Serum gastrin concentration and changes in G and D cell densities in gastric antrum in children with chronic gastritis

Constitutive programmed death ligand 1 expression protects gastric G-cells from Helicobacter pylori-induced inflammation

INTRODUCTION

Gastric intestinal metaplasia (GIM) is a premalignant lesion, highly associated with Helicobacter pylori infection. Previous studies have shown that H. pylori is able to induce the expression of programmed death ligand 1 (PD-L1), an inhibitory immune modulator, in gastric cells. Our aim was to investigate whether tissues from GIM patients may exploit PD-L1 expression upon H. pylori infection to evade immunosurveillance.

METHODS

Immunohistochemistry was performed for PD-L1 and enteroendocrine markers somatostatin and gastrin on samples derived from a cohort of patients with known GIM, both before and after H. pylori eradication. To determine the identity of any observed PD-L1-positive cells, we performed multiplex immunofluorescent staining and analysis of single-cell sequencing data.

RESULTS

GIM tissue was rarely positive for PD-L1. In normal glands from GIM patients, PD-L1 was mainly expressed by gastrin-positive G-cells. While the D-cell and G-cell compartments were both diminished 2-fold (p = .015 and p = .01, respectively) during H. pylori infection in the normal antral tissue of GIM patients, they were restored 1 year after eradication. The total number of PD-L1-positive cells was not affected by H. pylori, but the percentage of PD-L1-positive G-cells was 30% higher in infected subjects (p = .011), suggesting that these cells are preferentially rescued from destruction.

CONCLUSIONS

Antral G-cells frequently express PD-L1 during homeostasis. G-cells seem to be protected from H. pylori-induced immune destruction by PD-L1 expression. GIM itself does not express PD-L1 and is unlikely to escape immunosurveillance via expression of PD-L1.

Gastric Damage and Cancer-Associated Biomarkers in Helicobacter pylori-Infected Children

Helicobacter pylori (H. pylori) is well-known to be involved in gastric carcinogenesis, associated with deregulation of cell proliferation and epigenetic changes in cancer-related genes. H. pylori infection is largely acquired during childhood, persisting long-term in about half of infected individuals, a subset of whom will go on to develop peptic ulcer disease and eventually gastric cancer, however, the sequence of events leading to disease is not completely understood. Knowledge on carcinogenesis and gastric damage-related biomarkers is abundant in adult populations, but scarce in children. We performed an extensive literature review focusing on gastric cancer related biomarkers identified in adult populations, which have been detected in children infected with H. pylori. Biomarkers were related to expression levels (RNA or protein) and/or methylation levels (DNA) in gastric tissue or blood of infected children as compared to non-infected controls. In this review, we identified 37 biomarkers of which 24 are over expressed, three are under expressed, and ten genes are significantly hypermethylated in H. pylori-infected children compared to healthy controls in at least 1 study. Only four of these biomarkers (pepsinogen I, pepsinogen II, gastrin, and SLC5A8) have been studied in asymptomatically infected children. Importantly, 13 of these biomarkers (β-catenin, C-MYC, GATA-4, DAPK1, CXCL13, DC-SIGN, TIMP3, EGFR, GRIN2B, PIM2, SLC5A8, CDH1, and VCAM-1.) are consistently deregulated in infected children and in adults with gastric cancer. Future studies should be designed to determine the clinical significance of these changes in infection-associated biomarkers in children and their persistence over time. The effect of eradication therapy over these biomarkers in children if proven significant, could lead to modifications in treatment guidelines for younger populations, and eventually promote the development of preventive strategies, such as vaccination, in the near future.

Analysis of the Relationship between Helicobacter pylori Infection and Diabetic Gastroparesis

Background:

Whether Helicobacter pylori infection is associated with diabetic gastroparesis (DGP) is unclear. This study aimed to investigate the potential correlation between H. pylori infection and DGP.

Methods:

In this study, 163 patients with type 2 diabetes mellitus and 175 nondiabetic patients who were treated in our department were divided into DGP, simple diabetes, non-DGP (NDG), and normal groups based on their conditions. The H. pylori infection rate in each group was calculated. H. pylori eradication therapy was performed for patients with H. pylori infection in each group. The eradication rates were compared between the groups, and the improvements in gastroparesis-associated symptoms were compared before and after treatment in patients with DGP.

Results:

The H. pylori infection rate was 74.6% in the DGP group, which was significantly higher than that in the simple diabetes (51.1%, P < 0.01), NDG (57.7%, P < 0.05), and normal groups (48.0%, P < 0.01). With increased disease course, the incidence of DGP and the H. pylori infection rate gradually increased (P < 0.05). In the DGP group, the incidences of upper abdominal pain and distention, early satiety, and anorexia were 75.5%, 66.0%, and 67.9%, respectively, before eradication treatment; and 43.4%, 35.8%, and 39.6%, respectively, after eradication treatment, and the difference was statistically significant (P < 0.01). In patients with DGP with successful H. pylori eradication, the number of barium strips discharged after eradication was 5.9 ± 1.0, which was significantly larger than that before treatment (4.1 ± 0.7, P < 0.01). In addition, the number of barium strips discharged was significantly larger in patients with DGP with successful H. pylori eradication than those with failed H. pylori eradication (P < 0.01).

