Socio-demographic and comorbid risk factors for poor prognosis in patients hospitalized with community-acquired bacterial pneumonia in southeastern US

BACKGROUND

How socio-demographic characteristics and comorbidities affect bacterial community-acquired pneumonia (CAP) prognosis during/after hospitalization is important in disease management.

OBJECTIVES

To identify predictors of medical intensive care unit (MICU) admission, length of hospital stay (LOS), in-hospital mortality, and bacterial CAP readmission in patients hospitalized with bacterial CAP.

METHODS

ICD-9/10 codes were used to query electronic medical records to identify a cohort of patients hospitalized for bacterial CAP at a tertiary hospital in Southeastern US between 01/01/2013-12/31/2019. Adjusted accelerated failure time and modified Poisson regression models were used to examine predictors of MICU admission, LOS, in-hospital mortality, and 1-year readmission.

RESULTS

There were 1956 adults hospitalized with bacterial CAP. Median (interquartile range) LOS was 11 days (6-23), and there were 26 % (513) MICU admission, 14 % (266) in-hospital mortality, and 6 % (117) 1-year readmission with recurrent CAP. MICU admission was associated with heart failure (RR 1.38; 95 % CI 1.17-1.62) and obesity (RR 1.26; 95 % CI 1.04-1.52). Longer LOS was associated with heart failure (adjusted time ratio[TR] 1.27;95 %CI 1.12-1.43), stroke (TR 1.90;95 %CI 1.54,2.35), type 2 diabetes (TR 1.20;95 %CI 1.07-1.36), obesity (TR 1.50;95 %CI 1.31-1.72), Black race (TR 1.17;95 %CI 1.04-1.31), and males (TR 1.24;95 %CI 1.10-1.39). In-hospital mortality was associated with stroke (RR 1.45;95 %CI 1.03-2.04) and age ≥65 years (RR 1.34;95 %CI 1.06-1.68). 1-year readmission was associated with COPD (RR 1.55;95 %CI 1.05-2.27) and underweight BMI (RR 1.74;95 %CI 1.04-2.90).

CONCLUSIONS

Comorbidities and socio-demographic characteristics have varying impacts on bacterial CAP in-hospital prognosis and readmission. More studies are warranted to confirm these findings to develop comprehensive care plans and inform public health interventions.

Differentially co-expressed myofibre transcripts associated with abnormal myofibre proportion in chronic obstructive pulmonary disease

BACKGROUND

Skeletal muscle dysfunction is a common extrapulmonary manifestation of chronic obstructive pulmonary disease (COPD). Alterations in skeletal muscle myosin heavy chain expression, with reduced type I and increased type II myosin heavy chain expression, are associated with COPD severity when studied in largely male cohorts. The objectives of this study were (1) to define an abnormal myofibre proportion phenotype in both males and females with COPD and (2) to identify transcripts and transcriptional networks associated with abnormal myofibre proportion in COPD.

METHODS

Forty-six participants with COPD were assessed for body composition, strength, endurance and pulmonary function. Skeletal muscle biopsies from the vastus lateralis were assayed for fibre-type distribution and cross-sectional area via immunofluorescence microscopy and RNA-sequenced to generate transcriptome-wide gene expression data. Sex-stratified k-means clustering of type I and IIx/IIax fibre proportions was used to define abnormal myofibre proportion in participants with COPD and contrasted with previously defined criteria. Single transcripts and weighted co-expression network analysis modules were tested for correlation with the abnormal myofibre proportion phenotype.

RESULTS

Abnormal myofibre proportion was defined in males with COPD (n = 29) as <18% type I and/or >22% type IIx/IIax fibres and in females with COPD (n = 17) as <36% type I and/or >12% type IIx/IIax fibres. Half of the participants with COPD were classified as having an abnormal myofibre proportion. Participants with COPD and an abnormal myofibre proportion had lower median handgrip strength (26.1 vs. 34.0 kg, P = 0.022), 6-min walk distance (300 vs. 353 m, P = 0.039) and forced expiratory volume in 1 s-to-forced vital capacity ratio (0.42 vs. 0.48, P = 0.041) compared with participants with COPD and normal myofibre proportions. Twenty-nine transcripts were associated with abnormal myofibre proportions in participants with COPD, with the upregulated NEB, TPM1 and TPM2 genes having the largest fold differences. Co-expression network analysis revealed that two transcript modules were significantly positively associated with the presence of abnormal myofibre proportions. One of these co-expression modules contained genes classically associated with muscle atrophy, as well as transcripts associated with both type I and type II myofibres, and was enriched for genetic loci associated with bone mineral density.

CONCLUSIONS

Our findings indicate that there are significant transcriptional alterations associated with abnormal myofibre proportions in participants with COPD. Transcripts canonically associated with both type I and type IIa fibres were enriched in a co-expression network associated with abnormal myofibre proportion, suggesting altered transcriptional regulation across multiple fibre types.

Associations Between Coronary Artery Calcium Score and Exacerbation Risk in BLOCK-COPD

Introduction

In 2019, the Beta-Blockers for the Prevention of Acute Exacerbations of Chronic Obstructive Pulmonary Disease study (BLOCK-COPD) evaluated the effect of metoprolol on exacerbation risk and mortality in a COPD population without indications for beta-blocker use. We hypothesized that an imaging metric of coronary artery disease (CAD), the coronary artery calcium (CAC) score, would predict exacerbation risk and identify a differential response to metoprolol treatment.

Methods

The study population includes participants in the BLOCK-COPD study from multiple study sites. Participants underwent clinically indicated thoracic computed tomography (CT) scans ± 12 months from enrollment. The Weston scoring system quantified CAC. Adjusted Cox proportional hazards models evaluated for associations between CAC and time to exacerbation.

Results

Data is included for 109 participants. The mean CAC score was 5.1±3.7, and 92 participants (84%) had CAC scores greater than 0. Over a median (interquartile range) follow-up time of 350 (280 to 352) days, there were 61 mild exacerbations and 19 severe/very severe exacerbations. No associations were found between exacerbations of any severity and CAC>0 or total CAC. Associations were observed between total CAC and CAC>0 in the left circumflex (LCx) and time to exacerbation of any severity (adjusted hazard ratio [aHR]=1.39, confidence interval [CI]: 1.08-1.79, p=0.01) and (aHR=1.96, 95% CI: 1.04-3.70, p=0.04), respectively.

Conclusions

CAD is a prevalent comorbidity in COPD accounting for significant mortality. Our study confirms the high prevalence of CAD using the CAC score; however, we did not discover an association between CAC and exacerbation risk. We did find novel associations between CAC in the LCx and exacerbation risk which warrant further investigation in larger cohorts.

Anti-CELA1 antibody KF4 prevents emphysema by inhibiting stretch-mediated remodeling

There are no therapies to prevent emphysema progression. Chymotrypsin-like elastase 1 (CELA1) is a serine protease that binds and cleaves lung elastin in a stretch-dependent manner and is required for emphysema in a murine antisense oligonucleotide model of α-1 antitrypsin (AAT) deficiency. This study tested whether CELA1 is important in strain-mediated lung matrix destruction in non-AAT-deficient emphysema and the efficacy of CELA1 neutralization. Airspace simplification was quantified after administration of tracheal porcine pancreatic elastase (PPE), after 8 months of cigarette smoke (CS) exposure, and in aging. In all 3 models, Cela1-/- mice had less emphysema and preserved lung elastin despite increased lung immune cells. A CELA1-neutralizing antibody was developed (KF4), and it inhibited stretch-inducible lung elastase in ex vivo mouse and human lung and immunoprecipitated CELA1 from human lung. In mice, systemically administered KF4 penetrated lung tissue in a dose-dependent manner and 5 mg/kg weekly prevented emphysema in the PPE model with both pre- and postinjury initiation and in the CS model. KF4 did not increase lung immune cells. CELA1-mediated lung matrix remodeling in response to strain is an important contributor to postnatal airspace simplification, and we believe that KF4 could be developed as a lung matrix-stabilizing therapy in emphysema.

A Novel Provider Education Module to Enhance Detection of Alpha-1 Antitrypsin Deficiency

Background

Alpha-1 antitrypsin deficiency (AATD) is the most common genetic risk factor for early-onset emphysema. However, AATD continues to be underrecognized and underdiagnosed. Provider awareness about AATD, concerns with testing costs, and limited understanding about therapeutic options contribute to its underdiagnosis. We hypothesized that provider education would improve awareness of AATD and improve screening.

Objective

To evaluate the impact of a targeted provider education module on AATD screening.

Methods

We developed a web-based education module to address barriers to screening for AATD, deployed the education module using the Medscape Education platform, assessed perceived healthcare provider confidence in AATD screening, and conducted a prospective pre and postintervention study of AATD testing practices at a high-volume academic outpatient subspecialty pulmonary clinic.

Results

A total of 11,385 healthcare providers, including eight pulmonologists at our institution, completed the web-based education module. Confidence in identifying patients at high risk for AATD improved after completing the module ("not confident" in AATD screening was 7.7% postintervention compared with 19.4% preintervention). The rate of screening patients at high risk for AATD improved more than twofold (AATD screening rate 9.7% preintervention vs. 20.4% postintervention; P = 0.004). Among patients screened for AATD in our cohort, 27.2% had a genotype/phenotype or low alpha-1 antitrypsin concentration consistent with AATD.

Conclusion

Targeted healthcare provider education can improve the confidence in testing for AATD. Improvements in provider confidence corresponded to improvements in AATD screening in a subspecialty pulmonary clinic. More than one-fourth of screening tests suggested AATD, underpinning the value of testing in high-risk individuals.

