Calcitonin levels in autoimmune atrophic gastritis-related hypergastrinemia

PURPOSE

Calcitonin (Ct) is currently the most sensitive biochemical marker of C-cell disease (medullary thyroid cancer [MTC] and C-cell hyperplasia), but its specificity is relatively low. Our aim was to examine whether autoimmune atrophic gastritis (AAG) and chronic hypergastrinemia, with or without chronic autoimmune thyroiditis (AT), are conditions associated with increased Ct levels.

METHODS

Three groups of patients were consecutively enrolled in this  multicentric study: group A consisted of patients with histologically-proven AAG (n = 13; 2 males, 11 females); group B fulfilled the criteria for group A but also had AT (n = 92; 15 males, 77 females); and group C included patients with AT and without AAG (n = 37; 6 males, 31 females).

RESULTS

Median Ct levels did not differ between the three groups. Ct levels were undetectable in: 8/13 cases (61.5%) in group A, 70/92 (76.1%) in group B, and 27/37 (73.0%) in group C. They were detectable but ≤ 10 ng/L in 4/13 (30.8%), 20/92 (21.7%) and 7/37 (18.9%) cases, respectively; and they were > 10 ng/L in 1/13 (7.7%), 2/92 (2.2%) and 3/37 (8.1%) cases, respectively (P = 0.5). Only three patients had high Ct levels (> 10 ng/L) and high gastrin levels and had an MTC. There was no correlation between Ct and gastrin levels (P = 0.353, r = 0.0785).

CONCLUSIONS

High gastrin levels in patients with AAG do not explain any hypercalcitoninemia, regardless of whether patients have AT or not. This makes it mandatory to complete the diagnostic process to rule out MTC in patients with high Ct levels and AAG.

Robotically assisted total gastrectomy for lymphadenopathy after long-term follow-up for multiple type 1 gastric neuroendocrine tumor (NET): a case report

BACKGROUND

Type 1 gastric neuroendrine tumor (NET) is usually associated with chronic atrophic gastritis and forms multiple lesions. While most cases of type 1 gastric NET are generally slowly growing, some develop regional lymph node metastases even after long-term dormancy.

CASE PRESENTATION

A 73-year-old male patient with a 32-year history of multiple gastric NET was being followed-up at the study center after endoscopic submucosal dissection (ESD) of a large gastric NET. A blood examination revealed high serum gastrin (> 3000 pg/ml). An endoscopic examination found atrophic mucosa and multiple, elevated lesions in the upper to lower stomach body. Computed tomography (CT) revealed regional lymphadenopathy in the greater omentum along the gastroepiploic artery. Robotically assisted total gastrectomy was performed with D2 lymphadenectomy and Roux-en-Y reconstruction. Pathological analysis revealed a large number of gastric NET (grade 1) with a maximum size of 4.5 mm invading the submucosal layer. A single lymph node metastasis was also detected pathologically at station #4d. The postoperative course was uneventful, and serum gastrin normalized postoperatively. At postoperative year 3, the patient has been doing well without any recurrences.

CONCLUSIONS

The present case of multiple gastric NET with a single regional lymph node metastasis at year 32 of follow-up was successfully treated with a robotically assisted total gastrectomy.

A case of enterochromaffin-like cell neuroendocrine tumor associated with parietal cell dysfunction which was successfully treated with somatostatin analogue

We report here a case of a 62-year-old woman with multiple gastric enterochromaffin-like cell neuroendocrine tumor caused by hypergastrinemia due to parietal cell dysfunction that was successfully treated with somatostatin analogue. Esophagogastroduodenoscopy revealed several G1 neuroendocrine tumors, 10 mm in diameter, in the body of the stomach. No evidence of autoimmune gastritis, Helicobacter pylori infection, neuroendocrine neoplasia type 1, or Zollinger-Ellison syndrome was identified. The pattern of immunohistochemical staining of the background gastric mucosa was suggestive of parietal cell dysfunction. She was treated with long-acting release octreotide acetate. Complete response was confirmed after 9 months and was maintained for 22 months.

Gastric neuroendocrine neoplasms: A review

Gastric neuroendocrine neoplasms (g-NENs) or neuroendocrine tumors are generally slow-growing tumors with increasing incidence. They arise from enterochromaffin like cells and are divided into four types according to clinical characteristic features. Type 1 and 2 are gastrin dependent, whereas type 3 and 4 are sporadic. The reason for hypergastrinemia is atrophic gastritis in type 1, and gastrin releasing tumor (gastrinoma) in type 2 g-NEN. The diagnosis of g-NENs needs histopathological investigation taken by upper gastrointestinal endoscopy. g-NENs are positively stained with chomogranin A and synaptophysin. Grading is made with mitotic index and ki-67 proliferation index on histopathological analysis. It is crucial to discriminate between types of g-NENs, because the management, treatment and prognosis differ significantly between subtypes. Treatment options for g-NENs include endoscopic resection, surgical resection with or without antrectomy, medical treatment with somatostatin analogues, netazepide or chemotherapy regimens. Follow-up without excision is another option in appropriate cases. The prognosis of type 1 and 2 g-NENs are good, whereas the prognosis of type 3 and 4 g-NENs are close to the prognosis of gastric adenocancer.

