Update on the Axial Involvement in Psoriatic Arthritis (AXIS) Project

Psoriatic arthritis (PsA) is an inflammatory disease associated with psoriasis, often affecting both peripheral and axial skeletal structures. Axial symptoms affect a significant portion of individuals with PsA. The Axial Involvement in Psoriatic Arthritis (AXIS) study, a multinational, multicenter cross-sectional study conducted under the umbrella of the Group for Research on Psoriasis and Psoriatic Arthritis (GRAPPA) and Assessment of SpondyloArthritis international Society (ASAS), aimed to establish a unified definition and classification criteria for axial involvement in PsA. The study enrolled 409 patients from 41 centers across 19 countries. Comprehensive clinical and imaging assessments were conducted for each patient including radiographs and magnetic resonance imaging of the sacroiliac joints and spine. Imaging data were reviewed by both local investigators and a central imaging committee. Final judgment on the presence or absence of axial involvement was made by investigators following evaluation of all data by the investigators and the central expert imaging team. Axial involvement was assessed to be present in 112/409 patients (27.4%). Data analysis is ongoing and the full study results are expected shortly. This update was presented at the GRAPPA 2024 annual meeting.