Conclusions:

DGP development might be associated with H. pylori infection. H. pylori eradication can effectively improve dyspepsia-associated symptoms and delayed gastric emptying in patients with DGP.

A Five-Year-Old Boy with Marked Hypergastrinemia Associated with H. pylori Infection

A 5-year-old boy was referred to our department for persistent epigastric discomfort. Serum gastrin level was 635 pg/ml with a pepsinogen (PG) I level of 102.7 ng/ml and a PG I/II ratio of 23.2, indicating a hyperacidic state. Upper gastrointestinal endoscopy showed normal gastric mucosal folds and no abnormalities including no gastric mucosal atrophy. To investigate the cause of hypergastrinemia, a Ca injection test was performed and the patient showed no definitive response to a large load of Ca. Contrast-enhanced dynamic CT revealed no space-occupying lesions. The results from these two studies were not consistent with the presence of gastrinoma. A urea breath test showed 2.8%, and a test for the fecal H. pylori antigen was positive. Since H. pylori infection was considered to be a possible cause of hypergastrinemia, eradication therapy was introduced. The therapy was shown to be successful by using a repeated urea breath test that showed a normalization to 0.6%. 7 months after the therapy blood examination showed a gastrin level of 191 pg/ml, a PG I level of 36.7 ng/ml, and a PG I/II ratio of 7.3. An immunostaining study of the gastric mucosa suggested that a decrease in somatostatin secretion due to a reduction in D cell population might have induced hypergastrinemia in this case. In children with H. pylori infection showing marked hypergastrinemia, immunohistochemical examination and therapeutic diagnosis by eradication may be helpful in the differential diagnosis of gastrinoma.

Relationship among Helicobacter pylori infection, gut hormones and diabetic gastroparesis

AIM: To investigate the relationship among serum gastrin (GAS) and somatostatin (SS) and Helicobacter pylori (H.pylori) in patients with diabetic gastroparesis (DGP).

METHODS: Fifty-six patients with type 2 diabetes mellitus were divided into simple diabetes mellitus group and DGP group. Forty-seven non-diabetes mellitus patients were divided into control group and simple gastroparesis group. H.pylori infection in the mucosa of sinus ventriculi was evaluated by rapid urease test and Giemsa staining. The contents of serum GAS and SS were measured by radioimmunoassay.

RESULTS: There was no significant difference between the rapid urease test and Giemsa staining in detecting H.pylori. The detection rate of H.pylori was comparable between the simple diabetes mellitus group and the control group. The detection rate of H.pylori was higher in the simple gastroparesis group than in the control group (rapid urease test: 73.3% vs 47.1%, P < 0.05), and in the DGP group than in the control group (rapid urease test: 87.8% vs 47.1%, P < 0.01; Giemsa staining: 81.9% vs 41.2%, P < 0.01), the simple diabetes mellitus group (rapid urease test: 87.8% vs 47.8%, P < 0.01; Giemsa staining: 81.9 % vs 43.5%, P < 0.05) and the simple gastroparesis group (rapid urease test: 87.8% vs 73.3%, P < 0.01; Giemsa staining: 81.9% vs 66.7%, P < 0.01). In H.pylori-positive patients, the level of serum GAS in the DGP group was higher than that in the control group (147.58 ± 16.68 vs 80.91 ± 15.23, P < 0.01), and the level of serum SS in the DGP group was lower than that in the control group (16.29 ± 4.27 vs 47.81 ± 16.88, P < 0.01). In H.pylori-negative patients, there was no significant differences in serum GAS and SS levels between different groups.

CONCLUSION: H.pylori infection can increase serum GAS level but decrease serum SS level. The pathological alterations in the gastric mucosa induced by H.pylori infection are closely related with the development of DGP.

Helicobacter pylori infection in pediatrics

his review summarizes the articles published on Helicobacter pylori infection in children between April 2008 and March 2009. Recent evidence highlights the decreasing prevalence trend of H. pylori infection and supports both intrafamilial and extrafamilial transmission. The association with various symptoms is still being debated. Interestingly, H. pylori infection seems inversely associated with allergic diseases. Monoclonal stool antigen tests are widely used and accurate for the diagnosis of H. pylori infection, but less accurate in young children. The new biprobe real-time PCR assay applied to stools showed a poor sensitivity in children. Using the urea hydrolysis rate next to the delta over baseline values, the (13)C-urea breath test provides excellent results for all age children, even for young children. Treatment of H. pylori infection remains a challenge, considering suboptimal efficacy of current therapy. Among emerging alternatives, sequential treatment appears promising. The adjunction of probiotics to conventional regimens, although eliciting great interest, has shown limited therapeutic benefit.