Development of a Multidimensional Prediction Model for the Course and Outcome of Early-Onset Juvenile Idiopathic Arthritis (JIA)

This is a prospective-retrospective, translational, no profit, multicentric, observational study. A cohort of at least 100 early-onset JIA patients attending the Unit of Rheumatology and Autoinflammatory Diseases, Department of Pediatric Sciences, IRCCS Istituto Giannina Gaslini or selected Italian pediatric rheumatology centers, will be enrolled and evaluated at onset and at 5 time points of follow up to 24 months (month 3, month 6, month 12, month 18 and month 24) to monitor the course of the disease. A cohort of 30 patients with Iridocyclitis not correlated to JIA will be recruited in parallel at the time of disease diagnosis as a group of control for comparison.

Inclusion Criteria: * For patients with JIA * A diagnosis of JIA according to the ILAR criteria by the treating pediatric rheumatologist * Classification in one of the following ILAR JIA categories: oJIA, RF-pJIA, PsA, or undifferentiated arthritis * Age \< 6 years at onset * Onset of JIA symptoms no more than 6 months before enrolment * Duly executed, written, informed consent/assent obtained from the parents/patient. For control subjects * A diagnosis of Iridocyclitis not correlated to JIA by the treating pediatric ophtalmologist * Age ≤ 17 years at diagnosis * Duly executed, written, informed consent/assent obtained from the parents/patient. Exclusion Criteria: * For patients with JIA * Classification in one of the following ILAR JIA categories: systemic arthritis, RF-positive polyarthritis, enthesitis-related arthritis * Previous treatment with any synthetic or biologic DMARD before biologic sample collection. For control subjects ● Previous treatment with any synthetic or biologic DMARD before biologic sample collection.