Objective Anticitrullinated protein antibodies (ACPAs) are suggested to identify different subsets of patients with rheumatoid arthritis (RA). The authors compared the clinical and radiological responses to Disease Activity Score (DAS)-steered treatment in patients with RA positive or RA negative for ACPA.

Methods In the BehandelStrategieën (BeSt) study, 508 patients with recent-onset RA were randomised to four treatment strategies aimed at a DAS ≤2.4. Risks of damage progression and (drug-free) remission in 8 years were compared for ACPA-positive and ACPA-negative patients using logistic regression analysis. Functional ability and DAS components over time were compared using linear mixed models.

Results DAS reduction was achieved similarly in ACPA-positive and ACPA-negative patients in all treatment strategy groups, with a similar need to adjust treatment because of inadequate response. Functional ability and remission rates were not different for ACPA-positive and ACPA-negative patients. ACPA-positive patients had more radiological damage progression, especially after initial monotherapy. They had a lower chance of achieving (persistent) drug-free remission.

Conclusion Clinical response to treatment was similar in ACPA-positive and ACPA-negative patients. However, more ACPA-positive patients, especially those treated with initial monotherapy, had significant radiological damage progression, indicating that methotrexate monotherapy and DAS- (≤2.4) steered treatment might be insufficient to adequately suppress joint damage progression in these patients.