SAT0596 Ultrasonographic Evaluation of Subclinicial Enthesitis in Patients Affected by Pediatric Inflammatory Bowel Disease

Background Joint involvement is the most frequent extra-intestinal manifestation of paediatric inflammatory bowel disease (IBD). Various recent studies focused on the clinical prevalence of enthesitis in children and adults with IBD 1 , and others have demonstrated the ability of ultrasound (US) to visualise the acute and chronic signs of entheseal inflammation with greater sensitivity than a clinical examination, although there is a lack of consensus concerning the US definition of entheseal abnormalities and their prognostic value especially in the paediatric field 2 . Objectives The aim of this study was to evaluate the prevalence of subclinical entheseal involvement in patients with pediatric IBD using a high frequency ultrasound probe. Methods Twenty-seven pediatric IBD patients (13 with Crohn9s disease [CD] and 14 with ulcerative colitis [UC]; 15 females and 12 males; mean age 13.7 years, range 7-21 years) without any clinical signs or symptoms of musculo-skeletal involvement and 24 healthy age- and gender-matched controls (14 females and 13 males; mean age 14.2 years, range 8-20 years) underwent an US examination (ESAOTE MyLAB 70 6-18 MHz linear array transducer). Brachial triceps, femoral quadriceps, Achilles, plantar fascia, and proximal and distal patellar entheses were all scored using the 0-136 Madrid Sonographic Enthesis Index (MASEI). Clinical and clinimetrical variables were assessed in both groups (MASES, BASDAI, BASFI, cHAQ, PCAI/PCDAI). Results None of the patients had a MASEI score suggesting early spondyloarthritis involvement but their average score was significantly higher than controls (3.15±2.84 vs 0.96±1.12, p=0.0006). There was also a significantly higher percentage of patients with at least one enthesis with power Doppler (PD) score ≥2 (37% vs 16%; p=0.037) and at least one enthesis with dishomogeneous echostructure (59% vs 0%; p=0.000). There were no between-group differences in terms of erosions (0% vs 0%), calcifications (7.4% vs 12.5%; p=0.656) or structural thickness (37% vs 33.3%; p=0.507). In paediatric IBD group we cannot find correlation between the total MASEI score and gender (p=0.12), age (p=0.20), disease duration (p=0.18) or IBD activity (p=0.83). Conclusions US detectable enthesopathy is frequent in paediatric IBD patients without any clinical signs or symptoms of musculo-skeletal involvement. Further studies involving a larger number of patients are needed to confirm these preliminary data. References Horton DB. et Al. Enthesitis is an Extraintestinal Manifestation of Pediatric Inflammatory Bowel Disease. Ann Paediatr Rheumatol. 2012; 10:1.0 Bandinelli F, Milla M, Genise S, et al. Ultrasound discloses entheseal involvement in inactive and low active inflammatory bowel disease without clinical signs and symptoms of spondyloarthropaty. Rheumatology (Oxford) 2011; 50:1275-9 Disclosure of Interest None declared