Aina Noguera

Systemic effects of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterised by an inappropriate/excessive inflammatory response of the lungs to respiratory pollutants, mainly tobacco smoking. Recently, besides the typical pulmonary pathology of COPD (i.e. chronic bronchitis and emphysema), several effects occurring outside the lungs have been described, the so-called systemic effects of COPD. These effects are clinically relevant because they modify and can help in the classification and management of the disease. The present review discusses the following systemic effects of chronic obstructive pulmonary disease: 1) systemic inflammation; 2) nutritional abnormalities and weight loss; 3) skeletal muscle dysfunction; and 4) other potential systemic effects. For each of these, the potential mechanisms and clinical implications are discussed and areas requiring further research are highlighted.

Enhanced neutrophil response in chronic obstructive pulmonary disease

BACKGROUND Neutrophils are likely to play a major role in the inflammatory response seen in chronic obstructive pulmonary disease (COPD). This study sought to address the hypothesis that an enhanced neutrophil response to proinflammatory agents in COPD may contribute to their recruitment and activation in the lungs. METHODS Circulating neutrophils were obtained from 10 patients with COPD, eight long term smokers with normal lung function, and eight healthy never smoking controls. The in vitro production of reactive oxygen species (ROS) was measured by the NADPH oxidase method (respiratory burst) and the surface expression of several adhesion molecules (Mac-1, LFA-1 andl-selectin) was measured by flow cytometry. Measurements were obtained under basal conditions and after stimulation with phorbol myristate acetate (PMA) and tumour necrosis factor alpha (TNFα). mRNA levels of p22-phox (a subunit of NADPH oxidase) and Mac-1 (CD11b) were also determined by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS Patients with COPD showed enhanced respiratory burst compared with smokers with normal lung function, both under basal conditions (mean (SE) fluorescence intensity (MFI) 15.1 (0.5) v 11.6 (0.5); mean difference –3.4 (95% CI of the difference –5.1 to –1.8), p<0.01) and after PMA stimulation (MFI 210 (7) v 133 (10); mean difference –77 (95% CI of the difference –102 to –52), p<0.01). Mac-1 surface expression was also enhanced in patients with COPD, both under basal conditions (MFI 91 (5)v 45 (3); mean difference –46 (95% CI of the difference –61 to –31), p<0.001) and after stimulation with TNFα (MFI 340 (15) v 263 (11); mean difference –77 (95% CI of the difference –119 to –34), p=0.001). These differences were also apparent when patients with COPD were compared with non-smokers (p<0.05). The mRNA levels of p22-phox and Mac-1 (CD11b) were similar in patients with COPD and smokers with normal lung function, suggesting that the observed differences were due to post-transcriptional regulation. CONCLUSIONS These results demonstrate an enhanced neutrophil response to proinflammatory agents in patients with COPD which may contribute to their enhanced recruitment and activation in the lungs of these patients. These findings support those of other studies which have indicated that the neutrophil is likely to play a major role in the pathogenesis of this disease.

Low-dose theophylline enhances the anti- inflammatory effects of steroids during exacerbations of COPD

Background: Chronic obstructive pulmonary disease (COPD) is characterised by an abnormal inflammatory response mainly to cigarette smoke that flares up during exacerbations of the disease (ECOPD). Reduced activity of histone deacetylases (HDAC) contributes to enhanced inflammation in stable COPD. It was hypothesised that HDAC activity is further reduced during ECOPD and that theophylline, an HDAC activator, potentiates the anti-inflammatory effect of steroids in these patients. A study was performed to investigate HDAC activity during ECOPD and the effects of theophylline on the anti-inflammatory effects of steroids in a randomised single-blind controlled study. Methods: 35 patients hospitalised with ECOPD and treated according to international guidelines (including systemic steroids) were randomised to receive or not to receive low-dose oral theophylline (100 mg twice daily). Before treatment and 3 months after discharge, HDAC and nuclear factor-κB (NF-κB) activity in sputum macrophages, the concentration of nitric oxide in exhaled air (eNO) and total antioxidant status (TAS), tumour necrosis factor α (TNFα), interleukin (IL)-6 and IL8 levels in sputum supernatants were measured. Results: Patients receiving standard therapy showed decreased NF-κB activity, eNO concentration and sputum levels of TNFα, IL6 and IL8, as well as increased TAS during recovery of ECOPD, but HDAC activity did not change. The addition of low-dose theophylline increased HDAC activity and further reduced IL8 and TNFα concentrations. Conclusions: During ECOPD, low-dose theophylline increases HDAC activity and improves the anti-inflammatory effects of steroids. Trial registration number: NCT00671151

