LAUSR

OBJECTIVE To assess the ability of ultrasound to predict successful tapering and successful discontinuation of biological disease-modifying anti-rheumatic drugs (bDMARDs) at 2-year follow-up in rheumatoid arthritis (RA) patients in sustained remission. METHODS Patients in sustained remission (DAS28-CRP≤2.6) and no radiographic progression the previous year tapered bDMARD according to a standardized regime. One-hundred-and-nineteen of these patients were included in this ultrasound sub-study. At baseline, clinical assessment, MRI, x-ray and ultrasound of 24 joints were performed. Ultrasound-detected synovitis was defined and scored 0-3 using the Outcome in Rheumatology (OMERACT) scoring system at joint level for both greyscale and Doppler activity. Sum scores for each ultrasound modality were calculated for 24 joints at patient level. Final state of treatment was assessed after 2 years. The predictive value of ultrasound measures for successful tapering and discontinuation at 2-year follow-up was assessed via logistic regression analyses. RESULTS Negative IgM-RF (OR = 0.29; 95% Confidence Interval (CI)=0.10-0.85; p = 0.024) and lower Doppler sum score of 24 joints (OR(95%CI)=0.44;(0.15-0.87); p = 0.014) were independent predictors for successful discontinuation of bDMARD at 2-year follow-up. The predictive value of Doppler sum score was independent of MRI findings. Previous numbers of bDMARDs were predictive of successful tapering (OR(95% CI)=0.58(0.35-0.91); p = 0.018), whereas ultrasound was not. Clinical parameters were not predictive for successful tapering/discontinuation. CONCLUSIONS Doppler sum score was an independent predictor for successful discontinuation of bDMARDs at 2-year follow-up - the odds for achieving successful discontinuation decreased by 56% per one-unit increase in Doppler sum score. Ultrasound could not predict successful tapering.