Juvenile idiopathic arthritis-associated uveitis: a nationwide population-based study in Taiwan

Abstract

Objective: The incidence and prevalence of juvenile idiopathic arthritis (JIA) vary widely across the world but data in East Asia is lacking. Uveitis is a serious cause of morbidity in JIA. This study aimed to analyze the incidence and prevalence of JIA, and the characteristics of JIA-associated uveitis in Taiwan.

Methods: A population-based cohort study was conducted using the Taiwan National Health Insurance Research Database. Each patient was individually tracked from 1999 to 2009 to identify the diagnosis of JIA and uveitis using the International Classification of Diseases diagnostic codes. Multivariate logistic regression was used to determine the risk factors and complications of uveitis in patients with JIA.

Results: The study cohort had 2636 cases of JIA and included juvenile rheumatoid arthritis (57.7%), enthesitis-related arthritis (ERA) (39.2%), and psoriatic arthritis (3.1%). The average annual incidence of JIA and JIA-associated uveitis were 4.93 (range, 3.93-6.23) and 0.25 (range, 0.12-0.37) cases per 100,000 population, respectively. The average period prevalence of JIA was 33.8 cases per 100,000 population. Uveitis occurred in 4.7% of patients with JIA, while JIA-associated uveitis was complicated by cataract (11.2%) and glaucoma (24.8%). Enthesitis-related arthritis was significantly associated with uveitis (OR: 3.47; 95% CI: 2.24-5.37) (p<0.0001). Uveitis diagnosed before JIA was the most significant risk factor for complications of glaucoma or cataract (OR: 3.54; 95% CI: 1.44-8.72) (p = 0.006).

Conclusions: The incidence of JIA is low but that of JIA-associated uveitis is increasing. Higher percentage of males in patients with ERA and the strong association between ERA and uveitis are unique for children with JIA in Taiwan. Uveitis diagnosed before arthritis is an important risk factor for complications. Continuous ophthalmologic follow-up is needed for children with JIA or uveitis of unknown etiology.

Figure 1. Annual incidence of juvenile idiopathic arthritis (JIA), juvenile rheumatoid arthritis (JRA), enthesitis-related arthritis (ERA), and psoriatic arthritis (PsA) for the period 1999–2009.

Figure 2. Age- and sex-specific incidence of JIA, JRA, ERA, and PsA in 2009.

Incidence is higher in boys than in girls in patients with JIA aged 5–9 and 10–14 years old (male:female 2.4∶1 and 1.8∶1, respectively), ERA aged 5–9 and 10–15 years old (6.4∶1 and 3.5∶1, respectively), and PsA aged 10–15 years old (1.8∶1). Incidence is higher in females in JIA patients aged 0–4 years old (0.7∶1), JRA aged 0–4 and 10–15 years old (0.7∶1 and 0.9∶1, respectively), and PsA aged 0–9 years old (0.9∶1).

Figure 3. (A and B) Distribution of diagnostic age of uveitis in 125 uveitis patients considering JIA subtype and sex.

The mean age of uveitis was 15.1±4.4 years for patients with ERA, 11.8±5.6 years for JRA, 14.7±4.8 years for males, and 12.1±5.5 years for females. (C) Distribution of time interval for 125 patients considering JIA subtype. In the means time elapsed between diagnosis of JIA and uveitis, with 0 being the point at which JIA was diagnosed, patients with negative elapsed time were diagnosed as having uveitis before they were diagnosed as having JIA. (D) Distribution of age of glaucoma in uveitis patients considering JIA subtype. The median age of glaucoma was 11.6 years for patients with JRA and 14.7 years for those with ERA. (E) Distribution of age of cataract in uveitis patients considering JIA subtype. The median age of cataract was 8.4 years for patients with JRA and 12.2 years for those with ERA.