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Chronic Obstructive Pulmonary Disease (COPD) is a complex pulmonary condition characterized by chronic airflow limitation. Within the spectrum of COPD, distinct overlap conditions exist, including Asthma-COPD Overlap (ACO), COPD-Obstructive Sleep Apnea (COPD-OSA), Combined Pulmonary Fibrosis and Emphysema (CPFE), and Bronchiectasis-COPD Overlap (BCO). This review provides a comprehensive overview of the clinical and therapeutic implications of these conditions, highlighting the differences in complications compared with COPD alone in addition to the diagnostic challenges of identifying these conditions. Therapeutically tailored approaches are necessary for COPD overlap conditions considering the unique complications that may arise. Optimal pharmacological management, disease-specific interventions, and comprehensive patient-centered care are crucial components of treatment strategies. This review provides insights for healthcare professionals by enhancing their understanding and management of these conditions. This emphasizes the importance of accurate diagnosis and individualized treatment plans, considering the specific complications associated with each COPD overlap condition., Competing Interests: Declaration of competing interest No conflicts of interest or relationship with the industry to disclose by any of the authors. No funding or financial interests., (Copyright © 2024 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.)

Rationale: Chronic obstructive pulmonary disease (COPD) includes respiratory symptoms and chronic airflow limitation (CAL). In some cases, emphysema and impaired diffusing capacity of the lung for carbon monoxide (Dl CO ) are present, but characteristics and symptoms vary with smoking exposure. Objective: To study the prevalence of CAL, emphysema, and impaired Dl CO in relation to smoking and respiratory symptoms in a middle-aged population. Methods: We investigated 28,746 randomly invited individuals (52% women) aged 50-64 years across six Swedish sites. We performed spirometry, Dl CO testing, and high-resolution computed tomography and asked for smoking habits and respiratory symptoms. CAL was defined as post-bronchodilator forced expiratory volume in 1 second divided by forced vital capacity (FEV 1 /FVC) < 0.7. Results: The overall prevalence was 8.8% for CAL, 5.7% for impaired Dl CO (Dl CO  < LLN), and 8.8% for emphysema, with a higher prevalence in current smokers than in ex-smokers and never-smokers. The proportion of never-smokers among those with CAL, emphysema, and impaired Dl CO was 32%, 19%, and 31%, respectively. Regardless of smoking habits, the prevalence of respiratory symptoms was higher among people with CAL and impaired Dl CO than those with normal lung function. Asthma prevalence in never-smokers with CAL was 14%. In this group, asthma was associated with lower FEV 1 and more respiratory symptoms. Conclusions: In this large population-based study of middle-aged people, CAL and impaired Dl CO were associated with common respiratory symptoms. Self-reported asthma was not associated with CAL in never-smokers. Our findings suggest that CAL in never-smokers signifies a separate clinical phenotype that may be monitored and, possibly, treated differently from smoking-related COPD.

Background: The association of lipoprotein-associated phospholipase A2 (Lp-PLA2) with various cardiovascular events has been well-established. However, the exploration of its potential involvement in Chronic obstructive pulmonary disease (COPD) is currently limited. Therefore, our study aims to examine the relationship between Lp-PLA2 and pulmonary conditions, including emphysema, obstructive ventilatory dysfunction as well as small airway dysfunction, to provide further evidence of a possible association with COPD development., Methods: Using data from the Southwest Hospital Health Management Center, spanning January 2013 to July 2024, we analyze relationship of serum Lp-PLA2 levels with diffuse pulmonary emphysema and pulmonary functions. In univariate analysis, group differences were assessed with t-tests for numerical variables and Chi-square tests for categorical data. Variables found to be statistically significant (two-sided P < 0.05) in univariate analysis were subsequently included as covariates in multivariate analysis, performed using a binary logistic regression model. Odds ratios and 95% confidence intervals were calculated to assess the differences., Results: We established 2 case-control populations: the Imaging population (1056 subjects, mean age 57.666 ± 8.700 years old, 89.9% male) selected from 24,670 initial records, and the Pulmonary Function population (279 subjects, mean age 52.082 ± 11.473 years old, 71.4% male) selected from 1868 initial records. Univariate analysis revealed that serum Lp-PLA2 levels were significantly higher in patients with diffuse pulmonary emphysema, obstructive ventilatory dysfunction as well as small airway dysfunction compared to those without (454.682 ± 141.382U/L vs. 423.330 ± 140.658U/L, P < 0.001; 475.059 ± 157.181U/L vs. 420.824 ± 142.119U/L, P = 0.006; 475.31 ± 148.980U/L vs. 439.036 ± 157.977U/L, P = 0.049, respectively). Multivariate analysis further showed higher Lp-PLA2 levels were associated with increased risks of diffuse pulmonary emphysema, obstructive ventilatory dysfunction as well as small airway dysfunction. Using Lp-PLA2 ≤ 300 U/L as reference, odds ratios for the aforementioned conditions showed a gradually increasing trend with every 100U/L increase in Lp-PLA2 levels., Conclusions: Our preliminary study suggests that Lp-PLA2 is independently associated with diffuse pulmonary emphysema, obstructive ventilatory dysfunction as well as small airway dysfunction, which are commonly seen in COPD development. These findings indicated a possible association between Lp-PLA2 and COPD, though further validation is needed in a large cohort of COPD patients., Competing Interests: Declarations Ethics approval and consent to participate Our study has obtained approval from the ethics committee of First Affiliated Hospital (Southwest Hospital) of Army Medical University, and all subjects have been exempted from signing informed consent forms due to the retrospective study design. Consent for publication All authors have reviewed the manuscript and approved the submitted version to be publicated. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Introduction: Acute respiratory distress syndrome (ARDS) is characterized by diffuse lung injury. The impact of pre-existing chronic obstructive pulmonary disease (COPD) or emphysema on ARDS pathogenesis is not well characterized., Methods: Secondary analysis of ARDS patients enrolled in the Acute Lung Injury Registry and Biospecimen Repository at the University of Pittsburgh between June 2012 and September 2021. Patients were categorized into two mutually exclusive groups by the prevalence of COPD or emphysema at the time of ARDS diagnosis. The COPD/emphysema group comprised ARDS patients with radiological evidence of emphysema, chart diagnosis of COPD, or both. Demographics, lung mechanics, and clinical outcomes were obtained from the electronic medical record. Host-response biomarkers known to have validated associations with ARDS were previously measured in plasma and lower respiratory tract samples using a customized Luminex assay. Continuous and categorical variables were compared between groups with and without COPD/emphysema., Results: 217 patients with ARDS were included in the study, 57 (27%) had COPD/emphysema. Patients with COPD/emphysema were older (median 62 [interquartile range 55-69] versus 53 [41-64] years, p < 0.01), more likely to be male (62% vs. 44%, p = 0.02) and had a higher prevalence of congestive heart failure (25% vs. 4%, p < 0.01) compared to patients without COPD/emphysema. Baseline demographics, laboratory parameters, and mechanical ventilatory characteristics were otherwise similar between the two groups. No difference in 90-day mortality was observed between groups; however, patients with COPD/emphysema had shorter duration of intensive care unit (ICU) stay (median 10 [7-18] versus 16 [9-28] days, p = 0.04) and shorter duration of mechanical ventilation (median 7 [4-16] vs. 12 [6-20] days, p = 0.01). Host response biomarkers in serum and lower respiratory tract samples did not significantly differ between groups., Conclusion: ARDS patients with COPD or emphysema had similar respiratory mechanics, host response biomarker profiles, and mortality compared to those without COPD or emphysema but with a shorter median duration of mechanical ventilation and ICU length of stay. Future studies should address differences in clinical and biological responses by disease severity, and should investigate the impact of severity of COPD and emphysema on mechanical ventilation and targeted therapeutic strategies in ARDS., Clinical Trial Number: Not applicable., (© 2024. The Author(s).)

This study investigated the impact of bronchoscopic lung volume reduction treatment using endobronchial valves (EBV) on diaphragm configuration. We successfully analyzed the diaphragm index using a newly developed quantitative computed tomography (QCT) tool before and after EBV treatment in forty patients with severe emphysema. We evaluated whether changes in the diaphragm index were associated with improvements in forced expiratory volume in 1 s (FEV 1 ), residual volume (RV), Saint Georges Respiratory Questionnaire (SGRQ), and 6-min walking distance (6MWD) using Spearman's rho. The EBV treatment influenced the diaphragm configuration only on the treated side, resulting in an increased diaphragm curvature. There were significant associations of relative diaphragm index changes on the treated lung side or the entire diaphragm with improvements in FEV 1 and 6MWD. These findings provide valuable insights into how EBV treatment affects the diaphragm in COPD patients., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: JTB and JEH have nothing to disclose. DJS reports to have received clinical trial expenses from Pulmonx Corp, USA, Nuvaira, USA, PulmAir, USA, Apreo, USA and FreeFlowMedical, consulting fees paid to the institution from Nuvaira, USA, MoreAir, USA, Apreo, USA and PulmonX, USA, payment or honoraria for lectures, presentations, speakers, bureaus, manuscript writing or educational events paid to the institution from PulmonX, USA and Nuvaira, USA and support for attending meetings and/or travel from PulmonX, USA. KK reports to have received payment or honoraria for lectures, presentations, speakers, bureaus, manuscript writing or educational events from PulmonX., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: People with HIV (PWH) have nearly twice the risk of emphysema than people without HIV. This risk, which has been associated with HIV-mediated changes in the lung immune environment and more extensive radiographic emphysema, may result in different patterns of airflow limitation on pulmonary function testing (PFT) than those traditionally used in people without HIV., Methods: In this prospective cohort of PWH in Atlanta, Georgia, we analyzed PFT and chest computed tomography data from July 2013 through June 2018. After comparing the prevalence of PFT measures of airflow limitation for those with and without radiographic emphysema, we used binary recursive partitioning to identify PFT measures that differentiated between PWH with and without radiographic emphysema., Results: Among 167 PWH who had both PFT and computed tomography data during the study period, 89 (53%) had radiographic emphysema. Those with radiographic emphysema were more likely to have airflow limitations on PFTs. Recursive partitioning identified partitions at a forced expiratory volume in 1 second to forced vital capacity ratio (FEV1/FVC) of 0.78 and a residual volume of 116% predicted. These partitions enabled the identification of 84 (94%) PWH with radiographic emphysema, in contrast to the traditional diagnostic criteria of an FEV1/FVC ratio of 0.7, which only identified 49 (55%) of those with radiographic emphysema., Conclusions: Emphysema in PWH may have different patterns of airflow limitation on PFTs that are not adequately captured by traditional diagnostic criteria. Future studies can seek to validate these findings and determine optimal thresholds for diagnosing HIV-associated emphysema., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Aim: To assess the correlation of quantitative data of pulmonary Perfused Blood Volume (PBV) on Dual-Energy CT (DECT) datasets in patients with moderate - severe Pulmonary Emphysema (PE) with Lung Perfusion Scintigraphy (LPS) as the reference standard. The secondary endpoints are the correlation between the CT densitometric analysis and the visual assessment of parenchymal destruction with PBV., Materials and Methods: Patients with moderate - severe PE candidate to Lung Volumetric Reduction (LVR), with available a pre-procedural LS and a contrast-enhanced DECT were retrospectively included. DECT studies were performed with a 3rd generation Dual-Source CT and the PBV was obtained with a 3-material decomposition algorithm. The CT densitometric analysis was performed with a dedicated commercial software (Pulmo3D). The Goddard Score was used for visual assessment. The perfusion LS were performed after the administration of albumin macroaggregates labeled with 99m Technetium. The image revision was performed by two radiologists or nuclear medicine physicians blinded, respectively, to LS and DECT data. The statistical analysis was performed with nonparametric tests., Results: Thirty-one patients (18 males, median age 69 y.o., interquartile range 62-71 y.o.) with moderate - severe PE (Median Goddard Score 14/20 and 31% of emphysematous parenchyma at quantitative CT) candidate to LVR were retrospectively included. The median enhancement on PBV was 17 HU. Significant correlation coefficients were demonstrated between lung PBV and LS, poor in apical regions (Rho = 0.1-0.2) and fair (Rho = 0.3-0.5) in middle and lower regions. No significant correlations were recorded between the CT densitometric analysis, the visual score, and the PBV., Conclusions: Lung perfusion with PBV on DECT is feasible in patients with moderate - severe PE candidate to LVR, and has a poor to fair agreement with LPS., Competing Interests: Declarations Conflict of interests The authors have no relevant financial or non-financial interests to disclose. Ethical Approval This is a retrospective, observational study. The Local Research Ethics Committee has confirmed that no formal ethical approval is required., (© 2024. The Author(s).)

