Immune response in irritable bowel syndrome: A systematic review of systemic and mucosal inflammatory mediators

OBJECTIVE: To systematically review the available data on cytokine and immune cells in the peripheral blood and mucosal biopsy samples from patients with IBS.

METHODS: From a review of the literature, data on cytokines and immune cells that had been assayed in at least three independent studies were collated and trends examined.

RESULTS: Levels of interleukin (IL)-10 tended to be decreased and those of IL6, IL8, tumor necrosis factor-alpha and IL-1 beta increased in the systemic circulation in IBS, while in the mucosa, IL-10 was decreased and IL-8, mast cells, enterochromaffin cells and CD3+ and CD8+ T lymphocytes cells were increased. However, these findings were not consistent across all studies and, in some instances, were limited to certain IBS sub-populations.

CONCLUSIONS: The interpretation of this literature is limited by several factors, such as the intrinsic heterogeneity of IBS and a lack of standardization in study design. While a number of intriguing immunological observations have been made in IBS, much more work is needed before a compelling case can be made for a role for immune-mediated events in the etiology of IBS.This article is protected by copyright. All rights reserved.