High-resolution computed tomography quantitation of emphysema is correlated with selected lung function values in stable COPD

Two- and 3-year outcomes in convalescent individuals with COVID-19: A prospective cohort study

As the long-term consequences of coronavirus disease 2019 (COVID-19) have not been defined, it is necessary to explore persistent symptoms, long-term respiratory impairment, and impact on quality of life over time in COVID-19 survivors. In this prospective cohort study, convalescent individuals diagnosed with COVID-19 were followed-up 2 and 3 years after discharge from hospital. Participants completed an in-person interview to assess persistent symptoms and underwent blood tests, pulmonary function tests, chest high-resolution computed tomography, and the 6-min walking test. There were 762 patients at the 2-year follow-up and 613 patients at the 3-year follow-up. The mean age was 60 years and 415 (54.5%) were men. At 3 years, 39.80% of the participants had at least one symptom; most frequently, fatigue, difficulty sleeping, joint pain, shortness of breath, muscle aches, and cough. The participants experienced different degrees of pulmonary function impairment, with decreased carbon monoxide diffusion capacity being the main feature; results remained relatively stable over the 2-3 years. Multiple logistic regression analysis demonstrated that female sex and smoking were independently associated with impaired diffusion capacity. A subgroup analysis based on disease severity was performed, indicating that there was no difference in other parameters of lung function except forced vital capacity at 3-year follow-up. Persistent radiographic abnormalities, most commonly fibrotic-like changes, were observed at both timepoints. At 3 years, patients had a significantly improved Mental Component Score compared with that at 2 years, with a lower percentage with anxiety. Our study indicated that symptoms and pulmonary abnormalities persisted in COVID-19 survivors at 3 years. Further studies are warranted to explore the long-term effects of COVID-19 and develop appropriate rehabilitation strategies.

Diffusing capacity as an independent predictor of acute exacerbations in chronic obstructive pulmonary disease

A weak correlation between diffusing capacity of the lung for carbon monoxide (DLCO) and emphysema has been reported. This study investigated whether impaired DLCO in chronic obstructive pulmonary disease (COPD) is associated with increased risk of acute exacerbation independent of the presence or extent of emphysema. This retrospective cohort study included patients with COPD between January 2004 and December 2019. The participants were divided into four groups based on visually detected emphysema and impaired DLCO. Among 597 patients with COPD, 8.5% had no emphysema and impaired DLCO whereas 36.3% had emphysema without impaired DLCO. Among the four groups, patients with impaired DLCO and emphysema showed a higher risk of moderate-to-severe or severe exacerbation than those with normal DLCO. Impaired DLCO was an independent risk factor for severe exacerbation (hazard ratio, 1.524 [95% confidence interval 1.121-2.072]), whereas the presence of emphysema was not. The risk of moderate-to-severe or severe exacerbation increases with the severity of impaired DLCO. After propensity-score matching for the extent of emphysema, impaired DLCO was significantly associated with a higher risk of moderate-to-severe (p = 0.041) or severe exacerbation (p = 0.020). In patients with COPD and heterogeneous parenchymal abnormalities, DLCO can be considered an independent biomarker of acute exacerbation.

Bacterial load and related innate immune response in the bronchi of rapid decliners with chronic obstructive pulmonary disease

BACKGROUND

Characterization of COPD patients with rapid lung functional decline is of interest for prognostic and therapeutic reasons. We recently reported an impaired humoral immune response in rapid decliners.

OBJECTIVE

To determine the microbiota associated to markers of innate immune host response in COPD patients with rapid lung functional decline.

METHODS

In COPD patients monitored for at least 3 years (mean ± SD: 5.8 ± 3 years) for lung functional decline, the microbiota and related markers of immune response was measured in bronchial biopsies of patients with different lung functional decline (rate of FEV1% lung functional decline: no decline FEV1%, ≤20 ml/year n = 21, slow decline FEV1%, >20 ≤ 70 ml/year, n = 14 and rapid decline FEV1%, >70 ml/year, n = 15) using qPCR for microbiota and immunohistochemistry for cell-receptors and inflammatory markers.

