in MEDLINE and other databases for clinical trials and reviews done on the efficacy and safety of ambroxol, bromhexine, carbocysteine, erdosteine, NAC, and sobrerol.

Results

Clinical trials have shown that these mucolytics have an important place in the relief of cough symptoms by easing the elimination of mucus. All drugs have shown comparable efficacy in the symptomatic treatment of productive cough, with some shared characteristics and some specific features.

Conclusions and relevance

All mucolytics reviewed have a good safety profile, although some precautions should be taken when using ambroxol and bromhexine, and the use of NAC and carbocysteine should be monitored in special patient groups. Overall, however, the available evidence from randomised, controlled, and observational trials, as well as pragmatic, real-life experience, suggests that these products are useful in the therapy of upper respiratory airways infections, including bronchitis, sinusitis, and rhinosinusitis.

Oxidative stress and macrophages: driving forces behind exacerbations of asthma and chronic obstructive pulmonary disease?

Oxidative stress is a common feature of obstructive airway diseases like asthma and chronic obstructive pulmonary disease (COPD). Lung macrophages are key innate immune cells that can generate oxidants and are known to display aberrant polarization patterns and defective phagocytic responses in these diseases. Whether these characteristics are linked in one way or another and whether they contribute to the onset and severity of exacerbations in asthma and COPD remain poorly understood. Insight into oxidative stress, macrophages, and their interactions may be important in fully understanding acute worsening of lung disease. This review therefore highlights the current state of the art regarding the role of oxidative stress and macrophages in exacerbations of asthma and COPD. It shows that oxidative stress can attenuate macrophage function, which may result in impaired responses toward exacerbating triggers and may contribute to exaggerated inflammation in the airways.

Erdosteine: Drug exhibiting polypharmacy for the treatment of respiratory diseases

Mucoactive drugs are commonly used in the treatment of acute respiratory tract diseases, such as lower and acute respiratory infection and chronic bronchitis (CB) or chronic obstructive pulmonary disease (COPD) in which an increased mucus secretion is one of main clinical features. Indeed these drugs are designed to promote secretion clearance and to specifically alter the viscoelastic properties of mucus, restoring an effective mucociliary clearance and reducing broncho-obstructive symptoms. In association with mucolytics, these patients frequently also receive antibiotics to reduce the bacterial load, thus decreasing the release of infectious and pro-inflammatory products. Erdosteine is one of the most used mucoactive agents for the treatment of several respiratory diseases where the overlap of bacterial infection is frequent. Although the effectiveness in the reducing mucus in acute and chronic respiratory disease has been demonstrated for others mucolytic, some of them when given in combination with an antibiotic therapy, could reduce the antibiotic efficacy in some situation. Differently, erdosteine potentiates the antibiotic effect when given in combination with antibiotics. We have reviewed the literature available on both clinical and in vitro studies that have investigated this effect of erdosteine on the effect of antibiotics when used as combined therapy.

Antioxidants and Chronic Obstructive Pulmonary Disease

Antioxidants represent an attractive therapeutic avenue for individuals with chronic obstructive pulmonary disease (COPD). Cigarette smoke, the major cause of COPD, contains very high concentrations of gaseous and soluble oxidants that can directly induce cell injury and death. Furthermore, particulate matter in cigarette smoke activates lung macrophages that subsequently attract neutrophils. Both neutrophils and macrophages from the lungs of cigarette smokers continuously release large amounts of superoxide and hydrogen peroxide through the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. Once individuals with COPD stop smoking, the neutrophilic inflammation in the airways and lung parenchyma persists, as do the markers of oxidative stress. Several animal models of cigarette smoke-induced injury have provided evidence that various antioxidants may prevent inflammation and morphological changes associated with COPD however, evidence of benefit in patients is less abundant. Although oxidants can inactivate alpha-1 antitrypsin and other protective proteins, damage lung tissue, and increase mucus production, they also are essential for killing pathogens and resolving inflammation. This review will examine the pre-clinical and clinical evidence of a role for antioxidants in the therapy of patients with COPD.

Challenges in the management of asthma associated with smoking-induced airway diseases

INTRODUCTION

Smoking-induced airway diseases such as chronic bronchitis, emphysema, and small airway dysfunction contribute to the chronic respiratory symptoms experienced by adults with asthma, including those with spirometric chronic obstructive pulmonary disease (COPD), termed asthma-COPD overlap (ACO). Drug treatment of symptomatic smokers with asthma or ACO is uncertain due to their exclusion from most clinical trials.

AREAS COVERED

This review summarizes evidence for the efficacy of small molecule drugs used in the clinic to treat current and former smokers with a diagnostic label of asthma or ACO. Other therapeutic interventions are reviewed, including smoking cessation and biologics.

EXPERT OPINION

Clinical trials and observational studies suggest that smoking cessation and approved drugs used to treat non-smokers with asthma produce clinical benefits in smokers with asthma or ACO, although the overall quality of evidence is low. The efficacy of some treatments for asthma is altered in current smokers, including reduced responsiveness to short-term inhaled corticosteroids and possibly improved responsiveness to leukotriene receptor antagonists. Preliminary findings suggest that low-dose theophylline, statins, and biologics, such as omalizumab, mepolizumab, and dupilumab, may improve clinical outcomes in smokers with asthma or ACO. Improved phenotyping and endotyping of asthma and smoking-induced airway diseases should lead to better targeted therapies.

Impact of erdosteine on chronic bronchitis and COPD: A meta-analysis

A previous meta-analysis suggested that the treatment with erdosteine was associated with significant amelioration of the cumulative global efficacy index and symptoms in comparison to placebo or other mucolytics. However, this conclusion was criticized because the meta-analysis, as it had been done, made it impossible to preclude the potential operation of selection biases within and across trials, and identify any realised benefits of an individual patient data approach. Taking into consideration these criticisms and also the publication of two further recent articles focused on the prevention of chronic obstructive pulmonary disease (COPD) exacerbations with erdosteine, we have carried out a quantitative synthesis via meta-analysis of the currently available data on the use of this drug. Our findings included data from ten studies involving 1278 patients and show that erdosteine is able to improve the clinical score of patients with chronic bronchitis and COPD, and also reduces the overall risk of chronic bronchitis/COPD exacerbations, and reduces the risk of experiencing at least one exacerbation. Furthermore, our data suggest that erdosteine can lengthen the time to the first COPD exacerbation, reduce the duration of a COPD exacerbation and the risk of hospitalization from COPD. The documented effect of erdosteine in reducing the occurence and/or influencing COPD exacerbations is important because it indicates that erdosteine can be added to the list of drugs that can be recommended for treating COPD.

Targeting oxidant-dependent mechanisms for the treatment of respiratory diseases and their comorbidities

Oxidative stress is implicated in the pathogenesis of respiratory diseases, such as COPD and its comorbidities, asthma, idiopathic pulmonary fibrosis and radiation pneumonitis. Antioxidants drugs, such as small molecule thiols, nuclear erythroid-2 related factor 2 activators and catalytic enzyme mimetics have been developed to target oxidant-dependent mechanisms. The therapeutic effects of antioxidants have been generally disappointing. A small number of antioxidants are approved for clinical use, such as the small molecule thiol N-acetyl-l-cysteine for chronic obstructive pulmonary disease, and in the United States, the superoxide dismutase mimetic AEOL 10150 for severe radiation pneumonitis. The future use of antioxidants for the treatment of chronic respiratory diseases may require a precision medicine approach to identify responsive patients.