Bacterial load and degree of gastric mucosal inflammation in Helicobacter pylori infection

Helicobacter pylori induces an inflammatory immune response in the gastric mucosa. The degree of gastric mucosal inflammation and its topographic distribution are key factors in the diversity of H. pylori-related complications. Here we summarize substantial evidence reported in the literature concerning the impact of H. pylori density on gastric inflammation, the development of severe complications, and its relation to H. pylori suppression therapy. Most studies demonstrate a significant correlation between H. pylori density and the grade of acute and chronic inflammation, taking into account the limitations of each method for density assessment. Overall, high bacterial loads are associated with increased acute mucosal damage and long-term changes in the gastric mucosa. The influence of H. pylori density reduction on the improvement of gastric mucosal changes was observed in studies using 'clearance' therapies. Mucosal agents provoke a significant, but not persistent, reduction in gastritis activity. Treatments suppressing the density and virulence of H. pylori could become strategies to prevent H. pylori-associated disease in the future.

Helicobacter pylori and other gastric bacteria

The discovery of Helicobacter pylori opened a new field for extensive research on the interactions of this bacterium with the gastric mucosa in the past decades. Basic principles of infection, virulence factors, and treatment options have been identified and recognized. New questions have emerged concerning possible interactions of H. pylori with other bacteria in the human stomach. Herein we discuss hallmark findings in relation to H. pylori infection and the new evidence on other bacteria in the human stomach. Probiotic bacteria seem to interfere with colonizing H. pylori bacteria and thus influence the inflammatory response of the gastric mucosa to H. pylori infection.

Helicobacter pylori related and non-related lesions in the stomach

Gastric lesions may arise in gastric mucosa of patients with gastritis or gastropathies due to different etiopathogenic factors. As most lesions of the stomach result from a chronic infection of gastric mucosa with Helicobacter pylori (H. pylori), a possible classification of gastric lesions based on etiology may distinguish H. pylori-related lesions from those arising in a gastric mucosa not colonized from the bacterium. The repertoire of lesions one may find in the stomach is limited and different pathologies may present with a similar macroscopic aspect. Clinically relevant lesions of the stomach that are or are not associated with H. pylori infection include gastric ulcer, gastric atrophy, gastric neoplasia, and metastasis from other cancers. The detection or exclusion of an H. pylori infection in patients with gastric lesions has important consequences for the clinical management. In the present review we focus on H. pylori-related and non-related peptic lesions in the stomach.

The intriguing relationship of Helicobacter pylori infection and acid secretion in peptic ulcer disease and gastric cancer

Helicobacter pylori infection induces chronic inflammation of the gastric mucosa and thus profoundly affects gastric physiology. In the acute phase of infection, gastric acid secretion is transiently impaired. The morphological damage of the gastric mucosa, changes in gastric hormone release, and disruption of neural pathways all contribute to influence gastric acid secretion in a distinct manner. Changes in gastric acid secretion, whether impaired or increased, are intimately related with the topographic phenotypes of gastritis and the presence of atrophy or absence of corpus atrophy. The interplay of gastritis phenotype and acid secretion are key determinants in disease outcomes. Corpus-predominant gastritis and corpus atrophy are accompanied by hypochlorhydria and carry the highest risk for gastric cancer, whereas antrum-predominant gastritis with little involvement of the corpus-fundic mucosa is associated with hyperchlorhydria and predisposes to duodenal ulcer disease.

The intriguing relationship of Helicobacter pylori infection and acid secretion in peptic ulcer disease and gastric cancer

Helicobacter pylori infection induces chronic inflammation of the gastric mucosa and thus profoundly affects gastric physiology. In the acute phase of infection, gastric acid secretion is transiently impaired. The morphological damage of the gastric mucosa, changes in gastric hormone release, and disruption of neural pathways all contribute to influence gastric acid secretion in a distinct manner. Changes in gastric acid secretion, whether impaired or increased, are intimately related with the topographic phenotypes of gastritis and the presence of atrophy or absence of corpus atrophy. The interplay of gastritis phenotype and acid secretion are key determinants in disease outcomes. Corpus-predominant gastritis and corpus atrophy are accompanied by hypochlorhydria and carry the highest risk for gastric cancer, whereas antrum-predominant gastritis with little involvement of the corpus-fundic mucosa is associated with hyperchlorhydria and predisposes to duodenal ulcer disease.

