Mechanical and morphological characterization of the emphysematous lung tissue

Irreversible alveolar airspace enlargement is the main characteristic of pulmonary emphysema, which has been extensively studied using animal models. While the alterations in lung mechanics associated with these morphological changes have been documented in the literature, the study of the mechanical behavior of parenchymal tissue from emphysematous lungs has been poorly investigated. In this work, we characterize the mechanical and morphological properties of lung tissue in elastase-induced emphysema rat models under varying severity conditions. We analyze the non-linear tissue behavior using suitable hyperelastic constitutive models that enable to compare different non-linear responses in terms of hyperelastic material parameters. We further analyze the effect of the elastase dose on alveolar morphology and tissue material parameters and study their connection with respiratory-system mechanical parameters. Our results show that while the lung mechanical function is not significantly influenced by the elastase treatment, the tissue mechanical behavior and alveolar morphology are markedly affected by it. We further show a strong association between alveolar enlargement and tissue softening, not evidenced by respiratory-system compliance. Our findings highlight the importance of understanding tissue mechanics in emphysematous lungs, as changes in tissue properties could detect the early stages of emphysema remodeling. STATEMENT OF SIGNIFICANCE: Gas exchange is vital for life and strongly relies on the mechanical function of the lungs. Pulmonary emphysema is a prevalent respiratory disease where alveolar walls are damaged, causing alveolar enlargement that induces harmful changes in the mechanical response of the lungs. In this work, we study how the mechanical properties of lung tissue change during emphysema. Our results from animal models show that tissue properties are more sensitive to alveolar enlargement due to emphysema than other mechanical properties that describe the function of the whole respiratory system.

Inhibition of GBP5 activates autophagy to alleviate inflammatory response in LPS-induced lung injury in mice

BACKGROUND

Pulmonary emphysema is a condition that causes damage to the lung tissue over time. GBP5, as part of the guanylate-binding protein family, is dysregulated in mouse pulmonary emphysema. However, the role of GBP5 in lung inflammation in ARDS remains unveiled.

METHODS

To investigate whether GBP5 regulates lung inflammation and autophagy regulation, the study employed a mouse ARDS model and MLE-12 cell culture. Vector transfection was performed for the genetic manipulation of GBP5. Then, RT-qPCR, WB and IHC staining were conducted to assess its transcriptional and expression levels. Histological features of the lung tissue were observed through HE staining. Moreover, ELISA was conducted to evaluate the secretion of inflammatory cytokines, autophagy was assessed by immunofluorescent staining, and MPO activity was determined using a commercial kit.

RESULTS

Our study revealed that GBP5 expression was altered in mouse ARDS and LPS-induced MLE-12 cell models. Moreover, the suppression of GBP5 reduced lung inflammation induced by LPS in mice. Conversely, overexpression of GBP5 diminished the inhibitory impact of LPS on ARDS during autophagy, leading to increased inflammation. In the cell line of MLE-12, GBP5 exacerbates LPS-induced inflammation by blocking autophagy.

CONCLUSION

The study suggests that GBP5 facilitates lung inflammation and autophagy regulation. Thus, GBP5 could be a potential therapeutic approach for improving ARDS treatment outcomes, but further research is required to validate these findings.

cebil (Griseb.) Altschul IN EXPERIMENTAL ELASTASE-INDUCED PULMONARY EMPHYSEMA IN RATS

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal plants have shown promise in the search for new treatments of pulmonary emphysema. Anadenanthera colubrina, a species native to the Caatinga biome in northeastern Brazil, is widely recognized and traditionally employed in the treatment of pulmonary diseases. Many studies corroborate popular knowledge about the medicinal applications of A. colubrina, which has demonstrated a remarkable variety of pharmacological properties, however, its anti-inflammatory and antioxidant properties are highlighted.

AIM OF THE STUDY

The objective of this study was to investigate the anti-inflammatory potential of the crude hydroethanolic extract of A. colubrina var. cebil (Griseb.) Altschul on pulmonary emphysema in rats as well as to determine its potential genotoxic and cytotoxic effects using the micronucleus assay.

MATERIALS AND METHODS

The stem bark of the plant was collected in Pimenteiras-PI and sample was extracted by maceration using 70% ethanol. A portion of the extract underwent phytochemical analyses using TLC and HPLC. In this study, 8-week-old, male Wistar rats weighing approximately ± 200 g was utilized following approval by local ethics committee for animal experimentation (No. 718/2022). Pulmonary emphysema was induced through orotracheal instillation of elastase, and treatment with A. colubrina extract or dexamethasone (positive control) concomitantly during induction. Twenty-eight days after the initiation of the protocol, plasma was used for cytokine measurement. Bronchoalveolar lavage (BAL) was used for leukocyte count. After euthanasia, lung samples were processed for histological analysis and quantification of oxidative stress markers. The micronucleus test was performed by evaluating the number of polychromatic erythrocytes (PCE) with micronuclei (MNPCE) to verify potential genotoxic effects of A. colubrina. A differential count of PCE and normochromatic erythrocytes (NCE) was performed to verify the potential cytotoxicity of the extract. Parametric data were subjected to normality analysis and subsequently to analysis of variance and Tukey or Dunnett post-test, non-parametric data were treated using the Kruskal-Wallis test with Dunn's post-test for unpaired samples. P value <0.05 were considered significant.

RESULTS

The A. colubrina extract did not show a significant increase in the number of MNPCE (p>0.05), demonstrating low genotoxicity. No changes were observed in the PCE/NCE ratio of treated animals, compared with the vehicle, suggesting low cytotoxic potential of the extract. A significant reduction (p<0.05) in neutrophilic inflammation was observed in the lungs of rats treated with the extract, evidenced by presence of these cells in both the tissue and BAL. The extract also demonstrated pulmonary antioxidant activity, with a significant decrease (p<0.05) in myeloperoxidase, malondialdehyde, and nitrite levels. TNFα, IL-1β, and IL-6 levels, as well as alveolar damage, were significantly reduced in animals treated with A. colubrina extract. Phytochemical analyses identified the presence of phenolic compounds and hydrolysable tannins in the A. colubrina extract.

CONCLUSIONS

The findings of this study highlights the safety of the hydroethanolic extract of Anadenanthera colubrina, and demonstrates its potential as a therapeutic approach in the treatment of emphysema. The observed properties of this medicinal plant provide an optimistic outlook in the development of therapies for the treatment of pulmonary emphysema.

Differential decline of lung function in COPD patients according to structural abnormality in chest CT

Background

Different progressions or prognoses of chronic obstructive pulmonary disease (COPD) have been reported according to structural abnormalities based on chest computed tomography (CT). This study aimed to investigate whether different structural abnormalities independently affect annual lung function changes and clinical prognosis in patients with COPD.

Methods

This longitudinal multicenter observational study was conducted using the KOCOSS cohort (NCT02800499) database in Korea from January 2012 to December 2019. For COPD patients with chest CT findings at baseline enrolment and longitudinal spirometric data, annual forced expiratory volume in 1 s (FEV1) decline rate (mL/year) and clinical outcomes were compared according to structural abnormalities, including emphysema, bronchiectasis (BE), and tuberculosis-destroyed lung (TDL). We estimated the adjusted annual FEV1 changes using a mixed-effect linear regression model.

Results

Among the enrolled 237 patients, 152 showed structural abnormalities. Emphysema, BE, and TDL were observed in 119 (78.3%), 28 (18.4%), and 27 (17.8%) patients, respectively. The annual decline in FEV1 was faster in COPD patients with structural abnormalities than those without (β = -70.6 mL/year, P-value = 0.039). BE/TDL-dominant or emphysema-dominant structural abnormality contributed to an accelerated annual FEV1 decline compared to no structural abnormality (BE/TDL-dominant, β = -103.7 mL/year, P-value = 0.043; emphysema-dominant, β = -84.1 mL/year, P-value = 0.018). Structural abnormalities made no significant differences in acute exacerbation rate and mortality.

Conclusion

The lung function decline rate in COPD differed according to structural abnormalities on CT. These findings may suggest that more focus should be placed on earlier intervention or regular follow-up with spirometry in COPD patients with BE or TDL on chest CT.

Analysis of body composition with bioelectrical impedance analysis in patients with severe COPD and pulmonary emphysema

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) often suffer from cachexia and malnutrition. Less is known about body composition and nutritional behaviour in patients with advanced COPD and pulmonary emphysema.

METHODS

We performed a single-center prospective analysis of patients with COPD GOLD III/IV. Metabolic parameters, dietary and exercise behavior, lung function, exercise capacity and body composition by bioelectrical impedance analysis (BIA) were analyzed. Patients with severe emphysema (emphysema index [EI] >20%) were compared to patients with mild emphysema (EI ≤ 20%).

RESULTS

A total of 121 patients (45.5% female, mean age 64.8 ± 8.1 years, mean FEV1 31.0 ± 8.6%, mean RV 234.7 ± 50.6%) were analyzed, of whom 14.1% were underweight. Only 5% of the patients substituted protein and only about 1/3 performed regular exercise training. BIA showed an unfavourable body composition: body fat ↑, ECM/BCM-index ↑, phase angle ↓ (5.0 ± 0.9°), cell percentage ↓, FFMI (fat-free mass index) ↓. The 94 patients with severe emphysema (mean EI 36.6 ± 8.5%) had lower body-mass-index (22.8 ± 4.3 vs. 31.1 ± 5.8 kg/m2, p < 0.001), FFMI, body weight and body fat, but did not differ significantly in the quality of body composition (e.g. phase angle). Their lipid and glucose metabolism were even better than in mild emphysema patients.

CONCLUSION

The finding of significantly lower BMI but similar body composition and better metabolic status in severe emphysema patients needs further investigation. However, it should not distract from the necessity to implement dietary and exercise recommendations for advanced COPD patients.

