Applicability of color-coded computed tomography images in lung volume reduction surgery planning

Background

Adequate patient selection is the key to successful lung volume reduction in patients with pulmonary emphysema. Computed tomography (CT) enables a reliable detection of pulmonary emphysema and allows an accurate quantification of the severity. Our goal was to investigate the usefulness and reliability of color-coded (CC) CT images in classification of emphysema and preoperative lung volume reduction planning.

Methods

Fifty patients undergoing lung volume reduction surgery at our institution between September 2015 and February 2016 were retrospectively investigated. Three readers visually assessed the amount and distribution patterns of pulmonary emphysema on axial, multi-planar and CC CT images using the Goddard scoring system and a surgically oriented grading system (bilateral markedly heterogenous, bilateral intermediately heterogenous, bilateral homogenous and unilateral heterogenous emphysema). Observer dependency was investigated by using Fleiss' kappa (κ) and the intraclass correlation coefficient (ICC). Results were compared to quantitative results from densitometry measurements and lung perfusion scintigraphy by using Spearman correlation. Recommendations for lung volume reduction sites based on emphysema amount and distribution of all readers were compared to removal sites from the surgical reports.

Results

Inter-rater agreement for emphysema distribution rating was substantial for CC images (κ=0.70; 95% CI, 0.64-0.80) and significantly better compared to axial and multiplanar images (P≤0.001). The inter-rater agreement for recommended segment removal was moderate for CC images (κ=0.56; 95% CI, 0.49-0.63) and significantly better compared to axial and multiplanar images (P<0.001). Visual emphysema rating correlated significantly with measurements from densitometry and perfusion scintigraphy in the upper and lower lung zones in all image types.

Conclusions

CC CT images allow a precise, less observer-dependent evaluation of distribution of pulmonary emphysema and resection recommendation compared to axial and multiplanar CT images and might therefore be useful in lung volume resection surgery planning.

Magnetic resonance imaging of the time course of hyperpolarized 129Xe gas exchange in the human lungs and heart

Purpose

To perform magnetic resonance imaging (MRI), human lung imaging, and quantification of the gas-transfer dynamics of hyperpolarized xenon-129 (HPX) from the alveoli into the blood plasma.

Materials and methods

HPX MRI with iterative decomposition of water and fat with echo asymmetry and least-square estimation (IDEAL) approach were used with multi-interleaved spiral k-space sampling to obtain HPX gas and dissolved phase images. IDEAL time-series images were then obtained from ten subjects including six normal subjects and four patients with pulmonary emphysema to test the feasibility of the proposed technique for capturing xenon-129 gas-transfer dynamics (XGTD). The dynamics of xenon gas diffusion over the entire lung was also investigated by measuring the signal intensity variations between three regions of interest, including the left and right lungs and the heart using Welch’s t test.

Results

The technique enabled the acquisition of HPX gas and dissolved phase compartment images in a single breath-hold interval of 8 s. The y-intersect of the XGTD curves were also found to be statistically lower in the patients with lung emphysema than in the healthy group (p < 0.05).

Conclusion

This time-series IDEAL technique enables the visualization and quantification of inhaled xenon from the alveoli to the left ventricle with a clinical gradient strength magnet during a single breath-hold, in healthy and diseased lungs.

Key Points

• The proposed hyperpolarized xenon-129 gas and dissolved magnetic resonance imaging technique can provide regional and temporal measurements of xenon-129 gas-transfer dynamics.

• Quantitative measurement of xenon-129 gas-transfer dynamics from the alveolar to the heart was demonstrated in normal subjects and pulmonary emphysema.

• Comparison of gas-transfer dynamics in normal subjects and pulmonary emphysema showed that the proposed technique appears sensitive to changes affecting the alveoli, pulmonary interstitium, and capillaries.

Electronic supplementary material

The online version of this article (10.1007/s00330-018-5853-9) contains supplementary material, which is available to authorized users.

Impact of Model-Based Iterative Reconstruction on the Correlation between Computed Tomography Quantification of a Low Lung Attenuation Area and Airway Measurements and Pulmonary Function Test Results in Normal Subjects

Objective

To compare correlations between pulmonary function test (PFT) results and different reconstruction algorithms and to suggest the optimal reconstruction protocol for computed tomography (CT) quantification of low lung attenuation areas and airways in healthy individuals.

