Alejandro Comellas

Figure S2. (a) Internal properties in different clustering methods to find the best clustering approaches as well as the optimal number of clusters; (b) Bootstrapping stability analysis between K-means and hierarchical clustering with 4 or 5 numbers of clusters. (DOCX 58 kb)

Figure S1. Cigarette smoke extract alone does not increase bacterial growth. (A) S. aureus growth overnight in the presence of increasing concentrations of CSE assessed by CFU. (B) P. aeruginosa overnight growth in the presence of increasing concentrations of CSE assessed by CFU. (TIFF 601Â kb)

BACKGROUND Mild expiratory flow limitation may not be recognized using traditional spirometric criteria based on the ratio of Forced Expiratory Volume in 1 second (FEV1) to Forced Vital Capacity (FVC). RESEARCH QUESTION Does slow vital capacity (SVC) instead of FVC increase the sensitivity of spirometry to identify patients with early or mild obstructive lung disease? STUDY DESIGN AND METHODS We included 854 current and former smokers from the SPIROMICS cohort with a post-bronchodilator FEV1/FVC≥0.7 and FEV1%predicted≥80% at enrollment. We compared baseline characteristics, chest CT features, exacerbations, and progression to COPD (post-bronchodilator FEV1/FVC<0.7) during the follow-up period between 734 participants with post-bronchodilator FEV1/SVC≥0.7 and 120 with post-bronchodilator FEV1/SVC<0.7 at the enrollment. We performed multivariable linear and logistic regression models, negative binomial and interval-censored proportion hazards regression models adjusted for demographics and smoking exposure to examine the association of FEV1/SVC<0.7 with those characteristics and outcomes. RESULTS Participants with FEV1/SVC<0.7 were older, had lower FEV1 and more emphysema than those with FEV1/SVC≥0.7. In adjusted analysis, individuals with post-bronchodilator FEV1/SVC<0.7 had greater %emphysema by 0.45% (95%CI=0.09-0.82), % gas trapping by 2.52% (95%CI=0.59-4.44), and %functional small airways disease based on parametric response mapping (PRMfSAD) by 2.78%(95%CI = 0.72-4.83) at baseline than those with FEV1/SVC≥0.7. During a median follow-up time of 1500 days, FEV1/SVC<0.7 was not associated with total exacerbations (IRR=1.61;95%CI=0.97-2.64) but was associated with severe exacerbations (IRR=2.60;95%CI=1.04-4.89). FEV1/SVC<0.7 was associated with progression to COPD during a 3-year follow-up even after adjustment for demographics and smoking exposure (HR=3.93;95%CI=2.71-5.72). We found similar results when we examined the association of pre-bronchodilator FEV1/SVC<0.7 or FEV1/SVC<LLN with chest CT features, and progression to COPD. INTERPRETATION Low FEV1/SVC in current and former smokers with normal spirometry can identify individuals with CT features of COPD and at risk for severe exacerbations, and is associated with progression to COPD in the future.

BackgroundSmoking is a leading cause of respiratory infections worldwide. Tobacco particulate matter disrupts iron homeostasis in the lungs and increases the iron content in the airways of smokers. The airway epithelia secrete lactoferrin to quench iron required for bacteria to proliferate and cause lung infections. We hypothesized that smokers would have increased bacterial growth and biofilm formation via iron lactoferrin imbalance.MethodsWe collected bronchoalveolar lavage (BAL) samples from non-smokers and smokers. We challenged these samples using a standard inoculum of Staphylococcus aureus and Pseudomonas aeruginosa and quantified bacterial growth and biofilm formation. We measured both iron and lactoferrin in the samples. We investigated the effect of supplementing non-smoker BAL with cigarette smoke extract (CSE) or ferric chloride and the effect of supplementing smoker BAL with lactoferrin on bacterial growth and biofilm formation.ResultsBAL from smokers had increased bact...

