AB0578 SUBCLINICAL ENTHESITIS IN PSORIASIS patiEntS AS prediCtor OF ARTHRITIS (EPESCA STUDY): PRELIMINARY RESULTS
Authors: E. Di Donato, A. Becciolini, S. DI Nuzzo, N. Chernyschova, C. Commisso, S. Lamorte, M. Brusasco, E. Pierobon, D. Santilli, G. Lucchini, M. Riva, N. Sverzellati, F. Mozzani, A. Ariani
Journal: Annals of the Rheumatic Diseases (2021)

Background: Enthesitis is one of the typical pathological signs of spondyloarthritis such as psoriatic arthritis (PsA) and it seems to be the Primum movens of the disease. Clinical assessment of enthesitis showed to be less sensitive, compared to ultrasound (US) evaluation, in identifying enthesitis in patients with PsA [1]. OMERACT defined US enthesitis as: “hypoechoic and/or thickened insertion of the tendon close to the bone (within 2 mm from the bony cortex), which exhibits Doppler signal if active and that may show erosions, enthesophytes/calcifications as a sign of structural damage” [3] The reported prevalence of subclinical enthesitis in psoriasis (PsO) patients in different countries ranges between 7% and 20% [2]. Objectives: The main objective of this study was to estimate, by US evaluation, the prevalence of subclinical enthesitis in PsO patients without any clinical signs of enthesitis. Secondary objectives were to analyze differences, in terms of age, sex, BMI, PsO onset and diagnosis, among patients with enthesitis (active or not active), enthesopathy and without any alteration of enthesis. According to the OMERACT definition of ultrasound enthesitis, patients were divided into 4 groups: patients with active enthesitis (AE) defined as the presence of power-Doppler signal in a hypoechoic and/or thickened insertion of the tendon close to the bone; patient with enthesitis (En) defined as hypoechoic and/or thickened insertion of the tendon close to the bone without PD signal; patients with enthesopathy (Ep) defined as the presence of structural damage (erosions, enthesophytes/calcifications); patients without any alteration of enthesis (WE). Methods: Patients with at least 18 years and a diagnosis of PsO made by a Dermatologist were included. Exclusion criteria were the presence of clinical symptoms or signs of articular or entheseal involvement, diagnosis of arthritis and therapy with bDMARDs or tsDMARDs. All patients underwent US examination on grey scale and Power Doppler (PD) ultrasonography of 6 sites (Achilles, quadriceps, distal and proximal patellar, plantar fascia and triceps enthesis) bilaterally. Ultrasound was performed by an experienced sonographer, using a Logiq P9 equipped with 6-12 MHz broad band linear transducer. Data were reported as frequencies and median with interquartile range. To check differences among these four groups, we used chi-square test or Kruskall-Wallis test. P-value ≤ 0.05 is considered statistically significant. Results: We enrolled 124 consecutive psoriasis patients (47 [37.9%] female) with median age 57.7 (45.3-66.5) years, median disease duration 20.4 (10.1-30.8) years, median BMI 27 [24-29]. Patients with AE, En, Ep were 20.2% (25/124), 49.2% (61/124) and 18.5% (23/124), respectively. Patients WE (12.1%, 15/124) showed significantly lower BMI, younger age and shorter diagnostic delay compared to the other patients. All signs of enthesopathy/enthesitis were more frequently observed at Achilles (33.1%, 41/124), triceps (23.4%, 29/124), quadriceps (20.2%, 25/124), distal patellar (18.5%, 23/124) and proximal patellar (4.8%, 6/124) enthesis. Conclusion: Subclinical enthesitis is quite common in PsO patients, and about 20% showed active enthesitis. The enthesopathy seems to be more frequent in patients with increased delay in PsO diagnosis, older age and higher BMI. References: [1]Bandinelli F. et al. Ultrasound detects occult entheseal involvement in early psoriatic arthritis independently of clinical features and psoriasis severity. Clin Exp Rheumatology. Mar-Apr 2013;31(2):219-24. [2]Zuliani F. et al. Ultrasonographic detection of subclinical enthesitis and synovitis: a possible stratification of psoriatic patients without clinical musculoskeletal involvement. Clin Exp Rheumatol Jul-Aug 2019;37(4):593-599. [3]Balint P. V. et al. Reliability of a consensus-based ultrasound definition and scoring for enthesitis in spondyloarthritis and psoriatic arthritis: an OMERACT US initiative. Ann Rheum Dis 2018 Dec;77(12):1730-1735. Disclosure of Interests: None declared.