The impact of chronic obstructive pulmonary disease on bone strength

Chronic obstructive pulmonary disease (COPD) is a lifestyle-related disease that develops in middle-aged and older adults, often due to smoking habits, and has been noted to cause bone fragility. COPD is a risk factor for osteoporosis and fragility fracture, and a high prevalence of osteoporosis and incidence of vertebral fractures have been shown in patients with COPD. Findings of lung tissue analysis in patients with COPD are primarily emphysema with a loss of alveolar septal walls, and the severity of pulmonary emphysema is negatively correlated with thoracic spine bone mineral density (BMD). On the other hand, epidemiological studies on COPD and fracture risk have reported a BMD-independent increase in fracture risk; however, verification in animal models and human bone biopsy samples has been slow, and the essential pathogenesis has not been elucidated. The detailed pathological/molecular mechanisms of musculoskeletal complications in patients with COPD are unknown, and basic research is needed to elucidate the mechanisms. This paper discusses the impacts of COPD on bone strength, focusing on findings in animal models in terms of bone microstructure, bone metabolic dynamics, and material properties.

Machine learning slice-wise whole-lung CT emphysema score correlates with airway obstruction

OBJECTIVES

Quantitative CT imaging is an important emphysema biomarker, especially in smoking cohorts, but does not always correlate to radiologists' visual CT assessments. The objectives were to develop and validate a neural network-based slice-wise whole-lung emphysema score (SWES) for chest CT, to validate SWES on unseen CT data, and to compare SWES with a conventional quantitative CT method.

MATERIALS AND METHODS

Separate cohorts were used for algorithm development and validation. For validation, thin-slice CT stacks from 474 participants in the prospective cross-sectional Swedish CArdioPulmonary bioImage Study (SCAPIS) were included, 395 randomly selected and 79 from an emphysema cohort. Spirometry (FEV1/FVC) and radiologists' visual emphysema scores (sum-visual) obtained at inclusion in SCAPIS were used as reference tests. SWES was compared with a commercially available quantitative emphysema scoring method (LAV950) using Pearson's correlation coefficients and receiver operating characteristics (ROC) analysis.

RESULTS

SWES correlated more strongly with the visual scores than LAV950 (r = 0.78 vs. r = 0.41, p < 0.001). The area under the ROC curve for the prediction of airway obstruction was larger for SWES than for LAV950 (0.76 vs. 0.61, p = 0.007). SWES correlated more strongly with FEV1/FVC than either LAV950 or sum-visual in the full cohort (r =  - 0.69 vs. r =  - 0.49/r =  - 0.64, p < 0.001/p = 0.007), in the emphysema cohort (r =  - 0.77 vs. r =  - 0.69/r =  - 0.65, p = 0.03/p = 0.002), and in the random sample (r =  - 0.39 vs. r =  - 0.26/r =  - 0.25, p = 0.001/p = 0.007).

CONCLUSION

The slice-wise whole-lung emphysema score (SWES) correlates better than LAV950 with radiologists' visual emphysema scores and correlates better with airway obstruction than do LAV950 and radiologists' visual scores.

CLINICAL RELEVANCE STATEMENT

The slice-wise whole-lung emphysema score provides quantitative emphysema information for CT imaging that avoids the disadvantages of threshold-based scores and is correlated more strongly with reference tests than LAV950 and reader visual scores.

KEY POINTS

• A slice-wise whole-lung emphysema score (SWES) was developed to quantify emphysema in chest CT images. • SWES identified visual emphysema and spirometric airflow limitation significantly better than threshold-based score (LAV950). • SWES improved emphysema quantification in CT images, which is especially useful in large-scale research.

The influence of image reconstruction methods on the diagnosis of pulmonary emphysema with convolutional neural network

This study investigated the influence of iterative reconstruction (IR) methods on computed tomography (CT) images when training convolutional neural network (CNN) models to diagnose pulmonary emphysema. To evaluate the influence of the IR algorithm on CNN, the present study comprised two steps: the comparison of noise reduction by IR algorithms using phantom examinations and the change in performance of CNN with IR algorithms using patient data. We retrospectively analyzed 97 patients. Raw CT data were reconstructed using the filtered back-projection (FBP) and adaptive statistical iterative reconstruction V (ASIR-V) algorithms with blending levels of 30%, 50%, and 70%. The models were trained using reconstructed CT images and were named the FBP, ASIR-V30, ASIR-V50, and ASIR-V70 models. The mean and the standard deviation of the CT values were 11.3 ± 21.2 at FBP, 11.0 ± 17.3 at ASIR-V30, 11.0 ± 14.4 at ASIR-V50, and 11.0 ± 11.8 at ASIR-V70. For all the evaluation metrics, the best values were obtained with the FBP model applied to the ASIR-V70 test images. The worst values were obtained with the ASIR-V70 model applied to the FBP test images. The model trained with FBP images exhibited significantly better performance than the models trained using IR images. The reduction in image noise with the IR algorithm on the test images contributed to improving the accuracy of the classification of emphysema subtypes using CNN.

Delayed cortical bone healing due to impaired nuclear Nrf2 translocation in COPD mice

The effect of the pathogenesis of chronic obstructive pulmonary disease (COPD) on bone fracture healing is unknown. Oxidative stress has been implicated in the systemic complications of COPD, and decreased activity of Nrf2 signaling, a central component of the in vivo antioxidant mechanism, has been reported. We investigated the process of cortical bone repair in a mouse model of elastase-induced emphysema by creating a drill hole and focusing on Nrf2 and found that the amount of new bone in the drill hole was reduced and bone formation capacity was decreased in the model mice. Furthermore, nuclear Nrf2 expression in osteoblasts was reduced in model mice. Sulforaphane, an Nrf2 activator, improved delayed cortical bone healing in model mice. This study indicates that bone healing is delayed in COPD mice and that impaired nuclear translocation of Nrf2 is involved in delayed cortical bone healing, suggesting that Nrf2 may be a novel target for bone fracture treatment in COPD patients.

Prevalence of genetic mutations in alpha-1 antitrypsin deficiency (aatd) in patients with chronic obstructive pulmonary disease in Colombia

BACKGROUND

Alpha-1 antitrypsin deficiency (AATD) is an underrecognized genetic disorder associated mainly with pulmonary emphysema and Chronic Obstructive Pulmonary Disease (COPD). All individuals with COPD regardless of age or ethnicity should be tested for AATD, but in Colombia its prevalence in unknown.

MAIN OBJECTIVE

To determine the prevalence of the genetic mutations, present in AATD in adult patients with COPD in Colombia, using a genotyping test on cells from the oral mucosa.

METHODS

This was a multicentre, observational, cross-sectional study which included adult patients attending seven COPD care centres in Colombia. Demographic data, medical history, including history of exposure to smoking and biomass smoke, most recent spirometry, pharmacological and non-pharmacological treatment received, serum AAT levels, and mutations detected by the genotyping test were recorded for all the recruited patients. For the comparison of variables between the groups with and without mutation, we used the X² test for the qualitative variables and the Student's t-test or Mann-Whitney U test according to their distribution.

MAIN FINDINGS

We collected a sample of 1,107 patients, the median age was 73.8 years (87.6-79.9). Mutations were documented in 144 patients (13.01%), the majority had the M/S mutation (78.50%), followed by M/Z (9.72%). One patient had a ZZ mutation and two patients had null alleles. In total, 23 patients had mutations associated with serum AAT deficiency (levels below 60 mg/dl).

CONCLUSIONS

Genetic mutations were documented in 13.01% of patients with COPD in Colombia and 2.07% were AATD-related, showing that there is a significant number of underdiagnosed patients.

Pulmonary emphysema and coronary artery calcifications at baseline LDCT and long-term mortality in smokers and former smokers of the ITALUNG screening trial

OBJECTIVES

Cardiovascular disease (CVD), lung cancer (LC), and respiratory diseases are main causes of death in smokers and former smokers undergoing low-dose computed tomography (LDCT) for LC screening. We assessed whether quantification of pulmonary emphysematous changes at baseline LDCT has a predictive value concerning long-term mortality.

METHODS

In this longitudinal study, we assessed pulmonary emphysematous changes with densitometry (volume corrected relative area below - 950 Hounsfield units) and coronary artery calcifications (CAC) with a 0-3 visual scale in baseline LDCT of 524 participants in the ITALUNG trial and analyzed their association with mortality after 13.6 years of follow-up using conventional statistics and a machine learning approach.

RESULTS

Pulmonary emphysematous changes were present in 32.3% of subjects and were mild (6% ≤ RA950 ≤ 9%) in 14.9% and moderate-severe (RA950 > 9%) in 17.4%. CAC were present in 67% of subjects (mild in 34.7%, moderate-severe in 32.2%). In the follow-up, 81 (15.4%) subjects died (20 of LC, 28 of other cancers, 15 of CVD, 4 of respiratory disease, and 14 of other conditions). After adjusting for age, sex, smoking history, and CAC, moderate-severe emphysema was significantly associated with overall (OR 2.22; 95CI 1.34-3.70) and CVD (OR 3.66; 95CI 1.21-11.04) mortality. Machine learning showed that RA950 was the best single feature predictive of overall and CVD mortality.

CONCLUSIONS

Moderate-severe pulmonary emphysematous changes are an independent predictor of long-term overall and CVD mortality in subjects participating in LC screening and should be incorporated in the post-test calculation of the individual mortality risk profile.

KEY POINTS

• Densitometry allows quantification of pulmonary emphysematous changes in low-dose CT examinations for lung cancer screening. • Emphysematous lung density changes are an independent predictor of long-term overall and cardio-vascular disease mortality in smokers and former smokers undergoing screening. • Emphysematous changes quantification should be included in the post-test calculation of the individual mortality risk profile.

GBD 2019 Chronic Respiratory Diseases Collaborators. Global burden of chronic respiratory diseases and risk factors, 1990-2019: an update from the Global Burden of Disease Study 2019

Background

Updated data on chronic respiratory diseases (CRDs) are vital in their prevention, control, and treatment in the path to achieving the third UN Sustainable Development Goals (SDGs), a one-third reduction in premature mortality from non-communicable diseases by 2030. We provided global, regional, and national estimates of the burden of CRDs and their attributable risks from 1990 to 2019.

