Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatologic disease of childhood. The various subtypes of JIA differ in clinical features and treatments. The aim of this study was to analyze the frequency of JIA subtypes, patient demographic and clinical features, as well as the rates of macrophage activation syndrome, uveitis, and remission in Turkish JIA patients treated at a single center, and to compare the findings to those in the literature.
The files of all JIA patients treated at our pediatric rheumatology department between January 2017 and January 2019 were retrospectively reviewed. Patient demographic, clinical, and laboratory data were obtained from the patients' files and the hospital database.
The study included 305 patients (180 females) with a mean age at onset of 7.83 ± 4.62 years. Among all the JIA subtypes, the most frequent was oligoarthritis (41.6%), followed by enthesitis-related arthritis (29.2%), rheumatoid factor (RF)-negative polyarthritis (13.4%), systemic arthritis (9.5%), RF-positive polyarthritis (2.6%), psoriatic arthritis (2.0%), and undifferentiated arthritis (1.6%). At the time of data collection, 278 patients (91.0%) were in remission, whereas 27 patients (9.0%) had active disease. Macrophage activation syndrome developed in 12 of the 29 (41.0%) systemic arthritis. Uveitis was noted in 32 (10.0%) patients. Biological agents were administered in 142 of the patients.
The available data indicate that JIA as a whole is a heterogeneous disease with significant variability in course and long-term outcome. As such, each patient should be evaluated according to his / her disease subtype.