Psoriasis and Imaging Progression in early Axial Spondyloarthritis: Results from a 48-month follow-up (Italian arm of SPACE study).

OBJECTIVES: To assess the influence of psoriasis on spinal/pelvic radiographic progression and magnetic resonance imaging (MRI) features in early-stage axial spondyloarthritis (axSpA). METHODS: Analysis of baseline data from the Italian SPACE cohort, including patients with chronic-back-pain (CBP; duration ≥ 3 months and ≤2 years; onset <45 years) was performed. Patients underwent a diagnostic work-up, including MRI and X-rays of the sacroiliac joints (SIJ), to establish diagnosis of axSpA (ASAS criteria). Clinical features, disease activity and functional indices, imaging were collected at baseline and yearly during 48-months. Spinal and SIJ X-rays and MRIs were scored by 2 readers following SPARCC, mSASSS and mNY-criteria. Characteristics of axSpA patients with/without psoriasis were compared over-time with descriptive statistics; multivariate-logistic-regression model was constructed to assess predictors of spinal/pelvic radiographic progression. RESULTS: 88 patients had axSpA (84.1% non-radiographic; 15.9% radiographic); 36.4% had psoriasis. Patients with psoriasis were older; less frequently had HLA-B27+ and radiographic sacroiliitis with unilateral/asymmetric pattern and more signs of spondylitis. Functional and disease activity indices decreased with slightly higher BASDAI and BASFI in axSpA with psoriasis. All patients showed slight spinal/pelvic radiographic progression. Patients without psoriasis showed increased sacroiliitis progression and low-grade spinal progression. More inflammatory corner lesions on cervical/thoracic MRI-spine were observed in patients with psoriasis. Significant downtrend of SPARCC SIJ/spine scores in all patients was found. Psoriasis was a predictor of increased spinal progression (OR = 0.18; 95%CI : 0.04-0.78). CONCLUSIONS: Psoriasis was associated with distinct axSpA features, increased spinal radiographic progression and low-grade radiographic sacroiliitis.