MAIN RESULTS

Pseudomonas aeruginosa and Streptococcus pneumoniae were increased in rapid decliners vs slow decliners, S. pneumoniae was also increased compared to non decliners. In all patients, S. pneumoniae (copies/ml) positively correlated with pack-years consumption, lung function decline, TLR4, NOD1, NOD2 scored in bronchial epithelium and NOD1/mm² in lamina propria.

CONCLUSION

These data show an imbalance of microbiota components in rapid decliners which is associated to the expression of the related cell-receptors in all COPD patients. These findings may help in the prognostic stratification and treatment of patients.

Risk factors for impaired respiratory function post COVID-19: A prospective cohort study of nonhospitalized and hospitalized patients

BACKGROUND

Severe COVID-19 increases the risk for long-term respiratory impairment, but data after mild COVID-19 are scarce. Our aims were to determine risk factors for reduced respiratory function 3-6 months after COVID-19 infection and to investigate if reduced respiratory function would relate to impairment of exercise performance and breathlessness.

METHODS

Patients with COVID-19 were enrolled at the University Hospitals of Umeå and Örebro, and Karlstad Central Hospital, Sweden. Disease severity was defined as mild (nonhospitalized), moderate (hospitalized with or without oxygen treatment), and severe (intensive care). Spirometry, including diffusion capacity (DL_CO ), was performed 3-6 months after hospital discharge or study enrollment (for nonhospitalized patients). Breathlessness (defined as ≥1 according to the modified Medical Research Council scale) and functional exercise capacity (1-min sit-to-stand test; 1-MSTST) were assessed.

RESULTS

Between April 2020 and May 2021, 337 patients were enrolled in the study. Forced vital capacity and DL_CO were significantly lower in patients with severe COVID-19. Among hospitalized patients, 20% had reduced DL_CO , versus 4% in nonhospitalized. Breathlessness was found in 40.6% of the participants and was associated with impaired DL_CO . A pathological desaturation or heart rate response was observed in 17% of participants during the 1-MSTST. However, this response was not associated with reduced DL_CO .

CONCLUSION

Reduced DL_CO was the major respiratory impairment 3-6 months following COVID-19, with hospitalization as the most important risk factor. The lack of association between impaired DL_CO and pathological physiological responses to exertion suggests that these physiological responses are not primarily related to decreased lung function.

Gender specific airway gene expression in COPD sub-phenotypes supports a role of mitochondria and of different types of leukocytes

Chronic obstructive pulmonary disease (COPD) is a destructive inflammatory disease and the genes expressed within the lung are crucial to its pathophysiology. We have determined the RNAseq transcriptome of bronchial brush cells from 312 stringently defined ex-smoker patients. Compared to healthy controls there were for males 40 differentially expressed genes (DEGs) and 73 DEGs for females with only 26 genes shared. The gene ontology (GO) term “response to bacterium” was shared, with several different DEGs contributing in males and females. Strongly upregulated genes TCN1 and CYP1B1 were unique to males and females, respectively. For male emphysema (E)-dominant and airway disease (A)-dominant COPD (defined by computed tomography) the term “response to stress” was found for both sub-phenotypes, but this included distinct up-regulated genes for the E-sub-phenotype (neutrophil-related CSF3R, CXCL1, MNDA) and for the A-sub-phenotype (macrophage-related KLF4, F3, CD36). In E-dominant disease, a cluster of mitochondria-encoded (MT) genes forms a signature, able to identify patients with emphysema features in a confirmation cohort. The MT-CO2 gene is upregulated transcriptionally in bronchial epithelial cells with the copy number essentially unchanged. Both MT-CO2 and the neutrophil chemoattractant CXCL1 are induced by reactive oxygen in bronchial epithelial cells. Of the female DEGs unique for E- and A-dominant COPD, 88% were detected in females only. In E-dominant disease we found a pronounced expression of mast cell-associated DEGs TPSB2, TPSAB1 and CPA3. The differential genes discovered in this study point towards involvement of different types of leukocytes in the E- and A-dominant COPD sub-phenotypes in males and females.

Airflow limitation: is there a correlation between spirometry and quantitative computed tomography measurements in patients with chronic obstructive pulmonary disease?

