Proliferative Defects in Ulcerative Colitis Patients

Abstract

The proliferative characteristics of epithelial cells in rectal biopsies from a group of 18 patients (ages 18–72) with ulcerative colitis spanning several months to over 20 years duration were examined, using an in vitro ³HTdR labeling technique. Although the labeling indices for patients with inflammatory bowel disease did not differ significantly from that of control (8.9<±3.6 vs 7.7±3.9), the number of labeled cells I individual crypt column was higher among some crypts in ulcerative colitis patients. A normal proliferative pattern was demonstrated in crypts of 5/18 patients (27.8%) with DNA synthesis confined to the lower two-thirds of the crypt and the lower third the major zone of proliferation. Thirteen patients (72.2%) showed extension of the proliferative compartment to the surface of the glands, while retaining the lower third of the gland as the predominant proliferative zone (Stage I abnormality). Of these 13, seven had an additional abnormality, namely, a shift of the major zone of proliferation to the middle third of the crypt (Stage II abnormality), a pattern first reported in the colorectal mucosa of patients with a history of colon cancer. Precancerous lesions, including incompletely differentiated epithelium and lateral crypt budding, were recognized in all of these cases, suggesting that the Stage II abnormality is a proliferative parameter forecasting neoplastic transformation.