Background The sequelae of SARS-CoV-2 infection on pulmonary structure and function remain incompletely characterized. Methods Adults with confirmed COVID-19 who remained symptomatic more than thirty days following diagnosis were enrolled and classified as ambulatory, hospitalized or requiring the intensive care unit (ICU) based on the highest level of care received during acute infection. Symptoms, pulmonary function tests and chest computed tomography (CT) findings were compared across groups and to healthy controls. CT images were quantitatively analyzed using supervised machine-learning to measure regional ground glass opacities (GGO) and image-matching to measure regional air trapping. Comparisons were performed using univariate analyses and multivariate linear regression. Results Of the 100 patients enrolled, 67 were in the ambulatory group. All groups commonly reported cough and dyspnea. Pulmonary function testing revealed restrictive physiology in the hospitalized and ICU gr...

Smoking is the largest preventable cause of mortality and the largest environmental driver of epigenetic aging. Contingency management-based strategies can be used to treat smoking but require objective methods of verifying quitting status. Prior studies have suggested that cg05575921 methylation reverts as a function of smoking cessation, but that it can be used to verify the success of smoking cessation has not been unequivocally demonstrated. To test whether methylation can be used to verify cessation, we determined monthly cg05575921 levels in a group of 67 self-reported smokers undergoing biochemically monitored contingency management-based smoking cessation therapy, as part of a lung imaging protocol. A total of 20 subjects in this protocol completed three months of cotinine verified smoking cessation. In these 20 quitters, the reversion of cg05575921 methylation was dependent on their initial smoking intensity, with methylation levels in the heaviest smokers reverting to an a...

Background: It is widely unknown why respiratory infections follow a seasonal pattern. Variations in ultraviolet B (UVB) light during seasons affects cutaneous synthesis of vitamin D3. Serum vitamin D concentration influences the expression of airway surface liquid (ASL) antimicrobial peptides such as LL-37. Objective: We sought to determine the effect of seasons on serum vitamin D levels and ASL antimicrobial activity. Methods: Forty participants, 18–60 years old, were randomized 1:1 to receive 90 days of 1000 IU vitamin D3 or placebo. We collected ASL via bronchoscopy and measured serum 25(OH) vitamin D from participants before and after intervention across seasons. We measured ASL antimicrobial activity by challenging samples with bioluminescent Staphylococcus aureus and measured relative light units (RLUs) after four minutes. We also investigated the role of LL-37 using a monoclonal neutralizing antibody. Results: We found that participants, prior to any intervention, during sum...

Early stages of chronic obstructive pulmonary disease (COPD) are characterized by the loss and narrowing of terminal bronchioles in the lung resulting in 'air-trapping,' often occurring before overt emphysema manifests. Individuals with an airway-predominant phenotype of COPD display extensive lung air-trapping and are at greater cardiovascular disease (CVD) risk than COPD patients with an emphysema-predominant phenotype. We hypothesized that the degree of computed tomography (CT)-quantified lung air-trapping would be associated with greater aortic and carotid artery stiffness and lower endothelial function, known biomarkers of CVD risk. Lung air-trapping was associated with greater aortic stiffness (carotid femoral pulse wave velocity, CFPWV) (r=0.60, p=0.007) and carotid β-stiffness (r=0.75, p=0.0001) among adults with (n=10) and without (n=9) a clinical diagnosis of COPD and remained significant after adjusting for blood pressure (BP) and smoking history (pack-years) (car...

Classification of COPD is usually based on the severity of airflow, which may not sensitively differentiate subpopulations. Using a multiscale imaging-based cluster analysis (MICA), we aim to identify subpopulations for current smokers with COPD. Among the SPIROMICS subjects, we analyzed computed tomography images at total lung capacity (TLC) and residual volume (RV) of 284 current smokers. Functional variables were derived from registration of TLC and RV images, e.g. functional small airways disease (fSAD%). Structural variables were assessed at TLC images, e.g. emphysema and airway wall thickness and diameter. We employed an unsupervised method for clustering. Four clusters were identified. Cluster 1 had relatively normal airway structures; Cluster 2 had an increase of fSAD% and wall thickness; Cluster 3 exhibited a further increase of fSAD% but a decrease of wall thickness and airway diameter; Cluster 4 had a significant increase of fSAD% and emphysema. Clinically, Cluster 1 show...

