8-Hydroxydeoxyguanosine in leukocyte DNA and urine of quartz-exposed workers and patients with silicosis.

Abstract

To examine radical-induced DNA damage and its elimination in workers exposed to quartz and in patients with silicosis, and to assess the relationship of these effects to lung function. Blood and spontaneous urine samples were obtained from active, quartz-exposed workers without silicosis (n = 63), and from retired workers with silicosis (n = 42). Levels of 8-hydroxydeoxyguanosine (8-OHdG) were determined in peripheral blood leukocyte DNA and urine, by the use of high-performance liquid chromatography coupled with ultra violet- (UV) and electrochemical detection. No significant differences in the mean levels of 8-OHdG in leukocyte DNA and of urinary excretion of 8-OHdG were found between silicosis patients and quartz-exposed healthy workers. However, in the group of silicosis patients with increased oxidative DNA damage the urinary excretion of 8-OHdG was lower than in the corresponding group of active workers without silicosis. In the case of silicosis, urinary 8-OHdG correlated positively, and 8-OHdG in DNA correlated negatively, with forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). Healthy workers with a personally estimated high dust exposure in the workplace showed higher levels of 8-OHdG in DNA than did workers with moderate dust exposure. No association of 8-OHdG formation and/or elimination with duration of employment, field of activity, smoking or age was found. Our findings suggest that a less effective repair of 8-OHdG is associated with a higher degree of pulmonary airway obstruction in patients with silicosis.