Abstract
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.