A real-life study of Juvenile Idiopathic Arthritis from two Brazilian Centers of Pediatric Rheumatology

Abstract Background Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in childhood, but its outcomes are still difficult to determine. We aimed to obtain outcome measurements of disease activity, functional capacity, disease damage and therapeutic response, in a one-year follow-up study on a real-life basis.Methods An observational study from an Inception cohort of JIA from two Brazilian Pediatric Rheumatology Centers was conducted for one year. Clinimetric validated outcome measurements were applied over four visits (baseline: Vbaseline, week 12: V12, week 26: V26 and week 52: V52). The multivariable logistic regression was performed to evaluate baseline variables associated with disease activity, minimal disease activity, disease flare, remission on medication and remission off medication at one year of follow-up.Results A total of 127 patients were included in the study. Eighty-three (65.4%) were females, and median time to diagnosis was 6.0 months. The most frequent JIA subtypes were persistent oligoarticular and rheumatoid factor-negative polyarticular, 30.7% each. The clinimetric measurements used to assess disease activity and functional capacity showed significant improvement over the one-year follow-up period (p < 0.001 in both cases) as well as the therapeutic response assessed by the Ped-ACR-30,50,70,90 (p < 0.05). Inactive disease was present in 33% of patients at baseline, vs 67.9% at V52. Remission on medication and off medication was present in 46% and in 11% of patients at V52, respectively. Extra-articular and articular damage were not common at baseline and did not decrease significantly during the period of the study. The presence of active joints at baseline reduced the chance of the patient achieving remission off medication at the last visit by 84% (p = 0.039). Minimal disease activity was present in 80.6% at V52.Conclusion This study showed progressive improvement of several clinimetric outcome measurements and therapeutic response in an inception cohort of JIA patients. The presence of active joints at baseline represented a risk of not achieving remission at last visit. Long-term prospective and multicenter studies are needed to better assess the follow up of JIA and the differences between subtypes in real life.