Immunohistochemical characterization of abnormal innervation of colon in Hirschsprung's disease using D7 monoclonal antibody.

Innervation patterns in normal and aganglionic colon were studied using a panel of antineuronal cell antibodies. One antibody, D7, which recognizes a subset of neuronal cells of the peripheral and central nervous system reacted strongly with nerve fibers in the circular muscle of the normal colon. Immunohistochemical scanning of the entire resected specimen of colon from three children with Hirschsprung's disease demonstrated large numbers of D7 immunoreactive nerve fibers in the circular muscle of the ganglionic colon, few fibers in the transitional zone, and no immunoreactive fibers in the aganglionic segment of bowel. While the absence of D7 immunoreactive fibers paralleled the absence of myenteric ganglion cells in the aganglionic segment, a critical region of colon was identified wherein D7 reactive fibers were evident ahead of the appearance of ganglion cells. These findings indicate that the fundamental pathology in Hirschsprung's disease is not only the absence of ganglion cells of the myenteric and submucuous plexuses but also the absence of D7 immunoreactive fibers in the circular muscle of the colon.