The remission rate for juvenile idiopathic arthritis (JIA) may not increase with decreased use of medications over time, according to study results published in Arthritis Care & Research.
An 18-year, longitudinal, prospective, population-based Nordic Cohort Study of JIA was conducted to study the trajectory of JIA disease course over time.
Between 1997 and 2000, individuals from Denmark, Sweden, Norway, and Finland who were newly diagnosed with JIA, fulfilled the International League of Associations for Rheumatology (ILAR) category, and had at least 3 study visits at baseline and 8 and 18 years after disease onset were included in the analysis. Patient data, including blood samples, disease characteristics, treatment, and demographic characteristics, were collected.
At year 18 vs 8, there was a significantly higher percentage of participants who stopped taking medications (70% vs 59.7%; P =.003); however, remission rates did not increase among those who stopped vs did not stop taking medications (52% vs 51%).
Researchers noted changes in ILAR category among 7% of participants between baseline and year 8, and among 11% between years 8 and 18; 47.6% of these changes were due to updated information on relevant disease in a first-degree relative. During this period, 22 participants were added to the psoriatic group from other ILAR categories, 81.8% of whom developed psoriasis. By contrast, participants in the oligoarticular group decreased significantly (P =.02). Although the undifferentiated group increased by 24%, the change was not statistically significant (P =.06).
Limitations included that the study period started at the beginning of the biologics era, small sample sizes, potential bias resulting from lack of attendance, missing data, and potentially skewed outcomes from calculating the sensitivity of the best and worst scenarios.
The study researchers concluded that “significantly more patients were off medication at the 18-year follow-up compared [with] 8 years after disease onset; however, the number of patients whose disease was in remission off medication had not increased.” In addition, the researchers indicated that the baseline ILAR categories “were not sustained but changed significantly even beyond 8 years after disease onset.”
Glerup M, Arnstad ED, Rypdal V, et al. Changing patterns in treatment, remission status, and categories in a long-term Nordic Cohort Study of Juvenile Idiopathic Arthritis. Arthritis Care Res. Published online January 10, 2022. doi:10.1002/acr.24857