AB1133 AXIAL PSORIATIC ARTHRITIS: ISOLATED ENTITY OR PHENOTYPE FORM ONLY

Background The latest literature data increasingly emphasizes the axial involvement of Psoriatic Arthritis (PsA). clinical and radiographic characteristics suggest that it is a new entity compared to Ankylosing Spondylitis (AS), while therapeutic advances cytokine targets form only. Objectives objective our study compare patients with PsA (axPsA) AS (axAS). Methods Patients≥18 years old, axPsA or axAS, during registration in prospective monocentric register, between August 2012 2022. A rheumatological investigation including: clinical, laboratory genetic assessments as well imaging conventional radiography pelvic spine was performed. Results Of 250 (58 vs 192 AS) involvement, isolated were older at diagnosis (age 35.8 29.4). Patients more likely have: Less inflammatory back pain axAS: less limited schöber index (10/14 10/12), finger-to-ground distance often equal 0 cm axPsA, contracture paravertebral muscles, reduction thoracic expansion (4 2 cm). limitation inguinal (hip flexion 100 70), higher dactylitis count ±SD (0.3±1.2 0.1±0.8), nail lesions which could looking for an association damage presence PsA, extensive skin psoriasis [PASI= 2-13] uveitis (18.96% (11/58) 23,95% (46/192)). Human Leucocyte Antigen (HLAB27) positivity negatively associated disease (20 78%). AxPsA frequently had sacroiliitis unilateral/asymmetric pattern [On X-ray, SI either normal slightly modified, deliberately asymmetrical, rarely grade 4, syndesmophytes most coarse lumbar location, heels affected severe represented by simple shielding] average showed slight spinal/pelvic progression (OR: 0,14; 95% CI: 0,01, 0,58). Finally, lower BASDAI HAQ scores (OR 0.10, CI 0,01to 0.47/ OR 0.03, 0,00 0.17) PRO evaluation (PRO 39.65 49.47% fatigue 50 52.6%). Conclusion Isolated are uncommon, has different radiographical when AS. largely independent HLAB27, distinct ax features, increased spinal low activity impact scores. References [1]Feld J al. Axial psoriatic arthritis ankylosing spondylitis: critical comparison. 2018 Jun; Nat Rev Rheumatol 14(6):363-371. doi: 10.1038/s41584-018-0006-8. [2]Mease P, EULAR 2021 OP 0049 [3]Ann Rheum Dis 2022; 0:1-7. 10.1136/annrheumdis-2022-222537 [4]J Korean Med Sci.2022 Aug 22;37(33): e253 [5]Ann 81: 1534-1540 [6]Laurenzin M, Rheumatology, 2022;61 (6): 2275-2387 Acknowledgements: NIL. Disclosure Interests None Declared.