VISUALIZING E-SELECTIN IN THE DETECTION AND EVALUATION OF INFLAMMATORY BOWEL-DISEASE

Background-Vascular endothelial E-selectin expression is induced by pr oinflammatory cytokines and contributes to accumulation of leucocytes in tissues. Aims-To investigate the role of E-selectin in inflammatory bowel disease (IBD). Methods-E-selectin expression was assessed in pa tients with ulcerative colitis and Crohn's disease by measuring the co ncentration of circulating soluble E-selectin (sE-selectin) using ELIS A, by immunohistochemistry of colonic biopsy specimens, and by abdomin al immunoscintigraphy after injecting radiolabelled F(ab'), fragment o f a monoclonal anti-E-selectin antibody. The value of scintigraphy usi ng anti-E-selectin was judged by a prospective comparative study of au tologous leucocyte scanning and E-selectin antibody scanning in 17 pat ients with IBD. Results-Circulating sE-selectin was elevated in patien ts with clinically active disease. Tissue expression of E-selectin was enhanced in patients with active inflammation,with weak or absent exp ression in inactive disease and healthy controls. In-ill labelled anti -E-selectin scintiscans were compared with Tc-99m labelled leucocyte s cans performed 24 hours earlier. Twelve patients had areas of active i nflammation on leucocyte scan while 11 patients had positive E-selecti n scans. The results of the two scans were concordant in 14 patients, with those positive for both (10/17) showing similar disease localisat ion and extent. Conclusions-Tissue E-selectin and circulating sE-selcc tin are increased during active inflammatory bowel disease. Anti-E-sel ectin imaging with radiolabelled monoclonal antibody identified areas of inflammation in Crohn's disease and ulcerative colitis. The techniq ue should prove useful clinically for identifying the site and extent of disease.