Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

https://gut.bmj.com/content/gutjnl/66/1/6.full.pdf

Management of Helicobacter pylori infection—the Maastricht V/Florence Consensus Report

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(09)60938-7.pdf

Peptic ulcer disease

Helicobacter pylori is a gastric pathogen that colonizes approximately 50% of the world's population. Infection with H. pylori causes chronic inflammation and significantly increases the risk of developing duodenal and gastric ulcer disease and gastric cancer. Infection with H. pylori is the strongest known risk factor for gastric cancer, which is the second leading cause of cancer-related deaths worldwide. Once H. pylori colonizes the gastric environment, it persists for the lifetime of the host, suggesting that the host immune response is ineffective in clearing this bacterium. In this review, we discuss the host immune response and examine other host factors that increase the pathogenic potential of this bacterium, including host polymorphisms, alterations to the apical-junctional complex, and the effects of environmental factors. In addition to host effects and responses, H. pylori strains are genetically diverse. We discuss the main virulence determinants in H. pylori strains and the correlation between these and the diverse clinical outcomes following H. pylori infection. Since H. pylori inhibits the gastric epithelium of half of the world, it is crucial that we continue to gain understanding of host and microbial factors that increase the risk of developing more severe clinical outcomes.

Helicobacter pylori and Gastric Cancer: Factors That Modulate Disease Risk

Prospective double-blind trial of duodenal ulcer relapse after eradication of Campylobacter pylori.

Gastritis, inflammation of the gastric mucosa, represents the stomach’s response to injury. A continuing dilemma has been the very large size of the population with gastritis in contrast to the lack of knowledge about specific causes. The discovery of Helicobacter pylori as the major cause of inflammation of the gastric antrum has helped resolve this As a result, accurate and uniform documentation of gastritis from gastric endoscopic biopsies assumes prime importance for understanding the dynamics of gastritis and has a major contribution to make to the study of the natural history of peptic ulcer disease and also, perhaps, to the evolution of gastric cancer. Increasing numbers of papers are appearing in the literature documenting the pathology of gastritis, its relation to H. pylori and the response to therapeutic agents.+” At present, a variety of classifications and systems of grading are in use, making it difficult to compare the results.10*12-21 It is therefore appropriate to review the existing classifications and to produce a system that, in the light of new knowledge, will find widespread acceptance. This was the remit given to a small multidisciplinary Working Party by the Scientific Committee of the 9th World Congresses in Gastroenterology. The Working Party sought additional advice from an ad hoc Advisory Group of European pathologists sharing a special interest in gastric pathology. T o gain widespread acceptance, any proposed classification must be simple, easy to apply, flexible, correlate with existing classifications, be sensitive to monitoring therapy and appeal to generalists as well as dedicated gastroenterologists, and diagnosticians as well as research workers.

The Sydney System: histological division.

Biopsy specimens of gastric and duodenal mucosa from 290 patients were examined histologically for metaplasia and Campylobacter pyloridis. Estimates of pH on samples of fasting gastric juice from 55 of the patients were performed, and mucosal biopsy specimens from 33 patients were also cultured for C pyloridis. Active duodenitis was seen in 34 duodenal biopsy specimens. Thirty (88%) of the patients with active duodenitis had both greater than 5% gastric metaplasia in the duodenal specimen and C pyloridis associated gastritis. These two factors coexisted in only 0.43% of patients with no duodenal inflammation. When C pyloridis were seen histologically in duodenal biopsy specimens they were confined to areas of gastric metaplasia and never occurred in the absence of a polymorph infiltrate. Of the 55 patients with measurements of gastric juice pH, gastric metaplasia was present in the duodenum in 20 of 42 with a pH of less than 2.5, and in 0 of 13 with a pH of greater than 2.5. These results suggest that acid induced gastric metaplasia in the duodenum and C pyloridis associated gastritis may be synergistic in the pathogenesis of duodenitis; the metaplastic gastric epithelium allows C pyloridis to colonise the duodenal mucosa, where it produces an acute inflammatory response.

https://jcp.bmj.com/content/jclinpath/40/8/841.full.pdf

Campylobacter pyloridis and acid induced gastric metaplasia in the pathogenesis of duodenitis.

Ultrastructural examination of biopsies showing Helicobacter pylori associated chronic gastritis reveals close attachment between gastric surface epithelial cells and the organism. The finding of 'adhesion pedestals', which represents a cellular response to the presence of the organism, is analogous to the response of intestinal cells to enteropathogenic E coli. Thus the development of bacterial attachment sites in H pylori associated gastritis might be an indication of pathogenicity. We have therefore explored the relationship between the proportion of organisms forming attachment sites and histological indices of disease 'activity'. Antral biopsies from 40 patients with H pylori positive gastritis were examined histologically and ultrastructurally, and the percentage of attached organisms compared with subjective assessments of epithelial degeneration, mucin depletion, polymorphonuclear and chronic inflammatory cell infiltration. We found a significant increase in the proportion of attached bacteria in cases showing histological epithelial degeneration, and a significant decrease in cases showing intraepithelial polymorph infiltration. The direct relationship between bacterial attachment and cellular degeneration lends further support to a pathogenic effect. Reduced attachment in the face of polymorph infiltration might indirectly reflect aspects of the immune response--namely, blocking of adhesion by IgA, with complement activation and generation of leucotactic factors.

https://gut.bmj.com/content/gutjnl/31/2/134.full.pdf

Bacterial adhesion and disease activity in Helicobacter associated chronic gastritis.

