AB0547 PATIENTS WITH DIFFICULT-TO-TREAT RHEUMATOID ARTHRITIS HAVE HIGHER LEVELS OF INFLAMMATION ON ULTRASOUND
Authors: S. Aydin, U. Gazel, S. B. Açikgöz, C. Ivory, O. Bayindir Tsechelidis, R. Sabido-Sauri, S. Sangwa, E. Hepworth
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> With increasing numbers of advanced therapies, rheumatologists increasingly see Rheumatoid Arthritis (RA) patients who have failed multiple therapies. The management of difficult-to-treat (D2T)-RA patients is challenging, and there is an unmet need to understand the factors leading to D2T-RA. <h3>Objectives:</h3> In this study, we aimed to compare the disease characteristics and activity of our D2T-RA patients with other RA patients requiring advanced therapies. <h3>Methods:</h3> At the ORCHESTRA (Ottawa Rheumatology CompreHEnSive TReatment and Assessment) Clinic RA patients starting a new advanced bDMARD/tsDMARD therapy are assessed using a comprehensive screening process. Patients are evaluated in the same clinic three months after the new therapy initiation. A protocoled ultrasound (US) of 36 joints is conducted at baseline and three-month intervals, until reaching clinical remission. All joints are scored using the Global OMERACT-EULAR Synovitis Score (GLOESS). The D2T-RA definitions were based on the EULAR definition and patients falling into this category had failed ≥2 biologics therapies<sup>1</sup>. Here we present the results from a pilot exploratory comparative analysis to understand the differences between the D2T-RA patients with the rest of the cohort. <h3>Results:</h3> Among 98 RA patients included the study, 20 (20.4%) fulfilled the definition of D2T-RA. Demographic characteristics were similar between two groups, except female sex was slightly higher in D2T-RA patients (n=57/78(73.1%) vs n=17/20(85%); p=0.385) and they had longer disease duration (Table 1). Seropositivity was similar across groups, although there is numerically more erosive disease in the D2T-RA patients (n=41/76 (53.9%) vs n=14/20 (70%)). DT2-RA patients had statistically significantly more deformity in their joints than the rest of the group, and the HAQ scores were statistically higher (Table 1). There were no differences between groups for the comorbidities, except urate levels significantly higher in D2T-RA patients. Regarding disease activity, D2T patients have numerically higher tender joint counts with statistically higher SJC28. Also, Other disease activity scores, including CDAI and DAS28-ESR, also tend to be higher in D2T-RA patients (Table 1). The US scores of D2T-RA patients for inflammation were significantly higher on US (Table 1). <h3>Conclusion:</h3> In our D2T RA population, higher disease activity on US suggests an uncontrolled inflammatory process, which may or may not be complicated by centralized pain mechanisms. A greater portion of D2T patients were females, highlighting the importance of incorporating sex into research and understanding the factors leading to poor response in this group. Higher urate levels in D2T-RA may be due to increased disease duration. It would be noteworthy to look at the impact of urate crystals on joints' resistance to therapies. With higher number of patients and longer follow-up, our group is aiming to find predictors of D2T-RA and investigate alternative therapies. <h3>REFERENCES:</h3> [1] Nagy G.AnnRheumDis.2021. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> Sibel Aydin Abbvie, Jannsen, Novartis, Pfizer, and UCB, Abbvie, Celgene, Eli Lilly, Novartis, Pfizer, Sanofi, and UCB, Abbvie, Celgene, Eli Lilly, Jannsen, Novartis, Pfizer, Sanofi, Novartis, and UCB, Ummugulsum Gazel: None declared, Seyyid Bilal Açikgöz: None declared, Catherine Ivory: None declared, Ozun Bayindir Tsechelidis: None declared, Ricardo Sabido-Sauri: None declared, Sylvia Sangwa: None declared, Elliott Hepworth: None declared.