Despite the availability of new treatments, almost 46% of children and teenagers with juvenile idiopathic arthritis failed to achieve sustained remission without medication, a study that followed more than 400 of them for up to 18 years after diagnosis reports.
The study, “Long‐term outcomes in juvenile idiopathic arthritis: 18 years of follow‐up in the population‐based Nordic Juvenile Idiopathic Arthritis (JIA) cohort,” was published in Arthritis Care & Research.
Juvenile idiopathic arthritis (JIA) includes a group of chronic inflammatory conditions that affect the joints, causing swelling, stiffness, and pain in children and adolescents. While clinical remission on medication is an achievable goal for many patients, maintaining clinical remission after stopping treatment can be more challenging.
Over the last 20 years, multiple observational studies analyzed the safety and efficacy of biologic agents in groups of children and adolescents with JIA. However, all studies followed relatively small groups of patients for a short period of time (less than eight years).
A group of researchers from the Aarhus University Hospital in Norway and collaborators in other Scandinavian countries carried out a long-term, large population-based study of children and teenagers to characterize their disease progression, disease burden, and remission rates over 18 years.
This population-based study involved a total of 510 patients living in Denmark, Norway, Sweden and Finland, who were diagnosed with JIA between 1997 and 2000. Patient-reported demographic and clinical information were gathered at follow-up visits. Disease activity was determined using the juvenile arthritis disease activity score (JADAS71), ranging from 0 to 101, where 1 is considered the cutoff value for inactive disease.
From the 510 JIA patients initially enrolled, 76 (15%) were lost to follow-up. The remaining 434 (85%) — 297 (68%) females and 137 (32%) males — with a mean age of 24 at the study’s end.
According to the JADAS71, the mean disease score in all patients was 1.5, with almost half of the patients (48%) below the cutoff value of 1 for inactive disease. The highest median JADAS71 score of 4.5 was in patients with enthesitis-related arthritis (ERA), a JIA subtype that affects the tendons (the ligaments that connect muscles to bones).
In total, 45.6% of the participants had active JIA at the final 18-year exam, across all disease categories, although those with ERA were the largest subgroup (64.9%) among people with active disease.
At the final follow-up, 29.5% of patients were still on medications, either synthetic disease‐modifying anti‐rheumatic drugs (DMARDs) or biologic agents, “indicating that there is still a high disease burden even 18 years after disease onset,” the researchers wrote.
Among patients who stopped taking medications, clinical remission was found in 32.8% and most frequently observed in those with either oligoarticular (54.2%) or systemic JIA (53.8%). Only 8.1% of enthesitis-related arthritis patients experienced clinical remission over the course of the study.
“In summary, this study found a substantial prevalence of ongoing active disease and a high burden of medication and damage in JIA even 18 years after disease onset. Notably, the ERA [enthesitis-related arthritis] category of JIA had the worst outcomes in terms of JADAS score, remission rate and medication use,” the researchers concluded.