Correlation between circulating soluble ICAM-1 and prednisolone-induced amelioration of ulcerative colitis

Background: A soluble form of intercellular adhesion molecule-1 (sICAM-1) shed from endothelial cells is present in the circulation. Whether the circulating molecules represent passive turnover of surface ICAM-1 or may have some active functions in the inflammatory process is unknown. Glucocorticoids ( e. g. prednisolone) are cornerstones in the treatment of acute exacerbations of ulcerative colitis (UC), and influence of the leucocyte/endothelial interaction appears to be part of their mode of action. The aim of the present study was therefore to evaluate the ICAM-1-shedding through measurements of sICAM-1 concentrations during prednisolone treatment of UC patients. Methods: Prednisolone (40 mg) was prescribed to 15 patients with severe disease activity. At inclusion, and after 2 weeks of treatment, plasma sICAM-1 levels were measured using the ELISA technique. Results: The concentrations of sICAM-1 were significantly decreased during treatment from median 256.2 (ng/ml) (interquartile range 239.7-321.0 ng/ml) to 220.4 ng/ml (196.0-276.3 ng/ml) (P < 0.01). This reduction correlated with a decrease in disease activity (r(s) = 0.8; P < 0.003). Conclusions: sICAM-1 seems to be a poor diagnostic tool, but since plasma sICAM-1 concentrations decreased during the treatment period, it might prove to be applicable as an activity marker in the individual patient.