Causes of and Clinical Features Associated with Death in Tobacco Cigarette Users by Lung Function Impairment

Rationale: Cigarette smoking contributes to the risk of death through different mechanisms. Objectives: To determine how causes of and clinical features associated with death vary in tobacco cigarette users by lung function impairment. Methods: We stratified current and former tobacco cigarette users enrolled in Genetic Epidemiology of Chronic Obstructive Pulmonary Disease (COPDGene) into normal spirometry, PRISm (Preserved Ratio Impaired Spirometry), Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1-2 COPD, and GOLD 3-4 COPD. Deaths were identified via longitudinal follow-up and Social Security Death Index search. Causes of death were adjudicated after a review of death certificates, medical records, and next-of-kin interviews. We tested associations between baseline clinical variables and all-cause mortality using multivariable Cox proportional hazards models. Measurements and Main Results: Over a 10.1-year median follow-up, 2,200 deaths occurred among 10,132 participants (age 59.5 ± 9.0 yr; 46.6% women). Death from cardiovascular disease was most frequent in PRISm (31% of deaths). Lung cancer deaths were most frequent in GOLD 1-2 (18% of deaths vs. 9-11% in other groups). Respiratory deaths outpaced competing causes of death in GOLD 3-4, particularly when BODE index ⩾7. St. George's Respiratory Questionnaire score ⩾25 was associated with higher mortality in all groups: Hazard ratio (HR), 1.48 (1.20-1.84) normal spirometry; HR, 1.40 (1.05-1.87) PRISm; HR, 1.80 (1.49-2.17) GOLD 1-2; HR, 1.65 (1.26-2.17) GOLD 3-4. History of respiratory exacerbations was associated with higher mortality in GOLD 1-2 and GOLD 3-4, quantitative emphysema in GOLD 1-2, and airway wall thickness in PRISm and GOLD 3-4. Conclusions: Leading causes of death vary by lung function impairment in tobacco cigarette users. Worse respiratory-related quality of life is associated with all-cause mortality regardless of lung function.

LC-MS/MS method for proline-glycine-proline and acetylated proline-glycine-proline in human plasma

The extracellular cellular matrix (ECM) maintains tissue structure and regulates signaling functions by continuous degradation and remodeling. Inflammation or other disease conditions activate proteases including matrix metalloproteinases (MMPs) that degrade ECM proteins and in particular generate fragments of collagen and elastin, some of which are biologically active ECM peptides or matrikines. Stepwise degradation of collagen by MMP 8, 9 and prolyl endopeptidase release the matrikine proline-glycine-proline (PGP) and its product acetyl-PGP (AcPGP). These peptides are considered as potential biomarkers and therapeutic targets for many disease conditions such as chronic lung disease, heart disease, and cancer. However, there is no published, validated method for the measurement of PGP and AcPGP in plasma and therefore, we developed a sensitive, selective and reliable, isotope dilution LC-multiple reaction monitoring MS method for their determination in human plasma. The chromatographic separation of PGP and AcPGP was achieved in 3 min using Jupiter column with a gradient consisting of acidified acetonitrile and water at a flow rate of 0.5 ml/min. The limit of detection (LOD) for PGP and AcPGP was 0.01 ng/ml and the limit of quantification (LOQ) was 0.05 ng/ml and 0.1 ng/ml, respectively. Precision and accuracy values for all analytes were within 20 % except for the lowest QC of 0.01 ng/ml. The mean extraction recoveries of these analytes were > 90 % using a Phenomenex Phree cartridge and the matrix effect was < 15 % for all the QCs for PGP and AcPGP except the lowest QC. The stability of PGP and AcPGP was > 90 % in several tested conditions including autosampler use, storage at -80 °C, and after 6 times freeze-thaw cycles. Using this method, we successfully extracted and determined PGP levels in human plasma from healthy and COPD subjects. Therefore, this method is suitable for quantification of these peptides in the clinical setting.

Electrocardiogram to Determine Mitral and Aortic Valve Opening and Closure

PURPOSE

Knowledge of the timing of cardiac valve opening and closing is important in cardiac physiology. The relationship between valve motion and electrocardiogram (ECG) is often assumed, however is not clearly defined. Here we investigate the accuracy of cardiac valve timing estimated using only the ECG, compared to Doppler echocardiography (DE) flow imaging as the gold standard.

METHODS

DE was obtained in 37 patients with simultaneous ECG recording. ECG was digitally processed and identifiable features (QRS, T, P waves) were examined as potential reference points to determine opening and closure of aortic and mitral valves, as compared to DE outflow and inflow measurement. Timing offset of the cardiac valves opening and closure between ECG features and DE was measured from derivation set (n = 19). The obtained mean offset in combination with the ECG features model was then evaluated on a validation set (n = 18). Using the same approach, additional measurement was also done for the right sided valves.

RESULTS

From the derivation set, we found a fixed offset of 22 ± 9 ms, 2 ± 13 ms, 90 ± 26 ms, and - 2 ± - 27 ms when comparing S to aortic valve opening, Tend to aortic valve closure, Tend to mitral valve opening, and R to mitral valve closure respectively. Application of this model to the validation set showed good estimation of aortic and mitral valve opening and closure timing value, with low model absolute error (median of the mean absolute error of the four events = 19 ms compared to the gold standard DE measurement). For the right-sided (tricuspid and pulmonic) valves in our patient set, there was considerably higher median of the mean absolute error of 42 ms for the model.

CONCLUSION

ECG features can be used to estimate aortic and mitral valve timings with good accuracy as compared to DE, allowing useful hemodynamic information to be derived from this easily available test.

A blood and bronchoalveolar lavage protein signature of rapid FEV1 decline in smoking-associated COPD

Accelerated progression of chronic obstructive pulmonary disease (COPD) is associated with increased risks of hospitalization and death. Prognostic insights into mechanisms and markers of progression could facilitate development of disease-modifying therapies. Although individual biomarkers exhibit some predictive value, performance is modest and their univariate nature limits network-level insights. To overcome these limitations and gain insights into early pathways associated with rapid progression, we measured 1305 peripheral blood and 48 bronchoalveolar lavage proteins in individuals with COPD [n = 45, mean initial forced expiratory volume in one second (FEV1) 75.6 ± 17.4% predicted]. We applied a data-driven analysis pipeline, which enabled identification of protein signatures that predicted individuals at-risk for accelerated lung function decline (FEV1 decline ≥ 70 mL/year) ~ 6 years later, with high accuracy. Progression signatures suggested that early dysregulation in elements of the complement cascade is associated with accelerated decline. Our results propose potential biomarkers and early aberrant signaling mechanisms driving rapid progression in COPD.

Relationship Between Chronic Lung Disease Diagnosis and Susceptibility to E-Cigarette Use in Adults

BACKGROUND

Electronic cigarettes (e-cigarettes) are known to cause adverse pulmonary effects, yet paradoxically, the prevalence of e-cigarette use has increased among individuals with chronic lung disease. We assessed the relationship between chronic lung disease and the susceptibility to e-cigarette use in adults and determined if specific behavioral, social, and environmental factors influence this relationship.

METHODS

We enrolled adults age ≥ 18 y in Alabama with chronic lung disease from university medical clinics (n = 140) and individuals without chronic lung disease (n = 123, reference group) from January 2020-March 2021. A cross-sectional design was used where we administered questionnaires to collect sociodemographic information and assessed susceptibility to e-cigarette use, exposure to social and environmental factors (ie, advertisements, warning labels, special prices, others' e-cigarette vapors, use of an e-cigarette by others in the home, and visiting a web site or online discussion), and behavioral factors (ie, alcohol and cannabis use). Moderation analyses were conducted to determine if any of these factors would modify the association between chronic lung disease and susceptibility to e-cigarette use.

RESULTS

Susceptibility to e-cigarette use was higher among adults without chronic lung disease than among those with chronic lung disease. Noticing e-cigarette warning labels and visiting a web site or online discussion about e-cigarettes were significantly associated with an increased likelihood of susceptibility to using e-cigarettes in both groups. Exposure to e-cigarette vapor from close contacts, special pricing, living with someone who uses e-cigarettes, and cannabis use were significantly associated with an increased likelihood of susceptibility to e-cigarette use in individuals without chronic lung disease. However, our analyses did not indicate a statistically significant interaction between chronic lung disease and any social, environmental, or behavioral factors on susceptibility to e-cigarette use.

CONCLUSIONS

Individuals without chronic lung disease were more susceptible to e-cigarette use than those with chronic lung disease. Although the prevalence of some behavioral and environmental factors differed among individuals with and without chronic lung disease, these factors did not moderate the association between chronic lung disease and susceptibility to e-cigarette use. Longitudinal investigations are warranted to better test the temporal relationships between chronic lung disease, substance use, social and environmental factors, and the susceptibility to e-cigarette use among individuals with chronic lung disease to identify prevention strategies for this population.

Computed tomography measure of lung injury and future interstitial features: the CARDIA Lung Study

Introduction

Visually normal areas of the lung with high attenuation on computed tomography (CT) imaging, termed CT lung injury, may represent injured but not yet remodelled lung parenchyma. This prospective cohort study examined if CT lung injury is associated with future interstitial features on CT and restrictive spirometry abnormality among participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study.

Methods

CARDIA is a population-based cohort study. CT scans obtained at two time points were assessed objectively for amount of lung tissue characterised as CT lung injury and interstitial features. Restrictive spirometry was defined as having a forced vital capacity (FVC) <80% predicted with forced expiratory volume in 1 s/FVC ratio >70%.

Results

Among 2213 participants, the median percentage of lung tissue characterised as CT lung injury at a mean age of 40 years was 3.4% (interquartile range 0.8-18.0%). After adjustment for covariates, a 10% higher amount of CT lung injury at mean age 40 years was associated with a 4.37% (95% CI 3.99-4.74%) higher amount of lung tissue characterised as interstitial features at mean age 50 years. Compared to those with the lowest quartile of CT lung injury at mean age 40 years, there were higher odds of incident restrictive spirometry at mean age 55 years in quartile 2 (OR 2.05, 95% CI 1.20-3.48), quartile 3 (OR 2.80, 95% CI 1.66-4.72) and quartile 4 (OR 3.77, 95% CI 2.24-6.33).

Conclusions

CT lung injury is an early objective measure that indicates risk of future lung impairment.

