Background/Purpose: Tapering medication in rheumatoid arthritis (RA) patients is becoming increasingly important due to the effectiveness of both biological therapy and tight-controlled treatment. Patients are able to reach the state of remission in which they may be able to taper their medication. Whom to taper and when to taper (amount of time in remission) is unclear. Ultrasound (US) data from cross-sectional studies suggest that the presence of subclinical synovitis might increase the risk of disease flare preventing patients to be tapered. Our objective was to detect subclinical synovitis by US and to relate this to the occurrence of flare in RA patients that continue synthetic and biological DMARDs for 3 months while being in remission.

Methods: Patients who are participating in the TARA (TApering strategies in Rheumatoid Arthritis) study and were examined by US were selected for this analysis. TARA is a single-blinded randomized controlled trial that includes RA patients (aged >17 years) who are treated with the combination of a synthetic DMARD and adalimumab or etanercept and are in remission (DAS44<2.4 & SJC ≤1). In the first 3 months of this study patients continue their medication and if they maintain their disease state, are randomized to (i) tapering the synthetic DMARD or (ii) tapering their TNF blocker. US examination included 26 joints (MCP2-5, PIP2-5, wrists, MTP2-5) graded on greyscale (GS; 0-3) and power Doppler (PD; 0-3). A joint with subclinical synovitis was defined as GS>1 and/or PD>0, while flare was captured by DAS44≥2.4 or SJC>1.

Results: For this analysis we included 67 patients. In total 39 patients (58%) had subclinical synovitis. Three patients (8%) with subclinical synovitis experienced a flare while continuing their combination of synthetic and biological treatment. Patients without subclinical synovitis did not differ from patients with subclinical synovitis if we compared clinical features such as tender joints, serology or acute phase reactants. ACPA was slightly higher in the patients without subclinical synovitis but did not reach statistical significance.

Conclusion: In 58% of the patients we detected subclinical synovitis. However, after three months a low flare rate (4%) was observed among patients in remission continuing their combination therapy of synthetic and biological DMARDs. Although the patients who flared had subclinical synovitis, using GS>1 and/or PD>0 in at least one joint might not be sufficient to discriminate who will clinically flare.