Chronic obstructive pulmonary disease (COPD) is characterised by chronic inflammation of the airways and progressive destruction of lung parenchyma, a process that in most cases is initiated by cigarette smoking. Several mechanisms are involved in the development of the disease: influx of inflammatory cells into the lung (leading to chronic inflammation of the airways), imbalance between proteolytic and anti-proteolytic activity (resulting in the destruction of healthy lung tissue) and oxidative stress. Recently, an increasing number of data suggest a fourth important mechanism involved in the development of COPD: apoptosis of structural cells in the lung might possibly be an important upstream event in the pathogenesis of COPD. There is an increase in apoptotic alveolar epithelial and endothelial cells in the lungs of COPD patients. Since this is not counterbalanced by an increase in proliferation of these structural cells, the net result is destruction of lung tissue and the development of emphysema. Data from animal models suggest a role for Vascular Endothelial Growth Factor (VEGF) in the induction of apoptosis of structural cells in the lung. Other mediators of apoptosis, such as caspase-3 and ceramide, could be interesting targets to prevent apoptosis and the development of emphysema.In this review, recent data on the role of apoptosis in COPD from both animal models as well as from studies on human subjects will be discussed. The aim is to provide an up to date summary on the increasing knowledge on the role of apoptosis in COPD and pulmonary emphysema.

Background Patients with severe asthma are at increased risk of exacerbations and lower respiratory tract infections (LRTI). Severe asthma is heterogeneous, encompassing eosinophilic and non-eosinophilic (mainly neutrophilic) phenotypes. Patients with neutropilic airway diseases may benefit from macrolides. Methods We performed a randomised double-blind placebo-controlled trial in subjects with exacerbationprone severe asthma. Subjects received low-dose azithromycin (n=55) or placebo (n=54) as add-on treatment to combination therapy of inhaled corticosteroids and long-acting β 2 agonists for 6 months. The primary outcome was the rate of severe exacerbations and LRTI requiring treatment with antibiotics during the 26-week treatment phase. Secondary efficacy outcomes included lung function and scores on the Asthma Control Questionnaire (ACQ) and Asthma Quality of Life Questionnaire (AQLQ). Results The rate of primary endpoints (PEPs) during 6 months was not significantly different between the two treatment groups: 0.75 PEPs (95% CI 0.55 to 1.01) per subject in the azithromycin group versus 0.81 PEPs (95% CI 0.61 to 1.09) in the placebo group (p=0.682). In a predefined subgroup analysis according to the inflammatory phenotype, azithromycin was associated with a significantly lower PEP rate than placebo in subjects with noneosinophilic severe asthma (blood eosinophilia ≤200/ml): 0.44 PEPs (95% CI 0.25 to 0.78) versus 1.03 PEPs (95% CI 0.72 to 1.48) (p=0.013). Azithromycin significantly improved the AQLQ score but there were no significant between-group differences in the ACQ score or lung function. Azithromycin was well tolerated, but was associated with increased oropharyngeal carriage of macrolide-resistant streptococci. Conclusions Azithromycin did not reduce the rate of severe exacerbations and LRTI in patients with severe asthma. However, the significant reduction in the PEP rate in azithromycin-treated patients with non-eosinophilic severe asthma warrants further study. ClinicalTrials.gov number NCT00760838.

Dendritic cells (DC) are specialized antigen-presenting cells, linking innate and adaptive immune responses, and thus play an important role in immunologically mediated diseases, including pulmonary diseases such as asthma and respiratory viral infections. Although much is known about the characteristics of lung DC in animal models, very few data concerning human lung DC are available. The goal of our study was to identify and characterize dendritic cells in human lung by preparing single-cell suspensions from surgical resection specimens and subsequent labeling with the recently developed blood dendritic cell antigen (BDCA) markers. A straightforward isolation procedure was developed to avoid phenotypical and functional changes induced by extensive purification methods. In this way, human lung DC were directly identified without the need for an additional adherence step for further purification. For the first time, we demonstrate the presence of three previously unidentified DC subsets in human lung digests: myeloid DC type 1 (BDCA1+/HLA-DR+), myeloid DC type 2 (BDCA3+/HLA-DR+), and plasmacytoid DC (BDCA2+/CD123+). The presence of CD1a+ DC in the human lung was confirmed. The identification and characterization of different human pulmonary DC subtypes is of great importance for the future development of DC-based immunotherapies.