Colonising Campylobacter pyloridis were identified histologically in gastric biopsy specimens from 89% of 83 patients with non-ulcer dyspepsia and chronic gastritis, but not in 58 dyspeptic patients with normal mucosa. The presence and population density of organisms was associated with the presence of intraepithelial neutrophils. In vivo coating of the organisms by host immunoglobulin was investigated by immunoperoxidase staining of IgA, IgG, and IgM in 54 biopsy specimens. IgA coated bacteria were seen in all cases of active gastritis, and in 60% of biopsy specimens without intraepithelial neutrophils. Coating with IgG or IgM, or both, was correlated with activity of gastritis and was rarely seen in the absence of a neutrophil infiltrate.

https://jcp.bmj.com/content/jclinpath/39/8/863.full.pdf

Local immune response to gastric Campylobacter in non-ulcer dyspepsia.

Duodenal biopsy specimens from 471 adults and 47 children were examined to determine the prevalence and distribution of gastric epithelium in the duodenal bulb in relation to age, gender, gastroduodenal inflammation, smoking, alcohol and consumption of nonsteroidal anti-inflammatory drugs (NSAID). Gastric metaplasia was present in the anterior wall duodenal biopsy specimen in 31%, was significantly less common in patients under 17 than in adults, and was more common in males than females. In sixty two adults who underwent multiple radial duodenal biopsy gastric metaplasia was randomly distributed around the duodenal circumference; sixty three per cent of the patients with gastric metaplasia found on multiple biopsy were detected by just the anterior biopsy. Gastric metaplasia was not obviously associated with alcohol, cigarette, or NSAID consumption. While the presence of gastric metaplasia was associated with adulthood, male sex, and low fasting gastric juice pH, its extent was associated with active duodenitis and Helicobacter-associated gastritis. On logistic regression, gastric metaplasia in the duodenum and gastric Helicobacter pylori were independent predictors of active duodenitis, but were not significantly associated with inactive duodenal inflammation. H pylori was observed in duodenal biopsy specimens from 32 patients, all with active duodenitis; bacteria were present only on foci of gastric metaplasia, and were more likely to be seen when the metaplasia was extensive. It is proposed that inflammatory injury to the duodenal mucosa by H pylori may stimulate the development of further gastric metaplasia, and that the area of duodenum susceptible to colonisation with H pylori may therefore increase progressively until mucosal integrity is compromised and ulceration supervenes.

https://jcp.bmj.com/content/jclinpath/43/12/981.full.pdf

Gastric epithelium in the duodenum: its association with Helicobacter pylori and inflammation.

AIMS: To investigate whether Helicobacter pylori infection or autoimmune gastritis is responsible for the reported increase in gastric pathology and abnormalities of gastric function in patients with coeliac disease and dermatitis herpetiformis (DH). METHODS: Serum H pylori IgG antibodies were assayed by enzyme linked immunosorbent assay and intrinsic factor antibodies by radioimmunoassay in 99 patients with coeliac disease and 58 patients with dermatitis herpetiformis from two geographic areas. RESULTS: H pylori positivity in patients with coeliac disease and dermatitis herpetiformis increased with age, reaching 50% and 70%, respectively, in patients over 50 years. The percentage H pylori seropositivity in coeliac disease did not differ from the percentage positivity observed in 250 similarly aged blood donors from the same geographic area (Leeds). Seropositivity in patients with dermatitis herpetiformis was not significantly different from the level of positivity observed in 98 age matched patients without dermatitis herpetiformis attending the same Edinburgh dermatology clinic. Only one patient with coeliac disease had positive intrinsic factor antibodies. H pylori seropositivity in Edinburgh control subjects under 30 years of age (41.9%) was significantly higher (p less than 0.03) than in Leeds controls (18%) of corresponding age. An increasing prevalence of H pylori seropositivity with age in coeliac disease and dermatitis herpetiformis paralleled that of the control groups. CONCLUSIONS: Gastritis in coeliac disease and dermatitis herpetiformis is largely caused by H pylori infection at a level that is no different from that of the general population. Any increase in the prevalence of gastritis in these two diseases might be caused by lymphocytic gastritis rather than pernicious anaemia.

https://jcp.bmj.com/content/jclinpath/45/7/597.full.pdf

B J Rathbone

Papers

Campylobacter pyloridis and acid induced gastric metaplasia in the pathogenesis of duodenitis.

Bacterial adhesion and disease activity in Helicobacter associated chronic gastritis.

Local immune response to gastric Campylobacter in non-ulcer dyspepsia.

Gastric epithelium in the duodenum: its association with Helicobacter pylori and inflammation.

Helicobacter pylori serology in patients with coeliac disease and dermatitis herpetiformis