Soluble adhesion molecules in juvenile rheumatoid arthritis

To determine serum levels of soluble (s) adhesion molecules in patients with juvenile rheumatoid arthritis (JRA), and to determine whether differences exist in these levels among the 3 subtypes of JRA, and whether levels of these molecules correlate with other measures of disease activity.

Serum levels of soluble forms of intercellular adhesion molecule-1 (ICAM-1), ICAM-3, vascular (V) CAM-1, L-selectin, and E-selectin were determined by sandwich ELISA in 16 patients with JRA (6 systemic, 6 polyarticular, 4 pauciarticular). Differences in levels among JRA subtypes were determined by ANOVA, and correlations between levels and the following clinical variables were assessed by linear regression analysis: erythrocyte sedimentation rate (ESR), total white blood cell count (WBC), hematocrit (HCT), platelet count (PLT), and total swollen joint count (JC).

sE-selectin levels were significantly higher in patients with systemic disease compared to other subtypes (p<0.04). Furthermore, there was a trend toward higher levels of sICAM-1 in systemic disease, which did not reach statistical significance. Significant correlations were found between sE-selectin and ESR (r = 0.68, p<0.006), WBC (r = 0.70, p<0.003), and PLT (r = 0.54, p<0.05) and between sL-selectin and WBC (r = 0.55, p<0.03).

Because of the small number of patients studied, and the lack of age matched control data, our results must be interpreted with caution. Nonetheless, levels of sE-selectin, and possibly ICAM-1 appear to be relatively elevated in systemic JRA, and may indicate cytokine induction and endothelial cell activation in that subtype. Several molecules, especially sE-selectin, correlate with hematologic variables in JRA. These results suggest that serum levels of these molecules may provide a useful additional marker for disease activity in certain patients.