Mortality Risk and Serious Cardiopulmonary Events in Moderate-to-Severe COPD: Post Hoc Analysis of the IMPACT Trial

Background

In the InforMing the Pathway of COPD Treatment (IMPACT) trial, single-inhaler fluticasone furoate (FF) /umeclidinium (UMEC) /vilanterol (VI) significantly reduced severe exacerbation rates and all-cause mortality (ACM) risk versus UMEC/VI among patients with chronic obstructive pulmonary disease (COPD). This post hoc analysis aimed to define the risk of ACM during and following a moderate/severe exacerbation, and further determine the benefit-risk profile of FF/UMEC/VI versus FF/VI and UMEC/VI using a cardiopulmonary composite adverse event (AE) endpoint.

Methods

The 52-week, double-blind IMPACT trial randomized patients with symptomatic COPD and ≥1 exacerbation in the prior year 2:2:1 to once-daily FF/UMEC/VI 100/62.5/25mcg, FF/VI 100/25mcg, or UMEC/VI 62.5/25mcg. Post hoc endpoints included the risk of ACM during, 1-90 and 91-365 days post moderate or severe exacerbation and time-to-first cardiopulmonary composite event.

Results

Of the 10,355 patients included, 5034 (49%) experienced moderate/severe exacerbations. Risk of ACM was significantly increased during a severe exacerbation event compared with baseline (hazard ratio [HR]: 41.22 [95% confidence interval (CI) 26.49-64.15]; p<0.001) but not significantly different at 1-90 days post-severe exacerbation (HR: 2.13 [95% CI: 0.86-5.29]; p=0.102). Moderate exacerbations did not significantly increase the risk of ACM during or after an exacerbation. Cardiopulmonary composite events occurred in 647 (16%), 636 (15%), and 356 (17%) patients receiving FF/UMEC/VI, FF/VI, and UMEC/VI, respectively; FF/UMEC/VI significantly reduced cardiopulmonary composite event risk versus UMEC/VI by 16.5% (95% CI: 5.0-26.7; p=0.006).

Conclusion

Results confirm a substantial mortality risk during severe exacerbations, and an underlying CV risk. FF/UMEC/VI significantly reduced the risk of a composite cardiopulmonary AE versus UMEC/VI.

Spatial transcriptomic profiling of coronary endothelial cells in SARS-CoV-2 myocarditis

Objectives

Our objective was to examine coronary endothelial and myocardial programming in patients with severe COVID-19 utilizing digital spatial transcriptomics.

Background

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has well-established links to thrombotic and cardiovascular events. Endothelial cell infection was initially proposed to initiate vascular events; however, this paradigm has sparked growing controversy. The significance of myocardial infection also remains unclear.

Methods

Autopsy-derived cardiac tissue from control (n = 4) and COVID-19 (n = 8) patients underwent spatial transcriptomic profiling to assess differential expression patterns in myocardial and coronary vascular tissue. Our approach enabled transcriptional profiling in situ with preserved anatomy and unaltered local SARS-CoV-2 expression. In so doing, we examined the paracrine effect of SARS-CoV-2 infection in cardiac tissue.

Results

We observed heterogeneous myocardial infection that tended to colocalize with CD31 positive cells within coronary capillaries. Despite these differences, COVID-19 patients displayed a uniform and unique myocardial transcriptional profile independent of local viral burden. Segmentation of tissues directly infected with SARS-CoV-2 showed unique, pro-inflammatory expression profiles including upregulated mediators of viral antigen presentation and immune regulation. Infected cell types appeared to primarily be capillary endothelial cells as differentially expressed genes included endothelial cell markers. However, there was limited differential expression within the endothelium of larger coronary vessels.

Conclusion

Our results highlight altered myocardial programming during severe COVID-19 that may in part be associated with capillary endothelial cells. However, similar patterns were not observed in larger vessels, diminishing endotheliitis, and endothelial activation as key drivers of cardiovascular events during COVID-19.

Prolonged, physiologically relevant nicotine concentrations in the airways of smokers

Nicotine from cigarette smoke is a biologically active molecule that has pleiotropic effects in the airway, which could play a role in smoking-induced lung disease. However, whether nicotine and its metabolites reach sustained, physiologically relevant concentrations on airway surfaces of smokers is not well defined. To address these issues, concentrations of nicotine, cotinine, and hydroxycotinine were measured by mass spectrometry (MS) in supernatants of induced sputum obtained from participants in the subpopulations and intermediate outcome measures in COPD study (SPIROMICS), an ongoing observational study that included never smokers, former smokers, and current smokers with and without chronic obstructive pulmonary disease (COPD). A total of 980 sputum supernatants were analyzed from 77 healthy never smokers, 494 former smokers (233 with COPD), and 396 active smokers (151 with COPD). Sputum nicotine, cotinine, and hydroxycotinine concentrations corresponded to self-reported smoking status and were strongly correlated to urine measures. A cutoff of ∼8-10 ng/mL of sputum cotinine distinguished never smokers from active smokers. Accounting for sample dilution during processing, active smokers had airway nicotine concentrations in the 70-850 ng/mL (∼0.5-5 µM) range, and concentrations remained elevated even in current smokers who had not smoked within 24 h. This study demonstrates that airway nicotine and its metabolites are readily measured in sputum supernatants and can serve as biological markers of smoke exposure. In current smokers, nicotine is present at physiologically relevant concentrations for prolonged periods, supporting a contribution to cigarette-induced airway disease.

Clinical risk factors for admission with Pseudomonas and multidrug-resistant Pseudomonas community-acquired pneumonia

Background

Microbial etiology for community-acquired pneumonia (CAP) is evolving with pathogens known for high CAP mortality e.g., Pseudomonas species. Chronic obstructive pulmonary disease (COPD) patients are at risk for hospitalization for CAP. Understanding regional patterns and risk factors for multidrug-resistant (MDR) Pseudomonas acquisition has implications for antimicrobial stewardship.

Objectives

To evaluate the regional epidemiology of MDR Pseudomonas CAP and its association with COPD.

Methods

We queried the electronic medical records of the University of Alabama at Birmingham Healthcare System to identify patients hospitalized for CAP with Pseudomonas positive respiratory samples between 01/01/2013–12/31/2019. Log binomial regression models were used to examine associations between COPD diagnosis and risk of Pseudomonas/MDR Pseudomonas CAP.

Results

Cohort consisted of 913 culture positive CAP cases aged 59-year (IQR:48–68), 61% (560) male, 60% (547) white, 65% (580) current/past smokers, and 42% (384) COPD. Prevalence of Pseudomonas CAP in culture positive CAP was 18% (167), MDR Pseudomonas CAP in Pseudomonas CAP was 22% (36), and yearly incidence of MDR Pseudomonas CAP was stable (p = 0.169). COPD was associated with Pseudomonas CAP (RR 1.39; 95% CI 1.01, 1.91; p = 0.041) but not with MDR Pseudomonas CAP (0.71; 95% CI 0.35, 1.45; p = 0.349). Stroke (RR 2.64; 95% CI 1.51, 4.61; p = 0.0006) and use of supplemental oxygen (RR 2.31; 95% CI 1.30, 4.12; p = 0.005) were associated with MDR Pseudomonas CAP.

Conclusion

Incidence of MDR Pseudomonas CAP was stable over time. COPD was associated with Pseudomonas CAP but not with MDR Pseudomonas CAP. Larger cohort studies are needed to confirm findings.

Outcome Expectancies and Resistance Self-Efficacy Mediate the Relationship Between Asthma Diagnosis and E-cigarette Use among Youth and Young Adults

Introduction: The use of electronic cigarettes (e-cigarettes) may exacerbate pulmonary complications in youth and young adults with asthma. We sought to identify the cognitive mechanisms that might explain e-cigarette use in this population. We hypothesized that e-cigarette outcome expectancies and e-cigarette resistance self-efficacy would mediate the relationship between asthma diagnosis and e-cigarette use in youth and young adults. Methods: We enrolled youth and young adults (15-25 years old) in Alabama with a clinical diagnosis of asthma (n = 130) or without a diagnosis of any chronic pulmonary disease (n = 115; reference group). Author-constructed and validated questionnaires (young adult e-cigarette use outcome expectancies and modified Self-efficacy Scale for Adolescent Smoking) were administered to collect demographic data and assess susceptibility to e-cigarette use as well as current use of e-cigarettes, e-cigarette outcome expectancies, and e-cigarette resistance self-efficacy. We then conducted structural equation modeling to test whether e-cigarette expectancies and e-cigarette resistance self-efficacy mediate the relationship between asthma and susceptibility to e-cigarette use as well as current e-cigarette use. Results: The frequency of the susceptibility to e-cigarette use and current e-cigarette use was lower among those with clinically diagnosed asthma than among those without asthma (35.8% vs 59.8% for susceptibility and 6.0% vs 18.2% for current use). Individuals with asthma reported weaker expectancies that e-cigarettes would make them feel relaxed which, in turn, was a significant predictor of lower susceptibility to e-cigarette use and current e-cigarette use, suggesting mediation. Finally, individuals with asthma demonstrated greater e-cigarette resistance self-efficacy in the context of social opportunities and friends' influence to use e-cigarettes. This self-efficacy was associated with lower susceptibility to e-cigarette use as well as current e-cigarette use. Conclusion: Although longitudinal studies are needed to determine relationships prospectively, targeted interventions that reduce outcome expectancies and increase resistance self-efficacy to e-cigarette use may further reduce e-cigarette use among youth and young adults with asthma.

Spatial transcriptomic profiling of coronary endothelial cells in SARS-CoV-2 myocarditis

OBJECTIVES

Our objective was to examine coronary endothelial and myocardial programming in patients with severe COVID-19 utilizing digital spatial transcriptomics.

BACKGROUND

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has well-established links to thrombotic and cardiovascular events. Endothelial cell infection was initially proposed to initiate vascular events; however, this paradigm has sparked growing controversy. The significance of myocardial infection also remains unclear.

METHODS

Autopsy-derived cardiac tissue from control (n = 4) and COVID-19 (n = 8) patients underwent spatial transcriptomic profiling to assess differential expression patterns in myocardial and coronary vascular tissue. Our approach enabled transcriptional profiling in situ with preserved anatomy and unaltered local SARS-CoV-2 expression. In so doing, we examined the paracrine effect of SARS-CoV-2 infection in cardiac tissue.