Methods

Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we estimated mortality, years lived with disability, years of life lost, disability-adjusted life years (DALYs), prevalence, and incidence of CRDs, i.e. chronic obstructive pulmonary disease (COPD), asthma, pneumoconiosis, interstitial lung disease and pulmonary sarcoidosis, and other CRDs, from 1990 to 2019 by sex, age, region, and Socio-demographic Index (SDI) in 204 countries and territories. Deaths and DALYs from CRDs attributable to each risk factor were estimated according to relative risks, risk exposure, and the theoretical minimum risk exposure level input.

Findings

In 2019, CRDs were the third leading cause of death responsible for 4.0 million deaths (95% uncertainty interval 3.6-4.3) with a prevalence of 454.6 million cases (417.4-499.1) globally. While the total deaths and prevalence of CRDs have increased by 28.5% and 39.8%, the age-standardised rates have dropped by 41.7% and 16.9% from 1990 to 2019, respectively. COPD, with 212.3 million (200.4-225.1) prevalent cases, was the primary cause of deaths from CRDs, accounting for 3.3 million (2.9-3.6) deaths. With 262.4 million (224.1-309.5) prevalent cases, asthma had the highest prevalence among CRDs. The age-standardised rates of all burden measures of COPD, asthma, and pneumoconiosis have reduced globally from 1990 to 2019. Nevertheless, the age-standardised rates of incidence and prevalence of interstitial lung disease and pulmonary sarcoidosis have increased throughout this period. Low- and low-middle SDI countries had the highest age-standardised death and DALYs rates while the high SDI quintile had the highest prevalence rate of CRDs. The highest deaths and DALYs from CRDs were attributed to smoking globally, followed by air pollution and occupational risks. Non-optimal temperature and high body-mass index were additional risk factors for COPD and asthma, respectively.

Interpretation

Albeit the age-standardised prevalence, death, and DALYs rates of CRDs have decreased, they still cause a substantial burden and deaths worldwide. The high death and DALYs rates in low and low-middle SDI countries highlights the urgent need for improved preventive, diagnostic, and therapeutic measures. Global strategies for tobacco control, enhancing air quality, reducing occupational hazards, and fostering clean cooking fuels are crucial steps in reducing the burden of CRDs, especially in low- and lower-middle income countries.

Secretoglobin 3A2 protects lung from developing cigarette smoke-induced pulmonary emphysema

Secretoglobin (SCGB) 3A2 is a bioactive molecule exhibiting various functions such as improving allergic airway inflammation and pulmonary fibrosis and promoting bronchial branching and proliferation during lung development. To determine if and how SCGB3A2 is involved in chronic obstructive pulmonary disease (COPD), a multifactorial disease with both airway and emphysematous lesions, a COPD mouse model was created by exposing Scgb3a2-deficient (KO), Scgb3a2-lung-specific overexpressing (TG), and wild type (WT) mice to cigarette smoke (CS) for 6 months. The KO mice showed loss of lung structure under control condition, and CS exposure resulted in more expansion of airspace and destruction of alveolar wall than WT mouse lungs. In contrast, TG mouse lungs showed no significant changes after CS exposure. SCGB3A2 increased the expression and phosphorylation of signal transducers and activators of transcription (STAT)1 and STAT3, and the expression of α1-antitrypsin (A1AT) in mouse lung fibroblast-derived MLg cells and mouse lung epithelial-derived MLE-15 cells. In MLg cells, A1AT expression was decreased in Stat3-knockdown cells, and increased upon Stat3 overexpression. STAT3 formed a homodimer when cells were stimulated with SCGB3A2. Chromatin immunoprecipitation and reporter assays demonstrated that STAT3 binds to specific binding sites on the Serpina1a gene encoding A1AT and upregulates its transcription in lung tissues of mice. Furthermore, nuclear localization of phosphorylated STAT3 upon SCGB3A2 stimulation was detected by immunocytochemistry. These findings demonstrate that SCGB3A2 protects the lungs from the development of CS-induced emphysema by regulating A1AT expression through STAT3 signaling.

Pneumothorax in patients with COPD and emphysema receiving home chronic non-invasive ventilation: is it the emphysema phenotype or ventilator setting?

We describe three patients with chronic obstructive pulmonary disease (COPD) and emphysema who developed a pneumothorax while receiving chronic home non-invasive ventilation (NIV). These cases raise the question whether the high alveolar pressures given by NIV may have contributed to the development of their pneumothorax by barotrauma. Pneumothorax in patients with COPD receiving NIV is uncommon, the pressures in our patients with COPD who developed pneumothorax were not extremely high and time to development of pneumothorax was relatively long after the initiation of NIV. Further, in our patients, the CT scan showed paraseptal emphysema, a known risk factor for pneumothorax. This suggests that COPD/emphysema phenotype is probably a more important factor for indicating pneumothorax risk than ventilator settings. Better phenotyping of patients with COPD in whom benefits of NIV can be expected at minimal risk of serious side-effects is needed to inform our patients properly and bring the field of chronic NIV in COPD forward.

Oxidative stress causes muscle structural alterations via p38 MAPK signaling in COPD mouse model

INTRODUCTION

Sarcopenia is a complication of Chronic Obstructive Pulmonary Disease (COPD) that negatively affects physical activity and quality of life. However, the underlying mechanism by which COPD affects skeletal muscles remains to be elucidated. Therefore, we investigated the association between oxidative stress and structural alterations in muscles in elastase-induced emphysema mouse models.

MATERIALS AND METHODS

Twelve-week-old male C57BL/6J mice were treated with either intratracheal porcine pancreatic elastase (PPE) dissolved in saline, or saline alone. The mice were euthanized 12 weeks after treatment, and the lungs and limb muscles were used for protein analysis of oxidative stress, p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway and muscle atrophy signaling pathway related with oxidative stress. Furthermore, C57BL/6J mice treated with PPE or saline were analyzed for the effects of oral administration of astaxanthin or p38 inhibitor.

RESULTS

The weight of the soleus muscle, proportion of type I muscle fibers, and cross-sectional areas of muscle fibers in the PPE group were lower than those in the control group. Oxidative stress marker levels in the PPE group were elevated in skeletal muscles. The p38 MAPK signaling pathway was activated in the soleus muscles, leading to the activation of the ubiquitin-proteasome system and autophagy. Astaxanthin and p38 inhibitors attenuated alterations in muscle structure through the deactivation of the p38 MAPK signaling pathway.

CONCLUSIONS

This study provides first evidence in COPD mouse model that oxidative stress trigger a series of muscle structural changes. Our findings suggest a novel target for sarcopenia in COPD.

Acute Disseminated Panniculitis Associated with Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency, although one of the most common genetic diseases, is a very rare and often undiagnosed cause of panniculitis. The authors present a case characterized by an acute involvement of several areas in the thorax, abdomen, and limbs, occurring after repetitive trauma of the perineal area caused by a long period of cycling. After performing the differential diagnosis and establishing etiology, the patient was started on augmentation therapy with plasma-derived synthetic human alpha-1 proteinase inhibitor and the disease has been under control since then. We recommend lifelong treatment with this medication. At the end of a 10-year follow-up, there has been no evidence of pulmonary emphysema or liver disease. The authors perform a concise review of the genetic and pathogenic mechanisms behind this disease, with a special focus on panniculitis and its treatment.

[Computed tomographic imaging in chronic obstructive pulmonary disease : What pulmonologists and thoracic surgeons want to know]

Chronic obstructive pulmonary disease (COPD) begins with chronic inflammation of the bronchial system and leads to the development of emphysema in many patients. COPD patients are characterized by reduced performance, dyspnea in the context of an obstructive respiratory disorder and increased susceptibility to infections. COPD has a major impact on public health, as it is very common and many patients die from it. The most important preventable cause of COPD is tobacco smoke inhalation, which is why consistent smoking cessation is the most important component of any COPD treatment. There is no causal therapy, but in severely symptomatic patients with advanced emphysema, respiratory mechanics can be improved by lung volume reduction if all conservative treatment options have been exhausted. Diagnostic imaging is of great importance in the care of COPD patients. This article summarizes which indications warrant the performance of computed tomography (CT) and what we should pay special attention to during image analysis in order to provide optimal advice to our clinical partners.

[Alpha 1-antitrypsin deficiency]

INTRODUCTION

Pulmonary emphysema and liver disease are the clinical expressions of alpha 1-antitrypsin deficiency, an autosomal recessive genetic disease.

STATE OF THE ART

Alpha 1-antitrypsin deficiency is usually associated with the homozygous Z variant of the SERPINA1 gene. Its clinical expression always consists in a substantial reduction of alpha 1-antitrypsin serum concentration and its variants are analyzed by isoelectric focalization or molecular techniques. Assessed by CO transfer alteration and CT scan, risk of pulmonary emphysema is increased by tobacco consumption. Assessed by transient elastography and liver ultrasound, risk of liver disease is increased by alcohol consumption or obesity. Treatment of COPD-associated alpha 1-antitrypsin deficiency does not differ from that of other forms of COPD. In patients presenting with severe deficiency, augmentation therapy with plasma-derived alpha 1-antitrypsin reduces the progression of emphysema, as shown in terms of CT-based lung density metrics. Patients with alpha 1-antitrypsin deficiency with a ZZ genotype should refrain from alcohol or tobacco consumption, and watch their weight; so should their close relatives.

PERSPECTIVES

Modulation of alpha 1-antitrypsin liver production offers an interesting new therapeutic perspective.

CONCLUSION

Homozygous (Z) variants of the SERPINA1 gene confer an increased risk of pulmonary emphysema and liver disease, particularly among smokers, drinkers and obese persons.

