Comparison of the outcomes between early and late anti-tumor necrosis factor therapy in patients with enthesitis-related subcategory of juvenile idiopathic arthritis: a multi-center study in Southeast Asia

Little is known about the impact of delayed initiation of anti-tumor necrosis factor (TNF) therapy in patients with enthesitis-related arthritis (ERA). Here, we compared the impact of delayed treatment on disease outcomes of ERA patients in Southeast Asia. This retrospective study enrolled 149 ERA patients from Thailand and Singapore. Early (e-aTNF) and late (l-aTNF) treatment groups received anti-TNF therapy starting at ≤6 months and >6 months, respectively, after diagnosis. Outcomes included mean differences in disease activity parameters, Juvenile Spondyloarthritis Disease Activity (JSpADA) score, Juvenile Arthritis Diseases Activity (JADAS)-10 score, and American College of Rheumatology Pediatric (ACR Pedi) criteria, and the frequency of clinically inactive disease and first flare event. The mean changes in JSpADA (p = 0.002) and JADAS-10 (p < 0.001) scores over time were significantly higher in the e-aTNF group than in the l-aTNF group. A significantly higher proportion of patients in the e-aTNF group than l-aTNF group satisfied ACR Pedi 100 criteria at 2 years (p = 0.042). All other long-term outcomes were not significantly different between the groups. Although early anti-TNF treatment improved disease activity parameters somewhat better than delayed anti-TNF therapy, there was no significant difference in long-term outcomes.