Increased mucosal levels of leukotriene B4 in pouchitis: evidence for a persistent inflammatory state.

DESIGN AND METHODS: In order to evaluate its possible role in the pathogenesis of pouchitis we measured the release, into the incubation medium of leukotriene B4 from mucosal samples from patients with ileal pouch-anal anastomosis and correlated release with clinical, endoscopic and histological features. RESULTS: Leukotriene B4 release was significantly elevated in patients with active pouchitis in comparison to those with a normal pouch mucosa (P < 0.007). No overlap was observed between leukotriene B4 levels from patients with active pouchitis samples and those obtained from individuals without pouchitis. Effective treatment of pouchitis was associated with a significant reduction in leukotriene B4 mucosal release to the incubation medium (P < 0.03). However, even in remission, levels of leukotriene B4 release remained significantly increased in these patients in comparison to people who never experienced pouchitis (P < 0.003). A modest correlation was observed between pouchitis disease activity index and leukotriene B4 release (r = 0.596; P < 0.01). CONCLUSION: These results suggest that the increased production of leukotriene B4 may be implicated in the pathogenesis of pouchitis. The persistence of an increased mucosal release of leukotriene B4 in pouchitis patients during clinical remission suggests the presence of a chronic, ongoing, underlying inflammatory process.