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

Objective: To examine radical-induced DNA damage and its elimination ill wo rkers exposed to quartz and in patients with silicosis, and to assess the r elationship of these effects to lung function, Methods: Blood and spontaneo us urine samples were obtained from active, quartz-exposed workers without silicosis (n = 63), and from retired workers with silicosis (n = 42). Level s of 8-hydroxydeoxyguanosine (8-OHdG) were determined in peripheral blood l eukocyte DNA and urine, by the use of high-performance liquid chromatograph y coupled with ultra violet- (UV) and electrochemical detection. Results: N o 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 q uartz-exposed healthy workers. However, in the group of silicosis patients with increased oxidative DNA damage the urinary excretion of 8-OHdG was low er 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 ill one second (FE V1) and forced vital capacity (FVC). Healthy workers with a personally esti mated 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 activit y, smoking or age was found. Conclusion: Our findings suggest that a less e ffective repair of 8-OHdG is associated with a higher degree of pulmonary a irway obstruction in patients with silicosis.