Background and aims: Chronic obstructive pulmonary disease (COPD) is predominantly a result of the cumulative exposure to tobacco smoke and its progress is stimulated by oxygen-derived free radicals from tobacco smoke or activated structural and inflammatory cells. Superoxide dismutases (SODs) are the first line of antioxidants defence system. The present study investigates the expressions of SOD and their association to inflammatory cells and local destructive index (DI) in small airways of non-smokers and patients with severe COPD. Methods: Expression of macrophages, mast cells, neutrophils, and SODs (CuZn-SOD, Mn-SOD, EC-SOD) was evaluated by immunochemistry using formalin-fixed, paraffin-embedded sections from non-smoking controls (n=9) and COPD patients (n=10). Histological and immunohistochemical analyses were performed using the same Region-of-Interest within each small airway. Results: The mean percentage and intensity of CuZn-SOD-immunoreactive cells were greater in COPD patients (p< 0.05) and with a predominant expression in the small airway epithelium whereas epithelial Mn-SOD and EC-SOD expression was not altered. The DI was negatively correlated with SODs immunoreactivity. Macrophages were prominently present in the alveolar region and neutrophils in small bronchioles. Mast cells were prominent in both small airways and alveolar parenchyma, although the total numbers were decreased in COPD. Conclusions: We demonstrate overexpression of CuZn-SOD and the elevated number of inflammatory cells. A correlation has been shown between SODs immunoreactivity and DI.
Olejnicka et al. (Thu,) studied this question.