Effect of cigarette smoking on cervical epithelial immunity: a mechanism for neoplastic change?

Langerhans' cells in cervical epithelium in colposcopic biopsy specimens were identified by immunocytochemical staining for S100 protein and T6 (CD1) antigen, and their density was quantified. Possible cofactors for the development of cervical neoplasia were examined for any effect on the cell counts per unit area. Current cigarette smoking was associated with a significant decrease in the Langerhans' cell population in both normal epithelium and lesions due to cervical intraepithelial neoplasia. Ex-smokers tended to have cell counts between those of smokers and non-smokers. There was a dose-response relation between number of cigarettes smoked daily and effect on cell counts. These findings of a local immunological effect of smoking on cervical epithelium may explain the means by which cigarette smoking contributes to the development of cervical neoplasia.