Background. Oxidative stress plays a role in the pathogenesis of many chronic inflammatory lung diseases. Exhaled breath condensate (EBC) collection is a noninvasive method to investigate pulmonary oxidative stress biomarkers such as malondialdehyde (MDA). Subjects and Methods. We measured MDA levels in EBC in a large number of patients (N = 194) with respiratory diseases: asthma (N = 64), bronchiectasis (BE, N = 19), chronic obstructive pulmonary disease (COPD, N = 73), idiopathic pulmonary fibrosis (IPF, N = 38). Fourteen healthy nonsmoking subjects were included as controls. Results. Excluding IPF subjects, MDA levels were significantly higher in all disease groups than in control group. MDA was significantly higher in COPD than asthmatic and BE subjects. Among asthmatics, corticosteroids-treated subjects had lower MDA levels than untreated subjects. COPD subjects showed an inverse correlation between MDA concentrations and FEV1% (rho:
−0.24, P < .05). Conclusions. EBC-MDA is increased in subjects with chronic airway disorders, particularly in COPD, and it is related to FEV1 reduction.
Several studies on the prognosis of occupational asthma have shown that a significant proportion of patients continue to experience asthmatic symptoms and nonspecific bronchial hyperresponsiveness after cessation of work. The determinants of this unfavourable prognosis of asthma are: long duration of exposure before the onset of asthma; long duration of symptoms before diagnosis; baseline airway obstruction; dual response after specific challenge test; and the persistence of markers of airway inflammation in bronchoalveolar lavage fluid and bronchial biopsy. The relevance of immunological markers in the outcome of occupational asthma has not yet been assessed.Further occupational exposure in sensitized subjects leads to persistence and sometimes to progressive deterioration of asthma, irrespective of the reduction of exposure to the specific sensitizer, and only the use of particular protective devices effectively prevents the progression of the disease. A long-term follow-up study of toluene diisocyanate (TDI)-induced asthma showed that the improvement in bronchial hyperresponsiveness to methacholine occurred in a small percentage of subjects and only a long time after work cessation. Bronchial sensitivity to TDI may disappear, but nonspecific bronchial hyperresponsiveness often persists unchanged, suggesting a permanent deregulation of airway tone. Steroid treatment significantly reduces nonspecific bronchial hyperresponsiveness only when started immediately after diagnosis.
ACT score is a valid tool to simply assess the current level of asthma control in terms of symptoms, rescue medication use, and PEF variability. Pulmonary function and biomarkers of airway inflammation are not related to the clinical asthma control as assessed by ACT and may represent additional measurements potentially useful in asthma management.
There is a relationship between measures of sleep in patients with COPD and the amount of activity they undertake during the waking day. Identifying groups with specific sleep characteristics may be useful information when designing physical activity-enhancing interventions.
We investigated whether exposure to ozone (O(3)) 24 hours after an allergen challenge test would increase airway eosinophilia induced by allergen in subjects with mild asthma with late airway response. Twelve subjects with mild atopic asthma participated in a randomized, single-blind study. Subjects underwent allergen challenge 24 hours before a 2 hour exposure to O(3) (0.27 ppm) or filtered air. Pulmonary function was monitored during the allergen challenge and after the exposure to O(3) or air. Six hours later, induced sputum was collected. After 4 weeks, the experiment was repeated with the same subjects. Allergen induced a comparable late airway response in both challenges. O(3) exposure induced a significant decrease in FVC, FEV(1), and vital capacity, and was associated with a significant increase in total symptom score compared with air exposure. The percentage of eosinophils, but not the percentage of neutrophils, in induced sputum was significantly higher after exposure to O(3) than after exposure to air (p = 0.04). These results indicate that O(3) exposure after a late airway response elicited by allergen challenge can potentiate the eosinophilic inflammatory response induced by the allergen challenge itself in subjects with mild atopic asthma. This observation may help explain the synergistic effect of air pollution and allergen exposure in the exacerbation of asthma.
Background. Neutrophilic bronchial inflammation is a main feature of bronchiectasis, but not much is known about its relationship with other disease features. Aim. To compare airway inflammatory markers with clinical and functional findings in subjects with stable noncystic fibrosis bronchiectasis (NCFB). Methods. 152 NFCB patients (62.6 years; females: 57.2%) underwent clinical and functional cross-sectional evaluation, including microbiologic and inflammatory cell profile in sputum, and exhaled breath condensate malondialdehyde (EBC-MDA). NFCB severity was assessed using BSI and FACED criteria. Results. Sputum neutrophil percentages inversely correlated with FEV1 (P < 0.0001; rho = −0.428), weakly with Leicester Cough Questionnaire score (P = 0.068; rho = −0.58), and directly with duration of the disease (P = 0.004; rho = 0.3) and BSI severity score (P = 0.005; rho = 0.37), but not with FACED. Sputum neutrophilia was higher in colonized subjects, P. aeruginosa colonized subjects showing greater sputum neutrophilia and lower FEV1. Patients with ≥3 exacerbations in the last year showed a significantly greater EBC-MDA than the remaining patients. Conclusions. Sputum neutrophilic inflammation and biomarkers of oxidative stress in EBC can be considered good biomarkers of disease severity in NCFB patients, as confirmed by pulmonary function, disease duration, bacterial colonization, BSI score, and exacerbation rate.
We conclude that hypertonicity does not affect sputum cell composition, suggesting that inflammatory cells in hypertonic saline-induced sputum are probably preexisting and not acutely recruited in the airways by the hypertonic stimulus. However, the bronchoconstriction and the increase in bronchial hyper-responsiveness after hypertonic saline inhalation may imply the release of inflammatory mediators. This fact must be considered in the evaluation of soluble markers of inflammation in hypertonic saline-induced sputum.
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