SummaryBackground
Proton pump inhibitors (PPIs) have a well-established safety profile. However, concerns have been raised about a potential relationship between PPI-induced hypergastrinaemia and the development of enterochromaffin-like (ECL) cell hyperplasia, neuroendocrine tumours and gastric cancer during long-term therapy.

Aim
To review the effects of long-term PPI use on serum gastrin levels and gastric histopathology.

Methods
A systematic literature search was conducted in PubMed on 21 April 2015 to identify studies reporting the effects of long-term (defined as >3 years) PPI use on gastrin levels and gastric histopathology.

Results
A total of 16 studies (1920 patients) met the inclusion criteria. During long-term PPI therapy, mean gastrin levels rose to one to three times the upper limit of the normal range (~100 pg/mL), and an increased prevalence of ECL cell hyperplasia was observed (+7.8–52.0%). Helicobacter pylori-positive patients had a significantly increased risk of developing ECL linear/micronodular hyperplasia compared with H. pylori-negative patients [OR: 2.45 (95% CI: 1.47–4.10), P = 0.0006]; however, no evidence of neoplastic changes was found. The risk of corpus atrophy was markedly higher in H. pylori-positive patients than in H. pylori-negative patients [OR: 11.45 (95% CI: 6.25–20.99), P < 0.00001]. Not a single case of gastric adenocarcinoma was found.

Conclusions
Long-term PPI therapy induced moderate hypergastrinaemia in most patients and an increased prevalence of ECL cell hyperplasia. H. pylori-positive patients receiving long-term PPI therapy were exposed to a higher risk of corpus atrophy than H. pylori-negative patients. No neuroendocrine tumours or gastric cancers were found.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/apt.13324

Systematic review: the effects of long‐term proton pump inhibitor use on serum gastrin levels and gastric histology

Background
Proton pump inhibitors (PPIs) are the most effective drugs to reduce gastric acid secretion. PPIs are one of the most commonly prescribed classes of medications worldwide. Apart from short-term application, maintenance therapy with PPIs is recommended and increasingly used in certain diseases, such as Zollinger-Ellison syndrome and gastro-oesophageal reflux disease, especially for people with erosive oesophagitis or Barrett's oesophagus. Although PPIs are generally safe, their efficacy and safety of long-term use remains unclear. The question of whether the long-term use of PPIs could promote the development of gastric pre-malignant lesions has been widely investigated, but results are inconsistent. Limited insight on this problem leads to a dilemma in decision making for long-term PPI prescription.

Objectives
To compare the development or progression of gastric pre-malignant lesions, such as atrophic gastritis, intestinal metaplasia, enterochromaffin-like (ECL) cell hyperplasia, and dysplasia, in people taking long-term (six months or greater) PPI maintenance therapy.

Search methods
We searched the following databases (from inception to 6 August 2013): the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL. In addition, we searched the reference lists of included trials and contacted experts in the field.

Selection criteria
We searched for randomised controlled trials (RCTs) in adults (aged 18 years or greater) concerning the effects of long-term (six months or greater) PPI use on gastric mucosa changes, confirmed by endoscopy or biopsy sampling (or both).

Data collection and analysis
Two review authors independently performed selection of eligible trials, assessment of trial quality, and data extraction. We calculated odds ratios (OR) for analysis of dichotomous data and mean differences for continuous data, with 95% confidence intervals (CI).

Main results
We included seven trials (1789 participants). Four studies had high risk of bias and the risk of bias in the other three trials was unclear. In addition, it was difficult to assess possible reporting bias. We pooled 1070 participants from four RCTs to evaluate corporal atrophy development revealing an insignificantly increased OR of 1.50 (95% CI 0.59 to 3.80; P value = 0.39; low-quality evidence) for long-term PPI users relative to non-PPI users. In five eligible trials, corporal intestinal metaplasia was assessed among 1408 participants, also with uncertain results (OR 1.46; 95% CI 0.43 to 5.03; P value = 0.55; low-quality evidence). However, by pooling data of 1705 participants from six RCTs, our meta-analysis showed that participants with PPI maintenance treatment were more likely to experience either diffuse (simple) (OR 5.01; 95% CI 1.54 to 16.26; P value = 0.007; very-low-quality evidence) or linear/micronodular (focal) ECL hyperplasia (OR 3.98; 95% CI 1.31 to 12.16; P value = 0.02; low-quality evidence) than controls. No participant showed any dysplastic or neoplastic change in any included studies.