Historical impact to drive research in peptic ulcer disease

The story of gastric acid secretion began with early ideas on gastric secretion (Spallanzani and de Réaumur, 17th century) and with first descriptions of food digestion (Dupuytren and Bichat, Beaumont, early 18th century), followed by proof that gastric juice contained acid (Prout, early 18th century). The research continued with first descriptions of gastric glands as the source of gastric acid and its changes upon digestive stimulus (Purkinje and Golgi, mid and late 19th century). The theory of 'nervism' - the neuro-reflex stimulation of gastric secretion by vagal nerve (Pavlov, early 20th century) was contrasted by a histamine-mediated concept of gastric secretion (Popielski and Code, mid 20th century). Thus, gastric acid and pepsin (Schwann, early 19th century) were found to be essential for food digestion and studies also pointed to histamine, being the most potent final common chemostimulator of oxyntic cells. The discoveries in etiopathogenesis of mucosal injury were marked by the famous dictum: 'No acid, no ulcer' ('Ohne saueren Magensaft kein peptisches Geschwür', Schwarz, 1910) that later induced the term of 'mucosal defense' and the notion that the breaking of 'gastric mucosal barrier' represents the initial step in the process of mucosal injury (Davenport, Code and Scholer, mid 20th century). The prostaglandins were shown to influence all major components of gastric mucosal barrier, described with the term 'cytoprotection' (Vane, Robert and Jacobson, 1970s). Beginning in the latter half of 19th century, the studies on gastric bacteriology that followed enabled the discovery of association between Campylobacter (Helicobacter) pylori and peptic ulcers (Warren and Marshall, 1980s) that led to worldwide major interventions in treating peptic ulcer disease. The surgical approach to peptic ulcer had been outlined by resection procedures (Billroth, Pean, Moynihan, late 19 century) and vagotomy, with or without drainage procedures (Jaboulay, Latarjet, Dragstedt, mid 20th century). Antacids, protective agents, anticholinergics, and later gastrin antagonists and prostaglandins were used for decades in the treatment of peptic ulcer, with differing effects. The advent of the concept of H(2)-receptor antagonists (Black, 1970s) and the discovery of acid (proton) pumps in parietal cells (Ganser, Forte and Sachs, late 1970s) paved the way for potent (H(2) antagonists) and profound acid inhibition (proton pump inhibitors) that revolutionized the treatment of acid-related disorders, including peptic ulcer disease. Worldwide, peptic ulcer and its complications remain the cause of significant morbidity, especially in older age groups, representing a major burden for ambulatory and hospital healthcare resources.

Randomised clinical trial: effects of monotherapy with ADX10059, a mGluR5 inhibitor, on symptoms and reflux events in patients with gastro-oesophageal reflux disease

BACKGROUND

ADX10059, a metabotropic glutamate receptor 5 (mGluR5) negative allosteric modulator, has been shown to reduce gastro-oesophageal reflux events and oesophageal acid exposure in patients with gastro-oesophageal reflux disease (GERD) and healthy subjects.

AIM

  To evaluate the effects of ADX10059 monotherapy for 2 weeks on symptom control in patients with GERD.

METHODS

This was a double-blind, placebo-controlled, multi-centre trial in GERD patients who were responders to proton pump inhibitors (PPIs). Following PPIs withdrawal, a 2-week baseline washout period was followed by 2-week treatment with either ADX10059 120 mg or placebo b.d. The primary clinical efficacy endpoint was the number of GERD symptom-free days in treatment week 2 compared with the last 7 days of baseline. The effect on reflux events using 24-h impedance-pH monitoring was also determined in a subset of 24 patients.

