Objective: To characterize disease activity patterns in a large cohort of children with juvenile idiopathic arthritis (JIA), by applying newly developed preliminary definitions of inactive disease, clinical remission on medication, and clinical remission off medication.
Methods: Children with persistent or extended oligoarthritis, polyarthritis (either rheumatoid factor [RF] positive or RF negative), or systemic JIA who had been followed up for a period of at least 4 years were evaluated for episodes of inactive disease, clinical remission on medication, and clinical remission off medication. Descriptive statistics, correlation analyses, and survival analyses were performed.
Results: Four hundred thirty-seven children met the criteria for review. Three hundred ninety-one patients (89%) experienced a total of 878 episodes of inactive disease, with a median episode length of 12.7 months. Two hundred twenty-eight episodes of inactive disease (26%) resulted in clinical remission off medication; it was equally as likely that episodes of inactive disease would or would not follow a period of clinical remission on medication. Thirty-six percent of episodes of clinical remission off medication persisted for at least 2 years, and only 6% of such episodes persisted for 5 years. RF-positive patients were the least likely to achieve clinical remission off medication (5%), and patients with persistent oligoarticular JIA were the most likely (68%). Among patients with persistent oligoarticular JIA, most of the disease course was characterized by inactive disease; in most other patients the majority of the disease course involved active disease.
Conclusion: Using newly developed preliminary criteria for inactive disease, clinical remission on medication, and clinical remission off medication, we observed that only one-fourth of 878 episodes of inactive disease resulted in clinical remission off medication during followup of at least 4 years. Only a small proportion of episodes of clinical remission off medication were sustained for >5 years. These results highlight the critical need for therapies that have the ability to induce sustained remission of JIA.