Disease activity and damage in juvenile idiopathic arthritis: methotrexate era versus biologic era

Area of Science:

• Pediatric Rheumatology
• Immunology
• Clinical Medicine

Background:

• Juvenile idiopathic arthritis (JIA) is a chronic autoimmune disease affecting children.
• Treatment advancements have shifted from methotrexate (MTX) to biologic therapies.
• Long-term outcomes in JIA patients treated in different therapeutic eras require evaluation.

Purpose of the Study:

• To compare long-term disease activity and damage in JIA patients based on their treatment era: methotrexate (MTX) or biologic therapies.
• To assess the impact of early treatment strategies on the cumulative disease burden in JIA.
• To evaluate functional phenotypes, including oligoarthritis and polyarthritis, within these treatment cohorts.

Main Methods:

• Retrospective cohort study comparing patients from MTX and biologic eras (pre- and post-January 2000).
• Prospective cross-sectional assessment of disease activity (inactive disease/low disease activity) and damage (Juvenile Arthritis Damage Index - JADI).
• Inclusion criteria: JIA diagnosis, disease duration ≥5 years, and assessment of disease activity and damage.

Main Results:

• Biologic era cohort (269 patients) demonstrated higher frequencies of inactive/low disease activity compared to the MTX era cohort (239 patients).
• Significantly lower rates of articular damage (JADI-Articular items >1) were observed in the biologic era for both oligoarthritis and polyarthritis phenotypes.
• Reduced extra-articular damage (JADI-Extraarticular items >1) was also noted in the biologic era cohort.

Conclusions:

• The introduction of biologic therapies has led to substantial improvements in long-term outcomes for children with JIA.
• Current therapeutic advances in JIA management result in better disease control and reduced cumulative damage.
• This study underscores the efficacy of modern treatment strategies in mitigating the long-term effects of JIA.