Materials and Methods

A total of 259 subjects with normal PFT and chest CT results were included. CT scans were reconstructed using filtered back projection, hybrid-iterative reconstruction, and model-based IR (MIR). For quantitative analysis, the emphysema index (EI) and wall area percentage (WA%) were determined. Subgroup analysis according to smoking history was also performed.

Results

The EIs of all the reconstruction algorithms correlated significantly with the forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) (all p < 0.001). The EI of MIR showed the strongest correlation with FEV1/FVC (r = -0.437). WA% showed a significant correlation with FEV1 in all the reconstruction algorithms (all p < 0.05) correlated significantly with FEV1/FVC for MIR only (p < 0.001). The WA% of MIR showed the strongest correlations with FEV1 (r = -0.205) and FEV1/FVC (r = -0.250). In subgroup analysis, the EI of MIR had the strongest correlation with PFT in both ever-smoker and never-smoker subgroups, although there was no significant difference in the EI between the reconstruction algorithms. WA% of MIR showed a significantly thinner airway thickness than the other algorithms (49.7 ± 7.6 in ever-smokers and 49.5 ± 7.5 in never-smokers, all p < 0.001), and also showed the strongest correlation with PFT in both ever-smoker and never-smoker subgroups.

Conclusion

CT quantification of low lung attenuation areas and airways by means of MIR showed the strongest correlation with PFT results among the algorithms used, in normal subjects.

Coal Mine Dust Desquamative Chronic Interstitial Pneumonia: A Precursor of Dust-Related Diffuse Fibrosis and of Emphysema

Background:

Diseases associated with coal mine dust continue to affect coal miners. Elucidation of initial pathological changes as a precursor of coal dust-related diffuse fibrosis and emphysema, may have a role in treatment and prevention.

Objective:

To identify the precursor of dust-related diffuse fibrosis and emphysema.

Methods:

Birefringent silica/silicate particles were counted by standard microscope under polarized light in the alveolar macrophages and fibrous tissue in 25 consecutive autopsy cases of complicated coal worker's pneumoconiosis and in 21 patients with tobacco-related respiratory bronchiolitis.

Results:

Coal miners had 331 birefringent particles/high power field while smokers had 4 (p<0.001). Every coal miner had intra-alveolar macrophages with silica/silicate particles and interstitial fibrosis ranging from minimal to extreme. All coal miners, including those who never smoked, had emphysema. Fibrotic septa of centrilobular emphysema contained numerous silica/silicate particles while only a few were present in adjacent normal lung tissue. In coal miners who smoked, tobacco-associated interstitial fibrosis was replaced by fibrosis caused by silica/silicate particles.

Conclusion:

The presence of silica/silicate particles and anthracotic pigment-laden macrophages inside the alveoli with various degrees of interstitial fibrosis indicated a new disease: coal mine dust desquamative chronic interstitial pneumonia, a precursor of both dust-related diffuse fibrosis and emphysema. In studied coal miners, fibrosis caused by smoking is insignificant in comparison with fibrosis caused by silica/silicate particles. Counting birefringent particles in the macrophages from bronchioalveolar lavage may help detect coal mine dust desquamative chronic interstitial pneumonia, and may initiate early therapy and preventive measures.

The copper dependent-lysyl oxidases contribute to the pathogenesis of pulmonary emphysema in chronic obstructive pulmonary disease patients

Abnormalities in the elastic fiber biology are seen in pulmonary emphysema (PE). The copper-dependent lysyl oxidases regulate the production and accumulation of elastic fibers in the connective tissue. This study focused on the relationship between lysyl oxidase (LOX), LOX-like protein 1 (LOXL1), and LOXL2 and PE pathogenesis. Lung samples with or without PE from patients with chronic obstructive lung disease (n=35) were used. Protein levels of elastin, LOX, LOXL1, LOXL2, hypoxia inducible factor 1-alpha (HIF-1α), copper metabolism domain containing-1 (COMMD1), and phosphatase and tensin homolog (PTEN) were assayed using microscopic and biochemical methods The emphysematous areas were characterized by enlargement of the alveoli, destruction of the alveolar structure, accumulation of macrophages in the alveolar lumens, and showed increased HIF-1α immunoreactivity. Additionally, the emphysematous areas had significantly lower elastin, LOX, LOXL1, LOXL2, HIF-1α, COMMD1, and PTEN protein levels than the non-emphysematous areas. We suppose that the reductions in the HIF-1α levels led to decreases in the protein levels of active LOX, LOXL1, and LOXL2. These decreases might cause abnormalities in the elastic fiber biology. HIF-1α activation induced by decreased COMMD1 and protease activation induced by decreased PTEN might contribute to the development of PE. Finally, methods aimed at increasing the protein levels of LOXs, COMMD1 and PTEN might be effective for treating PE.

