111Indium autologous leucocytes in inflammatory bowel disease.

A non-invasive method of imaging and assessing inflammatory bowel disease is described. 111Indium labelled leucocyte scans were performed on 33 patients with a wide variety of inflammatory bowel diseases and 25 control patients. All patients with moderate or severe inflammatory bowel disease had positive scans with localisation of abnormal activity corresponding to the sites assessed to be diseased by radiology in either small or large bowel. No false positives were recorded in the control patients. Faecal excretion of 111In labelled leucocytes was increased in patients with inflammatory bowel disease according to disease severity and correlated with disease activity assessed by serum C-reactive protein levels (r = 0.74, p less than 0.001) or in those patients with Crohn's disease by Crohn's Disease Activity Index (r = 0.78, p less than 0.001). These data suggest that 111In labelled leucocytes may be used to provide a safe, non-invasive method of imaging diseased bowel and objectively assessing disease activity.