Smoking is a leading cause of respiratory infections worldwide. Tobacco particulate matter disrupts iron homeostasis in the lungs and increases the iron content in the airways of smokers. The airway epithelia secrete lactoferrin to quench iron required for bacteria to proliferate and cause lung infections. We hypothesized that smokers would have increased bacterial growth and biofilm formation via iron lactoferrin imbalance. We collected bronchoalveolar lavage (BAL) samples from non-smokers and smokers. We challenged these samples using a standard inoculum of Staphylococcus aureus and Pseudomonas aeruginosa and quantified bacterial growth and biofilm formation. We measured both iron and lactoferrin in the samples. We investigated the effect of supplementing non-smoker BAL with cigarette smoke extract (CSE) or ferric chloride and the effect of supplementing smoker BAL with lactoferrin on bacterial growth and biofilm formation. BAL from smokers had increased bacterial growth and biofi...

Blood biomarkers are increasingly used to stratify high risk chronic obstructive pulmonary disease (COPD) patients; however, there are fewer studies that have investigated multiple biomarkers and replicated in multiple large well-characterized cohorts of susceptible current and former smokers. We used two MSD multiplex panels to measure 9 cytokines and chemokines in 2123 subjects from COPDGene and 1117 subjects from SPIROMICS. These biomarkers included: interleukin (IL)-2, IL-6, IL-8, IL-10, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, eotaxin/CCL-11, eotaxin-3/CCL-26, and thymus and activation-regulated chemokine (TARC)/CCL-17. Regression models adjusted for clinical covariates were used to determine which biomarkers were associated with the following COPD phenotypes: airflow obstruction (forced expiratory flow at 1 s (FEV%) and FEV/forced vital capacity (FEV/FVC), chronic bronchitis, COPD exacerbations, and emphysema. Biomarker-genotype associations were assessed by genome-w...

Decreased but measurable serum IgA levels (≤70 mg/dL) have been associated with risk for infections in some populations, but are unstudied in COPD. This study tested the hypothesis that subnormal serum IgA levels would be associated with exacerbation risk in COPD. Data were analyzed from 1,049 COPD participants from the observational cohort study SPIROMICS (535 (51%) women; mean age 66.1 (SD 7.8), 338 (32%) current smokers) who had baseline serum IgA measured using the Myriad RBM biomarker discovery platform. Exacerbation data was collected prospectively (mean 944.3 (SD 281.3) days), and adjusted linear, logistic and zero-inflated negative binomial regressions were performed. Mean IgA was 269.1 mg/dL (SD 150.9). One individual had deficient levels of serum IgA (<7 mg/dL) and 25 (2.4%) had IgA level ≤70 mg/dL. Participants with IgA ≤70 mg/dL were younger (62 vs. 66 years, p = 0.01) but otherwise similar to those with higher IgA. In adjusted models, IgA ≤70 mg/dL was associated wit...

Quantitative CT (QCT) imaging-based metrics have quantified disease alterations in asthma and chronic obstructive pulmonary disease (COPD), respectively. We seek to characterise the similarity and disparity between these groups using QCT-derived airway and parenchymal metrics. Asthma and COPD subjects (former-smoker status) were selected with a criterion of post-bronchodilator FEV<80%. Healthy non-smokers were included as a control group. Inspiratory and expiratory QCT images of 75 asthmatic, 215 COPD and 94 healthy subjects were evaluated. We compared three segmental variables: airway circularity, normalised wall thickness and normalised hydraulic diameter, indicating heterogeneous airway shape, wall thickening and luminal narrowing, respectively. Using an image registration, we also computed six lobar variables including per cent functional small-airway disease, per cent emphysema, tissue fraction at inspiration, fractional-air-volume change, Jacobian and functional metric char...

