Crypt cell production rate in ulcerative proctocolitis: differential increments in remission and relapse.

Crypt cell production rate (CCPR) has been measured by a stathmokinetic technique in the relapse and remission phases of ulcerative proctocolitis. Rectal biopsies were obtained from eight patients with colitis in relapse, 14 patients with colitis in remission, and 14 patients with histologically normal mucosa. Biopsies were maintained in organ culture for 16 hours and were then exposed to vincristine for one to three hours. Crypt cell production rate was determined from the rate of accumulation of arrested metaphases. Mean CCPR in the relapse group (14.2 cells/crypt/hour) was 45% faster than in the remission group (9.8 cells/crypt/hour; p less than 0.001), which was in turn 14% faster than in normal mucosa (8.6 cells/crypt/hour; p less than 0.04). More rapid turnover of the rectal epithelium in quiescent as well as active colitis may help to explain the enhanced risk of carcinogenesis in this disease.