Background

The ability of computed tomography (CT) in illustrating the pathology of lung parenchyma in patients with chronic obstructive pulmonary disease (COPD) was discussed previously in many articles. However, the correlation between airflow limitation that is evaluated by spirometry and its corresponding airway diameter that is measured by multislice computed tomography (MSCT) still under investigation. Therefore, the objective of our study was to answer the questions about possible correlation between forced expiratory volume in first second (FEV1%), forced vital capacity (FVC%), FEV1/FVC, and peak expiratory flow25–75% (PEF25–75%), both before bronchodilator and post it with the diameters of airway at 3 different levels either during inspiratory or expiratory phase of respiration.

Results

The quantitative MSCT results at RB1 (apical bronchus of the right upper lobe), RB10 (the posterior basal bronchus of the right lower lobe), and LB3 (the anterior bronchus of the left upper lobe) showed weak positive correlation with FEV1% during inspiratory phase of respiration (r = 0.19, 0.20, and 0.18; P = 0.23, 0.22, and 0.26 respectively), but this correlation became more stronger and significant during expiratory phase of respiration (r = 0.76, 0.78, and 0.66; P < 0.001).

Conclusions

Expiratory CT parameters were significantly correlated with the predicted peak expiratory flow in 1 s.

Relationship between diffusion capacity and small airway abnormality in COPDGene

Abstract

Impaired single breath carbon monoxide diffusing capacity (DLCO) is associated with emphysema. Small airways disease (SAD) may be a precursor lesion to emphysema, but the relationship between SAD and DLCO is undescribed. We hypothesized that in mild COPD, functional SAD (fSAD) defined by computed tomography (CT) and Parametric Response Mapping methodology would correlate with impaired DLCO. Using data from ever-smokers in the COPDGene cohort, we established that fSAD correlated significantly with lower DLCO among both non-obstructed and GOLD 1–2 subjects. The relationship between DLCO with CT-defined emphysema was present in all GOLD stages, but most prominent in severe disease.

Trial registration

NCT00608764. Registry: COPDGene. Registered 06 February 2008, retrospectively registered.

Optimization of pulmonary emphysema quantification on CT scans of COPD patients using hybrid iterative and post processing techniques: correlation with pulmonary function tests

Objectives

The aim of this study was to assess the effect of hybrid iterative reconstruction and post processing on emphysema quantification in low-dose CT scans of COPD patients using pulmonary function tests (PFT) as a reference.

Methods

CT scans of 23 COPD patients diagnosed with GOLD I or higher were reconstructed with iDose⁴ level 1 to 7 in IntelliSpace Portal (ISP) 6 and 7. ISP7 was used with and without specific denoising filter for COPD. The extent of emphysema was measured as percentage of lung voxels with attenuation < − 950 Hounsfield units (%LAA-950). The correlation between %LAA-950 and PFT, age, BMI, pack years, and the Clinical COPD Questionnaire (CCQ) and Medical Research Council dyspnea scale (MRC) was determined.

Results

Denoising significantly reduced %LAA-950 as was demonstrated by lower %LAA-950 in ISP7 with denoising filter and a significant reduction in %LAA-950 with higher iDose⁴ levels. All PFT except forced vital capacity (FVC) were significantly inversely correlated with %LAA-950. There was a trend toward a stronger correlation at higher iDose⁴ levels. %LAA-950 was also significantly correlated with BMI, GOLD class, and CCQ scores.

Conclusions

Our study showed that hybrid iterative reconstruction and use of post processing denoising can optimize the use of emphysema quantification in CT scans as a complimentary diagnostic tool to stage COPD in addition to PFT.

TGF-β Signaling Pathways in Different Compartments of the Lower Airways of Patients With Stable COPD

BACKGROUND

The expression and localization of transforming growth factor-β (TGF-β) pathway proteins in different compartments of the lower airways of patients with stable COPD is unclear. We aimed to determine TGF-β pathway protein expression in patients with stable COPD.

METHODS

The expression and localization of TGF-β pathway components was measured in the bronchial mucosa and peripheral lungs of patients with stable COPD (n = 44), control smokers with normal lung function (n = 24), and control nonsmoking subjects (n = 11) using immunohistochemical analysis.