Disappearance of Gastric Hyperplastic Polyps after the Discontinuation of Proton Pump Inhibitor in a Patient with Liver Cirrhosis

Here, we report on a rare case of gastric hyperplastic polyps which disappeared after the discontinuation of proton pump inhibitor (PPI). The patient was an 83-year-old woman with liver cirrhosis and portal hypertension, along with gastroesophageal reflux disease treated by PPI. An initial upper gastrointestinal endoscopy showed unique polypoid lesions in the greater curvature of the stomach. Biopsy specimens of the lesions were diagnosed as hyperplastic polyps and she was followed. One year later, a second endoscopy showed that the lesions had increased in number and size, and an endoscopic mucosal resection (EMR) was performed for the main polyps. The resected specimens indicated a proliferation of foveolar epithelium cells with an increase of capillary ectasia and parietal cell hyperplasia, which was thought to be induced by hypergastrinemia from the PPI. Three months after the EMR, she was admitted because of bleeding from the remaining polyps along with an increase in new polyps. After conservative treatment, PPI was stopped and rebamipide was used. One year and 6 months later, an endoscopy showed the complete disappearance of all gastric polyps.

Gastric neuroendocrine tumor: A practical literature review

Gastric neuroendocrine tumors are gastric neoplasms originating from enterochromaffin type cells and are inserted in a larger group, named gastroenteropancreatic neuroendocrine tumors. They are considered rare and variable in terms of their clinical, morphological and functional characteristics and may be indolent or aggressive. They are classified into types I, II and III, according to their pathophysiology, behavior and treatment. Their diagnosis occurs, in most cases, incidentally during upper digestive endoscopies, presenting as simple gastric polyps. Most cases (type I and type II) are related to hypergastrinemia, can be multiple and are treated by endoscopic resection, whenever possible. The use of somatostatin analogs for tumor control may be one of the options for therapy, in addition to total or subtotal gastrectomy for selected cases. Adjuvant chemotherapy is only reserved for poorly differentiated neuroendocrine carcinomas. Although rare, gastric neuroendocrine tumors have an increasing incidence over the years, therefore deserving more comprehensive studies on its adequate treatment. The present study reviews and updates management recommendations for gastric neuroendocrine tumors.

Long-term use of proton pump inhibitors as a risk factor for various adverse manifestations

The long-term use of proton pump inhibitors (PPIs) can lead to increased gastric pH, hypochlorhydria and in some cases to achlorhydria when compared to other acid-suppressing agents like histamine-2 (H2) receptor blockers and antacids. These consequences by the use of long-term PPIs may lead to significant vitamin (B₁₂ and C) and mineral (iron, calcium and magnesium) deficiencies which needs gastric acid for their absorption and bioavailability. Long-term use of PPIs by the pregnant patients may impose a potential risk of congenital malformations. Various studies have recommended the life style modifications and antacid use as first choice among pregnant womens by preserving PPIs (omeprazole as a safe choice of PPI) for severe conditions of gastroesophageal reflux disease. The long-term acid suppression by PPIs can also lead to enteric, respiratory and urinary tract infections. The hypochlorhydria by chronic PPIs use may induce hypergastrinemia, which ultimately mediates the gastric polyps, gastric carcinoids and gastric cancer. The concomitant use of PPIs with antiplatelet drugs like clopidogrel can impose the patients to major adverse cardiac events. This review has enlisted the comprehensive information regarding the adverse effects induced by long-term use of PPIs and their possible relations. Considerable studies like case-control, randomized trials, cohort studies and meta-analysis were reported in supporting these adverse effects. The clinicians and patients should be cautious about these effects so that they can avoid the serious outcomes. PPIs should be avoided for long-term use mainly in older adults unless there is a proper indication.

Gastric Neuroendocrine Tumors (Carcinoids)

PURPOSE OF REVIEW

The diagnosis of gastric neuroendocrine tumors (NETs) is being made with increased frequency likely as a result of more upper endoscopies being done for unrelated reasons. It is therefore vital that gastroenterologists become familiar with the basic work-up and management of patients found to have these tumors. This review describes the classification, pathophysiology, clinical characteristics, and treatment options of the different gastric NETs.

RECENT FINDINGS

In addition to the three traditional subtypes of gastric NETs, additional cases associated with achlorhydria and appropriate hypergastrinemia may exist. The management of gastric NETs between 1 and 2 cm in size remains controversial and needs to be individualized. Gastric NETs are uncommon but are now diagnosed more frequently. This review highlights the role of hypergastrinemia in their development and the controversies around their management.

Old and New Gut Hormone, Gastrin and Acid Suppressive Therapy

Gastrin acts physiologically as a gut hormone to stimulate acid secretion after meal and as a cell-growth factor of oxyntic mucosa. Increase in serum gastrin level happens under various conditions including Zollinger-Ellison syndrome, antral G cell hyperplasia, autoimmune gastritis, atrophic gastritis, renal failure, vagotomy, Helicobacter pylori infection and acid suppressive therapy. As acid suppressive therapy causes hypergastrinemia, the association between acid suppressive therapy and gastric neuroendocrine cell tumor (NET) has been discussed during the past 30 years. In this review article, the definition of hypergastrinemia and the related disorders including acid suppressive therapy and gastric NET are discussed.

