Anti-endothelial cell antibodies are prevalent in juvenile idiopathic arthritis: implications for clinical disease course and pathogenesis.

To determine the prevalence of anti-endothelial cell antibodies (AECA) in children with juvenile idiopathic arthritis (JIA) versus healthy control children. Twenty-eight children with active JIA were studied (ten each with polyarticular and oligoarticular disease, and eight with systemic onset disease). AECA were determined by a cell-based ELISA from samples obtained every 3 months over a 2 year period in each subject. These levels were compared against previously determined levels of von Willebrand factor antigen, fibrin d-dimer, and soluble forms of ICAM-1 and E-selectin, as well as clinical measures of disease activity. AECA were detected in 5/10 oligoarticular, 6/10 polyarticular, and 7/8 systemic JIA subjects and 0/14 controls. Mean levels of AECA were significantly higher in subjects with oligoarticular, and especially systemic disease as compared to polyarticular and control groups when analyzed by ANOVA. AECA are prevalent in JIA and are present more often and at higher levels in systemic disease.