Signaling for inflammation and repair in inflammatory bowel disease.

In patients with inflammatory bowel diseases (IBD) the immune system leads to the polarization of intestinal immune cells towards a T helper one (Th1) pro-inflammatory response. The immunologic factors intervene in intestinal homeostasis and initiate the development of intestinal mucosal inflammation. Cytokines, which are important regulators of inflammation and repair as wells as leukocyte trafficking have become apparent as key immune molecules in the pathogenesis of IBD. In this review, recent advances in our understanding of the cytokine involvement in inflammation and repair in patients with ulcerative colitis (UC) and Crohn's disease (CD) are discussed. Knowledge of objective evidence of inflammatory activity may allow targeted treatment at an earlier stage to avoid the relapse, as well as assessment of new therapeutic strategies for maintenance of remission.