Persistence of power Doppler ultrasonography-detected synovitis over 1 year of follow-up predicts poor prognosis in rheumatoid arthritis in clinical remission: the SONORE prospective longitudinal study

Objectives (1) To assess the progression of ultrasonography-detected synovitis in a cohort of patients with rheumatoid arthritis (RA) in remission during 1 year of follow-up (2) to evaluate the ability of consecutive examinations of ultrasonography to predict relapse (R) or radiographic progression (RP) at 1 year. Methods Patients with RA (2010 American College of Rheumatology-European Alliance of Associations for Rheumatology criteria) in clinical remission (Disease Activity Score in 28 joints (DAS28)<2.6 without clinically active synovitis) were included. An independent investigator performed ultrasonography every 3 months for 1 year. Ultrasonography-detected synovitis was defined as power Doppler-positive ultrasonography synovitis (PDUS) grade ≥1 in at least one joint. PDUS at ≥2 consecutive visits during the follow-up defined persistent PDUS. An increase of ≥1 point in the modified total Sharp score defined RP. An increase in DAS28-C-reactive protein (CRP)>0.6 or DAS28-CRP>3.2 and any modification of disease-modifying anti-rheumatic drugs or glucocorticoids defined relapse. Univariate and multivariate Cox regression analyses were used to evaluate factors associated with R/RP at 1 year. Results PDUS was detected in 75 (65.2%), 66, 60, 46 and 29 of the 115 patients with RA at baseline and at months 3, 6, 9 and 12, respectively. 58 (50.4%) patients exhibited persistent PDUS. After 1 year, 22/85 (25.9%) experienced relapse and 12 (14.1%) showed RP. On multivariate analysis, factors predicting R/RP at 1 year were persistent PDUS (HR=2.98, p=0.014) and an increase in DAS28-CRP level at the visit before relapse (HR=4.36, p=0.004). Conclusion Persistent PDUS during follow-up, rather than at baseline, predicted worse outcome at 1 year and requires careful monitoring. All data relevant to the study are included in the article or uploaded as supplementary information. The data sets generated during and/or analysed during the current study are not publicly available. All data provided are anonymised to respect the privacy of patients who have participated in the study, in line with applicable laws and regulations. The data may be requested from the corresponding author.