RESULTS

We observed heterogeneous myocardial infection that tended to colocalize with CD31 positive cells within coronary capillaries. Despite these differences, COVID-19 patients displayed a uniform and unique myocardial transcriptional profile independent of local viral burden. Segmentation of tissues directly infected with SARS-CoV-2 showed unique, pro-inflammatory expression profiles including upregulated mediators of viral antigen presentation and immune regulation. Infected cell types appeared to primarily be capillary endothelial cells as differentially expressed genes included endothelial cell markers. However, there was limited differential expression within the endothelium of larger coronary vessels.

CONCLUSIONS

Our results highlight altered myocardial programming during severe COVID-19 that may in part be associated with capillary endothelial cells. However, similar patterns were not observed in larger vessels, diminishing endotheliitis and endothelial activation as key drivers of cardiovascular events during COVID-19.

CONDENSED ABSTRACT

SARS-CoV-2 is linked to thrombotic and cardiovascular events; however, the mechanism remains uncertain. Our objective was to examine coronary endothelial and myocardial programming in patients with severe COVID-19 utilizing digital spatial transcriptomics. Autopsy-derived coronary arterial and cardiac tissues from control and COVID-19 patients underwent spatial transcriptomic profiling. Our approach enabled transcriptional profiling in situ with preserved anatomy and unaltered local SARS-CoV-2 expression. We observed unique, pro-inflammatory expression profiles among all COVID-19 patients. While heterogeneous viral expression was noted within the tissue, SARS-CoV-2 tended to colocalize with CD31 positive cells within coronary capillaries and was associated with unique expression profiles. Similar patterns were not observed in larger coronary vessels. Our results highlight altered myocardial programming during severe COVID-19 that may in part be associated with capillary endothelial cells. Such results diminish coronary arterial endotheliitis and endothelial activation as key drivers of cardiovascular events during COVID-19 infection.

LIST OF HIGHLIGHTS

SARS-CoV-2 has variable expression patterns within the myocardium of COVID-19 patientsSARS-CoV-2 infection induces a unique myocardial transcriptional programming independent of local viral burdenSARS-CoV-2 myocarditis is predominantly associated with capillaritis, and tissues directly infected with SARS-CoV-2 have unique, pro-inflammatory expression profilesDiffuse endothelial activation of larger coronary vessels was absent, diminishing large artery endotheliitis as a significant contributor to cardiovascular events during COVID-19 infection.

Spatial transcriptomic profiling of coronary endothelial cells in SARS-CoV-2 myocarditis

OBJECTIVES

Our objective was to examine coronary endothelial and myocardial programming in patients with severe COVID-19 utilizing digital spatial transcriptomics.

BACKGROUND

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has well-established links to thrombotic and cardiovascular events. Endothelial cell infection was initially proposed to initiate vascular events; however, this paradigm has sparked growing controversy. The significance of myocardial infection also remains unclear.

METHODS

Autopsy-derived cardiac tissue from control (n = 4) and COVID-19 (n = 8) patients underwent spatial transcriptomic profiling to assess differential expression patterns in myocardial and coronary vascular tissue. Our approach enabled transcriptional profiling in situ with preserved anatomy and unaltered local SARS-CoV-2 expression. In so doing, we examined the paracrine effect of SARS-CoV-2 infection in cardiac tissue.

RESULTS

We observed heterogeneous myocardial infection that tended to colocalize with CD31 positive cells within coronary capillaries. Despite these differences, COVID-19 patients displayed a uniform and unique myocardial transcriptional profile independent of local viral burden. Segmentation of tissues directly infected with SARS-CoV-2 showed unique, pro-inflammatory expression profiles including upregulated mediators of viral antigen presentation and immune regulation. Infected cell types appeared to primarily be capillary endothelial cells as differentially expressed genes included endothelial cell markers. However, there was limited differential expression within the endothelium of larger coronary vessels.

CONCLUSIONS

Our results highlight altered myocardial programming during severe COVID-19 that may in part be associated with capillary endothelial cells. However, similar patterns were not observed in larger vessels, diminishing endotheliitis and endothelial activation as key drivers of cardiovascular events during COVID-19.

CONDENSED ABSTRACT

SARS-CoV-2 is linked to thrombotic and cardiovascular events; however, the mechanism remains uncertain. Our objective was to examine coronary endothelial and myocardial programming in patients with severe COVID-19 utilizing digital spatial transcriptomics. Autopsy-derived coronary arterial and cardiac tissues from control and COVID-19 patients underwent spatial transcriptomic profiling. Our approach enabled transcriptional profiling in situ with preserved anatomy and unaltered local SARS-CoV-2 expression. We observed unique, pro-inflammatory expression profiles among all COVID-19 patients. While heterogeneous viral expression was noted within the tissue, SARS-CoV-2 tended to colocalize with CD31 positive cells within coronary capillaries and was associated with unique expression profiles. Similar patterns were not observed in larger coronary vessels. Our results highlight altered myocardial programming during severe COVID-19 that may in part be associated with capillary endothelial cells. Such results diminish coronary arterial endotheliitis and endothelial activation as key drivers of cardiovascular events during COVID-19 infection.

LIST OF HIGHLIGHTS

SARS-CoV-2 has variable expression patterns within the myocardium of COVID-19 patientsSARS-CoV-2 infection induces a unique myocardial transcriptional programming independent of local viral burdenSARS-CoV-2 myocarditis is predominantly associated with capillaritis, and tissues directly infected with SARS-CoV-2 have unique, pro-inflammatory expression profilesDiffuse endothelial activation of larger coronary vessels was absent, diminishing large artery endotheliitis as a significant contributor to cardiovascular events during COVID-19 infection.

Identification of Sputum Biomarkers Predictive of Pulmonary Exacerbations in COPD

BACKGROUND

Improved understanding of the pathways associated with airway pathophysiologic features in COPD will identify new predictive biomarkers and novel therapeutic targets.

RESEARCH QUESTION

Which physiologic pathways are altered in the airways of patients with COPD and will predict exacerbations?

STUDY DESIGN AND METHODS

We applied a mass spectrometric panel of metabolomic biomarkers related to mucus hydration and inflammation to sputa from the multicenter Subpopulations and Intermediate Outcome Measures in COPD Study. Biomarkers elevated in sputa from patients with COPD were evaluated for relationships to measures of COPD disease severity and their ability to predict future exacerbations.

RESULTS

Sputum supernatants from 980 patients were analyzed: 77 healthy nonsmokers, 341 smokers with preserved spirometry, and 562 patients with COPD (178 with Global Initiative on Chronic Obstructive Lung Disease [GOLD] stage 1 disease, 303 with GOLD stage 2 disease, and 81 with GOLD stage 3 disease) were analyzed. Biomarkers from multiple pathways were elevated in COPD and correlated with sputum neutrophil counts. Among the most significant analytes (false discovery rate, 0.1) were sialic acid, hypoxanthine, xanthine, methylthioadenosine, adenine, and glutathione. Sialic acid and hypoxanthine were associated strongly with measures of disease severity, and elevation of these biomarkers was associated with shorter time to exacerbation and improved prediction models of future exacerbations.

INTERPRETATION

Biomarker evaluation implicated pathways involved in mucus hydration, adenosine metabolism, methionine salvage, and oxidative stress in COPD airway pathophysiologic characteristics. Therapies that target these pathways may be of benefit in COPD, and a simple model adding sputum-soluble phase biomarkers improves prediction of pulmonary exacerbations.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01969344; URL: www.

CLINICALTRIALS

gov.

A Metabolomic Severity Score for Airflow Obstruction and Emphysema

Chronic obstructive pulmonary disease (COPD) is a disease with marked metabolic disturbance. Previous studies have shown the association between single metabolites and lung function for COPD, but whether a combination of metabolites could predict phenotype is unknown. We developed metabolomic severity scores using plasma metabolomics from the Metabolon platform from two US cohorts of ever-smokers: the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) (n = 648; training/testing cohort; 72% non-Hispanic, white; average age 63 years) and the COPDGene Study (n = 1120; validation cohort; 92% non-Hispanic, white; average age 67 years). Separate adaptive LASSO (adaLASSO) models were used to model forced expiratory volume at one second (FEV₁) and MESA-adjusted lung density using 762 metabolites common between studies. Metabolite coefficients selected by the adaLASSO procedure were used to create a metabolomic severity score (metSS) for each outcome. A total of 132 metabolites were selected to create a metSS for FEV₁. The metSS-only models explained 64.8% and 31.7% of the variability in FEV₁ in the training and validation cohorts, respectively. For MESA-adjusted lung density, 129 metabolites were selected, and metSS-only models explained 59.0% of the variability in the training cohort and 17.4% in the validation cohort. Regression models including both clinical covariates and the metSS explained more variability than either the clinical covariate or metSS-only models (53.4% vs. 46.4% and 31.6%) in the validation dataset. The metabolomic pathways for arginine biosynthesis; aminoacyl-tRNA biosynthesis; and glycine, serine, and threonine pathway were enriched by adaLASSO metabolites for FEV₁. This is the first demonstration of a respiratory metabolomic severity score, which shows how a metSS can add explanation of variance to clinical predictors of FEV₁ and MESA-adjusted lung density. The advantage of a comprehensive metSS is that it explains more disease than individual metabolites and can account for substantial collinearity among classes of metabolites. Future studies should be performed to determine whether metSSs are similar in younger, and more racially and ethnically diverse populations as well as whether a metabolomic severity score can predict disease development in individuals who do not yet have COPD.

Genetic variation in genes regulating skeletal muscle regeneration and tissue remodelling associated with weight loss in chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death globally. COPD patients with cachexia or weight loss have increased risk of death independent of body mass index (BMI) and lung function. We tested the hypothesis genetic variation is associated with weight loss in COPD using a genome-wide association study approach.