Does the Novel Potassium-Competitive Acid Blocker Vonoprazan Cause More Hypergastrinemia than Conventional Proton Pump Inhibitors? A Multicenter Prospective Cross-Sectional Study

BACKGROUND/AIM

The long-term administration of proton pump inhibitors (PPIs) is useful for preventing recurrent reflux esophagitis. On the other hand, several adverse reactions, such as an increase in the blood gastrin level, have been reported. The aim of the present study was to examine the increase in the blood gastrin level due to the long-term administration of conventional PPIs compared with vonoprazan.

METHODS

A prospective cross-sectional study was conducted. We examined the blood gastrin levels of patients taking vonoprazan or conventional PPIs in whom the grade of atrophic gastritis had been endoscopically evaluated in the last year.

RESULTS

The blood gastrin level was significantly higher in the vonoprazan group than that in the PPI group in patients with milder or no atrophic gastritis, irrespective of the administration periods. However, no significant difference was observed between the groups in patients with severe atrophic gastritis.

CONCLUSION

Vonoprazan more markedly increased the blood gastrin level compared with conventional PPIs in patients with milder or no atrophic gastritis. This indicates that vonoprazan may have stronger acid-suppressing effects in such patients than conventional PPIs. Key Message: We should be aware of the potential development of hypergastrinemia during the long-term administration of vonoprazan, especially in patients with mild or no atrophic gastritis.

Strategies for Effective Discontinuation of Proton Pump Inhibitors

PURPOSE OF REVIEW

Proton pump inhibitors (PPIs) are effective for many conditions but are often overprescribed. Recent concerns about long-term risks have made patients re-evaluate their need to take PPIs chronically, though these population-based studies have methodological weaknesses. The goal of this review is to provide evidenced-based strategies for discontinuation of PPI therapy.

RECENT FINDINGS

Given that some patients experience rebound symptoms when abruptly stopping continuous PPI therapy due to its effect on hypergastrinemia, strategies focus on avoiding rebound. Tapering the PPI and then initiating a "step-down" approach with the use of alternative medications may be effective. "On-demand therapy" provides patients with the option to take intermittent PPI courses, reducing overall use and cost while preserving patient satisfaction. It is important for providers to consider ambulatory pH or pH/impedance testing to rule out diagnoses that may require alternative medications like neuromodulators. A number of studies reviewed here can provide guidance in counseling patients on PPI discontinuation. It is important for the provider to obtain a baseline needs assessment for PPI therapy and to elucidate predictors of difficulty in discontinuation prior to initiating a strategy.

A primary hepatic gastrinoma accompanied by hyperplasia of multi-nodular Brunner's glands

BACKGROUND

Primary hepatic gastrinoma causing severe ulcerogenic syndrome is extremely rare. Herein, we report a case of primary hepatic gastrinoma accompanied by hyperplasia of multi-nodular Brunner's glands in a patient who instead, preoperatively, was suspected of having multiple duodenal gastrinomas and hepatic metastasis.

CASE PRESENTATION

A 57-year-old woman consulted a clinic complaining of melena, intermittent abdominal pain, diarrhea, and vomiting which had persisted for about 3 years. Six months before her presentation, she underwent segmental resection of the jejunum for acute peritonitis due to the spontaneous jejunal perforation. A blood test revealed that her serum immunoreactive gastrin (IRG) level was 12,037 pg/mL. Subsequently, she was transferred to our hospital. On computed tomography (CT), a hypervascular tumor of 23 mm in the segment 5 (S5) region of the liver was visualized. A selective arterial secretagogue injection test (SASI test) was performed twice. The first SASI test revealed that the hepatic tumor was a gastrinoma, and there was no gastrinoma in the duodeno-pancreatic region. Additionally, somatostatin receptor scintigraphy only visualized the tumor in the liver. However, the second SASI test, which was performed during the administration of a proton pump inhibitor and a somatostatin analog (octreotide acetate), revealed that there may have been gastrinomas existing not only in the liver but also in the upper part of the duodenum or the head of the pancreas. Duodenal endoscopy revealed multiple submucosal tumors in the first and the second portion of the duodenum, although a pathological examination of biopsied specimens obtained from the duodenal lesions was negative for malignant cells. Multiple endocrine neoplasia type 1 (MEN1) was excluded from her family history, and serum levels of both intact parathyroid hormone (iPTH) and calcium were within normal ranges. An anterior segmentectomy of the liver and pancreas-preserving total duodenectomy were performed on September 9, 2013. Postoperatively, her serum immunoreactive gastrin level decreased to less than 50 pg/mL. Pathological study of the resected specimens revealed a gastrinoma in the liver, but no gastrinoma in the duodenum. Interestingly, the duodenal submucosal tumor-like lesions were hyperplastic Brunner's glands. Postoperatively, she has been well without recurrence of hypergastrinemia for 4 years.