Pulmonary fibrosis on the lateral chest radiograph: Kerley D lines revisited

Abstract

The retrosternal clear space (RCS) is a lucent area on the lateral chest radiograph located directly behind the sternum. The two types of pathology classically addressed in the RCS are anterior mediastinal masses and emphysema. Diseases of the pulmonary interstitium are a third type of pathology that can be seen in the RCS. Retrosternal reticular opacities, known as Kerley D lines, were initially described in the setting of interstitial oedema. Pulmonary fibrosis is another aetiology of Kerley D lines, which may be more easily identified in the RCS than elsewhere on the chest radiograph.

Teaching points

• The RCS is one of three lucent spaces on the lateral chest radiograph.

• Reticular opacities in the RCS are known as Kerley D lines.

• Pulmonary fibrosis can be seen in the RCS as Kerley D lines.

• Kerley D lines should be further evaluated with chest CT.

Improvement of metabolic disorders by an EP2 receptor agonist via restoration of the subcutaneous adipose tissue in pulmonary emphysema

Chronic obstructive pulmonary disease (COPD) is often associated with co-morbidities. Metabolic disorders like hyperlipidemia and diabetes occur also in underweight COPD patients, although the mechanism is uncertain. Subcutaneous adipose tissue (SAT) plays an important role in energy homeostasis, since restricted capacity to increase fat cell number with increase in fat cell size occurring instead, is associated with lipotoxicity and metabolic disorders. The aim of this study is to show the protective role of SAT for the metabolic disorders in pulmonary emphysema of a murine model. We found ectopic fat accumulation and impaired glucose homeostasis with wasting of SAT in a murine model of elastase-induced pulmonary emphysema (EIE mice) reared on a high-fat diet. ONO-AE1-259, a selective E-prostanoid (EP) 2 receptor agonist, improved angiogenesis and subsequently adipogenesis, and finally improved ectopic fat accumulation and glucose homeostasis with restoration of the capacity for storage of surplus energy in SAT. These results suggest that metabolic disorders like hyperlipidemia and diabetes occured in underweight COPD is partially due to the less capacity for storage of surplus energy in SAT, though the precise mechanism is uncertained. Our data pave the way for the development of therapeutic interventions for metabolic disorders in emphysema patients, e.g., use of pro-angiogenic agents targeting the capacity for storage of surplus energy in the subcutaneous adipose tissue.

A Case of Pulmonary Interstitial Emphysema Treated by Percutaneous Catheter Insertion in Extremely Low Birth Weight Infant

The pulmonary interstitial emphysema (PIE) is a life-threatening illness in premature infants with mechanical ventilation. While most are managed conservatively, decompression would be necessary. Here, we report the first case of PIE treated by percutaneous catheter insertion in an extremely low birth weight (ELBW) infant in Korea. The patient, born with 660 g in 23+2 weeks of gestation, showed PIE in left lower lung on postnatal day 12. Percutaneous catheter insertion was performed on postnatal day 25. The size of PIE decreased, but didn't disappear completely. On postnatal day 42, we exchanged catheter and inserted additional catheter in pleural space. However, sudden desaturation and pneumothorax occurred on postnatal day 44. We changed catheter in pleural space, and pneumothorax and PIE improved. Finally, we successfully removed catheters, and weaned patient out. As in our case, percutaneous catheter insertion would be a useful option for ELBW infants with PIE.

A case of pulmonary placental transmogrification

Pulmonary placental transmogrification is a rare lung lesion that microscopically resembles placenta with cystic spaces filled with papillary structures. Considered a histological variant of bullous emphysema, only 30 reported cases have been published in the world's literature. We report a rare case of pulmonary placental transmogrification in a 72-year-old man, in whom the clinical presentation of the disease mimicked lung carcinoma. Histopathology of the surgically resected segment showed a complex bulla with squamous metaplasia and placental transmogrification. Whilst rare, pulmonary placental transmogrification must be ruled out in all patients presenting with unilateral bullous emphysema, without known risk factors.

