Anna Ilar

Occupational exposure to textile dust increases the risk of rheumatoid arthritis: results from a Malaysian population-based case–control study

Objectives Lung exposures including cigarette smoking and silica exposure are associated with the risk of rheumatoid arthritis (RA). We investigated the association between textile dust exposure and the risk of RA in the Malaysian population, with a focus on women who rarely smoke. Methods Data from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis population-based case–control study involving 910 female early RA cases and 910 female age-matched controls were analysed. Self-reported information on ever/never occupationally exposed to textile dust was used to estimate the risk of developing anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA. Interaction between textile dust and the human leucocyte antigen DR β-1 (HLA-DRB1) shared epitope (SE) was evaluated by calculating the attributable proportion due to interaction (AP), with 95% CI. Results Occupational exposure to textile dust was significantly associated with an increased risk of developing RA in the Malaysian female population (OR 2.8, 95% CI 1.6 to 5.2). The association between occupational exposure to textile dust and risk of RA was uniformly observed for the ACPA-positive RA (OR 2.5, 95% CI 1.3 to 4.8) and ACPA-negative RA (OR 3.5, 95% CI 1.7 to 7.0) subsets, respectively. We observed a significant interaction between exposure to occupational textile dust and HLA-DRB1 SE alleles regarding the risk of ACPA-positive RA (OR for double exposed: 39.1, 95% CI 5.1 to 297.5; AP: 0.8, 95% CI 0.5 to 1.2). Conclusions This is the first study demonstrating that textile dust exposure is associated with an increased risk for RA. In addition, a gene–environment interaction between HLA-DRB1 SE and textile dust exposure provides a high risk for ACPA-positive RA.

Associations With Smoking and Shared Epitope Differ Between IgA‐ and IgG‐Class Antibodies to Cyclic Citrullinated Peptides in Early Rheumatoid Arthritis

Smoking and HLA–DRB1/shared epitope (SE) alleles are risk factors for rheumatoid arthritis (RA) characterized by seropositivity for antibodies targeting citrullinated proteins (ACPAs)/cyclic citrullinated peptides (anti‐CCP). Previously, mainly IgG‐class antibodies have been studied. IgA‐class antibodies are to a great extent related to mucosal immunity. The aim of this study was to explore interrelations between cigarette smoking, presence of SE, and seropositivity for circulating IgA and/or IgG anti‐CCP antibodies among patients with early RA, to determine whether ACPAs of the IgA subclass are regulated by different mechanisms than those of the IgG subclass.

Occupation and Risk of Developing Rheumatoid Arthritis: Results From a Population-Based Case-Control Study

Environmental factors are of importance for the etiology of rheumatoid arthritis (RA), but much remains unknown concerning the contributions from distinct occupational hazards. We explored the association between occupation and the risk of anti–citrullinated protein antibody (ACPA)+ RA or ACPA− RA.

Airborne Occupational Exposures and Risk of Developing Rheumatoid Arthritis: A Job‐Exposure Matrix Approach in a Swedish Population‐Based Case–Control Study

Professor Alexis Descatha suggests that we should have used job-exposure matrices (JEM) to understand the underlying increased risks we noted between certain occupations and risk of rheumatoid arthritis (RA) in our study Occupation and Risk of Developing Rheumatoid Arthritis: Results From a Population-Based Case-Control Study (1). This article is protected by copyright. All rights reserved.

0297 Occupational exposure to organic dust and risk of developing rheumatoid arthritis

Objective Airborne exposure to inorganic dust is a contributor to rheumatoid arthritis (RA). We therefore wanted to investigate potential risks from exposure to organic dust. Methods This population-based case-control study consisted of individuals living in Sweden during 1968–2012. RA patients were enrolled from the Swedish Rheumatology Quality Register. To each case we matched ten controls from the population register on sex, parish and age. We collected the participants’ job titles from national population and housing censuses carried out 1960, 1970, 1975, 1980 and 1990. Job-exposure matrices were applied to the job titles to estimate ever exposure to oil mist/cutting fluids, wood-, animal-, paper-, textile-, flour- and other organic dust from 1955–1995. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for ever exposure vs. never exposure in relation to seropositive or seronegative RA. Results In total, 237 243 women and 98 136 men were included in the analysis. Men exposed to animal dust (OR: 1.3, 95% CI: 1.2–1.5), oil mist/cutting fluids (OR: 1.1, 95% CI: 1.1–1.2) and other organic dusts (OR: 1.3, 95% CI: 1.2–1.4) had an increased risk of seropositive RA, whereas wood dust (OR: 1.2, 95% CI: 1.1–1.4), animal dust (OR: 1.3, 95% CI: 1.1–1.6) and other organic dusts (OR: 1.2, 95% CI: 1.1–1.4) increased the risk of seronegative RA. Women had no significantly increased risk of RA from organic dust exposure. Conclusions Certain organic dusts are associated with increased risks of RA in men.