Background and Objective: Mucus plugs and underlying airway tree structure can affect airflow limitation and prognosis in patients with chronic obstructive pulmonary disease (COPD), but their relative roles are unclear. This study used two COPD cohorts to examine whether mucus plugs on computed tomography (CT) were associated with airflow limitation and clinical outcomes independent of other airway structural changes and emphysema., Methods: Based on visual CT assessment, patients with mucus plugs in 0, 1-2 and ≥3 lung segments were assigned to no-, low- and high-mucus groups. Loss of health-related independence and mortality were prospectively recorded for 3 and 10 years in the Kyoto-Himeji and Hokkaido cohorts, respectively. The percentages of the wall area of the central airways (WA%), total airway count (TAC) and emphysema were quantified on CT., Results: Of 199 and 96 patients in the Kyoto-Himeji and Hokkaido cohorts, 34% and 30%, respectively, had high mucus scores. In both cohorts, TAC was lower in the high-mucus group than in the no-mucus group, whereas their emphysema severity did not differ. High mucus score and low TAC were independently associated with airflow limitation after adjustment for WA% and emphysema. In multivariable models adjusted for WA% and emphysema, TAC, rather than mucus score, was associated with a greater rate of loss of independence, whereas high mucus score, rather than TAC, was associated with increased mortality., Conclusion: Mucus plugs and lower airway branch count on CT had distinct roles in airflow limitation, health-related independence and mortality in patients with COPD., (© 2024 The Author(s). Respirology published by John Wiley & Sons Australia, Ltd on behalf of Asian Pacific Society of Respirology.)

Rationale: Knowledge regarding the prevalence and shared and unique characteristics of the restrictive spirometric pattern (RSP) and preserved ratio impaired spirometry (PRISm) is lacking for a general population investigated with post-bronchodilator spirometry and computed tomography of the lungs. Objectives: To investigate shared and unique features for RSP and PRISm. Methods: In the Swedish CArdioPulmonary bioImage Study (SCAPIS), a general population sample of 28,555 people aged 50-64 years (including 14,558 never-smokers) was assessed. The participants answered a questionnaire and underwent computed tomography of the lungs, post-bronchodilator spirometry, and coronary artery calcification score. Odds ratios with 95% confidence intervals (CIs) were calculated using adjusted logistic regression. RSP was defined as forced expiratory volume in 1 second (FEV 1 )/forced vital capacity (FVC) ≥0.70 and FVC <80%. PRISm was defined as FEV 1 /FVC ≥0.70 and FEV 1 <80%. A local reference equation was applied. Results: The prevalence of RSP and PRISm were 5.1% (95% CI, 4.9-5.4) and 5.1% (95% CI, 4.8-5.3), respectively, with similar values seen in never-smokers. For RSP and PRISm, shared features were current smoking, dyspnea, chronic bronchitis, rheumatic disease, diabetes, ischemic heart disease, bronchial wall thickening, interstitial lung abnormalities, and bronchiectasis. Emphysema was uniquely linked to PRISm (odds ratio, 1.69; 95% CI, 1.36-2.10) versus 1.10 (95% CI, 0.84-1.43) for RSP. Coronary artery calcification score ≥300 was related to PRISm, but not among never-smokers. Conclusions: PRISm and RSP have respiratory, cardiovascular, and metabolic conditions as shared features. Emphysema is only associated with PRISm. Coronary atherosclerosis may be associated with PRISm. Our results indicate that RSP and PRISm may share more features than not.

Background: Endoscopic lung volume reduction with valves is a minimally invasive treatment strategy for patients with severe pulmonary emphysema. Two valve systems are currently available: Zephyr and Spiration valves. As these can be implanted simultaneously in the same procedure, the question arose as to the effect on lung function, exercise capacity and subjective disease perception after combined valve treatment., Methods: We conducted a retrospective analysis of 108 patients with combined, simultaneous treatment of Zephyr and Spiration valves. The decision on which and how many valves to implant was based on the individual patient anatomy. Effects on lung function, exercise capacity and atelectasis formation as well as complications were evaluated 90- and 180-days post-treatment (90d-FU and 180d-FU)., Results: At 90d-FU (n = 90), the mean change was 86.7 ± 183.7 mL for FEV 1 and -645.3 ± 1276.5 mL for RV, with responder rates of 39.8 % and 46.5 %, respectively. Complete atelectasis occurred in 16.7 % and partial atelectasis in 25.5 % of patients. Six-minute walking distance increased by 27.00 m [-1.50 - 68.50m]. The rates of pneumothorax (10.2 %) 6 months after treatment were not higher than in randomized controlled trials (RCTs). Likely due to the inclusion of high-risk patients, there was a higher incidence of severe COPD exacerbation (21.3 %) and pneumonia (12.0 %) compared to RCTs., Conclusions: The combined implantation of Zephyr and Spiration valves resulted in significant clinical and functional improvements with an acceptable risk profile. Therefore, the ability to combine both valve types in severe emphysema could be a promising option in endoscopic lung volume reduction., Competing Interests: Declaration of competing interest The present manuscript was not supported by any external donors. Irrespective of this, the following grants or fees were paid to the individual authors in the last 36 months: ASD received a grant and charges for registry analysis by the German CF Foundation. KK received consulting fees from Cook Medical as well as presentation fees from AstraZeneca, Berlin Chemie, Boston Scientific and Olympus and received travel grants from AstraZeneca. FT received speaker honoraria from Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Grifols, Novartis, CSL Behring, Streamed up and RG Gesellschaft für Information und Organisation mbH. JMB received grants of the Thoraxstiftung Heidelberg and the Beatrice von Hardenberg Stiftung, consulting fees from Boehringer Ingelheim and Intuitive Surgical Inc as well as speaker fees from Boehringer Ingelheim, Astra Zeneca, Streamed up, Berlin Chemie and Olympus. DG received travel grants and lecture fees of Pulmonx, Olympus, Boehringer Ingelheim, Chiesi, AstraZeneca, BerlinChemie and MSD. CPH received consulting fees by Boehringer Ingelheim, lecture fees by AstraZeneca, Pfizer and Boehringer Ingelheim and received research funding by Exscientia. RE received honoraria from Olympus and Pulmonx for lectures and educational activities. FH received speaker fees from Olympus and Pulmonx., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Previous studies have shown that patients with pre-existing chronic obstructive pulmonary diseases (COPD) were more likely to be infected with coronavirus disease (COVID-19) and lead to more severe lung lesions. However, few studies have explored the severity and prognosis of COVID-19 patients with different phenotypes of COPD., Purpose: The aim of this study is to investigate the value of the deep learning and radiomics features for the severity evaluation and the nucleic acid turning-negative time prediction in COVID-19 patients with COPD including two phenotypes of chronic bronchitis predominant patients and emphysema predominant patients., Methods: A total of 281 patients were retrospectively collected from Hohhot First Hospital between October 2022 and January 2023. They were divided to three groups: COVID-19 group of 95 patients, COVID-19 with emphysema group of 94 patients, COVID-19 with chronic bronchitis group of 92 patients. All patients underwent chest computed tomography (CT) scans and recorded clinical data. The U-net model was pretrained to segment the pulmonary involvement area on CT images and the severity of pneumonia were evaluated by the percentage of pulmonary involvement volume to lung volume. The 107 radiomics features were extracted by pyradiomics package. The Spearman method was employed to analyze the correlation of the data and visualize it through a heatmap. Then we establish a deep learning model (model 1) and a fusion model (model 2) combined deep learning with radiomics features to predict nucleic acid turning-negative time., Results: COVID-19 patients with emphysema was lowest in the lymphocyte count compared to COVID-19 patients and COVID-19 companied with chronic bronchitis, and they have the most extensive range of pulmonary inflammation. The lymphocyte count was significantly correlated with pulmonary involvement and the time for nucleic acid turning negative (r=-0.145, P < 0.05). Importantly, our results demonstrated that model 2 achieved an accuracy of 80.9% in predicting nucleic acid turning-negative time., Conclusion: The pre-existing emphysema phenotype of COPD severely aggravated the pulmonary involvement of COVID-19 patients. Deep learning and radiomics features may provide more information to accurately predict the nucleic acid turning-negative time, which is expected to play an important role in clinical practice., (© 2024. The Author(s).)