Combined pulmonary fibrosis and emphysema: The many aspects of a cohabitation contract

Combined pulmonary fibrosis and emphysema (CPFE) is a clinical entity characterized by the coexistence of upper lobe emphysema and lower lobe fibrosis. Patients with this condition experience severe dyspnea and impaired gas exchange with preserved lung volumes. The diagnosis of the CPFE syndrome is based on HRCT imaging, showing the coexistence of emphysema and pulmonary fibrosis both in varying extent and locations within the lung parenchyma. Individual genetic background seem to predispose to the development of the disease. The risk of the development of pulmonary hypertension in patients with CPFE is high and related to poor prognosis. CPFE patients also present a high risk of lung cancer. Mortality is significant in patients with CPFE and median survival is reported between 2.1 and 8.5 years. Currently, no specific recommendations are available regarding the management of patients with CPFE. In this review we provide information on the existing knowledge on CPFE regarding the pathophysiology, clinical manifestations, imaging, complications, possible therapeutic interventions and prognosis of the disease.

Emphysematous lungs do not affect visibility of virtual-assisted lung mapping

BACKGROUND

It has recently been suggested that virtual-assisted lung mapping may enable safer and more reliable intraoperative navigation compared to conventional preoperative lung marking strategies. This study aimed to examine the relationship between emphysematous lungs and the intraoperative visibility of virtual-assisted lung mapping markings.

METHODS

We retrospectively analyzed the data of 21 patients who underwent virtual-assisted lung mapping followed by lung resection between October 2013 and May 2015. The visibility of the intraoperative lung markings was graded. The degree of pulmonary emphysema was assessed by the percentage of low attenuation area on computed tomography. We elucidated the associations between the marking grade and other factors such as patient age or sex, pulmonary lobe mapped, marking operator, Brinkman index, and percentage of low attenuation area of the pulmonary lobe.

RESULTS

In Spearman rank correlation analysis, there was no correlation between the Brinkman index and the percentage of low attenuation area (n = 26, r = -0.016, p = 0.937). In stepwise multivariate regression analysis, the marking grade correlated with the marking operator (p < 0.001) and the Brinkman index (p = 0.008), but not with patient age or sex, the pulmonary lobe mapped, or degree of pulmonary emphysema.

CONCLUSION

The skill of the marking operator and the patient's smoking history had significant effects on the intraoperative visibility of markings made by virtual-assisted lung mapping, whereas emphysematous lungs did not affect the intraoperative visibility of lung markings.

Evaluation of clinical characteristics and prognosis of chronic pulmonary aspergillosis depending on the underlying lung diseases: Emphysema vs prior tuberculosis

PURPOSE

There have been scarce data evaluating the differences of clinical characteristics and prognosis of chronic pulmonary aspergillosis (CPA) depending on underlying pulmonary diseases. We tried to clarify them in CPA patients who had pulmonary emphysema or previous pulmonary tuberculosis.

METHODS

We reviewed and evaluated CPA patients diagnosed between 2007 and 2013 with pulmonary emphysema (PE group; n = 29), with previous pulmonary tuberculosis (PT group; n = 47) and with combination of these 2 underlying conditions (CTE group; n = 24).

RESULTS

In CT findings, fungus balls were rare in PE group (7% in PE group and 36% in PT group; p = 0.006). Compared with PT group, PE group patients exhibited more frequent preceding antibiotics administration (45% vs 11%; p = 0.002) and fever (52% vs 17%; p = 0.002), less frequent hemosputum (24% vs 57%; p = 0.008), and more frequent consolidations in imaging (79% vs 38%; p = 0.001) and respiratory failure (34% vs 13%; p = 0.020), possibly suggesting more acute clinical manifestations of CPA in emphysematous patients. Trend of the differences between PT and PE group was not changed when patients with fungal balls were excluded. Multivariate Cox regression analysis of risks for all-cause mortality revealed age (HR, 1.079; p = 0.002) and emphysema (HR, 2.45; p = 0.040) as risk factors.

CONCLUSIONS

Assessment of underlying lung diseases is needed when we estimate prognosis and consider treatment of CPA patients. Particularly, emphysematous patients can be presented as refractory pneumonia and show poor prognosis.

