Background Smoking is the most-widely accepted risk factor for rheumatoid arthritis (RA), especially genetically-susceptible subjects (carriers of the shared epitope (SE)). Many studies also show an association between smoking and the presence of autoantibodies (rheumatoid factor (RF) and anti-citrullinated peptide antibodies (anti-CCP)), although there are discrepancies between cohorts and geographic areas.
Objectives To analyze the relationship between smoking and the number of cigarettes smoked and the presence of the SE and autoantibodies (RF and anti-CCP) in an early RA cohort.
Methods 204 patients (82.4% female) with early RA according to 1987 ACR criteria (disease duration <2 years) were included. Demographic, genetic (DRB genotype), clinical, laboratory and radiographic variables were obtained at disease diagnosis. Smoking status and packs/year were evaluated at baseline. Radiologic damage was evaluated using the Larsen score.
Results Of 204 patients, the smoking status was not available in 3, 111 (55%) were non-smokers and 90 (45%) ever-smokers (60 patients were active smokers and 30 ex-smokers). The mean packs/year was 18.66. Active-smokers had earlier disease onset and shorter disease duration at diagnosis than non-smokers. There were no differences in disease activity, disability or joint damage between groups (Table 1). Smokers were more-frequently RF positive than non-smokers. Likewise smoking was significantly associated with the SE. Anti-CCP positivity and titres were similar in both groups, but when heavy smokers (≥20p/y) (n=35) were compared with non-smokers (n=111) a significant association was found between smoking and anti-CCP+ (94% vs 74%, p=0.009, OR:5.83, CI 95%:1.32–25.86) and titres (703.3±616.2 U vs 587.4±633.6 UI/L, difference not significant p=0.350).
Conclusions In early RA patients, smoking was associated with SE and RF positivity. Smoking was associated with anti-CCP positivity only in heavy smokers.
Disclosure of Interest None Declared