Bronchoscopic lung volume reduction (BLVR) is an established treatment modality for the management of advanced chronic obstructive pulmonary disease complicated by severe emphysema and hyperinflation refractory to other therapies. BLVR aims to reduce hyperinflation and residual volume, thereby improving pulmonary function, symptom control, and quality of life. Multiple distinct devices and technologies, including endobronchial coils, thermal vapor ablation, bio-lung volume reduction, and airway bypass stenting, have been developed to achieve lung volume reduction with varying degrees of accessibility and evidence. The most promising BLVR treatment modality to date has been the placement of one-way endobronchial valves (EBVs), with more than 25,000 cases performed worldwide. Identifying symptomatic patients who would benefit from BLVR is challenging and can be time and resource intensive, and candidacy may be limited by physiologic parameters. Additional new technologies may be able to improve the identification and evaluation of candidates as well as increase the portion of evaluated patients who ultimately qualify for BLVR. In this review, we aim to provide historical context to BLVR, summarize the available evidence regarding its use, discuss potential complications, and provide readers with a clear guide to patient selection and referral for BLVR, with a focus on EBV placement. In addition, we will highlight potential future directions for the field., Competing Interests: None declared., (Thieme. All rights reserved.)

Chronic obstructive pulmonary disease (COPD) is an incurable, progressive respiratory disease that may have a significant negative impact on the morbidity and mortality of affected patients. A substantial portion of the world's population is affected by COPD, and despite optimal medical management with medications, supplemental oxygen, and pulmonary rehabilitation, many patients are left debilitated because of this disease. Bronchoscopic treatment modalities offer a less-invasive method for the treatment of refractory COPD compared to surgical interventions and have expanded the potential therapeutic options for these patients. Bronchoscopic lung volume reduction is aimed at decreasing the hyperinflation and air trapping that occur in emphysema, and the most studied and successful intervention is endobronchial valve placement. Endobronchial coils, polymeric sealants, and thermal ablation are other researched alternatives. Additional interventional procedures are being investigated for the treatment of the mucus hypersecretion and cough that are associated with the chronic bronchitis phenotype of COPD and include targeted lung denervation, metered dose spray cryotherapy, deobstruction balloon, and bronchial rheoplasty. This review summarizes the most recent evidence pertaining to available therapies for the management of COPD, including chronic bronchitis, with a particular focus on bronchoscopic interventions., Competing Interests: A.J.S. served as a consultant and advisory board member for Ambu., (Thieme. All rights reserved.)

Background: Chronic Obstructive Pulmonary Disease (COPD) is a respiratory condition characterized by heterogeneous abnormalities of the airways and lung parenchyma that cause different clinical presentations. The assessment of the prevailing pathogenetic components underlying COPD is not usually pursued in daily practice, also due to technological limitations and cost., Aim: To assess non-invasively the lung emphysema component of COPD by the simultaneous measurement of DL NO and DL CO via a single-breath (sDL NO and sDL CO )., Methods: COPD patients aged ≥40 years of both genders were recruited consecutively and labelled by computed tomography as "with significant" emphysema (>10% of CT lung volume) or "with negligible" emphysema otherwise. Current lung function tests such as sDL NO , sDL CO and Vc (the lung capillary blood volume) were measured. All possible subsets of independent spirometric and diffusive parameters were tested as predictors of emphysema, and their predicted power compared to each parameter alone by ROC analysis and area under the curve (AUC)., Results: Thirty-one patients with "significant emphysema" were compared to thirty-one with "negligible emphysema". FEV 1 and FEV1/FVC seemed to be the best spirometric predictors (AUC 0.80 and 0.81, respectively), while sDL CO and Vc had the highest predicted power among diffusive parameters (AUC 0.92 and 0.94, respectively). sDL CO and Vc values were the parameters most correlated to the extent of CT emphysema. Six subsets of independent predictors were identified and included at least one spirometric and one diffusive parameter. According to goodness-to-fit scores (AIC, BIC, log-likelihood and pseudo R 2 ), RV coupled with sDL CO or Vc proved the best predictors of emphysema., Conclusion: When investigating the parenchymal destructive component due to emphysema occurring in COPD, sDL NO , sDL CO and Vc do enhance the predictive power of current spirometric measures substantially. sDL NO , sDL CO and Vc contribute to phenotype of the main pathogenetic components of COPD easily and with high sensitivity. Organizational problems, radiation exposure, time and costs could be reduced, while personalized and precision medicine could be noticeably implemented., Competing Interests: The authors report no conflicts of interest in this work., (© 2024 Dal Negro et al.)

Endoscopic lung volume reduction (ELVR) is an established treatment option for patients with severe emphysema. Not all patients are candidates for this type of intervention, and in the context of significant airway secretions, they may be excluded from treatment. Bronchial Rheoplasty (BR) was developed to treat mucus hypersecretion by delivering nonthermal pulsed electric fields to the airway epithelium and submucosa. The literature to date demonstrates that patients treated with BR in clinical studies have a reduction in airway goblet cell hyperplasia as well as substantive clinical improvement in the setting of chronic bronchitis (CB). In this case series, we present four patients treated at three different institutions who had previously undergone ELVR with beneficial outcome. However, over time, these patients subsequently developed worsening clinical issues, including complaints of increased and thickened mucus, along with exacerbations in the setting of a loss of some ELVR-associated benefits. These patients then underwent exploratory treatment with BR with the intent of reducing their secretion burden and potentially restoring the efficacy associated with the initial placement of the airway valves. All BR procedures were well tolerated, and three of the four patients showed substantial improvement in their symptom burden. Airway examinations during the second of the two BR procedures also revealed what appeared to be less airway mucosal inflammation and a decrease in the quantity of airway secretions. Therefore, treatment with BR may have the potential to improve and restore the initial benefits associated with ELVR, thus enhancing long-term outcomes. Further clinical studies with sufficient follow-up are warranted to assess this in a larger cohort of patients, and to determine whether treatment with BR prior to ELVR may make more patients eligible for this treatment through reduction in their secretions and/or symptoms., Competing Interests: Dr Michael Perch reports personal fees from AstraZeneca, personal fees from PulmonX, grants from PulmonX, grants from Therakos, personal fees from Takeda, personal fees from Zambon, outside the submitted work. The authors report no other conflicts of interest in this work., (© 2024 Jensen et al.)

Background and Objective: Both bronchoscopic lung volume reduction with endobronchial valves (BLVR-EBV) and pulmonary rehabilitation (PR) are effective treatments for improving exercise capacity and patient-reported outcomes in patients with severe Chronic Obstructive Pulmonary Disease (COPD). According to current recommendations, all BLVR-EBV patients should have undergone PR first. Our aim was to study the effects of PR both before and after BLVR-EBV compared to BLVR-EBV alone., Methods: We included patients with severe COPD who were eligible for BLVR-EBV and PR. Participants were randomized into three groups: PR before BLVR-EBV, PR after BLVR-EBV or BLVR-EBV without PR. The primary outcome was change in constant work rate cycle test (CWRT) endurance time at 6-month follow-up of the PR groups compared to BLVR-EBV alone. Secondary endpoints included changes in 6-minute walking test, daily step count, dyspnoea and health-related quality of life., Results: Ninety-seven participants were included. At 6-month follow-up, there was no difference in change in CWRT endurance time between the PR before BLVR-EBV and BLVR-EBV alone groups (median: 421 [IQR: 44; 1304] vs. 787 [123; 1024] seconds, p = 0.82) or in any of the secondary endpoints, but the PR after BLVR-EBV group exhibited a smaller improvement in CWRT endurance time (median: 107 [IQR: 2; 573], p = 0.04) and health-related quality of life compared to BLVR-EBV alone., Conclusion: The addition of PR to BLVR-EBV did not result in increased exercise capacity, daily step count or improved patient-reported outcomes compared to BLVR-EBV alone, neither when PR was administered before BLVR-EBV nor when PR was administered after BLVR-EBV., (© 2024 The Authors. Respirology published by John Wiley & Sons Australia, Ltd on behalf of Asian Pacific Society of Respirology.)

Purpose: We compared pulmonary function indices and quantitative CT parameters of airway remodeling, air trapping, and emphysema in asthmatic patients and patients with COPD and asthma-COPD overlap (ACO) and explored their relationships with airflow limitation., Patients and Methods: Patients with asthma (n=48), COPD (n=52), and ACO (n=30) and controls (n=54) who completed pulmonary function tests and HRCT scans were retrospectively enrolled in our study. Quantitative CT analysis software was used to assess emphysema (LAA%), airway wall dimensions (wall area (WA), luminal area (LA), and wall area percentage (WA%)), and air trapping ((relative volume change of -860 HU to -950 HU (RVC -860 to-950 ) and the expiration-to-inspiration ratio of the mean lung density (MLD E/I) )). Differences in pulmonary function and HRCT parameters were compared among the groups. Spearman correlation analysis and regression analysis were utilized to explore structure‒function relationships., Results: The LAA% in COPD and ACO patients was significantly greater than that in asthmatic patients and controls. The WA% and WA in COPD and ACO patients were greater than those in controls, whereas the WA% and LA between asthmatic patients and controls reached statistical significance. The RVC -860 to -950 levels decreased in the following order: ACO, COPD, and asthma. RVC -860 to -950 independently predicted FEV1% in asthmatic patients; LAA% and MLD E/I in COPD patients; and LAA%, WA% and RVC -860 to -950 in ACO patients., Conclusion: Comparable emphysema was observed in patients with COPD and ACO but not in asthmatic patients. All patients exhibited proximal airway remodeling. The bronchi were thickened outward in COPD and ACO patients but are thickened inward in asthmatic patients. Furthermore, air trapping in ACO patients was the most severe among all the groups. Indirect lung densitometry measurements might be more predictive of the degree of airflow limitation than direct airway measurements in obstructive airway diseases., Competing Interests: The authors report no conflicts of interest in this work., (© 2024 Lu et al.)

Competing Interests: Disclosure: There is no conflict of interest or other disclosures.

