The @entity29 ( @entity29 ) are characterized by intestinal inflammation of unknown etiology. Two distinct disorders, @entity30 and @entity31 , have been identified. Three theories of @entity8787 etiology are currently under consideration: 1) reaction to a persistent @entity281 , 2) existence of a defective mucosal barrier to luminal antigens, and 3) a dysregulated host immune response to ubiquitous antigens. In each of these theories, either pathogenic or resident luminal bacteria constantly stimulate the mucosal and systemic immune systems to perpetuate the inflammatory cascade. @entity32 results from an interaction of the persistent stimulus of microbial antigens with genetically determined host susceptibility factors that determine the individual's immune response or mucosal barrier function. The pathogenesis of @entity8787 involves a series of steps, beginning with the breach of the intestinal mucosal barrier by infectious agents or toxins. The defective barrier exposes lamina propria immune cells to the continual presence of resident luminal bacteria, bacterial products, or dietary antigens, which perpetuates the inflammatory cascade. Many @entity854 are noted in @entity8787 , including the ratio of proinflammatory to immunosuppressive cytokines, selective activation of T(H) lymphocyte subsets, and abnormalities in epithelial antigen presentation. When activated during the initial inflammatory process, macrophages and T lymphocytes secrete a host of cytokines, which recruit other inflammatory cell types, thereby continuing the process. Tissue injury is the net result of the soluble products of the activated inflammatory cells. Knowledge of the pathogenesis in @entity8787 suggests that the ultimate goals of therapy should be to block the proinflammatory mediators toward the proximal, rather than the distal, end of the cascade, to decrease the constant antigenic drive of luminal bacteria, and to correct the dysregulated immune response.

Pathogenesis and immune mechanisms of chronic XXXX .

@entity32 :: ('MESH:D007249', 'Disease') :: ['Chronicity of inflammation'] @entity31 :: ('MESH:D003093', 'Disease') :: ['ulcerative colitis'] @entity29 :: ('MESH:D015212', 'Disease') :: ['IBDs', 'inflammatory bowel diseases'] @entity281 :: ('MESH:D007239', 'Disease') :: ['intestinal infection'] @entity854 :: ('MESH:D018376', 'Disease') :: ['immunoregulatory abnormalities'] @entity8787 :: ('MESH:C535541', 'Disease') :: ['IBD'] @entity30 :: ('MESH:D003424', 'Disease') :: ["Crohn's disease"]
@entity29 :: (MESH:D015212,Disease) :: ['inflammatory bowel diseases']
