PRESENCE AND PERSISTENCE OF SERUM ANTI-BENZO[A]PYRENE DIOLEPOXIDE-DNAADDUCT ANTIBODIES IN SMOKERS - EFFECTS OF SMOKING REDUCTION AND CESSATION

Among biomarkers of tobacco smoke (TS)-induced genotoxic damage, benzo [a]pyrene diolepoxide-DNA adducts (BPDE-DNA) are extensively studied. Adducted DNA becomes antigenic and antibodies anti-BPDE-DNA (BPDE-DNA- Abs) may be found in serum of exposed subjects. Little is known about the persistence of BPDE-DNA, and no study has been performed to evalua te the persistence of BPDE-DNA-Abs after cessation of exposure. Fifty heavy smokers, enrolled in a smoking cessation program with nicotine p atch substitution therapy, were evaluated for the presence of BPDE-DNA -Abs before (w0) and 1, 3, 6 and 12 weeks (w1-12) after the start of t he program. Nicotine or placebo patches were randomly assigned to the subjects. BPDE-DNA-Abs were determined in serum by non-competitive ELI SA. After the start of the cessation program, 28 subjects quit smoking (group Q) and the other 22 reduced by about 75% the number of cigaret tes smoked per day (group R). At the start of the program (w0) 8% of s ubjects were positive. At w1 the prevalence of positivity had increase d both in subjects who quit smoking (Q: 21%) and in subjects who had r educed the number of cigarettes per day (R: 27%). Positivity remained stable up to w12 (21%) for group Q, whereas it increased to 41% in gro up R. Serum BPDE-DNA-Abs can be detected in smokers, and their persist ence for months after smoking cessation suggests their usefulness for relatively long-term surveys. The low percentage of positivity in actu al heavy smokers and the increase in antibody positivity with smoking cessation or reduction must be taken into account when interpretating serum BPDE-DNA-Ab measurement in exposed individuals. (C) 1997 Wiley-L iss, Inc.