Purpose: The extent of honeycombing and reticulation predict the clinical prognosis of IPF. Emphysema, consolidation, and ground glass opacity are visible in HRCT scans. To date, there have been few comprehensive studies that have used these parameters. We conducted automated quantitative analysis to identify predictive parameters for clinical outcomes and then grouped the subjects accordingly., Methods: CT images were obtained while patients held their breath at full inspiration. Parameters were analyzed using an automated lung texture quantification system. Cluster analysis was conducted on 159 IPF patients and clinical profiles were compared between clusters in terms of survival., Results: Kaplan-Meier analysis revealed that survival rates declined as fibrosis, reticulation, honeycombing, consolidation, and emphysema scores increased. Cox regression analysis revealed that reticulation had the most significant impact on survival rate, followed by honeycombing, consolidation, and emphysema scores. Hierarchical and K-means cluster analyses revealed 3 clusters. Cluster 1 (n = 126) with the lowest values for all parameters had the longest survival duration, and relatively-well preserved FVC and DLCO. Cluster 2 (n = 15) with high reticulation and consolidation scores had the lowest FVC and DLCO values with a predominance of female, while cluster 3 (n = 18) with high honeycombing and emphysema scores predominantly consisted of male smokers. Kaplan-Meier analysis revealed that cluster 2 had the lowest survival rate, followed by cluster 3 and cluster 1., Conclusion: Automated quantitative CT analysis provides valuable information for predicting clinical outcomes, and clustering based on these parameters may help identify the high-risk group for management., (© 2024. The Author(s).)

Background: The role of obesity on dyspnea in chronic obstructive pulmonary disease (COPD) patients remains unclear. We aimed to provide an assessment of dyspnea in COPD patients according to their Body Mass Index (BMI) and to investigate the impact of obesity on dyspnea according to COPD severity., Methods: One hundred and twenty seven COPD patients with BMI ≥ 18.5 kg/m² (63% male, median (interquartile range) post bronchodilator forced expiratory volume of 1 second (post BD FEV 1 ) at 51 (34-66) % pred) were consecutively included. Dyspnea was assessed by mMRC (Modified medical research council) scale. Lung function tests were recorded, and emphysema was quantified on CT-scan (computed tomography-scan)., Results: Twenty-five percent of the patients were obese (BMI ≥ 30kg/m²), 66% of patients experienced disabling dyspnea (mMRC ≥ 2). mMRC scores did not differ depending on BMI categories (2 (1-3) for normal weight, 2 (1-3) 1 for overweight and 2 (1-3) for obese patients; p = 0.71). Increased mMRC scores (0-1 versus 2-3 versus 4) were associated with decreased post BD-FEV 1 (p < 0.01), higher static lung hyperinflation (inspiratory capacity/total lung capacity (IC/TLC), p < 0.01), reduced DLCO (p < 0.01) and higher emphysema scores (p < 0.01). Obese patients had reduced static lung hyperinflation (IC/TLC p < 0.01) and lower emphysema scores (p < 0.01) than non-obese patients. mMRC score increased with GOLD grades (1-2 versus 3-4) in non-obese patients but not in obese patients, in association with a trend towards reduced static lung hyperinflation and lower emphysema scores., Conclusion: By contrast with non-obese patients, dyspnea did not increase with spirometric GOLD grades in obese patients. This might be explained by a reduced lung hyperinflation related to the mechanical effects of obesity and a less severe emphysema in severe COPD patients with obesity., Competing Interests: GD reports personal fees from Chiesi, GSK and AstraZeneca outside the submitted work. SD reports personal fees from Boehringer Ingelheim and Sanofi-Aventis outside the submitted work. J.M. Perotin reports lecture honoraria from AstraZeneca and support for attending meetings from AstraZeneca and Chiesi; outside the submitted work. The authors report no other conflicts of interest in this work., (© 2024 Dupuis et al.)

Rationale: Endoscopic lung volume reduction improves lung function, quality of life and exercise capacity in severe emphysema patients. However, its effect on the diaphragm function is not well understood. We hypothesised that endoscopic lung volume reduction increases its strength by modifying its shape., Objectives: To investigate changes in both diaphragm shape and strength induced by the insertion of endobronchial valves., Methods: In 19 patients, both the diaphragm shape and strength were investigated respectively by 3D Slicer software applied on CT scans acquired at functional residual capacity and by transdiaphragmatic pressure measurements by bilateral magnetic stimulation of the phrenic nerves before and 3 months after unilateral valves insertion., Measurements and Main Results: After lung volume reduction (median (IQR), 434 mL (-597 to -156], p<0.0001), diaphragm strength increased (transdiaphragmatic pressure: 3 cmH 2 O (2.3 to 4.2), p<0.0001). On the treated side, this increase was associated with an increase in the coronal (16 mm (13 to 24), p<0.0001) and sagittal (26 mm (21 to 30), p<0.0001) lengths as well as in the area of the zone of apposition (62 cm 2 (3 to 100), p<0.0001) with a decrease in the coronal (8 mm (-12 to -4), p<0.0001) and sagittal (9 mm (-18 to -2), p=0.0029) radii of curvature., Conclusions: Endoscopic lung volume reduction modifies the diaphragm shape by increasing its length and its zone of apposition and by decreasing its radius of curvature on the treated side, resulting in an increase in its strength., Trial Registration Number: NCT05799352., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow obstruction and development of emphysema. Among the comorbidities associated with COPD, skeletal muscle dysfunction is known to affect exercise capacity and the survival rate of patients. Pulmonary rehabilitation (PR), via exercise training, is essential for COPD patients. However, the response to PR is most often moderate. An animal model that recapitulates critical features of chronic human disease and provides access to muscle function should therefore be useful to improve PR benefits., Methods: We used a rat model of induced emphysema based on pulmonary instillations of elastase (ELA) and lipopolysaccharides (LPS). We assessed the long-term effects of ELA/LPS and the potential effectiveness of endurance training on the skeletal muscle function. In vivo strength of the animals, and ex vivo contractility, endurance, type 1 fiber proportion, fiber cross-sectional area, and capillarization of both soleus and extensor digitorum longus (EDL) were assessed., Results: An impaired overall muscle strength with decreased force, reduced capillarization, and atrophy of type 1 fiber of EDL was observed in ELA/LPS rats. Soleus was not affected. Endurance training was able to reduce fatigability, and increase type 1 fiber proportion and capillarization of soleus, and improve force, endurance, and capillarization of EDL in control and ELA/LPS rats., Conclusion: Our rat model of induced emphysema, which shares some features with the phenotype present in patients with COPD, could represent a suitable model to study skeletal muscle dysfunction and the effects of exercise training on muscle function in patients., (© 2024 The Author(s). Acta Physiologica published by John Wiley & Sons Ltd on behalf of Scandinavian Physiological Society.)

Background Pre-existing emphysema is recognized as an indicator of future worsening in patients with chronic obstructive pulmonary disease (COPD) when observed through CT imaging. However, it remains uncertain whether additional factors, such as the spatial compactness of CT emphysema, might also serve as predictors of disease progression. Purpose To evaluate the relationship between the compactness of CT emphysema voxels and emphysema progression. Materials and Methods This secondary analysis uses data from the prospective Canadian Cohort Obstructive Lung Disease (CanCOLD) study, examining CT images obtained in participants with and without COPD at baseline and a 3-year follow-up time point (November 2009 to November 2018). Measurements of forced expiratory volume in first second of expiration (FEV 1 ) and diffusing capacity of lung for carbon monoxide (DLco) were collected. The normalized join-count (NJC) measurement from baseline CT images and lung density (LD) changes were analyzed. Emphysema progression was defined as an annualized LD change of less than half an SD below the mean of the participants without COPD with no smoking history. Multivariable linear and logistic regression models were used to assess the association between baseline CT NJC measurements and the annualized change in LD, FEV 1 , DLco, and emphysema progression versus nonprogression. Results A total of 524 participants (mean age, 66 years ± 10 [SD]; 293 male) (FEV 1 percent predicted, 88% ± 19; FEV 1 /FVC, 67% ± 9; DLco percent predicted, 105% ± 25) were analyzed, 187 (36%) of whom had COPD. CT NJC was associated with the annualized change in LD ( P < .001), FEV 1 ( P = .02), and DLco ( P = .01). Additionally, CT NJC predicted emphysema progression versus nonprogression (odds ratio, 2.24; 95% CI: 1.37, 3.50; P < .001). Conclusion The spatial distribution, or "compactness," of CT emphysema voxels predicted emphysema progression in individuals with and without COPD. ClinicalTrials.gov Identifier: NCT00920348 © RSNA, 2024 Supplemental material is available for this article.

Rationale: Rates of emphysema progression vary in chronic obstructive pulmonary disease (COPD), and the relationships with vascular and airway pathophysiology remain unclear. Objectives: We sought to determine if indices of peripheral (segmental and beyond) pulmonary arterial dilation measured on computed tomography (CT) are associated with a 1-year index of emphysema (EI; percentage of voxels <-950 Hounsfield units) progression. Methods: Five hundred ninety-nine former and never-smokers (Global Initiative for Chronic Obstructive Lung Disease stages 0-3) were evaluated from the SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study) cohort: rapid emphysema progressors (RPs; n  = 188, 1-year ΔEI > 1%), nonprogressors ( n  = 301, 1-year ΔEI ± 0.5%), and never-smokers ( n  = 110). Segmental pulmonary arterial cross-sectional areas were standardized to associated airway luminal areas (segmental pulmonary artery-to-airway ratio [PAAR seg ]). Full-inspiratory CT scan-derived total (arteries and veins) pulmonary vascular volume (TPVV) was compared with small vessel volume (radius smaller than 0.75 mm). Ratios of airway to lung volume (an index of dysanapsis and COPD risk) were compared with ratios of TPVV to lung volume. Results: Compared with nonprogressors, RPs exhibited significantly larger PAAR seg (0.73 ± 0.29 vs. 0.67 ± 0.23; P  = 0.001), lower ratios of TPVV to lung volume (3.21 ± 0.42% vs. 3.48 ± 0.38%; P  = 5.0 × 10 -12 ), lower ratios of airway to lung volume (0.031 ± 0.003 vs. 0.034 ± 0.004; P  = 6.1 × 10 -13 ), and larger ratios of small vessel volume to TPVV (37.91 ± 4.26% vs. 35.53 ± 4.89%; P  = 1.9 × 10 -7 ). In adjusted analyses, an increment of 1 standard deviation in PAAR seg was associated with a 98.4% higher rate of severe exacerbations (95% confidence interval, 29-206%; P  = 0.002) and 79.3% higher odds of being in the RP group (95% confidence interval, 24-157%; P  = 0.001). At 2-year follow-up, the CT-defined RP group demonstrated a significant decline in postbronchodilator percentage predicted forced expiratory volume in 1 second. Conclusions: Rapid one-year progression of emphysema was associated with indices indicative of higher peripheral pulmonary vascular resistance and a possible role played by pulmonary vascular-airway dysanapsis.