RESULTS

TGF-β1, TGF-β3, and connective tissue growth factor expression were significantly decreased in the bronchiolar epithelium, with TGF-β1 also decreased in alveolar macrophages, in patients with stable COPD compared with control smokers with normal lung function. TGF-β3 expression was increased in the bronchial lamina propria of both control smokers with normal lung function and smokers with mild/moderate stable COPD compared with control nonsmokers and correlated significantly with pack-years of smoking. However, TGF-β3⁺ cells decreased in patients with severe/very severe COPD compared with control smokers. Latent TGF-β binding protein 1 expression was increased in the bronchial lamina propria in subjects with stable COPD of all severities compared with control smokers with normal lung function. Bone morphogenetic protein and activin membrane-bound inhibitor expression (BAMBI) in the bronchial mucosa was significantly increased in patients with stable COPD of all severities compared with control subjects. No other significant differences were observed between groups for all the other molecules studied in the bronchial mucosa and peripheral lung.

CONCLUSIONS

Expression of TGF-βs and their regulatory proteins is distinct within different lower airway compartments in stable COPD. Selective reduction in TGF-β1 and enhanced BAMBI expression may be associated with the increase in autoimmunity in COPD.

Comparing airways clearance techniques in chronic obstructive pulmonary disease and bronchiectasis: positive expiratory pressure or temporary positive expiratory pressure? A retrospective study

•

Patients with chronic hypersecretion (CH) of tracheobronchial mucus are a clinical challenge. They have an impaired quality of life, frequent exacerbations, and hospitalizations with need of antibiotics and other type of expensive treatments.

•

Chest physical therapy evolved along the last decades and new techniques are currently used to help patients clear the airways efficiently. Among these airway clearance techniques (ACTs), the use of positive expiratory pressure (PEP) is considered one of the most effective.

•

We report the retrospective evaluation of 162 patients with CH due to chronic obstructive pulmonary disease or bronchiectasis undergoing ACT in our Pulmonary Rehabilitation Department. They were treated either with PEP or with a new PEP device called UNIKO^®, which applies PEP in a temporary manner (TPEP).

•

Comparing the two groups of patients, both treatments (i.e., PEP and TPEP) were followed by great improvements in physiological parameters of spirometry and gas exchange. However, subdividing patients, it was evident that TPEP had better effects than PEP in patients with emphysema and in patients on long-term oxygen treatment, while PEP was superior at least in some parameters in patients on mechanical ventilation.

•

This study, albeit retrospective and calling for controlled clinical trials, suggests that different ACTs can be applied in different populations of patients.

Background

Airway clearance techniques include positive expiratory pressure, commonly used in our clinical practice, and a recently introduced temporary positive expiratory pressure device called UNIKO^®. It is unclear which one provides the best benefit to patients.

Objectives

The aim of this observational 4-year study was to retrospectively compare the efficacy of and specific indications for temporary positive expiratory pressure compared to positive expiratory pressure in a standard rehabilitation program.

Method

We retrospectively collected data from 162 subjects (107 males, mean age 70 ± 9 years, 97 with primary diagnosis of chronic obstructive pulmonary disease, 65 with bronchiectasis), 51 treated with temporary positive expiratory pressure and 111 with positive expiratory pressure.

Results

Subjects showed significant improvement in ratio of partial pressure arterial oxygen and fraction of inspired oxygen (p < 0.001), forced vital capacity, forced expiratory volume in one second, peak expiratory flow, arterial oxygen saturation, and partial pressure arterial oxygen with no significant difference between positive expiratory pressure and temporary positive expiratory pressure groups apart from forced expiratory flow, which increased only in the positive expiratory pressure group. Evaluating specific subgroups, temporary positive expiratory pressure was more effective than positive expiratory pressure in improving gas transfer in subjects with emphysema and in those on oxygen therapy, as the effective supplement oxygen flow decreased significantly (p = 0.034 and 0.046 respectively for temporary positive expiratory pressure vs. positive expiratory pressure). In subjects on mechanical ventilation, positive expiratory pressure was superior to temporary positive expiratory pressure in increasing forced expiratory flow (p = 0.018).

Conclusion

The physiological parameters of both groups improved significantly and similarly. Subgroup analysis suggests that temporary positive expiratory pressure could provide some advantage to subjects with emphysema and those on oxygen therapy, while positive expiratory pressure would benefit patients on mechanical ventilation. Randomized clinical trials are necessary to confirm our preliminary results indicating that different subgroups/phenotypes can benefit more from one type of treatment.

