Objective: To investigate the relationship between the magnitude of clinical response in the first 6 months of methotrexate (MTX) therapy and the long-term outcome in children with juvenile idiopathic arthritis (JIA).
Methods: The clinical charts of 125 JIA patients who were started with MTX and were then followed for at least 5 years were reviewed. Based on the level of American College of Rheumatology (ACR) Pediatric response at 6 months, patients were divided in 4 mutually exclusive groups: 1) nonresponders; 2) responders at 30%; 3) responders at 50%; 4) responders at 70%. The long-term outcome in each response group was evaluated by calculating the percentage change in active and restricted joint counts from baseline to 1, 2 and 5 years and the frequency of inactive disease at 5 years.
Results: At 6 months, 42 patients were classified as nonresponders, 24 as 30% responders, 26 as 50% responders, and 33 as 70% responders. Patients who had achieved a 70% response showed a significantly greater percentage improvement in active joint count between baseline to 5 years compared with nonresponders and 30% responders, and a significantly greater percentage improvement in restricted joint count between baseline to 5 years compared with 30% responders. The 70% responders also had a greater frequency of inactive disease at 5 years compared with 30% responders.
Conclusions: Our results show that the achievement of an ACR Pediatric 70 response at 6 months after start of MTX therapy predicts a more favorable long-term outcome of patients with JIA.
- ACR Pediatric 30
- Juvenile idiopathic arthritis
- Long-term outcome
- Therapeutic response