Grating-based X-ray Dark-field Computed Tomography of Living Mice

Changes in x-ray attenuating tissue caused by lung disorders like emphysema or fibrosis are subtle and thus only resolved by high-resolution computed tomography (CT). The structural reorganization, however, is of strong influence for lung function. Dark-field CT (DFCT), based on small-angle scattering of x-rays, reveals such structural changes even at resolutions coarser than the pulmonary network and thus provides access to their anatomical distribution. In this proof-of-concept study we present x-ray in vivo DFCTs of lungs of a healthy, an emphysematous and a fibrotic mouse. The tomographies show excellent depiction of the distribution of structural – and thus indirectly functional – changes in lung parenchyma, on single-modality slices in dark field as well as on multimodal fusion images. Therefore, we anticipate numerous applications of DFCT in diagnostic lung imaging. We introduce a scatter-based Hounsfield Unit (sHU) scale to facilitate comparability of scans. In this newly defined sHU scale, the pathophysiological changes by emphysema and fibrosis cause a shift towards lower numbers, compared to healthy lung tissue.

•

We present so far unreported x-ray scatter dark-field CT scans of living mice performed with a Talbot–Lau interferometer.

•

Dark field gives access to structural information not provided by attenuation CT at scales below the detector pixel size.

•

Changes of lung alveoli structure are clearly visualized by dark-field CT for emphysema and fibrosis.

Lung diseases pose one of the leading causes of death worldwide. They are often difficult to diagnose at an early stage due to low sensitivity of conventional medical imaging systems towards structural changes of the lung tissue. With dark-field imaging based on scattering of x-rays such structural changes can be visualized even at imaging system resolutions coarser than the lung alveoli, as opposed to conventional x-ray imaging based on attenuation. By overcoming experimental scan time and dose issues, we report the first dark-field computed tomography scans on living mice, demonstrating excellent depiction of the anatomical distribution of pathological lung changes.

Normalizing computed tomography data reconstructed with different filter kernels: effect on emphysema quantification

Objectives

To propose and evaluate a method to reduce variability in emphysema quantification among different computed tomography (CT) reconstructions by normalizing CT data reconstructed with varying kernels.

Methods

We included 369 subjects from the COPDGene study. For each subject, spirometry and a chest CT reconstructed with two kernels were obtained using two different scanners. Normalization was performed by frequency band decomposition with hierarchical unsharp masking to standardize the energy in each band to a reference value. Emphysema scores (ES), the percentage of lung voxels below -950 HU, were computed before and after normalization. Bland-Altman analysis and correlation between ES and spirometry before and after normalization were compared. Two mixed cohorts, containing data from all scanners and kernels, were created to simulate heterogeneous acquisition parameters.

Results

The average difference in ES between kernels decreased for the scans obtained with both scanners after normalization (7.7 ± 2.7 to 0.3 ± 0.7; 7.2 ± 3.8 to -0.1 ± 0.5). Correlation coefficients between ES and FEV₁, and FEV₁/FVC increased significantly for the mixed cohorts.

Conclusions

Normalization of chest CT data reduces variation in emphysema quantification due to reconstruction filters and improves correlation between ES and spirometry.

Key Points

• Emphysema quantification is sensitive to the reconstruction kernel used.

• Normalization allows comparison of emphysema quantification from images reconstructed with varying kernels.

• Normalization allows comparison of emphysema quantification obtained with scanners from different manufacturers.

• Normalization improves correlation of emphysema quantification with spirometry.

• Normalization can be used to compare data from different studies and centers.

Infected tracheal diverticulum: a rare association with alpha-1 antitrypsin deficiency

Tracheal diverticulum, defined as a benign outpouching of the tracheal wall, is rarely diagnosed in clinical practice. It can be congenital or acquired in origin, and most cases are asymptomatic, typically being diagnosed postmortem. We report a case of a 69-year-old woman who was hospitalized after presenting with fever, fatigue, pleuritic chest pain, and a right neck mass complicated by dysphagia. Her medical history was significant: pulmonary emphysema (alpha-1 antitrypsin deficiency); bronchiectasis; and thyroidectomy. On physical examination, she presented diminished breath sounds and muffled heart sounds, with a systolic murmur. Laboratory tests revealed elevated inflammatory markers, a CT scan showed an air-filled, multilocular mass in the right tracheal wall, and magnetic resonance imaging confirmed the CT findings. Fiberoptic bronchoscopy failed to reveal any abnormalities. Nevertheless, the patient was diagnosed with tracheal diverticulum. The treatment approach was conservative, consisting mainly of antibiotics. After showing clinical improvement, the patient was discharged.

