A simple index for assessment of disease activity in patients with ulcerative colitis.

Based upon data from a prospective series of 61 patients with ulcerative colitis, most of them with the mild or quiescent form, a simple index for assessment of the disease's activity was devised. The activity index was the sum of three different scores evaluating history, macroscopic findings at endoscopy and microscopic findings in biopsy specimens, respectively. The index was consistent in itself and it may be of value in assessing spontaneous or drug-dependent variations in ulcerative colitis. The serum protein C1 inhibitor, belonging to the acute phase reactants, could not be shown to correlate significantly with the activity index or any of its components.