Computer quantification of "angle of collapse" on maximum expiratory flow volume curve for diagnosing asthma-COPD overlap syndrome

Background

In a previous study, we demonstrated that asthma patients with signs of emphysema on quantitative computed tomography (CT) fulfill the diagnosis of asthma-COPD overlap syndrome (ACOS). However, quantitative CT measurements of emphysema are not routinely available for patients with chronic airway disease, which limits their application. Spirometry was a widely used examination tool in clinical settings and shows emphysema as a sharp angle in the maximum expiratory flow volume (MEFV) curve, called the “angle of collapse (AC)”. The aim of this study was to investigate the value of the AC in the diagnosis of emphysema and ACOS.

Methods

This study included 716 participants: 151 asthma patients, 173 COPD patients, and 392 normal control subjects. All the participants underwent pulmonary function tests. COPD and asthma patients also underwent quantitative CT measurements of emphysema. The AC was measured using computer models based on Matlab software. The value of the AC in the diagnosis of emphysema and ACOS was evaluated using receiver-operating characteristic (ROC) curve analysis.

Results

The AC of COPD patients was significantly lower than that of asthma patients and control subjects. The AC was significantly negatively correlated with emphysema index (EI; r=−0.666, P<0.001), and patients with high EI had a lower AC than those with low EI. The ROC curve analysis showed that the AC had higher diagnostic efficiency for high EI (area under the curve =0.876) than did other spirometry parameters. In asthma patients, using the AC ≤137° as a surrogate criterion for the diagnosis of ACOS, the sensitivity and specificity were 62.5% and 89.1%, respectively.

Conclusion

The AC on the MEFV curve quantified by computer models correlates with the extent of emphysema. The AC may become a surrogate marker for the diagnosis of emphysema and help to diagnose ACOS.

Quantitative computed tomography measurements to evaluate airway disease in chronic obstructive pulmonary disease: Relationship to physiological measurements, clinical index and visual assessment of airway disease

PURPOSE

To correlate currently available quantitative CT measurements for airway disease with physiological indices and the body-mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index in patients with chronic obstructive pulmonary disease (COPD).

MATERIALS AND METHODS

This study was approved by our institutional review board (IRB number 2778). Written informed consent was obtained from all subjects. The subjects included 188 current and former cigarette smokers from the COPDGene cohort who underwent inspiratory and expiratory CT and also had physiological measurements for the evaluation of airflow limitation, including FEF25-75%, airway resistance (Raw), and specific airway conductance (sGaw). The BODE index was used as the index of clinical symptoms. Quantitative CT measures included % low attenuation areas [% voxels≤950 Hounsfield unit (HU) on inspiratory CT, %LAA_-950ins], percent gas trapping (% voxels≤-856HU on expiratory CT, %LAA _-856exp), relative inspiratory to expiratory volume change of voxels with attenuation values from -856 to -950HU [Relative Volume Change (RVC)_{-856 to -950}], expiratory to inspiratory ratio of mean lung density (E/I-ratio _MLD), Pi10, and airway wall thickness (WT), luminal diameter (LD) and airway wall area percent (WA%) in the segmental, subsegmental and subsubsegmental bronchi on inspiratory CT. Correlation coefficients were calculated between the QCT measurements and physiological measurements in all subjects and in the subjects with mild emphysema (%LAA_-950ins <10%). Univariate and multiple variable analysis for the BODE index were also performed. Adjustments were made for age, gender, smoking pack years, FEF25-75%, Raw, and sGaw.

RESULTS

Quantitative CT measurements had significant correlations with physiological indices. Among them, E/I-ratio _MLD had the strongest correlations with FEF25-75% (r=-0.648, <0.001) and sGaw (r=-0.624, <0.001) while in the subjects with mild emphysema subsegmental WA% and segmental WA% had the strongest correlation with FEF25-75% (r=-0.669, <0.001) and sGaw (r=-0.638, <0.001), respectively. The multiple variable analyses showed that RVC_{-856 to -950} was an independent predictor of the BODE index showing the highest R² (0.468) as an independent variable among the QCT measurements.

