肠化生黏膜微细结构与肠化亚型及CDX2、MUC2、MUC5AC异常表达的关系

Correlation between microstructure of gastric mucosa with intestinal metaplasia and the subtype of intestinal metaplasia and abnormal expression of CDX2, MUC2, MUC5AC

目的探讨胃黏膜肠化生组织的表面小凹结构与肠化生亚型及尾部同源异型盒基因2(CDX2)、黏蛋白2(MUC2)、黏蛋白5AC(MUC5AC)之间的关系。方法随机选择拟行胃镜检查的84例门诊患者进行美蓝色素放大内镜检查,观察美蓝染色阳性区域的肠化生黏膜的小凹结构特点。于相关部位取检,共取得标本91份,标本进行苏木精-伊红染色(HE)、奥辛蓝/过碘酸-雪夫染色(AB/PAS)、高铁二胺/奥辛蓝(HID/AB)染色,同时进行CDX2、MUC2、MUC5AC免疫组化染色。分析黏膜小凹结构与肠化生亚型及肠化生细胞中CDX2、MUC2、MUC5AC表达之间的关系。结果美蓝放大胃镜下肠化生黏膜表面小凹结构可分为四类:不规则斑点型(16例)、网格型(30例)、短棒型(23例)和绒毛型(22例),其中不规则斑点型与绒毛型两组中均表现为MUC5AC高表达,但不规则斑点型多提示为不完全性肠化生,而绒毛型表型多提示为完全性肠化生;网格型及短棒型是MUC5AC阴性肠化生黏膜的主要表型,MUC5AC在肠化生细胞内的表达与AB/PAS染色相关,而与HID/AB染色无关;CDX2、MUC2在所有肠化生标本中均为阳性表达(100%,91/91)。结论肠化生黏膜小凹结构的表型对初步判断肠化生亚型及其内黏蛋白的异常表达有一定的提示作用。

Objective To investigate the correlation between mucosal pit pattern of intestinal metaplasia(IM)tissue and the subtype of the gastric IM and the abnormal expression of audal-related homeoboxgene 2(CDX2), mucin 2(MUC2), mucin 5AC(MUC5AC) in metaplastic cells. Methods Eighty-four outpatients were enrolled in the study and examined by Methylene blue staining and magnifying chromoendoscopy. The characters of mucosal pit pattern in the positive area were observed. A total of 91 samples were collected in the positive area, which underwent hematoxylin-eosin(HE) staining, alcian blue/periodic acid-Schiff(AB/PAS) staining, high iron diamine/alcian blue(HID/AB) staining,as well as immunohistochemical staining of CDX2, MUC2, MUC5 AC. The correlation between mucosal pit pattern and the subtype of the gastric IM and the expression of CDX2, mucin MUC2, MUC5 AC were analzyled. Results The mucosal pit patterns observed can be classified to four groups: amorphous type(n=16), reticular type(n=30), tuberous rod type(n=23), villous type(n=22). High expression of MUC5 AC was observed in amorphous type and villous type, which mostly indicates an incomplete intestinal metaplasia and complete intestinal metaplasia, respectively. MUC5 AC negative expression was observed in reticular type and tuberous rod type. The expression of MUC5 AC was related to AB/PAS staining, but not to HID/AB staining. CDX2 and MUC2 were positively expressed in all biopsies of intestinal metaplasia(100%, 91/91). Conclusion The phenotype of mucosal pit pattern may be valuable to judge the subtype of intestinal metaplasia and the abnormal expression of CDX2, MUC2 and MUC5 AC in metaplastic cells.