IS INTESTINAL NEURONAL DYSPLASIA A DISORDER OF THE NEUROMUSCULAR-JUNCTION

Intestinal neuronal dysplasia (IND) is a malformation of the enteric p lexus and clinically resembles Hirschsprung's disease. The pathogenesi s of IND is not known. There is no information available regarding the nature of the neuromuscular junction in this disease. The authors exa mined immunohistochemically full-thickness biopsy specimens from 14 pa tients (aged 3 weeks to 26 months) with IND and 10 age-matched control s, using monoclonal antibodies to growth associated protein-43 (GAP-43 ), synaptophysin, and neural-cell adhesion molecule (NCAM) as neuromus cular junction markers. In the normal bower, GAP-43, synaptophysin, an d NCAM immunoreactivity was abundant in the submucous and myenteric pl exuses as well as in the muscularis mucosae and circular and longitudi nal muscle layers. However, of the biopsy specimens from patients with IND, five had absence of GAP-43, synaptophysin, and NCAM immunoreacti vity in muscularis mucosae and the circular and longitudinal muscle la yers; five had no immunoreactivity in the longitudinal muscle; and fou r had no immunoreactivity in the muscularis mucosae. The submucous and myenteric plexuses of all patients with IND displayed strong immunore activity for GAP-43, synaptophysin, and NCAM. The findings demonstrate that patients with IND have defective innervation of the neuromuscula r junction of the affected bowel. (C) 1996 by W.B. Saunders Company