Intracellular cytokine profile of T lymphocytes in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by an excessive inflammatory response to inhaled particles, mainly tobacco smoking. T lymphocytes are important regulatory cells that secrete several cytokines and participate actively in this inflammatory response. According to the pattern of cytokines secreted, the immune response is classified as cytotoxic or type 1 [interferon (IFN)‐γ‐, interleukin (IL)‐2‐dependent] and humoral or type 2 (IL‐4‐, IL‐5‐, IL‐10‐ and IL‐13‐dependent). This paper sought to compare the intracellular profile of cytokine expression determined by flow cytometry in T lymphocytes harvested from bronchoalveolar lavage (BAL) and peripheral blood in patients with COPD, smokers with normal lung function and never smokers. We found that BAL T lymphocytes from COPD patients had a higher percentage of positive stained cells for most of the cytokines analysed when compared to never smokers or smokers with normal lung function. Differences reached statistical significance for IL‐4, IL‐10 and IL‐13, particularly in CD8+ T cells. Furthermore, the expression of most of these cytokines was related inversely to the degree of airflow obstruction present suggesting local activation and/or selective homing of T lymphocytes to the lungs in COPD patients. These observations were not reproduced in circulating T lymphocytes. These results suggest that BAL T lymphocytes in patients with COPD produce more cytokines than in controls and tend to show a type 2 pattern of intracellular cytokine expression, particularly a Tc‐2 profile. This is related inversely to the degree of airflow obstruction present.

Anti-Tissue Antibodies Are Related to Lung Function in Chronic Obstructive Pulmonary Disease

RATIONALE Chronic obstructive pulmonary disease (COPD) is a multicomponent disease. Autoimmunity can contribute to the pathogenesis of COPD. OBJECTIVES This study investigates the prevalence of circulating antinuclear antibodies (ANA) and anti-tissue (AT) antibodies, two common markers of autoimmunity, in COPD and their relationship with several components of the disease. METHODS We determined lung function, the serum titers of ANA and AT by immunofluorescence, and the serum levels of C-reactive protein (CRP) by high sensitivity nephelometry in 328 patients with clinically stable COPD and in 67 healthy controls recruited in the PAC-COPD study. Multiple linear and logistic regression analysis was used to analyze results. MEASUREMENTS AND MAIN RESULTS The prevalence of abnormal ANA and AT titers was 34% and 26% in patients and 3% and 6% in controls, respectively. Levels of AT greater than or equal to 1:320 were seen in 21% of patients with COPD and were independently associated with the severity of airflow limitation and gas transfer impairment (P < 0.05). Neither ANA or AT titers was related to body mass index, current smoking status, use of inhaled steroids, the Charlson index, or serum C-reactive protein values. CONCLUSIONS Between a quarter and a third of patients with clinically stable COPD present abnormal titers of circulating ANA and AT. The observed relationship between AT and lung function supports a role for autoimmunity in the pathogenesis of COPD.

Phenotypic characterisation of alveolar macrophages and peripheral blood monocytes in COPD

Alveolar macrophages (AM) participate actively in the inflammatory response that characterises chronic obstructive pulmonary disease (COPD). The present study investigated potential changes in AM phenotypes in patients with COPD. Using flow cytometry, the surface expression of receptors implicated in phagocytosis (CD44, CD36, CD51, CD61, CD14), antigen-presenting capacity (human leukocyte antigen (HLA)-DR), costimulatory molecules (CD80, CD86, CD40) and complement receptor type 3 were assessed in AM from 18 patients with COPD, 14 smokers with normal lung function and nine nonsmokers. When compared to smokers with normal lung function and nonsmokers, the surface expression of HLA-DR and CD80 was lower in AM of patients with COPD. In addition, these patients had a higher percentage of AM with a low level surface expression of CD44. There did not appear to be any difference in the other receptors studied in AM between the three groups. The expression of all these receptors in peripheral blood monocytes also did not differ between groups. In conclusion, these observations suggest that the cell-mediated immune function of alveolar macrophages can be reduced in chronic obstructive pulmonary disease, and that this is a local rather than a systemic event.

Decreased macrophage release of TGF-β and TIMP-1 in chronic obstructive pulmonary disease

The present study tested the hypothesis that alveolar macrophages (AM) from patients with chronic obstructive pulmonary disease (COPD) release more pro-inflammatory and/or less anti-inflammatory mediators than those from smokers with normal lung function and never-smokers. AM were sorted by flow cytometry from bronchoalveolar lavage fluid in 13 patients with COPD (mean±SEM 67±2 yrs, forced expiratory volume in one second (FEV1) 61±4% reference), 16 smokers with normal lung function (55±2 yrs, FEV1 97±4% reference) and seven never-smokers (67±7 yrs, FEV1 94±4% reference). After sorting, AM were cultured (with and without lipopolysaccharide stimulation) after 4 h and 24 h, and the concentrations of leukotriene B4 (LTB4), transforming growth factor (TGF)-β1 and tissue inhibitor of metalloproteinase (TIMP)-1 were quantified in the supernatant by ELISA. The production of reactive oxygen intermediates (ROI) in freshly isolated AM was determined by flow cytometry. LTB4 secretion and ROI production were not different between groups. In contrast, AM from COPD patients released significantly less TGF-β1 and TIMP-1 than those from smokers with normal lung function and nonsmokers. In conclusion, these observations are compatible with reduced anti-inflammatory and anti-elastolytic capacity in chronic obstructive pulmonary disease, which is likely to contribute to the pathogenesis of the disease.

