CD4+CD25+ FOXP3-positive T-regulatory cells have an important role in controlling immune and inflammatory reactions. The present authors hypothesise that these cells may be involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). The aim of the present study was to characterise the expression of FOXP3 in large and small airways of nonsmokers, smokers with normal lung function and COPD patients.A total of 19 nonsmokers, 20 smokers with normal lung function and 20 smokers with moderate COPD, undergoing lung resection for a solitary peripheral nonsmall cell carcinoma, were enrolled in the study. Immunohistochemical methods were used to evaluate FOXP3 expression in large and small airways.Smokers with normal lung function and COPD patients had increased numbers of FOXP3-positive cells in large airways compared with nonsmokers. A positive correlation was observed between FOXP3 expression in large airways and smoked pack-yrs. In small airways, COPD patients had decreased numbers of FOXP3-positive cells, compared with asymptomatic smokers and nonsmokers, that negatively correlated with airflow obstruction.To conclude, chronic obstructive pulmonary disease is characterised by upregulation of FOXP3-positive cells in large airways but a downregulation in small airways that correlated with airflow limitation. The results of the present study contribute to a better understanding of the pathogenesis of chronic obstructive pulmonary disease.

Background: Chronic obstructive pulmonary disease (COPD) is characterised by progressive and irreversible airway obstruction. Smoking causes persistent inflammation in lung tissue. However, differences in inflammatory responses between the large and small airways have not been systematically explored among smokers with and without COPD. Objectives: The aim of our research was to characterise the expression and localisation of NF-ĸBp65 and histone deacetylase 2 (HDAC2) as well as inflammatory cell (macrophages, lymphocytes, neutrophils) distribution in large and small airways, in nonsmokers and in smokers with and without COPD. Methods: Nineteen nonsmokers, 20 smokers with normal lung ventilation function and 20 smokers with moderate COPD, undergoing lung resection for a solitary peripheral carcinoma, were enrolled in the study. Immunohistochemical methods were used to evaluate NF-ĸBp65 and HDAC2 expression and identify inflammatory cells in airways. Results: COPD patients had increased NF-ĸBp65 expression compared to nonsmokers and smokers without COPD, in both large and small airways, which corresponded to increased numbers of macrophages, CD8+ T lymphocytes and neutrophils. COPD patients had more macrophages in large compared to small airways and more CD8+ T lymphocytes and neutrophils in small compared to large airways. HDAC2 expression was significantly downregulated in smokers with COPD in small compared to large airways. Conclusions: Our findings indicate a nonuniform distribution of inflammatory cells throughout the bronchial tree. However, in both smokers with and without COPD, similar patterns of inflammatory processes occur in both large and small airways. The difference between smokers with and without COPD is only quantitative.

Background and Objective. Chronic obstructive pulmonary disease (COPD) is characterized by a persistence of inflammation in large and small airways. We hypothesized that this could be caused by the inability of an inflammatory process to resolve. In the resolution of inflammation, a switching of arachidonic acid metabolism from the production of proinflammatory leukotriene B4 (LtB4) to the synthesis of anti-inflammatory lipoxins plays an important role. The aim of our study was to determine the content of lipoxin A4 (LXA4) and LtB4 in induced sputum of patients with exacerbated COPD and to compare it to healthy controls, as well as to analyze the relationship between proinflammatory and anti-inflammatory mediators and an inflammatory cell spectrum in induced sputum. Material and Methods. Induced sputum from 17 COPD patients and 7 healthy controls were analyzed for LXA4 and LtB4 content and inflammatory cell spectrum. Results. COPD patients had a significantly lower sputum LXA4 concentration and LtB4/LXA4 ratio compared with healthy controls. A significant negative correlation was found between the LXA4 concentration and the relative neutrophil count and between the LtB4/LXA4 ratio and the relative macrophage count. Conclusions. COPD patients during the late phase of exacerbation had a suppressed production of LXA4 and an elevated LtB4/LXA4 ratio in induced sputum demonstrating a proinflammatory imbalance. The correction of a balance between proinflammatory and anti-inflammatory eicosanoids by the administration of stable analogues of lipoxins could improve the treatment of chronic obstructive pulmonary disease in the future.