This study was conducted to evaluate the oxidant/antioxidant balance (oxidative stress status) and plasma essential trace element levels in patients with bronchial asthma or allergic rhinitis.A total of 94 individuals consisting of 19 allergic asthmatics; 17 non-allergic asthmatics; 22 patients with allergic rhinitis; and 36 healthy control people were enrolled into this study. Superoxide dismutase (CuZnSOD) and glutathione peroxidase (GSH-Px) activity as antioxidant defence mechanism parameters, along with malondialdehyde (MDA) as a marker of lipid peroxidation, were determined in erythrocytes of patient groups and controls. Plasma copper and zinc levels were also determined in all groups.CuZnSOD activity was significantly lower in all groups of patients (p0.001 for allergic asthmatics, p=0.008 for allergic rhinitis patients, and p0.001 for non-allergic asthmatics) when compared to those of controls. Erythrocyte GSH-Px enzyme activity was not different when compared to that of the control group. Similarly, the patient groups had no difference from those of the controls with respect to erythrocyte MDA levels. While plasma Cu levels in all asthmatic patients were not different from those of the controls, allergic rhinitis patients had significantly elevated (p0.001) Cu levels compared to those of the controls. No statistically significant difference was established between patient groups and controls with respect to plasma zinc levels.While defective CuZnSOD activity observed in all patients groups was expected to cause an increase in lipid peroxidation indicated by high MDA levels in these patients groups, the fact that MDA levels were not different from those of controls in all patient groups indicates that other components of anti-oxidant defence system preserve their functions in these patients. On the other hand, statistically significant difference between all patients groups and controls with respect to trace elements was only observed in allergic rhinitis patients who had higher levels of Cu than those of controls.