Background: Endobronchial valve (EBV) insertion for lung volume reduction is a management option for patients with severe emphysema. One-way valves cause lobar deflation and improve lung function, exercise capacity and quality of life., Aims: To retrospectively analyse and compare the outcomes of the first 57 patients treated with EBVs between 2015 and 2021 at the Royal Adelaide Hospital to international standards., Methods: Clinical outcomes of forced expiratory volume in 1 s (FEV1), residual volume (RV), treated lobe volume reduction (TLVR) and 6-min walk distance (6MWD) at 3, 6 and 12 months after valve insertion were reviewed against established minimally clinically important differences (MCIDs). Complications and subjective breathlessness measured by Borg scores were also reviewed., Results: Fifty-seven patients were included. At 12 months, 77.2% achieved TLVR. FEV1 improved by 170 mL (95% confidence interval (CI): 100-250, P < 0.001), 80 mL (95% CI: 10-150, P = 0.019) and 40 mL (95% CI: -60 to 130, P 0.66) at 3, 6 and 12 months respectively. RV improved by -610 mL (95% CI: -330 to -900, P < 0.0001) at 3 months, -640 mL (95% CI: -360 to -920, P < 0.0001) at 6 months and -360 mL (95% CI: -60 to -680, P = 0.017) at 12 months. 6MWD improved by 57.34 m (95% CI: 36.23-78.45, P < 0.0001) and 44.93 m (95% CI: 7.19-82.67, P = 0.02) at 3 and 6 months. Borg score improved by -0.53 (95% CI: 0.11 to -1.2, P = 0.11) and -0.49 (95% CI: 0.17 to -1.15, P = 0.16) at 3 and 6 months. Complication rates aligned with international standards with mucous/infection (26.3%) and pneumothorax (17.5%) as the most common. Subgroup analysis signalled improved outcomes in patients with heterogeneous emphysema., Conclusion: Our study represents the first publicly funded Australian analysis of EBVs. The results align with international prospective trials demonstrating improved lung function and exercise capacity. Australians with severe emphysema and gas trapping should be referred to a multidisciplinary centre for consideration of EBVs., (© 2024 The Authors. Internal Medicine Journal published by John Wiley & Sons Australia, Ltd on behalf of Royal Australasian College of Physicians.)

Rationale and Objectives: Ex-smokers without spirometry or CT evidence of chronic obstructive pulmonary disease (COPD) but with mildly abnormal diffusing capacity of the lungs for carbon monoxide (DL CO ) are at higher risk of developing COPD. It remains difficult to make clinical management decisions for such ex-smokers without other objective assessments consistent with COPD. Hence, our objective was to develop a machine-learning and CT texture-analysis pipeline to dichotomize ex-smokers with normal and abnormal DL CO (DL CO ≥75% pred and DL CO <75% pred )., Materials and Methods: In this retrospective study, 71 ex-smokers (50-85yrs) without COPD underwent spirometry, plethysmography, thoracic CT, and 3 He MRI to generate ventilation defect percent (VDP) and apparent diffusion coefficients (ADC). PyRadiomics was utilized to extract 496 CT texture-features; Boruta and principal component analysis were used for feature selection and various models were investigated for classification. Machine-learning classifiers were evaluated using area under the receiver operator characteristic curve (AUC), sensitivity, specificity, and F1-measure., Results: Of 71 ex-smokers without COPD, 29 with mildly abnormal DL CO had significantly different MRI ADC (p < .001), residual-volume to total-lung-capacity ratio (p = .003), St. George's Respiratory Questionnaire (p = .029), and six-minute-walk distance (6MWD) (p < .001), but similar relative area of the lung < -950 Hounsfield-units (RA 950 ) (p = .9) compared to 42 ex-smokers with normal DL CO . Logistic-regression machine-learning mixed-model trained on selected texture-features achieved the best classification accuracy of 87%. All clinical and imaging measurements were outperformed by high-high-pass filter high-gray-level-run-emphasis texture-feature (AUC=0.81), which correlated with DL CO (ρ = -0.29, p = .02), MRI ADC (ρ = 0.23, p = .048), and 6MWD (ρ = -0.25, p = .02)., Conclusion: In ex-smokers with no CT evidence of emphysema, machine-learning models exclusively trained on CT texture-features accurately classified ex-smokers with abnormal diffusing capacity, outperforming conventional quantitative CT measurements., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Grace Parraga reports a relationship with Natural Sciences and Engineering Research Council of Canada that includes: funding grants. Grace Parraga reports a relationship with Canadian Institutes of Health Research that includes: funding grants. Maksym Sharma reports a relationship with Natural Sciences and Engineering Research Council of Canada that includes: funding grants. Miranda Kirby reports a relationship with Natural Sciences and Engineering Research Council of Canada that includes: funding grants., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Bronchoscopic lung volume reduction treatment with Zephyr one-way valves is an effective guideline-based treatment option for patients with severe emphysema and hyperinflation. However, in some cases the treatment response is less than anticipated or there might be a loss of initial treatment effect. Reasons for the lack of response can include incorrect assessment of collateral ventilation, improper valve placement, or patient related factors. Loss of initial benefit can be due to granulation tissue formation and subsequent valve dysfunction, or there may be side effects such as excessive coughing or infectious problems. Careful follow-up after treatment with valves is important and evaluation with a CT scan and/or bronchoscopy is helpful if there is no improvement after treatment or loss of initial benefit. This paper aims to describe the most important causes and provide a strategy of how to approach and manage these patients., Competing Interests: Declaration of competing interest PS declares consulting fees and educational fees. AV declares educational fees. GJC declares grants/contract, consulting fees, educational fees and participation on a DSMB. FJFH declares educational and consulting fees. DKH declares consulting fees and educational fees. AM declares consulting fees and educational fees. AC declares consulting fees and educational fees. MD declares consulting fees and support for attending meetings by GSK. JK declares consulting fees and educational fees. NS is a full-time employee of Pulmonx Corporation and declares stock options. DJS declares grants/contracts, consulting fees, educational fees and support for attending meetings. MP declares grants, consulting fees, educational fees, support for attending meetings and leadership or fiduciary roles. Regarding the consensus opinion meeting: PS, FJFH, RS, DH, RM, AM, RA, LK, AC, JK, DJS, and MP received travel and accommodation support and honoraria from Pulmonx. AV received an honorarium from Pulmonx. DEW, MD, GJC and TDK have no conflict., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Irreversible alveolar airspace enlargement is the main characteristic of pulmonary emphysema, which has been extensively studied using animal models. While the alterations in lung mechanics associated with these morphological changes have been documented in the literature, the study of the mechanical behavior of parenchymal tissue from emphysematous lungs has been poorly investigated. In this work, we characterize the mechanical and morphological properties of lung tissue in elastase-induced emphysema rat models under varying severity conditions. We analyze the non-linear tissue behavior using suitable hyperelastic constitutive models that enable to compare different non-linear responses in terms of hyperelastic material parameters. We further analyze the effect of the elastase dose on alveolar morphology and tissue material parameters and study their connection with respiratory-system mechanical parameters. Our results show that while the lung mechanical function is not significantly influenced by the elastase treatment, the tissue mechanical behavior and alveolar morphology are markedly affected by it. We further show a strong association between alveolar enlargement and tissue softening, not evidenced by respiratory-system compliance. Our findings highlight the importance of understanding tissue mechanics in emphysematous lungs, as changes in tissue properties could detect the early stages of emphysema remodeling. STATEMENT OF SIGNIFICANCE: Gas exchange is vital for life and strongly relies on the mechanical function of the lungs. Pulmonary emphysema is a prevalent respiratory disease where alveolar walls are damaged, causing alveolar enlargement that induces harmful changes in the mechanical response of the lungs. In this work, we study how the mechanical properties of lung tissue change during emphysema. Our results from animal models show that tissue properties are more sensitive to alveolar enlargement due to emphysema than other mechanical properties that describe the function of the whole respiratory system., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Introduction: Application of vapour ablation as a novel approach to lung volume reduction has positive effects in patients with severe emphysema. The BENTO study is a randomised, controlled, open, multicentre trial, to assess the effects of bronchoscopic thermal vapour ablation (BTVA) in the German healthcare system., Methods and Analysis: Patients with bilateral heterogeneous emphysema of the upper lobes in Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 3/4 will be enrolled in this trial and will receive either standard medical management alone (according to GOLD guidelines) or BTVA treatment with the InterVapor system together with standard medical management. Patients will be randomised in a 2:1 ratio (treatment group:control group). A total of 224 patients will be enrolled at 15 study sites. The primary endpoint is the change in patient-reported disease-specific quality of life, as measured by the St George's Respiratory Questionnaire for chronic obstructive pulmonary disease patients between randomisation and the 9-month follow-up visit. Secondary endpoints include adverse events, mortality, vital status, changes in lung function parameters, exercise capacity and other efficacy measures at 3, 9 and 12 months.The BENTO trial was commissioned by the German Federal Joint Committee, to demonstrate that this approach is an efficient and safe treatment option in the German healthcare system., Ethics and Dissemination: The protocol has been approved by the lead ethics committee in Germany (Ethics Committee of the Medical Faculty of Heidelberg) and until present also by the following ethics committees: Ethics Committee of the Medical Faculty of Duisburg-Essen, Ethics Committee of the Medical Faculty of Martin-Luther-University Halle-Wittenberg, Ethics Committee of the State Medical Association of Hessen, Ethics Commission of the State Office for Health and Social Affairs of the State of Berlin, Ethics Committee of the Medical Faculty of Greifswald. The results will be published in a peer-reviewed journal., Trial Registration Number: NCT05717192., Competing Interests: Competing interests: KK reports honoraria for lectures, presentations or educational events from AstraZeneca, streamed up and Berlin Chemie, lecturing honoraria with payments made to the institution from and CSL Behring and Olympus Medical and support for attending meetings and travel from Boston Scientific and AstraZeneca, all outside the submitted work. KD reports consulting fees from Bess, Lys Medical and PulmonX, honoraria or payment for lectures and presentations from bess, Boston Scientific, Böhringer I., Broncus Medical, Fujifilm, FreeFlow, Lys Medical, Morair, Medtech, Medtronic, Olympus, Storz, PulmonX and participation on a Data Safety Monitoring Board or Advisory Board for FujiFilm, bess, Lys Medical. RHH reports payment or honoraria for lectures and presentations from PulmonX. FH reports salary payments from IHF Ludwigshafen. TR reports salary payments from IHF Ludwigshafen. FJFH reports payment or honoraria for lectures, presentations, speakers’ bureaus, manuscript writing or educational events from Pulmonx and Uptake Medical. JB reports grants or contracts from Gräfin Beatrice von Hardenberg Stiftung, consulting fees from Intuitive Surgical, Boehringer Ingelheim, Astra Zeneca and payment or honoraria for lectures, presentations, speakers’ bureaus, manuscript writing or educational events from Astra Zeneca, Boehringer Ingelheim, Berlin Chemie, Olympus and streamed up., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: While pharmacologic therapy remains the cornerstone of lung emphysema treatment, surgery is an additional therapeutic option in selected patient groups with advanced emphysema. The aim of lung volume reduction surgery (LVRS) is to improve lung function, exercise capacity, quality of life and survival. We sought to determine the therapeutic value of surgical resection in specific patients with lung emphysema., Patients and Methods: A retrospective study was performed consisting of 58 patients with lung emphysema who underwent surgical intervention over a 10-year period and were followed for 2 years postoperatively. The clinical characteristics recorded were FEV 1 (forced expiratory volume in 1 s), the 6-min walk test (6-MWT), the Modified Medical Research Council (mMRC), body mass index (BMI) and quality of life prior to and 6, 12 and 24 months after surgical intervention. Moreover, all peri- and post-operative complications were noted., Results: Out of 58 emphysema patients (72% male, FEV 1 (L) 2.21 ± 0.17, RV (L) 3.39 ± 0.55), 19 underwent surgical bullectomy, 31 unilateral LVRS and 8 sequential bilateral LVRS. Six months after surgery, there was a statistically significant improvement in FEV 1 , RV, TLC, 6-MWT and mMRC. Over a period of 12 to 24 months postoperatively, clinical benefit gradually declines most likely due to COPD progression but patients still experienced a significant improvement in FEV 1 . The most common postoperative complications were persistent air leakage (> 7 days), arrhythmia and subcutaneous emphysema in 60%, 51.6% and 22.4%, respectively. No deaths were observed after surgical intervention., Conclusion: In a selected patient population, surgery led to significant improvement of lung function parameters, exercise capacity and quality of life. Over a period of 12 to 24 months postoperatively, clinical benefit gradually decreased most likely due to COPD progression., (© 2024. The Author(s).)