CONCLUSION

Quantitative CT measurements of gas trapping such as E/I-ratio _MLD, correlate better with physiological indices for airway disease than those of airway such as WA% or LD. In mild emphysema, however, quantitative CT measurements of airway correlate better with the physiological indices. RVC_{-856 to -950} is a predictor of the BODE index.

COPD immunopathology

The immunopathology of chronic obstructive pulmonary disease (COPD) is based on the innate and adaptive inflammatory immune responses to the chronic inhalation of cigarette smoking. In the last quarter of the century, the analysis of specimens obtained from the lower airways of COPD patients compared with those from a control group of age-matched smokers with normal lung function has provided novel insights on the potential pathogenetic role of the different cells of the innate and acquired immune responses and their pro/anti-inflammatory mediators and intracellular signalling pathways, contributing to a better knowledge of the immunopathology of COPD both during its stable phase and during its exacerbations. This also has provided a scientific rationale for new drugs discovery and targeting to the lower airways. This review summarises and discusses the immunopathology of COPD patients, of different severity, compared with control smokers with normal lung function.

The effect of comorbidities on COPD assessment: a pilot study

Introduction

Patients with chronic obstructive pulmonary disease (COPD) frequently suffer from comorbidities. COPD severity may be evaluated by the Global initiative for chronic Obstructive Lung Disease (GOLD) combined risk assessment score (GOLD score). Spirometry, body plethysmography, diffusing capacity of the lung for carbon monoxide (DLCO), and high-resolution computed tomography (HR-CT) measure lung function and elucidate pulmonary pathology. This study assesses associations between GOLD score and measurements of lung function in COPD patients with and without (≤1) comorbidities. It evaluates whether the presence of comorbidities influences evaluation by GOLD score of COPD severity, and questions whether GOLD score describes morbidity rather than COPD severity.

Methods

In this prospective study, 106 patients with stable COPD were included. Patients treated for lung cancer were excluded. Demographics, oxygen saturation (SpO₂), modified Medical Research Council Dyspnea Scale, COPD exacerbations, and comorbidities were recorded. Body plethysmography and DLCO were measured, and HR-CT performed and evaluated for emphysema and airways disease. COPD severity was stratified by the GOLD score. Correlation analyses: 1) GOLD score, 2) emphysema grade, and 3) airways disease and lung function parameters, described by: forced expiratory volume in the first second in percent of expected value (FEV₁%), inspiratory capacity (IC%), total lung volume (TLC%), IC/TLC, and SpO₂. Correlation analyses between subgroups and hierarchical cluster analysis were performed.

Results

Significant associations were found between GOLD score and both emphysema grade (correlation coefficients [cc]: −0.2, P=0.03) and lung function parameters (cc: −0.5 to −0.7, P-values all <0.001) weakened in patients with >1 comorbidity (cc: −0.4 to −0.5, P-values all 0.001). Significant differences between subgroups were found in GOLD score and both FEV₁% (cc: −0.2, P=0.02) and IC/TLC (cc: −0.2, P=0.02). Comorbidities were associated with GOLD score and composite measures in hierarchical cluster analysis.

Conclusion

The presence of comorbidities influences the relationship between GOLD score and lung function measurements. GOLD score may be more representative of morbidity than of COPD severity.

Noninvasive tests for the diagnostic evaluation of dyspnea among outpatients: the Multi-Ethnic Study of Atherosclerosis lung study

BACKGROUND

Dyspnea on exertion is a common and debilitating symptom, yet evidence for the relative value of cardiac and pulmonary tests for the evaluation of chronic dyspnea among adults without known cardiac or pulmonary disease is limited.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) enrolled participants aged 45 to 84 years who were free of clinical cardiovascular disease from 6 communities; participants with clinical pulmonary disease were excluded from this report. Dyspnea on exertion was assessed via structured interview. Tests included electrocardiograms, cardiac computed tomography (CT) for coronary artery calcium, cardiac magnetic resonance imaging, spirometry, percent emphysema (percent of lung regions <-950 HU) on CT, inflammatory biomarkers, and N-terminal pro-brain natriuretic peptide (NT-proBNP). Logistic regression was used to identify independent correlates of dyspnea after adjustment for age, sex, body mass index, physical activity, anxiety, and leg pain.

