Effects of bronchodilation on biomarkers of peripheral airway inflammation in COPD

Investigating effectiveness of adherence of long-acting bronchodilator in chronic obstructive pulmonary disease with influenza infection

Objectives

Long-acting bronchodilators are important treatments for chronic obstructive pulmonary disease (COPD) and adequate medication adherence decreases COPD exacerbations, especially in reducing the hazard of influenza infection. Therefore, the study aim was to evaluate adherence of long-acting bronchodilator treatment and the risk of influenza in patients with COPD.

Methods

This retrospective nested case-control study included patients with newly diagnosed COPD from 2012 to 2018. Cases with influenza infection were defined and matched to 2 randomly selected controls. The influenza infection date was the index date. Conditional logistic regressions were used to estimate odds ratios of influenza from proportion of days covered (PDC) of long-acting bronchodilators measured in one year before the index date. Adherence was divided into high adherence (PDC ≥80 %) and low adherence (PDC <80 %).

Results

This population-based study included 6,073 patients in the case group and 12,146 in the control group. High PDC of long-acting bronchodilators in COPD was associated with a 0.811-fold (95 % confidence interval: 0.754-0.883, P < 0.001) decreased influenza risk, where 906 (14.92 %) high PDC in case and 2,130 (17.54 %) in control. Low PDC without influenza vaccination in COPD patients is associated with increased influenza risk, regardless of exposure period.

Conclusion

In Taiwan, COPD patients with high PDC were associate with lower COPD exacerbation. Different long-acting bronchodilator exposure or dose need to be further investigated in COPD patients.

Early lung diffusion abnormalities and airways' inflammation in children with type 1 diabetes

BACKGROUND AND AIMS OF THE STUDY

Type 1 diabetes (T1D) impacts lung function and exercise capacity in adults, but limited information is available in children. We hypothesize that T1D causes alterations in pulmonary function and cardiorespiratory fitness, i.e., exercise capacity, at early stages of the disease, due to the presence of inflammation and vascular damage. Therefore, we aim to investigate pulmonary function before and after exercise in children with T1D as compared to age matched healthy controls.

METHOD

Twenty-four children with T1D and twenty healthy controls underwent body plethysmography, diffusion lung capacity for carbon monoxide and fractional exhaled nitric oxide at rest and after cardio-pulmonary exercise test.

RESULTS

In children with T1D, baseline total lung capacity and diffusion lung capacity for carbon monoxide were reduced as compared to healthy controls. Children with T1D also showed a reduced exercise capacity associated with poor aerobic fitness. Accordingly, diffusion lung capacity for carbon monoxide tended to increase with exercise in healthy controls, while no change was observed in children with T1D. Fractional exhaled nitric oxide was significantly higher at baseline and tended to increase with exercise in children with T1D, while no changes were observed in healthy controls.

CONCLUSIONS

Altered diffusion lung capacity for carbon monoxide, increased fractional exhaled nitric oxide and a poor aerobic fitness to exercise suggests the presence of early pulmonary abnormalities in children with T1D.

An Update on Outcomes for COPD Pharmacological Trials: A COPD Investigators Report - Reassessment of the 2008 American Thoracic Society/European Respiratory Society Statement on Outcomes for COPD Pharmacological Trials

Background: In 2008, a dedicated American Thoracic Society/European Respiratory Society task force published a paper on the possible use and limitations of clinical outcomes and biomarkers to evaluate the impact of pharmacological therapy in patients with chronic obstructive pulmonary disease. Since then, our scientific understanding of chronic obstructive pulmonary disease has increased considerably; there has been a progressive shift from a one-size-fits-all diagnostic and therapeutic approach to a personalized approach; and many new treatments currently in development will require new endpoints to evaluate their efficacy adequately. Objectives: The emergence of several new relevant outcome measures motivated the authors to review advances in the field and highlight the need to update the content of the original report. Methods: The authors separately created search strategies for the literature, primarily based on their opinions and assessments supported by carefully chosen references. No centralized examination of the literature or uniform criteria for including or excluding evidence were used. Measurements and Main Results: Endpoints, outcomes, and biomarkers have been revisited. The limitations of some of those reported in the American Thoracic Society/European Respiratory Society task force document have been highlighted. In addition, new tools that may be useful, especially in evaluating personalized therapy, have been described. Conclusions: Because the "label-free" treatable traits approach is becoming an important step toward precision medicine, future clinical trials should focus on highly prevalent treatable traits, and this will influence the choice of outcomes and markers to be considered. The use of the new tools, particularly combination endpoints, could help better identify the right patients to be treated with the new drugs.