Inhibition of elastase-pulmonary emphysema in dominant-negative MafB transgenic mice

Alveolar macrophages (AMs) play important roles in the pathogenesis of chronic obstructive pulmonary disease (COPD). We previously demonstrated upregulation of the transcription factor MafB in AMs of mice exposed to cigarette smoke. The aim of this study was to elucidate the roles of MafB in the development of pulmonary emphysema. Porcine pancreatic elastase was administered to wild-type (WT) and dominant-negative (DN)-MafB transgenic (Tg) mice in which MafB activity was suppressed only in macrophages. We measured the mean linear intercept and conducted cell differential analysis of bronchoalveolar lavage (BAL) cells, surface marker analysis using flow cytometry, and immunohistochemical staining using antibodies to matrix metalloproteinase (MMP)-9 and MMP-12. Airspace enlargement of the lungs was suppressed significantly in elastase-treated DN-MafB Tg mice compared with treated WT mice. AMs with projected pseudopods were decreased in DN-MafB Tg mice. The number of cells intermediately positive for F4/80 and weakly or intermediately positive for CD11b, which are considered cell subsets of matured AMs, decreased in the BAL of DN-MafB Tg mice. Furthermore, MMP-9 and -12 were significantly downregulated in BAL cells of DN-MafB Tg mice. Because MMPs exacerbate emphysema, MafB may be involved in pulmonary emphysema development through altered maturation of macrophages and MMP expression.

Promotion of adipogenesis by an EP2 receptor agonist via stimulation of angiogenesis in pulmonary emphysema

Body weight loss is a common manifestation in patients with chronic obstructive pulmonary disease (COPD), particularly those with severe emphysema. Adipose angiogenesis is a key mediator of adipogenesis and use of pro-angiogenic agents may serve as a therapeutic option for lean COPD patients. Since angiogenesis is stimulated by PGE2, we examined whether ONO-AE1-259, a selective E-prostanoid (EP) 2 receptor agonist, might promote adipose angiogenesis and adipogenesis in a murine model of elastase-induced pulmonary emphysema (EIE mice). Mice were intratracheally instilled with elastase or saline, followed after 4 weeks by intraperitoneal administration of ONO-AE1-259 for 4 weeks. The subcutaneous adipose tissue (SAT) weight decreased in the EIE mice, whereas in the EIE mice treated with ONO-AE1-259, the SAT weight was largely restored, which was associated with significant increases in SAT adipogenesis, angiogenesis, and VEGF protein production. In contrast, ONO-AE1-259 administration induced no alteration in the weight of the visceral adipose tissue. These results suggest that in EIE mice, ONO-AE1-259 stimulated adipose angiogenesis possibly via VEGF production, and thence, adipogenesis. Our data pave the way for the development of therapeutic interventions for weight loss in emphysema patients, e.g., use of pro-angiogenic agents targeting the adipose tissue vascular component.

Defeating the pores of Kohn

In the treatment of emphysema with an endobronchial valve, entire lobar treatment is important in achieving adequate atelectasis. This case illustrates that without treatment of the entire lobe, it can fail to collapse even after several years, leading to treatment failure. Intralobar collateral ventilation through the pores of Kohn is demonstrated in this case, as endobronchial valve blockage of the remaining patent anterior segment resulted in the desired atelectasis and significant improvements in pulmonary function.

Early chronic obstructive pulmonary disease: Beyond spirometry

The significant healthcare burden associated with chronic obstructive pulmonary disease (COPD) is driving us to improve our understanding of the natural history of this disease. Historically, the focus has been largely centred on diagnosing and treating individuals with moderate and severe disease. However, it is now recognised that the speed of decline in lung function as measured by forced expiratory volume in 1 s occurs faster in the earlier stages of the disease process. As a result, a clearer understanding of the potential benefits of treatment in early COPD is needed. It is recognised that many patients with COPD remain undiagnosed in the community which has prompted global case-finding initiatives. In this review we discuss the difficulties in diagnosing COPD in its early stages, examine the role of case-finding and look at the evidence for early intervention with therapeutic agents. There is a growing interest in the phenotypic variation amongst patients with COPD and we explore the role of phenotyping in early COPD and its potential benefits in providing a more individualised approach to COPD management. The majority of patients with COPD are known to die from non-respiratory causes such as cardiovascular disease. The mechanistic link is thought to relate to systemic inflammation, causing us to question whether earlier interventions could have a beneficial impact on the burden of co-morbidities for patients with COPD.

