Deciphering Respiratory-Virus-Associated Interferon Signaling in COPD Airway Epithelium

COPD is a chronic lung disorder characterized by a progressive and irreversible airflow obstruction, and persistent pulmonary inflammation. It has become a global epidemic affecting 10% of the population, and is the third leading cause of death worldwide. Respiratory viruses are a primary cause of COPD exacerbations, often leading to secondary bacterial infections in the lower respiratory tract. COPD patients are more susceptible to viral infections and associated severe disease, leading to accelerated lung function deterioration, hospitalization, and an increased risk of mortality. The airway epithelium plays an essential role in maintaining immune homeostasis, and orchestrates the innate and adaptive responses of the lung against inhaled and pathogen insults. A healthy airway epithelium acts as the first line of host defense by maintaining barrier integrity and the mucociliary escalator, secreting an array of inflammatory mediators, and initiating an antiviral state through the interferon (IFN) response. The airway epithelium is a major site of viral infection, and the interaction between respiratory viruses and airway epithelial cells activates host defense mechanisms, resulting in rapid virus clearance. As such, the production of IFNs and the activation of IFN signaling cascades directly contributes to host defense against viral infections and subsequent innate and adaptive immunity. However, the COPD airway epithelium exhibits an altered antiviral response, leading to enhanced susceptibility to severe disease and impaired IFN signaling. Despite decades of research, there is no effective antiviral therapy for COPD patients. Herein, we review current insights into understanding the mechanisms of viral evasion and host IFN antiviral defense signaling impairment in COPD airway epithelium. Understanding how antiviral mechanisms operate in COPD exacerbations will facilitate the discovery of potential therapeutic interventions to reduce COPD hospitalization and disease severity.

Clustering-based COPD Subtypes Have Distinct Longitudinal Outcomes and Multi-omics Biomarkers

Introduction: Chronic obstructive pulmonary disease (COPD) can progress across several domains, complicating the identification of the determinants of disease progression. In our previous work, we applied k-means clustering to spirometric and chest radiologic measures to identify four COPD-related subtypes: "Relatively resistant smokers (RRS)", "mild upper lobe predominant emphysema (ULE)", "airway-predominant disease (AD)", and "severe emphysema (SE)". In the current study, we examined longitudinal spirometric and radiologic emphysema changes and prospective risks of COPD exacerbations, incident comorbidities, and mortality of these clusters. We also compared their associations to protein and transcriptomic biomarkers. Methods: We included 8,266 non-Hispanic white and African-American smokers from the COPDGene study. We used linear regression to investigate associations to five-year prospective changes in spirometric and radiologic measures and to plasma protein and blood gene expression levels. We used Cox-proportional hazard modeling to test for associations to prospective exacerbations, comorbidities, and mortality. Results: The RRS, ULE, AD, and SE clusters represented 39%, 15%, 26%, and 20% of the studied cohort at baseline, respectively. The SE cluster had the greatest 5-year FEV1 and emphysema progression, and the highest risks of exacerbations, cardiovascular disease (CVD), and mortality. The AD cluster had the highest diabetes risk. After adjustments, only the ULE and AD clusters had elevated CVD mortality risks, while only the ULE cluster had the highest cancer-related mortality risk. These clusters also demonstrated differential protein and gene expression biomarker associations. Conclusion: COPD k-means subtypes demonstrate varying rates of disease progression, prospective comorbidities, mortality, and associations to proteomic and transcriptomic biomarkers.