Objective: There is an assumption that because EBLVR requires less use of hospital resources, offsetting the higher cost of endobronchial valves, it should therefore be the treatment of choice wherever possible. We have tested this hypothesis in a retrospective analysis of the two in similar groups of patients., Methods: In a 4-year experience, we performed 177 consecutive LVR procedures: 83 patients underwent Robot Assisted Thoracoscopic (RATS) LVRS and 94 EBLVR. EBLVR was intentionally precluded by evidence of incomplete fissure integrity or intra-operative assessment of collateral ventilation. Unilateral RATS LVRS was performed in these cases together with those with unsuitable targets for EBLVR., Results: EBLVR was uncomplicated in 37 (39%) cases; complicated by post-procedure spontaneous pneumothorax (SP) in 28(30%) and required revision in 29 (31%). In the LVRS group, 7 (8%) patients were readmitted with treatment-related complications, but no revisional procedure was needed. When compared with uncomplicated EBLVR, LVRS had a significantly longer operating time: 85 (14-82) vs 40 (15-151) minutes (p<0.001) and hospital stay: 7.5 (2-80) vs 2 (1-14) days (p<0.01). However, LVRS had a similar total operating time to both EBLVR requiring revision: 78 (38-292) minutes and hospital stay to EBLVR complicated by pneumothorax of 11.5 (6.5-24.25) days. Use of critical care was significantly longer in RATS group, and it was also significantly longer in EBV with SP group than in uncomplicated EBV group., Conclusion: Endobronchial LVR does use less hospital resources than RATS LVRS in comparable groups if the recovery is uncomplicated. However, this advantage is lost if one includes the resources needed for the treatment of complications and revisional procedures. Any decision to favour EBLVR over LVRS should not be based on the assumption of a smoother, faster perioperative course., Competing Interests: The authors report no conflicts of interest in this work., (© 2024 Lee et al.)

Introduction: Computed tomographic (CT) phenotypic patterns of chronic obstructive pulmonary disease (COPD) identify different clinical features of disease. The impact of these variables on the physiological response to exercise has been the focus of a great deal of research as it allows more individualized clinical approaches. The aim of our study was to evaluate the relationships between CT phenotyping of subjects with COPD and the ventilatory response during cardiopulmonary exercise testing (CPET)., Methods: Subjects with COPD were classified into four phenotypes based on CT metrics of emphysema (low attenuation area less than a threshold of -950 Hounsfield [%LAA-950]) and airwall thickness (bronchial wall area percentage [%WA])., Results: Eighty COPD patients (78.8% males, median age 65±11.3 years) were enrolled in the study. Based on CT phenotype, 25 (31.3%) patients were classified as normal, 27 (33.8%) air dominant, 17 (21.3%) emphysema dominant and 11 (13.8%) mixed type. The emphysema and mixed phenotypes showed the highest ventilatory equivalent for carbon dioxide (V E /VCO 2 ) and V E /VCO 2 slope (p<0,05). In all phenotypes, %LAA was positive correlated with V E /VCO 2 and V E /VCO 2 slope (r = 0.437, p = 0.006 and r = 0.503, p<0.001, respectively). %WA also showed a positive correlation with V E /VCO 2 and V E /VCO 2 slope (r = 0.541, p<0.001 and r = 0.299, p = 0.033, respectively). In multivariate regression models, after adjustment for age, BMI, sex and FEV1, %LAA was the only independent predictor of V E /VCO 2 and V E /VCO 2 slope (β 0.343, SE 0.147, 95% CI 0.009/0.610, p = 0.044 and β 0.496, SE 0.081, 95% CI 0.130/0.455, p = 0.001, respectively)., Conclusion: Emphysema (%LAA) and airways metrics (%WA) had strong relationships with the different characteristics of ventilatory response to exercise in subjects with mild to moderate COPD. In particular, %LAA seemed to play an important role as an independent predictor of V E /VCO 2 and V E /VCO 2 slope. These results suggested that CT phenotyping may help predicting ventilatory response to exercise in subjects with COPD., Competing Interests: Conflicts of interest The authors have no conflicts of interest to declare., (Copyright © 2022 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.)

Objective: The aim of the study is to assess the correlation between artificial intelligence (AI)-based low attenuation volume percentage (LAV%) with forced expiratory volume in the first second to forced vital capacity (FEV1/FVC) and visual emphysema grades in routine chest computed tomography (CT). Furthermore, optimal LAV% cutoff values for predicting a FEV1/FVC < 70% or moderate to more extensive visual emphysema grades were calculated., Methods: In a retrospective study of 298 consecutive patients who underwent routine chest CT and spirometry examinations, LAV% was quantified using an AI-based software with a threshold < -950 HU. The FEV1/FVC was derived from spirometry, with FEV1/FVC < 70% indicating airway obstruction. The mean time interval of CT from spirometry was 3.87 ± 4.78 days. Severity of emphysema was visually graded by an experienced chest radiologist using an established 5-grade ordinal scale (Fleischner Society classification system). Spearman correlation coefficient between LAV% and FEV1/FVC was calculated. Receiver operating characteristic determined the optimal LAV% cutoff values for predicting a FEV1/FVC < 70% or a visual emphysema grade of moderate or higher (Fleischner grade 3-5)., Results: Significant correlation between LAV% and FEV1/FVC was found (ϱ = -0.477, P < 0.001). Increasing LAV% corresponded to higher visual emphysema grades. For patients with absent visual emphysema, mean LAV% was 2.98 ± 3.30, for patients with trace emphysema 3.22 ± 2.75, for patients with mild emphysema 3.90 ± 3.33, for patients with moderate emphysema 6.41 ± 3.46, for patients with confluent emphysema 9.02 ± 5.45, and for patients with destructive emphysema 16.90 ± 8.19. Optimal LAV% cutoff value for predicting a FEV1/FVC < 70 was 6.1 (area under the curve = 0.764, sensitivity = 0.773, specificity = 0.665), while for predicting a visual emphysema grade of moderate or higher, it was 4.7 (area under the curve = 0.802, sensitivity = 0.766, specificity = 0.742). Furthermore, correlation between visual emphysema grading and FEV1/FVC was found. In patients with FEV1/FVC < 70% a high proportion of subjects had emphysema grade 3 (moderate) or higher, whereas in patients with FEV1/FVC ≥ 70%, a larger proportion had emphysema grade 3 (moderate) or lower. The sensitivity for visual emphysema grading predicting a FEV1/FVC < 70% was 56.3% with an optimal cutoff point at a visual grade of 4 (confluent), demonstrating a lower sensitivity compared with LAV% (77.3%)., Conclusions: A significant correlation between AI-based LAV% and FEV1/FVC as well as visual CT emphysema grades can be found in routine chest CT suggesting that AI-based LAV% measurement might be integrated as an add-on functional parameter in the evaluation of chest CT in the future., Competing Interests: S.O.S. has a cooperation with Siemens-Healthineers, which does not bias the content of the manuscript. The other authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Research on the condition of the lungs in senile people is an urgent task. This is due to the fact that degenerative or age-associated changes in the respiratory system play an important role in the formation of senile asthenia syndrome and a decrease in the age-related viability of the body as a whole. CT-scans of patients aged 80-90 years were analyzed (n=31). Age-associated changes were evaluated: the presence of linear fibrosis, increased pulmonary pattern by the type of reticular (reticular) changes, the presence of gross fibrous reticular changes with cystic cavities and air bullae (by the type of «cellular lung»), as well as the presence of pulmonary emphysema. Most naturally, senile people show changes characteristic of linear pulmonary fibrosis and emphysema. The progression of the process leads to diffuse reticular changes in the interalveolar and intersegmental septa and, in adverse cases, to the formation of gross changes in the type of «cellular lung». Fibro-emphysematous changes are significantly more common in men. A microbiological study of the microbiota of the lower respiratory tract in elderly people was also carried out (n=16). When studying the microbiocenosis of the lower respiratory tract in elderly people, the following data were obtained: resident microflora was found in 71% and clinically significant microorganisms were found in 29%.

