To investigate whether the integrity (completeness) of pulmonary fissures affects pulmonary function in patients with chronic obstructive pulmonary disease (COPD).
A dataset consisting of 573 CT ...exams acquired on different subjects was collected from a COPD study. According to the global initiative for chronic obstructive lung disease (GOLD) criteria, these subjects (examinations) were classified into five different subgroups, namely non-COPD (222 subjects), GOLD-I (83 subjects), GOLD-II (141 subjects), GOLD-III (63 subjects), and GOLD-IV (64 subjects), in terms of disease severity. An available computer tool was used to aid in an objective and efficient quantification of fissure integrity. The correlations between fissure integrity, and pulmonary functions (e.g., FEV1, and FEV1/FVC) and COPD severity were assessed using Pearson and Spearman's correlation coefficients, respectively.
For the five sub-groups ranging from non-COPD to GOLD-IV, the average integrities of the right oblique fissure (ROF) were 81.8%, 82.4%, 81.8%, 82.8%, and 80.2%, respectively; the average integrities of the right horizontal fissure (RHF) were 62.6%, 61.8%, 62.1%, 62.2%, and 62.3%, respectively; the average integrities of the left oblique fissure (LOF) were 82.0%, 83.2%, 81.7%, 82.0%, and 78.4%, respectively; and the average integrities of all fissures in the entire lung were 78.0%, 78.6%, 78.1%, 78.5%, and 76.4%, respectively. Their Pearson correlation coefficients with FEV1 and FE1/FVC range from 0.027 to 0.248 with p values larger than 0.05. Their Spearman correlation coefficients with COPD severity except GOLD-IV range from -0.013 to -0.073 with p values larger than 0.08.
There is no significant difference in fissure integrity for patients with different levels of disease severity, suggesting that the development of COPD does not change the completeness of pulmonary fissures and incomplete fissures alone may not contribute to the collateral ventilation.
Abstract Objective Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the United States but is often undertreated. COPD often overlaps with other conditions such as ...hypertension and osteoporosis, which are less morbid but may be treated more aggressively. We evaluated the prevalence of these comorbid conditions and compared testing, patient knowledge, and management in a national sample of patients with COPD. Methods A survey was administered by telephone in 2006 to 1003 patients with COPD to evaluate the prevalence of comorbid conditions, diagnostic testing, knowledge, and management using standardized instruments. The completion rate was 87%. Results Among 1003 patients with COPD, 61% reported moderate or severe dyspnea and 41% reported a prior hospitalization for COPD. The most prevalent comorbid diagnoses were hypertension (55%), hypercholesterolemia (52%), depression (37%), cataracts (31%), and osteoporosis (28%). Only 10% of respondents knew their forced expiratory volume in 1 second (95% confidence interval CI, 8-12) compared with 79% who knew their blood pressure (95% CI, 76-83). Seventy-two percent (95% CI, 69-75) reported taking any medication for COPD, usually a short-acting bronchodilator, whereas 87% (95% CI, 84-90) of patients with COPD and hypertension were taking an antihypertensive medication and 72% (95% CI, 68-75) of patients with COPD and hypercholesterolemia were taking a statin. Conclusion Although most patients with COPD in this national sample were symptomatic and many had been hospitalized for COPD, COPD self-knowledge was low and COPD was undertreated compared with generally asymptomatic, less morbid conditions such as hypertension.
Abstract
Motivation
Integration of data from different modalities is a necessary step for multi-scale data analysis in many fields, including biomedical research and systems biology. Directed ...graphical models offer an attractive tool for this problem because they can represent both the complex, multivariate probability distributions and the causal pathways influencing the system. Graphical models learned from biomedical data can be used for classification, biomarker selection and functional analysis, while revealing the underlying network structure and thus allowing for arbitrary likelihood queries over the data.
Results
In this paper, we present and test new methods for finding directed graphs over mixed data types (continuous and discrete variables). We used this new algorithm, CausalMGM, to identify variables directly linked to disease diagnosis and progression in various multi-modal datasets, including clinical datasets from chronic obstructive pulmonary disease (COPD). COPD is the third leading cause of death and a major cause of disability and thus determining the factors that cause longitudinal lung function decline is very important. Applied on a COPD dataset, mixed graphical models were able to confirm and extend previously described causal effects and provide new insights on the factors that potentially affect the longitudinal lung function decline of COPD patients.
