The Expression And Significance Of Microtubule Associated Protein-2 In The Colon Of Patients With Hirschsprung's Disease

Objectives:The distribution of Microtubule associated protein-2 (MAP-2) was investigated and compared with neurone specific enolase (NSE),S-100 protein (S-100) by using immunohistochemical markers techniques in the control group and the ganglionic bowel segment and aganglionic segment of Hirschsprung's disease (HD) group. We aim to know the relationship between the pathogenic mechanism of HD and the development of Enteric nervous system and find a simple and sensitive diagnosis of HD.Methods:1. The experimental group specimens were collected from the resected colon in aganglionic bowel segments and ganglionic segments of 30 HD patients. The control group colon were resected from 15 age-matched patients without HD and HAD.2. All specimens were underwent haematoxylin and eosin (HE) staining and scanned first, then we used the immunostaining with MAP-2,NSE,S-100 protein and the results were made quantitative and qualitative analysis. Immunostaining morphometric analysis of each was performed by image analysis program (Image-Pro-Plus). The positive stained area density was evaluated at×400 magnification by calculating the sum of the areas occupied by the positively stained area of the plexuses.Results:1. The ganglionic cells were detected in the dilated segments of HD by HE staining and the ganglionic cells were not detected in the narrow segments.The differental array of nerve fibres in the muscle layer were founded in the aganglionic bowel segments.2. Microtubule associated protein-2 immunohistochemical staining was strongly positive in ganglionic cells both in the myenteric and submucosal plexuses in the dilated segments of HD and the control group, and it was weakly positive in peripheral nerve fibers, but most of it was negative in the narrow segments of HD group; NSE immunohistochemical staining was positive in ganglionic cells and nerve fibers; S-100 immunohistochemical staining was negative in ganglionic cells and was positive in the nerve fibers,the nerve fibers turned to be bulky and tangle.3. The quantitive analysis shows that the average positive staining areas of MAP-2,NSE and S-100 between the ganglionic and aganglionic segments of HD were 0.26,0.12;0.32,0.22;0.25,0.39.Statistical analysis the data showed that it have significant deviation.Conclusions:1. Microtubule associated protein-2 immunohistochemical staining was positive in ganglionic cells and was negative or weakly positive in the nerve fibers, Compared with NSE,S-100 protein, Microtubule associated protein-2 immunohistochemistry was more specific for the ganglionic cells in the pathology.2. Microtubule associated protein-2 immunohistochemical staining was strongly positive in ganglionic cells both in the dilated segments of HD group and the normal colon, it was weakly positive in the peripheral nerve fibers, but most of it was negative in the narrow segments of HD group. It can be a good neuronic marker in the diagnosis of HD.3. Most of the Microtubule associated protein-2 immunohistochemical staining was obvious negative both in the myenteric and submucosal plexuses in the narrow segments of HD. It might help in the observation(interpretation) of smaller or submucosal biopsies and can serve as a simple and sensitive diagnosis of HD.