METHODS

Participants with COPD (N = 4308) from three studies (COPDGene, ECLIPSE, and SPIROMICS) were analysed. Discovery analyses were performed in COPDGene with replication in SPIROMICS and ECLIPSE. In COPDGene, weight loss was defined as self-reported unintentional weight loss > 5% in the past year or low BMI (BMI < 20 kg/m2 ). In ECLIPSE and SPIROMICS, weight loss was calculated using available longitudinal visits. Stratified analyses were performed among African American (AA) and Non-Hispanic White (NHW) participants with COPD. Single variant and gene-based analyses were performed adjusting for confounders. Fine mapping was performed using a Bayesian approach integrating genetic association results with linkage disequilibrium and functional annotation. Significant gene networks were identified by integrating genetic regions associated with weight loss with skeletal muscle protein-protein interaction (PPI) data.

RESULTS

At the single variant level, only the rs35368512 variant, intergenic to GRXCR1 and LINC02383, was associated with weight loss (odds ratio = 3.6, 95% confidence interval = 2.3-5.6, P = 3.2 × 10-8 ) among AA COPD participants in COPDGene. At the gene level in COPDGene, EFNA2 and BAIAP2 were significantly associated with weight loss in AA and NHW COPD participants, respectively. The EFNA2 association replicated among AA from SPIROMICS (P = 0.0014), whereas the BAIAP2 association replicated in NHW from ECLIPSE (P = 0.025). The EFNA2 gene encodes the membrane-bound protein ephrin-A2 involved in the regulation of developmental processes and adult tissue homeostasis such as skeletal muscle. The BAIAP2 gene encodes the insulin-responsive protein of mass 53 kD (IRSp53), a negative regulator of myogenic differentiation. Integration of the gene-based findings participants with PPI data revealed networks of genes involved in pathways such as Rho and synapse signalling.

CONCLUSIONS

The EFNA2 and BAIAP2 genes were significantly associated with weight loss in COPD participants. Collectively, the integrative network analyses indicated genetic variation associated with weight loss in COPD may influence skeletal muscle regeneration and tissue remodelling.

Supportive care of right ventricular failure due to fat embolism syndrome

Pulmonary fat embolism is a common phenomenon in cases of traumatic long bone fractures, with only a minority developing the more catastrophic Fat Embolism Syndrome (FES). Diagnosis is clinical and requires a high index of suspicion. Treatment remains under-investigated, with common interventions having low quality level-of-evidence and no mortality benefit. In severe cases, focus should be on supporting the failing right ventricle through use of inotropes, pulmonary vasodilators, and mechanical circulatory support. This requires a thorough understanding of the unique physiology through the pulmonary circulation.

•

Pulmonary fat embolism is a common phenomenon following long bone fracture. Only a minority develop the more serious complication Fat Embolism Syndrome (FES).

•

FES is a diagnosis of exclusion classically characterized by hypoxemia, altered mentation, and petechiae. Mortality is often a result of right ventricular (RV) failure.

•

The failing RV has unique physiology. Treatment focuses on supportive care through use of inotropes, pulmonary vasodilators, and mechanical circulatory devices.

Pulmonary Arterial Pruning and Longitudinal Change in Percent Emphysema and Lung Function: The Genetic Epidemiology of COPD Study

BACKGROUND

Pulmonary endothelial damage has been shown to precede the development of emphysema in animals, and vascular changes in humans have been observed in COPD and emphysema.

RESEARCH QUESTION

Is intraparenchymal vascular pruning associated with longitudinal progression of emphysema on CT imaging or decline in lung function over 5 years?

STUDY DESIGN AND METHODS

The Genetic Epidemiology of COPD Study enrolled ever smokers with and without COPD from 2008 through 2011. The percentage of emphysema-like lung, or "percent emphysema," was assessed at baseline and after 5 years on noncontrast CT imaging as the percentage of lung voxels < -950 Hounsfield units. An automated CT imaging-based tool assessed and classified intrapulmonary arteries and veins. Spirometry measures are postbronchodilator. Pulmonary arterial pruning was defined as a lower ratio of small artery volume (< 5 mm2 cross-sectional area) to total lung artery volume. Mixed linear models included demographics, anthropomorphics, smoking, and COPD, with emphysema models also adjusting for CT imaging scanner and lung function models adjusting for clinical center and baseline percent emphysema.

RESULTS

At baseline, the 4,227 participants were 60 ± 9 years of age, 50% were women, 28% were Black, 47% were current smokers, and 41% had COPD. Median percent emphysema was 2.1 (interquartile range, 0.6-6.3) and progressed 0.24 percentage points/y (95% CI, 0.22-0.26 percentage points/y) over 5.6 years. Mean FEV1 to FVC ratio was 68.5 ± 14.2% and declined 0.26%/y (95% CI, -0.30 to -0.23%/y). Greater pulmonary arterial pruning was associated with more rapid progression of percent emphysema (0.11 percentage points/y per 1-SD increase in arterial pruning; 95% CI, 0.09-0.16 percentage points/y), including after adjusting for baseline percent emphysema and FEV1. Arterial pruning also was associated with a faster decline in FEV1 to FVC ratio (-0.04%/y per 1-SD increase in arterial pruning; 95% CI, -0.008 to -0.001%/y).

INTERPRETATION

Pulmonary arterial pruning was associated with faster progression of percent emphysema and more rapid decline in FEV1 to FVC ratio over 5 years in ever smokers, suggesting that pulmonary vascular differences may be relevant in disease progression.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00608764; URL: www.clinicaltrials.gov.

Secondary polycythemia in chronic obstructive pulmonary disease: prevalence and risk factors

BACKGROUND

Secondary polycythemia is associated with cigarette smoking and chronic obstructive pulmonary disease (COPD). However, the prevalence of polycythemia in COPD and the contributing risk factors for polycythemia in COPD have not been extensively studied.

METHODS

We analyzed the presence of secondary polycythemia in current and former smokers with moderate to very severe COPD at the five-year follow-up visit in the observational COPDGene study. We used logistic regression to evaluate the association of polycythemia with age, sex, race, altitude, current smoking status, spirometry, diffusing capacity for carbon monoxide (DLCO), quantitative chest CT measurements (including emphysema, airway wall thickness, and pulmonary artery to aorta diameter ratio), resting hypoxemia, exercise-induced hypoxemia, and long-term oxygen therapy.

RESULTS

In a total of 1928 COPDGene participants with moderate to very severe COPD, secondary polycythemia was found in 97 (9.2%) male and 31 (3.5%) female participants. In a multivariable logistic model, severe resting hypoxemia (OR 3.50, 95% CI 1.41-8.66), impaired DLCO (OR 1.28 for each 10-percent decrease in DLCO % predicted, CI 1.09-1.49), male sex (OR 3.60, CI 2.20-5.90), non-Hispanic white race (OR 3.33, CI 1.71-6.50), current smoking (OR 2.55, CI 1.49-4.38), and enrollment in the Denver clinical center (OR 4.42, CI 2.38-8.21) were associated with higher risk for polycythemia. In addition, continuous (OR 0.13, CI 0.05-0.35) and nocturnal (OR 0.46, CI 0.21-0.97) supplemental oxygen were associated with lower risk for polycythemia. Results were similar after excluding participants with anemia and participants enrolled at the Denver clinical center.

CONCLUSIONS

In a large cohort of individuals with moderate to very severe COPD, male sex, current smoking, enrollment at the Denver clinical center, impaired DLCO, and severe hypoxemia were associated with increased risk for secondary polycythemia. Continuous or nocturnal supplemental oxygen use were associated with decreased risk for polycythemia.

Small Airway Disease and Emphysema Are Associated with Future Exacerbations in Smokers with CT-derived Bronchiectasis and COPD: Results from the COPDGene Cohort

Background Chronic obstructive pulmonary disease (COPD) and bronchiectasis can overlap and share pathologic features, such as small airway disease (SAD). Whether the presence of SAD and emphysema in smokers with CT-derived bronchiectasis is associated with exacerbations is unknown. Purpose To assess whether SAD and emphysema in smokers with CT-derived bronchiectasis are associated with future exacerbations. Materials and Methods SAD and emphysema were quantified using the parametric response map method in former and current heavy smokers with and without bronchiectasis at CT from the COPDGene Study (from July 2009 to July 2018). Exacerbations were prospectively assessed through biannual follow-up. An exacerbation was defined as an increase in or new onset of respiratory symptoms treated with antibiotics and/or corticosteroids. Severe exacerbations were defined as those that required hospitalization. The association of a high burden of SAD (≥15.6%) and high burden of emphysema (≥5%) at CT with exacerbations was assessed with generalized linear mixed models. Results Of 737 participants, 387 (median age, 64 years [interquartile range, 58-71 years]; 223 women) had CT-derived bronchiectasis. During a 9-year follow-up, after adjustment for age, sex, race, body mass index, current smoking status, pack-years, exacerbations before study entry, forced expiratory volume in 1 second, or FEV₁, and bronchiectasis severity CT score, high burden of SAD and high burden of emphysema were associated with a higher number of exacerbations per year (relative risk [RR], 1.89 [95% CI: 1.54, 2.33] and 1.37 [95% CI: 1.13, 1.66], respectively; P ≤ .001 for both). Results were comparable among participants with bronchiectasis meeting criteria for COPD (n = 197) (RR, 1.67 [95% CI: 1.23, 2.27] for high burden of SAD and 1.51 [95% CI: 1.20, 1.91] for high burden of emphysema; P ≤ .001 for both). Conclusion In smokers with CT-derived bronchiectasis and chronic obstructive pulmonary disease, structural damage to lung parenchyma and small airways was associated with a higher number of exacerbations per year. Clinical trial registration no. NCT00608764 © RSNA, 2021.

Binge Drinking Moderates the Association Between Chronic Lung Disease and E-Cigarette Use

BACKGROUND

There is a paucity of research on e-cigarette use among adults with chronic lung disease. Accordingly, little is known about the factors that may contribute to e-cigarette use in this population. The purpose of this study was to evaluate the relationship between chronic lung disease and e-cigarette use and to determine whether binge drinking moderates this relationship.

METHODS

Data were derived from the 2018 Behavioral Risk Factor Surveillance System (BRFSS). Logistic regression was used to test the association between chronic lung disease status and e-cigarette use, controlling for demographic variables and chronic health conditions. We conducted moderation analyses to test the hypothesis that the association between chronic lung disease and lifetime e-cigarette use would be modified by binge drinking.

