POS0355 THE RELATIONSHIP BETWEEN SMOKING STATUS AND SJÖGREN’S DISEASE DIAGNOSIS AND DISEASE ACTIVITY: RESULTS OF A SINGLE CENTRE COHORT STUDY
Authors: M. Bandeira, A. Baranskaya, V. Pucino, S. Bowman, B. Fisher
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> The relationship between smoking and the risk of Sjögren's disease (SjD) remains unclear. Most studies show that current smoking is negatively correlated with SjD whereas past smoking may be positively associated. The possibility of reverse causation, whereby patients stop smoking due to dryness, has not been excluded. <h3>Objectives:</h3> To assess if smoking status is a risk factor for SjD and how it affects the main features of the disease. <h3>Methods:</h3> Patients referred with suspected SjD were recruited into the Optimising Assessment in Sjögren's Syndrome (OASIS) cohort established in Birmingham, UK (2014-2023). Subjects were assessed and diagnosed as SjD or non-Sjögren's sicca. Smoking status was regularly obtained within clinic with additional information available through a risk factor questionnaire. Univariate analysis was performed using chi-square, Fisher's exact, Mann-Whitney or t-test, and correlation between continuous variables using Pearson or Spearman, according to their distribution. Predictors of Sjogren's disease diagnosis were identified through binomial logistic regression modelling. <h3>Results:</h3> 487 patients were included, 170 non-Sjögren's sicca syndrome and 317 SjD patients, 81.1% of whom (n=257) met 2016 ACR/EULAR classification criteria for SjD. Compared to sicca, SjD patients meeting 2016 criteria are more frequently never smokers and, amongst ever smokers, have a lower smoking exposure measured by pack-year units (Table 1). Time between onset of symptoms and smoking cessation for past smokers was calculated and the majority of patients stopped smoking before symptom onset. In the multivariate analysis, both current smoking (OR 0.37, 95%CI: 0.15-0.92, p=0.032) and white ethnicity (OR 0.26, 95%CI: 0.12-0.56, p=0.001) were protective factors for SjD diagnosis in suspected patients, irrespective of age and sex. Amongst SjD patients meeting 2016 criteria, rheumatoid factor (p=0.038), IgG (p=0.004) and IgM (p=0.006) levels are significantly higher in never smokers with no passive smoking history. Amongst patients with a clinical diagnosis of Sjögren's, those with smoking exposure are less frequently positive for anti-Ro antibodies (p=0.008) and rheumatoid factor (p=0.016) and have lower IgG levels (p=0.002). An inverse correlation trend was observed between smoking exposure (pack-years) and IgG levels (rho=-0.186, p=0.076) in the whole population. Never smoking was confirmed as a predictor of IgG levels (β 1.94, 95%CI: 0.12-3.77, p=0.037) in a linear regression model including age, sex, ethnicity, and disease classification [R<sup>2</sup>=0.287, F (5,254) = 20.487, p&lt;0.001]. Looking at 2016 criteria SjD patients, ESSPRI is higher in ever smokers (p=0.039), with fatigue (p=0.040) being accountable for this difference. Likewise, amongst sicca patients, symptoms of fatigue, but not dryness, were significantly higher in ever smokers (p=0.022). No differences in the main features of minor salivary gland biopsies attributable to smoking were seen. <h3>Conclusion:</h3> Our study shows that smoking is negatively associated with SjD. In the multivariate analysis, current smoking and white ethnicity were protective factors for SjD classification in suspected patients, irrespective of age and sex. Avoidance of factors that may exacerbate dryness symptoms might not explain the association with smoking status. Clinically diagnosed SjD patients exposed to tobacco are more frequently seronegative and have lower rheumatoid factor and IgG levels. <h3>REFERENCES:</h3> <b>NIL.</b> <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> Matilde Bandeira: None declared, Aliaksandra Baranskaya: None declared, Valentina Pucino: None declared, Simon Bowman SJB has received payment for consultancy advice on clinical trials and outcome measures in SjD in the past 3 years from Abbvie, Aurinia, BMS, Galapagos, Iqvia, J&amp;J and Novartis, Benjamin Fisher Consultancy: Novartis, BMS, Servier, Galapagos, Roche, UCB, Sanofi, Janssen, Funding: Janssen, Servier, Galapagos, Celgene.