AB0747 SPECIFIC ULTRASOUND LESIONS IN PSORIATIC ARTHRITIS: PREVALENCE AND CORRELATION WITH DISEASE ACTIVITY
Authors: K. Ben Abdelghani, H. Boussaa, S. Miladi, A. Fazaa, K. Ouenniche, L. Souabni, S. Kassab, S. Chekili, A. Laatar
Journal: Annals of the Rheumatic Diseases (2020)

Background: Psoriatic arthritis (PsA) is a systemic inflammatory disease with articular and extra-articular features. In recent years, Ultrasonography (US) is playing an important role in the diagnosis and monitoring of this disease. Specific US features of PsA have been reported such as enthesitis, peritenon extensor tendon inflammation (PTI) and soft tissue edema. Objectives: The aims of this study were to evaluate the prevalence of these US signs in PsA patients and to determine their association with disease duration and activity. Methods: Patients with peripheral PsA responding to the Classification Criteria for Psoriatic Arthritis (CASPAR) were enrolled. Clinical and biological data were extracted, and then US examination was performed by an experimented rheumatologist blinded to clinical data using a machine type Esaote MyLAb 60 with a linear probe of 6-18 MHz. The following US features were evaluated: PTI at the dorsal aspect of metacarpo-phalangeal (MCP) joints, soft edema at the volar aspect of MCP joints and enthesitis of the digitorum extensor at the dorsal aspect of distal inter-phalangeal (DIP) joints. A p&lt;0.05 was considered statistically significant. Results: We included twenty PsA patients, 8 men and 12 women, with a mean age of 55 ± 11 [33-77] years old. The mean disease duration was of 10±8 [1-34] years. A family history of PsA or psoriasis was reported in 53% of cases. Oral corticosteroids were used in 21% of patients, at a mean daily posology of 7 mg [5-10] of Prednisone equivalent, Methotrexate in 84% of cases at a mean posology of 15 mg [10-20] per week, Sulfasalazine in 10% of cases and a biological DMARD in 32% of cases (Etanercept=4, Infliximab=1, Adalimumab=1). The mean number of tender and swollen joints were respectively of 8 [0-16] and 2 [0-8]. The mean rate of patient global evaluation and visual analogue scale was of 5 [0-9]. The mean DAPSA (Disease Activity in PSoriatic Arthritis) score was of 32±27 [4-112]. US examination demonstrated that all patients had at least one of the three specific signs that we were looking for. At MCP level, PTI was noted in 11% of joints with Power Doppler (PD) signal in one case and soft tissue edema was noted in 3% of joints. At DIP level, enthesitis of digitorum extensor tendon was noted in 39% of joints. The elementary lesions reported were: enthesophyte in 25%, erosion in 8%, calcification in 5% and thickened or hypoecoic tendon in 4% of joints. However, no PD signal was detected at the enthesis. A positive association was found between DAPSA score and soft tissue edema (p=0.000), but not with PTI (0.668) and enthesitis (0.137). No relation was found between these three lesions and the disease duration. Conclusion: The presence of soft tissue edema, enthesitis and/or PTI on US can be an argument for the diagnosis of PsA. Soft tissue edema is shown to be associated with disease activity. Disclosure of Interests: None declared