INCREASED LEUKOTRIENE B-4 RELEASE FROM ILEAL POUCH MUCOSA IN ULCERATIVE-COLITIS COMPARED WITH FAMILIAL ADENOMATOUS POLYPOSIS

Pouchitis may complicate the construction of an heal pouch after colec tomy for ulcerative colitis (UC) but not familial adenomatous polyposi s (FAP). To examine whether differences in eicosanoid metabolism might explain why pouchitis is largely confined to UC patients, this study compared arachidonic acid stimulated release of immunoreactive leukotr iene B-4 (LTB(4)) and prostaglandin E(2) (PGE(2)) from macroscopically uninflamed pouch mucosal biopsy specimens incubated in vitro from pat ients with UC and FAP. The study also compared eicosanoid release from inflamed and uninflamed pouches in patients with UC, In uninflamed po uches, median LTB(4) release was nearly twice as high in UC as in FAP (p=0.001), but there was no significant difference in PGE(2) productio n. release pouch mucosa was not significantly different from that from either ileostomy or defunctioned pouch mucosa. LTB(4) and PGE(2) rele ase were significantly greater from inflamed than uninflamed pouch muc osa in UC (p=0.001 and 0.01, respectively). Leukotriene synthesis inhi bition or receptor antagonism, or both merit therapeutic evaluation in pouchitis. Increased release of LTB(4) from endoscopically normal pou ch mucosa suggests increased 5-lipoxygenase activity in patients with UC and could contribute to their predisposition to pouchitis.