The influence of cotinine on interleukin 6 expression in smokers with cervical preneoplasia

Background Several epidemiological investigations have shown that cigarette smoking leads to increased serum IL-6 levels and is a risk factor for cervical cancer. Methods. We examined the levels of interleukin 6 (IL-6) and the amount of cotinine in the cervical fluid of 78 women and compared the presence of human papillomavirus (HPV) in smokers and nonsmokers. Results. The results of our study showed that IL-6 levels were higher in the cervical mucus of smokers than in nonsmokers. Fourteen percent of smokers were in the category with highest IL-6 levels compared to 6% of nonsmokers. However, our IL-6 results were not significant as they were probably influenced by the higher rates of HPV infection in smokers (17 cases) than in nonsmokers (4 cases). Significant findings showed that smokers had a higher prevalence of squamous intraepithelial lesions (SILs) than nonsmokers. Smokers' cotinine levels also exceeded those of nonsmokers: 13.95 ng/ml compared with 5.00 ng/ml. However, less IL-6 activity was evident in smokers with high-grade SILs and HPV infection of high-risk types. Conclusion. Our results suggest that smoking has a stimulatory effect on the production of IL-6 in the cervix. Furthermore, smokers show a higher genital HPV infection rate and a higher prevalence of SILs.