SAT0416 ENTHESITIS AND CLINICAL RESPONSE IN PSORIATIC ARTHRITIS: REAL-LIFE DATA

Abstract

Background:Psoriatic arthritis (PsA) is an inflammatory arthritis that is characterized by a broad spectrum of clinical conditions, including axial skeletal involvement, enthesitis, dactylitis, uveitis and arthritis. Among those, enthesitis, the inflammation of the junction where the tendon, ligament or joint capsule inserts into the bone, is assigned to be the hallmark, affecting 35–50% of patients. Several clinical methods have been developed to measure it, including The Maastricht AS Enthesitis Score (MASES) index, which tests 13 entheses and the Spondyloarthritis Research Consortium of Canada (SPARCC) index that assesses 16.Objectives:To assess the relationship between enthesitis and clinical response in psoriatic arthritis.Methods:Retrospective study including all the patients with PsA meeting the CASPAR criteria, beginning first-line biologic therapy at our centre. Demographic and clinical data including age, gender, body mass index (BMI), smoking status, physical examination findings such as presence of enthesitis, dactylitis, chronic back pain, tender and swollen joint counts (TJC/ SJC), ESR, CRP, DAS 28 4vESR, BASDAI, BASFI, BASMI, ASDAS, HAQ, patient VAS score, MASES and SPARCC were collected from the Portuguese database Reumapt. Statistical analysis was performed with SPSS. Continuous variables were analysed through Spearman correlations.Results:We included 119 patients with PsA (60 female), of which 14.9% were active smokers. The mean age of patients was 46.3 ± 1.03 years. The median disease duration was 6.8 (0.3-33.8) years and the mean BMI was 26.8 ± 0.5 Kg/m2.Enthesitis, dactylitis, inflammatory back pain, peripheral arthritis, ungueal distrophy, and psoriasis were present in 53 (45.7%), 45 (38.8%), 76 (65.5%), 109 (94%), 45 (38.8%), 104 (89.7%) patients, respectively.At baseline, mean (SD) disease activity parameters were: DAS 28 4vESR 4.9 (0.2), ESR 33.2 (2.3) mm/h; CRP 2.35 (0.3) mg/dL, HAQ 1.3 (0.1), BASDAI 6.6 (0.2), ASDAS 3.9 (0.1), BASMI 3.7 (0.2), BASFI 5.8 (0.3), MASES 1.9 (0.3), SPARCC 2.3 (0.3). Median (min-max) values of TJC, SJC and patient VAS score at baseline were 4 (0-28), 3 (0-19), 76 (0-100), respectively.There were statistically significant positive correlations (0-12 months) between ΔMASES and ΔDAS 28 4vESR (p=0.02, rho=0.432), Δpatient VAS score (p=0.027, rho=0.307), ΔHAQ (p=0.02, rho=0.411), ΔBASDAI (p=0.025, rho=0.326), ΔBASFI (p=0.037, rho=0.315), ΔASDAS (p=0.023, rho= 0.331). Correlations between ΔSPARCC and ΔDAS 28 4vESR (p=0.023, rho=0.332), Δpatient VAS score (p=0.003, rho=0.402), ΔHAQ (p=0.012, rho=0.440), ΔBASDAI (p=0.011, rho=0.368), ΔBASFI (p=0.001, rho=0.445), ΔASDAS (p=0.002, rho= 0.437), ΔCDAI (p=0.039, rho=0.320) and ΔSDAI (p=0.039, rho=0.319), were also significant. However, there weren’t strong correlations between ΔMASES neither ΔSPARCC and PsARC response at 12 months.Conclusion:Our results suggest that enthesitis is correlated with clinical response in PsA, supporting the idea that it is a major determinant of disease activity. It should be given more importance, namely by incorporating it in daily clinical practice, due to its major role, both in establishing an early diagnosis and in assessing treatment response.