Synovitis Detection by Grey Scale Ultrasound Predicts Erosions in Rheumatoid Arthritis

Synovitis in grey scale ultrasound (GSUS) predicts joint damage progression in patients with rheumatoid arthritis (RA), according to study results published in Rheumatology.

Data from the Swiss Clinical Quality Management database between January 1, 2010 and August 10, 2018 were selected for patients with RA based on clinical diagnosis, availability of baseline radiograph, and presence of a follow-up radiograph at least 6 months after the initial radiograph. Data of 259, 287, and 250 patients were included for the power Doppler ultrasound synovitis (PDUS), GSUS, and combined composite score (CombUS), respectively. The primary outcome was the radiographically detectable change in joint damage progression between baseline and follow-up, defined as a >3.5% difference in the Ratingen score.

Researchers found that 69 of 250 patients with CombUS, 73 of 259 patients with PDUS, and 75 of 287 patients with GSUS data showed progression of joint damage at their respective 75th percentiles. There was a significant association of radiographic progression for PDUS scores beyond the upper limit of normal (1/54), and for the GSUS and CombUS scores at their 50th percentiles (9/54 and 10/54, respectively) and their 75th percentiles (14/54 and 15/54, respectively). The prediction was demonstrated in patients with and without biologic disease-modifying antirheumatic drug (bDMARD) therapies.

Subgroup analyses indicated that while GSUS >14/54 and CombUS >15/54 were associated with progression of joint damage in patients receiving bDMARDs, there was no significant prognostic power with clinical disease activity measures.

Overall, increased levels of GSUS and CombUS were linked to the development of erosions in patients with RA.

Potential study limitations included the fact that patients had follow-ups without a protocol with a large time variation in the intervals between baseline and follow-up radiographs, and no medical treatment was part of the protocol. Most patients were exposed to bDMARD therapy at some point. Investigators also imputed missing ultrasound data and missing patient global disease activity parameters. Finally, the data were unable to be adjusted for genetics or information about disease biology.

“This large, [multicenter], real-life study strongly suggests the usefulness of imaging synovitis to predict the structural disease outcome from a perspective of years, especially in patients [with RA] on bDMARD therapy […] While [the] observations highlight the importance of synovitis for the destructive course of RA, ongoing technical and [methodologic] improvements in US imaging synovitis appear likewise necessary and achievable.”

Disclosure: This study was supported by AbbVie Switzerland and Bristol-Myers Squibb Switzerland. Please see the original reference for a full list of authors’ disclosures.

Reference

Möller B, Aletaha D, Andor M, et al.  Synovitis in rheumatoid arthritis detected by grey scale ultrasound predicts the development of erosions over the next three years [published online October 19, 2019]. Rheumatology (Oxford). doi:10.1093/rheumatology/kez460