Smoking and systemic sclerosis: influence on microangiopathy and expression of anti-topoisomerase I antibodies in a monocentric cohort.

OBJECTIVES: To investigate whether systemic sclerosis (SSc) patients exposed to active tobacco smoke exhibit a different autoantibody profile or are at higher risk for severe microangiopathy compared to never-smokers, and to assess differences between men and women. METHODS: We performed an exploratory observational study in a cohort of SSc patients fulfilling the 2013 ACR/EULAR classification criteria. According to the smoking habit, patients were categorised as ever-smokers or never-smokers. Microvascular damage was assessed at baseline using nailfold videocapillaroscopy. The presence of SSc-specific autoantibodies was investigated. RESULTS: The studied population was composed of 361 patients (279 women, 82 men). Of these, 208 (58%) were ever-smokers and 153 (42%) were never-smokers. Anti-centromere, anti-topoisomerase I (ATA) and anti-RNA polymerase III antibodies were found, respectively, in 90 (43%), 41 (20%), and 11 (5%) ever-smokers, and in 66 (43%), 40 (26%) and 5 (3%) never-smokers (all p>0.05). Scleroderma patterns early, active and late were present respectively in 12%, 44% and 21% of ever-smokers, and in 9%, 48%, and 29% of never-smokers (all p>0.05). In multivariable logistic regression, being a never-smoker was significantly associated with ATA positivity (OR 1.77, 95% CI 1.04-2.99, p= 0.034). In the gender-based sub-cohorts, 36 (27%) female patients who never smoked were ATA positive, compared to 16 (11%) ever-smoking women (p<0.001). CONCLUSIONS: We observed a significant association between smoking history and positivity of ATA and we outlined the idea of a different effect of smoking on autoantibody expression between men and women.