CONCLUSION

We report a case of primary hepatic gastrinoma in a patient who has been cured for 4 years postoperatively. The diagnosis was somewhat difficult due to the coexisting, multiple hyperplastic Brunner's glands of the duodenum mimicking the submucosal neuroendocrine tumors, which might have developed due to long-term hypergastrinemia.

Effect of gastric acid-suppressive therapy and biological variation of serum gastrin concentrations in dogs with chronic enteropathies

BACKGROUND

Serum gastrin concentration can help diagnose gastrinomas in dogs if >3-10× the upper reference limit (URL), but antisecretory therapy and other conditions can also cause hypergastrinemia. Effects of antisecretory therapy (famotidine or ranitidine, omeprazole) on serum gastrin concentration in dogs with chronic enteropathy (CE) and its biological variation (BV) are unknown. Aim of the study was to evaluate serum gastrin in acid-suppressant-treated or -naïve CE dogs; test the association between serum gastrin and histopathologic findings in acid-suppressant-naïve CE dogs; and evaluate the BV of serum gastrin in dogs not receiving any gastric acid suppressive therapy. Samples from 231 dogs were used and serum gastrin was measured by chemiluminescence assay. Gastric and duodenal histologic lesions were evaluated and graded. BV of serum gastrin was evaluated in serial samples.

RESULTS

Serum gastrin concentrations were significantly higher in acid-suppressant-treated than acid-suppressant-naïve dogs (P = 0.0245), with significantly higher concentrations in proton pump inhibitor (PPI)- than H₂-antihistamine-treated patients (P = 0.0053). More PPI- than H₂-antihistamine-treated dogs had gastrin concentrations above URL (P = 0.0205), but not >3× nor >10× the URL. Serum gastrin concentrations correlated with the severity of gastric antral epithelial injury (P = 0.0069) but not with any other lesions or the presence/numbers of spiral bacteria in gastric biopsies. Intra- and inter-individual BV were 43.4 and 21.6%, respectively, in acid-suppressant-naïve dogs, with a reciprocal individuality index of 0.49 and a critical difference of ≥29.5 ng/L.

CONCLUSIONS

Antisecretory (particularly PPI) treatment leads to hypergastrinemia in CE dogs, but the concentrations seen in this study are unlikely to compromise a diagnosis of gastrinoma. Use of a population-based URL for canine serum gastrin and a URL of ≤27.8 ng/L are appropriate.

Catching the Zebra: Clinical Pearls and Pitfalls for the Successful Diagnosis of Zollinger-Ellison Syndrome

Zollinger-Ellison syndrome (ZES) results from an ectopic gastrin-secreting tumor leading to peptic ulcer disease, reflux, and chronic diarrhea. While early recognition portends an excellent prognosis with >80% survival at 15 years, symptoms are often nonspecific making the diagnosis difficult to establish. Diagnosis involves a series of tests, including fasting gastrin, gastric pH, chromogranin A, and secretin stimulation. Performing these tests in the correct sequence and at the proper time is essential to avoid inaccurate results. Tumor localization is equally nuanced. Although providers have classically used ¹¹¹indium-radiolabeled octreotide with somatostatin receptor scintigraphy to evaluate tumor size and metastases, recent studies have shown superior results with newer imaging modalities. In particular, ⁶⁸gallium (⁶⁸Ga)-labeled somatostatin radiotracers (i.e., ⁶⁸Ga-DOTATOC, ⁶⁸Ga-DOTANOC and ⁶⁸Ga-DOTATATE) used with positron emission tomography/computed tomography can provide excellent results. Endoscopic ultrasound is another useful modality, particularly in patients with ZES in the setting of multiple endocrine neoplasia type 1. This review aims to provide clinicians with an overview of ZES with a focus on both clinical presentation and the proper utilization of the various biochemical and imaging tests available.

A case of type 1 multiple endocrine neoplasia with esophageal stricture successfully treated with endoscopic balloon dilation and local steroid injection combined with surgical resection of gastrinomas

Background

In type 1 multiple endocrine neoplasia (MEN1), esophageal diseases association with excessive gastrin secretion in Zollinger-Ellison syndrome (ZES) sometimes develop. Here, we reported a case of MEN1/ZES, who developed dysphagia due to reflux esophagitis with severe esophageal stricture. Treatment for his esophageal stricture and ZES was discussed.

Case presentation

A 43-year-old man with progressive dysphagia and diarrhea was referred to the teaching hospital. He had a history of recurrent duodenojejunal perforations despite the anti-secretory medication. Blood examinations revealed elevated serum gastrin, calcium, and parathyroid hormone. Upper gastrointestinal endoscopy demonstrated a severe esophageal stricture, multiple gastroduodenal ulcer scars, and a duodenal submucosal tumor. Enhanced computed tomography showed multiple hypervascular tumors within the pancreas and duodenum, suggestive of MEN1. Genetic examination demonstrated a pathogenic MEN1 mutation. Repetitive endoscopic esophageal dilatation with intralesional corticosteroid injection, coupled with pancreatoduodenectomy were performed to improve the patient’s symptoms and to treat pancreatic tumors. The histology of multiple tumors in the duodenum and pancreas were all consistent with neuroendocrine tumors. His hypergastrinemia subsided and he remained asymptomatic in his gastrointestinal tract after these treatments.

