POS0016 IMPACT OF PERIPHERAL ARTHRITIS ON DISEASE ACTIVITY OUTCOMES IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS, PERIPHERAL SPONDYLOARTHRITIS AND PSORIATIC ARTHRITIS - DATA FROM THE ASAS-PerSpA STUDY
Authors: C. López-Medina, S. Ramiro, D. Capelusnik, A. Moltó
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Patients with spondyloarthritis (SpA) can present with several phenotypes (i.e., axial SpA (axSpA), peripheral SpA (pSpA) and Psoriatic Arthritis (PsA)) and peripheral arthritis can occur either concomitantly with the axial disease or independently. It is known that peripheral arthritis can impact disease activity outcomes, but data is lacking on the potentially different magnitude of this effect across the phenotypes of the disease. <h3>Objectives:</h3> a)to determine the independent impact of the presence of peripheral arthritis (previous history and current) on disease activity outcomes (BASDAI, ASDAS, DAPSA, DAS28 and DAS44), across all SpA phenotypes. b)to investigate differences in this impact across SpA phenotypes (axSpA, pSpA and PsA). <h3>Methods:</h3> This cross-sectional analysis is derived from the ASAS-PerSpA study. The impact of peripheral arthritis (i.e., history of peripheral arthritis and current peripheral arthritis) on BASDAI, ASDAS, DAPSA, DAS28 and DAS44 was initially explored in univariable models (linear mixed models with random effects with "country" as the random effect). Multivariable models were conducted encompassing the other peripheral manifestations (enthesitis) and other socio-demographic, disease-related and treatment variables. The interaction between SpA phenotype and peripheral arthritis was tested and, if significant, analyses were stratified by phenotype. All the obtained regression coefficients were standardized to allow for comparisons across the different disease activity measures (as outcomes have different scales). <h3>Results:</h3> A total of 4185 patients (2719 axSpA, 433 pSpA, 1033 PsA) were included. Univariable analyses in the entire population revealed that both history and current peripheral arthritis significantly impacted all assessed outcomes, but the latter with a greater extent: BASDAI (standardized beta coefficient and 95%CI) history of peripheral arthritis 0.25 (0.17 to 0.32) vs. current peripheral arthritis 0.61 (0.54 to 0.68), ASDAS 0.07 (0.04 to 0.11) vs. 0.28 (0.25 to 0.32), DAPSA 2.79 (2.43 to 3.16) vs. 5.65 (5.35 to 5.96), DAS28 2.79 (2.43 to 3.16) vs. 5.65 (5.35 to 5.96), and DAS44 0.25 (0.23 to 0.28) vs. 0.43 (0.41 to 0.45), respectively. Multivariate analyses in the overall population revealed that a history of arthritis exclusively affected DAS44, while current arthritis influenced all the disease activity outcomes, with a more important effect on DAPSA than in BASDAI, ASDAS, DAS28 and DAS44 (4.95 (4.63 to 5.28), vs. 0.44 (0.37 to 0.51), 0.27 (0.24 to 0.31), 0.48 (0.46 to 0.51), 0.36 (0.34 to 0.38)) (Table 1).Interactions between peripheral arthritis and the three phenotypes were statistically significant, and thus, we proceeded with separate analyses: multivariable analyses showed very similar results across phenotypes. Current arthritis significantly impacted BASDAI, ASDAS, DAPSA, DAS28 and DAS44 in the three subtypes. However, this effect was greater on DAPSA than on the other outcomes, but stable across phenotypes (Table 2). <h3>Conclusion:</h3> Peripheral arthritis, particularly its current presence, significantly impacts disease activity outcome measures in SpA patients. Notably, this impact remains consistent across the different phenotypes of SpA, but with a greater effect on DAPSA compared to the remaining disease activity measurement instruments. <h3>REFERENCES:</h3> <b>NIL.</b> <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> Clementina López-Medina UCB, Janssen, Lilly, Novartis and Abbvie, UCB, Lilly, Novartis and Abbvie, UCB, Lilly and Abbvie, Sofia Ramiro AbbVie, Eli Lilly, Novartis, Pfizer, Sanofi and UCB Pharma, AbbVie, Galapagos, MSD, Novartis, Pfizer and UCB Pharma, Dafne Capelusnik: None declared, Anna Moltó AbbVie, Biogen, BMS, Cyxone, Eisai, Galapagos, Gilead, Janssen, Lilly, Novartis, Pfizer, UCB Pharma.