A real-life study of juvenile idiopathic arthritis from two Brazilian referral centers for pediatric rheumatology.

Abstract

Background: Juvenile idiopathic arthritis (JIA) is the most common 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, at one-year follow-up study on a real-life basis.

Methods: An observational JIA cohort from two referral centers for pediatric rheumatology in Brazil Pediatric Rheumatology Centers was carried out over a period of one year. Clinimetric validated outcome measurements were applied over four visits. Multivariable logistic regression was performed to evaluate baseline variables associated with the following outcomes after one year of follow-up: disease activity, Minimal Disease Activity (MDA), disease flare, remission on medication and remission off medication.

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. JADAS71 and CHAQ improved during follow-up (mean Vbaseline 7.05 ± 9.3 vs. V52 3.52 ± 8.4; 0 ± 0.5 vs. 0.14 ± 0.4, p < 0.001, respectively) as well as JIA-ACR 30, 50, 70 and 90 (Vbaseline 79.8% vs. V52 88.8%; 71.4% vs. 84.1%; 59.7% vs. 77.6%; 49.6% vs. 69.2%, p < 0.05, respectively). Inactive disease was present in 33% of patients at baseline and in 67.9% at V52 (p < 0.001). Remission on medication, remission off medication and MDA were present in 46%, 11%, and 80.6% of patients at V52, respectively. Extra-articular and articular damage were not common at baseline (0.3 ± 0.7 and 1.1 ± 3.4 respectively) and did not decrease significantly during the period of the study. The presence of active joints 46/101 (45.5%) at baseline reduced the chance of the patient achieving remission off medication at the last visit by 84% (OR = 0.16; CI 95% from 0.03 to 0.91, p = 0.039).

Conclusion: This study showed improvement in clinimetric outcome measurements and therapeutic responses in an inception cohort of JIA patients. The presence of active joints at baseline is related to not achieving remission at last visit. Long-term prospective and multicenter studies are needed to better assess the outcome of JIA and the differences among JIA subtypes.