POS1135 ADVANCEMENTS IN DIAGNOSING STIFFNESS AND VASCULARIZATION OF SYNOVITIS IN HANDS AND WRISTS USING SHEAR WAVE ELASTOGRAPHY AND COLOR-DOPPLER ULTRASOUND IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background: Systemic lupus erythematosus (SLE) exhibits a wide range of symptoms and signs, often including joint manifestations. Subclinical inflammatory musculoskeletal involvement is frequently overlooked, and its impact on SLE patients remains unclear. Objectives: To compare the stiffness of synovial joint effusion detected by shear wave elastography (SWE), measured in kilopascals (kPa), across 3 groups of SLE patients with different intensity of joint manifestations and a group of healthy controls. To explore associations between the stiffness of synovial joint effusion and patient characteristics, both across all joint groups and in each joint separately. To investigate correlations between the presence of synovitis detected by color-doppler ultrasound (CDU) and patient characteristics. Methods: Patients with SLE who met the SLICC 2012 and EULAR/ACR 2019 criteria were recruited and classified into: hand/wrist arthritis (G1), hand/wrist arthralgia (G2), and no hand/wrist symptoms (G3). Exclusion criteria included conditions like Jaccoud's arthropathy and prior surgeries. Healthy subjects (HS) were recruited as control group (G4). SWE and CDU were performed on the non-dominant hand/wrist. Synovitis was defined according to EULAR-OMERACT ultrasound criteria for CDU, and for SWE, as synovial joint tissue stiffness greater than 30 kPa. Sociodemographic, clinical, serological data, and treatments were retrospectively collected. Various patient-reported outcomes (PROs) were gathered through questionnaires: pain numeric rating scale (NRS) (0-10), fatigue NRS (0-3), the Health Assessment Questionnaire (HAQ), and Fatigue Severity Scale (FSS-9). The collected data were statistically analyzed alongside the SWE and CDU findings. Results: A total of 80 subjects were recruited (G1:20, G2:20, G3:20, G4:20). Taking into account all joints together, cases showed significantly higher kPa values compared to controls (mean difference: 24.06530 kPa, 95% CI: 19.76655-28.36405, p < 0.001). No significant differences in kPa values were observed among the different case groups (G1, G2, G3). Specific joints showed significant differences in kPa values between cases and controls, including the radiocarpal, ulnocarpal (Figure 1), and metacarpophalangeal joints. Lower kPa values in the intercarpal joint were associated with a history of having presented more SLE manifestations throughout the course of the disease (p = 0.016). In the proximal interphalangeal joint of the second finger, lower kPa values positively correlated with the presence of systemic manifestations (SM) (p = 0.019). A significant positive correlation was observed between the number of joints with a positive CDU signal and higher SLICC values (p = 0.000) (Table 1). Conclusion: The study indicates that SLE patients have significantly higher kPa values than healthy subjects, even those without joint manifestations, probably indicating subclinical synovitis. The radiocarpal, ulnocarpal and metacarpophalangeal joints seem to be the most significate for assessing synovitis in SLE. Higher kPa values or CDU signal in specific localizations were associated with specific symptoms or less joint manifestations, maybe indicating different patterns of joint involvement still to be defined. REFERENCES: [1] S. Marsico, I. Carrión Barberà, A. Agustí Claramunt, J. Monfort Faure, J.M. Maiques Llácer, T.C. Salman Monte, A. Solano López. "Shear wave elastosonography applied to synovitis: A preliminary study, Radiología (English Edition), 2023, ISSN 2173-5107. https://doi.org/10.1016/j.rxeng.2023.06.005." Table 1. Key findings of the study. kPa: Kilopascal - CI: Confidence interval - vs: Versus - CDU: Color-doppler ultrasound Acknowledgements: NIL. Disclosure of Interests: None declared.