Conclusion

For esophageal stenosis in case of MEN1/ZES, anti-secretory therapy and endoscopic dilatation with corticosteroid injection could be recommended. However, in refractory cases with repetitive and/or severe complications due to high acid secretion, surgical treatment could be considered as an option.

A case of mixed adenoneuroendocrine carcinoma of the stomach with focal intestinal metaplasia and hypergastrinemia

Among neuroendocrine neoplasms, mixed exocrine and endocrine characteristics with at least 30% of each component are classified into mixed adenoneuroendocrine carcinoma (MANEC), according to the 2010 World Health Organization classification. We experienced a rare case of MANEC of the stomach with focal intestinal metaplasia and hypergastrinemia. A 76-year-old Japanese male was diagnosed as having gastric adenocarcinoma and underwent total gastrectomy. The pathologic diagnosis was MANEC of the stomach accompanied by unusual mucosal atrophy without Helicobacter pylori infection, the characteristics of which were different from both type A and type B atrophic gastritis. The patient has a history of long-term use of a proton pump inhibitor. Additional serum chemistry examination using preoperatively obtained plasma from the patient revealed hypergastrinemia. The mechanism of gastric MANEC carcinogenesis is still unclear, but that might be correlated with unusual intestinal metaplasia and hypergastrinemia in this case.

A knockin mouse model for human ATP4aR703C mutation identified in familial gastric neuroendocrine tumors recapitulates the premalignant condition of the human disease and suggests new therapeutic strategies

By whole exome sequencing, we recently identified a missense mutation (p.R703C) in the human ATP4a gene, which encodes the proton pump responsible for gastric acidification. This mutation causes an aggressive familial type I gastric neuroendocrine tumor in homozygous individuals. Affected individuals show an early onset of the disease, characterized by gastric hypoacidity, hypergastrinemia, iron-deficiency anemia, gastric intestinal metaplasia and, in one case, an associated gastric adenocarcinoma. Total gastrectomy was performed as the definitive treatment in all affected individuals. We now describe the generation and characterization of a knockin mouse model for the ATP4a^R703C mutation to better understand the tumorigenesis process. Homozygous mice recapitulated most of the phenotypical alterations that were observed in human individuals, strongly suggesting that this mutation is the primary alteration responsible for disease development. Homozygous mice developed premalignant condition with severe hyperplasia, dysplasia and glandular metaplasia in the stomach. Interestingly, gastric acidification in homozygous mice, induced by treatment with 3% HCl acid in the drinking water, prevented (if treated from birth) or partially reverted (if treated during adulthood) the development of glandular metaplasia and dysplasia in the stomach and partially rescued the abnormal biochemical parameters. We therefore suggest that, in this model, achlorhydria contributes to tumorigenesis to a greater extent than hypergastrinemia. Furthermore, our mouse model represents a unique and novel tool for studying the pathologies associated with disturbances in gastric acid secretion.

Summary: Gastric pathologies in an ATP4a knockin mouse model of a mutation responsible for the development of gastric neuroendocrine tumors in humans are prevented and reverted by adding HCl to drinking water.

Hypergastrinemia and a duodenal ulcer caused by gastric duplication

Background

Hypergastrinemia and the resultant peptic ulcer related to an enteric duplication has been quite rarely reported in the literature.

Case presentation

We herein report the case of a 4-year-old girl who presented with hypergastrinemia and a duodenal ulcer at 2 years of age. She had been followed up with a proton pump inhibitor, which resulted in resolution of the ulcer; however, unexplained hypergastrinemia had continued. A cystic lesion at the antrum was discovered at 4 years of age, which we suspected to be a gastric duplication. After we resected the lesion, the hypergastrinemia resolved without recurrence of the duodenal ulcer. The histology was compatible with a gastric duplication, and the lumen was lined with antral mucosa that strongly stained positive for gastrin. We presumed that the antral mucosa inside the duplication in our case had no hydrogen ion feedback inhibition of gastrin release from gastrin cells and increased release of gastrin from the mucosa inside the duplication led to the duodenal ulcer. Only two cases have been reported in the literature that had hypergastrinemia related to enteric duplication.

Conclusion

Gastric duplication should be included in the differential diagnosis of sustained hypergastrinemia in children.

Assessment of Gastric Emptying in Patients with Autoimmune Gastritis

BACKGROUND AND AIM

Symptoms of patients with autoimmune gastritis are not specific, and some patients may present symptoms suggestive of delayed gastric emptying. This study aims to investigate whether any delay in gastric emptying of solid food exists in patients with autoimmune gastritis and, if so, to identify the factors that might affect delayed gastric emptying.

METHODS

A total of 165 patients (106 women) diagnosed as having autoimmune gastritis were analyzed by means of a gastric emptying test. All patients underwent a standardized scintigraphic gastric emptying study. Patients with delayed gastric emptying and normal gastric emptying tests were then compared by means of factors that might affect gastric emptying. Also 65 patients with functional dyspepsia who had a gastric emptying study constituted the control group.