RESULTS

The full analysis set comprised 103 patients ADX10059 (N= 50), Placebo (N=53). In treatment week 2, ADX10059 significantly increased GERD symptom-free days (P=0.045) and heartburn-free days (P=0.037), reduced antacid use (P=0.017), improved total symptom score (P=0.048) including subscale heartburn/regurgitation (P=0.007) and sleep disturbance because of GERD (P= 0.022). ADX10059 significantly reduced total (P=0.034) and acidic reflux events (P=0.003). ADX10059 was well tolerated. Most common adverse events for ADX10059 were mild to moderate dizziness 16% and vertigo 12% (placebo 4% and 2%).

CONCLUSIONS

Inhibition of mGluR5 with ADX10059 monotherapy reduces reflux events and improves symptoms in GERD patients. This mechanism has promise for the management of GERD.

IL-17A and IL-17F gene expression is strongly induced in the mucosa of H. pylori-infected subjects from Kenya and Germany

Helicobacter pylori infection is the major cause of gastritis. Immunologically, H. pylori gastritis is associated with an infiltration of immune cells into gastric mucosa and the upregulation of various cytokines. Here, we analysed the gene expression of IL-1- and IL-17-related cytokines in regard to H. pylori infection in 85 German and 51 Kenyan patients with reflux-related or dyspeptic symptoms, respectively. Degree of gastritis and density of colonization were assessed histologically in accordance with the updated Sydney classification. Gene expression levels of cytokines IL-1β, IL-8, IL-18, IL-33, IL-17A, IL-17F and IL-23 as well as IL-23R were analysed by real-time RT-PCR. In both populations, H. pylori-infected individuals had significant higher inflammatory scores for activity and chronicity than H. pylori-negative subjects (P values between 0.006 and <0.0001). IL-8 mRNA was induced up to 6-fold in H. pylori-infected patients (P < 0.05), while the expression levels of IL-1β, IL-18, IL-23, IL-33 and IL-23R did not differ with respect to the H. pylori status in both groups. Most strikingly, a significant induction of both IL-17A and IL-17F was noted in H. pylori-infected individuals of both ethnic groups. Almost all IL-17F-positive samples revealed co-expression of IL-17A (40/42, 95.2%). Analysing IL-17A and IL-17F transcript levels of these 40 'double-positive' samples, a highly significant positive correlation between both genes was identified (P < 0.001). Taken together, H. pylori infection leads to a strong upregulation of both IL-17A and IL-17F in the gastric mucosa suggesting a regulatory link between both genes.

[Palliative treatment in gastroenterology at the border to (abdominal) surgery]

BACKGROUND

In the management of gastrointestinal tumour lesions, palliative treatment has attained an increasing role. As also in curative treatment, an interdisciplinary cooperation between gastroenterologists and surgeons has to be aimed for.

AIM

The aim of this study is to illustrate the diagnostic and therapeutic management of frequently occurring diseases in palliative medicine from a gastroenterological point of view.

METHODS

Complementary short overviews on clinical experience and selectively searched references from the current scientific literature were evaluated.

RESULTS

The symptomatic complex is very heterogeneous and requires an adequate approach taking into account the differential diagnosis. The palliative gastroenterological approach is characterised by the competent care on ascites, management of "malignant intestinal obstruction and obstipation" (MIO) as well as appropriate nutrition and analgetic therapy. The surgical approach is indicated after sequential exhaustion of medical, interventional endoscopic and (eventually) image-guided radiological measures; it comprises creation of a peritoneovenous shunt (ascites), bypass procedures (gastroenteral, biliodigestive, enteroenteral) as well as, in extraordinary cases, resection in addition to the implantation of an i. v. port-a-cath or surgical revision of a PEG / stent complication; in particular, in case of recurrent and massive haemorrhage and perforation (absolute indication), surgery becomes necessary.