Association between visual emphysema and lung nodules on low-dose CT scan in a Chinese Lung Cancer Screening Program (Nelcin-B3)

OBJECTIVES

This study aimed to evaluate the association between visual emphysema and the presence of lung nodules, and Lung-RADS category with low-dose CT (LDCT).

METHODS

Baseline LDCT scans of 1162 participants from a lung cancer screening study (Nelcin-B3) performed in a Chinese general population were included. The presence, subtypes, and severity of emphysema (at least trace) were visually assessed by one radiologist. The presence, size, and classification of non-calcified lung nodules (≥ 30 mm³) and Lung-RADS category were independently assessed by another two radiologists. Multivariable logistic regression and stratified analyses were performed to estimate the association between emphysema and lung nodules, Lung-RADS category, after adjusting for age, sex, BMI, smoking status, pack-years, and passive smoking.

RESULTS

Emphysema and lung nodules were observed in 674 (58.0%) and 424 (36.5%) participants, respectively. Participants with emphysema had a 71% increased risk of having lung nodules (adjusted odds ratios, aOR: 1.71, 95% CI: 1.26-2.31) and 70% increased risk of positive Lung-RADS category (aOR: 1.70, 95% CI: 1.09-2.66) than those without emphysema. Participants with paraseptal emphysema (n = 47, 4.0%) were at a higher risk for lung nodules than those with centrilobular emphysema (CLE) (aOR: 2.43, 95% CI: 1.32-4.50 and aOR: 1.60, 95% CI: 1.23-2.09, respectively). Only CLE was associated with positive Lung-RADS category (p = 0.02). CLE severity was related to a higher risk of lung nodules (ranges aOR: 1.44-2.61, overall p < 0.01).

CONCLUSION

In a Chinese general population, visual emphysema based on LDCT is independently related to the presence of lung nodules (≥ 30 mm³) and specifically CLE subtype is related to positive Lung-RADS category. The risk of lung nodules increases with CLE severity.

KEY POINTS

• Participants with emphysema had an increased risk of having lung nodules, especially smokers. • Participants with PSE were at a higher risk for lung nodules than those with CLE, but nodules in participants with CLE had a higher risk of positive Lung-RADS category. • The risk of lung nodules increases with CLE severity.

Natural products in the treatment of pulmonary emphysema: Therapeutic effects and mechanisms of action

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a class of lung diseases including chronic bronchitis, asthma, and emphysema. Long-time smoking is considered the main reason for developing emphysema. Emphysema can be defined as damage to the walls of the air sacs (alveoli) of the lung. It has been demonstrated that natural compounds with antioxidant and anti-inflammatory effects can effectively improve or protect the lung against this disease. This paper is dedicated to systematically review the effective natural compounds in the treatment of pulmonary emphysema.

PURPOSE

This is the first systematic and comprehensive review on the role of plant-derived secondary metabolites in managing and/or treating pulmonary emphysema STUDY DESIGN AND METHODS: A systematic and comprehensive review was done based on Scopus, PubMed, and Cochrane Library databases were searched using the "emphysema", "plant", "herb", and "phytochemical" keywords. Non-English, review, and repetitive articles were excluded from the study. Search results were included in the Prisma diagram.

RESULTS

From a total of 1285 results, finally, 22 articles were included in the present study. The results show that some herbs such as Scutellaria baicalensis Georgi and Monascus adlay and some phytochemicals such as gallic acid and quercetin and blackboard tree indole alkaloids affect more factors in improving the lung emphysema. Also, some natural compounds such as marijuana smoke and humic acid also play an aggravating role in this disease. It also seems that some of the medicinal plants such as PM014 herbal formula, pomegranate juice and açaí berry sometimes have side effects that are inconsistent with their therapeutic effects.

CONCLUSION

We concluded that natural compounds can effectively improve pulmonary emphysema due to their antioxidant, anti-inflammatory, and anti-apoptotic properties. However, additional studies are suggested to prove efficacy and side effects.

Association between plasma sRAGE and emphysema according to the genotypes of AGER gene

Background

Higher soluble receptor for advanced glycation end product (sRAGE) levels are considered to be associated with severe emphysema. However, the relationship remains uncertain when the advanced glycation end-product specific receptor (AGER) gene is involved. We aimed to analyse the association between sRAGE levels and emphysema according to the genotypes of rs2070600 in the AGER gene.

Methods

We genotyped rs2070600 and measured the plasma concentration of sRAGE in each participant. Emphysema was quantified based on the chest computed tomography findings. We compared sRAGE levels based on the presence or absence and severity of emphysema in each genotype. Multiple logistic and linear regression models were used for the analyses.

Results

A total of 436 participants were included in the study. Among them, 64.2% had chronic obstructive pulmonary disease and 34.2% had emphysema. Among the CC-genotyped participants, the sRAGE level was significantly higher in participants without emphysema than in those with emphysema (P < 0.001). In addition, sRAGE levels were negatively correlated with emphysema severity in CC-genotyped patients (r = − 0.268 P < 0.001). Multiple regression analysis revealed that sRAGE was an independent protective factor for the presence of emphysema (adjusted odds ratio, 0.24; 95% confidence interval (CI) 0.11–0.51) and severity of emphysema (β = − 3.28, 95% CI − 4.86 to − 1.70) in CC-genotyped participants.

Conclusion

Plasma sRAGE might be a biomarker with a protective effect on emphysema among CC-genotyped patients of rs2070600 on the AGER gene. This is important in determining the target group for the future prediction and treatment of emphysema.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01848-9.

Quantification of pulmonary perfusion abnormalities using DCE-MRI in COPD: comparison with quantitative CT and pulmonary function

Objectives

Pulmonary perfusion abnormalities are prevalent in patients with chronic obstructive pulmonary disease (COPD), are potentially reversible, and may be associated with emphysema development. Therefore, we aimed to evaluate the clinical meaningfulness of perfusion defects in percent (QDP) using DCE-MRI.

Methods

We investigated a subset of baseline DCE-MRIs, paired inspiratory/expiratory CTs, and pulmonary function testing (PFT) of 83 subjects (age = 65.7 ± 9.0 years, patients-at-risk, and all GOLD groups) from one center of the “COSYCONET” COPD cohort. QDP was computed from DCE-MRI using an in-house developed quantification pipeline, including four different approaches: Otsu’s method, k-means clustering, texture analysis, and 80^th percentile threshold. QDP was compared with visual MRI perfusion scoring, CT parametric response mapping (PRM) indices of emphysema (PRM_Emph) and functional small airway disease (PRM_fSAD), and FEV1/FVC from PFT.

Results

All QDP approaches showed high correlations with the MRI perfusion score (r = 0.67 to 0.72, p < 0.001), with the highest association based on Otsu’s method (r = 0.72, p < 0.001). QDP correlated significantly with all PRM indices (p < 0.001), with the strongest correlations with PRM_Emph (r = 0.70 to 0.75, p < 0.001). QDP was distinctly higher than PRM_Emph (mean difference = 35.85 to 40.40) and PRM_fSAD (mean difference = 15.12 to 19.68), but in close agreement when combining both PRM indices (mean difference = 1.47 to 6.03) for all QDP approaches. QDP correlated moderately with FEV1/FVC (r = − 0.54 to − 0.41, p < 0.001).

Conclusion

QDP is associated with established markers of disease severity and the extent corresponds to the CT-derived combined extent of PRM_Emph and PRM_fSAD. We propose to use QDP based on Otsu’s method for future clinical studies in COPD.

Key Points

• QDP quantified from DCE-MRI is associated with visual MRI perfusion score, CT PRM indices, and PFT.

• The extent of QDP from DCE-MRI corresponds to the combined extent of PRM_Emph and PRM_fSAD from CT.

• Assessing pulmonary perfusion abnormalities using DCE-MRI with QDP improved the correlations with CT PRM indices and PFT compared to the quantification of pulmonary blood flow and volume.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-08229-6.

Upregulation of leukocyte immunoglobulin-like receptor B4 on interstitial macrophages in COPD; their possible protective role against emphysema formation

Background

Leukocyte immunoglobulin-like receptor B4 (LILRB4) is one of the inhibitory receptors in various types of immune cells including macrophages. Previous reports suggested that LILRB4 could be involved in a negative feedback system to prevent excessive inflammatory responses. However, its role has been unclear in chronic obstructive pulmonary disease (COPD), in which macrophages play a crucial role in the pathogenesis. In this study, we aimed to examine the changes of LILRB4 on macrophages both in the lung specimens of COPD patients and the lungs of a mouse emphysema model. We then tried to compare the differences in both inflammation and emphysematous changes of the model between wild-type and LILRB4-deficient mice in order to elucidate the role of LILRB4 in the pathogenesis of COPD.

Methods

We prepared single-cell suspensions of resected lung specimens of never-smokers (n = 21), non-COPD smokers (n = 16), and COPD patients (n = 14). The identification of LILRB4-expressing cells and the level of LILRB4 expression were evaluated by flow cytometry. We analyzed the relationships between the LILRB4 expression and clinical characteristics including respiratory function. In the experiments using an elastase-induced mouse model of emphysema, we also analyzed the LILRB4 expression on lung macrophages. We compared inflammatory cell accumulation and emphysematous changes induced by elastase instillation between wild-type and LILRB4-deficient mice.

Results

The levels of surface expression of LILRB4 are relatively high on monocyte linage cells including macrophages in the human lungs. The percentage of LILRB4⁺ cells in lung interstitial macrophages was increased in COPD patients compared to non-COPD smokers (p = 0.018) and correlated with the severity of emphysematous lesions detected by CT scan (r_s = 0.559, p < 0.001), whereas the amount of smoking showed no correlation with LILRB4 expression. Increased LILRB4 on interstitial macrophages was also observed in elastase-treated mice (p = 0.008). LILRB4-deficient mice showed severer emphysematous lesions with increased MMP-12 expression in the model.

Conclusions

LILRB4 on interstitial macrophages was upregulated both in human COPD lungs and in a mouse model of emphysema. This upregulated LILRB4 may have a protective effect against emphysema formation, possibly through decreasing MMP-12 expression in the lungs.