RESULTS

The median gastric emptying T ½ time was 127.43 min (min-max 50-953) for patients with AIG and 81 min (min-max 21-121.6) for functional dyspepsia patients (p < 0.001), and median percent retention at 2 h was 63.8 versus 20.2 (p < 0.001). In multivariate analysis, parameters that affected gastric emptying T ½ time were found as serum gastrin level (OR 1.002, 95 % CI 1.001-1.004, p < 0.001, chronic inflammation (OR 3.689, 95 % CI 1.44-9.39, p < 0.001), and increase in the degree of the atrophy of the gastric mucosa (OR 8.96, 95 % CI 2.98-26.93, p < 0.001).

CONCLUSIONS

In patients with autoimmune gastritis, gastric emptying is generally delayed. Autoimmune gastritis is an important etiology to explain the finding of delayed gastric emptying on a radionuclide test. This new finding is likely to be relevant to clinicians when evaluating and initiating appropriate medical treatment for patients with autoimmune gastritis manifesting upper gastrointestinal symptoms.

Relationships between autonomic nerve function and gastric emptying in patients with autoimmune gastritis

PURPOSE

Autonomic nervous system dysfunction exists in autoimmune diseases. Symptoms of autoimmune gastritis are not specific, and some patients may present symptoms suggestive of delayed gastric emptying. This study aims to investigate whether any autonomic dysfunction exists in autoimmune gastritis patients, and if so, to clarify the relationship between the autonomic nervous dysfunction, delayed gastric emptying, and gastrointestinal symptoms.

METHODS

75 patients (50 women, mean age 56.73 ± 11.77) diagnosed with autoimmune gastritis were investigated by means of autonomic nervous system and gastric emptying tests. All patients underwent a standardized scintigraphic gastric emptying study and five tests evaluating autonomic nervous system. Patients with autonomic nervous system dysfunction were then analyzed and compared by means of existence of delayed gastric emptying and gastrointestinal symptoms.

RESULTS

62 patients had autonomic nervous system dysfunction (14 mild, 40 moderate, and 8 severe autonomic dysfunction). The mean total score of autonomic tests was 3.85 ± 2.35. Total autonomic score of patients (n = 60) with delayed gastric emptying was significantly higher than patients (n = 15) with normal gastric emptying (4.68 ± 1.7 vs. 1.53 ± 0.58, p < 0.001). Mean gastroparesis cardinal symptom index was significantly higher in patients (n = 60) with delayed gastric emptying half-time compared to patients (n = 15) with normal gastric emptying half-time (1.89 ± 1.16 vs 0.4 ± 0.3, p < 0.001).

CONCLUSIONS

Most of patients with autoimmune gastritis also have autonomic nerve dysfunction. There is a close relationship between autonomic nervous system dysfunction and delayed gastric emptying. Gastroparesis cardinal symptom index has a high sensitivity and specificity in predicting both autonomic nerve function and delay in gastric emptying.

The impact of proton pump inhibitors on the human gastrointestinal microbiome

Potent gastric acid suppression using proton pump inhibitors (PPIs) is common in clinical practice but may have important effects on human health that are mediated through changes in the gastrointestinal microbiome. In the esophagus, PPIs change the normal bacterial milieu to decrease distal esophageal exposure to inflammatory gram-negative bacteria. In the stomach, PPIs alter the abundance and location of gastric Helicobacter pylori and other bacteria. In the small bowel, PPIs cause polymicrobial small bowel bacterial overgrowth and have been associated with the diagnosis of celiac disease. In the colon, PPIs associate with incident but not recurrent Clostridium difficile infection.

Serum concentrations of gastrin after famotidine and omeprazole administration to dogs

Background

The duration of antacid‐induced hypergastrinemia after cessation of administration of omeprazole and famotidine apparently has not been determined in dogs.

Hypothesis

That serum gastrin will return to basal concentrations by 7 days after cessation of famotidine or omeprazole administration.

Animals

Nine healthy, adult, male, research colony dogs.

Methods

Randomized, cross‐over design. Serum gastrin was determined daily for 7 days to establish baseline concentrations. Famotidine (1.0 mg/kg q24h) or omeprazole (1.0 mg/kg q24h) was administered PO for 7 days followed by a 14‐day washout. Serum concentrations of gastrin were determined daily during 7 days of administration and daily for 7 days after cessation of administration. Each drug was evaluated in 8 of the 9 dogs.

Results

Omeprazole caused a significant increase in serum gastrin concentration (37.2 ± 7.3 to 71.3 ± 19.0 ng/L; P = .006). Famotidine induced a transient increase in serum gastrin (37.2 ± 7.3 to 65.5 ± 38.5 ng/L; P = .02) that peaked at administration day 3 and declined thereafter. By day 7 after cessation of both drugs, there was no difference in serum gastrin concentrations compared to those before administration (famotidine P = .99; omeprazole P = .99). During or after administration, gastrin concentrations above 3 times the upper reference range were rare (12 of 224 samples).

