Anti-citrullinated peptide antibodies and the progression of radiographic joint erosions in patients with early rheumatoid arthritis treated with FIN-RACo combination and single disease-modifying antirheumatic drug strategies.

Objectives To evaluate the impact of antibodies to cyclic citrullinated peptide (ACPAs) on radiographic progression in patients with early rheumatoid arthritis (RA) initially treated either with a combination of 3 disease-modifying antirheumatic drugs (DMARDs) or with a single DMARD. Methods This study included 129 patients with early active RA initially randomised to treatment either with a combination of methotrexate, sulfasalazine, hydroxychloroquine, and prednisolone (FIN-RACo) (n=69) or with a single DMARD (initially sulfalasalazine) with or without prednisolone (SINGLE) (n=60). After 2 years, the use of DMARDs and prednisolone became unrestricted. Radiographic progression in hands and feet was assessed at baseline and at 1, 2, 3, 4 and 5 years. ACPAs at baseline were determined with enzyme immunoassay. Results ACPAs were positive in 92 (71%) patients. ACPA-positive vs. negative patients were more frequently rheumatoid factor (RF) positive (83% vs. 22%, p<0.001) and had an erosive disease (54% vs. 22%, p<0.001) at baseline. The presence of ACPA was associated with radiographic progression in FIN-RACo group even when the impact of RF was controlled; the radiographic progression was remarkably slower in ACPA-negative than in ACPA-positive cases (RF adjusted change over time between groups p=0.034). In the SINGLE group, the radiographic changes progressed parallel in ACPA-negative and positive patients. Conclusion Most ACPA-positive RA patients have joint erosions already at diagnosis. ACPA positivity in early RA was related to radiographic progression even in patients treated initially with the FIN-RACo regimen. The initial FIN-RACo therapy seems to slow down the progression of joint damage in ACPA-negative patients.