Assessment of serum antioxidant status in patients with silicosis.

Prolonged exposure to silica dust causes an imbalance in the generation of free radicals and in the antioxidant system, thereby inducing oxidative stress. The antioxidant status of 113 silicosis patients and 116 control subjects without silicosis was examined. Serum superoxide dismutase (SOD) activity and serum levels of malondialdehyde (MDA) and glutathione (GSH) were significantly higher in silicosis patients than in controls. The GSH level in patients with stage I silicosis was higher than that in patients with other stages, but there was no difference in serum MDA level and SOD activity between disease stages. The GSH level of patients who worked with air drills was significantly lower than that of patients in other occupations, whereas the MDA level was significantly elevated in patients who used air drills. Serum SOD activity did not differ significantly according to the occupational group. It is concluded that the measurement of serum SOD, GSH and MDA levels could be beneficial in the clinical evaluation of serum antioxidant status in silicosis patients.