Conclusions and Clinical Importance

A 7‐day withdrawal from short‐term administration of famotidine or omeprazole is sufficient for serum gastrin to return to baseline concentrations. Withholding famotidine or omeprazole for longer before investigating pathologic causes of hypergastrinemia is unnecessary.

Role of gastrin-peptides in Barrett's and colorectal carcinogenesis

Gastrin is the main hormone responsible for the stimulation of gastric acid secretion; in addition, gastrin and its derivatives exert proliferative and antiapoptotic effects on several cell types. Gastrin synthesis and secretion are increased in certain situations, for example, when proton pump inhibitors are used. The impact of sustained hypergastrinemia is currently being investigated. In vitro experiments and animal models have shown that prolonged hypergastrinemia may be related with higher cancer rates; although, this relationship is less clear in human beings. Higher gastrin levels have been shown to cause hyperplasia of several cell types; yet, the risk for developing cancer seems to be the same in normo- and hypergastrinemic patients. Some tumors also produce their own gastrin, which can act in an autocrine manner promoting tumor growth. Certain cancers are extremely dependent on gastrin to proliferate. Initial research focused only on the effects of amidated gastrins, but there has been an interest in intermediates of gastrin in the last few decades. These intermediates aren’t biologically inactive; in fact, they may exert greater effects on proliferation and apoptosis than the completely processed forms. In certain gastrin overproduction states, they are the most abundant gastrin peptides secreted. The purpose of this review is to examine the gastrin biosynthesis process and to summarize the results from different studies evaluating the production, levels, and effects of the main forms of gastrin in different overexpression states and their possible relationship with Barrett’s and colorectal carcinogenesis.

Diagnosis of Zollinger-Ellison syndrome: Increasingly difficult

In the present paper the increasing difficulty of diagnosis of Zollinger-Ellison syndrome (ZES) due to issues raised in two recent papers is discussed. These issues involve the difficulty and need to withdraw patients suspected of ZES from treatment with Proton Pump Inhibitors (omeprazole, esomeprazole, lansoprazole, rabeprazole, pantoprazole) and the unreliability of many gastrin radioimmunoassays. The clinical context of each of these important issues is reviewed and the conclusions in these articles commented from the perspective of clinical management.

Hypergastrinemia and recurrent type 1 gastric carcinoid in a young Indian male: Necessity for antrectomy?

Carcinoid tumors are the most common neuroendocrine tumors. Gastric carcinoids represent 2% of all carcinoids and 1% of all gastric masses. Due to the widespread use of Esophagogastroduodenoscopy for evaluating a variety of upper gastrointestinal symptoms, the detection of early gastric carcinoids has increased. We highlight an alternative management of a young patient with recurrent type 1 gastric carcinoids with greater than 5 lesions, as well as lesions intermittently greater than 1 cm. Gastric carcinoids have a variable presentation and clinical course that is highly dependent on type. Type 1 gastric carcinoids are usually indolent and have a metastasis rate of less than 2%, even with tumors larger than 2 cm. There are a number of experts as well as organizations that recommend endoscopic resection for all type 1 gastric carcinoid lesions less than 1 cm, with a follow-up every 6-12 mo. They also recommend antrectomy for type 1 gastric carcinoids with greater than 5 lesions, lesions 1 cm or greater, or refractory anemia. However, the American Society of Gastrointestinal Endoscopy guidelines state that type 1 gastric carcinoid surveillance is controversial based on the evidence and could not make an evidence-based position statement on the best treatment modality. Our report illustrates a rare cause of iron deficiency anemia in a young male (without any medical history) due to multiple recurrent gastric carcinoid type 1 lesions in the setting of atrophic gastritis causing hypergastrinemia, and in the absence of a vitamin B12 deficiency. Gastric carcinoid type 1 can present in young males without an autoimmune history, despite the known predilection for women aged 50 to 70 years. Type 1 gastric carcinoids can be managed by endoscopic resection in patients with greater than 5 lesions, even with lesions larger than 1 cm. This course of treatment enabled the avoidance of early antrectomy in our patient, who expressed a preference against more invasive measures at his young age.

Successful type-oriented endoscopic resection for gastric carcinoid tumors: A case report

The standard treatment in Japan for gastric carcinoid has been gastrectomy with lymphadenectomy. This report describes the possibility of endoscopic treatment as an appropriate option for gastric carcinoid fulfilling certain conditions. A 46 year old woman underwent endoscopic mucosal resection for two 3 mm gastric carcinoids. The patient had hypergastrinemia with pernicious anemia and type A chronic atrophic gastritis, suggesting that the tumors were type I in Rindi's classification. Both tumors were located in the mucosal layer with no cellular polymorphism and were chromogranin A positive. Neither tumor recurrence in the stomach nor distant metastases have been documented during the 5 years of follow-up. Although many type I gastric carcinoids may be clinically indolent, reports on successful endoscopic treatment for this carcinoid have been scanty in the literature in Japan, presumably because of the hitherto surgical treatment stance for the disease. This report discusses how the size, number, depth and histological grading of the type I gastric carcinoid could allow the correct identification of a benign or malignant propensity of an individual tumor and how endoscopic resection could be a treatment of choice when these factors render it feasible. This stance could also obviate unnecessary surgical resection for more benign tumors.

