POS1062 ULTRASOUND ASSESSMENT OF SUB-CLINICAL HAND JOINT SYNOVITIS: A COMPARATIVE STUDY BETWEEN PSORIATIC AND RHEUMATOID ARTHRITIS
Authors: F. Liu, Y. Xin, D. LI, W. LI, J. Zhu
Journal: Annals of the Rheumatic Diseases (2021)

Background: Ultrasound (US) detected subclinical synovitis can be present in early psoriatic arthritis (PsA) and rheumatoid arthritis (RA), and also in patients fulfilling clinical remission criteria[1-2]. Numerous evidences support that the persistence of subclinical synovitis detected by US is associated with a high risk of disease progression [2-3]. Objectives: To evaluate sub-clinical synovitis of PsA and RA at the level of small joints of the hand and wrist by B-mode and Power Doppler US. Methods: 21 patients of early PsA and 25 patients of early RA (no clinical evidence of hand joint involvement, PsA disease duration &lt;2 years, and RA disease duration &lt;1 year) were recruited. DAS28 and DAPSA score used for assessment of articular disease activity for RA and PsA, respectively. US [grey scale (GS) and power Doppler (PD)] was performed to assess synovitis of bilateral wrists, metacarpophalangeal joints, proximal and distal interphalangeal joints, altogether 30 joints. A GS score ≥2 and/or a PD score ≥1 were used to identify US detected synovitis. Results: A total of 25 patients were included in the RA group, including 5 males and 20 females. A total of 21 patients were included in the PsA group, including 7 males and 14 females. There were no significant differences in gender composition, age, and duration of disease between the two groups ( P &gt;0.05) (Table 1). 14 (66.67%) PsA patients and 12 (48%) RA patients had sub-clinical hand joint synovitis. Among 630 hand joints scanned in PsA group, 49 (7.78%) joints showed evidence of sub-clinical synovitis. Wrist joint was most commonly involved (24.49%), followed by MCP3 (14.29%), MCP1 (12.24%) and DIP3 (10.20%). Among 750 hand joints scanned in RA group, 110 (14.67%) joints showed evidence of sub-clinical synovitis. Wrist joint was most commonly involved (60.00%), followed by MCP3 (8.24%), MCP1 (8.24%) and MCP2 (7.06%). No correlation noted between numbers of joints with subclinical synovitis with DAPSA and DAS28 score. There was no correlation between number of joints with sub-clinical synovitis and disease activity indices. Conclusion: Almost two-thirds patients with PsA and half patients with RA had US evidence of sub-clinical synovitis in wrist and hand joints, most commonly in wrist. There are some similarities in the joint involvement of sub-clinical synovitis between RA and PsA, physicians should take this into account in clinical work. Table 1. Demographic characteristics of RA and PsA patients RA (n=25) PsA (n=21) P Female, n(%) 20 (80.00%) 14 (66.67%) 0.305 Age, years, mean±SD 56.32±12.18 54.31±15.82 0.637 Disease duration, years, mean±SD 1.06±0.59 0.90±0.58 0.363 References: [1]Freeston JE, Coates LC, Nam JL, Moverley AR, Hensor EM, Wakefield RJ, et al. Is there subclinical synovitis in early psoriatic arthritis? A clinical comparison with gray-scale and power Doppler ultrasound. Arthritis care &amp; research 2014, 66:432-439. [2]Kawashiri SY, Suzuki T, Nakashima Y, Horai Y, Okada A, Iwamoto N, et al. Ultrasonographic examination of rheumatoid arthritis patients who are free of physical synovitis: Power doppler subclinical synovitis is associated with bone erosion. Rheumatology (Oxford), 2014, 53:562-569. [3]Vreju FA, Filippucci E, Gutierrez M, Di Geso L, Ciapetti A, Ciurea ME, et al. Subclinical ultrasound synovitis in a particular joint is associated with ultrasound evidence of bone erosions in that same joint in rheumatoid patients in clinical remission. Clinical and experimental rheumatology, 2016, 34:673-678. Acknowledgements: This work was supported by National Natural Science Foundation of China (No. 82071930 and 81571684). Disclosure of Interests: None declared.