Tumor size in patients with severe pulmonary emphysema might be underestimated on preoperative CT

OBJECTIVES

To evaluate the effect of emphysema on tumor diameter measured on preoperative computed tomography (CT) images versus pathological specimens.

MATERIALS AND METHODS

We investigated patients who underwent primary lung cancer surgery: 55 patients (57 tumors) with severe emphysema and 57 patients (57 tumors) without emphysema. The tumor diameters measured in the postoperative pathological specimens were compared with those measured on the axial CT images and on multiplanar reconstruction (MPR) CT images by two independent radiologists; a subgroup analysis according to tumor size was also performed. A paired or unpaired t test was performed, depending on the tested subjects.

RESULTS

In the emphysema group, the mean axial CT diameter was significantly smaller than the mean pathological diameter (p = 0.025/0.001 for reader 1/2), whereas in the non-emphysema group, the mean axial CT diameter was not significantly different from the pathological one for both readers. The difference between CT axial diameter and pathological diameter (= CT diameter - pathological diameter) was significantly smaller (i.e., had a stronger tendency toward underestimation on radiological measurements) in the emphysema group compared with the non-emphysema group (p = 0.014/0.008 for reader 1/2), and the difference was significantly smaller in tumors sized > 30 mm than tumors sized ≤ 20 mm in both groups.

CONCLUSIONS

Tumor size is significantly smaller on preoperative CT in patients with severe emphysema compared to patients without emphysema, especially in the case of large tumors. MPR measurement using the widest of three dimensions should be used to select T-stage for patients with severe emphysema.

KEY POINTS

• The presence of emphysema affects the accuracy of tumor size measurements on CT. • Compared to patients without emphysema, the tumor size in severe emphysema patients tends to be measured smaller in preoperative CT than the pathological specimen. • This trend is more evident when large tumors are measured on axial CT images alone.

Quasilobar minimalist lung volume reduction surgery

 

OBJECTIVES

Our goal was to assess the results and the costs of the quasilobar minimalist (QLM) thoracoscopic lung volume reduction (LVR) surgical method developed to minimize the trauma from the operation and the anaesthesia and to maximize the effect of the lobar volume reduction.

METHODS

Forty patients with severe emphysema underwent QLM-LVR that entailed adoption of sole intercostal block analgesia and lobar plication through a single thoracoscopic incision. Results were compared after propensity matching with 2 control groups undergoing non-awake resectional LVR with double-lumen tracheal intubation or awake non-resectional LVR by plication with thoracic epidural anaesthesia. As a result, we had 3 matched groups of 30 patients each.

RESULTS

Baseline forced expiratory volume in 1 s, residual volume, the 6-min walking test and the modified Medical Research Council dyspnoea index were 0.77 ± 0.18, 4.97 ± 0.6, 328 ± 65 and 3.3 ± 0.7, respectively, with no intergroup difference after propensity score matching. The visual pain score was better (P < 0.007), the hospital stay was shorter (P < 0.04) and overall costs were lower (P < 0.04) in the QLM-LVR group than in the control groups. The morbidity rate was lower with QLM-LVR than with non-awake resectional-LVR (P = 0.006). Significant improvements (P < 0.001) occurred in all study groups during the follow-up period. At 24 months, improvements in residual volume and dyspnoea index were significantly better with QLM-LVR (P < 0.04).

CONCLUSIONS

QLM-LVR proved safe and showed better perioperative outcomes and lower procedure-related costs than the control groups. Similar clinical benefit occurred at 12 months, but absolute improvements in residual volume and dyspnoea index were better in the QLM-LVR group at 24 months.

Ultra-low-dose CT combined with noise reduction techniques for quantification of emphysema in COPD patients: An intra-individual comparison study with standard-dose CT

PURPOSE

Phantom studies in CT emphysema quantification show that iterative reconstruction and deep learning-based noise reduction (DLNR) allow lower radiation dose. We compared emphysema quantification on ultra-low-dose CT (ULDCT) with and without noise reduction, to standard-dose CT (SDCT) in chronic obstructive pulmonary disease (COPD).

METHOD

Forty-nine COPD patients underwent ULDCT (third generation dual-source CT; 70ref-mAs, Sn-filter 100kVp; median CTDIvol 0.38 mGy) and SDCT (64-multidetector CT; 40mAs, 120kVp; CTDIvol 3.04 mGy). Scans were reconstructed with filtered backprojection (FBP) and soft kernel. For ULDCT, we also applied advanced modelled iterative reconstruction (ADMIRE), levels 1/3/5, and DLNR, levels 1/3/5/9. Emphysema was quantified as Low Attenuation Value percentage (LAV%, ≤-950HU). ULDCT measures were compared to SDCT as reference standard.

RESULTS

For ULDCT, the median radiation dose was 84 % lower than for SDCT. Median extent of emphysema was 18.6 % for ULD-FBP and 15.4 % for SDCT (inter-quartile range: 11.8-28.4 % and 9.2 %-28.7 %, p = 0.002). Compared to SDCT, the range in limits of agreement of emphysema quantification as measure of variability was 14.4 for ULD-FBP, 11.0-13.1 for ULD-ADMIRE levels and 10.1-13.9 for ULD-DLNR levels. Optimal settings were ADMIRE 3 and DLNR 3, reducing variability of emphysema quantification by 24 % and 27 %, at slight underestimation of emphysema extent (-1.5 % and -2.9 %, respectively).

CONCLUSIONS

Ultra-low-dose CT in COPD patients allows dose reduction by 84 %. State-of-the-art noise reduction methods in ULDCT resulted in slight underestimation of emphysema compared to SDCT. Noise reduction methods (especially ADMIRE 3 and DLNR 3) reduced variability of emphysema quantification in ULDCT by up to 27 % compared to FBP.

Swyer-James-MacLeod syndrome presenting as spontaneous pneumothorax in an adult: Case report and review of literature

Swyer-James-MacLeod Syndrome (SJMS) is an uncommon, emphysematous disease characterized by obliteration of the small bronchioles, hypoplasia/or absence of pulmonary artery and peripheral vascular bed. It is most commonly diagnosed in childhood. Patients are often asymptomatic or they could suffer from symptoms of recurrent pulmonary infections. Spontaneous pneumothorax is a rare presentation of this syndrome. We report a case of a 42-year old female patient presented at our Emergency Department with complaints of dyspnea and pleuritic chest pain with a diagnosis of spontaneous pneumothorax in emphysematous disease. The diagnosis of SJMS is usually based on imaging and clinical findings rather than on the results of pathologic examination; indeed, asymptomatic adult patients with SJMS are often diagnosed after a chest radiograph obtained for another reason. High-resolution computed tomography (HRCT) seems to be the most appropriate technique for the diagnosis. SJMS can be associated with spontaneous pneumothorax which represent an emergency condition due to the underlying pathological disease. The surgical treatment of the affected lung should be considered when conservative approach is ineffective.

Vascular Ehlers-Danlos syndrome (vEDS): CT and histologic findings of pleural and lung parenchymal damage

OBJECTIVES

To describe CT features of lung involvement in patients with vascular Ehlers-Danlos syndrome (vEDS), a rare genetic condition caused by pathogenic variants within the COL3A1 gene, characterized by recurrent arterial, digestive, and pulmonary events.

MATERIAL AND METHODS

All consecutive vEDS patients referred to the national tertiary referral center for vEDS, between 2004 and 2016, were included. Chest CT scans obtained during the initial vascular work-up were reviewed retrospectively by two chest radiologists for lung involvement. Five surgical samples underwent histologic examination.

RESULTS

Among 136 enrolled patients (83 women, 53 men; mean age 37 years) with molecularly confirmed vEDS, 24 (17.6%) had a history of respiratory events: 17 with pneumothorax, 4 with hemothorax, and 3 with hemoptysis that required thoracic surgery in 11. CT scans detected lung parenchymal abnormalities in 78 (57.3%) patients: emphysema (mostly centrilobular and paraseptal) in 44 (32.3%), comparable for smokers and non-smokers; clusters of calcified small pulmonary nodules in 9 (6.6%); and cavitated nodules in 4 (2.9%). Histologic examination of surgical samples found arterial abnormalities, emphysema with alveolar ruptures in 3, accompanied by diffuse hemorrhage and increased hemosiderin resorption.

CONCLUSION

In vEDS patients, identification of lung parenchymal abnormalities is common on CT. The most frequently observed CT finding was emphysema suggesting alveolar wall rupture which might facilitate the diagnostic screening of the disease in asymptomatic carriers of a genetic COL3A1 gene mutation. The prognostic value and evolution of these parenchymal abnormalities remain to be evaluated.

KEY POINTS

• Patients with vEDS can have lung parenchymal changes on top of or next to thoracal vascular abnormalities and that these changes can be present in asymptomatic cases. • The presence of these parenchymal changes is associated with a slightly higher incidence of respiratory events (although not statistically significant). • Identification of the described CT pattern by radiologists and chest physicians may facilitate diagnostic screening.

Pulmonary emphysema, bullae, and pneumothorax in COVID-19 pneumonia

In this paper, we described 2 cases with COVID-19 pneumonia, who developed pulmonary emphysema, bullae, and pneumothorax during therapy. In a 48-year-old man with mechanical ventilation, parts of ground glass opacities and consolidations transformed into emphysema and giant bulla, and bilateral pneumothorax were also observed. In a 35-year-old man, localized emphysema and pulmonary bullae were seen in subpleural area in bilateral upper lobes, where no previous lesions were presented. In conclusion, pulmonary emphysema, bullae, and pneumothorax could be complications of COVID-19. On one hand, surgical emphysema in ventilated COVID-19 patients was observed as in SARS patients. On the other hand, more serious destruction of lung parenchyma was found in COVID-19 patients.

