An immunohistochemical study of glial fibrillary acidic (GFA) protein and S-100 protein in the colon affected by Hirschsprung's disease.

The supportive cells of the enteric nervous system were examined in gut tissues from 15 patients with Hirschsprung's disease by means of immunohistochemistry, utilizing antisera to glial fibrillary acidic (GFA) protein and S-100 protein. In the normoganglionic segment, GFA protein immunoreactivity was predominantly found in association with the myenteric plexus and to a lesser extent in the submucous plexus. On the other hand, the extrinsic, hypertrophic nerve fasciculi were selectively immunostained with GFA protein antiserum throughout the entire length of the aganglionic intestinal walls from all children studied. The large fasciculi were numerous in the distal aganglionic segment and commonly appeared in the intermuscular zone and submucosal connective tissue. Both small- and medium-sized nerve fasciculi with GFA protein immunoreactivity were also encountered within the circular muscle layer of the proximal aganglionic segment. A subpopulation of supportive cells within the hypertrophic nerve fasciculi showed immunoreactivity for GFA protein, while all supportive elements of these fasciculi were stained for S-100 protein. The intrinsic nerve fibers within the circular muscle layer of normoganglionic segments were stained for S-100 protein, but not for GFA protein. The present study supports our previous findings that two types of supportive cells can be differentiated by immunohistochemistry in the enteric nervous system, utilizing antisera to GFA protein and S-100 protein. It is also concluded that the demonstration of GFA protein by immunohistochemical methods favors the diagnosis of aganglionic colons with Hirschsprung's disease, since GFA protein immunoreactivity is confined to the extrinsic, hypertrophic nerve fasciculi characteristic of aganglionic bowels.