Introduction: Patients with chronic obstructive pulmonary disease (COPD) and emphysema experience malnutrition and pulmonary cachexia. Endoscopic lung volume reduction (ELVR) with endobronchial valves has not only improved lung function, exercise capacity, and quality of life but also influenced body weight. Only a few data are available on body composition changes after ELVR., Methods: This single-center prospective study of patients with advanced COPD investigates body composition before and after endoscopic valve treatment using multifrequency bioelectrical impedance analysis (BIA). The following parameters were evaluated in addition to clinical data and routine tests: body weight, body mass index (BMI), basal metabolic rate, total body water, body fat, cell percentage, phase angle, intracellular water (ICW), extracellular water (ECW), extracellular mass (ECM), body cell mass (BCM), lean body mass (ECM + BCM), and fat-free mass index., Results: A total of 23 patients (mean emphysema index 37.2 ± 7.5%, BMI 23.4 ± 4.3 kg/m2) experienced improvements in lung function and exercise capacity with ELVR. Complete lobar atelectasis was achieved in 39.1% of participants. A non-statistically significant increase in body weight and BMI was observed after ELVR (p = 0.111 and p = 0.102). BIA measurement revealed a worsening of phase angle, cell percentage and ECM/BCM and thus of body composition, but without statistical significance. This is mainly due to a statistically significant increase in ECM, ECW, and ICW (all p &lt; 0.001)., Conclusion: ELVR demonstrated no beneficial changes in body composition, although patients tend to gain weight. A larger cohort is warranted to confirm these findings., (© 2024 S. Karger AG, Basel.)

Severe alpha-1 antitrypsin deficiency (AATD) is associated with an increased risk of emphysema. However, the clinical manifestations are very heterogeneous, and an individual prognosis is very difficult to establish. Intravenous augmentation therapy with alpha-1 antitrypsin (AAT) from pooled blood donors is the only specific treatment available, but it requires weekly or biweekly administration for life. Several guidelines provide the indication criteria for the initiation of AAT augmentation therapy. However, in clinical practice, there are situations in which the decision as to when to start treatment becomes uncertain and some studies have shown great variability in the indication of this treatment even among specialists. The usual dilemma is between initiating augmentation therapy in individuals who may not develop significant lung disease or in whom disease will not progress or delaying it in patients who may otherwise rapidly and irreversibly progress. We illustrate this dilemma with five clinical cases: from the case of a patient with normal lung function who requests initiation of therapy to a moderately stable patient without augmentation or a mild patient who, after several years of remaining stable without treatment, deterioration in lung function initiated and, consequently, augmentation therapy was begun. All the nuances associated with the indication of augmentation justify a personalised approach and the decision about initiating augmentation therapy must be made after careful consideration of the pros and cons with the patient in reference centres with experience in treatment. These reference centres can work in collaboration with local hospitals where patients can be closely followed and augmentation therapy can be administered to avoid unnecessary travelling, making periodical administrations more comfortable for the patient.

Purpose: To evaluate the association between the coronavirus disease 2019 (COVID-19) and post-inflammatory emphysematous lung alterations on follow-up low-dose CT scans., Methods: Consecutive patients with proven COVID-19 infection and a follow-up CT were retrospectively reviewed. The severity of pulmonary involvement was classified as mild, moderate and severe. Total lung volume, emphysema volume and the ratio of emphysema/-to-lung volume were quantified semi-automatically and compared inter-individually between initial and follow-up CT and to a control group of healthy, age- and sex-matched patients. Lung density was further assessed by drawing circular regions of interest (ROIs) into non-affected regions of the upper lobes., Results: A total of 32 individuals (mean age: 64 ± 13 years, 12 females) with at least one follow-up CT (mean: 52 ± 66 days, range: 5-259) were included. In the overall cohort, total lung volume, emphysema volume and the ratio of lung-to-emphysema volume did not differ significantly between the initial and follow-up scans. In the subgroup of COVID-19 patients with > 30 days of follow-up, the emphysema volume was significantly larger as compared to the subgroup with a follow-up < 30 days (p = 0.045). Manually measured single ROIs generally yielded lower attenuation values prior to COVID-19 pneumonia, but the difference was not significant between groups (all p > 0.05)., Conclusion: COVID-19 patients with a follow-up CT >30 days showed significant emphysematous lung alterations. These findings may help to explain the long-term effect of COVID-19 on pulmonary function and warrant validation by further studies., Competing Interests: The authors have declared that no competing interests exist.

We studied whether in patients with COPD the use of metformin for diabetes treatment was linked to a pattern of lung function decline consistent with the hypothesis of anti-aging effects of metformin. Patients of GOLD grades 1-4 of the COSYCONET cohort with follow-up data of up to 4.5 y were included. The annual decline in lung function (FEV 1 , FVC) and CO diffusing capacity (KCO, TLCO) in %predicted at baseline was evaluated for associations with age, sex, BMI, pack-years, smoking status, baseline lung function, exacerbation risk, respiratory symptoms, cardiac disease, as well as metformin-containing therapy compared to patients without diabetes and metformin. Among 2741 patients, 1541 (mean age 64.4 y, 601 female) fulfilled the inclusion criteria. In the group with metformin treatment vs. non-diabetes the mean annual decline in KCO and TLCO was significantly lower (0.2 vs 2.3, 0.8 vs. 2.8%predicted, respectively; p < 0.05 each), but not the decline of FEV 1 and FVC. These results were confirmed using multiple regression and propensity score analyses. Our findings demonstrate an association between the annual decline of lung diffusing capacity and the intake of metformin in patients with COPD consistent with the hypothesis of anti-aging effects of metformin as reflected in a surrogate marker of emphysema., (© 2022. The Author(s).)

Background: There is a strong need for biomarkers to better characterize individuals with COPD and to take into account the heterogeneity of COPD. The blood protein sRAGE has been put forward as promising biomarker for COPD in general and emphysema in particular. Here, we measured plasma sRAGE levels using quantitative LC-MS and assessed whether the plasma sRAGE levels associate with (changes in) lung function, radiological emphysema parameters, and radiological subtypes of emphysema., Methods: Three hundred and twenty-four COPD patients (mean FEV 1 : 63%predicted) and 185 healthy controls from the COPDGene study were selected. Plasma sRAGE was measured by immunoprecipitation in 96-well plate methodology to enrich sRAGE, followed by targeted quantitative liquid chromatography-mass spectrometry. Spirometry and HRCT scans (inspiration and expiration) with a 5-year follow-up were used; both subjected to high quality control standards., Results: Lower sRAGE values significantly associated with the presence of COPD, the severity of airflow obstruction, the severity of emphysema on HRCT, the heterogeneous distribution of emphysema, centrilobular emphysema, and 5-year progression of emphysema. However, sRAGE values did not associate with airway wall thickness or paraseptal emphysema., Conclusions: Rather than being a general COPD biomarker, sRAGE is especially a promising biomarker for centrilobular emphysema. Follow-up studies should elucidate whether sRAGE can be used as a biomarker for other COPD phenotypes as well., (© 2022. The Author(s).)

Background: In the clinical management of patients with combined pulmonary fibrosis and emphysema (CPFE), early recognition and appropriate treatment is essential. This study was designed to develop an accurate prognostic nomogram model to predict the presence of CPFE., Methods: We retrospectively enrolled 85 patients with CPFE and 128 patients with idiopathic pulmonary fibrosis (IPF) between January 2015 and January 2020. Clinical characteristics were compared between groups. A multivariable logistic regression analysis was performed to identify risk factors for CPFE. Then, and a nomogram to predict the presence of CPFE was constructed for clinical use. Concordance index (C-index), area under the receiver operating characteristic curve (AUC), and calibration plot was used to evaluate the efficiency of the nomogram., Results: Compared to the IPF group, the proportion of patients with male, smoking and allergies were significantly higher in the CPFE group. In terms of pulmonary function tests, patients with CPFE had lower FEV1/FVC%, DLCO/VA% pred, and higher RV, RV%pred, VC, VC%pred, TLC%pred, VA, TLC, TLC%pred, FVC, FVC%pred and FEV1 with significant difference than the other group. Positive correlation was found between DLCO and VA%, RV%, TLC% in patients with IPF but not in patients with CPFE. By multivariate analysis, male, smoking, allergies, FEV1/FVC% and DLCO/VA%pred were identified as independent predictors of the presence of CPFE. The nomogram was then developed using these five variables. After 1000 internal validations of bootstrap resampling, the C-index of the nomogram was 0.863 (95% CI 0.795-0.931) and the AUC was 0.839 (95% CI 0.764-0.913). Moreover, the calibration plot showed good concordance of incidence of CPFE between nomogram prediction and actual observation (Hosmer-Lemeshow test: P = 0.307)., Conclusions: Patients of CPFE have a characteristic lung function profile including relatively preserved lung volumes and ventilating function, contrasting with a disproportionate reduction of carbon monoxide transfer. By incorporating clinical risk factors, we created a nomogram to predict the presence of CPFE, which may serve as a potential tool to guide personalized treatment., (© 2021. The Author(s).)

Background: Interstitial lung disease (ILD) is a common and potentially life-threatening complication for rheumatoid arthritis (RA) patients. However, there is a lack of clear prognostic factors in rheumatoid arthritis-associated interstitial lung disease (RA-ILD) patients. The purpose of this study was to complete a systematic review and meta-analysis of the factors associated with mortality in RA-ILD patients., Methods: Medline, EMBASE and the Cochrane Library were searched up to September 1, 2020. The Newcastle-Ottawa Scale (NOS) was applied to assess the methodological quality of the eligible studies. Study characteristics and magnitude of effect sizes were extracted. Then, pooled hazard ratios (HRs) with the corresponding 95% confidence intervals (CIs) and pooled risk ratios (RRs) with 95% CIs were calculated to assess the factors associated with mortality in RA-ILD., Results: Twenty-three of 3463 articles were eligible, and ten factors associated with mortality for RA-ILD were evaluated in the meta-analysis. Older age (HRs = 1.04, 95% CI 1.03-1.05), male sex (HRs = 1.44, 95% CI 1.21-1.73), having a smoking history (HRs = 1.42, 95% CI 1.03-1.96), lower diffusing capacity of the lung for carbon monoxide (DLCO)% predicted (HRs = 0.98, 95% CI 0.97-1.00), forced vital capacity (FVC)% predicted (HRs = 0.99, 95% CI 0.98-1.00), composite physiological index (CPI) (HRs = 1.04, 95% CI 1.02-1.06), usual interstitial pneumonia (UIP) pattern on HRCT (HRs = 1.88, 95% CI 1.14-3.10 and RRs = 1.90, 95% CI 1.50-2.39), emphysema presence (HRs = 2.31, 95% CI 1.58-3.39), and acute exacerbation of ILD (HRs = 2.70, 95% CI 1.67-4.36) were associated with increased mortality in RA-ILD, whereas rheumatoid factor (RF) positive status was not associated., Conclusions: Through this systematic review and meta-analysis, we found that older age, male sex, smoking history, higher CPI, lower DLCO% predicted, lower FVC% predicted, UIP pattern on HRCT, emphysema presence and acute exacerbation of ILD were associated with an increased risk of mortality in RA-ILD., (© 2021. The Author(s).)