Fatal pulmonary fibrosis complicating COVID-19 infection in preexistent emphysema

Only a few earlier clinical radiologic reports exist describing post-COVID-19 pulmonary fibrosis. We report a case of 74-year-old woman referred with dizziness and hypoxemic respiratory failure with chest high resolution computer tomography (HRCT) showing ground glass opacities and emphysema. The patient was tested for Sars-CoV-2 and resulted positive, she was treated with medical therapy and supported with mechanical ventilation. Despite initial clinical and radiological improvements, subsequently the respiratory failure worsened as ground glass opacities evolved, with the appearance of combined pulmonary fibrosis and emphysema and the patient eventually died. Development of pulmonary fibrosis after SARS-CoV-2 infection and the overlap with preexistent emphysema could be a fatal complication.

Characteristics of non-small-cell lung cancer with interstitial pneumonia: variation in cancer location, histopathology, and frequency of postoperative acute exacerbations in interstitial pneumonia

Background

Non–small-cell lung cancer (NSCLC) has been reported to develop in patients with interstitial pneumonia (IP); however, clinical, radiological, and pathological features remain to be elucidated.

Methods

We retrieved the records of 120 consecutive NSCLC patients associated with IP who underwent surgery at Toranomon Hospital between June 2011 and May 2017. We classified the patients into three groups according to NSCLC location using high-resolution computed tomography: group A, within a fibrotic shadow and/or at the interface of a fibrotic shadow and normal lung; group B, within emphysematous tissue and/or at the interface of emphysematous tissue and normal lung; and group C, within normal lung. In 64 patients, programmed death ligand-1 (PD-L1) status was assessed with immunohistostaining.

Results

Most of the patients (89; 70%) were classified as group A. This group tended to have squamous cell carcinoma with the usual interstitial pneumonia (UIP). These cancers were located mainly in the lower lobes and seven of the eight postoperative acute exacerbations (pAE) of IP developed in this group. NSCLC in the group B were mainly squamous cell carcinomas located in the upper lobes. No patient with PD-L1 negative was classified into group B. None of the patients in group C showed UIP. and most of the cancers were adenocarcinoma. The frequency of epidermal growth factor receptor mutation-positive NSCLC was the highest in this group.

Conclusions

The three groups each showed characteristic features in terms of tumor location, histopathology, PD-L1 expression, and frequency of pAEof IP.

Differentiating combined pulmonary fibrosis and emphysema from pure emphysema: utility of late gadolinium-enhanced MRI

Background

Differentiating combined pulmonary fibrosis with emphysema (CPFE) from pure emphysema can be challenging on high-resolution computed tomography (HRCT). This has antifibrotic therapy implications.

Methods

Twenty patients with suspected CPFE underwent late gadolinium-enhanced (LGE) thoracic magnetic resonance imaging (LGE-MRI) and HRCT. Data from twelve healthy control subjects from a previous study who underwent thoracic LGE-MRI were included for comparison. Quantitative LGE signal intensity (SI) was retrospectively compared in regions of fibrosis and emphysema in CPFE patients to similar lung regions in controls. Qualitative comparisons for the presence/extent of reticulation, honeycombing, and traction bronchiectasis between LGE-MRI and HRCT were assessed by two readers in consensus.

Results

There were significant quantitative differences in fibrosis SI compared to emphysema SI in CPFE patients (25.8, IQR 18.4–31.0 versus 5.3, IQR 5.0–8.1, p < 0.001). Significant differences were found between LGE-MRI and HRCT in the extent of reticulation (12.5, IQR 5.0–20.0 versus 25.0, IQR 15.0–26.3, p = 0.038) and honeycombing (5.0, IQR 0.0–10.0 versus 20.0, IQR 10.6–20.0, p = 0.001) but not traction bronchiectasis (10.0, IQR 5–15 versus 15.0, IQR 5–15, p = 0.878). Receiver operator curve analysis of fibrosis SI compared to similarly located regions in control subjects showed an area under the curve of 0.82 (p = 0.002). A SI cutoff of 19 yielded a sensitivity of 75% and specificity of 86% in differentiating fibrosis from similarly located regions in control subjects.

Conclusion

LGE-MRI can differentiate CPFE from pure emphysema and may be a useful adjunct test to HRCT in patients with suspected CPFE.

Automated computed tomography quantification of fibrosis predicts prognosis in combined pulmonary fibrosis and emphysema in a real-world setting: a single-centre, retrospective study

BACKGROUND

Combined pulmonary fibrosis and emphysema (CPFE) is a heterogeneous clinico-radiological syndrome without a consensus definition. There are limited data on the relation between the amount of parenchymal fibrosis and prognosis. In this study, we assessed the prognostic implications of the extent of fibrosis assessed by an automated quantitative computed tomography (CT) technique and the radiological and functional change over time in patients with a broad spectrum of fibrotic interstitial lung diseases (ILDs) encountered in a real-world setting.

METHODS

We conducted a single-centre, retrospective study of 228 consecutive patients with CPFE, encountered from 2007 to 2015 at Kameda Medical Center, Chiba, Japan. We investigated the prognostic value of automated CT fibrosis quantification and the subsequent course of CPFE.

RESULTS

Among 228 patients with CPFE, 89 had fibrosis affecting < 5% of their lungs, 54 had 5 to < 10% fibrosis, and 85 had ≥ 10% fibrosis at the time of diagnosis. Lower volume of fibrosis correlated with lower rates of mortality and acute exacerbation (p < 0.001). In particular, among those with < 5% fibrosis, only 4.5% died and none experienced acute exacerbation during follow-up, whereas 57.6% and 29.4% of those with ≥ 10% fibrosis experienced death and acute exacerbation, respectively. Although, the ≥ 10% fibrosis group had the poorest overall survival as well as the highest incidence of acute exacerbation, the incidence of decline in pulmonary function tests, change per year in total lung volume, and progression of fibrosis on chest CT was highest in the 5 to < 10% fibrosis group. The Cox proportional hazard model for CPFE progression (defined by composite criteria of death, acute exacerbation, and decline in forced vital capacity or diffusing capacity) showed fibrosis proportion was a risk factor independent of age, sex, smoking pack-years, the Charlson Comorbidity Index, lung cancer, connective tissue disease, and idiopathic pulmonary fibrosis.

CONCLUSIONS

Less severe (< 5%) fibrosis at baseline was associated with disease stability and better prognosis compared to more severe fibrosis in CPFE occurring with fibrotic ILDs. Further studies including a validation cohort will be needed. Trial Registration Retrospectively registered.

Cluster analysis based clinical profiling of Idiopathic Pulmonary Fibrosis patients according to comorbidities evident prior to diagnosis: a single-center observational study

BACKGROUND

The characterization and clinical profiling of people affected by Idiopathic Pulmonary Fibrosis (IPF), based on clinical events occurring prior to the diagnosis of the fibrotic disease, may facilitate the understanding of events and comorbidities that occur before the diagnosis of IPF and aid in identifying patients at an earlier stage of the disease.

METHODS

In this observational study, a cohort of 96 patients, obtained from a community-based pulmonary clinic, were studied retrospectively. These patients were diagnosed with IPF between January 2008 and November 2016, based on findings on lung biopsy and/or high-resolution CT. Using clinical data obtained within the five years before diagnosis and the two-step method of cluster analysis, patients were assigned to one of four groups. The distribution of clinical characteristics and comorbidities present prior to diagnosis was analyzed among the clusters.

RESULTS

Cluster 1 is composed of male patients, smokers, with ischemic heart disease. Cluster 2 is composed of male patients, smokers with dyspnea at rest, dry cough and prevalent emphysema. Cluster 3 is composed of male patients without other significant comorbidities, half of whom had dyspnea at exertion. Cluster 4 includes female patients only, most of whom never-smokers and the largest portion of patients with hypothyroidism. The majority of patients had basal end-inspiratory crackles at time of diagnosis, equally distributed among clusters.

CONCLUSION

Different clinical phenotypes of IPF emerge years before time of diagnosis and if confirmed in larger cohorts may help in forming diagnostic algorithms that would allow earlier diagnosis of IPF.

Lowest observed adverse effect level of pulmonary pathological alterations due to nitrous acid exposure in guinea pigs

BACKGROUND

We previously demonstrated that continuous exposure to nitrous acid gas (HONO) for 4 weeks, at a concentration of 3.6 parts per million (ppm), induced pulmonary emphysema-like alterations in guinea pigs. In addition, we found that HONO affected asthma symptoms, based on the measurement of respiratory function in rats exposed to 5.8 ppm HONO. This study aimed to investigate the dose-response effects of HONO exposure on the histopathological alterations in the respiratory tract of guinea pigs to determine the lowest observed adverse effect level (LOAEL) of HONO.

METHODS

We continuously exposed male Hartley guinea pigs (n = 5) to four different concentrations of HONO (0.0, 0.1, 0.4, and 1.7 ppm) for 4 weeks (24 h/day). We performed histopathological analysis by observing lung tissue samples. We examined samples from three guinea pigs in each group under a light microscope and measured the alveolar mean linear intercept (Lm) and the thickness of the bronchial smooth muscle layer. We further examined samples from two guinea pigs in each group under a scanning electron microscope (SEM) and a transmission electron microscope (TEM).

RESULTS

We observed the following dose-dependent changes: pulmonary emphysema-like alterations in the centriacinar regions of alveolar ducts, significant increase in Lm in the 1.7 ppm HONO-exposure group, tendency for hyperplasia and pseudostratification of bronchial epithelial cells, and extension of the bronchial epithelial cells and smooth muscle cells in the alveolar duct regions.

CONCLUSIONS

These histopathological findings suggest that the LOAEL of HONO is < 0.1 ppm.

Indole alkaloids from leaves of Alstonia scholaris (L.) R. Br. protect against emphysema in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Alstonia scholaris (L.) R. Br. (Apocynaceae) is a medicinal plant in China traditionally used to treat pulmonary diseases, including bronchitis, whooping cough, asthma and chronic obstructive pulmonary disease.