Developing a Machine Learning Model to Predict Severe Chronic Obstructive Pulmonary Disease Exacerbations: Retrospective Cohort Study

Background Chronic obstructive pulmonary disease (COPD) poses a large burden on health care. Severe COPD exacerbations require emergency department visits or inpatient stays, often cause an irreversible decline in lung function and health status, and account for 90.3% of the total medical cost related to COPD. Many severe COPD exacerbations are deemed preventable with appropriate outpatient care. Current models for predicting severe COPD exacerbations lack accuracy, making it difficult to effectively target patients at high risk for preventive care management to reduce severe COPD exacerbations and improve outcomes. Objective The aim of this study is to develop a more accurate model to predict severe COPD exacerbations. Methods We examined all patients with COPD who visited the University of Washington Medicine facilities between 2011 and 2019 and identified 278 candidate features. By performing secondary analysis on 43,576 University of Washington Medicine data instances from 2011 to 2019, we created a machine learning model to predict severe COPD exacerbations in the next year for patients with COPD. Results The final model had an area under the receiver operating characteristic curve of 0.866. When using the top 9.99% (752/7529) of the patients with the largest predicted risk to set the cutoff threshold for binary classification, the model gained an accuracy of 90.33% (6801/7529), a sensitivity of 56.6% (103/182), and a specificity of 91.17% (6698/7347). Conclusions Our model provided a more accurate prediction of severe COPD exacerbations in the next year compared with prior published models. After further improvement of its performance measures (eg, by adding features extracted from clinical notes), our model could be used in a decision support tool to guide the identification of patients with COPD and at high risk for care management to improve outcomes. International Registered Report Identifier (IRRID) RR2-10.2196/13783

Quantitative analysis of efficacy and safety of LABA/LAMA fixed-dose combinations in the treatment of stable COPD

Objective: This study aimed to quantitatively compare the efficacy and safety of long-acting β2-agonist (LABA)/long-acting muscarinic antagonist (LAMA) fixed-dose combinations (FDCs) for the treatment of stable chronic obstructive pulmonary disease (COPD), especially in terms of their loss of efficacy in lung function. Methods: Randomized controlled clinical trials of LABA/LAMA FDCs for the treatment of stable COPD were comprehensively searched for in public databases. Pharmacodynamic models were established to describe the time course of the primary outcome [trough forced expiratory volume in the first second (FEV1)]. Secondary outcomes [COPD exacerbations, St. George’s Respiratory Questionnaire (SGRQ), Transition Dyspnoea Index (TDI), and rescue medication use] and safety outcomes [mortality, serious adverse events (SAEs), and withdrawals due to adverse events (AEs)] were also compared via a meta-analysis. Results: A total of 22 studies involving 16,486 participants were included in this study. The results showed that in terms of primary outcome (change from baseline in trough FEV1), the efficacy of vilanterol/umeclidinium was the highest, while the efficacy of formoterol/aclidinium was the lowest, with a maximum effect value (Emax) of 0.185 L [95% confidence interval (CI): 0.173–0.197 L] and 0.119 L (95% CI: 0.103–0.135 L), respectively. The efficacy of other drugs, such as formoterol/glycopyrronium, indacaterol/glycopyrronium, and olodaterol/tiotropium, were comparable, and their Emax values were 0.150–0.177 L. Except for vilanterol/umeclidinium, the other four LABA/LAMA FDCs showed a certain degree of loss of efficacy. Compared with the efficacy at 2 days, the trough FEV1 (L) relative to baseline at 24 weeks decreased by 0.029–0.041 L. In terms of secondary outcomes, the efficacy of different LABA/LAMA FDCs was similar in TDI and rescue medication use. However, formoterol/aclidinium was better in preventing the COPD exacerbations, while vilanterol/umeclidinium was the best in terms of SGRQ. In addition, different LABA/LAMA FDCs and placebo had similar safety outcomes. Conclusion: The present findings may provide necessary quantitative information for COPD medication guidelines.

