CIRCULATING SOLUBLE INTERCELLULAR-ADHESION MOLECULE-1 (SICAM-1) IN ACTIVE INFLAMMATORY BOWEL-DISEASE

Intercellular adhesion molecule (ICAM)-1 promotes the initial interact ion between macrophages and T cells during immune activation. We have measured serum levels of soluble ICAM-1 (sICAM-1) by ELISA in 27 patie nts with ulcerative colitis (UC), 31 with Crohn's disease (CD), and 29 healthy subjects. The median sICAM-1 serum concentration was signific antly increased in inflammatory bowel disease (IBD) patients (355 ng/m l, range 195-855) compared to controls (245 ng/ml, 155-580) (P = 0.001 ). Variance analysis for trend showed that sICAM-1 levels were signifi cantly higher in patients with active CD and UC, compared to those wit h inactive disease and controls (P = 0.00002). The concentration of sI CAM-1 was higher in CD patients (365 ng/ml 330-470) compared to UC (30 0 ng/ml 195-855) (P = 0.01). Furthermore, weak but significant correla tions were found between serum levels of sICAM-1 and: soluble IL-2 rec eptors, orosomucoid, and C-reactive protein. It is suggested that incr eased circulating sICAM-1 levels may reflect increased adhesiveness an d signal transmission across cells, probably as a result of shedding o f the parent molecule during local cellular immuneresponses in vivo.