The Prognostic Performance of Lung Diffusing Capacity in Preserved Ratio Impaired Spirometry: An Observational Cohort Study

Purpose

Similar to chronic obstructive pulmonary disease (COPD), the diffusing capacity of the lung (D_LCO) might be decreased and associated with poor prognosis in preserved ratio impaired spirometry (PRISm), a clinical entity as a prodromal phase of COPD. The aims of the present study were to evaluate the distributions of D_LCO and to assess the association between D_LCO and mortality among subjects with PRISm.

Patients and Methods

We conducted an observational cohort study at the National Hospital Organization Fukuoka National Hospital. We classified the 899 patients ≥ 40 years of age with an assessment of D_LCO into five groups based on spirometry: preserved spirometry, PRISm, mild COPD, moderate COPD, and severe/very severe COPD. The prevalence of low D_LCO (< 80% per predicted) was compared among the five groups. Using PRISm patients with follow-up data, we further investigated the association of low D_LCO with all-cause mortality.

Results

The prevalence of low D_LCO in the PRISm group (58.8%) was significantly higher than that in the preserved-spirometry group (21.8%), the mild-COPD group (23.5%), and the moderate-COPD group (36.0%) (all P < 0.01), and it was comparable to that in the severe/very severe-COPD group (63.2%). The results remained unchanged after adjusting for potential confounders. Among the PRISm subjects, the overall survival rate was significantly lower in the low-D_LCO group than in the preserved-D_LCO group (P < 0.01). The multivariable-adjusted hazard ratio (HR) for all-cause mortality was significantly higher in the low-D_LCO group than in the preserved-D_LCO group (HR = 10.10 (95% confidence interval 2.33–43.89)).

Conclusion

Diffusing capacity was more impaired in PRISm subjects than in those with preserved spirometry or mild to moderate COPD. Regarding PRISm, low D_LCO was a significant risk factor for all-cause mortality. Clinicians should assess D_LCO in the management of PRISm to predict the future risk of overall death.

A reappraisal of inspiratory capacity in chronic obstructive pulmonary disease: clinical correlates and role of long-acting muscarinic antagonists and long-acting β2 agonists

INTRODUCTION

In patients with chronic obstructive pulmonary disease (COPD), static and dynamic hyperinflation, together with expiratory flow limitation and gas exchange abnormalities, is one of the major causes of dyspnea, decreased exercise performance and ventilatory failure. An increase in functional residual capacity (FRC) is accompanied by a decrease in inspiratory capacity (IC), which is a volume readily available, repeatable, and simple to measure with any spirometer. Changes in IC and FRC after bronchodilation, contrary to changes in FEV₁, have been closely associated with improvements in dyspnea and exercise performance. We systematically searched PubMed and Embase databases for clinical trials that assessed the effects of dual bronchodilation on inspiratory capacity in patients with COPD.

AREAS COVERED

Despite their pivotal role in COPD, IC and static volumes have rarely been considered as primary outcomes in randomized clinical trials assessing the efficacy of bronchodilators. Available studies on dual bronchodilation have shown a significant and persistent positive impact on IC focusing mainly on patients with moderate-to-severe COPD, whereas dynamic hyperinflation is also present at milder disease stages.

EXPERT OPINION

This narrative review discusses the pathophysiological and clinical importance of measuring IC in patients with COPD and how IC can be modified by maximizing bronchodilation combining long-acting muscarinic antagonists and long-acting β2 agonists.

The association between transfer coefficient of the lung and the risk of exacerbation in asthma-COPD overlap: an observational cohort study

BACKGROUND

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) patients experience exacerbations more frequently than those with asthma or COPD alone. Since low diffusing capacity of the lung for carbon monoxide (DLCO) is known as a strong risk factor for severe exacerbation in COPD, DLCO or a transfer coefficient of the lung for carbon monoxide (KCO) is speculated to also be associated with the risk of exacerbations in ACO.

METHODS

This study was conducted as an observational cohort survey at the National Hospital Organization Fukuoka National Hospital. DLCO and KCO were measured in 94 patients aged ≥ 40 years with a confirmed diagnosis of ACO. Multivariable-adjusted hazard ratios (HRs) for the exacerbation-free rate over one year were estimated and compared across the levels of DLCO and KCO.

