Juvenile idiopathic arthritis in multiplex families: longitudinal follow-up.

Objective: To describe the physical, social, educational and employment status and clinical outcomes of patients with juvenile idiopathic arthritis (JIA) from multiplex families.

Methods: All familial JIA patients were treated and had regular follow-up between 1990 and 2015 at King Faisal Specialist Hospital and Research Center (KFSH-RC), Riyadh, were included. Demographic data, disease duration, active arthritis and articular and extra-articular damage at last follow-up visit were reviewed. Additionally, social, educational and employment history were obtained via personal or phone interviews.

Results: Twenty-three patients (20 females) belonging to 10 families were included. The mean age was 14.6 (±9) years with mean disease duration of 11.4 (±9) years and mean follow-up duration of 10.5 (±6). Fourteen patients had systemic JIA while eight patients had polyarticular subtype, and one patient had psoriatic arthritis. All patients received concomitant treatment. Twenty-one patients commenced biologic agents; treatment switched to another agent in all of them because of inadequate response. Most patients had progressive disease course. Twelve patients had active polyarthritis and 22 patients showed evidence of articular damage. All patients had raised inflammatory markers. Eighteen patients had short stature and 11 patients had delayed puberty. Two patients had lower limb lymphedema and one patient had a single kidney with refractory hypertension. Three patients underwent hip arthroplasty. Seventeen patients had satisfactory educational achievement and four patients were in employment. Two patients died due to infection.

Conclusion: Our results showed the largest familial clusters of JIA in the Middle East. Patients with familial JIA had refractory disease with progressive disease course.