Abstract
OBJECTIVE: To determine whether exposure to tobacco smoke is associated with double stranded DNA (dsDNA) seropositivity in patients with systemic lupus erythematosus (SLE). METHODS: Medical record review was used to confirm the diagnosis of SLE and evaluate dsDNA antibody status. Smoking status at the time of autoantibody testing was assessed by patients' questionnaire responses. Multivariate regression analysis was used to determine whether exposure to tobacco smoke is associated with dsDNA seropositivity, while controlling for sex and age at SLE diagnosis. RESULTS: A significantly higher risk of dsDNA seropositivity in current smokers than never smokers (odds ratio (OR) = 4.0, 95% confidence interval (CI) 1.6 to 10.4) was shown by multivariate analysis. Current smokers were found to be at higher risk for dsDNA seropositivity than former smokers (OR = 3.0, 95% CI 1.3 to 7.1). The association between current smoking and dsDNA seropositivity remained significant after adjustment for sex, age at SLE diagnosis, amount smoked, age when smoking began, and the duration of smoking cessation (for former smokers). CONCLUSION: The association of smoking with dsDNA seropositivity provides insight into the potential mechanisms underlying autoantibody formation. This information may also serve as a possible point of intervention to prevent disease or target treatment.