RESULTS

Within one year, 33.3% of the cohort experienced exacerbations. After adjustment for potential confounders, low KCO (< 80% per predicted) was positively associated with the incidence of exacerbation (multivariable-adjusted HR = 3.71 (95% confidence interval 1.32-10.4)). The association between low DLCO (< 80% per predicted) and exacerbations showed similar trends, although it failed to reach statistical significance (multivariable-adjusted HR = 1.31 (95% confidence interval 0.55-3.11)).

CONCLUSIONS

Low KCO was a significant risk factor for exacerbations among patients with ACO. Clinicians should be aware that ACO patients with impaired KCO are at increased risk of exacerbations and that careful management in such a population is mandatory.

Inhaled β2 Adrenergic Agonists and Other cAMP-Elevating Agents: Therapeutics for Alveolar Injury and Acute Respiratory Disease Syndrome?

Inhaled long-acting β-adrenergic agonists (LABAs) and short-acting β-adrenergic agonists are approved for the treatment of obstructive lung disease via actions mediated by β2 adrenergic receptors (β2-ARs) that increase cellular cAMP synthesis. This review discusses the potential of β2-AR agonists, in particular LABAs, for the treatment of acute respiratory distress syndrome (ARDS). We emphasize ARDS induced by pneumonia and focus on the pathobiology of ARDS and actions of LABAs and cAMP on pulmonary and immune cell types. β2-AR agonists/cAMP have beneficial actions that include protection of epithelial and endothelial cells from injury, restoration of alveolar fluid clearance, and reduction of fibrotic remodeling. β2-AR agonists/cAMP also exert anti-inflammatory effects on the immune system by actions on several types of immune cells. Early administration is likely critical for optimizing efficacy of LABAs or other cAMP-elevating agents, such as agonists of other Gs-coupled G protein-coupled receptors or cyclic nucleotide phosphodiesterase inhibitors. Clinical studies that target lung injury early, prior to development of ARDS, are thus needed to further assess the use of inhaled LABAs, perhaps combined with inhaled corticosteroids and/or long-acting muscarinic cholinergic antagonists. Such agents may provide a multipronged, repurposing, and efficacious therapeutic approach while minimizing systemic toxicity. SIGNIFICANCE STATEMENT: Acute respiratory distress syndrome (ARDS) after pulmonary alveolar injury (e.g., certain viral infections) is associated with ∼40% mortality and in need of new therapeutic approaches. This review summarizes the pathobiology of ARDS, focusing on contributions of pulmonary and immune cell types and potentially beneficial actions of β2 adrenergic receptors and cAMP. Early administration of inhaled β2 adrenergic agonists and perhaps other cAMP-elevating agents after alveolar injury may be a prophylactic approach to prevent development of ARDS.

Evaluation of small airway function and its application in patients with chronic obstructive pulmonary disease (Review)

Chronic obstructive pulmonary disease (COPD) is a chronic airway inflammatory disease characterized by incomplete reversible airflow limitation. The diagnosis of COPD is mainly based on pulmonary function examination. In recent years, it has been indicated that small airway dysfunction occurs in patients with all stages of COPD, even in high-risk smoking groups who have not yet met the diagnostic criteria for COPD. Early recognition of small airway dysfunction and early initiation of small airway targeted therapy have become foci of research. In the present review, the methods of evaluating small airway function were summarized and their merits and shortcomings were discussed. Furthermore, the potential of targeted treatment of small airways in patients with COPD was outlined.

Clinical Values of Nitric Oxide Parameters from the Respiratory System

BACKGROUND

Fractional exhaled nitric oxide (FENO) concentration reliably reflects central airway inflammation, but it is not sensitive to changes in the NO dynamics in the lung periphery. By measuring FENO at several different flow rates one can estimate alveolar NO concentration (C_ANO), bronchial NO flux (J_awNO), bronchial wall NO concentration (C_awNO) and the bronchial diffusivity of NO (D_awNO).

OBJECTIVE

We aimed to describe the current knowledge and clinical relevance of NO parameters in different pulmonary diseases.

METHODS

We conducted a systematic literature search to identify publications reporting NO parameters in subjects with pulmonary or systemic diseases affecting the respiratory tract. A narrative review was created for those with clinical relevance.