RESULTS

Among 1969 participants without known cardiopulmonary disease, 9% had dyspnea. The forced expiratory volume in 1 second (FEV1) (P < .001), NT-proBNP (P = .004), and percent emphysema on CT (P = .004) provided independent information on the probability of self-reported dyspnea. Associations with the FEV1 were stronger among smokers and participants with other recent respiratory symptoms or seasonal allergies; associations with NT-proBNP were present only among participants with coexisting symptoms of lower-extremity edema. Only the FEV1 provided a significant improvement in the receiver operating curve.

CONCLUSIONS

Among adults without known cardiac or pulmonary disease reporting dyspnea on exertion, spirometry, NT-proBNP, and CT imaging for pulmonary parenchymal disease were the most informative tests.

Molecular pathogenesis of cigarette smoking-induced stable COPD

Inflammation is a central feature of stable chronic obstructive pulmonary disease (COPD) and involves both activation of structural cells of the airways and the lungs and the activation and/or recruitment of infiltrating inflammatory cells. This results in enhanced expression of many pro-inflammatory proteins and reduced expression of some anti-inflammatory mediators. An altered protein expression is generally associated with concomitant changes in gene expression profiles in a cell-specific manner. Increased understanding of the role of transcription factors and of the signaling pathways leading to their activation in stable COPD will provide new targets to enable the development of potential anti-inflammatory drugs. Several new compounds targeting these pathways and/or transcription factors are now in development for the treatment of stable COPD. Furthermore, glucocorticoids drugs already in clinical use act through their own transcription factor, the glucocorticoid receptor, to control the expression of inflammatory and anti-inflammatory genes.

Association between emphysema-like lung on cardiac computed tomography and mortality in persons without airflow obstruction: a cohort study

BACKGROUND

Low lung function is known to predict mortality in the general population, but the prognostic significance of emphysema on computed tomography (CT) in persons without chronic obstructive pulmonary disease (COPD) is uncertain.

OBJECTIVE

To determine whether greater emphysema-like lung on CT is associated with all-cause mortality among persons in the general population without airflow obstruction or COPD.

DESIGN

Prospective cohort study.

SETTING

Population-based, multiethnic sample from 6 U.S. communities.

PARTICIPANTS

2965 participants aged 45 to 84 years without airflow obstruction on spirometry.

MEASUREMENTS

Emphysema-like lung was defined as the number of lung voxels with attenuation less than -950 Hounsfield units on cardiac CT and was adjusted for the number of total imaged lung voxels.

RESULTS

Among 2965 participants, 50.9% of whom had never smoked, there were 186 deaths over a median of 6.2 years. Greater emphysema-like lung was independently associated with increased mortality (adjusted hazard ratio per one-half interquartile range, 1.14 [95% CI, 1.04 to 1.24]; P=0.004) after adjustment for potential confounders, including cardiovascular risk factors and FEV1. Generalized additive models supported a linear association between emphysema-like lung and mortality without evidence for a threshold. The association was of greatest magnitude among smokers, although multiplicative interaction terms did not support effect modification by smoking status.

LIMITATIONS

Cardiac CT scans did not include lung apices. The number of deaths was limited among subgroup analyses.

CONCLUSION

Emphysema-like lung on CT was associated with all-cause mortality among persons without airflow obstruction or COPD in a general population sample, particularly among smokers. Recognition of the independent prognostic significance of emphysema on CT among patients without COPD on spirometry is warranted.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute.

Novel functional imaging of changes in small airways of patients treated with extrafine beclomethasone/formoterol

BACKGROUND

Inhaled formulations using extrafine particles of long-acting β2-agonists and corticosteroids were developed to optimize asthma treatment. Findings that these combinations reach and treat smaller airways more effectively are predominantly based on general non-specific outcomes with little information on regional characteristics.

OBJECTIVES

This study aims to assess long-term effects of extrafine beclomethasone/formoterol on small airways of asthmatic patients using novel functional imaging methods.

METHODS

Twenty-four stable asthma patients were subdivided into three groups (steroid naive, n = 7; partially controlled, n = 6; well controlled, n = 11). Current treatment was switched to a fixed combination of extrafine beclomethasone/formoterol (Foster®; Chiesi Pharmaceuticals, Parma, Italy). Patients underwent lung function evaluation and thorax high-resolution computerized tomography (HRCT) scan. Local airway resistance was obtained from computational fluid dynamics (CFD).

