Leucocyte scintigraphy to localize inflammatory activity in ulcerative colitis and Crohn's disease

The validity of using autologous leucocytes labelled with technetium -99m hexamethyl-propyleneamine-oxine (Tc-HMPAO) for scintigraphy in inflammatory bowel disease was evaluated in 12 patients with clinically active ulcerative colitis (UC) and 10 with Crohn's disease (CD). Colonoscopy and biopsy were used as reference. Scintigrams taken 1 h and 3 h after leucocyte reinjection were evaluated blindly by two independent observer groups. Full agreement was found in 11 of 12 UC patients when compared with colonoscopy but in only 3 of 10 CD patients. Segments with agreement in CD patients often showed neutrophilic granulocyte infiltration at biopsy. The judgements of clinicians and physiologists differed for only 2 of totally 70 UC segments but for 13 of 59 CD segments (kappa, 0.94 and 0.52). It is concluded that Tc-HMPAO scintigraphy might be an alternative to colonoscopy in the control of disease extent in UC. In CD patients the technique might warn about infections complications.