RESULTS

Estimation of pulmonary NO parameters allows for differentiation between central and peripheral inflammation and a more precise analysis of central airway NO output. C_ANO seems to be a promising marker of parenchymal inflammation in interstitial lung diseases and also a marker of tissue damage and altered gas diffusion in chronic obstructive pulmonary disease and systemic diseases affecting the lung. In asthma, C_ANO can detect small airway involvement left undetected by ordinary FENO measurement. Additionally, C_awNO and D_awNO can be used in asthma to assess if FENO is increased due to enhanced inflammatory activity (increased C_awNO) or tissue changes related to bronchial remodelling (altered D_awNO).

CONCLUSION

NO parameters may be useful for diagnosis, prediction of disease progression and prediction of treatment responses in different parenchymal lung and airway diseases. Formal trials to test the added clinical value of NO parameters are needed.

Day and Night Control of COPD and Role of Pharmacotherapy: A Review

The topic of 24-hour management of COPD is related to day-to-night symptoms management, specific follow-up and patients' adherence to therapy. COPD symptoms strongly vary during day and night, being worse in the night and early morning. This variability is not always adequately considered in the trials. Night-time symptoms are predictive of higher mortality and more frequent exacerbations; therefore, they should be a target of therapy. During night-time, in COPD patients the supine position is responsible for a different thoracic physiology; moreover, during some sleep phases the vagal stimulation determines increased bronchial secretions, increased blood flow in the bronchial circulation (enhancing inflammation) and increased airway resistance (broncho-motor tone). Moreover, in COPD patients the circadian rhythm may be impaired. The role of pharmacotherapy in this regard is still poorly investigated. Symptoms can be grossly differentiated according to the different phenotypes of the disease: wheezing recalls asthma, while dyspnea is strongly related to emphysema (dynamic hyperinflation) or obstructive bronchiolitis (secretions). Those symptoms may be different targets of therapy. In this regard, GOLD recommendations for the first time introduced the concept of phenotype distinction suggesting the use of inhaled corticosteroids (ICS) particularly when an asthmatic pattern or eosiophilic inflammations are present, and hypothesized different approaches to target symptoms (ie, dyspnea) or exacerbations. Pharmacotherapy should be evaluated and possibly directed on the basis of circadian variations, for instance, supporting the use of twice-daily rapid-action bronchodilators and evening dose of ICS. Recommendations on day and night symptoms monitoring strategies and choice of the specific drug according to patient's profile are still not systematically investigated or established. This review is the summary of an advisory board on the topic "24-hour control of COPD and role of pharmacotherapy", held by five pulmonologists, experts in respiratory pathophysiology, pharmacology and sleep medicine.

The Airways' Mechanical Stress in Lung Disease: Implications for COPD Pathophysiology and Treatment Evaluation

The airway epithelium stretches and relaxes during the normal respiratory cycle, and hyperventilation exaggerates this effect, resulting in changes in lung physiology. In fact, stretching of the airways influences lung function and the secretion of airway mediators, which in turn may cause a potentially injurious inflammatory response. This aim of the present narrative review was to illustrate the current evidence on the importance of mechanical stress in the pathophysiology of lung diseases with a particular focus on chronic obstructive pulmonary disease (COPD) and to discuss how this may influence pharmacological treatment strategies. Overall, treatment selection should be tailored to counterpart the effects of mechanical stress, which influences inflammation both in asthma and COPD. The most suitable treatment approach between a long-acting β2-agonists/long-acting antimuscarinic-agonist (LABA/LAMA) alone or with the addition of inhaled corticosteroids should be determined based on the underlying mechanism of inflammation. Noteworthy, the anti-inflammatory effects of the glycopyrronium/indacaterol combination on hyperinflation and mucociliary clearance may decrease the rate of COPD exacerbations, and it may synergistically improve bronchodilation with a double action on both the cyclic adenosine monophosphate (cAMP) and the acetylcholine pathways.

