Berkhout M et al. (2006) Low detoxification capacity in the ileal pouch mucosa of patients with ulcerative colitis. Inflamm Bowel Dis 12: 112–116

Malignancies in the pouch mucosa have been reported following ileal-pouch–anal anastomosis, which is the most common surgical treatment for ulcerative colitis. The glutathione S-transferase (GST) family of enzymes of the gastrointestinal mucosal cells detoxify carcinogens and are thought to have an important role in cancer prevention.

A Dutch team has examined GST activity in the ileal pouch of 18 patients (15 men) with ulcerative colitis. All patients had previously undergone colectomy with ileal-pouch–anal anastomosis. In each patient, three biopsies were taken from the pouch mucosa and three were taken from normal mucosa in the afferent ileal limb. A significant decrease in the levels of GSTA1 and GSTA2 was observed in the pouch mucosa when compared with their levels in the normal ileal mucosa of the same patient (P = 0.02). By contrast, the level of GSTP1 was higher in the pouch mucosa than in the ileum. Overall, however, GST activity was significantly lower in the pouch mucosa than in the normal ileal mucosa (P = 0.008). Ten patients were diagnosed with pouchitis (which has been suggested as a risk factor for malignancies), but neither GST activity nor levels correlated with its presence.

Previous studies of the risk of malignancies in the ileal pouch have yielded inconsistent results; nevertheless, the authors suggest that the decreased GST activity observed in the pouch mucosa of these patients indicates a lower detoxification capacity that might contribute to the risk of developing malignancies.