Evaluation of polycyclic aromatic hydrocarbon-DNA adducts in exfoliated oral cells by an immunohistochemical assay

Polycyclic aromatic hydrocarbon-DNA adducts were evaluated in oral cells fr om 98 healthy volunteers by an immunohistochemical method using a specific antiserum against benzo(a)pyrene-DNA adducts revealed by the immunoperoxida se reaction. Mean adduct content, determined as relative staining intensity by absorbance image analyzer, was significantly higher in the cells from t obacco smokers compared with nonsmokers (330 +/- 98, n = 33 versus 286 +/- 83, n = 64, respectively) with a P = 0.013 obtained by two-sample t test wi th equal variances, We found that in the smoker group, the PAH-DNA adduct c ontent increases with the number of cigarettes. Thus, the relative staining intensity was 305 +/- 105 in the group smoking 1-10 cigarettes/day (n = 16 ), 347 +/- 77 in the 11-20 group (n = 14), and 386 +/- 112 in the group smo king more than 20 cigarettes/day (n = 3; P = 0.03 by nonparametric test for trend). No significant association was detected between PAH-DNA adducts in oral cells and variables such as residential area, oral infections, alcoho l or vitamin intake, grilled food consumption, and professional activity, T his work confirms and extends previous data suggesting that this immunohist ochemical method might be used as a valuable dosimeter of genotoxic damage in a carcinogen-exposed population, although further studies are needed to verify the applicability of the test in high-risk populations other than sm okers.