Long-term Outcomes and Predictors of Biologic Treatment in Systemic Juvenile Idiopathic Arthritis in a Single-center Experience in Thailand

Background: The outcomes of systemic juvenile idiopathic arthritis (SJIA) vary from mild disability to mortality. Due to the socioeconomic problems in Thailand, the delay in receiving some medications, especially biologic agents, might affect the outcomes of this disease. This study aimed to determine the long-term outcomes and predictors of biologic treatment in SJIA patients. Methods: Patients with SJIA were enrolled over the study period between April 1997 and January 2015. The data were collected from medical records at the initial presentation and the most recent clinical visit. Outcomes evaluated included disease status, functional impairment, and joint destruction. Results: Of the 68 SJIA patients, 64 (94%) were eligible. The median (interquartile range) age at disease onset and duration of follow-up were 4.4 (2.9-7.9) and 4.2 (2.3-5.9) years, respectively. Nine patients (14%) achieved complete remission, while 12 (18.8%) had persistent active disease and 3 patients died; 2 of them had macrophage activation syndrome, while the other had a severe infection. A predictor of moderate-to-severe disability (childhood health assessment questionnaire 0.75) was hip involvement (odds ratios [OR] 27, 95% confidence interval [CI] 3.20-228.05). In addition, the predictors of biologic treatment were female gender (OR 6.4, 95% CI 1.74-23.74), younger age of onset (OR 4.7, 95% CI 1.31-16.66), hepatosplenomegaly (OR 5.9, 95% CI 1.29-27.29), and positive antinuclear antibody (ANA) (OR 6.3, 95% CI 1.19-33.75). Bone erosion was found in 34.2% of SJIA patients. Conclusion: Hip involvement was the important predictor of moderate-to-severe disability in SJIA, whereas female gender, younger age of onset, hepatosplenomegaly, and positive ANA were the predictors of biologic treatment.