AIM OF THE STUDY

To provide experimental data supporting clinical adaptation of total indole alkaloids ( TA) from A. scholaris leaves for treating emphysema.

MATERIALS AND METHODS

An emphysema model was induced by a single intratracheal instillation of porcine pancreatic elastase followed by administration of TA and four main alkaloid components (scholaricine, 19-epischolaricine, vallesamine, and picrinine) for 30 consecutive days. Cytokine levels, histopathological parameters and protein expression in lung tissues were examined.

RESULTS

Administering the TA, picrinine, scholaricine, 19-epischolaricine and vallesamine for 30 days effectively inhibited inflammatory cell accumulation and invasion in the lung tissue and relieved pulmonary tissue injury. Oxygen saturation was enhanced, and interleukin (IL)-1β, monocyte-chemo attractive peptide 1, IL-11, matrix metalloproteinase-12, transforming growth factor-β and vascular endothelial growth factor levels were significantly reduced, likely by suppressing overactivation of alveolar macrophages and pulmonary fibrosis. The elastin content was markedly elevated, and fibronectin was reduced. Bcl-2 expression was significantly increased, and nuclear factor-κB and β-catenin levels were decreased.

CONCLUSIONS

TA can be potentially used as an effective novel drug for pulmonary emphysema and exerts its effects through not only inhibiting inflammation of the airway wall and airflow resistance but also promoting lung elastic recoil and protease/anti-protease balance.

Comment on "Allogeneic umbilical cord-derived mesenchymal stem cell transplantation for treating chronic obstructive pulmonary disease: a pilot clinical study"

In the clinical study by Le Thi Bich et al., allogeneic expanded umbilical cord-derived mesenchymal stem cells (UC-MSCs) were intravenously infused to treat patients with chronic obstructive pulmonary disease (COPD). No severe or significant adverse effects were observed, while a significant improvement in COPD patients’ quality of life was reported up to 6 months. In addition, the authors argue that bone marrow-derived cells are not suitable to treat COPD based on the “failure” of 3 clinical trials (NCT01110252, NCT01306513, and NCT00683722). In fact, Le Thi Bich et al. and the three above-mentioned studies reported similar clinical outcomes, id est., no significant improvement in the pulmonary function of COPD patients. Therefore, since no COPD treatment involving cells either from bone marrow or umbilical cord was detrimental or provided lung regeneration in human patients, in our view, it is too early to point failures of cellular sources. Instead, it is a valuable opportunity to reflect on the poorly understood therapeutic mechanism of MSCs and the pathophysiology of COPD. In respect of cellular sources, only controlled trials with a strict comparison between different tissues might determine the suitability and efficacy of specific cell types to treat COPD. Finally, further studies are still required to determine whether and via which mechanism MSCs are able to provide structural and functional restoration of gas exchange in COPD patients.

Risk factors associated with the detection of pulmonary emphysema in older asymptomatic respiratory subjects

Background

Several lung structural and functional abnormalities may occur associated with aging, including emphysema. In this study, we evaluated the frequency and risk factors associated with emphysema in respiratory asymptomatic individuals enrolled in our Lung Aging Program. From a cohort of 687 subjects, we found by high-resolution computed tomography (HRCT) 29 individuals (4%) with emphysematous changes that were compared with 87 controls (3:1) randomly selected from the same cohort.

Methods

This was a transversal, observational, case-control study where we examined demographics and functional characteristics, as well as telomere length and serum Klotho concentration, two conditions that have been associated with aging and some aging-associated diseases including emphysema.

Results

Individuals with subclinical pulmonary emphysema were older (72 ± 9 versus 67 ± 6 years), and primarily smoker males with low body mass index. Despite that they were asymptomatic, two of them exhibited a decrease of forced expiratory volume in 1 s (FEV₁), with a lower FEV₁/FVC suggesting airway obstruction. Cigarette smoking (OR = 5.43, CI95% 1.8–16.7), family history of lung disease (OR = 4.32, CI95% 1.0–19.0) and lower body mass index (OR 7.22, CI95% 1.2–3.5) were risk factors for the development of lung emphysematous changes. No association was found with telomere length and Klotho serum concentration.

Conclusion

Our findings reveal that a small but important percentage of older people without respiratory symptoms, present pulmonary emphysema and indicate that smoking exposure and genetic background may contribute to etiological factors.

Thinking in paracoccidioidomycosis: a delayed diagnosis of a neglected tropical disease, case report and review of clinical reports and eco-epidemiologic data from Colombia since the 2000

BACKGROUND

Paracoccidioidomycosis is a neglected tropical disease, endemic in several countries of South America including Colombia. We report a case of a patient with Chronic Multifocal Paracoccidioidomycosis with long-standing symptoms and a delayed diagnosis caused by several barriers to achieve it. We did a review of the papers published in Colombia about this disease, focusing in clinical data and eco-epidemiology with the finding of a lack of new information on this topic since the 2000 in our region.

CASE PRESENTATION

We present a 54-year-old man, farmer in his youth, with a chronic ulcerated lesion in the lower lip similar to a lip carcinoma, a deforming lesion in the nose, and respiratory symptoms with emphysematous lung. Lip biopsy with silver methenamine stain revealed small and large budding yeasts that resembles a "mariner's wheel" confirming Chronic Multifocal Paracoccidioidomycosis. He was treated successfully but subsequently lost to follow up.

CONCLUSIONS

It is very important to focus attention, reinforce the search and create networks for the study of neglected tropical diseases. The presented case illustrates a usual clinical presentation, but with a delayed diagnosis due to the difficulties that still occur in some regions like ours for the early recognition of a case of chronic multifocal paracoccidioidomycosis.

Phytochemical study, molecular docking, genotoxicity and therapeutic efficacy of the aqueous extract of the stem bark of Ximenia americana L. in the treatment of experimental COPD in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ximenia americana L. is popularly known as yellow plum, brave plum or tallow wood. All the parts of this plant are used in popular medicine. Its reddish and smooth bark are used to treat skin infections, inflammation of the mucous membranes and in the wound healing process.

OBJECTIVE

Verification of phytochemical profile, the molecular interaction between flavonoid, (-) epi-catechin and 5-LOX enzyme, by means of in silico study, the genotoxic effect and to investigate the pharmacological action of the aqueous extract of the stem bark of X. americana in pulmonary alterations caused by experimental COPD in Rattus norvegicus.

MATERIALS AND METHODS

The identification of secondary metabolites was carried out by TLC and HPLC chromatographic methods, molecular anchoring tests were applied to analyze the interaction of flavonoid present in the extract with the enzyme involved in pulmonary inflammation process and the genotoxic effect was assessed by comet assay and micronucleus test. For induction of COPD, male rats were distributed in seven groups. The control group was exposed only to ambient air and six were subjected to passive smoke inhalations for 20 min/day for 60 days. One of the groups exposed to cigarette smoke did not receive treatment. The others were treated by inhalation with beclomethasone dipropionate (400 mcg/kg) and aqueous and lyophilized extracts of X. americana (500 mg/kg) separately or in combination for a period of 15 days. The structural and inflammatory pulmonary alterations were evaluated by histological examination. Additional morphometric analyses were performed, including the alveolar diameter and the thickness of the right ventricle wall.

RESULTS

The results showed that the aqueous extract of the bark of X. americana possesses (-) epi -catechin, in silico studies with 5-LOX indicate that the EpiC ligand showed better affinity parameters than the AracA ligand, which is in accordance with the results obtained in vivo studies. Genotoxity was not observed at the dose tested and the extract was able to stagnate the alveolar enlargement caused by the destruction of the interalveolar septa, attenuation of mucus production and decrease the presence of collagen fibers in the bronchi of animals submitted to cigarette smoke.

CONCLUSION

Altogether, the results proved that the aqueous extract of X. americana presents itself as a new option of therapeutic approach in the treatment of COPD.

[Bioinformatics analysis of severe emphysema genome microarray based on GEO database]

Objective: To investigate differential genes (DEGs) between no/mild and severe emphysema by bioinformatics analysis. Methods: The microarray dataset GSE1650, of lung tissue in no/mild and severe emphysema, was downloaded from the GEO database, and DEGs were obtained by t test. Analysis of DEGs based on DAVID database was used to obtain gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) pathway. The protein-protein interaction network (PPI) was established using STRING database to identify hub genes. Results: A total of 76 DEGs were obtained, of which 62 genes were up-regulated and 14 genes were down-regulated in severe emphysema group. Gene ontology showed that the DEGs were mainly involved in neutrophil chemotaxis, cellular response to interleukin-1, extracellular matrix organization, immune response, and KEGG pathway involved cytokine-cytokine receptor interaction, ECM-receptor interaction, PI3K-Akt signaling pathway, platelet activation. Seventeen hub genes were recognized by PPI analysis, including CXCL8, RRAD, CLU, TIMP1, SEPP1, ISLR, BGN, COL1A1, COLIA2, ACTA2, ACTN1, FIGF, TPM1, TPM2, LUM, COL6A3 and TAGLN. Among them, fifteen genes (CLU, TIMP1, SEPP1, ISLR, BGN, COLIA2, COL1A1, ACTA2, ACTN1, FIGF, TPM1, TPM2, LUM, COL6A3, TAGLN) were up-regulated and two genes (CXCL8, RRAD) were down-regulated. Conclusion: Bioinformatics analysis based on GEO database showed that there were DEGs between non/mild and severe emphysema patients.

Quantitative CT detects progression in COPD patients with severe emphysema in a 3-month interval

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) is characterized by variable contributions of emphysema and airway disease on computed tomography (CT), and still little is known on their temporal evolution. We hypothesized that quantitative CT (QCT) is able to detect short-time changes in a cohort of patients with very severe COPD.

