35. Air pollution risk factors for disease onset appear shared across systemic vasculitis and other autoimmune diseases

Background: Recent studies have identified long-term air pollution exposures as a risk factor for several autoimmune diseases. It is, however, unknown if these effects are generic or disease specific. In this study, we assessed the cumulative impact of long-term air pollution exposures on systemic vasculitis onset and other inflammatory autoimmune diseases. Methods: We undertook a case-control analysis using data from the UK Biobank (UKB) general population cohort. UKB enrolled over 500,000 adults, aged 37–73 years, between 2006 and 2010. Retrospective and prospective health outcomes data are linked from the UK national health service (NHS), death register and self-report information. Participants with systemic vasculitis (ICD-10 M30-31, n=1,206), rheumatoid arthritis (ICD-10 M05-06, n=6,451), systemic lupus erythematosus (ICD-10 M32, n=401), ankylosing spondylitis (ICD-10 M45, n=624) or psoriatic arthritis (ICD-10 M07, n=812) were classified into case groups and were each compared with the remainder of the UKB cohort who served as controls (n=487,942). Long-term air pollution data on particulate matter (PM10, PM2,5), nitrogen oxides (NO2, NOX), sulphur dioxide (SO2) and benzene (Bz) were linked for each participant’s place of residence (1km2 grid location based on postcode) annually from 2001-2018. This data was sourced from the UK department for environment, food, and rural affairs (Defra). Multivariable logistic regression models adjusting for age, sex, education, ethnicity, Townsend deprivation score, smoking and alcohol intake, time spent outdoors, and population density were used to assess the link between air pollution and inflammatory autoimmune disease status. Results: A 1µg/m3 increase in annual mean SO2 was associated with 6.4% increased odds of systemic vasculitis (OR: 1.064, 95% CI: 1.004 - 1.128). We observed similar associations in the other disease groups: a 1µg/m3 increase in SO2 was associated with 3.7% (OR: 1.037, 95% CI: 1.011 – 1.064) and 9.7% (OR: 1.097, 95% CI: 0.994 – 1.211) increased odds of rheumatoid arthritis and systemic lupus erythematosus, respectively (Figure 1). PM10 and PM2,5 were inversely associated with rheumatoid arthritis while no significant associations were observed for Bz, NO2 or NOX in relation to any of the disease groups. Conclusion: This is the first large scale study to evidence a link between long-term air pollution exposures and systemic vasculitis onset. Specifically, SO2 may be a risk factor for systemic vasculitis, but also other autoimmune diseases. Further work is needed to validate these results in cohorts with clinically well-defined disease phenotypes. Disclosures: None to declare Disclosures: None to declare Figure 1: Relationships between long-term residential air pollution exposures (2001-2018) and (A) systemic vasculitis, (B) RA and (C) systemic lupus erythematosus in UK Bioban