Objective: To determine whether soluble forms of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and E-selectin correlate with clinical measures or other markers of endothelial activation in children with juvenile idiopathic arthritis (JIA) over time.
Methods: A total of 28 children with JIA were studied every 3 months over 2 years. At each interval, serum was tested for soluble (s)ICAM-1 and sE-selectin, plasma for fibrin d-dimer and von Willebrand factor (vWF), and the following clinical variables were recorded: erythrocyte sedimentation rate (ESR), physician and parent global assessments, swollen and limited joint counts, and functional assessment by Childhood Health Assessment Questionnaire. Concentrations of the adhesion molecules were also determined once in 30 age matched healthy children.
Results: Among all JIA subtypes, baseline sICAM-1 was elevated compared to controls; sE-selectin was higher in patients with systemic disease compared to other subtypes and controls. sE-selectin correlated with ESR, but there were no other correlations between concentrations of either adhesion molecule or any other clinical variables or vWF antigen. sICAM-1 was higher in those with elevated compared to normal d-dimer. There were no differences between mean sICAM-1 and sE-selectin before or during disease flare or improvement periods, except for an increase in sICAM-1 with flares in patients with systemic disease.
Conclusion: sICAM-1 is elevated in children with active JIA. sE-selectin is only elevated in children with active systemic disease. Although some relationships were found between the adhesion molecules and other variables, they did not correlate with most variables, and did not parallel the disease course. Thus, we cannot recommend the routine use of these molecules as clinical biomarkers of disease activity. This study confirms that endothelial activation is key to the pathogenesis of JIA, especially in the systemic subtype.