[Immunohistochemical study of the enteric glia in chronic intestinal inflammatory disease]

Enteric glial cells, strictly associated with enteric neurons to build up enteric ganglia, belong to the enteric nervous system (ENS), which coordinates many bowel functions. The ENS is spread throughout the gut in myenteric and submucosal plexuses. In our research work, we studied immunohistochemically the ENS in two typical chronic inflammatory bowel diseases, Crohn's disease (CD) and ulcerative colitis (UC), by using specific antibodies against gliocyte (S-100) and neuronal (neurofilaments, NF) markers. We found high S-100 immunoreactivity within the submucosal and muscular layers in samples from CD patients, but not as such in those from UC patients; similar results were also achieved using anti-NF antibodies. Moreover, immunohistochemistry has pointed out that alterations of the ENS are associated, in CD more than in UC, with the expression of major histocompatibility complex class II antigens on components of the ENS, especially on enteroglial cells. These data suggest that histopathological differences exist between CD and UC also within the ENS, especially as far as the glial cells are concerned. Such ENS changes might significantly contribute to the immunopathogenesis and immunopathophysiology of chronic inflammatory bowel diseases.