Phase I clinical trial of cell therapy in patients with advanced chronic obstructive pulmonary disease: follow-up of up to 3 years

Background

Chronic obstructive pulmonary disease is a major inflammatory disease of the airways and an enormous therapeutic challenge. Within the spectrum of chronic obstructive pulmonary disease, pulmonary emphysema is characterized by the destruction of the alveolar walls with an increase in the air spaces distal to the terminal bronchioles but without significant pulmonary fibrosis. Therapeutic options are limited and palliative since they are unable to promote morphological and functional regeneration of the alveolar tissue. In this context, new therapeutic approaches, such as cell therapy with adult stem cells, are being evaluated.

Objective

This article aims to describe the follow-up of up to 3 years after the beginning of a phase I clinical trial and discuss the spirometry parameters achieved by patients with advanced pulmonary emphysema treated with bone marrow mononuclear cells.

Methods

Four patients with advanced pulmonary emphysema were submitted to autologous infusion of bone marrow mononuclear cells. Follow-ups were performed by spirometry up to 3 years after the procedure.

Results

The results showed that autologous cell therapy in patients having chronic obstructive pulmonary disease is a safe procedure and free of adverse effects. There was an improvement in laboratory parameters (spirometry) and a slowing down in the process of pathological degeneration. Also, patients reported improvements in the clinical condition and quality of life.

Conclusions

Despite being in the initial stage and in spite of the small sample, the results of the clinical protocol of cell therapy in advanced pulmonary emphysema as proposed in this study, open new therapeutic perspectives in chronic obstructive pulmonary disease. It is worth emphasizing that this study corresponds to the first study in the literature that reports a change in the natural history of pulmonary emphysema after the use of cell therapy with a pool of bone marrow mononuclear cells.

Does cannabis smoking predispose to lung bulla formation?

OBJECTIVE

The data of a consecutive series of habitual marijuana smokers were retrospectively evaluated and compared with that of non-marijuana smokers to assess differences between the 2 groups.

METHODS

13 consecutive habitual marijuana smokers were referred for treatment of spontaneous pneumothorax. The demographic, clinical, radiological, and pathological findings of these patients were reviewed and compared with 140 non-marijuana smokers treated for the same pathology at the same time.

RESULTS

Bullae were seen in 8/13 (62%) and 110/140 (78%) of marijuana smokers and non-marijuana smokers, respectively. However, when patients less than 35-years old were considered, the incidence of bulla was higher in marijuana smokers than non-marijuana smokers (7/10 vs. 3/10, p < 0.05). The pathological findings showed a greater presence of inflammatory cells in specimens from marijuana smokers than those of non-marijuana smokers (8/11 vs. 2/42, respectively, p < 0.05). No significant differences in hospital stay and clinical outcome were registered between the 2 groups.

CONCLUSIONS

Despite the fact that we were unable to demonstrate that marijuana had a causal role in the development of emphysema, our study showed that marijuana smokers had a higher incidence of inflammatory cells in pathological specimens, which may favor lung injury, thus predisposing to bulla formation.

Adiponectin is associated with dynamic hyperinflation and a favourable response to inhaled glucocorticoids in patients with COPD

OBJECTIVES

Adipokines are protein mediators first described as products of adipose tissue regulating energy metabolism and appetite. Recently, adipokines have also been found to modulate inflammation and smooth muscle cell responses. Therefore we investigated the association of two adipokines, adiponectin and leptin, with the degree of emphysema, pulmonary function, symptoms and glucocorticoid responsiveness in patients with COPD.

METHODS

Plasma adiponectin and leptin levels, spirometry, body plethysmography and symptoms were measured in 43 male COPD patients with smoking history ≥ 20 pack-years, post bronchodilator FEV1/FVC < 0.7 and pulmonary emphysema on HRCT. The measurements were repeated in a subgroup of patients after 4 weeks' treatment with inhaled fluticasone.

