FRI0342 POST-EFFORT SYNOVIAL AND ENTHESIC RESPONSE IN PATIENTS WITH PSORIATIC ARTHRITIS IN REMISSION OF LOW DISEASE ACTIVITY
Authors: C. Guillén-Astete, P. Zurita-Prada, C. Urrego-Laurín
Journal: Annals of the Rheumatic Diseases (2020)

Background: Synovial inflammation is part of the pathophysiological process of PsoA although it is considered secondary to enthesitis. It is of interest to assess the synovial joint, peritendinous and enthesic response of patients with PsoA in remission under controlled mechanical stress. Objectives: Our aim is to present our observational experience in patients with APso in remission or low activity of the disease exposed to controlled manual physical efforts adapted to the own grasping capacity of each subject. Methods: Before-after study of a consecutive cohort of patients with PsoA (CASPAR criteria), of at least two years d evolution and DAPSA≤14 at present. Patients with positive rheumatoid factor, patients with exclusively axial forms and patients on biological therapy at the beginning of the study were excluded. All patients underwent controlled basal ultrasound and post-dynamometric exercise (CAMRY EH101-17) of the dominant hand which included the carpus, MCFs, IFPs and IFDs of the 2nd to 5th fingers. The ultrasound findings were scored according to EULAR recommendations in grey scale (GS) and power Doppler (PD) for synovitis, enthesitis and tenosynovitis (maximum scores 71 and 87, respectively). For statistical analysis, comparisons were made with the results of their baseline and post-exercise ultrasound scores between subjects diagnosed with PsoA and controls. The Student’s T test was used for related and unrelated data according to correspondence. Results: Nineteen patients and controls were included, of which 73.7% were male. Mean age: 42.2 SD 6.6 and 42.21 SD 8.28, respectively. Basal DAPSA among patients: 7.26 SD 4.53. Mean traction strength of patients and controls: 23.8 SD 7.3 and 26.1 SD 6.9 kg, respectively (P=0.336). In the group of patients, the post exercise DAPSA had a mean of 7.52 SD 4.62 (P=0.021, with respect to the basal DAPSA). The mean total GS score in the patient group was 3.94 SD 2.36 and 7.31 SD 3.3, pre- and post-exercise, respectively (P&lt;0.001). The mean total score in the PD study was 0.73 SD 0.73 and 2.57 SD 1.16, respectively (P&lt;0.001). In patients with PsoA there were no detectable enthesic changes. In the control group, no ultrasound changes were statistically significant, although the score for tenosynovitis ranged from 0.1 SD 0.31 to 0.42 SD 0.6 (P=0.055). Conclusion: Patients with APso in clinical remission or low disease activity develop ultrasound changes after controlled exercise. These changes are appreciable in the joint synovium and tendon but not at an enthesic level. Although these changes are also detectable in a healthy population, their prevalence is much lower. Our interpretation is that control of the disease correlates with an absence of enthesic inflammatory activity although synovial susceptibility remains less evident. This reinforces the idea that PsoA is an inflammatory enthesitis with associated arthritis and not its opposite. Disclosure of Interests: None declared