P035 Occupational physical workload and development of anti-collagen type II antibodies in rheumatoid arthritis: results from the swedish EIRA population-based case-control study

Career situation of first and presenting author Young investigator. Introduction Separate studies have previously observed an association between exposure to physical workload (PW) and risk of developing rheumatoid arthritis (RA). Levels of antibodies against collagen type II (CII), which are associated with HLA-DRB*01 and *03 are transiently elevated at the time of RA diagnosis. PW might impose mechanical stress on the articular cartilage where CII is the main constituent, leading to immune activation and production of anti-CII antibodies. Objectives We hypothesize that exposure to PW would associate more strongly with anti-CII positive RA than with anti-CII negative RA. Methods Data involving 2916 incident RA cases and 5130 controls from the Swedish Epidemiological Investigations in Rheumatoid Arthritis (EIRA) population-based case-control study were analysed. Information on exposure to PW was collected through questionnaires. The odds ratios (OR) with 95% CI of developing anti-CII positive RA or anti-CII negative RA was calculated using logistic regression. Results The OR observed for the association between different types of PW and anti-CII positive RA ranged from 1.2 (0.8–1.8) to 1.7 (1.5–3.1). The OR for the association between PW and anti-CII negative RA ranged from 1.3 (1.1–1.4) to 1.6 (1.4–1.8). No statistically significant difference was observed between the OR for anti-CII positive RA and anti-CII negative RA (all p-values>0.10). Moreover, stratification for HLA-DRB*01 and *03 did not yield any statistical differences. Conclusions We found no evidence suggesting an association between PW and elevated anti-CII levels at the time of diagnosis. Acknowledgements We thank the investigators and participants from the EIRA study. The authors also thank Marie-Louise Serra and Lena Nise for data collection. Disclosure of Interest None declared.