Effects of Helicobacter pylori infection and hypergastrinemia on the growth of colonic adenoma

AIM: To investigate the association among gastrin level, Helicobacter pylori (H. pylori) infection and the development of colonic adenoma.

METHODS: Fasting serum samples from 48 patients with colonic adenomas and 43 demographically matched colonoscopy-negative controls were assayed for anti-H. pylori IgG and serum gastrin levels. Colonic adenoma patients received oral celecoxib for 6 months. At the end of the second, fourth and sixth months, serum gastrin levels were measured by radioimmunoassay (RIA) and H. pylori IgG antibody was analyzed by enzyme-linked immunosorbent assay (ELISA).

RESULTS: The prevalence of H. pylori seropositivity was significantly higher in patients with colonic adenomas than in controls (68.8% vs 9.30%, P < 0.05). Similarly, median gastrin level was significantly higher in patients with colonic adenomas than in controls (72.7% vs 37.8%, P < 0.05). There was a positive correlation between H. pylori IgG antibody and serum gastrin level in colonic adenoma patients (r = 0.854, P < 0.001). Of note, hypergastrinemia was associated with distal colon distribution of adenomas, but not with adenoma number, size, grade or histological features. After celecoxib treatment, there were parallel falls in serum gastrin levels and H. pylori seropositivity in colonic adenoma patients.

CONCLUSION: Hypergastrinemia induced by H. pylori infection is associated with increased cyclooxygenase-2 (COX-2) expression in colonic adenoma, suggesting the possibility that gastrin up-regulates COX-2 expression in colonic adenoma. Celecoxib can obviously decrease H. pylori seropositivity and gastrin levels and inhibit the growth of colonic adenomas by down-regulating COX-2 expression.

Gastric carcinoids: Between underestimation and overtreatment

Gastric carcinoids (GCs), which originate from gastric enterochromaffin-like (ECL) mucosal cells and account for 2.4% of all carcinoids, are found increasingly in the course of upper gastrointestinal tract endoscopy. Current nosography includes those occurring in chronic conditions with hypergastrinemia, as the type 1 associated with chronic atrophic gastritis, and the type 2 associated with Zollinger-Ellison syndrome in multiple endocrine neoplasia type 1, and type 3, which is unrelated to hypergastrinemia and is frequently malignant, with distant metastases. The optimal clinical approach to GCs remains to be elucidated, depending upon type, size and number of carcinoids. While there is agreement concerning the treatment of type 3 carcinoids, for types 1 and 2, current possibilities include simple surveillance, endoscopic polypectomy, surgical excision, associated or not with surgical antrectomy, or total gastrectomy. Moreover, the recent introduction of somatostatin analogues represents a therapeutic option of possibly outstanding relevance.

Importance of gastrin in the pathogenesis and treatment of gastric tumors

In addition to regulating acid secretion, the gastric antral hormone gastrin regulates several important cellular processes in the gastric epithelium including proliferation, apoptosis, migration, invasion, tissue remodelling and angiogenesis. Elevated serum concentrations of this hormone are caused by many conditions, particularly hypochlorhydria (as a result of autoimmune or Helicobacter pylori (H pylori)-induced chronic atrophic gastritis or acid suppressing drugs) and gastrin producing tumors (gastrinomas). There is now accumulating evidence that altered local and plasma concentrations of gastrin may play a role during the development of various gastric tumors. In the absence of H pylori infection, marked hypergastrinemia frequently results in the development of gastric enterochromaffin cell-like neuroendocrine tumors and surgery to remove the cause of hypergastrinemia may lead to tumor resolution in this condition. In animal models such as transgenic INS-GAS mice, hypergastrinemia has also been shown to act as a cofactor with Helicobacter infection during gastric adenocarcinoma development. However, it is currently unclear as to what extent gastrin also modulates human gastric adenocarcinoma development. Therapeutic approaches targeting hypergastrinemia, such as immunization with G17DT, have been evaluated for the treatment of gastric adenocarcinoma, with some promising results. Although the mild hypergastrinemia associated with proton pump inhibitor drug use has been shown to cause ECL-cell hyperplasia and to increase H pylori-induced gastric atrophy, there is currently no convincing evidence that this class of agents contributes towards the development of gastric neuroendocrine tumors or gastric adenocarcinomas in human subjects.

Gastric carcinoid tumor in a patient with a past history of gastrointestinal stromal tumor of the stomach

Gastrointestinal stromal tumor is the most common mesenchymal tumor in the gastrointestinal tract. It may coexist with other type of cancers, and if so, the tumors usually involve the stomach. The most common associated cancers are gastrointestinal carcinomas. We report a 65-year-old woman with a history of gastric gastrointestinal stromal tumor who had undergone subtotal segmental gastrectomy. New polypoid lesions were detected on a follow-up gastroscopy one year later. The lesions were biopsied and found to be carcinoid tumors. There was serum hypergastrinemia, and type 1 gastric carcinoid tumor was diagnosed. A total gastrectomy was performed. Pathologic examination revealed both carcinoid tumors and a recurrent gastrointestinal stromal tumor.