A Clinicopathological And Immunohistochemical Study Of Idiopathic Duodenal Ulcer

Objective:Idiopathic peptic ulcer is a non-Helicobacter pylori(H.pylori)non-NSAID related digestive diseases of unknown etiology.The diagnostic criteria and treatment strategies are not clear.The purpose of this study was to describe the clinical and pathological features of idiopathic duodenal ulcer,also detect the expression of certain factors related to mucosal protective barrier in the disease,so as to explore its possible pathogenesis.Methods:Subjects with indications of digestive endoscopy were collected.H.pylori infection was detected by ¹³C urea breath test,rapid urease test and gastric mucosal histology.H.pylori was positive for at least two of the tests and was considered to be negative if all three tests were negative.Subjects were divided into different groups according to H.pylori tests and gastroscopic diagnostic of duodenum.Clinical data and gastric and duodenal biopsy specimens were collected.Gastric mucosal inflammation was assessed according to the Sydney histological grading criteria for gastritis.Duodenal mucosal inflammation was assessed in terms of villus morphology,lamina propria and submucosal mononuclear and polymorphonuclear leukocytes infiltration,and Brunner's gland hyperplasia.The expression of claudin-4,claudin-18,goblet cells,mucin 5AC,and intraepithelial lymphocytes in duodenal mucosa of each group and H.pylori in duodenum were detected by immunohistochemical analysis.Results:125 subjects were included in this study and were divided into 5 groups:26cases in H.pylori-positive duodenal ulcer group(DU-P),26 cases in H.pylori-negative duodenal ulcer group(DU-N),20 cases in H.pylori-eradicated duodenal ulcer group(DU-E),25 cases in H.pylori-positive control group(NOR-P)and 28 cases in H.pylori-negative control group(NOR-N).Patients of DU-E were older than other groups.All of DU-N and DU-E had no gastric ulcer and the gastric mucosa of them showed no obvious inflammation(chronic inflammation grade 0.88±0.18 and 1.18±0.21,both without active inflammation).And the majority showed villous structural abnormalities(23/26,88.46%),lymphocyte mononuclear infiltration(17/26,65.38%)and duodenal hyperplasia(16/26,61.54%).The duodenal gland hyperplasia grade of DU-N was higher than that of the other groups(P<0.01).There was no significant difference in the average optical density of immunohistochemical staining of claudin-4,claudin-18 and the positive area of mucin 5AC among the groups.The mean number of mucin 2-positive goblet cells in DU-N was lower than that in DU-P(10.92±4.16 vs13.01±7.61,P=0.022).The mean number of CD3-positive intraepithelial lymphocytes in DU-E was lower than that in other groups(P<0.05).The number of CD3-positive intraepithelial lymphocytes was significantly correlated with the occurrence of idiopathic ulcer(r=-0.327,P=0.006).In DU-N and DU-E,13.04%(6/46)showed positive of H.pylori immunohistochemical staining in duodenal mucosa.After adjusting for age in the binary Logistic regression model,the risk of DU was increased in cases of H.pylori positive in duodenum compared with the negative cases(P=0.011,OR=8.40,95%CI:1.63-43.48).Conclusions:The clinical symptoms of idiopathic duodenal ulcer are not specific,histologically it showed obvious inflammation in the duodenum mucosa and obvious Brunner's gland hyperplasia may be present.Intraepithelial lymphocytes are reduced in the duodenal mucosa of H.pylori-eradicated duodenal ulcer.Partial cases of H.pylori-negative duodenal ulcer mucosa were H.pylori positive in duodenum mucosa immunohistochemically.