ASSESSING SYNOVITIS IN PATIENTS WITH RHEUMATOID ARTHRITIS BY ULTRASOUND – AN AGREEMENT STUDY EXPLORING THE MOST ACTIVE SIDE

Background: Though ultrasound examination of all RA patients - if offered a very tight clinical control – may not be necessary for obtaining clinical remission (1,2), there are still patients where ultrasound may have a role in monitoring disease activity. Scoring synovitis unilaterally will by far reduce the examination time, however, no consensus exists on how to choose the side to be examined and if one side per se is always the most inflamed side. Objectives: To assess ultrasound (US) inflammation and sensitivity to change in hands, aiming to identify if the right hand, the dominant hand, or the hand with more clinically swollen joints (SwJ) is per se the most inflamed and more sensitive to change, and hence the preferred side for unilateral scoring of synovitis by US in rheumatoid arthritis (RA) patients. Methods: This is an agreement study exploring the impact on US scoring methods in a longitudinal study of early RA (ARCTIC trial, n=230) and established RA (ULRABIT trial, n=212) patients initiating conventional and biological Disease Modifying Anti-Rheumatic Drugs, respectively. Tender and swollen joint count for 28 joints (TJC28 and SJC28) and C-reactive protein (CRP mg/L) were obtained. Using the hands as model, bilateral MCP 1-5, PIP 2+3 and wrists were evaluated by US using a 0–3 scoring system for grey-scale (GS) and power Doppler (PD) US according to the atlas by Hammer et al. (3) GS sum score, PD sum score and global synovitis score (GLOESS) were calculated for each hand (0-30). According to our prespecified protocol a reasonable equivalence margin in this study (agreement between groups) was defined to correspond to a 95% Confidence Interval around the observed paired mean difference: -2.99 to +2.99. Results: 437 RA patients were included in the current analysis; 71% women, 79% anti-CCP pos, 71% RF pos, median(IQR) age 54(42-62) years, CRP 7(3-16), SJC28 5(3-26) and TJC28 6(2-28). The median (IQR) PD sum score was 3(0-7) for right hand and 2(0-5) for left hand, GS sum score was 5(2-9) for both hands, and GLOESS was 5(2-10) for right hand and 5(2-9) for left hand. The average ultrasound measured inflammation at baseline and 3 months follow-up are shown in the table. The hands with more vs fewer SwJ had more inflammation at baseline for all sum scores, all p<.0001)) and had a greater change for all sum scores at 3 months follow-up (all p<0.0005)). No such differences were found between the dominant vs non-dominant or the right vs left hands at any time points – see table. Conclusion: Based on this study, assessment of the dominant hand is not superior to the non-dominant hand in inflammatory activity evaluated by US. The hand with clinically more SwJ at baseline is likely to have more active inflammation according to GS, Doppler and GLOESS sum scores and exhibit a greater change, and is potentially the best choice for unilateral US scoring systems. REFERENCES: [1] Dale J, Stirling A, Zhang R, Purves D, Foley J, Sambrook M, et al. Targeting ultrasound remission in early rheumatoid arthritis: the results of the TaSER study, a randomised clinical trial. Ann Rheum Dis. 2016;75:1043-50. [2] Haavardsholm EA, Aga AB, Olsen IC, Lillegraven S, Hammer HB, Uhlig T, et al. Ultrasound in management of rheumatoid arthritis: ARCTIC randomised controlled strategy trial. BMJ. 2016;354:i4205. [3] Hammer HB, Bolton-King P, Bakkeheim V, Berg TH, Sundt E, Kongtorp AK, et al. Examination of intra and interrater reliability with a new ultrasonographic reference atlas for scoring of synovitis in patients with rheumatoid arthritis. Ann Rheum Dis. 2011;70:1995-8. Disclosure of Interests: Lene Terslev Speakers bureau: Speakers fee from : Roche, Novartis, Pfizer, MSD, BMS, Celgene, Robin Christensen Grant/research support from: AbbVie Inc, and the Oak Foundation, Speakers bureau: Roche, Anna-Birgitte Aga Consultant for: UCB, AbbVie, and Pfizer, Paid instructor for: UCB, Joe Sexton: None declared, Espen A Haavardsholm Grant/research support from: research funding from Pfizer, UCB, Roche, MSD, and AbbVie., Hilde Berner Hammer Speakers bureau: speakers fee from AbbVie, Bristol-Myers Squibb, Roche, UCB Pharma and Pfizer DOI: 10.1136/annrheumdis-2019-eular.2837Citation: Ann Rheum Dis, volume 78, supplement 2, year 2019, page A1009Session: Diagnostics and imaging procedures (Scientific Abstracts)