Subclinical synovitis and tenosynovitis by ultrasonography (US) 7 score in patients with rheumatoid arthritis treated with synthetic drugs, in clinical remission by DAS28.

OBJECTIVE: To identify synovitis and tenosynovitis active by using the Ultrasound 7 (US 7) scoring system in patients with rheumatoid arthritis (RA) in clinical remission induced by synthetic disease-modifying antirheumatic drugs (DMARDs).

METHODS: This is a multicentric, cross-sectional, observational study including 94 RA patients >18 years old who were in remission as defined by the 28-joints disease activity score (DAS28) <2.6 induced by synthetic DMARD during at least 6 months. Patients with a previous or current history of biologic DMARD treatment were not included in the study. Demographic and clinical data were collected by the local rheumatologist; the US evaluation was performed by a calibrated rheumatologist, who intended to detect grayscale synovitis and power Doppler (PD) using the 7-joint scale. Intra and inter-reader exercises of images between 2 ultrasonographers were realized.

RESULTS: Patients' mean age was 49.1±13.7 years; 83% were women. The mean disease duration was 8±7 years and remission lasted for 27.5±31.8 months. The mean DAS28 score was 1.9±0.66. Grayscale synovitis was present in 94% of cases; it was mild in 87.5% and moderate in 12.5%. Only 12.8% of the patients had PD. The metatarsophalangeal, metacarpophalangeal, and carpal joints of the dominant hand were the joints more frequently affected by synovitis. Tenosynovitis by grayscale was observed in 9 patients (9.6%). The intra and inter-reading kappa value were 0.77, p<0.003 (CI 95%, 0.34-0.81) and 0.81, p<0.0001 (CI 95%, 0.27-0.83) respectively.

CONCLUSIONS: Low percentage of synovitis and tenosynovitis active were founded according to PD US by 7 score in RA patients under synthetic DMARDs during long remission. This score has benefit because evaluate tenosynovitis, another element of subclinical disease activity.