Pos0501 Gender and Age-of-Onset Are Associated With Radiographic Progression in Axial Spondyloarthritis

Background: Gender and age-of-onset are associated with radiographic damage in axial spondyloarthritis (axSpA), but detailed analyses of both factors are lacking. Objectives: First, to examine the associations between gender and (1) longitudinal radiographic progression, including specifically at the cervical and lumbar spine, (2) baseline radiographic damage at sacroiliac joints (SIJs) and hips. Second, to examine the same associations with age-of-onset as the explanatory variable. Methods: We used clinical and radiographic data from the Australo-Anglo-American Spondyloarthritis Consortium (TASC). Age-of-onset dichotomized into juvenile or adult (Results: Analyses included 1,150 individuals (mean age 44 (14) years, 84% HLA-B27 positive) over 3,441 patient-years (median follow-up 2.0 years, median 2 (IQR 1, 3) radiographs). Among 81% with available baseline data, 38% were on a TNFi. 857 (75%) were male and, compared to females, had longer mean symptom duration (20 vs 18 years, p=0.01), higher baseline mSASSS (13 vs 4 units, p0.10). In longitudinal models of radiographic progression, male gender was associated with greater total mSASSS progression over time (3.4 mSASSS units over 10 years on average; 95%CI 2.6, 4.2; pConclusion: Males with axSpA have more severe hip disease, and greater mSASSS radiographic progression, driven by more rapid progression at the L-spine than is observed in females. Participants with juvenile-onset axSpA had greater hip radiographic damage. REFERENCES: 1 Cortes A. Ann Rheum Dis 2015;74:1387–93 Acknowledgements: NIL. Disclosure of Interests: Sizheng Steven Zhao UCB, Novartis, Abbvie, UCB, Nicholas Harvey: None declared, Linda A Bradbury: None declared, Lianne S Gensler Acelyrin, Janssen, Novartis, Pfizer, UCB, Novartis, UCB, Zhixiu Li: None declared, Mohammad Rahbar: None declared, Michael M Ward: None declared, Michael H Weisman: None declared, John D Reveille: None declared, Tae-Hwan Kim: None declared, Matthew Brown Novartis, UCB, Clementia, Incyte, Ipsen, UCB, Xinthera, UCB.