DECAY-ACCELERATING FACTOR (DAF) IN STOOL SPECIMENS AS A MARKER OF DISEASE-ACTIVITY IN PATIENTS WITH ULCERATIVE-COLITIS (UC)

Colonic epithelial cells of patients with UC express DAF in relation t o the severity of mucosal inflammation. The aim of this study was to d etermine whether this factor in stool could be used as a marker of dis ease activity in UC patients. Stool DAF was measured by use of an immu noassay in 181 stool specimens obtained from 55 patients with UC of va rious levels of disease activity. Stool DAF concentrations in patients whose UC was active (0.0-785.6 ng/g stool; median 47.1 ng/g; n = 115) were significantly higher than concentrations in patients whose disea se was inactive (0.0-48.6 ng/g; median 0.0 ng/g; n = 66) (P < 0.0001). Values in active UC patients also were higher than those in control p atients with diarrhoea (0.0-30.0 ng/g; median 0.0 ng/g; n = 26) (P < 0 .0001) and in control subjects without apparent colorectal disease (0- 20.4 ng/g; median 0.0 ng/g; n = 44) (P < 0.0001). The elevated levels of stool DAF obtained from UC patients in relapse declined markedly in specimens collected after the disease went into remission following m edical therapy. Stool DAF levels correlated with the severity of endos copic and histological findings and the degree of DAF expression on th e colonic epithelia. Our results suggest that the measurement of stool DAF is useful as a non-invasive means of monitoring intestinal diseas e activity in patients with UC.