Availability and implementation
The CausalMGM package is available on http://www.causalmgm.org.
Supplementary information
Supplementary data are available at Bioinformatics online.
To study the relationship between emphysema and/or airflow obstruction and lung cancer in a high-risk population.
We studied lung cancer related to radiographic emphysema and spirometric airflow ...obstruction in tobacco-exposed persons who were screened for lung cancer using chest computed tomography (CT).
Subjects completed questionnaires, spirometry, and low-dose helical chest CT. CT scans were scored for emphysema based on National Emphysema Treatment Trial criteria. Multiple logistic regressions estimated the independent associations between various factors, including radiographic emphysema and airflow obstruction, and subsequent lung cancer diagnosis.
Among 3,638 subjects, 57.5, 18.8, 14.6, and 9.1% had no, trace, mild, and moderate-severe emphysema, and 57.3, 13.6, 22.8, and 6.4% had no, mild (Global Initiative for Chronic Obstructive Lung Disease GOLD I), moderate (GOLD II), and severe (GOLD III-IV) airflow obstruction. Of 3,638 subjects, 99 (2.7%) received a lung cancer diagnosis. Adjusting for sex, age, years of cigarette smoking, and number of cigarettes smoked daily, logistic regression showed the expected lung cancer association with the presence of airflow obstruction (GOLD I-IV, odds ratio OR, 2.09; 95% confidence interval CI, 1.33-3.27). A second logistic regression showed lung cancer related to emphysema (OR, 3.56; 95% CI, 2.21-5.73). After additional adjustments for GOLD class, emphysema remained a strong and statistically significant factor related to lung cancer (OR, 3.14; 95% CI, 1.91-5.15).
Emphysema on CT scan and airflow obstruction on spirometry are related to lung cancer in a high-risk population. Emphysema is independently related to lung cancer. Both radiographic emphysema and airflow obstruction should be considered when assessing lung cancer risk.
Background: A pre-specified meta-analysis of individual patient data from the 52-week METREX and METREO trials, which investigated mepolizumab for chronic obstructive pulmonary disease (COPD) in ...patients with blood eosinophil counts greater than or equal to 150 cells/microL (screening) or greater than or equal to 300 cells/microL (prior year) and frequent exacerbations, enables more robust characterization of mepolizumab efficacy in COPD and exploration of the relationship between blood eosinophil count and treatment responses. Methods: In METREX (117106/NCT02105948) and METREO (117113/NCT02105961), randomized patients received mepolizumab or placebo added to existing inhaled corticosteroid (ICS)-based triple maintenance therapy. The annual rate of moderate/severe exacerbations (primary endpoint) was compared between subcutaneous (SC) mepolizumab 100 mg versus placebo (primary comparison of interest) and all doses (100 mg and 300 mg SC) versus placebo in patients with blood eosinophil counts greater than or equal to 150 cells/microL at screening or greater than or equal to 300 cells/microL in the prior year. Secondary/other endpoints included time to first moderate/severe exacerbation, exacerbations leading to emergency department visit/hospitalization and health-related quality of life (HRQoL). A predictive model of the relationship between screening blood eosinophil counts and exacerbation rates included data from all randomized patients. Results: In total, 1510 patients were randomized in METREX and METREO and 1136 patients were included in the pre-specified meta-analysis. From the meta-analysis, mepolizumab 100 mg SC significantly reduced annual moderate/severe exacerbation rates versus placebo by 18% (rate ratio: 0.82; 95% confidence interval: 0.71, 0.95; p=0.006) and delayed time to first moderate/ severe exacerbation (hazard ratio: 0.80 0.68, 0.94; p=0.006). Mepolizumab 100 mg SC versus placebo numerically reduced exacerbations leading to ED visits/hospitalization and improved HRQoL. A modelling approach demonstrated increasing efficacy for moderate/severe exacerbations with increasing screening blood eosinophil count; this relationship was more pronounced for exacerbations requiring oral corticosteroids (post hoc). The all-doses comparison had similar results. Conclusion: Mepolizumab reduces exacerbations in patients with eosinophil-associated COPD. Results suggest that blood eosinophil counts (greater than or equal to 150 cells/microL at screening or greater than or equal to 300 cells/microL in the prior year) allow for identification of patients with COPD who experience exacerbations while treated with maximal ICS-based triple maintenance therapy who are likely to benefit from mepolizumab. Keywords: mepolizumab, COPD, eosinophil, exacerbation
Diverse autoantibodies are present in most patients with idiopathic pulmonary fibrosis (IPF). We hypothesized that specific autoantibodies may associate with IPF manifestations.