RESULTS

In patients with COPD, plasma adiponectin levels correlated positively with airway resistance (Raw) (r = 0.362, p = 0.019) and functional residual capacity (FRC) (r = 0.355, p = 0.046). Furthermore, the baseline adiponectin concentration correlated negatively with the fluticasone induced changes in St George's Respiratory questionnaire (SGRQ) symptom score (r = -0.413, p = 0.040) and in FRC % pred (r = -0.428, p = 0.003), i.e. a higher baseline plasma adiponectin level was associated with more pronounced alleviation of symptoms and dynamic hyperinflation. Plasma leptin levels were not related to the measures of lung function, symptoms or glucocorticoid responsiveness.

CONCLUSIONS

Plasma adiponectin levels were associated with peripheral airway obstruction and dynamic hyperinflation in patients with COPD. A higher adiponectin level predicted more favourable relief of symptoms and hyperinflation during glucocorticoid treatment. Adiponectin may have a role in the COPD pathogenesis; it may also be a biomarker of disease severity and treatment responses in this disease.

Predictors of phase III slope of nitrogen single-breath washout in COPD

The nitrogen (N₂) single-breath washout (SBW) test is a measure of ventilation distribution inhomogeneity and also a small airway function that offers complementary information to spirometry; however, the relevance to the forced oscillation technique (FOT) and pulmonary emphysema in COPD is not fully understood. We hypothesized that pulmonary functions, forced oscillatory parameters, and emphysema extent would contribute independently to the results of the SBW test. In this cross-sectional study we assessed the relationship between the phase III slope (delta N₂) derived from N₂ SBW and these parameters. Spirometry, lung volumes, N₂ SBW, and the broadband frequency FOT were performed in 56 patients with COPD. Emphysema extent was measured by high-resolution computed tomography and scored. In multiple regression analyses, the delta N₂ was independently predicted by forced vital capacity, resonant frequency, and emphysema score (R(2)=0.57, p<0.0001). The degree of ventilation inhomogeneity derived from N₂ SBW is independently predicted by spirometry, lung mechanics, and the degree of emphysema.

Treatment of intractable pneumothorax with emphysema using endobronchial watanabe spigots

Prolonged air leakage is a major cause of morbidity in pneumothorax. When conservative management is not effective, surgery should be performed. However, surgery is not appropriate in patients with low pulmonary function. In these patients, occlusion of the airway with endobronchial blockers may be attempted under bronchoscopy. We treated two patients with prolonged air leakage using endobronchial Watanabe spigots under fibrobronchoscopy.

Recovery of pulmonary structure and exercise capacity by treatment with granulocyte-colony stimulating factor (G-CSF) in a mouse model of emphysema

Emphysema is a chronic obstructive pulmonary disease characterized abnormal dilatation of alveolar spaces, which impairs alveolar gas exchange, compromising the physical capacity of a patient due to airflow limitations. Here we tested the effects of G-CSF administration in pulmonary tissue and exercise capacity in emphysematous mice. C57Bl/6 female mice were treated with elastase intratracheally to induce emphysema. Their exercise capacities were evaluated in a treadmill. Lung histological sections were prepared to evaluate mean linear intercept measurement. Emphysematous mice were treated with G-CSF (3 cycles of 200 μg/kg/day for 5 consecutive days, with 7-day intervals) or saline and submitted to a third evaluation 8 weeks after treatment. Values of run distance and linear intercept measurement were expressed as mean ± SD and compared applying a paired t-test. Effects of treatment on these parameters were analyzed applying a Repeated Measures ANOVA, followed by Tukey's post hoc analysis. p < 0.05 was considered statistically significant. Twenty eight days later, animals ran significantly less in a treadmill compared to normal mice (549.7 ± 181.2 m and 821.7 ± 131.3 m, respectively; p < 0.01). Treatment with G-CSF significantly increased the exercise capacity of emphysematous mice (719.6 ± 200.5 m), whereas saline treatment had no effect on distance run (595.8 ± 178.5 m). The PCR cytokines genes analysis did not detect difference between experimental groups. Morphometric analyses in the lung showed that saline-treated mice had a mean linear intercept significantly higher (p < 0.01) when compared to mice treated with G-CSF, which did not significantly differ from that of normal mice. Treatment with G-CSF promoted the recovery of exercise capacity and regeneration of alveolar structural alterations in emphysematous mice.