METHODS

Two paired in- and expiratory CT each from 70 patients with avg. GOLD stage of 3.6 (mean age = 66 ± 7.5, mean FEV1/FVC = 35.28 ± 7.75) were taken 3 months apart and analyzed by fully automatic software computing emphysema (emphysema index (EI), mean lung density (MLD)), air-trapping (ratio expiration to inspiration of mean lung attenuation (E/I MLA), relative volume change between - 856 HU and - 950 HU (RVC_856-950)), and parametric response mapping (PRM) parameters for each lobe separately and the whole lung. Airway metrics measured were wall thickness (WT) and lumen area (LA) for each airway generation and the whole lung.

RESULTS

The average of the emphysema parameters (EI, MLD) increased significantly by 1.5% (p < 0.001) for the whole lung, whereas air-trapping parameters (E/I MLA, RVC_856-950) were stable. PRM_Emph increased from 34.3 to 35.7% (p < 0.001), whereas PRM_Normal decrased from 23.6% to 22.8% (p = 0.012). WT decreased significantly from 1.17 ± 0.18 to 1.14 ± 0.19 mm (p = 0.036) and LA increased significantly from 25.08 ± 4.49 to 25.84 ± 4.87 mm² (p = 0.041) for the whole lung. The generation-based analysis showed heterogeneous results.

CONCLUSION

QCT detects short-time progression of emphysema in severe COPD. The changes were partly different among lung lobes and airway generations, indicating that QCT is useful to address the heterogeneity of COPD progression.

KEY POINTS

• QCT detects short-time progression of emphysema in severe COPD in a 3-month period. • QCT is able to quantify even slight parenchymal changes, which were not detected by spirometry. • QCT is able to address the heterogeneity of COPD, revealing inconsistent changes individual lung lobes and airway generations.

[Clinical analysis of 96 cases of congenital cystic lung lesions in children]

Objective: To summarize the diagnosis, clinical manifestations, treatment and prognosis of congenital cystic lung lesions. Methods: A retrospective study described the clinical course of 96 patients (46 female and 50 male) diagnosed with congenital cystic lung lesions treated at the Tianjin Children's Hospital from January 2010 to March 2019. The clinical findings, imaging examinations, pathological findings, treatment and follow-up were analyzed. Results: Totally 96 patients (aged from 4 days to 13 years) with congenital cystic lung lesions were included in this study. Eighty-six patients (90%) were diagnosed when they had cough and fever symptoms. Forty (42%) patients exhibited congenital cystic adenomatoid malformation, 30 underwent surgical excision, two were at emergency operations and one dead. There were 12 (13%) patients with pulmonary sequestration and four were surgical treated. Twelve (13%) patients with bronchogenic cyst were included and 4 were surgically treated. There were 3 (3%) patients with congenital lobar emphysema and one was surgically treated. Another patient with pneumothorax was operated in other hospital 2 months after discharge. Twenty-nine (30%) patients with unclassified congenital cystic lung lesions could not be definitively diagnosed by CT. Some of them were difficult to be distinguished from necrotizing pneumonia. Finally, 2 patients were diagnosed as necrotizing pneumonia after 6, 10 months follow-up. After operation 37 out of 39 patients recovered well. Conclusions: The diagnosis of congenital pulmonary cystic disease depend on imaging and pathological examination. Most patients are diagnosed when they have respiratory tract infection. The main clinical manifestations are cough and fever. The prognosis of operative management is good.

Clinical outcomes of radial probe endobronchial ultrasound using a guide sheath for diagnosis of peripheral lung lesions in patients with pulmonary emphysema

BACKGROUND

Generally, structural destruction of lung parenchyma, such as pulmonary emphysema, is considered to be related to the low diagnostic yields and high complication rates of lung biopsies of peripheral lung lesions. Currently, little is known about the clinical outcomes of using endobronchial ultrasound with a guide sheath (EBUS-GS) to diagnose peripheral lesions in patients with emphysema.

METHODS

This retrospective study was performed to identify the clinical outcomes of EBUS-GS in patients with pulmonary emphysema. This study included 393 consecutive patients who received EBUS-GS between February 2017 and April 2018. The patients were classified according to the severity of their emphysema, and factors possibly contributing to a successful EBUS-GS procedure were evaluated.

RESULTS

The overall diagnostic yield of EBUS-GS in patients with no or mild emphysema was significantly higher than in those with moderate or severe pulmonary emphysema (78% vs. 61%, P = 0.007). There were no procedure-related complications. The presence of a bronchus sign on CT (P <  0.001) and a "within the lesion" status on EBUS (P = 0.009) were independently associated with a successful EBUS-GS procedure. Although the diagnostic yield of EBUS-GS in patients with moderate-to-severe emphysema was relatively low, a bronchus sign and "within the lesion" status on EBUS were contributing factors for a successful EBUS-GS.

CONCLUSIONS

EBUS-GS is a safe procedure with an acceptable diagnostic yield, even when performed in patients with pulmonary emphysema. The presence of a bronchus sign and "within the lesion" status on EBUS were predictors of a successful procedure.

[Spontaneous lung volume reduction following pneumonia in a patient with emphysema]

INTRODUCTION

Lung volume reduction can be effective in appropriately selected patients with severe emphysema and is associated with reduced breathlessness and improved survival. Spontaneous resolution of emphysematous bullae can also sometimes occur.

CASE REPORT

We report a case of severe smoking-related emphysema in a 60-year-old patient, who presented in October 2013 with a right upper lobe acute community-acquired pneumonia on the background of previously undocumented emphysema. The patient improved following treatment with co-amoxiclav and serial radiology showed progressive cicatricial retraction. Nine months later there had been a major functional improvement characterized by a complete normalization of the patient's ventilatory parameters, specifically a 45% improvement in FEV₁. In the literature, the average FEV1 improvement obtained by surgical or endoscopic lung volume reduction techniques does not exceed 28%.

CONCLUSION

Rarely, emphysematous bullae resolve following infections. Further studies of the mechanisms involved in these natural regressions may be of interest in the development of new therapeutics.

Spirometric assessment of emphysema presence and severity as measured by quantitative CT and CT-based radiomics in COPD

Background

The mechanisms underlying airflow obstruction in COPD cannot be distinguished by standard spirometry. We ascertain whether mathematical modeling of airway biomechanical properties, as assessed from spirometry, could provide estimates of emphysema presence and severity, as quantified by computed tomography (CT) metrics and CT-based radiomics.

Methods

We quantified presence and severity of emphysema by standard CT metrics (VIDA) and co-registration analysis (ImbioLDA) of inspiratory-expiratory CT in 194 COPD patients who underwent pulmonary function testing. According to percentages of low attenuation area below − 950 Hounsfield Units (%LAA_-950insp) patients were classified as having no emphysema (NE) with %LAA_-950insp < 6, moderate emphysema (ME) with %LAA_-950insp ≥ 6 and < 14, and severe emphysema (SE) with %LAA_-950insp ≥ 14. We also obtained stratified clusters of emphysema CT features by an automated unsupervised radiomics approach (CALIPER). An emphysema severity index (ESI), derived from mathematical modeling of the maximum expiratory flow-volume curve descending limb, was compared with pulmonary function data and the three CT classifications of emphysema presence and severity as derived from CT metrics and radiomics.

Results

ESI mean values and pulmonary function data differed significantly in the subgroups with different emphysema degree classified by VIDA, ImbioLDA and CALIPER (p < 0.001 by ANOVA). ESI differentiated NE from ME/SE CT-classified patients (sensitivity 0.80, specificity 0.85, AUC 0.86) and SE from ME CT-classified patients (sensitivity 0.82, specificity 0.87, AUC 0.88).

Conclusions

Presence and severity of emphysema in patients with COPD, as quantified by CT metrics and radiomics can be estimated by mathematical modeling of airway function as derived from standard spirometry.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1049-3) contains supplementary material, which is available to authorized users.

Microenvironmental stimuli induce different macrophage polarizations in experimental models of emphysema

Macrophages play a pivotal role in the development of emphysema and depending on the microenvironment stimuli can be polarized into M1- or M2-like macrophage phenotypes. We compared macrophage polarizations in cigarette smoke (CS)- and porcine pancreatic elastase (PPE)-induced emphysema models. C57BL/6 mice were subdivided into four experimental groups. In the PPE group, animals received an intranasal instillation of PPE (0.677 IU); in the saline group, animals received an intranasal instillation of saline (0.9%). Animals from both groups were euthanized on day 28. In the CS group, animals were exposed to CS for 30 min, twice a day, 5 days per week for 12 weeks. In the control group, animals received filtered air. We observed an increase in total macrophages for both experimental models. For M1-like macrophage markers, we observed an increase in TNF-α⁺ and IFN-γ⁺ cells, Cxcl-9 and Cxcl-10 expressions in PPE and CS groups. Only in the CS group, we detected an increased expression of IL-12b For M2-like macrophages markers we observed a down regulation in IL-10, IL-4, IL-13, Arg1 and Fizz1 and an increase of TGF-β⁺ cells in the PPE group, while for the CS group there was an increase in TGF-β⁺ cells and IL-10 expression. All exposure groups were compared to their respective controls. In summary, we demonstrated that CS- and PPE-induced models resulted in different microenvironmental stimuli. CS exposure induced an environmental stimulus related to M1- and M2-like macrophage phenotypes similar to previous results described in COPD patients, whereas the elastase-induced model provided an environmental stimulus related only to the M1 phenotype.

[Imaging before and after endoscopic lung volume reduction]

The treatment of symptomatic lung emphysema by lung volume reduction has become established over the last 15 years. While surgical partial lung resection has profited from improved and less invasive surgical techniques, various endoscopic interventional procedures have been developed and are now available for use. All treatment approaches are dependent on individual anatomical variants and a regional distribution of the lung emphysema, which is why no procedure can be designated as the gold standard for all patients. High-resolution computed tomography can be qualitatively evaluated and provides decisive information for treatment, which is why radiologists play a particularly important role in treatment planning and aftercare of an intervention for reduction of the lung volume. This article presents the various endoscopic techniques, names the demands of the treating physician on the advising radiologist and finally describes how a treatment decision is derived from the results obtained.