BASELINE CHARACTERISTICS OF AN EARLY SPONDYLOARTHRITIS COHORT IN HONG KONG

J. So, A. S. De Craemer, M. De Hooge, S. L. Lau, F. Van den Bosch, D. Elewaut, L. S. TamPrince of Wales Hospital, Department of Medicine and Therapeutics, Hong Kong, Hong Kong (SAR) Ghent University Hospital, Department of Internal Medicine and Pediatrics, Ghent, Belgium Center for Inflammation Research, VIB-UGent, Zwijnaarde, Belgium The Chinese University of Hong Kong, Department of Medicine and Therapeutics, Hong Kong, Hong Kong (SAR)  Background Axial Spondyloarthritis (axSpA) is characterized by inflammation of the sacroiliac joint and the spine. It is a heterogeneous disease with variable musculoskeletal and extra-articular manifestations. The BelGian Inflammatory Arthritis and spoNdylitis cohorT (Be-Giant) is a cohort that recruited newly diagnosed SpA patients in Belgium and prospectively followed up the patients. Objectives Given the difference in genetic susceptibility and environmental exposure, we aimed to compare the disease nature, clinical presentation, and prognosis between Chinese and Caucasian axSpA patients. Methods The SPARK cohort (SPondyloARthritis in Hong Kong) resembled the Be-Giant cohort. Newly diagnosed, biologic naïve Chinese axSpA patients who fulfilled ASAS classification criteria were recruited. All patients underwent standardized clinical, laboratory and radiographic assessments as per Be-Giant protocol. Results A total of 53 newly diagnosed axSpA patients were recruited in the SPARK cohort (Table 1). The mean age at diagnosis (32 years old) and symptom duration (2 years) were comparable in both cohorts. There was a slight male predominance (59%) in the SPARK cohort as compared to the Be-Giant cohort (50%). More patients were HLAB27 positive in Chinese patients (SPARK 96% vs Be-Giant 71%). In both cohorts, less than one-fifth of the patients had radiographic sacroiliitis according to modified New York criteria (SPARK 17% vs Be-Giant 18%). Patients in the Be-Giant cohort and the SPARK cohort had similar disease activity clinically by ASDAS-CRP (SPARK 2.4 (SD 0.9) vs Be-Giant 2.6 (SD 1.0)) and radiographically by positive MRI SIJ according to the ASAS definition (SPARK 53% vs Be-Giant 87%). More patients in the SPARK cohort (37%) experienced uveitis compared to the Be-Giant cohort (12%). Around 9% and 5% of axSpA patients in Be-Giant cohort suffered from psoriasis and inflammatory bowel diseases (IBD) respectively while none in SPARK cohort did. Enthesitis (28%) and dactylitis (3.8%) were more common in Chinese as compared to Belgians. Whereas peripheral arthritis and dactylitis were more common in Belgians than Chinese axSpA patients. Conclusion Caucasian and Chinese axSpA patients display a similar burden regarding axial disease, yet appear to be different in the extent on peripheral and extra-musculoskeletal manifestations. Table 1. Baseline demographic and clinical characteristics of newly diagnosed axial SpA patients Be-Giant cohort (n=257) SPARK cohort (n=53) Male, no % 128 (49.8%) 31 (58.5%) Age at diagnosis, years 32 (8.3) 32(7.9) Symptoms duration, months 27 (10-83) 24 (13-54) Current smoker, no % 52 (20.5%) 10 (18.9%) HLAB27, no % 181 (70.7%) 51 (96.2%) Peripheral manifestation Enthesitis, no (%) 24 (9.3%) 15 (28.3%) Arthritis, no. (%) 38 (14.8%) 6 (11.3%) Dactylitis, no (%) 5 (1.9%) 2 (3.8%) Extra-musculoskeletal manifestation (now/ever) Acute anterior uveitis 31 (12.1%) 20 (37.7%) Psoriasis 23 (8.9%) 0 IBD 12 (4.7%) 0 ASDASCRP, mean+-SD 2.6 (1.0) 2.4 (0.93) BASDAI, mean+-SD 4.3 (2.0) 3.7 (2.2) REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests Jacqueline So: None declared, Ann-Sophie De Craemer: None declared, Manouk de Hooge Consultant of: consultancy fees from UCB, Sze-Lok Lau: None declared, Filip van den Bosch: None declared, Dirk Elewaut: None declared, Lai-Shan Tam: None declared. Keywords: Geographical differences, Spondyloarthritis, Descriptive studies DOI: 10.1136/annrheumdis-2023-eular.4776Citation: , volume 82, supplement 1, year 2023, page 1731Session: Spondyloarthritis - clinical aspects (other than treatment) (Publication only)