ASSOCIATION OF THE RHEUMATOID ARTHRITIS PROGNOSTIC FACTORS ANTI-CITRULLINATED PEPTIDE ANTIBODIES, RHEUMATOID FACTOR AND EROSIONS WITH DISEASE ACTIVITY AND WORK PRODUCTIVITY

Background: Autoantibody production, including RF and anti-citrullinated protein antibody (ACPA), may play a role in RA disease pathogenesis. ACPA positivity(+) in patients (pts) with RA is a strong predictor of joint erosions and radiographic progression. However, data evaluating the association of seropositive, erosive disease with disease activity and resource use (RU) are limited. Objectives: To evaluate the association of ACPA+/RF+ with erosions and disease activity; to compare activity, RU and work productivity (WP) in ACPA+ pts with erosions vs all other RA pts. Methods: Pts enrolled in the BRASS Registry were analysed. BRASS comprises mostly pts with established RA who were evaluated annually on clinical measures and semi-annually on clinical pt-reported outcomes and resource utilization parameters. Baseline (BL) visit was the time of enrolment into BRASS. ACPA levels at BL and annual follow-up were measured using a validated ELISA (Inova Diagnostics, San Diego, CA) until its discontinuation in 2011, and the Euro-Diagnostica assay (IBL-America, Minneapolis, MN) thereafter. RF levels at BL and follow-up were measured during the annual rheumatologist visit. RU and WP were measured at 6 months (M) via pt questionnaires. Subgroups at BL were described using Wilcoxon rank-sum test (continuous variables) and Pearson's chi-square test (categorical variables); multivariate logistic regression models (binary outcome variables) and ordinary least-square regression analysis (continuous outcome variables) were used. Covariates included in the multivariate models were age, sex, race, BMI, RA duration, number of co-morbidities and treatment. Results: Among 1309 pts with ACPA data, 82% were female, mean (SD) age was 56.5 (14.1) yrs and DAS28(CRP) was 3.7 (1.6). Pts had mean (SD) TJC of 14.3 (14.0), ACPA levels of 128.3 (151.9) units/mL and RF levels of 127.7 (301.6) units/mL. After controlling for covariates, odds ratio (OR) for erosive disease was 2.72 (95% CI: 1.77, 4.18) for ACPA+ and 1.36 (0.88, 2.08) for RF+ (Fig. 1a). The OR for attaining SDAI LDA (<3.3) was 0.37 (0.21, 0.66) for ACPA+ and 1.45 (0.82, 2.56) for RF+ (Fig. 1b). ACPA titres were associated with erosive disease: 61 vs 32% of pts had erosive disease in the high vs low ACPA quartiles. ACPA+ pts with erosions (n=498) had higher mean SDAI (28.0 vs 18.1) and joint counts (19.2 vs 11.1), and greater proportions (60 vs 38%) were treated with biologic (b)DMARDs compared with all other RA pts. In multivariate analyses, the OR for SDAI remission in ACPA+ pts with erosions was 0.19 (0.10, 0.37); a significantly (p<0.05) greater proportion of these pts had durable equipment use (30.6 vs 22.1%) and all-cause hospitalizations (20.1 vs 13.1%) compared with all other RA pts at 12M. This group also had lower employment (38.7 vs 53.5%) and higher long-term disability (25.4 vs 17.3%) and retirement (32.5 vs 22.1%). Conclusions: ACPA+ has a stronger association with erosions and disease activity. The presence of ACPA+ and erosions (vs absence) is associated with higher disease activity, lower odds of remission and lower WP, even when treated with standard-of-care bDMARDs. References: 1. Aggarwal R, et al. Arthritis Rheum 2009;61:1472–83. 2. Jilani AA and Mackworth-Young CG. Int J Rheumatol 2015;2015:72810. doi: 10.1155/2015/728610. Disclosure of Interest: E. Alemao Shareholder of: Bristol-Myers Squibb, Employee of: Bristol-Myers Squibb, Z. Guo Shareholder of: Bristol-Myers Squibb, Employee of: Bristol-Myers Squibb, C. Iannaccone: None declared, M. Frits: None declared, N. Shadick Grant/research support from: Bristol-Myers Squibb, Crescendo Biosciences, Amgen, UCB, Questcor, M. Weinblatt Grant/research support from: Bristol-Myers Squibb, Crescendo Bioscience, UCB, Amgen, Consultant for: Bristol-Myers Squibb, Crescendo Bioscience, UCB, AbbVie, Roche, Janssen, Pfizer, Lilly, Amgen DOI: 10.1136/annrheumdis-2016-eular.1646Citation: Annals of the Rheumatic Diseases, volume 75, supplement 2, year 2016, page 211Session: Rheumatoid arthritis - comorbidity and clinical aspects (Poster Presentations )