No abstract

An imbalance between oxidative stress and antioxidative capacity is thought to piay an important role in the development and progression of chronic obstructive pulmonary disease (COPD). To assess the lung oxidative status in patients with COPD, we studied whether exhaled hydrogen peroxide (H2O2) is increased in breath condensate of patients with stable COPD (n = 12, mean FEV1 51% pred) and in patients with exacerbated COPD (n = 19, actual FEVi 36% pred) compared with a healthy control group (n = 10, FEVi 108% pred). Expired breath condensate during 15 min of tidal breathing was collected by cooling. The concentration of H2O2 was measured spectrophotometrically by means of horse radish peroxidase-catalyzed oxidation of tetramethylbenzidine. Concentrations of H2O2 (mean ± SEM) were significantly elevated at 0.205 ± 0.054 nM in patients with stable COPD compared with 0.029 ± 0.012 n.M in the control group (p < 0.05) and were further increased to 0.600 ± 0.075 nM in patients with acutely exacerbated COPD (p < 0.001 compared with patients with stable COPD). Patients with pulmonary infiltrates on chest radiograph showed similar values compared with patients without obvious infiltrates. These findings demonstrate that patients with stable COPD exhibit increased oxidant production in the airways and that oxidant production increases further during exacerbations.

Oxidative stress has been implicated in the pathogenesis and progression of chronic obstructive pulmonary disease.Both reactive oxidant species from inhaled cigarette smoke and those endogenously formed by inflammatory cells constitute an increased intrapulmonary oxidant burden. Structural changes to essential components of the lung are caused by oxidative stress, contributing to irreversible damage of both parenchyma and airway walls. In addition, oxidative stress results in alterations in the local immune response, increasing the risk of infections and exacerbations, which, in turn, may accelerate lung function decline.The antioxidant N-acetylcysteine, a glutathione precursor, has been applied in these patients in order to reduce symptoms, exacerbations and the accelerated lung function decline. This article reviews the presently available experimental and clinical data on the antioxidative effects of N-acetylcysteine in chronic obstructive pulmonary disease.

The addition of an inhaled corticosteroid--but not an inhaled anticholinergic agent--to maintenance treatment with a beta 2-agonist (terbutaline) substantially reduced morbidity, hyperresponsiveness, and airways obstruction in patients with a spectrum of obstructive airways disease.

Background: The frequency of clinical isolation of nontuberculous mycobacteria (NTM) in the Netherlands is increasing, but its clinical relevance is often uncertain. Objective: To assess the frequency and clinical relevance of isolation of NTM in four associated hospitals in a single region in the Netherlands. Methods: Medical files of all patients from whom NTM were isolated between January 1999 and January 2005 were reviewed retrospectively. Diagnostic criteria for nontuberculous mycobacterial disease published by the American Thoracic Society (ATS) were used to determine clinical relevance. Results: 232 patients were found, from whom NTM were isolated from the respiratory tract in 91% of cases. Patients were mostly white men, with an average age of 60 years and pre-existing pulmonary disease. Fifty-three of 212 patients (25%) with pulmonary isolates met the ATS diagnostic criteria for pulmonary NTM disease; this percentage differed by species. Most patients were treated with rifampicin, ethambutol and clarithromycin. Treatment outcome for pulmonary NTM disease was suboptimal but differed by species: overall, improvement was seen in 67% of treated patients, but in only 50% of those with pulmonary M avium disease. Lymphadenitis was the most common extrapulmonary disease type. Conclusions: Twenty-five per cent of all patients with pulmonary NTM isolates met the ATS criteria. Clinical relevance differs by species. NTM isolation increases over time. Species distribution differs from that of neighbouring countries and the M avium complex isolates have traits different from those reported in the USA. Adherence to diagnostic and treatment guidelines can be improved.The clinical isolation of non-tuberculous mycobacteria (NTM) increases in many countries where the incidence of tuberculosis is decreasing, with marked geographical differences in the species encountered.