Background: Attenuation of transforming growth factor β by blocking angiotensin II has been shown to reduce emphysema in a murine model. General population studies have demonstrated that the use of angiotensin converting enzyme inhibitors (ACEis) and angiotensin-receptor blockers (ARBs) is associated with reduction of emphysema progression in former smokers and that the use of ACEis is associated with reduction of FEV 1 progression in current smokers., Research Question: Is use of ACEi and ARB associated with less progression of emphysema and FEV 1 decline among individuals with COPD or baseline emphysema?, Methods: Former and current smokers from the Genetic Epidemiology of COPD Study who attended baseline and 5-year follow-up visits, did not change smoking status, and underwent chest CT imaging were included. Adjusted linear mixed models were used to evaluate progression of adjusted lung density (ALD), percent emphysema (%total lung volume <-950 Hounsfield units [HU]), 15th percentile of the attenuation histogram (attenuation [in HU] below which 15% of voxels are situated plus 1,000 HU), and lung function decline over 5 years between ACEi and ARB users and nonusers in those with spirometry-confirmed COPD, as well as all participants and those with baseline emphysema. Effect modification by smoking status also was investigated., Results: Over 5 years of follow-up, compared with nonusers, ACEi and ARB users with COPD showed slower ALD progression (adjusted mean difference [aMD], 1.6; 95% CI, 0.34-2.9). Slowed lung function decline was not observed based on phase 1 medication (aMD of FEV 1 % predicted, 0.83; 95% CI, -0.62 to 2.3), but was when analysis was limited to consistent ACEi and ARB users (aMD of FEV 1 % predicted, 1.9; 95% CI, 0.14-3.6). No effect modification by smoking status was found for radiographic outcomes, and the lung function effect was more pronounced in former smokers. Results were similar among participants with baseline emphysema., Interpretation: Among participants with spirometry-confirmed COPD or baseline emphysema, ACEi and ARB use was associated with slower progression of emphysema and lung function decline., Trial Registry: ClinicalTrials.gov; No.: NCT00608764; URL: www.clinicaltrials.gov., (Copyright © 2021 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Excessive dynamic airway collapse (EDAC) contributes to breathlessness and reduced quality of life in individuals with emphysema. We tested a novel, portable, oral positive expiratory pressure (o-PEP) device in a patient with emphysema and EDAC. MRI revealed expiratory tracheal narrowing to 80 mm 2 that increased to 170 mm 2 with the o-PEP device. After 2-weeks use of the o-PEP device for 33% to 66% of activities, breathlessness, quality of life, and exertional dyspnea improved compared with minimal clinically important differences (MCID): University of California-San Diego Shortness of Breath questionnaire score declined 69 to 42 (MCID, ≥5), St. George's Respiratory Questionnaire score decreased 71 to 27 (MCID, ≥4), and before and after the 6-minute walk test Borg score difference improved from Δ3 to Δ2 (MCID, ≥1). During the 6-minute walk test on room air without the use of the o-PEP device, oxyhemoglobin saturation declined 91% to 83%; whereas, with the o-PEP device, the nadir was 90%. Use of the o-PEP device reduced expiratory central airway collapse and improved dyspnea, quality of life, and exertional desaturation in a patient with EDAC and emphysema., (Copyright © 2021 American College of Chest Physicians. All rights reserved.)

Background: GATA2 deficiency is a genetic disorder of hematopoiesis, lymphatics, and immunity caused by autosomal dominant or sporadic mutations in GATA2. The disease has a broad phenotype encompassing immunodeficiency, myelodysplasia, leukemia, and vascular or lymphatic dysfunction as well as prominent pulmonary manifestations., Research Question: What are the pulmonary manifestations of GATA2 deficiency?, Study Design and Methods: A retrospective review was conducted of clinical medical records, diagnostic imaging, pulmonary pathologic specimens, and tests of pulmonary function., Results: Of 124 patients (95 probands and 29 ascertained), the lung was affected in 56%. In addition to chronic infections, pulmonary alveolar proteinosis (11 probands) and pulmonary arterial hypertension (nine probands) were present. Thoracic CT imaging found small nodules in 54% (54 probands and 12 relatives), reticular infiltrates in 40% (45 probands and four relatives), paraseptal emphysema in 25% (30 probands and one relative), ground-glass opacities in 35% (41 probands and two relatives), consolidation in 21% (23 probands and two relatives), and a typical crazy-paving pattern in 7% (eight probands and no relatives). Nontuberculous mycobacteria were the most frequent organisms associated with chronic infection. Allogeneic hematopoietic stem cell transplantation successfully reversed myelodysplasia and immune deficiency and also improved pulmonary hypertension and pulmonary alveolar proteinosis in most patients., Interpretation: GATA2 deficiency has prominent pulmonary manifestations. These clinical observations confirm the essential role of hematopoietic cells in many aspects of pulmonary function, including infections, alveolar proteinosis, and pulmonary hypertension, many of which precede the formal diagnosis, and many of which respond to stem cell transplantation., (Published by Elsevier Inc.)

Background: Emphysema and exercise induced desaturation (EID) are both related to poorer COPD prognosis. More knowledge of associations between emphysema and desaturation is needed for more efficient disease management., Research Question: Is emphysema a risk factor for both new and repeated desaturation, and is emphysema of more or less importance than other known risk factors?, Methods: 283 COPD patients completed a 6-min walk test (6MWT) at baseline and one year later in the Bergen COPD cohort study 2006-2011. Degree of emphysema was assessed as percent of low attenuation areas (%LAA) under -950 Hounsfield units using high-resolution computed tomography at baseline. We performed multinomial logistic regression analysis, receiver operating curves (ROC) and area under the curve (AUC) estimations. Dominance analysis was used to rank emphysema and risk factors in terms of importance., Results: A one percent increase in %LAA increases the relative risk (RR) of new desaturation by 10 % (RR 1.1 (95%CI 1.1, 1.2)) and for repeated desaturation by 20 % (RR 1.2 (95%CI 1.1, 1.3)). Compared with other important desaturation risk factors, %LAA ranked as number one in the dominance analysis, accounting for 50 % and 37 % of the predicted variance for new and repeated desaturators, respectively. FEV 1 % predicted accounted for 9 % and 24 %, and resting SpO 2 accounted for 22 % and 21 % for new and repeated desaturation., Conclusion: Emphysema increases the risk of developing and repeatedly experiencing EID. Emphysema seems to be a more important risk factor for desaturation than FEV 1 % predicted and resting saturation., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Rationale: Necroptosis, mediated by RIPK3 (receptor-interacting protein kinase 3) and MLKL (mixed lineage kinase domain-like), is a form of regulated necrosis that can drive tissue inflammation and destruction; however, its contribution to chronic obstructive pulmonary disease (COPD) pathogenesis is poorly understood. Objectives: To determine the role of necroptosis in COPD. Methods: Total and active (phosphorylated) RIPK3 and MLKL were measured in the lung tissue of patients with COPD and control subjects without COPD. Necroptosis-related mRNA and proteins as well as cell death were examined in lungs and pulmonary macrophages of mice with cigarette smoke (CS)-induced experimental COPD. The responses of Ripk3 -/- and Mlkl -/- mice to acute and chronic CS exposure were compared with those of wild-type mice. The combined inhibition of apoptosis (with the pan-caspase inhibitor quinoline-Val-Asp-difluorophenoxymethylketone [qVD-OPh]) and necroptosis (with deletion of Mlkl in mice) was assessed. Measurements and Main Results: The total MLKL protein in the epithelium and macrophages and the pRIPK3 and pMLKL in lung tissue were increased in patients with severe COPD compared with never-smokers or smoker control subjects without COPD. Necroptosis-related mRNA and protein levels were increased in the lungs and macrophages in CS-exposed mice and experimental COPD. Ripk3 or Mlkl deletion prevented airway inflammation upon acute CS exposure. Ripk3 deficiency reduced airway inflammation and remodeling as well as the development of emphysematous pathology after chronic CS exposure. Mlkl deletion and qVD-OPh treatment reduced chronic CS-induced airway inflammation, but only Mlkl deletion prevented airway remodeling and emphysema. Ripk3 or Mlkl deletion and qVD-OPh treatment reduced CS-induced lung-cell death. Conclusions: Necroptosis is induced by CS exposure and is increased in the lungs of patients with COPD and in experimental COPD. Inhibiting necroptosis attenuates CS-induced airway inflammation, airway remodeling, and emphysema. Targeted inhibition of necroptosis is a potential therapeutic strategy in COPD.

Patients with pulmonary emphysema often develop locomotor muscle dysfunction, which is independently associated with disability and higher mortality in that population. Muscle dysfunction entails reduced force generation capacity, which partially depends on fibers' oxidative potential, yet very little mechanistic research has focused on muscle respiration in pulmonary emphysema. Using a recently established animal model of pulmonary emphysema-driven skeletal muscle dysfunction, we found downregulation of SDHC (succinate dehydrogenase subunit C) in association with lower oxygen consumption and fatigue tolerance in locomotor muscles. Reduced SDH activity has been previously observed in muscles from patients with pulmonary emphysema, and we found that SDHC is required to support respiration in cultured muscle cells. Moreover, in vivo gain of SDH function in emphysema animals' muscles resulted in better oxygen consumption rate and fatigue tolerance. These changes correlated with a larger number of relatively more oxidative type 2-A and 2X fibers and a reduced amount of 2B fibers. Our data suggest that SDHC is a key regulator of respiration and fatigability in pulmonary emphysema-driven skeletal muscles, which could be impactful in developing strategies aimed at attenuating this comorbidity.