RESULTS

The prevalence of lifetime e-cigarette use was higher among adults with chronic lung disease than among those without, and more frequent binge drinking was associated with an increased likelihood of lifetime e-cigarette use independent of chronic lung disease status. Binge drinking moderated the relationship between chronic lung disease and lifetime use of e-cigarettes such that the association between chronic lung disease and e-cigarette use was weaker among those who engaged in more episodes of binge drinking in the past 30 d. Among those without chronic lung disease, binge drinking was associated with an increased likelihood of e-cigarette use.

CONCLUSIONS

E-cigarette use appears to be more common among adults with chronic lung disease. Although binge drinking was positively associated with e-cigarette use, more frequent binge drinking weakened the relationship between chronic lung disease and e-cigarette use. Though future studies are needed to determine precisely how binge drinking affects this association, it is possible that individuals with chronic lung disease who binge drink more frequently use e-cigarettes less frequently, despite an increased likelihood of having ever used an e-cigarette. (ClinicalTrials.gov registration NCT04135404.).

Association of plasma mitochondrial DNA with COPD severity and progression in the SPIROMICS cohort

BACKGROUND

There is a lack of mechanism-driven, clinically relevant biomarkers in chronic obstructive pulmonary disease (COPD). Mitochondrial dysfunction, a proposed disease mechanism in COPD, is associated with the release of mitochondrial DNA (mtDNA), but plasma cell-free mtDNA has not been previously examined prospectively for associations with clinical COPD measures.

METHODS

P-mtDNA, defined as copy number of mitochondrially-encoded NADH dehydrogenase-1 (MT-ND1) gene, was measured by real-time quantitative PCR in 700 plasma samples from participants enrolled in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) cohort. Associations between p-mtDNA and clinical disease parameters were examined, adjusting for age, sex, smoking status, and for informative loss to follow-up.

RESULTS

P-mtDNA levels were higher in participants with mild or moderate COPD, compared to smokers without airflow obstruction, and to participants with severe COPD. Baseline increased p-mtDNA levels were associated with better CAT scores in female smokers without airflow obstruction and female participants with mild or moderate COPD on 1-year follow-up, but worse 6MWD in females with severe COPD. Higher p-mtDNA levels were associated with better 6MWD in male participants with severe COPD. These associations were no longer significant after adjusting for informative loss to follow-up.

CONCLUSION

In this study, p-mtDNA levels associated with baseline COPD status but not future changes in clinical COPD measures after accounting for informative loss to follow-up. To better characterize mitochondrial dysfunction as a potential COPD endotype, these results should be confirmed and validated in future studies.

TRIAL REGISTRATION

 ClinicalTrials.gov NCT01969344 (SPIROMICS).

Prolyl endopeptidase contributes to early neutrophilic inflammation in acute myocardial transplant rejection

Altered inflammation and tissue remodeling are cardinal features of cardiovascular disease and cardiac transplant rejection. Neutrophils have increasingly been understood to play a critical role in acute rejection and early allograft failure; however, discrete mechanisms that drive this damage remain poorly understood. Herein, we demonstrate that early acute cardiac rejection increases allograft prolyl endopeptidase (PE) in association with de novo production of the neutrophil proinflammatory matrikine proline-glycine-proline (PGP). In a heterotopic murine heart transplant model, PGP production and PE activity were associated with early neutrophil allograft invasion and allograft failure. Pharmacologic inhibition of PE with Z-Pro-prolinal reduced PGP, attenuated early neutrophil graft invasion, and reduced proinflammatory cytokine expression. Importantly, these changes helped preserve allograft rejection-free survival and function. Notably, within 2 independent patient cohorts, both PGP and PE activity were increased among patients with biopsy-proven rejection. The observed induction of PE and matrikine generation provide a link between neutrophilic inflammation and cardiovascular injury, represent a potential target to reduce allogenic immune responses, and uncover a mechanism of cardiovascular disease that has been previously unrecognized to our knowledge.

Lung microbiota associations with clinical features of COPD in the SPIROMICS cohort

Chronic obstructive pulmonary disease (COPD) is heterogeneous in development, progression, and phenotypes. Little is known about the lung microbiome, sampled by bronchoscopy, in milder COPD and its relationships to clinical features that reflect disease heterogeneity (lung function, symptom burden, and functional impairment). Using bronchoalveolar lavage fluid collected from 181 never-smokers and ever-smokers with or without COPD (GOLD 0-2) enrolled in the SubPopulations and InteRmediate Outcome Measures In COPD Study (SPIROMICS), we find that lung bacterial composition associates with several clinical features, in particular bronchodilator responsiveness, peak expiratory flow rate, and forced expiratory flow rate between 25 and 75% of FVC (FEF_25–75). Measures of symptom burden (COPD Assessment Test) and functional impairment (six-minute walk distance) also associate with disparate lung microbiota composition. Drivers of these relationships include members of the Streptococcus, Prevotella, Veillonella, Staphylococcus, and Pseudomonas genera. Thus, lung microbiota differences may contribute to airway dysfunction and airway disease in milder COPD.

Current smoking with or without chronic bronchitis is independently associated with goblet cell hyperplasia in healthy smokers and COPD subjects

COPD, chronic bronchitis (CB) and active smoking have all been associated with goblet cell hyperplasia (GCH) in small studies. Active smoking is strongly associated with CB, but there is a disconnect between CB clinical symptoms and pathology. Chronic cough and sputum production poorly correlate with the presence of GCH or COPD. We hypothesized that the primary determinant of GCH in ever smokers with or without airflow obstruction is active smoking. Goblet Cell Density (GCD) was measured in 71 current or former smokers [32 subjects without COPD and 39 COPD subjects]. Endobronchial mucosal biopsies were stained with Periodic Acid Schiff-Alcian Blue, and GCD was measured as number of goblet cells/mm basement membrane. GCD was divided into tertiles based on log₁₀ transformed values. Log₁₀GCD was greater in current smokers compared to former smokers. Those with classically defined CB or SGRQ defined CB had a greater log₁₀ GCD compared to those without CB. Current smoking was independently associated with tertile 3 (high log₁₀GCD) whereas CB was not in multivariable regression when adjusting for lung function and demographics. These results suggest that GCH is induced by active smoke exposure and does not necessarily correlate with the clinical symptoms of CB.

Increased airway iron parameters and risk for exacerbation in COPD: an analysis from SPIROMICS

Levels of iron and iron-related proteins including ferritin are higher in the lung tissue and lavage fluid of individuals with chronic obstructive pulmonary disease (COPD), when compared to healthy controls. Whether more iron in the extracellular milieu of the lung associates with distinct clinical phenotypes of COPD, including increased exacerbation susceptibility, is unknown. We measured iron and ferritin levels in the bronchoalveolar lavage fluid (BALF) of participants enrolled in the SubPopulations and InteRmediate Outcome Measures In COPD (SPIROMICS) bronchoscopy sub-study (n = 195). BALF Iron parameters were compared to systemic markers of iron availability and tested for association with FEV1 % predicted and exacerbation frequency. Exacerbations were modelled using a zero-inflated negative binomial model using age, sex, smoking, and FEV1 % predicted as clinical covariates. BALF iron and ferritin were higher in participants with COPD and in smokers without COPD when compared to non-smoker control participants but did not correlate with systemic iron markers. BALF ferritin and iron were elevated in participants who had COPD exacerbations, with a 2-fold increase in BALF ferritin and iron conveying a 24% and 2-fold increase in exacerbation risk, respectively. Similar associations were not observed with plasma ferritin. Increased airway iron levels may be representative of a distinct pathobiological phenomenon that results in more frequent COPD exacerbation events, contributing to disease progression in these individuals.

Association of e-cigarette use with oral health: a population-based cross-sectional questionnaire study

BACKGROUND

The impact of daily or intermittent electronic cigarette (e-cigarette) use on oral health is unknown.

METHODS

We performed a cross-sectional analysis using the 2016 Behavioral Risk Factor Surveillance System data. Poor oral health was determined by the number of permanent teeth removed due to non-traumatic causes, and e-cigarette use determined by daily or intermittent use within 30 days prior to survey administration. We performed logistic regression analysis to test associations between e-cigarette use and oral health with adjustment for factors associated with poor oral health, survey clustering, strata and weight.

RESULTS

We included survey responses from 456 343 adults. Over half of respondents (51.5%) reported having at least one permanent tooth removed because of tooth decay or gum disease in their lifetime. Daily e-cigarette use was reported by 4957 (1.1%) of respondents. In multivariable analysis, daily e-cigarette use, was independently associated with a 78% higher odds of poor oral health (adjusted OR = 1.78, 95% CI: 1.39-2.30; P < 0.001).

CONCLUSIONS

In a population-based health survey of US adults, self-reported health behavior and outcomes, daily use, but not intermittent use of e-cigarettes was independently associated with poor oral health. Care must be exercised in seeking 'healthier' cigarette alternatives.

Clinical Phenotypes of Atopy and Asthma in COPD: A Meta-analysis of SPIROMICS and COPDGene

BACKGROUND

Little is known about the concordance of atopy with asthma COPD overlap. Among individuals with COPD, a better understanding of the phenotypes characterized by asthma overlap and atopy is needed to better target therapies.

RESEARCH QUESTION

What is the overlap between atopy and asthma status among individuals with COPD, and how are categories defined by the presence of atopy and asthma status associated with clinical and radiologic phenotypes and outcomes in the Genetic Epidemiology of COPD Study (COPDGene) and Subpopulation and Intermediate Outcome Measures in COPD Study (SPIROMICS)?