Chronic obstructive pulmonary disease (COPD) is mainly caused by cigarette smoking, and is characterized by an increase in inflammatory cells in the airways and pulmonary tissue. The chemokine receptor CCR6 and its ligand MIP-3α/CCL20 may be involved in the recruitment of these inflammatory cells. To investigate the role of CCR6 in the pathogenesis of COPD, we analyzed the inflammatory responses of CCR6 knockout (KO) and wild-type mice upon cigarette smoke (CS) exposure. Both subacute and chronic exposure to CS induced an increase in cells of the innate and adaptive immune system in the bronchoalveolar lavage, both in CCR6 KO and wild-type mice. However, the accumulation of dendritic cells, neutrophils, and T lymphocytes, which express CCR6, was significantly attenuated in the CCR6 KO mice, compared with their wild-type littermates. In the lung tissue of CCR6 KO mice, there was an impaired increase in dendritic cells, activated CD8+ T lymphocytes, and granulocytes. Moreover, this attenuated inflammatory response in CCR6 KO mice offered a partial protection against pulmonary emphysema, which correlated with an impaired production of MMP-12. Importantly, protein levels of MIP-3α/CCL20, the only chemokine ligand of the CCR6 receptor, and MCP-1/CCL2 were significantly increased upon CS exposure in wild-type, but not in CCR6 KO mice. In contrast, CCR6 deficiency had no effect on the development of airway wall remodeling upon chronic CS exposure. These results indicate that the interaction of CCR6 with its ligand MIP-3α contributes to the pathogenesis of CS-induced pulmonary inflammation and emphysema in this murine model of COPD.

This is the first description of airway infiltration by DC in COPD. Moreover, interaction between CCL20 and CCR6 provides a possible mechanism for accumulation of DC in the lungs in COPD.

Small cell lung cancer (SCLC) is an aggressive lung tumour strongly associated with cigarette smoking, with patients often presenting with metastatic disease at the time of diagnosis. Although SCLC is very chemoradiosensitive and high response rates are obtained with treatment, relapse rates are high and the prognosis remains very poor.In limited-stage SCLC, the overall survival rate has been significantly improved by adding dosehyperfractionated thoracic radiotherapy and prophylactic cranial irradiation to systemic chemotherapy. In contrast, little progress has been made in the treatment of extensive-stage SCLC (ES-SCLC), apart from the recently documented survival gain by the addition of prophylactic cranial irradiation.First-line therapy in ES-SCLC currently consists of chemotherapy, combining a platinum drug with either etoposide or irinotecan as a possible alternative.New treatments are needed in order to improve the prognosis of ES-SCLC, as median survival with current standard treatment is still only 9-10 months from diagnosis. The present review focuses on the management of ES-SCLC, with special attention to the development of new treatment options.KEYWORDS: Chemotherapy, extensive disease, radiotherapy, small cell lung cancer, treatment S mall cell lung cancer (SCLC) is an aggressive malignant disease, with the majority of patients presenting with distant metastasis at diagnosis. A separate staging system has been developed for SCLC, classifying SCLC as limited or extensive disease [1]. The International Association for the Study of Lung Cancer defines limited-stage SCLC (LS-SCLC) as: ''disease restricted to one hemithorax with regional lymph node metastases, including hilar, ipsilateral and contralateral mediastinal, and ipsilateral and contralateral supraclavicular nodes and should also include patients with ipsilateral pleural effusion independent of whether cytology is positive or negative '' [2]. Patients with SCLC who do not fit this definition are considered to have extensive-stage SCLC (ES-SCLC). This staging system was used to select the appropriate treatment regimen: chemotherapy in combination with thoracic radiotherapy in patients with LS-SCLC, and chemotherapy alone in patients with ES-SCLC. Recent data suggest that the tumour, node, metastasis classification traditionally reserved for the staging of nonsmall cell lung cancer (NSCLC) can also be applied for the staging of SCLC [3].

Background: Several matrix metalloproteinases (MMPs) are involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). In mice, MMP-12 plays a crucial role in the development of cigarette smoke induced emphysema. A study was undertaken to investigate the role of MMP-12 in the development of COPD in human smokers. Methods: Induced sputum samples were collected from patients with stable COPD (n = 28), healthy smokers (n = 14), never smokers (n = 20), and former smokers (n = 14). MMP-12 protein levels in induced sputum were determined by ELISA and compared between the four study groups. MMP-12 enzymatic activity in induced sputum was evaluated by casein zymography and by cleaving of a fluorescence quenched substrate. Results: Median (IQR) MMP-12 levels were significantly higher in COPD patients than in healthy smokers, never smokers, and former smokers (17.5 (7.1-42.1) v 6.7 (3.9-10.4) v 4.2 (2.4-11.3) v 6.1 (4.5-7.6) ng/ml, p = 0.0002). MMP-12 enzymatic activity was significantly higher in patients with COPD than in controls (4.11 (1.4-8.0) v 0.14 (0.1-0.2) mg/ml, p = 0.0002). Conclusion: MMP-12 is markedly increased in induced sputum from patients with stable COPD compared with controls, suggesting a role for MMP-12 in the development of COPD in smokers.

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