Gastrin and antral G cells in course of Helicobacter pylori eradication: six months follow up study

Abstract

Aim: To assess long-term effects of Helicobacter pylori (H pylori) eradication on antral G cell morphology and function in patients with and without duodenal ulcer (DU).

Methods: Consecutive dyspeptic patients referred to the endoscopy entered the study. Out of 39 H pylori positive patients, 8 had DU (H pylori +DU) and 31 gastritis (H pylori +G). Control groups consisted of 11 uninfected dyspeptic patients (CG1) and 7 healthy volunteers (CG2). Basal plasma gastrin (PGL), antral tissue gastrin concentrations (ATGC), immunohistochemical and electron microscopic characteristics of G cells were determined, prior to and 6 mo after therapy.

Results: We demonstrated elevated PGL in infected patients compared to uninfected controls prior to therapy. Elevated PGL were registered in all H pylori+patients (H pylori +DU: 106.78+/-22.72 pg/mL, H pylori +G: 74.95+/-15.63, CG1: 68.59+/-17.97, CG2: 39.24+/-5.59 pg/mL, P<0.01). Successful eradication (e) therapy in H pylori+patients lead to significant decrease in PGL (H pylori+DU: 59.93+/-9.40 and H pylori +Ge: 42.36+/-10.28 pg/mL, P<0.001). ATGC at the beginning of the study were similar in infected and uninfected patients and eradication therapy lead to significant decrease in ATGC in H pylori +gastritis, but not in DU patients. In the H pylori +DU patients, the mean number of antral G cells was significantly lower in comparison with all other groups (P<0.01), but after successful eradication was close to normal values found in controls. By contrast, G cell number and volume density were significantly decreased (P<0.01) in H pylori +Ge group after successful eradication therapy (294+/-32 and 0.31+/-0.02, respectively), in comparison to values before eradication (416+/-40 and 0.48+/-0.09). No significant change of the G cell/total endocrine cell ratio was observed during the 6 mo of follow up in any of the groups. A reversible increase in G cell secretory function was seen in all infected individuals, demonstrated by a more prominent secretory apparatus. However, differences between DU and gastritis group were identified.

Conclusion: H pylori infection induces antral G cell hyperfunction resulting in increased gastrin synthesis and secretion. After eradication therapy complete morphological and functional recovery is observed in patients with gastritis. In the DU patients some other factors unrelated to the H pylori infection influence antral G cell morphology and function.

Figure 1

Basal plasma gastrin levels in patients with and without duodenal ulcer before and after eradication of H pylori infection. H pylori+Ge-H pylori+eradicated patients with gastritis; H pylori+Gne-H pylori+non eradicated patients with gastritis; H pylori+DU- patients with H pylori+duodenal ulcer; CG1- H pylori negative dyspeptic patients; CG2- asymptomatic volunteers; th-therapy; mths-months; ^bP < 0.001 in H pylori+DU vs all other groups, ^dP < 0.01 in CG2 vs all other groups, ^fP < 0.001 before vs after eradication therapy.

Figure 2

Antral tissue gastrin levels in patients with and without duodenal ulcer before and after eradication of H pylori infection. H pylori +Ge-H pylori+ eradicated patients with gastritis; H pylori+Gne- H pylori+non eradicated patients with gastritis; H pylori +DU-patients with H pylori+duodenal ulcer; CG1- H pylori negative dyspeptic patients; CG2- asymptomatic volunteers; th-therapy; mths-months.

Figure 3

Pyloric gland area of H pylori associated gastritis before (A) and after eradication (B) therapy. DAKO LSAB+ immunohistochemical staining and diaminobezydine (DAB) as chromogen; × 20 (A) and × 10 (B).There is evident lower gastrin cell number after succesful eradication therapy.

Figure 4

Synaptophysin and gastrin double immunostaining in pyloric gland of H pylori-associated gastritis before ( A) and after (B) eradication therapy. DAKO EnVision double stain method; DAB is chromogen for G cells and aminoethylcarbazole (AEC) is chromogen for synaptophysin containing endocrine cells. × 20 (A) and × 10 ( B). G cells (red)/ other endocrine cells (brown) ratio is equal before (A) and after (B) succesful eradication of H pylori infection.

Figure 5

Electron micrographs of gastrin producing cells from healthy persons antral mucosa. Normal ultrastructure is characterized by the presence of numerous secretory granules of different electron density. Uranyl acetate, lead citrate; × 8 400 (A) and × 12 680 (B).

Figure 6

Electron micrographs of gastrin producing cells from H pylori infected individuals with gastritis (A) and duodenal ulcer ( B) before eradication therapy. Uranyl acetate, lead citrate; x8 400 (both A and B). Note that total number of granules is higher than in controls and that dense core granules are more numerous in H pylori+patient with gastritis (A). Endoplasmatic reticulum is very prominent in H pylori+patient with duodenal ulcer.