Mast Cells Connections with Nerve Fibers in Hirschsprung’s Disease

Abstract

Introduction: Hirschsprung’s disease (HD) is rare (1/5000 newborns) congenital condition of the bowel nervous system, clinically characterized by dilatation and hypertrophy of colon. There are an increased number of mast cells (MC) in aganglionic bowel segments and in those with intestinal neuronal dysplasia (IND). The exact role of MC in HD is still not known. The aim of this study was to examine the colonic distribution of mast cells (MC) and the relationship between MC and nerve fibers and to estimate connections of these cells with gut nervous system. Material and Methods: Distal colon wall specimens were harvested from patients with normal bowel function and with normal ganglion cells, patients with constipations and with normal ganglion cells and a group of patients with Hirschsprung’s disease. The age of the patients ranged from 2nd day of live to 12 years. The density of the mast cells was calculated using a light microscope with digital camera. The connections of localization of a MC with nerve fibers and ganglions were taken under consideration and observed under light microscope. Test for the significance of differences between groups were performed using the Kruskal-Wallis test. Results: We revealed that there is a greater number of the MC in mucosa, lamina propria, submucosa and muscle layer of large bowel in patients with HD. There was no difference in density of the MC in serosa. Some of the colon MC in HD was located near or they were even attached to the hypertrophic nerve trunks. We found a correlation of MC number with the number of nerve fibers in HD patients. Conclusions: Higher number of MC and their localization in close connection with hypertrophied nerve trunks in patients with HD than in patients with constipation or normal bowel function, is a proof of the influence of MC on defected nervous system in aganglionic bowel. MC probably affect hypertrophied nerve trunks. Mobilization and activation of the mast cells which produce and store NGF can be directed to repair defective nervous system. Obviously, MC repairing reaction is not effective in restoring nervous system function of the gut.