FRI0674 THE ASSOCIATION BETWEEN JOINT EROSIONS PLUS AUTOANTIBODY POSITIVITY AT INITIATION OF METHOTREXATE OR BIOLOGIC THERAPY FOR RHEUMATOID ARTHRITIS AND DISEASE ACTIVITY AND DISABILITY OVER ONE YEAR

Background Joint erosions and autoantibody positivity (rheumatoid factor [RF], anti-cyclic citrullinated peptide antibody [anti-CCP]) predict poor outcomes in patients with rheumatoid arthritis (RA). There are limited data on the combination of these factors and clinical and patient reported outcomes over time. Objectives To compare the disease activity and disability over 1 year of those with poor prognostic factors at treatment initiation (methotrexate [MTX] or biologics) to those without. Methods Patients were recruited to 1 of 2 UK-based multi-centre prospective cohort studies: MTX-starters: Rheumatoid Arthritis Medication Study (RAMS); biologic-starters: Biologics in Rheumatoid Arthritis Genetics and Genomics Study Syndicate (BRAGGSS). Anti-CCP (Axis-Shield Anti-CCP test; U/ml; anti-CCP titre >5 U/ml = anti-CCP+)/RF (Beckman Coulter AU5400, RF latex assay; IU/ml; RF titre >14 IU/ml = RF+) status were determined from baseline (BL) blood samples at the co-ordinating centre; erosions (yes/no) were recorded from medical notes. Missing data resulting from anti-CCP assay failure were imputed using multiple imputation. Patients who were anti-CCP+ and/or RF+ and had erosions were classified as having poor prognosis (PP); all other patients were classified as not having poor prognosis (NPP). Patients completed the Health Assessment Questionnaire (HAQ) and the Disease Activity Score (DAS28) was calculated at BL, 6 months and 12 months. The DAS28 and HAQ scores of the prognostic groups were compared at each assessment using linear regression, adjusted for age, gender and disease duration. Results In total, 1179 (PP = 182 [15.4%]) MTX-starters and 1152 (PP = 467 [40.5%]) biologic-starters were included (BL characteristics in Table). For MTX-starters, PP and NPP patients had similar DAS28, whereas for biologic-starters, PP patients had lower DAS28 compared to NPP patients after baseline (adjusted mean difference [95% CI]: MTX-starters BL = 0.1 [-0.1, 0.3]; 6 months = -0.1 [-0.3, 0.2]; 12 months = -0.1 [-0.4, 0.2]; biologic-starters BL = -0.1 [-0.2, 0.0]; 6 months = -0.2 [-0.4, 0.0]; 12 months = -0.4 [-0.6, -0.1]). HAQ scores were similar between PP and NPP patients in both cohorts (adjusted mean difference [95% CI]: MTX-starters BL = 0.08 [-0.04, 0.20]; 6 months = 0.02 [-0.11, 0.15]; 12 months = -0.03 [-0.17, 0.10]; biologic-starters BL = 0.00 [-0.09, 0.08]; 6 months = 0.00 [-0.12, 0.13]; 12 months = 0.01 [-0.14, 0.16]). Conclusion PP and NPP MTX-starters had similar outcomes. For biologic-starters, PP patients had lower disease activity after baseline; knowledge of these prognostic factors may have prompted more intensive assessment of PP patients after starting treatment. Disclosure of Interests James Gwinnutt: None declared, Kimme Hyrich Grant/research support from: Grants to institution: BMS, Pfizer, UCB, Mark Lunt: None declared, Darren Plant: None declared, Nisha Nair: None declared, Anne Barton: None declared, Suzanne Verstappen: None declared