Differential response of lymphocytes and neutrophils to high intensity physical activity and to vitamin C diet supplementation.

We have determined the effects of chronic vitamin C intake on neutrophil and lymphocyte antioxidant defences during the acute phase immune response induced by intense exercise. Blood samples were taken from 16 voluntary athletes in basal conditions, both immediately after and 1 h after a duathlon competition. Sportsmens nutrient intakes were determined before the competition. After determining the basal plasmatic ascorbate levels, the results were analysed taking into account the vitamin C intake and their plasmatic levels. Two groups were constituted, the vitamin C supplemented group and the control group, with the dietary vitamin C intake as the only statistical difference between groups. The duathlon competition induced a significant neutrophilia, which was higher in the supplemented group. Lymphocyte antioxidant enzyme activities increased after the competition, with a higher increase in SOD activity in the control group than in the supplemented one. The competition decreased neutrophil antioxidant enzyme activities and neutrophil ascorbate concentration. The decrease in the SOD activity in the supplemented group was higher than in the control group. Finally, the duathlon competition increased the expression of MAC-1 neutrophil adhesion molecule in the supplemented group. High vitamin C intake influenced the response of neutrophils and lymphocytes to oxidative stress induced by exercise, increasing the neutrophil activation.

Molecular Mechanisms of Inflammation During Exacerbations of Chronic Obstructive Pulmonary Disease

Abstract Introduction Exacerbations of chronic obstructive pulmonary disease (COPD) are characterised by an inflammatory and systemic response that persists for some time after their clinical resolution. The mechanisms of this inflammatory process are not well known. Objectives To explore the inflammatory changes and possible mechanisms during COPD exacerbation. Methods We determined the inflammatory cell concentrations in blood and sputum, nitric oxide in exhaled air (FeNO), C-reactive protein (CRP) in plasma, cytokines (IL-6, 8, 1β, 10, 12, TNF-α) and SLPI (leukocyte protease inhibitor) and total antioxidant status (TAS) in blood and sputum, the activity of nuclear kappa B factor (NF-κ B) and of the histone deacetylase enzyme (HDAC) in 17 patients during COPD exacerbation and in stable phase, as well as in 17 smoker and 11 non-smoker controls. Results COPD exacerbations are characterised by high levels of FeNO (p Conclusions Changes were observed in different pulmonary and systemic inflammatory markers during COPD exacerbation, which did not completely resolve during stable phase. However, current treatment does not allow for HDAC activity to be modified, which limits its anti-inflammatory effects.

Variability and effects of bronchial colonisation in patients with moderate COPD

Sputum and lung function were periodically assessed in stable moderate chronic obstructive pulmonary disease (COPD) outpatients to determine relationships between bronchial colonisation and inflammation. Relationships between potentially pathogenic microorganism (PPM) typology, bronchial inflammation (neutrophilia, tumour necrosis factor-α, interleukin (IL)-1β, IL-6, IL-8, IL-10 and IL-12) and post-bronchodilator decline in forced expiratory volume in 1 s (FEV1) were analysed. PPMs periodically showing the same molecular profile using pulse field gel electrophoresis were considered long-term persistent. Bronchial colonisation was observed in 56 out of 79 follow-up examinations (70.9%) and was mainly due to Haemophilus influenzae, Pseudomonas aeruginosa and enterobacteria (n = 47). These PPMs were all related to sputum neutrophilia (p≤0.05, Chi-squared test), and H. influenzae was related to higher levels of IL-1β (p = 0.005) and IL-12 (p = 0.01), with a dose–response relationship (Spearman’s correlation coefficient of 0.38 for IL-1β (p = 0.001), and of 0.32 for IL-12 (p = 0.006)). Haemophilus parainfluenzae was not associated with an identifiable inflammatory response. Long-term persistence of the same strain was observed in 12 examinations (21.4%), mainly due to P. aeruginosa or enterobacteria. A neutrophilic bronchial inflammatory response was associated with a statistically significant decline in FEV1 during follow-up (OR 2.67, 95% CI 1.07–6.62). A load-related relationship to bronchial inflammation in moderate COPD was observed for colonisation by H. influenzae, but not for colonisation by H. parainfluenzae.