OCCUPATIONAL EXPOSURES TO CD, NI, AND CR MODULATE TITERS OF ANTIOXIDIZED DNA-BASE AUTOANTIBODIES

This study was undertaken to establish whether occupational exposures to derivatives of carcinogenic metals evoke inflammatory immune respon ses, as determined by the presence of elevated titers of antibodies (A b) that recognize oxidized DNA bases. Sera obtained from the blood of steel welders (Delaware) and from workers of the Centra Ni-Cd Battery Factory (Poznan, Poland) were analyzed by the enzyme-linked immunosorb ent assay. To determine specific and nonspecific binding, an oxidized thymidine [5-hydroxymethyl-2'-deoxyuridine (HMdU)] coupled to bovine s erum albumin (HMdU-BSA) as well as mock-coupled BSA (M-BSA) were used as antigens for coating the wells of microliter plates. Titers of anti -HMdU Ab were significantly elevated in the high Cd and Ni exposure gr oups (18.3 +/- 3.2 vs 10.8 +/- 2.1 A(499)/mu l; p<0.05). The sera of t he groups with low exposures to Cd and Ni also had enhanced titers of those Ab but those increases were not statistically significant. Inter estingly, the Ab liters present in the sera of controls for Cd and Ni exposures appear to be constant regardless of the protein content. In contrast, both lightly and heavily exposed subjects exhibited Ab titer s that increased with increasing protein content. When 12 randomly sel ected workers (4 from each of the control, lightly, and heavily expose d groups) were outfitted with personal monitors, anti-HMdU Ab titers o f those workers showed a significant difference between the groups wit h light (<100 mu g/m(3)) and heavy (>200 mu g/m(3)) exposures to Cd (9 .8 +/- 3.7 vs 22.1 +/- 3.7 A(492)/mu l; p<0.01) and Ni (11.7 +/- 1.4 v s 31.0 +/- 1.8; p<0.001). Workers exposed to welding fumes exhibited h igher anti-HMdU Ab titers than unexposed controls, but the difference was not statistically significant. These results point to anti-HMdU Ab as being potential biomarkers of exposure to proinflammatory and pote ntially carcinogenic agents.