Assessing Treatment Success or Failure as an Outcome in Randomised Clinical Trials of COPD Exacerbations. A Meta-Epidemiological Study

A recently published ERS core outcome set recommends that all trials of COPD exacerbation management should assess the treatment success (or “cure” of the exacerbation), defined as a dichotomous measure of the overall outcome of an exacerbation. This methodological systematic review describes and compares the instruments that were used to assess treatment success or failure in 54 such RCTs, published between 2006–2020. Twenty-three RCTs used composite measures consisting of several undesirable outcomes of an exacerbation, together defining an overall unfavourable outcome, to define treatment failure. Thirty-four RCTs used descriptive instruments that used qualitative or semi-quantitative descriptions to define cure, marked improvement, improvement of the exacerbation, or treatment failure. Treatment success and failure rates among patients receiving guidelines-directed treatments at different settings and timepoints are described and could be used to inform power calculations in future trials. Descriptive instruments appeared more sensitive to treatment effects compared to composite instruments. Further methodological studies are needed to optimise the evaluation of treatment success/failure. In the meantime, based on the findings of this systematic review, the ERS core outcome set recommends that cure should be defined as sufficient improvement of the signs and symptoms of the exacerbation such that no additional systemic treatments are required.

IL-20 Cytokines Are Involved in Epithelial Lesions Associated with Virus-Induced COPD Exacerbation in Mice

(1) Background: viral infections are a frequent cause of chronic obstructive pulmonary disease (COPD) exacerbations, which are responsible for disease progression and mortality. Previous reports showed that IL-20 cytokines facilitate bacterial lung infection, but their production and their role in COPD and viral infection has not yet been investigated. (2) Methods: C57BL/6 WT and IL-20 Rb KO mice were chronically exposed to air or cigarette smoke (CS) to mimic COPD. Cytokine production, antiviral response, inflammation and tissue damages were analyzed after PVM infection. (3) Results: CS exposure was associated with an increase in viral burden and antiviral response. PVM infection in CS mice enhanced IFN-γ, inflammation and tissue damage compared to Air mice. PVM infection and CS exposure induced, in an additive manner, IL-20 cytokines expression and the deletion of IL-20 Rb subunit decreased the expression of interferon-stimulated genes and the production of IFN-λ2/3, without an impact on PVM replication. Epithelial cell damages and inflammation were also reduced in IL-20 Rb-/- mice, and this was associated with reduced lung permeability and the maintenance of intercellular junctions. (4) Conclusions: PVM infection and CS exposure additively upregulates the IL-20 pathway, leading to the promotion of epithelial damages. Our data in our model of viral exacerbation of COPD identify IL-20 cytokine as a potential therapeutic target.

Effects of a Therapeutic Interchange Between Branded and Generic Inhaled Therapy on Chronic Obstructive Pulmonary Disease

Objective To evaluate the difference in the occurrence of chronic obstructive pulmonary disease (COPD) exacerbations six months preconversion compared with six months postconversion from the branded inhaled corticosteroid/long-acting beta 2-agonist inhalers to the generic fluticasone/salmeterol inhalers. Design Retrospective cohort study using a six-month pre-/post-test design Setting Three primary care offices within a Management Service Organization (MSO) in South Florida. Patients, Participants Patients were included in the study if they had a diagnosis of COPD (in electronic medical record [EMR]), were at least 18 years of age, were under the care of a provider at one of the three primary care clinics within an MSO, and were switched from a branded ICS/LABA inhaler to a generic ICS/LABA inhaler between May 2019 and February 2020. This study included a total of 22 patients. Interventions Not applicable; this was a retrospective chart review. Main Outcome Measure The prevalence of COPD exacerbations leading to hospitalizations, emergency room visits, urgent care visits, or clinic visits. Results In this study, 10 (45.5%) patients experienced at least one exacerbation while on generic inhaler therapy compared with four (18.2%) patients while on branded inhaler therapy (P = 0.05). Those on a generic inhaler were 3.8 times more likely to have a COPD exacerbation. Conclusion While changing patients from branded to generic inhalers may be appealing because of the potential benefits in cost-reduction, the results of this study conclude that the inhaler switch may lead to increased exacerbations. Prescribers need to be aware of potential complications that may be related to a therapeutic interchange.