RT Journal Article SR Electronic T1 Early Predictors of Juvenile Sacroiliitis in Enthesitis-related Arthritis JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP jrheum.100090 DO 10.3899/jrheum.100090 A1 Ilaria Pagnini A1 Sara Savelli A1 Marco Matucci-Cerinic A1 Claudio Fonda A1 Rolando Cimaz A1 Gabriele Simonini YR 2010 UL http://www.jrheum.org/content/early/2010/08/29/jrheum.100090.abstract AB Objective To identify early predictors of sacroiliac (SI) involvement in a cohort of patients with enthesitis-related arthritis (ERA). Methods During a 7-year followup period, all consecutive patients fulfilling the ILAR classification criteria for ERA were enrolled. Data collected included demographic, clinical and laboratory variables at disease onset, at the onset of inflammatory back pain, and at the last available followup visit. Pelvis radiographs and dynamic magnetic resonance imaging (MRI) scans for SI joints were obtained simultaneously in all patients who developed inflammatory back pain. Results Fifty-nine children with ERA were studied; 40 male, 19 female; median age at disease onset 9 years 4 months (range 6 yrs 6 mo – 13 yrs 3 mo). At a median interval after disease onset of 1 year 3 months, 21 children reported symptoms of inflammatory back pain. In all cases, radiographs of SI joints were negative, while dynamic MRI revealed acute sacroiliitis in 17 cases. Multivariate analysis showed that the early predictors of SI were the number of active joints (p < 0.03) and the number of active entheses (p < 0.001) at onset. Conclusion In our cohort, roughly 30% of children with ERA/juvenile idiopathic arthritis develop clinical and MRI evidence of sacroiliitis, detectable with dynamic MRI as early as 1 year after disease onset. Additional data from larger case series are needed to assess the specificity and sensitivity of this technique in the early phase of the disease and to confirm the rate of SI involvement reported in this cohort.