Gastric metaplasia of the duodenal bulb--a prospective endoscopic study

Prevalence of Helicobacter pylori infection rate in heterotopic gastric mucosa in histological analysis of duodenal specimens from patients with duodenal ulcer

Heterotopic gastric mucosa in the duodenal bulb is a rare congenital disorder with varied clinical presentations. The mechanism of formation of a duodenal ulcer is failure of balance of the attack factor and the defense factor, which is the same as the mechanism of formation of a gastric ulcer. However, the true etiology of the duodenal ulcer remains unknown. Gastric mucosa can secrete gastric juice which injures itself, but the duodenal mucosa does not contain cells secreting a digestive enzyme. We assume that duodenal ulcers are caused by the presence of heterotopic gastric mucosa that can secrete gastric acid. This study was designed to assess the prevalence and associations of heterotopic gastric mucosa in duodenal ulcers. The present study included 137 patients who underwent biopsy or resection of duodenal ulcer. We detected gastric foveolar metaplasia due to inflammation from a heterotopic gastric mucosa using immunohistochemical staining. Heterotopic gastric mucosa consists of foveolar epithelium (MUC5AC-positive) and fundic gland (H⁺K⁺ ATPase-positive parietal cells, pepsinogen I-positive chief cells and MUC6-positive mucous neck cells), whereas gastric metaplasia is composed of foveolar epithelium without fundic glands. These specimens were stained with toluidine blue for detection of Helicobacter pylori infection. Among the 137 patients with duodenal ulcer, 76 cases (55%) had heterotopic gastric mucosa in the obtained specimens, and Helicobacter pylori was found in 45 cases (59%,45/76) among those with heterotopic gastric mucosa. Our results suggest that heterotopic gastric mucosa was strongly associated with concurrent duodenal ulcer.

Duodenal bulb mucosa with hypertrophic gastric oxyntic heterotopia in patients with zollinger ellison syndrome

Objectives. Zollinger-Ellison Syndrome (ZES) results in hypersecretion of gastric acid (via gastrinoma) leading to peptic ulcers, diarrhea, and abdominal pain. We describe the novel discovery of hypertrophic, heterotopic gastric mucosa in the proximal duodenal bulb in patients with ZES, which we hypothesize results in an increased incidence of postbulbar ulcers in patients with ZES (a mechanism previously unreported). We determined the incidence of the novel finding of duodenal gastric oxyntic hypertrophic heterotopia (GOH) in patients with ZES. Methods. Seven patients with ZES were enrolled. The diagnosis of ZES was established by hypergastrinemia, gastric acid hypersecretion, and a positive secretin test or based on biopsy specimens (evaluated via tissue staining). Basal acid output (BAO) and baseline gastrin secretion were determined by established methods. Endoscopic examinations with methylene blue staining and biopsy of the gastric and duodenal mucosa were conducted in all patients every 3–6 months for an average of 5 years. Results. The duodenal mucosa demonstrated hypertrophic GOH in 5 out of 7 patients with ZES and an intact stomach and duodenum. Biopsies from the bowel mucosa demonstrated patchy replacement of surface epithelium by gastric-type epithelium with hypertrophic oxyntic glands in the lamina propria in 5 patients. Two of the patients had no evidence of GOH in the duodenal bulb. Patients with GOH had an average serum gastrin level of 1245 pg/mL and BAO of 2.92 mEq/hr versus 724 pg/mL and 0.8 mEq/hr in patients without GOH. Conclusions. This study demonstrated the presence of duodenal mucosa with GOH in 5 out of 7 patients with ZES and an intact stomach and duodenum. The presence of hypertrophic and heterotopic gastric mucosa is proposed to result from increased gastrin levels and may contribute to the increased incidence of postbulbar ulcers in these patients.

Heterotopic gastric tissue in the duodenal bulb

Heterotopic gastric tissue in the duodenal bulb is a rare congenital lesion. Its prevalence has been reported to be 0.5-2%. It must be differentiated from gastric metaplasia of the duodenal bulb because the two entities have different clinical implications. During one year, we found three cases of gastric heterotopia of the duodenal bulb. In one of the cases, active acid-secreting gastric mucosa was documented by performing the pentagastrin Congo red dye test. The differences between gastric heterotopia of the duodenal bulb and gastric metaplasia of the duodenal bulb have been discussed.

Gastric metaplasia and Helicobacter pylori infection

Duodenal and antral mucosal biopsy specimens were obtained from 139 patients with dyspeptic complaints to study the prevalence and extent of gastric metaplasia in the duodenal bulb in relation to Helicobacter pylori (H pylori) infection and duodenal ulcer disease. On logistic regression, the presence and extent of gastric metaplasia was not significantly associated with H pylori infection. The prevalence of gastric metaplasia, however, was found to be higher in patients with current or past evidence of duodenal ulcer disease in comparison with subjects with functional dyspepsia (p = 0.01). A follow up study on 22 patients before and at least one year after eradication of H pylori showed that the mean extent of gastric metaplasia did not change significantly after eradication and did not differ when compared with 21 patients with persisting infection. It is concluded that the unchanged gastric acid output after eradication of H pylori is a more important factor in the development of gastric metaplasia than the H pylori related inflammatory process.

Campylobacter pylori and peptic ulcer disease

Campylobacter pylori is now known to be the most common and important cause of gastritis, and C. pylori infections have been associated with duodenal ulcer, gastric ulcer, nonulcer dyspepsia, and gastric cancer. Although it has been only possible to culture C. pylori for about 5 yr, there are already sufficient data available to allow us to develop the basic framework that relates C. pylori gastritis to the causation of peptic ulcer disease. We review the data and propose mechanisms that implicate C. pylori as an important factor in the pathogenesis of peptic ulcer disease and consider the therapeutic implications. What we now know about C. pylori begins to unravel some of the mysteries surrounding peptic ulcer disease.