O18-6 Occupational exposure to textile dust increases the risk of RA: results from a malaysian population-based case-control study

Objectives Lung exposures including cigarette smoking and silica exposure are associated with the risk of rheumatoid arthritis (RA). We investigated the association between textile dust exposure and the risk of RA in the Malaysian population, with a focus on women who rarely smoke. Methods Data from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis (MyEIRA) population-based case-control study involving 910 female early RA cases and 910 female age-matched controls were analysed. Self-reported information on ever/never occupationally exposed to textile dust was used to estimate the risk of developing anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA. Interaction between textile dust and the HLA-DRB1 shared epitope (SE) was evaluated by calculating the attributable proportion due to interaction (AP), with 95% CI. Results Occupational exposure to textile dust was significantly associated with an increased risk of developing RA in the Malaysian female population (OR 2.8, 95% CI: 1.6–5.2). The association between occupational exposure to textile dust and risk of RA was uniformly observed for the ACPA-positive RA (OR 2.5, 95% CI: 1.3–4.8) and ACPA-negative RA (OR 3.5, 95% CI: 1.7–7.0) subsets, respectively. We observed a significant interaction between exposure to occupational textile dust and HLA-DRB1 SE alleles regarding the risk of ACPA-positive RA (OR for double exposed: 39.1, 95% CI: 5.1–297.5; AP: 0.8, 95% CI: 0.5–1.2). Conclusions This is the first study demonstrating that textile dust exposure is associated with an increased risk for RA. In addition a gene-environment interaction between HLA-DRB1 SE and textile dust exposure provides a high risk for ACPA-positive RA.

THU0417 Occupation and Risk of Developing Rheumatoid Arthritis

Background The etiology of rheumatoid arthritis (RA) is still fairly unknown. Finding occupations associated with the risk of disease could generate knowledge about occupational hazards that might be involved in disease development. Objectives The study explored the association between occupation and the risk of developing anti-citrullinated protein antibody-positive (ACPA+) RA or anti-citrullinated protein antibody-negative (ACPA-) RA in men and women. Methods The Epidemiological Investigation of Rheumatoid Arthritis (EIRA) study is a population-based case-control study, which enrolls newly diagnosed cases of RA in defined geographic areas of Sweden. Participants were 18-70 years of age. In total, 2,886 cases and 4,072 controls participated in the study. A questionnaire was collected to obtain information on occupational history and lifestyle factors. Blood samples were taken for serologic analyses. Logistic regression was used to calculate the odds ratio (OR) of RA due to last occupation before onset of disease symptoms in men and women separately. Results Among women, nurses had a reduced risk whereas assistant nurses, retail salesmen and machine fitters & assemblers had an increased risk of ACPA+ RA. Female attendants in psychiatric care had an increased risk while social workers had a reduced risk of ACPA- RA. Female business administrators had a reduced risk of RA, independent of ACPA status. Among men, wholesalers & retailers had a reduced risk whereas construction machine operators had an increased risk of ACPA+ RA. Men who worked as systems analysts had a decreased risk, while architects & engineers & technical workers, cargo & van drivers and machine & engine repairers had an increased risk of ACPA- RA. Male electricians were associated with an increased risk, whereas business administrators and advertisement workers had reduced point estimates in RA independent of ACPA status. Adjusting for smoking mainly affected the risk of developing ACPA+ RA. Conclusions This study found associations between several occupations and onset of RA. Considering sex and ACPA status were of considerable relevance. Differences were detected between men and women, where elevated risks among women were mainly seen in the health care sector, whereas increased risks among men were detected in mechanical and technical occupations. Disclosure of Interest : None declared DOI 10.1136/annrheumdis-2014-eular.4989