Authors' conclusions
There is presently no clear evidence that the long-term use of PPIs can cause or accelerate the progression of corpus gastric atrophy or intestinal metaplasia, although results were imprecise. People with PPI maintenance treatment may have a higher possibility of experiencing either diffuse (simple) or linear/micronodular (focal) ECL cell hyperplasia. However, the clinical importance of this outcome is currently uncertain.

Long-term proton pump inhibitor (PPI) use and the development of gastric pre-malignant lesions.

http://www.s188618569.websitehome.co.uk/resources/PPI+use+for+reflux.pdf

Over-Prescription of Acid-Suppressing Medications in Infants: How It Came About, Why It’s Wrong, and What to Do About It

Summary

Background

Sustained acid inhibition with PPI stimulates gastrin secretion, exerting a proliferative drive on enterochromaffin-like cells (ECL cells) of the oxyntic mucosa. It may also accelerate development of gastric gland atrophy in Helicobacter pylori-infected individuals.



Aims

To evaluate gastric exocrine and endocrine cell changes in GERD patients randomised to laparoscopic antireflux surgery (LARS, n = 288) or long-term (5 years) esomeprazole (ESO) treatment (n = 266).



Methods

Antral and corpus biopsies were taken at endoscopy and serum gastrin and chromogranin A levels were assayed, at baseline and after 1, 3 and 5 years’ therapy.



Results

Biopsies were available at each time point for 158 LARS patients and 180 ESO patients. In H. pylori-infected subjects, antral mucosal inflammation and activity improved significantly (P < 0.001) and stabilised after 3 years on esomeprazole while no change in inflammation was observed after LARS. Oxyntic mucosal inflammation and activity remained stable on esomeprazole but decreased slightly over time after LARS. Neither intestinal metaplasia nor atrophy developed in the oxyntic mucosa. ECL cell density increased significantly after ESO (P < 0.001), corresponding with an increase in circulating gastrin and chromogranin A. After LARS, there was a significant decrease in ECL cell density (P < 0.05), accompanied by a marginal decrease in gastrin and chromogranin.



Conclusions

Antral gastritis improved in H. pylori-infected GERD patients after 5 years on esomeprazole, with little change in laparoscopic antireflux surgery patients, who acted as a control. Despite a continued proliferative drive on enterochromaffin-like cells during esomeprazole treatment, no dysplastic or neoplastic lesions were found and no safety concerns were raised. NCT 00251927.

Gastric exocrine and endocrine cell morphology under prolonged acid inhibition therapy: results of a 5-year follow-up in the LOTUS trial.

Gastro-esophageal reflux (GER) is common in infants and children and has a varied clinical presentation: from infants with innocent regurgitation to infants and children with severe esophageal and extra-esophageal complications that define pathological gastro-esophageal reflux disease (GERD). Although the pathophysiology is similar to that of adults, symptoms of GERD in infants and children are often distinct from classic ones such as heartburn. The passage of gastric contents into the esophagus is a normal phenomenon occurring many times a day both in adults and children, but, in infants, several factors contribute to exacerbate this phenomenon, including a liquid milk-based diet, recumbent position and both structural and functional immaturity of the gastro-esophageal junction. This article focuses on the presentation, diagnosis and treatment of GERD that occurs in infants and children, based on available and current guidelines.

Gastro-esophageal reflux in children

Aliment Pharmacol Ther 2011; 33: 829–836



Summary

Background  There are longstanding concerns that carcinoid tumours or atrophic gastritis might develop in children receiving proton pump inhibitors (PPIs) long term. In children, this has not been studied using stains sensitive and specific for enterochromaffin-like (ECL) cells.



Aim  To evaluate gastric biopsies for ECL hyperplasia or gastric atrophy, in children treated long-term with PPIs.



Methods  Synaptophysin and chromogranin immunostaining, biopsies read anonymised, blinded. Endocrine cell numbers graded according to Rindi and Solcia.



Results  Of 130 children with gastro-oesophageal reflux disease (GERD), 65 had sequential gastric biopsies, starting at median 8.2 years ( 3 years in 24 patients. In nine patients who received H2-receptor antagonists, changes were present before PPI use. No patient had atrophic gastritis.



Conclusions  A high percentage of children (61%) receiving long-term PPI continuously for up to 10.8 years (median 2.84 years) develop minor degrees of ECL hyperplasia. This has no known clinical significance. Children on PPIs for this duration do not appear to develop atrophic gastritis or carcinoid tumours.

T. Sturby

Papers

Gastric histology in children treated with proton pump inhibitors long term, with emphasis on enterochromaffin cell-like hyperplasia.