DISCUSSION

A lack of appropriate studies, absence of adequate study results including the difficult initiation of medical studies with palliative intention aggravate a competent evidence-based approach. Therefore, the management is considerably affected by clinical experience.

CONCLUSION

Efficacious care in palliative visceral medicine requires relevant clinical expertise and interdisciplinary action because of the occurrence of clinical cases in gastroenterology at the border to surgery.

[Dilemma between gastroprotection and cardiovascular prevention]

Long-term low-dose aspirin intake leads to a 2 - 4-fold risk of risk for upper gastrointestinal bleeding. The additional intake of clopidogrel further increases the risk of upper GI bleeding (OR 7.4). Because of the potential interaction between proton pump inhibitors (PPI) and clopidogrel that compromises the efficacy of clopidogrel on platelet aggregation, there has been a warning in the product information by health authorities in the US and in Europe who discourage the concomitant use of PPI and clopidogrel. In the present study we performed a selected review of the published literature on the indications for gastric protection with PPI in patients on mono- or dual antiplatelet therapy focussing on the possible interaction between clopidogrel and PPI. In ex vivo analyses of platelet function, a reduced efficacy of clopidogrel was observed in patients on comedication with omeprazole. This was not the case with the comedication of other PPIs. To date, clear evidence is missing to state that comedication with PPI reduces the efficacy of clopidogrel IN VIVO. If both Clopidogrel and PPI need to be prescribed, a split dosage regimen of PPI in the morning and clopidogrel in the evening can be recommended. The short half-life of both medications explains the rationale of this recommendation.

Effect of procainhydrochloride on phospholipase A2 catalytic activity in sodium taurocholate-induced acute experimental pancreatitis in rats

BACKGROUND

In human acute pancreatitis (AP) the local anaesthetic procainhydrochloride (procain-HCl) is given intravenously for pain treatment. Procain has been shown to inhibit catalytic activity of pancreatic (group I) phospholipase A2 (PLA2) and non-pancreatic (group II) PLA2. Both enzymes are important mediators for the local and systemic inflammatory process in AP. To determine the effect of procain, we examined serum and tissue levels of both types of PLA2 activity in the experimental rodent taurocholate model of AP.

METHODS

In 60 rats, severe pancreatitis was induced by taurocholate. Forty rats were treated with procain-HCl intravenously at a dosage of 2 mg/kg body weight/h either at or 1 h after induction of pancreatitis. Twenty rats served as controls. We measured catalytic activities of group I and group II PLA2 in serum and tissue samples of lung and pancreas.

RESULTS

Serum group II PLA2 catalytic activity was significantly reduced 3 and 6 h after AP induction in rats treated with procain-HCl (p < 0.001) in both treatment groups. In pancreatic and lung tissue, group II PLA2 catalytic activity was significantly reduced compared with normal values (p < 0.001).

CONCLUSION

Procain-HCl given intravenously either at or 1 h after induction of necrotizing pancreatitis significantly inhibits group II PLA2 catalytic activity in serum and tissues.

Causes and mechanisms in acute pancreatitis

Acute pancreatitis (AP) presents clinically with either mild or severe clinical course. There are no effective specific drugs for treatment of AP today. Basic knowledge about pathophysiological processes is the key for the development of novel therapeutic principles. This article provides a review on the pathophysiological mechanisms involved in the early phase of AP.

[Bronchopulmonary manifestations of gastroesophageal reflux disease]

Gastroesophageal reflux disease (GERD) is a common disease in the western world. Usually it occurs with typical symptoms like heartburn and regurgitation, but almost every third GERD-patient presents with extraesophageal symptoms and diseases in which a causal relation with GERD is discussed. The extraesophageal symptoms possibly associated with GERD are chronic cough, bronchial asthma, sleep disturbances including obstructive sleep apnea, hoarseness, dental erosions, non-cardiac chest pain and idiopathic pulmonary fibrosis. This article gives an overview of the reflux-associated diseases of the airways as well as the proposed pathomechanisms and therapeutic options.