To determine the feasibility of using a cystic fibrosis transmembrane conductance regulator potentiator, ivacaftor (VX-770/Kalydeco, Vertex Pharmaceuticals, Boston, MA), as a therapeutic strategy for treating pulmonary edema. Prospective laboratory animal investigation. Animal research laboratory. Newborn and 3 days to 1 week old pigs. Hydrostatic pulmonary edema was induced in pigs by acute volume overload. Ivacaftor was nebulized into the lung immediately after volume overload. Grams of water per grams of dry lung tissue were determined in the lungs harvested 1 hour after volume overload. Ivacaftor significantly improved alveolar liquid clearance in isolated pig lung lobes ex vivo and reduced edema in a volume overload in vivo pig model of hydrostatic pulmonary edema. To model hydrostatic pressure-induced edema in vitro, we developed a method of applied pressure to the basolateral surface of alveolar epithelia. Elevated hydrostatic pressure resulted in decreased cystic fibrosis tr...

The obesity paradox in chronic obstructive pulmonary disease (COPD), whereby patients with higher body mass index (BMI) fare better, is poorly understood. Higher BMIs are associated with lower lung volumes and greater lung elastic recoil, a key determinant of expiratory airflow. The forced expiratory flow (25-75) (FEF25-75)/forced vital capacity (FVC) ratio reflects effort-independent expiratory airflow in the context of lung volume and could be modulated by BMI. We analysed data from the COPDGene study, an observational study of 10 192 subjects, with at least a 10 pack-year smoking history. Data were limited to subjects with BMI 20-40 kg/m2 (n=9222). Subjects were stratified according to forced expiratory volume in 1 s (FEV1) (%predicted)-quintiles. In regression analyses and Cox proportional hazard models, we analysed the association between BMI, the FEF25-75/FVC ratio, the imaging phenotype, COPD exacerbations, hospitalisations and death. There was no correlation between BMI and ...

Background: Readmission within 30 days of a COPD hospitalization is a common measure of performance for COPD care. However, most studies of COPD readmission risk have been constrained to a single data source, private payer claims, or Medicare claims data, making it difficult to generalize results from these studies to other populations. The purpose of this study was to examine the risk for readmission within 30 days from time of discharge in patients with COPD using the Healthcare Cost and Utilization Project (HCUP) State Inpatient Database for California for the years 2005-2011. This statewide dataset allows us to consider all readmissions for COPD regardless of age or payer status. Methods: The total dataset included 28,265,070 visits among 17,918,374 patients over 480 hospitals. We identified patients with a hospitalization, a primary diagnosis related to COPD, age 40 or older, and discharged alive. We found 286,313 hospitalizations that matched this definition and included infor...

Background: Symptomatic smokers (COPD assessment test [CAT]≥10) with preserved lung function were recently shown to have increased risks of exacerbations and activity limitation. In the general population, emphysema on computed tomography (CT) is associated with increased all-cause and respiratory mortality. However, the functional impact of emphysema on CT in smokers with preserved lung function has not been described. Methods: SPIROMICS recruited 2736 adults ages 40-80 years who were either never-smokers or current or former smokers with more than 20 pack-years. Symptom assessment included the St. Georges Respiratory Questionnaire (SGRQ) and CAT. Percent emphysema was defined as percentage of lung voxels Results: Of 897 smokers with post-bronchodilator FEV1/FVC≥0.7, 68 participants (8%) had emphysema on CT>ULN, of whom 42 (65%) had CAT≥10. Emphysema on CT was associated with impairment in SGRQ physical activity (P Conclusions: Among smokers with preserved lung function, emphysema measured quantitatively on CT was associated with self-reported activity limitation and desaturation.