Juvenile idiopathic arthritis in the biologic era: predictors of the disease progression and need for early introduction of biologic treatment.

To assess longitudinally the course and outcome of juvenile idiopathic arthritis (JIA) in patients diagnosed and followed-up exclusively in the biologic era; also, to define possible predictors of the disease progression and need for early implementation of biologicals. Prospective and retrospective, monocentric cohort study of 120 JIA patients, diagnosed between 2001 and 2010, and followed-up for ≥ 4 years (median 8.04). Disease activity, cumulative articular/extra-articular damage and quality of life were evaluated by the assessment tools Juvenile Arthritis Disease Activity Score (JADAS71), Juvenile Arthritis Damage Index (JADI) and Childhood Health Assessment Questionnaire (CHAQ), respectively. Moreover, potential predictors of the disease progression and their relation to biologic therapy were investigated. High JADAS71 score (> 9) at diagnosis was indicative of progression to polyarticular course and the need for early introduction of biologic treatment. Other independent predictors of progression to polyarthritis, were: involvement of upper limb, hip and ankle within 6 months following JIA diagnosis and percentage of cumulative time with active disease > 35% within the first year. At the end of the study, both the median JADAS71 score and the Disability Index were significantly lower than the initial (p < 0.001) and remission off medication was achieved in 25% of the patients. Articular and extra-articular (only ocular) cumulative damage was demonstrated only in 5 and 7.5% of patients, respectively. Physical functional ability was found normal/mildly restricted in 93.3% and moderately restricted in 6.7% of the patients. We believe that these findings, fit in with a picture of JIA course and outcome under current conditions of objective "disease status" evaluation and of tightly controlled follow-up. Predictors emerged from our study could contribute to the identification of patients who will need early implementation of biologic treatment.