STUDY DESIGN AND METHODS

Four hundred three individuals with COPD from SPIROMICS and 696 individuals from COPDGene with data about specific IgEs to 10 common allergens and mixes (simultaneous assessment of combination of allergens in similar category) were included. Comparison groups were defined by atopic and asthma status (neither, atopy alone, atopic asthma, nonatopic asthma, with atopy defined as any positive specific IgE (≥0.35 KU/L) to any of the 10 allergens or mixes and asthma defined as self-report of doctor-diagnosed current asthma). Multivariable regression analyses (linear, logistic, and zero inflated negative binomial where appropriate) adjusted for age, sex, race, lung function, smoking status, pack-years smoked, and use of inhaled corticosteroids were used to determine characteristics of groups and relationship with outcomes (exacerbations, clinical outcomes, CT metrics) separately in COPDGene and SPIROMICS, and then adjusted results were combined using meta-analysis.

RESULTS

The prevalence of atopy was 35% and 36% in COPD subjects from SPIROMICS and COPDGene, respectively, and less than 50% overlap was seen between atopic status with asthma in both cohorts. In meta-analysis, individuals with nonatopic asthma had the most impaired symptom scores (effect size for St. George's Respiratory Questionnaire total score, 4.2; 95% CI, 0.4-7.9; effect size for COPD Assessment Test score, 2.8; 95% CI, 0.089-5.4), highest risk for exacerbations (incidence rate ratio, 1.41; 95% CI, 1.05-1.88) compared with the group without atopy or asthma. Those with atopy and atopic asthma were not at increased risk for adverse outcomes.

INTERPRETATION

Asthma and atopy had incomplete overlap among former and current smokers with COPD in COPDGene and SPIROMICS. Nonatopic asthma was associated with adverse outcomes and exacerbation risk in COPD, whereas groups having atopy alone and atopic asthma had less risk.

Smaller Left Ventricle Size at Noncontrast CT Is Associated with Lower Mortality in COPDGene Participants

Background Smokers with chronic obstructive pulmonary disease (COPD) have smaller left ventricles (LVs) due to reduced preload. Skeletal muscle wasting is also common in COPD, but less is known about its contribution to LV size. Purpose To explore the relationships between CT metrics of emphysema, venous vascular volume, and sarcopenia with the LV epicardial volume (LV_EV) (myocardium and chamber) estimated from chest CT images in participants with COPD and then to determine the clinical relevance of the LV_EV in multivariable models, including sex and anthropomorphic metrics. Materials and Methods The COPDGene study (ClinicalTrials.gov identifier: NCT00608764) is an ongoing prospective longitudinal observational investigation that began in 2006. LV_EV, distal pulmonary venous blood volume for vessels smaller than 5 mm² in cross section (BV5), CT emphysema, and pectoralis muscle area were retrospectively extracted from 3318 nongated, unenhanced COPDGene CT scans. Multivariable linear and Cox regression models were used to explore the association between emphysema, venous BV5, pectoralis muscle area, and LV_EV as well as the association of LV_EV with health status using the St George's Respiratory Questionnaire, 6-minute walk distance, and all-cause mortality. Results The median age of the cohort was 64 years (interquartile range, 57-70 years). Of the 2423 participants, 1806 were men and 617 were African American. The median LV_EV between Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1 and GOLD 4 COPD was reduced by 13.9% in women and 17.7% in men (P < .001 for both). In fully adjusted models, higher emphysema percentage (β = -4.2; 95% confidence interval [CI]: -5.0, -3.4; P < .001), venous BV5 (β = 7.0; 95% CI: 5.7, 8.2; P < .001), and pectoralis muscle area (β = 2.7; 95% CI: 1.2, 4.1; P < .001) were independently associated with reduced LV_EV. Reductions in LV_EV were associated with improved health status (β = 0.3; 95% CI: 0.1, 0.4) and 6-minute walk distance (β = -12.2; 95% CI: -15.2, -9.3). These effects were greater in women than in men. The effect of reduced LV_EV on mortality (hazard ratio: 1.07; 95% CI: 1.05, 1.09) did not vary by sex. Conclusion In women more than men with chronic obstructive pulmonary disease, a reduction in the estimated left ventricle epicardial volume correlated with a loss of pulmonary venous vasculature, greater pectoralis muscle sarcopenia, and lower all-cause mortality. © RSNA, 2020 Online supplemental material is available for this article.

Heme metabolism genes Downregulated in COPD Cachexia

INTRODUCTION

Cachexia contributes to increased mortality and reduced quality of life in Chronic Obstructive Pulmonary Disease (COPD) and may be associated with underlying gene expression changes. Our goal was to identify differential gene expression signatures associated with COPD cachexia in current and former smokers.

METHODS

We analyzed whole-blood gene expression data from participants with COPD in a discovery cohort (COPDGene, N = 400) and assessed replication (ECLIPSE, N = 114). To approximate the consensus definition using available criteria, cachexia was defined as weight-loss > 5% in the past 12 months or low body mass index (BMI) (< 20 kg/m2) and 1/3 criteria: decreased muscle strength (six-minute walk distance < 350 m), anemia (hemoglobin < 12 g/dl), and low fat-free mass index (FFMI) (< 15 kg/m2 among women and < 17 kg/m2 among men) in COPDGene. In ECLIPSE, cachexia was defined as weight-loss > 5% in the past 12 months or low BMI and 3/5 criteria: decreased muscle strength, anorexia, abnormal biochemistry (anemia or high c-reactive protein (> 5 mg/l)), fatigue, and low FFMI. Differential gene expression was assessed between cachectic and non-cachectic subjects, adjusting for age, sex, white blood cell counts, and technical covariates. Gene set enrichment analysis was performed using MSigDB.

RESULTS

The prevalence of COPD cachexia was 13.7% in COPDGene and 7.9% in ECLIPSE. Fourteen genes were differentially downregulated in cachectic versus non-cachectic COPD patients in COPDGene (FDR < 0.05) and ECLIPSE (FDR < 0.05).

DISCUSSION

Several replicated genes regulating heme metabolism were downregulated among participants with COPD cachexia. Impaired heme biosynthesis may contribute to cachexia development through free-iron buildup and oxidative tissue damage.

Proline-Glycine-Proline Peptides Are Critical in the Development of Smoke-induced Emphysema

Chronic obstructive pulmonary disease (COPD) is a major cause of mortality worldwide and is characterized by an excessive airway neutrophilic response. The neutrophil chemoattractant proline-glycine-proline (PGP) and its more potent acetylated form (acPGP) have been found to be elevated in patients with COPD and act via CXCR2. Here, we investigated the impact of neutralizing PGP peptides in a murine model for emphysema. The PGP-neutralizing peptide l-arginine-threonine-arginine (RTR) was used first in a 6-week model of cigarette smoke exposure, where it attenuated lung inflammation. Then, in a model of chronic smoke exposure, mice were exposed to cigarette smoke and RTR treatment was initiated after 10 weeks of smoke exposure. This treatment was continued together with smoke exposure for another 13 weeks, for a total of 23 weeks of smoke exposure. RTR significantly inhibited neutrophil and macrophage influx into the lungs in the 6-week model of exposure. RTR also attenuated the development of emphysema, normalized lung volumes, and reduced right ventricular hypertrophy in the chronic exposure model. Murine epithelia expressed CXCR2, and this expression was increased after smoke exposure. In vitro, human bronchial epithelial cells also demonstrated robust expression of CXCR2, and stimulation of primary human bronchial epithelial cells with acPGP led to increased release of MMP-9 and IL-8. Overall, these results provide evidence that acPGP plays a critical role during the development of emphysema in cigarette smoke-induced injury, and highlight a new epithelial mechanism by which acPGP augments neutrophilic inflammation.

Practical recommendations for the use of beta-blockers in chronic obstructive pulmonary disease

INTRODUCTION

Controversies regarding the use of beta-blocker in chronic obstructive pulmonary disease (COPD) have been longstanding and based on inconsistent data. COPD and cardiovascular disease have many shared risk factors and potentially overlapping pathophysiologic mechanisms. Beta-blockers, a mainstay of treatment in ischemic heart disease, congestive heart failure, and cardiac arrhythmia, remain underutilized in COPD patients despite considerable evidence of safety. Furthermore, observational studies indicated the potential benefits of beta-blockers in COPD via a variety of possible mechanisms. Recently, a randomized controlled trial of metoprolol versus placebo failed to show a reduction in COPD exacerbation risk in subjects with moderate to severe COPD and no absolute indication for beta-blocker use.

AREAS COVERED

Physiology of beta-adrenergic receptors, links between COPD and cardiovascular disease, and the role of beta-blockers in COPD management are discussed.

EXPERT COMMENTARY

Beta-blockers should not be used to treat COPD patients who do not have conditions with clear guideline-directed recommendations for their use. Vigilance is recommended in prescribing these medications for indications where another drug class could be utilized.

Associations Among 25-Hydroxyvitamin D Levels, Lung Function, and Exacerbation Outcomes in COPD: An Analysis of the SPIROMICS Cohort

BACKGROUND

The relationship between 25-hydroxyvitamin D (25-OH-vitamin D) and COPD outcomes remains unclear. Using the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS), we determined associations among baseline 25-OH-vitamin D and cross-sectional and longitudinal lung function and COPD exacerbations.

METHODS

Serum 25-OH-vitamin D level was measured in stored samples from 1,609 SPIROMICS participants with COPD. 25-OH-vitamin D levels were modeled continuously and dichotomized as deficient (< 20 ng/mL) vs not deficient (≥ 20 ng/mL). Outcomes of interest included % predicted FEV1 (current and 1-year longitudinal decline) and COPD exacerbations (separately any and severe, occurring in prior year and first year of follow-up).

RESULTS

Vitamin D deficiency was present in 21% of the cohort and was more prevalent in the younger, active smokers, and blacks. Vitamin D deficiency was independently associated with lower % predicted FEV1 (by 4.11%) at enrollment (95% CI, -6.90% to -1.34% predicted FEV1; P = .004), 1.27% predicted greater rate of FEV1 decline after 1 year (95% CI, -2.32% to -0.22% predicted/y; P = .02), and higher odds of any COPD exacerbation in the prior year (OR, 1.32; 95% CI, 1.00-1.74; P = .049). Each 10-ng/mL decrease in 25-OH-vitamin D was associated with lower baseline lung function (-1.04% predicted; 95% CI, -1.96% to -0.12% predicted; P = .03) and increased odds of any exacerbation in the year before enrollment (OR, 1.11; 95% CI, 1.01-1.22; P = .04).

