Visualising E-selectin in the detection and evaluation of inflammatory bowel disease

Background-Vascular endothelial E-selectin expression is induced by proinflammatory 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 patients with ulcerative colitis and Crohn's disease by measuring the concentration of circulating soluble E-selectin (sE-selectin) using ELISA, by immunohistochemistry of colonic biopsy specimens, and by abdominal immunoscintigraphy after injecting radiolabelled F(ab'), fragment of a monoclonal anti-E-selectin antibody. The value of scintigraphy using anti-E-selectin was judged by a prospective comparative study of autologous leucocyte scanning and E-selectin antibody scanning in 17 patients with IBD. Results-Circulating sE-selectin was elevated in patients with clinically active disease. Tissue expression of E-selectin was enhanced in patients with active inflammation,with weak or absent expression in inactive disease and healthy controls. In-ill labelled anti-E-selectin scintiscans were compared with Tc-99m labelled leucocyte scans performed 24 hours earlier. Twelve patients had areas of active inflammation on leucocyte scan while 11 patients had positive E-selectin scans. The results of the two scans were concordant in 14 patients, with those positive for both (10/17) showing similar disease localisation and extent. Conclusions-Tissue E-selectin and circulating sE-selcctin are increased during active inflammatory bowel disease. Anti-E-selectin imaging with radiolabelled monoclonal antibody identified areas of inflammation in Crohn's disease and ulcerative colitis. The technique should prove useful clinically for identifying the site and extent of disease.