RESULTS

After 6 months, the entire population showed improvement in pre-bronchodilation imaging parameters, including small airway volume (p = 0.0007), resistance (p = 0.011), and asthma control score (p = 0.016). Changes in small airway volume correlated with changes in asthma control score (p = 0.004). Forced expiratory volume in 1 s (p = 0.044) and exhaled nitric oxide (p = 0.040) also improved. Functional imaging provided more detail and clinical relevance compared to lung function tests, especially in the well-controlled group where only functional imaging parameters showed significant improvement, while the correlation with asthma control score remained.

CONCLUSIONS

Extrafine beclomethasone/formoterol results in a significant reduction of small airway obstruction, detectable by functional imaging (HRCT/CFD). Changes in imaging parameters correlated significantly with clinically relevant improvements. This indicates that functional imaging is a useful tool for sensitive assessment of changes in the respiratory system after asthma treatment.

A challenge to the seven widely believed concepts of COPD

This review proposes a critical reassessment (based entirely on published evidence) of the following seven common beliefs about chronic obstructive pulmonary disease (COPD): (1) COPD is one disease. (2) There is a valid definition for COPD. (The current definition includes cases of irreversible asthma and bronchiectasis, and occasionally, other obstructive lung conditions). (3) Irreversible asthma in smokers and COPD cannot be differentiated. (4) A "chronic bronchitis" form of COPD exists and is characterized by blue bloater status and normal carbon monoxide diffusion studies. (5) Phenotyping has no bearing on medication choice in COPD. (6) Computerized scoring of lung attenuation on CT scans can diagnose emphysema. (Emphysema scores overlap in irreversible asthma and COPD); however, qualitative visual changes may be useful for differentiation. (7) A definable entity called the overlap (of COPD and asthma) syndrome exists. Conflict over the above-mentioned points denies patients proper phenotype-guided therapy and encourages a multidrug approach to COPD management. The recently coined term, overlap syndrome, invites a double-barreled therapy aimed at asthma and COPD, despite the absence of any agreement about how to define the syndrome and the lack of any related drug trials (in the area of inhaled corticosteroids). A diagnosis of COPD is associated with high morbidity and escalating costs, suggesting the need for a thorough new examination of the evidence.

Association Between Emphysema Score, Six-Minute Walk and Cardiopulmonary Exercise Tests in COPD

BACKGROUND

High-resolution computed tomography (HRCT) has allowed in detection of airway wall abnormalities and emphysema, whose extent may correlate with the clinical severity of the disease in patients with chronic obstructive pulmonary disease (COPD). Six minute walk test (6MWT) and cardiopulmonary exercise test (CPET) can determine functional status.

METHODS

A study was undertaken to investigate whether the extent of emphysema in COPD patients quantitatively confirmed by HRCT scoring was associated with distance walked, inspiratory capacity (IC) changes after exercise, anaerobic threshold of cardiopulmonary exercise and the BODE index (body mass index, airflow obstruction, dyspnea, exercise performance).

RESULTS

Seventeen patients with COPD underwent HRCT scanning, 6MWT and CPET. The emphysema score was highly correlated to forced vital capacity (FVC) (r=-0.748, p<0.001), forced expiratory volume in 1 second (FEV1) (r=-0.615, p<0.01), IC post exercise (r=-0.663, p<0.01) and dyspnea score post exercise (r=0.609, p<0.01), but was not associated with the BODE index. The distance walked during 6MWT was inversely correlated to emphysema score (r=-0.557, p<0.05). IC before exercise was highly related to the 6MWT. The change in IC after exercise was associated with the percent decline of oxygen saturation after exercise (r=0.633, p<0.01). Severity of lung emphysema in COPD patients was inversely correlated to VO(2) max (r=-0.514, p<0.05) and anaerobic threshold (r=-0.595, p<0.01) of cardiopulmonary exercise.

CONCLUSIONS

These results suggest that COPD associated with emphysema on HRCT is characterized by more severe lung function impairment, greater exercise impairment and cardiopulmonary dysfunction.