CONCLUSIONS

Vitamin D deficiency is associated with worse cross-sectional and longitudinal lung function and increased odds of prior COPD exacerbations. These findings identify 25-OH-vitamin D levels as a potentially useful marker of adverse COPD-related outcomes.

Pulmonary artery enlargement is associated with pulmonary hypertension and decreased survival in severe cystic fibrosis: A cohort study

BACKGROUND

Pulmonary artery (PA) enlargement, defined as pulmonary artery to ascending aorta diameter ratio (PA:A)>1 on computed tomography (CT), is a marker of pulmonary vascular disease in chronic lung diseases. PA enlargement is prevalent in cystic fibrosis (CF), but its relationship to hemodynamics and prognostic utility in severe CF are unknown. We hypothesized that the PA:A would have utility in identifying pulmonary hypertension (PH) in severe CF and that PA enlargement would be associated with reduced transplant-free survival.

METHODS

We conducted a retrospective study of adults with CF undergoing lung transplant evaluation at a single center between 2000 and 2015. CT, right heart catheterization (RHC), and clinical data were collected. The PA:A was measured from a single CT slice. We measured associations between PA:A and invasive hemodynamic parameters including PH defined as a mPAP ≥25mmHg using adjusted linear and logistic regression models. Kaplan-Meier and adjusted Cox regression models were used to measure associations between PA:A>1, RHC-defined PH, and transplant-free survival in severe CF.

RESULTS

We analyzed 78 adults with CF that had CT scans available for review, including 44 that also had RHC. RHC-defined PH defined as a mPAP ≥25mmHg was present in 36% of patients with CF undergoing transplant evaluation. The PA:A correlated with mPAP (r = 0.73; 95% CI 3.87-7.80; p<0.001) and PVR (r = 0.42, p = 0.005) and the PA:A>1 was an independent predictor of PH (aOR 4.50; 95% CI 1.05-19.2; p = 0.042). PA:A>1 was independently associated with increased hazards for death or transplant (aHR 2.69; 95% CI 1.41-5.14; P = 0.003). The presence of mPAP ≥25mmHg was independently associated with decreased survival in this cohort.

CONCLUSIONS

PA enlargement is associated with pulmonary hemodynamics and PH in severe CF. PA enlargement is an independent prognostic indicator of PH and decreased survival in this population.

Association of urine mitochondrial DNA with clinical measures of COPD in the SPIROMICS cohort

BACKGROUNDMitochondrial dysfunction, a proposed mechanism of chronic obstructive pulmonary disease (COPD) pathogenesis, is associated with the leakage of mitochondrial DNA (mtDNA), which may be detected extracellularly in various bodily fluids. Despite evidence for the increased prevalence of chronic kidney disease in COPD subjects and for mitochondrial dysfunction in the kidneys of murine COPD models, whether urine mtDNA (u-mtDNA) associates with measures of disease severity in COPD is unknown.METHODSCell-free u-mtDNA, defined as copy number of mitochondrially encoded NADH dehydrogenase-1 (MTND1) gene, was measured by quantitative PCR and normalized to urine creatinine in cell-free urine samples from participants in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) cohort. Urine albumin/creatinine ratios (UACR) were measured in the same samples. Associations between u-mtDNA, UACR, and clinical disease parameters - including FEV1 % predicted, clinical measures of exercise tolerance, respiratory symptom burden, and chest CT measures of lung structure - were examined.RESULTSU-mtDNA and UACR levels were measured in never smokers (n = 64), smokers without airflow obstruction (n = 109), participants with mild/moderate COPD (n = 142), and participants with severe COPD (n = 168). U-mtDNA was associated with increased respiratory symptom burden, especially among smokers without COPD. Significant sex differences in u-mtDNA levels were observed, with females having higher u-mtDNA levels across all study subgroups. U-mtDNA associated with worse spirometry and CT emphysema in males only and with worse respiratory symptoms in females only. Similar associations were not found with UACR.CONCLUSIONU-mtDNA levels may help to identify distinct clinical phenotypes and underlying pathobiological differences in males versus females with COPD.TRIAL REGISTRATIONThis study has been registered at ClinicalTrials.gov ( NCT01969344).FUNDINGUS NIH, National Heart, Lung and Blood Institute, supplemented by contributions made through the Foundation for the NIH and the COPD Foundation from AstraZeneca/MedImmune, Bayer, Bellerophon Therapeutics, Boehringer-Ingelheim Pharmaceuticals Inc., Chiesi Farmaceutici S.p.A., Forest Research Institute Inc., GlaxoSmithKline, Grifols Therapeutics Inc., Ikaria Inc., Novartis Pharmaceuticals Corporation, Nycomed GmbH, ProterixBio, Regeneron Pharmaceuticals Inc., Sanofi, Sunovion, Takeda Pharmaceutical Company, and Theravance Biopharma and Mylan.

Plasma Cathelicidin is Independently Associated with Reduced Lung Function in COPD: Analysis of the Subpopulations and Intermediate Outcome Measures in COPD Study Cohort

Ratrionale

The antimicrobial peptide cathelicidin, also known in humans as LL-37, is a defensin secreted by immune and airway epithelial cells. Deficiencies in this peptide may contribute to adverse pulmonary outcomes in chronic obstructive pulmonary disease (COPD).

Objectives

Using clinical and biological samples from the SubPopulations and InteRmediate Outcome Measures In COPD Study (SPIROMICS), we assessed the associations of plasma cathelicidin levels with cross-sectional and longitudinal COPD outcomes.

Methods

A total of 1609 SPIROMICS participants with COPD and available plasma samples were analyzed. Cathelicidin was modeled dichotomously (lowest quartile [< 50 ng/ml] versus highest 75% [≥ 50 ng/ml]) and continuously per 10 ng/ml. Fixed-effect multilevel regression analyses were used to assess associations between cathelicidin and cross-sectional as well as longitudinal lung function. The associations between cathelicidin and participant-reported retrospective and prospective COPD exacerbations were assessed via logistic regression.

Measurements and Main Results

Cathelicidin < 50 ng/ml (N=383) was associated with female sex, black race, and lower body mass index (BMI).At baseline,cathelicidin < 50 ng/ml was independently associated with 3.55% lower % predicted forced expiratory volume in 1 second (FEV₁)(95% confidence interval [CI] -6.22% to -0.88% predicted; p=0.01), while every 10 ng/ml lower cathelicidin was independently associated with 0.65% lower % predicted FEV₁ (95% CI -1.01% to -0.28% predicted; p< 0.001). No independent associations with longitudinal lung function decline or participant-reported COPD exacerbations were observed.

Conclusions

Reduced cathelicidin is associated with lower lung function at baseline. Plasma cathelicidin may potentially identify COPD patients at increased risk for more severe lung disease.

Metoprolol for the Prevention of Acute Exacerbations of COPD

BACKGROUND

Observational studies suggest that beta-blockers may reduce the risk of exacerbations and death in patients with moderate or severe chronic obstructive pulmonary disease (COPD), but these findings have not been confirmed in randomized trials.

METHODS

In this prospective, randomized trial, we assigned patients between the ages of 40 and 85 years who had COPD to receive either a beta-blocker (extended-release metoprolol) or placebo. All the patients had a clinical history of COPD, along with moderate airflow limitation and an increased risk of exacerbations, as evidenced by a history of exacerbations during the previous year or the prescribed use of supplemental oxygen. We excluded patients who were already taking a beta-blocker or who had an established indication for the use of such drugs. The primary end point was the time until the first exacerbation of COPD during the treatment period, which ranged from 336 to 350 days, depending on the adjusted dose of metoprolol.

RESULTS

A total of 532 patients underwent randomization. The mean (±SD) age of the patients was 65.0±7.8 years; the mean forced expiratory volume in 1 second (FEV1) was 41.1±16.3% of the predicted value. The trial was stopped early because of futility with respect to the primary end point and safety concerns. There was no significant between-group difference in the median time until the first exacerbation, which was 202 days in the metoprolol group and 222 days in the placebo group (hazard ratio for metoprolol vs. placebo, 1.05; 95% confidence interval [CI], 0.84 to 1.32; P = 0.66). Metoprolol was associated with a higher risk of exacerbation leading to hospitalization (hazard ratio, 1.91; 95% CI, 1.29 to 2.83). The frequency of side effects that were possibly related to metoprolol was similar in the two groups, as was the overall rate of nonrespiratory serious adverse events. During the treatment period, there were 11 deaths in the metoprolol group and 5 in the placebo group.

CONCLUSIONS

Among patients with moderate or severe COPD who did not have an established indication for beta-blocker use, the time until the first COPD exacerbation was similar in the metoprolol group and the placebo group. Hospitalization for exacerbation was more common among the patients treated with metoprolol. (Funded by the Department of Defense; BLOCK COPD ClinicalTrials.gov number, NCT02587351.).

Activated PMN Exosomes: Pathogenic Entities Causing Matrix Destruction and Disease in the Lung

Here, we describe a novel pathogenic entity, the activated PMN (polymorphonuclear leukocyte, i.e., neutrophil)-derived exosome. These CD63⁺/CD66b⁺ nanovesicles acquire surface-bound neutrophil elastase (NE) during PMN degranulation, NE being oriented in a configuration resistant to α1-antitrypsin (α1AT). These exosomes bind and degrade extracellular matrix (ECM) via the integrin Mac-1 and NE, respectively, causing the hallmarks of chronic obstructive pulmonary disease (COPD). Due to both ECM targeting and α1AT resistance, exosomal NE is far more potent than free NE. Importantly, such PMN-derived exosomes exist in clinical specimens from subjects with COPD but not healthy controls and are capable of transferring a COPD-like phenotype from humans to mice in an NE-driven manner. Similar findings were observed for another neutrophil-driven disease of ECM remodeling (bronchopulmonary dysplasia [BPD]). These findings reveal an unappreciated role for exosomes in the pathogenesis of disorders of ECM homeostasis such as COPD and BPD, providing a critical mechanism for proteolytic damage.