Ulcer associated cell lineage glands expressing trefoil peptide genes are induced by chronic ulceration in ileal pouch mucosa

Background-Chronic ulcerative conditions in the gastrointestinal tract resu lt in the appearance of the ulcer associated cell lineage (UACL). The gland s of this new cell lineage secrete epidermal growth factor, transforming gr owth factor alpha, and the trefoil factor family (TFF) peptides, which are known to participate in repair processes. Pouchitis is the most frequent co mplication of ileal pouch-anal anastomosis. Aim-Our aim was to determine whether the mucosal ulceration present in pouc hitis can induce the development of UACL glands. Methods-Biopsies from ileal pouches with pouchitis (n=10), healthy pouches (n=5), and normal terminal ileum (n=5) were studied. Expression of TFF mRNA was assessed by in situ hybridisation. TFF1 and TFF2 proteins were localis ed by immunochemistry. Results-UACL glands containing TFF1 and TFF2 were observed in six patients with pouchitis. In some glands, there was TFF3 mRNA as has been reported fo r Crohn's UACL. None of the biopsies from ileal reservoirs without pouchiti s showed UACL glands (p <0.05). Neither TFF1 nor TFF2 expression was detect ed in ileal reservoirs without pouchitis. Conclusion-UACL glands arise de novo in ileal pouch mucosa of patients with pouchitis and express all three TFF peptide genes. Chronic inflammation al one, present in healthy pouches, is not enough to stimulate the growth of t he UACL, and additional stimuli consequent on ulceration may be needed.