To identify ...clinically relevant, antigen-specific immune responses in patients with IPF.
Autoantibodies were detected by immunoblots and ELISA. Intrapulmonary immune processes were evaluated by immunohistochemistry. Anti-heat shock protein 70 (HSP70) IgG was isolated from plasma by immunoaffinity. Flow cytometry was used for leukocyte functional studies.
HSP70 was identified as a potential IPF autoantigen in discovery assays. Anti-HSP70 IgG autoantibodies were detected by immunoblots in 3% of 60 control subjects versus 25% of a cross-sectional IPF cohort (n = 122) (P = 0.0004), one-half the patients with IPF who died (P = 0.008), and 70% of those with acute exacerbations (P = 0.0005). Anti-HSP70 autoantibodies in patients with IPF were significantly associated with HLA allele biases, greater subsequent FVC reductions (P = 0.0004), and lesser 1-year survival (40 ± 10% vs. 80 ± 5%; hazard ratio = 4.2; 95% confidence interval, 2.0-8.6; P < 0.0001). HSP70 protein, antigen-antibody complexes, and complement were prevalent in IPF lungs. HSP70 protein was an autoantigen for IPF CD4 T cells, inducing lymphocyte proliferation (P = 0.004) and IL-4 production (P = 0.01). IPF anti-HSP70 autoantibodies activated monocytes (P = 0.009) and increased monocyte IL-8 production (P = 0.049). ELISA confirmed the association between anti-HSP70 autoreactivity and IPF outcome. Anti-HSP70 autoantibodies were also found in patients with other interstitial lung diseases but were not associated with their clinical progression.
Patients with IPF with anti-HSP70 autoantibodies have more near-term lung function deterioration and mortality. These findings suggest antigen-specific immunoassays could provide useful clinical information in individual patients with IPF and may have implications for understanding IPF progression.
Background Despite the high prevalence of respiratory symptoms and obstructive lung disease in HIV-infected subjects, the prevalence of bronchodilator reversibility (BDR) and asthma has not been ...systematically studied during the era of combination antiretroviral therapy (ART). Objective We sought to determine the prevalence of asthma diagnosis and related pulmonary function abnormalities in an HIV-infected cohort and to identify potential mechanisms. Methods We performed a cross-sectional analysis of 223 HIV-infected subjects with data on respiratory symptoms and diagnoses, pulmonary function, sputum cell counts, and asthma-related cytokines and chemokines in serum/sputum. Results Doctor-diagnosed asthma was present in 46 (20.6%), and BDR (≥200 mL and ≥12% increase in FEV1 or forced vital capacity) was present in 20 (9.0%) participants. Pulmonary symptoms and function were worse in those with doctor-diagnosed asthma. Doctor-diagnosed asthma was independently associated with female sex ( P = .04), body mass index of greater than 29.6 kg/m2 (vs <29.6 kg/m2 , P = .03), history of bacterial or Pneumocystis pneumonia ( P = .01), and not currently taking ART ( P = .04) and in univariate analysis with parental history of asthma (n = 180, P = .004). High sputum eosinophil percentages (>2.3% based on the highest decile) were more likely in those with doctor-diagnosed asthma ( P = .02) or BDR ( P = .02). Doctor-diagnosed asthma tended to be more common with high sputum IL-4 ( P = .02) and RANTES ( P = .02) levels, whereas BDR was associated with high plasma macrophage inflammatory protein 1α ( P = .002) and sputum macrophage inflammatory protein 1β ( P = .001) levels. Conclusion Asthma diagnosis and BDR are prevalent in an HIV-infected outpatient cohort, and associations with family history, obesity, allergic inflammation, prior infection, absence of ART, and increased HIV-stimulated cytokines suggest possible mechanisms of HIV-associated asthma.