A New Use for an Old Drug: Carmofur Attenuates Lipopolysaccharide (LPS)-Induced Acute Lung Injury via Inhibition of FAAH and NAAA Activities

Acute lung injury (ALI), characterized by a severe inflammatory process, is a complex syndrome that can lead to multisystem organ failure. Fatty acid amide hydrolase (FAAH) and N-acylethanolamine acid amidase (NAAA) are two potential therapeutic targets for inflammation-related diseases. Herein, we identified carmofur, a 5-fluorouracil-releasing drug and clinically used as a chemotherapeutic agent, as a dual FAAH and NAAA inhibitor. In Raw264.7 macrophages, carmofur effectively reduced the mRNA expression of pro-inflammatory factors, including IL-1β, IL-6, iNOS, and TNF-α, and down-regulated signaling proteins of the nuclear transcription factor κB (NF-κB) pathway. Furthermore, carmofur significantly ameliorated the inflammatory responses and promoted resolution of pulmonary injury in lipopolysaccharide (LPS)-induced ALI mice. The pharmacological effects of carmofur were partially blocked by peroxisome proliferator-activated receptor-α (PPARα) antagonist MK886 and cannabinoid receptor 2 (CB2) antagonist SR144528, indicating that carmofur attenuated LPS-induced ALI in a PPARα- and CB2-dependent mechanism. Our study suggested that carmofur might be a novel therapeutic agent for ALI, and drug repurposing may provide us effective therapeutic strategies for ALI.

COPD patients with peripheral airway obstruction reversibility identified by exhaled nitric oxide

RATIONALE

Besides its role as an inflammatory marker in asthma, fractional exhaled nitric oxide (F_ENO) provides information on the extent of the airway obstruction process through evaluating its change after bronchodilation.

OBJECTIVE

To investigate whether F_ENO change after bronchodilation can identify different sites of airway obstruction in COPD patients.

METHODS

F_ENO, FEV₁ and the slopes (S) of the alveolar plateau of the single breath washout test (SBWT) were measured in 61 stable COPD patients (FEV₁ 34.5% predicted) before and after the inhalation of 400 μg salbutamol. SBWT used Helium (He), and sulfur-hexafluoride (SF₆). Obstruction relief occurring in pre-acinar and intra-acinar small airways is expected to decrease S_He and S_SF6, respectively. Indices changes (Δ) after bronchodilation were expressed as a percentage of pre-bronchodilation values.

RESULTS

F_ENO stability (∣ΔF_ENO∣ ≤ 11%) was observed in 19 patients [-2.7(6.7)%] [mean (SD)] (NO = group); ΔF_ENO > 11% [+37.4(27.7)%] in 20 patients (NO+ group) and ΔF_ENO < -11% in 22 patients [-31.2(9.8)%] (NO- group). A similar ΔFEV₁ (p = 0.583; [+9.4(9.6)%]) was found in the three groups. In NO = and NO+ groups, neither S_He nor S_SF6 changed; in NO- both S_He [-12.4(27.5)%, p = 0.007] and S_SF6 [-20.2(20.4)%, p < 0.001] significantly decreased.

CONCLUSION

Different patterns of F_ENO response to β ₂-agonists were observed in COPD most likely depending on the extent of the dilation process. A profile of airway obstruction with an extensive β ₂-agonist response down to lung periphery is identified by F_ENO reduction after acute bronchodilation in 30% of COPD patients. The clinical relevance of this profile requires further investigation.

Exhaled particles and small airways

BACKGROUND

Originally, studies on exhaled droplets explored properties of airborne transmission of infectious diseases. More recently, the interest focuses on properties of exhaled droplets as biomarkers, enabled by the development of technical equipment and methods for chemical analysis. Because exhaled droplets contain nonvolatile substances, particles is the physical designation. This review aims to outline the development in the area of exhaled particles, particularly regarding biomarkers and the connection with small airways, i e airways with an internal diameter < 2 mm.

MAIN BODY

Generation mechanisms, sites of origin, number concentrations of exhaled particles and the content of nonvolatile substances are studied. Exhaled particles range in diameter from 0.01 and 1000 μm depending on generation mechanism and site of origin. Airway reopening is one scientifically substantiated particle generation mechanism. During deep expirations, small airways close and the reopening process produces minute particles. When exhaled, these particles have a diameter of < 4 μm. A size discriminating sampling of particles < 4 μm and determination of the size distribution, allows exhaled particle mass to be estimated. The median mass is represented by particles in the size range of 0.7 to 1.0 μm. Half an hour of repeated deep expirations result in samples in the order of nanogram to microgram. The source of these samples is the respiratory tract ling fluid of small airways and consists of lipids and proteins, similarly to surfactant. Early clinical studies of e g chronic obstructive pulmonary disease and asthma, reported altered particle formation and particle composition.

CONCLUSION

The physical properties and content of exhaled particles generated by the airway reopening mechanism offers an exciting noninvasive way to obtain samples from the respiratory tract lining fluid of small airways. The biomarker potential is only at the beginning to be explored.