To better understand the molecular basis of chronic obstructive pulmonary disease (COPD), we used serial analysis of gene expression (SAGE) and microarray analysis to compare the gene expression ...patterns of lung tissues from COPD and control smokers. A total of 59,343 tags corresponding to 26,502 transcripts were sequenced in SAGE analyses. A total of 327 genes were differentially expressed (1.5-fold up- or down-regulated). Microarray analysis using the same RNA source detected 261 transcripts that were differentially expressed to a significant degree between GOLD-2 and GOLD-0 smokers. We confirmed the altered expression of a select number of genes by using real-time quantitative RT-PCR. These genes encode for transcription factors (EGR1 and FOS), growth factors or related proteins (CTGF, CYR61, CX3CL1, TGFB1, and PDGFRA), and extracellular matrix protein (COL1A1). Immunofluorescence studies on the same lung specimens localized the expression of Egr-1, CTGF, and Cyr61 to alveolar epithelial cells, airway epithelial cells, and stromal and inflammatory cells of GOLD-2 smokers. Cigarette smoke extract induced Egr-1 protein expression and increased Egr-1 DNA-binding activity in human lung fibroblast cells. Cytomix (tumor necrosis factor α, IL-1β, and IFN-γ) treatment showed that the activity of matrix metalloproteinase-2 (MMP-2) was increased in lung fibroblasts from EGR1 control (+/+) mice but not detected in that of EGR1 null (-/-) mice, whereas MMP-9 was regulated by EGR1 in a reverse manner. Our study represents the first comprehensive analysis of gene expression on GOLD-2 versus GOLD-0 smokers and reveals previously unreported candidate genes that may serve as potential molecular targets in COPD.
Muscle loss is an important extrapulmonary manifestation of COPD. Dual energy X-ray absorptiometry (DXA) is the method of choice for body composition measurement but is not widely used for muscle ...mass evaluation. The pectoralis muscle area (PMA) is quantifiable by CT and predicts cross-sectional COPD-related morbidity. There are no studies that compare PMA with DXA measures or that evaluate longitudinal relationships between PMA and lung disease progression.
Participants from our longitudinal tobacco-exposed cohort had baseline and 6-year chest CT (n=259) and DXA (n=164) data. Emphysema was quantified by CT density histogram parenchymal scoring using the 15th percentile technique. Fat-free mass index (FFMI) and appendicular skeletal mass index (ASMI) were calculated from DXA measurements. Linear regression model relationships were reported using standardised coefficient (β) with 95% CI.
PMA was more strongly associated with DXA measures than with body mass index (BMI) in both cross-sectional (FFMI: β=0.76 (95% CI 0.65 to 0.86), p<0.001; ASMI: β=0.76 (95% CI 0.66 to 0.86), p<0.001; BMI: β=0.36 (95% CI 0.25 to 0.47), p<0.001) and longitudinal (ΔFFMI: β=0.43 (95% CI 0.28 to 0.57), p<0.001; ΔASMI: β=0.42 (95% CI 0.27 to 0.57), p<0.001; ΔBMI: β=0.34 (95% CI 0.22 to 0.46), p<0.001) models. Six-year change in PMA was associated with 6-year change in emphysema (β=0.39 (95% CI 0.23 to 0.56), p<0.001) but not with 6-year change in airflow obstruction.
PMA is an accessible measure of muscle mass and may serve as a useful clinical surrogate for assessing skeletal muscle loss in smokers. Decreased PMA correlated with emphysema progression but not lung function decline, suggesting a difference in the pathophysiology driving emphysema, airflow obstruction and comorbidity risk.
PDF
